Cold industrial park system based on LNG cold energy and cold supply method thereof

Abstract

The invention discloses a cold industrial park system based on LNG cold energy and a cold supply method of the cold industrial park system. The system comprises an LNG cold energy recovery module, an ice making module, a refrigeration house module, a freeze-drying and quick-freezing module and a heat pump module. The LNG cold energy recovery module comprises an LNG heat exchanger and a circulating refrigerant heater, an outlet of the circulating refrigerant heater is connected with the LNG heat exchanger, and an outlet of the LNG heat exchanger is divided into three paths which are connected to an inlet of the circulating refrigerant heater after passing through the ice making module, the cold storage module and the freeze-drying and quick-freezing module respectively; the heat pump module comprises a heat pump compressor, a heat pump expansion valve and an evaporator which are connected in sequence, the evaporator is connected with the water pool of the ice making module, and the two ends of the circulating refrigerant heater are connected with the heat pump compressor and the heat pump expansion valve respectively. The LNG cold energy is used for users such as ice making, refrigeration houses, quick freezing and freeze-drying, efficient energy utilization and industrial fusion are achieved, universality is high, and greater economic benefits are achieved.

Description

Technical Field

[0001] The present invention relates to the field of LNG cold energy recovery and utilization, and in particular to a cold industrial park system based on LNG cold energy and a cooling method thereof. Background Art

[0002] The traditional LNG receiving station uses cold energy mainly for air separation and power generation, with a single industry and low economic benefits due to the limitation of industrial scale, and the overall utilization rate of LNG cold energy is low. However, relying on LNG cold energy to build a cold industry park and using LNG cold energy for ice making, cold storage, quick freezing and freeze drying can not only improve the utilization rate of LNG cold energy, but also build a complete cold energy utilization industry chain, build a cycle within the park, and form a regional cold industry cluster, which has higher economic and social benefits.

[0003] Chinese patent authorization CN110513157B discloses a new energy-saving process and energy-saving system for LNG receiving stations. The system replaces the ORV open-frame seawater vaporizer group with an IFV intermediate vaporizer group. The intermediate medium collects the LNG cold energy and transmits it to various cold energy utilization projects. At the same time, LNG evaporated gas is used for triple power generation, and the waste heat from power generation is used for LNG vaporizers, which opens up a new way for receiving stations to save energy and reduce consumption and create profits. However, this patent focuses on the energy-saving process of LNG receiving stations, and does not design the downstream cold end, so it cannot provide a reference for the cold energy utilization of downstream industries.

[0004] Chinese patent application CN117804094A discloses a freeze-drying process system and method using LNG cold energy based on CO2 refrigerant. The system uses LNG cold energy for pre-freezing materials in the freeze-drying box and capturing water vapor in the cold trap; it is equipped with an electric compression refrigeration system and an LNG cold energy recovery and utilization system for cold supplementation to improve the flexibility of process operation, so that a set of process systems can meet the freeze-drying needs of all types of materials. This patent only uses LNG cold energy for freeze-drying, and does not combine it with other cold-using industries; the process uses an expansion valve and a compressor to provide lower cold energy for the freeze dryer, but does not recover the waste heat at the compressor outlet for use in the freeze-drying chamber, resulting in energy waste. At the same time, the outlet NG needs to be heated again, and there are many heat exchange equipment and complex process control. Summary of the invention

[0005] Based on the rapid development of the current domestic LNG industry, cold chain logistics industry, pre-prepared meals, central kitchens and other food processing industries, and combined with the current research status of LNG cold energy technology, the present invention proposes a cold industrial park system process based on LNG cold energy, which uses LNG cold energy for ice making, cold storage, quick freezing and freeze drying, etc., to achieve efficient energy utilization and industrial integration.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical solutions: a cold industrial park system based on LNG cold energy, including an LNG cold energy recovery module, an ice making module, a cold storage module, a freeze drying and quick freezing module, and a heat pump module;

[0007] The LNG cold energy recovery module includes an LNG heat exchanger and a circulating refrigerant heater. The outlet of the circulating refrigerant heater is connected to the LNG heat exchanger. The outlet of the LNG heat exchanger is divided into three paths, which are respectively connected to the inlet of the circulating refrigerant heater after passing through the ice making module, the cold storage module, and the freeze drying and quick freezing module;

[0008] The heat pump module includes a heat pump compressor, a heat pump expansion valve, and an evaporator which are connected in sequence, and the evaporator is connected to the water pool of the ice-making module. The two ends of the circulating refrigerant heater are respectively connected to the heat pump compressor and the heat pump expansion valve.

[0009] As a further improvement of the present invention, the heat pump module also includes a condenser, which is arranged between the heat pump compressor and the heat pump expansion valve to participate in the high-temperature refrigerant circulation of the heat pump module, and a high-temperature refrigerant circulation pipeline is formed between the condenser and the circulating refrigerant heater.

