CN210137561U

CN210137561U - Refrigeration system

Info

Publication number: CN210137561U
Application number: CN201920343760.0U
Authority: CN
Inventors: 周晓晓; 秦艳; 钟建法
Original assignee: Dunan Environment Technology Co Ltd
Current assignee: Dunan Environment Technology Co Ltd
Priority date: 2019-03-18
Filing date: 2019-03-18
Publication date: 2020-03-10
Anticipated expiration: 2029-03-18

Abstract

The utility model relates to a refrigerating system, which is used for cooling at least one group of backboard air conditioning units, each group of backboard air conditioning unit comprises at least one backboard air conditioner, and each backboard air conditioner comprises a first backboard and a second backboard; the refrigeration system comprises a heat exchanger and a refrigeration unit connected to the heat exchanger, at least one tube pass and at least two shell passes are arranged in the heat exchanger, each shell pass comprises a first shell pass and a second shell pass which are mutually spaced, the first shell pass and the second shell pass are respectively communicated with a first back plate and a second back plate of the back plate air conditioner, and the tube passes are communicated with the refrigeration unit and cool the first back plate and the second back plate through the shell passes. The utility model provides a refrigerating system can make the heat load uniform distribution of the backplate air conditioner that shell and tube type heat exchanger bore to refrigerating unit, and refrigerating unit redistribution heat load is given each compressor, guarantees that the life-span of each parts such as compressor keeps unanimous relatively, has reduced the system dimension degree of difficulty.

Description

Refrigeration system

Technical Field

The utility model relates to an air conditioning technology field especially relates to a refrigerating system.

Background

With the coming of big data era, a large number of informatization machine rooms are needed as basic supports, electronic information equipment in the machine rooms undertakes functions of data storage, calculation and the like, and in order to guarantee normal operation of the electronic information equipment, the machine rooms need uninterrupted refrigeration operation of an air conditioner all the year round to dissipate heat of the cabinet. The server of the cabinet radiates heat in the operation process, air near the server absorbs heat and rises in temperature and is discharged to form hot air, and the back plate air conditioner is close to the hot air and absorbs heat of the hot air to reduce the temperature of the hot air. Because the hot air working conditions and temperatures processed by the back plates of the back plate air conditioner are different, and the back plates are respectively connected with different refrigerating units, the loads borne by the corresponding refrigerating units are different, so that the running time and the switching frequency of each refrigerating unit are different, the service lives of the components of each refrigerating unit are different, for example, the running time, the switching frequency and the like of the compressor of each refrigerating unit are greatly different, and the maintenance difficulty of the refrigerating system is increased.

SUMMERY OF THE UTILITY MODEL

Therefore, it is necessary to provide a refrigeration system for cooling at least one group of back plate air conditioning units, where each group of back plate air conditioning units includes at least one back plate air conditioner, and each back plate air conditioner includes a first back plate and a second back plate; the refrigeration system comprises a heat exchanger and a refrigeration unit connected to the heat exchanger, at least one tube pass and at least two shell passes are arranged in the heat exchanger, each shell pass comprises a first shell pass and a second shell pass which are mutually spaced, the first shell pass and the second shell pass are respectively communicated with a first back plate and a second back plate of the back plate air conditioner, and the tube passes are communicated with the refrigeration unit and cool the first back plate and the second back plate through the shell passes.

In one embodiment, the first shell side and the second shell side have equal space size.

In one embodiment, each set of the back plate air conditioning units comprises a plurality of back plate air conditioners, and first back plates of the back plate air conditioners are communicated with the first shell pass; and/or the presence of a catalyst in the reaction mixture,

and the second back plates of the back plate air conditioners are communicated with the second shell pass.

In one embodiment, the number of the groups of the back plate air conditioning units is one, and the number of the shell sides is two; one shell pass is communicated with a first back plate of the back plate air conditioner, and the other shell pass is communicated with a second back plate of the back plate air conditioner.

In one embodiment, the number of the back plate air conditioning units is multiple, the number of the shell sides of the heat exchanger is at least twice of the number of the back plate air conditioning units, and the multiple shell sides are spaced from each other.

