A system for preventing reverse rotation of a centrifugal supercharger impeller

Abstract

The utility model relates to a system for preventing centrifugal supercharger impeller reverse rotation relates to supercharger field, including electric regulating valve, solenoid valve and manual ball valve, electric regulating valve input is connected with compressor output through pipeline, and electric regulating valve output is connected with compressor input through pipeline, and solenoden valve is connected with electric regulating valve in parallel through pipeline, and two manual ball valves are fixedly connected on solenoden valve input pipeline and output pipeline respectively to control natural gas flow direction electric regulating valve or solenoid valve, and the high pressure natural gas of compressor output flows through solenoid valve and flows to compressor input more quickly to balance the pressure difference before and after compressor and prevent impeller reverse rotation, the utility model has the advantages of realizing the quick balance to the supercharger entrance and exit pressure, avoiding impeller reverse rotation.

Description

Technical Field

[0001] This utility model relates to the field of booster technology, and in particular to a system for preventing the impeller of a centrifugal booster from reversing. Background Technology

[0002] In natural gas and other gas transmission systems, centrifugal booster compressors (natural gas compressors) are the core booster equipment, and the normal forward rotation of their impellers is crucial to ensuring the efficient and stable operation of the equipment. However, in actual operation, impeller reversal occurs frequently, posing a significant threat to equipment safety.

[0003] Under normal operating conditions, after the natural gas compressor is powered on, the impeller's forward rotation speed gradually increases to the normal operating state, and the pressure in the compressor's downstream pipeline gradually increases. When the motor is powered off, gas in the high-pressure zone of the downstream pipeline flows to the low-pressure zone of the upstream pipeline, causing the impeller to rotate in the opposite direction. Furthermore, although the compressor has return pipes before and after compression to balance the gas pressure, when the pressure ratio between the high-pressure zone and the low-pressure zone exceeds the design maximum compression ratio, the electric regulating valve needs to be opened to return the gas. However, if the electric regulating valve is not opened or its opening is insufficient, and the pressure difference before and after the compressor cannot be balanced instantaneously, it will also cause the impeller to reverse.

[0004] Impeller reversal can cause a series of serious hazards: shaft damage, increased vibration leading to failure of radial bearing hydrodynamic lubrication, dry friction between the journal and bearing, causing wear or even seizure in a short time; structural resonance, the reversing torque coupled with the shaft's natural frequency, exacerbating the failure of components such as seals and couplings; reverse current, the impeller reversal causes the motor to reverse, generating induced current, impacting the frequency converter and causing overload burnout.

[0005] Therefore, to address the above shortcomings, a system is needed to prevent the impeller of a centrifugal booster from reversing. Utility Model Content

[0006] (a) Technical problems to be solved The technical problem to be solved by this utility model is to address the issue that when the motor of a centrifugal booster is de-energized or the electric regulating valve is not working properly, the impeller reverses due to the inability to quickly balance the pressure difference between the inlet and outlet, which in turn causes damage to the shaft system, structural resonance, reverse current, and other hazards.

[0007] (II) Technical Solution To solve the above-mentioned technical problems, this utility model provides a system for preventing the impeller of a centrifugal booster compressor from reversing, including an electric regulating valve, a solenoid valve, and a manual ball valve. The input end of the electric regulating valve is connected to the output end of the compressor through a pipeline, and the output end of the electric regulating valve is connected to the input end of the compressor through a pipeline. The solenoid valve is connected in parallel with the electric regulating valve through a pipeline. Two manual ball valves are respectively fixed to the input and output pipelines of the solenoid valve to control the flow of natural gas to the electric regulating valve or the solenoid valve. The high-pressure natural gas output by the compressor flows through the solenoid valve to the compressor input end more quickly to balance the pressure difference before and after the compressor and prevent the impeller from reversing.

[0008] As a further explanation of this utility model, preferably, a first check valve is fixedly connected to the pipeline between the compressor output end and the electric regulating valve to prevent high-pressure natural gas from directly flowing back to the compressor output end.

[0009] As a further explanation of this utility model, preferably, a cooler is fixedly connected to the pipeline between the first one-way valve and the electric regulating valve to cool the natural gas.

[0010] As a further explanation of this utility model, preferably, a throttling plate is fixedly connected to the pipeline between the cooler and the electric regulating valve to control the flow to the electric regulating valve and the solenoid valve so as to make the pressure more stable.

