Device and method for testing operation stability of urban gas pressure regulating equipment under hydrogen-doped condition

Abstract

The invention belongs to the technical field of natural gas equipment testing, and particularly relates to a device and a method for testing the operation stability of urban gas pressure regulating equipment under a hydrogen-doped condition. The device comprises a gas mixing system, a working condition adjusting system, a testing system, an emptying system and a data management system. The gas mixing system comprises a high-purity hydrogen cylinder, a high-purity natural gas cylinder, a high-purity nitrogen cylinder and a gas mixing stainless steel tank; the working condition adjusting system comprises a compressor, a pressure reducing valve and a pressure stabilizing tank; the test system comprises a to-be-tested pressure regulating valve and a reducer union. The gas emptying system comprises an exhaust valve and a flame arrester; the data management system includes a computer. The device can determine whether the urban gas in-service pressure regulator adapts to the hydrogen doping condition or not.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas equipment testing, and in particular to a device and method for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions. Background Art

[0003] With the development of green hydrogen technology, the cost of green hydrogen is expected to be reduced on a large scale. Hydrogen blending and transportation will help expand the green hydrogen consumption channels, help achieve deep carbon reduction goals, and reduce carbon emissions during natural gas combustion. Making full use of the existing pipeline infrastructure can achieve large-scale, long-distance, and low-cost transportation of hydrogen. City gas receives upstream natural gas from the gate station and is transported to end users through multi-stage pressure regulation. However, hydrogen is a small molecule gas compared to natural gas, and may affect the pressure regulation characteristics during the pressure regulation process, especially the pressure stabilization performance and shutdown performance of the pressure regulator. Therefore, it is necessary to conduct operational stability tests under hydrogen blending conditions for city gas in-service pressure regulating equipment. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a device and method for testing the operating stability of city gas pressure regulating equipment under hydrogen blending conditions. Through a set of testing devices designed by the present invention, the gas flow and outlet pressure flowing through the pressure regulator are adjusted to test the pressure stabilization performance and closing performance of the pressure regulator under different hydrogen blending ratios, so as to determine whether the city gas in-service pressure regulator is suitable for hydrogen blending conditions, and provide technical support for the safe and stable operation of hydrogen-blended natural gas in city gas.

[0005] A device for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions comprises a gas mixing system, a working condition regulating system, a testing system, a venting system and a data management system.

[0006] The gas mixing system includes high-purity hydrogen cylinders, high-purity natural gas cylinders, high-purity nitrogen cylinders, and gas mixing stainless steel tanks;

[0007] The working condition adjustment system includes a compressor, a pressure reducing valve and a pressure stabilizing tank;

[0008] The test system includes a pressure regulating valve to be tested and a reducing joint;

[0009] The gas venting system includes a flame arrester;

[0010] Data management systems include computers;

[0011] The high-purity hydrogen cylinder and the high-purity natural gas cylinder are respectively connected to the gas-mixing stainless steel tank; the pipelines through which the high-purity hydrogen cylinder and the high-purity natural gas cylinder are respectively connected to the gas-mixing stainless steel tank are respectively connected to the high-purity nitrogen cylinder; the gas-mixing tank is respectively connected to the pressure-stabilizing tank through the compressor and the pressure reducing valve; the pressure-stabilizing tank is respectively connected to the flame arrester through the first pipeline provided with the pressure regulating valve to be tested and the second pipeline provided with a reducing joint;

[0012] A hydrogen flow control valve is provided on the pipeline between the high-purity hydrogen cylinder and the mixed gas stainless steel tank; a natural gas flow control valve is provided on the pipeline between the high-purity natural gas cylinder and the mixed gas stainless steel tank; a mixed gas turbine flowmeter, a pressure sensor and a temperature sensor are provided between the pressure stabilizing tank and the pressure regulating valve to be tested; a pressure sensor, a temperature sensor and a pressure regulating valve are provided between the pressure regulating valve to be tested and the flame arrester; the hydrogen flow control valve, the natural gas flow control valve, the mixed gas turbine flowmeter, the pressure sensor, the temperature sensor and the pressure regulating valve are respectively connected to computer signals.

