JPH0367918A - Controller of burner - Google Patents

Abstract

PURPOSE:To obtain stable state of combustion without receiving an influence of the temperature of supply air which accompanies changes in season by correcting the operation of a blower according to the temperature of supply air and at the same time correcting the state of control of a proportional valve so as to compensate for the correction of the blower operation. CONSTITUTION:When a hot water supplier is ignited, a target heat quantity Q is determined based on the temperature of the water supplied to a heat exchanger and a set temperature of a controlled 46. When an appropriate target heat quantity Q is calculated, a half-fixed resistor in a proportional valve control section 44 is regulated and the value of the electric current to the proportional valve is corrected so as to match the amount of the supplied fuel gas to the target heat quantity Q. Further, according to the scatter in casings the half-fixed resistor in the control section 43 of a blower is operated and the rotational speed of a blower 11 is regulated and an amount of air for combustion is supplied according to the target heat quantity Q. At this time in order to compensate for the change in rotational speed of the blower that is given by the regulation the value of the electric current to a governor proportional valve 37 is corrected so that a volume of the fuel gas corresponding to the target heat quantity Q is supplied to the burner.

Description

[Detailed description of the invention] Industrial use bone! l! F 1 The present invention supplies burning air to the burner using a blower that is controlled according to the target combustion amount, and also detects the operating state (rotation speed) of the blower and adjusts the proportional valve according to the blower. The present invention relates to a control device for a controlled blower advance control type combustor.

[Prior Art] For example, in a gas water heater, in order to obtain a large hot water supply capacity and supply combustion air for ], combustion air is supplied by a blower, and in order to obtain a stable combustion state, There is also one that controls the proportional valve according to the operating condition of the blower.

Furthermore, recently, gas water heaters have been made smaller, and the limited volume of the combustor is divided into a combustion chamber, a mixing chamber, an exhaust passage, and the like.

As water heaters and other devices become smaller, they become more susceptible to the effects of the air supply system and exhaust system, so microcompico, a compact and high-performance control device for controlling blowers and proportional valves, is recommended. The control characteristics are given by a program created based on the ventilation performance determined by the volume and shape of the combustion chamber, mixing chamber, exhaust passage, etc. of the designed combustor.

[Problem to be solved by the invention 1 However, as mentioned above, if the combustor is small, a limited space must be used as the combustion J/M chamber, so it is difficult to ensure that the combustion state is appropriate for the target combustion amount. The allowable range of the fuel supply amount and the combustion air (supply air) supply amount to be obtained becomes narrower. For this reason, even if the blower is controlled by a high-performance microcomputer and rotates at the same number of revolutions for the target combustion amount, the supply air temperature may differ due to seasonal changes, etc. In a system in which the trachea and exhaust pipe are double-configured or placed adjacent to each other, if the supply air temperature changes due to heat conduction, the actual amount of combustion air supplied will change accordingly. The amount of fuel supplied differs depending on the air supply temperature, and at this time, the amount of fuel supplied is controlled according to the target combustion amount, so there is a problem that it is difficult to obtain a stable combustion state.

The present invention includes a blower, and the operating state (rotation speed) of the blower
It is an object of the present invention to provide a control device that allows a stable combustion state to be obtained in a combustor in which a proportional valve is controlled based on the above, without being affected by supply air temperature accompanied by seasonal changes.

[Means for Solving the Problems] The present invention controls a blower that supplies combustion air to a burner in accordance with a target combustion amount, and also controls a proportional valve that adjusts the amount of fuel supplied to the burner in the blower. The control device for a combustor that controls the combustion air according to the operating state of the burner is provided with a supply air temperature detection means for detecting the temperature of the combustion air supplied to the burner by the blower, and the supply air temperature detection means detects The technical means is to adjust the control characteristics of the blower based on the temperature and to correct the control characteristics of the proportional valve so as to offset the change in the operating state of the blower due to the sleeve sleeve.

[Function] In the present invention 'C, the blower is controlled according to the target combustion amount, and its control characteristics are corrected according to the temperature detected by the supply air temperature detection means.

On the other hand, the proportional valve is controlled according to the operating state of the blower, but at this time, the proportional valve is adjusted so as to cancel out the change due to the MtTE of the blower, so even if the control characteristics of the blower are corrected, The proportional valve will be controlled according to the target combustion amount.

Therefore, the burner is supplied with combustion air and fuel according to the target combustion amount.

[Effect of the invention 1 In the present invention, the operation of the blower is controlled according to the supply air temperature.
In addition, the control state of the proportional valve is corrected to offset the correction, so combustion air and fuel are supplied to the burner according to the target combustion amount, regardless of the supply air temperature. . Therefore, a stable combustion state can be obtained regardless of temperature changes in the supply air due to seasonal changes, heating of the supply air by exhaust gas, and the like.

