Method and system for inspecting a fuel gas pressure regulator

Abstract

To make it possible to simply and suitably inspect occlusiveness of a switching valve.SOLUTION: An inspection method of a pressure regulator 1 for a fuel gas is provided. The pressure regulator comprises: a switching valve 5 opened and closed according to a pressure difference between the upstream side and the downstream side of a main flow path 2; a bypass flow path 3 for bypassing the upstream side and the downstream side of the switching valve 5; and an on-off valve 4 for opening and closing the bypass flow path 3. The inspection method comprises: a first measurement step of measuring a pressure of the downstream side or the bypass flow path 3 by making the fuel gas flow from the upstream side to the downstream side at a prescribed flow rate that can keep the closing state of the switching valve 5 in the state of the on-off valve 4 opened; a second measurement step of measuring the pressure of the downstream side or the bypass flow path 3 by making the fuel gas flow from the upstream side to the downstream side at the prescribed flow rate in the state of the on-off valve 4 closed; and a determination step of performing pass / fail determination of the switching valve 5 based on a difference between the pressure measured in the first measurement step and the pressure measured in the second measurement step.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method for inspecting a fuel gas pressure regulator and a system for inspecting a fuel gas pressure regulator. [Background technology]

[0002] A known fuel gas pressure regulator includes a switching valve that opens and closes according to the pressure difference between the upstream and downstream sides of a main flow path, a bypass flow path that bypasses the upstream and downstream sides of the switching valve in the main flow path, and a leakage detection sensor that detects minute amounts of fuel gas flowing through this bypass flow path (see, for example, Patent Document 1). The pressure regulator described in Patent Document 1 is set so that when the flow rate of the main flow path is less than a set flow rate, the switching valve is closed and a minute amount of fuel gas flows through the bypass flow path. The leakage detection sensor detects the minute amount of fuel gas in the bypass flow path, thereby detecting minute leakages of fuel gas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-200238 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the pressure regulator described in Patent Document 1, the premise is to inspect whether the switching valve is securely closed when the flow rate of the main flow path is less than the set flow rate, so it is necessary to inspect the blocking property of the switching valve. As a method for inspecting the blocking property of the switching valve, a diaphragm provided in the pressure regulator is used to increase the pressure upstream of the switching valve in the main flow path, and a pressure difference between the upstream and downstream of the switching valve in the main flow path is measured, thereby inspecting the blocking property of the switching valve.

[0005] However, this inspection method requires that the pressure in the main flow path upstream of the switching valve be adjusted to match the minute biasing force of the spring that biases the switching valve, but this adjustment is difficult. Also, since the volumes of the main flow path are different between the upstream and downstream of the switching valve, the pressure measurement is affected by temperature. Furthermore, it is necessary to open pressure measurement holes upstream and downstream of the switching valve in the main flow path.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a method for inspecting a fuel gas pressure regulator and an inspection system for a fuel gas pressure regulator that can easily and suitably inspect the blockage of a switching valve. [Means for solving the problem]

[0007] The method for inspecting a fuel gas pressure regulator according to the present invention includes the steps of: A main flow path through which fuel gas supplied to a consumer side flows, and a gas turbine installed in the main flow path is used by the consumer side to generate the above-mentioned Main channel Rather than the installation position in Pressure difference between the upstream and downstream When it exceeds a certain set value Open When the pressure difference between the upstream side and the downstream side of the installation position in the main flow path is less than the predetermined set value, closed character a switching valve in the main flow path; than the installation position a bypass flow passage that bypasses the upstream side and the downstream side, and an on-off valve that opens and closes the bypass flow passage; a leakage detector that is provided in the bypass flow passage and detects a minute amount of fuel gas flowing through the bypass flow passage when a minute amount of fuel gas leakage occurs downstream of the main flow passage and a pressure difference between the upstream side and the downstream side of an installation position of the switching valve in the main flow passage is less than the predetermined set value; A method for inspecting a fuel gas pressure regulator comprising: the law of nature , A method for inspecting a fuel gas pressure regulator for checking whether the switching valve can maintain a closed state when a pressure difference between an upstream side and a downstream side of an installation position of the switching valve in the main flow path is less than the predetermined set value, comprising: A predetermined flow rate of fuel gas is supplied to the main flow passage through the switching valve while the on-off valve is open and the switching valve is maintained in a closed state. than the installation position a first measurement step of flowing the fuel gas from the upstream side to the downstream side and measuring the pressure of the downstream side or the bypass flow path; than the installation position a second measurement step in which the pressure is measured on the downstream side or the bypass flow path by flowing the fluid from the upstream side to the downstream side; and a difference between the pressure measured in the first measurement step and the pressure measured in the second measurement step. is equal to or greater than the predetermined set value. , the switching valve Normal judgement When a difference between the pressure measured in the first measurement step and the pressure measured in the second measurement step is less than the predetermined set value, the switching valve is determined to be abnormal. and a determining step of:

[0009] Furthermore, the fuel gas pressure regulator inspection system of the present invention is a pressure regulator inspection system used to implement the pressure regulator inspection method described in claim 1 or 2, and includes an input section to which the pressure measured in the first measurement step and the pressure measured in the second measurement step are input, and a judgment section that calculates the difference between the pressure measured in the first measurement step and input to the input section and the pressure measured in the second measurement step and input to the input section, and executes the judgment step. Effect of the Invention

