JPH1096512A - Heating furnace with regenerative burner and method of operating the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To control the flow rate of exhaust gas discharged out of a furnace through an exhaust gas pipe line, and to set the exhaust gas temperature in the exhaust gas pipe line below the upper limit value of the heat-resistant temperature of equipment and / or above the dew point. It is an object of the present invention to provide a heating furnace provided with a regenerative burner that can be controlled at a high speed and a method of operating the furnace. SOLUTION: The heating furnace 2 is provided with a regenerative burner 3, and the heating furnace 2 is controlled by a control device 25. When the combustion exhaust gas is discharged through an exhaust gas pipe line, the heating furnace 2 is disposed on the exhaust gas discharge side of the regenerative burner 3. By the provided thermometer 21 and the thermometer 41 provided in the collective piping section 5 of the exhaust gas piping,
The exhaust gas temperature is measured, and the exhaust gas temperature is controlled so as to be equal to or lower than the upper limit value of the heat-resistant temperature and equal to or higher than the dew point of the device provided in the exhaust gas piping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating furnace provided with a regenerative burner and a method for operating the same, and more particularly, to a heating furnace which maintains a high heat recovery efficiency, and the temperature of exhaust gas passing through a heat storage body is reduced to the heat resistant temperature of equipment. The present invention relates to a heating furnace provided with a regenerative burner that can be set to an upper limit or less and / or to a dew point or more and an operation method thereof.

[0002]

2. Description of the Related Art A conventional heating furnace having a regenerative burner will be described with reference to FIGS. FIG. 19 shows a heating furnace provided with a regenerative burner, showing one cycle of alternating combustion, and FIG. 20 shows a regenerative burner.

First, a regenerative burner will be described with reference to FIG. 20. A burner tile 11 is provided on a furnace wall 2, and the burner tile 11 is provided with an air nozzle 12 and a fuel nozzle 13 which open inside the furnace. , The heat storage body 20 is a heat storage container 1
0. An air flow control valve 14 and a manual control valve 15 are connected to the pipe connected to the heat storage container 10,
An exhaust gas flow control valve 16 and a manual control valve 17 are connected to the branch pipe. The fuel nozzle 13 is connected with a fuel cutoff valve 18 and a manual adjustment valve 19.

[0004] Next, the heating furnace having the regenerative burner shown in Fig. 19 will be described. The heating furnace 1 is provided with a regenerative burner 3 arranged in pairs on furnace walls 2 facing each other. Each regenerative burner 3 is provided with a combustion air supply pipe, a fuel supply pipe, and an exhaust gas discharge pipe.
The piping connecting the air flow regulating valve 14 and the manual regulating valve 15 is assembled in the combustion air supply system piping, and is a piping system in which an air flow meter 44 is connected to the collective piping. The fuel supply system piping is a piping system in which piping connecting the fuel cutoff valve 18 and the manual adjustment valve 19 is collected, and a fuel flow meter 45 is connected to the collected piping. In the exhaust gas discharge system pipes, pipes connected to the exhaust gas flow control valve 16 and the manual control valve 17 are collected, and an exhaust gas flow meter 46 is connected to the collected pipe, and the pipe system is connected to the exhaust gas suction blower 6 and the chimney 7. It is. Further, a thermometer 21 is provided on the heat storage body outlet side of the exhaust gas of the regenerative burners 3 and 2, and a thermometer 40 is provided on a collective pipe of the exhaust gas discharge system pipe.

A regenerative burner 3 is disposed on the side wall of the heating furnace 1, F indicates a flame, I and V regenerative burners 3 are in a combustion state, and II and III regenerative burners 3 are in a state where exhaust gas is discharged. It is. In the regenerative burner 3 of I, the fuel cutoff valve 18 is opened, fuel is injected from the fuel nozzle 13 into the furnace, the air cutoff valve 14 is opened, and the exhaust gas cutoff valve 16 is closed,
Fuel and combustion air are supplied in the direction of the arrow, and the combustion air is preheated when passing through the regenerator 20 and injected into the furnace from the air nozzle 12, and the fuel and combustion air are mixed and burned. ing. On the other hand, II facing the regenerative burner 3 of I
Exhaust gas in the furnace is discharged from the regenerative burner 3 of I.

[0006] In the next cycle, the regenerative burner 3 of I enters the exhaust gas discharge state, and the regenerative burner 3 of III switches to the combustion state. The regenerative burner 3 of I is an air shutoff valve 1
4 and the fuel shutoff valve 18 are closed, the exhaust gas shutoff valve 16 is opened, and the high temperature exhaust gas in the furnace is sucked in the direction of the arrow by the exhaust gas suction blower 6 and discharged from the chimney 7 via the heat storage unit 20 and the exhaust gas flow meter 46. You. As described above, the regenerative burner 3 alternately repeats the combustion state and the heat storage state at a predetermined cycle.

[0007] In such a heating furnace, when exhaust gas is discharged, the indicated value of the thermometer 21 is monitored, and in order to protect the heat resistance of each device provided in the exhaust gas channel, the temperature of the exhaust gas when passing through each device is monitored. Needs to be controlled so that it is lower than the heat resistance temperature of the device.

When the temperature of the exhaust gas discharge pipe (flue) becomes low, the moisture in the exhaust gas becomes water droplets and collides with equipment such as a shutoff valve at high speed, causing wear, or the exhaust gas contains sulfur. In this case, sulfuric acid corrosion caused by the formation of water droplets of sulfur may occur, so that the temperature of the exhaust gas from the exhaust gas outlet side of the regenerator stored in the regenerative burner to the exhaust gas exhaust port does not cause water droplets. That is, it is necessary to maintain the temperature above the dew point.

[0009]

Conventionally, in the heating furnace shown in FIG. 19, when the number of regenerative burners installed is small, the exhaust gas temperature indicated by a thermometer 21 installed in each regenerative burner is monitored manually while monitoring. The exhaust gas flow rate is adjusted by operating the manual adjustment valve 17 so that the exhaust gas temperature is lower than the heat-resistant temperature of the device installed between the outlet of the regenerator and the exhaust gas outlet.

While monitoring the exhaust gas temperature indicated by the thermometer 21, the manual adjustment valve 17 is manually operated in order to prevent water in the exhaust gas from dropping due to a decrease in the temperature of the exhaust gas discharge pipe. The exhaust gas flow rate is adjusted to maintain the exhaust gas temperature at or above the dew point. Moreover, the flow rate of the exhaust gas is adjusted by operating the manual adjustment valve 17 for each regenerative burner.

However, when the number of installed regenerative burners is small, the exhaust gas temperature can be adjusted manually.
If the number of regenerative burners is large, manual adjustment of the exhaust gas temperature is not possible. In addition, it is difficult to adjust the flow rate of exhaust gas for each regenerative burner to adjust the temperature of exhaust gas on the outlet side of the regenerator.

The reason for controlling the exhaust gas outlet side temperature by adjusting the exhaust gas temperature on the outlet side of the regenerator with the exhaust gas flow rate is that the exhaust gas flow rate through the regenerator 20 is a factor that changes the exhaust gas temperature.
There are combustion air volume, exhaust gas temperature (furnace temperature) and heat storage volume on the heat storage body inlet side, but the furnace temperature and combustion air flow rate are important factors that affect combustion and directly affect the quality of the object to be heated. To be constrained. Further, the volume of the heat storage body is a fixed factor and cannot be freely changed in order to change the exhaust gas temperature at the outlet of the heat storage body. For these reasons, the flow rate of the exhaust gas is suitable as a factor that can be freely adjusted.

