JP5516965B2 - Gas combustion equipment - Google Patents

Description

The present invention relates to a gas combustion apparatus including a pressure adjusting valve that adjusts a supply pressure of a fluid such as fuel gas to a pressure corresponding to a desired signal pressure.

  One example of a conventional pressure regulating valve is described in Patent Document 1. The pressure adjusting valve described in the document is for adjusting the supply pressure of the fuel gas supplied to the gas burner via the gas pipe. The pressure regulating valve includes a valve main body for changing the flow rate of the fuel gas flowing from the primary flow path to the secondary flow path, and two diaphragms connected to the shaft portion of the valve main body. It has. Of these two diaphragms, one receives the secondary pressure of the fuel gas and the other receives the signal pressure. This signal pressure is the discharge pressure of a fan that sends combustion air to the gas burner. The pressure receiving areas of the two diaphragms are the same or substantially the same, and an intermediate chamber formed between the two diaphragms is connected to the intake side of the fan so that negative pressure is applied. State.

  According to such a configuration, the secondary pressure of the fuel gas is set to be substantially the same as the signal pressure, and the correspondence relationship between the supply amount of the combustion air supplied from the fan to the gas burner and the supply amount of the fuel gas to the gas burner It is possible to keep (air / fuel ratio) constant. Further, since the intermediate chamber formed between the two diaphragms is in a negative pressure state, even if the signal pressure is relatively low, the pressure between the signal pressure and the negative pressure intermediate chamber is low. The difference becomes large, and the diaphragm and the valve body can be effectively operated based on this pressure difference.

  However, in the past, as described below, there is still room for improvement.

  That is, in the conventional pressure regulating valve, since the pressure receiving areas of the two diaphragms are the same or substantially the same, based on the balance between the force of the signal pressure acting on the two diaphragms and the secondary pressure. Thus, it is difficult to set the secondary pressure higher than the signal pressure. This also applies to the conventional traditional pressure regulating valve in which only one diaphragm is used. On the other hand, in a gas combustion apparatus, a sirocco fan may be used as a fan for supplying combustion air. In this case, the discharge pressure is considerably low due to the characteristics of the sirocco fan. Under such conditions, if the conventional pressure regulating valve is used and the low discharge pressure of the sirocco fan is used as the signal pressure, the secondary pressure of the fuel gas becomes considerably low, and the combustibility of the fuel gas And other problems may occur. For example, in a case where the gas combustion device is installed indoors and the exhaust gas is exhausted outdoors using an appropriate duct, and the secondary pressure of the fuel gas is low, a ventilator for exhausting indoor air is used. It becomes difficult to establish the combustion performance of the gas combustion device when the room is in a negative pressure state due to driving or the like. As a means for suppressing such a problem, for example, it is conceivable to increase the discharge pressure by significantly increasing the rotation speed of the sirocco fan. However, if such a means is adopted, noise during driving of the sirocco fan is considered. Incurs a problem that becomes larger. Therefore, it is desirable to appropriately eliminate such problems.

Japanese Utility Model Publication No. 63-11460

The present invention has been proposed under the circumstances described above, a pressure regulating valve which can be performed easily and appropriately be set higher than the secondary pressure signal pressure of the fluid An object is to provide a gas combustion apparatus.

  In order to solve the above problems, the present invention takes the following technical means.

A gas combustion apparatus provided by the present invention is provided with a fan for supplying combustion air to a gas burner, a fuel gas supply path for supplying fuel gas to the gas burner, and a middle of the fuel gas supply path. And a main pressure regulating valve having a valve body part capable of changing the flow rate of the fuel gas from the primary side flow path to the secondary side flow path of the fuel gas supply path, and a diaphragm interlocking with the valve main body part, An auxiliary pressure adjustment valve connected to a fuel gas supply path and controlling a secondary pressure of the fuel gas using a discharge pressure of the fan as a signal pressure, the gas combustion device, wherein the auxiliary pressure adjustment the valve includes a valve body portion for changing the flow rate of the fluid passing from the primary side flow passage of the auxiliary pressure-regulating valve to the secondary-side flow path, a first diaphragm for receiving the signal pressure, the first The diaphragm is the signal A second diaphragm which receives the secondary pressure of the fluid in the opposite direction to the direction of receiving, together and wherein the first and second diaphragm, are connected so as to interlock with each other, these first and along with the movement of the second diaphragm is configured to vary the valve opening, the pressure receiving area of the first diaphragm is greater than the pressure receiving area of the second diaphragm, the auxiliary The primary flow path of the pressure regulating valve is connected to the primary flow path of the fuel gas supply path via the first flow path, and the second flow path branched from the first flow path is: The gas pressure in the second flow path is set to be a signal pressure acting on the diaphragm of the main pressure regulating valve, and the secondary flow path of the auxiliary pressure regulating valve is 2 of the fuel gas supply path. Connected to the secondary channel via the third channel It is characterized in that.

