Pressure transmitter on-line metering device for natural gas pipeline network

Abstract

The utility model provides a pressure transmitter on-line metering device for a natural gas pipeline network, which comprises a digital pressure gauge standard device, a primary gas pressure pump, a multi-channel pressure-resistant hose, a gas pressure pump gas inlet valve, a multi-channel pressure-resistant hose gas release valve and a multi-channel pressure-resistant hose expansion end, one end of the multi-channel pressure-resistant hose is connected with an outlet of a deflation pipeline of the compressed natural gas conveying pipeline, the other end of the multi-channel pressure-resistant hose is connected with the first-stage gas pressure pump, a gas pressure pump gas inlet valve is arranged at an outlet of the first-stage gas pressure pump, and the digital pressure gauge standard device is arranged on the multi-channel pressure-resistant hose. The multi-channel pressure-resistant hose expansion end is arranged at one end, close to the first-stage gas pressure pump, of the multi-channel pressure-resistant hose, and a multi-channel pressure-resistant hose deflation valve is arranged at an outlet of the multi-channel pressure-resistant hose expansion end. The device provided by the utility model can safely and effectively carry out full-scale metrological verification on the pressure transmitter under the condition that the to-be-verified pressure transmitter with various wiring lines is not disassembled.

Description

Technical Field

[0001] The utility model belongs to the technical field of pressure transmitter verification, and in particular relates to an online metering device for a pressure transmitter used in a natural gas pipeline network. Background Art

[0002] Pressure transmitter is a device that converts pressure into pneumatic or electric signals for control and remote transmission. It can convert physical pressure parameters such as gas and liquid sensed by the pressure measuring element sensor into standard electrical signals (such as 4-20mADC, etc.) to supply secondary instruments such as indicator alarms, recorders, and regulators for measurement, indication, and process regulation. The natural gas of the West-East Gas Transmission Project is compressed to a certain pressure and then transported by pipeline. Pressure transmitters are installed on the natural gas transmission pipelines of the national pipeline network natural gas metering stations, compression stations, and valve rooms for pressure monitoring, and high-precision pressure transmitters are also installed on the metering skids to participate in flow metering. Therefore, the accurate metering of pipeline pressure transmitters is the technical support for the safe transportation and precise metering of natural gas. The metering work of pipeline pressure transmitters is related to natural gas energy security and trade settlement, and its importance is self-evident.

[0003] However, to carry out the measurement of pipeline pressure transmitters, it is necessary to remove them from the pipeline and install them on pressure measurement standards such as automatic standard pressure generators or piston pressure gauges. The standards need to be brought to the measurement site, and piston pressure gauges are bulky and not easy to carry; the measurement site is an explosion-proof place, and the automatic standard pressure generator generally requires an external 220V power supply, which poses a safety hazard; and the pipeline pressure transmitter has many wiring connections to the station control PLC control network, especially the frequent disassembly and assembly of the pressure transmitter may lead to poor sealing and the risk of natural gas leakage; according to the JJG882 pressure transmitter verification regulations, the metrological verification of the pressure transmitter needs to be pressurized to the upper limit of the measurement range, and the upper limit of the measurement range of the pipeline pressure transmitter is generally as high as 16MPa or even higher. Therefore, for high-range pressure transmitters, it is difficult and inefficient to generate pressure by the gas pressure standard used on site alone; and from the perspectives of the feasibility, work efficiency and safety of complex on-site measurement, this traditional disassembly measurement method is inconvenient and needs to be improved.

[0004] Based on this, it is urgent to design an online metering device for pressure transmitters for natural gas pipeline networks, so as to safely and effectively perform full-range metrological calibration on the pressure transmitter without disassembling the pressure transmitter to be inspected. Utility Model Content

[0005] Based on the above defects, the utility model provides an online metering device for a pressure transmitter for a natural gas pipeline network. The device can safely and effectively perform full-range metering calibration on the pressure transmitter without disassembling the pressure transmitter to be inspected with complex wiring, thereby avoiding the risk of natural gas leakage caused by poor sealing due to frequent disassembly and assembly of the pressure transmitter.

