JP2005172373A - Evaporator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaporator capable of improving heat exchanging efficiency by uniformly distributing a two-phase refrigerant flowing in a tank to tubes. <P>SOLUTION: In this evaporator composed of the tubes 1 forming flow channels 4 for circulating the two-phase refrigerant 9, fins mounted among the tubes arranged at specific intervals, and the tank 3 to which both end parts of the tubes 1 are inserted, first introduction holes 7 for introducing a vapor-phase refrigerant 9b into the tubes 1 are mounted at the neighborhood parts of the bases to the tank 3, of the tubes 1 inserted into the tank 3, and second introduction holes 8 for introducing a liquid-phase refrigerant 9b into the tubes 1 are formed at lower ends of the tubes. By independently forming the holes for the liquid-phase refrigerant 9a and the holes for the vapor-phase refrigerant 9b, two-phase refrigerant 9 can be uniformly distributed into the tubes 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an evaporator used as an air conditioner for automobiles, and more specifically, to each tube without being influenced by variation in the distribution amount of a two-phase refrigerant separated into a gas-phase refrigerant and a liquid-phase refrigerant in a tank. The present invention relates to a technique capable of uniformly introducing a refrigerant.

As this type of evaporator, for example, it is composed of a pair of tanks arranged at a predetermined interval from each other, a plurality of tubes that communicate with each other, and fins provided between the tubes. The two-phase refrigerant that has flowed into the tank is introduced into the tubes from the holes opened at the lower ends of the tubes. (See, for example, Patent Document 1).
Japanese Utility Model Publication No. 64-22171 (pages 8 to 10, FIGS. 1 and 4)

  FIG. 6 is a diagram illustrating an example in which the tip of the tube 102 is inserted into the tank 101 and the two-phase refrigerant 103 is distributed to each tube 102. When the liquid-phase refrigerant 103a and the gas-phase refrigerant 103b are mixed in the tank 101, a large amount of gas-phase refrigerant (gas phase) 103b flows in the tube 102 near the inlet of the tank 101, and enters the tube 102 on the far side away from the inlet. The liquid phase refrigerant (liquid phase) 103a flows a lot.

  Thereby, the tube 102 close to the inlet of the tank 101 becomes gas rich when a large amount of the gas-phase refrigerant 103b flows, and the tube 102 on the back side of the tank 101 becomes liquid-rich when a large amount of the liquid-phase refrigerant 103a flows.

  Therefore, the air in the vicinity of the tube 102 having a large amount of the gas-phase refrigerant 103b is not easily cooled, and the air flowing in the vicinity of the tube 102 having a large amount of the liquid-phase refrigerant 103a is easily cooled. As described above, the amounts of the liquid-phase refrigerant 103 a and the gas-phase refrigerant 103 b introduced into each tube 102 vary depending on the attachment position to the tank 101. As a result, variation occurs in the temperature of the air heat exchanged by the evaporator, and a portion with good cooling efficiency and a portion with poor cooling efficiency coexist, making it impossible to improve the overall heat exchange efficiency.

  Therefore, the present invention has been made to solve the above-described problem, and provides an evaporator capable of improving heat exchange efficiency by evenly distributing two-phase refrigerant flowing in a tank to each tube. With the goal.

  According to the first aspect of the present invention, a tube in which a flow path through which a two-phase refrigerant flows is formed, fins provided between the tubes arranged at predetermined intervals, and tanks into which both ends of each tube are inserted, respectively. In the evaporator comprising: a first introduction hole for introducing a gas-phase refrigerant into the tube in the vicinity of the base of the tube inserted into the tank, and a liquid at the lower end of the tube. A second introduction hole for introducing the phase refrigerant into the tube is provided.

  A second aspect of the present invention is the evaporator according to the first aspect, wherein the first introduction hole has a diameter of 0.1 mm to 0.5 mm.

Invention of Claim 3 is an evaporator of Claim 1 or Claim 2, Comprising: The said tube protrudes to the bottom face vicinity in the said tank, It is characterized by the above-mentioned. The invention according to claim 3 is the evaporator according to claim 3, wherein the protruding amount of the tube protruding into the tank is 80% or more of the inner height of the tank.

  A fifth aspect of the present invention is the evaporator according to any one of the first to fourth aspects, wherein the inner width of the tank is 1.2 times or more the width of the tube. It is characterized by being.

  Invention of Claim 6 is an evaporator as described in any one of Claim 1-5 at least, Comprising: The lower end part of the said tube which protrudes in the said tank is made into the inclined surface. It is characterized by that.

  According to the first aspect of the present invention, the first introduction hole for introducing the gas-phase refrigerant into the tube and the second introduction hole for introducing the liquid-phase refrigerant into the tube are separated. A gas phase refrigerant with a low specific gravity that tends to stay flows in from a first introduction hole formed in the vicinity of the base of the tank, and a liquid phase refrigerant with a large specific gravity that tends to stay in the lower part of the tank is formed at the second end. Therefore, the two-phase refrigerant can be evenly distributed to each tube.

