KR0157359B1 - Gas combustion apparatus - Google Patents

Abstract

According to the present invention, it is possible to easily and surely determine the type of fuel gas supplied to the burner by a simple configuration, thereby controlling the gas supply to the burner according to the required combustion amount, and using the nozzles of the burner with respect to various fuel gases. The present invention relates to the provision of a gas combustion device that can be adapted to this type of fuel gas while being common.

A gas flow rate sensor 9 and a gas flow rate control valve 10 are provided in the gas supply pipe 8 to the burner 3. Under the control of the controller 16, gas is supplied to the burner 3 at the initial stage of the start of the combustion operation with the amount of energization to the gas flow control valve 10 set to a predetermined value, and the gas flow sensor 9 at this time is The type of fuel gas is determined based on the output level. After this determination, the gas flow control valve 10 is controlled in accordance with the data set in advance to be suitable for the type of fuel gas. As the flow rate sensor 9, a thermal flow rate sensor or a heat flow type flow rate sensor that varies in output characteristics according to the type of fuel gas is used.

Description

Gas combustion device

1 is a system configuration diagram showing an embodiment (gas water heater) of a gas combustion device according to the present invention.

2 is a block diagram of main parts of the gas water heater shown in FIG.

3 is an explanatory diagram for explaining the configuration of a gas flow sensor used in the gas water heater shown in FIG.

4 is a diagram showing the output characteristics of the gas flow sensor shown in FIG.

5 is a diagram for explaining the operation of the gas water heater shown in FIG.

6 is a diagram for explaining the operation of the gas water heater shown in FIG.

7 is a diagram for explaining the operation of the gas water heater shown in FIG.

8 is a diagram for explaining the operation of the gas water heater shown in FIG.

* Explanation of symbols for main parts of the drawings

3: burner 8: fuel gas supply passage

9 gas flow sensor 10 gas flow control valve

12: combustion fan 24: fan control unit (pen control means)

25: valve control unit (valve control means) 28, 30: storage means

29: target rotation speed setting unit (target rotation speed setting means)

31: target gas flow rate setting unit (target gas flow rate setting means)

The present invention relates to a gas combustion device such as a gas water heater using city gas or LP gas as fuel.

As a gas combustion device of this type in the related art, for example, by controlling a proportional valve equipped with a governor, which is a pressure-controlled flow rate control valve installed in a gas supply path to a burner, by controlling the amount of energization corresponding to the required combustion amount of the burner, It is generally known to generate a gas pressure corresponding to the required combustion amount on the inflow side (proportional valve downstream side) of the burner nozzle, thereby controlling the gas supply amount to the burner in an amount corresponding to the required combustion amount.

In this case, when controlling the proportional valve, the rotation speed of the combustion fan for supplying combustion air to the burner is controlled in advance with the required rotation amount, and the rotation speed of the combustion fan is adjusted to the required combustion amount. When the gas is supplied to the burner by controlling the preset rotational speed and energizing the proportional valve with the energization amount corresponding to the rotational speed of the combustion fan (fan lead type) )

By the way, the fuel gas used in this kind of gas combustion apparatus is currently classified into 15 types of gas including LP gas, and the kind of fuel gas used differs according to the gas company or region which provides fuel gas. In addition, the above-described types of fuel gas have different supply pressures, calorific value per unit volume, specific gravity, combustion rate index, and the like, so that the gas supply amount corresponding to the required combustion amount is used even if the required combustion amount is the same. Depends on the type of

On the other hand, in the conventional gas combustion apparatus as described above, the amount of gas supplied to the burner, that is, the amount of gas ejected from the nozzle of the burner does not depend only on the gas pressure at the inflow side of the nozzle, It is affected by the hole area and the like. For example, even if the gas pressure on the inflow side of the nozzle is the same, the larger the hole area of the nozzle, the larger the gas supply amount.

Here, in the conventional gas combustion apparatus, in order to correspond to each type of fuel gas described above, a plurality of nozzles having different pore areas are prepared according to the type of gas, and the burner is provided with a nozzle corresponding to the type of fuel gas to be used. I'm trying to. As described above, the gas pressure at the inflow side of the nozzle is controlled using the proportional valve to supply the burner with an amount of fuel gas corresponding to the required combustion amount, and to make the gas supply amount suitable for the type of fuel gas. have.

However, preparing different types of nozzles in accordance with the gas types used in this way is not only troublesome in terms of manufacturing / managing each type of nozzle, but also disadvantageous in terms of cost. In addition, the user must replace the nozzle of the existing gas combustion apparatus when the gas type is changed by the transfer or the like.

In order to solve such a problem, for example, Japanese Patent Laid-Open No. 58-214713 provides a throttle mechanism for varying the gas passage area in a gas supply passage to a burner, and also supplies a supply pressure of fuel gas. By measuring the specific gravity and the specific gravity with a detector, the type of fuel gas is determined, and the gas passage area is adjusted by the throttle mechanism according to the discriminated gas type, so that an appropriate amount corresponding to each type of fuel gas is used while using the same nozzle. It is proposed to supply fuel gas to a burner.

