1. Field of Invention
The invention relates to a refrigerant-distributing, device of a heat exchanger and a heat exchanger comprising the refrigerant-distributing device.
2. Description of Related Art
A distributing tube is generally inserted into a header of the heat exchanger to ensure uniform distribution of a refrigerant in the heat-exchange tubes of the heat exchanger. The distributing tube is formed with openings through which the refrigerant enters into the header from the distributing tube to be distributed to individual heat-exchange tubes.
The conventional distributing tube has disadvantages. For example, in use, a refrigerant at an inlet of a heat exchanger is in a gaseous-liquid two-phase state, and the density difference between the gaseous refrigerant and the liquid refrigerant is large, which may cause gas-liquid separation, thus affecting the refrigerant-distribution uniformity. The gaseous-liquid refrigerant directly flows into the header through openings of the distributing tube, and the gas-liquid separation tends to occur when the gaseous-liquid refrigerant leaves the openings, thus affecting the refrigerant-distribution uniformity. Pressures at individual openings are not balanced in a refrigerant flow direction, thus causing flow-rate imbalance between individual openings in a length direction of the distributing tube. The machining of the openings is difficult due to the increased amount or different types of the openings, and the distributing tube is difficult to clean due to the burrs on machining surfaces of the openings.
The invention seeks to solve at least one of the problems existing in the related art.
Accordingly, an object of a first aspect of the invention is to provide a refrigerant-distributing device capable of improving the refrigerant-distribution uniformity.
An object of a second aspect of the invention is to provide a heat exchanger comprising the refrigerant-distributing device according to the first aspect of the invention that may have improved heat-exchange performance.
Embodiments of the first aspect of the invention provide a refrigerant-distributing device comprising: a distributing tube defining a first end and a second end in a length direction thereof and a plurality of nozzles disposed on the distributing tube along the length direction of the distributing tube, each nozzle having a predetermined length and being formed with as through-hole communicating an interior of the distributing tube and an exterior of the distributing tube.
The refrigerant-distributing device according to embodiments of the invention is capable of improving the flow-rate balance. The flow resistance is increased because of the nozzles, the pressures at individual nozzles may be balanced, and the pressure imbalance between individual nozzles may be reduced greatly so that the refrigerant-flow rate along the length direction of the distributing tube is more balanced.
The refrigerant-distributing device according to embodiments of the invention can control and adjust the flow direction of the refrigerant. The gaseous-liquid refrigerant may be ejected out of the nozzles along the radial direction, the axial direction, the circumferential direction, and other directions of the distributing tube so that the refrigerant-distribution uniformity in the exterior of the distributing tube is improved greatly.
In some embodiments, the plurality of nozzles are arranged in a plurality of rows in a circumferential direction of the distributing tube, and the nozzles in each row are arranged spirally.
In some embodiments, the through-hole is a circular hole and passes through inner and outer end surfaces of the nozzle, and a length of the through-hole is 0.125-250 times as large as a hydraulic diameter of the through-hole.
In some embodiments, the through-hole passes through inner and outer end surfaces of the nozzle, and an axial direction of the through-hole is inclined relative to an axial direction of the nozzle.
In some embodiments, the through-hole has a rectangular or cross-shaped cross-section.
In some embodiments, the through-hole defines a first through-hole segment extending in a radial direction of the nozzle and a second through-hole segment extending in an axial direction of the nozzle, an inner end of the second through-hole segment is communicated with the interior of the distributing tube, an outer end of the second through-hole segment is closed, and the first through-hole segment communicates the second through-hole segment with the exterior of the distributing tube.
In some embodiments, a plurality of the first through-hole segments are formed and arranged in a circumferential direction of the second through-hole segment.
