Shell and tube heat exchanger and heat exchange system

Abstract

The utility model provides a shell and tube heat exchanger and a heat exchange system. The shell and tube heat exchanger comprises a shell. A liquid separation structure; and all the heat exchange pipes are arranged in the heat exchange cavity, and all the heat exchange pipes are divided into a first flow group, a second flow group and a third flow group in the height direction. According to the shell and tube heat exchanger and the heat exchange system, liquid separation of the liquid separation structure can guarantee the heat exchange efficiency of a gaseous working medium in the first flow set, meanwhile, liquid working medium in the tube pass is discharged in time, the heat transfer performance of the tube pass is improved, bubbles can be generated at the second flow set in the heat exchange process, and the heat exchange efficiency is improved. Bubbles can flow upwards to pass through the first flow group to generate additional disturbance on liquid around the first flow group, so that heat exchange of an upper tube bundle is strengthened, the shell side tube bundle effect is fully utilized to strengthen shell side heat exchange, and the overall heat transfer performance and heat exchange efficiency of the shell and tube heat exchanger are effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchange structures, in particular to a shell-and-tube heat exchanger and a heat exchange system. Background Art

[0002] The cascade refrigeration cycle system can greatly broaden the refrigeration or heating range, realize the cascade utilization of heat and cold, and can give full play to the performance advantages of each temperature zone through different refrigerant combinations in the high-temperature section and the low-temperature section to achieve energy conservation and meet the application requirements of special occasions. It is widely used in the fields of low-temperature refrigeration and high-temperature heat pumps. In the cascade system, the condensing evaporator is the core heat exchange module connecting the high-temperature section and the low-temperature section. It is both the condenser of the low-temperature section and the evaporator of the high-temperature section.

[0003] As a commonly used heat exchanger, the shell-and-tube heat exchanger has the advantages of simple structure, low cost, high safety, etc. Applying it to the cascade system as a condensing evaporator can improve the stability of the system and reduce the manufacturing cost. There are two forms of shell-and-tube condensing evaporators: one is condensation in the shell side and evaporation in the tube side; the other is evaporation in the shell side and condensation in the tube side. Both methods have their own advantages and disadvantages. Since phase changes occur on both sides, the actual situation needs to be compared and analyzed in combination with the types of heat transfer working fluids on both sides and the specific heat exchange working conditions to select the most suitable heat exchange form.

[0004] However, in the existing shell-and-tube heat exchangers, during the condensation inside the tube, the liquid film generated by the condensation inside the tube and the decrease in the flow velocity inside the tube will both cause the heat transfer coefficient inside the tube to gradually decrease, seriously affecting the heat exchange efficiency of the heat exchanger. Summary of the Utility Model

[0005] In order to solve the technical problem that the liquid refrigerant generated inside the heat exchange tube in the prior art will generate a liquid film and reduce the refrigerant flow velocity, thereby affecting the heat exchange efficiency of the heat exchanger, a shell-and-tube heat exchanger and a heat exchange system are provided, which use a liquid separation structure to separate the liquid refrigerant in the tube side to improve the heat exchange efficiency.

[0006] A shell-and-tube heat exchanger includes:

[0007] A shell, the shell having a left water chamber, a right water chamber, and a heat exchange chamber located between the left water chamber and the right water chamber;

[0008] A liquid separation structure, the liquid separation structure is arranged in the right water chamber, and the liquid separation structure divides the right water chamber into a liquid separation chamber and a liquid storage chamber;

[0009] Multiple heat exchange tubes, all the heat exchange tubes are arranged in the heat exchange chamber, and all the heat exchange tubes are divided into a first flow group, a second flow group, and a third flow group along the height direction;

[0010] In the first process group, the first end of the heat exchange tube communicates with the left water chamber, and the second end communicates with the liquid separation chamber;

[0011] In the second process group, the first end of the heat exchange tube communicates with the air inlet structure, and the second end communicates with the liquid separation chamber;

[0012] In the third process group, the first end of the heat exchange tube communicates with the left water chamber, and the second end communicates with the liquid storage chamber.

[0013] The liquid separation structure includes a liquid separation plate. The liquid separation plate divides the right water chamber into the liquid separation chamber and the liquid storage chamber, and the liquid separation plate is located between the second process group and the third process group. Liquid separation holes are provided on the liquid separation plate, and the liquid separation chamber and the liquid storage chamber communicate through the liquid separation holes.

[0014] The plane where the liquid separation plate is located forms an angle with the outflow direction of the heat exchange tube in the second process group.

[0015] The liquid separation plate includes a horizontal portion and an inclined portion. The inclined portion is provided on the side of the horizontal portion away from the heat exchange chamber, and the inclined portion inclines towards the first process group relative to the horizontal portion. The liquid separation holes are provided on the horizontal portion.

[0016] The air inlet structure is arranged in the left water chamber. An air inlet chamber is formed in the air inlet structure. The air inlet chamber is relatively sealed with the internal space of the left water chamber. The first end of the heat exchange tube in the second process group communicates with the air inlet chamber.

[0017] The air inlet structure divides the left water chamber into a first liquid storage chamber and a second liquid storage chamber. The first end of the heat exchange tube in the first process group communicates with the first liquid storage chamber, and the first end of the heat exchange tube in the third process group communicates with the second liquid storage chamber.

[0018] A liquid outlet is provided on the left water chamber, and the liquid outlet communicates with both the first liquid storage chamber and the second liquid storage chamber.

