JPH0875309A - Evaporator - Google Patents

Abstract

PURPOSE: To obtain an evaporator which has an excellent heat exchange efficiency as an entire heat exchanger since refrigerant with a high liquid ratio flows along even tubes located near an inlet pipe inside a lower manifold. CONSTITUTION: An evaporator has a lower manifold 7, an upper manifold 12, tubes 17 that are arranged between the lower and upper manifolds 7 and 12 and each have a flow hole through which refrigerant flows, fins 22 that are provided between the tubes 17, an inlet pipe 24 connected to the one end of the lower manifold 7, and an outlet pipe 28 connected to the one end of the upper manifold 12. A gas lead pipe 29, that has a cross sectional area equal to or larger than of the flow hole of the tube 17, is provided at the middle part on the lower manifold 7 between the one end of the inlet pipe 24 and the tube 17 closest to the said one end to connect the lower and upper manifolds 7 and 12. Therefore, gas refrigerant, that depresses the liquid level of liquid refrigerant toward the one end inside the manifold 7, is led to the upper manifold 12. The vertical distance between the open end of the lead pipe 29 on the lower manifold 7 side and the open ends of the evaporation tubes 17 on the lower manifold 7 side is at least 3mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporator for cooling a fluid, and more particularly, to an evaporator used in an air conditioner or a cooler for automobiles, houses, etc., which involves a plurality of parallel flows of refrigerant between upper and lower collecting tubes. It is about.

[0002]

2. Description of the Related Art An evaporator 1'used in an air conditioner or a cooler of a conventional automobile, house or the like has a lower collecting pipe 7 provided with an inlet pipe 24 and an outlet pipe 28 as shown in FIG. A plurality of tubes 1 are provided in parallel with each other in the heat exchange section 2 which is between the provided upper collecting tube 12.
7, a plurality of fins 22 are provided, the liquid refrigerant is supplied from the inlet pipe 24, is distributed to each tube 17 in the lower collecting pipe 7, and evaporates and vaporizes as the tubes 17 rise in parallel with each other. It was collected at 12 and discharged from the outlet pipe 28.

[0003]

However, in the conventional evaporator 1 ′, as shown in FIG. 9, the opening end 21 of the tube 17 near the one end 25 of the inlet pipe 24 is higher than the liquid surface of the liquid refrigerant 37. , Away from the liquid surface of the liquid refrigerant 37. However, the open end 21 of the tube 17 away from the one end 25 of the inlet pipe 24 is substantially the same as the liquid surface of the liquid refrigerant 37. Therefore, a part of the liquid refrigerant 37 supplied from the inlet pipe 24 is
Since the liquid surface near the inlet pipe is pushed down by the gas refrigerant 38 near the one end 25 of the inlet pipe 24 of the lower collecting pipe 7,
The gas refrigerant 38 preferentially flows into the tubes 17 in the vicinity thereof, and as a result, the heat exchange capacity of these tubes 17 is lowered, and the heat exchange efficiency of the entire evaporator 1'may be deteriorated. . Incidentally, reference numerals 35, 35
Is a support piece that supports the side surfaces of the fins 22 on both sides, and 9 is a lid on the inlet pipe side of the lower collecting pipe 7. Similarly, 14 in FIG. 8 is the position of the lid on the outlet pipe side of the upper collecting pipe 12, and 10 and 15 are the positions of the lid on the side opposite to the inlet pipe side of the lower collecting pipe 7, and the outlet pipe side of the upper collecting pipe 12. The position of the lid opposite to is shown.

FIG. 10 is a curve diagram showing the relationship between the tube position and the tube surface temperature of the evaporator 1'of FIGS. The horizontal axis is the tube position, that is, the total evaporator is 29
Although it has a tube 17 of a book, FIG. 9 and FIG.
0 As shown in the upper right figure, the tube 17 closest to the one end 25 of the inlet pipe 24 on the lower collecting pipe 7 side is the first pipe,
Shun 29 Honme farthest tube 17 from one end 25, the vertical axis to the tube surface temperature, i.e., the tube 17 surface temperature of the lower collecting pipe 7 near the heat exchange section 2 t ₁ (Curve Symbol:
□), the surface temperature of the tube 17 near the upper collecting pipe 12 is t
₃ (curve symbol: ◇), the surface temperature of the tube 17 in the central portion between the lower collecting pipe 7 and the upper collecting pipe 12 was represented by t ₂ (curve symbol: +), and a relationship curve between the tube position and the tube surface temperature was represented. It is a thing.