Further, furnace temperature, combustion air flow rate, and the like are factors that cannot be used for adjusting the exhaust gas temperature, and these factors vary depending on the operating conditions depending on the material and size of the object to be heated.
The exhaust gas temperature on the outlet side of the regenerator also changes in accordance with such a change in the operating conditions. Each time the operating conditions change,
Manually adjusting the suction exhaust gas flow rate of each regenerative burner has the disadvantage that an excessive workload is imposed. or,
When a large number of regenerative burners are installed, replacing the manual regulating valve 17 provided in each regenerative burner with an exhaust gas flow regulating valve and automating it has a disadvantage that a large capital investment is required.

Further, in a heating furnace using a regenerative burner, 60 to 95% of the amount of exhaust gas generated by combustion is the amount of exhaust gas to be controlled to be below the heat-resistant temperature of equipment and above the dew point of exhaust gas. The remaining 5 to 40% of the exhaust gas volume is discharged directly from the furnace. There is a method of improving the thermal efficiency by using some of the 5 to 40% of the calorific value of the directly discharged exhaust gas for preheating the combustion air or the like.

If the temperature of the collecting pipe section of the exhaust gas piping can be maintained as low as possible by measuring with a thermometer 40 from the viewpoint of thermal efficiency, the flow rate of exhaust gas sucked through the heat storage body 20 can be reduced. it can. That is, the regenerative burner 3
Can be reduced, and the flow rate of exhaust gas used for preheating the object to be heated, fuel, combustion air, and the like can be increased. In other words, it is possible to maintain the thermal efficiency of the entire heating furnace in a constantly high state.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and controls the flow rate of exhaust gas discharged outside the furnace through an exhaust gas piping to control the temperature of the exhaust gas in the exhaust gas piping. It is an object of the present invention to provide a heating furnace equipped with a regenerative burner that can be controlled to an upper temperature limit or lower and / or to a dew point or higher, and a method of operating the same.

[0017]

Means for Solving the Problems The present invention has been made to achieve the above object, and the invention of claim 1 has the following features.
In a heating furnace having a regenerative burner, the heating furnace having one or more regenerative burners supplies combustion air supply piping for supplying combustion air to the regenerative burner, and supplies fuel to the regenerative burner. A fuel supply system pipe to be exhausted, an exhaust gas discharge system pipe that discharges exhaust gas in the heating furnace through the regenerative burner, an exhaust gas cutoff valve provided in the exhaust gas discharge system pipe, and an exhaust gas flow rate provided in the collective pipe part. An adjusting device, a first thermometer provided on an exhaust gas outlet side of the regenerative burner, a second thermometer provided on a collective piping section of the exhaust gas discharge system piping, and control for operating the heating furnace. And a temperature detecting means for detecting an average temperature and a maximum instantaneous value by the first and second thermometers, and from the measurement position of the first thermometer to the vicinity of the exhaust gas outlet. Before the temperature drop Temperature drop from the measurement position of the second thermometer to the vicinity of the exhaust gas outlet, temperature rise from the measurement position of the second thermometer to the exhaust gas shutoff valve, heat-resistant temperature of equipment provided downstream from the regenerative burner And its upper limit,
Storage means for storing the dew point of the combustion exhaust gas from each of the measurement position of the first thermometer and the measurement position of the second thermometer to the exhaust gas outlet, and a lower limit thereof, and the first and second temperatures Based on the average value and the maximum instantaneous value of the temperature measured by the meter and the temperature drop and / or temperature rise from the measurement position, the exhaust gas temperature is set to be equal to or lower than the upper limit of the heat resistant temperature of the device and / or equal to or higher than the dew point. And a control means for controlling the exhaust gas temperature by operating the exhaust gas flow control device.

In the above invention, the temperature stored in the first to fourth storage means and the instantaneous temperature measurement value (average value, maximum instantaneous value) are used to determine whether the temperature is lower than the upper limit of the heat-resistant temperature of the device and / or higher than the dew point. The exhaust gas flow rate is controlled so as to be as follows. The control means includes (Ta> Td + ΔTd), (Ta ′> Td ′ +
ΔTd ′), (Ts <Tl−ΔTl), (Ts ′ <T
1′−ΔTl ′) is provided.

Where Ta 'is the first thermometer (thermometer 2).
1) average value, Ta: average value of the second thermometer (thermometer 40), Ts': maximum instantaneous value of the first thermometer, Ts: second value
Instantaneous value of the thermometer of Td ', Td: dew point, ΔT
d ': temperature drop (temperature drop from the measurement position of the first thermometer to the exhaust gas outlet), ΔTd: temperature drop (temperature drop from the second temperature measurement position to the exhaust gas outlet), Tl', T
l: Heat-resistant temperature (upper limit value) of equipment for exhaust gas piping, Δ
Tl ′: temperature drop (temperature drop or temperature rise from the measurement position of the first thermometer to the device), ΔTl: temperature drop (second
Temperature drop or temperature rise from the measuring position of the thermometer to the equipment)

According to a second aspect of the present invention, in a method of operating a heating furnace having a regenerative burner, the heating furnace having at least one pair of regenerative burners supplies combustion air to the regenerative burner. A combustion air supply system pipe, a fuel supply system pipe that supplies fuel to the regenerative burner, an exhaust gas discharge system pipe that discharges exhaust gas in the heating furnace through the regenerative burner, and the exhaust gas discharge system pipe are provided. Exhaust gas cutoff valve, and an exhaust gas flow rate adjusting device provided in a collective pipe portion of the exhaust gas discharge system pipe, a thermometer provided in the collective pipe portion, and a control device, and the control device includes:
Temperature drop (ΔTd) from the average value (Ta) of the temperature measurement values of the thermometer to the exhaust gas outlet from the measurement position of the thermometer
Is a method of operating the heating furnace, wherein the flow rate of the suctioned exhaust gas is adjusted by the exhaust gas flow rate adjusting device so that the value obtained by subtracting the difference is not less than the dew point (Td). The exhaust gas flow rate is adjusted by adjusting the opening degree of the exhaust gas flow rate adjusting device so as to satisfy the expression, and the collecting pipe section controls the suctioned exhaust gas flow rate at the limit point of the dew point.

According to a third aspect of the present invention, in a method of operating a heating furnace having a regenerative burner, a combustion air supply for supplying combustion air to one or more of the regenerative burners on a furnace wall of the heating furnace. System piping, a fuel supply system piping for supplying fuel to the regenerative burner, an exhaust gas discharging system piping for discharging exhaust gas in the heating furnace through the regenerative burner, and an exhaust gas shutoff provided in the exhaust gas discharging system piping A valve, an exhaust gas flow rate adjusting device provided in a collective piping portion of the exhaust gas discharge system piping, a thermometer provided on an exhaust gas outlet side of the regenerative burner, and a control device, the control device comprising: The temperature drop (ΔT) from the average value (Ta ′) of the temperature measurement values of the thermometer to the exhaust gas outlet from the measurement position of the thermometer.
d ') is a method of operating the heating furnace, wherein the flow rate of the exhaust gas is adjusted by the exhaust gas flow rate adjusting device so that the value obtained by subtracting d') is not less than the dew point (Td '). Adjusting the opening degree of the exhaust gas flow control device so as to satisfy the relational expression of '>Td' + ΔTd 'to adjust the exhaust gas flow rate and control the suction exhaust gas flow rate at the limit point of the dew point up to the exhaust gas outlet. It is.

