Liquefied natural gas cold energy driven water pump and water system

Abstract

The utility model discloses a kind of liquefied natural gas cold energy driven water pump and water system, belong to liquefied natural gas cold energy utilization technical field, including water pump body, turbine expander, the pump shaft of water pump body is coaxially fixedly connected with the rotor main shaft of turbine expander, and Rankine cycle system is connected between the gas inlet end, gas outlet end of turbine expander;Rankine cycle system includes first heat exchanger, medium pump, second heat exchanger, and heat source medium for heating is passed into in second heat exchanger;The second medium inlet of first heat exchanger is connected with the outlet of liquefied natural gas storage tank, and the second medium outlet of first heat exchanger is connected with gas pipeline.The utility model utilizes the cold energy in liquefied natural gas gasification process and the pressure energy in intermediate medium propane expansion process, effectively combines the both by turbine expander, to drive the operation of water pump body, i.e. the gasification cold energy of liquefied natural gas replaces the electric energy driving of water pump body, reduces the demand to electric energy.

Description

Technical Field

[0001] This utility model belongs to the field of liquefied natural gas cold energy utilization technology, specifically relating to a water pump and water system driven by liquefied natural gas cold energy. Background Technology

[0002] Existing water systems typically rely on electric motors to drive water pumps, consuming significant amounts of electricity. This is especially true in scenarios requiring high-flow-rate circulating water, where the high energy consumption of traditional electric pumps limits system efficiency and widespread application. Liquefied natural gas (LNG), as a clean energy source, offers the potential of cryogenic energy utilization technology, which is significant for both energy conservation and environmental protection. Cryogenic energy refers to the cold energy released during the vaporization of LNG into natural gas. Currently, this cryogenic energy is often directly released into the environment, resulting in underutilization and substantial energy waste.

[0003] Therefore, considering how to utilize the gasification cold energy of liquefied natural gas in water systems to reduce the dependence on power transmission and distribution, this application proposes a water pump and water system driven by liquefied natural gas cold energy. Utility Model Content

[0004] To comprehensively address the issues of wasted cold energy from liquefied natural gas (LNG) vaporization and high electricity demand in water systems, this invention provides a LNG cold energy-driven water pump and water system that enables efficient hydraulic transport, reduces electricity demand, and achieves energy conservation.

[0005] To achieve the above objectives, this utility model provides a liquefied natural gas cold energy driven water pump.

[0006] A liquefied natural gas cold energy driven water pump includes a water pump body and a turbine expander. The pump shaft of the water pump body is coaxially and fixedly connected to the rotor main shaft of the turbine expander. A Rankine cycle system is connected between the inlet end and the outlet end of the turbine expander. The Rankine cycle system includes a first heat exchanger, a medium pump, and a second heat exchanger. The outlet of the turboexpander is connected to the first medium inlet of the first heat exchanger, the first medium outlet of the first heat exchanger is connected to the inlet of the medium pump, the outlet of the medium pump is connected to the first medium inlet of the second heat exchanger, and the first medium outlet of the second heat exchanger is connected to the inlet of the turboexpander. A heat source medium for heating is introduced into the second heat exchanger. The second medium inlet of the first heat exchanger is connected to the outlet of the liquefied natural gas storage tank, and the second medium outlet of the first heat exchanger is connected to the gas transmission pipeline.

[0007] Preferably, the pump shaft of the water pump body and the rotor main shaft of the turbine expander are coaxially fixedly connected by a mechanical transmission shaft.

[0008] Preferably, the working medium of the turbine expander is propane.

[0009] Preferably, the heat source medium introduced into the second heat exchanger for heating is seawater or air.

[0010] Preferably, a first control valve is provided between the outlet end of the turbine expander and the first medium inlet of the first heat exchanger.

[0011] This utility model also provides a water system.

