An evaporator and a refrigeration system

Abstract

The present application discloses an evaporator and a refrigeration system including the evaporator. The evaporator includes: a housing having a cavity; a first set of heat exchange tubes, a second set of heat exchange tubes, and a third set of heat exchange tubes arranged from bottom to top. The second set of heat exchange tubes has a pair of side portions, and the top of the first set of heat exchange tubes has a pair of protruding portions that respectively extend beyond the pair of side portions in the width direction of the cavity; and a pair of bottom partitions that respectively adjoin and extend along the pair of side portions and the pair of protruding portions to jointly define a bottom heat exchange space with the housing through the pair of bottom partitions. In the evaporator of the present application, a part of the first set of heat exchange tubes used as a flooded tube bundle is set as the second set of heat exchange tubes, so that the amount of refrigerant to be charged only needs to submerge fewer first set of heat exchange tubes, reducing the required refrigerant charge amount. And the present application correspondingly sets bottom partitions to restrict the flow paths of gaseous refrigerant and liquid refrigerant, so that each set of heat exchange tubes can achieve the maximum heat exchange efficiency.

Description

Technical Field

[0001] The present application relates to the field of refrigeration systems, and particularly to a falling film evaporator and a refrigeration system using the falling film evaporator. Background Art

[0002] A refrigeration system mainly includes four components: a compressor, a condenser, a throttling device, and an evaporator. Among them, the evaporator is used to evaporate the liquid refrigerant into a gaseous refrigerant. A falling film evaporator is a commonly used evaporator, which includes falling film tubes. Usually, a distributor is used to distribute the refrigerant onto the surface of the heat exchange tubes of the falling film tubes, and a liquid film is formed on the surface of the heat exchange tubes for evaporation. The falling film evaporator utilizes the thin film evaporation mechanism on the surface of the heat exchange tubes, and has the advantages of high heat transfer efficiency and less refrigerant charge. It has been a research hotspot in the air conditioning industry in recent years.

[0003] The falling film evaporator usually includes a flooded tube bundle arranged at the bottom of the evaporator and a falling film tube bundle arranged above the flooded tube bundle. During operation, the refrigerant distributor evenly distributes the gas-liquid two-phase refrigerant after passing through the throttling device to the top of the falling film tube bundle. The gas-liquid two-phase refrigerant flows through the falling film tube bundle and exchanges heat with the hot fluid inside the heat exchange tubes of the falling film tube bundle. Part of the liquid refrigerant evaporates into a gaseous refrigerant, and the unevaporated liquid refrigerant falls into the flooded tube bundle area and exchanges heat with the hot fluid inside the heat exchange tubes of the flooded tube bundle for further evaporation. Summary of the Invention

[0004] On the one hand, in order to prevent dry spots from occurring on the heat exchange tubes at the bottom of the falling film tube bundle, thereby reducing the heat exchange efficiency of the falling film tube bundle, usually the proportion of the number of heat exchange tubes in the falling film tube bundle to the total number of tubes in the entire evaporator cannot be too high. On the other hand, in order to ensure the heat exchange efficiency of the flooded tube bundle, usually a sufficient refrigerant charge is required to completely immerse the flooded tube bundle in the liquid refrigerant. Thus, a falling film evaporator with a certain total number of tubes can achieve the maximum heat exchange efficiency.

[0005] At least one object of the present application is to reduce the flow rate of the liquid refrigerant charged while ensuring that the falling film evaporator achieves the maximum heat exchange efficiency.