However, in the above publication, the supply pressure of the fuel gas required for discriminating the gas type generally varies depending on the use situation or installation situation of the combustion apparatus even if the gas types are the same, and even if the fuel gases are different types, they are supplied to each other. The pressure is often cool. In addition, even in the case of different kinds of fuel gases, the specific gravity of the fuel gas may be close to each other.

Therefore, as in the above publication, it is difficult to accurately determine the type of gas only by the measured values obtained by measuring the supply pressure and specific gravity of the fuel gas, and it is easy to discriminate the type of gas incorrectly. If the gas type is incorrectly discriminated in this way, the amount of gas supplied to the burner does not correspond to the original gas type, but becomes inappropriate and causes combustion failure.

In addition, since a pressure detector and a proportional detector are required for discriminating the type of gas, the number of parts is increased, resulting in complicated device configuration and disadvantageous cost.

In addition, since the gas supply amount is controlled by adjusting the gas pressure at the inflow side of the burner nozzle, the conventional gas combustion device as described above or the above publication is basically the amount of gas actually supplied to the burner at the outflow side of the burner nozzle. It is also affected by atmospheric pressure. Therefore, for example, the air pressure in the combustion chamber is changed due to fluctuations in the air pressure of the combustion chamber accommodating the burner or the clogging of the exhaust port of the combustion chamber in which the combustion air is blown by the combustion fan. In the case of fluctuation, there is a fear that the control of the gas supply amount to the burner will be incorrect.

According to the present invention, it is possible to easily and surely determine the type of fuel gas supplied to the burner by a simple configuration, thereby controlling the gas supply to the burner according to the required combustion amount, and using the nozzles of the burner with respect to various fuel gases. It is an object of the present invention to provide a gas combustion device that can be adapted to this type of fuel gas while being common.

In addition, an object of the present invention is to provide a gas combustion apparatus capable of precisely controlling the gas supply amount to a burner according to a required combustion amount by using a configuration for discriminating gas types.

It is also an object of the present invention to provide a gas combustion apparatus capable of satisfactory combustion of a burner according to the type of gas to be discriminated.

The inventors of the present application have found the following as a result of various studies in view of the above-described background. That is, when the gas flow rate to the burner is detected for various fuel gases by a thermal flow rate sensor or a thermal wire flow rate sensor for detecting the flow rate or flow rate of the gas, the output level of the flow rate sensor is It basically changes depending on the gas flow rate, but even if the same gas flow rate is different, the output level of the flow sensor shows a relatively significant difference. Specifically, for example, a propane gas, 6A fuel gas, 13A fuel gas and 12A can be used as a thermal flow sensor using a platinum thin film resistance as a detection element (the outline of this configuration will be described later). As a result of measuring the output level of the flow sensor with respect to the gas flow rate with respect to the fuel gas, the output characteristic as shown in FIG. 4 was obtained. As can be clearly seen in FIG. 4, the output characteristics of the flow sensor for the fuel gas of 13A and 12A are almost the same, but the output of the flow sensor at any gas flow rate with respect to the relationship with other types of fuel gas The level shows a relatively large difference. The fuel gas of 13A and 12A has almost no output characteristics of the flow sensor, and these fuel gases have very close gas characteristics such as calorific value. In the gas supply control to the burner, it is not necessary to distinguish between 13 A fuel gas and 12 A fuel gas. The output characteristics of the flow sensor as described above are also the same as in the case of using a hot wire flow sensor using a platinum wire or the like as a detection element.

Therefore, if the fuel gas is supplied to the burner at a predetermined gas flow rate by installing the flow sensor having the above-described output characteristics in the fuel gas supply path to the burner, the type of fuel gas is determined by the output level of the flow sensor at this time. It is possible to determine. In this way, the type of fuel gas can be discriminated, and a gas flow rate control valve for varying the gas flow rate is provided in the fuel gas supply passage, such as a proportional valve used in a conventional gas combustion apparatus. By controlling the gas flow rate control valve appropriately for the type of fuel gas, it is possible to supply fuel gas in an amount corresponding to the required combustion amount of the burner with respect to these various fuel gases.

In addition, if the type of fuel gas can be determined as described above, the actual gas flow to the burner can be grasped based on the output characteristics of the flow sensor corresponding to the type of fuel gas. By controlling the gas flow rate control valve so that the flow rate matches the desired gas flow rate, it is also possible to increase the control accuracy of the gas flow rate.

On the other hand, when the gas flow rate to the burner is a predetermined gas flow rate to determine the type of fuel gas using the flow rate sensor as described above, the predetermined gas flow rate does not necessarily need to be precise. There may be a slight difference with respect to the gas flow rate.

As can be seen from FIG. 4, since the output level of the flow sensor with respect to the predetermined gas flow rate shows a relatively large difference depending on the type of fuel gas, the actual gas flow rate is in accordance with the predetermined gas flow rate. Although somewhat different, the output level of the flow sensor shows a difference such that the type can be determined according to the type of fuel gas. Therefore, when determining the type of fuel gas, if the gas flow rate is set to a predetermined gas flow rate, the type of fuel gas can be determined based on the output level of the flow sensor.

