Refrigeration total system comprising external supercooling system

Abstract

The utility model discloses a refrigeration total system comprising an external supercooling system, the refrigeration total system comprises the external supercooling system and a compression refrigeration system, the external supercooling system comprises an external refrigeration system and a water circulation system, and the water circulation system comprises a circulation driving device, a heat exchanger and a water circulation loop. The water circulation loop is connected in series with the hot side of the evaporator of the external refrigerating system, the circulation driving device and the cold side of the heat exchanger, the water circulation system transmits cold energy to an aqueous solution in the water circulation loop, and the water circulation loop transmits the cold energy to a refrigerant in the compression refrigerating system through the heat exchanger; the supercooling degree of a refrigerant in the compression type refrigerating system is improved, the amount of flash evaporation steam entering an evaporator of the compression type refrigerating system is effectively restrained or eliminated, and the refrigerating capacity and the refrigerating efficiency of the compression type refrigerating system are improved. The device is particularly suitable for being applied to a long-distance high-capacity compression type refrigerating system.

Description

Technical Field

[0001] The utility model relates to the technical field of refrigeration, and particularly relates to a total refrigeration system including an external subcooling system. Background Art

[0002] A compression refrigeration system is a system that utilizes the heat absorption and release phenomena during the phase change of a refrigerant with a relatively low boiling point, and through the cycle of suction and compression by a compressor, heat release and condensation by a condenser, throttling and pressure reduction by a throttle valve, and heat absorption and vaporization by an evaporator, the temperature of the object to be cooled is decreased. Generally, a compression refrigeration system can meet the cooling capacity required by the object to be cooled. However, during long-distance large-capacity cooling, more flash vapor will be generated when the refrigerant flows through the throttling device, reducing the subcooling degree of the refrigeration capacity and thus reducing the efficiency of the refrigeration system. Therefore, means need to be taken to suppress or eliminate the amount of flash vapor entering the evaporator. Summary of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems in the related art to some extent. For this purpose, an embodiment of the utility model provides a total refrigeration system including an external subcooling system.

[0004] The total refrigeration system according to the embodiment of the utility model includes: an external subcooling system, the external subcooling system includes an external refrigeration system and a water circulation system, the external refrigeration system includes a first compressor, a first evaporator, a first throttling device, a first condenser and a first refrigeration circuit, the cold sides of the first compressor, the first condenser, the first throttling device and the first evaporator are connected in series in the first refrigeration circuit, the water circulation system includes a circulation driving device, a heat exchanger and a water circulation circuit, the water circulation circuit connects in series the hot side of the first evaporator, the circulation driving device and the cold side of the heat exchanger, wherein, the first refrigeration circuit transfers the generated cold quantity to the aqueous solution in the water circulation circuit through the first evaporator; and a compression refrigeration system, the compression refrigeration system includes a second compressor, a second evaporator, a second throttling device, a second condenser and a second refrigeration circuit, the second compressor, the second condenser, the second throttling device and the second evaporator are connected in series in the second refrigeration circuit, wherein, the hot side of the heat exchanger of the water circulation system is connected between the second condenser and the second throttling device, and the water circulation circuit transfers the cold quantity to the refrigerant in the second refrigeration circuit through the heat exchanger.

[0005] Optionally, the aqueous solution in the water circulation circuit includes ethylene glycol solution.

[0006] Optionally, the compression refrigeration system includes: a first temperature detector and a first pressure detector, both of which are arranged on the inlet side of the second throttling device. The first temperature detector is used to measure the temperature of the liquid refrigerant before throttling in the second refrigeration circuit, and the first pressure detector is used to measure the pressure of the liquid refrigerant before throttling in the second refrigeration circuit; a second pressure detector, which is arranged on the outlet side of the second throttling device and is used to measure the pressure of the refrigerant after throttling in the second refrigeration circuit.

[0007] Optionally, there are multiple sets of the compression refrigeration systems. The water circulation system includes a water distribution and collection device connected to the water circulation loop. The water distribution and collection device is used to divide the aqueous solution in the water circulation loop into multiple paths to subcool multiple sets of the compression refrigeration systems respectively.

[0008] Optionally, the cold side and the hot side of the first evaporator are arranged in a countercurrent manner.

[0009] Optionally, the cold side and the hot side of the heat exchanger are arranged in a countercurrent manner.

[0010] Optionally, the cold side and the hot side of the first evaporator are arranged in a countercurrent manner; and / or, the cold side and the hot side of the heat exchanger are arranged in a countercurrent manner.

[0011] Optionally, the circulating drive device is a variable-frequency water pump.

[0012] Optionally, the first compressor is a variable-frequency compressor.

[0013] Optionally, the second compressor is a variable-frequency compressor.