[0010] As a further improvement of the present invention, the ice-making module comprises a first circulating refrigerant circulation barrel, a first circulating refrigerant heat exchanger, an ice-making circulation barrel, an ice-making machine, and a water pool which are connected in sequence;

[0011] The circulating refrigerant at the outlet of the LNG heat exchanger passes through the first circulating refrigerant circulation barrel, enters the first circulating refrigerant heat exchanger, exchanges heat with the ice-making refrigerant in the ice-making circulation barrel, and then flows to the circulating refrigerant heater; the ice-making circulation barrel and the ice-making machine constitute an ice-making refrigerant circulation pipeline.

[0012] As a further improvement of the present invention, the ice-making module comprises a first circulating refrigerant circulating barrel, a first circulating refrigerant heat exchanger, an ice-making pool, and a water pool which are connected in sequence;

[0013] The circulating refrigerant at the outlet of the LNG heat exchanger enters the first circulating refrigerant heat exchanger through the first circulating refrigerant circulating barrel and directly supplies cold to the ice making pool.

[0014] As a further improvement of the present invention, the cold storage module includes a second circulating refrigerant circulation barrel, a second circulating refrigerant heat exchanger, a cold storage circulation barrel, and a cold storage, which are connected in sequence;

[0015] The circulating refrigerant at the outlet of the LNG heat exchanger passes through the second circulating refrigerant circulation barrel, enters the second circulating refrigerant heat exchanger, exchanges heat with the cold storage refrigerant in the cold storage circulation barrel, and then flows to the circulating refrigerant heater; the cold storage circulation barrel and the cold storage constitute a cold storage refrigerant circulation pipeline.

[0016] As a further improvement of the present invention, the freeze-drying and quick-freezing module includes a third-cycle refrigerant circulation barrel, a third-cycle refrigerant heat exchanger, a low-temperature expansion valve, and a low-temperature circulation barrel which are connected in sequence, and the low-temperature circulation barrel is respectively connected to the quick freezer, the cold trap, and the low-temperature compressor, and the low-temperature compressor is connected to the three-way valve, the freeze-drying bin, and the third-cycle refrigerant heat exchanger in sequence.

[0017] On the other hand, the present invention also provides the following technical solution:

[0018] A cooling method for a cold industrial park based on LNG cold energy, characterized in that the cold industrial park system based on LNG cold energy as described above is used to perform the following steps, including:

[0019] LNG from the receiving station enters the LNG heat exchanger and exchanges heat with the gas circulating refrigerant to increase the temperature and gasify it into NG, and then returns to the receiving station. At the same time, the gas circulating refrigerant is cooled and liquefied into low-temperature liquid circulating refrigerant, and then divided into three routes to the ice-making module, cold storage module, freeze-drying and quick-freezing module for cooling; the low-temperature gas circulating refrigerant coming out of the ice-making module, cold storage module, freeze-drying and quick-freezing module enters the circulating refrigerant heater and exchanges heat with the high-temperature refrigerant to increase the temperature and enter the LNG heat exchanger; the high-temperature refrigerant exchanges heat and cools down, then enters the condenser and exchanges heat with the high-temperature refrigerant at the outlet of the heat pump compressor to increase the temperature, completing the cycle;

[0020] The circulating refrigerant in the ice-making module passes through the first circulating refrigerant circulation barrel and then enters the first circulating refrigerant heat exchanger to exchange heat with the gaseous ice-making refrigerant coming out of the ice-making circulation barrel and vaporize it, and then returns to the first circulating refrigerant circulation barrel and leaves the ice-making module; the ice-making refrigerant is liquefied after heat exchange and enters the return ice-making circulation barrel, and then is transported to the ice-making machine to release cold energy, and then returns to the ice-making circulation barrel after vaporization and temperature increase;

[0021] The circulating refrigerant in the cold storage module passes through the second circulating refrigerant circulation barrel (12), enters the second circulating refrigerant heat exchanger, exchanges heat with the gaseous cold storage refrigerant coming out of the cold storage circulation barrel, and then returns to the second circulating refrigerant circulation barrel to leave the cold storage module; the cold storage refrigerant enters the return cold storage circulation barrel after heat exchange and liquefaction, and then is transported to the cold storage to release cold energy, and then returns to the cold storage circulation barrel after gasification and temperature increase;

[0022] The circulating refrigerant in the freeze-drying and quick-freezing module passes through the third circulating refrigerant circulation barrel, enters the third circulating refrigerant heat exchanger to exchange heat with the gaseous low-temperature refrigerant for vaporization, returns to the third circulating refrigerant circulation barrel and leaves the freeze-drying and quick-freezing module; the low-temperature refrigerant is liquefied through heat exchange, expanded and cooled by the low-temperature expansion valve, and then enters the low-temperature circulation barrel, and then is divided into two paths, entering the quick freezer and cold trap for cooling respectively, and returns to the low-temperature circulation barrel after vaporization. After being pressurized and heated by the low-temperature compressor, it enters the freeze-drying bin to provide heat energy for the material, and then enters the third circulating refrigerant heat exchanger to complete the cycle.

