JPH0370947A - Lamination type heat exchanger - Google Patents

Abstract

PURPOSE:To prevent the residence of refrigerant in a refrigerant tube and improve the efficiency of heat exchange by installing an outlet of refrigerant of a refrigerant tube in the final stage to the upper stream side of cooled air flow and a refrigerant main passage for a passage partition wall which faces said refrigerant outlet to the downstream side of cooled air. CONSTITUTION:The refrigerant which flows from a tank section 6 is determined by a passage partition wall 9A in terms of its flow direction. The partition wall 9A is provided with a refrigerant main passage 30A on a far side of an inlet port 6. Therefore, the main stream of the refrigerant flowing in this refrigerant main passage 30A is zigzagged. The next passage partition wall 9B is provided with a refrigerant main passage 30B on the opposite side. This passage partition wall 9B forces the refrigerant to further zigzag. Even when the refrigerant flows to an outlet port 7 of refrigerant by way of the refrigerant main passage 30B, the refrigerant is bent in terms of its flow direction. A satisfactory heat exchange between the refrigerant and the cooled air can be obtained by the length of this flow. Furthermore, the auxiliary passages 31A and 32B for the both main passages are required to help to circulate the refrigerant which tends to remain at the corner section formed with the flow passage partition walls 9A and 9B and tube side walls 32 and 33, which improves the efficiency of heat exchange.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laminated heat exchanger that is incorporated into a vehicle air conditioner or the like.

[Prior art] Generally used by being incorporated into vehicle air conditioners, etc. 81
A layered heat exchanger (evaporator) includes a refrigerant inlet, a refrigerant outlet, and a flat refrigerant flow area disposed between the refrigerant inlet and the refrigerant outlet, and the refrigerant is connected to each other in parallel and in multiple stages. There is a type in which a number of refrigerant tubes and a number of fins through which air to be cooled passes are arranged in a stacked manner.

A conventional stacked heat exchanger will be explained with reference to the drawings. FIG. 7 is an overall view of a conventional laminated heat exchanger.
FIG. 8 shows the flow of refrigerant in this heat exchanger.

In FIGS. 7 and 8, the refrigerant in a gas-liquid mixed state is sent by the compressor power from the condenser side (not shown) via the refrigerant inlet pipe 18, and after passing through the expansion valve, first the refrigerant is attached to each tube that becomes the refrigerant inlet. The refrigerant flows in the direction of the arrow as shown in FIG. 8 through the refrigerant flow path inside the tube at the stage before the tank section. Next, the refrigerant flows through the tubes connected in multiple stages one after another, and during this flow, the coolant cools the air flowing between the tubes and the alternating corrugated fins.

That is, the refrigerant removes heat from the air to be cooled while flowing inside this tube, and the refrigerant itself evaporates and vaporizes while passing through the refrigerant discharge pipe 17.
It becomes more steam and returns to the compressor side. Thereafter, the refrigerant is compressed and liquefied again by the compressor and condenser to become a gas-liquid mixed state, and returns to the heat exchanger side via the expansion valve, repeating the process.

[Issue WJ to be solved by the invention] In a laminated heat exchanger, the direction of the refrigerant flow is orthogonal to the direction of the air flow to be cooled, so-called cross flow, but in principle, such a cross flow is not very effective. Great heat exchange efficiency cannot be expected.

Furthermore, the refrigerant flow area immediately before the refrigerant reaches the refrigerant discharge pipe in the heat exchanger is a so-called superheat region, and the refrigerant has already completely vaporized before this point. is given a temperature rise of about 5 to 10° C. by the heat of the air to be cooled while it remains in a vaporized state. This temperature rise is controlled by controlling the flow rate of the refrigerant in an expansion valve installed on the refrigerant inlet pipe side of the heat exchanger, but the air to be cooled is cooled by this superheat area. Due to the high temperature of this refrigerant, the temperature of the air is necessarily higher than that of the air cooled in other evaporative cooling regions. Therefore, in order to make the temperature distribution of the air to be cooled uniform and to obtain comfortable air conditioning, it is desirable to make the superheat region as short as possible. On the other hand, if the predetermined amount of heat is not exchanged in this superheat region, and as a result, the refrigerant may flow into the compressor in a liquid state, a situation called liquid compression in the compressor will occur, which can cause serious problems for the compressor. give.

Therefore, in this superheat region, there has been a demand for a heat exchanger that can exchange a predetermined amount of heat over as short a period as possible, and that can particularly increase heat exchange efficiency.