[0014] Optionally, the external refrigeration system further includes a first gas-liquid separator and a first liquid storage device. The first gas-liquid separator is connected between the first evaporator and the first compressor, and the first liquid storage device is connected between the first condenser and the first throttling device; and the compression refrigeration system further includes a second gas-liquid separator and a second liquid storage device. The second gas-liquid separator is connected between the second evaporator and the second compressor, and the second liquid storage device is connected between the second condenser and the hot side of the heat exchanger.

[0015] The overall refrigeration system provided by the embodiment of the present utility model includes an external subcooling system. The external subcooling system can transfer the cold generated by the external refrigeration system to the refrigerant in the compression refrigeration system through the heat exchanger in the water circulation loop, improving the subcooling degree of the refrigerant in the compression refrigeration system, effectively suppressing or eliminating the amount of flash vapor entering the evaporator, and improving the refrigeration capacity and refrigeration efficiency of the compression refrigeration system. It is particularly suitable for the application of long-distance and large-capacity compression refrigeration systems. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of the overall refrigeration system of the embodiment of the present utility model.

[0017] Reference Signs:

[0018] First compressor 1-1; first gas-liquid separator 1-2; first evaporator 1-3; first throttling device 1-4; first liquid storage tank 1-5; first condenser 1-6; first refrigeration circuit 1-7;

[0019] Circulation driving device 2-1; heat exchanger 2-2; water circulation loop 2-3;

[0020] Second compressor 3-1; second gas-liquid separator 3-2; second evaporator 3-3; second throttling device 3-4; second liquid storage tank 3-5; second condenser 3-6; second refrigeration circuit 3-7; first temperature detector 3-8; first pressure detector 3-9; second pressure detector 3-10; Detailed Embodiment

[0021] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present utility model, and should not be construed as a limitation to the present utility model.

[0022] Next, refer to Figure 1 Describe the external subcooling system of the present utility model and the overall refrigeration system including the external subcooling system. The external subcooling system includes an external refrigeration system and a water circulation system, and the overall refrigeration system includes an external subcooling system and a compression refrigeration system.

[0023] As Figure 1As shown, the external refrigeration system includes a first compressor 1-1, a first evaporator 1-3, a first throttling device 1-4, a first condenser 1-6, and a first refrigeration circuit 1-7. The cold sides of the first compressor 1-1, the first condenser 1-6, the first throttling device 1-4, and the first evaporator 1-3 are connected in series in the first refrigeration circuit 1-7 along the refrigerant flow direction. The refrigerant circulates in the first refrigeration circuit 1-7, is compressed, heated, and pressurized by the first compressor 1-1, enters the first condenser 1-6 and condenses into liquid refrigerant, then passes through the first throttling device 1-4 for throttling, and then evaporates through heat exchange in the first evaporator 1-3, and then returns to the first compressor 1-1 to perform the next round of refrigeration cycle.

[0024] The water circulation system includes a circulation driving device 2-1, a heat exchanger 2-2, and a water circulation loop 2-3. The circulation driving device 2-1 and the cold side of the heat exchanger 2-2 are arranged in the water circulation loop 2-3, and the hot side of the first evaporator 1-3 is connected in series in the water circulation loop 2-3, where the circulation driving device 2-1 is used to drive the circulation of the aqueous solution in the water circulation loop. The cold generated by the first refrigeration circuit 1-7 is transferred to the aqueous solution in the water circulation loop 2-3 through the first evaporator 1-3. The aqueous solution in the water circulation loop 2-3 is driven by the circulation driving device 2-1, carries the cold and circulates, and transfers the cold to the compression refrigeration system through the heat exchanger 2-2 to provide refrigeration capacity to the compression refrigeration system.

[0025] Optionally, the aqueous solution in the water circulation system includes ethylene glycol solution. Since the freezing point of ethylene glycol is relatively low, using ethylene glycol solution for circulation can prevent the pipeline from freezing during operation.

[0026] Optionally, the volume concentration of the ethylene glycol solution is 25% - 35%.

[0027] As Figure 1 shown, the compression refrigeration system includes a second compressor 3-1, a second evaporator 3-3, a second throttling device 3-4, a second condenser 3-6, and a second refrigeration circuit 3-7. The second compressor 3-1, the second condenser 3-6, the second throttling device 3-4, and the second evaporator 3-3 are connected in series in the second refrigeration circuit 3-7 in sequence along the refrigerant flow direction. The hot side of the heat exchanger 2-2 of the external subcooling system is connected between the second condenser 3-6 and the second throttling device 3-4, and the water circulation loop 2-3 transfers the cold to the refrigerant in the second refrigeration circuit 3-7 through the heat exchanger 2-2.

