Closed refrigeration and heating circulation device with compound evaporator

Abstract

The purpose of the present invention is to propose a closed refrigeration and heating cycle device with a compound evaporator. When in use, the first refrigeration system and the second refrigeration system can be used separately to meet the needs of ordinary refrigeration and ultra-low temperature refrigeration, and the evaporators of the first refrigeration system and the second refrigeration system used for cooling cycle refrigeration are an integrated structure, which can greatly reduce the equipment volume of the traditional dual refrigeration system. At the same time, this scheme can form a larger evaporation amount setting through the loop setting of the first evaporator and the second evaporator to obtain an ultra-low temperature working environment. Finally, the interval nested structure of the first evaporator and the second evaporator in this scheme forms a larger contact area with the refrigerant, and the refrigeration is faster and more efficient.

Description

Technical Field

[0001] The invention relates to heating and refrigeration equipment, in particular to a closed refrigeration and heating circulation device with a compound evaporator. Background Art

[0002] A closed-type refrigeration and heating cycler is an auxiliary laboratory instrument used to control low and high temperatures. It is commonly used in medical, biological, and environmental testing simulations, including automotive parts, new energy batteries, and semiconductor testing. Its core components include a cooling device, a heating device, an external circulation device, and a temperature sensing control system. To ensure stable temperature control, a PID algorithm is often used for temperature control.

[0003] The refrigeration control of the refrigeration and heating cycle device is relatively more difficult to control due to the complexity of the refrigeration system. It is even difficult to control at a lower temperature due to the limitation of refrigerants. In order to achieve lower temperature control, a multi-stage single-stage compression cascade cycle refrigeration method is often adopted, in which the low-temperature stage circuit and the high-temperature stage circuit are connected through a heat exchanger, and the evaporation heat in the high-temperature stage circuit is used to cool and condense the refrigerant in the low-temperature stage circuit.

[0004] How to achieve colder temperature control in refrigeration and heating cycle devices, and how to reduce energy consumption and costs during the refrigeration process have always been hot topics in this field. Traditionally, the production of lower temperatures is usually achieved through multi-stage refrigeration, that is, the evaporator of one refrigeration system is used as the condensing equipment of another refrigeration system until a lower temperature is achieved. However, for low-temperature control, such as minus 40 degrees Celsius, multi-stage refrigeration consumes a lot of energy, and multi-stage refrigeration is not necessary. In this case, dual or multiple systems are usually used to control low temperatures in different temperature ranges, such as 0 to -40℃ in one stage, -40℃ to 120℃ in one stage, or even lower. This involves the problem of multiple cooling media flowing through the same heat exchanger for cold transfer. In fact, the narrower the flow path of the plate heat exchanger, the narrower the gap between the pipes, which is not conducive to the cold transfer of the refrigerant. On the other hand, the increase in the number of circuits makes the heat exchanger bulky, which is not conducive to the design and use of the equipment. Summary of the Invention

[0005] In view of the above problems, the purpose of the present invention is to provide a closed refrigeration and heating cycle device with a compound evaporator to solve some of the above problems.

[0006] The technical solution is to include a refrigerant circulation system for cooling or heating the outside world and a refrigeration system for cooling the refrigerant, the refrigerant circulation system includes a heating circuit, an air-cooling circuit, and a refrigeration circuit, the refrigeration circuit forms a heat exchange structure with the refrigeration system through an evaporator, and forms a structure for the refrigeration system to cool the refrigerant; the refrigeration system includes a first refrigeration system and a second refrigeration system, the first refrigeration system includes a first compressor, a first condenser, a first evaporator and a condensing evaporator, the second refrigeration system includes a second compressor, a condensing evaporator, and a second evaporator, the water vapor mixture after condensation of the first refrigeration system is switched into two directions by an electromagnetic valve, one path passes through the first evaporator located in the refrigeration system, the cooling medium passing through the first evaporator passes through the intermediate cooling medium circuit of the first refrigeration system to the first compressor, and the other path passes through the condensing evaporator and enters the intermediate cooling medium circuit of the first refrigeration system to the first compressor; the second evaporator forms a heat exchange structure with the refrigeration system The heat exchange provides low-temperature refrigeration. The second evaporator and the first evaporator include a common closed shell. The first evaporator and the second evaporator respectively include a plurality of evaporation units. Each evaporation unit includes a plurality of unit tubes in a ring array. Each unit tube is connected at the head and arranged at intervals to form a structure in which the evaporation unit only includes one cooling medium inlet and one cooling medium outlet. It also includes a fixing member for fixing each unit tube. The fixing member is used to form a component of each unit tube and is fixed to the shell. Another evaporation unit is set in the cavity formed by each unit tube to form a nested structure. The evaporation units located inside are connected end to end to form the first evaporator, and the evaporation units located outside are connected end to end to form the second evaporator. A passage for the refrigerant to flow through is left between the shell and each evaporation unit. The shell inlet includes a circuit flowing through each unit of the first evaporator and also includes a circuit flowing through each unit of the second evaporator, and they are respectively controlled and switched by solenoid valves.