In some embodiments, the through-hole defines a first through-hole segment and a second through-hole segment extending in an axial direction of the nozzle, an inner end of the second through-hole segment is communicated with the interior of the distributing tube, an outer end of the second through-hole segment is closed, the first through-hole segment communicates the second through-hole segment with the exterior of the distributing tube, and an axial direction of the first through-hole segment is deviated from a radial direction of the nozzle.
In some embodiments, an inner end of each nozzle is extended into the interior of the distributing tube by a predetermined length.
In some embodiments, the inner end of the each nozzle is formed with a bent portion.
In some embodiments, an inner end of each nozzle is flush with an inner wall surface or an outer wall surface of the distributing tube.
In some embodiments, the through-hole passes through inner and outer end surfaces of the nozzle, an axial direction of the through-hole is parallel with an axial direction of the nozzle, the distributing tube has a circular cross-section, a ratio H/D of a length H of the through-hole to a hydraulic diameter D of the distributing tube is in a range of 0.027-25, and a ratio H/L of the length H of the through-hole to a length L of the distributing tube is in a range of 3.3×10−4−0.125.
In some embodiments, a sum of cross-sectional areas of the through-holes of the nozzles is 0.01%-40% of a circumferential surface area of the distributing tube.
Embodiments according to the second aspect of the invention provide a heat exchanger comprising: an inlet header; an outlet header; a plurality of heat-exchange tubes each having two ends connected with the inlet header and the outlet header, respectively, to communicate the inlet header and the outlet header; a plurality of fins disposed between adjacent heat-exchange tubes, respectively; and a refrigerant-distributing device according to embodiments of the first aspect of the invention disposed in the inlet header.
Other objects, features, and advantages of the invention are readily appreciated as the invention becomes better understood while a subsequent detailed description of embodiments of the invention is read taken in conjunction with the accompanying drawing thereof.
Reference will be made in detail to embodiments of the invention. The embodiments described herein with reference to the drawing are explanatory, illustrative, and used to generally understand the invention. The embodiments shall not be construed to limit the invention. The same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions.
In the specification, unless specified or limited otherwise, relative terms such as “length direction,” “lateral,” “axial direction,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal” “top,” “bottom,” “inner,” and “outer” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the figure(s) under discussion. These relative terms are for convenience of description and do not require that the invention be constructed or operated in a particular orientation.
The refrigerant-distributing device according to embodiments of the invention will be described below with reference to the drawing.
As shown in
In an example, as shown in
With the refrigerant-distributing device according to embodiments of the invention, the plurality of nozzles 2 are mounted on the distributing tube 1 along the length direction of the distributing tube 1, and the “pumping” effect may be generated in the nozzles 2 under the same pressure as that in the related art such that the flow rate in the nozzles 2 is larger than that in openings of a conventional distributing tube when the hydraulic diameter of the nozzle 2 is identical with that of the opening of the conventional distributing tube.
In addition, the gaseous refrigerant and the liquid refrigerant may be mixed again when flowing in the through-holes 21 of the nozzles 2, thus further reducing the gas-liquid separation. Moreover, the through-holes 21 of the nozzles 2 may increase the length of the refrigerant-ejection passage-so-as to increase the refrigerant-distribution-pressure difference such that the refrigerant flow-rate distribution is more uniform along the entire length direction of the distributing tube 1, thus improving the heat-exchange performance of the heat exchanger.
By comparison to the conventional distributing tube having distributing openings formed in a wall thereof with the refrigerant-distributing device according to embodiments of the invention, the nozzles 2 each having a predetermined length are disposed on the distributing tube 1. The refrigerant-flow rate Q follows a formula:
Q=μ0A√{square root over (2gH)},
where A is a cross-sectional area of the through-hole 21 of the nozzle 2, H is a pressure head, g is the gravity acceleration, and μ0 is a flow-rate coefficient. Because the flow-rate coefficient μ0 of the nozzle 2 is 0.82 and the flow-rate coefficient μ0 of the opening in the conventional distributing tube is 0.62, the flow rate in the nozzle 2 is larger than that in the opening in the conventional distributing tube when the hydraulic diameter of the nozzle 2 is identical with that of the opening in the conventional distributing tube.