[0011] According to the present invention, it is possible to easily and suitably test the blocking of a switching valve. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a front view showing a pressure regulator to be inspected using a method for inspecting a pressure regulator according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a side cross-sectional view of the pressure regulator shown in FIG. [Diagram 3] FIG. 3 is a front cross-sectional view showing the pressure regulator shown in FIGS. 1 and 2, and is a front cross-sectional view showing the pressure regulator in a first measurement step of the inspection method for the pressure regulator. [Figure 4] FIG. 4 is a front cross-sectional view showing the pressure regulator shown in FIGS. 1 and 2, and is a front cross-sectional view showing the pressure regulator in a second measurement step of the inspection method for the pressure regulator. [Diagram 5] FIG. 5 is a front cross-sectional view showing a pressure regulator in a measurement step of a method for inspecting a pressure regulator according to another embodiment of the present invention. [Figure 6] FIG. 6 is a diagram for explaining an experiment for verifying the method of inspecting a pressure regulator according to one embodiment and other embodiments of the present invention. [Figure 7] FIG. 7 is a table showing the experimental results. [Figure 8] FIG. 8 is a diagram showing an outline of an inspection system for a pressure regulator according to an embodiment of the present invention. [Figure 9]FIG. 9 is a schematic diagram showing an inspection system for a pressure regulator according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described below along with preferred embodiments. Note that the present invention is not limited to the embodiments shown below, and the embodiments can be appropriately modified within the scope of the present invention. In addition, in the embodiments shown below, some configurations are omitted from illustration and description, but for the details of the omitted technologies, publicly known or well-known technologies are appropriately applied within the scope of not causing any contradiction with the contents described below.

[0014] 1 is a front view showing a pressure regulator 1 to be inspected using a method for inspecting a pressure regulator 1 according to one embodiment of the present invention. As shown in this figure, the pressure regulator 1 includes a primary regulator 10, a secondary regulator 20, a leak detector 30, and piping 40. The pressure regulator 1 also includes a main flow path 2, a bypass flow path 3, an on-off valve 4, and a switching valve 5 (see FIGS. 2 to 6).

[0015] The upstream portion of the main flow path 2 constitutes a part of the secondary regulator 20, and the downstream portion of the main flow path 2 is constituted by a pipe 40. A switching valve 5 is provided at the boundary between the upstream portion and the downstream portion of the main flow path 2. This switching valve 5 opens and closes according to the pressure difference between the upstream side and the downstream side of the main flow path 2.

[0016] The bypass flow path 3 is a flow path that bypasses the upstream side and downstream side of the switching valve 5 in the main flow path 2. An on-off valve 4 and a lever 6 are provided in this bypass flow path 3. By operating the lever 6, the on-off valve 4 is switched between an open state and a closed state, and the bypass flow path 3 is opened and closed.

[0017] The primary regulator 10 is a so-called original regulator with a switching function, and is connected to LP gas cylinders (not shown) on the left and right. This primary regulator 10 is equipped with a switching lever 11. By operating this switching lever 11, it is possible to select from which of the left and right LP gas cylinders (not shown) the fuel gas is introduced.

[0018] Fig. 2 is a side cross-sectional view showing the pressure regulator 1 shown in Fig. 1. As shown in this figure, the primary regulator 10 has a diaphragm 12 and the like inside. The primary regulator 10 performs primary pressure reduction to reduce high-pressure fuel gas to medium pressure by opening and closing an internal valve body in response to the operation of the diaphragm 12. The fuel gas that has been primarily reduced in pressure by the primary regulator 10 is supplied to the secondary regulator 20.

[0019] The secondary regulator 20 performs secondary pressure reduction to reduce the medium-pressure fuel gas supplied from the primary regulator 10 to a low pressure. The secondary regulator 20 includes a piping section 21 constituting the upstream portion of the main flow path 2, a diaphragm 22 arranged facing the gas chamber G communicating with the piping section 21, a pressure reducing valve 25, and the like. The secondary regulator 20 performs secondary pressure reduction by opening and closing the pressure reducing valve 25 in response to the operation of the diaphragm 22. The fuel gas secondarily reduced in pressure by the secondary regulator 20 is supplied to the piping 40 on the downstream side.

[0020] In the secondary regulator 20, when the flow rate of the fuel gas is less than the set flow rate, the switching valve 5 is closed, causing the fuel gas to flow into the bypass flow path 3. On the other hand, in the secondary regulator 20, when the flow rate of the fuel gas is equal to or greater than the set flow rate, the switching valve 5 is opened, causing the fuel gas to flow into both the main flow path 2 and the bypass flow path 3.

[0021] Secondary regulator 20 includes piping section 21, diaphragm 22, coil spring 23, link mechanism 24, pressure reducing valve 25, and housing 26. Housing 26 includes cylindrical coil accommodating section 26A that accommodates coil spring 23, and disk-shaped air / gas chamber section 26B that constitutes air chamber A and gas chamber G. Coil accommodating section 26A protrudes from the center of air / gas chamber section 26B, and the central axis of coil accommodating section 26A is coaxial with the central axis of air / gas chamber section 26B.