[0007] In the above or some embodiments, the high-temperature and high-pressure steam compressed by the first compressor passes through the first condenser, the first gas-liquid separator, the dryer, the first return heat exchanger to the circuit switching point, including the first solenoid valve and the second solenoid valve, through the first solenoid valve and the thermal expansion valve to the first evaporator, through the second solenoid valve and the thermal expansion valve to the condensing evaporator to condense the cooling medium in the second refrigeration system. After condensation, the cooling medium of the second refrigeration system enters the second evaporator through the thermal expansion valve to achieve low-temperature refrigeration.

[0008] In the above or some embodiments, the second refrigeration system includes a pre-cooling system, which includes a first condenser and a pre-cooling heat exchanger. The first condenser includes a channel connected to the first refrigeration system and a refrigerant medium channel connected to the second refrigeration system. The cooling medium in the second system passes through the first condenser and flows into the pre-cooling heat exchanger and enters the inlet of the condenser evaporator. The pre-cooling heat exchanger forms a pre-cooling circuit with external cooling circulating water or cooling medium.

[0009] In the above or some embodiments, the cooling medium after passing through the condenser evaporator in the first refrigeration system flows through the shell side of the first regenerator, and the cooling medium after flowing out of the condenser evaporator in the second refrigeration system flows through the tube side of the first regenerator and flows through the tube side of the second regenerator in the second refrigeration system, forming a structure for obtaining a lower amount of supercooling, and the cooling medium after flowing out of the second evaporator flows through the tube side of the second regenerator.

[0010] In the above or some embodiments, the shell includes an upper and lower shell with two halves, and the edges of the upper and lower shells extend to form flanges, and the fixed sealing structure is formed by bolts and sealing gaskets at the flanges. The shell also includes a cavity formed by snapping, and the cavity forms a space for installing the first evaporator and the second evaporator.

[0011] In the above or some embodiments, the unit tube is a pipe bent to form a cylindrical structure, the upper and lower sections of the unit tube are respectively fixedly connected to fixing rings, and the shell forms a mounting seat for adapting to the fixing ring, forming a structure for fixing the evaporation unit by buckling the fixing ring.

[0012] In the above or some embodiments, the upper portion of the fixing ring of the evaporation unit located inside and the fixing ring of the evaporation unit located outside form a fixed sleeve structure through threads.

[0013] In the above or some embodiments, it also includes a flow control plate of a plate structure located between the adjacent external evaporation units, each of the flow control plates divides the cavity into multiple chambers, and a through hole connecting the chambers is provided on one side of each flow control plate, forming a structure in which the refrigerant flows through the chamber in a serpentine manner after being divided by the flow control plate.

[0014] When in use, the first refrigeration system and the second refrigeration system can be used separately to meet the needs of ordinary refrigeration and ultra-low temperature refrigeration, and the evaporators of the first refrigeration system and the second refrigeration system used for cooling cycle refrigeration are an integrated structure, which can greatly reduce the equipment volume of the traditional dual refrigeration system. At the same time, this solution can form a larger evaporation capacity setting through the loop setting of the first evaporator and the second evaporator to obtain an ultra-low temperature working environment. Finally, the interval nested structure of the first evaporator and the second evaporator in this solution forms a larger contact area with the refrigerant, and the refrigeration is faster and more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the present invention.

[0016] Figure 2 This is a diagram of the internal structure of the first evaporator and the second evaporator in the present invention.

[0017] Figure 3 This is the external structure diagram of the first evaporator and the second evaporator in the present invention.

[0018] Figure 4 Schematic diagram of the nested structure of the evaporation unit in the present invention.

[0019] Figure 5 Schematic diagram of the structure of the flow control plate in the present invention.

[0020] Figure 6 Schematic diagram of the combination of the flow control plate in the present invention. DETAILED DESCRIPTION

[0021] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0022] In the description of the present invention, “plurality” means two or more than two, unless otherwise clearly defined.

