Heat exchangers and air conditioning equipment

Abstract

The present disclosure provides a heat exchanger and air conditioning equipment. The heat exchanger includes: a vertical shell, a refrigerant inlet is provided at the top, and a falling film area and a full liquid area are formed inside respectively; a falling film area heat exchange coil is arranged in the falling film area; a full liquid area heat exchange coil is arranged in the full liquid area; and an inner cylinder is suspended in the vertical shell, the top end of which is connected to the top of the vertical shell, and the bottom end is suspended above the full liquid area; wherein the falling film area heat exchange coil is arranged outside the inner cylinder, the top of the vertical shell is provided with a refrigerant outlet communicating with the top end of the inner cylinder, and the bottom end of the inner cylinder is communicated with the falling film area. The falling film evaporation phase change heat transfer is adopted, and the heat transfer efficiency is high. In addition, the inner cylinder is arranged in the heat exchanger as a gaseous refrigerant discharge channel, so that the gas is discharged from the top of the heat exchanger. Due to the effect of the gravitational potential difference, the occurrence of the suction liquid phenomenon is greatly reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of air-conditioning equipment, and in particular to a heat exchanger and air-conditioning equipment. Background Art

[0002] The statements herein merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] As a new type of high-efficiency and energy-saving equipment, the horizontal tube falling film evaporator is gradually replacing the flooded evaporator with its advantages such as small refrigerant filling volume, small static pressure difference, high heat exchange efficiency and convenient oil return. Unlike the flooded evaporator, the falling film evaporator needs to use liquid distributors, liquid equalizing plates and other devices to spread the liquid refrigerant evenly outside the heat exchange tube to avoid the formation of dry spots and ensure heat transfer efficiency. At the same time, the commonly used horizontal tube falling film evaporator is equipped with a full liquid area to maintain a certain liquid level in the evaporator when the unit is running. Due to the existence of the falling film area, the cross-sectional area of ​​the channel for the gaseous refrigerant to flow out of the heat exchanger is greatly reduced, which increases the flow rate of the gaseous refrigerant. Therefore, it is easy to carry liquid to the outlet, resulting in the problem of suction liquid.

[0004] These problems become more obvious after the miniaturization design of the horizontal tube falling film evaporator. The reduction of the shell further reduces the gas flow path, and the shortening of the vertical distance weakens the gravitational potential difference, increasing the risk of liquid inhalation. The reduction in the flow rate of liquid refrigerant makes it more likely to produce dry spots on the surface of the heat exchange tube, making it more difficult to distribute the liquid. Coupled with the reduction in the flow rate of the refrigerant (usually water) in the tube, the heat transfer performance will further deteriorate. Therefore, the current horizontal shell and tube evaporators in the industry (including falling film and full liquid types) can only achieve a minimum of about 100RT, which is not suitable for units with smaller cooling capacity. Therefore, these units can only use dry evaporators or shell and tube heat exchangers with lower energy efficiency. Summary of the invention

[0005] The inventors have discovered through research that the related technology has a technical problem of low heat exchange efficiency.

[0006] In view of this, the embodiments of the present disclosure provide a heat exchanger and air conditioning equipment, which can improve heat exchange efficiency.

[0007] Some embodiments of the present disclosure provide a heat exchanger, comprising:

[0008] A vertical shell, with a refrigerant inlet at the top, and falling film areas and full liquid areas formed at the top and bottom of the shell;

[0009] Falling film zone heat exchange coil, the coil is arranged in the falling film zone;

[0010] The full liquid area heat exchange coil is arranged in the full liquid area; and

[0011] The inner cylinder is suspended in the vertical shell, with its top end connected to the top of the vertical shell and its bottom end suspended above the full liquid area;

[0012] The heat exchange coil in the falling film zone is arranged outside the inner cylinder, the top of the vertical shell is provided with a refrigerant outlet communicated with the top of the inner cylinder, and the bottom of the inner cylinder is communicated with the falling film zone.

[0013] In some embodiments, the inner cylinder is located in the center of the vertical shell, the falling film zone heat exchange coil is arranged outside the inner cylinder, and the height position of the bottom end of the inner cylinder is lower than the top of the falling film zone.

[0014] In some embodiments, the height position of the bottom end of the inner cylinder is lower than the bottom of the falling film zone.

[0015] In some embodiments, the flooded heat exchange coil is disposed at the bottom of the vertical shell.

