Method for inspecting fuel gas pressure regulators, and inspection system for fuel gas pressure regulators.

Abstract

To make it easy and convenient to check for blockage of a switching valve.SOLUTION: An inspection method for a fuel gas pressure regulator 1 including a switching valve 5 that opens and closes depending on the pressure difference between the upstream and downstream sides of a main flow path 2, a bypass flow path 3 that bypasses the upstream and downstream sides of the switching valve 5 in the main flow path 2, and an on-off valve 4 that opens and closes the bypass flow path 3, includes a measurement step of flowing a predetermined flow rate of fuel gas from the upstream side of the switching valve 5 in the main flow path 2 to the downstream side thereof with the on-off valve 4 open and the switching valve 5 maintained in a closed state, to measure the flow rate on the downstream side and the flow rate of the bypass flow path 3, and a determination step of determining the quality of the switching valve 5 based on the difference between the flow rate of the main flow path 2 and the flow rate of the bypass flow path 3 measured in the measurement step.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] As a pressure regulator for fuel gas, there is known one including a switching valve that opens and closes according to the pressure difference between the upstream side and the downstream side of the main flow path, a bypass flow path that bypasses the upstream side and the downstream side of the switching valve in the main flow path, and a leakage detection sensor that detects minute fuel gas flowing through this bypass flow path (see, for example, Patent Document 1). In the pressure regulator described in Patent Document 1, when the flow rate in the main flow path is less than the set flow rate, the switching valve is in a closed state and a minute flow rate of fuel gas is set to flow through the bypass flow path. The leakage detection sensor detects the minute flow rate of fuel gas in this bypass flow path, thereby detecting minute leakage of fuel gas.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the pressure regulator described in Patent Document 1, since it is premised on inspecting that the switching valve surely closes when the flow rate in the main flow path is less than the set flow rate, 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 method of inspecting the blocking property of the switching valve by raising the pressure on the upstream side of the switching valve in the main flow path using a diaphragm provided in the pressure regulator and measuring the pressure difference between the upstream side and the downstream side of the switching valve in the main flow path can be considered.

[0005] However, this inspection method requires adjusting the pressure upstream of the switching valve in the main flow path to match the minute biasing force of the spring that biases the switching valve, but this adjustment is difficult. Furthermore, because the volume differs between the upstream and downstream sides of the switching valve in the main flow path, temperature affects the pressure measurement. In addition, it is necessary to drill pressure-sensing holes on both the upstream and downstream sides of the switching valve in the main flow path.

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

[0007] The present invention relates to a method for inspecting a fuel gas pressure regulator, comprising: 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 an on-off valve that opens and closes the bypass flow path, comprising: a measurement step in which, with the on-off valve open, a predetermined flow rate of fuel gas maintained in a closed state by flowing it from the upstream side to the downstream side of the switching valve in the main flow path, and measuring the flow rate on the downstream side and the flow rate in the bypass flow path; and a determination step in which the quality of the switching valve is determined based on the difference between the flow rate of the main flow path and the flow rate of the bypass flow path measured in the measurement step.

[0008] The fuel gas pressure regulator inspection system according to the present invention is a pressure regulator inspection system used in carrying out the pressure regulator inspection method described in claim 1 or 2, comprising: an input unit to which the flow rate of the main flow path and the flow rate of the bypass flow path measured in the measurement step are input; and a determination unit to calculate the difference between the flow rate of the main flow path and the flow rate of the bypass flow path measured in the measurement step and input to the input unit, and to execute the determination step. [Effects of the Invention]

[0009] According to the present invention, it becomes possible to easily and suitably inspect the occlusion of a switching valve. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a front view showing a pressure regulator being inspected using a pressure regulator inspection method according to one embodiment. [Figure 2] Figure 2 is a side cross-sectional view showing the pressure regulator shown in Figure 1. [Figure 3] Figure 3 is a front cross-sectional view showing the pressure regulator shown in Figures 1 and 2, and is a front cross-sectional view showing the pressure regulator in the first measurement step of the pressure regulator inspection method. [Figure 4] Figure 4 is a front cross-sectional view showing the pressure regulator shown in Figures 1 and 2, and is a front cross-sectional view showing the pressure regulator in the second measurement step of the pressure regulator inspection method. [Figure 5] Figure 5 is a front cross-sectional view showing a pressure regulator in the measurement step of a pressure regulator inspection method according to one embodiment of the present invention. [Figure 6] Figure 6 is a diagram illustrating an experiment to demonstrate one embodiment of the present invention and a method for inspecting a pressure regulator according to one embodiment. [Figure 7] Figure 7 is a table showing the experimental results. [Figure 8] Figure 8 is a schematic diagram of an inspection system for a pressure regulator according to one embodiment of the present invention. [Figure 9] Figure 9 is a schematic diagram of a pressure regulator inspection system according to one embodiment of the present invention. [Modes for carrying out the invention]

