JPH1137610A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the heat transfer performance and the heat exchanging performance by providing a liquid phase component branching/combining circuit for branching a coolant, i.e., nonazeotropic coolant, temporarily at the inlet of a heating tube and recombining the nonazeotropic coolant in the gas/liquid two-phase region in the way of heating tube. SOLUTION: A nonazeotropic coolant contains much low boiling point component on the gas phase side and much high boiling point component on the liquid phase side in the region of gas/liquid two-phase state. The liquid coolant component is branched at the part of heating tube inlet, i.e., the lower side coolant tube inlet 12a, to vary the composition of a condensed coolant to be supplied such that the high boiling point component is decreased thus lowering the gas/liquid equilibrium temperature (saturation temperature). After the mean temperature difference is increased between the coolant and the hot fluid, they are recombined at the inlet of upper side coolant tube 11b on the downstream side. Since the gas/liquid equilibrium temperature is lowered to increase the mean temperature difference from the heat exchanging fluid, the heat exchanging capacity can be enhanced. Furthermore, the heat exchanging capacity can be prevented from lowering due to lowering of cooling capacity of the nonazeotropic coolant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a heat exchanger.

[0002]

2. Description of the Related Art In recent air conditioners, for example, R
The use of alternative refrigerants such as 407C (HFC-32 / 125 / 134a) is being considered.

As the refrigerant, R22, R12 and the like have been conventionally used in many cases, but since these destroy the ozone layer, a plan to completely eliminate them from the viewpoint of environmental conservation is being advanced. The substitutes for R22 and R12 include freons R32, R134a, and R134 that do not affect the ozone layer.
125 and the like. In particular, these R32, R1
The mixed refrigerant such as R407C mixed with the refrigerant such as 34a and R125 has a cooling capacity close to that of the conventional refrigerant R22 and the like, and is highly evaluated as a substitute because of its nonflammability.

[0004]

However, when such an alternative refrigerant is used as a refrigerant for a heat exchanger for air conditioning such as an evaporator, there are the following problems.

[0005] Generally, mixed refrigerants include azeotropic refrigerants and non-azeotropic refrigerants, and the mixed refrigerants such as R407C are non-azeotropic refrigerants. An azeotropic refrigerant has the same liquefaction start temperature (dew point) and liquefaction end temperature (boiling point) and exhibits the same behavior as a single-component refrigerant, so there is no particular problem. Since the liquefaction end temperature is different, during heat exchange, many high-boiling components are condensed in the gas-liquid interface region, and low-boiling components are concentrated in the gas phase. Then, this concentration difference causes diffusion resistance and thermal resistance inside the heat transfer tube, lowers the heat transfer coefficient, and causes a problem that the heat exchanger capacity is insufficient as compared with when a single component refrigerant is used.

That is, since the alternative refrigerant changes its phase as the heat exchange action progresses, the heat transfer performance in the heat transfer tube changes depending on the phase state, and the heat exchange performance deteriorates.

As a result, an attempt to improve the heat exchange performance necessarily entails an increase in size and cost of the heat exchanger.

The present invention has been made to solve such a problem, and employs a non-azeotropic refrigerant having a refrigerating capacity equivalent to that of a conventional CFC-based refrigerant. By branching the gas or liquid refrigerant component in the gas-liquid two-phase region, the composition of the refrigerant flowing in the heat transfer tube is changed, thereby changing the gas-liquid equilibrium temperature, which is a characteristic of the non-azeotropic refrigerant. Furthermore, by making the flow of the non-azeotropic refrigerant and the flow of the heat exchange fluid in the heat exchanger counterflow each other, the average temperature difference between them is increased, and the heat transfer is performed as much as possible. It is an object of the present invention to provide a heat exchanger having improved performance and heat exchange performance.

[0009]

Means for Solving the Problems In order to achieve the above objects, the present invention has the following means for solving the problems.

That is, the heat exchanger according to the first aspect of the present invention is a heat exchanger which forms a part of a refrigerant circuit and includes a heat transfer tube which exchanges heat with another fluid. A liquid-phase component branching / joining circuit is adopted which employs a refrigerant, branches the non-azeotropic refrigerant once at the inlet of the heat transfer tube, and joins again in the gas-liquid two-phase region in the middle of the heat transfer tube.