According to a fourth aspect of the present invention, there is provided a heating furnace having a regenerative burner, wherein at least one pair of regenerative burners is provided on a furnace wall of the heating furnace, and combustion air is supplied to the regenerative burner. A combustion air supply system pipe, a fuel supply system pipe that supplies fuel to the regenerative burner, an exhaust gas discharge system pipe that discharges exhaust gas in the heating furnace through the regenerative burner, and the exhaust gas discharge system pipe. Exhaust gas shut-off valve, and an exhaust gas flow rate adjusting device provided in the collective pipe section, a thermometer provided in a collective pipe section of the exhaust gas discharge system pipe, and a control device, the control device,
The maximum instantaneous value (Ts) of the temperature measurement value of the thermometer is detected, and the temperature rise (−ΔT1) from the temperature measurement position of the thermometer to the device provided upstream of the exhaust gas and the temperature downstream of the exhaust gas from the temperature measurement position. According to the exhaust gas flow rate adjusting device, the value obtained by subtracting the temperature drop from the maximum instantaneous value by the temperature drop to the device (ΔTl) is equal to or less than the upper limit value of the heat resistant temperature (Tl) of each device. An operation method of a heating furnace characterized by adjusting an exhaust gas flow rate, wherein a control device adjusts an opening degree of the exhaust gas flow rate adjusting device so as to satisfy a relationship of Ts <Tl-ΔTl, Control is performed so that the temperature from the exhaust gas discharge side to the discharge port is equal to or less than the upper limit value of the heat resistant temperature by the measurement value of the thermometer provided on the exhaust gas discharge side of the burner.

According to a fifth aspect of the present invention, in a method for operating a heating furnace having a regenerative burner, a furnace wall of the heating furnace is provided with at least one pair of regenerative burners, and the regenerative burner is used for combustion. A combustion air supply pipe for supplying air, a fuel supply pipe for supplying fuel to the regenerative burner, an exhaust gas discharge pipe for discharging exhaust gas in the heating furnace through the regenerative burner, and the exhaust gas discharge system. An exhaust gas cutoff valve provided in the pipe, an exhaust gas flow rate adjusting device provided in a collective pipe portion of the exhaust gas discharge system pipe, a thermometer provided on an exhaust gas outlet side of the regenerative burner, and a control device And
A value obtained by subtracting the downstream temperature drop (ΔTl ′) from the temperature measurement position from the maximum instantaneous value (Ts ′) of the temperature measurement value of the thermometer by the control device is an upper limit value (Tl ′) of the heat-resistant temperature of the device. A) a method of operating a heating furnace, characterized in that the exhaust gas flow rate adjusting device is operated so as to adjust the suctioned exhaust gas flow rate, as described below, wherein Ts ′ <Tl′− The exhaust gas flow rate is controlled such that the exhaust gas flow rate is adjusted by adjusting the opening degree of the exhaust gas flow rate adjusting device so as to satisfy ΔTl ′ so that the collecting pipe section is at or below the upper limit value of the equipment heat-resistant temperature. .

According to a sixth aspect of the present invention, in the method for operating a heating furnace having a regenerative burner, the temperature from the exhaust gas discharge side of the regenerative burner to the exhaust gas collecting pipe portion is an upper limit value of the equipment heat-resistant temperature. When the operating conditions to be controlled to be below and the operating conditions to be controlled so that the temperature from the collecting pipe portion to the exhaust gas outlet is equal to or higher than the dew point are required, the upper limit value of the equipment heat-resistant temperature or less is required. A method for controlling a heating furnace, wherein the suction gas flow rate is adjusted by operating the exhaust gas flow rate adjustment device provided in the collecting pipe section with priority given to the operating conditions to be controlled so that This is an operation method that adjusts the suction exhaust gas flow rate to protect the equipment by giving priority to the equipment heat-resistant temperature, even if the operating conditions generate water droplets, and to increase the safety and life of the heating furnace equipment. .

According to a seventh aspect of the present invention, in a method of operating a heating furnace having a regenerative burner, the exhaust gas is collected from a measurement position of a first thermometer provided on an exhaust gas outlet side of the regenerative burner. Operating conditions for controlling the temperature up to the pipe section to be equal to or lower than the upper limit value of the equipment heat-resistant temperature based on the maximum instantaneous value of the first thermometer, and the second thermometer provided in the collective pipe section. When operating conditions for controlling the temperature from the measurement position to the exhaust gas outlet to be a temperature equal to or higher than the dew point based on the average value of the measurement values obtained by the second thermometer are required, An operating method of a heating furnace characterized by adjusting the suction exhaust gas flow rate by operating the exhaust gas flow rate adjusting device provided in the collecting pipe section with priority given to operating conditions that are equal to or less than the upper limit value, Under operating conditions where water droplets are generated Even Tsu, to promote the protection of equipment by preferentially equipment heat-resistant temperature, and adjust the suction gas flow by the control means, a driving method to achieve survival and safety of the furnace equipment.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) An embodiment of a heating furnace having a regenerative burner according to the present invention and an operation method thereof will be described with reference to FIGS. In FIG. 1, a heating furnace 1 is provided with a pair of regenerative burners 3 on furnace walls 2 facing each other. As shown in FIG. 2, the regenerative burner 3 is provided with a burner tile 11 provided on the furnace wall 2, an air nozzle 12 and a fuel nozzle 13 opened inside the furnace, and the air nozzle 12 accommodates a heat storage body 20. The connected heat storage container 10 is connected to a pipe, an air cutoff valve 14 is connected to the pipe, and an exhaust gas cutoff valve 1 is connected to the branch pipe.
6 are connected. The fuel nozzle 13 has a fuel cutoff valve 1
8 are connected. A thermometer 21 is provided on the exhaust gas outlet side of the heat storage body 20.

Each regenerative burner 3 is provided with a combustion air supply pipe, a fuel supply pipe, and an exhaust gas discharge pipe. The combustion air supply system piping is assembled by connecting an air shutoff valve 14 to piping connected to each regenerative burner 3,
An air flow meter 44 and an air flow adjusting device 41
Is connected. The fuel supply system piping is the fuel nozzle 13
The fuel cutoff valve 18 is connected to the pipe to which is connected, and is connected to the collective pipe, and the fuel flow meter 45 and the fuel flow rate adjusting device 43 are connected to the collective pipe. The exhaust gas discharge system pipe is connected to a pipe connected to the regenerative burner 3 by an exhaust gas shutoff valve 1.
6 are connected to the pipe 4, and are further assembled to be connected to the collective pipe 5. An exhaust gas flow control device 42, an exhaust gas flow meter 46, and an exhaust gas suction blower 6 are connected to the collecting pipe section 5, and are connected to a chimney 7. A thermometer 21 is provided on the heat storage body outlet side of each regenerative burner 3, and a thermometer 40 is provided in the collective piping unit 5.

First, the control unit 25 controls the alternating combustion of the heating furnace. FIG. 1 shows one cycle of the alternating combustion, in which the regenerative burners 3 of I and V are in a combustion state, and the regenerative burners 3 of II and III are in an exhaust gas discharge state (heat storage operation). The regenerative burners 3 of I and V are the fuel shut-off valve 1
6, the fuel is supplied in the direction of the arrow, and the fuel nozzle 13 is opened.
From the furnace. The air shutoff valve 14 is opened, the exhaust gas shutoff valve 16 is closed, and combustion air is supplied in the direction of the arrow. The combustion air passing through the heat storage body 20 is preheated by the heat storage body 20 and injected into the furnace from the air nozzle 12, where the combustion air and fuel are mixed and burned.
On the other hand, the regenerative burner 3 of I and the pair of regenerative burner 3 of III
In the furnace, the exhaust gas in the furnace is discharged through the heat storage body 20 to perform a heat storage operation. When the exhaust gas passes through the heat storage unit 20, the sensible heat of the exhaust gas is accumulated.

In the next alternating combustion cycle, exhaust gas is discharged from the regenerative burners 3 of I and V to the outside of the furnace, and the regenerative burners 3 of II and III are brought into a combustion state. When the regenerative burner 3 of I is in the exhaust gas discharge state, the air shutoff valve 14 and the fuel shutoff valve 18 are closed, the exhaust gas shutoff valve 16 is opened, and the exhaust gas is sucked in the direction of the arrow. At that time, the sensible heat of the exhaust gas is
The exhaust gas passes through an exhaust gas flow control device 42 and an exhaust gas flow meter 46, and passes through an exhaust gas suction blower 6 to a chimney 7.
Released from Thus, the heating furnace is operated by repeating the combustion / heat storage state of the regenerative burner 3 at a predetermined cycle.

