US20180320950A1

US20180320950A1 - Freezer with Evaporative Condensing Arrangement

Info

Publication number: US20180320950A1
Application number: US16/038,156
Authority: US
Inventors: Zhiming Li; Sui LIU; Yong Zhang; Feng Zhang
Original assignee: Mgwide LLC
Current assignee: Mgwide LLC
Priority date: 2015-01-28
Filing date: 2018-07-17
Publication date: 2018-11-08

Abstract

A freezer includes a plurality of connecting pipes, a first freezer casing having a first storage compartment, a first compressor, a first evaporator received in the first freezer casing, and an evaporative condensing arrangement comprising an evaporative cooling unit. The evaporative cooling unit includes a first heat exchanger, a water pumping device, a water distribution apparatus, a water collection basin, and a cooling fan. A predetermined amount of refrigerant is guided to circulate between the first evaporator, the first compressor and the heat exchanger. A predetermined amount of cooling water is sprayed on the heat exchanger for performing heat exchange with the refrigerant flowing therethrough, wherein the cooling water is cooled by the ambient air which is drawn from an air inlet and flows out of the evaporative cooling unit through an air outlet.

Description

BACKGROUND OF THE PRESENT INVENTION

Field of Invention

The present invention relates to a freezer, and more particularly to a freezer comprising an evaporative condensing arrangement which allows cooling of refrigerant to be performed in an outdoor environment.

Description of Related Arts

A conventional freezer usually comprises a housing having a first storage compartment for storing food items, a compressor, a condenser and an evaporator connected in a particular configuration. A predetermined amount of refrigerant is guided to flow through the first compressor, the condenser and the first evaporator for performing heat exchange with air. The goal is to extract heat from the air delivered to the first storage compartment so that the food items stored in the first storage compartment may be stored in a very low temperature environment. The heat extracted from the air may be released to ambient environment in which the freezer locates.
A common disadvantage in association with the above-mentioned conventional freezer is that the entire freezer is usually located in an indoor environment so that the heat released by the condenser will be discharged to nearby indoor space. When there is only one freezer, there may not be much of a problem. However, when several freezers are required in a relatively smaller indoor space, the heat discharged by all freezers as a whole will substantially raise the temperature of that indoor space and this phenomenon is certainly not desirable.
From efficiency standpoint, when the temperature of the ambient environment in which the freezer locates increases, the heat exchange efficiency between the refrigerant circulating in the freezer and ambient air decreases. From practical standpoint, the people working or shopping around the freezers may experience increased ambient temperature which may make them uncomfortable and longing to leave.
As a result, there is a need to develop a freezer which is more energy efficient and may resolve the above-mentioned problem.

SUMMARY OF THE PRESENT INVENTION

Certain variations of the present invention provide a freezer comprising an evaporative condensing arrangement which allows cooling of refrigerant to be performed in an outdoor environment.
Certain variations of the present invention provide a freezer comprising an evaporative condensing arrangement wherein refrigerant may be cooled by cooling water spraying on a heat exchanger, while the cooling water may be cooled by ambient air so that heat from the freezer may be ultimately discharged to ambient environment.
In one aspect of the present invention, it provides a freezer, comprising:
a plurality of connecting pipes;
a first freezer casing having a first storage compartment;
a first compressor;
an first evaporator received in the first freezer casing, the first evaporator being connected to the first compressor through at least one of the connecting pipes; and
an evaporative condensing arrangement comprising an evaporative cooling unit having an air inlet and an air outlet, the evaporative cooling unit being positioned in an outdoor environment and comprising:
a first heat exchanger having a first heat exchanging inlet connected to the first compressor through at least one of the connecting pipes, and a first heat exchanging outlet connected to the first evaporator through at least one of the connecting pipes;
a water pumping device;
a water distribution apparatus connected to the water pumping device through at least one of the connecting pipes, and arranged to distribute a predetermined amount of water to the first heat exchanger;
a water collection basin arranged to collect the water from the heat exchanger; and
a cooling fan provided above the water distribution apparatus for drawing ambient air to flow from the air inlet to the air outlet;
wherein a predetermined amount of refrigerant is guided to circulate between the first evaporator, the first compressor and the heat exchanger, a predetermined amount of cooling water being sprayed on the first heat exchanger for performing heat exchange with the refrigerant flowing therethrough, the cooling water being cooled by the ambient air drawn from the air inlet, the ambient air being guided to flow out of the evaporative cooling unit through the air outlet.
This summary presented above is provided merely to introduce certain concepts and not to identify any key or essential features of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a freezer according to a first preferred embodiment of the present invention.

