Fabricated pressure-bearing cooling system

Abstract

The invention discloses an assembly type pressure-bearing refrigeration system, and particularly relates to the technical field of refrigeration equipment, the assembly type pressure-bearing refrigeration system comprises a container and a combined type refrigeration cycle unit integrated in the container, and the combined type refrigeration cycle unit comprises a low-temperature-stage refrigeration cycle assembly and a high-temperature-stage refrigeration cycle assembly; the low-temperature-stage refrigeration cycle assembly comprises a pressure-bearing liquid storage tank, and the bottom of the pressure-bearing liquid storage tank is fixedly communicated with a refrigerant liquid outlet. Through high-temperature-stage and low-temperature-stage double-circulation collaborative design and a safe pressure control mechanism, the technical bottleneck of a traditional refrigerating system is broken through, the contradiction that low temperature and safety of traditional high-pressure refrigerating equipment cannot be considered at the same time is solved, stable and safe operation at the ultralow temperature ranging from-20 DEG C to-30 DEG C is achieved, and the refrigerating efficiency is improved. Ultralow-temperature refrigeration is achieved through pressure bearing and high-temperature-level and low-temperature-level double-circulation cooling, so that larger-area refrigeration is achieved through lower temperature, modularized integration of the whole system is achieved through a container, and the adaptive pain point that a traditional refrigeration system is fixedly installed and cannot be moved is solved.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment technology, and more specifically, to a prefabricated pressure refrigeration system. Background Technology

[0002] With the acceleration of urbanization and the continuous expansion of building scale, from commercial complexes and data centers to biomedical parks, higher requirements are being placed on the coverage, operating efficiency and spatial adaptability of cooling systems.

[0003] Existing atmospheric pressure refrigeration systems suffer from limitations due to the high phase change temperatures of refrigerants such as R410A and R32 at atmospheric pressure, limiting their lower cooling limit to only 5°C and thus restricting their ability to meet low-temperature requirements below -20°C. Furthermore, they are poorly suited for prefabricated systems, with compressors, condensers, and liquid receivers being dispersed, requiring separate machine rooms and resulting in large footprints. There is also a conflict between pressure resistance and safety; some high-pressure refrigeration systems, lacking pressure-bearing structures designed for low-temperature environments, are prone to material brittleness and seal failure at low temperatures, posing risks of pressure runaway and refrigerant leakage. Additionally, their refrigeration efficiency drops significantly with pressure fluctuations, making it difficult to balance low temperatures, safety, and large-area cooling. Finally, the refrigeration efficiency also decreases dramatically with system pressure fluctuations, making it difficult to meet the demands of ultra-low temperatures, safe pressure resistance, and large-area cooling simultaneously. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a prefabricated pressure refrigeration system to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a prefabricated pressure refrigeration system, comprising a container and a composite refrigeration cycle unit integrated inside the container, wherein the composite refrigeration cycle unit comprises a low-temperature stage refrigeration cycle component and a high-temperature stage refrigeration cycle component; The cryogenic refrigeration cycle assembly includes a pressure-bearing liquid storage tank. A refrigerant outlet is fixedly connected to the bottom of the pressure-bearing liquid storage tank. A cryogenic shut-off valve is fixedly installed at the bottom of the refrigerant outlet. A cooling output pipe is fixedly connected to the bottom of the cryogenic shut-off valve. A cooling return pipe is fixedly connected to one side of the container. A shell-and-tube heat exchanger is fixedly installed at one end of the cooling return pipe. The shell-and-tube heat exchanger consists of an inner tube and an outer tube coaxially fitted together. A first return pipe is fixedly connected to the top of the outer tube of the shell-and-tube heat exchanger. A heat exchange box is fixedly connected to one side of the first return pipe. A second return pipe is provided on one side of the heat exchange box. A cryogenic throttling valve is fixedly installed on one side of the second return pipe. A circulation pump is fixedly connected to one end of the cryogenic throttling valve. A return pipe is fixedly connected between the circulation pump and the pressure-bearing liquid storage tank. The high-temperature refrigeration cycle assembly includes a high-temperature refrigerant tank, which is located on one side of a pressure-bearing liquid storage tank. A baffle-type gas-liquid separator is fixedly installed inside the high-temperature refrigerant tank. A gaseous refrigerant discharge pipe is fixedly connected to one side of the high-temperature refrigerant tank near the top of the baffle-type gas-liquid separator. A gas-liquid separator is fixedly installed at one end of the gaseous refrigerant discharge pipe. A liquid return pipe is provided between the gas-liquid separator and the high-temperature refrigerant tank. A one-way valve is fixedly installed at one end of the liquid return pipe. A high-pressure compressor is fixedly connected to the gas outlet of the gas-liquid separator. One end of the high-pressure compressor is connected to the inner tube of a shell-and-tube heat exchanger. An inlet pipe is fixedly connected to the output end of the inner tube of the shell-and-tube heat exchanger. An evaporative condenser is fixedly installed at the top of the inlet pipe. A connecting pipe is fixedly connected between the evaporative condenser and the heat exchange box. A high-temperature throttling valve is fixedly installed in the middle of the connecting pipe. A high-temperature refrigerant return pipe is fixedly connected between the heat exchange box and the high-temperature refrigerant tank.