[0006] The utility model discloses an online metering device for a pressure transmitter for a natural gas pipeline network, comprising a digital pressure gauge standard, a primary gas pressure pump, a multi-channel pressure-resistant hose, a gas pressure pump intake valve, a multi-channel pressure-resistant hose exhaust valve and a multi-channel pressure-resistant hose extension end, wherein one end of the multi-channel pressure-resistant hose is connected to the outlet of a exhaust pipe of a compressed natural gas transmission pipeline, the other end of the multi-channel pressure-resistant hose is connected to the primary gas pressure pump, a gas pressure pump intake valve is provided at the outlet of the primary gas pressure pump, the digital pressure gauge standard is arranged on the multi-channel pressure-resistant hose, the multi-channel pressure-resistant hose extension end is arranged on the multi-channel pressure-resistant hose at one end close to the primary gas pressure pump, and the multi-channel pressure-resistant hose exhaust valve is provided at the outlet of the multi-channel pressure-resistant hose extension end.

[0007] Preferably, a multi-channel pressure-resistant hose extension end valve is provided at the inlet of the multi-channel pressure-resistant hose extension end.

[0008] Preferably, it also includes a secondary gas pressure pump, which is arranged on the extended end of the multi-channel pressure-resistant hose between the extended end valve of the multi-channel pressure-resistant hose and the multi-channel pressure-resistant hose vent valve.

[0009] Preferably, the primary gas pressure pump and the secondary gas pressure pump have the same structure.

[0010] Preferably, the first-stage gas pressure pump includes a piston, a screw, a pressure regulator, a height-adjustable bracket and a gas pressure pump air release valve. The piston arranged at one end of the screw is located in a sealed housing of the pressure pump, the pressure regulator is arranged at the other end of the screw, the height-adjustable bracket is provided below the sealed housing of the pressure pump, and the gas pressure pump air release valve is provided on one side of the sealed housing of the pressure pump.

[0011] Preferably, a threaded adapter is also provided, which is used for connecting the multi-channel pressure-resistant hose with the outlet of the exhaust pipe, the digital pressure gauge standard, the gas pressure pump inlet valve and the extended end of the channel pressure-resistant hose respectively.

[0012] Preferably, the threaded adapter is also arranged on one end of the outlet of the extended end of the channel pressure-resistant hose.

[0013] Preferably, the digital pressure gauge standard is an explosion-proof digital pressure gauge standard.

[0014] Preferably, the upper pressure limit of the multi-channel pressure-resistant hose and the extended end of the multi-channel pressure-resistant hose is greater than 1.2 times the upper limit of the measuring range of the pressure transmitter to be tested.

[0015] Compared with the prior art, the online metering device for the pressure transmitter for the natural gas pipeline network provided by the utility model has the following beneficial effects:

[0016] The online metering device of the utility model uses the compressed natural gas in the pipeline which can be regarded as a constant pressure as the gas constant pressure source, and uses a multi-channel pressure-resistant hose to connect the pipeline venting end, a digital pressure gauge standard and n gas pressure pumps in parallel to form a pressure calibration system to perform online metering. When the pressure value at the test point is less than or equal to the pipeline pressure p 0 When the pressure value at the test point is greater than the pipeline pressure p 0 When the pressure is too high, the natural gas supplied by n gas pressure pumps is used as the gas source to supplement the pressure, thereby pressurizing the calibration system to reach the preset test point pressure value, recording the standard and measured pressure indications, and completing the metering work of all test points. The utility model can perform full-scale metrological calibration on the pressure transmitter without disassembling the pressure transmitter to be inspected with complex wiring, avoiding the risk of natural gas leakage caused by frequent disassembly and assembly of the pressure transmitter resulting in poor sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of an online metering device for a pressure transmitter for a natural gas pipeline network provided by the utility model;

[0019] The accompanying drawings are marked as follows:

[0020] 1. Compressed natural gas transmission pipeline; 2. Pipeline valve; 3. Pressure transmitter valve; 4. Pressure transmitter; 5. Pipeline vent valve; 6. Threaded adapter; 7. Digital pressure gauge standard; 8. Primary gas pressure pump; 9. Piston; 10. Screw; 11. Pressure regulator; 12. Bracket with height adjustment; 13. Multi-channel pressure-resistant hose; 14. Gas pressure pump vent valve; 15. Gas pressure pump inlet valve; 16. Multi-channel pressure-resistant hose vent valve; 17. Secondary gas pressure pump; 18. Multi-channel pressure-resistant hose extension end valve; 19. Multi-channel pressure-resistant hose extension end; 20. PLC automation control system. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] like Figure 1 As shown on the left side of , at the pressure transmitter on the compressed natural gas transmission pipeline in the prior art, there are provided a compressed natural gas transmission pipeline 1, a pipeline valve 2, a pressure transmitter valve 3, a pressure transmitter 4, a pipeline venting valve 5 and a PLC automatic control system 20. The pressure transmitter valve 3 can remotely transmit the detected natural gas pressure signal to the PLC automatic control system 20 through an electrical connection. The pipeline venting valve 5 is arranged at the outlet of the venting pipeline. The pipeline valve 2 is arranged at the gas source inlet where the compressed natural gas transmission pipeline 1 is connected to the venting pipeline and the pressure transmitter 4. The pressure transmitter valve 3 is arranged at the probe of the pressure transmitter 4, so as to detect the natural gas pressure in the compressed natural gas transmission pipeline 1 which can be regarded as a constant pressure.