[0016] In some embodiments, it also includes a U-shaped tube arranged in the inner cylinder, one end of the U-shaped tube is provided with an air inlet connected to the top of the inner cylinder, and the other end is configured as a refrigerant outlet, and a liquid inlet hole is formed at the bottom of the U-shaped tube, and the liquid inlet hole is located in the full liquid area.

[0017] In some embodiments, an exhaust hole is provided at the bottom of the inner cylinder.

[0018] In some embodiments, the falling film zone includes an upper falling film zone and a descending film zone arranged up and down, and the falling film zone heat exchange coil includes a falling film zone heat exchange upper coil and a falling film zone heat exchange lower coil respectively arranged in the upper falling film zone and the descending film zone, and the number of inner and outer layers of the falling film zone heat exchange upper coil is greater than the number of inner and outer layers of the falling film zone heat exchange lower coil.

[0019] In some embodiments, it also includes a liquid balancing plate disposed between the upper heat exchange coil in the falling film area and the lower heat exchange coil in the falling film area, and a plurality of through holes are formed on the liquid balancing plate.

[0020] In some embodiments, it also includes a liquid distributor disposed in the vertical shell and located above the falling film zone, and the refrigerant inlet provides refrigerant to the falling film zone through the liquid distributor.

[0021] In some embodiments, the liquid distributor includes a plurality of orifice plates arranged up and down, and a plurality of openings are evenly distributed on the orifice plates.

[0022] In some embodiments, the openings on any two adjacent orifice plates are staggered in the vertical direction.

[0023] In some embodiments, it also includes a refrigerant outlet disposed at the bottom of the vertical shell, and the refrigerant outlet is communicated with the full liquid area.

[0024] Some embodiments of the present disclosure provide an air conditioning device, comprising the aforementioned heat exchanger.

[0025] Therefore, based on the above technical solution, the heat exchanger disclosed in the present invention forms a falling film area and a full liquid area on the upper and lower parts of the interior, and respectively arranges a falling film area heat exchange coil and a full liquid area heat exchange coil, adopts falling film evaporation phase change heat transfer, and has high heat exchange efficiency. In addition, an inner cylinder is arranged in the heat exchanger as a gaseous refrigerant discharge channel, so that the gas is discharged from the top of the heat exchanger. Due to the effect of the gravitational potential difference, the occurrence of the liquid-carrying phenomenon is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0027] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0028] Figure 1 is a schematic cross-sectional structural diagram of some embodiments of the heat exchanger disclosed herein;

[0029] Figure 2 is a schematic diagram of a three-dimensional cross-sectional structure of some embodiments of the heat exchanger disclosed herein;

[0030] Figure 3 It is a schematic diagram of the structure of a liquid distributor in some embodiments of the heat exchanger disclosed herein.

[0031] Description of Reference Numerals

[0032] 1. Upper heat exchange coil in falling film area; 2. Lower heat exchange coil in falling film area; 3. Heat exchange coil in full liquid area; 4. Liquid distributor; 5. Liquid equalizing tray; 6. Refrigerant inlet; 7. Refrigerant air outlet; 8. Refrigerant liquid outlet; 9. Heat exchange coil in falling film area; 10. U-shaped tube; 11. Inner cylinder; 12. Vertical shell; 13. Upper cover plate; 14. Lower cover plate; 15. Exhaust hole; 16. Air inlet; 17. Liquid inlet hole; 41. Orifice plate. DETAILED DESCRIPTION

[0033] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0034] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediate device, or may not be directly connected to the other devices but have an intermediate device.

[0036] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined as such herein.

[0037] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0038] like Figure 1 to Figure 3 As shown, some embodiments of the present disclosure provide a heat exchanger, including: a vertical shell 12, a falling film area heat exchange coil 9, a full liquid area heat exchange coil 3 and an inner cylinder 11, wherein an upper cover plate 13 and a lower cover plate 14 are respectively provided at the top and bottom of the vertical shell 12, the upper cover plate 13 is provided with a refrigerant inlet 6, and a falling film area A and a full liquid area B are formed in the upper and lower parts of the vertical shell 12 respectively; the falling film area heat exchange coil 9 is coiled in the falling film area A; the full liquid area heat exchange coil 3 is coiled in the full liquid area B; the inner cylinder 11 is suspended in the vertical shell 12, the top end of which is connected to the upper cover plate 13, and the bottom end is suspended above the full liquid area B; the falling film area heat exchange coil 9 is arranged outside the inner cylinder 11, the upper cover plate 13 is provided with a refrigerant outlet 7 communicated with the top end of the inner cylinder 11, and the bottom end of the inner cylinder 11 is communicated with the falling film area A.