[0006] To solve the above problems, the present application provides an evaporator in a first aspect, including: a housing having a cavity, a refrigerant inlet and a refrigerant outlet communicating with the cavity, the cavity having a length direction, a width direction and a height direction; a first set of heat exchange tubes, a second set of heat exchange tubes and a third set of heat exchange tubes, each heat exchange tube in the first set of heat exchange tubes, the second set of heat exchange tubes and the third set of heat exchange tubes extending along the length direction of the cavity, the first set of heat exchange tubes and the second set of heat exchange tubes being located at the bottom of the cavity, the second set of heat exchange tubes being located above the first set of heat exchange tubes, the third set of heat exchange tubes being located above the second set of heat exchange tubes, the refrigerant inlet being located above the third set of heat exchange tubes and configured to supply liquid refrigerant to the third set of heat exchange tubes, and wherein the second set of heat exchange tubes has a pair of sides extending along the length direction of the cavity, there is a certain distance between each of the pair of sides of the second set of heat exchange tubes and the housing, and the top of the first set of heat exchange tubes has a pair of protrusions extending respectively beyond the pair of sides of the second set of heat exchange tubes in the width direction of the cavity; and a pair of bottom partitions respectively adjacent to and extending along the pair of sides of the second set of heat exchange tubes and the pair of protrusions of the first set of heat exchange tubes to jointly define a bottom heat exchange space with the housing, the bottom heat exchange space having a first fluid outlet located at the top of the bottom partition, the first fluid outlet being in fluid communication with the refrigerant outlet.

[0007] According to the above first aspect, the third set of heat exchange tubes has a pair of sides extending along the length direction of the cavity, there is a certain distance between each of the pair of sides of the third set of heat exchange tubes and the housing; the evaporator further includes a pair of upper partitions respectively adjacent to and extending along the pair of sides of the third set of heat exchange tubes to define an upper heat exchange space by the pair of upper partitions, the upper heat exchange space having a second fluid outlet located at the bottom of the upper partition, the second fluid outlet being in fluid communication with the refrigerant outlet.

[0008] According to the above first aspect, each of the pair of bottom partitions extends along the pair of protrusions of the first set of heat exchange tubes to abut against the housing.

[0009] According to the above first aspect, the heat exchange tubes in the first set of heat exchange tubes, the second set of heat exchange tubes and the third set of heat exchange tubes have the same diameter and are arranged in columns along the width direction of the cavity; wherein the number of columns of the second set of heat exchange tubes is less than the maximum number of columns of the first set of heat exchange tubes.

[0010] According to the above first aspect, the number of columns of the second set of heat exchange tubes is not less than the number of columns of the third set of heat exchange tubes.

[0011] According to the first aspect described above, each of the pair of bottom partitions includes a transverse partition extending along a pair of protruding portions of the first group of heat exchange tubes, and the transverse partition extends at least partially obliquely with respect to the width direction of the cavity.

[0012] According to the first aspect described above, each of the pair of bottom partitions includes a transverse partition extending along a pair of protruding portions of the first group of heat exchange tubes, and the transverse partition extends at least partially obliquely with respect to the length direction of the cavity.

[0013] According to the first aspect described above, the transverse partition has at least one through hole penetrating the transverse partition, and the at least one through hole is provided on a portion of the transverse partition that extends obliquely with respect to the width direction of the cavity or on a portion of the transverse partition that extends obliquely with respect to the length direction of the cavity.

[0014] According to the first aspect described above, the sum of the number of heat exchange tubes in the first group of heat exchange tubes and the second group of heat exchange tubes is equal to the number of heat exchange tubes in the third group of heat exchange tubes.

[0015] The present application provides a refrigeration system in a second aspect, including: a compressor, a condenser, a throttling device, and an evaporator disposed in a refrigerant circuit, wherein the evaporator is any one of the above first aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic block diagram of the refrigeration system of the present application;

[0017] Figure 2 is Figure 1 a three-dimensional structure diagram of the evaporator in

[0018] Figure 3 is Figure 2 a schematic structural diagram of an axial cross-section of an embodiment of the evaporator in

[0019] Figure 4 is Figure 3 a three-dimensional structure diagram of an embodiment of the bottom partition in

[0020] Figure 5 is Figure 2 a schematic structural diagram of an axial cross-section of another embodiment of the evaporator in

[0021] Figure 6A is Figure 3 a three-dimensional structure diagram of another embodiment of the bottom partition in

[0022] Figure 6B is Figure 6A a left view of DETAILED DESCRIPTION

[0023] The following will describe various specific embodiments of the present invention with reference to the accompanying drawings that form a part of this specification. It should be understood that although terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right", "top", "bottom", etc., are used in this application to describe various example structural parts and elements of this application, these terms are used herein only for the purpose of convenience of description and are determined based on the example orientations shown in the accompanying drawings. Since the embodiments disclosed in this application can be arranged in different directions, these terms indicating directions should be regarded as illustrative rather than restrictive.

