Heat exchangers and air conditioning units

Abstract

The present invention provides a heat exchanger and an air conditioning unit. The heat exchanger includes a shell, a liquid balancing structure, and an air return pipe. The air return pipe is arranged in the shell, one end of the air return pipe is connected to the exhaust port, and the other end of the air return pipe is connected to the inside of the shell. The liquid balancing structure is sleeved on the outer periphery of the air return pipe. The heat exchanger and air conditioning unit provided by the present invention, by providing multiple liquid balancing structures and multiple heat exchange mechanisms, and adopting a coil structure to effectively increase the length of the heat exchange tube, thereby increasing the falling film evaporation effect, and the vertical shell greatly increases the gravitational potential difference. At the same time, since the air return channel is arranged in the middle of the heat exchange mechanism, the heat exchanger structure is compact, and the liquid blocking pipe can effectively prevent the circulation of droplets, further avoiding the problem of air suction carrying liquid in the heat exchanger, and effectively improving the falling film heat exchange effect of the heat exchanger.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchange equipment, in particular to a heat exchanger and an air conditioning unit. Background Art

[0002] In the field of refrigeration, the common mainstream shell and tube evaporators are mainly flooded evaporators, dry evaporators, and falling film evaporators. Among them, the falling film evaporator, as a new type of high-efficiency and energy-saving equipment, 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 equalizers and other devices to spread the liquid refrigerant evenly outside the heat exchange tube to ensure the heat transfer efficiency. However, since the path of the droplets falling is opposite to the path of the gaseous refrigerant after evaporation, it is easy to carry droplets to the outlet during the process of the gaseous refrigerant rising to the outlet, resulting in the problem of suction liquid. This becomes more obvious especially after the miniaturization design of the horizontal falling film evaporator. The reduction of the shell further reduces the gas flow channel, and the shortening of the vertical distance weakens the gravitational potential difference, increasing the risk of suction liquid. The problems of small vertical height and uneven falling film are prominent. Summary of the invention

[0003] In order to solve the technical problem of unreliable falling film heat exchange in the prior art horizontal falling film heat exchanger, a heat exchanger and an air conditioning unit with good liquid distribution effect and high heat exchange efficiency are provided.

[0004] A heat exchanger, comprising:

[0005] A shell, wherein the upper end of the shell is provided with a liquid inlet and an exhaust port, the lower end of the shell is provided with a liquid outlet, and the interior of the shell is provided with a plurality of falling film zones from the upper end to the lower end;

[0006] a liquid balancing structure, the liquid balancing structure being arranged inside the shell, the liquid balancing structure being multiple, and at least one liquid balancing structure being arranged in the falling film region;

[0007] An air return pipe is arranged in the shell, one end of the air return pipe is connected to the exhaust port, the other end of the air return pipe is connected to the inside of the shell, and the liquid equalizing structure is sleeved on the outer periphery of the air return pipe.

[0008] The air return pipe is located in the middle of the shell.

[0009] The heat exchanger further comprises a heat exchange mechanism, and the heat exchange mechanism is arranged between the return air pipe and the shell.

[0010] The air return pipe includes a plurality of interconnected pipeline sections, the liquid equalizing structure is inserted between two adjacent pipeline sections, and a first distance exists between the pipeline section at the upper layer and the liquid equalizing structure.

[0011] The liquid equalizing structure between two adjacent pipeline sections includes a connected liquid equalizing plate and a liquid blocking tube. The liquid equalizing plate is located between the two pipeline sections. The liquid blocking tube extends into the pipeline section at the upper layer. There is an air return gap between the liquid blocking tube and the pipeline section.

[0012] The liquid balancing structure comprises a liquid balancing plate, on which a plurality of dripping holes are arranged. On the same liquid balancing plate, the total area of ​​all the dripping holes is greater than the flow area of ​​the liquid inlet.

[0013] The cross section of the liquid balancing plate is V-shaped, U-shaped or oblique L-shaped, and the dripping hole is located at the lowest point of the liquid balancing plate.

[0014] The drip holes of two adjacent liquid balancing plates are staggered.

[0015] A liquid baffle is provided between the liquid equalizing structure and the liquid inlet, the liquid baffle is sleeved on the air return pipe, and a liquid passing hole is provided on the liquid baffle.

[0016] The distance from the liquid passage hole to the corresponding surface of the air return pipe is smaller than the distance from the dripping hole to the corresponding surface of the air return pipe.