FIG. 2 is a schematic diagram of the freezer according to a first preferred embodiment of the present invention, illustrating the flow of refrigerant and cooling water.

FIG. 3 is a schematic diagram of an evaporative cooling unit of the freezer according to the first preferred embodiment of the present invention.

FIG. 4 is a schematic diagram of a freezer according to the first preferred embodiment of the present invention, illustrating a second freezer casing.

FIG. 5 is a schematic diagram of the freezer according to a first preferred embodiment of the present invention, illustrating that a number of freezer may be combined to form a complex refrigerating system.

FIG. 6 is a schematic diagram of the freezer according to a second preferred embodiment of the present invention, illustrating the flow of refrigerant and cooling water.

FIG. 7 is a schematic diagram of an evaporative cooling unit of the freezer according to the second preferred embodiment of the present invention.

FIG. 8 is a schematic diagram of the freezer according to a third preferred embodiment of the present invention, illustrating the flow of refrigerant and cooling water.

FIG. 9 is a schematic diagram of an evaporative cooling unit of the freezer according to the third preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following detailed description of the preferred embodiment is the preferred mode of carrying out the invention. The description is not to be taken in any limiting sense. It is presented for the purpose of illustrating the general principles of the present invention.
Referring to FIG. 1 to FIG. 4 of the drawings, a freezer 1 according a preferred embodiment of the present invention is illustrated. Broadly, the freezer 1 may comprise a plurality of connecting pipes 10, a first freezer casing 20 having a first storage compartment 21, a first compressor 30, a first evaporator 40, and an evaporative condensing arrangement 50.
The connecting pipes 10 may connect all components of the freezer 1. A predetermined amount of refrigerant may flow through the connecting pipes 10 for performing heat exchange for the relevant mediums described below.
The first evaporator 40 may be received in the first freezer casing 20 and connected to the first compressor 30 through at least one of the connecting pipes 10.
The evaporative condensing arrangement 50 may comprise an evaporative cooling unit 60 having an air inlet 601 and an air outlet 602. The evaporative cooling unit 60 may be positioned in an outdoor environment. The evaporative cooling unit 60 may comprise a first heat exchanger 61, a water pumping device 62, a water distribution apparatus 63, a water collection basin 64, and a cooling fan 65.
The first heat exchanger 61 may have a first heat exchanging inlet 611 connected to the first compressor 30 through at least one of the connecting pipes 10, and a first heat exchanging outlet 612 connected to the first evaporator 40 through at least one of the connecting pipes 10.
The water pumping device 62 may be connected between the water collection basin 64 and the water distribution apparatus 63.
The water distribution apparatus 63 may be connected to the water pumping device 62 through at least one of the connecting pipes 10, and may be arranged to distribute a predetermined amount of water to the first heat exchanger 61. The water collection basin 64 may be arranged to collect the water from the first heat exchanger 61.
The cooling fan 64 may be provided above the water distribution apparatus 63 for drawing ambient air to flow from the air inlet 601 to the air outlet 602.
A predetermined amount of refrigerant may be guided to circulate between the first evaporator 40, the first compressor 30 and the first heat exchanger 61. At the same time, a predetermined amount of cooling water may be sprayed on the first heat exchanger 61 for performing heat exchange with the refrigerant flowing therethrough. The cooling water may then be cooled by the ambient air drawn from the air inlet 601. The ambient air may be guided to flow out of the evaporative cooling unit 60 through the air outlet 602.
According to the preferred embodiment of the present invention, the freezer 1 of the present invention may be used for producing very low temperature environment in the first storage compartment 21. The first storage compartment 21 may be used to store foods or other items that need low temperature, such as frozen items.
The first freezer casing 20 may be positioned in an indoor environment and may provide a protective housing for the first compressor 30, the first evaporator 40, and other components as well. The first storage compartment 21 is the primary space for requiring low temperature. Refrigerant may act as a medium to extract heat from the first storage compartment 21.
