CN212390655U

CN212390655U - Evaporator and refrigerating system

Info

Publication number: CN212390655U
Application number: CN202021707950.5U
Authority: CN
Inventors: 苏秀平; 梅露; 袁斌
Original assignee: York Wuxi Air Conditioning and Refrigeration Co Ltd; Johnson Controls Technology Co
Current assignee: York Wuxi Air Conditioning and Refrigeration Co Ltd; Johnson Controls Technology Co
Priority date: 2020-08-14
Filing date: 2020-08-14
Publication date: 2021-01-22
Anticipated expiration: 2030-08-14

Abstract

The application discloses evaporimeter reaches refrigerating system including evaporimeter, and the evaporimeter includes: the shell is provided with a cavity; the heat exchange tube comprises a first group of heat exchange tubes, a second group of heat exchange tubes and a third group of heat exchange tubes, wherein the first group of heat exchange tubes, the second group of heat exchange tubes and the third group of heat exchange tubes are arranged from bottom to top; and a pair of bottom partitions respectively adjacent to and extending along the pair of side portions and the pair of extensions to define a bottom heat exchanging space together with the housing through the pair of bottom partitions. The evaporator of the application sets a part of the first group of heat exchange tubes used as the full liquid tube bundle as the second group of heat exchange tubes, so that the filled refrigerant only needs to submerge the first group of heat exchange tubes less, and the required refrigerant filling amount is reduced. And the present application correspondingly provides a bottom partition to restrict 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.

Description

Evaporator and refrigerating system

Technical Field

The application relates to the field of refrigeration systems, in particular to a falling film evaporator and a refrigeration system using the same.

Background

The refrigeration system mainly comprises four components of a compressor, a condenser, a throttling device and an evaporator, wherein the evaporator is used for evaporating liquid refrigerant into gaseous refrigerant. A falling film evaporator is a common evaporator, and includes a falling film tube bundle, and a distributor is usually used to distribute a refrigerant to the surfaces of heat exchange tubes of the falling film tube bundle, so as to form a liquid film on the surfaces of the heat exchange tubes for evaporation. The falling film evaporator utilizes a film evaporation mechanism on the surface of the heat exchange tube, has the advantages of high heat transfer efficiency and small refrigerant filling amount, and is a research hotspot in the air conditioning industry in recent years.

Falling film evaporators generally include a flooded tube bank disposed at the bottom of the evaporator and a falling film tube bank disposed above the flooded tube bank. 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 hot fluid flowing through the inside of the heat exchange tube of the falling film tube bundle, a part of liquid refrigerant is evaporated into gaseous refrigerant, the liquid refrigerant which is not evaporated falls into the full liquid tube bundle area and exchanges heat with the hot fluid inside the heat exchange tube of the full liquid tube bundle, and the liquid refrigerant is further evaporated.

SUMMERY OF THE UTILITY MODEL

On the one hand, in order to prevent the heat exchange tubes at the bottom of the falling film tube bundle from generating dry spots so as to reduce the heat exchange efficiency of the falling film tube bundle, the proportion of the number of the heat exchange tubes in the falling film tube bundle to the number of the header tubes in the whole evaporator cannot be too high. On the other hand, to ensure the heat exchange efficiency of the flooded tube bundle, a sufficient refrigerant charge is usually required to fully immerse the flooded tube bundle in the liquid refrigerant. Therefore, the falling film evaporator with a constant number of header pipes can achieve the maximum heat exchange efficiency.

At least one object of the present application is to reduce the flow of charged liquid refrigerant while ensuring maximum heat transfer efficiency of the falling film evaporator.