The control unit 25 includes a central processing unit (CPU)
And the storage device 26 is connected. In the storage device 26, a control program for alternating combustion and a control program for controlling the temperature of the exhaust gas in the exhaust gas discharge pipe line are written. The control device 25 is a thermometer 2
1, 40, an air flow meter 44, a fuel flow meter 45, an exhaust gas flow meter 46, and the like are digitized and input,
It is sampled at a predetermined cycle. These values are input to the control device 25, where they are subjected to arithmetic processing. Based on the output, the air cutoff valve 14, the exhaust gas cutoff valve 16, the fuel cutoff valve 18, and the fuel flow control device 43 are operated, and the regenerative burner 3 is operated. As the temperature inside the furnace rises due to alternating combustion,
The exhaust gas flow control device 42 is operated to control the suction exhaust gas flow rate, and the exhaust gas temperature downstream of the regenerative burner is controlled.

The above-described operating conditions, measured values, and the like are written in the storage device 26, and the data is supplied to the control device 25. The storage device 26 controls the average temperatures Ta and Ta 'of the measured exhaust gas temperatures (Ta: average temperature of the values measured by the thermometer 40, Ta': average temperature of the values measured by the thermometer 21), and the heat-resistant temperature of the device. Instantaneous values Ts, Ts' (Ts: thermometer 4)
0, the maximum instantaneous value of the measured value by Ts ': the maximum instantaneous value of the measured value by the thermometer 21), the dew points Td, Td' (Td: the dew point from the measurement position of the thermometer 40 to the exhaust gas outlet, T
d ': dew point from the measurement position of the thermometer 21 to the exhaust gas outlet), heat-resistant temperatures Tl, Tl' of the equipment (Tl: thermometer 40)
, Tl ′: heat-resistant temperature of equipment provided downstream or upstream from the measurement position of the thermometer 21), and temperature drop amounts ΔTd, ΔT
d '(ΔTd: temperature drop (negative value) or temperature rise from thermometer 40 to exhaust gas outlet (positive value), ΔTd': temperature drop from thermometer 21 to exhaust gas outlet (negative value)),
Temperature drop amounts ΔTl, ΔTl ′ (ΔTl: temperature drop (negative value) from thermometer 40 to equipment provided downstream or temperature rise (positive value) to equipment provided upstream, ΔT
l ': Temperature drop (negative value) from the thermometer 21 to the device provided between the exhaust gas outlets and the like are written.

The output of the thermometer 40 is inputted to the first temperature detecting means 25a, and the average value or the maximum instantaneous value of the temperature on the outlet side of the regenerator (the temperature at the measurement position A of the thermometer 40) is input to the control device 25. Is detected. Further, the output of the thermometer 21 is input to the second temperature detecting means 25b, and the temperature of the collecting pipe portion (the thermometer 2)
The average value or the maximum instantaneous value of (the temperature at one measurement position B) is detected. The measured temperature (the average value Ta ', the maximum instantaneous value Ts') from the first temperature detecting means 25a is input to the first temperature comparing means 25e. Further, the temperature measurement values (average value Ta, maximum instantaneous value Ts) from the second temperature detection means 25b are the second values.
It is input to the temperature comparing means 25f.

In the first and second calculating means 25c and 25d,
The heat-resistant temperature Tl stored in the storage device (storage means) 26,
Tl ′, dew point Td, Td ′ and temperature drop ΔTd, ΔT
d ′, ΔTl, ΔTl ′ are read out, the first calculating means 25c calculates the estimated heat-resistant temperature TL and the estimated dew point TD, and the second calculating means 25d calculates the estimated heat-resistant temperature TL ′ and the estimated dew point TD ′. You. Their outputs (TL, T
D) and (TL ', TD') are input to the first temperature comparing means 25e and the second temperature comparing means 25f, respectively. In the first temperature comparing means 25e and the second temperature comparing means 25f, (T
L, TD), (TL ', TD') and average values Ta, T
a 'and the maximum instantaneous values Ts, Ts' are compared. These outputs are input to the exhaust gas flow rate adjusting means 25h.

The output of the exhaust gas flow meter 46 is controlled by the controller 2
The exhaust gas flow rate is input to the exhaust gas flow rate detecting means 25g of No. 5 to detect the exhaust gas flow rate. The output from the exhaust gas flow detecting means 25g (current exhaust gas flow), the first temperature comparing means 25e, and the second temperature comparing means 2
The outputs of 5f are input. Based on the control amount from the exhaust gas flow control means 25h, the exhaust gas flow control device 4
2 is adjusted to control the flow rate of the exhaust gas flowing through the collecting pipe 5.

More specifically, the first calculating means performs the arithmetic processing according to the following equations (2) and (4), and the second calculating means performs the following equations (1) and (3). Is performed.

In the first temperature comparing means 25e, the following equation (5) and / or equation (6) is operated,
In the temperature comparing means 25f, the measurement value of the thermometer 40 of the collective piping section 5 is input from the regenerative burner 3, and the following equation (7) and / or (8) are processed.

Td + ΔTd = TD (1) Td ′ + ΔTd ′ = TD ′ (2) Tl−ΔTl = TL (3) Tl′−ΔTl ′ = TL ′ (4) TD ′ <Ta ′ (5) TL ′> Ts ′ ...... (5) 6) TD <Ta .................. (7) TL> Ts .................. (8)

(However, Td, Td ', Tl, Tl', T
D, TD ', TL, TL', Ta, Ta ', Ts, T
s' is as described above. )

In the above embodiment, both thermometers 21 and 4
Based on the measurement value of 0, the exhaust gas discharge temperature is controlled to be equal to or lower than the upper limit value of the heat-resistant temperature of the device and the temperature in the exhaust gas pipe (flue) is controlled to be equal to or higher than the dew point. Depending on the temperature measurement position A of the thermometer 21 or the temperature measurement position B of the thermometer 40, the temperature may be controlled to be equal to or less than the upper limit value and equal to or greater than the dew point of the heat-resistant temperature of the devices individually provided in the exhaust gas piping.

For example, the upper limit of the heat-resistant temperature and the dew point temperature of the equipment are monitored by the thermometer 21 between the regenerative burner 3 and the collecting pipe section 5 in the exhaust gas discharging pipe line. A total 40 monitors the upper limit value of the heat resistant temperature and the dew point temperature of the equipment from the collecting pipe section 5 to the exhaust gas discharge port.

Note that the heat-resistant temperature T described in the above embodiment is used.
l, Tl 'and dew points Td, Td' may be read as the upper limit value of the heat resistant temperature and the lower limit value of the dew point, respectively.

Next, a control method according to the temperature change of the exhaust gas discharge pipe will be described. The exhaust gas temperature on the exhaust gas outlet side of the regenerative burner tends to oscillate, as shown in FIG. FIG. 4 shows that the temperature of the collecting pipe changes depending on the control unit of the regenerative burner and the alternating combustion cycle.

FIGS. 4 (a) to 4 (c) show the relationship between the alternating combustion cycle and the temperature amplitude of the collecting pipe portion (downstream from the regenerative burner) of the exhaust gas piping. If necessary,
This will be described with reference to the symbols in FIGS.

FIG. 4 (a) shows a case where the combustion cycle of the regenerative burner is short or a case where the combustion cycle of each regenerative burner is shifted. The temperature waveform of the exhaust gas temperature of the collective piping section 5 has a substantially linear characteristic. Thus, the instantaneous value and the average value of the exhaust gas temperature become substantially equal.

