High-efficiency heat exchangers and air conditioning units

Abstract

This invention provides a heat exchanger and air conditioning unit with high subcooling efficiency. The heat exchanger includes a shell, a baffle structure, and a liquid spray structure. The inlet of the liquid spray structure is connected to the liquid refrigerant in the cooling chamber, and the outlet of the liquid spray structure is connected to the subcooling chamber. A heat exchange tube extends into the subcooling chamber, and a liquid outlet is connected to the subcooling chamber. The heat exchanger and air conditioning unit with high subcooling efficiency provided by this invention utilize nozzles to flash saturated liquid refrigerant into a saturated vapor-liquid two-phase mixed refrigerant. The gaseous refrigerant exchanges heat with the heat exchange tube in the subcooling chamber and condenses into liquid refrigerant. At this point, the condensed liquid refrigerant has a lower saturation temperature than before flashing, thereby increasing the subcooling degree of the refrigerant. After flashing, the refrigerant undergoes another phase change, heat exchange, and condensation, without requiring a large temperature difference or controlling the refrigerant flow rate. Compared to the existing technology that uses baffles, this effectively increases the subcooling efficiency of the refrigerant.

Description

Technical Field

[0001] This invention relates to the field of heat exchange equipment technology, and in particular to a heat exchanger and air conditioning unit with high subcooling efficiency. Background Technology

[0002] Large commercial air conditioning units typically use shell-and-tube condensers as key equipment for cooling high-temperature gaseous refrigerant. Through heat exchange tubes, the cooling fluid medium exchanges heat with the high-temperature gaseous refrigerant compressed by the compressor, cooling it and ultimately transforming it into a saturated liquid refrigerant. The saturated liquid refrigerant then enters a subcooling device for further temperature reduction, ultimately becoming a saturated liquid refrigerant capable of evaporative cooling. In this process, by increasing the subcooling of the liquid refrigerant to achieve a lower temperature liquid refrigerant, the cooling capacity of the air conditioning system can be improved, and the unit's energy efficiency can be increased. Current subcooling structures are divided into external subcooling and internal subcooling. Internal subcooling structures are integrated into the heat exchanger and have higher safety and practical value than independent external subcooling devices. However, existing internal subcooling technologies all adopt a structure similar to a baffle at the bottom of the heat exchanger, which, together with the subcooling tube area at the bottom of the condenser, further cools and heats the liquid refrigerant. However, this method only performs heat exchange on the liquid refrigerant and is limited by the flow rate of the refrigerant side, the need for sufficient contact with the heat exchange tube surface, and the requirement for multiple deflections in the baffle structure. This results in poor subcooling efficiency and low subcooling degree. Summary of the Invention

[0003] To address the low efficiency of existing heat exchangers using baffle structures for subcooling, a phase change subcooling method is provided, which utilizes nozzles to flash liquid refrigerant into gaseous refrigerant for heat exchange, thereby increasing subcooling efficiency and degree. This results in a heat exchanger and air conditioning unit with high subcooling efficiency.

[0004] A heat exchanger, comprising:

[0005] A housing, wherein a liquid outlet is provided on the housing;

[0006] A partition structure is disposed inside the housing, and the partition structure divides the interior of the housing into a cooling chamber and a subcooling chamber;

[0007] The liquid spraying structure has an inlet connected to the liquid refrigerant in the cooling chamber and an outlet connected to the subcooling chamber.

[0008] A heat exchange tube, which passes through the subcooling chamber;

[0009] The liquid outlet is connected to the subcooling chamber.

[0010] The liquid spraying structure includes a liquid spraying channel and a nozzle. The liquid spraying channel is located inside the subcooling chamber, and the first end of the liquid spraying channel is connected to the cooling chamber. The second end of the liquid spraying channel is provided with a sealing element, and the nozzle is located on the side wall of the liquid spraying channel.

[0011] The number of nozzles is multiple, and all the nozzles are evenly distributed along the length of the liquid spraying channel.