As described above, the gas flow rate can be made to be a predetermined gas flow rate. For example, a proportional back with a governor used in a conventional gas combustion device can be used. In other words, when the amount of energization to the proportional valve is a predetermined value, the gas pressure on the inflow side of the burner nozzle becomes a predetermined gas pressure. At this time, the gas flow rate to the burner basically depends on the hole area of the nozzle and the specific gravity of the fuel gas. Therefore, if the nozzles are the same regardless of the type of fuel gas, the gas flow rate to the burner is the specific gravity of the fuel gas ( This is dependent on the type of fuel gas) and causes dispersion. However, since the distribution of the gas flow rate due to the difference in specific gravity of the fuel gas is generally not so large, the actual gas flow rate to the burner when the energization amount to the proportional valve is a predetermined value is almost the same for various fuel gases. . In addition, for a fuel gas of a kind in which the gas supply pressure is almost the same, for example, even if a flow rate control valve is used so as to have a hole area according to the energization amount, The flow rate of the gas to the burner can be made almost the same regardless of the type of fuel gas.

Therefore, if the energization amount to the gas flow control valve that makes the gas flow variable according to the energization amount of the proportional valve or the like is a predetermined value, the gas flow rate to the burner can be almost the same as the predetermined gas flow rate for various fuel gases. When the output level of the gas flow sensor is detected at this time, the type of fuel gas can be determined thereby.

In fact, in the case where a proportional valve equipped with a governor is installed in the gas supply passage to the burner, the nozzles of the burner are the same and the fuel supply of the type shown in FIG. 4 is installed in the gas supply passage. As a result of measuring the relationship between the output level of the gas flow sensor and various energization amounts to the proportional valve, measurement data as shown in FIG. 5 was obtained. As can be seen in FIG. 5, the output level of the flow sensor for propane gas, 6A fuel gas and 13A and 12A fuel gas at any predetermined energization amount to the proportional valve is equal to the fuel gas. The difference was sufficient enough to determine the type of.

Based on the above, in order to achieve the said objective, this invention is provided in the fuel gas supply path to a burner, Comprising: The gas flow control valve which changes a gas flow amount according to an electricity supply amount; A gas flow rate sensor installed in the fuel gas supply path and outputting a level signal according to the gas flow rate to the burner, and having a different output level depending on the type of fuel gas even though the gas flow rate is the same; ; Gas type discriminating means for energizing the gas flow rate control valve at a predetermined energization amount and discriminating the type of the fuel gas based on an output level of the gas flow rate sensor at this time; Valve control means for controlling the gas flow rate control valve so as to supply the burner with the fuel gas in an amount corresponding to the required combustion amount of the burner in accordance with the type of fuel gas determined by the gas type discriminating means; It is characterized by.

Storage means for storing, in advance, gas supply data for setting a target gas flow rate corresponding to the required combustion amount of the burner for each type of fuel gas determined by the gas type discriminating means; Target gas flow rate setting means for setting a target gas flow rate corresponding to the required combustion amount on the basis of the gas supply data stored and stored in the storage means corresponding to the type of fuel gas determined by the gas type discrimination means; And the valve control means controls the gas flow rate control valve so that the output level of the gas flow rate sensor is an output level corresponding to the target gas flow rate in the determined type of fuel gas.

In addition, for each type of fuel gas determined by the gas type discriminating means, the energization amount data of the gas flow rate control valve for supplying the burner with the amount of fuel gas corresponding to the required combustion amount of the burner is stored in advance. And a storage means, wherein said valve control means controls said gas flow control valve on the basis of data stored and stored in said storage means corresponding to the type of fuel gas determined by said gas type discriminating means. .

In addition, a combustion fan for supplying combustion air to the burner; For each type of fuel gas determined by the gas type discriminating means, air supply data for setting a target rotational speed of the combustion fan for supplying combustion air of the amount corresponding to the required combustion amount to the burner is stored in advance. Second storage means; A target rotation for setting a target rotational speed of the combustion fan corresponding to the required combustion amount based on the gas supply data stored in the second storage means corresponding to the type of fuel gas determined by the gas type discriminating means; Water setting means; And fan control means for controlling the combustion fan such that the rotation speed of the combustion fan is the target rotation speed.

In addition, the gas flow rate sensor is characterized in that the thermal flow rate sensor or the hot wire flow rate sensor.

In addition, the gas flow control valve is characterized in that the gas flow control valve of the pressure control type for generating a gas pressure in accordance with the energization amount on the inlet side of the nozzle of the burner.

In addition, the kind of fuel gas by the said gas kind discrimination means is made in the beginning of a combustion operation, for example.

According to the present invention, the gas flow rate to the burner is almost a predetermined gas flow rate by energizing the gas flow rate control valve at a predetermined current flow rate, and the output level of the gas flow rate sensor varies depending on the type of fuel gas. Done. Therefore, the kind of fuel gas can be easily discriminated with a simple structure by the output level of the said gas flow sensor at this time. Since the gas flow control valve is controlled by the valve control means in accordance with the discriminated type of the fuel gas, the nozzles of the burners are made identical to each of these types of fuel gases, and the burner corresponding to the required combustion amount is supplied. It is possible to make the gas supply suitable for the type of fuel gas.

