JP2002090076A - Evaporator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure reliability of an air conditioner built with an evaporator 1a, to improve a heat exchanging performance and to substantially uniformly cool air passing through a core 5. SOLUTION: A resistance section 23 having a sectional area smaller than that of a channel 6 provided at an inside of another part of a heat transfer tube 3a from that of a channel 6a provided at its inside is provided at a protruding part of the inside of a tank 2 at one end of an outlet side end of the tube 3a of a part for constituting the core 5. A pair of heaters 24 and 24 are provided at both sides of the section 23 at outside faces. When the evaporator 1a is used, the heaters 24 and 24 are energized to heat the refrigerant passing through the inside of the section 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION An evaporator according to the present invention is incorporated in an air conditioner, in particular, an air conditioner for an automobile, to cool air for air conditioning in a vehicle interior.

[0002]

2. Description of the Related Art An automotive air conditioner incorporates an evaporator for evaporating a refrigerant inside and cooling air flowing outside. Conventionally, such an evaporator to be incorporated in an air conditioner for a vehicle is shown in FIG.
13 are known. This figure 1
The evaporator 1 shown in FIGS.
One row is provided on each side of the pair of tanks 2 and 2 in the width direction (the left-right direction in FIG. 12 and the front and back direction in FIG. 13). 2
From a plurality of flat heat transfer tubes 3, 3 arranged in parallel with each other at appropriate intervals in the lateral direction, and corrugated fins 4, 4 sandwiched between adjacent heat transfer tubes 3, 3. Having a pair of core portions 5, 5. Each of the above heat transfer tubes 3,
3, two metal plates 28, 28, each made of an aluminum alloy plate and having a recess formed on one side thereof and communicating with both ends in the longitudinal direction, are placed in the middle with the recesses facing each other. It is made by overlapping and joining each other air-tight and liquid-tight. And flat flow paths 6, 6 for flowing the refrigerant are provided inside the heat transfer tubes 3, 3, respectively.
The flow paths 6, 6 of the heat transfer tubes 3, 3 communicate with the insides of the tanks 2, 2, respectively.

One of the two tanks 2, 2 (above FIG. 11 to FIG. 13) has one end in the longitudinal direction (FIG. 1).
The left ends of the refrigerant feed pipes 1 and 13 are connected to the downstream end of the refrigerant feed pipe 7 and the upstream end of the refrigerant discharge pipe 8, respectively. Also, inside the one tank 2, there is provided a first partition portion 9 for dividing the inside into two in the longitudinal direction of the one tank 2, and a half portion in the longitudinal direction of the one tank 2 (FIG. 1).
1 and 13) are divided into two parts in the width direction of the one tank 2. Then, the inside of the one tank 2 is connected to the first tank flow path 1 connected to the downstream end of the refrigerant feed pipe 7.
1 and a fifth tank flow path 15 connected to the upstream end of the refrigerant discharge pipe 8 and a third tank flow path 13 on the other side in the longitudinal direction of the one tank 2 (the right side in FIGS. 11 and 13). , Is divided into three.

Further, of the pair of tanks 2 and 2, the inside of the intermediate portion of the other (lower in FIGS. 11 to 13) tank 2 is
A third partition 16 is provided for dividing the inside of the other tank 2 into two parts in the width direction of the other tank 2. The third partition 16 allows the inside of the other tank 2 to pass through the second tank flow path 12 on the refrigerant feed pipe 7 side and the fourth tank flow path 1 on the refrigerant discharge pipe 8 side.
4 and two. A plurality of heat transfer tubes 3, 3 having both ends of the pair of core portions 5, 5 communicating with the first tank flow path 11 and the second tank flow path 12, respectively, A portion composed of the fins 4 and 4 sandwiched between the heat tubes 3 and 3 is referred to as a first portion 17, and both ends of the pair of core portions 5 and 5 are connected to the second tank flow path 1.
The second part 18 is composed of a plurality of heat transfer tubes 3, 3 communicating with the second tank flow path 13 and the fins 4, 4 sandwiched between the plurality of heat transfer tubes 3, 3. And Further, a plurality of heat transfer tubes 3, 3 of which the both ends of the pair of core portions 5, 5 communicate with the third tank flow path 13 and the fourth tank flow path 14, respectively, The part consisting of the fins 4, 4 sandwiched between 3, 3
A plurality of heat transfer tubes 3 and 3 having both ends of the pair of core portions 5 and 5 communicating with the fourth tank flow path 14 and the fifth tank flow path 15, respectively; The portion including the fins 4, 4 sandwiched between the plurality of heat transfer tubes 3, 3 is referred to as a fourth portion 20.