As can be seen from FIG. 10, in the evaporator 1'according to the prior art, the surface temperature t of the tube 17 near the upper collecting pipe 12 is about the first to fourteenth tubes 17 near the inlet pipe 24 side. ₃ rises, showing that the latent heat of vaporization of the refrigerant is not used. 15th tube 17 ~
It can be seen that the surface temperature t ₃ of the tubes 17 near the 18th upper collecting pipe 12 decreases to a lesser degree, and that the refrigerant in which the liquid refrigerant and the gas refrigerant are mixed flows through the tubes 17. Therefore, the evaporator 1'according to the prior art has a poor heat exchange efficiency as a whole.

The object of the present invention is to solve the above-mentioned problems of the prior art, and to make the liquid refrigerant flow into the tubes in the vicinity of the inlet pipe inside the lower collecting pipe so that the evaporator as a whole has good heat exchange efficiency. Is to provide.

[0007]

In order to achieve the above object, the present invention provides a lower collecting pipe and an upper collecting pipe which are arranged parallel to each other at a predetermined interval in the vertical direction, and the lower collecting pipe and the upper collecting pipe. And a plurality of evaporation pipes having a flow hole through which the refrigerant flows, an evaporation promoting member provided between the evaporation pipes, and a refrigerant supply inlet pipe connected to one end of the lower collecting pipe. In an evaporator having a refrigerant discharge outlet pipe connected to one end of the upper collecting pipe, a lower collecting pipe and an upper collecting pipe are provided between one end of the inlet pipe on the lower collecting pipe side and the evaporation pipe closest to this one end. That is, a gas guide pipe is provided which is connected to the pipe and has a guide hole for guiding the gas refrigerant near one end inside the lower collecting pipe. Further, the opening end of the gas guide tube on the lower collecting pipe side is located above the opening end of the evaporation pipe on the lower collecting pipe side.

Further, the object of the present invention is achieved by forming the cross-sectional area of the guide hole of the gas guide tube to be at least equal to or larger than the cross-sectional area of one flow hole of the evaporation tube.

Further, the present invention achieves the above object by setting the vertical distance between the opening end of the gas guide pipe on the lower collecting pipe side and the opening end of the evaporation pipe on the lower collecting pipe side to be 3 mm or more.

Further, the gas guide tube is provided with a heat transfer promoting member on the outside of the gas guide tube in order to prevent the liquid refrigerant from flowing into the upper collecting pipe as a liquid in the guide hole of the gas guide tube. In addition, the heat transfer promotion member is provided integrally with the evaporation pipe.

[0011]

According to the present invention, the lower collecting pipe and the upper collecting pipe are connected between one end of the inlet pipe on the side of the lower collecting pipe and the evaporation pipe closest to the one end, and near one end inside the lower collecting pipe. Since the gas guide tube having the guide hole for guiding the gas refrigerant of is provided, the gas refrigerant that has pushed the liquid surface of the liquid refrigerant near the one end inside the lower collecting pipe by the guide hole of the gas guide tube The liquid refrigerant is guided to the pipes and flows into the evaporation pipe near the inlet pipe side of the lower collecting pipe, and the liquid refrigerant is evenly dispersed in all the evaporation pipes, and the heat exchange efficiency of the evaporator is improved. Since the opening end of the gas guide pipe on the lower collecting pipe side is located above the opening end of the evaporation pipe on the lower collecting pipe side, the liquid surface of the liquid refrigerant is pushed down near the inlet pipe of the lower collecting pipe. It is possible to reliably guide the previously used gas refrigerant.

Further, since the cross-sectional area of the guide hole of the gas guide tube is formed to be at least equal to or larger than the cross-sectional area of the flow hole of the evaporation tube, in addition to the function of the above invention, The gas refrigerant staying near the inlet pipe side is easily guided to the upper collecting pipe.

