Gas governor

Abstract

This gas governor provides a mechanism that allows for fine adjustment of the Venturi effect without being dependent on dimensional tolerances of the Venturi shape. [Solution] The flow rate change of the gas in the downstream pipeline R2 is detected as a pressure change, and an auxiliary pressure P3 lower than the secondary pressure P2 by the amount of negative pressure is generated. The auxiliary diaphragm pressure chamber AS is positioned opposite the pilot spring n1 of the pilot governor 3 to assist in opening and closing the pilot valve. The connecting pipeline Z includes a main line Z1 that connects the secondary orifice W and the auxiliary diaphragm pressure chamber, and a sub-line Z2 that is a downstream pipeline and connects the auxiliary diaphragm pressure chamber to the upstream or downstream side of the secondary orifice W. Variable throttles v1 and v2 are provided in the main line and sub-line, respectively. The internal pressure of the auxiliary diaphragm pressure chamber is the mixed pressure P2' of the auxiliary pressure of the gas passing through the main line and the secondary pressure of the gas passing through the sub-line.

Description

Technical Field

[0001] The present invention relates to a gas governor (also called a gas pressure regulator) that reduces the pressure of gas (such as city gas) transported at a primary pressure from the upstream side to a secondary pressure and supplies it to the downstream side.

Background Art

[0002] Conventional gas governors have been widely used mainly in city gas supply and industrial gas supply systems to maintain a stable gas supply. Its basic function is to control the gas pressure within a predetermined range and achieve a safe and efficient gas supply. A typical gas governor includes a valve mechanism for adjusting the pressure and various sensors and actuators for managing the gas flow rate.

[0003] In addition, various technical improvements have been made to conventional gas governors according to the environment in which they are used and the type of gas. Particularly in a city gas supply system, a technology that can quickly respond to fluctuations on the supply side and the use side while maintaining stable pressure control is required.

[0004] For this reason, a highly sensitive control mechanism and an adjustment function for improving the responsiveness to pressure fluctuations have been added, and in recent years, pilot-type governors have become mainstream. A pilot-type governor can perform precise pressure control because it finely adjusts the pressure with a sub-control valve prior to the main control valve.

[0005] Regarding the above pilot-type governor, the inventors of the present invention invented the gas governor described in Patent Document 1.

[0006] The gas governor described in Patent Document 1 is a gas governor equipped with a pilot governor, and a secondary-side orifice (venturi) is arranged in the pipeline on the downstream side of the governor body. Furthermore, an auxiliary diaphragm pressure chamber is installed in the pilot governor, which applies the pressure of the gas reduced in the venturi section, and together with the secondary pressure downstream, counteracts the pilot spring to assist in opening and closing the pilot valve. Furthermore, a throttling chamber and a tank are provided in the piping connecting the auxiliary diaphragm pressure chamber and the venturi, mitigating the effects of secondary pressure fluctuations occurring in the venturi section so that they do not abruptly affect the auxiliary diaphragm pressure chamber, thus ensuring proper function.

[0007] This allows for the detection of changes in secondary pressure, as well as an increase in the flow rate of gas that is reduced to secondary pressure and flows downstream, enabling control of the control pressure. Therefore, the responsiveness of the control pressure to an increase in flow rate can be improved, and the offset effect can be reduced, allowing for stable control of the control pressure, thus suppressing vibration and swaying.

[0008] Offset refers to the phenomenon where the secondary pressure drops below the set pressure as the flow rate increases. Recently, the gas governor described in Patent Document 1 has been designed to suppress offset by providing a venturi in the pipeline downstream of the governor body, as described above.

[0009] In other words, by providing a venturi, the secondary pressure generated in the venturi section decreases as the flow rate increases. Furthermore, the decrease in secondary pressure in the venturi section causes the diaphragm in the auxiliary diaphragm pressure chamber to lower, opening the pilot valve and thus reducing the control pressure on the sleeve of the governor body. As a result of the decrease in control pressure, the sleeve expands, increasing the gas flow rate through the governor body (AFV), and consequently raising the outlet pressure (pressure downstream of the venturi). Hereafter, the series of events described above resulting from the installation of a Venturi will be referred to as the "Venturi effect." [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 5698545 [Overview of the project] [Problems that the invention aims to solve]

[0011] However, even with the gas governor described in Patent Document 1, the following problems remained.

