JPH0629667B2 - Gas appliances - Google Patents

Description

Description: [Industrial field of use] The present invention relates to a gas appliance in which the amount of heating is adjusted by a heat control valve.

[Prior art]

Even if the conventional gas appliances can be used for different types of gas such as 11A, 12A, 13A, etc., the thermal power depends on the calorific value per unit volume of the gas used (hereinafter simply referred to as the calorific value of the gas). The heating amount change characteristics of the main burner with respect to the opening of the control valve are different, and accordingly, the maximum heating capacity of the main burner when the opening of the thermal power control valve is maximum is also different. Therefore, when the calorific value of the gas decreases, the prescribed performance cannot be obtained, and when the maximum heating capacity increases due to the increase in the calorific value, each part is overheated and durability deteriorates. However, there is a problem that boiling occurs and the thermal efficiency decreases. In order to deal with these problems, conventionally, the specifications have been changed such as changing the main nozzle of the burner according to the type of gas used.

[Problems to be solved by the invention]

However, in such a conventional technique, since it is necessary to change the main nozzle according to the type of gas used, there is a problem that the number of specifications increases, which is bothersome. In addition, even for the same type of gas, the calorific value may vary considerably within a predetermined allowable range, but it is not possible to cope with the change in the heating amount change characteristic due to this, and therefore the heating In a gas appliance of an automatic control system that particularly needs to have a constant amount change characteristic, there is a risk of malfunction of a safety device or the like. The present invention seeks to solve these problems.

[Means for solving problems]

To this end, the gas appliance according to the present invention is a gas appliance in which a heat control valve 21 is provided in a supply passage 20 for supplying gas to the main burner 10, as illustrated in the accompanying drawings.
The supply passage 20 is provided upstream of the heat control valve 21.
A motor-operated valve 100 that operates according to an applied current provided in the motor-operated valve 100, the opening degree of which varies, and the thermal power control valve 2
1 and the motor-operated valve 100, a detection burner 30 branched by the supply passage 20, a heat generation amount detection device 40 that is heated by the detection burner and generates a heat amount signal according to the heating amount of the detection burner, By inputting a heating amount signal and comparing the value with a reference value determined in advance by a gas appliance, the current applied to the motor 106 is changed to change the electric valve 1
The control device 50 reduces or increases the opening degree of 00.

[Action]

During operation of the gas appliance, the heating amount of the main burner 10 is adjusted by the thermal power control valve 21. A motor-operated valve 100 is provided in the supply passage 20 upstream of the heat-power control valve 21, and the detection burner 30 is branched from between the heat-power control valve 21 and the motor-operated valve 100. Therefore, the maximum heating capacity of the main burner 10 ( The heating amount corresponding to the full opening of the thermal power control valve 21) and the heating amount of the detection burner 30 both depend on the heat generation amount of the supplied gas and the opening degree of the electric valve 100, and always change in proportion. If the calorific value of the gas increases, the main burner 1
The maximum heating capacity of 0 and the heating amount of the detection burner 30 both increase, but at the same time, the heating signal generated in the heat generation amount detecting device 40 also increases, so that the control device 50 supplies a current corresponding to the increased heating amount signal. The motor-operated valve 1 is applied to the motor 106.
The opening amount of 00 is reduced to reduce the gas supply amount. Further, if the calorific value of the gas decreases, the opening degree of the motor-operated valve 100 is increased to increase the gas supply rate by the action opposite to the above. In either case, when the heating amount signal reaches a value corresponding to the predetermined maximum heating capacity of the main burner 10, the change in the opening degree of the motor-operated valve 10 is stopped. As a result, the maximum heating capacity of the main burner 10 is automatically kept constant even if the calorific value of the gas changes.

Since the maximum heating capacity of the main burner 10 is kept constant in this manner, the heating amount change characteristic of the main burner 10 with respect to the opening degree of the thermal power control valve 21 also automatically becomes a predetermined characteristic determined by design. .