On the other hand, FIGS. 4B and 4C show the case where the combustion timing of each regenerative burner matches and the case where the combustion interval (cycle) is long. 40 shows the characteristic that the measured temperature value has a temperature amplitude. In the case where the exhaust gas has the temperature amplitude as described above, the exhaust gas temperature control of the collecting pipe section 5 adjusts the exhaust gas flow rate adjusting device 42 so that the preset temperature is obtained at an instantaneous value. However, when the temperature change of the exhaust gas in the collecting pipe section 5 is fast, if the control is performed with the instantaneous value, a response delay may occur and the temperature amplitude may be increased conversely, which may cause damage to the equipment.

Generally, when a heating furnace having a large number of regenerative burners or a short burning interval between the regenerative burners is used, the temperature change in the collecting pipe portion is substantially linear, and the heat protection of equipment downstream of the exhaust gas is not protected. The control is performed such that the instantaneous value of the exhaust gas temperature always falls below the upper limit value of the heat-resistant temperature of the device. Similarly, when the temperature of the exhaust gas changes rapidly, the temperature is set to be equal to or lower than the upper limit value of the heat-resistant temperature by the instantaneous value, and the control to be higher than the dew point is controlled by the instantaneous value.

When the number of the regenerative burners is small or when the combustion timings of the regenerative burners are the same, the temperature measurement value in the collective piping section has a temperature amplitude synchronized with a certain time period. In order to control the exhaust gas temperature to be equal to or higher than the dew point, the control is performed by a time average value synchronized with the amplitude cycle of the temperature measurement value of the collective piping section. Separately, the instantaneous value of the exhaust gas temperature is also input to the control device, and the control is performed so that the maximum value of the measured value does not exceed the upper limit value of the allowable temperature limit. As described above, the change in the exhaust gas temperature specific to the heating furnace is grasped, and the exhaust gas flow rate is controlled using the time average value or the instantaneous value of the temperature measurement values.

For example, in this embodiment, the heat-resistant temperature of the equipment provided between each regenerative burner and the collecting pipe section, the heat-resistant temperature of the equipment provided in the collecting pipe section, and the temperature from the regenerative burner to the exhaust gas discharge port. Three control conditions for monitoring the dew point are determined alone or in combination. Specifically, the four control conditions shown in the following table are determined and controlled in a complex manner.

[0050]

[Table 1] However, ○: normal within the restricted range, ×: abnormal outside the restricted range, Δ: includes both inside and outside the restricted range

As shown in Table 1, the temperature of the exhaust gas is controlled according to the abnormality (x). In cases 1 and 4, whichever is stricter is selected and controlled. For example, Case 1
In the case of (1), the abnormality on the downstream side of the exhaust gas is prioritized, and in the case (4), the abnormality on the upstream side of the exhaust gas is prioritized. Of course, if an abnormality occurs in the pipe, whichever is more severe is selected. In addition, when the control condition for protection of the heat-resistant temperature of the device is required at the same time as the dew point or higher, the protection is performed with priority given to the protection of the heat-resistant temperature of the device. This means that even if the water drops continuously due to the dew point or less, the equipment will not immediately fail,
If the temperature exceeds the upper limit of the heat-resistant temperature, the device is immediately broken or damaged. Of course, if the abnormality occurs continuously, the operation of the heating furnace is stopped.

(Embodiment 2) Next, another embodiment of the present invention will be described. FIG. 17 shows a heating furnace according to another embodiment of the present invention, which is different from the heating furnace of FIG. 1 only in a control program written in the control device 25, and has the same other configuration. In the heating furnace of FIG. 17, for example, the maximum instantaneous value of the measured value of the temperature from the measurement position A of the thermometer 21 provided on the exhaust gas discharge side of the regenerative burner 3 to the exhaust pipe 5 is determined by Operating conditions are required to be controlled so as to be higher than or equal to the upper limit value of the heat-resistant temperature and lower than or equal to the upper limit value, and that the measured value of the temperature from the measurement position B of the thermometer 40 provided in the collecting pipe section 5 to the exhaust gas outlet is measured When an operating condition for controlling the temperature to be equal to or higher than the dew point based on the average value is required, the priority processing unit 25i of the control device 25
On the basis of the output from the exhaust gas flow controller 25, the exhaust gas flow rate adjusting means 25 is set so as to give priority to operating conditions that are equal to or lower than the upper limit value of the equipment heat resistance temperature.
h operates the exhaust gas flow rate adjusting device 42 to adjust the suctioned exhaust gas flow rate. By giving priority processing in this way,
The safety of the heating furnace is maintained by controlling the exhaust gas temperature so as to be set to be equal to or lower than the upper limit value of the heat-resistant temperature of the equipment provided in the exhaust gas discharge piping system of the collecting pipes 4 and 5.

Further, as another embodiment of the combustion control method, there is a combustion control method shown in the flowchart of FIG. The temperature of the exhaust gas is measured by a thermometer 21 provided on the outlet side of the regenerator in the exhaust gas discharge pipe line and a thermometer 40 provided on the collective pipe section, and the measured values (average value, maximum instantaneous value) at these temperature measurement positions are measured. ), The estimated heat-resistant temperature and the estimated dew point of the device are obtained, and compared with the measured values to control the exhaust gas flow rate.

The operation will be described with reference to FIG.
In this case, the regenerative burner of the heating furnace 1 alternately burns, and the temperature rises to shift to a steady combustion state. In steps S2 and S3,
A thermometer 21 provided on the outlet side of the regenerator in the exhaust gas pipe line,
The measurement value of the thermometer 40 provided in the collecting pipe part is detected. Based on the measured values at the temperature measurement position A of the thermometer 21 and the temperature measurement position B of the thermometer 40, the estimated heat-resistant temperature with respect to the upper limit value of the heat-resistant temperature of the device provided in the exhaust gas pipeline, and the exhaust gas outlet of the exhaust gas pipeline. The estimated dew point up to is calculated (step S4).

In the calculation means, the calculation formulas (1) to (4) are provided, and (Td + ΔTd = TD), (T
d ′ + ΔTd ′ = TD ′), (Tl−ΔTl = TL),
(Tl′−ΔTl ′ = TL ′) is calculated. Here, TD is an estimated dew point based on the measurement value of the thermometer 40, TD '
Is the estimated dew point based on the value measured by the thermometer 21, and TL is the thermometer 4
The estimated heat-resistant temperature based on the measured value of 0, TL 'is an estimated heat-resistant temperature based on the measured value of the thermometer 21, and the other symbols are defined as described above.

Subsequently, the process proceeds to step S5, where the estimated heat-resistant temperature TL 'based on the position A and the maximum instantaneous value Ts' of the measured temperature are determined. If (TL '>Ts'), the process proceeds to step S6, and if (TL '<Ts'), the process proceeds to step S7. In step S7, the number of times of abnormality is measured, and it is determined whether or not it is abnormal. If the number of abnormalities has not reached the predetermined number, the process proceeds to step S8, the exhaust gas flow rate is adjusted, and the process returns to step S2.

In step S6, the estimated heat-resistant temperature TL is compared with the maximum instantaneous value Ts of the measured temperature based on the measured value at the position B, and if (TL <Ts), step S7.
Then, the same number of abnormalities as described above are counted, and when it is determined that there is no abnormality, the flow proceeds to step S8, the exhaust gas flow rate is adjusted, and the flow returns to step S2. If (TL> Ts) in step S6, the process proceeds to step S9.

In step S9, the thermometer 2 based on the position A
Temperature measurement value (average value) Ta 'and estimated dew point TD'
If (TD '<Ta'), the process proceeds to step S10, and if (TD '>Ta'), the process proceeds to step S8. In step S8, the exhaust gas flow rate is controlled to increase, and the process returns to step S2. Step S1
At 0, the temperature in the exhaust gas piping is estimated to be the dew point T based on the value (average value) Ta measured by the thermometer 40 at the position B.
D and the average value Ta of the temperature measurement values are determined, and (TD
If <Ta), the process proceeds to step S11, and the exhaust gas temperature control program is repeatedly executed. Also, (TD
If> Ta), the process returns to step S8 to adjust the exhaust gas flow rate, and returns to step S2 to execute the same exhaust gas temperature control program.

