CN219934320U

CN219934320U - Refrigerating unit

Info

Publication number: CN219934320U
Application number: CN202321311983.1U
Authority: CN
Inventors: 孟庆超; 谢吉培; 李林; 陈见兴; 丛辉
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2023-05-26
Filing date: 2023-05-26
Publication date: 2023-10-31
Anticipated expiration: 2033-05-26

Abstract

The utility model discloses a refrigerating unit, and relates to the technical field of refrigerating systems. The refrigerating unit comprises an oilless compressor, an evaporative condenser and a plurality of evaporators connected in parallel; the outlet of the oil-free compressor is communicated with the inlet of the evaporative condenser, the outlet of the evaporative condenser is communicated with the inlets of a plurality of evaporators which are connected in parallel, and the outlets of the evaporators which are connected in parallel are communicated with the inlet of the oil-free compressor; the inlets of the evaporators connected in parallel are respectively and correspondingly communicated with an expansion valve; each expansion valve is used for adjusting the refrigerant quantity in the corresponding evaporator. According to the refrigerating unit disclosed by the embodiment of the utility model, the opening degree of each expansion valve is regulated, so that the temperature control of the space where different evaporators are positioned is realized, and the energy consumption of the system is reduced.

Description

Refrigerating unit

Technical Field

The utility model relates to the technical field of refrigeration systems, in particular to a refrigeration unit.

Background

In the prior art, the cooling water unit conveys the cold source to the indoor end system through the chilled water pump, so that the space is cooled, and the cooling or heating problems of most buildings are solved.

However, the traditional water chilling unit system is divided into a host system and a tail end system, the host system can only output a fixed water temperature according to the setting of a user, the temperature is constant in each room or temperature zone, and the regulation range is narrow only through the wind speed regulation of a tail end fan coil.

Disclosure of Invention

The embodiment of the utility model provides a refrigerating unit, which solves the problems that the output of the traditional water chilling unit can only output one water temperature and the temperature of each temperature zone can not be accurately controlled.

In order to achieve the above object, an embodiment of the present utility model provides a refrigeration unit, including an oil-free compressor, an evaporative condenser, and a plurality of evaporators connected in parallel; the outlet of the oil-free compressor is communicated with the inlet of the evaporative condenser, the outlet of the evaporative condenser is communicated with the inlets of a plurality of evaporators which are connected in parallel, and the outlets of the evaporators which are connected in parallel are communicated with the inlet of the oil-free compressor; the inlets of the evaporators connected in parallel are respectively and correspondingly communicated with an expansion valve; each expansion valve is used for adjusting the refrigerant quantity in the corresponding evaporator.

In some embodiments, the oil-free compressor is a magnetic levitation centrifugal compressor.

In some embodiments, the refrigeration unit further comprises a reservoir having an inlet in communication with the outlet of the evaporative condenser, the outlet of the reservoir in communication with the inlets of the plurality of evaporators in parallel.

In some embodiments, the outlet of the reservoir is further in communication with a flash vessel, the outlet of the flash vessel being in communication with the oil-free compressor.

In some embodiments, the refrigeration unit further comprises a gas-liquid separator, an inlet of the gas-liquid separator being in communication with a plurality of outlets of the evaporators in parallel, an outlet of the gas-liquid separator being in communication with an inlet of the oil-free compressor.

In some embodiments, the refrigeration unit further comprises a chopper valve having an inlet in communication with the outlet of the oil-free compressor and an outlet in communication with the inlet of the gas-liquid separator.

In some embodiments, the outlet of the evaporative condenser is provided with a plurality of branch lines on the inlet communication lines of the plurality of evaporators connected in parallel. Each branch pipeline comprises a main pipe, a first branch pipe and a second branch pipe, wherein the inlet of the first branch pipe and the inlet of the second branch pipe are communicated with the outlet of the main pipe, and an included angle between the flowing direction of the refrigerant in the first branch pipe and the flowing direction of the refrigerant in the second branch pipe and the flowing direction of the refrigerant in the main pipe is an acute angle.

The first branch pipe of the former branch pipe of the adjacent branch pipes is communicated with the main pipe of the latter branch pipe, and the second branch pipe of the former branch pipe is communicated with the main pipe of the other latter branch pipe; the main pipe of the first branch pipeline is communicated with the outlet of the condenser, and the first branch pipe and the second branch pipe of the last branch pipeline are communicated with the expansion valves.