[0017] The total area of ​​all the liquid holes is smaller than the area of ​​the liquid inlet.

[0018] Among the two adjacent liquid equalizing plates, the liquid equalizing plate at the lower layer is provided with a liquid blocking tube, the liquid blocking tube extends into the corresponding pipeline section, and there is an air return gap between the liquid blocking tube and the inner surface of the pipeline section.

[0019] The pipeline section is provided with an air return hole, and the falling film zone is communicated with the air return gap through the air return hole.

[0020] Along the direction from the liquid outlet to the exhaust port, the air return gap gradually decreases.

[0021] The heat exchange mechanism comprises a heat exchange coil, which is disposed around the pipeline section and the shell, and the upper end of the heat exchange coil constitutes a water inlet, and the lower end of the heat exchange coil constitutes a water outlet.

[0022] The pipeline section is provided with air return holes, and all the air return holes are located below the water outlets of the corresponding heat exchange coils.

[0023] All of the heat exchange coils are arranged in series; or, all of the heat exchange coils are arranged in parallel.

[0024] There is a third distance between the lower end of the pipeline section at the lowest layer and the liquid outlet.

[0025] Along the direction from the liquid outlet to the exhaust port, the flow area of ​​the pipeline section gradually decreases; or, the flow area of ​​the pipeline section at the lower layer is larger than the flow area of ​​the pipeline section at the upper layer.

[0026] The total area of ​​the dripping holes on the liquid equalizing plate in the upper layer is greater than the total area of ​​the dripping holes on the liquid equalizing plate in the lower layer.

[0027] The number of the pipeline sections, the number of the heat exchange mechanisms, and the number of the liquid equalizing structures are all two.

[0028] An air conditioning unit comprises the above-mentioned heat exchanger.

[0029] The heat exchanger and air conditioning unit provided by the present invention, by providing multiple liquid balancing structures and multiple heat exchange mechanisms, and adopting a coil structure to effectively increase the length of the heat exchange tube, thereby increasing the falling film evaporation effect, and at the same time greatly increasing the gravity potential difference by utilizing the height of the shell. At the same time, since the return air channel is arranged in the middle of the heat exchange mechanism, the heat exchanger structure is compact, and the liquid blocking pipe can effectively prevent the flow of droplets, further avoiding the problem of air intake carrying liquid in the heat exchanger, and effectively improving the falling film heat exchange effect of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a heat exchanger according to an embodiment of the present invention;

[0031] Figure 2 A cross-sectional view of a heat exchanger according to an embodiment of the present invention;

[0032] Figure 3 A partial schematic diagram of the liquid inlet of the heat exchanger of an embodiment provided by the present invention;

[0033] Figure 4 A schematic diagram of the structure of a liquid balancing plate according to an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of the structure of a liquid balancing plate and a liquid blocking tube according to an embodiment of the present invention;

[0035] Figure 6 A schematic structural diagram of a pipeline section of an embodiment provided by the present invention;

[0036] In the figure:

[0037] 1. Shell; 11. Liquid inlet; 12. Exhaust port; 13. Liquid outlet; 3. Pipeline section; 4. Heat exchange mechanism; 2. Liquid equalizing plate; 14. Falling film area; 21. First spacing; 22. Drip hole; 5. Liquid retaining plate; 51. Liquid passage hole; 31. Return air hole; 6. Liquid retaining pipe; 61. Return air gap; 7. Third spacing. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] like Figures 1 to 6 The heat exchanger shown includes: a shell 1, wherein a liquid inlet 11 and an exhaust port 12 are provided at the upper end of the shell 1, a liquid outlet 13 is provided at the lower end of the shell 1, and a plurality of falling film zones are provided from the upper end to the lower end of the interior of the shell; a liquid equalizing structure, wherein the liquid equalizing structure is provided inside the shell, and there are a plurality of liquid equalizing structures, and at least one liquid equalizing structure is provided in the falling film zone; a return air pipe, wherein the return air pipe is provided inside the shell, one end of the return air pipe is connected to the exhaust port, and the other end of the return air pipe is connected to the interior of the shell, and the liquid equalizing structure is sleeved on the outer periphery of the return air pipe.

