JPH0526539A - Heat-exchanger - Google Patents

Abstract

PURPOSE:To provide a heat-exchanger which eliminates a receiver located on the downstream side of a heat-exchanger and having a liquid separating function, in a heat-exchanger used as a condenser for a car air-conditioner. CONSTITUTION:In a heat-exchanger, upper and lower headers 1 and 2 are arranged in parallel to a horizontal direction, a plurality of heat transfer pipes 3 are connected in parallel to the two header pipes so that a refrigerant is caused to flow in the direction of gravity, and a radiation fin 4 is arranged to an air passage part between the heat transfer pipes. The size in the direction of gravity of the lower header 2 is increased, and a refrigerant outlet piping 6 is located to the bottom part of the lower header 2. Since the upper surface of a liquid refrigerant gathering to the lower header 2 and a refrigerant outlet is increased, gas liquid separation for a refrigerant being a receiver function is easily performed while being therebetween. Further, provision of a receiver function for the heat-exchanger causes elimination of a receiver, reduction of a refrigerant amount, reduction of an assembly work, and reduction of an installation space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger used as a condenser for a car air conditioner, and more particularly to a heat exchanger having both the function of a condenser and the function of a receiver for separating gas and liquid of condensed refrigerant.

[0002]

2. Description of the Related Art Conventionally, a heat exchanger used as a condenser for a car air conditioner has a structure in which a flat extruded flat tube is bent in a meandering shape and fins are arranged between the parallel parts, or a heat exchanger arranged in parallel. A pair of headers of the same shape,
A plurality of heat transfer tubes arranged so as to form a refrigerant flow path in parallel between both headers, and a radiation fin arranged in contact with the heat transfer tubes in an air passage portion between the adjacent heat transfer tubes. The thing which has was used many.

A receiver is arranged on the downstream side of the condenser via a pipe, and the receiver separates gas and liquid and removes water with a desiccant incorporated therein. The condensed liquid refrigerant has a structure in which it passes through the pipe from the lower part of the condenser and flows into the receiver from the inlet of the receiver attached to the central part of the condenser.

[0004]

In the above-mentioned prior art, since a receiver is installed on the downstream side of the heat exchanger, a bracket for supporting the receiver is required, and the assembly work, the reduction in size and weight, and the space saving are required. I had a problem with. Also, the refrigerant near the outlet installed in the lower part of the condenser is a condensed liquid, and more liquid refrigerant must be stored in the receiver in order to secure the necessary amount of refrigerant due to the outside air load. Was required.

According to the present invention, the shape of the lower header of the heat exchanger is made larger than that of the upper header, and the refrigerant outlet is located at the lower part of the lower header so that the header arranged at the lower part of the condenser has a receiver function. It is an object of the present invention to provide a heat exchanger that can reduce the amount of refrigerant in the cycle.

[0006]

In order to achieve the above object, a heat exchanger of the present invention has a tubular upper header which is arranged in a horizontal direction and has a refrigerant inlet, and one end of which is connected to the upper header and gravity is applied. A plurality of heat transfer tubes extending parallel to each other, a heat radiation fin provided in a portion where air passes between adjacent heat transfer tubes, and a heat transfer tube that is arranged in parallel with the upper header and connects the other end of the heat transfer tube to the upper part. However, it has a refrigerant outlet directed downward from the bottom, and is composed of an upper header and a tubular lower header having a similar shape and a larger cross section.

Another heat exchanger of the present invention is a tubular upper header which is horizontally arranged and has a refrigerant inlet, and a plurality of heat transfer tubes which are connected to the upper header at one end and extend in parallel in the direction of gravity. A heat radiating fin provided in a portion through which air passes between adjacent heat transfer tubes and a refrigerant arranged in parallel to the upper header, connecting the other end of the heat transfer tube to the upper part, and directing downward from the bottom part. And a tubular lower header having an outlet and having a larger cross-section than the upper header and a vertical dimension of the cross-section larger than a lateral dimension.

Further, in each heat exchanger of the present invention,
It is advisable to put a desiccant in the lower header near the refrigerant outlet. Further, in each of the heat exchangers of the present invention, a plate piece may be installed in the lower header so as to cover above the refrigerant outlet.

