Gas governor

Abstract

Provided is a gas governor wherein a Venturi effect can be finely adjusted without being dependent on the dimensional tolerances of a Venturi shape, or similar. The present invention has: a secondary-side orifice W that is positioned in a downstream-side pipeline R2; an auxiliary diaphragm pressure chamber AS that, in accordance with the internal pressure thereof, controls the opening / closing degree of a pilot valve V, and is included in a pilot governor 3; and a connection pipeline Z that connects the auxiliary diaphragm pressure chamber AS and the downstream-side pipeline R2. The secondary-side orifice W produces a negative pressure on the basis of the flow of a gas in the downstream-side pipeline R2, detects a change in the flow rate of the gas in the downstream-side pipeline R2 as a change in pressure, and produces an auxiliary pressure P3 that is lower than a secondary pressure P2 by the amount of the negative pressure. The auxiliary diaphragm pressure chamber AS opposes a pilot spring n1 of the pilot governor 3 and supplements a force which opens and closes the pilot valve V. The connection pipeline Z includes a main line Z1 that connects the secondary-side orifice W and the auxiliary diaphragm pressure chamber AS, and a sub-line Z2 that connects the downstream-side pipeline R2, on the upstream side or the downstream side of the secondary-side orifice W, and the auxiliary diaphragm pressure chamber AS. The main line Z1 and the sub-line Z2 are respectively provided with variable throttles v1, v2. The interior pressure of the auxiliary diaphragm pressure chamber AS is a mixed pressure P2' of the auxiliary pressure P3 of the gas passing through the main line Z1 and the secondary pressure P2 of the gas passing through the sub-line Z2.

Description

Gas governor

[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 the primary pressure from the upstream side to the secondary pressure and supplies it to the downstream side.

[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 to 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. In particular, in the city gas supply system, there is a need for technology that can quickly respond to fluctuations on the supply side and the user side while maintaining stable pressure control.

[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 fine pressure adjustment with a sub-control valve prior to the main control valve, enabling highly accurate pressure control.

[0005] Regarding the above-mentioned 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 orifice (venturi) is located in the pipeline downstream 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 downstream secondary pressure, counteracts the pilot spring to assist in opening and closing the pilot valve. In addition, a throttle and a tank are provided in the pipeline connecting the auxiliary diaphragm pressure chamber and the venturi, so as to mitigate the effects of fluctuations in the secondary pressure occurring in the venturi section from acting abruptly on the auxiliary diaphragm pressure chamber and enable it to function.

[0007] This allows the system to sense not only changes in secondary pressure but also increases in the flow rate of the gas that is reduced to secondary pressure and flows downstream, thereby controlling the control pressure. As a result, the responsiveness of the control pressure to increases in flow rate can be improved, and the offset effect can be reduced, allowing for stable control of the control pressure, which in turn suppresses vibration and swaying.

[0008] Offset refers to the phenomenon where the secondary pressure falls below the set pressure as the flow rate increases. Recently, the gas governor described in Patent Document 1 suppresses 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 decreases as the flow rate increases. Furthermore, the decrease in secondary pressure in the venturi 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. This decrease in control pressure causes the sleeve to expand, increasing the gas flow rate through the governor body (AFV), and consequently increasing the outlet pressure (pressure downstream of the venturi). Hereafter, the above-described sequence of events resulting from the provision of a venturi will be referred to as the "Venturi effect."

[0010] Patent No. 5698545

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

[0012] Specifically, the venturi installed in the downstream pipeline is intended to detect an increase in the downstream gas flow rate and mitigate the occurrence of offset, but the degree of this mitigation depends on the venturi shape. Therefore, individual differences occur in the degree of the venturi effect due to dimensional tolerances of the venturi shape. Furthermore, since the venturi shape cannot be easily changed, increasing the maximum flow rate may increase the secondary pressure more than necessary, and adjusting this 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.

[0014] To accomplish this objective, this disclosure provides gas governors [1] to [4].

[0015] [1] A gas governor comprising: a governor body installed in the middle of a pipeline that reduces the pressure of gas transported from the upstream side at primary pressure to secondary pressure and flows it downstream; a pilot loop connected between the upstream pipeline and the downstream pipeline of the governor body, and provided with a restrictor that generates a control pressure for controlling the operation of the governor body; and a pilot governor installed in the pilot loop that opens and closes a pilot valve according to the secondary pressure of the gas, controls the amount of gas passing through the pilot loop, and is configured to provide feedback control of the governor body so that the secondary pressure remains constant; wherein the gas governor reduces the pressure of the gas supplied from the upstream side and supplies it downstream by changing the valve opening of the governor body using the control pressure controlled by the pilot governor, and comprises: a secondary orifice arranged in the downstream pipeline; an auxiliary diaphragm pressure chamber included in the pilot governor and controlling 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 in opening and closing 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 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 throttle; 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 governor.

[0016] [2] The gas governor according to [1], wherein the subline connects the downstream conduit upstream of the secondary orifice to the auxiliary diaphragm pressure chamber.

