LNG (Liquefied Natural Gas) gasification station cold energy utilization system coupled with liquid air energy storage

Abstract

The invention belongs to the technical field of LNG (liquefied natural gas) cold energy utilization, and provides an LNG gasification station cold energy utilization system coupled with liquid air energy storage, which comprises a first LNG heat exchange assembly, a second LNG heat exchange assembly and a third LNG heat exchange assembly, the second LNG heat exchange assembly comprises a second heat exchange subsystem, and a cold source and a heat source of the second heat exchange subsystem are LNG and power plant warm discharged water correspondingly; the ORC power generation assembly comprises a sixth heat exchanger and a first turbine generator, a cold source of the sixth heat exchanger is LNG, the LNG is output through an LNG outlet of the sixth heat exchanger, and a driving medium flowing part is arranged between a propane outlet of the sixth heat exchanger and the first turbine generator; and the air energy release assembly comprises a liquid air storage tank, and the output end of the liquid air storage tank communicates with a power generation mechanism. Liquefied air energy storage is conducted through LNG, meanwhile, the ORC cold energy power generation system is coupled, LNG cold energy is efficiently recycled, and self-generation and self-use of electric power are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of LNG cold energy utilization, and particularly relates to a cold energy utilization system for an LNG gasification station coupled with liquid air energy storage. Background Technique

[0002] In order to transport natural gas to users through pipelines in an LNG gasification station, LNG needs to be gasified from -162 °C to above 1 °C. During this process, seawater is used to exchange heat with LNG through a heat exchanger to gasify LNG, and the released cold energy is directly discharged into the sea, resulting in a large amount of energy waste. Only a very small number of gasification stations utilize it through methods such as cold energy air separation and cold energy power generation, but the cold energy utilization rate is low. At the same time, a large amount of electricity is required to drive equipment such as heat exchangers, high-pressure pumps, low-pressure pumps, and compressors during the daily operation of LNG gasification stations, resulting in huge power consumption. By using the method of LNG cold energy power generation for self-use, the electricity cost of the gasification station can be reduced, and energy can be saved and consumption reduced. In addition, the gap between peak and valley electricity prices for industrial electricity in the Tangshan area is relatively large. This characteristic can be utilized for liquid air energy storage (LAES), and the production and operation costs of the gasification station can be reduced by cutting peaks and filling valleys, thereby improving economic benefits.

[0003] At the same time, the losses in ordinary LAES systems mainly occur in compressors and heat storage and cold storage devices. Due to the lack of a cold source to reduce the power consumption of compressors, the cycle efficiency is relatively low, usually between 50% and 60%. By coupling with LNG to utilize its cold energy to assist in air liquefaction, the power consumption of compressors can be reduced, and the cycle efficiency can be greatly improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a cold energy utilization system for an LNG gasification station coupled with liquid air energy storage to solve the above problems, achieve liquid air energy storage using LNG while coupling with an ORC cold energy power generation system, efficiently recover the cold energy of LNG, and enable the LNG station to realize valley electricity peak usage and self-use, thereby reducing the electricity cost of the gasification station.

[0005] To achieve the above purpose, the present invention provides the following solution: A cold energy utilization system for an LNG gasification station coupled with liquid air energy storage, comprising:

[0006] A first LNG heat exchange assembly, including a first heat exchange subsystem, wherein the cold source and heat source of the first heat exchange subsystem are LNG and air respectively;

[0007] A second LNG heat exchange assembly, including a second heat exchange subsystem, wherein the cold source and heat source of the second heat exchange subsystem are LNG and power plant warm drainage respectively;

[0008] The ORC power generation assembly includes a sixth heat exchanger and a first turbine generator. The cold source of the sixth heat exchanger is LNG, and the LNG is transported out through the LNG outlet of the sixth heat exchanger. A driving medium flow component is arranged between the propane outlet of the sixth heat exchanger and the first turbine generator;

[0009] The air energy release assembly includes a liquid air storage tank for storing the liquid air flowing out of the first heat exchange subsystem. The output end of the liquid air storage tank is connected to a power generation mechanism, and the power generation mechanism generates electricity by using the energy released during the gasification process of the liquid air.