In addition, with the conventional distributing tube, the refrigerant flows out of the distributing tube through individual openings formed in the wall of the distributing tube, the pressure drops in the individual openings are unequal, and a pressure difference between the refrigerant inlet and the opening farthest from the refrigerant inlet (i.e., the last opening) differs greatly from that between the refrigerant inlet and the opening nearest to the refrigerant inlet (i.e., the first opening) such that the refrigerant flow-rate distribution along a length direction of the distributing tube is non-uniform (that is, the flow rate in the first opening is much larger than that in the last opening). In contrast, with the refrigerant-distributing device according to embodiments of the invention, because the nozzles 2 each having a predetermined length are disposed on the distributing tube 1, the refrigerant-flow passage in each nozzle 2 is lengthened, and the refrigerant-distribution-pressure drop in the nozzles 2 is larger than that in the openings in the conventional distributing tube such that a pressure difference between the refrigerant inlet and the first nozzle 2 (for example, the left-most nozzle in
The refrigerant-distributing device according to a first embodiment of the invention will be described below with reference to
In the embodiment shown in
As shown in
As shown in
As shown in
In other examples, an inner end (i.e., the end of each nozzle 2 close to the distributing tube 1) of each nozzle 2 is extended into the interior of the distributing tube 1 by a predetermined length. Because the nozzle 2 is inserted into the interior of the distributing tube 1, the refrigerant is agitated when flowing in the distributing tube 1 along the axial direction of the distributing tube 1, and the gaseous refrigerant and the liquid refrigerant are separated from and then remixed with each other continuously such that the gaseous refrigerant and the liquid refrigerant may be still mixed uniformly when flowing to a region in the distributing tube 1 away from the refrigerant inlet of the distributing tube 1. Alternatively, the inner end of each nozzle 2 is flush with the inner wall surface or the outer wall surface of the distributing tube 1.
In some embodiments, the through-hole 21 passes through the inner end surface and the outer end surface of the nozzle 2, and the axial direction of the through-hole 21 is parallel with the axial direction of the nozzle 2. The distributing tube 1 is a circular tube, a ratio H/D of a length H of the through-hole 21 to a hydraulic diameter D of the distributing tube 1 is in a range of 0.027-25, and a ratio of the length of the through-hole 21 to a length L of the distributing tube 1 is in a range of 3.3×10−4−0.125.
According to some embodiments of the invention, if the local pressure drop is not considered, according to a formula of the frictional resistance (i.e., frictional drag in the distributing tube:
ΔP=λ(1/d)ρμ2/2,
the resistance in a single nozzle is:
ΔPnozzle=λ1(H/d)ρμ2i/2,
the frictional resistance in the distributing tube is:
ΔPtube=λ2(L/D)ρμ2/2,
when ΔPnozzle is larger than ΔPtube, the optimization of the flow rate in the nozzle may be realized.
Therefore, when the ratio H/D of the length H of the through-hole 21 to the hydraulic diameter D of the distributing tube 1 is in a range of 0.027-25 and the ratio H/L of the length H of the through-hole 21 to the length L of the distributing tube 1 is in a range of 3.3×10−4−0.125, the flow-rate distribution between individual nozzles 2 of the distributing tube 1 may be optimized. For example, in a specific example, H=1-25 millimeters, d=0.1-8 millimeters, D=1-36 millimeters, and L=0.2-3 meters.
Likewise, based on the above analysis, when a sum of cross-sectional areas of the through-holes 21 of the nozzle 2 is 0.01%-40% of a circumferential-surface area of the distributing tube 1, the flow-rate distribution between individual nozzles 2 of the distributing tube 1 may be optimized.