In order to solve the above problems, the present application provides, in a first aspect, an evaporator comprising: the refrigerator comprises a shell, a refrigerator and a refrigerator, wherein the shell is provided with a cavity, a refrigerant inlet and a refrigerant outlet which are communicated with the cavity, and the cavity is provided with a length direction, a width direction and a height direction; each of the first group of heat exchange tubes, the second group of heat exchange tubes and the third group of heat exchange tubes extends along the length direction of the cavity, the first group of heat exchange tubes and the second group of heat exchange tubes are positioned at the bottom of the cavity, the second group of heat exchange tubes are positioned above the first group of heat exchange tubes, the third set of heat exchange tubes is positioned above the second set of heat exchange tubes, the refrigerant inlet is positioned above the third set of heat exchange tubes and is configured to provide liquid refrigerant toward the third set of heat exchange tubes, and the second group of heat exchange tubes are provided with a pair of side parts extending along the length direction of the cavity, a certain distance is reserved between the pair of side parts of the second group of heat exchange tubes and the shell respectively, the top of the first group of heat exchange tubes is provided with a pair of protrusions respectively extending beyond a pair of side parts of the second group of heat exchange tubes in the width direction of the cavity; and a pair of bottom baffles respectively adjacent to and extending along a pair of sides of the second set of heat exchange tubes and a pair of extensions of the first set of heat exchange tubes to cooperatively define a bottom heat exchange space with the housing through the pair of bottom baffles, the bottom heat exchange space having a first fluid outlet at a top of the bottom baffles, the first fluid outlet being in fluid communication with the refrigerant outlet.

According to the first aspect, the third group of heat exchange tubes has a pair of side portions extending along the length direction of the cavity, and a certain distance is formed between each of the pair of side portions of the third group of heat exchange tubes and the shell; the evaporator further comprises a pair of upper baffles respectively adjacent to and extending along a pair of sides of the third set of heat exchange tubes to define an upper heat exchange space therethrough, the upper heat exchange space having a second fluid outlet at a bottom of the upper baffles, the second fluid outlet being in fluid communication with the refrigerant outlet.

According to the first aspect described above, each of the pair of bottom partitions extends along the pair of extensions of the first set of heat exchange tubes to meet the shell.

According to the first aspect, the heat exchange tubes in the first group of heat exchange tubes, the second group of heat exchange tubes and the third group of heat exchange tubes have the same tube diameter and are arranged in a row along the width direction of the cavity; wherein the number of rows of the second group of heat exchange tubes is less than the maximum number of rows of the first group of heat exchange tubes.

According to the first aspect, the number of rows of the second group of heat exchange tubes is not less than the number of rows of the third group of heat exchange tubes.

According to the first aspect described above, each of the pair of bottom partitions includes a transverse partition extending along a pair of extensions of the first group of heat exchange tubes, the transverse partition extending at least partially obliquely with respect to the width direction of the plenum.

According to the first aspect described above, each of the pair of bottom partitions includes a transverse partition extending along a pair of extensions of the first set of heat exchange tubes, the transverse partition extending at least partially obliquely with respect to the length of the plenum.

According to the first aspect, the transverse partition has at least one through hole penetrating through the transverse partition, and the at least one through hole is provided in a portion of the transverse partition extending obliquely with respect to the width direction of the cavity or in a portion of the transverse partition extending obliquely with respect to the length direction of the cavity.

According to the first aspect, the sum of the number of the heat exchange tubes of the first group of heat exchange tubes and the second group of heat exchange tubes is equal to the number of the heat exchange tubes of the third group of heat exchange tubes.

The present application provides, in a second aspect, a refrigeration system comprising: a compressor, a condenser, a throttling device and an evaporator arranged in a refrigerant circuit, wherein the evaporator is as described in any one of the above first aspects.

Drawings

FIG. 1 is a schematic block diagram of a refrigeration system of the present application;

FIG. 2 is a perspective view of the evaporator of FIG. 1;

FIG. 3 is a schematic axial cross-sectional view of one embodiment of the evaporator of FIG. 2;

FIG. 4 is a perspective view of one embodiment of the bottom spacer of FIG. 3;

FIG. 5 is a schematic axial cross-sectional view of another embodiment of the evaporator of FIG. 2;

FIG. 6A is a perspective view of another embodiment of the bottom spacer of FIG. 3;

fig. 6B is a left side view of fig. 6A.