[0012] The liquid spraying structure includes a support member, a liquid inlet is provided on the partition structure, the support member is disposed in the subcooling cavity, and a flow groove is formed on the support member. The opening of the flow groove is sealed with the inner surface of the shell to form the liquid spraying channel, and one end of the flow groove is connected to the liquid inlet, and the other end of the flow groove is provided with the sealing member.

[0013] The cross-section of the flow channel is trapezoidal, and the nozzle is disposed on the upper base of the trapezoid.

[0014] The partition structure includes a top plate and a side plate. The top plate forms the top surface of the subcooling cavity, and the side plate forms one side of the subcooling cavity. The first end of the liquid spraying channel passes through the side plate and communicates with the cooling cavity.

[0015] The nozzle is provided on the side plate.

[0016] The partition structure also includes a connector with a U-shaped cross-section. The top plate is connected to the first edge of the connector, and the side plate is connected to the second edge of the connector.

[0017] A beveled edge structure is provided at the connection between the side plate and the second edge of the connector, and the nozzle is disposed on the beveled edge structure.

[0018] The nozzle includes at least two pressure-reducing sections and one diffuser section. All the pressure-reducing sections are connected in sequence along the fluid flow direction, and the diffuser section is connected to the pressure-reducing section located at the last stage.

[0019] Along the direction of fluid flow, the flow area of ​​all the pressure-reducing sections gradually decreases.

[0020] An air conditioning unit includes the heat exchanger described above.

[0021] The heat exchanger and air conditioning unit with high subcooling efficiency provided by this invention utilizes nozzles to flash saturated liquid refrigerant into a saturated vapor-liquid two-phase mixed refrigerant. The gaseous refrigerant exchanges heat with the heat exchange tubes in the subcooling chamber and condenses into liquid refrigerant. At this time, the condensed liquid refrigerant has a lower saturation temperature than before flashing, thereby increasing the subcooling degree of the refrigerant. After flashing, the refrigerant undergoes phase change, heat exchange, and condensation again, without requiring a large temperature difference or control of the refrigerant flow rate. Compared with the method of setting baffles in the prior art, this effectively increases the subcooling efficiency of the refrigerant. Attached Figure Description

[0022] Figure 1 A schematic diagram of the structure of the heat exchanger in an embodiment of the high subcooling efficiency heat exchanger and air conditioning unit provided by the present invention;

[0023] Figure 2 A schematic diagram of the baffle structure and the jet structure of an embodiment of the heat exchanger and air conditioning unit with high subcooling efficiency provided by the present invention;

[0024] Figure 3 A side view of the baffle structure and the injection structure of an embodiment of the heat exchanger and air conditioning unit with high subcooling efficiency provided by the present invention;

[0025] Figure 4 A cross-sectional view of the nozzle of an embodiment of the heat exchanger and air conditioning unit with high subcooling efficiency provided by the present invention;

[0026] In the picture:

[0027] 1. Shell; 11. Liquid outlet; 2. Baffle structure; 12. Cooling chamber; 13. Subcooling chamber; 4. Heat exchange tube; 31. Liquid spray channel; 32. Nozzle; 5. Support component; 21. Top plate; 22. Side plate; 23. Connecting component; 321. Pressure reduction section; 322. Pressure diffuser section. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0029] like Figures 1 to 4The heat exchanger shown includes: a shell 1 with a liquid outlet 11; a partition structure 2 disposed inside the shell 1, dividing the interior of the shell 1 into a cooling chamber 12 and a subcooling chamber 13; a liquid spray structure, the inlet of which is connected to the liquid refrigerant in the cooling chamber 12, and the outlet of which is connected to the subcooling chamber 13; and heat exchange tubes 4 passing through the subcooling chamber 13, wherein the heat exchange tubes 4 passing through the subcooling chamber 13 may be completely inside the subcooling chamber 13, or partially inside the subcooling chamber 13 with the remaining portion inside the cooling chamber 12; the liquid outlet 11 is connected to the subcooling chamber 13, and gaseous refrigerant enters the cooling chamber 12 through the air inlet of the shell 1, exchanges heat with the heat exchange tubes 4 in the cooling chamber 12, condenses to form liquid refrigerant, and accumulates at the bottom of the shell 1, thus forming a liquid refrigerant region in the lower half of the shell 1. The liquid refrigerant in the region undergoes flashing action through the spray structure to form a vapor-liquid two-phase mixed refrigerant, which enters the subcooling chamber 13. The gaseous refrigerant in the vapor-liquid two-phase mixed refrigerant exchanges heat with the heat exchange tubes 4 within the subcooling chamber 13, resulting in phase change condensation. After condensation, it mixes with the liquid refrigerant in the vapor-liquid two-phase mixed refrigerant, thus obtaining a liquid refrigerant with a lower saturation temperature than the liquid refrigerant region. This liquid refrigerant is then discharged from the shell 1 through the liquid outlet 11, completing the heat exchange and subcooling of the gaseous refrigerant. Because the gaseous refrigerant enters the cooling chamber 12 through the air inlet of the shell 1, it increases the pressure inside the cooling chamber 12, thereby forcing the liquid refrigerant in the liquid refrigerant area to flash through the spray structure and enter the subcooling chamber 13 and finally flow out through the liquid outlet 11. A water chamber is formed at the end of the shell 1. The heat exchange tubes 4 in the cooling chamber 12 and the heat exchange tubes 4 in the subcooling chamber 13 are both connected to the water chamber, and the cooling water in the water chamber is introduced into the corresponding structure to exchange heat with the gaseous refrigerant.

[0030] The liquid spraying structure includes a liquid spraying channel 31 and a nozzle 32. The liquid spraying channel 31 is disposed inside the subcooling chamber 13, and the first end of the liquid spraying channel 31 is connected to the cooling chamber 12. The second end of the liquid spraying channel 31 is provided with a sealing element. The nozzle 32 is disposed on the side wall of the liquid spraying channel 31. The liquid spraying channel 31 is used to guide the liquid refrigerant in the liquid refrigerant area to the inlet of the nozzle 32, and at the same time facilitates the arrangement of the nozzle 32. The liquid refrigerant in the liquid refrigerant area enters the liquid spraying channel 31 from the first end of the liquid spraying channel 31. Due to the pressure of the gaseous refrigerant entering the cooling chamber 12 and the sealing effect of the sealing element at the second end of the liquid spraying channel 31, the liquid refrigerant can only be sprayed and flashed by the nozzle 32, ensuring the reliability of the liquid spraying structure.

[0031] The number of nozzles 32 is multiple, and all the nozzles 32 are evenly distributed along the length direction of the liquid spraying channel 31. Preferably, the arrangement direction of the nozzles 32 is the same as the length direction of the heat exchange tube 4. In particular, the spraying direction of the nozzles 32 is towards the heat exchange tube 4, thereby maximizing the contact area between the gaseous refrigerant in the gas-liquid two-phase mixed refrigerant after the nozzles 32 flash and the heat exchange tube 4, thereby increasing the subcooling degree and subcooling efficiency of the refrigerant.

[0032] The liquid spraying structure includes a support member 5. A liquid inlet is provided on the partition structure 2. The support member 5 is disposed within the subcooling chamber 13, and a flow groove is formed on the support member 5. The opening of the flow groove is sealed to the inner surface of the housing 1 to form the liquid spraying channel 31. One end of the flow groove communicates with the liquid inlet, and the other end of the flow groove is provided with a sealing member. That is, the support member 5 is disposed on the inner surface of the housing 1, and the opening of the flow groove is sealed to the inner surface of the housing 1 to form the liquid spraying channel 31. Preferably, the support member 5 is disposed on the inner surface of the housing 1. The bottom of the body 1 is such that the liquid spray channel 31 is located at the lowest point of the housing 1, facilitating the entry of liquid refrigerant from the liquid refrigerant area into the liquid spray channel 31. At the same time, one end of the flow channel is connected to the liquid inlet, allowing the liquid refrigerant to flow smoothly into the flow channel. Meanwhile, a seal is provided at the other end of the flow channel to prevent the liquid refrigerant from flowing into the subcooling chamber 13 through the flow channel and failing to flash. Preferably, one end of the flow channel penetrates the corresponding side of the support member 5 to allow the liquid refrigerant to enter, while the other end of the flow channel does not penetrate the support member 5, thus effectively providing a seal.