In one embodiment, the number of the back plate air conditioning units is two, and the number of the shell sides is four; two of the four shell passes are communicated with a first back plate of the back plate air conditioner, and the remaining two shell passes are communicated with a second back plate of the back plate air conditioner.

In one embodiment, the heat exchanger includes a shell and an intermediate tube sheet disposed inside the shell, the intermediate tube sheet spacing the shell and forming the shell side.

In one embodiment, the heat exchanger further comprises a heat exchange tube extending through the intermediate tube sheet and forming the tube pass.

In one embodiment, the number of the tube passes is multiple, the number of the refrigerating unit groups is multiple, and each tube pass is correspondingly communicated with one group of the refrigerating unit groups.

In one embodiment, the number of the tube passes is more than two.

The utility model provides a refrigerating system can make the heat load of the backplate air conditioner that the heat exchanger bore distribute each refrigerating unit on average in unison to make the load that each compressor bore average, balanced operation guarantees that the life-span of each part such as compressor keeps unanimous relatively, has reduced the system maintenance degree of difficulty.

Drawings

Fig. 1 is a schematic structural diagram of a refrigeration system and a back plate air conditioning unit according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a backplane air conditioner in the backplane air conditioning unit shown in FIG. 1;

FIG. 3 is a schematic diagram of the configuration of the refrigeration unit of the refrigeration system of FIG. 1;

FIG. 4 is a schematic diagram of a heat exchanger in the refrigeration system of FIG. 1;

FIG. 5 is a schematic view of the heat exchanger shown in FIG. 4 from another perspective;

FIG. 6 is a schematic view of the heat exchanger shown in FIG. 4 from yet another perspective;

fig. 7 is a schematic structural diagram of a refrigeration system and a back plate air conditioning unit according to another embodiment of the present invention;

FIG. 8 is a schematic diagram of a heat exchanger in the refrigeration system of FIG. 7;

FIG. 9 is a schematic view of another perspective of the heat exchanger shown in FIG. 8;

fig. 10 is a schematic view of the heat exchanger shown in fig. 8 from a further perspective.

Description of the main elements

The following detailed description of the invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

It will be understood that when an element is referred to as being "mounted on" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 and 2, fig. 1 is a schematic structural diagram of a refrigeration system 100 and a backplane air conditioning unit 200 according to an embodiment of the present invention, and fig. 2 is a schematic structural diagram of a backplane air conditioner 210 in the backplane air conditioning unit 200 shown in fig. 1. The utility model provides a refrigerating system 100, it is used for cooling backplate air conditioning unit 200 for backplate air conditioning unit 200 resumes cryogenic ability again.

In this embodiment, the backplane air conditioning unit 200 of the refrigeration system 100 is used for cooling the servers 300 in the cabinets of the computer room to solve the problem of heat dissipation of the cabinets. The first refrigerant flows through the back plate air conditioning unit 200, evaporates and absorbs heat to be gasified into gas in the back plate air conditioning unit 200, the gasified gas enters the refrigerating system 100 to be condensed into liquid, and then returns to the back plate air conditioning unit 200 again, and the liquid is circulated in sequence to continuously absorb heat emitted by the server 300 in the computer room, so that the heat dissipation problem of the server 300 is solved. It is understood that the refrigeration system 100 may also be used in a factory or other location to address heat dissipation issues.

The refrigeration system 100 includes a heat exchanger 10 and a refrigeration unit 20, and the heat exchanger 10 is connected to the refrigeration unit 20 and the backplate air conditioning unit 200, respectively. The heat exchanger 10 is used for communicating the refrigeration unit 20 and the backplate air conditioning unit 200 and providing a heat exchange space, the refrigeration unit 20 is used for providing a second refrigerant to cool a first refrigerant in the backplate air conditioning unit 200, and the first refrigerant and the second refrigerant exchange heat in the heat exchanger 10. It is understood that the first refrigerant and the second refrigerant may adopt the same refrigerant medium or different refrigerant media.