Detailed Description

Various embodiments of the present invention will now be described with reference to the accompanying drawings, which form a part hereof. It should be understood that although directional terms, such as "front," "rear," "upper," "lower," "left," "right," "top," "bottom," and the like may be used herein to describe various example structural portions and elements of the application, these terms are used herein for convenience of description only and are to be determined based on the example orientations shown in the figures. Because the embodiments disclosed herein can be arranged in a variety of orientations, these directional terms are used for purposes of illustration only and are not to be construed as limiting.

Fig. 1 is a schematic block diagram of a refrigeration system 190 of the present application for illustrating the location and function of an evaporator 100 in the refrigeration system 190.

As shown in fig. 1, the refrigeration system 190 includes a compressor 193, a condenser 191, a throttling device 192, and an evaporator 100, which are connected by piping to form a closed system, and a refrigerant is charged in the system. Wherein the refrigerant sequentially flows through the compressor 193, the condenser 191, the throttling device 192, and the evaporator 100, so that the refrigeration system 190 can cool the outside. Specifically, the high-pressure gas refrigerant discharged from the compressor 193 flows into the condenser 191, releases heat in the condenser 191, is condensed into a high-pressure liquid refrigerant, then flows into the expansion device 192, is expanded into a low-pressure two-phase refrigerant, flows into the evaporator 100 through the refrigerant inlet 101 of the evaporator 100, absorbs heat in the evaporator 100, is evaporated into a low-pressure gas refrigerant, and finally flows out of the refrigerant outlet 102 of the evaporator 100 and flows into the compressor 193 again, thereby completing the refrigerant cycle. As one example, evaporator 100 is a falling film evaporator.

Fig. 2 is a perspective view of the evaporator 100 of fig. 1, illustrating an external structure of the evaporator 100.

As shown in fig. 2, the falling film evaporator 100 has a housing 203, and the housing 203 has a substantially cylindrical shape, and has a longitudinal direction L, a width direction W, and a height direction H. The shell 203 is provided with a refrigerant inlet 101, a refrigerant outlet 102, and inlet and

outlet pipes

207, 208. Wherein the refrigerant inlet 101 is disposed at an upper middle portion of the housing 203 and is in fluid communication with an outlet of the throttling device 192 to provide a two-phase refrigerant to the interior of the housing 203. The flow rate of the refrigerant flowing through the refrigerant inlet 101 may be controlled by a known control device such as a valve, which is not specifically described herein, and a plurality of refrigerant inlets may be provided according to different designs of the falling film evaporator. The refrigerant outlet 102 is in fluid communication with the suction side of the compressor 193 to discharge the gaseous refrigerant evaporated inside the housing 203 to the suction side of the compressor 193. In the present embodiment, the refrigerant outlet 102 is disposed above the middle of the housing 203.

The shell 203 has tube plates 205 at both ends for closing the shell 203, wherein the tube plate 205 at the front side is further provided with water inlet and

outlet tubes

207, 208. The inlet and

outlet pipes

207, 208 are in fluid communication with the hot water and with the interior of the heat exchange tubes in the housing 203 for providing the heat exchange tubes with hot water for heat exchange.

Accordingly, the two-phase refrigerant from the expansion device 192 enters the interior of the shell 203 of the falling film evaporator 100 from the refrigerant inlet 101, exchanges heat with the heat exchange tubes in the shell, absorbs heat and is evaporated into a gas, and then is discharged from the falling film evaporator 100 through the refrigerant outlet 102 and flows into the suction end of the compressor 193. Wherein, the medium water for heat exchange in the heat exchange tube flows in and out from the heat exchange tube through the water inlet and

outlet tubes

207 and 208.