If it is determined in step S11 that the operation of the heating furnace is to be stopped, the process proceeds to step S12,
A control program for stopping the operation of the heating furnace is executed. If it is determined in step S7 that there is an abnormality, the process proceeds to step S12, and a control program for stopping the operation of the heating furnace is executed.

The above control program has shown a method of judging the temperatures of the positions A and B in order, but judging in parallel according to the temperatures of the positions A and B, and finally giving priority to the heat protection of the equipment. It may be controlled.

Further, the characteristics of the exhaust gas outlet temperature will be described based on another embodiment, and the operation method of the heating furnace will be described in detail.

(Embodiment 3) Next, an embodiment in which the exhaust gas temperature of the collecting pipe portion shown in FIG. 4A is flattened will be described with reference to FIGS. As shown in FIG. 5, five pairs of regenerative burners 3 are provided in the heating furnace 1, and the cycle of the alternating combustion is performed at 40 sec as shown in FIG. 6, and as shown in FIG. Are controlled so that the period of the period gradually shifts. Regenerative burner # 1a,
# 3a and # 5a are in a combustion state, and the heat storage type burners # 1b, # 3b and # 5b on the opposite side are in a heat storage state. In the next alternating combustion cycle, the combustion state is reversed.

As shown in FIG. 5, it is assumed that the heat-resistant temperature of the exhaust gas shut-off valve 16 is 345 ° C., and the heat-resistant temperatures of the exhaust gas flow control device 42 and the exhaust gas suction blower 6 are 300 ° C. Temperature detection position A (thermometer 2) provided in regenerative burner
The temperature drop from 1) to the temperature detection position B (the thermometer 40) of the exhaust gas cutoff valve 16 and the collecting pipe section 5 is 5 ° C., respectively.
10 ° C., the temperature drop from the temperature detection position B of the collecting pipe section 5 to the exhaust gas outlet is 20 ° C., and 5 ° C. respectively from the flow control device 42 to the temperature detection position B and from the temperature detection position B to the exhaust gas suction blower 6. I do. Dew point of exhaust gas is 100 ℃
And

The heating furnace of FIG. 5 has a large number of regenerative burners and a short combustion pitch. The combustion waveform is shown in FIG.
The temperature waveform becomes as shown in FIG. FIG. 7A shows the temperature of the exhaust gas on the outlet side of the regenerator, and FIG. 7B shows the temperature waveform of the temperature of the exhaust gas at the collecting pipe. The upper limit alarm value (control start value) is shown in the figure based on the same viewpoint as described above.

As shown in FIGS. 7A and 7B, the upper limit of the thermometer 21 is 340 ° C., and the lower limit is 110 ° C. The upper limit value is 295 ° C and the lower limit value is 120
However, if the control is performed after exceeding these upper and lower limits, the response becomes slow. Therefore, considering the delay, the upper limit of the alarm value (control start value) of the thermometer 21 is 33.
The lower limit is 0 ° C., the lower limit is 120 ° C., and the upper limit in the collecting pipe section is 285 ° C., and the lower limit is 130 ° C. Furthermore, in order to maintain the thermal efficiency at a high level, the exhaust gas flow control device 42 controls a temperature measured value of the collective piping section 5 by setting a set value and performing control so as to satisfy the set value. That is, the exhaust heat is minimized to the extent that the dew point is not reached, and the thermal efficiency of the heating furnace is optimized. The set temperature of the temperature detection position B is 150 ° C.

Next, as shown in FIG. 8, when the furnace temperature is 1000 ° C., the measured temperature of the collecting pipe section and the collecting pipe section from the regenerative burner is as shown in FIG. It is assumed that the measured value of the collective piping section is controlled at approximately 150 ° C. at the set temperature. Furnace temperature from 1000 ° C to 1100
When the temperature changes to ℃, the temperature of the exhaust gas also rises, so the temperature indication of the collective piping section, which had been controlled up to that point, is set to 150 ° C.
The control device reduces the amount of exhaust gas suction,
By adjusting the temperature to be lower than the set temperature, if the control condition from the regenerative burner to the collecting pipe section is satisfied, the operation can be continued without causing damage or failure of the equipment.
Conversely, when the furnace temperature is lowered, the exhaust gas suction amount is controlled to increase.

Next, a description will be given of a case where the constraint between the regenerative burner 3 and the collecting pipe section 5 is not satisfied.
For example, if the amount of exhaust gas sucked from the burner decreases due to clogging of dust in the flow path between the regenerative burner and the collecting pipe section, the temperature between the regenerative burner and the collecting pipe section decreases, as shown in FIG. Thus, the time average temperature may be lower than the lower limit alarm value. At the same time, the temperature measurement value of the collecting pipe section also decreases, but its influence is small because the average value includes exhaust gas from other regenerative burners. Therefore, by controlling the exhaust gas flow rate adjusting device 42 to increase the exhaust gas suction amount and return the temperature measurement value of the collective piping section 5 to the set value, the measured temperature value of the collective pipe section becomes larger than the set value. growing. As a result, the flow rate can be increased by the device, and damage or failure of the device can be avoided.

Further, if the flow path between the regenerative burner and the collecting pipe portion is extremely clogged with dust and the amount of exhaust gas suctioned is greatly reduced, as shown in FIG. The temperature amplitude increases from the burner to the collecting pipe. On the other hand, in the channel filled with dust, FIG.
As shown in the figure, the temperature of the exhaust gas in the collecting pipe section may drop below the dew point and become a temperature range where water droplets are generated.If such an operation is performed for a long time and cannot be ignored, each heat storage type If the burner has a manual control valve, shut off the manual control valve and stop the operation, and restart the operation after cleaning the dust.

(Embodiment 4) Next, as shown in FIG. 12, when the number of regenerative burners installed is as small as four pairs or when the interval between combustions of regenerative burners is long, the temperature of the collecting pipe section is Has amplitude. A prominent example having this temperature amplitude is when the combustion timings of the regenerative burners match, as indicated by the dots in FIG. As shown in FIG. 12, for example, when four pairs of regenerative burners repeat a heat storage operation and a combustion operation, the temperature amplitude is as shown in FIGS. 14 (a) and 14 (b).
Is shown in

The temperature of the heat storage body outlet side and the temperature of the exhaust gas in the collecting pipe section will be described. As shown in FIG. 14A, the upper alarm value is 330 ° C. and the lower alarm value is 120 ° C.
As shown in FIG. 4 (b), the upper limit alarm value is 285 ° C. and the lower limit alarm value is 130 ° C. downstream from the collective piping section. The set temperature of the collecting pipe section is set to 150 ° C.

As shown in FIG. 13, the monitoring target is the same as the temperature change, that is, the temperature amplitude, when the exhaust gas is sucked from the regenerative burner to the collecting pipe section because the combustion timing is simultaneous in the collecting pipe section. Shows a tendency to increase. In such a case, the exhaust gas flow rate is adjusted with the time average value. In this case, if the control is performed according to the set temperature, it is not necessary to particularly care about the lower limit alarm value in the collective piping section 5, but since the control is performed with the time average value, the upper limit alarm value is set to 285 ° C. or less. ,
The instantaneous maximum value of the temperature measurement value is also monitored separately from the above-mentioned time average.

At the same time, the temperature amplitude between the regenerative burner and the collecting pipe section is as shown in FIG. The instantaneous maximum value of the exhaust gas temperature is set to an upper limit alarm value of 330 ° C. or less due to the heat resistance of the device. In order to prevent the generation of water droplets, the average temperature at the time of exhaust gas suction is controlled so as to be 120 ° C.