In this case, when the storage means for storing the gas supply data for setting the target gas flow rate for each type of fuel gas is provided, after determining the type of the fuel gas, the fuel gas of each type is supplied to the fuel gas. The target gas flow rate is set by the target gas flow rate setting means on the basis of the corresponding gas supply data, and the target gas is used in the type of fuel gas whose output level of the gas flow rate sensor is determined by the valve control means. By controlling the gas flow rate control valve so as to be an output level corresponding to the gas flow rate, it is possible to ensure the gas supply of the amount corresponding to the required combustion amount for each kind of fuel gas.

When the storage means for storing the energization amount of the gas flow rate control valve for each type of fuel gas is provided, after determining the type of the fuel gas, the communication corresponding to this for each type of fuel gas is carried out. By controlling the gas flow rate control valve by the valve control means based on the total amount of data, it is possible to supply a gas corresponding to the required combustion amount to each type of fuel gas with a simple configuration.

When the type of fuel gas is provided with the second storage means for storing and maintaining the air supply data of the target rotational speed of the combustion fan for each type of fuel gas, after determining the type of the fuel gas, By setting the target rotational speed of the combustion fan by the target rotational speed setting means based on the air supply data corresponding to the control unit, and controlling the rotational speed of the combustion fan by the fan control means to control the rotational speed of the fuel gas. It is possible to supply the burner with an appropriate amount of combustion air to the burner, and it becomes possible to perform a good combustion operation of the burner with the required combustion amount for each kind of fuel gas.

In addition, when a thermal flow rate sensor or a hot wire flow rate sensor is used as the gas flow rate sensor, these flow rate sensors exhibit a remarkable difference in output characteristics depending on the type of fuel gas as described above. It is possible to discriminate easily.

In addition, when a gas flow control valve of a pressure control type that generates a gas pressure corresponding to a flow amount on the inflow side of the nozzle of the burner is used as the gas flow rate control valve, a flow rate of a predetermined flow rate is determined when determining the type of fuel gas. By setting it as the whole quantity, it becomes possible to make gas flow volume nearly the same gas flow volume with respect to various fuel gas irrespective of the supply pressure of fuel gas, and it becomes possible to make sure the kind of fuel gas using the said gas flow sensor more accurately. .

An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a system configuration diagram of a gas water heater, which is a gas combustion device of the present embodiment, FIG. 2 is a block diagram of a main part of the gas water heater shown in FIG. 1, and FIG. 3 is a diagram of a gas flow sensor for use in the gas water heater shown in FIG. 4 is a diagram showing the output characteristics of the gas flow sensor shown in FIG. 3, and FIGS. 5 to 8 are diagrams for explaining the operation of the gas water heater shown in FIG.

In FIG. 1, 1 is a hot water supply main body incorporating a heat exchanger 2 and a burner 3 which heats it, 4 is a water supply pipe piped through the heat exchanger 2, 5 is a water supply pipe 4 inside. Water flow rate sensors for detecting the flow rate of the flowing water on the upstream side of the heat exchanger (2), 6, 7 is the water inlet temperature and tapping temperature of the water flowing in the water pipe (3) upstream and downstream of the heat exchanger (2), respectively The temperature sensor for detecting the 8, the gas supply pipe (gas supply path) for supplying fuel gas to the burner (3), 9 is the gas flow rate installed in the gas supply pipe (8) to detect the gas flow rate supplied to the burner (3) Sensors 10 and 11 are gas flow control valves and on-off solenoid valves installed in the gas supply pipe 8, 12 are combustion fans for supplying combustion air to the burner 3, and 13 are fans for driving the combustion fan 12. Motor, 14 is a rotation speed sensor for detecting the rotation speed of the combustion fan 12, 15 is a control unit for the user to set the tapping temperature, etc., 16 is a fan (13), the controller for operating the gas flow control valve (10), the solenoid valve 11, etc., 17 is an igniter for igniting the burner (3), 18 is the combustion of the burner (3), etc. Flame load that detects state.

In this case, the burner 3 and the heat exchanger 2 are accommodated in the combustion chamber 19 formed in the hot water supply main body 1, and the exhaust port 20 formed above the hot water supply main body 1 communicates with the combustion chamber 19. It is.

Moreover, the upstream side of the water flow pipe 4 is connected to the water pipe which is not shown in figure, and the downstream side is connected to the hot water supply opening / closing apparatus which is not shown, such as a kitchen and a bathroom.

The gas flow control valve 10 is, for example, a proportional valve equipped with a governor for generating a gas pressure (secondary pressure) proportional to the amount of energization downstream thereof.

The fuel gas used in the gas water heater of this embodiment is, for example, any one of propane, 6A, 12A, and 13A, and the nozzle 3a of the burner 3 may be used for any kind of fuel gas. Use the same thing.

