Liquid return heat exchange device, refrigeration system and refrigeration equipment

Abstract

The utility model provides a kind of back liquid heat exchange device, the back liquid heat exchange device includes: pipe body, the pipe body is placed along vertical direction;Upper tube sheet and lower tube sheet, the upper tube sheet and lower tube sheet are arranged in the pipe body, and the upper tube sheet is located above the lower tube sheet, and the upper tube sheet and the lower tube sheet divide the pipe body into upper cavity, middle cavity and lower cavity;Heat exchange tube, the quantity of the heat exchange tube is at least one, and the upper and lower ends of the heat exchange tube are respectively communicated with upper cavity and lower cavity.The back liquid heat exchange device, refrigeration system and refrigeration equipment of the utility model make the liquid refrigerant of low pressure side not overheated to be fully and effectively overheated, and the liquid refrigerant of high pressure side can be supercooled, greatly improve the heat exchange efficiency of evaporator, greatly improve the refrigeration efficiency of compressor, improve the efficiency of gas-liquid separation, while providing sufficient suction volume of compressor, maintain the stable operation of compressor unit, and there is no liquid strike problem.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration technology, and in particular to a liquid return heat exchange device, a refrigeration system and refrigeration equipment. Background Technology

[0002] With the growing public demand for low-carbon, environmentally friendly, energy-efficient, and high-performance products, improving the energy efficiency ratio of refrigeration equipment has become a crucial direction for the sustainable development of the refrigeration industry.

[0003] In the refrigeration industry, to reduce energy consumption, single-unit two-stage screw compressors are typically selected for refrigeration units. During compressor operation, unheated liquid refrigerant in the evaporator is drawn into the compressor cylinder along with the gas, causing liquid accumulation. Once liquid accumulation occurs in the compressor, the resulting high pressure can deform and damage the load-bearing components within the cylinder. To prevent liquid accumulation in the compressor, a gas-liquid separator is usually installed before the compressor's suction port.

[0004] Existing gas-liquid separators only separate gaseous and liquid states. The presence of liquid increases the resistance to compressor intake, affecting the compressor's cooling capacity. At the same time, gas-liquid separators do not have the ability to store liquid for heat exchange. After long-term operation, the separated liquid refrigerant accumulates more and more, which wastes refrigerant and may still lead to liquid slugging.

[0005] In view of this, it is necessary to improve the existing liquid return heat exchanger to solve the above problems. Utility Model Content

[0006] The purpose of this invention is to provide a liquid return heat exchange device to solve the problem that existing gas-liquid separators can only perform gas-liquid separation and cannot achieve liquid storage and heat exchange.

[0007] To achieve the above objectives, this utility model discloses a liquid return heat exchange device, which includes:

[0008] A tube body, wherein the tube body is placed vertically; An upper tube sheet and a lower tube sheet are disposed within the tube body, with the upper tube sheet located above the lower tube sheet. The upper tube sheet and the lower tube sheet divide the tube body into an upper cavity, a middle cavity, and a lower cavity. The heat exchange tube is at least one in number, and the upper and lower ends of the heat exchange tube are respectively connected to the upper cavity and the lower cavity; The tube body is provided with a liquid inlet communicating with the lower cavity, a liquid outlet communicating with the upper cavity, and an air inlet and an air outlet communicating with the middle cavity. The air outlet is located above the air inlet. Liquid refrigerant enters the lower cavity from the liquid inlet and enters the upper cavity through the heat exchange tube. The liquid refrigerant in the heat exchange tube exchanges heat with the gaseous refrigerant entering the middle cavity from the air inlet and the liquid refrigerant in the middle cavity. The gaseous refrigerant is discharged from the air outlet.

[0009] As a further improvement of this utility model, the number of heat exchange tubes is at least two, and the liquid return heat exchange device also includes a liquid equalization plate, which is located below the lower tube sheet, and the liquid equalization plate is provided with openings corresponding to the heat exchange tubes.

[0010] As a further improvement of this utility model, the central cavity is provided with baffles arranged alternately in the vertical and radial directions.

[0011] As a further improvement of this utility model, the baffle plate adjacent to the air outlet in the vertical direction is located below the air outlet.

[0012] As a further improvement of this utility model, the baffle plate adjacent to the air inlet in the vertical direction is located above the air inlet.

[0013] As a further improvement of this utility model, the liquid return heat exchange device also includes a level gauge, the upper end of which is connected to the upper end of the middle cavity through a first connecting pipe, and the lower end of which is connected to the lower end of the middle cavity through a second connecting pipe.