[0010] Preferably, the first heat exchange subsystem includes a plurality of LNG temperature-rising heat exchangers, and the LNG pipelines and air pipelines of the plurality of LNG temperature-rising heat exchangers are sequentially connected end to end;

[0011] It further includes a first valve. The inlet end of the first valve is connected to the LNG low-temperature storage tank, the outlet end of the first valve is connected to the LNG pipeline of the LNG temperature-rising heat exchanger close to the first valve, and the LNG pipeline outlet of the LNG temperature-rising heat exchanger far from the first valve is connected to the LNG pipeline inlet of the sixth heat exchanger.

[0012] Preferably, an air compressor is respectively connected between the air inlet of the LNG temperature-rising heat exchanger far from the first valve and between the air pipelines of two adjacent LNG temperature-rising heat exchangers. The air pipeline outlet of the LNG temperature-rising heat exchanger close to the first valve is connected to the liquid air storage tank, and the air compressor is used to compress air step by step into the liquid air storage tank.

[0013] Preferably, the second heat exchange subsystem includes a second valve and a fifth heat exchanger. The inlet end of the second valve is connected to the LNG low-temperature storage tank, the outlet end of the second valve is connected to the LNG pipeline inlet of the fifth heat exchanger, the LNG pipeline outlet of the fifth heat exchanger is connected to the LNG pipeline of the sixth heat exchanger, and the heat source of the fifth heat exchanger is the warm wastewater of the power plant.

[0014] Preferably, the driving medium flow component includes an eighth heat exchanger. The propane pipeline inlet of the eighth heat exchanger is connected to the propane pipeline outlet of the sixth heat exchanger through a circulation pump, the propane pipeline outlet of the eighth heat exchanger is connected to the propane pipeline inlet of the sixth heat exchanger through the first turbine generator, and the heat source of the eighth heat exchanger is the warm wastewater of the power plant.

[0015] Preferably, it further includes a seventh heat exchanger. The LNG pipeline inlet of the seventh heat exchanger is communicated with the LNG pipeline outlet of the sixth heat exchanger. The LNG is exported through the LNG pipeline outlet of the seventh heat exchanger. The power plant warm drainage pipeline outlet of the seventh heat exchanger is communicated with the power plant warm drainage pipeline inlet of the eighth heat exchanger.

[0016] Preferably, the air pipeline outlet in the LNG heating heat exchanger near the first valve is sequentially communicated with the inlet of the liquid air storage tank through a cold storage device and a sixth turbine generator.

[0017] Preferably, the cold storage device includes a cold storage and a gasification heat exchanger. The air pipeline inlet of the cold storage is communicated with the air pipeline outlet of the LNG heating heat exchanger. The air pipeline outlet of the cold storage is communicated with the inlet of the liquid air storage tank through the sixth turbine generator;

[0018] The propane pipeline outlet of the cold storage is communicated with the propane pipeline inlet of the gasification heat exchanger through a propane heat storage tank. The propane pipeline outlet of the gasification heat exchanger is communicated with the propane pipeline inlet of the cold storage through a propane cold storage tank.

[0019] Preferably, the power generation mechanism includes a number of air heat exchangers. The cold-end pipeline outlets and the hot-end pipeline inlets of the number of air heat exchangers are sequentially connected end to end;

[0020] The air pipeline inlet of the air heat exchanger near the liquid air storage tank, the air pipeline outlet of the air heat exchanger far from the liquid air storage tank, and the air pipelines between two adjacent air heat exchangers are respectively communicated with a turbine generator. The liquid air storage tank is communicated with the air pipeline inlet of the air heat exchanger near the liquid air storage tank through a pressurizing pump and a gasification heat exchanger. The air in the liquid air storage tank is discharged through a number of turbine generators in sequence.