[0024] Figure 1 is a schematic block diagram of the refrigeration system 190 of this application, used to show the position and function of the evaporator 100 in the refrigeration system 190.

[0025] As Figure 1 shown, the refrigeration system 190 includes a compressor 193, a condenser 191, a throttling device 192, and an evaporator 100, which are connected through pipelines to form a closed system, and a refrigerant is filled in the system. Among them, the refrigerant flows through the compressor 193, the condenser 191, the throttling device 192, and the evaporator 100 in sequence, so that the refrigeration system 190 can refrigerate externally. Specifically, the high-pressure gaseous refrigerant discharged from the compressor 193 flows into the condenser 191, releases heat in the condenser 191 and is condensed into a high-pressure liquid refrigerant, then flows into the throttling device 192, is throttled into a low-pressure two-phase refrigerant and flows into the evaporator 100 through the refrigerant inlet 101 of the evaporator 100, absorbs heat in the evaporator 100 and is evaporated into a low-pressure gaseous refrigerant, and finally flows out from the refrigerant outlet 102 of the evaporator 100 and flows back into the compressor 193 to complete the refrigerant cycle. As an example, the evaporator 100 is a falling film evaporator.

[0026] Figure 2 is Figure 1 a three-dimensional structure diagram of the evaporator 100 in, used to show the external structure of the evaporator 100.

[0027] As Figure 2As shown in the figure, the falling film evaporator 100 has a housing 203, which is generally cylindrical in shape and has a length direction L, a width direction W, and a height direction H. The housing 203 is provided with a refrigerant inlet 101, a refrigerant outlet 102, and water inlet and outlet pipes 207, 208. Among them, the refrigerant inlet 101 is arranged in the upper middle part of the housing 203 and is in fluid communication with the outlet of the throttling device 192 to supply two-phase refrigerant to the inside of the housing 203. It should be noted that the flow rate of the refrigerant flowing through the refrigerant inlet 101 can be controlled by a known valve body or other control devices, which will not be specifically described here. And according to different designs of the falling film evaporator, multiple refrigerant inlets can also be provided. The refrigerant outlet 102 is in fluid communication with the suction end of the compressor 193 to discharge the gaseous refrigerant evaporated inside the housing 203 to the suction end of the compressor 193. In this embodiment, the refrigerant outlet 102 is arranged above the middle part of the housing 203.

[0028] Tube sheets 205 for closing the housing 203 are provided at both ends of the housing 203. Among them, the water inlet and outlet pipes 207, 208 are also provided on the front tube sheet 205. The water inlet and outlet pipes 207, 208 are in fluid communication with the hot water and are in fluid communication with the inside of the heat exchange tubes in the housing 203 to supply the hot water used for heat exchange to the heat exchange tubes.

[0029] Thus, after the two-phase refrigerant from the throttling device 192 enters the inside of the housing 203 of the falling film evaporator 100 through the refrigerant inlet 101, it exchanges heat with the heat exchange tubes in the housing. After the refrigerant absorbs heat and is evaporated into a gas, it is discharged from the falling film evaporator 100 through the refrigerant outlet 102 and flows into the suction end of the compressor 193. Among them, the medium water for heat exchange in the heat exchange tubes flows into and out of the heat exchange tubes through the water inlet and outlet pipes 207, 208.

[0030] Figure 3 It is a schematic cross-sectional structure diagram of an embodiment of the falling film evaporator 100, used to show the internal structure of the housing 203 of the falling film evaporator 100. As Figure 3As shown, within the housing 203, there is a cavity 310 defined by the housing 203. The refrigerant inlet 101 and the refrigerant outlet 102 are in fluid communication with the cavity 310. The cavity 310 includes a number of heat exchange tubes, a distributor 341, and a demister 313. The distributor 341 is connected to the tube sheets 205 at both ends of the housing 203. The pipe of the refrigerant inlet 101 extends into the housing 203 and is in fluid communication with the distributor 341. The heat exchange tubes are arranged below the distributor 341. The demister 313 is connected between the distributor 341 and the housing 203 and is located between these heat exchange tubes and the refrigerant outlet 102. As an example, the demister 313 can be a wire mesh or the like, which is used to filter the liquid droplets entrained in the gaseous refrigerant. Thus, the two-phase refrigerant flowing in from the refrigerant inlet 101 is first distributed by the distributor 341, then undergoes heat exchange with these heat exchange tubes below the distributor 341 to become gaseous refrigerant, and then flows through the demister 313 to remove the entrained liquid droplets and is discharged from the cavity 310 through the refrigerant outlet 102.