Further, instead of the refrigerant outlet which faces downward from the bottom surface provided in each heat exchanger of the present invention, the refrigerant outlet pipe may be formed by inserting the refrigerant outlet pipe from the side to the bottom of the lower header in a substantially horizontal direction. Good. Then, it is preferable that the refrigerant outlet pipe has an end cut obliquely to form an opening and the opening is directed toward the bottom surface side of the lower header.

[0010]

In the heat exchanger of the present invention, the vapor-phase refrigerant that has entered the upper header from the refrigerant inlet flows while being distributed to the plurality of heat transfer tubes, and the heat radiating fins are generated by the air flow passing around the heat transfer tubes during this period. The liquid refrigerant is cooled and liquefied through the liquefied liquid, and the liquefied liquid refrigerant flows down and accumulates in the lower header.

In the heat exchanger of the present invention, the inner volume of the lower header is made larger than before, the amount of liquid refrigerant accumulated is increased, and the refrigerant outlet of the exchanger is provided at the bottom of the lower header. The distance from the liquid surface of the existing liquid refrigerant to the refrigerant outlet becomes large, and the gas phase refrigerant that cannot be completely condensed becomes difficult to come out from the refrigerant outlet, that is, only the liquid refrigerant comes out from the refrigerant outlet and the gas-liquid separation function is achieved. In addition to having the liquid refrigerant stored in the conventional receiver, a necessary amount of the refrigerant can be secured.

When a desiccant is charged near the refrigerant outlet in the lower header, the desiccant removes water in the liquid refrigerant and blocks the vapor-phase refrigerant here, so that only the liquid refrigerant is practically used as the refrigerant. Supply to the exit.

Further, by mounting the plate piece above the refrigerant outlet of the lower header, the gas-phase refrigerant that has flowed out of the heat transfer tube and could not be condensed is prevented from flowing out of the refrigerant outlet by being blocked by the plate piece.

By thus providing the lower header with a receiver function, the receiver used in the conventional heat exchanger can be omitted, and by storing the liquid refrigerant in one place of the lower receiver, it is possible to save the liquid refrigerant from the conventional one. This is advantageous in that the amount of refrigerant can be reduced, the assembling work of the receiver is reduced, and the mounting space is unnecessary.

[0015]

EXAMPLES Examples of the heat exchanger according to the present invention will be described below with reference to FIGS. 1 to 7. This heat exchanger is used as a refrigerant condenser of an automobile refrigeration cycle.

The condenser is a component of the refrigeration cycle and liquefies and condenses the high temperature, high pressure gas phase refrigerant sent from the refrigerant compressor. Conventionally, a receiver is installed on the downstream side from the condenser, and in addition to the gas-liquid separation function, it has the function of storing a certain amount of refrigerant in order to respond immediately to changes in the refrigerant circulation amount due to the conditions of the refrigeration cycle. The desiccant used is absorbing water in the cycle.

FIG. 1 is a front view showing a first embodiment of the heat exchanger of the present invention.

The condenser, which is the heat exchanger of the present invention, comprises an upper header 1, a lower header 2, a heat transfer tube 3 and a radiating fin 4. The upper header 1 and the lower header 2 are installed parallel to each other in the horizontal direction, and the plurality of heat transfer tubes 3 are inserted into the headers 1 and 2 at their ends, respectively, so that the refrigerant flows in the gravity direction between the headers. They are arranged in parallel. Radiating fins 4 are installed in contact with the heat transfer tubes 3 and 3 in the air passage portions between the adjacent heat transfer tubes 3 and 3. A refrigerant inlet pipe 5 is installed in the upper header 1, and a refrigerant outlet pipe 6 is installed in the lower portion of the lower header 2. The lower header 2 has a larger internal volume than the upper header 1, and can store a certain amount of refrigerant in order to immediately respond to changes in the refrigerant circulation amount depending on the conditions of the refrigeration cycle. Also, the refrigerant outlet pipe 6
Since the liquid refrigerant existing in the lower header 2 is located closer to the refrigerant outlet pipe 6 than the gas-phase refrigerant, the liquid refrigerant is preferentially supplied to the lower header 1 than the condenser. Can drain. Thus, the lower header can be provided with the gas-liquid separation function, and the conventionally provided receiver can be omitted.

Here, the sum of the inner volumes of the upper header 1 and the lower header 2 is the upper header 1 of the conventional condenser.
And smaller than the sum of the respective inner volumes of the lower header 2 and the receiver. Therefore, it is possible to save the refrigerant in the entire cycle.