Further, the vertical distance between the opening end of the gas guide pipe on the lower collecting pipe side and the opening end of the evaporation pipe on the lower collecting pipe side is
Since it is 3 mm or more, in addition to any of the effects of the above-mentioned invention, the gas guide tube can guide the gas refrigerant even if the liquid refrigerant surface position of the lower collecting pipe fluctuates to some extent.

Further, the gas guide tube is provided with a heat transfer promoting member for promoting heat transfer to the refrigerant guided in the guide hole of the gas guide tube on the outside of the gas guide tube. In addition to the above action, even if the liquid refrigerant flows into the guide hole of the gas guide tube, the liquid refrigerant is prevented from flowing into the upper collecting pipe as a liquid.

Since the heat transfer promoting member is provided integrally with the evaporation pipe, in addition to the operation of any one of the above inventions, the heat transfer promoting member causes the liquid refrigerant to flow into the upper collecting pipe as a liquid. And the structural strength of the evaporator is improved, and the manufacturing is easy and economical.

[0016]

Embodiments of the evaporator according to the present invention will be described below in detail with reference to the drawings. 1 is a front view showing a first embodiment of the evaporator according to the present invention, FIG. 2 is a partially omitted sectional view for explaining the operation of the evaporator of the first embodiment of FIG. 1, and FIG. 4 is a front view showing a second embodiment of the evaporator according to the present invention, and FIG. 5 is an evaporator of the second embodiment of FIG. 4. 6 is a front view showing the third and fourth embodiments of the evaporator according to the present invention, respectively.

In FIG. 1, the evaporator according to the present embodiment has a lower collecting pipe 7 and an upper collecting pipe 12, which are arranged in parallel with each other at predetermined intervals in the vertical direction, and the lower collecting pipe 7 and the upper collecting pipe 12. The refrigerant arranged between the lower collecting pipe 7 and the upper collecting pipe 1 receives heat from the air as an external fluid and evaporates.
Tubes 17 that are a plurality of evaporation tubes having circulation holes that flow toward 2, and fins 22 that are evaporation promotion members that are provided between the tubes 17 and that promote evaporation of the refrigerant.
And an inlet pipe 24 connected to one end 8 of the lower collecting pipe 7 for supplying the refrigerant, and an outlet pipe 28 connected to one end 13 of the upper collecting pipe 12 for discharging the evaporated gas refrigerant of the refrigerant. . In addition, reference numerals 9, 10 and 14, 15
Shows the positions only with the lids fitted to both ends of the lower collecting pipe 7 and the upper collecting pipe 12, respectively.

Further, as shown in FIG. 2, a lower collecting pipe 7 and an unillustrated upper collecting pipe 12 are provided between one end 25 of the inlet pipe 24 on the lower collecting pipe 7 side and the tube 17 closest to the one end 25. And a gas guide tube 29 having a guide hole 30 for guiding the gas refrigerant 38 that has pushed down the liquid surface of the liquid refrigerant is provided in the vicinity of the one end 8 inside the lower collecting pipe 7. The open end 31 on the side of the collecting pipe 7 is located above the open end 21 of the tube 17 on the side of the lower collecting pipe.

Further, the gas guide tube 29 of the evaporator 1 of the present embodiment.
The cross-sectional area of the guide hole 30 is at least 1 of the tube 17.
The cross-sectional area of the flow hole 18 of the book is formed to be equal to or larger than that, and the opening end 31 of the gas guide tube 29 on the lower collecting pipe 7 side
The vertical distance D between the tube 17 and the open end 21 of the tube 17 on the side of the lower collecting pipe is 3 mm or more, preferably about 6 mm.

Members used in the evaporator 1 of the first embodiment, for example, the tubes 17, the fins 22, the gas guide tube 2
For the lower collecting pipe 9, the upper collecting pipe 12, the upper collecting pipe 12, etc., an aluminum or aluminum alloy plate or extruded shape material is optimally selected, and it is manufactured by using a joining means such as brazing. By applying the heat treatment, it is possible to obtain an evaporator having heat transfer properties for heat exchange, corrosion resistance against internal and external environments, and ease of manufacture.