[0031] Specifically, these heat exchange tubes sequentially include a first group of heat exchange tubes 315, a second group of heat exchange tubes 316, and a third group of heat exchange tubes 317 from bottom to top along the height direction H. Each group of heat exchange tubes includes a number of heat exchange tubes extending along the length direction L. The front and rear ends of the heat exchange tubes in the length direction L are supported on the tube sheets 205, and the interior of the heat exchange tubes is in communication with the inlet and outlet water pipes 207, 208. As an example, the heat exchange tubes of each group are arranged in columns. Of course, in other examples, the heat exchange tubes can also be arranged in other ways, such as in rows. In this embodiment, the first group of heat exchange tubes 315 is located at the bottom of the cavity 310 and serves as a flooded tube bundle for being immersed in the liquid refrigerant for flooded heat exchange. The third group of heat exchange tubes 317 is located in the upper middle part of the cavity 310 and serves as a falling film tube bundle for falling film heat exchange. The second group of heat exchange tubes 316 is located between the first group of heat exchange tubes 315 and the third group of heat exchange tubes 317 and is used for the transition between the flooded tube bundle and the falling film tube bundle. It can both exchange heat with the excessive liquid refrigerant flowing downward from the third group of heat exchange tubes 317 and with the liquid refrigerant entrained in the gaseous refrigerant flowing upward from the first group of heat exchange tubes 315. As a specific example, the first group of heat exchange tubes 315 covers the bottom of the cavity 310, and the second group of heat exchange tubes 316 and the third group of heat exchange tubes 317 are generally arranged in a square shape. In the width direction W, the width of the second group of heat exchange tubes 316 is smaller than the width of the top of the first group of heat exchange tubes 315 and not less than the width of the third group of heat exchange tubes 317. When the tube diameters of the heat exchange tubes in each group are the same, the number of columns of the second group of heat exchange tubes 316 is less than the maximum number of columns of the first group of heat exchange tubes 315 (i.e., the number of columns at its top) and greater than or equal to the number of columns of the third group of heat exchange tubes 317.

[0032] The cavity 310 further includes some partition plates, the front and rear ends of which in the length direction L are connected to the tube sheets 205 at both ends of the housing 203, and the upper heat exchange space 332 and the bottom heat exchange space 331 are defined and formed by these partition plates and the housing 203. The refrigerant exchanges heat with these heat exchange tubes in the defined upper heat exchange space 332 and bottom heat exchange space 331. Specifically, the cavity 310 includes a pair of upper partition plates 323 and a pair of bottom partition plates 320. The third set of heat exchange tubes 317 has a pair of side portions 325 that are opposite in the width direction W and extend along the length direction L. The pair of upper partition plates 323 are connected to the tube sheets 205 at both ends of the housing 203, and are respectively disposed outside the pair of side portions 325 and extend adjacent to the pair of side portions 325. There is a certain distance between the outside of the pair of upper partition plates 323 and the housing 203 for the gaseous refrigerant to flow. An upper heat exchange space 332 can be defined and formed between the pair of upper partition plates 323, and the bottom of the upper partition plate 323 forms a fluid outlet 329 of the upper heat exchange space 332. The gaseous refrigerant obtained by heat exchange in the upper heat exchange space 332 can escape from the fluid outlet 329 and is discharged from the refrigerant outlet 102 after passing through the demister 313. As a specific example, another part of the heat exchange tubes of the third set of heat exchange tubes 317 is located below the fluid outlet 329 to prevent the liquid droplets (i.e., liquid refrigerant) entrained in the escaping gaseous refrigerant from flowing with the gaseous refrigerant.