[0017] [3] The gas governor according to [1] or [2], wherein the subline connects the downstream pipeline and the auxiliary diaphragm pressure chamber via the mainline.

[0018] [4] The variable aperture is a needle valve, a gas governor as described in any of [1] to [3].

[0019] According to the present invention, it is possible to provide a gas governor that allows for fine adjustment of the Venturi effect without depending on the dimensional tolerances of the Venturi shape.

[0020] This is a schematic diagram showing an embodiment of the present invention applied to an axial flow governor. This is a graph showing the relationship between gas flow rate and outlet pressure according to the degree of throttling of the main line and sub-line in an embodiment of the present invention.

[0021] A gas governor according to an embodiment of the present invention will be described below with reference to Figures 1 and 2. Note that the embodiments shown below are examples of the present invention and the present invention is not limited to these embodiments. In these figures, the reference numeral X indicates the gas governor according to this embodiment.

[0022] <Configuration> As shown in Figure 1, the gas governor X comprises a governor body 1, a pilot loop 2, and a pilot governor 3. The gas governor X also 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 1 using the control pressure Pc controlled by the pilot governor 3.

[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, comprising a pair of truncated cone-shaped closures 11 having multiple slits on their circumferential surface, a rubber sleeve 12 that closes the slits of the closures 11, and a cylindrical valve body 13 that houses these components. This configuration is similar to AFVs that are currently widely used. Furthermore, the AFV is configured such that a control pressure Pc is applied to the space between the sleeve 12 and the valve body 13, causing the slits of the pair of closures 11, which form a drum shape when connected facing each other, to be opened and closed by the sleeve 12.

[0025] The pilot loop 2 is a pipeline connected between the upstream pipeline R1 and the downstream pipeline R2 of the governor body 1, in such a way that it bypasses the governor body 1. A restrictor K is provided to generate a control pressure Pc for controlling the operation of 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. In this way, the pilot governor 3 is configured to provide feedback control of the governor body 1 so that the secondary pressure P2 remains constant.

[0027] Furthermore, the pilot governor 3 has a housing H that is partitioned by multiple diaphragms D1 to D3 and a partition wall, 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 houses 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 to 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 arranged 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 which 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. The diaphragms D1 and D2, and the diaphragms D2 and D3 are connected by connecting rods j1 and j2, respectively, so that all diaphragms D1 to D3 are interlocked and the differential pressure acting on each diaphragm D1 to D3 influences each other.

[0033] Furthermore, a pilot valve V for opening and closing the pilot loop 2 is built into the second diaphragm pressure chamber S2, which is connected to 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 the 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 upstream 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, acting on the governor body 1 via the branch pipe m.

[0036] The set pressure of the pilot governor 3 is determined by the pilot spring n1. More specifically, the difference between the spring force of the pilot spring n1 and the spring force of the 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 the change in the gas flow rate in the downstream pipeline R2 as a pressure change. For example, in the case of this embodiment, it is configured by connecting a Venturi to the downstream pipeline R2. Further, the secondary orifice W detects, as representing the change in the gas flow rate, the auxiliary pressure P3 which is the gas pressure at the minimum diameter portion of the Venturi generated when a gas flow occurs in the downstream pipeline R2. That is, the auxiliary pressure P3 (= P2 - ΔPv) downstream of the secondary orifice W provided in the downstream pipeline R2 is detected as representing the change in the gas flow rate. In the present invention, the term "secondary orifice" is used to include a Venturi.

[0039] The connection 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 and the auxiliary diaphragm pressure chamber AS.

[0040] As described above, the gas having the auxiliary pressure P3 taken out from the secondary orifice W passes through the main line Z1. The gas having the secondary pressure P2 inside the downstream pipeline R2 passes through the sub-line Z2. The auxiliary pressure P3 is the same as the secondary pressure P2 when there is no flow rate, but when a flow rate occurs, a differential pressure of ΔPv occurs and P3 = P2 - ΔPv.

[0041] From the above, a mixed pressure P2' (P2 > P2' > P3) of the auxiliary pressure P3 (= P2 - ΔPv) by the main line Z1 and the secondary pressure P2 by the sub-line Z2 acts on the auxiliary diaphragm pressure chamber AS. Thereby, the occurrence of an offset, that is, the decrease in the outlet pressure (the secondary pressure P2 downstream of the secondary orifice W) can be suppressed.

[0042] Specifically, first, when the flow rate increases, as described above, due to the differential pressure of ΔPv, the pressure of the auxiliary pressure P3 decreases. The differential pressure 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 mixed pressure P2' also decreases.

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

[0044] Next, as the valve body descends, the opening degree of the pilot valve V increases, and the control pressure Pc flows through the inside of the pilot governor 3 (the second diaphragm pressure chamber S2) to the downstream side (low pressure side). As a result, the gas flow rate flowing to the downstream side through the inside of the pilot governor 3 is larger than the gas flow rate passing through the restrictor K, and the control pressure Pc decreases.

