Centrifugal transfer pump for liquefied gas

Abstract

The utility model belongs to the technical field of liquefied gas unloading, specifically relates to a centrifugal type conveying pump for liquefied gas unloading, including tank wagon, tank wagon is located on the high platform, tank wagon is connected through first pipe line with energy storage tank between, energy storage tank is connected through second pipe line with steady flow tank between, steady flow tank is connected through third pipe line with centrifugal pump between, steady flow tank is used for the cooling of liquefied gas to make it liquefied;Centrifugal pump discharge port is connected with fourth pipe line, fourth pipe line is connected with three -way pipe line, three -way pipe line side export is connected with return line, three -way pipe line upper export is connected with output pipe line, return line discharge port enters energy storage tank and is connected with jet flow ware, jet flow ware is located in mixed flow pressurizing pipe line, mixed flow pressurizing pipe line is connected with second pipe line;The utility model can liquefy a part of liquefied gas vaporization through mixed flow pressurizing pipe line, then through the cooling of steady flow tank can make all liquefied gas vaporization compressed to liquefaction, thereby solve the problem of centrifugal pump idling and cavitation.

Description

Technical Field

[0001] This utility model belongs to the field of liquefied gas unloading technology, specifically relating to a centrifugal transfer pump for liquefied gas unloading. Background Technology

[0002] Liquefied petroleum gas (LPG) is a toxic, hazardous, easily vaporized, and extremely flammable and explosive dangerous commodity. Its safety requirements are extremely high, and its transportation and unloading are highly dangerous. The question of whether LPG can be safely, promptly, and quickly unloaded from tank trucks is becoming increasingly prominent. Because LPG has a very high vaporization pressure, it often vaporizes immediately after being extracted and cannot be discharged. Commonly, LPG unloading involves placing the tank truck on a high platform and using a reverse-flow unloading method. However, due to the limited height of the platform, unloading can proceed normally when the tank is full, but as the unloading nears its end and only a small amount of LPG remains, the pressure inside the tank drops rapidly. The height difference between the tank truck and the centrifugal pump is insufficient to prevent the LPG from vaporizing after it flows out. Even adding a jet pump to the centrifugal pump inlet to increase the pressure head cannot compress all the vaporized LPG into liquid to ensure the normal operation of the centrifugal pump. Instead, because the jet pump can transport both liquid and gas, it may force vaporized LPG into the centrifugal pump inlet, causing the centrifugal pump to run dry or even cavitate. How to solve these problems has become an urgent issue. Utility Model Content

[0003] To address the problems of existing technologies, this utility model proposes a centrifugal transfer pump for unloading liquefied gas, which can liquefy the liquefied gas that is vaporized before entering the centrifugal pump, thereby preventing damage to the centrifugal pump.

[0004] A centrifugal transfer pump for unloading liquefied gas includes a tank truck and a centrifugal pump. The tank truck is located on a raised platform. The tank truck is connected to an energy storage tank via a first pipeline, the energy storage tank is connected to a flow stabilizing tank via a second pipeline, and the flow stabilizing tank is connected to the centrifugal pump via a third pipeline. The flow stabilizing tank is used to cool the liquefied gas to liquefy it. The centrifugal pump outlet is connected to a fourth pipeline, which is connected to a tee pipe. The side outlet of the tee pipe is connected to a return pipeline, and the upper outlet of the tee pipe is connected to an output pipeline. The outlet of the return pipeline enters the energy storage tank and is connected to an ejector. The ejector is located in a mixed-flow pressurization pipeline. The mixed-flow pressurization pipeline is equipped with a suction pipeline, and the suction inlet of the suction pipeline is located at the bottom of the energy storage tank. The mixed-flow pressurization pipeline is connected to a second pipeline. The height of the energy storage tank, the flow stabilizing tank, and the centrifugal pump is all lower than the tank truck's tank outlet.

[0005] The height of the tank truck, energy storage tank, flow stabilizing tank, and centrifugal pump decreases progressively.

[0006] The tanker truck is equipped with a tanker valve, and the output pipeline is equipped with an output valve.

[0007] The mixed flow pressurization pipeline is provided with a mixed flow zone and a pressurization zone. The jet injector is located in the mixed flow zone, and a suction pipeline is provided below the mixed flow zone. The pressurization zone is connected to the second pipeline.

