JPH0210325B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an evaporation amount measuring device for automatically measuring the steam load of a boiler system, that is, the amount of evaporation, and particularly relates to a heating control device for heating canned water in a boiler system. The present invention relates to an evaporation amount measuring device that measures evaporation amount based on a heating period in intermittent control of a system.

In general, in boiler systems, it is known that during long-term operation, factors that inhibit operation increase in accordance with the cumulative amount of evaporation, such as carry over and scale growth due to concentration of canned water.

Furthermore, since there are control targets in the boiler system, such as water supply volume, which are controlled to appropriate amounts according to the amount of evaporation, it is necessary to judge whether these controls are being performed appropriately based on the amount of evaporation. However, backup measures are taken in case of unsuitability, and it is also known that the amount of evaporation is important basic data for the operational management of boiler systems.

Therefore, in order to understand the amount of evaporation as basic data for operation management, the flow rate of steam load is often measured using a flowmeter, but in small boiler systems, the flow rate is Since the economic burden of equipping a vehicle with a meter is relatively large, it has generally been difficult to adopt it.

Therefore, with conventional small boiler systems, it was not possible to accurately determine the amount of evaporation, so not only was it not possible to provide sufficient backup protection for water supply control systems, etc. The drawback was that there was an extremely high risk of water pipe burnout due to breakage and scale growth.

The purpose of the present invention is to measure the heating period in intermittent control of the heating control system without using a flow meter, and to measure the evaporation amount based on the measurement result, in view of the problems in measuring the amount of evaporation in a boiler system based on the above-mentioned conventional technology. It is an object of the present invention to provide an excellent evaporation amount measuring device in a boiler system that can eliminate the above-mentioned drawbacks and automatically measure the evaporation amount by calculating the evaporation amount.

The configuration of the present invention in accordance with the above object includes a pressure sensor that outputs a steam pressure signal corresponding to the steam pressure in the water pipe, and a pressure sensor that detects that the steam pressure signal has reached an upper and lower limit set value corresponding to the upper and lower limit steam pressure. a first and second comparator to form a vapor pressure detection section;
A heating device, typically a heating control, for starting or stopping a burner is provided for heating the water tube in response to an output signal from each of the first and second comparators, so that the water tube is heated as steam is consumed. When the vapor pressure of When the vapor pressure increases and reaches the upper limit vapor pressure, the second comparator detects this and sends an upper limit vapor pressure signal to the heating control section to stop the heating device.Intermittent control heating control In a boiler system equipped with a heating period measuring section, a heating period measuring section is attached to measure the heating period from when the heating device starts until it is stopped, and an evaporation amount calculating section is attached to measure the heating period. The method is characterized in that the amount of evaporation corresponding to the measured heating period is searched according to a table representing the relationship between the heating period and the amount of evaporation, and the search result is output as an evaporation amount signal. .

Now, before explaining the subsequent embodiments of the present invention, the structure and operation of a typical small boiler system to which the structure of the present invention can be attached will be explained as follows.

FIG. 1A is a block explanatory diagram showing the configuration of such a boiler system, and a cross section of the boiler 1 is shown.

FIG. 1B is a sectional view taken along the line AA in FIG. 1A.

In the figure, inside the boiler 1, a large number of water pipes 1b are installed along the inner peripheral surface of the wall 1a.
consists of a hollow cylindrical body, its lower end communicates with the annular lower header 1c (water chamber), and its upper end communicates with the annular upper header 1d (steam chamber). Canned water is stored in the lower part of the water pipe 1b.

A combustion chamber 1e is formed in the center of the boiler 1 surrounded by water pipes 1b, and an electric motor 1f is provided above the combustion chamber 1e.
An air passage 1h is provided which communicates with a blower 1g driven by a blower 1g, and a nozzle rod 1i and an electrode rod 1j are vertically provided within the air passage 1h.

The lower end of the combustion chamber 1e communicates with the flue 1k through the hollow portions of a large number of water pipes 1b. From the upper header 1d, a communication pipe 1l extends outside the wall 1a and communicates with the lower header 1c.

A water level gauge 1m and a water level detector 2 for visually displaying the canned water level are installed in the middle of the communication pipe 1l. A water supply control section 3 is connected to the water level detection section 2, and an electric motor 4a that drives a water supply pump 4 is connected to an output terminal thereof. An inlet pipe of the water supply pump 4 communicates with a water source (not shown), and a discharge pipe thereof communicates with the lower header 1c.