[0013] Furthermore, a hydrogen cylinder outlet switch valve and a hydrogen turbine flowmeter are provided at the outlet of the hydrogen cylinder; a natural gas cylinder outlet switch valve and a natural gas turbine flowmeter are provided at the outlet of the natural gas cylinder; a nitrogen cylinder outlet switch valve is provided at the outlet of the nitrogen cylinder; the front ends of the compressor and the pressure reducing valve are respectively connected to electric switch valves; the rear ends of the compressor and the pressure reducing valve are respectively connected to stop valves; both ends of the pressure regulating valve to be tested and the reducer are respectively connected to full-bore ball valves; the front end of the flame arrester is connected to a stop valve; the gas mixing tank and the pressure stabilizing tank are respectively provided with a pressure transmitter and a temperature transmitter.

[0014] A method for testing the operating stability of a city gas pressure regulating device under hydrogen mixing conditions is implemented using the above-mentioned device and comprises the following steps:

[0015] S1: According to the interface size of the test voltage regulator, select the reducer and complete the installation of the voltage regulator to be tested on the test system;

[0016] S2: Input the required hydrogen-blended natural gas flow rate into the computer, calculate and automatically adjust the flow control valves of hydrogen and natural gas cylinders, and mix to form a hydrogen-blended mixed gas with a specific hydrogen-blending ratio;

[0017] S3: Test voltage stabilization performance;

[0018] S4: Test closing performance;

[0019] S5: After the test is completed, gas replacement and safe discharge are carried out.

[0020] Furthermore, step S1 specifically includes the following steps:

[0021] According to the port size of the pressure regulating equipment to be tested, select the appropriate reducer size and connect it through the flange; open the full-bore ball valve on the test pipeline and close the full-bore valves on other non-test pipelines in the test system.

[0022] Furthermore, step S2 specifically includes the following steps:

[0023] According to the parameters of the hydrogen and natural gas ratio and the test requirements, open the valves and flow control valves of the hydrogen and natural gas cylinders, control the turbine flowmeter reading within the test requirements, and form a stable mixed gas in the mixing tank; use the hydrogen concentration detector to analyze the hydrogen content in the mixing tank and make adjustments until the ratio of the natural gas and hydrogen mixed gas meets the test requirements.

[0024] Furthermore, step S3 specifically includes the following steps:

[0025] The hydrogen bottle outlet flow control valve and the natural gas bottle outlet flow control valve are controlled by a turbine flowmeter and a computer to adjust the flow through the pressure regulator to be tested to 20%, 30%, 50%, 70%, 80% and 90% of the maximum working flow of the pressure regulator, respectively. The computer automatically collects the outlet pressure value of the pressure regulator to be tested through the pressure transmitter; the pressure stabilization performance is calculated through the flow change and the corresponding pressure regulator outlet pressure, taking the pressure regulator outlet pressure of pure natural gas, i.e., when the hydrogen blending ratio is 0, as the reference value.

[0026] Furthermore, step S4 specifically includes the following steps:

[0027] The compressor, pressure reducing valve, computer and pressure transmitter control and adjust the inlet pressure of the pressure regulator to be tested. The pressure transmitter indicates the inlet pressure value of the pressure regulator; the pressure transmitter measures the outlet pressure value of the pressure regulator to be tested; the turbine flowmeter measures the flow rate through the pressure regulator to be tested. The pressure transmitter indication rate of the pressure regulator to be tested is set by the computer to be higher than the maximum allowable inlet pressure of the pressure regulator to be tested; the outlet control valve is slowly closed by computer control until the turbine flowmeter indication is 0, and the outlet control valve is immediately closed. The pressure transmitter pressure regulator outlet pressure measured by the computer is taken as the pressure value 10 minutes after closing. The pressure regulator outlet closing pressure when the pure natural gas, i.e. the hydrogen blending ratio is 0, is used as the reference value to calculate the influence of the hydrogen blending ratio on the closing performance.