[0008] The flow stabilizing tank includes a cooling water pipe, a tank body, a liquefied gas pipe, a cooling flow stabilizing pipe, and baffles. Two baffles are installed inside the tank body, and multiple cooling flow stabilizing pipes are fixedly connected between the two baffles. The cooling flow stabilizing pipes are connected to the tank body outside the two baffles. A cooling water pipe is installed on the tank body, located outside the two baffles and connected to a cooling water conveying device. One end of each of the two liquefied gas pipes extends into the inside of the two baffles. The other end of one liquefied gas pipe is connected to a second pipeline, and the other end of the other liquefied gas pipe is connected to a third pipeline.

[0009] The two partitions are symmetrically provided with water inlets and outlets, and the ports of the cooling flow stabilizing pipes correspond to the water inlets and outlets. Multiple blades are evenly distributed on the outer side of the cooling flow stabilizing pipes.

[0010] The beneficial effects of this utility model are as follows: 1. The energy storage tank of this application is equipped with a mixed flow pressurization pipeline. A portion of the vaporized liquefied gas can be liquefied through the mixed flow pressurization pipeline. Then, the cooling of the flow stabilizing tank can compress all the vaporized liquefied gas into liquefied gas, thereby solving the problems of idling and cavitation of the centrifugal pump.

[0011] 2. The flow stabilizer tank of this application is equipped with a cooling flow stabilizer pipe, which can cool the liquefied gas to make it liquefied. The cooling flow stabilizer pipe is evenly distributed with multiple blades, which can increase the heat exchange area between the cooling water and the liquefied gas, and also reduce the flow rate of the liquefied gas. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of a centrifugal transfer pump for unloading liquefied gas according to the present invention; Figure 2 This is a schematic diagram showing the connection between the return pipeline and the ejector of a centrifugal pump for unloading liquefied gas according to this utility model. Figure 3 This is a schematic diagram of the flow stabilizer of a centrifugal pump for unloading liquefied gas according to the present invention. Figure 4 A schematic diagram of the cooling and flow stabilizing pipe structure of a centrifugal transfer pump for unloading liquefied gas; 1. Tank truck; 2. Tank truck valve; 3. Energy storage tank; 4. T-junction; 5. Output pipeline; 6. Output valve; 7. First pipeline; 8. Second pipeline; 9. Flow stabilizer; 901. Cooling water pipeline; 902. Tank body; 903. Liquefied gas pipeline; 904. Cooling and flow stabilizing pipeline; 90401. Blade; 905. Baffle; 10. Third pipeline; 11. Centrifugal pump; 12. Fourth pipeline; 13. Return pipeline; 14. Mixed flow pressurization pipeline; 15. Suction pipeline; 16. Ejector. Detailed Implementation

[0013] The present invention will now be described in detail with reference to the accompanying drawings.

[0014] like Figures 1-4 As shown, a centrifugal transfer pump for unloading liquefied gas includes a tank truck 1 and a centrifugal pump 11. The tank truck 1 is located on a raised platform and is equipped with a tank truck valve 2. The tank truck 1 is connected to an energy storage tank 3 via a first pipeline 7. The energy storage tank 3 is connected to a flow stabilizing tank 9 via a second pipeline 8. The flow stabilizing tank 9 is connected to the centrifugal pump 11 via a third pipeline 10. The flow stabilizing tank 9 is used to cool the liquefied gas to liquefy it. The outlet of the centrifugal pump 11 is connected to a fourth pipeline 12, which is connected to a three-way pipeline 4. The three-way pipeline 4 has a side... The outlet is connected to the return pipe 13, and the outlet above the tee pipe 4 is connected to the output pipe 5. The output pipe 5 is equipped with an output valve 6. The outlet of the return pipe 13 enters the energy storage tank 3 and is connected to the ejector 16. The ejector 16 is located in the mixed flow pressurization pipe 14 inside the energy storage tank 3. The mixed flow pressurization pipe 14 is equipped with a suction pipe 15. The suction port of the suction pipe 15 is located at the bottom of the energy storage tank 3. The mixed flow pressurization pipe 14 is connected to the second pipe 8. The height of the energy storage tank 3, the stabilizing tank 9, and the centrifugal pump 11 is all lower than the tank outlet of the tank truck 1.