The heat is radiated during the operation of the server 300, the air near the server 300 absorbs heat and is heated and discharged to form hot air, and the backplane air conditioning unit 200 approaches the hot air and absorbs heat to reduce the temperature of the hot air. When passing through the hot air near the server 300, the first refrigerant in the backplate air conditioning unit 200 absorbs the energy of the hot air, and undergoes phase change, the phase-changed first refrigerant exchanges heat with the second refrigerant from the refrigerator unit 20 at the heat exchanger 10, and undergoes phase change again, the first refrigerant flows through the vicinity of the cabinet server 300 again to absorb heat, so as to form a cycle, and the second refrigerant absorbs heat, evaporates, and is cooled again by the refrigerator unit 20, so as to form a cycle.

Referring to the schematic structural diagram of the backplane air conditioner 210 in the backplane air conditioning unit 200 shown in fig. 2, the backplane air conditioning unit 200 includes at least one backplane air conditioner 210, and since the backplane air conditioner 210 includes a first backplane 211 and a second backplane 212, and the first backplane 211 and the second backplane 212 are respectively connected to the heat exchanger 10, air is changed into hot air by the server 300 and is sequentially cooled by the first backplane 211 and the second backplane 212, that is, the hot air is cooled by the first backplane 211 and then is cooled by the second backplane 212 again, and the working temperatures of the hot air processed by the first backplane 211 and the second backplane 212 are different.

Referring to the schematic structural diagram of the refrigeration unit 20 shown in fig. 3, the refrigeration unit 20 includes a natural cold source circulation loop and a compressor circulation loop, the natural cold source circulation loop and the compressor circulation loop are respectively connected to the heat exchanger 10, the natural cold source circulation loop and the compressor circulation loop respectively represent two refrigeration modes, the natural cold source circulation loop can operate without a compressor 26, energy can be saved under the same refrigeration capacity, and the compressor circulation loop can be suitable for an environment temperature of more than 10 ℃; when the ambient temperature is less than 10 ℃, the system runs in a heat pipe mode and adopts a natural cold source circulation loop.

The natural cold source circulation loop comprises a check valve 21, a condenser 22, a liquid storage device 23 and an electric valve 242, wherein the check valve 21 is connected with the heat exchanger 10, the inlet of the condenser 22 is connected with the check valve 21, the outlet of the condenser 22 is connected with the liquid storage device 23, the liquid storage device 23 is connected with the electric valve 242, and the electric valve 242 is connected with the heat exchanger 10. The flowing process of the second refrigerant in the natural cold source circulation loop is as follows: heat exchanger 10-check valve 21-condenser 22-reservoir 23-electric valve 242-heat exchanger 10.

The compressor circulation loop comprises a gas-liquid separator 25, a compressor 26, a condenser 22, a liquid accumulator 23 and a throttling device 241, wherein the gas-liquid separator 25 is connected with the heat exchanger 10, the inlet of the compressor 26 is connected with the gas-liquid separator 25, the outlet of the compressor 26 is connected with the condenser 22, the condenser 22 is connected with the liquid accumulator 23, the liquid accumulator 23 is connected with the throttling device 241, and the throttling device 241 is connected with the heat exchanger 10. The flowing process of the second refrigerant in the circulating loop of the compressor is as follows: the heat exchanger 10, the gas-liquid separator 25, the compressor 26, the condenser 22, the accumulator 23, the throttling device 241 and the heat exchanger 10.

Specifically, the condenser 22 may be, for example, an air-cooled condenser 22. The throttling device 241 may be an expansion valve, such as an electronic expansion valve, a thermostatic expansion valve, etc.; the electric valve 242 may be, for example, a solenoid valve or an electric ball valve.

It is understood that the refrigeration unit 20 only needs to absorb the heat of the first refrigerant, and in other embodiments, the refrigeration unit 20 may also adopt other structures and corresponding connection manners, for example, only adopts a compressor for refrigeration.

In the present embodiment, the heat exchanger 10 is a shell-and-tube heat exchanger. Referring to fig. 4 to 6 and fig. 8 to 10, a tube side 11 and at least two shell sides 12 are formed inside the heat exchanger 10, and the shell sides include a first shell side 121 and a second shell side 122 which are spaced from each other. Tube side 11 and shell side 12 are formed by separating the internal space of heat exchanger 10, and first shell side 121 and second shell side 122 are formed by separating the space of shell side 12, first shell side 121 and second shell side 122 are spaced from each other, and first shell side 121 and second shell side 122 are two independent shell side 12 spaces.