The gas flow rate sensor 9 is, for example, a thermal flow rate sensor, and its outline structure is three thin film resistive elements 21a to 21c made of platinum and these thin film resistive elements 21a as shown in FIG. And a sensor circuit section 22 for energizing ˜21c to generate an output signal, in which the thin film resistor elements 21a to 21c are directed from the upstream side to the downstream side as shown in the gas supply pipe 8. It is arranged at equal intervals. In the gas flow sensor 9, the thin film resistor element 21b in the center functions as a heater, and the sensor circuit unit 22 is supplied with a constant current or a constant electric power to generate heat, and both thin film resistor elements 21a, Heat 21c). In addition, both thin film resistor elements 21a and 21c function as temperature sensors that cause a change in resistance value according to temperature. When fuel gas is supplied to the gas supply pipe 8, the thin film resistor elements 21a and 21c are positioned at the positions of the thin film resistor elements 21a and 21c. The temperature difference occurs according to the flow rate of the fuel gas, causing a change in the resistance value according to the flow rate. The sensor circuit unit 22 converts the resistance value change according to the flow rate of the fuel gas of the thin film resistor elements 21a and 21c into an electric signal, and outputs a signal of the level corresponding to the flow rate to the controller 16. In this case, the gas flow rate of the fuel gas flowing in the gas supply pipe 8 is multiplied by the flow rate multiplied by the cross-sectional area of the gas supply pipe 8 so that it is proportional to the flow rate of the fuel gas, and thus output from the sensor circuit 21 to the controller 16. The signal level to be used corresponds to the gas flow rate to the burner 3.

In this embodiment, a thermal flow sensor using the thin film resistor elements 21a to 21c is employed as the gas flow sensor 9, but a platinum wire or the like is used instead of the thin film resistor elements 21a to 21c. You may use the hot wire flow sensor.

In the gas flow sensor 9, the propane, 6A, 12A, and 13A fuel gas used in the present embodiment have output characteristics as shown in FIG. 4, so that the output is basically increased as the gas flow rate increases. The level is increased. The 13A and 12A fuel gases exhibit almost the same output characteristics, and the 6A fuel gas and propane gas exhibit different output characteristics.

As shown in FIG. 2, the controller 16 is constituted by an electronic circuit including a microcomputer and the like. As a main functional configuration, the controller 16 is applied to the set temperature applied by the operation unit 15 or the temperature sensors 6 and 7. Required combustion amount calculation unit 23 for obtaining the required combustion amount of the burner 3 necessary to match the tapping temperature with the set temperature on the basis of the water temperature and tapping temperature detected by the tap water, and the tapping amount detected by the tapping water sensor 5, etc. And a fan control unit 24 (fan control means) for controlling the operation of the combustion fan 12 as the fan motor 13 according to the required combustion amount calculated by the calculation unit 23 and the like, and the rotation speed sensor 14. The valve control unit 25 (valve control means) for controlling the gas flow control valve 10 in accordance with the detected rotation speed of the combustion fan 12, the output level of the gas flow sensor 9, and the like at the beginning of the initial combustion operation. Type of fuel gas In order to discriminate, the gas type discrimination command part 26 which controls the fan motor 13 and the gas flow control valve 10 through the fan control part 24 and the valve control part 25, and the gas flow rate sensor 9 at this time And a gas kind discrimination unit 27 for discriminating the kind of fuel gas according to the output level.

The fan control unit 24 supplies gas for supplying air, which will be described later, for supplying the burner 3 with the combustion air of the amount corresponding to the required combustion amount obtained by the required combustion amount calculation unit 23 to the burner 3 by the combustion fan 12. Based on the air supply data storage unit 28 (second storage means) previously stored and held for each gas type determined by the type discrimination unit 27, and the gas type is determined, the corresponding combustion amount is made on the basis of the air supply data. The target rotation speed setting part 29 (target rotation speed setting means) which sets the target rotation speed of the combustion fan 12 is provided.

In addition, the valve control unit 25 supplies the gas type discriminating unit 27 with gas supply data, which will be described later, for controlling the gas flow rate control valve 10 for supplying the burner 3 with the fuel gas corresponding to the required combustion amount. The gas supply data storage unit 30 (first storage means) previously stored and held for each gas type determined by the gas and the target gas flow rate corresponding to the required combustion amount based on the gas supply data after the gas type is determined. Reference of the target gas flow rate setting section 31 (target gas flow rate setting means) set according to the output level of the sensor 9 and the gas flow control valve 10 corresponding to the required combustion amount based on the supply data as described above. A reference conduction amount setting unit 32 for setting the energization amount is provided.

Here, the gas type discrimination commanding section 26 and the gas type discrimination section 27 constitute the gas type discriminating means 33 in parallel with the valve control section 25 in accordance with the configuration of the present invention.

Next, operation | movement of the gas water heater which is a present Example is demonstrated.

The controller 16 detects this through the water flow sensor 5 when water flow of the water pipe 4 is started, and the combustion fan 12 through the fan motor 13 by the fan control unit 24 according to the detection. ) Is rotated and the solenoid valve 11 is opened to start the gas supply to the burner 3. In this state, the burner 3 is ignited through the igniter 17 to start the combustion operation (water supply operation) of the burner 3.