[0028] Furthermore, step S5 specifically includes the following steps:

[0029] After the test is completed, gas replacement and safe discharge are carried out. The specific operations are as follows: After the test is completed, open all valves except the outlet switch valves of the hydrogen cylinder, natural gas cylinder, and nitrogen cylinder to make the integrated system a passage and release the pressure; open the nitrogen cylinder outlet switch valve, and inject nitrogen from the hydrogen cylinder and natural gas cylinder outlet pipelines respectively, purge the gas mixing system, operating condition adjustment system, and test system, and vent the gas through the venting system for no less than 5 minutes; after completing the gas replacement of hydrogen and natural gas, close the nitrogen cylinder outlet valve to realize the gas replacement of hydrogen pipelines and natural gas pipelines with nitrogen; finally, close all valves.

[0030] The embodiments of the present invention have the following beneficial effects:

[0031] Through a set of testing devices designed by the present invention, the gas flow and outlet pressure flowing through the pressure regulator are adjusted, aiming to test the influence of different hydrogen blending ratios on the pressure stabilizing performance and closing performance of the pressure regulator to determine whether the city gas in-service pressure regulator is suitable for hydrogen blending conditions, so as to provide technical support for the safe and stable operation of hydrogen-blended natural gas in city gas.

[0032] Automatic natural gas hydrogen blending adjustment system based on flow calculation control. According to the flow adjustment conditions required for the stability test of the pressure regulating equipment, the hydrogen flow and natural gas flow are adjusted through computer-assisted automatic control to achieve automatic real-time matching.

[0033] Based on the pressure before the pressure regulating device, the compressor and the pressure reducing valve are automatically controlled to achieve stepless pressure regulation throughout the whole process. According to the pressure adjustment working conditions required for the stability test of the pressure regulating equipment, the start and stop conditions of the compressor and the pressure reducing valve are automatically identified through the pressure sensor before the pressure regulating device and computer-aided calculation, and the pressure environment required by the test system is met through joint automatic adjustment.

[0034] The full range of pressure regulating devices with a diameter of DN300mm and below can be tested on the test bench. The full range of pressure regulating devices with a diameter of DN300mm and below can be installed and tested by connecting two test pipelines of DN300mm and DN100mm in parallel and using reducers; the two sections of the pressure regulating device are full-bore ball valves to isolate the two pipelines, and the full-bore ball valve eliminates the influence of valve pressure drop.

[0035] Convenient and safe venting system. After the test is completed, open all valves except the outlet switch valves of the hydrogen cylinder, natural gas cylinder, and nitrogen cylinder to make the integrated system a passage and release the pressure; open the outlet switch valve of the nitrogen cylinder, inject nitrogen from the outlet pipelines of the hydrogen cylinder and the natural gas cylinder respectively, purge the gas mixing system, the working condition adjustment system, and the test system, and vent the gas through the venting system. The venting time is not less than 5 minutes; after completing the gas replacement of hydrogen and natural gas, close the outlet valve of the nitrogen cylinder to realize the gas replacement of the hydrogen pipeline and the natural gas pipeline with nitrogen; finally, close all valves. This venting system is equipped with a flame arrester, which has the characteristics of safety; the system is purged with pressurized nitrogen through the nitrogen cylinder, which has the characteristics of convenience. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a schematic structural diagram of a device for testing the operating stability of a city gas pressure regulating device under hydrogen mixing conditions. DETAILED DESCRIPTION

[0037] The present application is further described below in conjunction with embodiments.

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, in the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. Different embodiments can be replaced or combined, and for ordinary technicians in this field, other implementation methods can be obtained based on these embodiments without creative work.

[0039] Combined with Figure 1 A device for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions, including a gas mixing system, an operating condition adjustment system, a testing system, a venting system, and a data management system.

[0040] The gas mixing system includes a high-purity hydrogen cylinder 1, a high-purity natural gas cylinder 2, a high-purity nitrogen cylinder 3, and a gas mixing stainless steel tank;

[0041] The working condition adjustment system includes a compressor 13, a pressure reducing valve 14 and a pressure stabilizing tank 19;

[0042] The test system includes a pressure regulating valve 25 to be tested and a reducer 30;

[0043] The gas venting system includes a flame arrester 35;

[0044] The data management system includes a computer 36;