[0023] As a further improvement of the present invention, the high-temperature refrigerant in the heat pump module is liquefied and cooled through heat exchange by a circulating refrigerant heater or a condenser, and then throttled and expanded by a heat pump expansion valve to a gas-liquid mixture, and then enters the evaporator, exchanges heat with the water in the water pool and heats up, and then enters the heat pump compressor to complete the cycle, so that the cold energy generated in the heat pump module is used for pre-cooling the water in the water pool, thereby accelerating the ice making speed of the ice maker.

[0024] As a further improvement of the present invention, the condenser in the heat pump module is cancelled according to actual conditions, and the high-temperature refrigerant at the outlet of the heat pump compressor directly enters the circulating refrigerant heater to reheat the circulating refrigerant.

[0025] As a further improvement of the present invention, when the temperature of the cold storage is 7-12°C higher than the circulating refrigerant, the second circulating refrigerant heat exchanger and the cold storage circulating barrel are cancelled, and the circulating refrigerant is directly supplied to the cold storage.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. High energy efficiency. The heat pump heats up the circulating refrigerant and generates cold energy for precooling the pool, achieving efficient energy utilization while improving ice-making efficiency; at the same time, the low-temperature compressor pressurizes the low-temperature refrigerant and generates heat energy for melting ice crystals in the freeze-drying warehouse, reducing the use of freeze-drying warehouse heating equipment and compressor condensers, achieving efficient energy utilization.

[0028] 2. Strong universality and high operational flexibility. Equipped with expansion valves and low-temperature compressors, it can meet the cooling needs of users with different low temperatures and flexibly adjust the gasification pressure and temperature of low-temperature refrigerants.

[0029] 3. Expand the field of cold energy utilization and achieve greater economic benefits. Providing feasible cold energy utilization technology for LNG cold energy to be used in different cold industries in the cold industry park will be conducive to industrial collaboration and create greater benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solution, the drawings required for use in the implementation will be briefly introduced below. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 A schematic diagram of a cold industrial park system process for realizing a cold industrial park system based on LNG cold energy provided by an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of a process in which a circulating refrigerant directly enters a cold storage provided in an embodiment of the present invention;

[0033] Figure 3A schematic diagram of a process for making ice using brine provided in an embodiment of the present invention;

[0034] As shown in the figure: 1 is an LNG heat exchanger, 2 is a heat pump compressor, 3 is a condenser, 4 is a heat pump expansion valve, 5 is an evaporator, 6 is a circulating refrigerant heater, 7 is a first circulating refrigerant circulating barrel, 8 is a first circulating refrigerant heat exchanger, 9 is an ice-making circulating barrel, 10 is an ice-making machine, 11 is a water tank, 12 is a second circulating refrigerant circulating barrel, 13 is a second circulating refrigerant heat exchanger, 14 is a cold storage circulating barrel, 15 is a cold storage, 16 is a third circulating refrigerant circulating barrel, 17 is a third circulating refrigerant heat exchanger, 18 is a low-temperature expansion valve, 19 is a low-temperature circulating barrel, 20 is a low-temperature compressor, 21 is a three-way valve, 22 is a quick freezer, 23 is a freeze-drying bin, and 24 is a cold trap. DETAILED DESCRIPTION

[0035] In order to enable a clear and complete understanding of the technical solution, the present invention is further described in conjunction with the embodiments and drawings. Obviously, the described embodiments are only some embodiments of the present invention, and all other embodiments obtained by technicians in the relevant field without making creative work are within the scope of protection of the present invention.

[0036] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0037] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0038] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0039] The embodiment of the present invention discloses a cold industrial park system based on LNG cold energy, which uses LNG cold energy for ice making, cold storage, quick freezing and freeze drying, etc., to achieve efficient energy utilization and industrial integration. Figure 1-3 As shown, the system includes LNG cold energy recovery module, ice making module, cold storage module, freeze drying and quick freezing module, and heat pump module;

[0040] It should be noted that the present invention does not impose any limitation on the circulating refrigerant and other refrigerants. The technicians can set it according to the actual use requirements. Generally speaking, the circulating refrigerant of the present invention includes but is not limited to all phase change refrigerants such as ammonia, CO2, Freon, light hydrocarbons, etc.; Freon refrigerants include but are not limited to any one of R23, R507, and R410a, and light hydrocarbon refrigerants include but are not limited to any one of ethane, propane, ethylene, and propylene or a mixture thereof.