[0039] The falling film zone heat exchange coil 9 and the full liquid zone heat exchange coil 3 are fixed by a pipe clamp fixed on the vertical shell 12. The refrigerant on the surface of the falling film zone heat exchange coil 9 performs falling film evaporation heat exchange, while the surface of the full liquid zone heat exchange coil 3 performs pool boiling evaporation heat exchange. The refrigerant (usually water) flows in the coil tube for heat exchange. The refrigerant flow in the coils of different falling film zones A and full liquid zones B can be parallel flow, or can be connected outside the shell to become a series flow, which can be flexibly changed according to the coil tube length and the pressure drop in the tube in different areas.

[0040] In this schematic embodiment, the heat exchanger adopts falling film evaporation phase change heat transfer with high heat exchange efficiency, and an inner cylinder 11 is provided in the heat exchanger to serve as a gaseous refrigerant discharge channel, so that the refrigerant is vaporized after heat exchange with the falling film zone heat exchange coil 9 and enters the inner cylinder 11 from the bottom end of the inner cylinder 11, and is then discharged from the top of the heat exchanger. Due to the effect of gravitational potential difference, the heat exchange efficiency is improved and the occurrence of liquid suction phenomenon is greatly reduced, and it has high feasibility.

[0041] like Figure 1 and Figure 2 As shown, in some embodiments, the inner cylinder 11 is located in the center of the vertical shell 12, the falling film zone heat exchange coil 9 is coiled outside the inner cylinder 11, and the height position of the bottom end of the inner cylinder 11 is lower than the top of the falling film zone A, so that the space layout is reasonable, the occupied space is reduced, and it has high feasibility. In some embodiments, the full liquid zone heat exchange coil 3 is coiled at the bottom of the vertical shell 12 to facilitate the discharge of liquid refrigerant; in some embodiments, the heat exchanger also includes a refrigerant outlet 8 arranged at the bottom of the vertical shell 12, and the refrigerant outlet 8 is connected to the full liquid zone B.

[0042] like Figure 1 and Figure 2 As shown, in some embodiments, the height position of the bottom end of the inner cylinder 11 is lower than the bottom of the falling film area A, so that the refrigerant can be discharged only after completely passing through the falling film area A, further improving the heat exchange efficiency and having high feasibility.

[0043] In some embodiments, the heat exchanger further comprises a U-shaped tube 10 disposed in the inner cylinder 11, one end of the U-shaped tube 10 is provided with an air inlet 16 communicating with the top of the inner cylinder 11, and the other end is configured as a refrigerant outlet 7, and a liquid inlet hole 17 is formed at the bottom of the U-shaped tube 10, and the liquid inlet hole 17 is located in the full liquid area B. All gaseous refrigerants generated by evaporation enter from the lower outlet at the bottom of the inner cylinder 11, and when flowing to the upper outlet of the inner cylinder 11, since the upper part of the inner cylinder 11 is blocked by the upper cover plate 13, the gas can only enter the U-shaped tube from the air inlet 16 of the U-shaped tube 10 to accelerate, and then flow out from the refrigerant outlet 7 of the U-shaped tube. The U-shaped tube is provided with a liquid inlet hole 17, and a part of the oil-containing liquid refrigerant is taken away from the full liquid area B of the heat exchanger through the high-speed airflow in the tube and the liquid inlet hole 17, so as to achieve the effect of oil return.

[0044] like Figure 1 As shown, in order to prevent the liquid level in the full liquid area B from being too high and causing the liquid refrigerant to seal the bottom end of the inner cylinder 11, in some embodiments, an exhaust hole 15 is provided at the bottom of the inner cylinder 11, and the gaseous refrigerant can enter the inner cylinder 11 from the exhaust hole 15 and then be discharged.