[0006] Preferably, a serpentine coil is fixedly installed inside the heat exchange box. One end of the serpentine coil is sealed and fixedly connected to the first return pipe, and the other end of the serpentine coil is sealed and fixedly connected to the second return pipe. The serpentine coil is made of stainless steel.

[0007] Preferably, the top and bottom inner walls of the heat exchange box are fixedly connected with a plurality of spaced baffles. The baffles are arranged perpendicular to the inner wall of the heat exchange box and extend to abut against the outer wall of the serpentine coil, thereby changing the flow path of the high-temperature refrigerant flowing through the heat exchange box.

[0008] Preferably, the pressure storage tank is formed by welding low-temperature toughness steel and titanium alloy composite plate, and the inner wall of the tank is coated with polytetrafluoroethylene anti-corrosion coating.

[0009] Preferably, a pressure sensor is fixedly installed on one side of the inner wall of the pressure-bearing liquid storage tank, a pressure relief pipe is fixedly connected to one side of the pressure-bearing liquid storage tank, and a safety valve is fixedly installed at one end of the pressure relief pipe.

[0010] Preferably, it also includes a controller and an audible and visual alarm, wherein the controller is electrically connected to a pressure sensor, an audible and visual alarm, a cryogenic shut-off valve and a circulating pump installed on the pressure storage tank; The controller is configured to: adjust the opening of the cryogenic shut-off valve and the power of the circulation pump when the pressure detected by the pressure sensor exceeds a first preset value; and trigger the audible and visual alarm when the pressure detected by the pressure sensor exceeds a second preset value higher than the first preset value.

[0011] Preferably, multiple support columns are fixedly connected between the container and the pressure storage tank and the high-temperature refrigerant tank.

[0012] Preferably, the end of the liquid return pipe away from the gas-liquid separator is connected to the lower part of the side wall of the high-temperature refrigerant tank, and the one-way valve on the liquid return pipe only allows the liquid refrigerant in the gas-liquid separator to flow unidirectionally to the high-temperature refrigerant tank.

[0013] Preferably, the inner tube of the shell-and-tube heat exchanger is connected to the inlet pipe for the flow of high-temperature, high-pressure liquid refrigerant in the high-temperature stage refrigeration cycle assembly, and the outer tube of the shell-and-tube heat exchanger is connected to the first return pipe for the flow of low-temperature liquid refrigerant in the low-temperature stage refrigeration cycle assembly. The low-temperature liquid refrigerant flowing through the outer tube can pre-cool the high-temperature, high-pressure liquid refrigerant flowing through the inner tube.

[0014] Preferably, the container wall adopts a double-layer color steel plate structure.

[0015] The technical effects and advantages of this invention are as follows: 1. Through the dual-cycle collaborative design of high-temperature and low-temperature stages and a safe pressure control mechanism, the technical bottleneck of traditional refrigeration systems is completely broken through. On the one hand, the high-temperature stage cycle depressurizes and cools the refrigerant to a cold source of -10℃ to -15℃, providing basic cooling capacity for the low-temperature stage cycle. Combined with heat exchange in the low-temperature stage cycle, the temperature is further reduced. Furthermore, through the pressure-temperature correlation characteristics of the low-temperature stage throttling valve, the pressure reduction operation reduces the refrigeration temperature from the lower limit of 5℃ in the normal pressure system to -20℃ to -30℃, meeting the needs of cryogenic scenarios. On the other hand, the pressure-bearing liquid storage tank adopts a special structure of low-temperature tough steel and titanium alloy composite plate, combined with a polytetrafluoroethylene anti-corrosion coating, which solves the problems of low-temperature brittleness and corrosion. Combined with the triple pressure control of pressure sensors, controllers, and safety valves, the contradiction between low temperature and safety in traditional high-pressure refrigeration equipment is resolved, achieving stable and safe operation at ultra-low temperatures of -20℃ to -30℃. Ultra-low temperature refrigeration is achieved through dual-cycle cooling of pressure-bearing, high-temperature, and low-temperature stages, thereby achieving cooling of a larger area at a lower temperature. 2. Through multiple design features, high efficiency, energy saving, and long-term reliable operation are achieved. In terms of cascade utilization of cold energy, the shell-and-tube heat exchanger uses the cold energy of the low-temperature refrigerant to pre-cool the high-temperature refrigerant, reducing the heat dissipation load of the evaporator condenser and lowering the energy consumption of the high-pressure compressor. In terms of heat exchange efficiency optimization, the baffle plate inside the heat exchange box forces the high-temperature refrigerant to flow back, and with the large contact area of ​​the stainless steel serpentine coil, the heat exchange temperature difference is increased from 5℃ to 10℃~15℃, accelerating the condensation of the low-temperature refrigerant. In terms of equipment protection, the double separation of the baffle-type gas-liquid separator plate and the gas-liquid separator, as well as the one-way valve, prevent liquid refrigerant from entering the compressor and causing liquid slugging damage. The double-layer color steel plate structure of the container takes into account both heat preservation and impact resistance, which reduces cold energy loss and protects the internal equipment from the influence of the outdoor environment, ensuring the long-term stable operation of the system. 3. By relying on containers to achieve modular integration of the entire system, there is no need to build separate machine rooms for distributed equipment such as compressors, condensers, and liquid storage tanks. This greatly reduces the footprint compared to traditional distributed refrigeration systems. At the same time, containers support overall hoisting and relocation, which can flexibly adapt to outdoor scenarios that require mobility, solving the adaptability pain points of traditional refrigeration systems that are fixed and cannot be moved. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 This is a side view of the structure of the present invention.