FIG. 2 is a side view of the heat exchanger of this embodiment,
The flow direction of the air for exchanging heat to cool the refrigerant is the left-right direction in the figure. The liquid refrigerant condensed in the heat transfer tube 3 goes from the refrigerant outlet pipe 6 installed at the bottom of the lower header 2 to the expansion valve (not shown). The cross-sectional shape of the lower header 2 is similar to that of the upper header 1 and is larger than that of the upper header 1. The lower header 2 can store the liquid refrigerant, and can immediately respond to the change in the refrigerant circulation amount depending on the conditions of the refrigeration cycle. Further, even if the vapor-phase refrigerant that could not be condensed flows into the lower header 2, the distance from the liquid surface of the liquid refrigerant accumulated in the lower header 2 to the refrigerant outlet is large, so that the vapor-phase refrigerant exits from the refrigerant outlet 6. Only the liquid refrigerant can flow out without the occurrence.

FIG. 3 is a side view of the second embodiment of the present invention. In this embodiment, the shape of the lower header 2 is such that the vertical dimension in the direction of gravity is larger than the dimension in the direction orthogonal to the direction of gravity, and is, for example, elliptical. Accordingly, when the inner volume of the lower header 2 is the same as that of the embodiment of FIG. 2, the distance from the bottom of the lower header 2 to the liquid surface of the retained refrigerant can be increased even with a smaller amount of liquid refrigerant. Further, by providing the refrigerant outlet 6 at the bottom portion of the lower header 2 as in the embodiment of FIG. 2, even if the gas phase refrigerant that could not be condensed flows into the lower header 2, the liquid refrigerant will flow into the lower header 2 to some extent. Therefore, only the liquid-phase refrigerant can flow from the refrigerant outlet pipe 6. Further, in this embodiment, since the dimension of the heat exchanger in the air flow direction can be made equal to that of the conventional product, there is no problem of space for mounting.

FIG. 4 shows a third embodiment of the present invention, in which a desiccant for absorbing water in the refrigerant is installed in the lower header 2 in the first or second embodiment. . In this embodiment, a desiccant 8 is placed in a bag 7 made of a material through which a refrigerant can pass, and is placed in the lower header 2.

FIG. 5 shows a fourth embodiment of the present invention, which is a modification of the third embodiment. A mesh 9 having a diameter smaller than that of the desiccant 8 is fixed between the refrigerant outlet portion of the lower header 2 and the heat transfer pipe projecting into the lower header 2, and the mesh 9 and the lower header 2 are fixed to the refrigerant outlet portion. The desiccant 8 is put between the bottom of the and. Here, instead of the net 9, a plate having a hole having a size such that the desiccant 8 cannot pass through may be used. As a result, the desiccant can absorb water in the liquid refrigerant in the heat exchanger, and also has a function of weakening the momentum of the refrigerant dropped from the heat transfer tube colliding with the liquid surface in the header and suppressing the generation of bubbles.

6 to 8 are sectional views showing embodiments in which the tip shape, the mounting position or the mounting direction of the refrigerant outlet pipe attached to the lower header 2 are changed, and the refrigerant outlet pipes shown in FIGS. Is a first embodiment shown in FIG.
Alternatively, it is attached instead of the refrigerant outlet pipe 6 in the second embodiment shown in FIG. In the fifth embodiment shown in FIG. 6, the refrigerant outlet pipe 6a is installed horizontally by penetrating the lower header 2 from near the bottom of the lower header 2 so that the opening of its inlet is perpendicular to the pipe axis. Further, in the sixth embodiment shown in FIG. 7, the refrigerant outlet pipe 6b has its refrigerant suction port inclined with respect to the pipe axis, and is directed toward the bottom of the lower header 2 from the vicinity of the bottom of the lower header 2 to the lower header 2. Is horizontally attached to the refrigerant outlet pipe 6 in the lower header 2 by increasing the cross-sectional area of the end portion of the refrigerant outlet pipe 6 for sucking the refrigerant to slow the refrigerant flow velocity and prevent the generation of vortices from the liquid surface. Avoid inhaling vapor-phase refrigerant. Furthermore, since the suction port faces the bottom of the lower header 2, it is easy to suck the liquid refrigerant. Further, in the seventh embodiment shown in FIG. 8, the refrigerant outlet pipe 6c has its refrigerant suction port inclined with respect to the pipe axis,
Further, since it is attached to the lower header 2 so as to be opposed to the bottom surface of the lower header 2 and inclined upward from the horizontal direction, the distance between the refrigerant suction port of the refrigerant outlet pipe 6 and the bottom portion of the lower header 2 becomes shorter, and the liquid refrigerant is further cooled. Will be easier to inhale.