In some embodiments, the outlet of the evaporative condenser is further provided with a main valve on the inlet communication pipe of the plurality of parallel evaporators, and the outlet of the condenser is communicated with the main pipe of the first branch pipe through the main valve.

According to the refrigerating unit provided by the embodiment of the disclosure, as the evaporators are respectively and correspondingly positioned in the indoor environments, the opening degree of the corresponding expansion valve is adjusted according to the environment temperature of the corresponding evaporator, so that the flow of the refrigerant entering the evaporator is adjusted, and the temperatures of different indoor environments can be independently controlled.

In addition, in each branch pipeline, because the included angle between the flowing direction of the refrigerant in the first branch pipe and the second branch pipe and the flowing direction of the refrigerant in the main pipe is an acute angle, the resistance when the liquid refrigerant is shunted into the first branch pipe and the second branch pipe from the main pipe is reduced, the flowing of the liquid refrigerant is smoother, and the pressure loss of the liquid refrigerant flowing to the inlet of the evaporator is reduced.

Drawings

Fig. 1 is a schematic diagram of connection of a refrigeration unit according to an embodiment of the present utility model;

fig. 2 is a schematic structural diagram of a branch pipeline according to an embodiment of the present utility model;

FIG. 3 is a schematic diagram illustrating the connection of a plurality of branch pipes according to an embodiment of the present utility model;

fig. 4 is a second connection schematic diagram of a refrigeration unit according to an embodiment of the present utility model;

FIG. 5 is a second schematic diagram illustrating the connection of a plurality of branch pipes according to an embodiment of the present utility model;

fig. 6 is a third schematic connection diagram of a refrigeration unit according to an embodiment of the present utility model;

fig. 7 is a schematic diagram of connection of a refrigeration unit according to an embodiment of the present utility model;

fig. 8 is a schematic diagram fifth connection diagram of a refrigeration unit according to an embodiment of the present utility model;

fig. 9 is a schematic structural diagram of an evaporative condenser according to an embodiment of the present utility model;

fig. 10 is a schematic diagram showing connection of a refrigeration unit according to an embodiment of the present utility model;

fig. 11 is a connection schematic diagram seven of a refrigeration unit according to an embodiment of the present utility model.

Reference numerals illustrate: 1. a refrigerating unit; 2. an indoor unit; 3. an outdoor unit; 4. an evaporator; 5. an expansion valve; 6. magnetic suspension centrifugal compressor; 7. an evaporative condenser; 8. a throttle device; 9. a branch pipeline; 10. a dry pipe; 11. a first branch pipe; 12. a second branch pipe; 13. a first branch line; 14. a second branch line; 15. a third branch line; 16. a main valve; 17. a reservoir; 18. a flash evaporator; 19. a condenser housing; 20. a refrigerant coil; 21. a shower pipe; 22. a liquid pump; 23. a gas-liquid separator; 24. a cutter valve; 25. a temperature sensor.

Detailed Description

In the description of the present utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art. In addition, when describing a pipeline or channel, the terms "connected" and "connected" as used herein have the meaning of conducting. The specific meaning is to be understood in conjunction with the context.

In embodiments of the utility model, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g." in an embodiment should not be taken as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

As used herein, "about," "approximately" or "approximately" includes the stated values as well as average values within an acceptable deviation range of the particular values as determined by one of ordinary skill in the art in view of the measurement in question and the errors associated with the measurement of the particular quantity (i.e., limitations of the measurement system).

Embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.

Referring to fig. 1, an embodiment of the present utility model provides a refrigeration unit 1, which includes an outdoor unit 3 and an indoor unit 2, wherein the outdoor unit 3 includes a magnetic suspension centrifugal compressor 6 and an evaporative condenser 7, an outlet of the magnetic suspension centrifugal compressor 6 is communicated with an inlet of the evaporative condenser 7, the indoor unit 2 includes a plurality of evaporators 4, outlets of the evaporators 4 are all used for communicating with an inlet of the magnetic suspension centrifugal compressor 6 through an inlet of the outdoor unit 3, and an inlet of each evaporator 4 is communicated with an outlet of the evaporative condenser 7 through an expansion valve 5.

The inlet of each evaporator 4 is communicated with an expansion valve 5, wherein a controller (not shown) is electrically connected with the expansion valves 5, and the controller is used for controlling the opening degree of the expansion valves 5; it will be appreciated that the greater the opening of the expansion valve 5, the greater the flow of refrigerant through the expansion valve 5 into the corresponding evaporator 4, the better the cooling power and effect of the evaporator 4 on the indoor environment.