[0023] In order to safely and effectively perform full-range measurement verification on the pressure transmitter without disassembling the pressure transmitter to be inspected, the utility model improves and designs an online measurement device for the pressure transmitter used in the natural gas pipeline network at the original pressure transmitter of the natural gas pipeline.

[0024] See also Figure 1 As shown, the utility model of the online metering device of the pressure transmitter for natural gas pipeline network includes a digital pressure gauge standard 7, a primary gas pressure pump 8, a multi-channel pressure-resistant hose 13, a gas pressure pump intake valve 15, a multi-channel pressure-resistant hose exhaust valve 16 and a multi-channel pressure-resistant hose extension end 19. One end of the multi-channel pressure-resistant hose 13 is connected to the outlet of the exhaust pipe of the compressed natural gas transmission pipeline 1, and the other end of the multi-channel pressure-resistant hose 13 is connected to the primary gas pressure pump 8. The gas pressure pump intake valve 15 is provided at the outlet of the primary gas pressure pump 8. The primary gas pressure pump 8 can inject natural gas into the multi-channel pressure-resistant hose 13. The digital pressure gauge standard 7 is arranged on the multi-channel pressure-resistant hose 13 to calibrate the pressure in the pipeline. The multi-channel pressure-resistant hose extension end 19 is arranged on the multi-channel pressure-resistant hose 13 at one end close to the primary gas pressure pump 8. The multi-channel pressure-resistant hose exhaust valve 16 is provided at the outlet of the multi-channel pressure-resistant hose extension end 19 for discharging excess natural gas.

[0025] It can be seen that through the above improvements, the device of the utility model can safely and effectively perform full-scale online measurement calibration of the pressure transmitter without disassembling the pressure transmitter to be inspected with complicated wiring, avoiding the risk of natural gas leakage caused by poor sealing due to frequent disassembly and assembly of the pressure transmitter. In addition, the use of a flexible multi-channel pressure-resistant hose 13 and a channel pressure-resistant hose extension end 19 can prevent excessive space from being occupied when calibrating the pressure transmitter 4, and facilitate the connection of various parallel gas pressure pumps and digital pressure gauge standards and other equipment.

[0026] In another embodiment, a multi-channel pressure-resistant hose expansion end valve 18 is provided at the inlet of the multi-channel pressure-resistant hose expansion end 19, and a secondary gas pressure pump 17 is provided on the multi-channel pressure-resistant hose expansion end 19, that is, between the multi-channel pressure-resistant hose expansion end valve 18 and the multi-channel pressure-resistant hose air release valve 16, so as to form a parallel gas supply source with the primary gas pressure pump 8, and a gas pressure pump inlet valve is also provided at the outlet of the secondary gas pressure pump 17 (shown in the figure, not marked). It should be pointed out that Figure 1 In the figure, there are only two gas pressure pumps connected in parallel. Those skilled in the art can set up several gas pressure pumps on the extended end 19 of the multi-channel pressure-resistant hose as needed to meet the pressure requirements of the calibration.

[0027] At this time, the multi-channel pressure hose extension end 19 is provided with n-1 gas pressure pumps in parallel, thereby cooperating with the primary gas pressure pump 8 to form a pressure source of n gas pressure pumps in parallel; before the test, according to the current pressure value p of the pipeline natural gas 0 , upper limit of pressure transmitter measurement range p max The pressure multiplication coefficient N that a single pressure pump can generate is used to estimate the number of pressure pumps n (n is an integer) that need to be configured, that is, the following relationship should be satisfied:

[0028] n≥(p max / p 0 ) / N (1)

[0029] For example, if the calculation result is n>1, two or more gas pressure pumps need to be incorporated into the calibration system through the pressure hose extension end (if the calculation result n is 1.6, the number of gas pressure pumps is 2). If the calculation result is n≤1, only one gas pressure pump can be used (i.e., only one-stage gas pressure pump 8 is used), and the extension end is not needed. The valve 18 of the multi-channel pressure hose extension end is closed, which is only opened when exhausting.