[0018] Figure 3 This is a schematic diagram of the internal structure of the container of the present invention.

[0019] Figure 4 This is a schematic diagram of the internal structure of the heat exchanger box of the present invention.

[0020] Figure 5 This is a partial structural diagram of the present invention.

[0021] Figure 6 This is a schematic diagram of the connection between the cooling return pipe and the high-temperature refrigerant tank of the present invention.

[0022] Figure 7 This is a schematic diagram of the internal structure of the high-temperature refrigerant tank of the present invention.

[0023] Figure 8 This is a front cross-sectional view of the pressure storage tank of the present invention.

[0024] The attached diagram is labeled as follows: 1. Container; 2. Pressure tank; 3. Refrigerant outlet; 4. Cryogenic shut-off valve; 5. Cooling output pipe; 6. Cooling return pipe; 7. Shell-and-tube heat exchanger; 8. High-pressure compressor; 9. High-temperature refrigerant tank; 10. Baffle-type gas-liquid separator; 11. Gaseous refrigerant discharge pipe; 12. Gas-liquid separator; 13. Liquid return pipe; 14. Check valve; 15. First return pipe; 16. Heat exchanger box; 7. Second return pipe; 18. Low-temperature stage throttle valve; 19. Circulation pump; 20. Return pipe; 21. High-temperature stage refrigerant return pipe; 22. High-temperature stage throttle valve; 23. Connecting pipe; 24. Evaporative condenser; 25. Inlet pipe; 26. Serpentine coil; 27. Baffle plate; 28. Controller; 29. ​​Anti-corrosion coating; 30. Pressure sensor; 31. Pressure relief pipe; 32. Safety valve; 33. Audible and visual alarm; 34. Support column. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] As attached Figures 1-8 The prefabricated pressure refrigeration system shown includes a container 1 and a composite refrigeration cycle unit integrated inside the container 1. The composite refrigeration cycle unit includes a low-temperature stage refrigeration cycle component and a high-temperature stage refrigeration cycle component. The cryogenic refrigeration cycle assembly includes a pressurized liquid storage tank 2, with a refrigerant outlet 3 fixedly connected to the bottom of the pressurized liquid storage tank 2. A cryogenic shut-off valve 4 is fixedly installed at the bottom of the refrigerant outlet 3. A cooling output pipe 5 is fixedly connected to the bottom of the cryogenic shut-off valve 4. A cooling return pipe 6 is fixedly connected to one side of the container 1. A shell-and-tube heat exchanger 7 is fixedly installed at one end of the cooling return pipe 6. The shell-and-tube heat exchanger 7 is composed of an inner tube and an outer tube coaxially fitted. A first return pipe 15 is fixedly connected to the top of the outer tube of the shell-and-tube heat exchanger 7. A heat exchange box 16 is fixedly connected to one side of the first return pipe 15. A second return pipe 17 is provided on one side of the heat exchange box 16. A cryogenic throttling valve 18 is fixedly installed on one side of the second return pipe 17. A circulation pump 19 is fixedly connected to one end of the cryogenic throttling valve 18. A return pipe 20 is fixedly connected between the circulation pump 19 and the pressurized liquid storage tank 2. The refrigerant outlet 3 ensures directional refrigerant output, and the refrigerant output can be adjusted as needed with the low-temperature shut-off valve 4 to avoid waste of cooling capacity or overload. The cooling output pipe 5 directly delivers the -20℃ to -30℃ cooling capacity to the external load, and the cooling return pipe 6 simultaneously recovers the liquid refrigerant after heat exchange, forming a closed loop of cooling capacity delivery and refrigerant recovery. The coaxial structure of the inner and outer tubes of the shell-and-tube heat exchanger 7 creates space for heat exchange of the high and low temperature stage refrigerants. The first return pipe 15 and the second return pipe 17 respectively realize the entry and exit of the low-temperature liquid refrigerant into and out of the heat exchange box 16, ensuring the continuity of the low-temperature stage circulation. The low-temperature stage throttling valve 18 reduces the refrigerant temperature to -20℃ to -30℃ by reducing the pressure. The circulation pump 19, combined with the return pipe 20, provides power for the refrigerant to return to the pressurized liquid storage tank 2, ensuring the stable operation of the low-temperature stage circulation.