In the embodiment shown in
The refrigerant-distributing device according to a second embodiment of the invention will be described below with reference to
The refrigerant-distributing device according to a third embodiment of the invention will be described below with reference to
The refrigerant-distributing device according to a fourth embodiment of the invention will be described below with reference to
The refrigerant-distributing device according to a fifth embodiment of the invention will be described below with reference to
The refrigerant-distributing device according to a sixth embodiment of the invention will be described below with reference to
The refrigerant-distributing device according to a seventh embodiment of the invention will be described below with reference to
The refrigerant-distributing device according to an eighth embodiment of the invention will be described below with reference to
In the above embodiments, the plurality of nozzles 2 are arranged in one row. However, it should be appreciated that the plurality of nozzles 2 may be arranged in a plurality of rows in a circumferential direction of the distributing tube 1 and the nozzle 2 in each row may be arranged spirally or linearly.
In the above embodiments, the nozzles 2 are cylindrical. However, the-invention is not limited to this. For example, the nozzles 2 may be of a prism having a rectangular cross-section or a cross-section of other shapes.
In some embodiments, the nozzles 2 may be manufactured separately and mounted onto the distributing tube 1. Alternatively, the nozzles 2 and the distributing tube 1 may be integrally manufactured (for example, the nozzles 2 and the distributing tube 1 are integrally cast).
With the refrigerant-distributing device according to embodiments of the invention, because the nozzles 2 are disposed on the distributing tube 1, the “distribution” effect may be improved, and the separation of the gaseous refrigerant and the liquid refrigerant may be reduced, thus improving the “heat exchange” effect.
The heat exchanger according to an embodiment of the invention will be described below with reference to
Two ends of each heat-exchange tube 300 are connected with the inlet header 100 and the outlet header 200, respectively, to communicate the inlet header 100 and the outlet header 200. The plurality of fins 400 are disposed between adjacent heat-exchange tubes 300, respectively. The refrigerant-distributing device is disposed in the inlet header 100. As shown in
It should be appreciated that, in some embodiments, the refrigerant-distributing device according to an embodiment of the invention may also be disposed in the outlet header 200. In this case, the refrigerant-distributing device is used as a refrigerant-collecting device. Alternatively, the refrigerant-distributing device according to an embodiment of the invention may be disposed in the inlet header 100 and the outlet header 200 simultaneously.
In conclusion, the refrigerant-distributing device and the heat exchanger according to embodiments of the invention are capable of improving the flow-rate balance. Since the flow resistance is increased by the through-holes of the nozzles, the pressure difference between individual nozzles may be balanced, and the pressure imbalance between individual nozzles may be reduced largely so that the refrigerant-flow rate along the length direction of the distributing tube may be more balanced.
The refrigerant-distributing device and the heat exchanger according to embodiments of the invention are capable of controlling and adjusting the direction of the refrigerant. The gaseous refrigerant and the liquid refrigerant may be ejected out of the nozzles not only along the radial direction of the distributing tube, but also along the axial direction, the circumferential direction, or other directions of the distributing tube so that the refrigerant-distribution uniformity in the exterior of the distributing tube may be improved largely.
Reference throughout this specification to “a first embodiment,” “a second embodiment,” “some embodiments,” “an example,” “a specific example,” or “some examples” means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. Thus, the appearances of the above phrases in various places throughout this specification are not necessarily referring to the same embodiment or example of the invention. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one embodiment or example or more embodiments or examples.
Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the related art that the above embodiments cannot be construed to limit the invention, and changes, alternatives, and modifications can be made in the embodiments without departing from the spirit, principles, and scope of the invention.
Number | Date | Country | Kind |
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201010590176.9 | Dec 2010 | CN | national |
This is a “national phase” application of International Patent Application PCT/CN2011/073846 filed on May 9, 2011, which, in turn, is based upon and claims priority to Chinese Patent Application 201010590176.9 filed on Dec. 8, 2010.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CN11/73846 | 5/9/2011 | WO | 00 | 8/12/2013 |