As the shape of the tube 17 and the gas guide tube 29, a known round tube or a flat tube or a deformed tube in which the refrigerant passage is divided into a plurality of flow holes can be used, and the fins 22 are the above-mentioned round tubes. It is possible to use a plate-shaped fin in which a large number of thin plates used for the tube 17 are inserted, or a corrugated fin having a louver used for the flat tube. Further, it may be a fin formed on the tube 17 itself.

The evaporator 1 of the first embodiment having the above construction
Works as follows. That is, one end 8 of the inlet pipe 24 on the lower collecting pipe 7 side and the tube 17 closest to the one end 8
Between the lower collecting pipe 7 and the upper collecting pipe 12,
Since the gas guide pipe 29 having the guide hole 30 for guiding the gas refrigerant 38 that has pushed down the liquid surface of the liquid refrigerant is provided near the one end 8 inside the lower collecting pipe 7, the guide hole 30 of the gas guide pipe 29 is provided. , The gas refrigerant 38 that has pushed the liquid surface of the liquid refrigerant near the one end 8 inside the lower collecting pipe 7 is guided to the upper collecting pipe 12, and the open ends 21 of all the tubes 17 are connected to the liquid surface of the liquid refrigerant 37. The liquid refrigerant 37 flows to the tubes 17 near the inlet pipe 24 side of the lower collecting pipe 7, and the liquid refrigerant 37 is evenly dispersed in all the tubes 17 so that the heat exchange of the entire evaporator is performed. Efficiency is improved. Since the opening end 31 of the gas guiding pipe 29 on the lower collecting pipe 7 side is located above the opening end 21 of the tube 17 on the lower collecting pipe side, the liquid refrigerant is provided near the inlet pipe 24 side of the lower collecting pipe 7. Make sure that the gas refrigerant 38 that has pushed down the liquid surface of the upper guide tube 1
Can be guided to 2.

Further, since the cross-sectional area of the guide hole 30 of the gas guide tube 29 is at least equal to or larger than the cross-sectional area of the one flow hole 18 of the tube 17,
The gas refrigerant 38 pressing the liquid surface of the liquid refrigerant near the inlet pipe 24 side of the lower collecting pipe 7 is easily guided to the upper collecting pipe 12.

Furthermore, the open end 31 of the gas guide pipe 29 on the lower collecting pipe 7 side and the open end 21 of the tube 17 on the lower collecting pipe side 21.
Since the vertical distance D from the gas guide pipe 2 is 3 mm or more, even if the surface of the liquid refrigerant 37 of the lower collecting pipe 7 fluctuates to some extent.
9 can guide the gas refrigerant 38.

FIG. 3 is a curve diagram showing the relationship between the tube position and the tube surface temperature of the evaporator 1 of the first embodiment shown in FIG. As described in the relation curve of the prior art of FIG. 10, the tube position on the horizontal axis, that is, the evaporator of this embodiment has 29 tubes 17 in total.
As shown in FIGS. 2 and 3 attached on the upper right side, the tube 17 closest to one end 25 of the inlet pipe 24 on the side of the lower collecting pipe 7 is
The tube 17 farthest from the one end 25 is the 29th tube, and the vertical axis indicates the tube 17 surface temperature, that is, the tube 17 surface temperature in the vicinity of the lower collecting pipe 7 of the heat exchanging section 2.
₁ (curve symbol: □), tube 1 near the upper collecting pipe 12
7 shows the relational curve diagram where the surface temperature is t ₃ (curve symbol: ◇) and the tube 17 surface temperature in the central portion between the lower collecting pipe 7 and the upper collecting pipe 12 is t ₂ (curve symbol: +). .

As can be seen from FIG. 3, in the evaporator 1 of the first embodiment, even in the tube 17 near the inlet pipe 24 side, the surface temperature of the tube 17 in the vicinity of the upper collecting pipe 12 of the heat exchange section 2 does not rise so much. No (curve indicated by curve symbol ◇), it can be seen that the liquid refrigerant flows and uses the latent heat of vaporization of the refrigerant. Therefore, the evaporator 1 of the first embodiment has good heat exchange efficiency as a whole.