According to such a configuration, since the pressure receiving area of the first diaphragm that receives the signal pressure is large in the auxiliary pressure regulating valve, the force by which the signal pressure pushes the first diaphragm even when the signal pressure is low. And the valve main body can be operated in a direction in which the secondary pressure of the fluid is increased by the operation of the first diaphragm. On the other hand, since the pressure receiving area of the second diaphragm is small, the force exerted by the second diaphragm on the secondary pressure is reduced so that the valve body does not operate greatly in the direction of reducing the secondary pressure. Can do. For this reason, it is easy and appropriate to make the secondary pressure higher than the signal pressure.
Further, according to the above configuration, since the secondary pressure of the fuel gas can be set higher than the discharge pressure of the fan, for example, a sirocco fan having a low discharge pressure is used as the fan. Thus, it is possible to increase the secondary pressure of the fuel gas so as not to cause a problem in the drive combustion of the gas burner while reducing the drive noise by lowering the rotational speed of the sirocco fan. Further, if the secondary pressure of the fuel gas can be increased as described above, the combustion performance of the gas combustion device is established when the gas combustion device is installed indoors, for example, when the indoor is in a negative pressure state. Conventional problems such as difficult to do are also solved appropriately.
Furthermore, by controlling the main pressure regulating valve with the auxiliary pressure regulating valve, the pressure (secondary pressure) of the fuel gas in the fuel gas supply path can be made higher than the discharge pressure of the fan. The main pressure adjustment valve is provided in the middle of the fuel gas supply path and controls the fuel gas supplied to the gas burner. With regard to, there is no need to adopt a diaphragm double structure or the like, and a simple structure similar to a conventional traditional pressure regulating valve may be used. On the other hand, the auxiliary pressure regulating valve only needs to be configured to transmit pressure between the main pressure regulating valve and other predetermined portions, and is formed in a small size, and the stroke of the valve main body is small. can do. Therefore, according to the above configuration, compared with the case where the fuel gas pressure is adjusted using only one pressure regulating valve, the overall number of parts is increased, but the structure of the main pressure regulating valve is avoided. In addition, it is possible to appropriately obtain the effect intended by the present invention while suppressing the overall enlargement.

  In the present invention, preferably, a first spring that biases the first diaphragm in a direction to approach the second diaphragm, and a bias in a direction to cause the second diaphragm to approach the first diaphragm. The first and second springs have different spring constants.

  According to such a configuration, as will be understood from an embodiment of the gas combustion apparatus described later, the elastic force of the first and second springs is used to change the correspondence between the signal pressure and the secondary pressure. Can be added. In the pressure regulating valve of the present invention, the flow rate of the fluid in the secondary side flow path is increased as compared with the conventional pressure regulating valve in which the signal pressure and the secondary pressure of the fluid are set to be substantially the same. Show the trend. For this reason, when the pressure regulating valve of the present invention is used for adjusting the fuel gas pressure of a gas combustion apparatus, for example, the air-fuel ratio is different from the conventional one. However, according to the above configuration, it is possible to adjust so that a specific secondary pressure is obtained when the signal pressure is a predetermined value, and it is possible to correct the deviation of the air-fuel ratio.

  In the present invention, preferably, the first spring has a larger spring constant than the second spring.

  According to such a configuration, as will be understood from the embodiments described later, the elastic force of the first spring can be effectively applied as a force that increases the secondary pressure of the fluid. It is more efficient to increase the secondary pressure than when the spring constant of the second spring is increased.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

It is sectional drawing which shows typically an example of the gas combustion apparatus provided with the pressure control valve to which this invention was applied. It is sectional drawing which shows the pressure regulation valve used for the gas combustion apparatus shown in FIG. It is sectional drawing which shows the other example of the pressure regulation valve to which this invention was applied.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

A gas combustion apparatus GC shown in FIG. 1 is configured as a gas hot water supply apparatus provided with a heat exchanger 19 for heating hot water, and includes a gas burner 2 disposed in a can 1, a fan 3 for supplying combustion air, A fuel gas supply path 4, an on-off valve Vc, a main pressure adjustment valve Va, and an auxiliary pressure adjustment valve Vb formed in series from the gas pipe 40 to the gas ejection nozzle head 41 are provided. The auxiliary pressure regulating valve Vb corresponds to an example of a pressure regulating valve according to the present invention.