[Example] Next, the present invention will be explained based on examples.

The waste water heater 1 shown in FIG. 2 includes a combustor 10 and a heat exchanger 20 in a water heater case 1a.
is controlled by a control device 40.

The combustor 10 is disposed below inside the water heater case 1a, and uses combustion air supplied from a fuel supply pipe 30 through a combustion air blower 11 provided below the water heater case 1a. A large number of sheet metal burners 12 are integrated in a single row in a burner case (not shown).

Below each sheet metal burner 12, each sheet metal burner 12 arranged in a row is divided into two sets at the middle part, and a first burner B is installed.
Two fuel injection pipes 31 and 32 to be used independently as Y 10 A and the second burner group 10B are arranged at a predetermined distance from the intake port of each sheet metal burner 12.

These two fuel injection pipes 31 and 32 separately supply fuel gas to each set of sheet metal burners 12,
Upstream of each fuel injection pipe 3 ]-132, electromagnetic valves 33 and 34 that control fuel supply are provided, respectively.

Each electromagnetic valve 33, 34 is provided downstream of a branch pipe 35 that branches fuel waste supplied from the fuel supply pipe 30, and supplies fuel waste to each fuel injection pipe 31, 32 according to the control state. do.

The fuel supply pipe 30 includes an original solenoid valve 36 from the upstream side, and a power proportional valve 3 that adjusts the supply force on the downstream side according to the energized current.
7 and C are provided in order.

Both ends of the sheet metal burner 12 are provided with a spark electrode f215 as a discharge electrode of a combustor (not shown) and a flame rod 16 for detecting the flame of the combustor 10.

The heat exchanger 20 is of a water tube type equipped with a large number of fins. An automatic water flow control device 22 and a water flow switch 23 are provided to limit the amount of hot water flowing out from the heat exchanger to a hot water supply 11/\ (not shown).
The hot water supply pipe 2/I for guiding the hot water is equipped with a hot water outlet temperature thermistor 25 that detects the hot water temperature.

Further, near the outlet of the scroll casing 1]a of the blower 11, a supply air temperature thermistor 26 is provided for detecting the temperature of the combustion air supplied to the burner.

The combustor 10 having the above configuration is controlled by a control device 40 mainly including a microcomputer.

As shown in FIG. 1, the control device 40 has a sequence control section 41, a temperature control section 42, a blower control section 43, a proportional valve control section 44, and a supply temperature correction section 45, which are separated into functional sections.

The sequence control unit 41 performs ignition control and extinguishing control in a predetermined sequence based on each detection signal B from the water flow switch 23 and the flame rod X6.

In particular, in this embodiment, in consideration of safety during ignition, the timing to open the solenoid valve 34 is slightly delayed from the timing to open the solenoid valve 33, and by igniting each burner group, the famous flame This reduces the amount of combustion during combustion and suppresses the ignition pressure.

In addition, after ignition, the target ripeness temperature of the temperature control section 42, which will be described later, is
Q Controls opening and closing of the solenoid valve 33 according to [Kcal/min].

The temperature control unit 42 calculates the temperature and flow rate of the water entering the heat exchanger 20 based on the temperature detected by the outlet hot water temperature thermistor 25, and also calculates the temperature set by the controller 46 or fixed when the controller 46 is not used. The target heat ITtQ [KCal/min] is calculated from the set temperature.

The blower control section 43 determines the rotation speed ΦD [Hz] of the blower 1 based on the target heat amount Q of the temperature adjustment control section 42, and controls the blower 11 based on this rotation speed Φゎ.

This rotation speed Φ3. is given as a function of the target heat iQ as shown in the following equation (2).

Φ1. + = f, (Q) x TH fan x VR fan
...■Here, T Hfan is the supply temperature ■Part 45
is the supply temperature Pura variable given by , and the target heat amount Q
The basic rotational speed fl (Q) determined based on is adjusted to tIIiN according to the temperature of combustion air (supply air) supplied to the combustor 10 during operation.

VR and fan are blower adjustment variables, and fl (Q)
This is for determining Hfan.

The proportional valve control unit 44 determines a current value Ip [mA1] to be supplied to the governor proportional valve 37 based on the detected rotational speed Φ, A [Hz] detected as the operating state of the blower 1, and controls the current value Ip [mA1] according to this current value Ip. to control the governor proportional valve 37.

This current value 1p is the detected rotational speed Φ1, the supply temperature sleeve ■variable'
As a function of l'Hfan and the blower adjustment variable VRfan, jj can be calculated as shown in the following equation (2).