[0012] In other words, the venturi installed in the downstream pipeline is intended to detect an increase in the gas flow rate downstream and mitigate the occurrence of offset, but the degree of this mitigation depends on the shape of the venturi. Therefore, due to dimensional tolerances of the Venturi shape, individual differences occur in the degree of the Venturi effect described above. Furthermore, because the venturi shape cannot be easily changed, increasing the maximum flow rate can sometimes lead to an excessive increase in secondary pressure, and adjusting this pressure was difficult.

[0013] This invention has been made in view of the above-mentioned circumstances, and aims to provide a gas governor that allows for fine adjustment of the Venturi effect without depending on the dimensional tolerances of the Venturi shape. [Means for solving the problem]

[0014] To accomplish this task, this disclosure provides a gas governor [1] to [4].

[0015] [1] The governor itself is installed in the middle of the pipeline and reduces the pressure of the gas transported from the upstream side at primary pressure to secondary pressure before flowing it downstream. A restrictor is provided to generate a control pressure for controlling the operation of the governor body, and a pilot loop is connected between the upstream and downstream pipelines of the governor body. A pilot governor installed in the pilot loop, configured to open and close a pilot valve according to the secondary pressure of the gas, control the amount of the gas passing through the pilot loop, and feedback-control the governor body so that the secondary pressure becomes constant; comprising A gas governor that uses the control pressure controlled by the pilot governor to change the valve opening degree of the governor body, thereby reducing the pressure of the gas supplied from the upstream side and supplying it to the downstream side, having a secondary-side orifice disposed in the downstream pipeline, an auxiliary diaphragm pressure chamber included in the pilot governor and configured to control the opening degree of the pilot valve according to its internal pressure, and a connection pipeline connecting the auxiliary diaphragm pressure chamber and the downstream pipeline; The secondary-side orifice generates a negative pressure based on the gas flow in the downstream pipeline, detects the change in the gas flow rate in the downstream pipeline as a pressure change, and generates an auxiliary pressure lower than the secondary pressure by the amount of the negative pressure; The auxiliary diaphragm pressure chamber opposes the pilot spring of the pilot governor and assists in the force for opening and closing the pilot valve; The connection pipeline includes a main line connecting the secondary-side orifice and the auxiliary diaphragm pressure chamber, and a sub-line connecting the downstream pipeline, either upstream or downstream of the secondary-side orifice, and the auxiliary diaphragm pressure chamber; Variable throttles are provided in the main line and the sub-line, respectively; The internal pressure of the auxiliary diaphragm pressure chamber is a mixed pressure of the auxiliary pressure of the gas passing through the main line and the secondary pressure of the gas passing through the sub-line; Gas governor.

[0016] [2] The sub-line connects the downstream pipeline, upstream of the secondary-side orifice, and the auxiliary diaphragm pressure chamber; The gas governor according to [1].

[0017] [3] The sub-line connects the downstream pipeline and the auxiliary diaphragm pressure chamber via the main line. The gas governor according to [1] or [2].

[0018] [4] The variable throttle is a needle valve. The gas governor according to any one of [1] to [3]. [Effect of the Invention]

[0019] According to the present invention, it is possible to provide a gas governor capable of finely adjusting the Venturi effect without depending on dimensional tolerances of the Venturi shape or the like. [Brief Description of the Drawings]

[0020] [Figure 1] It is a principle diagram showing an embodiment in which the present invention is applied to an axial flow governor. [Figure 2] In an embodiment of the present invention, it is a graph showing the relationship between the gas flow rate and the outlet pressure according to the degree of throttling of the main line and the sub-line. [Modes for Carrying Out the Invention]

[0021] Hereinafter, a gas governor according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. Note that the embodiments shown below are examples of the present invention, and the present invention is not limited to the following embodiments. Also, in these figures, reference numeral X indicates the gas governor according to the present embodiment.

[0022] [Configuration] As shown in FIG. 1, the gas governor X includes a governor body 1, a pilot loop 2, and a pilot governor 3. Furthermore, the gas governor X utilizes the control pressure Pc controlled by the pilot governor 3 to change the valve opening of the governor body 1, thereby reducing the pressure of the gas supplied from the upstream side and supplying it to the downstream side.

[0023] Governor body 1 is an axial flow type governor (hereinafter referred to as AFV) installed in the middle of a pipeline, which reduces the pressure of gas transported from the upstream side at a primary pressure P1 to a secondary pressure P2 and allows it to flow downstream.

