KR20000059368A - Improved inlet for an evaporator - Google Patents

Abstract

The evaporator according to the present invention is an evaporator which increases the evaporation efficiency by uniformly distributing the injected liquid refrigerant, a pair of spaced apart header; At least one tube extending between the headers and in fluid communication with each header on one side of the header and defining a plurality of refrigerant passages spaced apart between the headers; And a first port designed to be connected to a refrigerant source to be evaporated, a second port and a third port connected to the first port and oriented in a direction opposite to the first port, the second port coming out of the one side. Direction in which the third port comprises a refrigerant inlet in at least one of the headers oriented to face the one side.

Description

Improved evaporator inlet {IMPROVED INLET FOR AN EVAPORATOR}

The present invention relates to a refrigerant evaporator, and more particularly, to an improved inlet for refrigerant evaporator capable of improving the efficiency of the evaporation action.

Hughes et al. Disclose a unique refrigerant evaporator that is ideal for use in residential air conditioners in US Pat. Nos. 5,341,870 (registered August 30, 1994) and 5,533,259 (registered July 9, 1996). The structure disclosed in Hughes et al. Works well for the desired purpose and is a significantly improved form over the evaporator used in conventional air conditioners, but in terms of efficiency if the refrigerant is not properly distributed in the evaporator, It has the same disadvantages as

In the case of poor distribution of the refrigerant, some of the evaporator cores are excessively provided with liquid refrigerant, while others are often deficient in actual refrigerant. An infrared thermal image of an actual evaporator with poor refrigerant distribution is shown in FIG. 1. The distributor used is in the general form set forth by the above-mentioned US patent, in which one header 10 is provided with the inlet fixture 12 and the opposite header 14 with the outlet fixture 16 is provided. It is kind. Typically, such evaporators are known in the art as parallel flow variety end feeds, end draws, "V" evaporators.

A tube 18 connecting headers 10, 14 to each other is schematically illustrated, with serpentine fins (not shown) extending between adjacent tubes 18.

Tubes deficient in refrigerant in such evaporators quickly run out of liquid, ie mixed refrigerant. Accordingly, one phase of superheated gaseous refrigerant is present in a substantial portion along the length of each tube in which the refrigerant is insufficient, resulting in poor heat transfer.

In addition, where the superheated gas flows, the air side surface temperature is usually above the dew point, so that moisture condensation from the air passing through the evaporator does not occur where the superheated gas flow occurs. do. Therefore, no dehumidification occurs in that part.

In areas where dehumidification occurs, moisture is present on the outer surface of the tube, which increases the resistance to air flow through the evaporator. In other words, at the point where there is a superheated gas stream, the resistance to the air flow is smaller, so that too much of the total air flowing through the evaporator is accommodated in this section and is less efficient.

Tubes provided with excessive refrigerant provide good heat transfer throughout, but often fail to evaporate the entire liquid refrigerant. As a result, the refrigerant not evaporated is not used, so the work used to condense the gas into the liquid is actually wasted. In addition, when liquid that has not evaporated is in the suction line, the thermal expansion valve used in the system "hunts" and the evaporation action becomes unstable.

The part where the superheated gas flow occurs is shown by the hatched part of FIG. Unhatched portions represent portions that function normally or are provided with excessive refrigerant in the tube.

The present invention is directed to a more uniform distribution of the refrigerant by eliminating or minimizing the overheated portion of the refrigerant due to the lack of refrigerant in the evaporator core in common evaporators and "V" evaporators of co-current type.

It is an object of the present invention to provide a new and improved refrigerant evaporator. More specifically, it is an object of the present invention to provide an improved new inlet structure for a refrigerant evaporator in order to allow the refrigerant in the evaporator to be more evenly distributed.

1 is a perspective view showing an evaporator manufactured according to the prior art.

2 is a perspective view showing an evaporator manufactured according to the present invention.

3 is an enlarged view of a part of an inlet injector used in the evaporator.

4 is an enlarged cross-sectional view of a portion of the inlet injector.

FIG. 5 is a view similar to FIG. 1, illustrating an evaporator made in accordance with the present invention.