The evaporators 4 can be respectively and correspondingly arranged in a plurality of indoor environments, namely, each indoor environment is provided with one evaporator 4, each evaporator 4 independently realizes the refrigeration of the corresponding indoor environment, and the evaporators 4 are mutually independent and are convenient to control. Of course, the plurality of evaporators 4 may be disposed in the same indoor environment, for example, 2 evaporators 4 are disposed in the same indoor environment, or 3 evaporators 4 are disposed in the same indoor environment, the plurality of evaporators 4 jointly implement refrigeration of the corresponding indoor environment, and the efficiency of the multi-connected air conditioning system 1 for refrigeration of the same indoor environment is increased in the process of simultaneously operating the plurality of evaporators 4.

When the evaporator 4 is cooling the indoor environment, if the indoor environment does not need to be cooled any more, the controller controls the corresponding expansion valve 5 to be closed. Since the refrigerant does not enter the evaporator 4 again to cool the indoor environment after the expansion valve 5 is closed, the temperature of the indoor environment may rise, so that the controller controls the expansion valve 5 to be opened again. In addition, when the indoor environment temperature gradually rises, the opening of the corresponding expansion valve can be controlled by the controller to gradually increase so as to avoid overhigh temperature; in contrast, when the indoor environment temperature gradually decreases, the opening of the corresponding expansion valve can be controlled by the controller to gradually decrease so as not to excessively lower the temperature.

In the above implementation manner, the evaporator 4 may be a standard evaporator, or may be a pipeline coiled in an indoor environment, and when the refrigerant flows through the pipeline coiled in the indoor environment, the refrigerant is gasified in the pipeline, so as to absorb heat of air around the pipeline, and further realize refrigeration of the indoor environment.

When the outdoor unit 3 and the indoor unit 2 are operated, the low-pressure gaseous refrigerant is compressed into the high-pressure gaseous refrigerant in the magnetic suspension centrifugal compressor 6, the high-pressure gaseous refrigerant enters the evaporative condenser 7 through the outlet of the magnetic suspension centrifugal compressor 6 and the inlet of the evaporative condenser 7, and the evaporative condenser 7 condenses the high-pressure gaseous refrigerant into the high-pressure liquid refrigerant; before the liquid refrigerant in the high pressure state enters each evaporator 4 through each expansion valve 5, the liquid refrigerant in the high pressure state flows through the throttling device 8, the throttling device 8 suddenly reduces the pressure received by the liquid refrigerant in the high pressure state, and the liquid refrigerant in the high pressure state expands into the liquid refrigerant in the low pressure state; the liquid refrigerant in a low pressure state enters the evaporator 4 and then evaporates to absorb heat, so that the indoor space is refrigerated; the evaporated and gasified liquid refrigerant in the evaporator 4 is converted into low-pressure gaseous refrigerant, and enters the magnetic suspension centrifugal compressor 6 again for continuous compression, and the refrigerant is cooled in a circulating way.

Referring to fig. 2 and 4, in the embodiment of the utility model, the refrigeration unit 1 further includes a plurality of branch pipes 9, each branch pipe 9 includes a main pipe 10, a first branch pipe 11 and a second branch pipe 12, the inlet of the first branch pipe 11 and the inlet of the second branch pipe 12 are both communicated with the outlet of the main pipe 10, and an included angle between the refrigerant flowing directions in the first branch pipe 11 and the second branch pipe 12 and the refrigerant flowing direction in the main pipe 10 is an acute angle a.

A first branch pipe 11 in a previous branch pipe 9 in the adjacent branch pipes 9 is communicated with a trunk pipe 10 of one subsequent branch pipe 9, and a second branch pipe 12 in the previous branch pipe 9 is communicated with the trunk pipe 10 of the other subsequent branch pipe 9; the main pipe 10 of the first branch pipe 9 communicates with the outlet of the evaporative condenser 7, and the first branch pipe 11 and the second branch pipe 12 of the last branch pipe 9 communicate with the expansion valves 5.