[0024] The AFV used in this embodiment has a general structure, as shown in Figure 1, that includes a pair of truncated cone-shaped closures 11 having multiple slits on their circumferential surface, rubber sleeves 12 that close the slits of the closures 11, and a cylindrical valve body 13 that houses these components. This configuration is similar to that of AFVs that are currently widely used. Furthermore, the AFV is designed so that by applying a control pressure Pc to the space between the sleeve 12 and the valve body 13, the sleeve 12 opens and closes the slits of a pair of closures 11 that form a drum shape when connected facing each other.

[0025] The pilot loop 2 is equipped with a restrictor K that generates a control pressure Pc to control the operation of the governor body 1, and is a pipeline connected between the upstream pipeline R1 and the downstream pipeline R2 of the governor body 1 so as to bypass the governor body 1. In this invention, the term "restrictor" is used to include the venturi.

[0026] The pilot governor 3 is installed in the pilot loop 2 and controls the amount of gas passing through the pilot loop 2 by opening and closing the pilot valve V in accordance with the secondary gas pressure P2, thereby changing the control pressure Pc of the sleeve 12 that seals the closure 11 of the governor body 1. As a result, the pilot governor 3 is configured to provide feedback control over the governor body 1 so that the secondary pressure P2 remains constant.

[0027] Furthermore, the pilot governor 3 has its housing H partitioned by multiple diaphragms D1 to D3 and partition walls, thereby forming a first diaphragm pressure chamber S1 to a fourth diaphragm pressure chamber S4 and an auxiliary diaphragm pressure chamber AS.

[0028] The first diaphragm pressure chamber S1 is a space that houses the pilot spring n1 and is open to the atmosphere. The second diaphragm pressure chamber S2 is a space to which the pilot loop 2 is connected, and which also contains a pilot valve V that opens and closes the pilot loop 2. The third diaphragm pressure chamber S3 is a space that houses a return spring n2 that applies a force opposite to the pilot spring n1, and to which a secondary pressure P2 is applied via the branch pipe m of the pilot loop 2. The fourth diaphragm pressure chamber S4 is a space in which atmospheric pressure is applied to the diaphragm D3 of the third diaphragm pressure chamber S3.

[0029] The auxiliary diaphragm pressure chamber AS is a space into which a mixed pressure P2' of the auxiliary pressure P3, which has been reduced by the secondary orifice W described later, and the secondary pressure P2 is applied.

[0030] To elaborate further on the relationship between each diaphragm pressure chamber S1 to S4 and the auxiliary diaphragm pressure chamber AS, diaphragms D1, D2, and D3 are positioned between the first diaphragm pressure chamber S1 and the second diaphragm pressure chamber S2, between the second diaphragm pressure chamber S2 and the auxiliary diaphragm pressure chamber AS, and between the fourth diaphragm pressure chamber S4 and the third diaphragm pressure chamber S3, respectively.

[0031] As a result, each chamber is partitioned such that the pressure difference between the diaphragm pressure chambers S1, S2, S3, S4 and the auxiliary diaphragm pressure chamber AS acts on the diaphragms D1, D2, and D3, respectively.

[0032] Furthermore, the auxiliary diaphragm pressure chamber AS and the fourth diaphragm pressure chamber S4 are separated by a partition wall that is part of the housing H, and the differential pressure between the auxiliary diaphragm pressure chamber AS and the fourth diaphragm pressure chamber S4 is designed not to be involved in the opening and closing of the pilot valve V. Furthermore, diaphragms D1 and D2, and diaphragms D2 and D3 are connected by connecting rods j1 and j2, respectively, so that all diaphragms D1 to D3 work in conjunction and the differential pressure acting on each diaphragm D1 to D3 influences each other.

[0033] Furthermore, the second diaphragm pressure chamber S2, which is connected to the pilot loop 2, contains a pilot valve V that opens and closes the pilot loop 2. The pilot valve V, like a typical valve, consists of a valve body (not shown) attached to the connecting rod j1 and a valve seat (not shown) molded on the housing H side.

[0034] As a result, when the secondary pressure P2 falls below the set pressure, the connecting rods j1 and j2 move in conjunction with the deformation of all diaphragms D1 to D3, causing the pilot valve V to open as the valve body attached to the connecting rod j1 separates from the valve seat on the housing side.

[0035] As described above, when the pilot valve V is open, a portion of the gas on the upstream side of the governor body 1 flows into the pilot loop 2, passes through the second diaphragm pressure chamber S2 of the pilot governor 3, and is discharged into the downstream pipeline R2. At this time, a pressure change (reduced pressure) occurs in the restrictor K due to the gas flow, and this pressure change becomes the control pressure Pc that causes the governor body 1 to open and close, and acts on the governor body 1 via the branch pipe m.

