JP6531431B2 - Gas boiler combustion control mechanism - Google Patents

Description

  The present invention relates to a combustion control mechanism of a gas boiler.

  The combustion control in the gas boiler is performed, for example, by the mechanism shown in FIG. In the mechanism of FIG. 2, the differential pressure of the flow rate measurement resistive element 11 in the combustion air supply passage 1 is detected by the first pressure sensor 31, and the flow rate adjustment valve 23 of the fuel gas supply passage 2 is detected based on the detected value. I have control. And in the mechanism of FIG. 2, in order to make the supply pressure of fuel gas constant, the governor attached cutoff valve 25 is provided on the upstream side (primary side) of the flow control valve 23.

JP 2014-40948 Japanese Patent Application Publication No. 2014-502337 JP, 2013-92315, A JP 2008-157553 A

  However, since the governor-equipped shutoff valve 25 is expensive, the gas boiler employing the mechanism of FIG. 2 is expensive.

  An object of the present invention is to provide a combustion control mechanism of a gas boiler which can adopt an inexpensive shutoff valve without a governor.

The present invention relates to a first pressure sensor for detecting a differential pressure of a flow rate measurement resistive element provided in a combustion air supply passage in a combustion control mechanism of a gas boiler in a combustion control mechanism of a gas boiler, and a fuel gas supply passage And a fuel gas amount control mechanism for controlling an amount of fuel gas supplied to the burner, wherein the fuel gas amount control mechanism is provided in the fuel gas supply passage. A flow control valve provided on the primary side of the element and adjusting a flow passage cross-sectional area of the fuel gas supply passage by adjusting the opening degree of the valve; and provided on the primary side of the flow control valve for opening and closing the fuel gas supply passage by opening and closing the valve, and shut-off valve, for detecting a pressure between said flow control valve and the shut-off valve comprises a second pressure sensor, wherein the flow rate Regulating valve has constant air ratio And adjusting the opening degree of the valve in accordance with the pressure value detected by the first pressure sensor and the second pressure sensor so as to control the amount of fuel gas flowing through the fuel gas supply passage. the mechanism has to operate when the ignition operations to the burner is executed, the burner misfire cause determination means, and further comprising, the burner misfire cause determination means detects a flame of the burner A flame sensor, and a misfire determination and notification unit that operates when the flame sensor does not detect the flame of the burner to determine the cause of misfire and notify the outside, and the misfire determination When the second pressure sensor does not detect an increase in pressure between the flow rate adjustment valve and the shutoff valve, the notification unit misfires “user operation error” or “failure of the shutoff valve”. Determined as the cause and notified, the second pressure sensor If the sensor detects an increase in pressure between the flow control valve and the shutoff valve, it determines that "the malfunction of the flow control valve" or "the maladjustment due to the adjustment mechanism" is the cause of misfire and notifies has so doing, it is characterized in that.

  According to the present invention, the fuel gas supply pressure is made constant by adjusting the opening degree of the flow rate adjusting valve according to the pressure value detected by the second pressure sensor as well as the first pressure sensor. be able to. Therefore, according to the present invention, since the governor can be eliminated, that is, a normal shutoff valve without the governor can be used, the combustion control mechanism can be constructed inexpensively.

It is a figure showing the combustion control mechanism of the gas boiler of one embodiment of the present invention. It is a figure which shows the combustion control mechanism of the conventional gas boiler.

  FIG. 1 shows a combustion control mechanism of a gas boiler according to an embodiment of the present invention. Elements in FIG. 1 that are the same as those in FIG. 2 indicate the same or corresponding elements as those in FIG. In FIG. 1, the cross section of the upper part of the gas boiler 4 is shown. The gas boiler 4 has a burner 41 at the upper center. The combustion air supply passage 1 and the fuel gas supply passage 2 are connected to the burner 41. In the gas boiler 4, illustration of a water pipe is omitted.

  The combustion control mechanism 100 of the present embodiment includes a flow rate measurement resistive element 11, a first pressure sensor 31, and a fuel gas amount control mechanism 10. The first pressure sensor 31 is configured to detect a differential pressure of the flow rate measurement resistive element 11 provided in the supply path 1. The fuel gas amount control mechanism 10 is provided in the supply passage 2 so as to control the amount of fuel gas supplied to the burner 41. For example, an orifice for flow rate measurement can be used as the flow rate measurement resistive element 11.