In the above embodiment, the branch pipe 9 closest to the outlet of the evaporative condenser 7 is the first branch pipe 9, the trunk pipe 10 of the first branch pipe 9 is communicated with the outlet of the evaporative condenser 7, so that the liquid refrigerant flowing out of the outlet of the evaporative condenser 7 can flow into the first branch pipe 11 and the second branch pipe 12, that is, the liquid refrigerant in one pipe is split into two pipes, while the first branch pipe 11 and the second branch pipe 12 of the first branch pipe 9 are respectively communicated with the trunk pipes 10 of the two branch pipes 9, the trunk pipes 10 of the two branch pipes 9 are respectively communicated with the first branch pipe 11 and the second branch pipe 12, that is, the liquid refrigerant in the two pipes is split into four pipes, and so on, while the first branch pipe 11 and the second branch pipe 12 of the branch pipe 9 closest to the expansion valves 5 are respectively communicated with the expansion valves 5.

Referring to fig. 5 in conjunction with fig. 3, for example, if the refrigeration unit 1 includes 8 expansion valves 5, the refrigeration unit 1 should include 1 first branch line 13, 2 second branch lines 14, and 4 third branch lines 15, where the third branch line 15 is the last branch line 9. The connection mode is as follows: the main pipe 10 of the first branch pipe 13 is communicated with the outlet of the evaporative condenser 7, the first branch pipe 11 and the second branch pipe 12 of the first branch pipe 13 are respectively communicated with 2 main pipes 10 of 2 second branch pipes 14, 2 first branch pipes 11 and 2 second branch pipes 12 of the 2 second branch pipes 14 are respectively communicated with 4 main pipes 10 of 4 third branch pipes 15, and 4 first branch pipes 11 and 4 second branch pipes 12 of the 4 third branch pipes 15 are respectively communicated with 8 expansion valves 5.

Through the above arrangement, in each branch pipe 9, since the included angle between the refrigerant flowing direction in the first branch pipe 11 and the second branch pipe 12 and the refrigerant flowing direction in the main pipe 10 is an acute angle, the change of the refrigerant flowing direction is small, the resistance when the liquid refrigerant is shunted into the first branch pipe 11 and the second branch pipe 12 from the main pipe 10 is reduced, the flow of the liquid refrigerant is smoother, and the pressure loss of the liquid refrigerant flowing to the inlet of the evaporator 4 is reduced.

Referring to fig. 6, in the embodiment of the present utility model, the refrigerating unit 1 further includes a main valve 16, the outlet of the evaporative condenser 7 is communicated with the main pipe 10 of the first branch pipe 9 through the main valve 16, and the main valve 16 is electrically connected with the controller; the refrigerating unit 1 further comprises a first thermometer (not shown) and a second thermometer (not shown), the first thermometer is used for measuring the temperature value of the outlet of the magnetic suspension centrifugal compressor 6, the second thermometer is used for measuring the temperature value of the inlet of the magnetic suspension centrifugal compressor 6, the temperature value of the inlet of the magnetic suspension centrifugal compressor 6 is subtracted from the temperature value of the outlet of the magnetic suspension centrifugal compressor 6 to obtain the air return superheat degree of the magnetic suspension centrifugal compressor 6, and the controller is used for adjusting the opening of the main valve 16 according to the air return superheat degree of the magnetic suspension centrifugal compressor 6.

Through the arrangement, the controller can adjust the opening of the main valve 16 according to the air return superheat degree of the magnetic suspension centrifugal compressor 6, and when the air return superheat degree of the magnetic suspension centrifugal compressor 6 is larger than the standard air return superheat degree of the magnetic suspension centrifugal compressor 6, the controller controls the opening of the main valve 16 to be reduced, so that the air return temperature of the magnetic suspension centrifugal compressor 6 is prevented from being too high; when the air return superheat degree of the magnetic suspension centrifugal compressor 6 is smaller than the standard air return superheat degree of the magnetic suspension centrifugal compressor 6, the controller controls the opening degree of the main valve 16 to be increased, so that the air return amount of the magnetic suspension centrifugal compressor 6 is ensured, and the working efficiency of the magnetic suspension centrifugal compressor 6 is improved.

Referring to fig. 7, in the embodiment of the present utility model, the refrigerating unit 1 further includes a liquid storage 17, an inlet of the liquid storage 17 is communicated with an outlet of the evaporative condenser 7, and an outlet of the liquid storage 17 is respectively communicated with the main valve 16 and the magnetic suspension centrifugal compressor 6.