[0019] The air inlet structure includes an upper sealing plate and a lower sealing plate. Both the upper sealing plate and the lower sealing plate are sealingly matched with the inner wall of the left water chamber. The left water chamber above the upper sealing plate forms the first liquid storage chamber, the left water chamber between the upper sealing plate and the lower sealing plate forms the air inlet chamber, and the left water chamber below the lower sealing plate forms the second liquid storage chamber.

[0020] A liquid outlet is provided on the left water chamber, and a liquid passing channel is provided on the air inlet structure. The liquid passing channel is relatively sealed with the air inlet chamber, and the first liquid storage chamber and the second liquid storage chamber communicate through the liquid passing channel. The liquid outlet communicates with the second liquid storage chamber.

[0021] The intake structure further includes side seal plates. The upper seal plate, the lower seal plate and the side seal plates together enclose the intake cavity. A first liquid return port is provided on the upper seal plate located outside the intake cavity, and a second liquid return port is provided on the lower seal plate located outside the intake cavity.

[0022] The intake structure further includes a liquid passing pipe. A first liquid return port is provided on the upper seal plate, and a second liquid return port is provided on the lower seal plate. One end of the liquid passing pipe communicates with the first liquid storage cavity through the first liquid return port, and the other end communicates with the second liquid storage cavity through the second liquid return port.

[0023] The intake structure further includes a flow equalizing plate. The flow equalizing plate is arranged in the intake cavity, and the flow equalizing plate is located between the intake port of the intake cavity and the second process group. A plurality of flow equalizing holes are evenly distributed on the flow equalizing plate.

[0024] The cross-section of the flow equalizing plate is V-shaped, and the apex angle of the V shape points to the intake port.

[0025] The number P1 of the heat exchange tubes in the first process group is 20%-35% of the total number P of all the heat exchange tubes; and / or, the number P2 of the heat exchange tubes in the second process group is 55-65% of the total number P of all the heat exchange tubes; and / or, the number P3 of the heat exchange tubes in the third process group is 10%-15% of the total number P of all the heat exchange tubes.

[0026] The distance between two adjacent heat exchange tubes in the first process group is greater than the distance between two adjacent heat exchange tubes in the second process group.

[0027] Fins are provided on at least part of the outer wall of the heat exchange tube.

[0028] The cross-section of the fin is T-shaped.

[0029] Internal teeth are provided on at least part of the inner wall of the heat exchange tube.

[0030] The internal teeth are distributed in a spiral shape.

[0031] In the first process group, the angle range of the spiral angle β of the internal teeth on the heat exchange tube is 30°≤β≤70°; and / or, in the second process group, the angle range of the spiral angle β of the internal teeth on the heat exchange tube is 30°≤β≤70°; and / or, in the third process group, the angle range of the spiral angle β of the internal teeth on the heat exchange tube is β≤3°.

[0032] A heat exchange system includes the above shell-and-tube heat exchanger.

[0033] The shell-and-tube heat exchanger and heat exchange system provided by the present utility model divide the heat exchange tubes into three groups along the height direction, and the inlet gas in the tube side first flows through the second process group located in the middle for heat exchange. Then, a liquid separation structure is used to separate the unexchanged gaseous working medium and the exchanged liquid working medium in the second process group. The gaseous working medium can flow into the first process group for heat exchange again. At this time, there is less liquid working medium in the first process group, which can ensure the heat exchange efficiency. The separated liquid working medium can directly flow back along the third process group, and after converging with the liquid working medium that has completed heat exchange in the first process group in the left water chamber, it is discharged, completing the heat exchange process of the tube side. The liquid separation of the liquid separation structure can ensure the heat exchange efficiency of the gaseous working medium in the first process group, and at the same time, timely discharge the liquid working medium in the tube side, improving the heat transfer performance of the tube side. Moreover, during the heat exchange process, bubbles will be generated at the second process group. The bubbles will flow upward and pass through the first process group to generate additional disturbance to the liquid around the first process group, thereby strengthening the heat exchange of the upper tube bundle and making full use of the tube bundle effect on the shell side to strengthen the heat exchange on the shell side, effectively improving the overall heat transfer performance and heat exchange efficiency of the shell-and-tube heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of the shell-and-tube heat exchanger provided by an embodiment of the present utility model;

[0035] Figure 2 is a side view of the shell-and-tube heat exchanger provided by an embodiment of the present utility model;

[0036] Figure 3 is a cross-sectional view of the shell-and-tube heat exchanger provided by an embodiment of the present utility model;

[0037] Figure 4 is another cross-sectional view of the shell-and-tube heat exchanger provided by an embodiment of the present utility model;

[0038] Figure 5 is a schematic structural diagram of the right water chamber and liquid separation structure of the shell-and-tube heat exchanger provided by an embodiment of the present utility model;

[0039] Figure 6 is a schematic structural diagram of the liquid separation structure of the shell-and-tube heat exchanger provided by an embodiment of the present utility model;

[0040] Figure 7 is a cross-sectional view of the right water chamber and liquid separation structure of the shell-and-tube heat exchanger provided by an embodiment of the present utility model;

[0041] Figure 8 is a schematic structural diagram of the right water chamber and liquid separation structure of the shell-and-tube heat exchanger provided by an embodiment of the present utility model;

[0042] Figure 9 is a cross-sectional view of the left water chamber and air inlet structure of the shell-and-tube heat exchanger provided by an embodiment of the present utility model;

[0043] Figure 10 Another cross-sectional view of the left water chamber and the air inlet structure of the shell-and-tube heat exchanger provided by the embodiment of the present utility model;

[0044] Figure 11 Schematic structural diagram of the air inlet structure of the shell-and-tube heat exchanger provided by the embodiment of the present utility model;