[0040] The liquid refrigerant enters the shell 1 from the liquid inlet 11, passes through all the liquid-equalizing structures in sequence, and exchanges heat with the corresponding heat exchange structure after passing through each liquid-equalizing structure. The gaseous refrigerant generated after the heat exchange enters the return air channel, and finally all the gaseous refrigerant is discharged through the exhaust port 12, and the remaining liquid refrigerant is discharged from the shell 1 through the liquid outlet 13. By providing multiple liquid-equalizing structures and multiple heat exchange mechanisms 4, the heat exchange effect of the liquid refrigerant is increased, and the pipeline section 3 is provided on the inner side of the heat exchange mechanism 4, so that the heat exchanger structure is compact, which is conducive to miniaturization of the heat exchanger.

[0041] The air return pipe is located in the middle of the shell. Preferably, the axis of the air return pipe is colinear with the axis of the shell.

[0042] The heat exchanger further comprises a heat exchange mechanism, and the heat exchange mechanism is arranged between the return air pipe and the shell.

[0043] The return air pipe includes a plurality of interconnected pipe sections, the liquid balancing structure is inserted between two adjacent pipe sections, and a first spacing is provided between the pipe section at the upper layer and the liquid balancing structure. The first spacing 21 enables the falling film area 14 to be connected to the return air channel, and because the fluid resistance at the first spacing 21 is small, the gaseous refrigerant generated by heat exchange in the falling film area 14 can flow downward along the overall flow field in the falling film area 14, and finally flow back to the return air channel through the first spacing 21.

[0044] The liquid equalizing structure between two adjacent pipeline sections includes a connected liquid equalizing plate and a liquid blocking tube, wherein the liquid equalizing plate is located between the two pipeline sections, and the liquid blocking tube extends into the pipeline section on the upper layer, and there is a return air gap between the liquid blocking tube and the pipeline section. By setting the liquid blocking tube 6, the path of the gaseous refrigerant entering the return air channel is shielded to a certain extent, so that the liquid refrigerant in the gaseous refrigerant can be collected by the liquid blocking tube 6 under the blocking effect of the liquid blocking tube 6 and flow to the liquid equalizing plate 2 on the lower layer, which effectively overcomes the problem of return air carrying liquid in the existing heat exchanger.

[0045] The liquid balancing structure includes a liquid balancing plate 2, and a plurality of drip holes 22 are arranged on the liquid balancing plate 2. On the same liquid balancing plate 2 (preferably the uppermost liquid balancing plate 2), the total area of ​​all the drip holes 22 is greater than the flow area of ​​the liquid inlet 11. Preferably, the total area of ​​all the drip holes 22 on the same liquid balancing plate 2 is 1.05 to 1.2 times the flow area of ​​the liquid inlet 11, so as to avoid the accumulation of liquid refrigerant on the liquid balancing plate 2 and affect the heat exchange effect of the heat exchanger.

[0046] The cross section of the liquid balancing plate 2 is V-shaped, U-shaped or oblique L-shaped, and the dripping hole 22 is located at the lowest point of the liquid balancing plate 2. The shape of the liquid balancing plate 2 is used to collect the liquid refrigerant at the liquid inlet 11 or the liquid refrigerant dripping from the upper side, thereby ensuring the liquid balancing effect of the liquid balancing plate 2.

[0047] The drip holes 22 of two adjacent liquid balancing plates 2 are staggered. That is, the axis of the drip hole 22 of the upper liquid balancing plate 2 is not in the same straight line as the axis of the drip hole 22 of the lower liquid balancing plate 2, thereby ensuring that the liquid balancing plate 2 can collect the liquid refrigerant to a certain extent, ensuring that the liquid output of each drip hole 22 of the liquid balancing plate 2 is basically the same, thereby ensuring the heat exchange effect of the heat exchanger.

[0048] A liquid baffle plate 5 is provided between the liquid balancing structure and the liquid inlet 11, the return air channel is connected to the exhaust port 12 through the middle of the liquid baffle plate 5, and a liquid hole 51 is provided on the liquid baffle plate 5. The liquid baffle plate 5 is used to prevent the liquid refrigerant in the liquid inlet 11 from directly impacting the uppermost liquid balancing structure and affecting the liquid balancing effect of the liquid balancing structure. At the same time, the liquid baffle plate 5 can also distribute the liquid refrigerant to a certain extent, so that the liquid refrigerant received by each position of the liquid balancing structure is basically the same, thereby further increasing the liquid balancing effect of the liquid balancing structure.

[0049] The distance between the liquid-passing hole 51 and the corresponding surface of the return air pipe is smaller than the distance between the dripping hole 22 and the corresponding surface of the return air pipe. That is, on the projection of the shell 1, the projection of the liquid-passing hole 51 is located inside the projection of the dripping hole 22, so as to prevent the refrigerant of the liquid-passing hole 51 from directly dripping through the dripping hole 22 instead of passing through the liquid-distributing structure, thereby ensuring the liquid-distributing effect of the liquid-distributing structure.