[0033] The cross-section of the flow channel is trapezoidal, and the nozzle 32 is disposed on the upper base of the trapezoid. The upper base of the trapezoid provides an installation position for the nozzle 32, allowing the nozzle 32 to be installed on a plane, thus ensuring the sealing and reliability of the installation. At the same time, the liquid refrigerant in the gas-liquid two-phase mixed refrigerant formed by the flashing of the nozzle 32 and the liquid refrigerant formed by condensation after heat exchange with the heat exchange tube 4 can flow along the inclined side of the trapezoid to the bottom of the subcooling chamber 13, avoiding the liquid refrigerant from affecting the heat exchange efficiency of the gaseous refrigerant, and allowing the liquid refrigerant in the subcooling chamber 13 to flow out smoothly through the liquid outlet 11.

[0034] Specifically, the inner surface of the housing 1 forms the lower base of the trapezoid.

[0035] The partition structure 2 includes a top plate 21 and a side plate 22. The top plate 21 forms the top surface of the subcooling cavity 13, and the side plate 22 forms one side of the subcooling cavity 13. The first end of the liquid spraying channel 31 passes through the side plate 22 and communicates with the cooling cavity 12. Preferably, the cross-section of the partition structure 2 is L-shaped, so that a smaller subcooling cavity 13 can be formed inside the shell 1, avoiding the subcooling cavity 13 from affecting the heat exchange efficiency of the cooling cavity 12. At the same time, the side plate 22 facilitates the installation of the spraying structure. It is only necessary to open an inlet in the part of the side plate 22 below the liquid refrigerant surface to introduce the liquid refrigerant into the spraying channel, simplifying the structural complexity of the partition structure 2 and the spraying structure.

[0036] The side plate 22 is provided with the nozzle 32. When the amount of liquid refrigerant in the cooling chamber 12 is too large and exceeds the amount of liquid refrigerant in the nozzle 32 on the side plate 22, the nozzle 32 on the side plate 22 can spray the refrigerant at the same time to increase the amount of refrigerant entering the subcooling chamber 13.

[0037] The partition structure 2 also includes a connector 23. The connector 23 has a U-shaped cross-section. The top plate 21 is connected to the first edge of the connector 23, and the side plate 22 is connected to the second edge of the connector 23. The connector 23 is used to change the pressure direction at the connection between the top plate 21 and the side plate 22, so that the liquid refrigerant can enter the injection channel better.

[0038] A beveled edge structure is provided at the connection between the side plate 22 and the second edge of the connector 23. The nozzle 32 is disposed on the beveled edge structure, providing an installation position for the nozzle 32 and increasing the reliability of the nozzle 32. The liquid level of the liquid refrigerant in the cooling chamber 12 is not lower than the inlet of the nozzle 32 on the beveled edge structure, thereby ensuring that the nozzle 32 can also work normally. The liquid level of the liquid refrigerant in the cooling chamber 12 can be obtained according to the refrigerant filling amount of the heat exchanger.