As described above, the non-azeotropic refrigerant contains a lot of low-boiling components in the gas phase and a lot of high-boiling components in the liquid phase in the region of the gas-liquid two-phase state. Therefore, utilizing this, first, the liquid refrigerant component is branched at the inlet of the heat transfer tube, the composition is changed, and the gas-liquid equilibrium temperature (saturation temperature) is changed, so that the refrigerant and the water or air or other heat exchange fluid are exchanged. After increasing the average temperature difference, they are joined again on the downstream side.

As described above, when the composition of the non-azeotropic refrigerant is changed by branching the liquid-phase refrigerant in the gas-liquid two-phase region, the gas-liquid equilibrium temperature changes due to the change in the composition of the refrigerant. In addition, the average temperature difference with the heat exchange fluid can be increased, and the heat exchange capacity can be improved. Furthermore, as a result, it is possible to prevent a decrease in the amount of heat exchange due to a decrease in the refrigerant performance of the non-azeotropic refrigerant.

Next, the heat exchanger according to the second aspect of the present invention comprises:
In a heat exchanger that forms a part of a refrigerant circuit and includes a heat transfer tube that exchanges heat with another fluid, a non-azeotropic refrigerant is adopted as a refrigerant, and the non-azeotropic refrigerant is vapor-liquid 2 in the middle of the heat transfer tube. A gas-phase component branching / joining circuit is provided to branch the gas-phase refrigerant once in the phase region and join again at the outlet of the heat transfer tube.

As described above, the non-azeotropic refrigerant contains a lot of low-boiling components in the gas phase and a lot of high-boiling components in the liquid phase in the region of the gas-liquid two-phase state. Therefore, utilizing this, the gas-phase refrigerant is branched in the gas-liquid two-phase region in the middle of the heat transfer tube, the composition is changed, and the gas-liquid equilibrium temperature (saturation temperature) is changed, so that the average between the refrigerant and air is changed. Increase the temperature difference.

As described above, when the composition of the non-azeotropic refrigerant is changed by branching the gas-phase refrigerant in the gas-liquid two-phase region in the middle of the heat transfer tube, the change in the composition of the refrigerant causes heat exchange. The average temperature difference with the fluid can be increased, and the heat exchange capacity can be improved. Furthermore, as a result, it is possible to prevent a decrease in the amount of heat exchange due to a decrease in the refrigerant performance of the non-azeotropic refrigerant.

Next, the heat exchanger according to the third aspect of the present invention comprises:
In the configuration of the heat exchanger according to the first or second aspect of the present invention, the heat transfer pipe has a double pipe structure of a heat exchange fluid pipe through which a heat exchange fluid flows and a refrigerant pipe through which a non-azeotropic refrigerant flows, The non-azeotropic refrigerant flowing in the refrigerant pipe flows opposite to the heat exchange fluid flowing in the heat exchange fluid pipe.

With this configuration, the average temperature difference can be further increased particularly in a double-pipe heat exchanger having a high counterflow effect.

Further, according to the heat exchanger of the invention of claim 4 of the present application, in the heat exchanger of the invention of claim 1 or 2, the heat transfer tubes are arranged in a plurality of rows from the downstream side of the air flow to the upstream side. The heat transfer tubes are arranged so that the non-azeotropic refrigerant flowing in the heat transfer tubes is supplied from the downstream row to the upstream row of the heat transfer tubes so as to flow in opposition to the external air flow.

With this configuration, for example, in a cross-fin coil type heat exchanger, the average temperature difference can be made larger.

[0020]

As described above, according to the heat exchangers of the present invention, it is possible to reduce as much as possible the deterioration of the refrigerant performance due to the phase change of the non-azeotropic refrigerant. Exchange capacity can be ensured.

As a result, it is not necessary to increase the size of the heat exchanger and thereby increase the cost.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) First, FIG. 1 shows a configuration of a heat exchanger according to Embodiment 1 of the present invention.

In this embodiment, the heat transfer tube portion of the heat exchanger has a double tube structure. In the double tube heat exchanger, the liquid-phase refrigerant at the inlet of the heat transfer tube is supplied. The method is characterized in that after branching and extraction, the composition of the refrigerant is changed by being joined again in the middle of the heat transfer tube, and the refrigerant and the heat fluid are caused to flow in a counterflow state in the direct direction.

In the figure, reference numeral 10 denotes a U-shaped heat fluid pipe (heat transfer pipe) through which a heat fluid (heat exchange fluid) such as water to be exchanged with the refrigerant flows.
The heat fluid is made to flow in a U-turn in the 0b direction.