[0012] A water system includes a primary water pump, a water heat exchanger unit, and a water pump driven by liquefied natural gas cold energy; The inlet of the primary water pump is connected to an external water source via a water intake pipe, the outlet of the primary water pump is connected to the inlet of the pump body, and the outlet of the pump body is connected to a water heat exchange unit.

[0013] Preferably, a third control valve is installed on the pipeline at the water inlet of the water pump body.

[0014] Preferably, the outlet of the water pump body is connected to the inlet pipe of the water heat exchange unit.

[0015] Preferably, a check valve is installed on the water inlet pipe of the water heat exchanger unit.

[0016] Preferably, a bypass pipeline is connected in parallel between the outlet of the primary water pump and the outlet of the water pump body, and a second control valve is installed on the bypass pipeline.

[0017] The beneficial effects of this utility model are: (1) This utility model utilizes the cold energy in the gasification process of liquefied natural gas and the pressure energy in the expansion process of the intermediate medium propane. The two are effectively combined through a turbine expander to drive the operation of the water pump body. That is, the cold energy of liquefied natural gas gasification replaces the electric energy drive of the water pump body, reducing the demand for electric energy.

[0018] (2) When the liquefied natural gas supply is sufficient, the water system of this utility model can adopt an energy-saving operation mode. The first-stage water pump draws water from the water source through the water intake pipe and is connected in series with the water pump body. The water is pumped into the water heat exchange unit through the unit inlet pipe. On the one hand, two-stage pressurization is achieved. On the other hand, only the first-stage water pump is driven by electric power, while the water pump body is driven by the gasification cold energy of liquefied natural gas instead of electric power, reducing the demand for electric power and achieving efficient hydraulic transportation. This reduces the waste problem of direct release of liquefied natural gas cold energy and achieves the purpose of energy saving. When the liquefied natural gas supply is insufficient, only the first-stage water pump is started. The water pressurized by the first-stage water pump flows directly into the water heat exchange unit through the unit inlet pipe through the second control valve. Therefore, it can be applied to the water supply needs under different liquefied natural gas volumes. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0020] Figure 1 This is a connection diagram of the liquefied natural gas cold energy driven water pump of this utility model; Figure 2 This is a schematic diagram of the water system connection in Embodiment 2 of this utility model; Figure 3 This is a schematic diagram of the water system connection in Embodiment 3 of this utility model; in: 1. Liquefied natural gas storage tank; 2. Second heat exchanger; 3. First heat exchanger; 4. Turbine expander; 5. Medium pump; 6. Mechanical drive shaft; 7. Pump body; 8. First stage water pump; 9. Water heat exchange unit; 10. Water intake pipe; 11. Unit inlet pipe; 12. Unit outlet pipe; 13. First control valve; 14. Second control valve; 15. Check valve; 16. Third control valve. Detailed Implementation

[0021] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] In this utility model, terms such as "upper", "lower", "bottom", and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the structural relationship between the various components or elements of this utility model and do not specifically refer to any component or element in this utility model. They should not be construed as limiting this utility model.

[0024] In this utility model, terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and should not be construed as a limitation of this utility model.

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Example 1: like Figure 1 As shown, a liquefied natural gas cold energy driven water pump includes a water pump body 7 and a turbine expander 4. The pump shaft of the water pump body 7 is coaxially and fixedly connected to the rotor main shaft of the turbine expander 4. A Rankine cycle system is connected between the air inlet end and the air outlet end of the turbine expander 4. The Rankine cycle system includes a first heat exchanger 3, a medium pump 5, and a second heat exchanger 2. The outlet of the turboexpander 4 is connected to the first medium inlet of the first heat exchanger 3, the first medium outlet of the first heat exchanger 3 is connected to the inlet of the medium pump 5, the outlet of the medium pump 5 is connected to the first medium inlet of the second heat exchanger 2, and the first medium outlet of the second heat exchanger 2 is connected to the inlet of the turboexpander 4. A heat source medium for heating is introduced into the second heat exchanger 2. The second medium inlet of the first heat exchanger 3 is connected to the outlet of the liquefied natural gas storage tank 1, and the second medium outlet of the first heat exchanger 3 is connected to the gas transmission pipeline.