  According to the second aspect of the present invention, since the diameter of the first introduction hole for introducing the gas-phase refrigerant is reduced to 0.1 mm to 0.5 mm, the inflow resistance is increased as compared with that of the large hole. Therefore, the amount of inflow is suppressed, and the inflow is uniformly performed from the inlet of each tube.

  According to the third aspect of the present invention, since the tube protrudes to the vicinity of the bottom surface in the tank, the liquid-phase refrigerant staying at the bottom of the tank can be distributed to the plurality of tubes.

  According to the invention described in claim 4, since the protruding amount of the tube protruding into the tank is 80% or more of the inner height of the tank, the liquid-phase refrigerant staying at the bottom of the tank is surely distributed to each tube. Can be made.

  According to the fifth aspect of the present invention, since the inner width of the tank is 1.2 times or more the tube width, it is easy for the two-phase refrigerant to flow from the inlet to the innermost part of the tank. can do.

  According to the sixth aspect of the present invention, since the lower end portion of the tube protruding into the tank is an inclined surface, the liquid-phase refrigerant and the gas-phase refrigerant at the bottom of the tank can easily flow into the flow path of the tube.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In the present embodiment, the present invention is applied to an evaporator of an automotive air conditioner.

"Evaporator configuration"
1 is an exploded perspective view of a main part of the evaporator, FIG. 2 is a cross-sectional view of the evaporator, FIG. 3 is an enlarged view of a main part showing a portion where the tube is attached to the tank, and FIG. 4 is a two-phase refrigerant flowing into each tube. It is a schematic diagram which shows a mode.

  As shown in FIGS. 1 and 2, the evaporator according to the present embodiment includes fins provided between a tube 1 in which a flow path through which a two-phase refrigerant circulates is formed and the tubes 1 arranged at predetermined intervals. 2 and a pair of tanks 3 into which both ends of each tube 1 are inserted.

  The tube 1 is formed of a long hollow plate such as aluminum, for example, and forms a flow path 4 through which a two-phase refrigerant flows at the center thereof. A plurality of such tubes 1 are provided with their longitudinal directions oriented in the vertical direction, and at a predetermined interval. In addition, the tube 1 used what was formed by extrusion molding.

  The fin 2 is formed, for example, by bending an aluminum plate into a bellows shape. The fins 2 are respectively disposed between the tubes 1 so that the folded portions are in contact with the tubes 1.

  The tank 3 is made of aluminum like the tubes 1 and the fins 2, and forms a flow passage 5 through which a two-phase refrigerant flows at the center thereof. The tank 3 is formed with tube insertion holes 6 for inserting both ends of each tube 1 into the tank 3. A plurality of tube insertion holes 6 are formed along the longitudinal direction of the tank 3 at positions opposite to the tubes 1.

  These tubes 1, fins 2 and tank 3 are assembled together and then brazed to form an evaporator. In particular, in the evaporator of the present embodiment, as shown in FIG. 3, the gas phase refrigerant 9 b of the two-phase refrigerant 9 is disposed in the vicinity of the root of the tube 1 of the tube 1 inserted into the tank 3. Is provided in the flow path 4 of the tube 1, and a second introduction hole 8 is provided in the lower end of the tube for introducing the liquid refrigerant into the flow path 4.

  The first introduction hole 7 is formed as a small circular hole penetrating the tube wall surface in the vicinity of the base with the tank 3 in the portion inserted into the tank 3 from the tube insertion hole 6. The first introduction hole 7 is a small small circular hole having a diameter of about 0.1 mm to 0.5 mm, for example.

  When the diameter of the first introduction hole 7 is less than 0.1 mm, if the gas-phase refrigerant 9b flows into the tube 1 from the first introduction hole 7, the flow resistance of the gas increases, so the refrigerant of the heat exchanger The resistance on the side increases. On the other hand, when the diameter of the first introduction hole 7 is more than 0.5 mm, a large amount of the gas-phase refrigerant 9b flows from the first introduction hole 7 and more gas phase is introduced into the tube 1 near the inlet side of the tank 3. The refrigerant 9b enters, and the amount of inflow of the gas-phase refrigerant 9b decreases in the tube 1 disposed on the back side, resulting in variations as a whole.

  The second introduction hole 8 is formed as a large opening at the lower end of the tube 1. The second introduction hole 8 communicates with the flow path 4 formed in the center portion of the tube 1 along the longitudinal direction.

  In the present embodiment, the tube 1 is provided with a lower end portion protruding into the tank 3 extending to the vicinity of the bottom surface 3 a of the tank 3. As described above, the lower end portion of the tube is provided in the vicinity of the bottom surface 3 a of the tank 3, so that the liquid-phase refrigerant 9 a staying at the bottom portion of the tank 3 can be distributed to the plurality of tubes 1.