  The fan 3 is a sirocco fan, for example, and sends air into the can 1. The gas ejection nozzle head 41 is located at the end of the fuel gas supply path 4 and ejects fuel gas from the nozzle 41a. The jetted fuel gas is supplied to the gas burner 2 and burned while being mixed with combustion air. From the combustion gas generated by this combustion, heat is recovered by the heat exchanger 19, and hot water flowing through the heat exchanger 19 is heated. The combustion gas after heat recovery is discharged from the exhaust port 11 as exhaust gas.

  The fuel gas supply path 4 has a configuration in which an on-off valve Vc and a main pressure adjustment valve Va are connected to a gas pipe 40 that supplies fuel gas. In the drawing, the main pressure regulating valve Va and the gas ejection nozzle head 41 are connected via the gas pipe 40a, but they can also be directly connected. The on-off valve Vc is for turning on / off the fuel gas supply, and is provided with a mechanism for reciprocating the valve main body 51 using a solenoid 50, as in the known art.

  The main pressure adjustment valve Va is connected to the downstream side of the on-off valve Vc, and controls the pressure of the fuel gas in cooperation with the auxiliary pressure adjustment valve Vb. The main pressure regulating valve Va has a basic configuration similar to that of a conventional traditional pressure regulating valve, and a pressure regulating hole 42 at the boundary between the primary side flow path 4a and the secondary side flow path 4b of the fuel gas. A valve main body 60 that opens and closes, a diaphragm 61 that supports the valve main body 60, and a return spring 62. The diaphragm 61 receives a secondary pressure P2 of the fuel gas and a signal pressure Pd (described later) input to the port p4 of the signal pressure input chamber 63.

  The auxiliary pressure adjustment valve Vb does not directly control the pressure in the fuel gas supply path 4, but controls the main pressure adjustment valve Va as described later. In FIG. 1, for convenience of explanation, the main pressure adjustment valve Va and the auxiliary pressure adjustment valve Vb are shown not to have a large difference. However, the auxiliary pressure regulating valve Vb in this embodiment is actually considerably smaller in size than the main pressure regulating valve Va (for example, the dimensions of the width and height in the vertical and horizontal directions are 1 / th that of the main pressure regulating valve Va. (Small size suppressed to a size of about 4 to 1/7 or less).

  As shown well in FIG. 2, the auxiliary pressure regulating valve Vb has a cylindrical shape having a casing 70, first and second diaphragms D <b> 1 and D <b> 2, first and second springs S <b> 1 and S <b> 2, and a pressure adjusting hole 71. And a valve main body 73 for changing the flow rate of the fuel gas passing through the pressure adjusting hole 71. The auxiliary pressure regulating valve Vb is connected to the main pressure regulating valve Va and the position of the fan 3 to be described later via first to fourth flow paths 74a to 74d.

  The valve main body 73 is constituted by a part of the second diaphragm D2, and the portion of the second diaphragm D2 that faces the pressure adjusting hole 71 is the valve main body 73. Of course, instead of such a configuration, a member facing the pressure adjusting hole 71 may be attached to the second diaphragm D2, and this member may be used as the valve body. When the second diaphragm D2 moves downward in FIG. 2 and approaches the pressure adjusting hole 71, the valve opening (the distance between the valve main body 73 and the pressure adjusting hole 71) decreases, and the fuel gas passing through the pressure adjusting hole 71 The amount of decreases.

The casing 70 is partitioned into a signal input chamber 75a, a secondary pressure chamber 75b, and an intermediate chamber 75c by first and second diaphragms D1 and D2. One end of a fourth flow path 74d is connected to the port p1 of the signal input chamber 75a. The other end of the fourth flow path 74d is connected to the air discharge side region of the fan 3 (see FIG. 1). For this reason, the discharge pressure Ps of the fan 3 is directly input to the signal input chamber 75a as the signal pressure Ps. The intermediate chamber 75c is a space portion sandwiched between the first and second diaphragms D1 and D2, and is open to the atmosphere via the port p2. The secondary pressure chamber 75b communicates with the secondary flow path 4b of the fuel gas supply path 4 via a third flow path 74c connected to the port p3 (see FIG. 1). Therefore, the pressure in the secondary pressure chamber 75b becomes the secondary pressure P2 of the secondary side flow path 4b.