[0014] As a further improvement of this utility model, an oil return port is provided on the second connecting pipe.

[0015] As a further improvement of this utility model, the liquid return heat exchange device also includes a safety valve and a pressure gauge connected to the middle cavity.

[0016] This utility model also provides a refrigeration system, which includes a condenser, a liquid receiver connected to the condenser for storing liquid refrigerant, a liquid return heat exchange device as described above, an expansion valve, an evaporator connected to the expansion valve, and a compressor. The liquid receiver is connected to the liquid inlet of the liquid return heat exchange device, the expansion valve is connected to the liquid outlet of the liquid return heat exchange device, the evaporator is connected to the air inlet of the liquid return heat exchange device, and the compressor is connected to the air outlet of the liquid return heat exchange device.

[0017] This utility model also provides a refrigeration device, which includes the refrigeration system as described above.

[0018] The beneficial effects of this utility model are: the liquid return heat exchange device, refrigeration system and refrigeration equipment of this utility model enable the unsuperheated liquid refrigerant on the low-pressure side to be fully and effectively superheated, and the liquid refrigerant on the high-pressure side to be supercooled, which greatly improves the heat exchange efficiency of the evaporator, greatly improves the refrigeration efficiency of the compressor, improves the efficiency of gas-liquid separation, and maintains the stable operation of the compressor unit while providing sufficient suction volume to the compressor, without causing liquid slugging problems. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the refrigeration system of this utility model; Figure 2 This is a schematic diagram of the liquid return heat exchange device of this utility model; Figure 3 This is a schematic diagram of the liquid refrigerant flow direction in the liquid return heat exchange device of this utility model; Figure 4 This is a schematic diagram of the gas-liquid refrigerant flow direction in the liquid return heat exchange device of this utility model. Detailed Implementation

[0020] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0021] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0023] like Figures 1 to 4 As shown, the liquid return heat exchange device 1 of this utility model includes a tube body 11, an upper tube sheet 12 and a lower tube sheet 13, and a heat exchange tube 14.

[0024] The tube 11 is placed vertically, which means it is placed vertically along the height direction. In this embodiment, the tube 11 is columnar.

[0025] The upper tube sheet 12 and the lower tube sheet 13 are disposed inside the tube body 11, with the upper tube sheet 12 located above the lower tube sheet 13. The upper tube sheet 12 and the lower tube sheet 13 divide the tube body 11 into an upper cavity 111, a middle cavity 112 and a lower cavity 113.

[0026] The upper cavity 111 and lower cavity 113 are mainly used to contain liquid refrigerant, while the middle cavity 112 is mainly used to contain gaseous and liquid refrigerant. Therefore, in this embodiment, the upper tube sheet 12 is located near the top of the tube body 11, and the lower tube sheet 13 is located near the bottom of the tube body 11, making the height of the middle cavity 112 greater than that of the upper cavity 111 and lower cavity 113. The gaseous and liquid refrigerant can be either gaseous or liquid.

[0027] The number of heat exchange tubes 14 is at least one, and the upper and lower ends of the heat exchange tube 14 are respectively connected to the upper cavity 111 and the lower cavity 113. The heat exchange tube 14 is used to transfer liquid refrigerant and at the same time complete heat exchange with the refrigerant in the external middle cavity 112. Therefore, the heat exchange tube 14 needs to be made of a material with good thermal conductivity, such as a metal material.

[0028] The tube 11 is provided with a liquid inlet 114 communicating with the lower cavity 113, a liquid outlet 115 communicating with the upper cavity 111, an air inlet 116 communicating with the middle cavity 112, and an air outlet 117. The air outlet 117 is located above the air inlet 116. Liquid refrigerant enters the lower cavity 113 from the liquid inlet 114 and enters the upper cavity 111 through the heat exchange tube 14. The liquid refrigerant in the heat exchange tube 14 exchanges heat with the gaseous and liquid refrigerant entering the middle cavity 112 from the air inlet 116 and the liquid refrigerant in the middle cavity 112. The gaseous refrigerant is discharged from the air outlet 117. The gaseous and liquid refrigerant fully exchange heat with the liquid refrigerant in the heat exchange tube 14. A small amount of liquid refrigerant remaining in the gaseous and liquid refrigerant falls into the middle cavity 112, and at the same time further exchanges heat with the liquid refrigerant in the heat exchange tube 14 to evaporate into gaseous refrigerant and be discharged from the outlet 117.