FIG. 4 is a front view showing a second embodiment of the evaporator according to the present invention. The gas guide tube 29 of the evaporator 1 of the second embodiment is a fin 3 that is a heat transfer promotion member that promotes heat transfer to the refrigerant guided in the guide hole 30 of the gas guide tube 29.
3 is provided outside the gas guide tube 29. The fins 33 may have the same shape and material as the fins 22 used for the tube 17. In other structural parts, the same structure and function as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. As described above, by providing the fins 33 in the gas guide tube 29, even if the liquid refrigerant 37 flows into the gas guide tube 29, the heat transfer to the refrigerant is promoted by the fins 33, and the refrigerant becomes the gas refrigerant 38,
The liquid refrigerant is prevented from flowing into the upper collecting pipe 12.

FIG. 5 is a curve diagram showing the relationship between the tube position and the tube surface temperature of the evaporator of the second embodiment shown in FIG. FIG.
Similarly to the relationship curve diagram of the tube position and tube surface temperature of the evaporator of the first embodiment, the evaporator 1 of the second embodiment has an inlet pipe 2 as shown by the curve indicated by the curve symbol ◇.
Even in the tube 17 near the 4 side, the surface temperature of the tube 17 in the vicinity of the upper collecting pipe 12 does not rise so much, and it can be seen that the liquid refrigerant 37 flows and uses the latent heat of vaporization of the refrigerant. Therefore, the evaporator 1 of the second embodiment has good heat exchange efficiency as a whole.

FIG. 6 is a front view showing a third embodiment of the evaporator according to the present invention. In the gas guide tube 29 of the evaporator 1 of the third embodiment, the fin 33, which is a heat transfer promoting member for promoting heat transfer to the refrigerant guided in the guide hole 30 of the guide tube 29, is integrated with the tube 17. It is provided. In other structural parts, the same structure and function as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. By doing so, even if the liquid refrigerant 37 flows into the gas guide tube 29, the fin 33 can transfer the heat of the external fluid to both the tube 17 and the gas guide tube 29. The liquid refrigerant is prevented from flowing into the upper collecting pipe 12 by 29, the structural strength of the evaporator is improved, and the manufacturing is easy and economical.

FIG. 7 is a front view showing a fourth embodiment of the evaporator according to the present invention. The evaporator 1 of the fourth embodiment has the outlet pipes 28, 28 'on both left and right sides of the upper collecting pipe 12 in the first to third embodiments. In other structural parts, the same structure and function as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. By adopting such a structure, the evaporator 1 can achieve good heat exchange efficiency as the entire heat exchange section.

Although the present invention has been described in detail with reference to the embodiments shown in the drawings, the present invention is not limited only to those embodiments, and various modifications can be made without departing from the spirit of the present invention. In addition, it goes without saying that various modifications can be made.

[0032]

According to the present invention, the lower collecting pipe and the upper collecting pipe are connected between one end of the inlet pipe on the lower collecting pipe side and the evaporation pipe closest to this one end, and the inside of the lower collecting pipe is connected. A gas guide tube having a guide hole for guiding the gas refrigerant that has pushed down the liquid surface of the liquid refrigerant is provided near one end, and the open end of the gas guide tube on the lower collecting pipe side is located on the lower collecting pipe side of the evaporation pipe. Since it is located above the opening end, it is possible to reliably guide the gas refrigerant that has pushed down the liquid refrigerant surface near the inlet pipe side of the lower collecting pipe, and the liquid refrigerant is evenly dispersed in all evaporation tubes. Therefore, the heat exchange efficiency of the evaporator can be improved.

Further, since the cross-sectional area of the guide hole of the gas guide tube is formed to be at least equal to or larger than the cross-sectional area of one flow hole of the evaporation tube, the lower part in addition to the effect of the above invention is obtained. The gas refrigerant, which has pushed down the liquid surface of the liquid refrigerant in the vicinity of the inlet pipe side of the collecting pipe, is easily guided to the upper collecting pipe.

