CN110762902A - Micro-channel evaporator and air conditioning system - Google Patents

Abstract

The invention relates to the technical field of refrigeration, and discloses a microchannel evaporator and an air conditioning system, so as to reduce production cost and improve refrigeration energy efficiency. The micro-channel evaporator includes: at least two flat tube groups located at positions with different air volumes in the air conditioning system, each flat tube group includes a liquid inlet header and a liquid outlet header and is connected to the liquid inlet header and the liquid outlet. A group of flat tubes between the headers, the liquid inlet header is inserted with a distribution tube, and the distribution tube is provided with a number of through holes along the axial direction; the distributor includes the liquid inlet and the corresponding flat tube group for each piece. a liquid outlet; capillaries corresponding to at least two flat tube groups respectively, each capillary is used to connect the distribution pipe of the corresponding flat tube group with the liquid outlet; a water pan, located at the bottom of the at least two flat tube groups; Wherein, different sizes of capillaries corresponding to different flat tube groups are selected according to different air volumes at the positions where the flat tube groups are located.

Description

A microchannel evaporator and an air conditioning system

technical field

The invention relates to the technical field of refrigeration, in particular to a microchannel evaporator and an air conditioning system.

Background technique

In-row air conditioners are mostly used in modular computer rooms, and are mainly cooled by vapor compression and direct expansion. The refrigerant circulates in the closed pipeline formed by the sequential connection of the compressor, condenser, throttling element and evaporator. The specific process is as follows: : The refrigerant is compressed into high temperature and high pressure gas by the compressor and then enters the condenser, condenses and releases heat in the condenser into low temperature and high pressure liquid, and then is throttled into low temperature and low pressure liquid through the throttling element, and then enters the evaporator for evaporative heat exchange and evaporation. The latter refrigerant gas is returned to the compressor to complete a cycle. Among them, the evaporator of the inter-column air conditioner usually uses a more traditional copper tube fin evaporator.

As shown in FIG. 1, the structure of the existing copper tube fin type evaporator includes heat exchange copper tube 01 and fins covering the outer surface of the heat exchange copper tube. In order to achieve a larger heat exchange, the evaporator will Setting up multiple rows of heat exchange copper tubes 01 will increase production costs on the one hand, and on the other hand, densely arranged heat exchange copper tubes 01 will also increase wind resistance and affect the heat exchange efficiency of the air conditioning unit.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a microchannel evaporator and an air conditioning system, so as to reduce production costs and improve refrigeration energy efficiency.

An embodiment of the present invention provides a microchannel evaporator, comprising:

At least two flat tube groups located at positions with different air volumes in the air conditioning system, each flat tube group includes a liquid inlet header and a liquid outlet header and is connected to the liquid inlet header and the outlet header. A group of flat tubes between them, a distribution tube is inserted in the liquid inlet header, and the distribution tube is provided with a number of through holes along the axial direction;

The distributor, including the liquid inlet and the liquid outlet corresponding to each flat tube group;

Capillaries corresponding to the at least two flat tube groups respectively, each of the capillaries is used to connect the distribution pipe of the corresponding flat tube group with the liquid outlet;

a water tray, located at the bottom of the at least two flat tube groups;

Wherein, different sizes of capillaries corresponding to different flat tube groups are selected according to the size of the air volume at the positions where the flat tube groups are located.

In a specific embodiment, the inner diameter of the capillary tube of the flat tube group located at the position where the air volume is larger is larger than the inner diameter of the capillary tube of the flat tube group located at the position where the air volume is smaller.

In a specific embodiment, the capillary length of the flat tube group located at the position where the air volume is larger is smaller than the capillary length of the flat tube group located at the position where the air volume is smaller.

In a specific embodiment, for each flat tube group, the distribution density of the through holes on the distribution pipe located in the area with a large air volume is smaller than the distribution density of the through holes on the distribution pipe located in the area with a small air volume.

In a specific embodiment, the number of the flat tube groups is two, and the two flat tube groups are arranged in a V-shaped body, and the opening of the V-shaped body forms the air outlet of the micro-channel evaporator.

In a specific embodiment, the number of the flat tube groups is four, each two flat tube groups are arranged in a first V-shaped body and a second V-shaped body respectively, and the second V-shaped body is stacked on the Above the first V-shaped body, the opening of the first V-shaped body and the opening of the second V-shaped body form the air outlet of the micro-channel evaporator.