[0045] Figure 12 Schematic structural diagram of the upper sealing plate of the shell-and-tube heat exchanger provided by the embodiment of the present utility model;

[0046] Figure 13 Schematic structural diagram of the lower sealing plate of the shell-and-tube heat exchanger provided by the embodiment of the present utility model;

[0047] Figure 14 Cross-sectional view of the air inlet structure of the shell-and-tube heat exchanger provided by the embodiment of the present utility model;

[0048] Figure 15 Stereogram of the liquid distribution plate of the shell-and-tube heat exchanger provided by the embodiment of the present utility model;

[0049] Figure 16 Cross-sectional view of the liquid distribution plate of the shell-and-tube heat exchanger provided by the embodiment of the present utility model;

[0050] In the figure:

[0051] 1. Shell; 11. Left water chamber; 12. Right water chamber; 13. Heat exchange chamber; 2. Liquid distribution structure; 14. Liquid distribution chamber; 15. Liquid storage chamber; 3. Heat exchange tube; 31. First process group; 32. Second process group; 33. Third process group; 21. Horizontal part; 22. Inclined part; 4. Air inlet structure; 41. Air inlet chamber; 16. First liquid return chamber; 17. Second liquid return chamber; 18. Liquid outlet; 42. Upper sealing plate; 43. Lower sealing plate; 44. Liquid passing pipe; 45. Flow equalizing plate; 34. Fins; 35. Inner teeth; 19. Liquid inlet. Detailed implementation manners

[0052] In order to make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model 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 only used to explain the present utility model and are not used to limit the present utility model.

[0053] To enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0054] It should be noted that the terms "first", "second", etc. in the description and claims of the present utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances for the embodiments of the present utility model described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0055] It should be noted that in the description of the present utility model, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0056] In addition, it should also be noted that in the description of the present utility model, unless otherwise clearly specified and defined, the terms "installation", "setting", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0057] As a commonly used heat exchanger, the shell-and-tube heat exchanger has the advantages of simple structure, low cost, high safety, etc. Applying it in a cascade system as a condensing evaporator can improve the stability of the system and reduce the manufacturing cost. There are two forms of shell-and-tube condensing evaporators: one is condensation in the shell side and evaporation in the tube side; the other is evaporation in the shell side and condensation in the tube side. Both methods have their own advantages and disadvantages. Since phase changes occur on both sides, the actual situation needs to be compared and analyzed in combination with the types of heat transfer working fluids on both sides and the specific heat transfer conditions to select the most suitable heat transfer form. However, in the existing shell-and-tube heat exchangers, as the condensation process progresses, the proportion of the liquid phase of the working fluid in the tube gradually increases, that is, the gas dryness gradually decreases along the flow direction of the tube length, and the liquid volume gradually increases. The increasing amount of condensed liquid leads to an increasingly thick liquid film layer in the tube. Since the heat transfer from the gaseous refrigerant in the tube to the outside needs to pass through the liquid film layer, the gradually thickening liquid film layer caused by the accumulation of condensate leads to a gradual decrease in the heat transfer in the tube. The liquid film generated by the condensation in the tube and the decrease in the flow velocity in the tube will both cause the heat transfer coefficient in the tube to gradually decrease, seriously affecting the heat transfer efficiency of the heat exchanger.

[0058] For this reason, the present application provides a kind of as Figures 1 to 16The shell-and-tube heat exchanger shown includes: a shell 1, the shell 1 having a left water chamber 11, a right water chamber 12, and a heat exchange chamber 13 located between the left water chamber 11 and the right water chamber 12; a liquid separation structure 2, the liquid separation structure 2 being disposed within the right water chamber 12, and the liquid separation structure 2 dividing the right water chamber 12 into a liquid separation chamber 14 and a liquid storage chamber 15; a plurality of heat exchange tubes 3, all of the heat exchange tubes 3 being disposed within the heat exchange chamber 13, and all of the heat exchange tubes 3 being divided into a first flow group 31, a second flow group 32, and a third flow group 33 along the height direction; in the first flow group 31, a first end of the heat exchange tube 3 communicates with the left water chamber 11, and a second end communicates with the liquid separation chamber 14; in the second flow group 32, a first end of the heat exchange tube 3 communicates with an air inlet structure 4, and a second end communicates with the liquid separation chamber 14; in the third flow group 33, a first end of the heat exchange tube 3 communicates with the left water chamber 11, and a second end communicates with the liquid storage chamber 15. The heat exchange tubes 3 are divided into three groups along the height direction, and the inlet air in the tube side first flows through the second flow group 32 located in the middle for heat exchange. Then, the liquid separation structure 2 separates the unexchanged gaseous working medium and the heat-exchanged liquid working medium in the second flow group 32. The gaseous working medium can flow into the first flow group 31 for heat exchange again. At this time, the first flow group 31 can maintain a relatively high dryness and flow rate, and the heat exchange performance of the heat exchange tubes 3 in this part can be greatly improved, ensuring the heat exchange efficiency. The separated liquid working medium can directly flow back along the third flow group 33 and converge with the heat-exchanged liquid working medium in the first flow group 31 in the left water chamber 11 and then be discharged, completing the heat exchange process in the tube side. The liquid separation of the liquid separation structure 2 can ensure the heat exchange efficiency of the gaseous working medium in the first flow group 31, and at the same time, timely discharge the liquid working medium in the tube side, improving the heat transfer performance of the tube side. Moreover, during the heat exchange process, bubbles will be generated at the second flow group 32, and the bubbles will flow upward and pass through the first flow group 31 to generate additional disturbance to the liquid around the first flow group 31, thereby strengthening the heat exchange of the upper tube bundle and making full use of the tube bundle effect on the shell side to strengthen the heat exchange on the shell side, effectively improving the overall heat transfer performance and heat exchange efficiency of the shell-and-tube heat exchanger.