[0033] The second set of heat exchange tubes 316 also has a pair of side portions 324 that are opposite in the width direction W and extend along the length direction L. The top of the first set of heat exchange tubes 315 has a pair of protruding portions 326 that respectively extend beyond the pair of side portions 324 of the second set of heat exchange tubes 316 in the width direction W. A pair of bottom partitions 320 are connected to the tube sheets 205 at both ends of the housing 203 and respectively extend closely along the pair of side portions 324 of the second set of heat exchange tubes 316 and the pair of protruding portions 326 of the first set of heat exchange tubes 315. Specifically, each bottom partition 320 includes a transverse partition 321 and a longitudinal partition 322. One side edge of each transverse partition 321 is connected to the bottom of the corresponding longitudinal partition 322, and the other side edge is connected to the housing 203. In this embodiment, each transverse partition 321 extends horizontally approximately along one protruding portion 326 of the first set of heat exchange tubes 315 to be connected to the housing 203, and each longitudinal partition 322 extends vertically approximately along one side portion 324 of the second set of heat exchange tubes 316, and there is a certain distance between the outer side of each longitudinal partition 322 and the housing 203 for the gaseous refrigerant to flow. A bottom heat exchange space 331 is jointly defined by the pair of bottom partitions 320 and the housing 203, and a fluid outlet 328 of the bottom heat exchange space 331 is formed at the top of the longitudinal partition 322 of the bottom partition 320. The gaseous refrigerant obtained by heat exchange in the bottom heat exchange space 311 can escape from the fluid outlet 328 and be discharged from the refrigerant outlet 102 after passing through the demister 313. As a specific example, there is also one or two rows of heat exchange tubes at the top of the second set of heat exchange tubes 316 above the fluid outlet 328 to prevent the liquid droplets (i.e., liquid refrigerant) entrained in the escaping gaseous refrigerant from flowing with the gaseous refrigerant.

[0034] Thus, in a first aspect, the two-phase refrigerant that enters from the refrigerant inlet 101 and is distributed by the distributor 341 exchanges heat with the third set of heat exchange tubes 317 in the upper heat exchange space 332, and the liquid refrigerant therein is evaporated into gaseous refrigerant. The gaseous refrigerant is restricted by the upper partition 323 and escapes from the fluid outlet 329. The gaseous refrigerant flows upward and is discharged from the refrigerant outlet 102 after passing through the demister 313, and the remaining liquid refrigerant that is not completely evaporated continues to flow downward under the action of gravity. Since the width of the top of the second set of heat exchange tubes 316 is not less than the width of the bottom of the third set of heat exchange tubes 317, the liquid refrigerant can flow downward to enter the bottom heat exchange space 311. After flowing through the second set of heat exchange tubes 316, a part of the liquid refrigerant accumulates at the bottom of the cavity 310 and submerges the first set of heat exchange tubes 315, and another part of the liquid refrigerant exchanges heat with the second set of heat exchange tubes 316 to become gaseous refrigerant and then escapes from the fluid outlet 328 of the bottom heat exchange space 311, flows upward and is discharged from the refrigerant outlet 102 after passing through the demister 313.

[0035] In a second aspect, the liquid refrigerant gathered at the bottom of the cavity 310 exchanges heat with the first set of heat exchange tubes 315 immersed therein in the lower part of the bottom heat exchange space 311, generating a gaseous refrigerant airflow (hereinafter referred to as airflow) carrying the liquid refrigerant. The airflow generated by the heat exchange tubes in the first set of heat exchange tubes 315 directly below the second set of heat exchange tubes 316 flows upward through the second set of heat exchange tubes 316 in the upper part of the bottom heat exchange space 311. The airflow generated by a pair of protruding portions 326 of the first set of heat exchange tubes 315 and the heat exchange tubes directly below the protruding portions 326, under the restriction of the transverse partition 321 of the bottom partition 320, first flows centrally towards the middle and then flows upward through the second set of heat exchange tubes 316 in the upper part of the bottom heat exchange space 311. After the liquid refrigerant therein exchanges heat with the second set of heat exchange tubes 316 and turns into gaseous refrigerant, it is restricted by the longitudinal partition 322 of the bottom partition 320 together with the gaseous refrigerant and escapes from the fluid outlet 328 of the bottom heat exchange space 311, and then flows upward to be discharged from the refrigerant outlet 102 after passing through the demister 313.