  The first and second diaphragms D1 and D2 are connected via a connecting portion 76 and interlock with each other. The first diaphragm D1 receives the signal pressure Ps and the atmospheric pressure Po in the intermediate chamber 75c on both sides. The second diaphragm D2 receives the secondary pressure P2 and the atmospheric pressure Po in the intermediate chamber 75c on both sides. However, the sizes of the pressure receiving areas (effective pressure receiving areas) A1 and A2 of the first and second diaphragms D1 and D2 are different and have a relationship of A1> A2. Based on this configuration, as will be described later, the secondary pressure P2 becomes higher than the signal pressure Ps.

  A first flow path 74 a is connected to the pressure regulation hole forming portion 72. As shown in FIG. 1, the first flow path 74 a connects the primary flow path 4 a of the fuel gas supply path 4 and the inside of the pressure regulation hole forming portion 72. Is provided. Therefore, part of the fuel gas in the primary side flow path 4 a reaches the pressure regulation hole forming portion 72 in a state where the flow rate is reduced by the orifice 49. The primary flow path 77a in the auxiliary pressure regulating valve Vb is a portion on the first flow path 74a side of the pressure adjustment hole 71 (the lower side of the pressure adjustment hole 71 in FIG. 2), and the secondary flow path 77b is Inside the secondary pressure chamber 75b and the third flow path 74c.

  The second flow path 74b branches off from the first flow path 74a and is connected to the port p4 of the main pressure adjustment valve Va as shown in FIG. As a result, the pressure Pd of the second flow path 74b acts on the signal pressure input chamber 63 of the main pressure adjustment valve Va. This pressure Pd changes corresponding to the valve opening degree of the auxiliary pressure regulating valve Vb. That is, when the distance between the valve main body 73 and the pressure adjusting hole 71 is large, the fuel gas in the first flow path 74a flows to the secondary flow path 77b, and thus the pressure Pd decreases. On the other hand, the pressure Pd increases as the distance decreases.

  As the first and second springs S1 and S2, for example, compression coil springs are used, and the first spring S1 is provided with a first diaphragm D1 in the direction of decreasing the valve opening (downward in FIG. 2). Rush. The second spring S2 biases the second diaphragm D2 in the opposite direction to the first spring S1. The spring constants k1 and k2 of the first and second springs S1 and S2 are different from each other and have a relationship of k1> k2. The resilience (initial compression amount) of the first and second springs S1 and S2 can be adjusted by changing the height of the pressing member 78 for the first spring S1.

  Next, the operation of the gas combustion apparatus GC will be described.

First, as described with reference to FIG. 2, the auxiliary pressure regulating valve Vb gradually increases the pressure Pd as the valve body 73 approaches the pressure adjusting hole 71 and the valve opening decreases. The pressure Pd depends on the valve opening degree of the auxiliary pressure regulating valve Vb. On the other hand, the valve opening degree of the main pressure adjusting valve Va is changed corresponding to the pressure Pd input to the signal pressure input chamber 63. For example, as the pressure Pd increases, the valve opening increases and the secondary pressure P2 increases. By the way, in the main pressure regulating valve Va, if the pressure receiving area of the diaphragm 61 is A3, the pressure receiving area of the valve body 60 is A4, and the spring force of the spring 62 is F3, the force balance equation is as follows: It is.
Pd · A3 = P1 · A4 + P2 · A3 + F3 Formula 1

In the auxiliary pressure regulating valve Vb, since the pressure receiving area A1 of the first diaphragm D1 is larger than the pressure receiving area A2 of the second diaphragm D2, the secondary pressure P2 is set to the signal pressure Ps as shown below. Can be higher.
Considering the balance of forces in the auxiliary pressure regulating valve Vb, the following formula 1 is established. However, the spring forces of the first and second springs S1 and S2 are F1 and F2, respectively, and the atmospheric pressure is Po.
(Ps−Po) · A1 + F1 = (P2−Po) · A2 + F2 Equation 2
However, for simplicity, if the influence of Po on both sides is very small,
Ps · A1 + F1≈P2 · A2 + F2 is obtained, and the following Expression 3 is obtained.
P2≈ (A1 / A2) · Ps + (F1−F2) / A2 Equation 3
Here, for simplicity of explanation, if F1≈F2,
P2≈ (A1 / A2) · Ps Equation 4
On the other hand, in this embodiment, there is a relationship of A1> A2.
Therefore, (A1 / A2) in Expression 4 is larger than 1, and the following Expression 5 is established.
P2> Ps Formula 5
As can be understood from Equation 5, in the auxiliary pressure regulating valve Vb, the secondary pressure P2 can be set higher than the signal pressure Ps. Further, as understood from Equation 4, the secondary pressure P2 increases as the pressure receiving area A1 becomes larger than the pressure receiving area A2.

