This patent arises from an application that is a continuation of International PCT Application No. PCT/CN2020/085869, filed on Apr. 21, 2020, and is hereby incorporated by reference in its entirety. Further, this patent claims priority to Chinese Patent Application 201910778507.2, which was filed on Aug. 22, 2019, which is hereby incorporated by reference in its entirety.
Technical Field
This disclosure relates to the field of air conditioning technologies, and in particular to a refrigerant distributor and an evaporator comprising the refrigerant distributor.
Background
A refrigeration system is mainly composed of a compressor, an evaporator, a condenser and a throttling device, in which the mainstream evaporator structure are of two types: a flooded type and a falling film type. With the increasing demand for energy saving and environmental protection, researches for water chillers have been turned to the direction of high performance and low refrigerant charge, and a flooded evaporator cannot effectively control the refrigerant charge of the water chiller on the premise of meeting high performance. Falling film evaporators are now widely used in central air conditioning refrigeration units. This type of heat exchangers has the advantages of small amount of refrigerant charge, compact structures, high heat transfer efficiencies, and stable heat exchange, etc.
In a falling film evaporator, a refrigerant distributor is a key component. In order to evenly distribute the refrigerant on an evaporating tube bundle, it is generally required that there is a sufficient pressure difference between inside and outside of the refrigerant distributor. For example, in a refrigeration system that uses high pressure refrigerant, such as R134a, etc., a pressure drop of the distributor often needs to reach 60 kpa or more, such that the refrigerant can be more evenly scattered on the heat exchange tube bundle.
Nowadays, in response to higher performance and environmental protection requirements at home and abroad, low-pressure refrigerant, such as R123 and R1233zd(e), are increasingly used in the air conditioning industry.
Under typical working conditions in which the evaporation temperature is 6° C. and the condensation temperature is 37° C., a pressure difference between the condenser and evaporator of the low-pressure refrigerant R1233zd(e) is only 23.1% of a pressure difference between a condenser and evaporator of a traditional refrigerant R134a.
It should be noted that the above description of the background is merely provided for clear and complete explanation of this disclosure and for easy understanding by those skilled in the art. And it should not be understood that the above technical solution is known to those skilled in the art as it is described in the background of this disclosure.
It was found by the inventors that a low-pressure refrigerant is more prone to phase change due to a relatively small system pressure difference. Therefore, in a heat exchange system using the low-pressure refrigerant, requirements on pressure drop in a falling film evaporator refrigerant distributor have also changed dramatically. For example, the refrigerant throttled by a throttling device of the heat exchange system has a dryness of about 10%-20%, that is, the refrigerant entering a liquid inlet pipe of the evaporator is in gas and liquid phases, especially for a low-pressure refrigerant, a volume fraction of gaseous refrigerant can account for about 80% of the inlet refrigerant in gas liquid phases. The presence of gaseous refrigerant will cause excessive pressure drop in the distributor, which will have a relatively great impact on uniform distribution of the refrigerant in the falling film evaporator, thereby affecting a heat exchange effect of the refrigerant.
This disclosure provides a refrigerant distributor and an evaporator including the refrigerant distributor. A width of a box body of the refrigerant distributor increases gradually within a predetermined height range starting from a bottom of the box body. Hence, the gradually increasing width may effectively reduce a velocity of flow of the refrigerant in a gas-liquid mixture phase, facilitate separation of the gaseous refrigerant and the liquid refrigerant, reduce a pressure drop in the distributor, and facilitate uniform distribution of the liquid refrigerant in the distributor.
According to an aspect of the embodiments of this disclosure, there is provided a refrigerant distributor, including:
An advantage of the embodiments of this disclosure exists in that the width of the box body of the refrigerant distributor increases gradually within a predetermined height range starting from the bottom of the box body. Hence, the gradually increasing width may effectively reduce a velocity of flow of the refrigerant in a gaseous state, facilitate separation of the gaseous refrigerant and the liquid refrigerant, reduce a pressure drop in the distributor, and facilitate uniform distribution of the liquid refrigerant in the distributor. And the pre-distributor is arrange within the box body of the refrigerant distributor, in which the refrigerant in a gas-liquid mixture phase jetted from through holes in two side walls of the pre-distributor in the length direction collides with the inner side wall of the box body to form swirl flows, thereby promoting liquid drops falling off the gas flows and falling back to the bottom of the box body under the action of gravity.