[0027] The high-temperature refrigeration cycle assembly includes a high-temperature refrigerant tank 9, which is located on one side of the pressurized liquid storage tank 2. A baffle-type gas-liquid separator 10 is fixedly installed inside the high-temperature refrigerant tank 9. A gaseous refrigerant discharge pipe 11 is fixedly connected to one side of the high-temperature refrigerant tank 9 near the top of the baffle-type gas-liquid separator 10. A gas-liquid separator 12 is fixedly installed at one end of the gaseous refrigerant discharge pipe 11. A liquid return pipe 13 is provided between the gas-liquid separator 12 and the high-temperature refrigerant tank 9. One end of the liquid return pipe 13 is fixedly installed... Equipped with a one-way valve 14, the outlet end of the gas-liquid separator 12 is fixedly connected to a high-pressure compressor 8. One end of the high-pressure compressor 8 is connected to the inner tube of the shell-and-tube heat exchanger 7. The outlet end of the inner tube of the shell-and-tube heat exchanger 7 is fixedly connected to an inlet pipe 25. An evaporative condenser 24 is fixedly installed at the top of the inlet pipe 25. A connecting pipe 23 is fixedly connected between the evaporative condenser 24 and the heat exchange box 16. A high-temperature throttling valve 22 is fixedly installed in the middle of the connecting pipe 23. A high-temperature refrigerant return pipe 21 is fixedly connected between the heat exchange box 16 and the high-temperature refrigerant tank 9.

[0028] The high-temperature refrigerant tank 9 stores high-temperature refrigerant. Its internal baffle-type gas-liquid separator 10 performs initial gas-liquid separation, ensuring that gaseous refrigerant enters the gas-liquid separator 12 through the gaseous refrigerant discharge pipe 11, preventing liquid refrigerant from directly entering the high-pressure compressor 8 and causing liquid slugging damage. The gas-liquid separator 12 performs secondary separation of the gaseous refrigerant; the separated liquid refrigerant flows back to the high-temperature refrigerant tank 9 through the liquid return pipe 13. A one-way valve 14 prevents refrigerant backflow, ensuring separation efficiency. The compressor 8 compresses the gaseous refrigerant into a high-temperature, high-pressure state, providing conditions for subsequent condensation and heat exchange; the inner tube of the shell-and-tube heat exchanger 7, in conjunction with the inlet pipe 25, transports the pre-cooled high-temperature, high-pressure refrigerant to the evaporative condenser 24 for heat dissipation and condensation; the connecting pipe 23, in conjunction with the high-temperature stage throttling valve 22, reduces the pressure and temperature of the condensed refrigerant to a cold source of -10℃ to -15℃, providing low-temperature heat exchange conditions for the heat exchange box 16; the high-temperature stage refrigerant return pipe 21 realizes the recovery of the refrigerant after heat exchange, completing the high-temperature stage closed-loop circulation.

[0029] As attached Figure 4 As shown, a serpentine coil 26 is fixedly installed inside the heat exchange box 16. One end of the serpentine coil 26 is sealed and fixedly connected to the first return pipe 15, and the other end of the serpentine coil 26 is sealed and fixedly connected to the second return pipe 17. The serpentine coil 26 is made of stainless steel.

[0030] The stainless steel serpentine coil 26 is resistant to low temperatures of -20℃ to -30℃ and refrigerant corrosion, avoiding the risk of leakage caused by low-temperature brittleness or material corrosion. The serpentine structure greatly increases the contact area with the high-temperature cold source, improving heat exchange efficiency. The sealed connection design between the serpentine coil 26 and the first return pipe 15 and the second return pipe 17 ensures that the low-temperature liquid refrigerant flows in a closed loop inside the pipe, with no loss of cooling capacity or refrigerant leakage, ensuring the low-temperature condensation effect.