  Due to the above-described action, in this gas combustion apparatus GC, even if the fan 3 is, for example, a sirocco fan having a low discharge pressure and the signal pressure Ps is relatively low, the fuel gas is gas at a relatively high pressure. It becomes possible to supply to the ejection nozzle 41a. Therefore, it is possible to prevent the gas ejection pressure from becoming insufficient and causing trouble in the drive combustion of the gas burner 2.

  On the other hand, when the relationship between the signal pressure Ps and the secondary pressure P2 is the relationship of the above-described equation 4, the air-fuel ratio is different from that in the case of the relationship of P2 = Ps. That is, P2 = Ps is a straight line with a slope of “1” as shown in the graph of the horizontal axis Ps and the vertical axis P2, whereas P2≈ (A1 / A2) · Ps in the above-described equation 4 is The straight line has an inclination of (A1 / A2), and these two straight lines have a deviation. For this reason, it is more preferable that the influence of such a shift is reduced and the secondary pressure P2 can be a desired value when the signal pressure Ps is a specific value.

  On the other hand, in this embodiment, the spring constants k1 and k2 of the first and second springs S1 and S2 are made different from each other, and the secondary pressure P2 is set to a desired value by setting them to appropriate values. Alternatively, it can be set to a value close to that. This can be understood from Equation 3 described above. That is, in the expression 3, the term (F1-F2) / A2 is included as a term for determining the magnitude of the secondary pressure P2. Therefore, the spring constants k1 and k2 may be determined so that the (F1-F2) / A2 becomes a predetermined value excluding zero so that the secondary pressure P2 becomes a desired value. When F1 <F2, the value of (F1-F2) / A2 is negative, and the value of the secondary pressure P2 is smaller than when the value is positive. Therefore, from the viewpoint of making the secondary pressure P2 higher than the signal pressure Ps, it is preferable to make the spring constant k1 larger than the spring constant k2 so that F1> F2.

In the gas combustion apparatus GC of the present embodiment, the main pressure adjustment valve Va has a relatively large size, but the main pressure adjustment valve Va does not need to have a double structure in its diaphragm, and is simple. It can be a structure. As described above, the auxiliary pressure regulating valve Vb has a considerably smaller size than the main pressure regulating valve Va, although the double diaphragm structure is adopted, and the first and second diaphragms D1, D2 The movement stroke of is also small. Accordingly, the combination of the main pressure adjusting valve Va and the auxiliary pressure adjusting valve Vb increases the overall number of parts, but avoids complication of the structure of the main pressure adjusting valve Va having a larger size. Therefore, as a total, it is possible to suitably reduce the manufacturing cost and suppress the increase in the overall size.

  FIG. 3 shows another embodiment of the pressure regulating valve according to the present invention. In the figure, the same or similar elements as those in the above embodiment are given the same reference numerals as in the above embodiment.

  In the pressure regulating valve Vb ′ shown in FIG. 3, the shaft portion 730 of the valve main body portion 73A is connected to the first and second diaphragms D1 and D2. The valve main body 73A has a conical inclined surface, and can change the opening degree of the pressure adjusting hole 71 by moving into the pressure adjusting hole 71 and moving. In the figure, the upper side of the pressure adjusting hole 71 is a primary flow path 77a, and the lower side is a secondary flow path 77b. A third diaphragm 79 is provided below the second diaphragm D2 to form a pressure chamber 75d. The secondary pressure P2 is input to the pressure chamber 75d through the flow path 79a. The third diaphragm 79 has a considerably smaller pressure receiving area than the second diaphragm D2, and the force of the primary pressure P1 acting on the third diaphragm 79 has a great influence on the operation of the valve main body 73A. It is set not to. The spring S3 receives the weight of a movable part such as the valve body 73A.