[0027] Preferably, the pump shaft of the water pump body 7 and the rotor main shaft of the turboexpander 4 are coaxially fixedly connected via a mechanical transmission shaft 6. In this application, the turboexpander 4 and the water pump body 7 are connected by a simple mechanical transmission via a mechanical transmission shaft 6, which minimizes energy loss and ensures efficient operation of the system.

[0028] Preferably, the working medium of the turbine expander 4 is propane.

[0029] Preferably, the heat source medium introduced into the second heat exchanger 2 for heating is seawater or air.

[0030] Preferably, a first control valve 13 is provided between the outlet end of the turbine expander 4 and the first medium inlet of the first heat exchanger 3.

[0031] In Example 1, propane vapor at the outlet of turboexpander 4 exchanges heat with liquefied natural gas in the first heat exchanger 3, becoming liquid propane. After being pressurized by the medium pump 5, the liquid propane enters the second heat exchanger 2 to exchange heat with seawater or air, forming pressurized propane vapor. This pressurized propane vapor then enters turboexpander 4 through the inlet. The propane vapor expands, driving the turbine blades to rotate. The mechanical energy of the turbine blades is transmitted to the pump shaft of the water pump body 7 via the rotor shaft of turboexpander 4 and the mechanical transmission shaft 6 between turboexpander 4 and the water pump body 7, driving its impeller to rotate, thus completing the pressurization and transportation of water. The expanded propane vapor re-enters the Rankine cycle system through the outlet of turboexpander 4 for recycling. The natural gas, after heat exchange and vaporization with the propane vapor, is transported via a gas pipeline for further use.

[0032] In Example 1, the cold energy from the gasification process of liquefied natural gas and the pressure energy from the expansion process of the intermediate medium propane are used to effectively combine the two through the turbine expander 4 to drive the operation of the water pump body 7. That is, the cold energy from the gasification of liquefied natural gas replaces the electrical energy drive of the water pump body 7, reducing the demand for electrical energy.

[0033] Example 2: A water system, such as Figure 2 As shown, it includes a primary water pump 8, a water heat exchange unit 9, and a liquefied natural gas cold energy driven water pump as in Example 1; The inlet of the primary water pump 8 is connected to an external water source through a water intake pipe 10, the outlet of the primary water pump 8 is connected to the inlet of the pump body 7, and the outlet of the pump body 7 is connected to the water heat exchange unit 9.

[0034] Preferably, a third control valve 16 is installed on the pipeline at the water inlet of the water pump body 7.

[0035] Preferably, the outlet of the water pump body 7 is connected to the inlet pipe 11 of the water heat exchanger unit 9, and the outlet pipe 12 of the water heat exchanger unit 9 is provided at the outlet.

[0036] Preferably, a check valve 15 is installed on the water inlet pipe 11 of the water heat exchanger unit 9.

[0037] In Example 2, the components of the water system are connected by pipes to form a complete system structure for water extraction and pressurization. Specifically, the primary water pump 8 draws water from the water source through the water intake pipe 10 and is connected in series with the pump body 7. The water is then pumped through the unit inlet pipe 11 into the water heat exchange unit 9 for subsequent use. Finally, the water is discharged back to the external water body through the unit outlet pipe 12. This connection method achieves two-stage pressurization and ensures that only the primary water pump 8 is electrically driven, while the pump body 7 uses the vaporization cold energy of liquefied natural gas instead of electricity. This reduces the demand for electricity, achieves efficient hydraulic transportation, reduces the waste caused by the direct release of liquefied natural gas cold energy, and achieves energy saving.

[0038] Example 3: Based on Example 2, such as Figure 3 As shown, a bypass pipeline is connected in parallel between the outlet of the primary water pump 8 and the outlet of the water pump body 7, and a second control valve 14 is installed on the bypass pipeline.