〔The invention's effect〕

As described above, according to the present invention, when the calorific value of the gas changes, the supply amount of the gas also changes accordingly, and the heating amount change characteristic of the main burner with respect to the opening of the thermal power control valve is set by design. Since it has the specified characteristics and the maximum heating capacity of the main burner is maintained at the standard value of the gas appliance, it can be used for many types of gas with one type of specification, and therefore the specifications of gas appliances can be adjusted by region. Since the trouble of changing it is reduced, inventory management and shipping management become easier. Moreover, not only when the type of gas is different, but also when the amount of heat generated within the allowable range of the same type of gas is automatically changed, it is possible to maintain the heating amount change characteristics of the gas appliance more precisely and more precisely. Therefore, even in gas appliances such as water heaters of the automatic control system that require constant heating amount change characteristics,
There is no risk of malfunction of safety devices, etc. due to fluctuations in heating amount change characteristics, and since it is used within the preset design criteria of gas appliances, durability and failure can be sufficiently guaranteed. Become.

〔Example〕

1 and 2 show an embodiment of an instantaneous gas water heater.

As shown in FIG. 1, a motor-operated valve 100, which will be described later, and a thermal power control valve 21 for controlling the heating amount of the main burner 10 are provided in a supply passage 20 for supplying gas to the main burner 10 provided in the lower portion of the inner case 15. A safety valve 23 is provided in series to shut off gas when the device is stopped or when an abnormality occurs. The main nozzle 24 formed at the tip of the supply passage 20 is arranged to face the supply port 11 of the main burner 10, and
The gas supplied from the main nozzle 24 is mixed with the primary air flowing in through the gap 13 between the main nozzle 24 and the supply port 11 and is sent into the main burner 10 where it burns and burns the main flame 12.
The generated high-temperature combustion gas passes through the heat exchanger 16 to heat the water supply inside, and is discharged to the outside through the exhaust hood 17. In the supply passage 20, there is a branch passage 25 that is located between the thermal power control valve 21 and the electric valve 100 located upstream thereof and that supplies gas to the detection burner 30 that heats the heat generation amount detection device 40 described below. It is connected.

In the present embodiment, the calorific value detection device 40 includes a thermocouple 45.
And a heating element 41, and generates a heating amount signal according to the heating amount of the detection burner 30. As shown in FIG. 2, a tubular heating element 41 and a protective tube 35 are coaxially attached to the base 31 of the detection burner 30 which is attached to the body of the gas appliance by a bracket (not shown) so as to surround the detection burner 30. ing. The heating element 41 on the inner side is closed at the top and a large number of through holes 4 are provided on the peripheral wall excluding the top.
2 is provided, the hot junction 46 and the cold junction 47 of the thermocouple 45.
Are attached to the upper end surface and the lower end portion of the heating body 41 so as to be capable of heat conduction and electrically insulated from each other. The gas supplied from the branch passage 25 and ejected from the detection burner 30 is burned by the air flowing in from the flow hole 42 in the lower part of the heating body 41 to generate a detection flame 32, and the generated combustion gas is the flow hole in the upper part of the heating body 41. It is discharged from 42. In the present embodiment, since the combustion gas temporarily stays in the upper portion of the heating body 41 and then is inverted and discharged, the upper end portion of the heating body 41 is sufficiently and stably heated by the detection flame 32. Since the lower end portion of the heating body 41 is stably cooled by the inflowing air, the temperature difference between the upper end portion and the lower end portion of the heating body 41 becomes stable according to the heating amount of the detection burner 30.
Therefore, the hot junction 46 and the cold junction 47 are provided at the upper end and the lower end.
The thermoelectromotive force of the thermocouple 45 to which is attached, that is, the heating amount signal also becomes stable according to the heating amount of the detection burner 30.