In the above implementation manner, the outlet of the liquid storage 17 is communicated with the inlet of the evaporator 4 through the main valve 16, the liquid storage 17 is used for storing part of liquid refrigerant in the refrigerating unit 1, when the opening of the main valve 16 is controlled to be increased by the controller, the flow demand of the refrigerant participating in circulation in the refrigerating unit 1 is also increased, and at the moment, part of the refrigerant stored in the liquid storage 17 can timely participate in the circulation of the refrigerating unit 1, so that the refrigerating effect of the refrigerating unit 1 is ensured; when the controller controls the opening degree of the main valve 16 to decrease, the liquid refrigerant condensed by the evaporative condenser 7 cannot fully participate in the circulation of the refrigeration unit 1 due to the decrease of the opening degree of the main valve 16, and the accumulator 17 is used for storing part of the liquid refrigerant.

In the implementation manner, the outlet of the liquid reservoir 17 is also communicated with the magnetic suspension centrifugal compressor 6, and the refrigerant in the liquid reservoir 17 can cool down the components in the magnetic suspension centrifugal compressor 6 after entering the magnetic suspension centrifugal compressor 6, so that the performance of the magnetic suspension centrifugal compressor 6 is improved.

Referring to fig. 8, in the above implementation manner, the refrigerating unit 1 further includes a flash evaporator 18, the outlet of the liquid storage 17 is communicated with the magnetic suspension centrifugal compressor 6 through the flash evaporator 18, and due to the pressure difference generated by the air suction of the magnetic suspension centrifugal compressor 6, when the liquid refrigerant in the liquid storage 17 flows out from the outlet of the liquid storage 17, part of the liquid refrigerant can be sucked into the flash evaporator 18 and then enter the magnetic suspension centrifugal compressor 6, the flash evaporator 18 can gasify the liquid refrigerant into a gaseous refrigerant, so that the liquid refrigerant is prevented from entering the magnetic suspension centrifugal compressor 6, the normal operation of the magnetic suspension centrifugal compressor 6 is affected, the operation of the magnetic suspension centrifugal compressor 6 is protected, and the service life of the magnetic suspension centrifugal compressor 6 is prolonged.

Through the arrangement, the liquid storage device 17 is communicated with the main valve 16 to store or release the refrigerant flow of the liquid refrigerant in the refrigerating unit 1, and the liquid storage device 17 is communicated with the magnetic suspension centrifugal compressor 6 to cool down the components in the magnetic suspension centrifugal compressor 6.

Referring to fig. 9, in the embodiment of the present utility model, the evaporative condenser 7 includes a condenser housing 19, a refrigerant coil 20, a spray pipe 21 and a liquid pump 22, the housing of the evaporative condenser 7 encloses to form a cavity, the refrigerant coil 20 is located in the cavity, an inlet of the refrigerant coil 20 is communicated with an outlet of the magnetic suspension centrifugal compressor 6, an outlet of the refrigerant coil 20 is communicated with an inlet of the liquid storage 17, the spray pipe 21 is located above the refrigerant coil 20, a spray hole is arranged above the spray pipe 21, the liquid pump 22 is communicated with one end of the spray pipe 21, and the liquid pump 22 is used for delivering liquid into the spray pipe 21 so that the liquid is sprayed to the refrigerant coil 20 through the spray hole.

Through the arrangement, the magnetic suspension centrifugal compressor 6 conveys the gaseous refrigerant in a high-pressure state to the refrigerant coil 20, when the evaporative condenser 7 is in an operating state, the liquid pump 22 conveys water to the spray pipe 21, the spray pipe 21 sprays the water to the outer surface of the refrigerant coil 20, the water absorbs heat of the refrigerant in the refrigerant coil 20 and evaporates, the gaseous refrigerant in the high-pressure state in the refrigerant coil 20 is converted into a liquid refrigerant in the high-pressure state, and the liquid refrigerant flows into the liquid reservoir 17 to participate in the circulation of the refrigerating unit 1.

Referring to fig. 10, in the embodiment of the present utility model, the refrigerating unit 1 further includes a gas-liquid separator 23, wherein an inlet of the gas-liquid separator 23 is connected to an outlet of the evaporator 4, and an outlet of the gas-liquid separator 23 is connected to an inlet of the magnetic suspension centrifugal compressor 6. The gas-liquid separator 23 is used for separating the gaseous refrigerant and the liquid refrigerant in the refrigerant, so that the gaseous refrigerant can return to the magnetic suspension centrifugal compressor 6 to realize circulation, and the liquid refrigerant is remained in the gas-liquid separator 23 to prevent the refrigerant which is not completely gasified from returning to the magnetic suspension centrifugal compressor 6, so that lubricating oil in the magnetic suspension centrifugal compressor 6 is diluted, serious abrasion of a rotor, a cylinder, a valve plate and the like of the magnetic suspension centrifugal compressor 6 is caused, and even the motor of the magnetic suspension centrifugal compressor 6 is burnt.