Further, the vertical distance between the opening end of the gas guide pipe on the lower collecting pipe side and the opening end of the evaporation pipe on the lower collecting pipe side is 3 m.
m or more, in addition to any of the effects of the above invention,
The gas guide tube can guide the gas refrigerant even if the liquid refrigerant surface of the lower collecting pipe fluctuates to some extent.

Further, the gas guide tube is provided with a heat transfer promoting member for promoting heat transfer to the refrigerant guided in the guide hole of the gas guide tube on the outside of the gas guide tube. In addition to the above effect, even if the liquid refrigerant flows into the guide hole of the gas guide pipe, the liquid refrigerant vaporizes, so that the liquid refrigerant can be prevented from flowing into the upper collecting pipe.

Further, since the heat transfer promoting member is provided integrally with the evaporation pipe, in addition to the effect of any one of the above-mentioned inventions, the heat transfer promoting member is provided outside both the evaporation pipe and the gas guide pipe. The heat of the fluid can be transferred, the heat exchange efficiency is further improved, the structural strength of the evaporator is improved, and the manufacturing is easy and economical.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of an evaporator according to the present invention.

FIG. 2 is a partially omitted sectional view for explaining the operation of the evaporator of the first embodiment shown in FIG.

FIG. 3 is a curve diagram showing a relationship between a tube position and a tube surface temperature of the evaporator of the first embodiment shown in FIG.

FIG. 4 is a front view showing a second embodiment of the evaporator according to the present invention.

5 is a relationship curve diagram of tube position to tube surface temperature of the evaporator of the second embodiment of FIG.

FIG. 6 is a front view showing a third embodiment of the evaporator according to the present invention.

FIG. 7 is a front view showing a fourth embodiment of the evaporator according to the present invention.

FIG. 8 is a front view showing an evaporator according to a conventional technique.

FIG. 9 is a partially omitted cross-sectional view illustrating the operation of the evaporator of FIG.

10 is a relational curve diagram of the tube position and the tube surface temperature of the evaporator of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 evaporator 7 lower collecting pipe 8 one end 12 upper collecting pipe 13 one end 17 tube (evaporating pipe) 18 flow hole 21 opening end 22 fin (evaporation promoting member) 24 inlet pipe 28 outlet pipe 29 gas guiding pipe 30 guiding hole 31 opening end 33 fins (heat transfer promoting member) 36 refrigerant 38 gas refrigerant D vertical distance

Claims (5)

[Claims] 1. A lower collecting pipe and an upper collecting pipe, which are arranged parallel to each other at predetermined intervals in the vertical direction, and receive heat from an external fluid which is arranged between the lower collecting pipe and the upper collecting pipe. A plurality of evaporation tubes having a flow hole through which the refrigerant to be evaporated flows from the lower collecting tube toward the upper collecting tube, and an evaporation promoting member that is provided between the evaporation tubes to promote evaporation of the refrigerant, and In an evaporator having an inlet pipe connected to one end of a lower collecting pipe to supply the refrigerant, and an outlet pipe connected to one end of the upper collecting pipe to discharge a gas refrigerant evaporated from the refrigerant, A guide hole that connects the lower collecting pipe and the upper collecting pipe between one end on the lower collecting pipe side and the evaporation pipe closest to the one end, and guides the gas refrigerant near one end inside the lower collecting pipe. A gas guide tube having An evaporator that is characterized by 2. The cross-sectional area of the guide hole of the gas guide pipe according to claim 1, which is at least equal to or larger than the cross-sectional area of one flow hole of the vaporization pipe. And an evaporator. 3. The vertical distance between the opening end of the gas guide pipe on the lower collecting pipe side and the opening end of the evaporation pipe on the lower collecting pipe side according to claim 1 or 2, wherein the vertical distance is 3 mm or more. Characteristic evaporator. 4. The gas guide tube according to claim 1, wherein the gas guide tube is provided with a heat transfer promotion member that promotes heat transfer to a refrigerant guided in a guide hole of the gas guide tube. An evaporator characterized by being provided on the outside. 5. The evaporator according to claim 4, wherein the heat transfer promotion member is provided integrally with the evaporation pipe.