When the evaporator 1 as described above is used, a refrigerant in a liquid or gas-liquid mixed state discharged from a condenser and passed through an expansion valve is supplied to the refrigerant inlet pipe 7.
Is supplied to the first tank flow path 11 of the one tank 2 through the refrigerant supply port 21 provided in the first tank 2. The refrigerant sent into the first tank flow path 11 in this manner subsequently flows through the flow paths 6 and 6 in each of the heat transfer tubes 3 and 3 constituting the first portion 17, and the pair of tanks 2 and The other tank 2 of 2
To the second tank flow path 12. Then, the refrigerant that has reached the second tank flow path 12 flows in the second tank flow path 12 in the horizontal direction, and then flows through the heat transfer tubes 3 and 3 that constitute the second portion 18. , 6 and is sent to the third tank channel 13 of the one tank 2.

The refrigerant thus sent into the third tank flow path 13 flows in the third tank flow path 13 in a horizontal direction, and then flows into each of the heat transfer tubes 3 and 3 constituting the third portion 19.
Through the inner flow paths 6 and 6 to reach the fourth tank flow path 14 of the other tank 2. And this fourth tank flow path 1
The refrigerant that has reached No. 4 flows in the fourth tank flow path 14 in the horizontal direction, and then flows in each of the heat transfer tubes 3, 3 that constitute the fourth part 20, and the fifth refrigerant in the one tank 2. It reaches the tank channel 15. The refrigerant that has reached the fifth tank flow path 15 is taken out to the outside through a refrigerant outlet 22 provided in the refrigerant outlet pipe 8 and sent to a compressor (not shown). While flowing through the plurality of flow paths 6, the refrigerant takes ambient heat and evaporates. As a result, the temperature of each of the core portions 5, 5 is reduced. If air for air conditioning is passed in the thickness direction of each of the core portions 5, 5,
This air can be cooled and further dehumidified.

[0007]

In the case of the above-mentioned conventional evaporator 1, if the refrigerant sent from the inside of the evaporator 1 to the compressor through the refrigerant outlet pipe 8 is not fully vaporized, it is in a liquid or vapor state. A so-called liquid back in which the refrigerant in a liquid mixed state is sent to the compressor may occur, which may cause a failure of the compressor. For this reason, conventionally, in order to prevent the occurrence of such liquid back, a portion (for example, the fourth portion 20) inside the core portions 5, constituting the evaporator 1, immediately before the refrigerant flows out from the refrigerant outlet pipe 8. Is provided with a so-called superheat region for sufficiently vaporizing the refrigerant.

However, since the superheat region is a region where the refrigerant has a high degree of dryness, the heat exchange between the air passing outside the superheat region and the refrigerant flowing inside the superheat region is not performed. Not done enough. Therefore, the air that has passed outside the superheat region is not sufficiently cooled, and a large temperature is generated between the air that has passed through the superheat region and the air that has passed through other portions of the core portions 5 and 5. In addition to the difference, the heat exchange performance of the evaporator 1 is reduced by providing the superheat region in a part of the core portions 5 and 5. Therefore, from the viewpoint of improving the heat exchange performance of the evaporator 1 and uniformly cooling the air passing through each of the core portions 5, 5, it is preferable to make the superheat region as small as possible.