[0031] As attached Figure 4 As shown, multiple baffles 27 are fixedly connected to the inner walls of the top and bottom of the heat exchange box 16. The baffles 27 are arranged perpendicular to the inner wall of the heat exchange box 16 and extend to abut against the outer wall of the serpentine coil 26 to change the flow path of the high-temperature refrigerant flowing through the heat exchange box 16.

[0032] The baffles 27 are arranged at intervals and abut against the serpentine coil 26, forcing the high-temperature refrigerant to form a zigzag flow in the heat exchange box 16, extending the residence time of the high-temperature refrigerant, and increasing the contact frequency and area between the high-temperature refrigerant and the outer wall of the serpentine coil 26. This increases the heat exchange temperature difference from the traditional 5℃ to 10℃~15℃, solving the problem of low condensation efficiency under low temperature difference, accelerating the condensation rate of the low-temperature liquid refrigerant in the serpentine coil 26, and ensuring efficient operation of the low-temperature stage cycle.

[0033] As attached Figure 1 , 2 As shown in Figures 3, 5, and 8, the pressure storage tank 2 is formed by welding low-temperature toughness steel and titanium alloy composite plate, and the inner wall of the tank is coated with polytetrafluoroethylene anti-corrosion coating 29. Low-temperature toughness steel refers to steel for low-temperature pressure vessels that conforms to national or international standards. Low-temperature toughness steel can be selected from, but is not limited to, 16MnDR specified in GB 3531-2014.

[0034] The combination of low-temperature toughness steel and titanium alloy composite plate solves the problem of brittleness of traditional steel in low-temperature environments of -20℃ to -30℃ from the material level, ensuring the structural strength and safe pressure bearing capacity of the pressure storage tank 2 under low-temperature and high-pressure conditions; the polytetrafluoroethylene anti-corrosion coating 29 on the inner wall of the tank can resist the long-term corrosion of ultra-low temperature refrigerant, extend the service life of the pressure storage tank 2, and at the same time prevent the coating from falling off and contaminating the refrigerant, ensuring the safety of system operation.

[0035] As attached Figure 1 , 2 As shown in Figures 3, 5, and 8, a pressure sensor 30 is fixedly installed on one side of the inner wall of the pressure storage tank 2, and a pressure relief pipe 31 is fixedly connected to one side of the pressure storage tank 2. A safety valve 32 is fixedly installed at one end of the pressure relief pipe 31.

[0036] When the pressure inside the tank exceeds the safety threshold, the safety valve 32 automatically opens and quickly releases pressure through the pressure relief pipe 31 to prevent the pressure-bearing liquid storage tank 2 from being damaged due to overpressure or refrigerant leakage, thus building a safety barrier under low temperature and high pressure conditions from a hardware perspective.

[0037] As attached Figure 1 , 2 As shown in Figures 3, 5, and 8, it also includes a controller 28 and an audible and visual alarm 33. The controller 28 is electrically connected to the pressure sensor 30, the audible and visual alarm 33, the cryogenic shut-off valve 4, and the circulating pump 19 installed on the pressure storage tank 2. The controller 28 is configured to: adjust the opening of the cryogenic shut-off valve 4 and the power of the circulation pump 19 when the pressure detected by the pressure sensor 30 exceeds the first preset value; and trigger the audible and visual alarm 33 when the pressure detected by the pressure sensor 30 exceeds the second preset value which is higher than the first preset value.

[0038] When the pressure exceeds the first preset value, the refrigerant output is reduced by decreasing the opening of the low-temperature shut-off valve 4, the power of the circulating pump 19 is increased, and the refrigerant return is accelerated, thus actively reducing the pressure inside the tank. When the pressure exceeds the second preset value, the audible and visual alarm 33 is triggered to promptly remind the staff to intervene. Combined with the hardware pressure relief of the safety valve 32, a multi-layered safety pressure control mechanism is formed, which greatly improves the safety of system operation.

[0039] As attached Figure 1 , 2 As shown in Figures 3, 5, 6, 7, and 8, multiple support columns 34 are fixedly connected between container 1, pressure storage tank 2, and high-temperature refrigerant tank 9.

[0040] The support column 34 securely fixes the pressure storage tank 2 and the high-temperature refrigerant tank 9 to the container 1, preventing the equipment from shifting or being damaged by collision during the hoisting and relocation of the container 1. At the same time, the support column 34 raises the bottom of the equipment, reducing direct contact between the equipment and the bottom of the container 1, facilitating air circulation and heat dissipation inside the container 1, and also reserving operating space for maintenance at the bottom of the equipment, ensuring long-term stable operation of the equipment.