Further, a pressure detection section 5 is connected to the upper part of the communication pipe 1l, and its output terminal is connected to a combustion control section 6. From the combustion control section 6, control signal lines 6a' to 6
c' extends and is connected to each of the electric motor 1f, electrode rod 1j, and fuel pump 6d'. An inlet pipe of the fuel pump 6d' communicates with a fuel tank (not shown), and a discharge pipe thereof communicates with the nozzle rod 1i. A blow pipe 1n extends from the lower header 1c and communicates with a drainage channel (not shown) via a blower stock 1p, and a steam pipe 1q extends from the upper header 1d and communicates with a desired steam load (not shown).

In the configuration of the boiler system described above, when generating steam, the electric motor 1f drives the blower 1g to forcefully feed air into the air passage 1h while applying a high voltage to the electrode rod 1j to generate steam from the tip of the nozzle rod 1i. The injected fuel is ignited and combusted within the combustion chamber 1e. High-temperature combustion gas generated by such combustion enters the hollow part of the water pipe 1b from the lower end of the combustion chamber 1e, passes through it, reaches the flue 1k, and is exhausted. During this time, heat exchange takes place and the canned water in the water pipe 1b is heated and turned into steam, which is then transferred to the upper header 1.
The steam is collected and accumulated at the steam pipe 1q, and is supplied to the steam load through the steam pipe 1q.

Regarding combustion control, the upper header 1d
The steam pressure in the upper header 1d is extracted through the communication pipe 1l and supplied to the pressure detector 5.
When the combustion control section detects that the vapor pressure within the combustion chamber has reached a preset lower limit vapor pressure, the lower limit vapor pressure signal is sent to the combustion control section. Send to 6.

When the combustion control unit 6 receives a lower limit steam pressure signal from the pressure detection unit 5 due to continued consumption of steam and the steam pressure in the upper header 1d falls, the combustion control unit 6 connects the control signal line 6 to the lower limit steam pressure signal from the pressure detection unit 5.
Start electric motor 1f through a' and blower 1g
After purging the air passage 1h with air, a high voltage is applied to the electrode rod 1j through the control signal line 6b', and at the same time, a high voltage is applied to the electrode rod 1j through the control signal line 6c'.
d' is started to ignite the fuel injected from the nozzle rod 1i to start combustion, and further, steam generation continues and the steam pressure rises, and an upper limit steam pressure signal is received from the pressure detector 5. Sometimes, the fuel pump 6d' is stopped via the control signal line 6c' to cut off the fuel supply, thereby stopping combustion, and the electric motor 1f is stopped via the control signal line 6a' after waiting for the combustion gas to be discharged. Cut off the air from the blower 1g.

Thus, even with intermittent control of combustion, the steam pressure in the upper header 1d can be maintained at a pressure value between the two pressure values preset as the upper and lower steam pressure limits.

In addition, in a simple device, the start/stop control of the electric motor 1f and the fuel pump 6d', and the application of high voltage to the electrode rod 1j may be performed simultaneously.

Furthermore, regarding the water supply system, changes in the canned water level in the air-water interface in the communication pipe 1l, that is, in the water pipe 1b, are transmitted to the water level detection section 2, and the water level detection section 2 detects the canned water level set in advance. When it is detected that the lower limit water level has been reached, a lower limit water level signal is sent to the water supply control unit 3, and similarly, when it is detected that the upper limit water level has been reached, an upper limit water level signal is sent to the water supply control unit 3.

When the canned water level in the water pipe drops due to steam consumption and a lower limit water level signal is received from the water level detection unit 2, the water supply control unit 3 starts the electric motor 4a and causes the water supply pump 4 to lower the water pipe through the lower header 1c. 1
When the water supply to the water pipe 1 is started and the water supply continues and the can water level rises and an upper limit water level signal is received from the water level detector 2, the electric motor 4a is stopped and the water pipe 1
Cut off the water supply to b.

Thus, even with the intermittent water supply control, the water level of the canned water in the water pipe 1b can be maintained at a water level between the upper and lower limit water levels preset.

The intermittent control of water supply and the intermittent control of combustion are performed separately and independently from each other.

Further, when blowing canned water, by opening the blowing tank 1p, part or all of the canned water in the lower header 1c and the water pipe 1b can be blown out through the drain pipe 1n.

In addition, blower 1g, air passage 1h, nozzle rod 1i,
The burner consisting of the electrode rod 1j is not limited to this, and if necessary, it is sufficient to heat the canned water in the water pipe 1b to generate steam, so generally an electric heater or the like is also used. Any heating device including the above may be used.

Similarly, the combustion control section 6 may also be a heating control section that turns on and off the heating device.