FIG. 9 shows another embodiment in which the lower header 2 has a gas-liquid separating function. In the eighth embodiment, the plate piece 10 is installed between the outlet of the heat transfer tube 3 in the lower header 2 and the outlet 6 of the refrigerant with the surfaces thereof facing the outlet. It is attached to the lower header in the first embodiment shown in FIG. 2 or the second embodiment shown in FIG. As a result, even if a gas-phase refrigerant that cannot be completely condensed flows from the outlet of the heat transfer tube, it is blocked by the plate and does not reach the refrigerant outlet, and vortexes do not occur from the liquid surface, and gas-liquid separation is performed more reliably. .

10 and 11 are sectional views of the lower header. As described above, the refrigerant outlet pipe shown in any of FIGS. 6 to 8 and the plate piece shown in FIG. 9 may be combined. Further, a combination of the desiccant shown in FIG. 4 or 5 and the plate piece shown in FIG. 9 is also possible.

[0027]

According to the present invention, the heat exchangers functioning as condensers of the refrigerant are provided in the upper headers arranged in parallel to each other in the horizontal direction, and in the header pipes in parallel in the gravity direction. It is composed of multiple heat transfer tubes and heat dissipation fins provided between the heat transfer tubes, and the inner volume of the lower header is made larger than that of the upper header, and the refrigerant outlet pipe of the lower header is at the bottom of the lower header. Since it is provided, it is possible to increase the distance from the liquid surface of the liquid refrigerant existing in the lower header to the refrigerant outlet, and it is possible to suppress the vapor phase refrigerant that cannot be completely condensed from coming out of the refrigerant outlet, thus providing the lower header with a receiver function. It is possible to reduce the amount of refrigerant from the conventional heat exchanger to the receiver, omit the receiver, and reduce the receiver assembly work and installation space.

Further, in the heat exchanger of the present invention, the desiccant conventionally contained in the receiver is put in the lower header,
Alternatively, by providing a plate piece near the refrigerant outlet of the lower header, it is possible to more reliably provide a gas-liquid separation function of the refrigerant, and as in the above case, the receiver can be omitted to reduce the assembly work and the installation space. It will be possible.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a heat exchanger according to a first embodiment of the present invention.

2 is a side view of the heat exchanger shown in FIG. 1. FIG.

FIG. 3 is a side view of a heat exchanger according to a second embodiment of the present invention, which includes a lower header having a vertically long elliptical cross section.

FIG. 4 is a view showing a lower header containing a desiccant according to a third embodiment of the present invention.

FIG. 5 is a view showing a lower header including a desiccant having a mesh placed one above another according to a fourth embodiment of the present invention.

FIG. 6 is a view showing a structure of a refrigerant outlet pipe of a lower header in the heat exchanger of the fifth embodiment of the present invention.

FIG. 7 is a diagram showing the structure of another refrigerant outlet pipe of the lower header in the heat exchanger of the sixth embodiment of the present invention.

FIG. 8 is a view showing the structure of another refrigerant outlet pipe of the lower header in the heat exchanger of the seventh embodiment of the present invention.

FIG. 9 is a partial exploded view of a heat exchanger using a plate piece for gas-liquid separation according to an eighth embodiment of the present invention.

FIG. 10 is a view showing a combination of a plate piece for gas-liquid separation and a refrigerant outlet pipe in a lower header.

FIG. 11 is a view showing a combination of a plate piece for gas-liquid separation and another refrigerant outlet pipe in the lower header.