[0011] The present invention will be described below in accordance with preferred embodiments. However, the present invention is not limited to the embodiments shown below, and the embodiments can be modified as appropriate without departing from the spirit of the invention. Furthermore, in the embodiments shown below, some illustrations and descriptions of certain components are omitted. For details of the omitted technologies, publicly known or well-known technologies can be applied as appropriate, to the extent that they do not contradict the content described below.

[0012] Figure 1 is a front view showing a pressure regulator 1 being inspected using an inspection method for a pressure regulator 1 according to one embodiment. As shown in this figure, the pressure regulator 1 comprises a primary regulator 10, a secondary regulator 20, a leak detector 30, and piping 40. The pressure regulator 1 also comprises a main flow path 2, a bypass flow path 3, an on-off valve 4, and a switching valve 5 (see Figures 2-6).

[0013] The upstream portion of the main flow path 2 constitutes part of the secondary regulator 20, and the downstream portion of the main flow path 2 is composed of piping 40. A switching valve 5 is provided at the boundary between the upstream and downstream portions of the main flow path 2. This switching valve 5 opens and closes according to the pressure difference between the upstream and downstream sides of the main flow path 2.

[0014] The bypass channel 3 is a channel that bypasses the upstream and downstream sides of the switching valve 5 in the main channel 2. This bypass channel 3 is equipped with an on-off valve 4 and a lever 6. When the lever 6 is operated, the on-off valve 4 is switched between an open state and a closed state, and the bypass channel 3 is opened and closed.

[0015] The primary regulator 10 is a so-called switching-function main regulator, to which LP gas cylinders (not shown) are connected on the left and right sides. This primary regulator 10 is equipped with a switching lever 11. By operating this switching lever 11, it is selected whether to introduce fuel gas from either the left or right LP gas cylinder (not shown).

[0016] 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 includes 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 according to the operation of the diaphragm 12. The fuel gas that has been primarily pressure-reduced by the primary regulator 10 is supplied to the secondary regulator 20.

[0017] The secondary regulator 20 performs secondary pressure reduction to reduce the medium-pressure fuel gas supplied from the primary regulator 10 to low pressure. The secondary regulator 20 includes a pipe portion 21 that constitutes an upstream portion of the main flow path 2, a diaphragm 22 disposed facing a gas chamber G communicating with the pipe portion 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 according to the operation of the diaphragm 22. The fuel gas that has been secondarily pressure-reduced by the secondary regulator 20 is supplied to the downstream pipe 40.

[0018] 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, so that the fuel gas flows through the bypass flow path 3. On the other hand, in the secondary regulator 20, when the flow rate of the fuel gas is greater than or equal to the set flow rate, the switching valve 5 is opened, so that the fuel gas flows through both the main flow path 2 and the bypass flow path 3.

[0019] The secondary regulator 20 includes a pipe portion 21, a diaphragm 22, a coil spring 23, a link mechanism 24, a pressure reducing valve 25, and a housing 26. The housing 26 includes a cylindrical coil accommodating portion 26A that accommodates the coil spring 23, and a disk-shaped air / gas chamber portion 26B that constitutes an air chamber A and a gas chamber G. The coil accommodating portion 26A protrudes from the central portion of the air / gas chamber portion 26B, and the central axis of the coil accommodating portion 26A is arranged coaxially with the central axis of the air / gas chamber portion 26B.

[0020] The coil spring 23 is a compression coil spring and is housed in the coil housing 26A in a state that allows it to expand and contract in the axial direction of the coil housing 26A. One end of the coil spring 23 is fixed to the front end of the coil housing 26A. The diaphragm 22 is an elastically deformable disc that separates the air / gas chamber 26B into an air chamber A on the coil housing 26A side and a gas chamber G on the piping section 21 side. The other end of the coil spring 23 is attached to the center of the diaphragm 22. The peripheral edge of the diaphragm 22 is attached to the inner circumferential wall of the air / gas chamber 26B.