Since the combustion timing is simultaneous,
If the tendency of the temperature change of the collecting pipe section is the same as the temperature change pattern at the time of exhaust gas suction from the regenerative burner to the collecting pipe section, if the operating conditions and the tendency of the temperature change in each regenerative burner are exactly the same However, if only the temperature drop between the regenerative burner and the collecting pipe section is taken into account, it can be dealt with only by monitoring the collecting pipe section.However, if an abnormality such as dust clogging occurs, the exhaust gas from other regenerative burners will also be collected in the collecting pipe section. For this reason, it is difficult to recognize the abnormality of the temperature change, and it is not possible to recognize which regenerative burner is abnormal. That is, monitoring is performed for each regenerative burner at the upper limit alarm value and the lower limit alarm value between the regenerative burner and the collecting pipe section.

A case where the furnace temperature changes from 1000 ° C. to 1100 ° C. as shown in FIG. 15 will be described. From the regenerative burner, the measured temperature of the collecting pipe and collecting pipe is
FIGS. 15A and 15B show that the time average value of the collecting pipe section is controlled at approximately 150 ° C. according to the set temperature, and when the furnace temperature changes to 1100 ° C., the exhaust gas temperature also increases. The time average value of the collective piping section controlled to above exceeds the set value of 150 ° C. The exhaust gas suction amount is reduced by the control of the control device 25, and the temperature is controlled to the set temperature.
The temperature change of each part is controlled as shown in FIG. As a result of such control, if other control conditions are satisfied, the operation can be continued without causing damage or failure of the device.

In some cases, the monitored temperature of the dew point is increased, or the monitored temperature of the heat-resistant temperature of the device is decreased, that is, the operable range between the upper limit alarm value and the lower limit alarm value may be narrowed. . In such a case, the time average temperature in the collecting pipe section is as set, but the temperature amplitude increases,
Exceeding the upper limit alarm value between the regenerative burner and the collecting pipe section or the collecting pipe section. If one of the two exceeds the upper limit alarm value, the exhaust gas suction amount is adjusted so as to be equal to or lower than the upper limit alarm value. In addition, by this, the time average temperature of the collecting pipe section or the collecting pipe section from the regenerative burner falls below the lower limit alarm value,
Priority is given to heat protection, and control is performed so as to be below the upper limit alarm value.

For example, only the dew point monitoring temperature of exhaust gas is 200
When the temperature reaches ℃, the lower limit considering the temperature drop is 210 ° C for the set temperature between the collecting pipe section from the regenerative burner and 220 ° C for the set pipe section, and the lower limit alarm value is from the regenerative burner. The set temperature between the collective pipes is 220 ° C. and the set temperature of the collective pipes is 230 ° C. Accordingly, the set temperature at the collective pipes is set to 250 ° C.

When the temperature change between the regenerative burner and the collecting pipe section, that is, the temperature amplitude, reaches 300 ° C. as shown in FIG. The upper limit alarm value between the sections is 330 ° C, which is within the limit range. According to the temperature indication of the collecting pipe section, the maximum measured value is 290 ° C due to the temperature drop of the exhaust gas, whereas the upper limit alarm value is 285 ° C. The restricting condition of the piping section is more severe. Therefore, as shown in FIG. 16, the control device takes measures to reduce the exhaust gas suction amount so that the maximum measured value of the collecting pipe portion temperature becomes equal to or lower than the upper limit alarm value 285 ° C.
As a result, the time average value between the regenerative burner and the collecting pipe section becomes equal to or lower than the lower limit alarm value, but the control is performed with priority given to the heat protection of the devices and the like.

If both the heat storage type burner and the collective piping section and the collective pipe section exceed the upper limit alarm value, the controller determines which condition is more severe, and determines the maximum temperature under the severer condition. Take measures to reduce the flow rate adjustment so that the measured value is less than or equal to the upper limit alarm value.

If the heat-resistant temperature of the equipment located after the collecting pipe is 355 ° C., the temperature detection position B
Is set to 350 ° C. in consideration of the temperature drop, and 340 ° C. if an allowance of 10 ° C. is given as an upper limit alarm value. On the other hand, the upper limit alarm value between the regenerative burner and the collecting pipe section is as low as 330 ° C, but the temperature drop of exhaust gas is 1
Since it is 0 ° C., it is substantially the same. In other words, if the heat-resistant temperature of the equipment located after the collecting pipe section is higher than 355 ° C., as a constraint, the temperature from the regenerative burner to the collecting pipe section becomes stricter, so that only the upper limit alarm value needs to be monitored. It is not necessary to monitor the upper limit alarm value of the collective piping.

As described above, according to the present invention, by controlling the exhaust gas temperature of the exhaust gas pipe in accordance with the characteristics or state of various exhaust gas temperatures of the heating furnace provided with the regenerative burner, the exhaust gas is provided in the exhaust gas pipe. By keeping the heat-resistant temperature of the device and the exhaust gas temperature low enough not to be higher than or lower than the dew point, the thermal efficiency of the heating furnace is optimized and the device can be prevented from being damaged.

[0081]

As described above, according to the present invention,
Even if the temperature of the exhaust gas at the outlet of the heat storage unit is properly maintained and the operating conditions or conditions change, the temperature of the exhaust gas should be lower than the heat-resistant temperature of the exhaust gas flow control device and exhaust gas suction blower located downstream of the outlet of the exhaust gas storage unit. The dew point is controlled so as not to be higher than or lower than the dew point, so that it is possible to maintain and control the exhaust gas temperature within the restricted range, and to prevent equipment damage. Further, since the exhaust gas temperature is maintained low enough that no water droplets are generated due to the exhaust gas temperature being below the dew point, the amount of discharged heat can be minimized, the thermal efficiency of the heating furnace is improved, and the energy cost is reduced. This has the advantage that the thermal efficiency of the heating furnace can be maintained optimally.

Further, the control device is provided with a priority processing means, so that even if heat protection and control for maintaining the temperature above the dew point are required at the same time, processing is performed with priority given to heat protection. This is extremely effective without causing breakage of the device.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a heating furnace provided with a regenerative burner according to the present invention.

FIG. 2 is a view schematically showing a regenerative burner used in the present invention.

FIG. 3 is a diagram showing a temperature change on a heat storage body outlet side.

FIG. 4 is a diagram showing alternating combustion and a temperature amplitude of a collecting pipe portion.

FIG. 5 is a view showing one embodiment of a heating furnace provided with a regenerative burner according to the present invention.

FIG. 6 is a diagram showing alternating combustion timing.

FIG. 7 is a temperature waveform chart showing a temperature change of a heat storage body outlet side and a temperature change of a collecting pipe portion.

FIG. 8 is a diagram showing a change in furnace temperature.

FIG. 9 is a temperature waveform diagram showing a temperature change on the outlet side of the heat storage body and the collecting pipe portion.

FIG. 10 is a temperature waveform diagram showing a temperature change on the outlet side of the heat storage body and on the collective piping.

FIG. 11 is a temperature waveform diagram showing a temperature change on the outlet side of the heat storage body and the collecting pipe portion.

FIG. 12 is a view showing another embodiment of a heating furnace provided with a regenerative burner according to the present invention.

FIG. 13 is a diagram showing alternating combustion timing.

FIG. 14 is a temperature waveform diagram showing a temperature change on the outlet side of the heat storage body and the collecting pipe portion.

FIG. 15 is a temperature waveform diagram showing a temperature change on the outlet side of the heat storage body and the collecting pipe portion.

FIG. 16 is a temperature waveform diagram showing temperature changes on the outlet side of the heat storage body and the collecting pipe portion.

FIG. 17 is a view showing another embodiment of the heating furnace provided with the regenerative burner according to the present invention.

FIG. 18 is a flowchart showing a method of operating the heating furnace of FIG.

FIG. 19 is a view for explaining an example of a heating furnace having a conventional regenerative burner.