[Explanation of symbols]

1 Upper header 2 Lower header 3 heat transfer tubes 4 radiating fins 5 Refrigerant inlet piping 6 Refrigerant outlet piping 8 desiccant 10 pieces

Claims (9)

[Claims] 1. A tubular upper header that is horizontally arranged and has a refrigerant inlet, a plurality of heat transfer tubes connected to the upper header at one end and extending in parallel in the direction of gravity, and between adjacent heat transfer tubes. A radiating fin provided in the area through which air passes,
From a tubular lower header that is arranged parallel to the upper header, has a refrigerant outlet that connects the other end of the heat transfer tube to the upper portion, faces downward from the bottom, and is similar to the upper header and has a larger cross section. The configured heat exchanger. 2. A tubular upper header which is arranged in a horizontal direction and has a refrigerant inlet, a plurality of heat transfer tubes connected at one end to the upper header and extending in parallel in the direction of gravity, and between adjacent heat transfer tubes. A radiating fin provided in the area through which air passes,
It is arranged parallel to the upper header, has the refrigerant outlet that connects the other end of the heat transfer tube to the upper part, and faces downward from the bottom, and has a larger cross section than the upper header and the vertical and vertical dimensions of the cross section are greater than the horizontal dimension. A heat exchanger composed of a large tubular lower header. 3. A tubular upper header which is arranged in a horizontal direction and has a refrigerant inlet, a plurality of heat transfer tubes which are connected to the upper header at one end and extend in parallel in the direction of gravity, and between the adjacent heat transfer tubes. A radiating fin provided in the area through which air passes,
A tubular lower header that is arranged parallel to the upper header, has the refrigerant outlet that connects the other end of the heat transfer tube to the upper portion, and faces downward from the bottom, and has a larger cross-section similar to the upper header, A heat exchanger comprising a desiccant charged in the lower header near the refrigerant outlet. 4. A tubular upper header which is arranged in a horizontal direction and has a refrigerant inlet, a plurality of heat transfer tubes connected at one end to the upper header and extending in parallel in the direction of gravity, and between adjacent heat transfer tubes. A radiating fin provided in the area through which air passes,
It is arranged parallel to the upper header, has the refrigerant outlet that connects the other end of the heat transfer tube to the upper part, and faces downward from the bottom, and has a larger cross section than the upper header and the vertical and vertical dimensions of the cross section are greater than the horizontal dimension. A heat exchanger comprising a large tubular lower header and a desiccant charged in the lower header near the refrigerant outlet. 5. A tubular upper header that is horizontally arranged and has a refrigerant inlet, a plurality of heat transfer tubes that are connected to the upper header at one end and extend in parallel in the direction of gravity, and between adjacent heat transfer tubes. A radiating fin provided in the area through which air passes,
A tubular lower header that is arranged parallel to the upper header, has the refrigerant outlet that connects the other end of the heat transfer tube to the upper portion, and faces downward from the bottom, and has a larger cross-section similar to the upper header, A heat exchanger composed of a plate piece installed in the lower header so as to cover above the refrigerant outlet. 6. A tubular upper header which is arranged in a horizontal direction and has a refrigerant inlet, a plurality of heat transfer tubes which are connected to the upper header at one end and extend in parallel in the direction of gravity, and between adjacent heat transfer tubes. A radiating fin provided in the area through which air passes,
It is arranged parallel to the upper header, has the refrigerant outlet that connects the other end of the heat transfer tube to the upper part, and faces downward from the bottom, and has a larger cross section than the upper header and the vertical and vertical dimensions of the cross section are greater than the horizontal dimension. A heat exchanger comprising a large tubular lower header and a plate piece installed in the lower header so as to cover above the refrigerant outlet. 7. A tubular upper header that is horizontally arranged and has a refrigerant inlet, a plurality of heat transfer tubes that are connected to the upper header at one end and extend in parallel in the direction of gravity, and between adjacent heat transfer tubes. A radiating fin provided in the area through which air passes,
It has a refrigerant outlet pipe that is arranged in parallel to the upper header, connects the other end of the heat transfer pipe to the upper portion, and is inserted into and connected to the bottom portion in a substantially horizontal direction, and has a larger cross-section similar to the upper header. And a tubular lower header having a heat exchanger. 8. A tubular upper header which is arranged in a horizontal direction and has a refrigerant inlet, a plurality of heat transfer tubes connected at one end to the upper header and extending in parallel in the direction of gravity, and between the adjacent heat transfer tubes. A radiating fin provided in the area through which air passes,
It has a refrigerant outlet pipe which is arranged in parallel to the upper header, connects the other end of the heat transfer pipe to the upper portion, and is inserted into and connected to the bottom portion in a substantially horizontal direction, and has a larger cross section than the upper header and A heat exchanger composed of a tubular lower header whose vertical and vertical dimensions are larger than its horizontal dimension. 9. The heat exchanger according to claim 7, wherein the refrigerant outlet pipe has an opening formed by obliquely cutting a part end, and the opening faces the bottom surface side of the lower header.