Referring to fig. 11, in the embodiment of the present utility model, the refrigerating unit 1 further includes a cutter valve 24, an inlet of the cutter valve 24 is connected to an outlet of the magnetic suspension centrifugal compressor 6, an outlet of the cutter valve 24 is connected to an inlet of the gas-liquid separator 23, the cutter valve 24 is connected to a controller, when the working power of the magnetic suspension centrifugal compressor 6 is greater than the rated working power, the controller controls the cutter valve 24 to be opened, and a high-pressure gaseous refrigerant compressed by the magnetic suspension centrifugal compressor 6 directly enters the gas-liquid separator 23 through the cutter valve 24 and directly returns to the magnetic suspension centrifugal compressor 6, and as the part of the gaseous refrigerant is already in the high-pressure state, the magnetic suspension centrifugal compressor 6 is not required to be compressed again, thereby reducing the working efficiency of the magnetic suspension centrifugal compressor 6.

Although the utility model is described herein in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed utility model, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Although the utility model has been described in connection with specific features and embodiments thereof, it will be apparent that various modifications and combinations can be made without departing from the spirit and scope of the utility model. Accordingly, the specification and drawings are merely exemplary illustrations of the present utility model as defined in the appended claims and are considered to cover any and all modifications, variations, combinations, or equivalents that fall within the scope of the utility model. It will be apparent to those skilled in the art that various modifications and variations can be made to the present utility model without departing from the spirit or scope of the utility model. Thus, it is intended that the present utility model also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

The foregoing is merely illustrative of the present utility model, and the present utility model is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims

1. A refrigeration unit, comprising:

the system comprises an oil-free compressor, an evaporative condenser and a plurality of evaporators connected in parallel;

the outlet of the oil-free compressor is communicated with the inlet of the evaporative condenser, the outlet of the evaporative condenser is communicated with the inlets of a plurality of evaporators which are connected in parallel, and the outlets of the evaporators which are connected in parallel are communicated with the inlet of the oil-free compressor;

the inlets of the evaporators connected in parallel are respectively and correspondingly communicated with an expansion valve; each expansion valve is used for adjusting the refrigerant quantity in the corresponding evaporator.

2. The refrigeration unit of claim 1 wherein the oil-free compressor is a magnetic levitation centrifugal compressor.

3. The refrigeration unit as recited in claim 1 further comprising a reservoir having an inlet in communication with an outlet of the evaporative condenser, the outlet of the reservoir being in communication with the inlets of the plurality of evaporators in parallel.

4. A refrigeration unit as recited in claim 3 wherein the outlet of said accumulator is further in communication with a flash evaporator, the outlet of said flash evaporator being in communication with said oil-free compressor.

5. The refrigeration unit as recited in any one of claims 1 to 4 further comprising a gas-liquid separator, an inlet of said gas-liquid separator being in communication with a plurality of outlets of said evaporators in parallel, an outlet of said gas-liquid separator being in communication with an inlet of said oil-free compressor.

6. The refrigeration unit as recited in claim 5 further comprising a chopper valve having an inlet in communication with an outlet of the oil-free compressor and an outlet in communication with an inlet of the gas-liquid separator.

7. The refrigeration unit as recited in claim 1 wherein a plurality of branch lines are provided on the inlet communication line of the evaporator and the outlet of the evaporative condenser in parallel.

8. The refrigeration unit as recited in claim 7 wherein each of said branch lines includes a main pipe, a first branch pipe, and a second branch pipe, said inlet of said first branch pipe and said inlet of said second branch pipe each communicating with said outlet of said main pipe, said first branch pipe and said second branch pipe having a refrigerant flow direction at an acute angle to said refrigerant flow direction within said main pipe.

9. The refrigeration unit as set forth in claim 8 wherein said first one of said branch lines adjacent said branch line communicates with said main of a subsequent said branch line and said second one of said branch lines communicates with said main of another subsequent said branch line; the main pipe of the first branch pipeline is communicated with the outlet of the condenser, and the first branch pipe and the second branch pipe of the last branch pipeline are communicated with the expansion valves.

10. The refrigeration unit as recited in claim 9 wherein said evaporator condenser outlet is further provided with a main valve on said inlet communication line of said plurality of evaporators connected in parallel, said condenser outlet being in communication with said main pipe of a first of said branch lines through said main valve.