[0022] The coil spring 23 is a compression coil spring, and is accommodated in the coil accommodating portion 26A in a state in which it can expand and contract in the axial direction of the coil accommodating portion 26A. One end of the coil spring 23 is fixed to the tip side of the coil accommodating portion 26A. The diaphragm 22 is an elastically deformable disk that separates the inside of the air / gas chamber 26B into an air chamber A on the coil accommodating portion 26A side and a gas chamber G on the piping portion 21 side. The other end of the coil spring 23 is attached to the center of the diaphragm 22. The peripheral portion of the diaphragm 22 is attached to the inner peripheral wall of the air / gas chamber 26B.

[0023] When the pressure in the gas chamber G increases, the diaphragm 22 deforms so as to bulge toward the air chamber A against the elastic force of the coil spring 23. On the other hand, when the pressure in the gas chamber G decreases, the diaphragm 22 is biased toward the gas chamber G by the elastic force of the coil spring 23 and elastically returns to its original state.

[0024] The link mechanism 24 includes a first shaft portion 24A, a second shaft portion 24B, and an L-shaped link 24C. The first shaft portion 24A is attached to the center of the diaphragm 22. The first shaft portion 24A is arranged coaxially with the center of the coil spring 23 and the coil accommodating portion 26A, and protrudes from the center of the diaphragm 22 into the gas chamber G. On the other hand, one end of the second shaft portion 24B is attached to the center of the valve body 25A of the pressure reducing valve 25. The second shaft portion 24B is arranged coaxially with the central axis of the piping portion 21, and protrudes from the center of the valve body 25A of the pressure reducing valve 25 into the gas chamber G.

[0025] The link 24C includes a first link portion 24C1 and a second link portion 24C2 that is longer than the first link portion 24C1. The first link portion 24C1 is disposed so as to straddle the inside of the piping portion 21 and the inside of the housing 26 through a hole 21H formed in the piping portion 21. One end of the first link portion 24C1 is connected to the other end of the second shaft portion 24B, and the other end of the first link portion 24C1 is integrally formed with one end of the second link portion 24C2. A central portion of the first link portion 24C1 is rotatably supported on the periphery of the hole 21H in the piping portion 21.

[0026] The other end of the second link portion 24C2 is connected to the tip of the first shaft portion 24A. When the diaphragm 22 is deformed to bulge toward the air chamber A due to an increase in pressure in the gas chamber G, the other end of the second link portion 24C2 is displaced toward the air chamber A, and one end of the first link portion 24C1 is displaced in a direction away from the valve seat 25B of the pressure reducing valve 25. At this time, when the diaphragm 22 reaches a predetermined state, the valve body 25A is in a closed state in which it is pressed against the valve seat 25B, and the introduction of the fuel gas into the gas chamber G is blocked. On the other hand, when the pressure in the gas chamber G decreases and the diaphragm 22 elastically returns from the predetermined state to the gas chamber G side, the other end of the second link portion 24C2 is displaced toward the piping portion 21, and one end of the first link portion 24C1 is displaced toward the valve seat 25B of the pressure reducing valve 25. At this time, the valve body 25A is separated from the valve seat 25B to an open state, and the fuel gas is introduced into the gas chamber G. The secondary regulator 20 reduces the pressure of the fuel gas by repeatedly introducing the fuel gas into the gas chamber G and blocking the introduction of the fuel gas into the gas chamber G.

[0027] The pipe 40 is disposed coaxially with the pipe section 21. The upstream end of the pipe 40 is connected to the downstream end of the pipe section 21. A switching valve 5 is provided at the connection between the pipe 40 and the pipe section 21. The switching valve 5 includes a valve body 51, a valve seat 52, a shaft section 53, a guide 54, and a coil spring 55.

[0028] Valve seat 52 is provided at the connection between piping 40 and piping section 21, and valve element 51 is disposed downstream of valve seat 52. Shaft portion 53 is attached to the center of valve element 51 and protrudes from valve element 51 toward piping section 21 through an insertion hole in valve seat 52. A flange portion 53A is provided at the tip of shaft portion 53. Guide 54 is provided at the connection between piping 40 and piping section 21, and guides shaft portion 53 along the axial direction of piping section 21.

[0029] The coil spring 55 is a compression coil spring, and is provided in a state of being sandwiched between the flange portion 53A and the guide 54. When the pressure difference between the piping portion 21 and the piping 40 is less than a predetermined set value, the switching valve 5 is in a closed state with the valve body 51 pressed against the valve seat 52, and the flow of fuel gas from the piping portion 21 to the piping 40 is blocked. On the other hand, when the pressure difference between the piping portion 21 and the piping 40 is equal to or greater than the above-mentioned predetermined set value, the switching valve 5 is in an open state with the valve body 51 separated from the valve seat 52 against the elastic force of the coil spring 55, and the fuel gas flows from the piping portion 21 to the piping 40.

[0030] Figures 3 and 4 are front cross-sectional views showing the pressure regulator 1 shown in Figure 1. As shown in these figures, the leak detector 30 includes a bypass flow path 3, an on-off valve 4, a lever 6 (see Figure 1), a leak detection sensor 31, and a pressure sensor 32, and detects a minute leakage of fuel gas occurring downstream of the secondary regulator 20 (see Figure 2) by detecting a minute flow rate of fuel gas flowing through the bypass flow path 3 with the leak detection sensor 31.