The first compressor 30 may be connected to the first storage compartment 21 through at least one connecting pipe 10. The first compressor 30 may also be connected to the first heat exchanger 61 of the evaporative cooling unit 60 through at least one connecting pipe 10. Refrigerant may flow from the first storage compartment 21 to the first compressor 30 which may convert the refrigerant into high-pressure vaporous state. The refrigerant leaving the first compressor 30 may be guided to flow into the first heat exchanger 61.
The first evaporator 40 may be provided in the first freezer casing 20 and may thermally communicate with the first storage compartment 21. Refrigerant may flow through the first evaporator 40 and extract heat from the first storage compartment 21. In the first preferred embodiment of the present invention, the first evaporator 40 may comprise at least one heat exchanging pipe 401 configured to form a manifold structure for thermally communicating with the air circulating in the first storage compartment 21. When air from the first storage compartment 21 comes into contact with the heat exchanging pipe 401, heat may be extracted from the air and transferred to the refrigerant flowing through the heat exchanging pipe 401.
The evaporative cooling unit 60 of the evaporative condensing arrangement 50 may be positioned in an outdoor environment so that heat from the first storage compartment 21 may eventually be discharged to ambient environment (and will not be trapped in the indoor space in which the first freezer casing 20 is located).
The first heat exchanger 61 may comprise a first heat exchanging tube 613 configured to form a manifold structure in which the first heat exchanging inlet 611 and the first heat exchanging outlet 612 may be connected to or formed on the first heat exchanging tube 613. Refrigerant from the first compressor 30 may be guided to flow through the first heat exchanging tube 613 through the first heat exchanging inlet 611.
As shown in FIG. 2 of the drawings, when the evaporative cooling unit 60 is positioned in a vertical manner, the water distribution apparatus 63 may be positioned above the first heat exchanger 61. The water distribution apparatus 63 may comprise a water distributing basin 631, and a water spraying device 632 provided underneath the water distributing basin 631. The water collection basin 631 may have a distributing cavity 6311 for storing a predetermined amount of cooling water. The cooling water stored in the distributing cavity 6311 may be guided to pass through the water spraying device 632 so that the cooling water may be evenly sprayed and distributed on the first heat exchanging tube 613.
The cooling water spraying on the first heat exchanging tube 613 may perform heat exchange with the refrigerant circulating therein so as to absorb the heat from the refrigerant. Some of the cooling water may be evaporated while the remaining cooling water may be dripped down along the first heat exchanging tube 613 and may be collected by the water collection basin 64. The cooling water collected in the water collection basin 64 may be have been cooled by the ambient air drawing from the air inlet 601. The evaporative cooling unit 60 may have two air inlets 601 forming on two sides of the first heat exchanger 61 while the air outlet 602 may be formed on top of the cooling fan 64.
The water pumping device 62 may be connected between the water collection basin 64 and the water distributing basin 631 so that the cooling water collected in the water collection basin 64 may be pumped back into the water distributing basin 631 for another cycle of cooling the first heat exchanging tube 613.
The freezer 1 may further comprise a first flow regulator 70 connected between the first evaporator 40 and the first heat exchanger 61 for regulating the flow rate of the refrigerant between the first heat evaporator 40 and the first heat exchanger 61.
In the first preferred embodiment of the present invention, the freezer 1 may further comprise a second freezer casing 200 which may comprise a second storage compartment 22. The first storage compartment 21 and the second storage compartment 22 may share a single evaporative cooling unit 60 for extracting heat. Accordingly, the freezer 1 may further comprise a second evaporator 41 provided in the second freezer casing 200. The second evaporator may thermally communicate with the second storage compartment 22.
The second freezer casing 200 may also be positioned in an indoor environment and may provide a protective housing for the second evaporator 41, and other components as well. The freezer 1 may further comprise a second compressor 31 connected between the second evaporator 41 and the evaporative cooling unit 60. In the first preferred embodiment of the present invention, the second evaporator 41 may comprise at least one second heat exchanging pipe 411 configured to form a manifold structure for thermally communicating with the air circulating in the second storage compartment 22. When air from the second storage compartment 22 comes into contact with the second heat exchanging pipe 411, heat may be extracted from the air and transferred to the refrigerant flowing through the second heat exchanging pipe 411.