[0041] Specifically, the LNG cold energy recovery module includes an LNG heat exchanger 1 and a circulating refrigerant heater 6. The outlet of the circulating refrigerant heater 6 is connected to the LNG heat exchanger 1. The outlet of the LNG heat exchanger 1 is divided into three paths, which are respectively connected to the inlet of the circulating refrigerant heater 6 after passing through the ice making module, the cold storage module, and the freeze drying and quick freezing module;

[0042] The heat pump module includes a heat pump compressor 2, a heat pump expansion valve 4, and an evaporator 5 which are connected in sequence, and the evaporator 5 is connected to the water pool 11 of the ice-making module. The two ends of the circulating refrigerant heater 6 are respectively connected to the heat pump compressor 2 and the heat pump expansion valve 4.

[0043] In some embodiments, the heat pump module also includes a condenser 3, which is arranged between the heat pump compressor 2 and the heat pump expansion valve 4 to participate in the high-temperature refrigerant circulation of the heat pump module, and a high-temperature refrigerant circulation pipeline is formed between the condenser 3 and the circulating refrigerant heater 6.

[0044] In this embodiment, the circulating refrigerant is CO2, the LNG flow rate is 180t / h, the temperature is -150~-160℃, and the pressure is 9.2MPa;

[0045] LNG at -160~-150℃ from the receiving station enters LNG heat exchanger 1 and exchanges heat with gaseous CO2 with a flow rate of 270~300t / h, a temperature of 20~55℃, and a pressure of 1.2~1.4MPa to raise the temperature to 0~5℃ and return to the receiving station; gaseous CO2 is cooled by heat exchange and liquefied into liquid CO2 at -40~-30℃, and then divided into three routes to ice making module, cold storage module, freeze drying and quick freezing module for cooling;

[0046] The CO2 at -25 to -10℃ coming out of the ice-making module, cold storage module, freeze-drying and quick-freezing module enters the circulating refrigerant heater 6 and exchanges heat with the 60℃ circulating hot water to raise the temperature to 20 to 55℃ and enters the LNG heat exchanger 1; the circulating hot water is cooled to 30 to 40℃ and then enters the condenser 3 and exchanges heat with the 80 to 90℃ high-temperature refrigerant at the outlet of the heat pump compressor 2 to complete the cycle.

[0047] In some implementations, the condenser 3 in the heat pump module can be removed according to actual conditions, and the high-temperature refrigerant at the outlet of the heat pump compressor 2 is directly sent to the circulating refrigerant heater 6 to reheat the circulating refrigerant.

[0048] That is to say, the CO2 at -25 to -10℃ coming out of the ice-making module, cold storage module, freeze-drying and quick-freezing module enters the circulating refrigerant heater 6 and exchanges heat with the 80 to 90℃ high-temperature refrigerant at the outlet of the heat pump compressor 2 to raise the temperature to 20 to 55℃ and enters the LNG heat exchanger 1; the high-temperature refrigerant exchanges heat and liquefies to cool down to 30 to 35℃ liquid, and then expands to 0 to 5℃ gas-liquid mixture through the heat pump expansion valve 4, enters the evaporator 5, exchanges heat with water to raise the temperature to 10 to 20℃, and enters the heat pump compressor 2 to complete the cycle.

[0049] In the above embodiment, the heat pump module generates cold energy for precooling the water in the water pool 11, which can speed up the ice making speed of the ice maker 10, achieve efficient use of energy and improve ice making efficiency.

[0050] In order to better understand the role of the ice-making module in the system, in an optional embodiment, the ice-making module includes a first circulating refrigerant circulation barrel 7, a first circulating refrigerant heat exchanger 8, an ice-making circulating barrel 9, an ice-making machine 10, and a water tank 11 connected in sequence; the circulating refrigerant at the outlet of the LNG heat exchanger 1 passes through the first circulating refrigerant circulation barrel 7 and enters the first circulating refrigerant heat exchanger 8 to exchange heat with the ice-making refrigerant in the ice-making circulating barrel 9, and then flows to the circulating refrigerant heater 6; the ice-making circulating barrel 9 and the ice-making machine 10 constitute an ice-making refrigerant circulation pipeline.

[0051] Furthermore, the ice maker 10 is not limited to ice makers, but is also applicable to ice pools. When an ice pool is used, the ice circulation barrel 9 can be removed. In order to better understand the use of an ice pool, an optional implementation is provided. The ice making module includes a first circulating refrigerant circulation barrel 7, a first circulating refrigerant heat exchanger 8, an ice pool, and a water pool 11 connected in sequence; the circulating refrigerant at the outlet of the LNG heat exchanger 1 passes through the first circulating refrigerant circulation barrel 7 and enters the first circulating refrigerant heat exchanger 8 to directly supply cold to the ice pool.

[0052] In an optional implementation, the liquid CO2 at -40 to -30°C in the ice-making module passes through the first circulating refrigerant circulation barrel 7 and then enters the first circulating refrigerant heat exchanger 8 to exchange heat with the gaseous R507 at -10 to 0°C coming out of the ice-making circulation barrel 9 and vaporizes to -25 to -10°C, returns to the first circulating refrigerant circulation barrel 7 and then leaves the ice-making module; the gaseous R507 is liquefied into a liquid at -20 to -15°C and then returns to the ice-making circulation barrel 9, and then is transported to the ice-making machine 10 to release cold energy, and returns to the ice-making circulation barrel 9 after vaporization and heating.