[0039] The nozzle 32 includes at least two pressure-reducing sections 321 and one diffuser section 322. All the pressure-reducing sections 321 are connected in sequence along the fluid flow direction, and the diffuser section 322 is connected to the pressure-reducing section 321 located at the last stage. That is, after the liquid refrigerant enters the nozzle 32, it passes through all the pressure-reducing sections 321 in sequence and is finally discharged from the nozzle 32 through the diffuser section 322. When the liquid refrigerant enters the pressure-reducing section 321, the pressure change is caused by the rapid change in the cross-sectional area of ​​the adjacent pressure-reducing sections 321, which creates a pressure difference. Under the action of the pressure difference, the liquid refrigerant flashes to form a gas-liquid two-phase mixed refrigerant. Due to the presence of the diffuser section 322, the gas-liquid two-phase mixed refrigerant will further diffuse, which can better exchange heat with the heat exchange tube 4.

[0040] Along the flow direction of the fluid (liquid refrigerant), the flow area of ​​all the pressure-reducing sections 321 gradually decreases, such as... Figure 4 The nozzle inlet corresponds to D1, the first pressure reducing section corresponds to D2, the second pressure reducing section corresponds to D3, and the diffuser section corresponds to D4, where D1 > D2 > D3.

[0041] An air conditioning unit includes the heat exchanger described above.

[0042] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A heat exchanger, characterized in that: include: The housing (1) is provided with a liquid outlet (11). A partition structure (2) is disposed inside the housing (1), and the partition structure (2) divides the interior of the housing (1) into a cooling chamber (12) and a subcooling chamber (13). The liquid spraying structure has an inlet connected to the liquid refrigerant in the cooling chamber (12) and an outlet connected to the subcooling chamber (13). Heat exchange tube (4) passes through the subcooling cavity (13); The liquid outlet (11) is connected to the subcooling chamber (13); The liquid spraying structure includes a liquid spraying channel (31) and a nozzle (32). The liquid spraying channel (31) is located inside the subcooling chamber (13), and the first end of the liquid spraying channel (31) is connected to the cooling chamber (12). The second end of the liquid spraying channel (31) is provided with a sealing element, and the nozzle (32) is located on the side wall of the liquid spraying channel (31). The spray structure includes a support member (5), the partition structure (2) is provided with a liquid inlet, the support member (5) is provided in the subcooling cavity (13), and a flow groove is formed on the support member (5). The opening of the flow groove is sealed with the inner surface of the shell (1) to form the spray channel (31), and one end of the flow groove is connected to the liquid inlet, and the other end of the flow groove is provided with the sealing member. The nozzle (32) includes at least two pressure-reducing sections (321) and a diffuser section (322). All the pressure-reducing sections (321) are connected in sequence along the fluid flow direction, and the diffuser section (322) is connected to the pressure-reducing section (321) located at the last stage.

2. The heat exchanger according to claim 1, characterized in that: The number of nozzles (32) is multiple, and all the nozzles (32) are evenly distributed along the length direction of the liquid spraying channel (31).

3. The heat exchanger according to claim 1, characterized in that: The cross-section of the flow channel is trapezoidal, and the nozzle (32) is disposed on the upper bottom of the trapezoid.

4. The heat exchanger according to claim 1, characterized in that: The partition structure (2) includes a top plate (21) and a side plate (22). The top plate (21) forms the top surface of the subcooling cavity (13), and the side plate (22) forms one side of the subcooling cavity (13). The first end of the liquid spray channel (31) passes through the side plate (22) and communicates with the cooling cavity (12).

5. The heat exchanger according to claim 4, characterized in that: The nozzle (32) is provided on the side plate (22).

6. The heat exchanger according to claim 5, characterized in that: The partition structure (2) also includes a connector (23), the connector (23) has a U-shaped cross section, and the top plate (21) is connected to the first edge of the connector (23), and the side plate (22) is connected to the second edge of the connector (23).

7. The heat exchanger according to claim 6, characterized in that: The side plate (22) and the connector (23) are provided with a chamfered edge structure at the second edge connection, and the nozzle (32) is provided on the chamfered edge structure.

8. The heat exchanger according to claim 1, characterized in that: Along the direction of fluid flow, the flow area of ​​all the pressure-reducing sections (321) gradually decreases.

9. An air conditioning unit, characterized in that: The heat exchanger includes any one of claims 1 to 8.

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