The heat exchanger 10 includes a shell 13, a heat exchange tube 14, a first tube plate 15, and a second tube plate 16, wherein the first tube plate 15 and the second tube plate 16 are fixed at two ends of the shell 13, so that a sealed space is formed inside the shell 13, the heat exchange tube 14 extends to two ends of the shell 13 along an axial direction of the shell 13, and two ends of the heat exchange tube 14 are respectively inserted and fixed to the first tube plate 15 and the second tube plate 16. It will be appreciated that tube side 11 is defined by the interior space of heat exchange tube 14 and shell side 12 is defined by the space between the outer wall of heat exchange tube 14 and the inner wall of shell 13.

The first shell side 121 and the second shell side 122 are respectively communicated with a first back plate 211 and a second back plate 212 of the back plate air conditioner 210, and the tube side 11 is communicated with the refrigeration unit 20 and cools the first back plate 211 and the second back plate 212 through the shell side 12.

It can be understood that the first shell side 121 is communicated with the first back plate 211, the second shell side 122 is communicated with the second back plate 212, the refrigerant in the first shell side 121 and the refrigerant in the first back plate 211 exchange heat in the heat exchanger 10 and perform a refrigeration cycle, the refrigerant in the second shell side 122 and the refrigerant in the second back plate 212 exchange heat in the heat exchanger 10 and perform a refrigeration cycle, and the two cycles are independent. When the first back plate 211 is communicated with the first shell pass 121, the heat of the first back plate is taken away by the first refrigerant circulating inside, and similarly, when the second back plate 212 is communicated with the second shell pass 122, the heat of the second back plate is taken away by the first refrigerant circulating inside, so that the first back plate 211 and the second back plate 212 continuously absorb the ambient heat. In this embodiment, the first refrigerant undergoes a phase change during the circulation process to achieve the purpose of heat exchange.

In one embodiment, the first shell side 121 and the second shell side 122 have the same space size, and the heat exchange volume for the refrigerant to circulate is the same, so that the heat exchange between each shell side and the tube side is balanced, the running time of each component in the refrigeration unit is equivalent, and the problems of uneven service life and maintenance frequency of the refrigeration system component caused by unbalanced load of the back plate air conditioning unit are reduced. Further, the heat exchanger 10 further includes an intermediate tube sheet 17 disposed inside the shell 13, the intermediate tube sheet 17 spacing the shell and dividing the shell side into a plurality of separate shell sides. Specifically, the middle tube plate 17 is fixedly connected with the inner wall of the shell 13, and the heat exchange tube 14 penetrates through the middle tube plate 17. For example, when there are two shell sides 12, that is, there is one first shell side 121 and one second shell side 122, and the number of the intermediate tube plates 17 is one; when the number of the shell sides 12 is four, that is, the number of the first shell side 121 and the second shell side 122 is two, the number of the middle tube plates 17 is three.

Specifically, the heat exchange tubes 14 extend through the intermediate tube sheet 17 and form the tube pass 11. The tube side 11 formed by the heat exchange tubes 14 has an inlet end 111 and an outlet end 112, the heat exchange tubes 14 are not limited to a winding shape and may be U-shaped tubes, W-shaped tubes or straight parallel tubes, and the inlet end 111 and the outlet end 112 may be distributed on the same side or both sides of the housing 13. In this embodiment, the inlet end 111 and the outlet end 112 of the tube pass 11 are distributed on the same side of the shell 13, the second refrigerant flows through the tube pass 11 once, and reciprocates once or twice along the axial direction of the shell 13, where the number of reciprocation times is not limited, and the heat exchange tube 14 may be a U-shaped tube, for example, to increase the heat exchange rate.