  In the pressure regulating valve Vb ′ of the present embodiment, the valve opening increases when the first diaphragm D1 is pressed by the signal pressure Pa and the valve body 73A moves in the pressing direction (downward in FIG. 3). (In the pressure regulating valve V of the previous embodiment, the valve opening decreases). However, the point that the secondary pressure P2 rises when the first diaphragm D1 moves while being pressed by the signal pressure Pa coincides with the previous pressure regulating valve Vb. Therefore, also in this pressure regulating valve Vb ′, the same principle as the pressure regulating valve Vb is based on the fact that the pressure receiving area A1 of the first diaphragm D1 is larger than the pressure receiving area A2 of the second diaphragm D2. Thus, the secondary pressure P2 can be made higher than the signal pressure Ps. This pressure regulating valve Vb ′ is not used in combination with the main pressure regulating valve Va shown in FIG. 1, but is used in the fuel gas supply passage 4 alone as an alternative to the main pressure regulating valve Va. Applies to

The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the gas combustion apparatus provided with the pressure regulating valve according to the present invention can be varied in design in various ways.

The first diaphragm and the second diaphragm need only have a pressure receiving area larger than that of the second diaphragm, and their specific area values and area ratios are not limited. In the auxiliary pressure regulating valve , the intermediate chamber 75c formed between the first and second diaphragms has no particular problem in setting the atmosphere open state. However, as in Patent Document 1, the intermediate chamber 75c may be set to a negative pressure state by connecting it to the intake side of the fan to reduce the influence of atmospheric pressure.

The gas combustion apparatus according to the present invention can be configured as a combustion apparatus such as a gas fan heater or a gas stove instead of a hot water apparatus such as a hot water supply apparatus provided with a heat exchanger.

GC gas combustion device Va main pressure regulating valve Vb auxiliary pressure regulating valve (pressure regulating valve)
Vb 'Pressure regulating valve D1 First diaphragm D2 Second diaphragm Pd Signal pressure P2 Secondary pressure S1 First spring S2 Second spring 2 Gas burner 3 Fan 4 Fuel gas supply path 4a Primary side flow path (fuel gas Of supply channel)
4b Secondary channel (of fuel gas supply channel)
60 Valve body (main pressure regulating valve)
61 Diaphragm (main pressure regulating valve)
73 Valve body (for auxiliary pressure regulating valve)
73A Valve body portions 74a to 74c 1st to 3rd flow paths 77a Primary side flow path (for auxiliary pressure regulating valve)
77b Secondary channel (auxiliary pressure regulating valve)

Claims (3)

A fan for supplying combustion air to the gas burner;
A fuel gas supply path for supplying fuel gas to the gas burner;
A valve main body provided in the middle of the fuel gas supply path and capable of changing the flow rate of the fuel gas from the primary flow path to the secondary flow path of the fuel gas supply path, and interlocked with the valve main body section. A main pressure regulating valve having a diaphragm;
An auxiliary pressure regulating valve connected to the fuel gas supply path and controlling the secondary pressure of the fuel gas using the discharge pressure of the fan as a signal pressure;
A gas combustion device comprising:
The auxiliary pressure regulating valve includes a valve main body for changing the flow rate of fluid passing from the primary side flow path of the auxiliary pressure regulating valve to the secondary side flow path, and a first diaphragm receiving the signal pressure. , together with the first diaphragm is provided with a second diaphragm for receiving a secondary pressure of the fluid in the opposite direction to the direction for receiving the signal pressure, the first and second diaphragm is interlocked with each other are connected to is configured so as to change the valve opening in accordance with the movement of the first and second diaphragms,
The pressure receiving area of the first diaphragm is larger than the pressure receiving area of the second diaphragm ,
The primary flow path of the auxiliary pressure regulating valve is connected to the primary flow path of the fuel gas supply path via the first flow path,
The second flow path branched from the first flow path is provided so that the gas pressure in the second flow path is a signal pressure acting on the diaphragm of the main pressure regulating valve,
The gas combustion apparatus according to claim 1, wherein the secondary flow path of the auxiliary pressure regulating valve is connected to the secondary flow path of the fuel gas supply path via a third flow path . The gas combustion apparatus according to claim 1,
The auxiliary pressure regulating valve biases the first spring to bias the first diaphragm toward the second diaphragm, and biases the second diaphragm toward the first diaphragm. A second spring that
A gas combustion device in which the spring constants of the first and second springs are different. The gas combustion apparatus according to claim 2,
The gas combustion apparatus , wherein the first spring has a larger spring constant than the second spring .

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