In view of the above-mentioned problems, the present invention focuses on the flow direction of the refrigerant with respect to the direction of the flow to be cooled near the refrigerant outlet of the refrigerant tube in the final stage, and provides a stacked heat exchanger that increases the heat exchange efficiency at least in the final stage. The purpose is to provide equipment.

[Means for Achieving the Object] The object of the present invention is to provide a laminated heat exchanger of the type mentioned at the beginning, in which at least the final stage refrigerant tube is provided with a refrigerant disposed on the upstream side of the air flow to be cooled. an outlet, and at least one flow path partition disposed in the refrigerant flow area substantially parallel to the air flow to be cooled and having a main refrigerant passage on one side and an auxiliary refrigerant passage smaller than the main refrigerant passage on the other side. It is equipped with a wall and.

The flow path partition wall faces the refrigerant outlet.

This is achieved by having the main refrigerant passage downstream of the airflow to be cooled.

It is preferable that the flow path partition walls be provided at two locations, with the refrigerant main passages provided on mutually opposite sides, and the refrigerant inflow port provided on the downstream side of the air flow to be cooled.

[Function] By providing the refrigerant outlet of the final stage refrigerant tube on the upstream side of the airflow to be cooled, and the main refrigerant passage of the flow path partition wall facing the refrigerant outlet on the downstream side of the airflow to be cooled, heat can be removed. The direction of the main flow of the refrigerant near the outlet of the exchanger, that is, the superheat region, is opposite to the direction of the air flow to be cooled. In addition, the auxiliary flow of refrigerant through the auxiliary refrigerant passage creates a corner defined by the side wall of the refrigerant flow area and the flow path partition wall.
stagnation of refrigerant in the area can be prevented. As a result, accumulation of the refrigerant in the refrigerant tube is prevented, and the -layer heat exchange efficiency is increased.

[Example] The configuration of the present invention will be further explained with reference to the drawings. FIG. 1 is a perspective view showing the overall structure of tubes of a laminated heat exchanger according to an embodiment of the present invention, together with the flow of refrigerant indicated by arrows.

Each tube of this heat exchanger is provided with four tank sections, and communicates with each of the tubes placed before and after the tubes at the attached tank sections.

When viewed from the front half (first half) of the refrigerant inlet pipe 18 and refrigerant discharge pipe 7, each tube arranged at an odd number from the front becomes a refrigerant inlet when viewed from the front. The upper right tank section communicates with the refrigerant inlet pipe 18, and has refrigerant channels therein that connect the upper right tank section and the lower left tank section. The tubes in the front half and the even-numbered tubes from the front are connected to the refrigerant discharge pipe 17 at the tank section located at the upper left when viewed from the front, which serves as the refrigerant outlet, and the upper left tank section and the lower right tube are connected inside the tank section at the upper left when viewed from the front. Each of the refrigerant channels is provided with a refrigerant flow path that communicates with the tank section.

The first half and the subsequent (second half) tank sections are prevented from communicating with each other in the upper tank section, and communicate with each other in the lower tank section. Each of the odd-numbered tubes in the rear half, counting from the frontmost part, is provided with a refrigerant flow path that communicates the lower left tank part and the upper right tank part, and Each of the even-numbered tubes has a refrigerant flow path therein that connects the upper left tank section and the lower right tank section. Furthermore, all the tubes in the rear half have refrigerant passages between the upper left and right tank parts, respectively. The numbers of tubes in the first half and the second half are even numbers. Although not shown, corrugated fins, indicated by large arrows, through which the airflow to be cooled passes, are arranged between each tube, and each tube and each corrugated fin are arranged alternately in a stacked state. A single heat exchanger is constructed.

The structure of each tube will be explained based on FIGS. 3 to 5.

For ease of understanding, FIG. 3 shows each tube disposed in the front half of the heat exchanger of FIG. 1 disassembled into two panel-shaped tube elements. The tube element 1 shown on the back side has a substantially rectangular panel-shaped part, and has four tank parts (A) to (D), respectively numbered 5 to 8, at its upper and lower ends, Furthermore, the panel-shaped portion is provided with a refrigerant flow area 2B that serves as a refrigerant flow path between it and the other tube element. Tank parts (A) to (D) have communication holes 2 that communicate with adjacent tank parts of other tubes arranged before and after each tube.
0 to 23 respectively.

The two tank parts (B) 6 and (C) 7 are respectively.

Although it is directly connected to the refrigerant basin section 2B to serve as a refrigerant inlet or a refrigerant outlet, the other two tank sections (A>5 and (D) 8) are blocked from communicating with this refrigerant basin section. Therefore, when assembled as a heat exchanger, it merely serves to communicate with the tank portions of the front and rear tubes.