In one embodiment, the number of the tube passes 11 is multiple, the number of the refrigeration unit 20 is multiple, and a plurality of the tube passes 11 are correspondingly communicated with a plurality of the refrigeration units 20. The tube pass 11 is correspondingly communicated with each refrigerating unit 20, the plurality of refrigerating units 20 provide a refrigerating cold source for the heat exchanger 10 together, and the heat load conducted by the backboard air conditioning unit 200 is averagely distributed to each refrigerating unit 20. Preferably, the number of refrigeration units 20 is two or more.

Further, the number of the tube passes 11 may be two, three or four, and the number of the connected refrigeration unit 20 is two, three or four, so that inconvenience in installation caused by too many refrigeration units 20 can be prevented.

In one embodiment, the backplane air conditioning assembly 200 includes a plurality of backplane air conditioners 210, and the first backplates 211 of the plurality of backplane air conditioners 210 are all communicated with the first shell side 121.

Specifically, the second backplates 212 of the plurality of backplane air conditioners 210 are all communicated with the second shell pass 122.

It is understood that the backplane air conditioner 210 may be at least one, such as a, for example a may be 1, 2 … … 6, etc. Accordingly, the first shell side 121 is connected to the first backplane 211 of the a backplane air conditioners 210. Further, the second shell side 122 is connected to the second backplates 212 of the a backplane air conditioners 210. By adding a plurality of the back plate air conditioners 210, the number of the heat exchangers 10 is reduced, each back plate air conditioner 210 is not required to be provided with one heat exchanger 10, and heat load brought by the back plate air conditioners 210 is uniformly and evenly transmitted to each refrigerating unit through the heat exchangers 10.

In one embodiment, the number of the backplane air conditioning units 200 is multiple, the number of the shell sides 12 of the heat exchanger 10 is at least twice the number of the backplane air conditioning units 200, and the shell sides 12 are spaced from each other. Each shell side 12 of the heat exchanger 10 is connected to the first back plate 211 and the second back plate 212 of each group of the back plate air conditioning unit 200.

Further, the number of the shell sides 12 is plural and even, and the plural shell sides 12 are spaced from each other. For example, two, four, six, etc., shell sides 12. Correspondingly, the backplane air conditioning assembly 200 is also provided with a plurality of groups, for example, a group B, where B may be 1, 2, 3 … …, etc. Taking 2 sets of backplate air conditioning units 200 as an example, please refer to the refrigeration system 100 shown in fig. 7 to 10, at this time, the number of corresponding shell sides should be 4, which are shell side one, shell side two, shell side three and shell side four, respectively, where the shell side one is communicated with the first backplate 211 of the first set of backplate air conditioning units 200, the shell side two is communicated with the second backplate 212 of the first set of backplate air conditioning units 200, the shell side three is communicated with the first backplate 211 of the second set of backplate air conditioning units 200, the shell side four is communicated with the second backplate 212 of the second set of backplate air conditioning units 200, and the heat exchanger 10 simultaneously bears the heat loads of the two sets of backplate air conditioning units 200. The first shell side and the third shell side connected to the first back plate 211 are the first shell side 121, and the second shell side and the fourth shell side connected to the second back plate 212 are the second shell side 122. Here, the number of the refrigerating unit 20 connected to the heat exchanger may be two or three or four, and is not limited thereto as long as the refrigerating requirement can be satisfied.

In one embodiment, the number of the backplane air conditioning units 200 is one, and the number of the shell sides 12 is two; one shell pass is communicated with the first back plate 211 of the back plate air conditioner 210, and the other shell pass is communicated with the second back plate 212 of the back plate air conditioner 210.

Specifically, please refer to fig. 1 to 2 and fig. 4 to 6, which show a refrigeration system 100, wherein the backplane air conditioning units 200 are 1 group, that is, B is 1, and the number of backplane air conditioning units 200 in each group is a, that is, a backplane air conditioners 210. Correspondingly, the number of the shell sides 12 of the heat exchanger 10 is 2, the number of the first shell side 121 is 1, the first shell side 121 is communicated with the first back plate 211 of the back plate air conditioner 210, the number of the second shell side 122 is 1, the second shell side 122 is communicated with the second back plate 212 of the back plate air conditioner 210, the first shell side 121 is provided with a first shell side inlet 1211 and a first shell side outlet 1212 which are distributed at two sides of the shell 13, and the second shell side 122 is also provided with a second shell side inlet 1221 and a second shell side outlet 1222 which are distributed at two sides of the shell 13. The first refrigerant from the first back plate 211 flows in from the first shell-side inlet 1211 and flows out from the first shell-side outlet 1212, and the first refrigerant from the second back plate 212 flows in from the second shell-side inlet 1221 and flows out from the second shell-side outlet 1222. The number of the refrigerating unit sets 20 is 2, each refrigerating unit set 20 is connected with one tube pass 11, so that the number of the tube passes 11 is 2, and the inlet end 111 and the outlet end 112 of each tube pass 11 are distributed on the same side.