[0028] For a compression refrigeration system, the refrigerant circulates in the compression refrigeration system loop 3-7, generates cooling capacity after being compressed by the second compressor 3-1, enters the second condenser 3-6 and condenses into liquid refrigerant. The condensed liquid refrigerant enters the heat exchanger 2-2, and the cooling capacity of the aqueous solution on the cold side of the heat exchanger 2-2 is transferred to the liquid refrigerant on the hot side of the heat exchanger 2-2, thereby providing subcooling for the liquid refrigerant before it enters the second throttling device 3-4.

[0029] The overall refrigeration system provided by the embodiment of the present invention includes an external subcooling system. The external subcooling system transfers the generated cooling capacity to the refrigerant in the compression refrigeration system, increases the subcooling degree of the refrigerant in the compression refrigeration system, effectively suppresses or eliminates the amount of flash vapor entering the evaporator, and improves the refrigeration capacity and refrigeration efficiency of the compression refrigeration system. It is particularly suitable for the application of long-distance and large-capacity compression refrigeration systems.

[0030] In some embodiments, the compression refrigeration system is a long-distance and large-capacity compression refrigeration system. In order to ensure the normal operation of the long-distance and large-capacity compression refrigeration system, an external refrigeration system with an appropriate design power is designed. The present invention does not require the distance and cooling capacity of the compression refrigeration system, and only needs to adjust the equipment selection and the installation position according to the number and operating condition parameters of the long-distance and large-cooling-capacity compression refrigeration systems.

[0031] As Figure 1 shown, the external refrigeration system further includes a first gas-liquid separator 1-2 and a first liquid storage tank 1-5. The first gas-liquid separator 1-2 is connected between the first evaporator 1-3 and the first compressor 1-1, and the first liquid storage tank 1-5 is connected between the first condenser 1-6 and the first throttling device 1-4. The first gas-liquid separator 1-2 is used to separate the gas and liquid of the refrigerant before it enters the first compressor 1-1 to prevent too much liquid refrigerant from entering the first compressor 1-1. The first liquid storage tank 1-5 is used to store the condensed liquid refrigerant.

[0032] The compression refrigeration system further includes a second gas-liquid separator 3-2 and a second liquid storage tank 3-5. The second gas-liquid separator 3-2 is connected between the second evaporator 3-3 and the second compressor 3-1, and the second liquid storage tank 3-5 is connected between the second condenser 3-6 and the second throttling device 3-4. The second gas-liquid separator 3-2 is used to separate the gas and liquid of the refrigerant before it enters the second compressor 3-1 to prevent too much liquid refrigerant from entering the second compressor 3-1. The second liquid storage tank 3-5 is used to store the condensed liquid refrigerant.

[0033] As Figure 1As shown, the compression refrigeration system further includes a first temperature detector 3-8 and a first pressure detector 3-9. Both the first temperature detector 3-8 and the first pressure detector 3-9 are provided on the inlet side of the second throttling device 3-4. The first temperature detector 3-8 is used to measure the temperature of the liquid refrigerant before throttling in the second refrigeration circuit 3-7, and the first pressure detector 3-9 is used to measure the pressure of the liquid refrigerant before throttling in the second refrigeration circuit 3-7. The compression refrigeration system further includes a second pressure detector 3-10. The second pressure detector 3-10 is provided on the outlet side of the second throttling device 3-4 and is used to measure the pressure of the refrigerant after throttling in the second refrigeration circuit 3-7.

[0034] According to the temperature of the liquid refrigerant before throttling measured by the first temperature detector 3-8 and the pressure of the liquid refrigerant before throttling measured by the first pressure detector 3-9, the subcooling degree a of the liquid refrigerant on the inlet side of the second throttling device 3-4 can be calculated. According to the pressure of the liquid refrigerant before throttling measured by the first pressure detector 3-9 and the pressure of the liquid refrigerant after throttling measured by the second pressure detector 3-10, the difference ΔT in the saturation temperature corresponding to the pressure of the refrigerant before and after throttling can be calculated. Thus, during the operation of the long-distance large-cooling-capacity compression refrigeration system, the subcooling degree a of the refrigerant before the second throttling device 3-4 can be controlled through the heat exchanger 2-2, such that the subcooling degree a is less than ΔT, and the difference between a and ΔT is 5°C to 10°C. Thereby, the amount of flash vapor entering the evaporator during the cycle can be significantly suppressed or even eliminated, and the refrigeration efficiency during the operation of the compression refrigeration system is significantly improved.

[0035] In some embodiments, the superheat degree at the outlet of the second evaporator 3-3 is monitored in real time, and the superheat degree at the outlet of the second evaporator 3-3 is controlled to be 5°C to 10°C to prevent liquid refrigerant from appearing at the outlet of the second evaporator 3-3.

[0036] Preferably, the cold side and the hot side of the first evaporator 1-3 are arranged in a countercurrent manner. Preferably, the cold side and the hot side of the heat exchanger 2-2 are arranged in a countercurrent manner.