[0021] As the pressure in the gas chamber G increases, the diaphragm 22 deforms to bulge outwards toward the air chamber A, resisting the elastic force of the coil spring 23. On the other hand, as 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 also elastically returns to its original position.

[0022] The link mechanism 24 comprises 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. This first shaft portion 24A is arranged coaxially with respect to the center of the coil spring 23 and the coil housing 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. This second shaft portion 24B is arranged coaxially with respect to 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.

[0023] Link 24C comprises a first link portion 24C1 and a second link portion 24C2 which is longer than the first link portion 24C1. The first link portion 24C1 is arranged to span both 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. The central part of the first link portion 24C1 is rotatably supported on the periphery of the hole 21H in the piping portion 21.

[0024] The other end of the second link section 24C2 is connected to the tip of the first shaft section 24A. When the pressure in the gas chamber G increases, the diaphragm 22 deforms so as to bulge out toward the air chamber A, the other end of the second link section 24C2 is displaced toward the air chamber A, and one end of the first link section 24C1 is displaced 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 pressed against the valve seat 25B, resulting in a closed state, and the introduction of fuel gas into the gas chamber G is shut off. On the other hand, when the pressure in the gas chamber G decreases, the diaphragm 22 elastically returns to the gas chamber G side from the predetermined state, the other end of the second link section 24C2 is displaced toward the piping section 21, and one end of the first link section 24C1 is displaced toward the valve seat 25B of the pressure reducing valve 25. At this time, the valve body 25A opens, separating from the valve seat 25B, and the fuel gas is introduced into the gas chamber G. The secondary regulator 20 reduces the pressure of the fuel gas by repeatedly performing the operations of introducing the fuel gas into the gas chamber G and shutting off the introduction of the fuel gas into the gas chamber G.

[0025] The pipe 40 is arranged coaxially with the piping section 21. The upstream end of the pipe 40 is connected to the downstream end of the piping section 21. A switching valve 5 is provided at the connection point between the pipe 40 and the piping section 21. The switching valve 5 comprises a valve body 51, a valve seat 52, a shaft 53, a guide 54, and a coil spring 55.

[0026] The valve seat 52 is provided at the connection point between the pipe 40 and the pipe section 21, and the valve body 51 is positioned downstream of the valve seat 52. The shaft 53 is attached to the center of the valve body 51 and protrudes from the valve body 51 towards the pipe section 21 through the insertion hole of the valve seat 52. A flange portion 53A is provided at the tip of the shaft 53. The guide 54 is provided at the connection point between the pipe 40 and the pipe section 21 and guides the shaft 53 along the axial direction of the pipe section 21.

[0027] The coil spring 55 is a compression coil spring and is installed 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 greater than or equal to the 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 fuel gas flows from the piping portion 21 to the piping 40.

[0028] 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 comprises a bypass passage 3, an on-off valve 4, a lever 6 (see Figure 1), a leak detection sensor 31, and a pressure sensor 32. The leak detector 31 detects the minute flow rate of fuel gas through the bypass passage 3, thereby detecting minute leaks of fuel gas occurring downstream of the secondary regulator 20 (see Figure 2).

[0029] The leak detector 30 includes a downstream bypass pipe 33 and an upstream bypass pipe 34 that constitute 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. The downstream end of the downstream bypass pipe 33 is connected downstream of the switching valve 5 in the piping 40. The upstream bypass pipe 34 is equipped with an on / off valve 4 and a lever 6.

[0030] When the on-off valve 4 is open and the pressure difference between the piping section 21 and the piping 40 is greater than or equal to a predetermined set value, the switching valve 5 opens, and the fuel gas flows directly from the piping section 21 to the piping 40, as well as from the piping section 21 to the piping 40 via the bypass passage 3. On the other hand, when the on-off valve 4 is open and the pressure difference between the piping section 21 and the piping 40 is less than a predetermined set value, the switching valve 5 closes, and the fuel gas flows only from the piping section 21 to the piping 40 via the bypass passage 3.