Next, the structure and operation of the embodiment of the present invention will be described below based on FIGS. 2 to 7.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and in the figure, components denoted by the same reference numerals as those in FIG. 1 correspond to those in FIG. 1, respectively.

The pressure detection unit 5 includes a pressure sensor 5a to which the steam pressure in the upper header 1d is guided through the communication pipe 1l;
First and second comparators 5 whose respective first input terminals are connected to the output terminal of the pressure sensor 5a.
b, 5c, and first and second comparators 5b, 5
and reference voltage sources 5d and 5e, respectively connected to the second input terminal of c.

The heating control section 6 includes a flip-flop 6b, in which the output terminal of the first comparator 5b is connected to its set terminal, and the output terminal of the second comparator 5c is connected to its reset terminal through an inverter 6a, and a positive-phase flip-flop 6b. It consists of a relay 6e whose output terminal is connected to one end through a driver 6c and the other end connected to a power source 6d, and the contacts 6e', 6e'', 6e of the relay 6e are as follows:
It is inserted between the power source and control signal lines 6a', 6b', and 6c' for controlling the electric motor 1f, electrode rod 1j, and combustion pump 6d'.

The heating period measuring section 7 includes a clock pulse oscillator 7.
a and one input terminal is the clock pulse oscillator 7.
an AND gate 7b, which is connected to the output terminal of the flip-flop 6b, and whose other input terminal is connected to the positive phase output terminal of the flip-flop 6b; and a counter 7c, whose input terminal is connected to the output terminal of the AND gate 7b.
, its input terminal is connected to the positive phase output terminal of flip-flop 6b, and its output terminal is connected to counter 7
It consists of a monostable multivibrator 7d connected to the clear terminal of c.

The evaporation amount calculating section 9 includes a microprocessor 9d and a memory 9e, which are interconnected through a data bus 9a, an address bus 9b, and a control bus 9c.
, an input port 9f, an output port 9g, and a monostable multivibrator 9i whose complementary output terminal is connected to the interrupt control line 9h, and the input terminal of the input port 9f is connected to the output terminal of the counter 7c. The input terminal of the monostable multivibrator 9i is connected to the positive phase output terminal of the flip-flop 6b.

10 is a display unit connected to the output port 9g.

Figures 3 and 5 show the change A in the steam pressure in the upper header 1d extracted to the communication pipe 1l, and the upper and lower limit steam pressure signals B and C output by the first and second comparators 5b and 5c. , is a waveform diagram showing a comparison of the positive phase output signals D and E of the flip-flop 6b.

In the above configuration, first, the operations of the pressure detection section 5 and the heating control section 6 will be explained as follows.

The pressure sensor 5a responds to the steam pressure in the upper header 1d guided through the communication pipe 1l and outputs a corresponding steam pressure signal _S1 , as shown in FIG. 3Aa. When the vapor pressure is higher than the lower limit vapor pressure L, the vapor pressure signal corresponding to the lower limit vapor pressure L is supplied from the reference voltage source 5d.
Since the vapor pressure signal S ₁ is larger than the reference voltage V _L which is equal to the lower limit set value of S ₁ , the first comparator 5b detects this and outputs "1" as shown in FIG. 3 Cb. do.

Then, as the steam pressure decreases as the steam is consumed or the temperature decreases, and as shown in Figure 3 Ac, when the lower limit steam pressure L is reached, the steam pressure signal S ₁ changes to the reference voltage.
Since this becomes smaller than V _L , the first comparator 5b detects this and operates as shown in FIG. 3 Cd.
Outputs "0".

Upon receiving the inversion of the output signal of the first comparator 5b from "1" to "0" at the set terminal, the flip-flop 6b is set to "1", and its positive phase output signal is as shown in FIG. 3 De. ``0''
to "1". Upon receiving this signal, the driver 6c becomes conductive, the relay 6e is energized, the contacts 6e', 6e'', and 6e are closed, and the motor 1
Since power is supplied to the electrode rod 1j and the combustion pump 6d', the canned water is heated.

Thus, while the flip-flop 6b is at "1", heating continues and the vapor pressure continues to rise as shown in FIG. 3Af.

Eventually, as shown in FIG. 3Ag, when the vapor pressure reaches the upper limit vapor pressure H, the vapor pressure signal S ₁
is smaller than the reference voltage _VH , which is equal to the upper limit set value of the vapor pressure signal _S1 corresponding to the upper limit vapor pressure supplied from the reference power source 5e, so it is set to "0" as shown in FIG. 3Bh. The second comparator 5c, which had been outputting, now outputs "1" as shown in FIG. 3 Bi.