The first to fourth tank flow paths 11 to 1
A large amount of liquid refrigerant having a large inertia flowing through the inside of the tank flow path 4 is easily sent to the deep side of each of the tank flow paths 11 to 14 and easily flows.
Therefore, depending on the amount of the refrigerant flowing in the evaporator 1, the heat transfer tubes 3,
There is a possibility that the so-called drift may occur, in which the liquid refrigerant sent to 3 is not uniformly divided. When such a drift occurs, a large temperature difference is generated in each of the core portions 5 and 5, and the temperature difference of the air blown into the vehicle cabin becomes uneven, so that the air conditioning is comfortable for the occupant. It becomes difficult to realize the state. The present invention has been made in view of the above-described circumstances, and ensures the reliability of an air conditioner incorporating an evaporator,
The present invention has been made to improve the heat exchange performance and reduce the size, and to further uniformly cool the air passing through the core portion.

[0010]

The evaporator according to the present invention has a core comprising a plurality of heat transfer tubes and fins each having a flow path for flowing a refrigerant therein, similarly to the above-mentioned conventionally known evaporator. And a tank that communicates the inside of at least a part of the plurality of heat transfer tubes with the inside thereof.

In particular, in the evaporator of the present invention,
The cross-sectional area of the flow path provided inside the heat transfer tube provided at the exit side end of at least a part of the plurality of heat transfer tubes is defined as the flow area provided inside the other portion of the heat transfer tube. A resistance section having a smaller cross-sectional area than the path and a heating section for heating the refrigerant passing through the flow path inside the resistance section are provided.

[0012]

According to the evaporator of the present invention configured as described above, the refrigerant flowing in each heat transfer tube constituting the core portion can be flowed in a state where it is not sufficiently vaporized in most of the heat transfer tubes. In addition to this, the refrigerant immediately before flowing out of the evaporator can be sufficiently vaporized. That is, in a heat transfer tube in which the outlet end is connected to a part of a tank that feeds the refrigerant just before flowing out of the evaporator, the liquid refrigerant flows through the flow path inside the resistance portion provided at the outlet end. When the liquid refrigerant passes through, the liquid refrigerant is heated and evaporated by the heating unit, its specific volume becomes large, its outflow speed is accelerated, and pressure loss (resistance) increases. Therefore, in this case, the outflow amount of the gaseous refrigerant flowing out of the resistance portion is greatly reduced. Then, the amount of the liquid refrigerant entering the heat transfer tube from the inlet end of the heat transfer tube provided with the resistance portion is reduced.

On the other hand, when the gaseous refrigerant that has been sufficiently vaporized tries to pass through the flow path inside the resistance section, even if the gaseous refrigerant is heated by the heating section. However, the degree to which the specific volume changes only by increasing the temperature of the refrigerant is small, and the pressure loss caused by accelerating the outflow speed is small. For this reason, in this case, the amount of the refrigerant that enters the heat transfer tube from the inlet end of the heat transfer tube provided with the resistance portion increases. Therefore, the amount of the liquid refrigerant sent to each heat transfer tube is substantially uniform between the heat transfer tubes, and the refrigerant flowing inside each of the heat transfer tubes is almost all of the heat transfer tubes. Heat exchange with the air passing through the outside. As a result, the refrigerant immediately before flowing out of the evaporator can be sufficiently vaporized, and the reliability of the air conditioner incorporating the evaporator can be secured, and the heat exchange performance can be improved. In addition, the size can be reduced, and the air passing through the core can be cooled substantially uniformly.

[0014]

1 to 5 show a first embodiment of the present invention. The evaporator according to the present invention is characterized in that the structure of one end of at least a part of the heat transfer tubes 3a of the plurality of heat transfer tubes 3 and 3a constituting the core portion 5 is devised, and the refrigerant flowing through the one end is formed. The point is that a structure for heating is provided. The configuration and operation of the other parts are the same as in the case of the conventional structure shown in FIGS. 11 to 13 described above, and therefore, the same reference numerals are given to the same parts, and redundant description will be omitted. The following description focuses on the features of the present invention.