  The protruding amount H1 (projecting length) of the tube 1 protruding into the tank 3 is 80% or more of the inner height H2 of the tank 3. With such a protruding amount H1, the lower end portion of the tube 1 is always in the liquid even if the liquid refrigerant undulates due to some vibration. For this reason, the liquid-phase refrigerant 9 a staying at the bottom of the tank 3 can flow into the flow path 4 from the lower end of the tube 1.

  Moreover, in this Embodiment, the inner side width W1 of the said tank 3 is 1.2 times or more with respect to the width W2 of the said tube 1. FIG. By doing in this way, inflow of the two-phase refrigerant | coolant 9 from the inlet part of the tank 3 to the innermost part can be made easy.

[Action / Effect]
In the evaporator configured as described above, as shown in FIG. 4, the liquid phase refrigerant 9 a having a large specific gravity staying in the lower portion of the tank 3 is formed in the second introduction hole 8 formed in the lower end portion of the tube 1. Flows into the tube 1. On the other hand, the gas phase refrigerant 9 b having a low specific gravity staying in the upper part of the tank 3 flows into the tube 1 from the first introduction hole 7 formed in the vicinity of the base with the tank 3. The inflow amounts of the liquid-phase refrigerant 9a and the gas-phase refrigerant 9b flowing into the tubes 1 are almost equal from the inlet side to the back side of the tank 3.

  However, if the first introduction hole 7 is a large hole, a larger amount of the gas-phase refrigerant 9b flows into the tube 1 disposed in the vicinity of the inlet of the tank 3, and the tube 1 disposed on the back side has a gas flow. The amount of inflow of the phase refrigerant 9b is reduced, causing variations. However, since the inflow resistance is increased and the amount of inflow is suppressed by using a relatively small hole having the above-described size (diameter of about 0.1 mm to about 0.5 mm), each tube 1 is uniformly in the gas phase. The refrigerant 9b flows in.

  Therefore, according to the evaporator of the present embodiment, the two-phase refrigerant 9 flowing in the tank 3 can be evenly distributed to each tube 1 and the heat exchange efficiency can be greatly improved.

"Other embodiments"
Although specific embodiments to which the present invention is applied have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  In the above-described embodiment, the shape of the lower end portion of the tube 1 inserted into the tank 3 is a straight shape. However, as shown in FIG. 5, an inclined surface 1a having a tapered shape inclined obliquely may be used. Good. In the evaporator formed in this way, the same effect as that of the above-described embodiment can be obtained.

It is a principal part disassembled perspective view of the evaporator of this Embodiment. It is sectional drawing of the evaporator of this Embodiment. It is a principal part enlarged view which shows the attachment part to the tank of a tube. It is a schematic diagram which shows a mode that a two-phase refrigerant | coolant flows in into each tube. It is the principal part enlarged view which shows the other example of this Embodiment and shows the attachment part to the tank of a tube. It is a schematic diagram which shows a mode that a two-phase refrigerant | coolant flows in into each tube in the conventional evaporator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tube 2 ... Fin 3 ... Tank 4 ... Flow path 5 ... Flow path 7 ... 1st introduction hole 8 ... 2nd introduction hole 9 ... Two-phase refrigerant 9a ... Liquid phase refrigerant 9b ... Gas-phase refrigerant

Claims (6)

The tube (1) in which the flow path (4) through which the two-phase refrigerant (9) flows is formed, the fin (2) provided between the tubes (1) arranged at a predetermined interval, and the tubes (1) ) In the evaporator comprising the tanks (3) into which both ends of each are inserted,
Of the tube (1) inserted into the tank (3), a first inlet hole (9b) for introducing a gas-phase refrigerant (9b) into the tube (1) near the base of the tank (3). 7) and an evaporator having a second introduction hole (8) for introducing the liquid refrigerant (9a) into the tube (1) at the lower end of the tube. The evaporator according to claim 1, comprising:
The first introduction hole (7) has a diameter of 0.1 mm to 0.5 mm. An evaporator according to claim 1 or claim 2, wherein
The said tube (1) protrudes to the bottom face (3a) vicinity part in the said tank (3). The evaporator characterized by the above-mentioned. The evaporator according to claim 3, wherein
The protrusion amount (H1) of the tube (1) protruding into the tank (3) is 80% or more of the inner height (H2) of the tank (3). An evaporator according to any one of claims 1 to 4, comprising:
The evaporator characterized in that the inner width (W1) of the tank (3) is 1.2 times or more the width (W2) of the tube (1). An evaporator according to any one of claims 1 to 5, comprising:
The evaporator, wherein the lower end of the tube (1) protruding into the tank (3) is an inclined surface (1a).

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