[0011] As a further explanation of this utility model, preferably, a differential pressure transmitter is connected in parallel with the throttling plate through a pipeline to monitor the pressure difference between the input and output ends of the throttling plate.

[0012] As a further explanation of this utility model, preferably, the cooler output end is also connected to a second one-way valve via a pipeline, and the output end of the second one-way valve is connected to a rear pipeline to pass natural gas to the next set of compressors or liquefaction systems.

[0013] (III) Beneficial Effects The above-mentioned technical solution of this utility model has the following advantages: This invention, by adding a solenoid valve with a ball valve and a first check valve, can effectively and quickly balance the pressure difference between the inlet and outlet of a centrifugal booster compressor, fundamentally preventing impeller reversal and eliminating safety hazards such as shaft damage, structural resonance, and reverse current caused by impeller reversal. This improves the overall safety and reliability of the booster compressor and ensures the safety of core components. Furthermore, the solenoid valve and the first check valve can be used individually or in combination, adapting to the booster compressor's operating needs under different conditions, with particularly outstanding effects in special conditions such as motor power failure and electric regulating valve malfunction. Moreover, the improved solutions are all based on existing piping systems, requiring no major modifications to the main structure of the booster compressor, making installation and maintenance convenient and cost-effective. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the pipeline of this utility model.

[0015] In the diagram: 1. Electric regulating valve; 2. Solenoid valve; 3. Manual ball valve; 4. Compressor; 5. First check valve; 6. Cooler; 7. Low-pressure input pipe; 71. High-pressure output pipe; 72. Throttling plate; 73. Differential pressure transmitter; 74. Second check valve; 75. Rear end pipe. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] A system for preventing the impeller of a centrifugal booster from reversing, such as Figure 1 As shown, an improvement is made to the existing pipeline system, which consists of an electric regulating valve 1, a compressor 4, a cooler 6, a low-pressure input pipe 7, and a high-pressure output pipe 71. The low-pressure input pipe 7 is fixedly connected to the input end of the compressor 4, and the output end of the compressor 4 is connected to the high-pressure output pipe 71. The cooler 6 is fixedly connected to the high-pressure output pipe 71, and the electric regulating valve 1 is connected in parallel to the compressor 4 and the cooler 6. A second one-way valve 74 and a rear-end pipe 75 are also sequentially connected to the high-pressure output pipe 71 at the output end of the cooler 6. The rear-end pipe 75 is connected to the next set of compressors or a liquefaction system to introduce the high-pressure natural gas, pressurized by the compressor 4 and cooled by the cooler 6, into the next process stage.

[0018] like Figure 1As shown, the input end of the electric regulating valve 1 is connected to the output end of the compressor 4 via a pipeline, and the output end of the electric regulating valve 1 is connected to the input end of the compressor 4 via a pipeline. The solenoid valve 2 is connected in parallel with the electric regulating valve 1 via a pipeline. Two manual ball valves 3 are fixedly connected to the input and output pipelines of the solenoid valve 2 respectively to ensure good pipeline sealing. This controls the flow of natural gas to either the electric regulating valve 1 or the solenoid valve 2. By installing a bypass pipeline with the solenoid valve 2 outside the electric regulating valve 1, when the compressor 4 is running normally, the solenoid valve 2 is energized and the valve body is closed. The bypass pipeline does not participate in gas flow and does not affect the normal operation of the original return pipeline. When the compressor 4 is de-energized due to a fault or operational needs, the solenoid valve 2 automatically opens with the power outage, simultaneously opening the manual ball valves 3 at both ends of the bypass pipeline (which can be kept normally open and only closed during maintenance). Gas from the high-pressure area at the rear end of the compressor 4 flows quickly into the low-pressure area at the front end through the bypass pipeline, balancing the pressure difference between the front and rear ends in a short time and preventing the impeller from reversing when the gas flows backward. Once the pressure is balanced, subsequent shutdown and maintenance operations can be carried out.

[0019] Electric control valve 1 typically requires 2-3 seconds or even longer to respond. This slow response is only suitable for normal operating conditions with slow pressure changes and cannot cope with emergency scenarios involving sudden increases in pressure difference. In contrast, solenoid valve 2 requires only 0.1-0.5 seconds from power failure to valve core activation, which is 5-30 times faster than the electric control valve. Furthermore, using electric control valve 1 for fine pressure regulation under normal operating conditions avoids the lifespan loss caused by frequent start-stop cycles of the solenoid valve. Using solenoid valve 2, on the other hand, can handle instantaneous pressure protection in emergency situations, compensating for the fatal flaw of the electric control valve's slow response and ensuring system safety in extreme scenarios.