[0045] The high-purity hydrogen cylinder 1 and the high-purity natural gas cylinder 2 are respectively connected to the gas-mixing stainless steel tank 12; the pipelines through which the high-purity hydrogen cylinder 1 and the high-purity natural gas cylinder 2 are respectively connected to the gas-mixing stainless steel tank 12 are respectively connected to the high-purity nitrogen cylinder 3; the gas-mixing tank 12 is respectively connected to the pressure-stabilizing tank 19 through the compressor 13 and the pressure reducing valve 14; the pressure-stabilizing tank 19 is respectively connected to the flame arrester 35 through the first pipeline provided with the pressure regulating valve 25 to be tested and the second pipeline provided with the reducer 30;

[0046] A hydrogen flow control valve 10 is provided on the pipeline between the high-purity hydrogen cylinder 1 and the mixed gas stainless steel tank 12; a natural gas flow control valve 11 is provided on the pipeline between the high-purity natural gas cylinder 2 and the mixed gas stainless steel tank 12; a mixed gas turbine flowmeter 20, a pressure sensor 23 and a temperature sensor 24 are provided between the pressure stabilizing tank 19 and the pressure regulating valve 25 to be tested; a pressure transmitter 31, a temperature sensor 32 and a pressure regulating valve 33 are provided between the pressure regulating valve 25 to be tested and the flame arrester 35; the hydrogen flow control valve, the natural gas flow control valve, the mixed gas turbine flowmeter, the pressure sensor, the temperature sensor and the pressure regulating valve are respectively connected to computer signals.

[0047] Furthermore, the outlet of the hydrogen cylinder 1 is provided with a hydrogen cylinder outlet switch valve 4 and a hydrogen turbine flowmeter 8; the outlet of the natural gas cylinder 2 is provided with a natural gas cylinder outlet switch valve 7 and a natural gas turbine flowmeter 9; the outlet of the nitrogen cylinder 3 is provided with nitrogen cylinder outlet switch valves 5 and 6; the front ends of the compressor 13 and the pressure reducing valve 14 are respectively connected with electric switch valves 15 and 16; the rear ends of the compressor 13 and the pressure reducing valve 14 are respectively connected with stop valves 17 and 18; the two ends of the pressure regulating valve 25 to be tested and the reducer 30 are respectively connected with full-diameter ball valves (26, 27, 28, 29); the front end of the flame arrester 35 is connected with a stop valve 34; the mixing tank 12 and the pressure stabilizing tank 19 are respectively provided with pressure transmitters (37, 39) and temperature transmitters (38, 22).

[0048] A method for testing the operating stability of a city gas pressure regulating device under hydrogen mixing conditions is implemented using the above-mentioned device and comprises the following steps:

[0049] S1: According to the interface size of the test voltage regulator, select the reducer and complete the installation of the voltage regulator to be tested on the test system;

[0050] S2: Input the required hydrogen-blended natural gas flow rate into the computer, calculate and automatically adjust the flow control valves of hydrogen and natural gas cylinders, and mix to form a hydrogen-blended mixed gas with a specific hydrogen-blending ratio;

[0051] S3: Test voltage stabilization performance;

[0052] S4: Test closing performance;

[0053] S5: After the test is completed, gas replacement and safe discharge are carried out.

[0054] In some embodiments, step S1 specifically includes the following steps:

[0055] According to the port size of the pressure regulating equipment to be tested, select the appropriate reducer size and connect it through the flange; open the full-bore ball valve on the test pipeline and close the full-bore valves on other non-test pipelines in the test system.

[0056] In some embodiments, step S2 specifically includes the following steps:

[0057] According to the parameters of the hydrogen and natural gas ratio and the test requirements, open the valves and flow control valves of the hydrogen and natural gas cylinders, control the turbine flowmeter reading within the test requirements, and form a stable mixed gas in the mixing tank; use the hydrogen concentration detector to analyze the hydrogen content in the mixing tank and make adjustments until the ratio of the natural gas and hydrogen mixed gas meets the test requirements.

[0058] In some embodiments, step S3 specifically includes the following steps:

[0059] The hydrogen bottle outlet flow control valve 10 and the natural gas bottle outlet flow control valve 11 are controlled by the turbine flowmeter 20 and the computer 36, and the flow through the pressure regulator 25 to be tested is adjusted to 20%, 30%, 50%, 70%, 80% and 90% of the maximum working flow of the pressure regulator respectively. The computer 36 automatically collects the outlet pressure value of the pressure regulator 25 to be tested through the pressure transmitter 31; the pressure stabilization performance is calculated through the flow change and the corresponding pressure regulator outlet pressure, taking the pressure regulator outlet pressure of pure natural gas, i.e., when the hydrogen blending ratio is 0, as the reference value.