At this time, at the start of the first combustion operation of the gas water heater, the gas type discrimination command unit 26 of the controller 16 sets a predetermined constant rotation speed in which the combustion fan 12 is preset by the fan control unit 24. The fan motor 13 is controlled to rotate in a low speed, and the valve control unit 25 energizes the gas flow rate control valve 10 at a predetermined constant current amount. Therefore, the gas pressure at the inflow side (downstream side of the gas flow control valve 10) is applied to the nozzle 3a of the burner 3 corresponding to the predetermined amount of energization to the gas flow control 10 regardless of the type of fuel gas. Fuel gas is supplied in the state which becomes a predetermined | prescribed gas pressure. The gas flow rate to the burner 3 in this case is slightly different due to the difference in specific gravity by the type of fuel gas, but the gas flow rate sensor 9 is almost equal to the predetermined gas flow rate for any kind of gas. ) Output level depends on the type of fuel gas.

As described above, in the state where the gas flow rate control valve 10 is energized with a predetermined amount of energization, the gas type discriminating portion 27 of the controller 16 is driven by the output level of the gas flow rate sensor 9 at this time. Determine the type of fuel gas.

That is, as shown in FIG. 5, the gas type discrimination unit 27 has a level range L1 in which the output level of the gas flow sensor 9 at the predetermined current flow rate IO to the gas flow control valve 10 is preset. , L2 and L3 are maintained as gas type identification data corresponding to propane, 6A fuel gas, 13A and 12A fuel gas, respectively. As described above, when the output level of the gas flow sensor 9 when the gas flow control valve 10 is energized with the predetermined energization amount IO is within the level range L1, the type of fuel gas is determined by propane. When it is in the level range L2, the type of fuel gas is determined as 6A, and when it is in the level range L3, the type of fuel gas is determined as 13A or 12A.

In the combustion operation of the burner 3 after the type of fuel gas is determined as described above, the controller 16 controls the tapping temperature detected by the temperature sensor 7 by the required combustion amount calculation unit 23. The required combustion amount of the burner necessary to match the set temperature set by the above is obtained every time based on the intake temperature, the tapping temperature, and the detected data of the amount of water obtained by the temperature sensors 6 and 7 and the water flow rate sensor 5. Then, the target rotation speed setting unit 29 of the fan control unit 24 of the controller 16 burns for supplying the burner 3 with the amount of combustion air corresponding to the required combustion amount determined by the required combustion amount calculation unit 23. The target rotational speed of the fan 12 is set according to the air supply data stored in the air supply data storage unit 28. In this case, in the air supply data storage unit 28, as shown in FIG. 6, target rotational speed data of the combustion fan 12 with respect to the required combustion amount is stored as air supply data for each type of fuel gas. Reference numeral 29 sets the target rotational speed in accordance with the data corresponding to the type of fuel gas determined as described above by the gas type discriminating unit 27. When the target rotation speed is set in this manner, the fan control unit 24 fan the rotation speed of the combustion fan 12 such that the rotation speed of the combustion fan 12 detected by the rotation speed sensor 14 matches the target rotation speed. Control via the motor 13. Therefore, the supply amount of combustion air to the burner 3 is controlled to be suitable for the required combustion amount of the burner 3 for each type of fuel gas.

In addition, when controlling the combustion fan 12 in this manner, the rotation speed of the combustion fan 12 is basically controlled to the target rotational speed, and for example, the actual air flow amount (supply amount) of combustion air to the burner 3. ) Is detected using the air volume sensor, and the target air volume of the combustion fan 12 corresponding to the required combustion amount is set for each type of fuel gas, and the combustion fan 12 is rotated so that the detected air volume matches the target air volume. The number may be controlled to increase or decrease with respect to the target rotational speed.

On the other hand, in parallel with the control of the combustion fan 12 as described above, the target gas flow rate setting unit 31 of the valve control unit 25 of the controller 16 stores the gas stored in the gas supply data storage unit 30. According to the supply data, the target gas flow rate of the fuel gas for supplying to the burner 3 according to the rotation speed of the combustion fan 12 detected by the rotation speed sensor 14 is set as the output level of the gas flow sensor 9. Set it. As described above, the reference energization amount setting unit 32 of the valve control unit 25 is configured to supply the appropriate amount of fuel gas to the burner 3 according to the rotation speed of the combustion fan 12. Set the standard energization amount. Here, the gas supply data storage unit 30 has data of the output level of the gas flow sensor 9 corresponding to the target gas flow rate with respect to the rotation speed of the combustion fan 12 as shown in FIGS. 7 and 8, respectively. And data of the reference energization amount of the gas flow control valve 10 are stored as gas supply data for each type of fuel gas, and the target gas flow rate setting unit 31 and the reference current amount setting unit 32 are each gas type. The output level of the gas flow sensor corresponding to the target gas flow rate and the reference energization amount are set in accordance with the data corresponding to the type of fuel gas determined by the determination unit 27. In this case, since the rotation speed of the combustion fan 12 is controlled to the target rotation speed corresponding to the required combustion amount, the output level of the gas flow sensor 9 corresponding to the target gas flow rate corresponding to the required combustion amount is consequently consequently. (Hereinafter referred to as 'target output level') and the reference energization amount of the gas flow control valve 10 are set. In addition, the data of the target output level of the gas flow sensor 9 includes gas such as the output characteristics of the gas flow sensor 9 and the calorific value of the fuel gas for each type of fuel gas determined by the gas type discrimination unit 27. It is set in consideration of characteristics. In addition, the data of the reference flow amount of the gas flow control valve 10 is the appropriate amount of fuel gas corresponding to the required combustion amount in the burner 3 when the gas flow control valve 10 is energized at the reference flow rate (this is the target value described above). Each of the types of fuel gas is set in consideration of the gas characteristics such as the calorific value so as to supply the gas flow rate.