As shown, large-diameter refrigerant pipes (heat transfer pipes) 11a and 11b are provided around the outer circumference of each of the upper and lower straight pipe portions of the thermal fluid pipe 10 as shown in the figure, and have a double pipe structure. A heat exchanger consisting of heat transfer tubes is formed.

The refrigerant pipes 11a and 11b are closed at both ends. The other end side (the right end side in the figure) is communicated with each other by a communication pipe 11c, and the lower end refrigerant pipe 11a has a refrigerant inlet 12a below one end side (the left end side in the figure) and an upper side refrigerant pipe 11b. The refrigerant outlet 13 to the compressor is provided at one end side (left end side in the figure).
a is provided.

The refrigerant inlet 12a of the lower refrigerant pipe 11a is connected to, for example, a connection pipe 12 to a condenser via a gas-liquid separator 15. The connection pipe 12 supplies a non-azeotropic refrigerant in a gas-liquid two-phase state (for example, a mixed refrigerant such as R407C) through a pressure reducing valve (not shown).

On the other hand, from the gas-liquid separator 15, a liquid refrigerant branch pipe 12b is further provided.
Is connected to the middle of the communication pipe 11c via a mixer 16.

Accordingly, in the case of this configuration, a predetermined amount of liquid refrigerant is supplied to the lower refrigerant pipe 11a from the refrigerant inlet 12a through the gas-liquid separator 15 through the liquid refrigerant branch pipe 12b.
While the condensed refrigerant extracted and having a changed composition ratio is supplied to the upper side, the condensed refrigerant partially evaporated through the lower side refrigerant pipe 11a and the gas-liquid separator are connected to the upper side refrigerant pipe 11b. A mixture with the predetermined amount of the liquid refrigerant extracted in advance through the line 15 is supplied.

The hot fluid and the condensed refrigerant flow into the hot fluid pipe 10 and the upper and lower refrigerant pipes 11a and 11b, respectively, as shown by arrows in FIG. It is made to flow in a state.

As described above, the non-azeotropic refrigerant contains a large amount of low-boiling components in the gas phase and a high-boiling component in the liquid phase in the region of the gas-liquid two-phase state. Therefore, by utilizing this, first, as described above, the composition of the condensed refrigerant supplied by branching the liquid refrigerant component at the lower refrigerant pipe inlet 12a which is the heat transfer tube inlet portion is reduced to reduce the high boiling component. After reducing the gas-liquid equilibrium temperature (saturation temperature) to increase the average temperature difference between the refrigerant and the heat fluid, the refrigerant is joined again at the inlet of the upper-side refrigerant pipe 11b on the downstream side.

As described above, when the composition of the non-azeotropic refrigerant is changed by branching the liquid refrigerant component in the gas-liquid two-phase region on the inlet side of the heat exchanger to reduce the high-boiling component, the non-azeotropic refrigerant is reduced. Since the composition of the refrigerant is changed so as to reduce the high boiling point component, the gas-liquid equilibrium temperature is lowered, and the average temperature difference with the heat exchange fluid can be increased, so that the heat exchange capacity can be improved. . Furthermore, as a result, it is possible to prevent a decrease in the amount of heat exchange due to a decrease in the refrigerant performance of the non-azeotropic refrigerant.

Further, in the case of the present embodiment, the heat transfer pipe portion has a double pipe structure of the heat fluid pipe 10 through which the heat exchange fluid flows and the refrigerant pipes 11a and 11b through which the non-azeotropic refrigerant flows. The non-azeotropic refrigerant flowing in the refrigerant pipes 11a and 11b is made to flow in a direction directly opposite to the heat fluid flowing in the heat fluid pipe 10.

Therefore, the average temperature difference can be made sufficiently large by the counterflow effect.

Therefore, in the heat exchanger having the above configuration,
Even when a non-azeotropic refrigerant is used, the average temperature difference between the heat fluid and the refrigerant can be secured sufficiently large, and the heat exchange capacity can be sufficiently improved. As a result, the heat exchanger can be effectively reduced in size and cost.

(Embodiment 2) Next, FIG. 2 shows a configuration of a heat exchanger according to Embodiment 2 of the present invention.

In this embodiment, the heat exchanger tube portion of the heat exchanger has a double-pipe structure as in the first embodiment, and in the double-pipe heat exchanger, Once the gas-phase refrigerant in the middle of the heat transfer tube is branched and extracted, the composition of the refrigerant is changed by merging again with the outlet of the heat transfer tube, and the refrigerant and the heat fluid are caused to flow in a counterflow state in the direct direction. It is characterized by the following.

