JPS6247035Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention aims to improve the heat exchange efficiency of heat exchangers such as evaporators used in automobile air conditioners. .

(Prior Art) An example of an air conditioner for an automobile is shown in FIG. 1, in which an intake door 4 for opening and closing an inside air intake port 2 and an outside air intake port 3 is installed inside an intake unit 1. Furthermore, a fan 6 rotated by a motor 5 is built-in. The air flowing in from the inside air inlet 2 or the outside air intake 3, or both, is sent to the intake unit 1 by the fan 6.
It is discharged from the air and sent into the cooler unit 7.
An evaporator 8, which is a component of the cooling cycle and through which refrigerant circulates, is installed in the cooler unit 7, and air entering the cooler unit 7 from the intech unit 1 is cooled here. Air leaving the cooler unit 7 is sent to a heater unit 10 having a heater core 9 through which engine cooling water is passed and heated. Then, the duct is opened and closed by a room door or a vent door attached therein, and air is discharged to any desired position within the vehicle interior. The temperature of the air inside the vehicle is determined by mixing door 11.
Air heated through the heater core 9, which is adjusted by opening and closing the heater core 9, is mixed with low-temperature air that has bypassed the heater core.

The above-mentioned evaporator is of the so-called irregular tube type shown in FIG.
One end 13 of the flat liquid passage pipe 15 has a flat liquid passage pipe 15 formed in a meandering manner from one end to the other end 14, and a fin 16 attached to this flat liquid passage pipe 15.
An inlet conduit 17 is attached to the end 14, and an outlet conduit 18 is attached to the other end 14.

The inlet conduit 17 is connected to a condenser via an expansion valve and a liquid tank (not shown), and the outlet conduit 18 is connected to a compressor (not shown). Therefore, the refrigerant sent from the inlet conduit 17 to one end 13 of the flat liquid passage pipe 15 exchanges heat with the air flowing along the fins 16 while flowing to the outlet conduit 18.

(Problems to be solved by the invention) However, in such a conventional heat exchanger, the part of the flat liquid passage pipe 15 that is closer to the inlet side conduit 17 has better cooling power than other parts. It will be cooled down. This is due to the effect of adiabatic expansion caused by the expansion valve and the fact that less air flows along the fins 16 than other parts in the part near the inlet conduit 17, so that sufficient heat exchange is not performed, and the temperature of the evaporator itself increases. This is because the flow rate is low, and the flow rate is highest in the central part of the evaporator 8, and the flow rate is low in the peripheral part. Therefore, it is contained in the air flowing along the fins 16, and the fins 16 and the flat liquid passage pipe 15
The amount of moisture adhering as condensed water to the outer circumferential surface of the tube increases in a portion close to the inlet conduit 17, and condensed water freezes in this portion more often than in other portions.

However, if the evaporator has the above-mentioned temperature distribution, it is not preferable for improving heat exchange efficiency.

An object of the present invention is to improve heat exchange efficiency by making the temperature distribution of the entire heat exchanger substantially uniform.

(Means for Solving the Problems) The present invention to achieve the above object has a fluid passageway formed in a meandering manner from one end to the other end for guiding a heat exchange fluid such as a refrigerant. In a heat exchanger that performs heat exchange between a flat liquid passage pipe, air flowing in the fluid passage, and fluid flowing along the fins, the heat exchange fluid is guided from the one end to the other end. Outward fluid passages and return passage fluid passages that guide the heat exchange fluid in the opposite direction are arranged alternately in the air flow direction and formed in the flat liquid passage pipe, and the outward passage A small-diameter first inlet/outlet pipe that communicates with only one of the side fluid passage and the return side fluid passage, and a large-diameter second inlet/outlet pipe that communicates only with the other fluid passage are connected to the flat surface. The heat exchanger is characterized in that a mixing tank is attached to one end of the liquid passage tube and connected to the fluid passage on the outgoing side, and is attached to the other end of the flat liquid passage tube.

(Function) In the flat liquid passage pipe, fluid passages on the forward side and fluid passages on the return side are formed alternately in the air flow direction along the fins, and an inlet/outlet pipe is provided at one end of the flat liquid passage pipe. A mixing tank is provided at the other end to mix the respective fluids in the fluid passages on the outbound side and the fluid passages on the return side, so that the entire surface of the flat liquid passage pipe is kept in a uniform temperature state. This results in
Heat exchange efficiency will be improved.

(Example) Next, an example of the present invention shown in FIGS. 3 to 6 will be described.

FIG. 3 is a diagram showing an evaporator used in an air conditioner for an automobile, similar to the heat exchanger shown in FIGS. 1 and 2, in which a fluid passage 21 for guiding a heat exchange fluid such as a refrigerant is formed. , has a flat liquid passage pipe 24 formed in a meandering manner from one end 22 to the other end 23, and fins 25 attached to this flat liquid passage pipe 24.

The fluid passage 21 includes an outgoing fluid passage 21a that guides the heat exchange fluid from one end 22 to the other end 23 of the flat liquid pipe 24, and a return fluid passage 21b that guides the heat exchange fluid in the opposite direction. It is made up of. As is clear from FIGS. 4 to 6, in the illustrated embodiment, the outward fluid passage 21a and the returning fluid passage 21b are arranged in the width direction of the flat liquid passage pipe 24.
That is, they are formed alternately one by one in the air flow direction along the fins 25.