[0021] Preferably, it further includes a mixing pool. The power plant warm drainage flows in the hot-end pipelines of a number of air heat exchangers. The power plant warm drainage flows into the mixing pool through a number of air heat exchangers and is mixed with seawater to meet the sea discharge standard.

[0022] Compared with the prior art, the present invention has the following advantages and technical effects:

[0023] 1. The present invention innovatively proposes an LNG station liquid air energy storage coupled with cold energy power generation system. By efficiently utilizing the cold energy of LNG to absorb the compression heat generated during the compression of air, the efficiency of air energy storage is significantly improved. During the energy release process, LNG and air perform inter-stage heat exchange to cool the air and heat up the LNG, reducing energy consumption.

[0024] 2. Meanwhile, through the coupled cold energy power generation technology, the LNG station of the present invention can generate and use electricity by itself, reducing the dependence on externally purchased electricity, lowering the electricity cost of the gasification station, and enhancing the economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 It is a schematic diagram of the cold energy utilization system of the present invention;

[0027] Figure 2 It is the schematic diagram of the monitoring system in the second embodiment of the present invention;

[0028] Among them, 1. First valve; 2. First heat exchanger; 3. Second heat exchanger; 4. Third heat exchanger; 5. Fourth heat exchanger; 6. First compressor; 7. Second compressor; 8. Third compressor; 9. Fourth compressor; 10. Sixth heat exchanger; 11. Circulation pump; 12. Eighth heat exchanger; 13. First turbine generator; 14. Seventh heat exchanger; 15. Cold storage; 16. Sixth turbine generator; 17. Gas-liquid separator; 18. Liquid air storage tank; 19. Pressurizing pump; 20. Gasification heat exchanger; 21. Second valve; 22. Fifth heat exchanger; 23. Propane hot storage tank; 24. Propane cold storage tank; 25. Second turbine generator; 26. Ninth heat exchanger; 27. Third turbine generator; 28. Tenth heat exchanger; 29. Fourth turbine generator; 30. Eleventh heat exchanger; 31. Fifth turbine generator; 32. Mixing pool. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0030] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0031] Embodiment 1:

[0032] Refer to Figure 1, the present invention provides a cold energy utilization system for an LNG gasification station coupled with liquid air energy storage, including:

[0033] The first LNG heat exchange component, including a first heat exchange subsystem, the cold source and heat source of the first heat exchange subsystem are LNG and air respectively;

[0034] The second LNG heat exchange component, including a second heat exchange subsystem, the cold source and heat source of the second heat exchange subsystem are LNG and power plant warm drainage respectively;

[0035] The ORC power generation component, including a sixth heat exchanger 10 and a first turbine generator 13, the cold source of the sixth heat exchanger 10 is LNG, LNG is exported through the LNG outlet of the sixth heat exchanger 10, and a driving medium flow member is arranged between the propane outlet of the sixth heat exchanger 10 and the first turbine generator 13;

[0036] The air energy release component, including a liquid air storage tank 18, the liquid air storage tank 18 is used to store the liquid air flowing out of the first heat exchange subsystem, and the output end of the liquid air storage tank 18 is connected with a power generation mechanism, and the power generation mechanism generates electricity by using the energy released during the gasification process of the liquid air.

[0037] In a further optimized scheme, the first heat exchange subsystem includes a plurality of LNG temperature-rising heat exchangers, and the LNG pipelines and air pipelines of the plurality of LNG temperature-rising heat exchangers are sequentially connected end to end;

[0038] It further includes a first valve 1, the inlet end of the first valve 1 is connected with the LNG low-temperature storage tank, the outlet end of the first valve 1 is connected with the LNG pipeline of the LNG temperature-rising heat exchanger close to the first valve 1, and the LNG pipeline outlet of the LNG temperature-rising heat exchanger far from the first valve 1 is connected with the LNG pipeline inlet of the sixth heat exchanger 10.