[0059] As an implementation manner, the liquid separation structure 2 includes a liquid separation plate which divides the right water chamber 12 into a liquid separation chamber 14 and a liquid storage chamber 15. The liquid separation plate is located between the second process group 32 and the third process group 33. The liquid separation plate is provided with liquid separation holes through which the liquid separation chamber 14 and the liquid storage chamber 15 communicate. The gaseous working medium that needs to flow through the tube side will directly flow into the second process group 32 and exchange heat inside the heat exchange tubes 3 in the second process group 32. During this process, part of the gaseous working medium will condense into a liquid state, and part of the gaseous working medium does not exchange heat. Finally, both the liquid working medium and the gaseous working medium are discharged from the second process group 32 and reach the liquid separation plate. Due to the action of gravity, the liquid working medium will flow into the liquid storage chamber 15 through the liquid separation holes, while the gaseous working medium will flow towards the area in the liquid separation chamber 14 away from the liquid storage chamber 15. Since the first process group 31 is located above the second process group 32, the gaseous working medium in the liquid separation chamber 14 can flow into the first process group 31 and exchange heat and condense again through the part of the first process group 31 located in the heat exchange chamber 13, and finally completely liquefy to form a liquid working medium and flow into the left water chamber 11. At the same time, the third process group 33 is connected to the liquid storage chamber 15 and the left water chamber 11, so that the liquid working medium separated in the liquid storage chamber 15 can flow back to the left water chamber 11 along the heat exchange tubes 3 of the third process group 33. The liquid working medium passing through the first process group 31 and the liquid working medium passing through the third process group 33 are mixed in the left water chamber 11 and then discharged, completing the entire heat exchange process of the tube side. At this time, the gaseous working medium flowing into the shell and tube heat exchanger can be completely liquefied. Compared with the prior art in which the gaseous working medium and the liquid working medium flow mixed in the heat exchange tubes 3, the heat exchange efficiency of the shell and tube heat exchanger is effectively improved.

[0060] The plane where the liquid separation plate is located forms an angle with the outflow direction of the heat exchange tubes 3 of the second process group 32. By setting the angle, the mixture of the gaseous working medium and the liquid working medium discharged from the second process group 32 can impact the liquid separation plate to improve the separation effect. Moreover, the gaseous working medium at the separation position can flow upward along the inclined direction of the liquid separation plate, further increasing the separation effect of the liquid separation structure 2, and at the same time, it can also improve the flowing effect of the gaseous working medium towards the first process group 31 direction, further improving the heat exchange efficiency of the shell and tube heat exchanger.

[0061] As Figure 1As shown, the liquid separation plate includes a horizontal portion 21 and an inclined portion 22. The inclined portion 22 is disposed on a side of the horizontal portion 21 away from the heat exchange chamber 13, and the inclined portion 22 is inclined toward the first process group 31 relative to the horizontal portion 21. The liquid separation holes are provided on the horizontal portion 21. The horizontal portion 21 and the inclined portion 22 jointly partition the right water chamber 12. The mixture of gaseous working medium and liquid working medium discharged from the second process group 32 will first flow through the horizontal portion 21 for separation. The gaseous working medium can continue to flow along the horizontal portion 21 to reach the inclined portion 22, and under the inclined guiding action of the inclined portion 22, it flows toward the first process group 31, improving the effect of the gaseous working medium flowing toward the first process group 31 and further improving the heat exchange efficiency of the shell-and-tube heat exchanger. At the same time, the separated liquid working medium will accumulate below the horizontal portion 21 and submerge the second ends of the heat exchange tubes 3 in the third process group 33 to form a liquid seal, effectively preventing the gaseous working medium from flowing back to the left water chamber 11 through the third process group 33 and ensuring the heat exchange reliability of the shell-and-tube heat exchanger. Further, the liquid working medium can accumulate on the surface of the horizontal portion 21 to further form a liquid seal effect, further preventing the gaseous working medium from flowing back to the left water chamber 11 through the third process group 33 and ensuring the heat exchange reliability of the shell-and-tube heat exchanger.

[0062] The air inlet structure 4 is disposed in the left water chamber 11. An air inlet chamber 41 is formed in the air inlet structure 4. The air inlet chamber 41 is relatively sealed with the internal space of the left water chamber 11. The first ends of the heat exchange tubes 3 in the second process group 32 are communicated with the air inlet chamber 41. By arranging the water inlet structure in the left water chamber 11, the space occupied by the water inlet structure and the shell-and-tube heat exchanger is reduced. Moreover, by using the water inlet structure to form a relatively independent air inlet chamber 41 in the left water chamber 11, it can ensure that the gaseous working medium to be heat-exchanged can smoothly flow into the second process group 32. At the same time, the gaseous working medium will not directly enter the left water chamber 11 and be directly discharged, ensuring the working reliability of the shell-and-tube heat exchanger.