[0023] The closed refrigeration and heating cycle device includes a refrigerant circulation system 100 for cooling or heating the outside world and a refrigeration system 200 for cooling the refrigerant. The refrigerant circulation system 100 includes a heating circuit 101, an air-cooling circuit 102, and a refrigeration circuit 103. During heating, the refrigerant circulation system 100 activates the heating circuit 101 and shuts down the air-cooling circuit 102. The heater heats the thermal oil used for heat exchange. After heat exchange, the thermal oil is routed through external pipes to raise the temperature of equipment such as the reactor. During cooling, if the temperature is relatively high, such as 15-8°C, the air-cooling circuit 102 can cool the refrigerant flowing through it until the desired cooling effect is achieved. When low temperature is required, it is usually necessary to start the refrigeration circuit 103. The refrigeration circuit 103 forms a heat exchange structure with the refrigeration system 200 through the evaporator, forming a structure for the refrigeration system to cool the refrigerant. The first refrigeration system and the second refrigeration system are set according to the low temperature control needs. At this time, the first refrigeration system and the second refrigeration system exchange heat with the refrigerant flowing through to obtain lower temperature control, and the air cooling circuit 102 and the heating circuit 101 are closed.

[0024] The refrigeration system includes a first refrigeration system and a second refrigeration system. The first refrigeration system includes a first compressor 1, a first condenser 2, a first evaporator 3 and a condenser-evaporator 4. The second refrigeration system includes a second compressor 5, a condenser-evaporator 4, and a second evaporator 7. The second evaporator 7 forms a heat exchange with the refrigeration system 200 to provide low-temperature refrigeration.

[0025] In the first refrigeration system, the condensed water vapor mixture is switched into two directions by the solenoid valve. One direction is through the first evaporator 3 located in the refrigeration system 200. The cooling medium passing through the first evaporator 3 passes through the intermediate cooling medium circuit of the first refrigeration system 200 to the first compressor 1. The other direction is through the condensing evaporator 4 and enters the intermediate cooling medium circuit of the first refrigeration system 200 to the first compressor 1; in the above or some embodiments, the high-temperature and high-pressure steam compressed by the first compressor 1 passes through the first condenser 2 through the first gas-liquid separator 10, the dryer 11, and the first return heat exchanger 12 to the circuit switching point, including the first solenoid valve 13 and the second solenoid valve 14, through the first solenoid valve 13 and the thermal expansion valve to the first evaporator 3, through the second solenoid valve 14 and the thermal expansion valve to the condensing evaporator 4 to condense the cooling medium in the second refrigeration system. After condensation, the cooling medium of the second refrigeration system enters the second evaporator 7 through the thermal expansion valve to realize low-temperature refrigeration.

[0026] The second refrigeration system includes a precooling system, which includes a first condenser 2 and a precooling heat exchanger 15. The first condenser 2 includes a channel communicating with the first refrigeration system and a refrigerant medium channel communicating with the second refrigeration system. The cooling medium in the second system passes through the first condenser 2 and flows into the precooling heat exchanger 15 and enters the inlet of the condenser evaporator 4. The precooling heat exchanger 15 is cooled by external circulating water or cooling medium to form a precooling circuit 16. The gas circuit in the second gas-liquid separator can also flow through the precooling heat exchanger for further condensation.

[0027] In order to save space and improve the cooling effect, the second evaporator 7 and the first evaporator 3 include a common closed shell 9, and the first evaporator 3 and the second evaporator 7 respectively include a plurality of evaporation units 300 connected in series.

[0028] In the above or some embodiments, the housing 9 comprises upper and lower halves of the split shell 9. Flanges 19 extend from the edges of the upper and lower shells 9. Bolts and gaskets 20 at the flanges 19 form the fixed sealing structure. The housing 9 also includes a cavity formed by snapping together, which forms the evaporation units 300 for mounting the first and second evaporators 3 and 7. The inlet of the housing 9 includes a circuit that flows through the units of the first evaporator 3 and also includes a circuit that flows through the units of the second evaporator 7. These circuits are switched by solenoid valves. Of course, the first and second evaporators 3 and 7 can be connected in parallel, with the solenoid valve switching to allow a single circuit or two circuits to operate simultaneously.

[0029] The evaporation unit 300 includes a plurality of unit tubes 301 arranged in an annular array. Each unit tube 301 is connected end-to-end and spaced apart, forming a structure in which the evaporation unit 300 includes only one cooling medium inlet 302 and one cooling medium outlet 303. The evaporation unit 300 also includes fixtures for securing each unit tube 301. These fixtures are used to form components of each unit tube 301 and are secured to the housing 9. Each evaporation unit 300 has a cylindrical main structure. The refrigerant in the refrigerant circulation system 100 flows between the unit tubes 301 within each evaporation unit 300. When connected in series, the evaporation units 300 are connected end-to-end, forming a path for the cooling medium to flow through.