Fig. 3 is a schematic axial sectional view of an embodiment of the falling film evaporator 100, illustrating the internal structure of the shell 203 of the falling film evaporator 100. As shown in fig. 3, the housing 203 has a cavity 310 defined therein by the housing 203, and the refrigerant inlet 101 and the refrigerant outlet 102 are in fluid communication with the cavity 310. The vessel 310 includes a plurality of heat exchange tubes, a distributor 341, and a demister 313 therein. Distributor 341 is attached to tube sheet 205 at both ends of shell 203. The tubes of the refrigerant inlet 101 extend into the housing 203 and are in fluid communication with the distributor 341. The heat exchange pipe is disposed under the distributor 341. The demister 313 is connected between the distributor 341 and the case 203, and is located between the heat exchange tubes and the refrigerant outlet 102. As one example, the mist eliminator 313 may be a wire mesh or the like for filtering droplets entrained in the gaseous refrigerant. Thus, the two-phase refrigerant flowing from the refrigerant inlet 101 is distributed by the distributor 341, exchanges heat with the heat exchange tubes below the distributor 341 to become a gaseous refrigerant, and then passes through the demister 313 to be discharged out of the receiving chamber 310 through the refrigerant outlet 102 after removing entrained liquid droplets.

Specifically, the heat exchange tubes 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 in order from bottom to top in the height direction H. Each group of heat exchange tubes comprises a plurality of heat exchange tubes extending along the length direction L, the front end and the rear end of each heat exchange tube in the length direction L are supported on the tube plate 205, and the interiors of the heat exchange tubes are communicated with the water inlet tube 207 and the water outlet tube 208. As an example, the sets of heat exchange tubes are arranged in a row. Of course, in other examples, the heat exchange tubes may be arranged in other manners, such as in rows. In this embodiment, a first set of heat exchange tubes 315 is located at the bottom of the chamber 310 as a flooded tube bundle for flooded heat exchange immersed in liquid refrigerant. A third set of heat exchange tubes 317 is located in the upper middle portion of the vessel 310 as a falling film tube bundle for falling film heat exchange. A second set of heat exchange tubes 316 is positioned between the first set of heat exchange tubes 315 and the third set of heat exchange tubes 317 for transition between a liquid full tube bundle and a falling film tube bundle, capable of exchanging heat with both excess liquid refrigerant flowing downwardly from the third set of heat exchange tubes 317 and liquid refrigerant entrained in gaseous refrigerant flowing upwardly from the first set of heat exchange tubes 315. As a specific example, a first set of heat exchange tubes 315 extends across the bottom of the vessel 310, and a second set of heat exchange tubes 316 and a third set of heat exchange tubes 317 are arranged in a generally square configuration. The width of the second group of heat exchange tubes 316 is smaller than the width of the tops of the first group of heat exchange tubes 315 and not smaller than the width of the third group of heat exchange tubes 317 in the width direction W. Under the condition that the pipe diameters of the heat exchange pipes in each group of heat exchange pipes are the same, the number of the rows of the second group of heat exchange pipes 316 is less than the maximum number of the rows of the first group of heat exchange pipes 315 (namely, the number of the rows at the top of the first group of heat exchange pipes), and is greater than or equal to the number of the rows of the third group of heat exchange pipes 317.

The chamber 310 further includes partitions connected at front and rear ends thereof in the length direction L to the tube sheets 205 at both ends of the shell 203, and defining an upper heat exchange space 332 and a bottom heat exchange space 331 with the partitions and the shell 203. The refrigerant exchanges heat with the heat exchange tubes in the defined upper and lower

heat exchange spaces

332 and 331. Specifically, the housing 310 includes a pair of upper baffles 323 and a pair of bottom baffles 320. The third group 317 of heat exchange tubes has a pair of side portions 325 opposed in the width direction W and extending in the length direction L, and a pair of upper separators 323 are attached to the tube sheet 205 at both ends of the shell 203 and are respectively disposed outside the pair of side portions 325 so as to extend adjacent to the pair of side portions 325. The pair of upper partition plates 323 have a certain distance between the outer sides thereof and the case 203 to allow the gaseous refrigerant to flow. An upper heat exchange space 332 can be defined between the pair of upper separators 323, and the bottom of the upper separator 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, pass through the demister 313, and be discharged from the refrigerant outlet 102. As a specific example, another portion of the heat exchange tubes of the third set of heat exchange tubes 317 are positioned below the fluid outlet 329 to prevent entrained liquid droplets (i.e., liquid refrigerant) in the escaping gaseous refrigerant from flowing with the gaseous refrigerant.