[0039] In a further optimized scheme, an air compressor is respectively connected between the air inlet of the LNG temperature-rising heat exchanger far from the first valve 1 and between the air pipelines of two adjacent LNG temperature-rising heat exchangers, and the air pipeline outlet of the LNG temperature-rising heat exchanger close to the first valve 1 is connected with the liquid air storage tank 18, and the air compressor is used to compress air step by step into the liquid air storage tank 18.

[0040] As Figure 1 shown, in this embodiment, a total of four groups of LNG temperature-rising heat exchangers are provided, which are the first heat exchanger 2, the second heat exchanger 3, the third heat exchanger 4, and the fourth heat exchanger 5 respectively. A total of four groups of air compressors are provided, which are the first compressor 6, the second compressor 7, the third compressor 8, and the fourth compressor 9 respectively.

[0041] Specifically, the outlet of the first compressor 6 is connected to the air inlet of the fourth heat exchanger 5, the air outlet of the fourth heat exchanger 5 is connected to the inlet of the second compressor 7, the outlet of the second compressor 7 is connected to the air inlet of the third heat exchanger 4, the air outlet of the third heat exchanger 4 is connected to the inlet of the third compressor 8, the outlet of the third compressor 8 is connected to the air inlet of the second heat exchanger 3, the air outlet of the second heat exchanger 3 is connected to the inlet of the fourth compressor 9, and the outlet of the fourth compressor 9 is connected to the air inlet of the first heat exchanger 2.

[0042] In a further optimized solution, the second heat exchange subsystem includes a second valve 21 and a fifth heat exchanger 22. The inlet end of the second valve 21 is connected to the LNG cryogenic storage tank, the outlet end of the second valve 21 is connected to the LNG pipeline inlet of the fifth heat exchanger 22, the LNG pipeline outlet of the fifth heat exchanger 22 is connected to the LNG pipeline of the sixth heat exchanger 10, and the heat source of the fifth heat exchanger 22 is the warm wastewater discharged from the power plant.

[0043] In a further optimized solution, the driving medium flow component includes an eighth heat exchanger 12. The propane pipeline inlet of the eighth heat exchanger 12 is connected to the propane pipeline outlet of the sixth heat exchanger 10 through a circulation pump 11, the propane pipeline outlet of the eighth heat exchanger 12 is connected to the propane pipeline inlet of the sixth heat exchanger 10 through a first turbine generator 13, and the heat source of the eighth heat exchanger 12 is the warm wastewater discharged from the power plant.

[0044] In a further optimized solution, it further includes a seventh heat exchanger 14. The LNG pipeline inlet of the seventh heat exchanger 14 is connected to the LNG pipeline outlet of the sixth heat exchanger 10, the LNG is exported through the LNG pipeline outlet of the seventh heat exchanger 14, and the warm wastewater pipeline outlet of the seventh heat exchanger 14 is connected to the warm wastewater pipeline inlet of the eighth heat exchanger 12.

[0045] In a further optimized solution, the air pipeline outlet in the LNG heating-up heat exchanger near the first valve 1 is sequentially connected to the inlet of the liquid air storage tank 18 through a cold storage device and a sixth turbine generator 16.

[0046] In a further optimized solution, the cold storage device includes a cold storage tank 15 and a vaporization heat exchanger 20. The air pipeline inlet of the cold storage tank 15 is connected to the air pipeline outlet of the LNG heating-up heat exchanger, and the air pipeline outlet of the cold storage tank 15 is connected to the inlet of the liquid air storage tank 18 through a sixth turbine generator 16;

[0047] The propane pipeline outlet of the cold storage tank 15 is connected to the propane pipeline inlet of the vaporization heat exchanger 20 through a propane hot storage tank 23, and the propane pipeline outlet of the vaporization heat exchanger 20 is connected to the propane pipeline inlet of the cold storage tank 15 through a propane cold storage tank 24.