The evaporative cooling unit 60 may further comprise a second heat exchanger 66 provided underneath the first heat exchanger 61. The second heat exchanger 66 may comprise a first heat exchanging tube 663 configured to form a manifold structure in which the second heat exchanging inlet 661 and the second heat exchanging outlet 662 may be connected to or forming on the second heat exchanging tube 663. Refrigerant from the second compressor 31 may be guided to flow through the second heat exchanging tube 663 through the second heat exchanging inlet 661.
The second compressor 31 may be connected to the second storage compartment 22 through at least one connecting pipe 10. The second compressor 31 may also be connected to the second heat exchanger 66 of the evaporative cooling unit 60 through at least one connecting pipe 10. Refrigerant may flow from the second storage compartment 22 to the second compressor 31 which may convert the refrigerant into high-pressure vaporous state. The refrigerant leaving the second compressor 31 may be guided to flow into the second heat exchanger 66.
As shown in FIG. 2 of the drawings, when the evaporative cooling unit 60 is positioned in a vertical manner, the water distribution apparatus 63 may be positioned above the first heat exchanger 61, which may be positioned above the second heat exchanger 66. The cooling water stored in the distributing cavity 6311 may be guided to pass through the water spraying device 632 so that the cooling water may be evenly sprayed and distributed on the first heat exchanging tube 613 and eventually reach the second heat exchanging tube 663 down the evaporative cooling unit 60.
Moreover, the first heat exchanging inlet 611 may be positioned above the first heat exchanging outlet 612 so that refrigerant may flow from an elevated position to a lower altitude. Similarly, the second heat exchanging inlet 661 may be positioned above the second heat exchanging outlet 662 so that refrigerant may flow from an elevated position to a lower altitude.
The cooling water spraying on the first heat exchanging tube 613 may perform heat exchange with the refrigerant circulating therein so as to absorb the heat from the refrigerant. Some of the cooling water may be evaporated while the remaining cooling water may be dripped down along the first heat exchanging tube 613 and may reach the second heat exchanging tube 663. At the same time, ambient air drawn from the air inlets 601 may cool down the cooling water on the first heat exchanging tube 613.
The cooling water dripping from the first heat exchanging tube 613 may perform heat exchange with the refrigerant circulating in the second heat exchanging tube 663 so as to absorb the heat from the refrigerant. Some of the cooling water may be evaporated while the remaining cooling water may be dripped down along the second heat exchanging tube 663 and may be collected by the water collection basin 64. The cooling water traveling along the first heat exchanging tube 613 and the second heat exchanging tube 663 may be eventually collected in the water collection basin 64 may have been cooled by the ambient air drawing from the air inlet 601. The air inlets 601 may be formed on two sides of the first heat exchanger 61 and the second heat exchanger 66, while the air outlet 602 may be formed on top of the cooling fan 65.
The water pumping device 62 may be connected between the water collection basin 64 and the water distributing basin 631 so that the cooling water collected in the water collection basin 64 may be pumped back into the water distributing basin 631 for another cycle of cooling the first heat exchanging tube 613 and the second heat exchanging tube 663.
The freezer 1 may further comprise a second flow regulator 71 connected between the second evaporator 41 and the second heat exchanger 66 for regulating the flow rate of the refrigerant between the second heat evaporator 41 and the second heat exchanger 66.
The operation of the present invention is as follows: the heat extracted from the first storage compartment 21 and the second storage compartment 22 may be carried by the refrigerant to the evaporative cooling unit 60. The evaporative cooling unit 60 may comprise the first heat exchanger 61 and the second heat exchanger 66 for cooling the refrigerant circulating from the first evaporator 40 and the second evaporator 41 respectively. The heat exchange medium is the cooling water described above. The cooling water may be pumped to the water distribution apparatus 63 and sprayed first on the first heat exchanger 61 for absorbing heat from the first heat exchanging tube 613. Part of the cooling water may be evaporated while remaining cooling water may be cooled by ambient air drawn from the air inlet 601, and eventually drop down to the second heat exchanging tube 663. Again, some of the cooling water may be evaporated while remaining cooling water may be cooled by ambient air and eventually be collected in the water collection basin 64. The cooling water may then be pumped back to the water distributing basin 631 and undergo another cycle of cooling as described above.