[0031] The leak detector 30 includes a downstream bypass pipe 33 and an upstream bypass pipe 34 which configure the bypass flow path 3. The upstream end of the upstream bypass pipe 34 is connected between the pressure reducing valve 25 and the switching valve 5 in the piping section 21, and the downstream end of the upstream bypass pipe 34 is connected to the upstream end of the downstream bypass pipe 33. In addition, the downstream end of the downstream bypass pipe 33 is connected to the pipe 40 downstream of the switching valve 5. An opening / closing valve 4 and a lever 6 are provided in the upstream bypass pipe 34.

[0032] When the on-off valve 4 is in an open state and the pressure difference between the piping section 21 and the piping 40 is equal to or greater than a predetermined set value, the switching valve 5 is opened, and the fuel gas flows directly from the piping section 21 to the piping 40, and also flows from the piping section 21 to the piping 40 via the bypass flow path 3. On the other hand, when the on-off valve 4 is in an open state and the pressure difference between the piping section 21 and the piping 40 is less than a predetermined set value, the switching valve 5 is closed, and the fuel gas only flows from the piping section 21 to the piping 40 via the bypass flow path 3.

[0033] An example of the downstream bypass piping 33 is a multilayer unit. This multilayer unit is a rectangular tubular pipe having a plurality of flow dividing plates therein. An example of the leak detection sensor 31 is an ultrasonic flow sensor. This ultrasonic flow sensor includes two pairs of ultrasonic transmitters and receivers, and a calculation device that calculates the flow rate from the propagation time of ultrasonic signals transmitted and received by the two pairs of ultrasonic transmitters and receivers. The pressure sensor 32 measures the pressure of the downstream bypass piping 33.

[0034] When the pressure difference between the piping section 21 and the piping 40 becomes equal to or greater than a predetermined set value due to the use of fuel gas on the consumer side, the switching valve 5 opens, and the fuel gas is supplied to the consumer side from the piping section 21 directly or via the bypass flow path 3. On the other hand, when a slight leakage of fuel gas occurs downstream of the piping 40 and the pressure difference between the piping section 21 and the piping 40 is less than a predetermined set value, a minute flow rate of fuel gas flows from the piping section 21 to the piping 40 via the bypass flow path 3. At this time, the minute flow rate of fuel gas flowing through the bypass flow path 3 is detected by the leakage detection sensor 31, and the minute leakage of fuel gas is detected.

[0035] Here, in order for the leak detector 30 to detect minute leaks of fuel gas, it is a prerequisite that the switching valve 5 maintains a closed state when the pressure difference between the piping section 21 and the piping 40 is less than a predetermined set value. Therefore, it is necessary to perform an inspection to check whether the switching valve 5 can normally maintain a closed state. Below, an inspection method for determining whether the pressure regulator 1, and in particular the switching valve 5, is good or bad will be described.

[0036] Fig. 3 shows the state of the pressure regulator 1 in a first measurement step of the inspection method of the pressure regulator 1 of this embodiment, and Fig. 4 shows the state of the pressure regulator 1 in a second measurement step of the inspection method of the pressure regulator 1 of this embodiment. As shown in these figures, in the inspection method of the pressure regulator 1 of this embodiment, a pressure gauge 8 is connected to the downstream side of the piping 40 to measure the outlet pressures P1, P2 of the pressure regulator 1, and the fuel gas is burned in a gas stove 9 on the consumer side to cause the fuel gas to flow from the pressure regulator 1 to the consumer side. Note that the outlet pressures P1, P2 of the pressure regulator 1 may be referred to as the pressures P1, P2 of the main flow path 2.

[0037] As shown in Fig. 3, in the first measurement step, the on-off valve 4 is opened and fuel gas is burned in a gas stove 9, causing the fuel gas to flow from the pressure regulator 1 to the consumer side. Here, the flow rate of the fuel gas is set to a flow rate (e.g., 50 to 100 L / h) at which the switching valve 5 is maintained in a closed state when the on-off valve 4 is open. At this time, the outlet pressure P1 of the pressure regulator 1 is measured by the pressure gauge 8.

[0038] 4, in the second measurement step, the on-off valve 4 is switched to a closed state while maintaining the flow rate of the fuel gas in the first measurement step. At this time, the outlet pressure P2 of the pressure regulator 1 is measured by the pressure gauge 8.

[0039] Next, in the judgment step, the quality of the switching valve 5 is judged based on the difference between the outlet pressure P1 measured in the first measurement step and the outlet pressure P2 measured in the second measurement step. Specifically, when the difference (P1-P2) between the outlet pressure P1 and the outlet pressure P2 is equal to or greater than a predetermined value (e.g., 0.1 kPa), the switching valve 5 is judged to be normal (i.e., there is no problem with obstruction), and when the difference (P1-P2) between the outlet pressure P1 and the outlet pressure P2 is less than the predetermined value, the switching valve 5 is judged to be abnormal (i.e., there is a problem with obstruction).

[0040] Here, if there is no problem with the blocking of the switching valve 5, the fuel gas does not flow from the piping section 21 to the piping 40 unless the switching valve 5 changes to an open state in the second measurement step. Therefore, the outlet pressure P2 measured in the second measurement step is lower than the outlet pressure P1 measured in the first measurement step. In contrast, if there is a problem with the blocking of the switching valve 5, the fuel gas flows from the piping section 21 to the piping 40 in the second measurement step even if there is no change in the state of the switching valve 5. Therefore, the outlet pressure P2 measured in the second measurement step does not change from the outlet pressure P1 measured in the first measurement step, or changes only slightly (for example, less than 0.1 kPa).