The inversion of the output signal of the second comparator 5c from "0" to "1" is converted by the inverter 6a into an inversion from "1" to "0" and supplied to the reset terminal of the flip-flop 6b.
Reset this to "0".

Therefore, as shown in FIG. 3Dj, the positive phase output signal of the flip-flop 6b becomes "0", so
Relay 6e becomes de-energized and contacts 6e', 6
e'' and 6e are opened, and heating of the canned water is stopped.

In this way, the period from when the heating device starts until it stops (hereinafter referred to as the heating period) can be specified even during the period when the flip-flop 6b is set to "1", and furthermore, the period from when the heating device stops until it stops is specified. The period until this happens (hereinafter referred to as the heating stop period) is as follows:
This is specified even during the period when the flip-flop 6b is at "0".

After stopping heating, as shown in Figure 3 Ak,
The flip-flop 6b remains at "0" until the steam pressure decreases again as the steam is consumed or the temperature decreases and reaches the lower limit steam pressure L, forming a heating stop period _T2 , after which the same cycle occurs. The operation is repeated to maintain the vapor pressure between the upper limit vapor pressure H and the lower limit vapor pressure L.

For example, if the amount of evaporation (steam load) increases during the process of increasing steam pressure, heating of canned water,
The amount of heat flowing into the boiler system due to the supply of canned water,
Where the amount of heat flowing out of the boiler system due to heat radiation is approximately constant during the heating period during steady operation,
As the amount of heat flowing out from the boiler system increases in proportion to the evaporation of canned water, more heat is taken away from the boiler system, as shown in Figure 3 Af'. The slope of increase in vapor pressure slows down.

Therefore, hypothetically, at the point shown in Figure 3 Ac,
At the same time, as shown in FIG. 3Ee', assuming that the flip-flop 6b is inverted to "1" and the heating period begins, if the amount of evaporation increases, the third
At the time shown in Figure Ag', the flip-flop 6b is inverted to "0" as shown in Figure 3 Ej', so the heating period is longer than the heating period _T1 before the amount of evaporation increases. T ₁ ′ is formed.

A quantitative consideration of changes in the heating period T ₁ depending on changes in the amount of evaporation is as follows.

Generally, the change dU in the internal thermal energy possessed by a boiler system is expressed as dU = ηB・H _U・dt+G _W・I _W・dt −G _S・I _S・dt−Q _R・dt (1).

However, η...Boiler efficiency (excluding heat radiation loss) B...Fuel consumption (flow rate) H _U ...Fuel calorific value G _W ...Water supply amount to the boiler (flow rate) I _W ...Water supply enthalpy G _S ...Amount of evaporation (flow rate) I _S ...Enthalpy of steam Q _R ...Amount of heat released from the boiler (heat flow rate).

Regarding the right side of equation (1), the first term is the amount of heat flowing into the boiler system due to heating of can water, the second term is the amount of heat flowing into the boiler system due to supply of can water, and the third term is the amount of heat flowing into the boiler system due to the supply of can water.
The term represents the amount of heat flowing out from the boiler system due to evaporation of canned water, and the fourth term represents the amount of heat flowing out from the boiler system due to heat radiation.

By the way, in general, in a boiler system, the amount of fluctuating canned water that is replenished by intermittent control of the water supply system is negligibly small compared to the amount of canned water held during operation. The minimum amount of water that can be stored is 40, whereas the amount of water that can fluctuate is about 1.5.

Therefore, the amount of water held in the can during operation can be considered to be a constant value unique to each boiler system.
Internal thermal energy possessed by the boiler system at the start of the heating period _T1 corresponding to the lower limit steam pressure L
The heating period corresponds to U _L and the upper limit vapor pressure H.
Each of the internal thermal energy U _H possessed by the boiler system at the end of T ₁ is specified to a value unique to each boiler system.

Therefore, based on equation (1), the increase in internal thermal energy (U _H − U _L ) generated in the boiler system as one heating period T ₁ passes is: U _H − U _L = (η・B・H _U )T ₁ +I _W ∫ ^T1 ₀ G _W dt −G _S ∫ ^T1 ₀ I _S dt−Q _R・T ₁ …(2)

In reality, the difference in enthalpy between the upper and lower vapor pressure limits H and L is not large, so for simplicity, calculate the average enthalpy value I _SM corresponding to the upper and lower vapor pressure limits, and set I _S = I _SM . And, formula (2) is, U _H − U _L = (η・B・H _U )T ₁ + (G _W・I _W )T ₁ − ( _GS・I _SM )T ₁ −Q _R・T ₁ …(3) becomes.