[0041] As attached Figure 1 , 2 As shown in Figures 3, 6, and 7, the end of the liquid return pipe 13 away from the gas-liquid separator 12 is connected to the lower part of the side wall of the high-temperature refrigerant tank 9, and the one-way valve 14 on the liquid return pipe 13 only allows the liquid refrigerant in the gas-liquid separator 12 to flow unidirectionally to the high-temperature refrigerant tank 9.

[0042] The liquid return pipe 13 is connected to the lower side wall of the high-temperature refrigerant tank 9, so that the separated liquid refrigerant can flow back smoothly to the bottom of the tank for storage, avoiding the accumulation of liquid refrigerant in the gas-liquid separator 12 and affecting the separation effect; the one-way valve 14 strictly restricts the one-way flow of refrigerant, preventing the gaseous or liquid refrigerant in the high-temperature refrigerant tank 9 from flowing back into the gas-liquid separator 12, avoiding disruption of the secondary separation operation of the gas-liquid separator 12, ensuring that only gaseous refrigerant enters the high-pressure compressor 8, and protecting the high-pressure compressor 8 from liquid slugging damage.

[0043] As attached Figure 1 , 2 As shown in Figures 3, 4, and 6, the inner tube of the shell-and-tube heat exchanger 7 is connected to the inlet pipe 25, allowing the high-temperature, high-pressure liquid refrigerant in the high-temperature stage refrigeration cycle assembly to flow through. The outer tube of the shell-and-tube heat exchanger 7 is connected to the first return pipe 15, allowing the low-temperature stage liquid refrigerant in the low-temperature stage refrigeration cycle assembly to flow through. The low-temperature stage liquid refrigerant flowing through the outer tube can pre-cool the high-temperature, high-pressure liquid refrigerant flowing through the inner tube.

[0044] By utilizing the cooling capacity of the low-temperature liquid refrigerant to pre-cool the high-temperature refrigerant, the heat dissipation load of the subsequent evaporative condenser 24 is reduced, the energy consumption of the high-pressure compressor 8 is lowered, and the cooling capacity is utilized in stages, avoiding the waste of the low-temperature refrigerant and achieving energy-saving effects.

[0045] As attached Figure 1 , 2 As shown, the container wall of container 1 adopts a double-layer color steel plate structure. The double-layer color steel plate structure of container 1 has excellent thermal insulation performance, which can effectively block the heat exchange between the inside of container 1 and the external environment, prevent the external environment heat from entering the interior and causing cold loss, ensure that the low temperature stage and high temperature stage refrigeration cycle components operate in a stable low temperature environment, and reduce the energy consumption required for the system to maintain the low temperature; at the same time, the double-layer color steel plate structure of container 1 has high strength and strong impact resistance, which can protect the internal precision equipment from the impact of external factors such as outdoor wind, rain, and collisions, and is suitable for various usage scenarios such as outdoor and temporary sites.