[0036] The set pressure of pilot governor 3 is determined by pilot spring n1. More specifically, the difference between the spring force of pilot spring n1 and the spring force of return spring n2 determines the set pressure. Therefore, the operator can adjust the set pressure by tightening or loosening the pilot spring n1 using the adjustment screw s as needed.

[0037] Here, the gas governor X has a secondary orifice W located in the downstream pipeline R2, and a connecting pipeline Z that connects the auxiliary diaphragm pressure chamber AS and the downstream pipeline R2.

[0038] The secondary orifice W detects changes in the gas flow rate in the downstream pipeline R2 as pressure changes. In this embodiment, for example, it is configured by connecting a venturi to the downstream pipeline R2. Furthermore, the secondary orifice W detects the auxiliary pressure P3, which is the gas pressure at the smallest diameter of the venturi that occurs when gas flows in the downstream pipeline R2, as an indicator of the change in gas flow rate. In other words, it detects the auxiliary pressure P3 (=P2-ΔPv) downstream of the secondary orifice W installed in the downstream pipeline R2 as an indicator of the change in gas flow rate. In this invention, the term "secondary orifice" is used to include the Venturi.

[0039] The connecting pipeline Z includes a main line Z1 connecting the secondary orifice W and the auxiliary diaphragm pressure chamber AS, and a sub-line Z2 connecting the downstream pipeline R2 upstream of the secondary orifice W to the auxiliary diaphragm pressure chamber AS.

[0040] As described above, the main line Z1 passes through a gas with auxiliary pressure P3, which is taken from the secondary orifice W. Subline Z2 carries gas with a secondary pressure P2 inside the downstream pipeline R2. Note that the auxiliary pressure P3 is the same as the secondary pressure P2 when there is no flow rate, but when a flow rate is generated, a differential pressure of ΔPv is created, and P3 = P2 - ΔPv.

[0041] Based on the above, the auxiliary diaphragm pressure chamber AS is subjected to a mixed pressure P2' (P2>P2'>P3) consisting of the auxiliary pressure P3 (=P2-ΔPv) from the main line Z1 and the secondary pressure P2 from the sub-line Z2. This makes it possible to suppress the occurrence of offset, i.e., the decrease in outlet pressure (secondary pressure P2 downstream of the secondary orifice W).

[0042] To elaborate, first, as the flow rate increases, the pressure of the auxiliary pressure P3 decreases due to the differential pressure of ΔPv, as described above. Furthermore, the pressure difference between the secondary pressure P2 and the auxiliary pressure P3 is proportional to the square of the flow rate, and the auxiliary pressure P3 decreases as the flow rate increases. As a result, the mixing pressure P2' also decreases.

[0043] Next, as the mixing pressure P2' in the auxiliary diaphragm pressure chamber AS decreases, the valve body is pushed down by the pilot spring n1 via the connecting rod j1 and diaphragm D2.

[0044] Next, as the valve body lowers, the opening of the pilot valve V increases, and the control pressure Pc flows downstream (to the low-pressure side) through the pilot governor 3 (second diaphragm pressure chamber S2). As a result, the gas flow rate through the pilot governor 3 and downstream becomes greater than the gas flow rate through restrictor K, causing the control pressure Pc to decrease.

[0045] Finally, as the control pressure Pc decreases as described above, the sleeve 12 of the governor body 1 expands, allowing more gas to flow into the governor body 1 and the downstream pipeline R2. As a result, the outlet pressure increases (Venturi effect).

[0046] Here, needle valves v1 and v2 are provided as variable apertures in the main line Z1 and sub-line Z2, respectively. The operator can investigate the outlet pressure by operating the needle valves v1 and v2.

[0047] In particular, the operator can adjust the strength of the Venturi effect by adjusting the valve opening of the main line Z1 with the needle valve v1, and adjust the degree of mitigation of the Venturi effect by adjusting the valve opening of the sub-line Z2 with the needle valve v2. A strong Venturi effect refers to a state where the control pressure Pc decreases excessively in response to an excessive decrease in the auxiliary pressure P3, resulting in an excessive increase in the outlet pressure.

[0048] To elaborate on the above adjustments, if the Venturi effect is strong, the operator increases the opening of needle valve v2, and if it is still strong, decreases the opening of needle valve v1. Furthermore, if the Venturi effect is strong, the operator increases the opening of needle valve v1, and if it is still weak, decreases the opening of needle valve v2.