[0053] In some embodiments, liquid CO2 at -40 to -30°C in the ice-making module passes through the first circulating refrigerant circulation barrel 7 and then enters the first circulating refrigerant heat exchanger 8 to exchange heat with the -15 to -10°C calcium chloride aqueous solution coming out of the ice-making pool and vaporizes to -25 to -15°C, returns to the first circulating refrigerant circulation barrel 7, and then leaves the ice-making module; the calcium chloride aqueous solution is cooled to -22 to -17°C and then transported to the ice-making machine 10 to release cold energy, and then returns to the first circulating refrigerant heat exchanger 8 after being heated up.

[0054] In order to better understand the role of the cold storage module in the system, in an optional implementation, the cold storage module includes a second circulating refrigerant circulation barrel 12, a second circulating refrigerant heat exchanger 13, a cold storage circulation barrel 14, and a cold storage 15 connected in sequence; the circulating refrigerant at the outlet of the LNG heat exchanger 1 passes through the second circulating refrigerant circulation barrel 12 and enters the second circulating refrigerant heat exchanger 13 and the cold storage circulation barrel 14 for heat exchange with the cold storage refrigerant, and then flows to the circulating refrigerant heater 6; the cold storage circulation barrel 14 and the cold storage 15 constitute a cold storage refrigerant circulation pipeline.

[0055] In this embodiment, specific refrigerant parameters are used as an example: the liquid CO2 at -40 to -30°C in the cold storage module passes through the second circulating refrigerant circulation barrel 12 and enters the second circulating refrigerant heat exchanger 13 to exchange heat with the gaseous CO2 at -23 to -20°C coming out of the cold storage circulation barrel 14 to be vaporized to -27 to -25°C, and then returns to the second circulating refrigerant circulation barrel 12 to leave the cold storage module; the gaseous CO2 from the cold storage circulation barrel is liquefied by heat exchange and cooled to -30 to -25°C, and then enters the return cold storage circulation barrel 14, and is then transported to the cold storage 15 to release cold energy, and then returns to the cold storage circulation barrel 14 after vaporization and heating.

[0056] In some implementations, when the temperature of the cold storage is higher than the circulating refrigerant by more than 7°C, the second circulating refrigerant heat exchanger 13 and the cold storage circulating barrel 14 can be eliminated, and the circulating refrigerant can be directly supplied to the cold storage. That is, the liquid CO2 at -40 to -30°C in the cold storage module enters the cold storage circulating barrel 14 and then enters the cold storage 15 to release cold energy, and then returns to the cold storage circulating barrel 14 after gasification and temperature rise to -30 to -25°C.

[0057] Furthermore, the cold storage 15 is not limited to cold storage, but is also applicable to cold storage in production workshop environments, hallways, air conditioning systems, etc.

[0058] In order to better understand the role of the freeze-drying and quick-freezing module in the system, in an optional implementation, the freeze-drying and quick-freezing module includes a third-cycle refrigerant circulation barrel 16, a third-cycle refrigerant heat exchanger 17, a low-temperature expansion valve 18, and a low-temperature circulation barrel 19, which are connected in sequence, and the low-temperature circulation barrel 19 is respectively connected to the quick freezer 22, the cold trap 24, and the low-temperature compressor 20, and the low-temperature compressor 20 is connected to the three-way valve 21, the freeze-drying bin 23, and the third-cycle refrigerant heat exchanger 17 in sequence.

[0059] Furthermore, the heat energy of the high-temperature refrigerant at the outlet of the low-temperature compressor 20 is used for the melting of ice crystals of materials in the freeze-drying bin 23, thereby realizing efficient energy utilization. When the freeze-drying bin does not need to be heated or the heat demand is reduced, the flow rate can be adjusted by the three-way valve to ensure load balance.

[0060] Further explanation: the liquid CO2 at -40~-30℃ in the freeze-drying and quick-freezing module passes through the third circulating refrigerant circulation barrel 16 and enters the third circulating refrigerant heat exchanger 17 to exchange heat with the gaseous R23 at 1.2~1.4MPa and -20~-10 to gasify to -25~-20℃, and then returns to the third circulating refrigerant circulation barrel 16 and leaves the freeze-drying and quick-freezing module; the gaseous R23 is liquefied by heat exchange and cooled to -25~-20℃ and then throttled and expanded by the low-temperature expansion valve 18. The gas-liquid mixture with a temperature of 0.4-0.5MPa and -55--50℃ enters the low-temperature circulation barrel 19, and then is divided into two paths, entering the quick freezer 22 and the cold trap 24 for cooling respectively. After being vaporized and heated to -35--30℃, it returns to the low-temperature circulation barrel 19, and is pressurized and heated to 1.0-1.2MPa and 35-50℃ by the low-temperature compressor 20, and then enters the freeze-drying chamber 23 to provide heat energy for the material, and then enters the third circulating refrigerant heat exchanger 17 to complete the cycle.