In the case of the evaporator 1a of the present invention, one of a pair of tanks 2 and 2 (FIG. 1) among the two ends of each of the heat transfer tubes 3a and 3a constituting the fourth portion 20 of the core portion 5 is used.
One end (the upper end in FIGS. 1 to 3), which is the outlet side end connected to the tank 2 (above), protrudes greatly from the inside of this one tank 2. A length d in the thickness direction (the left-right direction in FIGS.
₂₃ is smaller than the maximum length d _{3a in} the thickness direction of the other portions of the heat transfer tubes 3a, _3a (FIG. 3).
3 are provided. Then, the cross-sectional area of the flow passages 6 a provided inside each of the resistance portions 23 is determined by the heat transfer tube 3.
a, 3a are smaller than the cross-sectional area of the flow channels 6, 6 provided inside the other portions. In the case of this example, a large number of projections 30, 30 are formed in concave portions 29, 29 formed on one surface of the metal plates 28, 28 constituting the heat transfer tubes 3, 3a. The tip surfaces of the projections 30, 30 are joined to each other together with the peripheral edges of the metal plates 28, 28 when the metal plates 28, 28 are combined in the middle. In addition, the heat transfer tubes 3 and 3a serve to ensure the pressure resistance of the heat transfer tubes 3 and 3a, and also serve to disrupt the flow of the refrigerant flowing in the flow path 6 formed by the concave portions 29 and 29. Further, in the case of the present example, each of the resistance portions 23, 2
The cross-sectional area of the flow paths 6a, 6a inside 3 is about 50% of the cross-sectional area of the flow paths 6, 6 provided inside the other parts. Further, the total length L ₂₃ of each of these resistance parts _{23, 23} (FIG. 2)
To each of the heat transfer tubes 3a having these resistance portions 23, 23,
It is about 10% of the total length L _{3a of} FIG. _3a (FIG. 1).

Further, in the case of the evaporator 1a of the present invention, heating portions are provided on both sides of the outer surfaces of the resistance portions 23 provided at one end of each of the heat transfer tubes 3a constituting the fourth portion 20. , A pair of heaters 24, 24 are fixed. Each of the heaters 24 includes a substrate made of a non-conductive material and a heating wire provided between an inner surface of the substrate and an outer surface of the resistor portions 23. Then, the conducting wires 25, 25 derived from both ends of each heating wire are connected to the one tank 2.
Is connected to an electrode plug 26 fixed to the upper side surface of the electrode plug. Then, a connector connected to a power supply (not shown) is connected to a connection portion 27 provided on the electrode plug 26, and the heaters 24 are heated by energizing the heating wires, so that the resistance portions 23, The refrigerant passing through the inside 23 can be heated. Further, of the heat transfer tubes 3a, 3a made of an aluminum alloy plate, which are in contact with the heating wires, an electrical insulating layer is provided on at least an outer surface of a portion where the resistance portions 23, 23 are provided. And, the heating of the refrigerant passing through the inside of each of the resistance portions 23, 23 can be efficiently performed.

Each of the heaters 24, 24
The amount (heating amount) of heating the refrigerant passing through the flow path 6a inside the resistance portion 23 provided in one heat transfer tube 3a depends on the amount of the refrigerant flowing through the flow path 6 inside the one heat transfer tube 3a. By heat exchange, it is about 10% of the amount of heat taken from the air passing through the outside.

According to the evaporator of the present invention configured as described above, the refrigerant flowing in each of the heat transfer tubes 3 and 3a constituting the core portion 5 is sufficiently vaporized in most of the heat transfer tubes 3 and 3a. It is possible to allow the refrigerant to flow as it is, and to sufficiently vaporize the refrigerant immediately before flowing out of the evaporator 1a. That is, a heat transfer tube which constitutes the fourth portion 20 and has one end connected to the fifth tank flow path 15 of the one tank 2 for feeding the refrigerant in a gas-liquid mixed state immediately before flowing out of the evaporator 1a. 3a, when the liquid refrigerant attempts to pass through the flow path 6a inside the resistance portion 23 provided at one end, the liquid refrigerant
It is heated and evaporated by 4, 24, and its specific volume increases, its outflow speed is accelerated, and the pressure loss (resistance) increases. Therefore, in this case, the outflow of the gaseous refrigerant flowing out of the resistance portion 23 is greatly reduced. Then, the amount of the liquid refrigerant that enters the heat transfer tube 3a from the other end (the lower end in FIG. 1), which is the end of the heat transfer tube 3a provided with the resistance portion 23, is reduced.