[0036] In the cavity 310 between the outer sides of a pair of upper partitions 323 and the housing 203, and between the outer sides of a pair of lower partitions 320 and the housing 203, the remaining liquid refrigerant flows back to the bottom of the cavity 310 through the through holes in the bottom partition 320 (see Figure 4 or Figure 6A , Figure 6B ) and exchanges heat with the heat exchange tubes in the bottom heat exchange space 311 again.

[0037] It can be seen that by providing the bottom partition 320, the second set of heat exchange tubes 316 can not only exchange heat with the liquid refrigerant flowing through the third set of heat exchange tubes 317 from top to bottom, but also exchange heat with the liquid refrigerant flowing through the first set of heat exchange tubes 315 from bottom to top, so that each heat exchange tube in the second set of heat exchange tubes 316 can achieve the maximum heat exchange efficiency. And in this application, it only needs to ensure that the liquid refrigerant piled up at the bottom of the cavity 310 can submerge the first set of heat exchange tubes 315 to guarantee the maximum heat exchange efficiency of the heat exchange tubes in the first set of heat exchange tubes 315.

[0038] Compared with the falling film evaporator that does not include the second set of heat exchange tubes 316, in the case where the total number of heat exchange tubes and the number of heat exchange tubes in the third set of heat exchange tubes 317 (roughly the number of heat exchange tubes in the upper heat exchange space 332) are certain in this application, although the sum of the number of heat exchange tubes in the first set of heat exchange tubes 315 and the second set of heat exchange tubes 316 (roughly the number of heat exchange tubes in the bottom heat exchange space 311) remains unchanged, the number of heat exchange tubes immersed in the refrigerant is reduced. It can not only ensure that each heat exchange tube reaches the maximum heat exchange efficiency, but also reduce the refrigerant filling amount.

[0039] It should be noted that in this embodiment, "adjacent" means that the partition is close to the heat exchange tube but does not contact the outer surface of the heat exchange tube, so as to restrict the flow of gaseous refrigerant and liquid refrigerant in the corresponding heat exchange space. And it should be noted that the top or bottom of each group of heat exchange tubes refers to the uppermost or lowermost heat exchange tube on its outer contour, and the side of each group of heat exchange tubes refers to the outermost heat exchange tube on its outer contour. In this embodiment, the top or bottom of each group of heat exchange tubes refers to the uppermost or lowermost row or two rows of heat exchange tubes in each group of heat exchange tubes, and the side of each group of heat exchange tubes refers to the outermost one or two columns of heat exchange tubes.

[0040] Figure 4 FIG. 4 is a perspective view of an embodiment of the bottom partition 320, which is used to show the through holes 435 on the bottom partition 320. As Figure 4 shown, the bottom partition 320 includes a transverse partition 321 and a longitudinal partition 322, which extend along the same length direction L as the heat exchange tubes and are connected to the tube sheets 205 at both ends of the housing 203. In the embodiment shown in the figure, four through holes 435 are provided on the transverse partition 321, and each through hole 435 is spaced along the length direction of the transverse partition 321 and penetrates the transverse partition 321. And each through hole 435 is provided on the side edge of the transverse partition 321 for connecting to the housing 203, so as to communicate the upper and lower sides of the transverse partition 321 through the through hole 435, that is, to communicate the outside and inside of the bottom partition 320. The liquid refrigerant between the outside of the bottom partition 320 and the housing 203 can flow back into the bottom heat exchange space 311 inside the bottom partition 320 through the through hole 435. And the through holes 435 are arranged in several intervals. In some embodiments, the size of the through holes 435 is small and the number is not large, so that most of the air flow generated by the first group of heat exchange tubes 315 will still be restricted by the transverse partition 321 and flow to the second group of heat exchange tubes 316.

[0041] Combined with Figure 3 it can be seen that in this embodiment, by arranging the through holes 435 at the outer edge of the transverse partition 321 (that is, the side edge for connecting to the housing 203), it is convenient for a part of the accumulated liquid refrigerant to directly pass through the through holes 435 along the inner wall of the housing 203 and flow into the bottom heat exchange space 311. Those skilled in the art can understand that as long as the liquid refrigerant can flow back from the outside of the bottom partition 320 to the inner bottom heat exchange space 311 under the action of gravity, the through holes 435 can also be arranged at other positions on the transverse partition 321. And in some other examples, the through holes 435 can also be arranged in other numbers.