Furthermore, considering the heating period T ₁ ,
Within one heating period T ₁ , water is supplied a number of times according to the amount of evaporation through intermittent control of water supply, which is performed independently of heating control. Therefore, during the water supply period, the amount of water supplied ( On the other hand, during the water supply stop period, water is not supplied at all, and the amount of water supplied (flow rate) flowing into the boiler becomes zero.

However, from a long-term perspective over many heating periods, in an operating boiler system, the average water supply amount (flow rate) supplied by water supply control is in equilibrium with the evaporation amount (flow rate), so the amount of water held in the boiler is approximately It is kept at a constant value.

Therefore, ∫ ^T1 ₀ G _W dt=G _S T ₁ …(4) holds true.

Then, when the evaporation amount G _S is calculated from equations (3) and (4), it becomes G _S =C _B −C _R −C _V /T ₁ (5).

However, C _B = η・B・H _U /I _SM −I _W …(5a) C _R =Q _R /I _SM −I _W …(5b) C _V =U _H −U _L /I _SM −I _W ...(5c), and if the feed water enthalpy is constant, both are constants specific to each boiler system.

Therefore, in equation (5), if C=C _B −C _R (6), then the evaporation amount G _S is expressed as G _S =C − C _V /T ₁ (7).

And for C, the heating period T ₁ is infinite (continuous heating)
In other words, it represents the maximum evaporation amount unique to each boiler system.

Furthermore, the heating period T ₁₀ at G _S =0 is T ₁₀ =C _V /C (8), and even if the amount of evaporation (steam load) is zero, the heating period T ₁₀ is mainly due to the amount of heat from the boiler. This is the minimum heating period required to maintain the boiler system in operation by supplementing the thermal energy that flows out due to heat radiation.

FIG. 4 is a graph illustrating the relationship between the heating period T ₁ and the evaporation amount G _S expressed by the above equation (7).

In this way, the boiler system heating period T ₁ is the amount of evaporation
Since it is specified as a value unique to each boiler system according to G _S , if you measure the heating period T ₁ and specify this,
Evaporation amount according to the graph shown in Figure 4.
_GS can be specified.

Next, for example, if the amount of evaporation (steam load) increases during the step of lowering the steam pressure, there is no amount of heat flowing into the boiler system due to the heating of the canned water, and furthermore, the amount of heat flowing into the boiler system is increased by the supply of canned water. Where the amount of heat flowing into the system and the amount of heat flowing out from the boiler system due to heat radiation are approximately constant during the heating stop period during steady operation,
The amount of heat flowing out of the boiler system due to evaporation of canned water increases in proportion to the amount of evaporation, so as in the process of increasing steam pressure, more heat is taken away from the boiler system, as shown in Figure 3. Figure 5 corresponds to
As shown by Ak′, the downward gradient of vapor pressure becomes steeper.

Therefore, hypothetically, at the point shown in Figure 5Ag,
At the same time, as shown in FIG. 5 Ej', assuming that the flip-flop 6b is reversed to "0" and the heating stop period has started, if the amount of evaporation increases, then
At the time shown in Fig. 5 Al', the flip-flop 6b is inverted to "1" as shown in Fig. 5 Em', so that the heating stop period _T2 before the evaporation amount increases is shorter A heating stop period T ₂ ' is formed.

The heating stop period depends on the change in the amount of evaporation.
A quantitative consideration of the change in T ₂ is as follows.

During the heating stop period, the canned water is not heated, the first term on the right side of equation (1) becomes zero, and the internal thermal energy changes.
dU is expressed as dU＝G _W・I _W dt−G _S・I _S・dt−Q _R dt (9), and the internal thermal energy as one heating stop period T ₂ elapses. Decrement (U _L −U _H )
is expressed as U _L −U _H =I _W ∫ ^T2 ₀ G _W dt −( _GS・I _SM )T ₂ −Q _R −T ₂ (10).

In equation (10), if ∫ ^T2 ₀ G _W dt=G _S T ₂ and the evaporation amount G _S is determined, G _S =C _V ′/T ₂ −C _R (11).

However, C _V ′=U _H −U _L /I _SM −I _W =C _V …(11a) C _R =Q _R /I _SM −I _W …(11b) Then, heating stops at G _S =0. Period T ₂₀
is T ₂₀ = C _V ′/C _R , and even if the amount of evaporation (steam load) is zero during this heating stop period T ₂₀ , the upper steam limit is This is the maximum heating stop period required to reach the lower limit vapor pressure.

Therefore, even when the steam load is no load, the boiler system heating device is controlled intermittently during the heating period T ₁₀ and the heating stop period T ₂₀ .