When the target gas flow rate and the reference energization amount are set as described above, the valve control unit 25 basically energizes the gas flow control valve 10 at the set reference energization amount.

Therefore, basically, the fuel gas of the quantity corresponding to the required combustion amount is supplied to the burner 3 according to the kind of fuel gas. However, if the air pressure in the combustion chamber 19 fluctuates due to an external wind or the like, the gas flow rate control valve 10 does not actually correspond to the required combustion amount due to the effect. In some cases.

Here, the valve control unit 25 compares the target output level set by the target gas flow rate setting unit 31 with the actual output level of the gas flow sensor 9, and according to the comparison result, By increasing or decreasing the energization amount with respect to the reference energization amount, the gas flow rate control valve 10 is controlled so that the actual output level of the gas flow rate sensor 9 matches the target output level.

Specifically, when the output level of the gas flow rate sensor 9 is smaller than the target output level, the amount of current supplied to the gas flow rate control valve 10 is increased from the amount of reference current, thereby increasing the gas flow rate to the burner 3. On the contrary, when the output level of the gas flow sensor 9 is larger than the target output level, the amount of current supplied to the gas flow control valve 10 is reduced from the amount of reference current, thereby reducing the gas flow rate to the burner 3.

Therefore, the burner 3 is supplied with the above-described fuel gas in an amount corresponding to the required combustion amount while using the common nozzle 3a in an amount suitable for the type of fuel gas. Since the combustion air is supplied to the burner 3 in an amount suitable for the type of fuel gas, the burner 3 can satisfactorily combust each of the above-described types of fuel gas with the required combustion amount.

In addition, when the water supply of the water supply pipe 4 is completed, the controller 16 in the gas water heater of this embodiment detects this through the water flow amount sensor 5, and closes the solenoid valve 11 according to the detection. The gas supply to the burner 3 is interrupted and the combustion operation of the burner 3 is stopped by stopping the combustion fan 12 by the fan control unit 24. Such a stop operation of the combustion operation is similarly performed even when a burner misfire or the like is detected by the flame rod 18 during operation.

The above-described gas types are basically determined at the start of the first combustion operation, and the control corresponding to the gas types first identified in the next combustion operation is performed. However, when the type of fuel gas to be used is changed by a transfer or the like, by operating a reset switch or the like not shown, the type of gas can be determined at the start of the first combustion operation after the type of gas is changed.

In the above-described embodiment, the gas flow control valve 10 is controlled so that the output level of the gas flow sensor 9 matches the target output level corresponding to the target gas flow in order to control the gas supply. Since the fuel gas of the amount corresponding to the required combustion amount can be supplied to the burner 3 by energizing the reference energizing amount to 10), gas flow control is simply performed without monitoring the output level of the gas flow sensor 9 for the sake of simplicity. The valve 10 may be energized only by the reference energization amount. In this case, in the present embodiment, only the data of the reference current amount is stored in the gas supply data storage means 30, and the target gas flow rate setting part 31 is deleted, and the gas is simply changed in accordance with the data of the reference current amount. What is necessary is just to control the flow control valve 10.

In addition, in the present embodiment, a gas water heater using any one of 13A, 12A, 6A, and propane fuel gas has been described. However, a gas flow rate sensor such as a thermal flow rate sensor or a hot wire flow rate sensor may be used for other types of fuel gas. Similarly to this embodiment, it is also possible to provide a device capable of performing a combustion operation suitable for each type of fuel gas while determining the type of gas.

In the present embodiment, the gas water heater is described as an example, but the present invention can be applied to other gas combustion devices such as a gas fan heater.

In addition, in this embodiment, although the proportional valve equipped with the governor of a pressure control type | mold was used as the gas flow control valve 10, a governor may be provided separately, for example, the fuel gas of the kind similar to gas supply pressure. As for the gas flow rate control valve, a control valve whose hole area changes depending on the amount of energization can be used.

In this embodiment, the target gas flow rate and the reference energization amount are set in accordance with the rotational speed of the combustion fan 12 which is controlled at the target rotational speed corresponding to the required combustion amount of the burner 3. The target gas flow rate and the reference energization amount may be set.