[0031] A multilayer unit can be exemplified as the downstream bypass piping 33. This multilayer unit is a rectangular tubular pipe having multiple flow dividers inside. An ultrasonic flow sensor can be exemplified as the leak detection sensor 31. This ultrasonic flow sensor comprises two sets of ultrasonic transceivers and a calculation device that calculates the flow rate from the propagation time of ultrasonic signals transmitted and received by the two sets of ultrasonic transceivers. The pressure sensor 32 measures the pressure in the downstream bypass piping 33.

[0032] When the pressure difference between piping section 21 and piping 40 exceeds a predetermined set value due to the use of fuel gas on the consumer side, the switching valve 5 opens, and fuel gas is supplied to the consumer side either directly from piping section 21 or via the bypass passage 3. Conversely, if a small leak of fuel gas occurs downstream of piping 40, and the pressure difference between piping section 21 and piping 40 is less than a predetermined set value, a small flow rate of fuel gas flows from piping section 21 to piping 40 via the bypass passage 3. In this case, the small flow rate of fuel gas flowing through the bypass passage 3 is detected by the leak detection sensor 31, thereby detecting the small fuel gas leak.

[0033] Here, in order for the leak detector 30 to detect minute fuel gas leaks, it is a prerequisite that the switching valve 5 remains closed when the pressure difference between the piping section 21 and the piping 40 is below a predetermined set value. Therefore, it is necessary to perform an inspection to confirm whether the switching valve 5 can maintain a closed state properly. The inspection method for determining the quality of the pressure regulator 1, and especially the switching valve 5, will be described below.

[0034] Figure 3 shows the state of the pressure regulator 1 in the first measurement step of the inspection method for the pressure regulator 1 of this embodiment, and Figure 4 shows the state of the pressure regulator 1 in the second measurement step of the inspection method for the pressure regulator 1 of this embodiment. As shown in these figures, in the inspection method for 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 and P2 of the pressure regulator 1, and fuel gas is flowed from the pressure regulator 1 to the consumer side by burning fuel gas in the gas stove 9 on the consumer side. Note that the outlet pressures P1 and P2 of the pressure regulator 1 are sometimes referred to as the pressures P1 and P2 of the main flow path 2.

[0035] As shown in Figure 3, in the first measurement step, the on-off valve 4 is opened and fuel gas is burned in the 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 the flow rate at which the switching valve 5 is kept closed when the on-off valve 4 is open (for example, 50 to 100 L / h). At this time, the outlet pressure P1 of the pressure regulator 1 is measured by the pressure gauge 8.

[0036] As shown in Figure 4, in the second measurement step, the on-off valve 4 is switched to the closed state while maintaining the fuel gas flow rate from the first measurement step. At this time, the outlet pressure P2 of the pressure regulator 1 is measured using the pressure gauge 8.

[0037] Next, in the determination step, the quality of the switching valve 5 is determined 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, if the difference between the outlet pressure P1 and the outlet pressure P2 (P1-P2) is greater than or equal to a predetermined value (for example, 0.1 kPa), the switching valve 5 is determined to be normal (i.e., there is no problem with its occlusion), and if the difference between the outlet pressure P1 and the outlet pressure P2 (P1-P2) is less than the above predetermined value, the switching valve 5 is determined to be abnormal (i.e., there is a problem with its occlusion).

[0038] In this case, if there is no problem with the occlusion of the switching valve 5, fuel gas will 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 will be lower than the outlet pressure P1 measured in the first measurement step. On the other hand, if there is a problem with the occlusion of the switching valve 5, fuel gas will flow 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 will not change from the outlet pressure P1 measured in the first measurement step, or will change only by a small amount (for example, less than 0.1 kPa).

[0039] 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 a small amount (for example, less than 0.1 kPa), it is determined that the occlusion performance of the switching valve 5 is poor, and the inspected pressure regulator 1 is deemed unacceptable.

[0040] Furthermore, in the first and second measurement steps, the pressures P1' and P2' of the bypass flow path 3 are measured by the pressure sensor 32 of the leak detector 30. If the difference between these pressures (P1'-P2') is zero or very small (for example, less than 0.1 kPa), it may be determined that the occlusion performance of the switching valve 5 is poor, and the inspected pressure regulator 1 may be deemed unacceptable.

[0041] Next, a method for inspecting a pressure regulator 1 according to one embodiment of the present invention will be described. Figure 5 is a front cross-sectional view showing the pressure regulator 1 in the measurement step of the inspection method for the pressure regulator 1 according to one embodiment of the present invention. As shown in this figure, in this embodiment, a flow sensor 101 for measuring the flow rate of fuel gas flowing from the piping 40 to the consumer side is installed on the downstream side of the piping 40.