[0041] Therefore, in the inspection method for the pressure regulator 1 of this embodiment, if the difference (P1-P2) between the outlet pressure P1 measured in the first measurement step and the outlet pressure P2 measured in the second measurement step is 0 or is small (e.g., less than 0.1 kPa), it is determined that the blocking property of the switching valve 5 is poor, and the inspected pressure regulator 1 is rejected.

[0042] In addition, the pressures P1', P2' of the bypass flow path 3 are measured by the pressure sensor 32 of the leak detector 30 in the first measurement step and the second measurement step, and if the difference between these (P1'-P2') is 0 or is small (for example, less than 0.1 kPa), it is determined that the blocking ability of the switching valve 5 is poor and the inspected pressure regulator 1 is rejected.

[0043] Next, an inspection method for pressure regulator 1 according to another embodiment of the present invention will be described. Fig. 5 is a front cross-sectional view showing pressure regulator 1 in a measurement step of the inspection method for pressure regulator 1 according to another embodiment of the present invention. As shown in this figure, in this embodiment, a flow sensor 101 that measures the flow rate of fuel gas flowing from piping 40 to the consumer side is installed downstream of piping 40.

[0044] In the inspection method for the pressure regulator 1 of this embodiment, in the measurement step, the on-off valve 4 is opened and fuel gas is burned by the gas stove 9, thereby causing the fuel gas to flow from the pressure regulator 1 to the consumer side. As in the above-mentioned embodiment, the flow rate of the fuel gas is set to a flow rate (e.g., 50 to 100 L / h) at which the switching valve 5 is maintained in a closed state when the on-off valve 4 is open. At this time, the flow rate F1 of the fuel gas flowing from the pipe 40 to the consumer side is measured by the flow sensor 101, and the flow rate F2 of the fuel gas flowing through the bypass flow path 3 is measured by the leak detection sensor 31.

[0045] Next, in the judgment step, the quality of the switching valve 5 is judged based on the difference between the flow rate F1 in the main flow path 2 and the flow rate F2 in the bypass flow path 3 measured in the measurement step. Specifically, the difference (second value (F1'-F2')) between the flow rate F1' in the main flow path 2 and the flow rate F2' in the bypass flow path 3 when the switching valve 5 and the on-off valve 4 are opened and the same flow rate of fuel gas is flowed from the pressure regulator 1 to the consumer side is obtained in advance, and the difference (first value (F1-F2)) between the flow rate F1 in the main flow path 2 and the flow rate F2 in the bypass flow path 3 measured in the measurement step is compared with the second value (F1'-F2'). If the comparison shows that the first value (F1-F2) is significantly smaller than the second value (F1'-F2') (for example, 1 / 2 to 1 / 10 or less), it is determined that there is no problem with the obstruction of the switching valve 5, and if there is no significant difference between the first value (F1-F2) and the second value (F1'-F2') (for example, the first value (F1-F2) is greater than 1 / 2 to 1 / 10 times the second value (F1'-F2')), it is determined that there is a problem with the obstruction of the switching valve 5.

[0046] Here, if there is no problem with the blocking property of the switching valve 5, the fuel gas will not flow from the piping section 21 to the piping 40 without passing through the bypass flow path 3 unless the switching valve 5 is changed to an open state in the measurement step. Therefore, the flow rate F2 of the bypass flow path 3 measured in the measurement step is larger than the flow rate F2' of the bypass flow path 3 when the switching valve 5 is in an open state. On the other hand, if there is a problem with the blocking property of the switching valve 5, the fuel gas will flow directly from the piping section 21 to the piping 40 in the measurement step even if the state of the switching valve 5 does not change. Therefore, the flow rate F2 of the bypass flow path 3 measured in the measurement step does not have a significant difference from the flow rate F2' of the bypass flow path 3 when the switching valve 5 is in an open state.

[0047] Therefore, in the inspection method for the pressure regulator 1 of this embodiment, if there is no significant difference between a first value (F1-F2), which is the difference between the flow rate F1 in the main flow path 2 and the flow rate F2 in the bypass flow path 3 measured in the measurement step, and a second value (F1'-F2'), which is the difference between the flow rate F1' in the main flow path 2 and the flow rate F2' in the bypass flow path 3 when the switching valve 5 is in the open state, the blocking property of the switching valve 5 is determined to be poor, and the inspected pressure regulator 1 is deemed to fail.

[0048] Hereinafter, an experiment conducted to verify the inspection method of the pressure regulator 1 according to one embodiment of the present invention and other embodiments will be described. Fig. 6 is a diagram for explaining the experiment.

[0049] As shown in Fig. 6, in this experiment, a main flow path meter 102 and a flow rate control valve 103 were installed downstream of the pipe 40. The main flow path meter 102 measures the flow rate and pressure of the fuel gas flowing downstream from the pipe 40. The flow rate control valve 103 adjusts the flow rate of the fuel gas flowing downstream from the pipe 40. In this experiment, the inlet pressure of the pressure regulator 1 was set to 0.1 MPa, and the switch lever 11 was used to select the LP gas cylinder on the right.

[0050] 7 is a table showing the experimental results. As shown in the table, in this experiment, measurements of the flow rate of the fuel gas by the main passage meter 102 and the leak detection sensor 31, and measurements of the pressure by the main passage meter 102 and the pressure sensor 32 were carried out under first to eighth conditions.