[0061] Obviously, the above embodiments are only used to illustrate the system structure of the present invention, and are not intended to limit the scope of protection of the present invention. Without departing from the concept of the present invention, those skilled in the art can adjust the above system structure so that the present invention can be applied to more specific application scenarios.

[0062] In order to better understand the above system structure, the cooling method of the system is described below in combination with an embodiment, but it is not intended to limit the technical solution of the embodiment of the present invention. Specifically:

[0063] An embodiment of the present invention provides a cooling method for a cold industrial park based on LNG cold energy, and the following steps are performed using a cold industrial park system based on LNG cold energy according to one or more of the above embodiments:

[0064] LNG from the receiving station enters the LNG heat exchanger 1 and exchanges heat with the gas circulating refrigerant to increase temperature and gasify into NG, and then returns to the receiving station. At the same time, the gas circulating refrigerant is cooled and liquefied into low-temperature liquid circulating refrigerant, and then divided into three routes to the ice making module, cold storage module, freeze drying and quick freezing module for cooling;

[0065] The low-temperature gas circulation refrigerant from the ice-making module, cold storage module, freeze-drying and quick-freezing module enters the circulation refrigerant heater 6 to exchange heat with the high-temperature refrigerant and heat up before entering the LNG heat exchanger 1;

[0066] After the high-temperature refrigerant cools down through heat exchange, it enters the condenser 3 and exchanges heat with the high-temperature refrigerant at the outlet of the heat pump compressor 2 to heat up, completing the cycle;

[0067] The circulating refrigerant in the ice-making module passes through the first circulating refrigerant circulation barrel 7 and enters the first circulating refrigerant heat exchanger 8 to exchange heat with the gaseous ice-making refrigerant coming out of the ice-making circulation barrel 9 and vaporize it, and then returns to the first circulating refrigerant circulation barrel 7 and leaves the ice-making module; the ice-making refrigerant is liquefied after heat exchange and enters the return ice-making circulation barrel 9, and then is transported to the ice-making machine 10 to release cold energy, and returns to the ice-making circulation barrel 9 after vaporization and temperature rise;

[0068] The circulating refrigerant in the cold storage module enters the second circulating refrigerant heat exchanger 13 after passing through the second circulating refrigerant circulation barrel 12, exchanges heat with the gaseous cold storage refrigerant coming out of the cold storage circulation barrel 14, and then returns to the second circulating refrigerant circulation barrel 12 and leaves the cold storage module; the cold storage refrigerant enters the return cold storage circulation barrel 14 after heat exchange and liquefaction, and then is transported to the cold storage 15 to release cold energy, and returns to the cold storage circulation barrel 14 after gasification and temperature increase;

[0069] The circulating refrigerant in the freeze-drying and quick-freezing module passes through the third circulating refrigerant circulation barrel 16, enters the third circulating refrigerant heat exchanger 17, exchanges heat with the gaseous low-temperature refrigerant for vaporization, returns to the third circulating refrigerant circulation barrel 16, and then leaves the freeze-drying and quick-freezing module; the low-temperature refrigerant is liquefied through heat exchange, expands and cools through the low-temperature expansion valve 18, and then enters the low-temperature circulation barrel 19, and then is divided into two paths, respectively entering the quick freezer 22 and the cold trap 24 for cooling, and then returns to the low-temperature circulation barrel 19 after vaporization, and enters the freeze-drying bin 23 after pressurization and heating by the low-temperature compressor 20 to provide heat energy for the material, and then enters the third circulating refrigerant heat exchanger 17 to complete the cycle.

[0070] Based on the above embodiment, the high-temperature refrigerant in the heat pump module is liquefied and cooled through heat exchange in the circulating refrigerant heater 6 or the condenser 3, and then throttled and expanded into a gas-liquid mixture through the heat pump expansion valve 4 to enter the evaporator 5, and then heat-exchanged with the water in the water pool 11 to heat up and enter the heat pump compressor 2 to complete the cycle, so that the cold energy generated in the heat pump module is used for pre-cooling the water in the water pool 11, thereby accelerating the ice-making speed of the ice maker 10.

[0071] In an optional embodiment, the condenser 3 in the heat pump module is cancelled according to actual conditions, and the high-temperature refrigerant at the outlet of the heat pump compressor 2 directly enters the circulating refrigerant heater 6 to reheat the circulating refrigerant.

[0072] In an optional embodiment, when the temperature of the cold storage is 7-12° C. higher than the circulating refrigerant, the second circulating refrigerant heat exchanger 13 and the cold storage circulating barrel 14 are cancelled, and the circulating refrigerant is directly supplied to the cold storage.