Then, the heating stop period expressed by the above equation (11)
FIG. 6 is a graph illustrating the relationship between T ₂ and the amount of evaporation G _S.

In this way, the heating stop period T ₂ of the boiler system is also specified to a value unique to each boiler system according to the evaporation amount G _S , so if the heating stop period T ₂ is measured and specified, the sixth The evaporation amount G _S can be specified according to a graph as illustrated in the figure.

Next, the operations of the heating period measuring section 7, the evaporation amount calculating section 9, and the display section 10 will be explained with reference to FIGS. 2, 3, 4, and 7.

FIG. 7 is a flowchart of calculation processing in the evaporation amount calculation section 9.

First, when the evaporation amount calculating section 9 starts operating, the microprocessor _9d shifts to the step shown in FIG. do.

When the heating device is controlled intermittently under such conditions, the positive phase output signal of the flip-flop 6b becomes "1" during the heating period _T1 ' as shown in FIG. 3E.
Therefore, in response to this positive phase output signal, the AND gate 7b is opened only during the heating period, and the clock pulse from the clock pulse oscillator 7a is guided to the counter 7c to be counted.

Then, as shown in FIG. 3 Ej', when the flip-flop 6b is inverted from "1" to "0", the AND gate 7b is closed and the supply of clock pulses to the counter 7c is cut off, and the counter 7c has the following values:
A digital code representing the heating period T ₁ ′ is generated;
It is output as a heating period signal _S2 .

At the same time, due to the inversion of the positive phase output signal of the flip-flop 6b from "1" to "0", the monostable multivibrator 9i is triggered and shifts to a quasi-stable state, setting the interrupt control line 9h to "0". Then, an interrupt command signal is given to the microprocessor 9d.

Microprocessor 9d receives the interrupt command signal
executes the process of FIG. 7b and connects the address bus 9b.
An address signal specifying the input port 9f is sent to the control bus 9c, and a control signal is sent to the control bus 9c to determine the heating period output by the counter 7c.
A heating period signal S ₂ representing T ₁ ' is read from input port 9f and transferred into microprocessor 9d via data bus 9a.

Then, the heating period signal outputted by the counter 7c
After S ₂ is loaded into the microprocessor 9d,
The monostable multivibrator 7d was triggered and transitioned to a quasi-stable state by the reversal of the positive phase output signal of the flip-flop 6b from "1" to "0".
returns to a stable state, clears counter 7c,
This is prepared for measurement during the next heating period.

During this time, the microprocessor 9d executes the program shown in FIG.
Based on the transferred heating period signal S ₂ , an evaporation amount signal representing the evaporation amount G _S corresponding to the heating period T′ ₁ represented by this heating period signal S ₂ is generated.
The address where S ₃ is stored is calculated, and then the process moves to the process shown in FIG. Move on to the process.

In this step, the address of the memory stored in the register is transferred to the memory 9e via the address bus 9b, and the address is specified, and a control signal is sent to the memory 9e via the control bus 9c to operate it in read mode. By doing so, the evaporation amount signal _S3 stored at the specified address is read out and sent to the data bus 9.
This is processed into the microprocessor 9d through a.

During such search processing, the memory 9e contains:
Since a table is formed according to the relationship between each address and the memory contents stored therein, an address in the memory 9e is specified based on a certain heating period signal, and the address corresponds to the heating period represented by that heating period signal. If the evaporation amount signal representing the evaporation amount is stored in advance at the specified address, the evaporation amount signal corresponding to the heating period signal can be searched according to the table.

The relationship between the heating period T ₁ and the evaporation amount G _S in the above table is as shown in the graph in Figure 4 mentioned above, and such a relationship can be easily determined for each boiler system by actual measurement. .

The above search process will be further explained with reference to the graph of _FIG . Identify the value of the heating period T ₁ expressed on the horizontal axis, and as shown in Figure b,
The evaporation amount G _S is determined from the heating period T ₁ by searching for a specific value of the evaporation amount G _S expressed on the vertical axis corresponding to the value on the horizontal axis.

When the execution of the above search process is completed, the microprocessor 9d moves to the _step shown in FIG.

After that, the microprocessor 9d operates as shown in FIG.
In the return process, the process returns to the process shown in FIG. 3A, and enters a state of waiting for an interrupt, in which it waits to measure the next heating period, that is, to receive an interrupt command signal.

The display section 10 receives the evaporation amount signal _S3 and displays the evaporation amount.
Visually display G _S.