[0051] In the first to fourth conditions, the switching valve 5 was closed, and in the fifth to eighth conditions, the switching valve 5 was opened. The flow rate of the fuel gas flowing downstream from the pipe 40 was changed by the flow rate control valve 103 to 0 [L / h] in the first and fifth conditions, 3 [L / h] in the second and sixth conditions, 50 [L / h] in the third and seventh conditions, and 100 [L / h] in the fourth and eighth conditions. In the closed state of the switching valve 5, the gap between the valve body 51 and the valve seat 52 was 0 mm, and in the open state of the switching valve 5, the gap between the valve body 51 and the valve seat 52 was about 0.08 mm.

[0052] Then, under each condition, the on-off valve 4 was opened, and the flow rate of the fuel gas was measured by the main flow path meter 102 and the leak detection sensor 31, and the pressure was measured by the main flow path meter 102 and the pressure sensor 32. Also, under each condition, the on-off valve 4 was closed, and the flow rate of the fuel gas was measured by the main flow path meter 102, and the pressure was measured by the main flow path meter 102 and the pressure sensor 32.

[0053] Then, for the first to eighth conditions, the difference between the flow rate of the main flow path 2 measured by the main flow path meter 102 when the on-off valve 4 is in the open state and the flow rate of the bypass flow path 3 measured by the leak detection sensor 31 was calculated. Moreover, for the second to fourth and sixth to eighth conditions, the difference between the pressure of the main flow path 2 measured by the main flow path meter 102 when the on-off valve 4 is in the open state and the pressure of the main flow path 2 measured by the main flow path meter 102 when the on-off valve 4 is in the closed state was calculated. Furthermore, for the second to fourth and sixth to eighth conditions, the difference between the pressure of the bypass flow path 3 measured by the pressure sensor 32 when the on-off valve 4 is in the open state and the pressure of the bypass flow path 3 measured by the pressure sensor 32 when the on-off valve 4 is in the closed state was calculated.

[0054] First, the difference between the flow rate of the main flow path 2 and the flow rate of the bypass flow path 3 when the on-off valve 4 is in an open state (hereinafter referred to as the flow rate difference) will be examined. No significant difference in the flow rate difference was confirmed between the first condition and the fifth condition, in which the set flow rate of the flow rate adjustment valve 103 is 0 [L / h]. However, significant differences in the flow rate difference were confirmed between the second condition and the sixth condition, in which the set flow rate of the flow rate adjustment valve 103 is 3 [L / h], between the third condition and the seventh condition, in which the set flow rate of the flow rate adjustment valve 103 is 50 [L / h], and between the fourth condition and the eighth condition, in which the set flow rate of the flow rate adjustment valve 103 is 100 [L / h]. Specifically, it was confirmed that the flow rate difference under the second condition was significantly smaller, about 1 / 5 of the flow rate difference under the sixth condition, the flow rate difference under the third condition was significantly smaller, about 1 / 10 of the flow rate difference under the seventh condition, and the flow rate difference under the fourth condition was significantly smaller, about 1 / 10 of the flow rate difference under the eighth condition.

[0055] From the above, the effectiveness of the inspection method has been demonstrated, in which fuel gas is allowed to flow through the main flow path 2 and the bypass flow path 3 with the on-off valve 4 in the open state, the flow rate F1 in the main flow path 2 and the flow rate F2 in the bypass flow path 3 are measured, and the difference (F1-F2) between the flow rate F1 in the main flow path 2 and the flow rate F2 in the bypass flow path 3 is compared with the difference (F1'-F2') between the flow rate F1' in the main flow path 2 and the flow rate F2' in the bypass flow path 3 when the switching valve 5 is in the open state, and if there is a significant difference between these, it is determined that there is no problem with the blocking property of the switching valve 5, and if there is no significant difference between these, it is determined that there is a problem with the blocking property of the switching valve 5.

[0056] Next, the difference between the pressure in the main flow path 2 when the on-off valve 4 is in an open state and the pressure in the main flow path 2 when the on-off valve 4 is in a closed state (hereinafter referred to as the pressure difference in the main flow path 2) will be examined. It was confirmed that there was a significant difference in the pressure difference in the main flow path 2 between the second and sixth conditions where the set flow rate of the flow control valve 103 is 3 [L / h], between the third and seventh conditions where the set flow rate of the flow control valve 103 is 50 [L / h], and between the fourth and eighth conditions where the set flow rate of the flow control valve 103 is 100 [L / h]. Specifically, in addition to the pressure difference in the main flow path 2 under the fifth to eighth conditions being less than 0.1 [kPa] and equal to 0, it was confirmed that the pressure difference in the main flow path 2 under the second condition was significantly larger than the pressure difference in the main flow path 2 under the sixth condition, being at least about 0.1 [kPa] larger, the pressure difference in the main flow path 2 under the third condition was significantly larger than the pressure difference in the main flow path 2 under the seventh condition, being at least about 0.3 [kPa] larger, and the pressure difference in the main flow path 2 under the fourth condition was significantly larger than the pressure difference in the main flow path 2 under the eighth condition, being at least about 0.3 [kPa] larger.