[0015] In this embodiment, when the tanker truck 1 is full, the liquefied gas sequentially passes through the tanker truck 1, the energy storage tank 3, and the flow stabilizing tank 9 into the centrifugal pump 11. A portion of the liquefied gas is output through the centrifugal pump 11, and the other portion enters the ejector 16 through the return pipe 13. Under the action of the ejector 16, the liquefied gas in the energy storage tank 3 is transported together through the mixed-flow pressurization pipe 14 to the flow stabilizing tank 9. When the liquefied gas in the tanker truck 1 decreases, and a gas-liquid mixture exists, the gas-liquid mixture enters the energy storage tank 3 through the first pipe 7. The return pipe 13 on the three-way pipe 4 will carry a portion of the liquefied gas... The gas is fed into the storage tank 3. Under the action of the ejector 16, the gas-liquid mixture in the storage tank 3 is transported to the mixed flow pressurization pipeline 14 for preliminary liquefaction to form a portion of liquefied gas. Then, the gas-liquid mixture is transported to the stabilizing tank 9 through the second pipeline 8. The stabilizing tank 9 cools the gas-liquid mixture and compresses it into liquefied gas. The liquefied gas is then output through the centrifugal pump 11. The fourth pipeline 12 connected to the centrifugal pump 11 is connected to the tee pipeline 4. A portion of the liquefied gas is output through the output pipeline 5 connected to the tee pipeline 4, and a portion re-enters the storage tank 3 through the return pipeline 13.

[0016] The mixed flow pressurization pipeline 14 is provided with a mixed flow zone and a pressurization zone. The jet ejector 16 is located in the mixed flow zone. The suction pipeline 15 is provided below the mixed flow zone. The pressurization zone is connected to the second pipeline 8.

[0017] In this embodiment, the suction line 15 is used to draw in liquefied gas. The liquefied gas in the return line 13 enters the pressurization zone of the mixed flow pressurization line 14 through the ejector 16, thereby repressurizing a portion of the vaporized liquefied gas into a liquid state. The liquefied gas drawn in through the suction line 15 is input into the pressurization zone of the mixed flow pressurization line 14 under the pressure of the ejector 16, thereby repressurizing a portion of the vaporized liquefied gas into a liquid state. The liquefied gas that has been pressurized into a liquid state and the liquefied gas that has not been pressurized into a liquid state enter the flow stabilizing tank 9 through the second line 8 for cooling, thereby compressing the vaporized liquefied gas into a liquid state, and finally output through the centrifugal pump 11.

[0018] The flow stabilizing tank 9 includes a cooling water pipe 901, a tank body 902, a liquefied gas pipe 903, a cooling flow stabilizing pipe 904, and a partition 905. Two partitions 905 are installed inside the tank body 902, and multiple cooling flow stabilizing pipes 904 are fixedly connected between the two partitions 905. The cooling flow stabilizing pipes 904 communicate with the tank body 902 outside the two partitions 905. A cooling water pipe 901 is installed on the tank body 902, located outside the two partitions 905 and connected to a cooling water conveying device. One end of each of the two liquefied gas pipes 903 extends into the inside of the two partitions 905. The other end of one liquefied gas pipe 903 is connected to a second pipe 8, and the other end of the other liquefied gas pipe 903 is connected to a third pipe 10.

[0019] The two partitions 905 are symmetrically provided with water inlets and outlets, and the ports of the cooling flow stabilizing pipe 904 correspond to the water inlets and outlets. Multiple blades 90401 are evenly distributed on the outer side of the cooling flow stabilizing pipe 904.

[0020] In this embodiment, one of the cooling water pipes 901 on both sides of the two partitions 905 is an input pipe and the other is an output pipe. The cooling water conveying device inputs cooling water through the input pipe to the area between the outer side of the partition 905 and the tank 902. The cooling water flows into the cooling flow stabilizing pipe 904 through the water inlet on the partition 905. The gas-liquid mixture of liquefied gas is input into the area between the inner side of the two partitions 905 and the tank 902 through the liquefied gas pipe 903 connected to the second pipe 8. The cooling water is used to cool and compress the gas-liquid mixture of liquefied gas so that it is completely converted into liquid. Here, the liquefied gas is input into the centrifugal pump 11 from the third pipe 10. The cooling water flows back to the cooling water conveying device from the outlet and through the output pipe, completing the cooling water circulation. Multiple blades 90401 on the outer side of the cooling flow stabilizing pipe 904 increase the heat dissipation area with the liquefied gas. The blades 90401 can also reduce the flow velocity of the liquefied gas, further achieving flow stabilization.