[0042] 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 in the gas stove 9, thereby allowing fuel gas to flow from the pressure regulator 1 to the consumer side. Similar to the embodiment described above, the flow rate of the fuel gas is set to a flow rate (for example, 50 to 100 L / h) at which the switching valve 5 is kept closed when the on-off valve 4 is open. At this time, the flow rate F1 of the fuel gas flowing from the piping 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 channel 3 is measured by the leak detection sensor 31.

[0043] Next, in the judgment step, the quality of the switching valve 5 is determined based on the difference between the flow rate F1 of the main flow path 2 and the flow rate F2 of the bypass flow path 3, which were measured in the measurement step. Specifically, the difference between the flow rate F1' of the main flow path 2 and the flow rate F2' of the bypass flow path 3 (the second value (F1'-F2')) 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 determined in advance, and the difference between the flow rate F1 of the main flow path 2 and the flow rate F2 of the bypass flow path 3 (the first value (F1-F2)) 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, less than or equal to 1 / 2 to 1 / 10), then it is determined that there is no problem with the occlusion of the switching valve 5. 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')), then it is determined that there is a problem with the occlusion of the switching valve 5.

[0044] Here, if there is no problem with the occlusion of the switching valve 5, in the measurement step, unless the switching valve 5 changes to an open state, the fuel gas will not flow from the piping section 21 to the piping 40 without passing through the bypass passage 3. Therefore, the flow rate F2 of the bypass passage 3 measured in the measurement step will be larger than the flow rate F2' of the bypass passage 3 when the switching valve 5 is in the open state. On the other hand, if there is a problem with the occlusion of the switching valve 5, in the measurement step, even if there is no change in the state of the switching valve 5, the fuel gas will flow directly from the piping section 21 to the piping 40. Therefore, the flow rate F2 of the bypass passage 3 measured in the measurement step will not have a significant difference compared to the flow rate F2' of the bypass passage 3 when the switching valve 5 is in the open state.

[0045] Therefore, in the inspection method for the pressure regulator 1 of this embodiment, if there is no significant difference between the first value (F1-F2), which is the difference between the flow rate F1 of the main flow path 2 and the flow rate F2 of the bypass flow path 3 measured in the measurement step, and the second value (F1'-F2'), which is the difference between the flow rate F1' of the main flow path 2 and the flow rate F2' of the bypass flow path 3 when the switching valve 5 is in the open state, it is determined that the occlusion performance of the switching valve 5 is poor, and the inspected pressure regulator 1 is deemed unacceptable.

[0046] The following describes an experiment conducted to demonstrate one embodiment of the present invention and a method for inspecting the pressure regulator 1 according to one embodiment. Figure 6 is a diagram illustrating the experiment.

[0047] As shown in Figure 6, in this experiment, a main flow meter 102 and a flow control valve 103 were installed downstream of the piping 40. The main flow meter 102 measures the flow rate and pressure of the fuel gas flowing downstream from the piping 40. The flow control valve 103 adjusts the flow rate of the fuel gas flowing downstream from the piping 40. In this experiment, the inlet pressure of the pressure regulator 1 was set to 0.1 MPa, and the LP gas cylinder on the right was selected using the selector lever 11.

[0048] Figure 7 is a table showing the experimental results. As shown in this table, in this experiment, under conditions 1 to 8, the flow rate of the fuel gas was measured using the main flow meter 102 and the leak detection sensor 31, and the pressure was measured using the main flow meter 102 and the pressure sensor 32.

[0049] Under conditions 1 to 4, the switching valve 5 was closed, and under conditions 5 to 8, the switching valve 5 was opened. In addition, the flow rate of the fuel gas flowing downstream from the piping 40 was varied by the flow rate adjustment valve 103 to 0 [L / h] under conditions 1 and 5, 3 [L / h] under conditions 2 and 6, 50 [L / h] under conditions 3 and 7, and 100 [L / h] under conditions 4 and 8. When the switching valve 5 is closed, the gap between the valve body 51 and the valve seat 52 is 0 mm, and when the switching valve 5 is open, the gap between the valve body 51 and the valve seat 52 is approximately 0.08 mm.