In a specific embodiment, the number of the water pans is two, which are a middle water pan and a lower water pan, and the middle water pan is located between the second V-shaped body and the first V-shaped body, so The drain pan is located at the bottom of the first V-shaped body.

In the embodiment of the present invention, after the liquid refrigerant enters the distributor, it is sent to different flat tube groups through capillaries connected to the various liquid outlets of the distributor. Different flat tube groups can control the flow of refrigerant that actually enters the flat tube group by designing the corresponding capillaries to have different sizes. The flow rate can meet its heat exchange requirements, and on the other hand, it avoids waste caused by too much refrigerant in the flat tube group located at a position where the air volume is small. Compared with the copper tube fin evaporator in the prior art, the present invention The microchannel evaporator provided by the embodiment not only has lower production cost, but also greatly improves the cooling energy efficiency.

An embodiment of the present invention further provides an air-conditioning system, comprising a compressor, a condenser, a throttling element and a micro-channel evaporator according to any of the foregoing technical solutions, which are sequentially connected through pipelines to form a closed cycle, wherein the The throttling element is connected with the liquid inlet of the distributor of the microchannel evaporator, and the compressor is connected with the liquid outlet collecting pipe of the microchannel evaporator. The air conditioning system has high cooling energy efficiency.

In a specific embodiment, the throttling element is an electronic expansion valve; or, the throttling element is a thermal expansion valve.

Description of drawings

Fig. 1 is the structural representation of the copper tube fin type evaporator in the prior art;

FIG. 2 is a schematic structural diagram of a microchannel evaporator according to an embodiment of the present invention.

Reference number:

Part of the prior art:

01-Heat exchange copper tube

Embodiments of the present invention:

10-Flat tube group 11-Inlet header 12-Outlet header 13-Flat tube

14-Distribution pipe 20-Distributor 21-Liquid inlet 22-Liquid outlet

30-capillary 40-water tray 15-first V-shaped body 16-second V-shaped body

41-Middle water tray 42-Drain tray 50-Throttle element

Detailed ways

In order to reduce production costs and improve refrigeration energy efficiency, embodiments of the present invention provide a microchannel evaporator and an air conditioning system. In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail with reference to the following examples.

As shown in FIG. 2, the microchannel evaporator provided in the embodiment of the present invention includes:

At least two flat tube groups 10 located at positions with different air volumes in the air conditioning system, each flat tube group 10 includes a liquid inlet header 11 and a liquid outlet header 12 and is connected to the liquid inlet header 11 and the outlet header. A group of flat tubes 13 between the flow tubes 12, a distribution tube 14 is inserted in the liquid inlet header 11, and the distribution tube 14 is provided with a number of through holes (not shown in the figure) along the axial direction;

The distributor 20 includes a liquid inlet 21 and a liquid outlet 22 corresponding to each flat tube group 10;

Capillary tubes 30 corresponding to at least two flat tube groups 10 respectively, each capillary tube 30 is used to connect the distribution pipe 14 of the corresponding flat tube group 10 to the liquid outlet 22;

The water pan 40 is located at the bottom of the at least two flat tube groups 10;

Wherein, the capillary tubes 30 corresponding to different flat tube groups 10 are selected in different sizes according to the size of the air volume at the positions where the flat tube groups 10 are located.

When the micro-channel evaporator is in operation, the liquid refrigerant enters the distribution pipe 14 through the capillary 30, and is sprayed into the liquid inlet header 11 through the through holes opened on the distribution pipe 14, and then the liquid inlet header 11 passes through the flat tube 13. At the same time, under the suction of the fan located on the front side of the air outlet of the microchannel evaporator, the external hot air passes through the flat tube 13 of the microchannel evaporator and communicates with the air in the flat tube 13. The liquid refrigerant undergoes heat exchange and forms condensed water on the surface of the flat tubes 13 . However, because the internal structure of the air-conditioning cabinet is relatively compact, the air duct formed between the fan and the air outlet of the micro-channel evaporator will inevitably be blocked by pipelines or other structural components, which will lead to the location where different flat tube groups 10 are located. The air volume will be different at different positions. At this time, if the refrigerant flow rate distributed to each flat tube group 10 is the same, it will not only cause the refrigerant flow in the flat tube group 10 located at the position with larger air volume to be unable to meet its replacement. The heat demand will also cause waste of too much refrigerant in the flat tube group 10 located at a position with a small air volume, thereby affecting the cooling energy efficiency.