[0039] When using the water system in Example 3, the first-stage water pump 8 is started first, allowing water from an external water source to enter the system through the water intake pipe 10. If the liquefied natural gas (LNG) supply is insufficient, the second control valve 14 is opened and the third control valve 16 is closed. The turboexpander 4 does not operate, and the first-stage water pump 8 is driven by an electric motor to pump the pressurized water directly into the water exchanger unit 9 through the unit inlet pipe 11 via the second control valve 14. If the LNG supply is sufficient, an energy-saving operation mode is adopted, the second control valve 14 is closed, and the third control valve 16 is opened. After the water is initially pressurized by the first-stage water pump 8, it enters the water pump body 7 through the third control valve 16. The turboexpander 4 is started to drive the water pump body 7, further pressurizing the water to meet the operating requirements of the water exchanger unit 9. The water exchanger unit 9 uses water as a cold source for heat exchange, and finally, the water is discharged back to the external water body through the unit outlet pipe 12, completing the entire process. When shutting down the system in energy-saving operation mode, the turbine expander 4 is turned off, the expansion process of the intermediate medium propane is stopped, and the operation of the water pump body 7 and the first-stage water pump 8 is stopped to ensure that the system is shut down safely and orderly.

[0040] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, they are not intended to limit the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the protection scope of the present utility model.

Claims

1. A water pump driven by liquefied natural gas (LNG) cold energy, characterized in that, It includes a water pump body and a turbine expander. The pump shaft of the water pump body is coaxially and fixedly connected to the rotor main shaft of the turbine expander. A Rankine cycle system is connected between the air inlet and air outlet of the turbine expander. The Rankine cycle system includes a first heat exchanger, a medium pump, and a second heat exchanger. The outlet of the turboexpander is connected to the first medium inlet of the first heat exchanger, the first medium outlet of the first heat exchanger is connected to the inlet of the medium pump, the outlet of the medium pump is connected to the first medium inlet of the second heat exchanger, and the first medium outlet of the second heat exchanger is connected to the inlet of the turboexpander. A heat source medium for heating is introduced into the second heat exchanger. The second medium inlet of the first heat exchanger is connected to the outlet of the liquefied natural gas storage tank, and the second medium outlet of the first heat exchanger is connected to the gas transmission pipeline.

2. The liquefied natural gas cold-powered water pump as described in claim 1, characterized in that, The pump shaft of the water pump body and the rotor main shaft of the turboexpander are coaxially fixedly connected through a mechanical transmission shaft.

3. The liquefied natural gas cold-powered water pump as described in claim 1, characterized in that, The working medium of the turboexpander is propane.

4. The liquefied natural gas cold-powered water pump as described in claim 1, characterized in that, The heat source medium introduced into the second heat exchanger for heating is seawater or air.

5. The liquefied natural gas cold-powered water pump as described in claim 1, characterized in that, A first control valve is provided between the outlet of the turbine expander and the inlet of the first medium of the first heat exchanger.

6. A water supply system, characterized in that, Includes a primary water pump, a water heat exchange unit, and a liquefied natural gas cold energy driven water pump as described in any one of claims 1 to 5; The inlet of the primary water pump is connected to an external water source via a water intake pipe, the outlet of the primary water pump is connected to the inlet of the pump body, and the outlet of the pump body is connected to a water heat exchange unit.

7. The water system as described in claim 6, characterized in that, A third control valve is installed on the pipeline at the water inlet of the water pump body.

8. The water system as described in claim 6, characterized in that, The outlet of the water pump body is connected to the inlet pipe of the water heat exchange unit.

9. The water system as described in claim 8, characterized in that, A check valve is installed on the water inlet pipe of the water-cooled heat exchanger unit.

10. The water system as described in claim 6, characterized in that, A bypass pipeline is connected in parallel between the outlet of the primary water pump and the outlet of the water pump body, and a second control valve is installed on the bypass pipeline.

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