[0030] In another embodiment, if Figure 1As shown, for n gas pressure pumps of various levels connected in parallel (including a primary gas pressure pump 8 and a secondary gas pressure pump 17), the structures of the gas pressure pumps of various levels are the same. Taking the primary gas pressure pump 8 as an example, it includes a piston 9, a screw 10, a pressure regulator 11, a height-adjusting bracket 12 and a gas pressure pump air release valve 14. The piston 9 arranged at one end of the screw 10 is located in the pressure pump sealed housing, and the pressure regulator 11 is arranged at the other end of the screw 10. The screw 10 and the piston 9 are pushed to move horizontally through external rotation to push the natural gas to pressurize the multi-channel pressure-resistant hose 13. A height-adjusting bracket 12 is provided below the pressure pump sealed housing, and a gas pressure pump air release valve 14 is provided on one side for adjusting the height and releasing excess gas in the pressure pump.

[0031] In another embodiment, a threaded adapter 6 is further provided. Figure 1 As shown, the threaded adapter 6 can be used for the connection between the multi-channel pressure-resistant hose 13 and the outlet of the venting pipe, the digital pressure gauge standard 7, the gas pressure pump inlet valve 15 and the channel pressure-resistant hose extension end 19 respectively, and can also be set at the outlet of the channel pressure-resistant hose extension end 19 to facilitate the subsequent extension and expansion connection of the next-level gas pressure pump.

[0032] In another embodiment, the digital pressure gauge standard 7 should use an explosion-proof digital pressure gauge standard, whose upper limit of measurement range can cover the upper limit of measurement of the pressure transmitter to be measured; the accuracy level of the digital pressure gauge standard 7 should not be lower than level 0.05 and the periodic stability should be qualified; its maximum allowable error absolute value should not be greater than 1 / 4 of the maximum allowable error absolute value of the pressure transmitter to be measured. In addition, based on safety considerations, the upper limit of the pressure resistance of the multi-channel pressure-resistant hose 13 and the multi-channel pressure-resistant hose extension end 19 and the gas pressure pumps of each level (including the primary gas pressure pump 8 and the secondary gas pressure pump 17) should be greater than 1.2 times the upper limit of the measurement range of the pressure transmitter 4 to be measured.

[0033] In order to facilitate understanding of the advantages and working principle of the online metering device of the pressure transmitter for natural gas pipeline network in the utility model, the following detailed introduction is given to its better safety operation mode:

[0034] (a). After connecting the required gas pressure pumps of each level to the calibration system, close the pipeline valve 2, open the pressure transmitter valve 3 and the pipeline vent valve 5 to release all the natural gas at the pressure transmitter end. At this time, if the indication of the gauge pressure transmitter is not zero, it should be reset. For the absolute pressure transmitter, directly record its indication.

[0035] (b) Connect the digital pressure gauge standard 7, which has been preheated for at least 30 minutes, to the multi-channel pressure-resistant hose 13. The gauge pressure type pressure gauge standard should be reset to zero, while the absolute pressure type pressure gauge standard should directly record the indicated value, thus completing the zero-position measurement.

[0036] (c) Connect the multi-channel pressure-resistant hose 13 to the outlet end of the venting pipe through the threaded adapter 6, adjust the gas pressure pumps at each level to the initial position and load the natural gas to maximize the pressure pump cavity space, open all gas pressure pump inlet valves, close the gas pressure pump vent valves, and the entire calibration system is completed.

[0037] (d) Open the pipeline vent valve 5 and pipeline valve 2. At this time, the compressed natural gas in the pipeline enters the calibration system and the pressure of the calibration system rises. When the pressure reaches the first non-zero test point, close the pipeline valve 2. After the pressure stabilizes, record the indications of the digital pressure gauge standard 7 and the pressure transmitter 4 being tested (the indication of the pressure transmitter uses the pressure value transmitted to the PLC system for display) to complete the measurement of the test point.

[0038] (e) Open pipeline valve 2 to pressurize the calibration system and measure the next test point. If the pressure value at the test point exceeds the current pressure value p of the pipeline natural gas, which can be regarded as constant pressure, 0 , when the calibration system pressure reaches p 0 When near, close the pipeline valve 2, use the first-level gas pressure pump 8 pressure regulator to compress the volume of natural gas in the cavity, so as to pressurize the calibration system to reach the preset test point pressure value, and record the standard and measured pressure indications after the indication stabilizes to complete the measurement of the test point.