[0050] The total area of ​​all the liquid holes 51 is smaller than the area of ​​the liquid inlet 11 , which means that part of the liquid refrigerant is accumulated above the liquid baffle plate 5 , so that all the liquid holes 51 are in a full flow state, thereby increasing the uniform distribution effect of the liquid baffle plate 5 .

[0051] The pipeline section 3 is provided with an air return hole 31, and the falling film area 14 is connected to the air return gap 61 through the air return hole 31. The air return hole 31 is used to make the gaseous refrigerant in the falling film area 14 flow back to the air return gap 61 and finally flow back to the air return channel.

[0052] Along the direction from the liquid outlet 13 to the exhaust port 12, the return air gap 61 gradually decreases, that is, the liquid blocking tube 6 is trumpet-shaped, further increasing the reflux effect of the liquid refrigerant.

[0053] Optionally, the liquid retaining tube 6 includes a straight tube section and a gradually expanding section. The straight tube section is used to increase the size of the liquid retaining tube 6, and the gradually expanding section is used to increase the collection effect of fine liquid droplets.

[0054] The gradually expanding section may be obtained by bending the upper edge of the straight pipe section toward the outside of the liquid retaining tube 6 .

[0055] Preferably, the cross section of the gradually expanding section is an arc with the center located outside the liquid blocking tube 6 .

[0056] The heat exchange mechanism 4 includes a heat exchange coil, which is disposed between the pipeline section 3 and the shell 1, and the upper end of the heat exchange coil constitutes a water inlet, and the lower end of the heat exchange coil constitutes a water outlet. The effective heat exchange length of the heat exchange tube is increased by arranging the heat exchange coil, thereby increasing the heat exchange effect of the heat exchange mechanism 4 on the liquid refrigerant.

[0057] The pipeline section 3 is provided with air return holes 31, and all the air return holes 31 are located below the water outlet of the corresponding heat exchange coil, so as to avoid the heat exchange coil interfering with the air return holes 31 and affecting the flow of gaseous refrigerant into the air return channel.

[0058] All of the heat exchange coils are arranged in series; or, all of the heat exchange coils are arranged in parallel.

[0059] There is a third distance 7 between the lower end of the pipeline section 3 at the bottom layer and the liquid outlet 13. Preferably, the third distance 7 is not less than 100 mm to avoid affecting the remaining liquid refrigerant.

[0060] During the heat exchange process, as the liquid refrigerant gradually decreases, the required space of the falling film area 14 also gradually decreases. Therefore, the size of the pipeline section 3 can be appropriately increased to reduce the size of the falling film area 14, that is, along the direction from the liquid outlet 13 to the exhaust port 12, the flow area of ​​the pipeline section 3 gradually decreases; or, the flow area of ​​the pipeline section 3 at the lower layer is larger than the flow area of ​​the pipeline section 3 at the upper layer. The adjacent two pipeline sections 3 are guided and connected by corresponding liquid baffles 5.

[0061] During the heat exchange process, as the liquid refrigerant gradually decreases, in order to ensure the liquid balancing effect of each layer of the liquid balancing plate 2, the total area of ​​the drip holes 22 on the liquid balancing plate 2 in the upper layer is greater than the total area of ​​the drip holes 22 on the liquid balancing plate 2 in the lower layer. Preferably, the total area of ​​the drip holes 22 of the liquid balancing plate 2 in the lower layer is 0.6 to 0.9 times the total area of ​​the drip holes 22 of the liquid balancing plate 2 in the upper layer.

[0062] The number of the pipeline sections 3, the number of the heat exchange mechanisms 4, and the number of the liquid equalizing structures are all two.

[0063] An air conditioning unit comprises the above-mentioned heat exchanger.

[0064] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A heat exchanger, characterized in that: include: A shell (1), wherein the upper end of the shell (1) is provided with a liquid inlet (11) and an exhaust port (12), the lower end of the shell (1) is provided with a liquid outlet (13), and the interior of the shell (1) is provided with a plurality of falling film zones from the upper end to the lower end; a liquid balancing structure, the liquid balancing structure being arranged inside the shell (1), the liquid balancing structure being multiple, and at least one liquid balancing structure being arranged in the falling film zone; An air return pipe is arranged in the shell, one end of the air return pipe is connected to the exhaust port, the other end of the air return pipe is connected to the inside of the shell, and the liquid equalizing structure is sleeved on the outer periphery of the air return pipe.