[0045] like Figure 1 and Figure 2 As shown, in some embodiments, the heat exchanger further includes a liquid distributor 4 disposed in the vertical shell 12 and located above the falling film area A, and the refrigerant inlet 6 provides refrigerant to the falling film area A through the liquid distributor 4. The liquid distributor 4 can evenly distribute the liquid refrigerant on the heat exchange coil 9 in the falling film area, thereby improving the heat dissipation efficiency and having high feasibility.

[0046] like Figure 3 As shown, in some embodiments, the liquid distributor 4 includes a multi-layer orifice plate 41 arranged up and down, and a plurality of openings are evenly distributed on the orifice plate 41. After the flow is evenly distributed through the orifice plate, it flows evenly from the outlet of the liquid distributor to the falling film zone heat exchange coil 9 of the falling film zone A. The structure is simple and easy to implement. In some embodiments, the openings on any two adjacent orifice plates 41 are staggered in the vertical direction to further improve the uniform distribution performance.

[0047] In some embodiments, the aperture of the orifice plate 41 is 1 mm to 6 mm. In some embodiments, the aperture of the non-exit orifice plate is 2.5 mm; the aperture of the outlet orifice plate is 3 mm. In some embodiments, the number of orifice plate layers is 2 to 5. In some embodiments, the spacing between adjacent orifice plates 41 is 5 mm to 40 mm. In some embodiments, the spacing between adjacent orifice plates 41 is 20 mm.

[0048] like Figure 1 As shown, in some embodiments, the falling film zone includes an upper falling film zone A1 and a descending film zone A2 arranged up and down, and the falling film zone heat exchange coil 9 includes a falling film zone heat exchange upper coil 1 and a falling film zone heat exchange lower coil 2 arranged in the upper falling film zone A1 and the descending film zone A2 respectively, the falling film zone heat exchange upper coil 1 is located above the falling film zone heat exchange lower coil 2, and the number of inner and outer layers of the falling film zone heat exchange upper coil 1 is greater than the number of inner and outer layers of the falling film zone heat exchange lower coil 2. The coil lengths, numbers of turns, and numbers of inner and outer layers of different falling film zones A and full liquid zones may be different. The number of inner and outer layers of the falling film zone heat exchange upper coil 1 is greater than the number of inner and outer layers of the falling film zone heat exchange lower coil 2. For example, the number of inner and outer layers of the falling film zone heat exchange upper coil 1 is 2, and the number of inner and outer layers of the falling film zone heat exchange lower coil 2 is 1, thereby realizing gradient heat exchange and improving heat exchange efficiency. In some embodiments, such as Figure 1 and Figure 2 As shown, the number of inner and outer layers of the heat exchange coil 3 in the full liquid area is 2.

[0049] In some embodiments, the heat exchanger also includes a liquid balancing plate 5 arranged between the upper heat exchange coil 1 in the falling film area and the lower heat exchange coil 2 in the falling film area. A plurality of through holes are formed on the liquid balancing plate 5. The liquid balancing plate 5 can evenly arrange the liquid refrigerant on the lower heat exchange coil 2 in the falling film area, thereby improving the heat dissipation efficiency and having high feasibility.

[0050] Below Figure 1 to Figure 3 The working process of the heat exchanger disclosed in the present invention is described by taking the embodiment shown as an example as follows:

[0051] In the refrigeration condition, the heat exchanger acts as an evaporator, the refrigerant liquid outlet 8 is closed, and the refrigerant gas outlet 7 is opened. Figure 1 As shown, the liquid refrigerant (which may also be mixed with a certain amount of gaseous refrigerant) enters the liquid distributor 4 from the refrigerant inlet 6 for liquid distribution. After the orifice plate is evenly distributed, it flows out from the outlet of the liquid distributor 4 evenly to the falling film area heat exchange coil 9. The remaining liquid refrigerant that has not been completely evaporated after heat exchange flows to the full liquid area B and is heated and boiled by the full liquid area heat exchange coil 3. All gaseous refrigerants produced by evaporation enter from the lower outlet of the inner cylinder 11. When flowing to the upper outlet of the inner cylinder 11, since the upper part of the inner cylinder 11 is welded to the upper cover plate 13, the gas can only enter the U-shaped tube 10 from the air inlet 16 of the U-shaped tube 10 to accelerate and then flow out from the refrigerant outlet of the U-shaped tube. The U-shaped tube is provided with a liquid inlet hole 17, and a part of the oil-containing liquid refrigerant is taken away by the high-speed airflow in the tube and the liquid inlet hole, and flows out of the heat exchanger to achieve the effect of oil return.