[0048] For a further optimized solution, auxiliary cold storage pipelines are also connected end to end inside the first heat exchanger 2, the second heat exchanger 3, the third heat exchanger 4, and the fourth heat exchanger 5, and auxiliary cold storage pipelines are also provided inside the cold storage device 15. At the same time, a gas-liquid separator 17 is provided, which is connected between the outlet of the sixth turbine generator 16 and the liquid air storage tank 18. The gas outlet of the gas-liquid separator 17 is connected to the auxiliary cold storage air inlet of the cold storage device 15, and the auxiliary cold storage air outlet of the cold storage device 15 is connected to the auxiliary cold storage air inlet of the first heat exchanger 2. The unliquefied air finally discharges from the auxiliary cold storage air outlet of the fourth heat exchanger 5.

[0049] As Figure 1 shown, during the energy storage process, when LNG exchanges heat with air in stages, through auxiliary cold storage, the low-temperature air that has not been liquefied can be fully utilized to help LNG cool the air auxiliarily together. The sixth turbine generator 16 can drive the generator to reduce the pressure of the air to liquid normal-pressure air while generating electricity for its own use.

[0050] For a further optimized solution, the power generation mechanism includes a number of air heat exchangers, and the cold-end pipeline outlets and hot-end pipeline inlets of the number of air heat exchangers are connected end to end in sequence;

[0051] The air pipeline inlet of the air heat exchanger near the liquid air storage tank 18, the air pipeline outlet of the air heat exchanger far from the liquid air storage tank 18, and between the air pipelines of two adjacent air heat exchangers are respectively connected with a turbine generator. The liquid air storage tank 18 is connected to the air pipeline inlet of the air heat exchanger near the liquid air storage tank 18 through a pressure pump 19 and a vaporization heat exchanger 20, and the air in the liquid air storage tank 18 is discharged out through a number of turbine generators in sequence.

[0052] As Figure 1 shown, in this embodiment, three groups of air heat exchangers are provided, namely the ninth heat exchanger 26, the tenth heat exchanger 28, and the eleventh heat exchanger 30. Four groups of turbine generators are provided, namely the second turbine generator 25, the third turbine generator 27, the fourth turbine generator 29, and the fifth turbine generator 31.

[0053] Specifically, the inlet of the second turbine generator 25 is connected to the air outlet of the vaporization heat exchanger 20, the outlet of the second turbine generator 25 is connected to the air inlet of the ninth heat exchanger 26, the air outlet of the ninth heat exchanger 26 is connected to the inlet of the third turbine generator 27, the outlet of the third turbine generator 27 is connected to the air inlet of the tenth heat exchanger 28, the air outlet of the tenth heat exchanger 28 is connected to the inlet of the fourth turbine generator 29, the outlet of the fourth turbine generator 29 is connected to the air inlet of the eleventh heat exchanger 30, the air outlet of the eleventh heat exchanger 30 is connected to the inlet of the fifth turbine generator 31, and the air finally discharges from the outlet of the fifth turbine generator 31.

[0054] A further optimized solution further includes a mixing pool 32. The hot end pipelines of a number of air heat exchangers are circulated with the warm discharged water from the power plant. After passing through the number of air heat exchangers, the warm discharged water from the power plant flows into the mixing pool 32 and is mixed with seawater to meet the sea discharge standard.

[0055] As Figure 1 shown, in this embodiment, the water source for heat exchange is the warm discharged water from the power plant. The warm discharged water from the power plant has the characteristics of being higher in temperature than seawater and containing more heat, and can also be used in winter, making the heat exchange efficiency higher and more energy-saving. Finally, natural seawater is introduced into the mixing pool 32 to be mixed with the warm discharged water from the power plant to meet the sea discharge standard and be discharged.