In order to achieve the object of the present invention, an evaporator according to a preferred embodiment of the present invention includes a pair of spaced headers. At least one tube extends between the headers, the tube in fluid communication with each header on one side of the header, and defining a plurality of refrigerant passages spaced between the header and the header. At least one refrigerant inlet is located in one of the headers. The inlet has a first port connected to the refrigerant source to be evaporated, and is located connected to the first port in the one header, and is oriented in a direction opposite to one side of the header to which the one header and the tube are connected. And a second port. Accordingly, the refrigerant to be evaporated is injected into the header in a direction opposite to the refrigerant passage position, and the header itself functions as an impingement distributor.

In a preferred embodiment, the inlet comprises a third port connected to the first port as well as the second port. The third port faces the opposite side of the second port, that is, toward the header through the passage. The third port impinges and distributes the refrigerant in a tube located close to the inlet, and the second port distributes the refrigerant in a passage located farther from the inlet.

In a preferred embodiment, the third port is smaller than the second port.

Preferably, the plurality of passages are defined by the plurality of tubes, and the plurality of tubes are spaced apart from each other.

In a preferred embodiment, each end of the plurality of tubes is inserted into the header on one side of the header adapted to engage the tube.

Each tube preferably defines a plurality of refrigerant passages spaced apart from each other.

In a more preferred embodiment, the one header is elongated and a plurality of refrigerant inlets spaced apart from each other along the length of the one header is provided.

In a preferred embodiment at least one header is generally in the form of a tube.

Evaporators comprising elongated headers have been considered in the preferred embodiment. A plurality of spaced flat tubes are provided, the ends of which are inserted into one side of the header at equal intervals. The header is provided with an inlet, the inlet comprising a plurality of injectors spaced apart from each other, each injector being designed to be connected to the same refrigerant source to be evaporated. Each injector includes an ejection orifice extending in a direction opposite to one side of the header into which the end of the flat tube is inserted.

In a preferred embodiment, the end of the tube extends into the header and the injector is located between the ends of adjacent tube pairs.

The discharge orifice being a primary discharge orifice, further comprising a second discharge orifice that is smaller in size than the discharge orifice and is oriented toward one side of the header between the ends of the adjacent tube pairs desirable.

Other objects and advantages of the present invention will become more apparent from the following detailed description and drawings.

Preferred embodiments of the invention shown in FIGS. 2 to 5 are described in the context of cocurrent type "V" evaporators. However, the present invention is not limited to this type of evaporator. The present invention can be effectively used in all evaporators including one header having a plurality of spaced refrigerant passages and fluid flows.

The evaporator includes an inlet header 20 in the form of an elongated tube and an outlet header 22. A series of flat multi-port tubes 24 are provided to connect the headers 20, 22 to each other, with serpentine pins 26 positioned between the flat tubes 24 adjacent to each other.

The outlet header 22 includes a single outlet fixture 28 of the same structure as the prior art. Four refrigerant injectors 30, 32, 34, 36 are preferably connected at regular intervals to the inlet. The injectors 30, 32, 34 and 36 are conventional tubes, which are connected to a conventional distributor 38, which has a common liquid refrigerant source, ie ultimately for refrigeration purposes, heat pumps or air. It can be connected to the condenser of the refrigerating device, which is used exclusively for the conditioning device or in combination with all three purposes.

Referring to FIG. 3, each tube 24 has an end 40 inserted into the inlet header 20 by a significant distance. As can be seen in the form of the end 40, each of these tubes comprises a plurality of separate passages 42, the hydraulic diameter of which is preferably 0.07 ", or less. Fluid diameter means, as defined generally, four times the number of cross sections of each passage 42 divided by the wetted perimeter of the passage.

The ends 40 are spaced apart and are located between the ends of the pair of tubes 24, as can be seen in the injector 34 of FIG. 3. In addition, as shown in the figure, the injector 34 and the injectors 30, 32, 36 are formed in a cylindrical shape smaller in diameter than the tube forming the inlet header 20. The injector 34 inserted in the header 20 is arranged at a nominal perpendicular to the horizontal plane formed by the header and the tube 24 near the header 20.

As shown in FIG. 4, the tube 24 is inserted into one side 44 of the header 20, and the end 40 penetrates almost half of the interior of the header 20. The injector 34 includes a sealed end 48 located in the header. Opposite the sealed end is a port 49 to which refrigerant is to be injected. The injector 34 also has a first ejection orifice 50, which is a ejection orifice that ejects the tube 24 toward the inner surface 52 of the header 20 in the opposite direction to the side 44 into which it is inserted into the header 20. It includes. In addition, a second release orifice 54 having the same centerline as the centerline of the first release orifice 50 is located in the injector 34 in the header 20. The second discharge orifice 54 is smaller in size than the ejection orifice and sprays the liquid refrigerant toward the side 44. The injection point may be a point between adjacent tube ends 40, or a point in line with the tube end.