[0020] like Figure 1 As shown, a first one-way valve 5 is also fixedly connected to the high-pressure output pipe 71 between the output end of compressor 4 and cooler 6. During normal operation of compressor 4, gas can flow smoothly from the front end to the rear high-pressure zone after compression by the compressor, and the first one-way valve 5 does not obstruct this flow. When compressor 4 stops, if gas in the rear high-pressure zone attempts to flow back to the front low-pressure zone, the first one-way valve 5 quickly closes, preventing most of the high-pressure gas from flowing back to compressor 4. At this time, only a small amount of gas remaining inside compressor 4 can slowly flow back through internal channels such as the gap between the impeller and the casing. Because the gas volume is extremely small, it will not generate enough impact force to drive the impeller to reverse, thus preventing impeller reversal.

[0021] like Figure 1 As shown, a throttling plate 72 is fixedly connected to the pipeline between the cooler 6 and the electric regulating valve 1. A differential pressure transmitter 73 is connected in parallel to the throttling plate 72 through the pipeline to monitor the pressure difference between the input and output ends of the throttling plate 72. The throttling plate 72, combined with the differential pressure monitoring of the differential pressure transmitter 73, can further reduce the risk of uncontrolled pressure difference between the inlet and outlet of the compressor 4 caused by sudden flow changes by adjusting the flow rate, so as to make the pressure more stable.

[0022] In summary, when compressor 4 stops, the solenoid valve 2 of the bypass pipeline opens to quickly balance the pressure, while the first one-way valve 5 further prevents a large amount of high-pressure gas from flowing back. This dual protection more reliably prevents impeller reversal, making it suitable for operating environments with extremely high safety requirements. Furthermore, it effectively addresses pressure difference issues under different operating conditions, extends equipment lifespan, and ensures safe and stable system operation.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A system for preventing the impeller of a centrifugal booster from reversing, characterized in that: It includes an electric regulating valve (1), a solenoid valve (2) and a manual ball valve (3). The input end of the electric regulating valve (1) is connected to the output end of the compressor (4) through a pipeline. The output end of the electric regulating valve (1) is connected to the input end of the compressor (4) through a pipeline. The solenoid valve (2) is connected in parallel with the electric regulating valve (1) through a pipeline. The two manual ball valves (3) are respectively fixed on the pipeline at the input end and the pipeline at the output end of the solenoid valve (2) to control the flow of natural gas to the electric regulating valve (1) or the solenoid valve (2). The high-pressure natural gas output by the compressor (4) flows through the solenoid valve (2) to the input end of the compressor (4) faster to balance the pressure difference before and after the compressor (4) and prevent the impeller from reversing.

2. The system for preventing reverse rotation of a centrifugal booster impeller according to claim 1, characterized in that: A first check valve (5) is fixedly connected to the pipeline between the output end of the compressor (4) and the electric regulating valve (1) to prevent high-pressure natural gas from flowing back directly to the output end of the compressor (4).

3. The system for preventing reverse rotation of a centrifugal booster impeller according to claim 2, characterized in that: A cooler (6) is fixedly connected to the pipeline between the first check valve (5) and the electric regulating valve (1) to cool the natural gas.

4. A system for preventing reverse rotation of a centrifugal booster impeller according to claim 3, characterized in that: A throttling plate (72) is fixed on the pipe between the cooler (6) and the electric regulating valve (1) to control the flow to the electric regulating valve (1) and the solenoid valve (2) to make the pressure more stable.

5. A system for preventing reverse rotation of a centrifugal booster impeller according to claim 4, characterized in that: The throttle plate (72) is connected in parallel with a differential pressure transmitter (73) through a pipeline to monitor the pressure difference between the input and output ends of the throttle plate (72).

6. A system for preventing reverse rotation of a centrifugal booster impeller according to claim 5, characterized in that: The output end of the cooler (6) is also connected to a second check valve (74) via a pipeline. The output end of the second check valve (74) is connected to a rear pipeline (75) to pass natural gas to the next set of compressors or liquefaction systems.

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