Tp=f 2 (Φ, /('I' fan XV
Rfan ))
In order to offset the characteristics of the blower 11 corrected by n and the blower adjustment variable V Rfan, the detected rotational speed Φ divided by the supply temperature variable]' Hfan and the blower adjustment variable VRf a n is calculated. and
Supply air pressure stop variable THfan 1. The blower adjustment variable VRfan is given by the operation of a semi-fixed resistor in the blower control section 43.

Here, V RpOV is a proportional valve adjustment variable, and by operating a semi-fixed resistor (not shown), the basic current value f2 + ΦM is determined based on the detected rotation speed Φ6 of C5.
/ (THfan xVR, fan) ) is X1iI- according to each water heater.

The air supply vortex pressure section 45 is connected to a resistor R1 as shown in FIG.
Supply temperature F+i positive variable 1'I
-1fan is determined by the supply air vortex part old variable 1'H
As a fan, it is 0.8-1-. 2 or - given.

Next, the operation of the vine correction section 45 in the gas water heater of this embodiment will be explained.

During inspections in the factory, water exceeding a predetermined flow rate was detected in heat exchanger 2.
When it passes through 0, the water flow switch 23 closes and detects water flow, and ignition control is performed.

When ignited in a predetermined sequence, the target amount of heat Q is determined based on the temperature of the water supplied to the heat exchanger 20 and the set temperature of the l-r, -r 46.

At this time, due to fluctuations in the hot water temperature thermistor 25,
If the value of the calculated target heat amount Q is not appropriate, compensation is performed by ARK using a semi-fixed resistor (not shown).

When the appropriate target heat ff1Q is calculated, it is determined whether the amount of generated heat corresponds to the target heat amount Q, and the proportional valve control unit 4 is operated so that the amount of fuel gas supplied matches the target heat 1i1Q.
The semi-fixed resistor at 4 is adjusted to correct the proportional valve current value.

Furthermore, it is checked whether one blower is supplying combustion air corresponding to the target heat amount Q, and depending on the fluctuation of the casing, etc. It is operated and the number of revolutions of the air blower is adjusted to 1/11,
Combustion air corresponding to the target amount of heat Q is supplied.

At this time, even if the operating state of the blower 111 changes due to the adjustment of the semi-fixed resistor, the proportional valve control unit 44 controls the Kahana proportional valve 37 so as to offset the rotational speed of the blower 11 that has changed due to the adjustment. Since the current value ■p is calculated, there is no need to readjust the proportional valve current value.

As described above, in the adjusted water heater, the blower 11
The temperature of the combustion air supplied by the combustion air differs depending on the season, etc., or the rotational speed of the air blower 11.1 is adjusted according to the temperature, so the target heat amount is Combustion air according to Q can be supplied to the combustor IO.

Furthermore, even if the rotational speed of the blower 1 is corrected, the proportional valve current value is corrected to offset the change in rotational speed, so that fuel scum corresponding to 1'' ripening 4iQ is sent to the combustor 10. Supplied.

As described above, according to the present invention! Since the blower is corrected according to the L'-introduction air temperature, it is possible to supply combustion air according to the target heat amount, and at this time, the proportional valve current value is adjusted so as to offset the blower's uramasaki. Therefore, fuel waste can be supplied according to the target amount of heat.

In this embodiment, the supply air temperature thermistor is provided near the outlet of the scroll casing of the blower, but it may also be provided on the supply air "1" side of the scroll casing.

2 In the above embodiment, a waste water heater is shown, but a heater or a burner for a bathtub may be used.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the functions of a control device 11 according to an embodiment of the present invention, FIG. 2 is a schematic diagram of a gas water heater according to this embodiment, and FIG. 3 is a schematic diagram of a gas water heater according to this embodiment. FIG. 3 is a circuit diagram showing the main part. In the figure, 10 ・Combustor (burner), 1】 ・Blower, 3
7... Governor proportional valve (proportional valve), 40... Control valve: i
τ (combustor control equipment).

Claims (1)

[Scope of Claims] 1) A blower that supplies combustion air to the burner is controlled according to the target combustion amount, and a proportional valve that adjusts the amount of fuel supplied to the burner is controlled according to the operating state of the blower. A control device for a combustor, comprising supply air temperature detection means for detecting the temperature of combustion air supplied to the burner by the blower, and controlling characteristics of the blower based on the temperature detected by the supply air temperature detection means. A control device for a combustor, characterized in that the control characteristic of the proportional valve is corrected so as to compensate for the change in the operating state of the blower due to the correction.