[0063] Since the intake structure 4 needs to be correspondingly arranged with the second process group 32, the intake structure 4 needs to be arranged at the middle position of the left water chamber 11. At this time, the intake structure 4 divides the left water chamber 11 into a first liquid return chamber 16 and a second liquid return chamber 17. The first end of the heat exchange tube 3 in the first process group 31 is communicated with the first liquid return chamber 16, and the first end of the heat exchange tube 3 in the third process group 33 is communicated with the second liquid return chamber 17. The liquid working medium that has completed heat exchange in the first process group 31 can flow into the first liquid return chamber 16, and the liquid working medium flowing in the third process group 33 flows into the second liquid return chamber 17. Finally, it can be discharged from the left water chamber 11 separately according to requirements or discharged from the left water chamber 11 together after reflux. Specifically, a liquid outlet 18 is arranged on the left water chamber 11, and the liquid outlet 18 is communicated with both the first liquid return chamber 16 and the second liquid return chamber 17. The liquid working medium that has completed heat exchange in the first process group 31 and the liquid working medium that has refluxed in the third process group 33 can flow together and be discharged from the shell-and-tube heat exchanger through the liquid outlet 18 to complete the heat exchange process.

[0064] As Figure 4 shown, the intake structure 4 includes an upper sealing plate 42 and a lower sealing plate 43. Both the upper sealing plate 42 and the lower sealing plate 43 are hermetically fitted with the inner wall of the left water chamber 11. The left water chamber 11 above the upper sealing plate 42 forms the first liquid return chamber 16, the left water chamber 11 between the upper sealing plate 42 and the lower sealing plate 43 forms the intake chamber 41, and the left water chamber 11 below the lower sealing plate 43 forms the second liquid return chamber 17. The intake chamber 41 is surrounded in the left water chamber 11 by the upper sealing plate 42 and the lower sealing plate 43, so that an air inlet can be directly arranged on the outer wall of the left water chamber 11, which is convenient for the structural design of the shell-and-tube heat exchanger. The upper sealing plate 42 is located between the first process group 31 and the second process group 32, and reliably separates the first process group 31 and the second process group 32, ensuring that the gaseous working medium can flow smoothly into the second process group 32. At the same time, it avoids the liquid working medium in the first process group 31 from entering the intake chamber 41, ensuring the reliable operation of the shell-and-tube heat exchanger. The lower sealing plate 43 is located between the second process group 32 and the third process group 33, and reliably separates the second process group 32 and the third process group 33, ensuring that the gaseous working medium can flow smoothly into the second process group 32. At the same time, it avoids the liquid working medium in the third process group 33 from entering the intake chamber 41, ensuring the reliable operation of the shell-and-tube heat exchanger.

[0065] An outlet 18 is provided on the left water chamber 11, and a liquid passing channel is provided on the air intake structure 4. The liquid passing channel is relatively sealed with the air intake cavity 41, and the first liquid return cavity 16 and the second liquid return cavity 17 are communicated through the liquid passing channel. The outlet 18 is communicated with the second liquid return cavity 17. Among them, the number of the outlets 18 is one, and the outlet 18 is located at the lowest point of the left water chamber 11, which can ensure the reliable drainage of the left water chamber 11 and also reduce the processing difficulty of the shell-and-tube heat exchanger. The first liquid return cavity 16 can also send the liquid working medium into the second liquid return cavity 17 through the liquid passing channel to ensure the smooth drainage of the first liquid return cavity 16, and further ensure the working reliability of the shell-and-tube heat exchanger.

[0066] The air intake structure 4 further includes a side sealing plate. The upper sealing plate 42, the lower sealing plate 44 and the side sealing plate jointly enclose the air intake cavity 41. A first liquid return port is provided on the upper sealing plate 42 outside the air intake cavity 41, and a second liquid return port is provided on the lower sealing plate 43 outside the air intake cavity 41. The side sealing plate is used for partitioning in the area between the upper sealing plate 42 and the lower sealing plate 44 to form the air intake cavity 41, and a space for the flow of the liquid working medium is formed outside the air intake cavity 41. The liquid working medium flowing into the first liquid return cavity 16 can directly flow into the aforementioned space, or can flow into the aforementioned space through the first liquid return port and flow into the second liquid return cavity 17 through the second liquid return port to ensure the reliable operation of the shell-and-tube heat exchanger. At this time, the size of the upper sealing plate 42 can be smaller than that of the lower sealing plate 44, so that there is a gap between the upper sealing plate 42 and the inner wall of the left water chamber 11 to improve the flow reliability of the liquid working medium, and the lower sealing plate 44 is in sealing cooperation with the left water chamber 11 to avoid the splashing of the liquid working medium in the second liquid return cavity 17 from affecting the flow rate of the outlet, and further improve the reliability of the shell-and-tube heat exchanger.

[0067] As another embodiment not shown in the figure, the air intake structure 4 further includes a liquid passing pipe 44. A first liquid return port is provided on the upper sealing plate 42, a second liquid return port is provided on the lower sealing plate 43, one end of the liquid passing pipe 44 is communicated with the first liquid return cavity 16 through the first liquid return port, and the other end is communicated with the second liquid return cavity 17 through the second liquid return port. The liquid passing pipe 44 is used for draining the liquid working medium in the first liquid return cavity 16, and the inside of the liquid passing pipe 44 forms the liquid passing channel, so as to ensure the reliable sealing of the liquid passing channel and the air intake cavity 41.