[0056] The specific working process of this embodiment is as follows:

[0057] In the energy storage stage:

[0058] Step 1: Open the first valve 1 and close the second valve 21; LNG sequentially enters the first heat exchanger 2, the second heat exchanger 3, the third heat exchanger 4, and the fourth heat exchanger 5 to heat up LNG to about -80°C; at this time, air enters the first compressor 6 for compression, and then sequentially enters the fourth heat exchanger 5, the second compressor 7, the third heat exchanger 4, the third compressor 8, the second heat exchanger 3, the fourth compressor 9, and the first heat exchanger 2 for a total of four-stage compression and inter-stage refrigeration. Then it enters the cold storage device 15 for further cooling. Among them, the circulating medium of the cold storage device 15 is propane, and the propane is heated up and stored in the propane heat storage tank 23. Then the liquid air passes through the sixth turbine generator 16 to restore the liquid air to normal pressure. In this process, the sixth turbine generator 16 can do work to generate electricity. Finally, after being separated by the gas-liquid separator 17, the normal pressure liquid air is stored in the liquid air storage tank 18, and the gaseous low-temperature air returns from the gas-liquid separator 17 to the cold storage device 15 and sequentially passes through the first heat exchanger 2 to the fourth heat exchanger 5 to assist in cold storage.

[0059] Step 2: After flowing out from the fourth heat exchanger 5, LNG enters the ORC power generation assembly. Specifically, it first exchanges heat with the circulating medium propane through the sixth heat exchanger 10. After the propane is liquefied by LNG (-40°C), it is pressurized by the circulating pump 11 (because it will be depressurized after passing through the first turbine generator 13 later, so it is pressurized to balance the pressure), and then enters the eighth heat exchanger 12 to exchange heat with the warm discharged water from the power plant (usually about 30°C) to heat up the propane to gasify to about 12°C, and then the first turbine generator 13 does work to generate electricity (this part of the electricity can be connected to the 6kV bus for self-use by the LNG receiving station), and then returns to the sixth heat exchanger 10 for circulation.

[0060] Step 3: At this time, the LNG is vaporized to about -40°C and enters the seventh heat exchanger 14 to exchange heat with the warm wastewater of the power plant. The LNG is heated to above 1°C, meeting the export conditions, and the outlet pressure is about 10 Mpa.

[0061] In the energy release stage:

[0062] Step 1: Close the first valve 1 and open the second valve 21; the LNG directly exchanges heat with the warm wastewater of the power plant through the fifth heat exchanger 22 to increase in temperature, and then enters the ORC power generation assembly; at the same time, the liquid air comes out of the liquid air storage tank 18 and is pressurized by the pressure pump 19. The air exchanges heat and is vaporized through the vaporization heat exchanger 20, and the circulating medium propane is cooled and stored in the propane cold storage tank 24. Subsequently, the low-temperature air sequentially enters the second turbine generator 25, the ninth heat exchanger 26, the third turbine generator 27, the tenth heat exchanger 28, the fourth turbine generator 29, the eleventh heat exchanger 30, and the fifth turbine generator 31 for four-stage expansion and inter-stage heat exchange to restore the air to normal temperature and pressure for external transmission.

[0063] Step 2: After the LNG flows out of the fifth heat exchanger 22, it first exchanges heat with the circulating medium propane through the sixth heat exchanger 10. The propane is liquefied by the LNG (-40°C) and then pressurized by the circulating pump 11. Subsequently, it enters the eighth heat exchanger 12 to exchange heat with the warm wastewater of the power plant, causing the propane to be heated and vaporized to about 12°C, and then it performs work and generates electricity through the first turbine generator 13, and then returns to the sixth heat exchanger 10 for circulation.

[0064] Step 3: At this time, the LNG is vaporized to about -40°C and enters the seventh heat exchanger 14 to exchange heat with the warm wastewater of the power plant. The LNG is heated to above 1°C, meeting the export conditions, and the outlet pressure is about 10 Mpa.

[0065] Example 2:

[0066] The difference between this example and Example 1 is only that the cold energy utilization system is equipped with an intelligent monitoring and control device. By installing sensors at key positions, parameters such as the temperature, pressure, and flow rate of the LNG and air are monitored in real time. The system automatically adjusts the operating parameters of the equipment according to the monitoring data to optimize the system performance, and at the same time provides real-time alarm and remote monitoring functions to ensure the safe and efficient operation of the system.