  The fuel gas amount control mechanism 10 includes, in order from the upstream side (primary side), the first shutoff valve 21, the second shutoff valve 22, the flow rate adjustment valve 23, and the flow rate measuring resistance element 24 in the supply passage 2 There is. The first shutoff valve 21 opens and closes the supply passage 2 by opening and closing the valve, and the same applies to the second shutoff valve 22. The flow rate adjustment valve 23 adjusts the flow passage cross-sectional area of the supply passage 2 by adjusting the opening degree of the valve.

The fuel gas amount control mechanism 10 further includes a second pressure sensor 32. The second pressure sensor 32 is adapted to detect the flow amount adjusting valve 23 pressure force between the second shut-off valve 22.

  Furthermore, the flow rate adjusting valve 23 has an adjusting mechanism 33, and the opening degree of the valve is adjusted by the adjusting mechanism 33. And in the combustion control mechanism 100 of this embodiment, the adjustment mechanism 33 controls the first pressure sensor 31 and the second pressure sensor so as to control the amount of fuel gas flowing through the supply path 2 so that the air ratio becomes constant. The opening degree of the valve is adjusted in accordance with the pressure value detected by.

  The adjustment mechanism 33 has a control unit 331 connected to the first pressure sensor 31 and the second pressure sensor 32, and a valve drive unit 332 connected to the control unit 331. Then, the control unit 331 operates the valve drive unit 332 based on the pressure value detected by the first pressure sensor 31 and the second pressure sensor 32, thereby making the valve open or close. , Is made to rotate. In addition, as the valve drive part 332, a stepping motor can be used, for example.

  Furthermore, the combustion control mechanism 100 of the present embodiment includes the over-valve leakage determination means 90 that operates when the gas boiler 4 is in the standby state. The over-valve leak determination unit 90 includes a leak determination unit 91, a notification unit 92, and a forced purge unit 93. The leak determination unit 91 determines “leak occurrence” when the pressure value detected by the second pressure sensor 32 exceeds a predetermined set value. The notification unit 92 is configured to notify the outside of "presence of occurrence of leakage" when the determination of "presence of occurrence of leakage" is performed by the leakage determination unit 91. Specifically, the notification unit 92 (1) generates a sound from a speaker, or (2) turns on a lamp, or (3) displays characters on a display panel, or (4) By letting two or more of them be executed, "leak occurrence" is notified to the outside. The forced purge unit 93 is configured to continue the purge, for example, by continuing the operation of the blower that performs the purge, when the leak determination unit 91 determines that “the leak has occurred”.

  Furthermore, the combustion control mechanism 100 of the present embodiment is provided with burner misfire cause determination means 80 that operates when the ignition operation to the burner 41 is performed. The burner misfire cause determining means 80 operates when the flame sensor 81 detecting the flame 411 of the burner 41 and the flame sensor 81 does not detect the flame 411 of the burner 41 to determine the cause of the misfire And a misfire determination and notification unit 82 for making a notification. If (a) the second pressure sensor 32 does not detect an increase in pressure between the flow rate adjustment valve 23 and the second shut-off valve 22, the misfire determination / notification unit 82 determines that the user has made a mistake in operation or When “the failure of the second shutoff valve 22” is determined as a misfire cause and reported, and (b) the second pressure sensor 32 detects an increase in pressure between the flow control valve 23 and the second shutoff valve 22 , “Incorrect operation of the flow rate adjustment valve 23” or “Incorrect adjustment by the adjustment mechanism 33” is determined as a misfire cause and reported. Specifically, the misfire determination notification unit 82 makes a notification by displaying characters on the display panel.

  The control unit 331, the leak determination unit 91, the notification unit 92, the forced purge unit 93, and the misfire determination notification unit 82 are realized by a CPU, a ROM, a RAM, and the like.

Next, the operation of the combustion control mechanism 100 of the present embodiment will be described.
When the shutoff valve 12 of the supply passage 1 is switched to the open state, combustion air is supplied to the burner 41 through the supply passage 1 and the first shutoff valve 21 and the second shutoff valve 22 of the supply passage 2 are opened. When switched to the state, fuel gas is supplied to the burner 41 through the supply passage 2. Then, the fuel gas is jetted from the burner 41 toward the combustion chamber 43 in the gas boiler 4 together with the combustion air, and is ignited and burned. The combustion continues as long as the supply of fuel gas and combustion air continues, and the burner 41 continues to form the flame 411.