As can be clarified in the above description, according to the present invention, a gas flow rate sensor having a different output characteristic depending on the type of fuel gas in the fuel gas supply path to the burner and a gas whose flow rate is variable depending on the amount of energization. A flow rate control valve is provided and energized at a predetermined energization amount of the gas flow rate control valve at the beginning of the combustion operation, and the type of fuel gas is determined by the output level of the gas flow rate sensor at this time, and then the determined fuel By controlling the gas flow control valve so that the amount of fuel gas corresponding to the required combustion amount is supplied to the burner appropriately for the type of gas, the type of fuel gas supplied to the burner can be easily identified with a simple configuration and discriminated. Afterwards, the gas supply to the burner according to the required combustion amount is shared with the burner nozzles for a plurality of types of fuel gases. On can be appropriately controlled. In addition, since the nozzle of the burner can be shared with a plurality of types of fuel gas, the manufacturing and management of the nozzle can be facilitated, and the manufacturing cost can be reduced.

Therefore, after determining the type of fuel gas, the target gas flow rate is set according to the required combustion amount corresponding to the type of fuel gas, and the output level of the gas flow rate sensor is the output level corresponding to the target gas flow rate. By controlling the gas flow control valve, it is possible to effectively supply the burner with the amount of fuel gas corresponding to the required combustion amount by effectively utilizing the gas flow rate sensor for the discrimination for each type of fuel gas to be discriminated. Can precisely control the amount of gas supplied to the burner.

After the type of fuel gas is determined, the gas flow control valve is controlled in accordance with the data of the amount of energization corresponding to the type of fuel gas, so that the burner nozzles are shared for a plurality of types of fuel gases. A gas combustion device capable of supplying a gas suitable for a kind can be provided in a simple configuration.

Further, by setting the target rotational speed of the combustion fan for supplying combustion air to the burner corresponding to the type of the identified fuel gas, and controlling the rotational speed of the combustion fan to be the target rotational speed, for each type of fuel gas Combustion of the burner can be made favorable by the required combustion amount.

In addition, by using a thermal flow rate sensor or a hot wire flow rate sensor as the gas flow rate sensor, the difference in the output characteristics of the gas flow rate sensor according to the type of fuel gas can be made remarkable, thereby making it possible to reliably determine the type of fuel gas. have.

In addition, by using a pressure-controlled gas flow control valve as the gas flow control valve, the amount of current supplied to the gas flow control valve is set to a predetermined value at the time of discriminating the type of fuel gas so that the gas flow rate is almost the same without the supply pressure of the fuel gas. The burner can be supplied at a flow rate, and the gas type can be surely determined for various fuel gases.

Claims (6)

A gas flow rate control valve installed in the fuel gas supply path to the burner and varying the gas flow rate in accordance with the energization amount; A gas flow rate sensor installed in the fuel gas supply path and outputting a level signal according to the gas flow rate to the burner, and having a different output level depending on the type of fuel gas even though the gas flow rate is the same; ; Gas type discriminating means for energizing the gas flow control valve at a predetermined energization amount and discriminating the type of the fuel gas based on an output level of the gas flow sensor at this time; Valve control means for controlling the gas flow rate control valve so as to supply the burner with the fuel gas in an amount corresponding to the required combustion amount of the burner in accordance with the type of fuel gas determined by the gas type discriminating means; Gas combustion apparatus, characterized in that. 2. The apparatus according to claim 1, further comprising: storage means for storing in advance gas supply data for setting a target gas flow rate corresponding to a required combustion amount of said burner for each type of fuel gas determined by said gas type discriminating means; Target gas flow rate setting means for setting a target gas flow rate corresponding to the required combustion amount on the basis of the gas supply data stored and stored in the storage means corresponding to the type of fuel gas determined by the gas type discrimination means; And the valve control means controls the gas flow rate control valve such that the output level of the gas flow rate sensor is an output level corresponding to the target gas flow rate in the determined type of fuel gas. . 2. The energization amount data of the gas flow control valve for supplying the burner with the fuel gas in an amount corresponding to the required combustion amount of the burner for each type of fuel gas determined by the gas type discriminating means. And a storage means held in advance, wherein the valve control means controls the gas flow control valve on the basis of the data stored and stored in the storage means in response to the type of fuel gas determined by the gas type discriminating means. Gas combustion apparatus, characterized in that. According to any one of claims 1 to 3, Combustion fan for supplying combustion air to the burner; For each type of fuel gas determined by the gas type discriminating means, air supply data for setting a target rotational speed of the combustion fan for supplying combustion air of the amount corresponding to the required combustion amount to the burner is stored in advance. Second storage means; A target rotation for setting a target rotational speed of the combustion fan corresponding to the required combustion amount based on the gas supply data stored in the second storage means corresponding to the type of fuel gas determined by the gas type discriminating means; Water setting means; And a fan control means for controlling the combustion fan so that the rotational speed of the combustion fan is the target rotational speed. The gas combustion device according to any one of claims 1 to 4, wherein the gas flow rate sensor is a thermal flow rate sensor or a hot wire flow rate sensor. The gas combustion valve according to any one of claims 1 to 5, wherein the gas flow control valve is a pressure control type gas flow control valve that generates a gas pressure according to the amount of energization at the inflow side of the nozzle of the burner. Device.