[0050] Then, under each condition, with the on-off valve 4 in the open position, the fuel gas flow rate was measured using the main flow meter 102 and the leak detection sensor 31, and the pressure was measured using the main flow meter 102 and the pressure sensor 32. Also, under each condition, with the on-off valve 4 in the closed position, the fuel gas flow rate was measured using the main flow meter 102, and the pressure was measured using the main flow meter 102 and the pressure sensor 32.

[0051] For conditions 1 through 8, the difference between the flow rate in the main channel 2 measured by the main channel meter 102 when the on-off valve 4 is open and the flow rate in the bypass channel 3 measured by the leak detection sensor 31 was calculated. Furthermore, for conditions 2 through 4 and 6 through 8, the difference between the pressure in the main channel 2 measured by the main channel meter 102 when the on-off valve 4 is open and the pressure in the main channel 2 measured by the main channel meter 102 when the on-off valve 4 is closed was calculated. In addition, for conditions 2 through 4 and 6 through 8, the difference between the pressure in the bypass channel 3 measured by the pressure sensor 32 when the on-off valve 4 is open and the pressure in the bypass channel 3 measured by the pressure sensor 32 when the on-off valve 4 is closed was calculated.

[0052] First, we examine the difference between the flow rate in the main flow path 2 and the flow rate in the bypass flow path 3 (hereinafter referred to as the flow rate difference) when the on-off valve 4 is in the open position. While no significant difference in the flow rate difference was observed between the first condition and the fifth condition, where the set flow rate of the flow control valve 103 is 0 [L / h], significant differences in the flow rate difference were observed between the second condition and the sixth condition, where the set flow rate of the flow control valve 103 is 3 [L / h], between the third condition and the seventh condition, where the set flow rate of the flow control valve 103 is 50 [L / h], and between the fourth condition and the eighth condition, where the set flow rate of the flow control valve 103 is 100 [L / h]. Specifically, the flow rate difference in the second condition was significantly smaller, about 1 / 5 of the flow rate difference in the sixth condition; the flow rate difference in the third condition was significantly smaller, about 1 / 10 of the flow rate difference in the seventh condition; and the flow rate difference in the fourth condition was significantly smaller, about 1 / 10 of the flow rate difference in the eighth condition.

[0053] Based on the above, the effectiveness of the inspection method was demonstrated, in which fuel gas is flowed through the main passage 2 and the bypass passage 3 with the on / off valve 4 in the open state, the flow rate F1 of the main passage 2 and the flow rate F2 of the bypass passage 3 are measured, the difference between the flow rate F1 of the main passage 2 and the flow rate F2 of the bypass passage 3 (F1-F2) is compared with the difference between the flow rate F1' of the main passage 2 and the flow rate F2' of the bypass passage 3 (F1'-F2') 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 occlusion of the switching valve 5, and if there is no significant difference between these, it is determined that there is a problem with the occlusion of the switching valve 5.

[0054] Next, we examined the difference in pressure in the main flow path 2 when the on-off valve 4 is open and when the on-off valve 4 is closed (hereinafter referred to as the pressure difference in the main flow path 2). We 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, we confirmed that the pressure difference in main channel 2 under conditions 5 to 8 was less than 0.1 [kPa] and equal to 0. In addition, the pressure difference in main channel 2 under condition 2 was significantly larger, by approximately 0.1 [kPa] or more, than the pressure difference in main channel 2 under condition 6. The pressure difference in main channel 2 under condition 3 was significantly larger, by approximately 0.3 [kPa] or more, than the pressure difference in main channel 2 under condition 7. The pressure difference in main channel 2 under condition 4 was significantly larger, by approximately 0.3 [kPa] or more, than the pressure difference in main channel 2 under condition 8.

[0055] Based on the above, the effectiveness of the inspection method, which involves opening the on-off valve 4 and flowing fuel gas through the main passage 2 and the bypass passage 3 to measure the pressure P1 in the main passage 2, closing the on-off valve 4 and flowing fuel gas through the main passage 2 to measure the pressure P2 in the main passage 2, and determining that there is no problem with the occlusion of the switching valve 5 if the difference between pressure P1 and pressure P2 (P1-P2) is of a significant magnitude, and determining that there is a problem with the occlusion of the switching valve 5 if the difference between pressure P1 and pressure P2 (P1-P2) is equal to 0 or negligible (for example, less than 0.1 [kPa]), has been demonstrated.