[0057] From the above, the effectiveness of the inspection method has been demonstrated, in which the on-off valve 4 is opened, fuel gas is allowed to flow through the main flow path 2 and the bypass flow path 3, and pressure P1 in the main flow path 2 is measured, and the on-off valve 4 is closed, fuel gas is allowed to flow through the main flow path 2, and pressure P2 in the main flow path 2 is measured, and if the difference between pressure P1 and pressure P2 (P1-P2) is significant, it is determined that there is no problem with the blocking property of the switching valve 5, and if the difference between pressure P1 and pressure P2 (P1-P2) is equal to 0 or is small (for example, less than 0.1 kPa), it is determined that there is a problem with the blocking property of the switching valve 5.

[0058] Next, the difference between the pressure in the bypass flow path 3 when the on-off valve 4 is in an open state and the pressure in the bypass flow path 3 when the on-off valve 4 is in a closed state (hereinafter referred to as the pressure difference in the bypass flow path 3) will be examined. It was confirmed that there was a significant difference in the pressure difference in the bypass flow path 3 between the second condition and the sixth condition where the set flow rate of the flow rate adjustment valve 103 is 3 [L / h], between the third condition and the seventh condition where the set flow rate of the flow rate adjustment valve 103 is 50 [L / h], and between the fourth condition and the eighth condition where the set flow rate of the flow rate adjustment valve 103 is 100 [L / h]. Specifically, in addition to the pressure difference of the bypass flow path 3 under the fifth to eighth conditions being less than 0.1 [kPa] and equal to 0, it was confirmed that the pressure difference of the bypass flow path 3 under the second condition was significantly larger than the pressure difference of the bypass flow path 3 under the sixth condition, being 0.1 [kPa] or more, the pressure difference of the bypass flow path 3 under the third condition was significantly larger than the pressure difference of the bypass flow path 3 under the seventh condition, being 0.3 [kPa] or more, and the pressure difference of the bypass flow path 3 under the fourth condition was significantly larger than the pressure difference of the bypass flow path 3 under the eighth condition, being 0.3 [kPa] or more.

[0059] From the above, the effectiveness of the inspection method has been demonstrated, in which the on-off valve 4 is opened, fuel gas is allowed to flow through the main flow path 2 and the bypass flow path 3, and pressure P1' in the bypass flow path 3 is measured, and the on-off valve 4 is closed, fuel gas is allowed to flow through the main flow path 2, and pressure P2' in the bypass flow path 3 is measured, and if the difference between pressure P1' and pressure P2' (P1'-P2') is significant, it is determined that there is no problem with the blocking property of the switching valve 5, and if the difference between pressure P1' and pressure P2' (P1'-P2') is 0 or is small (for example, less than 0.1 [kPa]), it is determined that there is a problem with the blocking property of the switching valve 5.

[0060] 8 is a diagram showing an outline of an inspection system 100 for a pressure regulator 1 according to one embodiment of the present invention. As shown in this figure, the inspection system 100 includes a terminal 110 to which pressures P1', P2' measured by pressure sensor 32 are input and which judges whether the pressure regulator 1 is good or bad based on the input pressures P1', P2'.

[0061] Terminal 110 is a personal computer, a mobile terminal, or the like, and includes an input unit 111 to which pressures P1', P2' are input from pressure sensor 32, a processing unit 112 that judges the quality of pressure regulator 1 based on pressures P1', P2' input to input unit 111, an operation unit 113, and a display unit 114. Terminal 110 may include a touch panel that integrates the functions of operation unit 113 and display unit 114.

[0062] This terminal 110 and the pressure sensor 32 can be connected by wire or wirelessly, and the pressures P1', P2' measured by the pressure sensor 32 are input to the input unit 111. Note that the pressures P1', P2' may be input to the input unit 111 by an input operation by an operator.

[0063] The processing unit 112 causes the display unit 114 to display a display instructing the operator to perform a first measurement step of opening the on-off valve 4 and measuring the pressure P1'. The operator performs the first measurement step in accordance with the instructions displayed on the display unit 114. When this first measurement step is performed, the pressure P1' in the bypass flow path 3 is measured by the pressure sensor 32, and this pressure P1' is input to the input unit 111. The processing unit 112 causes the pressure P1' input to the input unit 111 to be stored in a memory unit (not shown).

[0064] The processing unit 112 causes the display unit 114 to display a display instructing the operator to perform a second measurement step of measuring the pressure P2' by closing the on-off valve 4. The operator performs the second measurement step in accordance with the instructions displayed on the display unit 114. When the second measurement step is performed, the pressure P2' in the bypass flow path 3 is measured by the pressure sensor 32, and this pressure P2' is input to the input unit 111. The processing unit 112 causes the pressure P2' input to the input unit 111 to be stored in the memory unit.

[0065] The processing unit 112 judges whether the difference (P1'-P2') between the pressure P1' and the pressure P2' stored in the memory unit is equal to or greater than a predetermined threshold (e.g., 0.1 [kPa]), and judges the pressure regulator 1 to be acceptable if it is equal to or greater than the predetermined threshold, and judges the pressure regulator 1 to be unacceptable if it is less than the predetermined threshold. The processing unit 112 causes the display unit 114 to display the judgment result of the pressure regulator 1.

[0066] In addition, a pressure gauge 8 may be used instead of the pressure sensor 32, and the pressures P1, P2 in the main flow path 2 measured by the pressure gauge 8 may be input to the input unit 111, and the processing unit 112 may determine whether the pressure regulator 1 is good or bad based on the pressures P1, P2 in the main flow path 2.