[0073] In the above method embodiment, LNG cold energy is used for ice making, cold storage, quick freezing and freeze drying, etc., to achieve efficient energy utilization and industrial integration. Specific refrigerant parameter examples and the connection and process in each method step have been described in the above system structure embodiment. Although the control of each module is described in the above sequence, those skilled in the art can understand that some control steps of some modules can be independently operated and the modules can be combined and operated through some control steps. It is not necessary to run all steps to achieve the corresponding technical effect, and no repetition is given here.

[0074] Through the above steps, the heat pump module of this embodiment generates cold energy while heating the circulating refrigerant, which is used for pre-cooling the water pool, thereby achieving efficient energy utilization and improving ice-making efficiency; at the same time, the low-temperature compressor generates heat energy while pressurizing the low-temperature refrigerant, which is used for the melting of ice crystals of materials in the freeze-drying chamber, reducing the use of freeze-drying chamber heating equipment and compressor condensers, thereby achieving efficient energy utilization.

[0075] In order to achieve the effect of this embodiment, different steps do not have to be executed in this order. They can be executed simultaneously (in parallel) or in a reverse order. These simple changes are within the protection scope of the present invention.

[0076] The above disclosure is only one or more preferred embodiments of the present invention, which are used to help understand the inventive concept of the technical solution, and is not intended to limit the present invention in other forms. Technical personnel in the relevant field may make other equivalent or customary replacement schemes based on the features defined by the present invention, which still fall within the scope of the present invention.

Claims

1. A cold industrial park system based on LNG cold energy, characterized in that: Including LNG cold energy recovery module, ice making module, cold storage module, freeze drying and quick freezing module, heat pump module; The LNG cold energy recovery module comprises an LNG heat exchanger (1) and a circulating refrigerant heater (6); the outlet of the circulating refrigerant heater (6) is connected to the LNG heat exchanger (1); the outlet of the LNG heat exchanger (1) is divided into three paths, which respectively pass through an ice making module, a cold storage module, and a freeze drying and quick freezing module and are then connected to the inlet of the circulating refrigerant heater (6); The heat pump module comprises a heat pump compressor (2), a heat pump expansion valve (4), and an evaporator (5) which are connected in sequence, and the evaporator (5) is connected to a water pool (11) of the ice-making module, and the two ends of the circulating refrigerant heater (6) are respectively connected to the heat pump compressor (2) and the heat pump expansion valve (4).

2. A cold industrial park system based on LNG cold energy according to claim 1, characterized in that: The heat pump module also includes a condenser (3), which is arranged between the heat pump compressor (2) and the heat pump expansion valve (4) and participates in the high-temperature refrigerant circulation of the heat pump module, and a high-temperature refrigerant circulation pipeline is formed between the condenser (3) and the circulating refrigerant heater (6).

3. The cold industrial park system based on LNG cold energy according to claim 1 is characterized in that: The ice-making module comprises a first circulating refrigerant circulation barrel (7), a first circulating refrigerant heat exchanger (8), an ice-making circulation barrel (9), an ice-making machine (10), and a water pool (11) which are connected in sequence; A circulating refrigerant at the outlet of the LNG heat exchanger (1) passes through a first circulating refrigerant circulation barrel (7) and enters a first circulating refrigerant heat exchanger (8) for heat exchange with the ice-making refrigerant in an ice-making circulation barrel (9), and then flows to a circulating refrigerant heater (6); the ice-making circulation barrel (9) and the ice-making machine (10) form an ice-making refrigerant circulation pipeline.

4. The cold industrial park system based on LNG cold energy according to claim 1 is characterized in that: The ice-making module comprises a first circulating refrigerant circulating barrel (7), a first circulating refrigerant heat exchanger (8), an ice-making pool, and a water pool (11) which are connected in sequence; The circulating refrigerant at the outlet of the LNG heat exchanger (1) passes through the first circulating refrigerant circulation barrel (7) and enters the first circulating refrigerant heat exchanger (8) to directly supply cold to the ice making pool.

5. The cold industrial park system based on LNG cold energy according to claim 1 is characterized in that: The cold storage module comprises a second circulating refrigerant circulation barrel (12), a second circulating refrigerant heat exchanger (13), a cold storage circulation barrel (14), and a cold storage (15) which are connected in sequence; The circulating refrigerant at the outlet of the LNG heat exchanger (1) passes through the second circulating refrigerant circulation barrel (12) and enters the second circulating refrigerant heat exchanger (13) to exchange heat with the cold storage refrigerant in the cold storage circulation barrel (14) and then flows to the circulating refrigerant heater (6); the cold storage circulation barrel (14) and the cold storage (15) constitute a cold storage refrigerant circulation pipeline.