[0045] Finally, due to the decrease in the above-mentioned control pressure Pc, the sleeve 12 of the governor body 1 expands, and more gas flows into the governor body 1 and the downstream pipeline R2. As a result, the outlet pressure rises (Venturi effect).

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

[0047] In particular, the operator can adjust the strength of the Venturi effect by adjusting the valve opening degree of the main line Z1 with the needle valve v1, and can adjust the degree of relaxation of the Venturi effect by adjusting the valve opening degree of the sub-line Z2 with the needle valve v2. The state where the Venturi effect is strong means that following the excessive decrease in the auxiliary pressure P3, the control pressure Pc has decreased excessively, and as a result, the outlet pressure has risen excessively.

[0048] Regarding the above adjustment in detail, when the Venturi effect is strong, the operator increases the opening degree of the needle valve v2, and if it is still strong, decreases the opening degree of the needle valve v1. Also, when the Venturi effect is strong, the operator increases the opening degree of the needle valve v1, and if it is still weak, decreases the opening degree of the needle valve v2.

[0049] Here, the valve openings of needle valves v1 and v2 can be calculated using the following formulas. 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') Se １ : Cross-sectional area inside needle valve v1 Se ２ : Cross-sectional area of ​​the inside of needle valve v2 u １ : Flow velocity inside needle valve v1 u ２ : Flow velocity inside needle valve v2 ρ: Density of city gas (kg / m³) ２ )

[0050]

[0051]

[0052]

[0053]

[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, when the Venturi effect is strong and the outlet pressure rises excessively, supplying pressure exceeding the allowable range of the combustor or regulator, which is the supplying device, can cause equipment failure. Recently, with the gas governor X, by adjusting the needle valves v1 and v2, a mixed pressure P2' such that P2 > P2' > P3 can be generated, and an excessive drop in pressure inside the auxiliary diaphragm pressure chamber AS can be suppressed. As a result, the occurrence of equipment failure due to an excessive rise in outlet pressure can be suppressed.

[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). That is, when sub-line Z2 is connected downstream of the secondary orifice W, this downstream portion corresponds to the various pipelines to which gas governor X is applied, so the design of sub-line Z2 etc. needs to be adjusted according to the pipeline to which it is applied. However, according to this embodiment, gas governor X can be manufactured as a single product including sub-line Z2, so it is only necessary to design and connect the secondary orifice W according to the pipeline to which it is applied, thus improving versatility.

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

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

[0060] <Example> Below, using Figure 2, we will show the gas flow rate (m³) according to the valve opening of the main line Z1 (aperture 1) and sub-line Z2 (aperture 2). ３ The relationship between the pressure ( / h) and the outlet pressure (kPa) will be explained. As shown in Figure 2, in this example, the set pressure (secondary pressure P2) is 50 kPa, the primary pressure P1 is 0.5 MPa, and the test fluid is 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 (throttle 1), shown by the thick dashed line, is set to 100%, and the valve opening of the sub-line Z2 (throttle 2) is set to 10%. However, the valve opening that maintains stability will vary depending on the usage conditions. The operator can easily vary the valve openings of the main line Z1 and sub-line Z2 by adjusting the needle valves v1 and v2.

[0065] <Example of modification> Note that the shapes and dimensions of each component 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 is applicable to pilot-operated pressure regulators in general. That is, it is also applicable to governors with a general valve structure consisting of a valve seat and a sliding valve body that opens and closes it, where the valve body is driven by the control pressure.

[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.

[0072] X Gas Governor 1 Governor Body 11 Closure 12 Sleeve 13 Valve Body 2 Pilot Loop 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 Line Z1 Main Line Z2 Sub-line v1, v2 Needle Valve P1 Primary Pressure P2 Secondary Pressure P2' Mixing Pressure P3 Auxiliary Pressure Pc Control Pressure R1 Upstream Line R2 Downstream Line

Claims

1. A gas governor comprising: a governor body installed in the middle of a pipeline to reduce the pressure of gas transported from the upstream side at primary pressure to secondary pressure and flow it downstream; a pilot loop connected between the upstream pipeline and the downstream pipeline of the governor body, and equipped with a restrictor that generates a control pressure to control the operation of the governor body; and a pilot governor installed in the pilot loop, which opens and closes a pilot valve according to the secondary pressure of the gas, controls the amount of gas passing through the pilot loop, and is configured to provide feedback control of the governor body so that the secondary pressure remains constant; wherein the gas governor reduces the pressure of the gas supplied from the upstream side and supplies it downstream by changing the valve opening of the governor body using the control pressure controlled by the pilot governor, and comprises: a secondary orifice arranged in the downstream pipeline; an auxiliary diaphragm pressure chamber included in the pilot governor and controlling 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 in opening and closing 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 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 throttle; 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 governor.

2. The gas governor according to claim 1, wherein the subline connects the downstream conduit upstream of the secondary orifice to the auxiliary diaphragm pressure chamber.

3. The gas governor according to claim 1, wherein the subline connects the downstream pipeline and the auxiliary diaphragm pressure chamber via the mainline.

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

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