FIG. 20 is a diagram showing an example of a regenerative burner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating furnace 3 Regenerative burner 4 Piping 5 Collecting piping part 6 Exhaust gas suction blower 7 Chimney 10 Heat storage container 14 Air shutoff valve 16 Exhaust gas shutoff valve 18 Fuel shutoff valve 20 Regenerator 21 Thermometer (first thermometer) 25 Control Apparatus (control means) 25a first temperature detecting means 25b second temperature detecting means 25c first calculating means 25d second calculating means 25e first temperature comparing means 25f second temperature comparing means 25g exhaust gas flow detecting means 25h exhaust gas flow adjusting means 26 Storage device (storage means) 40 Thermometer (second thermometer) 41 Air flow control device 42 Exhaust gas flow control device 43 Fuel flow control device 44 Air flow meter 45 Fuel flow meter 46 Exhaust gas flow meter

Claims (7)

[Claims] 1. A heating furnace having a regenerative burner, wherein the heating furnace having at least one pair of regenerative burners includes a combustion air supply system pipe for supplying combustion air to the regenerative burner; A fuel supply pipe for supplying fuel to the burner; an exhaust gas discharge pipe for discharging exhaust gas in the heating furnace through the regenerative burner; an exhaust gas cutoff valve provided in the exhaust gas discharge pipe; An exhaust gas flow control device provided in a collective pipe portion of the pipe, a first thermometer provided on an exhaust gas outlet side of the regenerative burner, a second thermometer provided in the collective pipe portion, and the heating furnace. A control device for operating the control device, wherein the control device detects an average temperature and a maximum instantaneous value by the first and second thermometers;
Temperature drop from the measurement position of the thermometer to the vicinity of the exhaust gas outlet, the temperature drop from the measurement position of the second thermometer to the vicinity of the exhaust gas outlet, and the temperature drop from the measurement position of the second thermometer to the exhaust gas shutoff valve. Temperature rise, heat-resistant temperature of equipment provided downstream of the regenerative burner and its upper limit, and
Storage means for storing the dew point of the combustion exhaust gas from each of the measurement position of the thermometer and the measurement position of the second thermometer to the exhaust gas outlet and the lower limit thereof, and the temperature measured by the first and second thermometers Based on the average value and the maximum instantaneous value and the temperature drop and / or temperature rise from their measurement position, so that the exhaust gas temperature is equal to or lower than the upper limit of the heat resistant temperature of the device and / or equal to or higher than the dew point. A heating furnace equipped with a regenerative burner, comprising: a control means for controlling an exhaust gas temperature by operating an adjusting device. 2. A method of operating a heating furnace having a regenerative burner, wherein the heating furnace having at least one pair of regenerative burners includes a combustion air supply pipe for supplying combustion air to the regenerative burner; A fuel supply system pipe that supplies fuel to the regenerative burner, an exhaust gas discharge system pipe that discharges exhaust gas in the heating furnace through the regenerative burner, an exhaust gas cutoff valve provided in the exhaust gas discharge system pipe, An exhaust gas flow control device provided in a collective pipe section, a thermometer provided in a collective pipe section of the exhaust gas discharge system pipe, and a control device, wherein the control device controls the temperature measurement value of the thermometer. Adjusting the suction exhaust gas flow rate by the exhaust gas flow rate adjusting device so that the average value is equal to or higher than the dew point, the value obtained by subtracting the temperature drop from the measurement position of the thermometer to the exhaust gas outlet. The method of operating a furnace comprising a regenerative burner that. 3. A method of operating a heating furnace having a regenerative burner, wherein a combustion air supply system pipe for supplying combustion air to at least one pair of the regenerative burners on a furnace wall of the heating furnace; A fuel supply pipe for supplying fuel to the burner, an exhaust gas discharge pipe for discharging the exhaust gas in the heating furnace through the regenerative burner, an exhaust gas cutoff valve provided in the exhaust gas discharge pipe, and the exhaust gas discharge system. An exhaust gas flow control device provided in a collective piping portion of the pipe, a thermometer provided on the exhaust gas outlet side of the regenerative burner, and a control device, wherein the control device controls the temperature of the thermometer. Adjusting the suction exhaust gas flow rate by the exhaust gas flow rate adjusting device so that a value obtained by subtracting the temperature drop from the measurement position of the thermometer to the exhaust gas outlet from the average value of the thermometer is equal to or higher than the dew point. The method of operating a furnace comprising a regenerative burner. 4. A method for operating a heating furnace having a regenerative burner, wherein a pair of or more regenerative burners are provided on a furnace wall of the heating furnace, and a combustion air supply for supplying combustion air to the regenerative burner. System piping, a fuel supply system piping for supplying fuel to the regenerative burner, an exhaust gas discharging system piping for discharging exhaust gas in the heating furnace through the regenerative burner, and an exhaust gas shutoff provided in the exhaust gas discharging system piping A valve, an exhaust gas flow control device provided in the collective piping section, a thermometer provided in a collective pipe section of the exhaust gas discharge system pipe, and a control device, wherein the control device controls the thermometer. The maximum instantaneous value of the temperature measurement value is detected, and the temperature rise from the temperature measurement position of the thermometer to the device provided upstream of the exhaust gas and the temperature drop from the temperature measurement position to the device downstream of the exhaust gas increase the temperature. The exhaust gas flow control device controls the exhaust gas flow so that the value obtained by adding the temperature rise from the instantaneous value and the value obtained by subtracting the temperature drop from the maximum instantaneous value are equal to or less than the upper limit value of the heat-resistant temperature of each of the devices. A method for operating a heating furnace provided with a regenerative burner, wherein the flow rate is adjusted. 5. A method of operating a heating furnace provided with a regenerative burner, wherein the furnace wall of the heating furnace is provided with at least one pair of regenerative burners, and a combustion air supply for supplying combustion air to the regenerative burner. System piping, a fuel supply system piping for supplying fuel to the regenerative burner, an exhaust gas discharging system piping for discharging exhaust gas in the heating furnace through the regenerative burner, and an exhaust gas shutoff provided in the exhaust gas discharging system piping A valve, an exhaust gas flow control device provided in a collective piping portion of the exhaust gas discharge system piping, a thermometer provided on an exhaust gas outlet side of the regenerative burner, and a control device, the control device comprising: The exhaust gas flow rate adjustment is performed so that a value obtained by subtracting a temperature drop from the temperature measurement position to a downstream device from the maximum instantaneous value of the temperature measurement value of the thermometer is equal to or less than an upper limit value of a heat-resistant temperature of the device. The method of operating a furnace comprising a regenerative burner which is characterized by adjusting the suction gas flow operates the location. 6. A method for operating a heating furnace having a regenerative burner, wherein the temperature from the exhaust gas discharge side of the regenerative burner to the exhaust gas collecting pipe is controlled to be equal to or lower than the upper limit value of the equipment heat-resistant temperature. When an operating condition and an operating condition for controlling the temperature from the collecting pipe portion to the exhaust gas outlet to be equal to or higher than the dew point are required, an operation for controlling the temperature to be equal to or lower than the upper limit value of the equipment heat-resistant temperature. A method of operating a heating furnace equipped with a regenerative burner, wherein a suction gas flow rate is adjusted by operating a flue gas flow rate adjusting device provided in the collective piping section with priority given to conditions. 7. A method of operating a heating furnace having a regenerative burner, wherein a temperature from a measurement position of a first thermometer provided on an exhaust gas outlet side of the regenerative burner to a collecting pipe portion of the exhaust gas is: An operating condition for controlling the temperature to be equal to or lower than an upper limit value of the equipment heat-resistant temperature based on a maximum instantaneous value of the first thermometer, and a measuring position of a second thermometer provided in the collecting pipe section to an exhaust gas outlet. Is required to be equal to or higher than the dew point based on the average value of the measurement values obtained by the second thermometer. A method of operating a heating furnace provided with a regenerative burner, wherein a suction gas flow rate is adjusted by operating a flue gas flow control device provided in the collective piping section with priority given to.