In the concave part of the tube element that becomes the refrigerant flow area 26 in the tube, there are two refrigerant main passages 30A and 3 at both ends, respectively.
0B and two straight partition walls 9 that block the refrigerant flow leaving the refrigerant auxiliary passages 31A and 31B.
A, 9B are formed horizontally by a length approximately equal to the width of the refrigerant flow area + the length of the refrigerant flow area, and these two partition walls 9A, 9B form refrigerant main passages 30A, 30B and refrigerant auxiliary passages 31A, alternating left and right as shown in the figure. 31B.

A large number of linear ribs 10 are provided for the purpose of stirring the refrigerant in the tube inside the refrigerant flow area 2B and improving the heat exchange efficiency of the refrigerant.
are formed obliquely and parallel to each other over the entire panel-shaped portion of the tube element. Note that in FIG. 3, only a portion of the rib 1O is shown for the sake of simplicity. The tube element on the near side indicated by code 2 is rib 1.
It is manufactured to be symmetrical to the inner tube element 1 except that 0' is formed so as to cross and abut against the rib 10 of the inner tube element 1. By overlapping both tube elements 1 and 2, one flat bag-like tube is formed. The tubes in the first half of the heat exchanger shown in FIG. 1 are arranged with the front and back directions of the tubes made up of the tube elements shown in FIG. 3 alternated between odd-numbered tubes and even-numbered tubes from the front.

As shown in FIG. 1, in the final stage refrigerant tube of the heat exchanger of this embodiment, a tank portion 6 serving as a refrigerant outlet is arranged on the upstream side of the air flow to be cooled, and this outlet The flow path partition wall 9A facing the cooling medium has a main refrigerant passage 30A on the downstream side of the air to be cooled.

In FIG. 4, the tubes disposed in the latter half of the heat exchanger in FIG. 1 are shown disassembled into elements as in FIG. 3. The difference from FIG. 3 is that the upper left and right tank sections communicate with each other through a communication section 12 within the tube. Although the rib 10 is not shown in FIG. 4 for simplicity, it is formed in the same manner as in FIG. 3. Tube element 1 located in the last row of the front half and the front row of the rear half
9 does not have a communicating hole in its upper tank portion, as shown in FIG. Note that FIG. 2 schematically shows the refrigerant flow in the heat exchanger of FIG. 1.

Refrigerant flow path wall 2 arranged between the upper tank part of the first half and the second half
4 schematically shows a tank portion that does not have this communication hole.

The flow of refrigerant in the heat exchanger configured as described above will be explained.

In FIG. 1, the refrigerant in a gas-liquid mixed state is compressed by a compressor (not shown), liquefied in a condenser, passes through an expansion valve, and flows into the refrigerant introduction pipe 18. It flows into the tube from the upper right tank part of the odd-numbered tube from the front,
The refrigerant mainly flows in a U-shape along the partition walls 9A and 9B as shown by the arrows in the refrigerant flow area.

The refrigerant that has passed through these tubes further flows into the refrigerant flow path in each tube from the tank section on the lower left side of each odd-numbered tube from the front side in the latter half, and passes through this refrigerant flow path to the upper right side. side, and via this it reaches both tanks on the upper left side. Next, the refrigerant flows into the tubes from the right and upper left tank portions of the even-numbered tubes that follow and adjoin each odd-numbered tube in the latter half, and flows through the refrigerant flow path into each tube. Reach the tank section on the bottom right.

The water flows sequentially from the back through the tank section on the front side and returns to the tube side in the front half.

Next, this refrigerant flows into the refrigerant passage 26 in the tube from the lower right tank part 7 of each even-numbered tube from the front in the front half, and passes through this refrigerant passage to the upper left tank part 6 of each tube. Then, as shown in the figure, the refrigerant flows sequentially along the arrow through the tank section on the near side, and returns to the compressor side through the refrigerant discharge pipe 17. The airflow to be cooled, indicated by the large arrow, passes between the corrugated fins arranged between the tubes, is cooled by the refrigerant, and vaporizes the refrigerant. A diagram of this refrigerant flow is schematically shown in FIG.

The flow direction of the refrigerant in each tube is shown as an example in the explanatory diagram of the refrigerant flow in FIG. 6.