[0046] Working principle of this invention: This prefabricated pressure refrigeration system achieves modular integration based on container 1. Through the coordinated operation of the low-temperature refrigeration cycle component and the high-temperature refrigeration cycle component, combined with a safety pressure control mechanism, it achieves ultra-low temperature cooling from -20℃ to -30℃. The high-temperature refrigerant in the high-temperature refrigerant tank 9 first undergoes preliminary gas-liquid separation through its internal baffle-type gas-liquid separator 10. The separated gaseous high-temperature refrigerant enters the gas-liquid separator 12 through the gaseous refrigerant discharge pipe 11 for secondary gas-liquid separation. The separated liquid high-temperature refrigerant flows back to the lower side wall of the high-temperature refrigerant tank 9 through the liquid return pipe 13 and the one-way valve 14. The one-way valve 14 prevents reverse flow. The gaseous high-temperature refrigerant after secondary separation enters the high-pressure compressor 8 and is compressed into a high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant then enters the inner tube of the shell-and-tube heat exchanger 7, while the low-temperature refrigerant... In the first-stage refrigeration cycle assembly, the cryogenic liquid refrigerant in the pressurized liquid storage tank 2 flows out through the bottom refrigerant outlet 3. After the flow rate is controlled by the cryogenic shut-off valve 4, it enters the cooling output pipeline 5 to provide cryogenic cooling capacity to the external load. After completing the cooling, the refrigerant becomes cryogenic refrigerant and enters the outer tube of the shell-and-tube heat exchanger 7 through the cooling return pipeline 6 on one side of the container 1. At this time, the cryogenic liquid refrigerant in the outer tube of the shell-and-tube heat exchanger 7 undergoes indirect heat exchange with the high-temperature and high-pressure gaseous refrigerant in the inner tube, pre-cooling the high-temperature and high-pressure gaseous refrigerant, reducing compressor energy consumption, and achieving higher overall refrigeration efficiency and energy saving. The pre-cooled high-temperature and high-pressure gaseous refrigerant enters the evaporative condenser 24 through the inlet pipe 25 to dissipate heat and condense into high-temperature and high-pressure liquid refrigerant. This high-temperature and high-pressure liquid refrigerant then passes through the connecting pipe 23 and the high-temperature stage throttling valve 22 in the middle to reduce pressure and temperature, forming a cryogenic liquid cold source and entering the heat exchange box 16. Meanwhile, the low-temperature refrigerant, which has been pre-cooled in the outer tube of the shell-and-tube heat exchanger 7, enters the serpentine coil 26 inside the heat exchange box 16 through the first return pipe 15. Baffles 27, spaced apart on the inner walls of the top and bottom of the heat exchange box 16, alter the flow path of the high-temperature stage low-temperature liquid cold source, extending its residence time within the heat exchange box 16. This allows for sufficient indirect heat exchange between the high-temperature stage low-temperature liquid cold source and the low-temperature liquid refrigerant in the serpentine coil 26. After further cooling by the high-temperature stage refrigeration cycle components, the low-temperature liquid refrigerant in the serpentine coil 26 enters the second return pipe 17. The low-temperature stage throttling valve 18 reduces pressure and temperature to produce ultra-low temperature liquid refrigerant. This ultra-low temperature liquid refrigerant is driven by the circulation pump 19 and flows back to the pressure storage tank 2 through the return pipe 20 to complete the low-temperature stage cycle. The ultra-low temperature refrigerant exchanges heat with the external evaporator through the cooling output pipe 5 and the cooling return pipe 6, reducing the refrigeration temperature from atmospheric pressure 5℃ to -20℃ to -30℃ to achieve ultra-low temperature refrigeration. Meanwhile, the high-temperature stage refrigerant in the heat exchange box 16, after exchanging heat with the serpentine coil 26, flows back to the high-temperature stage refrigerant tank 9 through the high-temperature stage refrigerant return pipe 21 to complete the high-temperature stage cycle. Throughout the operation, the pressure sensor 30 on one side of the inner wall of the pressure storage tank 2 detects the pressure inside the tank in real time and transmits the data to the controller 28. When the pressure exceeds the first preset value, the controller 28 adjusts the opening of the low-temperature shut-off valve 4 and the power of the circulating pump 19 to control the pressure. When the pressure exceeds the second preset value, which is higher than the first preset value, the controller 28 triggers the audible and visual alarm 33. If the pressure continues to rise, the safety valve 32 on the pressure relief pipe 31 on one side of the pressure storage tank 2 automatically opens to release pressure, ensuring the stable and efficient operation of the overall refrigeration process.

[0047] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change. Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other. In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A packaged pressure-bearing refrigeration system comprising a container (1) and a combined refrigeration cycle unit integrated inside the container (1), characterized in that: The composite refrigeration cycle unit comprises a low-temperature stage refrigeration cycle assembly and a high-temperature stage refrigeration cycle assembly; The low-temperature stage refrigeration cycle assembly comprises a pressure-bearing liquid storage tank (2), a refrigerant outlet (3) is fixedly communicated at the bottom of the pressure-bearing liquid storage tank (2), a low-temperature stop valve (4) is fixedly installed at the bottom of the refrigerant outlet (3), a cold supply output pipeline (5) is fixedly communicated at the bottom of the low-temperature stop valve (4), a cold supply return pipeline (6) is fixedly connected to one side of the container (1), a double-pipe heat exchanger (7) is fixedly installed at one end of the cold supply return pipeline (6), the double-pipe heat exchanger (7) is composed of an inner pipe and an outer pipe coaxially sleeved, a first return pipe (15) is fixedly communicated at the top of the outer pipe of the double-pipe heat exchanger (7), a heat exchange box (16) is fixedly connected to one side of the first return pipe (15), a second return pipe (17) is arranged at one side of the heat exchange box (16), a low-temperature stage throttling valve (18) is fixedly installed at one side of the second return pipe (17), a circulating pump (19) is fixedly connected to one end of the low-temperature stage throttling valve (18), and a return pipeline (20) is fixedly communicated between the circulating pump (19) and the pressure-bearing liquid storage tank (2). The high-temperature stage refrigeration cycle assembly comprises a high-temperature stage refrigerant tank body (9), the high-temperature stage refrigerant tank body (9) is arranged at one side of the pressure-bearing liquid storage tank (2), a baffle-type gas-liquid separation plate (10) is fixedly installed in the high-temperature stage refrigerant tank body (9), a gaseous refrigerant discharge pipe (11) is fixedly communicated at one side of the high-temperature stage refrigerant tank body (9) and close to the top of the baffle-type gas-liquid separation plate (10), a gas-liquid separator (12) is fixedly installed at one end of the gaseous refrigerant discharge pipe (11), a liquid return pipe (13) is arranged between the gas-liquid separator (12) and the high-temperature stage refrigerant tank body (9), a one-way valve (14) is fixedly installed at one end of the liquid return pipe (13), a high-pressure compressor (8) is fixedly communicated at the gas outlet end of the gas-liquid separator (12), one end of the high-pressure compressor (8) is communicated with the inner pipe of the double-pipe heat exchanger (7), an inlet pipe (25) is fixedly communicated at the output end of the inner pipe of the double-pipe heat exchanger (7), an evaporative condenser (24) is fixedly installed at the top of the inlet pipe (25), a connecting pipe (23) is fixedly communicated between the evaporative condenser (24) and the heat exchange box (16), a high-temperature stage throttling valve (22) is fixedly installed in the connecting pipe (23), and a high-temperature stage refrigerant return pipe (21) is fixedly communicated between the heat exchange box (16) and the high-temperature stage refrigerant tank body (9).