With reference to the following description and drawings, the particular embodiments of this disclosure are disclosed in detail, and the principle of this disclosure and the manners of use are indicated. It should be understood that the scope of the embodiments of this disclosure is not limited thereto. The embodiments of this disclosure contain many alternations, modifications and equivalents within the scope of the terms of the appended claims.
The drawings are included to provide further understanding of this disclosure, which constitute a part of the specification and illustrate the preferred embodiments of this disclosure, and are used for setting forth the principles of this disclosure together with the description. It is obvious that the accompanying drawings in the following description are some embodiments of this disclosure, and for those of ordinary skills in the art, other accompanying drawings may be obtained according to these accompanying drawings without making an inventive effort. In the drawings:
These and further aspects and features of this disclosure will be apparent with reference to the following description and attached drawings. In the description and drawings, particular embodiments of the disclosure have been disclosed in detail as being indicative of some of the ways in which the principles of the disclosure may be employed, but it is understood that the disclosure is not limited correspondingly in scope. Rather, the disclosure includes all changes, modifications and equivalents coming within the terms of the appended claims.
In the following description of this disclosure, for the convenience of description, a direction in which a central axis of an evaporator housing extends is referred to as “an axial direction”, a radius direction centered on the axis is referred to as “a radial direction”, a circumferential direction centered on the axis is referred to as “a circumferential direction”, a direction from a lower surface of the distributor box body to an upper surface is referred to as “an upper direction”, a direction opposite to the “upper direction” is referred to as “a down direction”, sides of components of the refrigerant distributor and the evaporator towards the “upper direction” are referred to as “upper sides”, and side opposite to the “upper sides” are referred to as “down sides”. It should be noted that the above definitions of the upper direction, the lower direction, the upper sides and the lower sides are only for convenience of description, and do not limit orientations of the refrigerant distributor and the evaporator when they are used.
Embodiment 1
The embodiment of this disclosure provides a refrigerant distributor.
As shown in
As shown in
In this embodiment, the refrigerant in a gas-liquid mixture phase may enter the box body 42 from the refrigerant inlet 41. In the box body 42, the gaseous refrigerant and the liquid refrigerant are separated, and the liquid refrigerant flows out through the liquid exit openings 46 of the lower surface 422, thereby distributing the refrigerant.
In this embodiment, as shown in
Furthermore, the octagonal shape has a high tolerance, and the eight corners are all obtuse angles, which is convenient for processing. Pre-distributors of various shapes may be arranged therein without being restricted by shapes of the pre-distributors. Heights of vertical sides at both sides of the octagonal shape may be set according to sizes and positions of components within the box body 42, and sizes of the upper and lower openings are not affected; in addition, when the refrigerant distributor 4 is arranged in a falling film evaporator, as the bottom of the octagonal shape is relatively wide, the refrigerant distributor 4 may cover as many heat exchange tube bundles as possible, which helps to even distribution of the refrigerant on the heat exchange tube bundles.
In this embodiment, in the octagonal shape shown in
In addition, this embodiment may not be limited thereto, and the shape of the cross section of the box body 42 perpendicular to the length direction L may also be other figures composed of straight line segments and/or curved segments. For example,
In this embodiment, the lower surface 422 of the box body 42 may be of a planar shape or a non-planar shape. The non-planar shape is, for example, an arc, an inverted cone, or an inverted trapezoid, etc.
As shown in
It should be noted that, as the refrigerant distributor 4 of
As shown in
Due to the support plates 44, when the refrigerant distributor 4 is obliquely installed, the support plates 44 may prevent the refrigerant from flowing on the lower surface 422 of the box body 42, thereby avoiding serious tilting of the liquid level of the liquid refrigerant and avoiding severe dry liquid at parts of the lower surface 422. In addition, when the liquid level of the lower surface 422 has a certain height, the liquid refrigerant may flow through the through holes 441 in the support plates 44, thereby ensuring the fluidity of the liquid refrigerant.
It should be noted that the support plates 44 shown in
In this embodiment, the refrigerant distributor 4 may further include a pre-distributor. Following description shall be given by taking that the pre-distributor is arranged in the refrigerant distributor 4 of
As shown in
As shown in
As shown in
As shown in
In this embodiment, the cover plate 34 and the distribution box 32 are hermetically connected. As shown in
In this embodiment, a bending portion 341 bent toward the distribution box 32 is formed at edges of the cover plate 34. The cover plate 34 is beneficial to that the liquid refrigerant is not subjected to an upward air flow in flowing out of the first pre-distributor openings 33; and furthermore, the bending portion 341 is advantageous to the liquid refrigerant collected on the surface of the cover plate 34 to flow down.