In the embodiment of the present invention, after the liquid refrigerant enters the distributor 20, it is sent to different flat tube groups 10 through the capillary tubes 30 connected to the respective liquid outlets 22 of the distributor 20. Therefore, for different flat tube groups 10, by designing the corresponding capillary tubes 30 to have different sizes, the flow of the refrigerant actually entering the flat tube group 10 can be controlled. The refrigerant flow in the flat tube group 10 at the location can meet its heat exchange requirements, and on the other hand, it avoids waste caused by excessive refrigerant in the flat tube group 10 located at a position with a small air volume. The copper tube fin evaporator, the micro-channel evaporator provided by the embodiment of the present invention not only has a lower production cost, but also greatly improves the refrigeration energy efficiency.

The number of flat tube groups is not limited. In a preferred embodiment of the present invention, the number of flat tube groups is two, and the two flat tube groups are arranged in a V-shaped body, and the opening of the V-shaped body forms the opening of the microchannel evaporator. For the air outlet, by adopting the solution of this embodiment, the height of the evaporator of the inter-column air conditioner can be reduced, which is beneficial to the discharge of condensed water.

More preferably, as shown in FIG. 1 , the number of flat tube groups 10 is four, and each two flat tube groups 10 are arranged in a first V-shaped body 15 and a second V-shaped body 16 respectively, and the second V-shaped body 16 is stacked. Placed on the first V-shaped body 15, the opening of the first V-shaped body 15 and the opening of the second V-shaped body 16 form the air outlet of the micro-channel evaporator. Compared with the whole-chip evaporator in the prior art, this solution can The height of the evaporator of the inter-column air conditioner is further reduced, and the heat exchange area of the evaporator is significantly increased, thereby improving the heat exchange effect.

In the microchannel evaporator in the above-mentioned embodiment, a water pan 40 can be arranged under the first V-shaped body 15, so that the condensed water generated by the heat exchange between the first V-shaped body 15 and the second V-shaped body 16 can be under the action of gravity. into the water pan 40 . In order to make the condensed water more convenient to discharge, in the preferred embodiment of the present invention, as shown in FIG. 1 , the number of water pans 40 is two, which are the middle water pan 41 and the lower water pan 42 respectively, and the middle water pan 41 is located in the second Between the V-shaped body 16 and the first V-shaped body 15 , the drain pan 42 is located at the bottom of the first V-shaped body 15 .

The amount of water passing through the capillary tube 30 is related to its inner diameter and length. The smaller the inner diameter and/or the longer the length of the capillary tube 30, the greater the resistance and the less refrigerant flow through the capillary tube 30; conversely, the larger the inner diameter and/or the longer the length of the capillary tube 30, the greater the resistance. Shorter, the smaller the resistance, the more refrigerant flow through the capillary 30. Therefore, in the embodiment of the present invention, the flow rate of refrigerant distributed to each flat tube group can be adjusted by changing the inner diameter and length of the capillary corresponding to different flat tube groups. In a specific embodiment, the inner diameter of the capillary tube 30 of the flat tube group 10 located at the position where the air volume is larger is larger than the inner diameter of the capillary tube 30 of the flat tube group 10 located at the position where the air volume is smaller; in another specific embodiment , the length of the capillary tube 30 of the flat tube group 10 located at the position where the air volume is larger is smaller than the length of the capillary tube 30 of the flat tube group 10 located at the position where the air volume is smaller. It can be understood that, during the specific setting, the refrigerant flow can be adjusted by changing only one of the parameters of the inner diameter or length of the capillary 30. Of course, two parameters can be changed at the same time for adjustment. The present invention does not limit this. The adjusted refrigerant flow can meet the heat exchange demand without causing waste. It should be noted that the specific size of the capillary tube 30 needs to be designed according to the air volume in the air conditioning system where the flat tube group 10 is located, which will not be repeated here.