The liquid discharged from the first discharge orifice spreads along the inner surface 52 of the header 20, dispersing the refrigerant a considerable distance within the header, and the tube 24 between the points of the injectors 30, 32, 34, 36. Refrigerant is provided throughout. In most cases, only the first discharge orifice is required, but in particular when the tube end 40 extends to a considerable distance inside the header 20, as a result of the impingement on the inner surface 52, the coolant may end up in the end 40. Since the air is blown past the tube closest to the injectors 30, 32, 34, 36, the refrigerant may not be sufficiently supplied. Thus, a second discharge orifice 54 may be provided to each injector 30, 32, 34, 36 so that the liquid refrigerant is properly supplied to the tube 24 adjacent to each injector's position.

5 shows a real infrared thermal image of the evaporator according to the invention. The hatched area is where overheated gas flows occur. In the evaporator according to the present invention shown in Figure 5 is reduced hatched, it can be seen that the evaporator operating efficiency is significantly improved compared to the evaporator shown in FIG.

As in the case of the illustrated evaporator, four injectors are installed in the evaporator designed at 30,000 BTU / hour. Each injector consists of a tube with an outer diameter of 0.25 "and a wall thickness of 0.035". The diameter of the first release orifice 50 is 0.125 "and the diameter of the second release orifice 54 is 0.052". In one embodiment, the evaporator core is provided with 54 flat tubes 24, with each injector having 11.25 tubes 24.

The evaporator according to the present invention has excellent performance in distributing the injected liquid refrigerant, and increases the evaporation efficiency. The structure used in the evaporator according to the present invention is relatively simple, since the injector is manufactured using a tube having a discharge orifice drilled in a suitable size, so that the efficiency can be practically improved in a minimal cost and in an uncomplicated manner.

Claims (13)

A pair of spaced headers; At least one tube extending between the headers and in fluid communication with each header on one side of the header and defining a plurality of refrigerant passages spaced apart between the headers; And A first port designed to be connected to a refrigerant source to be evaporated, a second port and a third port connected to the first port and oriented in a direction opposite to the first port, wherein the second port is directed from the one side At least one refrigerant inlet in one of the headers, the third port being oriented to face the one side Evaporator comprising a. The evaporator of claim 1 wherein said third port is smaller than said second port. The evaporator of claim 1, wherein the plurality of passages are defined by the plurality of tubes, the plurality of tubes spaced apart. 4. The evaporator of claim 3 wherein each end of the plurality of tubes is inserted into the one side of each of the headers. 4. The evaporator of claim 3 wherein each of said tubes further defines a plurality of spaced refrigerant passages. The evaporator of claim 1, wherein the one header is elongated and spaced apart from the plurality of refrigerant inlets along a length of the one header. The evaporator of claim 1 wherein at least one of said headers is generally in the form of a tube. A pair of spaced headers; At least one tube extending between the headers and in fluid communication with each header on one side of the header and defining a plurality of refrigerant passages spaced apart between the headers; And A first port designed to be connected to a refrigerant source to be evaporated, a second port connected to the first port and located in the one header and oriented in a direction exiting the one side of the one header, wherein the header At least one refrigerant inlet in one of the Evaporator comprising a. 9. The evaporator of claim 8 wherein said inlet comprises a third port connected to said first port and located within said header, oriented toward said one side of said one header. 10. The evaporator of claim 9 wherein the plurality of passages are defined by a plurality of spaced tubes, wherein the second and third ports are located between two adjacent tubes. Elongated headers; A plurality of spaced flat tubes, the ends of which are inserted at substantially the same spacing to one side of the header; And An inlet connected to said header having a plurality of spaced injectors, each having an ejection orifice adapted to be connected to a common refrigerant source to be evaporated and oriented in a direction exiting said one side of said header; Evaporator comprising a. 12. The evaporator of claim 11 wherein said end extends into said header and said injector is located between the ends of an adjacent pair of tubes. The ejection orifice of claim 11, wherein the ejection orifice is a ejection orifice and each of the injectors further comprises a second ejection orifice that is smaller than the ejection orifice and oriented to face one side between the ends of an adjacent tube pair. Evaporator.