As shown in
In this embodiment, when the cross-sectional shape of the box body 42 of the refrigerant distributor 4 is of an octagonal shape, in the height direction, at least a part of the first pre-distributor openings 33 may be located within the height range of the vertical sides on both sides of the octagonal shape, hence, the refrigerant in a gas-liquid mixture phase jetted out of the through holes on the two side walls of the pre-distributor in the length direction collides with the inner side walls of the box body 42, thereby forming upper and lower swirls in the box body 42, promoting droplets to fall off from the air flow and fall back to the bottom of the box body 42 under the action of gravity, and facilitating separation of the liquid refrigerant and the gaseous refrigerant.
In this embodiment, as shown in
In this embodiment, as shown in
In this embodiment, as shown in
As shown in
As shown in
In a variant implementation of this embodiment, the pre-distributor may be cylindrical.
As shown in
In the height direction, distances from at least a part of the second pre-distributor openings 33a and a bottom of the distribution pipe 32a are less than a half of a height of the distribution pipe 32a and greater than zero. That is, at least a part of the second pre-distributor openings 33a are provided in the lower half of the pipe wall 321a. Therefore, it is advantageous for the liquid refrigerant to flow out of the second pre-distributor openings 33a. In addition, settings of the positions of the second pre-distributor openings 33a may not be limited thereto.
As shown in
In this embodiment, the closer to the inlet 31, the larger the sizes and/or the greater the distribution density of the second pre-distributor openings 33a, thereby enabling the liquid refrigerant to uniformly flow in the second pre-distributor openings 33a.
In this embodiment, in the length direction L, the distribution of the second pre-distributor openings 33a is asymmetrical with respect to the inlet 31, that is, in
A difference between
In addition, the second cover plate 34a may include a bending structure inclined with respect to the height direction, the bending structure being advantageous to the liquid refrigerant collected on the surface of the second cover plate 34a to flow down.
In addition, reference may be made to related description of
In addition, in
According to this embodiment, when the pre-distributor 3 does not exist in the box body 42 of the refrigerant distributor 4, the refrigerant in a gas-liquid mixture phase enters the box body 42 through the refrigerant inlet 41. As the width of the box body 42 gradually increases, the velocity of flow of the gaseous refrigerant may be effectively reduced, which is beneficial to the separation of the gaseous refrigerant and the liquid refrigerant, reduces a pressure drop in the distributor, and is beneficial to uniform distribution of the liquid refrigerant in the distributor. The liquid refrigerant in the box body 42 flows out through the liquid exit openings 46 on the lower surface 422 of the box body 42.
When the box body 42 of the refrigerant distributor 4 includes the pre-distributor 3, the gas-liquid mixed refrigerant enters the pre-distributor 3 (or 3a) through a liquid inlet pipe which is connected to the inlet 31 of the pre-distributor 3 (or 3a) and passes through the upper surface 421 of the box body 42 through the refrigerant inlet 41. The mixed refrigerant is distributed in the length direction in the pre-distributor 3 (or 3a), and the refrigerant in a mixed phase is initially uniformly distributed, flows out of the pre-distributor 3 (or 3a) through the first pre-distributor openings 33 (or the second pre-distributor openings 33a) and enters the box body 42; the refrigerant in the box body 42 undergoes gas-liquid separation, and as the width of the box body 42 gradually increases, the velocity of flow of the gaseous refrigerant is effectively reduced, which is beneficial to the separation of the gaseous refrigerant and the liquid refrigerant and reduction of the pressure drop in the distributor, and is beneficial to uniform distribution of the liquid refrigerant in the distributor. At the same time, the refrigerant in a gas-liquid mixture phase jetted from through holes 33 (or 33a) in two side walls of the pre-distributor 3 in the length direction collides with the inner side wall of the box body to form swirl flows, thereby promoting liquid drops falling off the gas flows and falling back to the bottom of the box body under the action of gravity. And the liquid refrigerant in the box body 42 flows out through the liquid exit openings 46 on the lower surface 422 of the box body 42.