The outer protective cylinder 35 is provided with an inflow hole 36 in the outer periphery of the lower part and an exhaust hole 37 in the upper end part, and the air necessary for combustion of the detection flame 32 is supplied into the heating body 41 through the inflow hole 36.
The combustion gas passes through the gap between the heating body 41 and the exhaust hole 37.
More discharged. If this protective cylinder 35 is provided, the combustion state of the detection flame 32 is affected by disturbance such as gusts, and the thermocouple 4
5 to prevent the thermal electromotive force from fluctuating, and the heat generation amount detecting device 4
The operation of 0 can be further stabilized.

The motor-operated valve 100 of this embodiment also has a gas governor function. As shown in FIG. 1, the interior of the casing body 101 has a partition wall 102 having a valve hole 102a and a diaphragm 10.
5, the first valve chamber 110, the second valve chamber 111 and the atmosphere chamber 11
It is divided into two, and the first and second valve chambers 110 and 111 are connected to the downstream side and the upstream side of the supply passage 20, respectively. Servo motor 1 provided in casing body 101
The rod 107 of No. 06 is arranged coaxially with the valve hole 102a, and is controlled by the controller 50 to reciprocate in the axial direction. Valve hole 102a through the support rod 104
Valve body 1 coaxially attached to the diaphragm 105
03 is elastically supported by a spring 108 interposed between the casing main body 101 and a rod 107 of the servomotor 106.
The opening area between the partition wall 102 and the valve hole 102a is changed.

First, the gas governor function of the electric valve 100 will be described. When the gas pressure on the upstream side of the supply passage 20 rises, the pressure inside the first valve chamber 110 rises, so that the diaphragm 105 moves in the direction against the spring 109 and the opening between the valve body 103 and the valve hole 102a. If the area is reduced, that is, the opening degree of the motor-operated valve 100 is reduced to reduce the flow rate of gas passing through the valve hole 102a, and the gas pressure on the upstream side of the supply passage 20 is reduced, the opposite of the above is performed. Due to the action, the valve hole 102a
Increase the flow rate of gas through the. As a result, the motor-operated valve 10
First, 0 is the first valve chamber 1 communicating with the downstream side of the supply passage 20.
The pressure inside 10 is maintained at a predetermined value so that the gas supply amount to the main burner 10 is not affected by fluctuations in the gas pressure on the upstream side of the supply passage 20.

Therefore, the predetermined pressure in the first valve chamber 110 and the gas supply amount to the main burner 10 are adjusted by the axial movement of the rod 107 of the servomotor 106. That is, when the rod 107 moves forward in the direction toward the diaphragm 105, the urging force of the spring 109 increases and the valve body 103 moves to the side where the opening degree of the motor-operated valve 100 increases. When the gas supply amount to the burner 10 increases and the rod 107 retracts in the opposite direction to the above, the predetermined pressure is reduced by the action opposite to the above, and the gas supply amount to the main burner 10 is reduced.

While the gas appliance is operating, the heating amount of the main burner 10 can be adjusted by adjusting the gas supply amount to the main burner 10 by the heat control valve 21. Since the motor-operated valve 100 is branched from between the heat-power control valve 21 and the motor-operated valve 100 provided on the upstream side of the heat-power control valve 21, the maximum heating capacity of the main burner 10 (the heating amount corresponding to the full opening of the heat-power control valve 21) and the detection burner 30.
The heating amount of each is in accordance with the heating value of the supplied gas and the opening degree of the motor-operated valve 100, and always changes in proportion. The control device 50 uses the thermocouple 45 of the heat generation amount detection device 40.
The thermoelectromotive force is input, and this is compared with a reference value that is defined in advance by the specifications of the combustor, and a current is applied to the servomotor 106 according to the comparison result to drive the servomotor 106. If so, the rod 107 is moved forward toward the diaphragm 105, and if the thermoelectromotive force is large, the rod 107 is moved backward.