2. An assembled pressure-bearing refrigeration system according to claim 1, characterized in that: A coiled pipe (26) is fixedly installed in the heat exchange box (16), one end of the coiled pipe (26) is sealingly and fixedly communicated with the first return pipe (15), the other end of the coiled pipe (26) is sealingly and fixedly communicated with the second return pipe (17), and the coiled pipe (26) is made of stainless steel.

3. An assembled pressure-bearing refrigeration system as claimed in claim 2, characterized in that: The top inner wall and the bottom inner wall of the heat exchange box (16) are fixedly connected with a plurality of baffle plates (27) arranged at intervals, the baffle plates (27) are arranged perpendicularly to the inner wall of the heat exchange box (16), and the baffle plates (27) extend to abut against the outer wall of the serpentine coil (26), so as to change the flow path of the high-temperature refrigerant flowing through the heat exchange box (16).

4. The packaged refrigeration system of claim 1, wherein: The pressure-bearing liquid storage tank (2) is formed by welding a low-temperature toughness steel and a titanium alloy composite plate, and the inner wall of the tank body is coated with a polytetrafluoroethylene anti-corrosion coating (29).

5. The packaged refrigeration system of claim 1, wherein: A pressure sensor (30) is fixedly installed on one side of the inner wall of the pressure-bearing liquid storage tank (2), a pressure relief pipe (31) is fixedly and communicatively connected to one side of the pressure-bearing liquid storage tank (2), and a safety valve (32) is fixedly installed at one end of the pressure relief pipe (31).

6. The packaged refrigeration system of claim 1, wherein: A controller (28) and an audible and visual alarm (33) are further included, and the controller (28) is electrically connected with the pressure sensor (30), the audible and visual alarm (33), the low-temperature stop valve (4) and the circulating pump (19) arranged on the pressure-bearing liquid storage tank (2); The controller (28) is configured to adjust the opening degree of the low-temperature stop valve (4) and the power of the circulating pump (19) when the pressure detected by the pressure sensor (30) exceeds a first preset value, and trigger the audible and visual alarm (33) to alarm when the pressure detected by the pressure sensor (30) exceeds a second preset value higher than the first preset value.

7. The packaged refrigeration system of claim 1, wherein: A plurality of support columns (34) are fixedly connected between the container (1) and the pressure-bearing liquid storage tank (2) and the high-temperature refrigerant tank body (9).

8. The packaged refrigeration system of claim 1, wherein: One end of the liquid return pipe (13) away from the gas-liquid separator (12) is in communication with the lower part of the side wall of the high-temperature refrigerant tank body (9), and the one-way valve (14) on the liquid return pipe (13) only allows the liquid refrigerant in the gas-liquid separator (12) to flow to the high-temperature refrigerant tank body (9) in one direction.

9. The packaged refrigeration system of claim 1, wherein: The inner tube of the double-pipe heat exchanger (7) is in communication with the inlet pipe (25) for the high-temperature and high-pressure liquid refrigerant in the high-temperature refrigeration cycle assembly to flow therethrough, and the outer tube of the double-pipe heat exchanger (7) is in communication with the first return pipe (15) for the low-temperature liquid refrigerant in the low-temperature refrigeration cycle assembly to flow therethrough, and the low-temperature liquid refrigerant flowing through the outer tube can pre-cool the high-temperature and high-pressure liquid refrigerant flowing through the inner tube.

10. The packaged refrigeration system of claim 1, wherein: The container wall of the container (1) adopts a double-layer color steel plate structure.

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