[0030] Both the first evaporator 3 and the second evaporator 7 are formed by multiple evaporation units 300 connected in series. In the above or some embodiments, each unit tube 301 encloses a cavity within which another evaporation unit 300 is housed, forming a nested structure. Each evaporation unit 300 of the first evaporator 3 is located inside, while each evaporation unit 300 of the second evaporator 7 is located outside, forming a mutually nested structure. The evaporation units 300 located inside are connected end-to-end to form the first evaporator 3, while the evaporation units 300 located outside are connected end-to-end to form the second evaporator 7.

[0031] In the above or some embodiments, the unit tube 301 is a cylindrical structure formed by bending a single tube. The upper and lower sections of the unit tube 301 are respectively fixedly connected to a fixing ring 304. The housing 9 forms a mounting seat for the fixing ring 304, thereby securing the evaporation unit 300 by pressing the fixing ring 304. The upper portion of the fixing ring 304 of the evaporation unit 300 located inside is fixedly connected to the fixing ring 304 of the evaporation unit 300 located outside via threads.

[0032] The refrigerant flow passage also includes a plate-like flow control plate 21 located between adjacent external evaporation units 300. Each flow control plate 21 divides the cavity into multiple chambers 22. A through hole 23 connecting the chambers 22 is provided on one side of each flow control plate 21, forming a structure in which the refrigerant flowing through the chambers 22 is serpentine. Grooves for mounting sealing rings are provided at the edges of the flow control plates. Grooves for inserting the ends of the flow control plates are provided at the corresponding upper and lower housings of the cavity. The flow control plates are compressed by the seal between the upper and lower housings.

[0033] In the above or some embodiments, the cooling medium after passing through the condenser evaporator 4 in the first refrigeration system flows through the shell side of the first reheater 17, and the cooling medium after flowing out of the condenser evaporator 4 in the second refrigeration system flows through the tube side of the first reheater 17 and flows through the tube side of the second reheater 18 in the second refrigeration system, forming a structure for obtaining a lower amount of supercooling, and the cooling medium after flowing out of the second evaporator 7 flows through the tube side of the second reheater 18.

[0034] When in use, the first refrigeration system and the second refrigeration system can be used separately to meet the needs of ordinary refrigeration and ultra-low temperature refrigeration, and the evaporators of the first refrigeration system and the second refrigeration system used for cooling cycle refrigeration are an integrated structure, which can greatly reduce the equipment volume of the traditional dual refrigeration system. At the same time, this solution can form a larger evaporation amount setting through the loop setting of the first evaporator 3 and the second evaporator 7 to obtain an ultra-low temperature working environment. Finally, the interval nested structure of the first evaporator 3 and the second evaporator 7 in this solution forms a larger contact area with the refrigerant, and the refrigeration is faster and more efficient.

Claims

1. A closed refrigeration and heating cycle device with a compound evaporator, comprising a refrigerant circulation system (100) for cooling or heating the outside world and a refrigeration system (200) for cooling the refrigerant, wherein the refrigerant circulation system (100) comprises a heating circuit (101), an air cooling circuit (102), and a refrigeration circuit (103), wherein the refrigeration circuit (103) forms a heat exchange structure with the refrigeration system (200) through the evaporator, thereby forming a structure in which the refrigeration system (200) cools the refrigerant; and wherein the device is characterized in that: The refrigeration system comprises a first refrigeration system and a second refrigeration system, wherein the first refrigeration system comprises a first compressor (1), a first condenser (2), a first evaporator (3) and a condenser-evaporator (4), and the second refrigeration system comprises a second compressor (5), a condenser-evaporator (4) and a second evaporator (7). The water vapor mixture after condensation in the first refrigeration system is switched into two directions by a solenoid valve. One direction is through the first evaporator (3) located in the refrigeration circuit. The cooling medium of the first evaporator (3) is passed through the intermediate cooling medium circuit of the first refrigeration system (200) to the first compressor (1). The other direction is through the condenser-evaporator (4) and enters the intermediate cooling medium circuit of the first refrigeration system (200) to the first compressor (1); the second evaporator (7) forms a heat exchange with the refrigeration system (200) to provide low-temperature refrigeration. The second evaporator (7) and the first evaporator (3) comprise a common closed shell (9). The first evaporator (3) and the second evaporator (7) respectively comprise a plurality of evaporation units (300), each of which is The evaporation unit (300) includes a plurality of unit tubes (301) in a circular array. The unit tubes (301) are connected to each other and arranged at intervals to form a structure in which the evaporation unit (300) includes only one cooling medium inlet (302) and one cooling medium outlet (303). The evaporation unit (300) also includes a fixing member for fixing each unit tube (301). The fixing member is used to form a component of each unit tube (301) and is fixed to the shell (9). The cavity formed by each unit tube (301) is provided with another evaporation unit. (300), forming a nested structure, the evaporation units (300) located inside are connected end to end to form the first evaporator (3), and the evaporation units (300) located outside are connected end to end to form the second evaporator (7), and a passage for the refrigerant to flow through is reserved between the shell (9) and each evaporation unit (300), and the shell (9) inlet includes a circuit flowing through each unit of the first evaporator (3), and also includes a circuit flowing through each unit of the second evaporator (7), and the switching is controlled by the solenoid valve respectively.