[0056] Next, we examined the difference between the pressure in the bypass channel 3 when the on-off valve 4 is open and the pressure in the bypass channel 3 when the on-off valve 4 is closed (hereinafter referred to as the pressure difference in the bypass channel 3). We confirmed that there was a significant difference in the pressure difference in the bypass channel 3 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, we confirmed that the pressure difference in bypass channel 3 under conditions 5 to 8 was less than 0.1 [kPa] and equal to 0. In addition, the pressure difference in bypass channel 3 under condition 2 was significantly larger than the pressure difference in bypass channel 3 under condition 6, by more than 0.1 [kPa]. The pressure difference in bypass channel 3 under condition 3 was also significantly larger than the pressure difference in bypass channel 3 under condition 7, by more than 0.3 [kPa]. Furthermore, the pressure difference in bypass channel 3 under condition 4 was also significantly larger than the pressure difference in bypass channel 3 under condition 8, by more than 0.3 [kPa].

[0057] Based on the above, the effectiveness of the inspection method, in which the on-off valve 4 is opened and fuel gas is flowed through the main passage 2 and the bypass passage 3 to measure the pressure P1' in the bypass passage 3, and the on-off valve 4 is closed and fuel gas is flowed through the main passage 2 to measure the pressure P2' in the bypass passage 3, and if the difference between pressure P1' and pressure P2' (P1'-P2') is a significant magnitude, it is determined that there is no problem with the occlusion of the switching valve 5, and if the difference between pressure P1' and pressure P2' (P1'-P2') is 0 or a small amount (for example, less than 0.1 [kPa]) to determine that there is a problem with the occlusion of the switching valve 5, has been demonstrated.

[0058] Figure 8 is a schematic diagram 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 that receives pressures P1' and P2' measured by a pressure sensor 32 and determines whether the pressure regulator 1 is good or bad based on the input pressures P1' and P2'.

[0059] The terminal 110 is a personal computer or a mobile terminal, and includes an input unit 111 that receives pressures P1' and P2' from the pressure sensor 32, a processing unit 112 that determines whether the pressure regulator 1 is functioning correctly based on the pressures P1' and P2' input to the input unit 111, an operation unit 113, and a display unit 114. The terminal 110 may also include a touch panel that integrates the functions of the operation unit 113 and the display unit 114.

[0060] The terminal 110 and the pressure sensor 32 can be connected by wire or wireless connection, and the pressures P1' and P2' measured by the pressure sensor 32 are input to the input unit 111. Alternatively, the pressures P1' and P2' may be input to the input unit 111 by an operator's input operation.

[0061] The processing unit 112 displays an instruction on the display unit 114 to perform the first measurement step, which involves opening the on-off valve 4 and measuring the pressure P1'. The operator will perform the first measurement step according to the instructions displayed on the display unit 114. Once this first measurement step is performed, the pressure sensor 32 measures the pressure P1' in the bypass flow path 3, and this pressure P1' is input to the input unit 111. The processing unit 112 stores the pressure P1' input to the input unit 111 in a storage unit (not shown).

[0062] The processing unit 112 displays an instruction on the display unit 114 to perform the second measurement step, which involves closing the on-off valve 4 and measuring the pressure P2'. The operator will perform the second measurement step according to the instructions displayed on the display unit 114. Once this second measurement step is performed, the pressure sensor 32 measures the pressure P2' in the bypass flow path 3, and this pressure P2' is input to the input unit 111. The processing unit 112 stores the pressure P2' input to the input unit 111 in the storage unit.

[0063] The processing unit 112 determines whether the difference between pressure P1' and pressure P2' (P1'-P2') stored in the memory unit is greater than or equal to a predetermined threshold (for example, 0.1 [kPa]). If it is greater than or equal to the predetermined threshold, the processing unit 1 determines that the pressure regulator 1 is acceptable; if it is less than the predetermined threshold, the processing unit 1 determines that the pressure regulator 1 is unacceptable. The processing unit 112 displays the determination result for the pressure regulator 1 on the display unit 114.

[0064] Alternatively, a pressure gauge 8 may be used instead of the pressure sensor 32, and the pressures P1 and P2 of 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 functioning correctly based on the pressures P1 and P2 of the main flow path 2.