[0060] In some embodiments, step S4 specifically includes the following steps:

[0061] The compressor 11, the pressure reducing valve 14, the computer 36 and the pressure transmitter 23 control and adjust the inlet pressure of the pressure regulator 25 to be tested. The pressure transmitter 23 indicates the inlet pressure value of the pressure regulator; the pressure transmitter 31 measures the outlet pressure value of the pressure regulator to be tested; the turbine flowmeter 20 measures the flow rate through the pressure regulator to be tested. The computer 36 sets the reading rate of the pressure transmitter 23 of the pressure regulator to be tested to be higher than the maximum allowable inlet pressure of the pressure regulator 25 to be tested; the computer 36 controls the outlet control valve 33 to be slowly closed until the turbine flowmeter 20 indicates 0, and the outlet control valve 33 is immediately closed. The closing pressure shown by the pressure transmitter 31 measured by the computer 36 is taken as the pressure value 10 minutes after closing, and the pressure regulator outlet closing pressure when the pure natural gas, that is, the hydrogen blending ratio is 0, is used as the reference value to calculate the influence of the hydrogen blending ratio on the closing performance.

[0062] In some embodiments, step S5 specifically includes the following steps:

[0063] After the test is completed, gas replacement and safe discharge are carried out. The specific operations are as follows: After the test is completed, open all valves except the outlet switch valves of the hydrogen cylinder, natural gas cylinder, and nitrogen cylinder to make the integrated system a passage and release the pressure; open the nitrogen cylinder outlet switch valve, and inject nitrogen from the hydrogen cylinder and natural gas cylinder outlet pipelines respectively, purge the gas mixing system, operating condition adjustment system, and test system, and vent the gas through the venting system for no less than 5 minutes; after completing the gas replacement of hydrogen and natural gas, close the nitrogen cylinder outlet valve to realize the gas replacement of hydrogen pipelines and natural gas pipelines with nitrogen; finally, close all valves.

[0064] Through a set of testing devices designed by the present invention, the gas flow and outlet pressure flowing through the pressure regulator are adjusted, aiming to test the pressure stabilizing performance and closing performance of the pressure regulator under different hydrogen blending ratios, the relationship with the hydrogen blending ratio, and the degree of influence of the hydrogen blending ratio on it, so as to determine whether the city gas in-service pressure regulator is suitable for the hydrogen blending conditions, and provide technical support for the safe and stable operation of hydrogen-blended natural gas in city gas.

[0065] Automatic natural gas hydrogen blending adjustment system based on flow calculation control. According to the flow adjustment conditions required for the stability test of the pressure regulating equipment, the hydrogen flow and natural gas flow are adjusted through computer-assisted automatic control to achieve automatic real-time matching.

[0066] Based on the pressure before the pressure regulating device, the compressor and the pressure reducing valve are automatically controlled to achieve stepless pressure regulation throughout the whole process. According to the pressure adjustment working conditions required for the stability test of the pressure regulating equipment, the start and stop conditions of the compressor and the pressure reducing valve are automatically identified through the pressure sensor before the pressure regulating device and computer-aided calculation, and the pressure environment required by the test system is met through joint automatic adjustment.

[0067] The full range of pressure regulating devices with a diameter of DN300mm and below can be tested on the test bench. The full range of pressure regulating devices with a diameter of DN300mm and below can be installed and tested by connecting two test pipelines of DN300mm and DN100mm in parallel and using reducers; the two sections of the pressure regulating device are full-bore ball valves to isolate the two pipelines, and the full-bore ball valve eliminates the influence of valve pressure drop.