[0042] Figure 5Schematic cross-sectional view of another embodiment of the falling film evaporator according to the present application. The general structure of the falling film evaporator 500 shown in this embodiment and the arrangement of the heat exchange tubes are the same as those of the falling film evaporator 200, and the difference from the falling film evaporator 200 is only the bottom partition structure. As Figure 5 shown, the bottom partition 520 also includes a transverse partition 521 and a longitudinal partition 522. One side edge of the transverse partition 521 is connected to the housing 203, and the other side edge is connected to the bottom of the longitudinal partition 522. In this embodiment, the transverse partition 521 is not horizontal relative to the width direction W, but extends obliquely. Specifically, each transverse partition 521 extends obliquely downward from the bottom of the longitudinal partition 522 to be connected to the housing 203. Although not shown in the figure, a number of through holes for communicating the outside of the transverse partition 521 with the bottom heat exchange space are also provided at the outer edge of each transverse partition 521, that is, the edge for connecting to the housing 203.

[0043] Such a setting can facilitate guiding the remaining liquid refrigerant to flow to the outer edge of the transverse partition 521, so that the remaining liquid refrigerant can be more concentratedly returned to the bottom heat exchange space through the through holes (not shown in the figure) to exchange heat with the heat exchange tubes again.

[0044] Figure 6A and Figure 6B Schematic structural view of another embodiment of the bottom partition, where Figure 6B is Figure 6A left view. As Figure 6A and Figure 6B shown, the bottom partition 620 also includes a transverse partition 621 and a longitudinal partition 622. One side edge of the transverse partition 621 is for connecting to the housing, and the other side edge is for connecting to the bottom of the longitudinal partition 622. In this embodiment, the transverse partition 621 extends obliquely relative to the length direction L. Specifically, each transverse partition 621 extends obliquely downward from the rear end to the front end (at the angle shown in Figure 6B the transverse partition 621 extends obliquely downward from the left end to the right end). The through hole 635 is provided at the lower end of the transverse partition 621, such as the front end. As an example, the through hole 635 is provided at the outer edge of the front end of the transverse partition 621. In this embodiment, only one through hole 635 is provided to further reduce the possibility of air flow rushing out from the through hole 635.

[0045] Such a setting can also facilitate guiding the remaining liquid refrigerant to gather and then more concentratedly return to the bottom heat exchange space through the through hole 635 to exchange heat with the heat exchange tubes again.

[0046] It should be noted that according to the specific design requirements of the falling film evaporator, the transverse partition of the bottom partition can also be designed to extend obliquely relative to both the length direction L and the width direction W.

[0047] In the falling film evaporator of the present application, a part of the first group of heat exchange tubes used as the flooded tube bundle is set as the second group of heat exchange tubes, so that the amount of refrigerant to be charged only needs to submerge fewer first group of heat exchange tubes, reducing the required refrigerant charge. And the present application correspondingly sets a bottom partition to limit the flow paths of the gaseous refrigerant and the liquid refrigerant, so that each group of heat exchange tubes can achieve the maximum heat exchange efficiency.

[0048] Although the present application will be described with reference to the specific embodiments shown in the accompanying drawings, it should be understood that the evaporator of the present application can have many variations without departing from the spirit, scope and background of the teachings of the present application. Those of ordinary skill in the art will also realize that there are different ways to change the structural details in the embodiments disclosed in the present application, all of which fall within the spirit and scope of the present invention and the claims.