6. The cold industrial park system based on LNG cold energy according to claim 1 is characterized in that: The freeze-drying and quick-freezing module comprises a third-cycle refrigerant circulation barrel (16), a third-cycle refrigerant heat exchanger (17), a low-temperature expansion valve (18), and a low-temperature circulation barrel (19) which are connected in sequence, and the low-temperature circulation barrel (19) is respectively connected to a quick freezer (22), a cold trap (24), and a low-temperature compressor (20), and the low-temperature compressor (20) is connected in sequence to a three-way valve (21), a freeze-drying chamber (23), and a third-cycle refrigerant heat exchanger (17).

7. A cooling method for a cold industrial park based on LNG cold energy, characterized in that: The following steps are performed using a cold industrial park system based on LNG cold energy as described in any one of claims 1 to 6, including: LNG from the receiving station enters the LNG heat exchanger (1) and exchanges heat with the gaseous circulating refrigerant to increase its temperature and gasify it into NG, and then returns to the receiving station. At the same time, the gaseous circulating refrigerant is cooled and liquefied into low-temperature liquid circulating refrigerant, and then is divided into three routes to the ice-making module, the cold storage module, and the freeze-drying and quick-freezing module for cooling; the low-temperature gaseous circulating refrigerant coming out of the ice-making module, the cold storage module, the freeze-drying and quick-freezing module enters the circulating refrigerant heater (6) and exchanges heat with the high-temperature refrigerant to increase its temperature and enters the LNG heat exchanger (1); the high-temperature refrigerant exchanges heat and cools down, and then enters the condenser (3) and exchanges heat with the high-temperature refrigerant at the outlet of the heat pump compressor (2) to increase its temperature, thus completing the cycle; The circulating refrigerant in the ice-making module passes through the first circulating refrigerant circulation barrel (7) and enters the first circulating refrigerant heat exchanger (8) to exchange heat with the gaseous ice-making refrigerant from the ice-making circulation barrel (9) and vaporize it, and then returns to the first circulating refrigerant circulation barrel (7) and leaves the ice-making module; the ice-making refrigerant exchanges heat and liquefies, and then enters the return ice-making circulation barrel (9), and then is transported to the ice-making machine (10) to release cold energy, and then returns to the ice-making circulation barrel (9) after vaporization and temperature increase; The circulating refrigerant in the cold storage module passes through the second circulating refrigerant circulation barrel (12) and enters the second circulating refrigerant heat exchanger (13) to exchange heat with the gaseous cold storage refrigerant coming out of the cold storage circulation barrel (14) to be vaporized, and then returns to the second circulating refrigerant circulation barrel (12) to leave the cold storage module; the cold storage refrigerant is liquefied after heat exchange and enters the return cold storage circulation barrel (14), and then is transported to the cold storage (15) to release cold energy, and then returns to the cold storage circulation barrel (14) after being vaporized and heated; The circulating refrigerant in the freeze-drying and quick-freezing module passes through the third circulating refrigerant circulation barrel (16) and enters the third circulating refrigerant heat exchanger (17) to exchange heat with the gaseous low-temperature refrigerant for vaporization, returns to the third circulating refrigerant circulation barrel (16) and leaves the freeze-drying and quick-freezing module; the low-temperature refrigerant is liquefied through heat exchange and expansion by the low-temperature expansion valve (18) and then enters the low-temperature circulation barrel (19), and then is divided into two paths, respectively entering the quick freezer (22) and the cold trap (24) for cooling, and then returns to the low-temperature circulation barrel (19) after being vaporized, and enters the freeze-drying bin (23) after being pressurized and heated by the low-temperature compressor (20) to provide heat energy for the material, and then enters the third circulating refrigerant heat exchanger (17) to complete the cycle.

8. A cooling method for a cold industrial park based on LNG cold energy according to claim 7, characterized in that: The high-temperature refrigerant in the heat pump module is liquefied and cooled by heat exchange in a circulating refrigerant heater (6) or a condenser (3), and then expanded to a gas-liquid mixture through a heat pump expansion valve (4) before entering the evaporator (5), exchanging heat with the water in the water pool (11) and heating it before entering the heat pump compressor (2), completing the cycle, so that the cold energy generated in the heat pump module is used for precooling the water in the water pool (11), thereby accelerating the ice making speed of the ice maker (10).

9. A cooling method for a cold industrial park based on LNG cold energy according to claim 7, characterized in that: The condenser (3) in the heat pump module is removed according to actual conditions, and the high-temperature refrigerant at the outlet of the heat pump compressor (2) is directly introduced into the circulating refrigerant heater (6) to reheat the circulating refrigerant.

10. A cooling method for a cold industrial park based on LNG cold energy according to claim 7, characterized in that: When the temperature of the cold storage is 7 to 12° C. higher than the circulating refrigerant, the second circulating refrigerant heat exchanger (13) and the cold storage circulating barrel (14) are cancelled, and the circulating refrigerant is directly supplied to the cold storage.

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