In this example, the flow direction of the refrigerant flowing from the tank portion 6 on the refrigerant inflow side is first determined by the flow path partition wall 9A. That is, the partition wall 9A facing the inlet 6 has a main refrigerant passage 30A on the side far from the inlet, and therefore the main flow of the refrigerant flowing through the main refrigerant passage 30A meanders. The next flow path partition wall 9B has a refrigerant main path 30B on the opposite side,
The refrigerant is further meandered by this flow path partition wall. The direction of the refrigerant is also bent when it passes through the refrigerant main passage 30B of the second flow path partition wall 9B and heads toward the refrigerant outlet 7.

The length of this streamline allows sufficient heat exchange between the refrigerant and the air to be cooled. Furthermore, both refrigerant auxiliary passages 31A, 31
In B, the refrigerant flows through the flow path partition walls 9A, 9B and the tube side wall 32.
It has the role of auxiliary circulation of the refrigerant so that it does not stagnate in a part of the corner formed by 33, thereby increasing the heat exchange efficiency.

Referring to FIG. 1, in the superheat region 25 near the exit of the final stage tube of the heat exchanger, the refrigerant outlet 6 and the refrigerant main passage are arranged such that the main flow direction of the refrigerant is opposite to the direction of the air flow to be cooled. 30A is arranged. Thereby, in combination with the refrigerant auxiliary passage, high heat exchange efficiency can be obtained in this part. This reliably prevents the refrigerant from flowing into the compressor in a liquid state.

Furthermore, due to this counterflow, the proportion of the superheat area within the heat exchanger can be made smaller than that of conventional products. As a result, the ratio of the evaporative cooling area can be increased, making it possible to increase the capacity of the air conditioner.

In this embodiment, all of the refrigerant tubes are provided with a flow path partition wall having a main refrigerant passage and an auxiliary refrigerant passage. The object of the present invention is achieved by having a flow path partition wall having a flow path partition wall, and in which the main flow of the refrigerant flows in a direction opposite to the air flow to be cooled in the superheat region, and it is not necessary that the entire tube has such a configuration. It is not necessary to have one.

[Effects of the Invention] In the present invention, at least the final stage refrigerant tube has a refrigerant outlet disposed on the upstream side of the air flow to be cooled, and a refrigerant main passage disposed in the refrigerant basin region on one side and a refrigerant main passage on the other side. and a flow path partition wall having a refrigerant auxiliary passage.

In addition, the flow path partition wall facing the refrigerant outlet has a configuration in which the main refrigerant passage is placed on the downstream side of the air flow to be cooled, so that the main flow of the refrigerant is in the superheat region of the refrigerant tube in the final stage. Since the auxiliary refrigerant passage faces the air flow to be cooled and eliminates the possibility of refrigerant stagnation in a part of the corner, it is possible to provide a heat exchanger with high heat exchange efficiency at least in the superheat region of the final stage. This makes it possible to provide a heat exchanger that eliminates the risk of failure of the following compressor due to liquid compression.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the tube arrangement of a laminated heat exchanger according to an embodiment of the present invention, together with the direction of refrigerant flow in the heat exchanger. 2nd v! J is a diagram schematically showing a refrigerant flow in the heat exchanger of FIG. 1. 3 to 5 are structural explanatory diagrams of tube elements of each tube of the heat exchanger of FIG. 1. FIG. 6 is an explanatory diagram showing the flow of refrigerant within the refrigerant tube. FIG. 7 is a perspective view showing the structure of a conventional stacked heat exchanger. FIG. 8 is a diagram schematically showing the refrigerant flow in the heat exchanger of FIG. 7. [Explanation of symbols] 1 to 4, 19...Tube elements 5 to 8...Tank parts 9A, 9B...Flow path partition walls 10, 10'...Ribs 17...Refrigerant discharge pipe 1
8... Refrigerant introduction pipes 20 to 23. 20' to 23'... Communication holes 25... Super heat area 26... Refrigerant basin areas 30A, 30B... Refrigerant main passages 31A, 31B... Refrigerant auxiliary passage Figure 3

Claims (1)

[Scope of Claims] A large number of refrigerant tubes that are connected to each other in parallel and in multiple stages, each having a refrigerant inlet, a refrigerant outlet, and a flat refrigerant flow area disposed between the refrigerant inlet and the refrigerant outlet. and a large number of fins through which the air to be cooled passes, in a stacked heat exchanger, in which at least the final stage refrigerant tube is arranged on the upstream side of the flow of the air to be cooled. a refrigerant outlet, and at least one flow path arranged substantially parallel to the air flow to be cooled in the refrigerant flow area and having a main refrigerant passage on one side and an auxiliary refrigerant passage smaller than the main refrigerant passage on the other side. a partition wall, and the flow path partition wall facing the refrigerant outlet has a main refrigerant passage on the downstream side of the air flow to be cooled. exchanger.