An outgoing fluid passage 21a projects in a columnar manner from one end 22 of the flat liquid passage pipe 24, and a small-diameter first inlet/outlet pipe 26 is hermetically attached to this projected outgoing fluid passage 21a. Furthermore, the one end 22
In addition to surrounding the first small-diameter inlet/outlet pipe 26, a second large-diameter inlet/outlet pipe 27 is hermetically sealed in the return side fluid passage 21b forming the bottom of the concave portion relative to the outgoing side fluid passage 21a. installed. The first inlet/outlet pipe 26 is connected to the fluid passage 2 on the outgoing side.
1a, and the second inlet/outlet pipe 27 communicates with the fluid passage 21b on the return side. Therefore, in the illustrated embodiment, the heat exchange fluid such as refrigerant flowing in from the first inlet/outlet pipe 26 flows out from the second inlet/outlet pipe 27, but heat is transferred in the opposite direction. An exchange fluid may be supplied.

The other end 23 of the flat liquid passage pipe 24 is connected to the fluid passage 21a on the outbound side and the fluid passage 21b on the return side, so that the heat exchange fluid sulfurized from the fluid passage 21a on the outbound side is transferred to the fluid on the return side. A mixing tank 28 is attached to the passage 21b to mix the heat exchange fluids flowing out from the respective outward fluid passages 21a.

Two inlet and outlet pipes 26, 27 and a mixing tank 28
and the flat liquid passage pipe 24 are joined by brazing.

Therefore, the refrigerant sent into the first inlet/outlet conduit 26 reaches the mixing tank 28 through the outward fluid passage 21a. In this mixing tank 28, based on the fact that the fluid passages 21a on the outbound side and the fluid passages 21b on the return side are arranged alternately,
Since the refrigerants from the many outgoing fluid passages 21a mix efficiently, even if there is a difference in the temperature of the refrigerant depending on each of the outgoing fluid passages 21a, it becomes uniform here. And the refrigerant in the mixing tank is
It passes through the fluid passage 21b on the return side and reaches the second inlet/outlet pipe.

The refrigerant that has flowed into the flat liquid passage pipe 24 from the first inlet/outlet pipe 26 gradually exchanges heat with the air as it moves toward the mixing tank 28.
The temperature will rise. However, since the fluid passage 21a on the outbound side where the refrigerant temperature is relatively low and the fluid passage 21b on the return side where the temperature is relatively high are adjacent to each other, the temperature of the refrigerant in the fluid passage 12 is
The outward and return sides interfere with each other, resulting in a substantially uniform temperature distribution throughout the evaporator 20.

Since the air flowing along the fins 25 has a high flow velocity in the central part of the evaporator 20, in the conventional evaporator 20, the air volume at the inlet side end is relatively small, and therefore this part is cooled the most. However, in this invention, the inlet end, which is the lowest temperature, and the outlet end, which is the highest temperature, are in the same flat liquid passage pipe 24. Moreover, since the outgoing fluid passages 21a and the incoming fluid passages 21b are arranged alternately, freezing will not occur. Since heat exchange is significantly inhibited when freezing occurs, it is also preferable from the viewpoint of improving heat exchange efficiency. Furthermore, by forming an outgoing fluid passage 21a and an incoming fluid passage 21b in the flat liquid passage pipe 24, a substantially uniform temperature distribution is maintained throughout the evaporator 20, thereby improving heat exchange efficiency. be able to.

[Effects of the invention] As described above, according to the invention, the fluid passages on the outbound side and the fluid passages on the return side are formed alternately in the air flow direction along the fins in the flat liquid passage pipe. An inlet/outlet pipe is provided at one end of the flat liquid passage pipe, and a mixing tank is provided at the other end for allowing the fluid on the outgoing side to flow thereinto, mix it once, and then flow into each of the fluid passages on the incoming side. Therefore, even if there is a temperature difference in the fluids flowing in the outgoing flow path, they mix in the mixing tank and reach a uniform temperature before flowing into the return path, and the total amount of heat in the outgoing and return paths is as high as possible. As a result, the surface of the flat liquid passage pipe has a uniform temperature distribution as a whole, and the heat exchange efficiency of the heat exchanger has been improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of an automotive air conditioner, FIG. 2 is a perspective view of a conventional evaporator, FIG. 3 is a front view of a heat exchanger according to an embodiment of the present invention, and FIG. The figure is a sectional view taken along the - line in Figure 3, and Figure 5 is a perspective view showing the end of the flat liquid passage pipe.
FIG. 6 is a partially cutaway perspective view of FIG. 4. 20... Evaporator, 21... Fluid passage, 2
1a... Fluid passage on the outgoing side, 21b... Fluid passage on the returning side, 24... Flat liquid passage pipe, 25... Fin, 26... First inlet/outlet pipe, 27... Second inlet/outlet pipe, 28... mixing tank.

Claims (1)

[Scope of utility model registration request] A flat liquid passage pipe that is formed in a meandering manner from one end to the other end and has a fluid passage therein for guiding a heat exchange fluid such as a refrigerant, and the fluid that flows within the fluid passage and the air that flows along the fins. a heat exchanger that performs heat exchange between the two ends, an outgoing fluid passageway that guides the heat exchange fluid from the one end to the other end, and a return path that guides the heat exchange fluid in the opposite direction. side fluid passages are arranged alternately in the air flow direction and formed in the flat liquid passage pipe, and communicate with only one of the outgoing fluid passage and the return passage side fluid passage. A first small-diameter inlet/outlet pipe that communicates only with the other fluid passage and a second large-diameter inlet/outlet pipe that communicates only with the other fluid passage are attached to one end of the flat fluid passage, respectively, and the outgoing fluid passage and the incoming fluid passage are connected to each other. A heat exchanger characterized in that a mixing tank is attached to the other end of the flat liquid passage pipe.