2. The closed refrigeration and heating cycle device of the compound evaporator according to claim 1, characterized in that: The high-temperature and high-pressure steam compressed by the first compressor (1) passes through the first condenser (2), the first gas-liquid separator (10), the dryer (11), the first return heat exchanger (12) to the circuit switching point, including the first solenoid valve (13), the second solenoid valve (14), and then passes through the first solenoid valve (13) and the thermal expansion valve to the first evaporator (3), and then passes through the second solenoid valve (14) and the thermal expansion valve to the condensing evaporator (4) to condense the cooling medium in the second refrigeration system. After condensation, the cooling medium of the second refrigeration system enters the second evaporator (7) through the thermal expansion valve to achieve low-temperature refrigeration.

3. The closed refrigeration and heating cycle device of the compound evaporator according to claim 2, characterized in that: The second refrigeration system includes a precooling system, the precooling system includes a first condenser (2) and a precooling heat exchanger (15), the first condenser (2) includes a channel connected to the first refrigeration system and also includes a refrigeration medium channel connected to the second refrigeration system, the cooling medium in the second system passes through the first condenser (2) and flows into the precooling heat exchanger (15) and enters the inlet of the condenser evaporator (4), and the precooling heat exchanger (15) forms a precooling circuit (16) with external cooling circulating water or cooling medium.

4. The closed refrigeration and heating cycle device of the compound evaporator according to claim 3, characterized in that: The cooling medium in the first refrigeration system after passing through the condenser evaporator (4) flows through the shell side of the first regenerator (17), and the cooling medium in the second refrigeration system after flowing out of the condenser evaporator (4) flows through the tube side of the first regenerator (17) and flows through the tube side of the second regenerator (18) in the second refrigeration system, forming a structure for obtaining a lower amount of supercooling, and the cooling medium after flowing out of the second evaporator (7) flows through the tube side of the second regenerator (18).

5. The closed refrigeration and heating cycle device of the compound evaporator according to claim 4, characterized in that: The shell (9) comprises an upper shell and a lower shell in two halves, wherein flanges (19) are extended at the edges of the upper shell and the lower shell, and a fixed sealing structure is formed by bolts and sealing gaskets (20) at the flange (19). The shell (9) also comprises a cavity formed by snapping, and the cavity forms a space for installing the first evaporator (3) and the second evaporator (7).

6. The closed refrigeration and heating cycle device of the compound evaporator according to claim 5, characterized in that: The unit tube (301) is a cylindrical structure formed by bending a pipe. The upper and lower sections of the unit tube (301) are respectively fixedly connected to the fixing ring (304). The shell (9) forms a mounting seat for adapting to the fixing ring (304), forming a structure for fixing the evaporation unit (300) by buckling the fixing ring (304).

7. The closed refrigeration and heating cycle device of the compound evaporator according to claim 6, characterized in that: The upper portion of the fixing ring (304) of the evaporation unit (300) located inside and the fixing ring (304) of the evaporation unit (300) located outside form a fixed sleeve structure through threads.

8. The closed refrigeration and heating cycle device of the compound evaporator according to claim 7, characterized in that: It also includes a flow control plate (21) of a plate structure located between the adjacent external evaporation units (300), each of the flow control plates (21) divides the cavity into a plurality of chambers (22), and a through hole (23) connecting the chambers (22) is provided on one side of each flow control plate (21), forming a structure in which the refrigerant flowing through the chambers (22) is divided by the flow control plate (21) and serpentine-shaped.

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