  At this time, in the supply passage 1, when the combustion air passes through the flow rate measurement resistive element 11, the first pressure sensor 31 detects a differential pressure of the flow rate measurement resistive element 11.

Further, in the supply passage 2, the fuel gas amount control mechanism 10 operates. That is, in the supply path 2, the fuel gas passes through the first shut-off valve 21 and the second shut-off valve 22 in the open state, the flow rate is adjusted by the flow rate adjustment valve 23, and passes through the flow rate measurement resistive element 24. At that time, by the second pressure sensor 32, pressure between the flow rate adjusting valve 23 and the second shut-off valve 22 is detected. Further, the opening degree of the flow control valve 23 is adjusted by the adjustment mechanism 33, whereby the flow rate of the fuel gas (i.e., the amount of fuel gas) is adjusted. That is, according to the pressure value detected by the first pressure sensor 31 and the second pressure sensor 32, the adjustment mechanism 33 controls the amount of fuel gas flowing through the supply passage 2 so that the air ratio becomes constant. Adjust the opening of the valve. Specifically, based on the pressure value detected by the first pressure sensor 31 and the second pressure sensor 32, the control unit 331 operates the valve drive unit 332, thereby making the valve open or It is pivoted in the closing direction, thereby adjusting the opening of the valve.

  Thus, according to the combustion control mechanism 100, by adjusting the opening degree of the flow rate adjustment valve 23 according to the pressure value detected by the second pressure sensor 32 as well as the first pressure sensor 31, The fuel gas supply pressure can be made constant. Therefore, the governor can be eliminated, that is, a normal shutoff valve without the governor can be used as the second shutoff valve 22. Therefore, the combustion control mechanism 100 can be constructed inexpensively.

  Further, in the combustion control mechanism 100, the over-valve leakage determination means 90 operates when the gas boiler 4 is in the standby state. When the over-valve leak determination means 90 is activated, the leak determination unit 91 first detects whether the pressure value detected by the second pressure sensor 32 exceeds a predetermined set value, and if it exceeds It is determined that "occurrence occurs". Then, when the leak determination unit 91 determines “leak occurrence”, the notification unit 92 and the forced purge unit 93 further operate. The notification unit 92 notifies the outside of "leak occurrence". The forced purge unit 93 continues the purge.

As described above, according to the combustion control mechanism 100, it is possible to detect the leak of the fuel gas in the supply passage 2 by operating the over-valve leak determination unit 90. Moreover, in the conventional mechanism as shown in FIG. 2 , it is necessary to open and close the two shut-off valves in order to detect the leak of the fuel gas, but according to the combustion control mechanism 100 of this embodiment Since leakage of fuel gas can be detected without opening and closing operations, damage to the two shutoff valves, ie, the first shutoff valve 21 and the second shutoff valve 22 can be prevented by the opening and closing operations.

  Moreover, since the "reporting occurrence" is notified to the outside by the notifying unit 92, it is possible to urge the user to be careful about the gas leakage.

  Furthermore, since the purge is continued by the forced purge unit 93, unexpected explosion can be prevented.

  Furthermore, in the combustion control mechanism 100, when the burner 41 is ignited, the burner misignition cause determination means 80 operates. When the burner misignition cause determining means 80 operates, first, the flame sensor 81 operates to detect the flame 411 of the burner 41. When the ignition is performed, the burner 41 forms the flame 411, so the flame sensor 81 detects the flame 411. In the case where ignition is not achieved, that is, in the case of misfire, the flame sensor 81 does not detect the flame 411, that is, misfire is detected. When the flame sensor 81 detects a misfire, the misfire determination and notification unit 82 operates. If (a) the second pressure sensor 32 does not detect an increase in pressure between the flow rate adjustment valve 23 and the second shut-off valve 22, the misfire determination / notification unit 82 determines that the user has made a mistake in operation or When “the failure of the second shutoff valve 22” is determined as a misfire cause and reported, and (b) the second pressure sensor 32 detects an increase in pressure between the flow control valve 23 and the second shutoff valve 22 , “Incorrect operation of the flow control valve 23” or “Incorrect adjustment by the adjustment mechanism 33” is determined as a misfire cause and reported.