Next, the operation of the above embodiment will be described. During operation of the instantaneous gas water heater, the detection burner 30 is provided with the supply passage 20.
The gas branched from is supplied via the branch passage 25, and the detection flame 32 is generated. Since the amount of heating by the detection flame 32 per unit time depends on the amount of gas supplied and the amount of heat generation, the temperature difference between the upper end and the lower end of the heating element 41 heated by this, and thus the thermocouple. The thermoelectromotive force generated in 45 also depends on the gas supply amount and the heat generation amount. When the calorific value of the gas is large, the thermoelectromotive force of the thermocouple 45 increases, so that the rod 107 of the servomotor 106 operated by the control device 50 moves backward, thereby reducing the opening degree of the motor-operated valve 100 and supplying it. The amount of gas supplied from the passage 20 to the main burner 10 is reduced. Since the gas supply amount to the detection burner 30 also decreases in accordance with the above operation, the thermoelectromotive force of the thermocouple 45 also decreases, and when this reaches the predetermined reference value, the operation of the servomotor 106 is stopped and the motor-operated valve 10 is stopped. The change in the opening of is also stopped. When the calorific value of the gas becomes small, the amount of the gas supplied to the main burner 10 increases due to the opposite effect to the above, the gas supply amount to the detection burner also increases, and the thermoelectromotive force becomes the predetermined reference value. By the way, the change of the opening degree of the electric valve 100 is stopped. As a result of the above operation, the main burner 1
The maximum heating capacity of 0 does not change even if the calorific value of the gas changes, and is maintained at the specification standard of the combustor.

Since the detection burner 30 is branched from the upstream side of the thermal power control valve 21, even if the heating amount of the main burner 10 is adjusted by the thermal power control valve 21, the heating amount of the detection burner 30 does not change. Therefore, even if the heating amount is adjusted by the heat control valve 21, it is not affected.

In this way, the maximum heating capacity of the main burner 10 is maintained at the specification standard of the combustor, so the heating amount change characteristic of the main burner 10 with respect to the opening degree of the thermal power control valve 21 is irrespective of the change in the heating value of the gas. The predetermined characteristics are automatically determined by design. As a result, the range in which gas appliances with the same specifications can be used for gases with different heating values is expanded, and even in gas appliances such as water heaters with automatic control that require constant heating amount change characteristics, There is no risk of malfunction of the safety device or the like due to the change in the change characteristic. Further, since the specifications are within the predetermined design specifications of the gas appliance, the durability is not lowered and the breakdown is reduced.

Further, although the motor-operated valve 100 of the above-described embodiment is also provided with the function of a gas burner, this motor-operated valve is assumed to change its opening degree only in accordance with the current applied from the control device, and to the upstream side or the downstream side thereof. A separate gas governor may be provided.

The present invention is not limited to the instant gas water heater as in the above embodiment, but can be applied to other various gas appliances.

[Brief description of drawings]

1 and 2 show an embodiment of a gas appliance according to the present invention, FIG. 1 is an overall explanatory view partially broken, and FIG. 2 is a cross-sectional view near a detection burner and a heat generation amount detection device. Explanation of reference numerals 10 ... Main burner, 20 ... Supply passage, 21 ... Thermal power control valve, 30 ... Detection burner, 40 ... Heat generation amount detection device, 50 ... Control device, 100 ... Motorized valve, 106 ... …
Motor (servo motor).

Claims (1)

[Claims] 1. A gas appliance having a heat control valve provided in a supply passage for supplying gas to a main burner, which is opened by a motor provided in the supply passage upstream of the heat control valve and operating according to an applied current. Degree variable valve, a detection burner branched from the supply passage between the thermal power control valve and the electric valve, and a heating amount signal generated according to the heating amount of the detection burner is heated by the detection burner. A heat generation amount detection device, and control for inputting the heating amount signal and comparing the value with a reference value determined in advance by a gas appliance to change the current applied to the motor to decrease or increase the opening degree of the electrically operated valve. A gas appliance comprising a device.