CN213066640U

CN213066640U - Vertical pipeline of refrigerating system and refrigerating system

Info

Publication number: CN213066640U
Application number: CN202021703865.1U
Authority: CN
Inventors: 杜玉清
Original assignee: Trane Air Conditioning Systems China Co Ltd
Current assignee: Trane Air Conditioning Systems China Co Ltd
Priority date: 2020-08-14
Filing date: 2020-08-14
Publication date: 2021-04-27
Anticipated expiration: 2030-08-14

Abstract

The application discloses refrigerating system's vertical pipeline and refrigerating system. The vertical pipeline of the refrigeration system comprises a pipe body and at least two sub-pipelines positioned in the pipe body. Because the vertical pipeline comprises a pipe body and at least two sub-pipelines, and the original single channel is replaced by the multi-channel, under the condition that the flow change of the refrigerant is large, the pressure drop under the rated load is not large, and the oil loss can be avoided; and under the condition of variable working conditions, large load and small load can be considered.

Description

Vertical pipeline of refrigerating system and refrigerating system

Technical Field

The application relates to refrigeration technology, in particular to a vertical pipeline of a refrigeration system and the refrigeration system.

Background

The refrigeration system includes a length of vertical tubing through which the refrigerant needs to pass upwardly to carry the oil back to other tubing connected to the vertical tubing so that the oil is ultimately returned to the compressor. However, the inner walls of the vertical tubes can stick oil, allowing the refrigeration system to lose oil.

As shown in fig. 1, the conventional practice for preventing oil loss is to add a plurality of U-shaped oil traps 1 (also referred to in the industry as oil return traps) in the vertical pipe 10. The relevant standards require that every 5 meters a U-shaped trap 1 is recommended to avoid oil loss, and additionally the minimum flow velocity in the horizontal pipe is recommended to be 3.6 m/s; the minimum flow rate for the vertical pipe is recommended to be 7.6 m/s.

In a refrigeration system including a vertical pipe, whether or not the vertical pipe includes a U-shaped oil trap, there are problems as follows: under the variable working condition, the flow change of the refrigerant is expected to be large, and in order to ensure oil return under the lowest load, the pipe diameter of the vertical pipeline needs to be reduced, so that the pressure drop under the rated load is large. Particularly, in the case of multi-split air conditioning, the load change of the unit is large, and the vertical pipeline is difficult to take large load and small load into consideration.

Disclosure of Invention

To overcome some or all of the problems of the related art, the present application discloses a vertical pipe of a refrigeration system and a refrigeration system, wherein the vertical pipe can ensure that the refrigeration system does not lose oil.

To achieve the above object, the vertical pipe of the refrigeration system of the embodiment of the present application includes a pipe body and at least two sub-pipes located inside the pipe body.

Optionally, in any two sub-pipelines, the cross-sectional area of one sub-pipeline is 90% to 110% of the cross-sectional area of the other sub-pipeline.

Optionally, the cross section of the vertical pipeline is circular, all the sub-pipelines include a central sub-pipeline with a circular cross section and edge sub-pipelines distributed around the central sub-pipeline, and the cross section of each edge sub-pipeline is in a sector ring shape.

Optionally, the cross-section of each of the sub-circuits is the same shape.

Optionally, in case the cross-section of the sub-pipe is circular, the hydraulic diameter of the sub-pipe is between 3mm and 12 mm.

Optionally, the inner wall of at least one of the sub-conduits is of an oleophobic material or is provided with an oleophobic coating.

Optionally, the sub-conduits form a profile.

Optionally, the vertical pipe comprises a casing, all sub-pipes are located in the casing, and a channel is formed between the outer wall of the pipe body and the inner wall of the casing.

In another aspect, embodiments of the present application also disclose a refrigeration system. The refrigerant system includes a compressor and a vertical line of any of the foregoing refrigeration systems, the compressor being in circuit with the vertical line such that oil discharged from the compressor passes through the vertical line back to the compressor.

Optionally, the refrigeration system includes a direct expansion unit or a flooded water chilling unit on a high drop occasion, and the direct expansion unit or the flooded water chilling unit includes the compressor.