[0052] Under heating conditions, the heat exchanger acts as a condenser, the refrigerant liquid outlet 8 is opened, the refrigerant gas outlet 7 is closed, and the gaseous refrigerant enters from the refrigerant inlet 6, exchanges heat with the coil surface and condenses. The condensed liquid flows to the full liquid area B and flows out from the refrigerant liquid outlet 8. The flow of the refrigerant is consistent with the refrigeration condition.

[0053] Some embodiments of the present disclosure provide an air conditioning device, including the aforementioned heat exchanger. The air conditioning device also has the above-mentioned beneficial technical effects.

[0054] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0055] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A heat exchanger, characterized in that: include: A vertical shell (12) is provided with a refrigerant inlet (6) at the top, and a falling film area (A) and a full liquid area (B) are formed at the top and bottom of the shell; A falling film zone heat exchange coil (9), which is arranged in the falling film zone (A); A liquid-filled area heat exchange coil (3), which is arranged in the liquid-filled area (B); An inner cylinder (11) is suspended in the vertical shell (12), with its top end connected to the top of the vertical shell (12) and its bottom end suspended above the full liquid area (B); as well as A U-shaped tube (10) is arranged in the inner cylinder (11), one end of the U-shaped tube (10) is provided with an air inlet (16) which is in communication with the top end of the inner cylinder (11), and the other end is configured as a refrigerant air outlet (7), a liquid inlet hole (17) is formed at the bottom of the U-shaped tube (10), and the liquid inlet hole (17) is located in the full liquid area (B), The falling film zone heat exchange coil (9) is arranged outside the inner cylinder (11), the refrigerant outlet (7) is arranged at the top of the vertical shell (12), and the refrigerant outlet (7) is communicated with the top end of the inner cylinder (11), and the bottom end of the inner cylinder (11) is communicated with the falling film zone (A).

2. The heat exchanger according to claim 1, characterized in that: The inner cylinder (11) is located at the center of the vertical shell (12), the falling film zone heat exchange coil (9) is arranged outside the inner cylinder (11), and the height position of the bottom end of the inner cylinder (11) is lower than the top of the falling film zone (A).

3. The heat exchanger according to claim 2, characterized in that: The height position of the bottom end of the inner cylinder (11) is lower than the bottom of the falling film zone (A).

4. The heat exchanger according to claim 1, characterized in that: The full liquid area heat exchange coil (3) is arranged at the bottom of the vertical shell (12).

5. The heat exchanger according to claim 1, characterized in that: An exhaust hole (15) is provided at the bottom of the inner cylinder (11).

6. The heat exchanger according to claim 2, characterized in that: The falling film zone (A) comprises an upper falling film zone (A1) and a descending film zone (A2) arranged in upper and lower parts, and the falling film zone heat exchange coil (9) comprises a falling film zone heat exchange upper coil (1) and a falling film zone heat exchange lower coil (2) respectively arranged in the upper falling film zone (A1) and the descending film zone (A2), and the number of inner and outer layers of the falling film zone heat exchange upper coil (1) is greater than the number of inner and outer layers of the falling film zone heat exchange lower coil (2).

7. The heat exchanger according to claim 6, characterized in that It also comprises a liquid balancing plate (5) arranged between the falling film zone heat exchange upper coil (1) and the falling film zone heat exchange lower coil (2), wherein a plurality of through holes are formed on the liquid balancing plate (5).

8. The heat exchanger according to claim 1, characterized in that It also includes a liquid distributor (4) arranged in the vertical shell (12) and located above the falling film area, and the refrigerant inlet (6) provides refrigerant to the falling film area (A) through the liquid distributor (4).

9. The heat exchanger according to claim 8, characterized in that The liquid distributor (4) comprises a plurality of orifice plates (41) arranged vertically, with a plurality of openings evenly distributed on the orifice plates (41).

10. The heat exchanger according to claim 9, characterized in that The openings on any two adjacent perforated plates (41) are arranged in a staggered manner in the vertical direction.

11. The heat exchanger according to claim 1, characterized in that It also includes a refrigerant liquid outlet (8) arranged at the bottom of the vertical shell (12), and the refrigerant liquid outlet (8) is communicated with the full liquid area (B).

12. An air conditioning device, characterized in that: A heat exchanger comprising any one of claims 1 to 11.

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