[0021] In use, the tanker truck 1 is driven onto the platform, the flow stabilizer 9 is connected to the cooling water conveying device, and the tanker truck valve 2 and the centrifugal pump 11 outlet valve are opened. Since the energy storage tank 3, the flow stabilizer 9 and the centrifugal pump 11 are all lower than the tanker truck 1's tank outlet and the height decreases step by step, under the action of gravity, high-pressure liquefied gas enters the energy storage tank 3, the centrifugal pump 11 and each pipeline. The centrifugal pump 11 is filled with liquefied gas and discharges the gas. The centrifugal pump 11 is started, and a portion of the high-pressure liquefied gas is drawn back to the ejector 16 through the return pipeline 13 through the centrifugal pump outlet tee pipeline 4, serving as the power source for the ejector 16. The suction pipeline 15 draws in the liquefied gas in the energy storage tank 3, and after passing through the mixed flow pressurization pipeline 14, it is discharged through the second pipeline 8 into the flow stabilizer 9. During the later stages of unloading, the liquefied gas level in tanker truck 1 drops, causing a decrease in pressure within the tank. This results in some of the liquefied gas vaporizing and entering storage tank 3. The gas-liquid mixture is accelerated and pressurized by ejector 16 and mixed-flow pressurization pipeline 14 before entering stabilizing tank 9, where a portion of the gas-liquid mixture is liquefied. Cooling water enters cooling stabilizing pipeline 904 from cooling water pipeline 901. The blades 90401 on cooling stabilizing pipeline 904 increase the heat exchange area with the liquefied gas in stabilizing tank 9. When the high-temperature, high-speed liquefied gas enters stabilizing tank 9, it exchanges heat with cooling stabilizing pipeline 904 while its speed is reduced by blades 90401, thus lowering the pressure and temperature of the liquefied gas. After stabilization and cooling in stabilizing tank 9, the gas-liquid mixture is recompressed into a liquid state, ensuring that centrifugal pump 11 only draws in liquid and no gas.

Claims

1. A centrifugal transfer pump for unloading liquefied gas, characterized in that, The system includes a tank truck and a centrifugal pump. The tank truck is located on a raised platform. The tank truck is connected to the energy storage tank via a first pipeline, the energy storage tank is connected to the flow stabilizing tank via a second pipeline, and the flow stabilizing tank is connected to the centrifugal pump via a third pipeline. The flow stabilizing tank is used to cool the liquefied gas and liquefy it. The centrifugal pump outlet is connected to a fourth pipeline, which is connected to a tee pipe. The side outlet of the tee pipe is connected to a return pipeline, and the top outlet of the tee pipe is connected to an output pipeline. The return pipeline outlet enters the energy storage tank and connects to an ejector. The ejector is located in a mixed-flow pressurization pipeline. The mixed-flow pressurization pipeline has a suction pipeline with its suction inlet located at the bottom of the energy storage tank. The mixed-flow pressurization pipeline is connected to a second pipeline. The height of the energy storage tank, flow stabilizing tank, and centrifugal pump is all lower than the tank truck's tank outlet.

2. The centrifugal transfer pump for unloading liquefied gas according to claim 1, characterized in that, The height of the tank truck, energy storage tank, flow stabilizing tank, and centrifugal pump decreases progressively.

3. The centrifugal transfer pump for unloading liquefied gas according to claim 1, characterized in that, The tanker truck is equipped with a tanker valve, and the output pipeline is equipped with an output valve.

4. A centrifugal transfer pump for unloading liquefied gas according to claim 1, characterized in that, The mixed flow pressurization pipeline is provided with a mixed flow zone and a pressurization zone. The jet injector is located in the mixed flow zone, and a suction pipeline is provided below the mixed flow zone. The pressurization zone is connected to the second pipeline.

5. A centrifugal transfer pump for unloading liquefied gas according to claim 1, characterized in that, The flow stabilizing tank includes a cooling water pipe, a tank body, a liquefied gas pipe, a cooling flow stabilizing pipe, and baffles. Two baffles are installed inside the tank body, and multiple cooling flow stabilizing pipes are fixedly connected between the two baffles. The cooling flow stabilizing pipes are connected to the tank body outside the two baffles. A cooling water pipe is installed on the tank body, located outside the two baffles and connected to a cooling water conveying device. One end of each of the two liquefied gas pipes extends into the inside of the two baffles. The other end of one liquefied gas pipe is connected to a second pipeline, and the other end of the other liquefied gas pipe is connected to a third pipeline.

6. A centrifugal transfer pump for unloading liquefied gas according to claim 5, characterized in that, The two partitions are symmetrically provided with water inlets and outlets, and the ports of the cooling flow stabilizing pipes correspond to the water inlets and outlets. Multiple blades are evenly distributed on the outer side of the cooling flow stabilizing pipes.

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