[0029] The liquid return heat exchange device 1 of this invention, by setting up a heat exchange tube 14, allows the high-temperature liquid refrigerant in the heat exchange tube 14 to fully exchange heat with the liquid and gaseous refrigerants in the middle cavity 112, thereby achieving more complete gas-liquid separation. The liquid return heat exchange device 1 of this invention allows the unsuperheated liquid refrigerant on the low-pressure side to be stored in the second cavity, where it undergoes sufficient and effective superheating before returning to the system. The liquid refrigerant on the high-pressure side can be subcooled, significantly improving the heat exchange efficiency of the evaporator 5, significantly improving the refrigeration efficiency of the compressor 6, and improving the efficiency of gas-liquid separation. This provides the compressor 6 with sufficient suction capacity while maintaining the stable operation of the compressor unit 6.

[0030] In this embodiment, the number of heat exchange tubes 14 is at least two, and the liquid return heat exchange device 1 further includes a liquid distribution plate 15 located below the lower tube sheet 13. The liquid distribution plate 15 has openings corresponding to the heat exchange tubes 14. In this embodiment, liquid refrigerant is transferred through multiple heat exchange tubes 14, thereby improving the efficiency of heat exchange. The liquid distribution plate 15 ensures that the liquid refrigerant in the lower cavity 113 can uniformly enter each heat exchange tube 14. More specifically, the multiple heat exchange tubes 14 are arranged in a circumferential array.

[0031] In this embodiment, the central cavity 112 is provided with baffles 16 arranged alternately in the vertical and radial directions. The gaseous and liquid refrigerant from the evaporator 5 enters the central cavity 112 through the inlet 116. Due to the obstruction of the staggered baffles 16, the liquid refrigerant remains in the lower part of the central cavity 112, while the gaseous refrigerant flows upwards. The remaining liquid refrigerant evaporates into gaseous refrigerant through heat exchange with the liquid refrigerant in the heat exchange tube 14, and merges with the previously separated gaseous refrigerant, entering the suction port of the compressor 6 through the outlet 117 for further compression and circulation. The baffles 16 improve the gas-liquid separation rate, prevent liquid refrigerant from entering the compressor 6, and avoid liquid slugging.

[0032] The baffle 16 adjacent to the outlet 117 in the vertical direction is located below the outlet 117 and on the side close to the outlet 117. The baffle 16 can minimize the discharge of liquid refrigerant from the outlet 117.

[0033] The baffle plate 16 adjacent to the air inlet 116 in the vertical direction is located above the air inlet 116 and on the side close to the air inlet 116. The baffle plate 16 can maximize the separation of gaseous refrigerant and liquid refrigerant, and multiple baffle plates 16 can extend the transmission path of gaseous and liquid refrigerant.

[0034] The liquid return heat exchange device 1 also includes a level gauge 17. The upper end of the level gauge 17 is connected to the upper end of the middle cavity 112 via a first connecting pipe 171, and the lower end of the level gauge 17 is connected to the lower end of the middle cavity 112 via a second connecting pipe 172. The level gauge 17 is exposed to the outside, and the liquid level in the tube 11 is level with the liquid level in the level gauge 17, which is convenient for the user to observe. If the liquid level in the tube 11 is too high, it may affect the refrigerant gas-liquid separation effect, and manual intervention is required. The first connecting pipe 171 is located below the gas outlet 117.

[0035] The second connecting pipe 172 is provided with an oil return port 173, and the oil in the pipe body 11 can be discharged from the oil return port 173. This setting extends the maintenance cycle of the equipment in the low superheat refrigeration system 100, improves the oil return effect, and enhances the system safety.

[0036] In this embodiment, the liquid return heat exchanger 1 further includes a safety valve 18 and a pressure gauge 19 connected to the central cavity 112. The safety valve 18 can monitor the air pressure inside the central cavity 112. The safety valve 18 releases pressure when there is high pressure to prevent excessive pressure from damaging the liquid return heat exchanger 1.

[0037] This embodiment also provides a refrigeration system 100, including a condenser 2, a liquid receiver 3 connected to the condenser 2 for storing liquid refrigerant, a liquid return heat exchange device 1, an expansion valve 4, an evaporator 5 connected to the expansion valve 4, and a compressor 6. The liquid receiver 3 is connected to the liquid inlet 114 of the liquid return heat exchange device 1, the expansion valve 4 is connected to the liquid outlet 115 of the liquid return heat exchange device 1, the evaporator 5 is connected to the air inlet 116 of the liquid return heat exchange device 1, and the compressor 6 is connected to the air outlet 117 of the liquid return heat exchange device 1.