  As described above, according to the combustion control mechanism 100, since the cause of the misfire can be notified to the outside promptly by operating the burner misfire cause determining means 80, it is possible to prompt the user to take a prompt action. . Moreover, since the burner misfire cause determining means 80 is constructed using the second pressure sensor 32 of the fuel gas amount control mechanism 10, it can be realized without causing a substantial cost increase.

(Modification)
(1) In the present invention, the over-valve leak determination means 90 is not essential.
(2) In the present invention, the notification unit 92 and / or the forced purge unit 93 of the over-valve leak determination unit are not essential.
(3) In the present invention, the burner misfire cause determining means 80 is not essential.

  INDUSTRIAL APPLICABILITY The present invention has great industrial utility value because the combustion control mechanism of the gas boiler can be constructed inexpensively using the shutoff valve without the governor.

1 combustion air supply passage 10 fuel gas amount control mechanism 100 combustion control mechanism 11 resistance element for flow rate measurement 2 fuel gas supply passage 21 first shut-off valve 22 second shut-off valve 23 flow adjustment valve 31 first pressure sensor 32 second pressure Sensor 33 Adjustment mechanism 331 Control unit 332 Valve drive unit 41 Burner 411 Flame 80 Burner misfiring cause determination means 81 Flame sensor 82 Misfire determination notification part 90 Over-valve leak determination means 91 Leak determination part 92 Notification part 93 Forced purge part

Claims (5)

In the combustion control mechanism of the gas boiler,
A first pressure sensor for detecting a differential pressure of a flow rate measurement resistive element provided in the combustion air supply passage;
A fuel gas amount control mechanism provided in the fuel gas supply path to control the amount of fuel gas supplied to the burner;
Equipped with
The fuel gas amount control mechanism
A flow control valve provided on the primary side of a flow rate measurement resistive element provided in the fuel gas supply path, and adjusting a flow path cross-sectional area of the fuel gas supply path by adjusting an opening degree of the valve;
A shutoff valve provided on the primary side of the flow rate adjustment valve, which opens and closes the fuel gas supply passage by opening and closing the valve;
Detecting the pressure between the shut-off valve and the flow control valve, a second pressure sensor,
Equipped with
The flow rate adjusting valve controls the pressure value detected by the first pressure sensor and the second pressure sensor so as to control the amount of fuel gas flowing through the fuel gas supply passage so that the air ratio becomes constant. depending adjusting the opening of the valve, the adjustment mechanism has,
The apparatus further comprises burner misfire cause determination means that operates when the burner firing operation is performed.
The burner misfiring cause determining means operates a flame sensor that detects a flame of the burner, and operates when the flame sensor does not detect a flame of the burner to determine a misfiring cause and notify the outside. And an ignition determination notification unit;
If the second pressure sensor does not detect an increase in pressure between the flow rate adjustment valve and the shutoff valve, the misfire judgment informing unit may indicate “a user operation error” or “a failure of the shutoff valve”. When the second pressure sensor detects an increase in pressure between the flow control valve and the shut-off valve, “the malfunction of the flow control valve” or "It is determined that the adjustment failure due to the adjustment mechanism" as the cause of the misfire, and is notified.
Combustion control mechanism of a gas boiler characterized in that. There is further provided over-valve leakage determination means that operates when the gas boiler is in a standby state,
The valve-passing-leak determination unit includes a leak determination unit that determines “leak occurrence” when the pressure value detected by the second pressure sensor exceeds a predetermined set value.
The combustion control mechanism of the gas boiler according to claim 1. The valve over leak determination means further comprises a notification unit;
The notification unit is configured to notify the outside of "presence of occurrence of leak" when the determination of "presence of occurrence of leak" is performed by the leak determination unit.
The combustion control mechanism of the gas boiler according to claim 2. The valve-opened leak judging means further comprises a forced purge unit,
The forced purge unit is configured to continue the purge when the leak determination unit determines that “a leak has occurred”.
A combustion control mechanism of a gas boiler according to claim 2 or 3. The adjustment mechanism includes a control unit connected to the first pressure sensor and the second pressure sensor, and a valve drive unit connected to the control unit.
The control unit operates the valve driving unit based on pressure values detected by the first pressure sensor and the second pressure sensor, thereby turning the valve in the opening direction or in the closing direction. Is made to move,
A combustion control mechanism of a gas boiler according to any one of claims 1 to 4.

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