The second group of heat exchange tubes 316 also has a pair of side portions 324 opposed in the width direction W and extending in the length direction L, and the top of the first group of heat exchange tubes 315 has a pair of projecting portions 326 extending beyond the pair of side portions 324 of the second group of heat exchange tubes 316, respectively, in the width direction W. A pair of bottom baffles 320 are attached to tube sheet 205 at either end of shell 203 and extend adjacent to and along a pair of sides 324 of the second set of heat exchange tubes 316 and a pair of extensions 326 of the first set of heat exchange tubes 315, respectively. Specifically, each bottom partition 320 includes a transverse partition 321 and a longitudinal partition 322, and 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 the present embodiment, each of the transverse partitions 321 extends transversely substantially horizontally along one of the extensions 326 of the first group of heat exchange tubes 315 to be connected to the shell 203, each of the longitudinal partitions 322 extends longitudinally substantially vertically along one of the sides 324 of the second group of heat exchange tubes 316, and the outside of each of the longitudinal partitions 322 is spaced apart from the shell 203 for the flow of gaseous refrigerant. A bottom heat exchange space 331 is defined by a pair of bottom partitions 320 and the shell 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 heat-exchanged in the bottom heat exchange space 311 can escape from the fluid outlet 328, pass through the demister 313, and be discharged from the refrigerant outlet 102. As a specific example, the top of the second set of heat exchange tubes 316 also has one to two rows of heat exchange tubes positioned above the fluid outlet 328 to prevent entrained liquid droplets (i.e., liquid refrigerant) in the escaping gaseous refrigerant from flowing with the gaseous refrigerant.

Thus, in the first aspect, two-phase refrigerant entering from the refrigerant inlet 101 and distributed through the distributor 341 exchanges heat with the third group of heat exchange tubes 317 in the upper heat exchange space 332, in which liquid refrigerant is evaporated to gaseous refrigerant, and the gaseous refrigerant is restrained by the upper partition 323 to escape from the fluid outlet 329. The gaseous refrigerant flows upward to pass through the demister 313 and is discharged from the refrigerant outlet 102, and the remaining liquid refrigerant that has not completely evaporated continues to flow downward by gravity. Since the width of the top of the second set of heat exchange tubes 316 is no less than the width of the bottom of the third set of heat exchange tubes 317, liquid refrigerant can flow downwardly into the bottom heat exchange space 311. After passing through the second set of heat exchange tubes 316, a part of the liquid refrigerant accumulates at the bottom of the chamber 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 a gaseous refrigerant and then escapes from the fluid outlet 328 of the bottom heat exchange space 311, flows upward to pass through the demister 313, and is discharged from the refrigerant outlet 102.

In a second aspect, liquid refrigerant collected at the bottom of the chamber 310 exchanges heat with the first set of heat exchange tubes 315 immersed therein at the lower portion of the bottom heat exchange space 311 to generate a gaseous refrigerant stream (hereinafter referred to as gas stream) carrying liquid refrigerant. The air flow generated by the heat exchange tubes in the first group of heat exchange tubes 315 directly below the second group of heat exchange tubes 316 flows from bottom to top through the second group of heat exchange tubes 316 above the bottom heat exchange space 311. The air flow generated by the pair of protrusions 326 of the first group of heat exchange tubes 315 and the heat exchange tubes directly below the protrusions 326 is first concentrated toward the middle under the restriction of the lateral partition 321 of the bottom partition 320, and then flows through the second group of heat exchange tubes 316 at the upper portion of the bottom heat exchange space 311 from bottom to top. After the liquid refrigerant is changed into gaseous refrigerant by heat exchange with the second group of heat exchange tubes 316, the gaseous refrigerant is limited by the longitudinal partition 322 of the bottom partition 320 and escapes from the fluid outlet 328 of the bottom heat exchange space 311, and then flows upwards to pass through the demister 313 to be discharged from the refrigerant outlet 102.