In the first preferred embodiment, the first heat exchanger 61 and the second heat exchanger 66 may be arranged in a vertical up-and-down manner in which the first heat exchanger 61 may be provided on top of the second heat exchanger 66.
Referring to FIG. 5 of the drawings, two freezers 1 of the present invention may be combined to form a complex refrigerating system in which each freezer may form one freezer module. The advantage of having such a complex refrigerating system is that each of the freezers may be independently controlled so that a suitable number of freezers may be turned on to suit different refrigerating needs.
Referring to FIG. 6 to FIG. 7 of the drawings, a freezer 1′ according to a second preferred embodiment of the present invention is illustrated. The second preferred embodiment is similar to the first preferred embodiment, except the evaporative cooling unit 60′. In the second preferred embodiment, the first heat exchanger 61′ and the second heat exchanger 66′ may be configured to be positioned in a side-by-side manner.
The advantage of having a side-by-side configuration of the first heat exchanger 61′ and the second heat exchanger 66′ is that the evaporative cooling unit 60′ may be suitable to be located in an outdoor environment in which height may be a limiting factor. The structures of the first heat exchanger 61′ and the second heat exchanger 66′ may be identical to those disclosed in the first preferred embodiment.
Thus, in the second preferred embodiment of the present invention, the cooling water from the water distribution apparatus 63 may be sprayed on the first heat exchanging tube 613′ and the second heat exchanging tube 663′ at the same time. The refrigerant flowing through the first heat exchanging tube 613′ and the second heat exchanging tube 663′ may be cooled down by the cooling water. The cooling water may then flow down exterior surfaces of the first heat exchanging tube 613′ and the second heat exchanging tube 663′. Some of the cooling water may be evaporated while the remaining cooling water may be collected in the water collection basin 64 and pumped back to the water distributing basin 631 by the water pumping device 62 performing another cycle of cooling.
The first heat exchanging inlet 611′ may be positioned above the first heat exchanging outlet 612′ so that refrigerant may flow from an elevated position to a lower altitude. Similarly, the second heat exchanging inlet 661′ may be positioned above the second heat exchanging outlet 662′ so that refrigerant may flow from an elevated position to a lower altitude.
Referring to FIG. 8 to FIG. 9 of the drawings, a freezer according to a third preferred embodiment of the present invention is illustrated. The third preferred embodiment is similar to the first preferred embodiment, except the evaporative cooling unit 60″. In the third preferred embodiment, the first heat exchanger 61″ and the second heat exchanger 66″ may be configured to be positioned in a front-and-rear manner, in which the first heat exchanger 61″ may be positioned in front of the second heat exchanger 66″.
The advantage of having a front-and-rear configuration of the first heat exchanger 61″ and the second heat exchanger 66″ is that the evaporative cooling unit 60″ may be suitable to be located in an outdoor environment in which width may be a limiting factor. The structures of the first heat exchanger 61″ and the second heat exchanger 66″ may be identical to those disclosed in the first preferred embodiment.
Thus, in the second preferred embodiment of the present invention, the cooling water from the water distribution apparatus 63 may be sprayed on the first heat exchanging tube 613″ and the second heat exchanging tube 663″ at the same time. The refrigerant flowing through the first heat exchanging tube 613″ and the second heat exchanging tube 663″ may be cooled down by the cooling water. The cooling water may then flow down exterior surfaces of the first heat exchanging tube 613″ and the second heat exchanging tube 663″. Some of the cooling water may be evaporated while the remaining cooling water may be collected in the water collection basin 64 and pumped back to the water distributing basin 631 by the water pumping device 62 performing another cycle of cooling.
The first heat exchanging inlet 611″ may be positioned above the first heat exchanging outlet 612″ so that refrigerant may flow from an elevated position to a lower altitude. Similarly, the second heat exchanging inlet 661″ may be positioned above the second heat exchanging outlet 662″ so that refrigerant may flow from an elevated position to a lower altitude.
The present invention, while illustrated and described in terms of a preferred embodiment and several alternatives, is not limited to the particular description contained in this specification. Additional alternative or equivalent components could also be used to practice the present invention.