[0067] For a further optimized solution, in this embodiment, the installation positions of the temperature sensor and the pressure sensor are as follows: 1. At the LNG inlet of the entire system (before the first valve 1 and the second valve 21); 2. At the LNG pipeline inlet and outlet of the sixth heat exchanger 10; 3. At the LNG pipeline outlet of the seventh heat exchanger 14; 4. At the air inlet and outlet of the regenerator 15; 5. At the outlet of the sixth turbine generator 16; 6. At the inlet and outlet of the liquid air storage tank 18; 7. At the outlet of the pressure pump 19; 8. At the air pipeline outlet of the vaporization heat exchanger 20; 9. At the outlet of the fifth turbine generator 31; 10. At the air inlet of the first compressor 6.

[0068] Meanwhile, install the flowmeter at the following positions: 1. At the LNG inlet of the entire system (before the first valve 1 and the second valve 21); 2. At one inlet and two outlets of the gas-liquid separator 17; 3. At the outlet of the exported NG (i.e., the seventh heat exchanger 14); 4. At the air inlet of the sixth turbine generator 16.

[0069] As Figure 2 shown, the sensor module collects the temperature, pressure, and flow rate data of LNG in real time. The data acquisition module transmits the data to the central processing unit. The central processing unit compares the collected parameters with the preset safety thresholds. Once an abnormality is detected, an alarm is immediately issued and measures are taken through the control execution module (such as closing the valve or shutting down the machine).

[0070] The central processing unit automatically adjusts the operating parameters of the equipment (such as the compressor speed, valve opening, etc.) according to the collected data. Optimize the heat exchange efficiency of the heat exchanger, reasonably adjust the operating states of the compressor and the turbine generator, and achieve efficient utilization of energy. The central processing unit analyzes and mines the historical data. Predict the fault trends of the equipment and the operating trends of the system, and provide a basis for equipment maintenance and system optimization. The user can view the system operating status and parameters in real time through the user interface. Support remote access and operation, which is convenient for centralized management and monitoring of multiple LNG heat exchangers.

[0071] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0072] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A cold energy utilization system for an LNG gasification station coupled with liquid air energy storage, characterized in that , including: The first LNG heat exchange component, including a first heat exchange subsystem, where the cold source and heat source of the first heat exchange subsystem are LNG and air respectively; The second LNG heat exchange component, including a second heat exchange subsystem, where the cold source and heat source of the second heat exchange subsystem are LNG and power plant warm drainage respectively; The ORC power generation component, including a sixth heat exchanger (10) and a first turbine generator (13). The cold source of the sixth heat exchanger (10) is LNG, and LNG is exported through the LNG outlet of the sixth heat exchanger (10). A driving medium flow member is provided between the propane outlet of the sixth heat exchanger (10) and the first turbine generator (13); The air energy release component, including a liquid air storage tank (18), which is used to store the liquid air flowing out of the first heat exchange subsystem. The output end of the liquid air storage tank (18) is connected to a power generation mechanism, and the power generation mechanism generates electricity using the energy released during the gasification process of the liquid air.

2. The cold energy utilization system of an LNG gasification station coupled with liquid air energy storage according to claim 1, characterized in that: The first heat exchange subsystem includes several LNG temperature rise heat exchangers, and the LNG pipelines and air pipelines of the several LNG temperature rise heat exchangers are sequentially connected end to end; It also includes a first valve (1). The inlet end of the first valve (1) is connected to the LNG low-temperature storage tank, and the outlet end of the first valve (1) is connected to the LNG pipeline of the LNG temperature rise heat exchanger close to the first valve (1). The LNG pipeline outlet of the LNG temperature rise heat exchanger far from the first valve (1) is connected to the LNG pipeline inlet of the sixth heat exchanger (10).

3. A cold energy utilization system for an LNG gasification station coupled with liquid air energy storage according to claim 2, characterized in that: An air compressor is connected respectively at the air inlet of the LNG temperature rise heat exchanger far from the first valve (1) and between the air pipelines of two adjacent LNG temperature rise heat exchangers. The air pipeline outlet of the LNG temperature rise heat exchanger close to the first valve (1) is connected to the liquid air storage tank (18), and the air compressor is used to compress air step by step into the liquid air storage tank (18).