[0068] Convenient and safe venting system. After the test is completed, open all valves except the outlet switch valves of the hydrogen cylinder, natural gas cylinder, and nitrogen cylinder to make the integrated system a passage and release the pressure; open the outlet switch valve of the nitrogen cylinder, inject nitrogen from the outlet pipelines of the hydrogen cylinder and the natural gas cylinder respectively, purge the gas mixing system, the working condition adjustment system, and the test system, and vent the gas through the venting system. The venting time is not less than 5 minutes; after completing the gas replacement of hydrogen and natural gas, close the outlet valve of the nitrogen cylinder to realize the gas replacement of the hydrogen pipeline and the natural gas pipeline with nitrogen; finally, close all valves. This venting system is equipped with a flame arrester, which has the characteristics of safety; the system is purged with pressurized nitrogen through the nitrogen cylinder, which has the characteristics of convenience.

[0069] Example:

[0070] A method for testing the operating stability of a city gas pressure regulating device under hydrogen mixing conditions is implemented using the above-mentioned device and comprises the following steps:

[0071] S1: According to the interface size of the test voltage regulator, select the reducer and complete the installation of the voltage regulator to be tested on the test system;

[0072] S2: Input the required hydrogen-blended natural gas flow rate into the computer, calculate and automatically adjust the flow control valves of hydrogen and natural gas cylinders, and mix them to form a hydrogen-blended mixed gas;

[0073] S3: Test voltage stabilization performance;

[0074] S4: Test closing performance;

[0075] S5: After the test is completed, gas replacement and safe discharge are carried out.

[0076] In some embodiments, step S1 specifically includes the following steps:

[0077] According to the port size of the pressure regulating equipment to be tested, select a DN100 mm reducer and connect it through a flange; open the full-bore ball valve on the test pipeline and close the full-bore valves on other non-test pipelines in the test system.

[0078] In some embodiments, step S2 specifically includes the following steps:

[0079] According to the hydrogen blending ratio of 0, 5%, 10% and 20%, the valves and flow control valves of the hydrogen cylinder and natural gas cylinder are opened respectively, and the indication of the turbine flowmeter is controlled within the test requirements to form a stable mixed gas in the mixing tank; the hydrogen content in the mixing tank is analyzed by the hydrogen concentration detector and adjusted until the ratio of the natural gas and hydrogen mixed gas meets the test requirements.

[0080] In some embodiments, step S3 specifically includes the following steps:

[0081] The hydrogen bottle outlet flow control valve 10 and the natural gas bottle outlet flow control valve 11 are controlled by the turbine flow meter 20 and the computer 36 to adjust the flow through the pressure regulator 25 to be tested to 20%, 30%, 50%, 70%, 80% and 90% of the maximum working flow of the pressure regulator, respectively. The computer 36 automatically collects the outlet pressure value of the pressure regulator 25 to be tested through the pressure transmitter 31; when the hydrogen blending ratio is 0, the outlet pressure value of the pressure regulator at each flow rate is recorded as P 0x , this value is the reference value; when the hydrogen blending ratio is 5%, the outlet pressure of the pressure regulator at each flow rate is P 5x When the hydrogen blending ratio is 10%, the outlet pressure of the pressure regulator at each flow rate is P 10x , record the outlet pressure of the regulator at each flow rate when the hydrogen blending ratio is 20% 20x .

[0082] Calculation of the pressure stabilization performance A of hydrogen-blended natural gas:

[0083] Voltage stabilization performance with 5% hydrogen doping

[0084]

[0085] The same applies to other hydrogen blending ratios.

[0086] The pressure stabilization performance A of hydrogen-blended natural gas should be less than 5%.

[0087] In some embodiments, step S4 specifically includes the following steps:

[0088] The compressor 11, the pressure reducing valve 14, the computer 36 and the pressure transmitter 23 control and adjust the inlet pressure of the pressure regulator 25 to be tested. The pressure transmitter 23 indicates the inlet pressure value of the pressure regulator; the pressure transmitter 31 measures the outlet pressure value of the pressure regulator to be tested; the turbine flowmeter 20 measures the flow rate through the pressure regulator to be tested. The computer 36 sets the reading rate of the pressure transmitter 23 of the pressure regulator to be tested higher than the maximum allowable inlet pressure of the pressure regulator 25 to be tested; the computer 36 controls the outlet control valve 33 to be slowly closed until the turbine flowmeter 20 indicates 0, and the outlet control valve 33 is immediately closed. The pressure transmitter 31 outlet pressure of the pressure regulator measured by the computer 36 is the pressure value 10 minutes after closing, and the pressure regulator outlet closing pressure P when the pure natural gas, i.e., the hydrogen blending ratio is 0 0x As the reference value, calculate the influence of hydrogen admixture ratio on the closing performance. Record the closing pressure value of the pressure regulator outlet pressure transmitter 31 at each flow rate when the hydrogen admixture ratio is 5%. 5x , record the pressure value of the pressure transmitter 31 at the outlet of the pressure regulator at each flow rate when the hydrogen blending ratio is 10% 10x , record the closing pressure value of the pressure regulator 31 at each flow rate when the hydrogen blending ratio is 20% 20x.