[0049] Here, the valve openings of needle valves v1 and v2 can be calculated using the following formula. Using the assumptions shown in Equations 1 to 3, the mixing ratio (needle valve opening) shown in Equation 4 is calculated. The parameters used in each formula are as follows: Q: Gas flow rate to auxiliary diaphragm pressure chamber AS(P2') Se1: Cross-sectional area inside needle valve v1 Se2: Cross-sectional area inside needle valve v2 u1: Flow velocity inside needle valve v1 u2: Flow velocity inside needle valve v2 ρ: Density of city gas (kg / m³) 2 )

[0050]

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[0051]

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[0054] <Effects> According to this embodiment as described above, the gas governor X provides the following effects.

[0055] In other words, the gas governor X produces a Venturi effect by providing a secondary orifice W. Compared to conventional gas governors, the presence of a sub-line Z2 allows for fine-tuning of the Venturi effect by adjusting the valve opening of the sub-line Z2 in conjunction with the main line Z1 using needle valves v1 and v2.

[0056] In particular, if the Venturi effect is strong and the outlet pressure rises excessively, supplying pressure that exceeds the tolerance range of the combustor or regulator to which the pressure is supplied can cause equipment failure. Recently, with the gas governor X, by adjusting the needle valves v1 and v2, a mixing pressure P2' such that P2 > P2' > P3 can be generated, thereby suppressing an excessive drop in pressure inside the auxiliary diaphragm pressure chamber AS. As a result, it is possible to suppress the occurrence of equipment failures due to excessive increases in outlet pressure.

[0057] Furthermore, since sub-line Z2 connects the downstream pipeline R2, which is upstream of the secondary orifice W, to the auxiliary diaphragm pressure chamber AS, the pipeline up to the secondary orifice W can be manufactured as a single product (gas governor X). In other words, if sub-line Z2 is connected downstream of the secondary orifice W, this downstream portion corresponds to the various pipelines to which the gas governor X is applied. Therefore, the design of sub-line Z2 will need to be adjusted according to the pipeline to which it is applied. Recently, according to this embodiment, the gas governor X, including the sub-line Z2, can be manufactured as a single product, so the secondary orifice W can be designed and connected according to the pipeline to which it is applied, thus improving versatility.

[0058] Furthermore, since sub-line Z2 connects the downstream pipeline R2 and the auxiliary diaphragm pressure chamber AS via main line Z1, a mixed pressure P2' is generated at the end of main line Z1. This allows the mixing pressure P2' to be applied more directly to the auxiliary diaphragm pressure chamber AS, thereby suppressing the offset.

[0059] Furthermore, because the variable aperture is a needle valve v1 and v2, fine adjustments to the valve opening of the main line Z1 and sub-line Z2 can be easily made.

[0060] <Example> The following shows the gas flow rate (m³) corresponding to the valve opening of the main line Z1 (aperture 1) and sub-line Z2 (aperture 2) using Figure 2. 3 We will explain the relationship between (hours) and outlet pressure (kPa). As shown in Figure 2, in this example, the set pressure (secondary pressure P2) was set to 50 kPa, the primary pressure P1 to 0.5 MPa, and the test fluid was air.

[0061] As shown in Figure 2, when the valve opening of the main line Z1 (throttle 1) is set to 100% and the valve opening of the sub-line Z2 (throttle 2) is set to 0%, that is, in the same configuration as a conventional gas governor, the outlet pressure increases with increasing flow rate.

[0062] Conversely, when the valve opening of the main line Z1 (throttle 1) is set to 0% and the valve opening of the sub-line Z2 (throttle 2) is set to 100%, the outlet pressure decreases as the flow rate increases.

[0063] Recently, by opening both the main line Z1 (aperture 1) and the sub-line Z2 (aperture 2), it has been observed that, compared to the two examples above, the outlet pressure remains stable at around the set pressure of 50 kPa even when the flow rate increases.

[0064] In this example, the most stable outlet pressure is achieved when the valve opening of the main line Z1 (aperture 1), shown by the thick dashed line, is set to 100%, and the valve opening of the sub-line Z2 (aperture 2) is set to 10%. However, the valve opening that maintains stability will vary depending on the usage conditions. Furthermore, the operator can easily vary the valve opening of each main line Z1 and sub-line Z2 by adjusting the needle valves v1 and v2.

[0065] <Example of changes> The shapes and dimensions of the components shown in the above embodiment are examples only and can be modified in various ways based on design requirements, etc.