[0068] Since the heat exchange tubes 3 are divided into a first process group 31, a second process group 32 and a third process group 33 along the height direction, that is, all the heat exchange tubes 3 within a certain height range of the shell and tube heat exchanger belong to the second process group 32, and the heat exchange tubes 3 are not only arranged along the height direction of the shell and tube heat exchanger, but also arranged along the width direction of the shell and tube heat exchanger, and the diameter of the air inlet of the air inlet cavity 41 is smaller than the width dimension of the shell and tube heat exchanger. Therefore, the heat exchange tubes 3 in the second process group 32 will have a larger gaseous working medium flow rate at the heat exchange tubes 3 relative to the air inlet, while the gaseous working medium flow rate of the heat exchange tubes 3 located at the edge in the width direction is smaller. For this reason, the air intake structure 4 also includes a flow equalizing plate 45, which is arranged in the air intake cavity 41, and the flow equalizing plate 45 is located between the air inlet of the air intake cavity 41 and the second process group 32, and a plurality of gas equalizing holes are evenly distributed on the flow equalizing plate 45. The equalizing plate 45 is used to equalize the flow of the gaseous working medium that is about to flow into the second process group 32, ensuring that all the heat exchange tubes 3 in the second process group 32 can evenly obtain the gaseous working medium, avoiding excessive refrigerant flow in individual tubes, resulting in excessive condensate and deterioration of heat transfer, or too little flow in individual tubes, resulting in insufficient utilization of the heat exchange area, and too much or too little flow causing uneven heat exchange and poor performance of the entire tube bundle, thereby improving the heat exchange efficiency of the working medium in the second process group 32, and thereby improving the heat exchange efficiency of the shell and tube heat exchanger.

[0069] Preferably, the cross section of the flow equalizer 45 is V-shaped, and the top angle of the V-shape points to the air inlet. The top angle of the V-shape is used to divert the gaseous working medium flowing into the air inlet, increase the ability of the gaseous working medium to flow in the width direction of the shell and tube heat exchanger, ensure that all heat exchange tubes 3 in the second process group 32 can evenly obtain the gaseous working medium, improve the heat exchange efficiency of the gaseous working medium in the second process group 32, and further improve the heat exchange efficiency of the shell and tube heat exchanger.

[0070] After the gaseous working medium delivered by the air intake structure 4 passes through the second process group 32 for heat exchange, part of the gaseous working medium will be liquefied into liquid working medium, that is, only a part of the gaseous working medium remains in a gaseous state and flows into the first process group 31. Therefore, the number P1 of the heat exchange tubes 3 in the first process group 31 is 20%-35% of the number P of all the heat exchange tubes 3, which can meet the flow heat exchange of the gaseous working medium separated by the liquid separation structure 2, increase the number of heat exchange tubes 3 in the second process group 32 as much as possible, and improve the heat exchange capacity of the shell and tube heat exchanger.

[0071] Similarly, since the gaseous working medium fed by the intake structure 4 first flows through the second process group 32, it is necessary to ensure that the number of heat exchange tubes 3 in the second process group 32 meets the flow requirements of the gaseous working medium fed by the intake structure 4. Therefore, the number P2 of the heat exchange tubes 3 in the second process group 32 is 55%-65% of the number P of all the heat exchange tubes 3, ensuring the intake air volume of the shell-and-tube heat exchanger and improving the heat exchange capacity of the shell-and-tube heat exchanger.

[0072] After the gaseous working medium fed by the intake structure 4 exchanges heat through the second process group 32, part of the gaseous working medium will be liquefied into a liquid working medium, that is, only a part of the gaseous working medium is liquefied and flows into the third process group 33. Therefore, the number P3 of the heat exchange tubes 3 in the third process group 33 is 10%-15% of the number P of all the heat exchange tubes 3, which can meet the flow heat exchange of the gaseous working medium separated by the liquid separation structure 2, and as much as possible increase the number of heat exchange tubes 3 in the second process group 32 to improve the heat exchange capacity of the shell-and-tube heat exchanger.

[0073] For example, P1, P2 and P3 can be 10% + 55% + 35% respectively, or 15% + 65% + 20%.

[0074] Since the shell-and-tube heat exchanger requires the working medium in the tube side and the working medium in the shell side to exchange heat, the working medium in the shell side will contact the outer wall of the heat exchange tube 3 and evaporate from liquid to gas under the action of the heat of the working medium in the heat exchange tube 3. In order to improve the heat exchange efficiency of the shell side, at least part of the outer wall of the heat exchange tube 3 is provided with fins 34, and the fins 34 are used to increase the heat exchange area of the outer wall of the heat exchange tube 3 and improve the heat exchange efficiency of the heat exchange tube 3. Preferably, the cross section of the fin 34 is T-shaped. Using the T-shaped can not only increase the heat exchange area, but also disturb the process of the working medium in the shell side evaporating into gas, improving the heat exchange efficiency of the heat exchange tube 3.

[0075] In order to further increase the heat exchange efficiency of the heat exchange tube 3, at least part of the inner wall of the heat exchange tube 3 is provided with internal teeth 35. The internal teeth 35 are used to locally reduce the wall of the heat exchange tube 3 to improve the heat transfer effect. At the same time, the internal teeth 35 can also guide the working medium in the heat exchange tube 3 inside the heat exchange tube 3, improving the flow distance and the wall attachment effect of the working medium in the heat exchange tube 3, so as to achieve the purpose of improving the heat exchange efficiency of the heat exchange tube 3. Optionally, the internal teeth 35 are distributed in a spiral shape. The working medium in the heat exchange tube 3 flows in a spiral, effectively increasing the flow distance, and can also use the centrifugal force generated during the spiral flow to improve the wall attachment effect of the working medium, thereby improving the heat exchange efficiency of the heat exchange tube 3.