[0089] Calculation of the closing performance S of the regulator under hydrogen doping conditions:

[0090] Shutdown performance with 5% hydrogen doping

[0091]

[0092] The same applies to other hydrogen blending ratios.

[0093] The closing performance S of hydrogen-blended natural gas should be less than 10%.

[0094] In some embodiments, step S5 specifically includes the following steps:

[0095] After the test is completed, gas replacement and safe discharge are carried out. The specific operations are as follows: After the test is completed, open all valves except the outlet switch valves of the hydrogen cylinder, natural gas cylinder, and nitrogen cylinder to make the integrated system a passage and release the pressure; open the nitrogen cylinder outlet switch valve, and inject nitrogen from the hydrogen cylinder and natural gas cylinder outlet pipelines respectively, purge the gas mixing system, operating condition adjustment system, and test system, and vent the gas through the venting system for no less than 5 minutes; after completing the gas replacement of hydrogen and natural gas, close the nitrogen cylinder outlet valve to realize the gas replacement of hydrogen pipelines and natural gas pipelines with nitrogen; finally, close all valves.

[0096] It should be noted that the above embodiments can be freely combined as needed. The above description is only the preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions, characterized in that: Including gas mixing system, working condition adjustment system, testing system, venting system and data management system; The gas mixing system includes high-purity hydrogen cylinders, high-purity natural gas cylinders, high-purity nitrogen cylinders, and gas mixing stainless steel tanks; The working condition adjustment system includes a compressor, a pressure reducing valve and a pressure stabilizing tank; The test system includes a pressure regulating valve to be tested and a reducing joint; The gas venting system includes a flame arrester; Data management systems include computers; The high-purity hydrogen cylinder and the high-purity natural gas cylinder are respectively connected to the gas-mixing stainless steel tank; the pipelines through which the high-purity hydrogen cylinder and the high-purity natural gas cylinder are respectively connected to the gas-mixing stainless steel tank are respectively connected to the high-purity nitrogen cylinder; the gas-mixing tank is respectively connected to the pressure-stabilizing tank through the compressor and the pressure reducing valve; the pressure-stabilizing tank is respectively connected to the flame arrester through the first pipeline provided with the pressure regulating valve to be tested and the second pipeline provided with a reducing joint; A hydrogen flow control valve is provided on the pipeline between the high-purity hydrogen cylinder and the mixed gas stainless steel tank; a natural gas flow control valve is provided on the pipeline between the high-purity natural gas cylinder and the mixed gas stainless steel tank; a mixed gas turbine flowmeter, a pressure sensor and a temperature sensor are provided between the pressure stabilizing tank and the pressure regulating valve to be tested; a pressure sensor, a temperature sensor and a pressure regulating valve are provided between the pressure regulating valve to be tested and the flame arrester; the hydrogen flow control valve, the natural gas flow control valve, the mixed gas turbine flowmeter, the pressure sensor, the temperature sensor and the pressure regulating valve are respectively connected to computer signals.

2. The device for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions according to claim 1, characterized in that: The outlet of the hydrogen cylinder is provided with a hydrogen cylinder outlet switch valve and a hydrogen turbine flowmeter; the outlet of the natural gas cylinder is provided with a natural gas cylinder outlet switch valve and a natural gas turbine flowmeter; the outlet of the nitrogen cylinder is provided with a nitrogen cylinder outlet switch valve; the front ends of the compressor and the pressure reducing valve are respectively connected with electric switch valves; the rear ends of the compressor and the pressure reducing valve are respectively connected with stop valves; the two ends of the pressure regulating valve to be tested and the reducer are respectively connected with full-bore ball valves; the front end of the flame arrester is connected with a stop valve; the gas mixing tank and the pressure stabilizing tank are respectively provided with a pressure transmitter and a temperature transmitter.