[0038] The working process of the refrigeration system 100 is as follows: After being compressed by compressor 6, the high-temperature and high-pressure gaseous refrigerant enters condenser 2 for cooling. After cooling, the liquid refrigerant enters liquid return heat exchange device 1 through liquid receiver 3, enters heat exchange tube 14 from lower cavity 113 for heat exchange and subcooling, and then enters expansion valve 4 through liquid outlet 115 of upper cavity 111 for throttling.

[0039] The refrigerant then enters the evaporator 5 for evaporation. The liquid and gaseous refrigerant from the evaporator 5 then enter the middle cavity 112 of the liquid return heat exchanger 1 through the inlet 116. Blocked by the staggered baffles 16, the liquid refrigerant flows to the lower middle part of the middle cavity 112, while the gaseous refrigerant continues to flow upwards. The remaining liquid refrigerant evaporates into gaseous refrigerant through heat exchange with the heat exchange tube 14, merges with the previously separated gaseous refrigerant, and together they enter the suction port of the compressor 6 through the outlet 117 for another compression cycle.

[0040] The refrigeration equipment of this utility model includes a refrigeration system 100.

[0041] The liquid return heat exchange device 1, refrigeration system 100, and refrigeration equipment of this utility model enable the unsuperheated liquid refrigerant on the low-pressure side to be fully and effectively superheated, and the liquid refrigerant on the high-pressure side to be supercooled, which greatly improves the heat exchange efficiency of the evaporator 5, greatly improves the refrigeration efficiency of the compressor 6, improves the efficiency of gas-liquid separation, and maintains the stable operation of the compressor 6 group while providing sufficient suction volume to the compressor 6, without causing liquid slugging problems.

[0042] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0043] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A liquid return heat exchanger, characterized in that: The liquid return heat exchanger includes: A tube body, wherein the tube body is placed vertically; An upper tube sheet and a lower tube sheet are disposed within the tube body, with the upper tube sheet located above the lower tube sheet. The upper tube sheet and the lower tube sheet divide the tube body into an upper cavity, a middle cavity, and a lower cavity. The heat exchange tube is at least one in number, and the upper and lower ends of the heat exchange tube are respectively connected to the upper cavity and the lower cavity; The tube body is provided with a liquid inlet communicating with the lower cavity, a liquid outlet communicating with the upper cavity, and an air inlet and an air outlet communicating with the middle cavity. The air outlet is located above the air inlet. Liquid refrigerant enters the lower cavity from the liquid inlet and enters the upper cavity through the heat exchange tube. The liquid refrigerant in the heat exchange tube exchanges heat with the gaseous refrigerant entering the middle cavity from the air inlet and the liquid refrigerant in the middle cavity. The gaseous refrigerant is discharged from the air outlet.

2. The liquid return heat exchanger according to claim 1, characterized in that: The number of heat exchange tubes is at least two, and the liquid return heat exchange device also includes a liquid equalization plate, which is located below the lower tube sheet, and the liquid equalization plate is provided with openings corresponding to the heat exchange tubes.

3. The liquid return heat exchanger according to claim 1, characterized in that: The central cavity is equipped with baffles arranged alternately in the vertical and radial directions.

4. The liquid return heat exchanger according to claim 3, characterized in that: The baffle plate adjacent to the air outlet in the vertical direction is located below the air outlet.

5. The liquid return heat exchanger according to claim 3, characterized in that: The baffle plate adjacent to the air inlet in the vertical direction is located above the air inlet.

6. The liquid return heat exchanger according to claim 1, characterized in that: The liquid return heat exchange device also includes a level gauge, the upper end of which is connected to the upper end of the middle cavity through a first connecting pipe, and the lower end of which is connected to the lower end of the middle cavity through a second connecting pipe.

7. The liquid return heat exchanger according to claim 6, characterized in that: The second connecting pipe has an oil return port.

8. The liquid return heat exchanger according to claim 1, characterized in that: The liquid return heat exchange device also includes a safety valve and a pressure gauge connected to the central cavity.

9. A refrigeration system, characterized in that: The refrigeration system includes a condenser, a liquid receiver connected to the condenser for storing liquid refrigerant, a liquid return heat exchange device as described in any one of claims 1-8, an expansion valve, an evaporator connected to the expansion valve, and a compressor. The liquid receiver is connected to the liquid inlet of the liquid return heat exchange device, the expansion valve is connected to the liquid outlet of the liquid return heat exchange device, the evaporator is connected to the air inlet of the liquid return heat exchange device, and the compressor is connected to the air outlet of the liquid return heat exchange device.

10. A refrigeration device, characterized in that: The refrigeration equipment includes the refrigeration system as described in claim 9.

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