The vertical tube or refrigeration system of the above embodiment has at least the following advantageous effects. Because the vertical pipeline comprises the pipe body and at least two sub-pipelines, compared with a vertical pipeline adopting an oil return bend or a vertical pipeline not adopting an oil return bend (for simplicity of description, the two pipelines are called as a single pipeline), the vertical pipeline adopts multiple channels to replace the original single channel, and has at least the following advantages:

1) the cross-sectional area of each sub-pipeline is reduced relative to the cross-sectional area of a single pipeline (for the sub-pipeline with a circular cross section, the pipe diameter is reduced), however, as the sum of the cross-sectional areas of a plurality of sub-pipelines is equal to the cross-sectional area of the single pipeline, the flow speed of a vertical pipeline formed by the plurality of sub-pipelines is the same as that of the single pipeline, under the condition of large flow change of refrigerant, the pressure drop under the rated load is not large, and oil loss can be avoided;

2) under the condition of variable operating mode, the load of unit changes greatly, under the condition of small-load, because the cross-sectional area of every sub-pipeline diminishes for the cross-sectional area of single pipeline, oil and gaseous segmentation, the sub-pipeline is blocked to oil and the gas that can the sub-pipeline is being pushed to remove is carried out vertical pipeline finally gets back to the compressor, can not lose oil, under the condition of large-load, because the cross-sectional area of every sub-pipeline diminishes for the cross-sectional area of single pipeline, oil drips on the inner wall of sub-pipeline, also can be pushed to remove by gas, to sum up, the vertical pipeline of the embodiment of this application can compromise the condition of large-load and small-load under the variable operating mode.

Drawings

FIG. 1 is a schematic diagram of a vertical tube of a prior art refrigeration system;

FIG. 2 is a cross-sectional view of a first vertical conduit of the present application;

FIG. 3 is a cross-sectional view of a second vertical conduit of the present application;

FIG. 4 is a cross-sectional view of a third vertical conduit of the present application.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The use of the terms "a" or "an" and the like in the description and in the claims of this application do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, means that the element or item listed as preceding "comprising" or "includes" covers the element or item listed as following "comprising" or "includes" and its equivalents, and does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "plurality" includes two, and is equivalent to at least two. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

Referring to fig. 2, a vertical pipe 20 of a refrigeration system disclosed in the first embodiment of the present application includes a pipe 21 and at least two sub-pipes located inside the pipe 21. In fig. 2, 5 sub-circuits are illustrated, which are labeled 221, 222, 223, 224 and 225, respectively, for ease of understanding.

Referring to fig. 3, a second embodiment of the present application discloses a vertical tube 30 of a refrigeration system including a tube 21 and at least two sub-tubes located in the tube 21, wherein 3 sub-tubes are illustrated in fig. 3 and are labeled 321, 322, and 323 for ease of understanding.

Referring to fig. 4, the third vertical pipe 40 shown in fig. 4 is different from the vertical pipe 20 in that the vertical pipe 40 further includes a sleeve 41. All of the

sub-lines

221, 222, 223, 224, and 225 are located within the casing 41.

Based on the above teachings of vertical pipes, skilled artisans will appreciate that in various embodiments of the present application, a vertical pipe comprises a pipe body and at least two sub-pipes located within the pipe body, the number of sub-pipes is not limited to the above embodiments, for example, 7/8 "(in) may be divided into 4 1/2" (in) sub-pipes or 6 3/8 "(in) sub-pipes. The shape of the cross section of the sub-pipeline is not limited to the above embodiments, for example, the shape of the cross section of the sub-pipeline is one of a circle, a sector ring, or a polygon (a triangle, a square, a hexagon, etc.), and the like, and thus, the shape of the cross section of the vertical pipeline includes one of the above shapes or a combination thereof. Because the vertical pipeline comprises the pipe body and at least two sub-pipelines, compared with a vertical pipeline adopting an oil return bend or a vertical pipeline not adopting an oil return bend (for simplicity of description, the two pipelines are called as a single pipeline), the vertical pipeline adopts multiple channels to replace the original single channel, and has at least the following advantages:

1) the cross section area of each sub-pipeline is reduced relative to that of a single pipeline (for the sub-pipeline with a circular cross section (the cross section is a plane perpendicular to the length direction of the pipeline, and the cross section can be considered to be parallel to a horizontal plane), the pipe diameter is reduced), but because the sum of the cross sections of a plurality of sub-pipelines is equal to that of the single pipeline, the flow rate of a vertical pipeline formed by the plurality of sub-pipelines is the same as that of the single pipeline, the pressure drop under the rated load can not be large under the condition of large flow change of refrigerant, and oil loss can be avoided; 2) under the condition of variable operating mode, the load of unit changes greatly, under the condition of small-load, because the cross-sectional area of every sub-pipeline diminishes for the cross-sectional area of single pipeline, oil and gaseous segmentation, the sub-pipeline is blocked to oil and the gas that can the sub-pipeline is being pushed to remove is carried out vertical pipeline finally gets back to the compressor, can not lose oil, under the condition of large-load, because the cross-sectional area of every sub-pipeline diminishes for the cross-sectional area of single pipeline, oil drips on the inner wall of sub-pipeline, also can be pushed to remove by gas, to sum up, the vertical pipeline of the embodiment of this application can compromise the condition of large-load and small-load under the variable operating mode.

In one embodiment, in order to achieve better oil loss prevention, for example, the flow rate of each sub-pipeline is the same, the cross-sectional area of one sub-pipeline in any two sub-pipelines is 90% -110% of the cross-sectional area of the other sub-pipeline, for example, 90%, 92%, 95%, 98%, 100%, 103%, 105%, 108% or 110%. For example, in fig. 2, the cross-sectional area of the sub-pipe 221 is 90% to 110% of the cross-sectional area of the sub-pipe 222, the cross-sectional area of the sub-pipe 224 is 90% to 110% of the cross-sectional area of the sub-pipe 222, and the cross-sectional area of the sub-pipe 224 is 90% to 110% of the cross-sectional area of the sub-pipe 221.

Although the shape of the sub-pipes is not limited as described above, and may be circular, fan ring, polygonal, etc., in one embodiment, the cross section of the vertical pipe is circular, the sub-pipes include a central sub-pipe 221 having a circular cross section and

edge sub-pipes

222, 223, 224, and 225 distributed around the central sub-pipe 221, and the cross section of each

edge sub-pipe

222, 223, 224, and 225 is fan ring shaped. So set up, satisfying under the requirement of not losing oil, can also make the consumptive material of vertical pipeline few and save the cost, the structure is also simple and is convenient for make.

The cross-section of each sub-pipe is of the same shape. For example, in fig. 3, all of the sub-circuits are circular in shape. In other embodiments, the cross-section of each sub-pipeline may be triangular, and the cross-section of each sub-pipeline is uniformly distributed around a circle to form a regular polygon. So set up, satisfying under the requirement of not losing oil, can also make the simple structure of vertical pipeline, be convenient for make.

In one embodiment, where the cross-section of the sub-pipe is circular, the hydraulic diameter of the sub-pipe is between 3mm and 12 mm. So set up, the hydraulic diameter is at above-mentioned scope not only makes vertical pipeline can not lose oil, moreover, makes the cost of vertical pipeline can not be too high.

In one embodiment, the inner wall of at least one of the sub-conduits is of an oleophobic material or is provided with an oleophobic coating. For example, in fig. 2 and 4, the inner wall of the sub-pipeline 221 is made of an oleophobic material or provided with an oleophobic coating, or the inner walls of all the sub-pipelines 221, 222, 223, 224, and 225 may be made of an oleophobic material or provided with an oleophobic coating. In fig. 3, the inner walls of each of the sub-conduits 321, 322 and 323 are of an oleophobic material or are provided with an oleophobic coating. So set up, the viscous force of oil drop and the inner wall of sub-pipeline is littleer, is promoted by gas more easily to, oil pushes away more easily from vertical pipeline gets back to the compressor, ensures not losing oily effectual.