For each flat tube group 10 , in fact, the air volume at different regions of the flat tube group 10 is also different. Therefore, it is also necessary to adjust the refrigerant flow rate of the flat tubes 13 in different regions of the flat tube group 10 . In the process of realizing the present invention, the inventor found that the distribution density of the through holes on the distribution pipe 14 affects the flow of refrigerant sent from the header pipe 11 into the flat pipe 13 , which is specifically expressed as the distribution density of the through holes on the distribution pipe 14 The smaller it is, the more refrigerant flow is sent from the header 11 to the flat tubes 13 in the area with larger air volume. Therefore, in the embodiment of the present invention, for each flat tube group 10, the sub-sections located in the area with larger air volume are divided. The distribution density of the through holes on the piping 14 is smaller than the distribution density of the through holes on the distribution pipe 14 located in the area with a small air volume, so that the flat tubes 13 in the area with a large air volume of the flat tube group 10 can be distributed to more refrigerant to ensure the heat exchange effect.

The embodiment of the present invention also provides an air conditioning system, including a compressor, a condenser, a throttle element 50 that are sequentially connected to form a closed cycle through pipelines, and the micro-channel evaporator according to any of the foregoing technical solutions, wherein the throttle element 50 is connected with the liquid inlet 21 of the distributor 20 of the microchannel evaporator, and the compressor is connected with the liquid outlet header 12 of the microchannel evaporator, wherein the throttling element 50 can be specifically an electronic expansion valve or a thermal expansion valve, The present invention does not limit this. The air conditioning system has high cooling energy efficiency.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (9)

1. A microchannel evaporator, comprising:

the air conditioner comprises at least two flat pipe groups positioned at different air volume positions in an air conditioning system, wherein each flat pipe group comprises a liquid inlet collecting pipe, a liquid outlet collecting pipe and a group of flat pipes connected between the liquid inlet collecting pipe and the liquid outlet collecting pipe;

the distributor comprises a liquid inlet and a liquid outlet corresponding to each flat tube group;

capillary tubes respectively corresponding to the at least two flat tube groups, wherein each capillary tube is used for connecting the distribution tube of the corresponding flat tube group with the liquid outlet;

the water tray is positioned at the bottoms of the at least two flat tube groups;

wherein, the capillary corresponding to different flat tube groups selects different sizes according to different air volume at the position of the flat tube group.

2. The microchannel evaporator of claim 1, wherein the inner diameters of the capillaries of the flat tube group at a position where the air flow rate is large are larger than the inner diameters of the capillaries of the flat tube group at a position where the air flow rate is small.

3. The microchannel evaporator of claim 1, wherein the length of the capillaries of the flat tube group at a location where the air volume is large is smaller than the length of the capillaries of the flat tube group at a location where the air volume is small.

4. The microchannel evaporator of claim 1, wherein for each of the flat tube groups, the distribution density of the openings in the distribution tube in the region of greater air flow is less than the distribution density of the openings in the distribution tube in the region of lesser air flow.

5. The microchannel evaporator of claim 1, wherein the number of flat tube groups is two, and the two flat tube groups are arranged in a V-shape, and an opening of the V-shape forms an air outlet of the microchannel evaporator.

6. The microchannel evaporator of claim 1, wherein the number of flat tube groups is four, each flat tube group having a first V-shaped body arrangement and a second V-shaped body arrangement, and the second V-shaped body arrangement is stacked on the first V-shaped body, and the openings of the first V-shaped body and the second V-shaped body form the outlet of the microchannel evaporator.

7. The microchannel evaporator of claim 6, wherein the number of water pans is two, a mid-water pan and a lower-water pan, the mid-water pan being located between the second V-shaped body and the first V-shaped body, the lower-water pan being located at the bottom of the first V-shaped body.

8. An air conditioning system, which is characterized by comprising a compressor, a condenser, a throttling element and the microchannel evaporator as claimed in any one of claims 1 to 7, wherein the compressor, the condenser and the throttling element are sequentially connected through pipelines to form a closed cycle, the throttling element is connected with a liquid inlet of a distributor of the microchannel evaporator, and the compressor is connected with a liquid outlet collecting pipe of the microchannel evaporator.

9. The air conditioning system of claim 8, wherein the throttling element is an electronic expansion valve; alternatively, the throttling element is a thermostatic expansion valve.

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