4. The cold energy utilization system of an LNG gasification station coupled with liquid air energy storage according to claim 1, characterized in that: The second heat exchange subsystem includes a second valve (21) and a fifth heat exchanger (22). The inlet end of the second valve (21) is connected to the LNG low-temperature storage tank, the outlet end of the second valve (21) is connected to the LNG pipeline inlet of the fifth heat exchanger (22), the LNG pipeline outlet of the fifth heat exchanger (22) is connected to the LNG pipeline of the sixth heat exchanger (10), and the heat source of the fifth heat exchanger (22) is power plant warm drainage.

5. The cold energy utilization system of an LNG gasification station coupled with liquid air energy storage according to claim 1, characterized in that: The driving medium flow member includes an eighth heat exchanger (12). The propane pipeline inlet of the eighth heat exchanger (12) is connected to the propane pipeline outlet of the sixth heat exchanger (10) through a circulation pump (11). The propane pipeline outlet of the eighth heat exchanger (12) is connected to the propane pipeline inlet of the sixth heat exchanger (10) through the first turbine generator (13), and the heat source of the eighth heat exchanger (12) is power plant warm drainage.

6. The cold energy utilization system of an LNG gasification station coupled with liquid air energy storage according to claim 5, wherein: It further includes a seventh heat exchanger (14). The LNG pipeline inlet of the seventh heat exchanger (14) is communicated with the LNG pipeline outlet of the sixth heat exchanger (10). LNG is exported through the LNG pipeline outlet of the seventh heat exchanger (14). The power plant warm waste water pipeline outlet of the seventh heat exchanger (14) is communicated with the power plant warm waste water pipeline inlet of the eighth heat exchanger (12).

7. The cold energy utilization system of an LNG gasification station coupled with liquid air energy storage according to claim 2, wherein: The air pipeline outlet in the LNG heating heat exchanger near the first valve (1) is successively communicated with the inlet of the liquid air storage tank (18) through a cold storage device and a sixth turbine generator (16).

8. A cold energy utilization system for an LNG gasification station coupled with liquid air energy storage according to claim 7, characterized in that: The cold storage device includes a cold storage cooler (15) and a vaporization heat exchanger (20). The air pipeline inlet of the cold storage cooler (15) is communicated with the air pipeline outlet of the LNG heating heat exchanger. The air pipeline outlet of the cold storage cooler (15) is communicated with the inlet of the liquid air storage tank (18) through the sixth turbine generator (16). The propane pipeline outlet of the cold storage cooler (15) is communicated with the propane pipeline inlet of the vaporization heat exchanger (20) through a propane heat storage tank (23). The propane pipeline outlet of the vaporization heat exchanger (20) is communicated with the propane pipeline inlet of the cold storage cooler (15) through a propane cold storage tank (24).

9. The cold energy utilization system of an LNG gasification station coupled with liquid air energy storage according to claim 8, wherein: The power generation mechanism includes a plurality of air heat exchangers. The cold-end pipeline outlets and the hot-end pipeline inlets of the plurality of air heat exchangers are successively communicated end to end. The air pipeline inlet of the air heat exchanger near one end of the liquid air storage tank (18), the air pipeline outlet of the air heat exchanger far from the liquid air storage tank (18), and the air pipelines between two adjacent air heat exchangers are respectively communicated with a turbine generator. The liquid air storage tank (18) is communicated with the air pipeline inlet of the air heat exchanger near it through a pressure pump (19) and a vaporization heat exchanger (20). The air in the liquid air storage tank (18) is successively discharged through the plurality of turbine generators.

10. A cold energy utilization system for an LNG gasification station coupled with a liquid air energy storage according to claim 9, characterized in that: It further includes a mixing pool (32). The power plant warm waste water flows in the hot-end pipelines of the plurality of air heat exchangers. The power plant warm waste water flows into the mixing pool (32) after passing through the plurality of air heat exchangers and is mixed with seawater to meet the sea discharge standard.

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