[0067] 9 is a diagram showing an outline of an inspection system 200 for a pressure regulator 1 according to another embodiment of the present invention. As shown in this diagram, the inspection system 200 includes a terminal 210 to which a flow rate F1 in the main flow path 2 measured by the flow sensor 101 and a flow rate F2 in the bypass flow path 3 measured by the leak detection sensor 31 are input, and which judges whether the pressure regulator 1 is good or bad based on the input flow rates F1 and F2.

[0068] The terminal 210 is a personal computer, a mobile terminal, or the like, and includes an input unit 211 to which the flow rate F1 is input from the flow sensor 101 and the flow rate F2 is input from the leak detection sensor 31, a processing unit 212 that judges the quality of the pressure regulator 1 based on the flow rates F1 and F2 input to the input unit 211, an operation unit 213, and a display unit 214. The terminal 210 may include a touch panel that integrates the functions of the operation unit 213 and the display unit 214.

[0069] This terminal 210 can be connected to the flow rate sensor 101 and the leakage detection sensor 31 by wire or wirelessly, and a flow rate F1 of the main flow path 2 measured by the flow rate sensor 101 and a flow rate F2 of the bypass flow path 3 measured by the leakage detection sensor 31 are input to an input unit 211. The flow rates F1 and F2 may be input to the input unit 211 by an input operation by an operator.

[0070] The processing unit 212 causes the display unit 214 to display a display instructing the implementation of a measurement step in which the on-off valve 4 is opened and the flow rates F1 and F2 are measured. The operator implements the measurement step in accordance with the instructions displayed on the display unit 214. When this measurement step is implemented, the flow rate F1 of the main flow path 2 is measured by the flow sensor 101, and this flow rate F1 is input to the input unit 211. In addition, the leakage detection sensor 31 measures the flow rate F2 of the bypass flow path 3, and this flow rate F2 is input to the input unit 211.

[0071] The processing unit 212 judges whether the difference (F1-F2) between the flow rates F1 and F2 input to the input unit 211 is less than a predetermined threshold (for example, less than 10% of the flow rate F1), and judges the pressure regulator 1 to be acceptable if it is less than the predetermined threshold, and judges the pressure regulator 1 to be unacceptable if it is equal to or greater than the predetermined threshold. The processing unit 212 causes the display unit 214 to display the judgment result for the pressure regulator 1.

[0072] The present invention has been described above based on the above embodiment, but the present invention is not limited to the above embodiment, and modifications may be made without departing from the spirit of the present invention, and publicly known or well-known technologies may be combined as appropriate. [Explanation of symbols]

[0073] 1 Pressure Regulator 2 Main channel 3 Bypass flow path 4. On-off valve 5. Switching valve 100 Inspection Systems 111 Input section 112 Processing section (judgment section) 200 Inspection System 211 Input section 212 Processing section (judgment section) F1 flow rate F2 flow rate F1' flow rate F2' flow rate P1 Pressure P2 Pressure P1' Pressure P2' Pressure

Claims

1. An inspection method for a fuel gas pressure regulator comprising: a main flow path through which fuel gas supplied to a consumer side flows; a changeover valve installed in the main flow path and opening when a pressure difference between the upstream and downstream sides of an installation position in the main flow path becomes equal to or greater than a predetermined set value due to use of fuel gas at the consumer side and closing when the pressure difference between the upstream and downstream sides of an installation position in the main flow path is less than the predetermined set value; a bypass flow path bypassing the upstream and downstream sides of an installation position of the changeover valve in the main flow path; an on-off valve for opening and closing the bypass flow path; and a leak detector installed in the bypass flow path and detecting minute amounts of fuel gas flowing through the bypass flow path when a minute leakage of fuel gas occurs downstream of the main flow path and the pressure difference between the upstream and downstream sides of an installation position of the changeover valve in the main flow path is less than the predetermined set value, A method for inspecting a fuel gas pressure regulator for checking whether the switching valve can maintain a closed state when a pressure difference between an upstream side and a downstream side of an installation position of the switching valve in the main flow path is less than the predetermined set value, comprising: a first measurement step of flowing a predetermined flow rate of fuel gas, with the on-off valve being open and the switching valve being maintained in a closed state, from an upstream side to a downstream side of an installation position of the switching valve in the main flow path to measure a pressure on the downstream side or in the bypass flow path; a second measurement step of flowing the fuel gas at the predetermined flow rate from an upstream side to a downstream side of an installation position of the switching valve in the main flow path while the on-off valve is closed, and measuring a pressure on the downstream side or in the bypass flow path; a determining step of determining that the switching valve is normal when a difference between the pressure measured in the first measuring step and the pressure measured in the second measuring step is equal to or greater than the predetermined set value, and determining that the switching valve is abnormal when a difference between the pressure measured in the first measuring step and the pressure measured in the second measuring step is less than the predetermined set value; A method for inspecting a fuel gas pressure regulator comprising:

2. 2. The method for inspecting a fuel gas pressure regulator according to claim 1, wherein the predetermined set value is 0.1 kPa.

3. A pressure regulator inspection system used to carry out the pressure regulator inspection method according to claim 1 or 2, comprising: an input unit to which the pressure measured in the first measuring step and the pressure measured in the second measuring step are input; a determination unit that calculates a difference between the pressure measured in the first measurement step and input to the input unit and the pressure measured in the second measurement step and input to the input unit, and executes the determination step; A pressure regulator inspection system comprising:

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