Claims

What is claimed is:

1. A freezer, comprising:

a plurality of connecting pipes;

a first freezer casing having a first storage compartment;

a first compressor;

an first evaporator received in said first freezer casing, said first evaporator being connected to said first compressor through at least one of said connecting pipes; and

an evaporative condensing arrangement comprising an evaporative cooling unit having an air inlet and an air outlet, said evaporative cooling unit being positioned in an outdoor environment and comprising:

a first heat exchanger having a first heat exchanging inlet connected to said first compressor through at least one of said connecting pipes, and a first heat exchanging outlet connected to said first evaporator through at least one of said connecting pipes;

a water pumping device;

a water distribution apparatus connected to said water pumping device through at least one of said connecting pipes, and arranged to distribute a predetermined amount of water to said first heat exchanger;

a water collection basin arranged to collect said water from said heat exchanger; and

a cooling fan provided above said water distribution apparatus for drawing ambient air to flow from said air inlet to said air outlet;

wherein a predetermined amount of refrigerant is guided to circulate between said first evaporator, said first compressor and said heat exchanger, a predetermined amount of cooling water being sprayed on said first heat exchanger for performing heat exchange with said refrigerant flowing therethrough, said cooling water being cooled by said ambient air drawn from said air inlet, said ambient air being guided to flow out of said evaporative cooling unit through said air outlet.

2. The freezer, as recited in claim 1, wherein said first heat exchanger comprises a first heat exchanging tube configured to form a manifold structure in which said first heat exchanging inlet and said first heat exchanging outlet are connected to said first heat exchanging tube, refrigerant from said first compressor being guided to flow through said first heat exchanging tube through said first heat exchanging inlet.

3. The freezer, as recited in claim 2, wherein said water distribution apparatus is positioned above said first heat exchanger, and comprises a water distributing basin, and a water spraying device provided underneath said water distributing basin, said water collection basin having a distributing cavity for storing a predetermined amount of cooling water, said cooling water stored in said distributing cavity being guided to pass through said water spraying device and sprayed on said first heat exchanging tube.

4. The freezer, as recited in claim 3, wherein said evaporative cooling unit comprises two air inlets forming on two sides of said first heat exchanger while said air outlet is formed on top of said cooling fan.

5. The freezer, as recited in claim 4, wherein said first heat exchanging inlet is positioned above said first heat exchanging outlet so that said refrigerant is guided to flow from an elevated altitude to a lower altitude.

6. The freezer, as recited in claim 5, further comprising a first flow regulator connected between said first evaporator and said first heat exchanger for regulating a flow rate of said refrigerant between said first heat evaporator and said first heat exchanger.

7. The freezer, as recited in claim 3, further comprising a second freezer casing which comprises a second storage compartment, a second evaporator provided in said second freezer casing and thermally communicating with said second storage compartment, and a second compressor connected between said second evaporator and said evaporative cooling unit, said second evaporator comprising at least one second heat exchanging pipe configured to form a manifold structure for thermally communicating with said air circulating in said second storage compartment.