On the other hand, when the gaseous refrigerant that has been sufficiently vaporized enters the flow path 6a inside the resistance portion 23, the gaseous refrigerant is supplied to the heaters 24, 2
Even when the refrigerant is heated by 4, the degree to which the specific volume changes only by increasing the temperature of the refrigerant is small, and the pressure loss caused by accelerating the outflow speed is small. Because of this,
In this case, the amount of the refrigerant that enters the heat transfer tube 3a from the other end of the heat transfer tube 3a provided with the resistance portion 23 increases. Therefore, the amount of the liquid refrigerant sent to each of the heat transfer tubes 3 and 3a is substantially equalized between the heat transfer tubes 3 and 3a, and the refrigerant flowing inside each of the heat transfer tubes 3 and 3a is Most of these heat transfer tubes 3, 3a can exchange heat with the air passing through the outside. As a result,
It is possible to sufficiently vaporize the refrigerant immediately before flowing out of the evaporator 1a, thereby ensuring the reliability of the automotive air conditioner incorporating the evaporator 1a and improving the heat exchange performance. In addition, the size can be reduced, and the air passing through the core portion 5 can be cooled substantially uniformly. Further, according to the present invention, the state of the refrigerant flowing inside the heat transfer tubes 3a, 3a constituting the fourth portion 20 can be equalized between the heat transfer tubes 3a, 3a. The characteristics of each heat transfer tube 3a, 3a can be made substantially uniform.

Incidentally, the inventor of the present invention has proposed that the flow passages 6, 6 of the heat transfer tubes 3a, 3a constituting the fourth portion 20 of the core portion 5 are provided.
a, the fifth tank flow path 1 of the one tank 2
When the degree of dryness of the refrigerant that has reached inside 5 is measured, in the case of the present invention, all the heat transfer tubes 3 constituting the fourth portion 20 are formed.
In a and 3a, it was confirmed that the degree of dryness was close to 1 (the state was fully vaporized).

In the case of the present invention, assuming that the heaters 24, 24 are not provided, the resistance portions 23, 24
Whatever liquid or gaseous refrigerant enters the inside of the refrigerant 23, resistance corresponding to the flow velocity of the refrigerant is applied to the refrigerant. For this reason, it is difficult to make only the liquid refrigerant enter the resistance portions 23 and 23, and to make it difficult for the liquid refrigerant to drift, and to sufficiently vaporize the refrigerant just before flowing out of the evaporator. It becomes difficult. On the other hand, in the case of the present invention, since the heaters 24, 24 for heating the refrigerant passing through the inside of the resistance portions 23, 23 are provided, the liquid refrigerant enters the resistance portions 23, 23. Only in this case, the resistance applied to the refrigerant can be increased, and the amount of the liquid refrigerant flowing through each of the heat transfer tubes 3a, 3a constituting the fourth portion 20 can be made substantially uniform. It is possible to sufficiently vaporize the refrigerant immediately before flowing out of 1a.

The amount of heat applied to the refrigerant passing through the resistance portions 23 by the heaters 24 is the same between the heat transfer tubes 3a constituting the fourth portion 20. The amount of heat given to the refrigerant by the heaters 24 is appropriately changed in accordance with the flow rate of the refrigerant flowing through the heat transfer tubes 3a, 3a, or a predetermined optimum value regardless of the change in the flow rate of the refrigerant. It can be maintained at a value.

FIG. 6 shows a second embodiment of the present invention.
An example is shown. In the case of the present example, one end (upper end in FIG. 6) of each heat transfer tube 3b constituting the fourth portion 20 (FIG. 1)
A metal foam 31 having a plurality of open cells formed therein is inserted into the inside of the inside. Then, a resistance portion 23 is provided at one end of the heat transfer tube 3b into which the foamed metal 31 is inserted and in which a flow path 6a through which the refrigerant can freely pass is provided. The flow path 6 provided inside the resistance portion 23
The cross-sectional area of “a” is smaller than the cross-sectional area of the flow path 6 provided inside the other part of the heat transfer tube 3b. Further, a pair of heaters 24, 24 are provided on both sides of the outer surface of the resistance portion 23.