The liquid refrigerant remaining in the receiving chamber 310 between the outer sides of the pair of upper partition plates 323 and the shell 203 and between the outer sides of the pair of lower partition plates 320 and the shell 203 is returned to the bottom of the receiving chamber 310 through the through holes (see fig. 4 or fig. 6A and 6B) in the bottom partition plate 320 to be heat-exchanged with the heat exchange tubes in the bottom heat exchange space 311.

It can be seen that, by providing the bottom partition 320, the second group of heat exchange tubes 316 can exchange heat with the liquid refrigerant flowing through the third group of heat exchange tubes 317 from top to bottom, and can exchange heat with the liquid refrigerant flowing through the first group of heat exchange tubes 315 from bottom to top, so that each heat exchange tube in the second group of heat exchange tubes 316 can achieve the maximum heat exchange efficiency. In addition, the present application only needs the liquid refrigerant accumulated at the bottom of the cavity 310 to submerge the first group of heat exchange tubes 315, so that the maximum heat exchange efficiency of the heat exchange tubes in the first group of heat exchange tubes 315 can be ensured.

Compared to a falling film evaporator without the second group of heat exchange tubes 316, the falling film evaporator of the present application reduces the number of heat exchange tubes for immersion in the refrigerant, although the sum of the number of heat exchange tubes of the first group of heat exchange tubes 315 and the second group of heat exchange tubes 316 (which is substantially the number of heat exchange tubes in the bottom heat exchange space 311) remains unchanged, given the total number of heat exchange tubes and the number of heat exchange tubes of the third group of heat exchange tubes 317 (which is substantially the number of heat exchange tubes in the upper heat exchange space 332). The heat exchange efficiency of each heat exchange tube can be ensured to be maximum, and the filling amount of the refrigerant can be reduced.

It should be noted that the close proximity in this embodiment means that the partition is close to the heat exchange tubes but does not contact the outer surfaces of the heat exchange tubes to restrict the flow of the gas refrigerant and the liquid refrigerant in the respective heat exchange spaces. 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 the present embodiment, the top or bottom of each group of heat exchange tubes refers to the uppermost or lowermost one 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 rows of heat exchange tubes.

FIG. 4 is a perspective view of one embodiment of the bottom partition 320, illustrating the through holes 435 on the bottom partition 320. As shown in fig. 4, the bottom partition 320 includes a transverse partition 321 and a longitudinal partition 322 which extend in the same length direction L as the heat exchange tubes and are connected to the tube sheets 205 at both ends of the shell 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 arranged at intervals in the length direction of the transverse partition 321 and penetrates through the transverse partition 321. And each through hole 435 is provided on one side edge of the lateral partition 321 for connection with the case 203 to communicate the upper and lower sides of the lateral partition 321, i.e., the outside and inside of the bottom partition 320, through the through hole 435. The liquid refrigerant between the outside of the bottom partition 320 and the shell 203 can flow back into the bottom heat exchange space 311 inside the bottom partition 320 through the through holes 435. And the through holes 435 are arranged in a plurality of spaced apart positions, in some embodiments, the through holes 435 are small in size and not large in number, so that most of the air flow generated by the first group of heat exchange tubes 315 is limited by the transverse partition 321 and flows to the second group of heat exchange tubes 316.