The utility model provides a refrigerating system 100's theory of operation does: the first refrigerant of the backplate air conditioning unit 200 absorbs the heat dissipated by the server 300 when passing through the cabinet, then flows through the shell side 12 of the heat exchanger 10, and exchanges heat with the second refrigerant of the tube side 11 at the shell side 12, that is, the first refrigerant is cooled and condensed, the second refrigerant absorbs the heat, the first refrigerant returns to the backplate air conditioner 210 again under the action of gravity to absorb the heat, and the second refrigerant passes through the refrigerating unit 20 to obtain the low-temperature second refrigerant. The utility model provides a refrigerating system 100, the heat load that can make backplate air conditioning unit 200 that shell and tube type heat exchanger bore is unified and evenly distributes to refrigerating unit 20, and refrigerating unit 20 redistributes the heat load and gives each compressor 26 for the heat load that each part such as compressor 26 bore is impartial, guarantees that the life-span of each part of compressor 26 keeps unanimous relatively, has reduced the system maintenance degree of difficulty.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A refrigeration system is used for cooling at least one group of back plate air conditioning units, each group of back plate air conditioning units comprises at least one back plate air conditioner, and each back plate air conditioner comprises a first back plate and a second back plate; the refrigeration system comprises a heat exchanger and a refrigeration unit connected to the heat exchanger, and is characterized in that at least one tube side and at least two shell sides are arranged in the heat exchanger, each shell side comprises a first shell side and a second shell side which are mutually spaced, the first shell side and the second shell side are respectively communicated with a first back plate and a second back plate of the back plate air conditioner, and the tube sides are communicated with the refrigeration unit and cool the first back plate and the second back plate through the shell sides.

2. The refrigerant system as set forth in claim 1, wherein said first shell side and said second shell side are of equal spatial size.

3. The refrigeration system of claim 1 wherein each of said backplane air conditioning units comprises a plurality of said backplane air conditioners, a first backplane of each of said plurality of backplane air conditioners being in communication with said first shell side; and/or the presence of a catalyst in the reaction mixture,

4. The refrigerant system as set forth in claim 1, wherein said backplane air conditioning units are in one group and said shell passes are two in number; one shell pass is communicated with a first back plate of the back plate air conditioner, and the other shell pass is communicated with a second back plate of the back plate air conditioner.

5. The refrigerant system as set forth in claim 1, wherein said back panel air conditioning packs are in groups, said heat exchangers have shell sides at least twice as many as said back panel air conditioning packs, and a plurality of said shell sides are spaced from one another.

6. The refrigerant system as set forth in claim 5, wherein said back panel air conditioning units are two in number and said shell side is four in number; two of the four shell passes are communicated with a first back plate of the back plate air conditioner, and the remaining two shell passes are communicated with a second back plate of the back plate air conditioner.

7. The refrigerant system as set forth in claim 1, wherein said heat exchanger includes a shell and an intermediate tube sheet disposed inside said shell, said intermediate tube sheet spacing said shell and forming said shell side.

8. The refrigerant system as set forth in claim 7, wherein said heat exchanger further includes heat exchange tubes extending through said intermediate tube sheet and forming said tube side.

9. The refrigerant system as set forth in claim 1, wherein said number of tube passes is plural, said number of refrigeration unit groups is plural, and each of said tube passes communicates with a corresponding one of said refrigeration unit groups.

10. The refrigerant system as set forth in claim 9, wherein said number of tube passes is two or more.