A second aspect of the invention that is related to this invention is that, in the configuration of this invention, a heating stop period measuring section is attached instead of the heating period measuring section to measure the period from when the heating device is stopped until it is started. Then, the evaporation amount calculation section searches for the evaporation amount corresponding to the heating stop period measured by the heating stop period measuring section according to the table representing the relationship between the heating stop period and the evaporation amount, and uses the search result as an evaporation amount signal. This feature is characterized in that it is output as .

The configuration and operation of the second invention will be explained based on FIGS. 8 and 9 and with reference to FIGS. 5 and 6 as follows.

FIG. 8 is a block diagram showing the configuration of the second invention, and in the figure, the heating stop period measuring section 8 is configured similarly to the heating period measuring section 7 in FIG. 2, and one input of the AND gate 8b. Both the terminal and the input terminal of the monostable multivibrator 8d are connected to the complementary output terminal of the flip-flop 6b.

In the figure, the input terminal of a monostable multivibrator 9i included in the evaporation amount calculating section 9 is also connected to the complementary output terminal of the flip-flop 6b.

The other components are the same as those indicated by the same reference numerals in FIG.

FIG. 9 is a flowchart of the calculation process of the evaporation amount calculation section 9 in FIG.

In the above configuration, the microprocessor 9d is the ninth
If intermittent control of the heating device is performed while the heating device is on standby in the state of waiting for an interrupt in the step shown in FIG _. Since it becomes "0" during the heating stop period T 2 ', its complementary output signal becomes "1" during the heating stop period T ₂ '. In response to this complementary output signal, the AND gate 8b is opened only during the heating stop period, and the clock pulse from the clock pulse oscillator 8a is guided to the counter 8c for counting.

Then, as shown in FIG. 5 Em', when the flip-flop 6b is inverted from "0" to "1", its complementary output signal is inverted from "1" to "0", and the AND gate 8b is closed. The supply of clock pulses to the counter 8c is cut off, and the counter 8c has the following information:
A digital code representing the heating stop period T ₂ ' is generated and output as a heating stop period signal S ₂ '.

At the same time, the complementary output signal of the flip-flop 6b is inverted from ``1'' to ``0'', which triggers the monostable multivibrator 9i to enter a quasi-stable state, and sets the interrupt control line 9h to ``0''. Then, an interrupt command signal is given to the microprocessor 9d.

Microprocessor 9d receives the interrupt command signal
9b', executes the same process as the process of FIG. 7b, reads the heating stop period _T2 ', and then goes through the steps of FIG. 9c to d. Figure 9
Move on to step e′.

In this step, by executing a search process similar to the step in FIG. 7e, the heating stop period T _{2 ' corresponding to the heating stop period signal S 2 '} read in the step in FIG. 9 b' is determined. Evaporation amount G _S , heating stop period T ₂
The search is performed according to a table representing the relationship between the amount of evaporation and the amount of evaporation G _S .

The above search process is performed based on the heating stop period signal S ₂ ' obtained by the heating stop period measuring section 8, as shown in a in the graph of FIG. By specifying the value of ₂ and searching for the specific value of the evaporation amount G _S expressed on the vertical axis corresponding to the value on the horizontal axis, as shown in Figure b,
The evaporation amount G _S is determined from the heating stop period T ₂ .

Following the above step e', the steps f to g in FIG. 9 are executed to signal the evaporation amount through the output port 9g.
S ₃ is output, and in response to this, the display section 10 displays the amount of evaporation.
Visually display G _S.

In addition, in the configuration of the above-mentioned present invention and the second invention related to the present invention, the heating period measuring section 7 and the heating stop period measuring section 8 measure the heating period T ₁ and the heating stop period T ₂ for one intermittent control. and one heating period signal S ₂ and one heating stop period signal, respectively.
S ₂ ′ is output and the amount of evaporation is searched based on each, but the heating period and heating stop period are measured for multiple intermittent control, and the average value of these is calculated to obtain one heating period signal. , it can also be processed as one heating stop period signal.

By doing so, it is possible to avoid instantaneous fluctuations in the boiler system, especially variations in the heating period signal and heating stop period signal caused by intermittent control of water supply, and there is the practical benefit of obtaining a more stable and accurate amount of evaporation. .

Further, the heating period measuring section 7 and the heating stop period measuring section 8 are configured to operate in response to the "1" or "0" state of the flip-flop 6b of the heating control section 6, but the present invention is not limited to this. Rather, it is sufficient to measure the period from when the heating device starts until it stops, or from when the heating device stops until it starts, so start the heating device as described above. - It may be configured to respond directly to the signal for stopping, that is, the "1" or "0" state of the flip-flop 6b;
The heating period and heating stop period are measured in response to the operating state of the heating device as a result of control based on the signal, for example, the intermittent state of the combustion pump 6d', the application state of high voltage to the electrode rod 1j, etc. It is also possible to have a configuration in which

Furthermore, it should be noted that the first and second comparators 5b and 5c referred to in this specification are not limited to a configuration that is realized as separate and independent hardware; It may also be configured to be realized as a single piece of hardware.