[0076] Since the working fluid flowing in the heat exchange tubes 3 in the first process group 31 is gaseous and efficient heat exchange is required, in the first process group 31, the angle range of the helix angle β of the internal teeth 35 on the heat exchange tubes 3 is 30° ≤ β ≤ 70°. This helix angle can effectively increase the flow distance and also utilize the centrifugal force generated during the helical flow to improve the wall attachment effect of the working fluid, thereby improving the heat exchange efficiency of the heat exchange tubes 3.

[0077] Similarly, the working fluid flowing in the heat exchange tubes 3 in the first process group 31 is mainly gaseous and efficient heat exchange is required. Therefore, in the second process group 32, the angle range of the helix angle β of the internal teeth 35 on the heat exchange tubes 3 is 30° ≤ β ≤ 70°. This helix angle can effectively increase the flow distance and also utilize the centrifugal force generated during the helical flow to improve the wall attachment effect of the working fluid, thereby improving the heat exchange efficiency of the heat exchange tubes 3.

[0078] The state of the working fluid flowing in the heat exchange tubes 3 in the third process group 33 is liquid, and it is necessary to quickly transport the liquid working fluid to the left water chamber 11 (the second liquid return chamber 17). Therefore, in the third process group 33, the angle range of the helix angle β of the internal teeth 35 on the heat exchange tubes 3 is β ≤ 3°. This reduces the flow distance and flow resistance of the liquid working fluid, and can also utilize the capillary action in the channels formed between the internal teeth 35 to promote the liquid flow, improving the conveying capacity of the heat exchange tubes 3 in the third process group 33, avoiding the accumulation of the liquid working fluid at the liquid distribution structure 2 and affecting the heat exchange efficiency of the shell-and-tube heat exchanger, and ensuring the heat exchange reliability of the shell-and-tube heat exchanger.

[0079] The bottom of the heat exchange chamber 13 of the shell-and-tube heat exchanger is provided with a liquid inlet 19, and the top is provided with an air outlet. The gas-liquid two-phase state of the high-temperature section working fluid after throttling enters the heat exchange chamber 13 through the liquid inlet 198 for shell-side flow, and the gas-liquid two-phase working fluid can form a certain liquid level in the heat exchange chamber 13. The heat exchange tubes 3 heat the working fluid in the heat exchange chamber 13, causing the working fluid in the heat exchange chamber 13 to evaporate into a gaseous state, and then flowing through the liquid-blocking and gas-distributing plate at the top of the heat exchange chamber 13 to the air outlet, completing the shell-side heat exchange process of the shell-and-tube heat exchanger.

[0080] Since the shell-and-tube heat exchanger is a flooded evaporator, it is necessary to fill the heat exchange chamber 13 with the heat exchange working fluid to exchange heat with the heat exchange tubes 3. At this time, the bubbles generated by heat absorption and evaporation at the heat exchange tubes 3 flow upward, and the upward-flowing bubbles cause additional disturbances to the liquid refrigerant around the upper heat exchange tubes 3, which can strengthen the heat exchange effect of the upper heat exchange tubes 3. This phenomenon is the tube bundle strengthening effect of flooded evaporation. In this application, by arranging the first process group 31 at the top, the tube bundle strengthening effect can be fully utilized to further enhance the heat exchange effect of the heat exchange tubes 3 in the first process group 31.

[0081] Since the diameter of the bubbles gradually increases and the number of bubbles gradually increases in the vertical direction, in order to avoid an excessively high gas flow velocity around the upper heat exchange tubes 3, the distance between two adjacent heat exchange tubes 3 in the first process group 31 is greater than the distance between two adjacent heat exchange tubes 3 in the second process group 32, ensuring the heat exchange reliability of the heat exchange tubes 3 in the first process group 31. Preferably, the distance refers to the distance between two adjacent heat exchange tubes 3 in the height direction.

[0082] A heat exchange system includes the above shell-and-tube heat exchanger.

[0083] The above embodiments merely represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed. However, it should not be construed as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these 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 appended claims.

Claims

1. A shell and tube heat exchanger, characterized in that: include: A shell (1), the shell (1) comprising a left water chamber (11), a right water chamber (12), and a heat exchange chamber (13) located between the left water chamber (11) and the right water chamber (12); A liquid separation structure (2), wherein the liquid separation structure (2) is arranged in the right water chamber (12), and the liquid separation structure (2) separates the right water chamber (12) into a liquid separation chamber (14) and a liquid storage chamber (15); A plurality of heat exchange tubes (3), all of the heat exchange tubes (3) being arranged in the heat exchange cavity (13), and all of the heat exchange tubes (3) being divided into a first process group (31), a second process group (32) and a third process group (33) along a height direction; In the first process group (31), the first end of the heat exchange tube (3) is in communication with the left water chamber (11), and the second end is in communication with the liquid separation chamber (14); In the second process group (32), the first end of the heat exchange tube (3) is in communication with the air inlet structure (4), and the second end is in communication with the liquid separation chamber (14); In the third process group (33), the first end of the heat exchange tube (3) is connected to the left water chamber (11), and the second end is connected to the liquid storage chamber (15).

2. The shell and tube heat exchanger according to claim 1, characterized in that: The liquid separation structure (2) comprises a liquid separation plate, which separates the right water chamber (12) into the liquid separation chamber (14) and the liquid storage chamber (15), and the liquid separation plate is located between the second process group (32) and the third process group (33), and a liquid separation hole is provided on the liquid separation plate, and the liquid separation chamber (14) and the liquid storage chamber (15) are connected through the liquid separation hole.

3. The shell and tube heat exchanger according to claim 2, characterized in that: The plane where the liquid separation plate is located has an angle with the outflow direction of the heat exchange tube (3) of the second process group (32).