As can be seen in fig. 3, in the present embodiment, the through holes 435 are disposed at the outer side edge (i.e., the side edge for connecting with the shell 203) of the transverse partition 321, so that a part of the accumulated liquid refrigerant can flow along the inner wall of the shell 203 directly through the through holes 435 into the bottom heat exchange space 311. It will be appreciated by those skilled in the art that the through holes 435 may be provided at other locations on the transverse partition 321 as long as the liquid refrigerant is allowed to flow back into the inner bottom heat exchanging space 311 from the outside of the bottom partition 320 by the force of gravity. And in some other examples, other numbers of through-holes 435 may be provided.

Figure 5 is an axial cross-sectional schematic view of another embodiment of a falling film evaporator according to the present application. The general structure of the falling film evaporator 500 and the arrangement of the heat exchange tubes in the present embodiment are the same as those of the falling film evaporator 200, and differ from the falling film evaporator 200 only in the bottom partition structure. As shown in fig. 5, 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 the present embodiment, the lateral partition 521 is not horizontal with respect to the width direction W, but extends obliquely. Specifically, each of the transverse partitions 521 extends from the bottom of the longitudinal partition 522 with a slight downward inclination to be connected to the housing 203. Although not shown in the figure, a plurality of through holes for communicating the outside of the transverse partition 521 with the bottom heat exchange space are also formed at the outer edge of each transverse partition 521, i.e. the edge for connecting with the housing 203.

This arrangement facilitates guiding the remaining liquid refrigerant to the outer side edges of the transverse partition 521, thereby enabling the remaining liquid refrigerant to flow more intensively through the through-holes (not shown) back into the bottom heat exchange space to exchange heat with the heat exchange tubes again.

Fig. 6A and 6B are schematic structural views of another embodiment of the bottom spacer, wherein fig. 6B is a left side view of fig. 6A. As shown in fig. 6A and 6B, the bottom partition 620 also includes a transverse partition 621 and a longitudinal partition 622, the transverse partition 621 having one side edge for connection to the housing and the other side edge for connection to the bottom of the longitudinal partition 622. In the present embodiment, the lateral partition 621 extends obliquely with respect to the longitudinal direction L. Specifically, each of the lateral partitions 621 extends slightly obliquely downward from the rear end to the front end (the lateral partitions 621 extend slightly obliquely downward from the left end to the right end at the angle shown in fig. 6B). The through hole 635 is provided on a lower end, e.g., a front end, of the lateral partition 621. As an example, the through-hole 635 is provided at an outer side edge of the front end of the lateral partition 621. In this embodiment, only one through hole 635 is provided to further reduce the possibility of air flow rushing out of the through hole 635.

This arrangement also facilitates directing the collected residual liquid refrigerant to flow more intensively through the through-holes 635 back to the bottom heat exchange space to exchange heat again with the heat exchange tubes.

Depending on the particular falling film evaporator design, the transverse partitions of the bottom partition may also be designed to extend obliquely to both the longitudinal direction L and the width direction W.

The falling film evaporator sets a part of first group of heat exchange tubes used as the liquid full tube bundle as a second group of heat exchange tubes, so that the filled refrigerant only needs to submerge the first group of heat exchange tubes less, and the required refrigerant filling amount is reduced. And the present application correspondingly provides a bottom partition to restrict 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.

Although the present application will be described with reference to the particular embodiments shown in the drawings, it should be understood that many variations of the evaporator of the present application are possible without departing from the spirit and 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 of varying the details of the structures in the embodiments disclosed herein that fall within the spirit and scope of the invention and the claims.