2. The heat exchanger according to claim 1, characterized in that: The air return pipe is located in the middle of the shell.

3. The heat exchanger according to claim 2, characterized in that: The heat exchanger further comprises a heat exchange mechanism (4), and the heat exchange mechanism (4) is arranged between the return air pipe and the shell (1).

4. The heat exchanger according to claim 3, characterized in that: The air return pipe comprises a plurality of interconnected pipeline sections (3), the liquid equalizing structure being inserted between two adjacent pipeline sections (3), and a first distance being provided between the pipeline section (3) at the upper layer and the liquid equalizing structure.

5. The heat exchanger according to claim 4, characterized in that: The liquid equalizing structure between two adjacent pipeline sections (3) comprises a connected liquid equalizing plate (2) and a liquid blocking tube (6); the liquid equalizing plate (2) is located between the two pipeline sections (3); the liquid blocking tube (6) extends into the pipeline section (3) located at the upper layer; and an air return gap (61) is provided between the liquid blocking tube (6) and the pipeline section (3).

6. The heat exchanger according to claim 1, characterized in that: The liquid balancing structure comprises a liquid balancing plate (2), on which a plurality of dripping holes (22) are arranged, and on the same liquid balancing plate (2), the total area of ​​all the dripping holes (22) is greater than the flow area of ​​the liquid inlet (11).

7. The heat exchanger according to claim 6, characterized in that: The cross section of the liquid balancing plate (2) is V-shaped, U-shaped or oblique L-shaped, and the dripping hole (22) is located at the lowest point of the liquid balancing plate (2).

8. The heat exchanger according to claim 6, characterized in that: The drip holes (22) of two adjacent liquid balancing plates (2) are arranged in a staggered manner.

9. The heat exchanger according to claim 6, characterized in that: A liquid baffle plate (5) is provided between the liquid equalizing structure and the liquid inlet (11); the liquid baffle plate (5) is sleeved on the air return pipe; and a liquid passage hole (51) is provided on the liquid baffle plate (5).

10. The heat exchanger according to claim 9, characterized in that: The distance from the liquid passage hole (51) to the corresponding surface of the air return pipe is smaller than the distance from the dripping hole (22) to the corresponding surface of the air return pipe.

11. The heat exchanger according to claim 9, characterized in that: The total area of ​​all the liquid passage holes (51) is smaller than the area of ​​the liquid inlet (11).

12. The heat exchanger according to claim 5, characterized in that: The pipeline section (3) is provided with an air return hole (31), and the falling film zone (14) is connected to the air return gap (61) through the air return hole (31).

13. The heat exchanger according to claim 5, characterized in that: Along the direction from the liquid outlet (13) to the exhaust port (12), the air return gap (61) gradually decreases.

14. The heat exchanger according to claim 12, characterized in that: The heat exchange mechanism (4) comprises a heat exchange coil, and the heat exchange coil is arranged in a surrounding manner on the pipeline section (3).

15. The heat exchanger according to claim 14, characterized in that: The pipeline section (3) is provided with air return holes (31), and all the air return holes (31) are located below the water outlets of the corresponding heat exchange coils.

16. The heat exchanger according to claim 14, characterized in that: All of the heat exchange coils are arranged in series; or, all of the heat exchange coils are arranged in parallel.

17. The heat exchanger according to claim 5, characterized in that: There is a third distance (7) between the lower end of the pipeline section (3) at the lowest layer and the liquid outlet (13).

18. The heat exchanger according to claim 5, characterized in that: Along the direction from the liquid outlet (13) to the exhaust port (12), the flow area of ​​the pipeline section (3) gradually decreases; or, the flow area of ​​the pipeline section (3) at the lower layer is greater than the flow area of ​​the pipeline section (3) at the upper layer.

19. The heat exchanger according to claim 6, characterized in that: The total area of ​​the dripping holes (22) on the liquid balancing plate (2) in the upper layer is greater than the total area of ​​the dripping holes (22) on the liquid balancing plate (2) in the lower layer.

20. The heat exchanger according to claim 5, characterized in that: The number of the pipeline sections (3), the number of the heat exchange mechanisms (4), and the number of the liquid equalizing structures are all two.

21. An air conditioning unit, characterized in that: A heat exchanger comprising any one of claims 1 to 20.

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