[0066] For example, although this embodiment describes an example of application to an axial flow governor (AFV), it is not limited to AFVs and can be applied to pilot-operated pressure regulators in general. In other words, it is also applicable to governors whose valve body is driven by a control pressure, and which consists of a general valve structure comprising a valve seat and a sliding valve body that opens and closes it.

[0067] Furthermore, in this embodiment, the variable apertures provided on the main line Z1 and sub-line Z2 are needle valves v1 and v2, but the invention is not limited to these, and may also be a nozzle flapper (which has the same function as an aperture by adjusting the distance between the valve seat and the valve body).

[0068] Furthermore, in this embodiment, an example was given in which a restrictor K was used as a means to reduce the gas pressure at the primary pressure P1 in the pilot loop 2 to generate the control pressure Pc. However, a venturi may be used in some cases to achieve a similar function.

[0069] Furthermore, in this embodiment, an example using a secondary orifice W was mainly described as a means of generating a differential pressure ΔPv when gas flow occurs in the downstream pipeline R2, but in some cases, a venturi can also be used to achieve a similar function.

[0070] Furthermore, in this embodiment, an example is shown where the subline Z2 is connected upstream of the secondary orifice W in the downstream conduit R2, but it may also be connected downstream of the secondary orifice W.

[0071] Furthermore, in this embodiment, an example is shown in which the sub-line Z2 connects the downstream pipeline R2 and the auxiliary diaphragm pressure chamber AS via the main line Z1. However, the downstream pipeline R2 and the auxiliary diaphragm pressure chamber AS may be connected directly without going through the main line Z1. [Explanation of Symbols]

[0072] X Gas Governor 1. Governor body 11 Closure 12 sleeves 13 Valve body 2 Pilot Loops K Restrictor 3 Pilot Governor S1-S4 Diaphragm pressure chamber D1~D3 Diaphragm AS Auxiliary Diaphragm Pressure Chamber V Pilot Valve W Secondary orifice Z connecting conduit Z1 Mainline Z2 Subline v1, v2 needle valve P1 Primary pressure P2 Secondary pressure P2' Mixing pressure P3 Auxiliary pressure Pc control pressure R1 Upstream pipeline R2 Downstream pipe line

Claims

1. The governor itself is installed in the middle of the pipeline and reduces the pressure of the gas transported from the upstream side at primary pressure to secondary pressure before flowing it downstream. A restrictor is provided to generate a control pressure for controlling the operation of the governor body, and a pilot loop is connected between the upstream and downstream pipelines of the governor body. A pilot governor is installed in the pilot loop and is configured to open and close a pilot valve in accordance with the secondary pressure of the gas, thereby controlling the amount of gas passing through the pilot loop, and to provide feedback control to the governor body so that the secondary pressure remains constant. Equipped with, A gas governor that reduces the pressure of the gas supplied from the upstream side and supplies it to the downstream side by changing the valve opening of the governor body using the control pressure controlled by the pilot governor, The system includes a secondary orifice located in the downstream pipeline, an auxiliary diaphragm pressure chamber included in the pilot governor which controls the degree of opening and closing of the pilot valve according to its internal pressure, and a connecting pipeline connecting the auxiliary diaphragm pressure chamber and the downstream pipeline. The secondary orifice generates negative pressure based on the gas flow in the downstream pipeline, detects changes in the gas flow rate in the downstream pipeline as pressure changes, and generates an auxiliary pressure lower than the secondary pressure by the amount of the negative pressure. The auxiliary diaphragm pressure chamber is positioned opposite the pilot spring of the pilot governor to assist the force that opens and closes the pilot valve. The connecting pipeline includes a main line connecting the secondary orifice and the auxiliary diaphragm pressure chamber, and a sub-line connecting the downstream pipeline, either upstream or downstream of the secondary orifice, to the auxiliary diaphragm pressure chamber. The main line and the sub-line are each provided with a variable aperture. The internal pressure of the auxiliary diaphragm pressure chamber is the mixed pressure of the auxiliary pressure of the gas passing through the main line and the secondary pressure of the gas passing through the sub-line. Gas cabana.

2. The sub-line connects the downstream conduit upstream of the secondary orifice to the auxiliary diaphragm pressure chamber. The gas governor according to claim 1.

3. The sub-line connects the downstream pipeline and the auxiliary diaphragm pressure chamber via the main line. The gas governor according to claim 1.

4. The variable aperture is a needle valve. A gas governor according to any one of claims 1 to 3.

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