[0039] (f) If the primary gas pressure pump 8 has reached its working limit but the system pressure has not yet reached the test point, close the primary pressure pump inlet valve 8 and use the secondary gas pressure pump 17 to increase the pressure…, by gradually operating multiple gas pressure pumps until the calibration system pressure reaches the required pressure value, complete the measurement to the upper limit of the measurement point by point, and complete the positive stroke measurement step.

[0040] (g) Then reverse the pressure regulator 11 to perform the return stroke test until all non-zero pressure test points are measured; open the vent valves of all gas pressure pumps, vent the natural gas of the calibration system, and record the zero position indication of the digital pressure gauge standard 7 and the pressure transmitter 4 in the reverse stroke; complete the reverse stroke measurement step.

[0041] (h). Disconnect the multi-channel pressure hose 13 from the venting pipeline; close the pipeline venting valve 5, open the pipeline valve 2 and the pressure transmitter valve 3, and the natural gas in the pipeline enters the pressure transmitter end. Then open the pipeline venting valve 5 to exhaust the air. Repeat the operation several times until the residual air at the pressure transmitter end is exhausted. Finally, completely close the pipeline venting valve 5, open the pipeline valve 2 and the pressure transmitter valve 3, and the pressure transmitter 4 will resume normal working state.

[0042] (i) Use tools such as spray bottles and combustible gas alarms to check the sealing of the calibration system and complete the calibration work.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. An online metering device for a pressure transmitter for a natural gas pipeline network, characterized in that: It includes a digital pressure gauge standard, a primary gas pressure pump, a multi-channel pressure-resistant hose, a gas pressure pump intake valve, a multi-channel pressure-resistant hose exhaust valve and a multi-channel pressure-resistant hose extension end, wherein one end of the multi-channel pressure-resistant hose is connected to the outlet of the exhaust pipe of the compressed natural gas transmission pipeline, the other end of the multi-channel pressure-resistant hose is connected to the primary gas pressure pump, a gas pressure pump intake valve is provided at the outlet of the primary gas pressure pump, the digital pressure gauge standard is arranged on the multi-channel pressure-resistant hose, the multi-channel pressure-resistant hose extension end is arranged on one end of the multi-channel pressure-resistant hose close to the primary gas pressure pump, and the multi-channel pressure-resistant hose exhaust valve is provided at the outlet of the multi-channel pressure-resistant hose extension end.

2. The online metering device for pressure transmitter for natural gas pipeline network according to claim 1 is characterized in that: A multi-channel pressure-resistant hose extension end valve is provided at the inlet of the multi-channel pressure-resistant hose extension end.

3. The online metering device for pressure transmitter for natural gas pipeline network according to claim 2 is characterized in that: It also includes a secondary gas pressure pump, which is arranged on the extended end of the multi-channel pressure-resistant hose between the extended end valve of the multi-channel pressure-resistant hose and the multi-channel pressure-resistant hose deflation valve.

4. The online metering device for pressure transmitter for natural gas pipeline network according to claim 3 is characterized in that: The primary gas pressure pump and the secondary gas pressure pump have the same structure.

5. The online metering device for pressure transmitter for natural gas pipeline network according to claim 4, characterized in that: The first-stage gas pressure pump includes a piston, a screw, a pressure regulator, a height-adjustable bracket and a gas pressure pump air release valve. The piston arranged at one end of the screw is located in a sealed housing of the pressure pump, the pressure regulator is arranged at the other end of the screw, the height-adjustable bracket is arranged below the sealed housing of the pressure pump, and the gas pressure pump air release valve is arranged on one side of the sealed housing of the pressure pump.

6. The online metering device for pressure transmitter for natural gas pipeline network according to claim 1, characterized in that: A threaded adapter is also provided, which is arranged at the connection between the multi-channel pressure-resistant hose and the outlet of the venting pipeline, the digital pressure gauge standard, the gas pressure pump inlet valve and the extended end of the channel pressure-resistant hose.

7. The online metering device for pressure transmitter for natural gas pipeline network according to claim 6, characterized in that: The threaded adapter is also arranged on one end of the outlet of the expanded end of the channel pressure-resistant hose.

8. The online metering device for pressure transmitter for natural gas pipeline network according to claim 1, characterized in that: The digital pressure gauge standard is specifically an explosion-proof digital pressure gauge standard.

9. The online metering device for pressure transmitter for natural gas pipeline network according to claim 1, characterized in that: The upper pressure limit of the multi-channel pressure-resistant hose and the extended end of the multi-channel pressure-resistant hose is greater than 1.2 times the upper limit of the measuring range of the pressure transmitter to be tested.

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