As described above, this invention and the second invention connected thereto are such that, in a boiler system in which the heating device is controlled intermittently, the heating period and the heating stop period are measured and the amount of evaporation is searched based on each of them. As a result, the amount of evaporation in the boiler system can be automatically measured and accurately grasped.

Therefore, according to this invention and the second invention related thereto, by providing backup protection for a control system based on evaporation amount, typically a water supply control system,
In addition to completely preventing dry firing, by securing basic data such as evaporation amount, which is important for boiler system operation management, it is possible to prevent equipment damage and burnout caused by carry over and scale growth. It has excellent effects.

Moreover, the vapor pressure detection section and the heating control section in the configuration of this invention and the second invention linked thereto are as follows:
These are indispensable components for intermittent control of the heating device, and it is sufficient to use them as they are and add a configuration for processing the heating device start/stop signals obtained from the heating control section. It also has the advantage of being simple, efficient, and can be realized at low cost.

[Brief explanation of drawings]

Figure 1A is a block diagram showing the configuration of a small boiler system to which the configuration of the present invention can be attached.
FIG. B is a cross-sectional view of the boiler 1 taken along the line AA in FIG. 1A. 2 to 7 relate to an embodiment of the present invention, FIG. 2 is a block diagram showing its configuration, and FIGS. 3 and 5 show waveforms of main parts of the heating control section 6 in FIG. 2. Figure 4 is a graph showing the relationship between heating period T ₁ and evaporation amount G _S , Figure 6 is a graph showing the relationship between heating stop period T ₂ and evaporation amount G _S , and Figure 7 is a graph showing the relationship between heating period T 1 and evaporation amount G S. It is a flowchart showing the procedure of calculation processing in the evaporation amount calculation section 9. Figures 8 to 9
The figures relate to an embodiment of the second invention linked to this invention, FIG. 8 is a block diagram showing its configuration, and FIG. 9 shows the procedure of calculation processing in the evaporation amount calculation section 9 in FIG. This is a flowchart. 1... Boiler, 5... Pressure detection section, 5a... Pressure sensor, 5b, 5c... Comparator, 6...
Heating control section, 7... Heating period measuring section, 8... Heating stop period measuring section, 9... Evaporation amount calculation section, 10...
Display section.

Claims (1)

[Claims] 1. A pressure sensor that outputs a steam pressure signal corresponding to the steam pressure of the boiler, a comparator that detects that the steam pressure signal is at the lower limit set value and outputs the lower limit steam pressure signal, and A steam pressure detection means comprising a comparator which detects that the signal is the upper limit set value and outputs an upper limit steam pressure signal, and starts a heating device for heating the canned water in response to the lower limit steam pressure signal. In a boiler system equipped with heating control means that stops the heating device in response to an upper limit steam pressure signal, the period from when the heating device starts until it stops is measured, and the measurement result is used as a heating period signal. The evaporation amount calculation means is provided with a heating period measuring means for outputting, and an evaporation amount calculation means for calculating the evaporation amount based on the heating period signal and outputting the calculation result as an evaporation amount signal. 1. An evaporation amount measuring device for a boiler system, characterized in that the evaporation amount corresponding to a heating period is searched according to a table representing the relationship between the heating period and the corresponding evaporation amount. 2. A pressure sensor that outputs a steam pressure signal corresponding to the steam pressure of the boiler, a comparator that detects that the steam pressure signal is at the lower limit set value and outputs the lower limit steam pressure signal, and a comparator that outputs the lower limit steam pressure signal when the steam pressure signal is at the upper limit set value. A steam pressure detecting means includes a comparator that detects that the upper limit vapor pressure signal is detected and outputs an upper limit vapor pressure signal, and a heating device for heating the canned water is started in response to the lower limit vapor pressure signal, and In a boiler system equipped with a heating control means that stops the heating device in response, the heating stop period measurement measures the period from when the heating device stops until it starts and outputs the measurement result as a heating stop period signal. and an evaporation amount calculation means for calculating the evaporation amount based on the heating stop period and outputting the calculation result as an evaporation amount signal, and the evaporation amount calculation means calculates the evaporation amount based on the heating stop period stored in advance. An evaporation amount measuring device for a boiler system, characterized in that the evaporation amount corresponding to a heating stop period is searched according to a table representing the relationship between the evaporation amount and the corresponding evaporation amount.