In the case of the present embodiment having such a configuration, the heat transmitted to the resistance portion 23 of each heat transfer tube 3b by the heaters 24, 24 is transferred into the open cells of the foamed metal 31 and the foamed metal 31. And the refrigerant flowing between the heat transfer tube 3b and the inner surface of the heat transfer tube 3b. Therefore, in the case of this example, the refrigerant flowing inside the resistance portion 23 can be efficiently heated. Other configurations and operations are the same as those of the first example shown in FIGS. 1 to 5 described above, and thus redundant description will be omitted.

Next, FIGS. 7 and 8 show a third embodiment of the present invention. In the case of this example, the fourth part 20
An inner fin 32 formed by forming a corrugated metal plate is provided inside one end (upper end in FIG. 7) of each heat transfer tube 3c constituting (FIG. 1). And this inner fin 3
A portion provided with a flow path 6a through which a refrigerant can pass is provided as a resistance portion 23 at one end of the heat transfer tube 3c into which the heat transfer tube 2 is inserted. The cross-sectional area of the flow path 6a provided inside the resistance portion 23 is smaller than the cross-sectional area of the flow path 6 provided inside the other portion of the heat transfer tube 3c.

In the case of the present embodiment in which the inner fins 32 are provided partially inside the heat transfer tubes 3c constituting the fourth portion 20 as described above, the heat transferred to the resistance portion 23 by the heaters 24, 24 is provided. The heat can be efficiently transmitted to the refrigerant flowing inside the resistance portion 23 to efficiently heat the refrigerant. Other configurations and operations are described in the first embodiment shown in FIGS.
Since this is the same as the case of the example, the duplicate description will be omitted.

Next, FIGS. 9 to 10 show a fourth embodiment of the present invention. In the case of this example, one of the pair of tanks 2 and 2 (see FIGS. 9 and 10) is used instead of the heater 24 (see FIGS.
Inside the fifth tank flow path 15 of the tank 2 (above), a hot water tank 33 in which high-temperature hot water flows is provided. The hot water feed pipe 3 connected to the hot water tank 33
4 and the middle part of the hot water outlet pipe 35 are led out from a part of the outer surface of the one tank 2. In addition, evaporator 1
When a is used, the upstream end of the hot water feed pipe 34 and the downstream end of the hot water discharge pipe 35 are connected to a part of a cooling water passage (not shown) of the engine, and pass through the cooling water passage to thereby provide the engine. The high-temperature cooling water heated inside flows in the hot water tank 33. The hot water tank 33 and the high-temperature cooling water flowing in the hot water tank 33 constitute a heating unit. The resistance portions 23 of the heat transfer tubes 3a constituting the fourth portion 20 are passed through both sides of the hot water tank 33 in a state of maintaining airtightness and liquid tightness. Therefore, an intermediate portion of each of the resistance portions 23 is disposed inside the hot water tank 33.

In the case of the present embodiment configured as described above, the refrigerant passing through the resistance portions 23 provided at one end of each of the heat transfer tubes 3a constituting the fourth portion 20 is heated by the hot water. It is heated by high-temperature cooling water flowing in the tank 33.
As a result, the refrigerant immediately before flowing out of the evaporator 1a can be sufficiently vaporized, the heat exchange performance can be improved, and the air passing through each core 5 can be substantially uniformly cooled. You can do it.

In place of the hot water tank 33, an oil tank for flowing engine oil or a high temperature discharged from a discharge port of a compressor is provided inside the fifth tank flow path 15 of the one tank 2. It is also possible to provide a high-temperature refrigerant tank through which the above-mentioned gaseous refrigerant flows, and to configure a heating unit with these oil tanks or high-temperature refrigerant tanks. However, when the heating section is constituted by the high-temperature refrigerant tank, the high-temperature gaseous refrigerant extracted from the high-temperature refrigerant tank is sent to the condenser. Other configurations and operations are the same as in the case of the first example shown in FIGS. 1 to 5 described above, and thus redundant description will be omitted.