Claims

1. An evaporator, comprising:

a housing (203), said housing (203) having a cavity (310) and a refrigerant inlet (101) and a refrigerant outlet (102) in communication with said cavity (310), said cavity (310) having a length direction (L), a width direction (W), and a height direction (H);

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), each of 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) extending along a length direction (L) of the chamber (310), the first group of heat exchange tubes (315) and the second group of heat exchange tubes (316) being located at a bottom of the chamber (310), the second group of heat exchange tubes (316) being located above the first group of heat exchange tubes (315), the third group of heat exchange tubes (317) being located above the second group of heat exchange tubes (316), the refrigerant inlet (101) being located above the third group of heat exchange tubes (317) and configured to supply a liquid refrigerant toward the third group of heat exchange tubes (317), and wherein the second group of heat exchange tubes (316) has a pair of side portions (324) extending along the length direction of the chamber (310), a pair of side portions (324) of the second group of heat exchange tubes (316) are respectively spaced from the shell (203), and the top of the first group of heat exchange tubes (315) is provided with a pair of protrusions (326) which respectively extend beyond the pair of side portions (324) of the second group of heat exchange tubes (316) in the width direction (W) of the cavity (310); and

a pair of bottom baffles (320), said pair of bottom baffles (320) extending respectively adjacent and along a pair of sides (324) of said second set of heat exchange tubes (316) and a pair of extensions (326) of said first set of heat exchange tubes (315) to cooperatively define a bottom heat exchange space (331) with said housing (203) through said pair of bottom baffles (320), said bottom heat exchange space (331) having a first fluid outlet (328) at a top of said bottom baffles (320), said first fluid outlet (328) being in fluid communication with said refrigerant outlet (102).

2. The evaporator of claim 1, wherein:

the third group of heat exchange tubes (317) is provided with a pair of side parts (325) extending along the length direction (L) of the cavity (310), and a certain distance is reserved between each pair of side parts (325) of the third group of heat exchange tubes (317) and the shell (203);

the evaporator (100) further comprises a pair of upper baffles (323), the pair of upper baffles (323) respectively extending adjacent to and along a pair of sides (325) of the third set of heat exchange tubes (317) to define an upper heat exchange space (332) with the pair of upper baffles (323), the upper heat exchange space (332) having a second fluid outlet (329) at the bottom of the upper baffles (323), the second fluid outlet (329) being in fluid communication with the refrigerant outlet (102).

3. An evaporator according to claim 2 wherein:

each of the pair of bottom baffles (320) extends along a pair of extensions (326) of the first set of heat exchange tubes (315) to meet the shell (203).

4. An 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 tube diameter and are arranged in a row along the width direction (W) of the cavity (310);

wherein the number of rows of the second group of heat exchange tubes (316) is less than the maximum number of rows of the first group of heat exchange tubes (315).

5. An evaporator according to claim 4 wherein:

the number of columns of the second group of heat exchange tubes (316) is not less than that of the third group of heat exchange tubes (317).

6. The evaporator of claim 1, wherein:

each of the pair of bottom partitions (320) comprises a transverse partition (321) extending along a pair of extensions (326) of the first set of heat exchange tubes (315), the transverse partition (321) extending at least partially obliquely with respect to the width direction (W) of the plenum (310).

7. The evaporator of claim 1, wherein:

each of the pair of bottom baffles (320) comprises a transverse baffle (321) extending along a pair of extensions (326) of the first set of heat exchange tubes (315), the transverse baffle (321) extending at least partially obliquely with respect to the length direction (L) of the plenum (310).

8. An evaporator according to claim 6 or 7 wherein:

the transverse partition (321) has at least one through-hole (335) extending through the transverse partition (321), the at least one through-hole (335) being provided on a portion of the transverse partition (321) extending obliquely with respect to the width direction (W) of the receptacle (310) or on a portion of the transverse partition (321) extending obliquely with respect to the length direction (L) of the receptacle (310).

9. The evaporator of claim 1, wherein:

the sum of the number of the first group of heat exchange tubes (315) and the second group of heat exchange tubes (316) is equal to the number of the third group of heat exchange tubes (317).

10. A refrigeration system, comprising:

a compressor (193), a condenser (191), a throttling device (192) and an evaporator (100) arranged in a refrigerant circuit, wherein the evaporator (100) is according to any one of claims 1-9.