8. The freezer, as recited in claim 7, wherein said evaporative cooling unit further comprises a second heat exchanger provided underneath said first heat exchanger, said second heat exchanger having a second heat exchanging inlet and a second heat exchanging outlet, and comprising a second heat exchanging tube configured to form a manifold structure in which said second heat exchanging inlet and said second heat exchanging outlet are connected to said second heat exchanging tube, refrigerant from said second compressor being guided to flow through said second heat exchanging tube through said second heat exchanging inlet.

9. The freezer, as recited in claim 8, wherein said water collection basin is positioned below said second heat exchanger so that said cooling water spraying on said first heat exchanging tube is arranged to flow down to said second heat exchanging tube and eventually collected in said water collection basin.

10. The freezer, as recited in claim 9, wherein said second heat exchanging inlet is positioned above said second heat exchanging outlet so that said refrigerant is arranged to flow from an elevated attitude to a lower altitude.

11. The freezer, as recited in claim 10, wherein said evaporative cooling unit comprises two air inlets forming on two sides of said first heat exchanger and said second heat exchangers while said air outlet is formed on top of said cooling fan.

12. The freezer, as recited in claim 11, further comprising a second flow regulator connected between said second evaporator and said second heat exchanger for regulating a flow rate of said refrigerant flowing between said second heat evaporator and said second heat exchanger.

13. The freezer, as recited in claim 7, wherein said evaporative cooling unit further comprises a second heat exchanger provided adjacent to said first heat exchanger, said second heat exchanger having a second heat exchanging inlet and a second heat exchanging outlet, and comprising a second heat exchanging tube configured to form a manifold structure in which said second heat exchanging inlet and said second heat exchanging outlet are connected to said second heat exchanging tube, refrigerant from said second compressor being guided to flow through said second heat exchanging tube through said second heat exchanging inlet.

14. The freezer, as recited in claim 13, wherein said first heat exchanger and said second heat exchanger are configured to be positioned in a side-by-side manner, said cooling water from said water distribution apparatus being sprayed on said first heat exchanging tube and said second heat exchanging tube simultaneously, said cooling water spraying on said first heat exchanging tube and said second heat exchanging tube being collected by said water collection basin.

15. The freezer, as recited in claim 13, wherein said first heat exchanger and said second heat exchanger are configured to be positioned in a front-and-rear manner, in which said first heat exchanger is positioned in front of said second heat exchanger, said cooling water from said water distribution apparatus being sprayed on said first heat exchanging tube and said second heat exchanging tube simultaneously, said cooling water spraying on said first heat exchanging tube and said second heat exchanging tube being collected by said water collection basin.

16. The freezer, as recited in claim 14, wherein said water collection basin is positioned below said second heat exchanger so that said cooling water spraying on said first heat exchanging tube is arranged to flow down to said second heat exchanging tube and eventually collected in said water collection basin.

17. The freezer, as recited in claim 15, wherein said water collection basin is positioned below said second heat exchanger so that said cooling water spraying on said first heat exchanging tube is arranged to flow down to said second heat exchanging tube and eventually collected in said water collection basin.

18. The freezer, as recited in claim 16, wherein said second heat exchanging inlet is positioned above said second heat exchanging outlet so that said refrigerant is arranged to flow from an elevated attitude to a lower altitude.

19. The freezer, as recited in claim 17, wherein said second heat exchanging inlet is positioned above said second heat exchanging outlet so that said refrigerant is arranged to flow from an elevated attitude to a lower altitude.

20. The freezer, as recited in claim 18, wherein said evaporative cooling unit comprises two air inlets forming on two sides of said first heat exchanger and said second heat exchangers while said air outlet is formed on top of said cooling fan.

21. The freezer, as recited in claim 19, wherein said evaporative cooling unit comprises two air inlets forming on two sides of said first heat exchanger and said second heat exchangers while said air outlet is formed on top of said cooling fan.

22. The freezer, as recited in claim 20, further comprising a second flow regulator connected between said second evaporator and said second heat exchanger for regulating a flow rate of said refrigerant flowing between said second heat evaporator and said second heat exchanger.

23. The freezer, as recited in claim 21, further comprising a second flow regulator connected between said second evaporator and said second heat exchanger for regulating a flow rate of said refrigerant flowing between said second heat evaporator and said second heat exchanger.