Although not shown, the metal foam 31 used in the case of the second example shown in FIG.
8, instead of the inner fins 32 used in the case of the third example, a metal mesh or a sintered metal, or a metal plate having irregularities on both side surfaces, or a metal plate having a through hole formed in the center is provided. A part of the heat transfer tube provided with the wire mesh, sintered metal or metal plate inside thereof may be used as the resistance portion. In the first example shown in FIGS. 1 to 5 described above, the metal foam 31 used in the second example and the second The inner fin 32 used in the case of three examples can be provided. In addition, evaporator 1
Only the inside of one end of each heat transfer tube constituting the fourth portion 20a is provided with a protrusion formed on one surface of two metal plates butted and joined to each other, and the protrusion is provided on the inside. Alternatively, a part of the heat transfer tube may be used as a resistance part. Further, the heat transfer tube provided with the resistance portion is not limited to the flat heat transfer tube as in each of the above-described examples, and may be a circular tube heat transfer tube.

In each of the above-described examples, a fifth tank flow path 15 to which an end of the refrigerant discharge pipe 8 is connected is provided in a part of the tank 2 disposed on the upper side, and the fifth tank flow Each of the heat transfer tubes 3a to 3c is provided with a resistance portion 23 at an outlet end located at an upper end of each of the heat transfer tubes 3a to 3c, and a heater 24 or a hot water tank 33 as a heating portion provided around the resistance portion 23. ing. However, the present invention is not limited to such a structure, and a resistance portion is provided at an outlet side end located at the lower end of the heat transfer tube, which protrudes into a tank disposed below, and a resistance portion is provided around the resistance portion. A heating unit can be provided respectively. Also, regarding the path of the refrigerant flowing inside the evaporator and the number of turns of the refrigerant in each tank,
The present invention is not limited to the same as the first example described above, and the present invention is also applied to a case where the path of the refrigerant and the number of turns in the tank are different from those in the first example. Can be.

[0032]

The evaporator of the present invention is constructed and operates as described above, so that the reliability of the air conditioner incorporating the evaporator is ensured, the heat exchange performance is improved, and the evaporator passes through the core. The cooling air can be cooled almost uniformly.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an enlarged view of a part B of FIG.

FIG. 4 is a sectional view taken along line CC of FIG. 3;

FIG. 5 is a perspective view showing a resistance portion provided at one end of the heat transfer tube and a heater.

FIG. 6 is a view corresponding to FIG. 3, showing a second example of the embodiment of the present invention.

FIG. 7 is a view showing the third example and corresponding to FIG. 3;

FIG. 8 is a view of FIG. 7 as viewed from above.

FIG. 9 is a front view showing a fourth example of the embodiment of the present invention.

FIG. 10 is a diagram corresponding to the upper half of FIG. 1;

FIG. 11 is a schematic perspective view for explaining a flow state of a refrigerant in an example of a conventional structure.

FIG. 12 is a view shown by an arrow D in FIG. 11;

FIG. 13 is a sectional view taken along line EE of FIG. 12;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Evaporator 2 Tank 3, 3a-3c Heat transfer tube 4 Fin 5 Core part 6, 6a Flow path 7 Refrigerant sending pipe 8 Refrigerant taking-out pipe 9 First partition part 10 Second partition part 11 First tank flow path 12 Second tank flow path 13 Third tank flow path 14 Fourth tank flow path 15 Fifth tank flow path 16 Third partition 17 First part 18 Second part 19 Third part 20 Fourth part 21 Refrigerant inlet 22 Refrigerant Take-out port 23 Resistance part 24 Heater 25 Conductor 26 Electrode plug 27 Connection part 28 Metal plate 29 Concave part 30 Projection 31 Foam metal 32 Inner fin 33 Hot water tank 34 Hot water feed pipe 35 Hot water discharge pipe

Claims (1)

[Claims] 1. A core section comprising a plurality of heat transfer tubes and fins each having a flow path for flowing a coolant therein, and at least a part of the plurality of heat transfer tubes inside the heat transfer tubes. In the evaporator provided with the communicating tank, provided at the exit side end of at least a part of the plurality of heat transfer tubes, the cross-sectional area of the flow path present inside, It is characterized by comprising a resistance portion having a smaller cross-sectional area than the flow path existing inside the other portion of the heat transfer tube, and a heating portion for heating the refrigerant passing through the flow path inside the resistance portion. Evaporator.