3. A method for testing the operating stability of a city gas pressure regulating equipment under hydrogen mixing conditions, characterized in that: The method is accomplished by using the device described in claim 1 or 2, comprising the following steps: S1: According to the interface size of the test voltage regulator, select the reducer and complete the installation of the voltage regulator to be tested on the test system; S2: Input the required hydrogen-blended natural gas flow rate into the computer, calculate and automatically adjust the flow control valves of hydrogen and natural gas cylinders, and mix to form a hydrogen-blended mixed gas with a specific hydrogen-blending ratio; S3: Test voltage stabilization performance; S4: Test closing performance; S5: After the test is completed, gas replacement and safe discharge are carried out.

4. The method for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions according to claim 3 is characterized in that: Step S1 specifically includes the following steps: According to the port size of the pressure regulating equipment to be tested, select the appropriate reducer size and connect it through the flange; open the full-bore ball valve on the test pipeline and close the full-bore valves on other non-test pipelines in the test system.

5. The method for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions according to claim 4, characterized in that: Step S2 specifically includes the following steps: According to the parameters of the hydrogen and natural gas ratio and the test requirements, open the valves and flow control valves of the hydrogen and natural gas cylinders, control the turbine flowmeter reading within the test requirements, and form a stable mixed gas in the mixing tank; use the hydrogen concentration detector to analyze the hydrogen content in the mixing tank and make adjustments until the ratio of the natural gas and hydrogen mixed gas meets the test requirements.

6. The method for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions according to claim 5, characterized in that: Step S3 specifically includes the following steps: The hydrogen bottle outlet flow control valve and the natural gas bottle outlet flow control valve are controlled by a turbine flowmeter and a computer to adjust the flow through the pressure regulator to be tested to 20%, 30%, 50%, 70%, 80% and 90% of the maximum working flow of the pressure regulator, respectively. The computer automatically collects the outlet pressure value of the pressure regulator to be tested through a pressure transmitter; the pressure stabilization performance is obtained through performance calculation based on the flow change and the corresponding pressure regulator outlet pressure, taking the pressure regulator outlet pressure of pure natural gas, i.e., when the hydrogen blending ratio is 0, as the reference value.

7. The method for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions according to claim 6, characterized in that: Step S4 specifically includes the following steps: The compressor, pressure reducing valve, computer and pressure transmitter control and adjust the inlet pressure of the pressure regulator to be tested. The pressure transmitter indicates the inlet pressure value of the pressure regulator; the pressure transmitter measures the outlet pressure value of the pressure regulator to be tested; the turbine flowmeter measures the flow rate through the pressure regulator to be tested. The pressure transmitter indication rate of the pressure regulator to be tested is set by the computer to be higher than the maximum allowable inlet pressure of the pressure regulator to be tested; the outlet control valve is slowly closed by computer control until the turbine flowmeter indication is 0, and the outlet control valve is immediately closed. The pressure transmitter pressure regulator outlet pressure measured by the computer is taken as the pressure value 10 minutes after closing. The pressure regulator outlet closing pressure when the pure natural gas, i.e. the hydrogen blending ratio is 0, is used as the reference value to calculate the influence of the hydrogen blending ratio on the closing performance.

8. The method for testing the operating stability of city gas pressure regulating equipment under hydrogen mixing conditions according to claim 7, characterized in that: Step S6 specifically includes the following steps: After the test is completed, gas replacement and safe discharge are carried out. The specific operations are as follows: After the test is completed, open all valves except the outlet switch valves of the hydrogen cylinder, natural gas cylinder, and nitrogen cylinder to make the integrated system a passage and release the pressure; open the nitrogen cylinder outlet switch valve, and inject nitrogen from the hydrogen cylinder and natural gas cylinder outlet pipelines respectively, purge the gas mixing system, operating condition adjustment system, and test system, and vent the gas through the venting system for no less than 5 minutes; after completing the gas replacement of hydrogen and natural gas, close the nitrogen cylinder outlet valve to realize the gas replacement of hydrogen pipelines and natural gas pipelines with nitrogen; finally, close all valves.

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