Claims

1. An evaporator, characterized in that Comprising: A housing (203) having a cavity (310) and a refrigerant inlet (101) and a refrigerant outlet (102) communicating with the cavity (310), the cavity (310) having a length direction (L), a width direction (W) and a height direction (H); A first set of heat exchange tubes (315), a second set of heat exchange tubes (316) and a third set of heat exchange tubes (317), each heat exchange tube in the first set of heat exchange tubes (315), the second set of heat exchange tubes (316) and the third set of heat exchange tubes (317) extending along the length direction (L) of the cavity (310), the first set of heat exchange tubes (315) and the second set of heat exchange tubes (316) being located at the bottom of the cavity (310), the second set of heat exchange tubes (316) being located above the first set of heat exchange tubes (315), the third set of heat exchange tubes (317) being located above the second set of heat exchange tubes (316), the refrigerant inlet (101) being located above the third set of heat exchange tubes (317) and configured to supply liquid refrigerant towards the third set of heat exchange tubes (317), and wherein the second set of heat exchange tubes (316) has a pair of side portions (324) extending along the length direction of the cavity (310), and there is a certain distance between each of the pair of side portions (324) of the second set of heat exchange tubes (316) and the housing (203), and the top of the first set of heat exchange tubes (315) has a pair of protruding portions (326) respectively extending beyond the pair of side portions (324) of the second set of heat exchange tubes (316) in the width direction (W) of the cavity (310); And A pair of bottom partitions (320) respectively adjacent to and extending along the pair of side portions (324) of the second set of heat exchange tubes (316) and the pair of protruding portions (326) of the first set of heat exchange tubes (315) to jointly define a bottom heat exchange space (331) with the housing (203) through the pair of bottom partitions (320), the bottom heat exchange space (331) having a first fluid outlet (328) located at the top of the bottom partition (320), and the first fluid outlet (328) being in fluid communication with the refrigerant outlet (102).

2. The evaporator according to claim 1, characterized in that: The third set of heat exchange tubes (317) has a pair of side portions (325) extending along the length direction (L) of the cavity (310), and there is a certain distance between each of the pair of side portions (325) of the third set of heat exchange tubes (317) and the housing (203); The evaporator (100) further includes a pair of upper partition plates (323), and the pair of upper partition plates (323) respectively extend adjacent to and along a pair of side portions (325) of the third group of heat exchange tubes (317) to define an upper heat exchange space (332) through the pair of upper partition plates (323). The upper heat exchange space (332) has a second fluid outlet (329) at the bottom of the upper partition plate (323), and the second fluid outlet (329) is in fluid communication with the refrigerant outlet (102).

3. The evaporator according to claim 2, wherein: Each of the pair of bottom partition plates (320) extends along a pair of extending portions (326) of the first group of heat exchange tubes (315) to be connected to the housing (203).

4. The evaporator according to claim 3, wherein: The heat exchange tubes in the first group of heat exchange tubes (315), the second group of heat exchange tubes (316), and the third group of heat exchange tubes (317) have the same diameter and are arranged in columns along the width direction (W) of the cavity (310); wherein the number of columns of the second group of heat exchange tubes (316) is less than the maximum number of columns of the first group of heat exchange tubes (315).

5. The evaporator according to claim 4, wherein: The number of columns of the second group of heat exchange tubes (316) is not less than the number of columns of the third group of heat exchange tubes (317).

6. The evaporator according to claim 1, wherein: Each of the pair of bottom partition plates (320) includes a transverse partition plate (321) extending along a pair of extending portions (326) of the first group of heat exchange tubes (315), and the transverse partition plate (321) extends at least partially obliquely with respect to the width direction (W) of the cavity (310).

7. The evaporator according to claim 1, wherein: Each of the pair of bottom partition plates (320) includes a transverse partition plate (321) extending along a pair of extending portions (326) of the first group of heat exchange tubes (315), and the transverse partition plate (321) extends at least partially obliquely with respect to the length direction (L) of the cavity (310).

8. The evaporator according to claim 6 or 7, wherein: The transverse partition plate (321) has at least one through hole (435) penetrating through the transverse partition plate (321), and the at least one through hole (435) is provided on a portion of the transverse partition plate (321) extending obliquely with respect to the width direction (W) of the cavity (310) or on a portion of the transverse partition plate (321) extending obliquely with respect to the length direction (L) of the cavity (310).

9. The evaporator according to claim 1, wherein: The sum of the number of heat exchange tubes in the first group of heat exchange tubes (315) and the second group of heat exchange tubes (316) is equal to the number of heat exchange tubes in the third group of heat exchange tubes (317).

10. A refrigeration system, characterized in that Comprising: A compressor (193), a condenser (191), a throttling device (192) and an evaporator (100) are provided in a refrigerant circuit, wherein the evaporator (100) is the evaporator according to any one of claims 1-9.

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