4. The shell and tube heat exchanger according to claim 2, characterized in that: The liquid separation plate comprises a horizontal portion (21) and an inclined portion (22); the inclined portion (22) is arranged on a side of the horizontal portion (21) away from the heat exchange chamber (13), and the inclined portion (22) is inclined relative to the horizontal portion (21) in a direction toward the first process group (31); and the liquid separation hole is arranged on the horizontal portion (21).

5. The shell and tube heat exchanger according to claim 1, characterized in that: The air intake structure (4) is arranged in the left water chamber (11), and an air intake cavity (41) is formed in the air intake structure (4). The air intake cavity (41) is relatively sealed with the internal space of the left water chamber (11), and the first end of the heat exchange tube (3) in the second process group (32) is connected to the air intake cavity (41).

6. The shell and tube heat exchanger according to claim 5, characterized in that: The air intake structure (4) divides the left water chamber (11) into a first liquid return chamber (16) and a second liquid return chamber (17); the first end of the heat exchange tube (3) in the first process group (31) is connected to the first liquid return chamber (16), and the first end of the heat exchange tube (3) in the third process group (33) is connected to the second liquid return chamber (17).

7. The shell and tube heat exchanger according to claim 6, characterized in that: The left water chamber (11) is provided with a liquid outlet (18), and the liquid outlet (18) is communicated with both the first liquid return chamber (16) and the second liquid return chamber (17).

8. The shell and tube heat exchanger according to claim 6, characterized in that: The air intake structure (4) comprises an upper sealing plate (42) and a lower sealing plate (43), and the upper sealing plate (42) and the lower sealing plate (43) are both sealed with the inner wall of the left water chamber (11), and the left water chamber (11) located above the upper sealing plate (42) forms the first liquid return chamber (16), the left water chamber (11) located between the upper sealing plate (42) and the lower sealing plate (43) forms the air intake chamber (41), and the left water chamber (11) located below the lower sealing plate (43) forms the second liquid return chamber (17).

9. The shell and tube heat exchanger according to claim 8, characterized in that: The left water chamber (11) is provided with a liquid outlet (18), the air intake structure (4) is provided with a liquid passage, the liquid passage is relatively sealed with the air intake chamber (41), the first liquid return chamber (16) and the second liquid return chamber (17) are connected via the liquid passage, and the liquid outlet (18) is connected with the second liquid return chamber (17).

10. The shell and tube heat exchanger according to claim 9, characterized in that: The air intake structure (4) further comprises a side sealing plate, wherein the upper sealing plate (42), the lower sealing plate (43) and the side sealing plate together enclose the air intake cavity (41), a first liquid return port is arranged on the upper sealing plate (42) located outside the air intake cavity (41), and a second liquid return port is arranged on the lower sealing plate (43) located outside the air intake cavity (41).

11. The shell and tube heat exchanger according to claim 9, characterized in that: The air intake structure (4) further comprises a liquid passage pipe (44), the upper sealing plate (42) is provided with a first liquid return port, the lower sealing plate (43) is provided with a second liquid return port, one end of the liquid passage pipe (44) is connected to the first liquid return chamber (16) through the first liquid return port, and the other end is connected to the second liquid return chamber (17) through the second liquid return port.

12. The shell and tube heat exchanger according to claim 5, characterized in that: The air intake structure (4) further comprises a flow equalizing plate (45), wherein the flow equalizing plate (45) is arranged in the air intake cavity (41), and the flow equalizing plate (45) is located between the air intake port of the air intake cavity (41) and the second process group (32), and a plurality of flow equalizing holes are evenly distributed on the flow equalizing plate (45).

13. The shell and tube heat exchanger according to claim 12, characterized in that: The cross section of the flow equalizing plate (45) is V-shaped, and the top angle of the V-shape points toward the air inlet.

14. The shell and tube heat exchanger according to claim 1, characterized in that: The number P1 of the heat exchange tubes (3) in the first process group (31) is 20%-35% of the number P of all the heat exchange tubes (3); and / or the number P2 of the heat exchange tubes (3) in the second process group (32) is 55-65% of the number P of all the heat exchange tubes (3); and / or the number P3 of the heat exchange tubes (3) in the third process group (33) is 10%-15% of the number P of all the heat exchange tubes (3).

15. The shell and tube heat exchanger according to claim 1, characterized in that: The distance between two adjacent heat exchange tubes (3) in the first process group (31) is greater than the distance between two adjacent heat exchange tubes (3) in the second process group (32).

16. The shell and tube heat exchanger according to claim 1, characterized in that: Fins (34) are provided on at least part of the outer wall of the heat exchange tube (3).

17. The shell and tube heat exchanger according to claim 16, characterized in that: The cross section of the fin (34) is T-shaped.

18. The shell and tube heat exchanger according to claim 1, characterized in that: Internal teeth (35) are provided on at least part of the inner wall of the heat exchange tube (3).

19. The shell and tube heat exchanger according to claim 18, characterized in that: The inner teeth (35) are distributed in a spiral shape.

20. The shell and tube heat exchanger according to claim 19, characterized in that: In the first process group (31), the angle range of the helix angle β of the internal teeth (35) on the heat exchange tube (3) is 30°≤β≤70°; and / or, in the second process group (32), the angle range of the helix angle β of the internal teeth (35) on the heat exchange tube (3) is 30°≤β≤70°; and / or, in the third process group (33), the angle range of the helix angle β of the internal teeth (35) on the heat exchange tube (3) is β≤3°.

21. A heat exchange system, characterized in that: A shell and tube heat exchanger comprising any one of claims 1 to 20.

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