In one embodiment, the sub-pipes constitute profiles, which facilitate processing and manufacturing, thereby saving costs of the vertical pipes.

Referring to fig. 4, in the flooded chiller, in the case where the temperature of the condensed water is low, the evaporation amount is low, and the oil may not be brought back to the compressor. The oil concentration at the oil return port of the evaporator is 5-10%; the oil concentration at the thermosyphon outlet is estimated to be 50% to 75%; namely, the gas is 25-50 percent, the specific volume of the gas is 20 times of that of the liquid, and the liquid with the inlet liquid column height H can be conveyed to the height of 20 times of the oil liquid mixture through thermosiphon under the condition of overcoming the friction force. However, at low flow rates, the liquid is trapped by the piping, sticks, causes the oil to rise to a low level, and deposits, thereby creating a loss of oil condition. In order to solve the problem of oil loss of the flooded water chiller, the vertical pipeline comprises a casing pipe 41, all the sub-pipelines 221, 222, 223, 224 and 225 are positioned in the casing pipe 41, and a channel 42 is formed between the outer wall of the pipe body 21 and the inner wall of the casing pipe 41. With this arrangement, the refrigerant flowing from the condenser in the passage 42 accelerates the viscous oil and refrigerant in the pipe walls of the sub-pipes 221, 222, 223, 224, and 225 to further evaporate, the mixture evaporates to form gas, and the oil is prevented from being viscous, so that the oil is easier to return to the compressor, and the refrigerant cooling system is suitable for the flooded water chiller.

In another aspect, the present application further discloses a refrigeration system comprising a compressor and any of the foregoing vertical tubes. The vertical conduit is in circuit with the compressor to enable oil to be discharged from the compressor, through the vertical conduit back to the compressor. How the vertical conduit is looped with the compressor can be in any number of ways, including, but not limited to, ways known to the skilled person. The refrigerating system comprises a direct expansion unit or a flooded water chilling unit on a high-fall occasion, and the direct expansion unit or the flooded water chilling unit comprises the compressor.

The above description is only for the purpose of illustrating the preferred embodiments of the present application and is not to be construed as limiting the present application, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present application should be included in the scope of the present application.

Claims

1. The vertical pipeline of the refrigerating system is characterized by comprising a pipe body and at least two sub-pipelines positioned in the pipe body.

2. The vertical tube of a refrigeration system of claim 1, wherein the cross-sectional area of one of any two sub-tubes is 90% to 110% of the cross-sectional area of the other sub-tube.

3. The vertical tube of claim 1, wherein the vertical tube has a circular cross-section, and wherein all of the sub-tubes comprise a central sub-tube having a circular cross-section and edge sub-tubes distributed around the central sub-tube, each edge sub-tube having a cross-section in the shape of a sector of a circle.

4. The vertical tube of a refrigeration system of claim 1, wherein the cross-section of each of the sub-tubes is the same shape.

5. Vertical tube of a refrigeration system according to claim 3 or 4, characterized in that the hydraulic diameter of the sub-tube is between 3mm and 12mm in the case of a circular cross section of the sub-tube.

6. Vertical pipe of a refrigeration system according to claim 1, characterized in that the inner wall of at least one of the sub-pipes is of an oleophobic material or is provided with an oleophobic coating.

7. The vertical tube of a refrigeration system of claim 1, wherein each of the sub-tubes comprises a profile.

8. The vertical tube of a refrigeration system of claim 1, wherein the vertical tube comprises a sleeve, all sub-tubes being located within the sleeve, a channel being formed between an outer wall of the tube and an inner wall of the sleeve.

9. Refrigeration system, characterized in that it comprises a compressor and a vertical conduit of the refrigeration system according to any one of claims 1 to 8, the compressor being in circuit with the vertical conduit so that the oil discharged from the compressor returns to the compressor through the vertical conduit.

10. The refrigeration system of claim 9, wherein the refrigeration system comprises a direct expansion unit or a flooded chiller on a high head application, and wherein the direct expansion unit or the flooded chiller comprises the compressor.