[0065] Figure 9 is a schematic diagram of an inspection system 200 for a pressure regulator 1 according to one embodiment of the present invention. As shown in this figure, the inspection system 200 includes a terminal 210 that receives the flow rate F1 of the main flow path 2 measured by a flow sensor 101 and the flow rate F2 of the bypass flow path 3 measured by a leak detection sensor 31, and determines whether the pressure regulator 1 is good or bad based on the input flow rates F1 and F2.

[0066] The terminal 210 is a personal computer or mobile terminal, and includes an input unit 211 that receives flow rate F1 from the flow sensor 101 and flow rate F2 from the leak detection sensor 31, a processing unit 212 that determines whether the pressure regulator 1 is functioning correctly 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 also include a touch panel that integrates the functions of the operation unit 213 and the display unit 214.

[0067] The terminal 210, the flow sensor 101, and the leak detection sensor 31 can be connected by wire or wireless connection. The flow rate F1 of the main channel 2 measured by the flow sensor 101 and the flow rate F2 of the bypass channel 3 measured by the leak detection sensor 31 are input to the input unit 211. Alternatively, the flow rates F1 and F2 may be input to the input unit 211 by an operator's input operation.

[0068] The processing unit 212 displays an instruction on the display unit 214 to perform a measurement step in which the on-off valve 4 is opened and the flow rates F1 and F2 are measured. The operator will perform the measurement step according to the instructions displayed on the display unit 214. When this measurement step is performed, the flow rate sensor 101 measures the flow rate F1 of the main flow path 2 and inputs this flow rate F1 to the input unit 211. In addition, the leak detection sensor 31 measures the flow rate F2 of the bypass flow path 3 and inputs this flow rate F2 to the input unit 211.

[0069] The processing unit 212 determines whether the difference between the flow rates F1 and F2 (F1-F2) input to the input unit 211 is less than a predetermined threshold (for example, less than 10% of the flow rate F1). If it is less than the predetermined threshold, the processing unit 212 determines that the pressure regulator 1 is acceptable; if it is equal to or greater than the predetermined threshold, the processing unit 212 determines that the pressure regulator 1 is unacceptable. The processing unit 212 displays the result of the pressure regulator 1 on the display unit 214.

[0070] Although the present invention has been described above based on the embodiments described above, the present invention is not limited to the embodiments described above, and modifications may be made, or publicly known or well-known technologies may be combined as appropriate, without departing from the spirit of the present invention. [Explanation of Symbols]

[0071] 1. Pressure Regulator 2 Main channel 3 Bypass channel 4. Shut-off valves 5. Switching valve 100 Inspection Systems 111 Input Section 112 Processing Unit (Determination Unit) 200 inspection systems 211 Input section 212 Processing Unit (Determination Unit) F1 flow rate F2 flow rate F1' flow rate F2' flow rate P1 Pressure P2 pressure P1' Pressure P2' Pressure

Claims

1. A method for inspecting a fuel gas pressure regulator comprising 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 an on / off valve that opens and closes the bypass flow path, A measurement step in which, with the on / off valve open, a predetermined flow rate of fuel gas is flowed from the upstream side to the downstream side of the switching valve in the main flow path, maintaining the switching valve in a closed state, and the flow rate on the downstream side and the flow rate in the bypass flow path are measured. A determination step is performed to determine whether the switching valve is good or bad based on the difference between the flow rate of the main channel and the flow rate of the bypass channel measured in the measurement step. A method for inspecting a fuel gas pressure regulator equipped with [a specific feature / function].

2. A method for inspecting a fuel gas pressure regulator according to claim 1, wherein in the determination step, a first value is compared with a second value which is the difference between the flow rate of the main flow path and the flow rate of the bypass flow path when the fuel gas at a predetermined flow rate flows from the upstream side to the downstream side of the switching valve in the main flow path with the on-off valve and the switching valve open, and the switching valve is determined to be abnormal if there is no predetermined difference between the first value and the second value.

3. A pressure regulator inspection system used for carrying out the pressure regulator inspection method described in claim 1 or 2, An input unit into which the flow rate of the main channel and the flow rate of the bypass channel measured in the measurement step are input, A determination unit calculates the difference between the flow rate of the main channel and the flow rate of the bypass channel, which are measured in the measurement step and input to the input unit, and executes the determination step. A pressure regulator inspection system equipped with [specific features / features].

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