As shown in
In addition, due to the existence of the upper and lower swirling flows 17a and 17b, the gas-liquid mixed refrigerant stays in the box body 42 for a longer time, and the refrigerant droplets entrained by the high-speed air flow are more likely to fall back to the bottom of the box body under the action of inertia and gravity, and are difficult to flow out from the ventilation slot on the upper part of the box body 42, thereby reducing the risk of liquid entrainment.
Embodiment 2
The embodiment of this disclosure provides an evaporator, including the refrigerant distributor described in Embodiment 1.
As shown in
As shown in
As shown in
As shown in
As shown in
In this embodiment, the heat exchange tube bundle support plate 6 may be located under the refrigerant distributor 4 and used for supporting the heat exchange tube bundle 5. For example, the heat exchange tube bundle 5 passes through the heat exchange tube bundle support plate 6. The side baffles 7 may be located below the refrigerant distributor 4 and on both sides of the heat exchange tube bundle 5. The mist catcher 8 is located between the side baffles 7 and the evaporator housing 1 in the width direction, and is supported by the heat exchange tube bundle support plate 6 in the height direction. The mist catcher 8 may be, for example, a wire mesh separator.
In this embodiment, as shown in
In
In this embodiment, due to the use of the refrigerant distributor of this disclosure, the liquid refrigerant may be more evenly distributed to the heat exchange tube bundle, so the heat exchange efficiency of the evaporator is improved.
The evaporator of this embodiment may be used in a heat exchange system, and due to the use of the evaporator of this embodiment, the heat exchange efficiency of the heat exchange system may be improved, and the risk of liquid entrainment of the evaporator may be effectively controlled, which is conducive to the use of low-pressure refrigerant in the heat exchange system.
This disclosure is described above with reference to particular embodiments. However, it should be understood by those skilled in the art that such a description is illustrative only, and not intended to limit the protection scope of the present disclosure. Various variants and modifications may be made by those skilled in the art according to the principle of the present disclosure, and such variants and modifications fall within the scope of the present disclosure.
Number | Date | Country | Kind |
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201910778507.2 | Aug 2019 | CN | national |
Number | Name | Date | Kind |
---|---|---|---|
5588596 | Hartfield | Dec 1996 | A |
6167713 | Hartfield | Jan 2001 | B1 |
6253571 | Fujii | Jul 2001 | B1 |
20100107676 | Liu et al. | May 2010 | A1 |
20160341457 | Christians | Nov 2016 | A1 |
20170254573 | Numata | Sep 2017 | A1 |
Number | Date | Country |
---|---|---|
202158699 | Mar 2012 | CN |
204214172 | Mar 2015 | CN |
106482400 | Mar 2017 | CN |
108709339 | Oct 2018 | CN |
109489308 | Mar 2019 | CN |
2019507862 | Mar 2019 | JP |
2019078893 | Apr 2019 | WO |
Entry |
---|
Japanese Patent Office, “Notice of Reasons for Refusal,” issued in connection with Japanese Patent Application No. 2021-531535, dated Apr. 19, 2022, 9 pages. |
IP Australia, “Examination report No. 1,” issued in connection with Australian Patent Application No. 2020334589, dated Mar. 21, 2022, 3 pages. |
Intellectual Property India, “Examination Report,” issued in connection with Indian Patent Application No. 202147023869, dated Apr. 4, 2022, 4 pages. |
International Searching Authority, “Written Opinion,” issued in connection with PCT Application No. PCT/CN2020/085869, dated Jul. 20, 2020, 7 pages. |
International Searching Authority, “International Preliminary Report on Patentability,” issued in connection with PCT Application No. PCT/CN2020/085869, dated Feb. 17, 2022, 9 pages. |
International Searching Authority, “International Search Report,” issued in connection with PCT Application No. PCT/CN2020/085869, dated Jul. 20, 2020, 2 pages. |
European Patent Office, “Extended European Search Report,” issued in connection with European Patent Application No. 20855144.0, dated Jul. 4, 2022, 7 pages. |
Intellectual Property Office of Singapore, Search Report and Written Opinion, issued in connection with Singapore Patent Application No. 11202105411U, dated Jan. 2, 2024, 9 pages. |
European Patent Office, “Communication Pursuant to Article 94(3) EPC,” issued in connection with European Patent Application No. 20855144.0, dated Feb. 13, 2024, 5 pages. |
Number | Date | Country | |
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20210285701 A1 | Sep 2021 | US |
Number | Date | Country | |
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Parent | PCT/CN2020/085869 | Apr 2020 | US |
Child | 17334232 | US |