[0037] Optionally, the circulation driving device 2-1 is a variable-frequency water pump. Optionally, the first compressor 1-1 is a variable-frequency compressor. Optionally, the second compressor 3-1 is a variable-frequency compressor.

[0038] Preferably, the water circulation circuit 2-3 of the external subcooling system should be made of materials with strong resistance, light weight, and good toughness. At the same time, the pipeline should be wrapped with a heat-insulating layer.

[0039] Preferably, a flexible joint is used at the connection between the water circulation circuit 2-3 of the external subcooling system and the pipeline of the circulation driving device 2-1 to reduce the vibration influence during the operation of the circulation driving device 2-1.

[0040] In some embodiments, there are multiple sets of compression refrigeration systems. The water circulation system includes a manifold (not shown in the figure) connected to the water circulation loop 2-3. The manifold is used to divide the aqueous solution in the water circulation loop 2-3 into multiple paths to subcool multiple sets of compression refrigeration systems respectively. In other words, by providing a manifold in the water circulation loop 2-3, the aqueous solution in the water circulation loop 2-3 can be divided into multiple streams, flowing to the corresponding compression refrigeration systems respectively, and transferring the cooling capacity to the compression refrigeration systems. In Figure 1 In the illustrated embodiment, since there is one set of compression refrigeration system, there is no need to provide a manifold in the water circulation loop 2-3.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0042] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0043] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present utility model, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature has a lower horizontal height than the second feature.

[0045] In the present utility model, the terms "an embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples.

[0046] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. A refrigeration system including an external subcooling system, characterized in that: include: An external supercooling system, the external supercooling system includes an external refrigeration system and a water circulation system, the external refrigeration system includes a first compressor, a first evaporator, a first throttling device, a first condenser and a first refrigeration circuit, the first compressor, the first condenser, the first throttling device, and the cold side of the first evaporator are connected in series in the first refrigeration circuit, the water circulation system includes a circulation drive device, a heat exchanger and a water circulation circuit, the water circulation circuit is connected in series with the hot side of the first evaporator, the circulation drive device and the cold side of the heat exchanger, wherein the first refrigeration circuit transfers the generated cold energy to the aqueous solution in the water circulation circuit through the first evaporator; and A compression refrigeration system, the compression refrigeration system includes a second compressor, a second evaporator, a second throttling device, a second condenser and a second refrigeration circuit, the second compressor, the second condenser, the second throttling device and the second evaporator are connected in series in the second refrigeration circuit, wherein the hot side of the heat exchanger of the water circulation system is connected between the second condenser and the second throttling device, and the water circulation circuit transfers the cold energy to the refrigerant in the second refrigeration circuit through the heat exchanger.

2. The refrigeration system according to claim 1, characterized in that: The aqueous solution in the water circulation loop includes an ethylene glycol solution.

3. The refrigeration system according to claim 1, characterized in that: The compression refrigeration system comprises: a first temperature detector and a first pressure detector, wherein the first temperature detector and the first pressure detector are both arranged at the inlet side of the second throttling device, the first temperature detector is used to measure the temperature of the liquid refrigerant before throttling in the second refrigeration circuit, and the first pressure detector is used to measure the pressure of the liquid refrigerant before throttling in the second refrigeration circuit; and A second pressure detector is provided at the outlet side of the second throttling device and is used to measure the pressure of the throttled refrigerant in the second refrigeration circuit.

4. The refrigeration system according to claim 1, characterized in that: The compression refrigeration system is composed of multiple groups, and the water circulation system includes a manifold connected to the water circulation loop. The manifold is used to divert the aqueous solution in the water circulation loop into multiple paths to supercool the multiple groups of compression refrigeration systems respectively.

5. The refrigeration system according to claim 1, characterized in that: The cold side and the hot side of the first evaporator are arranged in countercurrent.

6. The refrigeration system according to claim 1, characterized in that: The cold side and the hot side of the heat exchanger are arranged in counter-flow.

7. The refrigeration system according to claim 1, characterized in that: The circulation driving device is a variable frequency water pump.

8. The refrigeration system according to claim 1, characterized in that: The first compressor is a variable frequency compressor.

9. The refrigeration system according to claim 1, characterized in that: The second compressor is a variable frequency compressor.

10. The refrigeration system according to claim 1, characterized in that: The external refrigeration system further comprises a first gas-liquid separator and a first liquid receiver, wherein the first gas-liquid separator is connected between the first evaporator and the first compressor, and the first liquid receiver is connected between the first condenser and the first throttling device; and The compression refrigeration system further comprises a second gas-liquid separator and a second liquid receiver, wherein the second gas-liquid separator is connected between the second evaporator and the second compressor, and the second liquid receiver is connected between the second condenser and the hot side of the heat exchanger.

Images