In the drawing, reference numeral 10 denotes a U-shaped heat fluid pipe (heat transfer tube) through which a heat fluid such as water to be exchanged with the refrigerant flows.
The heat fluid flows in a U-turn from the inlet 10a toward the outlet 10b.

As shown, large-diameter refrigerant pipes (heat transfer pipes) 11a and 11b are provided around the outer periphery of each of the upper and lower straight pipe portions of the thermal fluid pipe 10, as shown in the figure, and have a double pipe structure. A heat exchanger consisting of heat transfer tubes is formed.

The refrigerant pipes 11a and 11b are closed at both ends. The other end side (the right end side in the figure) is communicated with each other by a communication pipe 11c, and the lower end refrigerant pipe 11a has a refrigerant inlet 12a below one end side (the left end side in the figure) and an upper side refrigerant pipe 11b. The refrigerant outlet 13 to the compressor is provided at one end side (left end side in the figure).
a is provided.

Further, for example, a connection pipe to a condenser (not shown) is directly connected to the refrigerant inlet 12a of the lower refrigerant pipe 11a. The connection pipe supplies a non-azeotropic refrigerant in a gas-liquid two-phase state (for example, a mixed refrigerant such as R407C) through a pressure reducing valve (not shown).

On the other hand, a gas-liquid separator 17 is provided in the communication pipe 11c serving as a refrigerant inlet of the upper refrigerant pipe 11b, and a gas refrigerant branch pipe 13b further extends from the gas-liquid separator 17. The downstream end of the gas refrigerant branch pipe 13b is connected to the refrigerant outlet 13a of the upper refrigerant pipe 11b via a mixer 18. And the mixer 18
Is further connected to a connection pipe 13 for connection to the compressor.

Therefore, in the case of this configuration, a predetermined amount of gas refrigerant is extracted from the upper refrigerant pipe 11b through the gas-liquid separator 17 at the communication pipe 11c, which is the refrigerant inlet, and the composition changes. While the condensed refrigerant is supplied, the condensed refrigerant from the condenser is directly supplied to the lower refrigerant pipe 11a via the pressure reducing valve.

The hot fluid and the condensed refrigerant flow into the hot fluid pipe 10 and the upper and lower refrigerant pipes 11a and 11b, respectively, as shown by arrows in FIG. It is made to flow in a state.

As described above, the non-azeotropic refrigerant contains a large amount of low-boiling components in the gas phase and a high-boiling component in the liquid phase in the region of the gas-liquid two-phase state. Therefore, utilizing this, first, as described above, the upper refrigerant pipe 11b in the middle of the heat transfer pipe
The composition of the condensed refrigerant supplied to the upper refrigerant pipe 11b is changed so that the low boiling point component is reduced by branching the gas refrigerant component at the inlet portion of the gaseous refrigerant, and the gas-liquid equilibrium temperature (saturation temperature)
To increase the average temperature difference between the refrigerant and the heat fluid, and then join again at the outlet of the upper-side refrigerant pipe 11b on the downstream side.

As described above, when the composition of the non-azeotropic refrigerant is changed so that the low-boiling point component is reduced by branching the gas refrigerant component in the gas-liquid two-phase region in the middle of the heat transfer tube, the non-azeotropic refrigerant is reduced. Since the composition in the boiling refrigerant is reduced in low-boiling components, the gas-liquid equilibrium temperature is increased and the average temperature difference with the heat fluid can be increased, so that the heat exchange capacity can be improved. Furthermore, as a result, it is possible to prevent a decrease in the amount of heat exchange due to a decrease in the refrigerant performance of the non-azeotropic refrigerant.

Further, in the case of the present embodiment, the heat transfer pipe portion has a double pipe structure of a heat fluid pipe 10 through which a heat fluid flows and refrigerant pipes 11a and 11b through which a non-azeotropic refrigerant flows. The non-azeotropic refrigerant flowing in the pipes 11a and 11b is made to flow in a direction directly opposite to the heat fluid flowing in the heat fluid pipe 10.

Therefore, the average temperature difference can be made sufficiently large by the counterflow effect.

Therefore, in the heat exchanger having the above configuration,
Even when a non-azeotropic refrigerant is used, the average temperature difference between the heat fluid and the refrigerant can be secured sufficiently large, and the heat exchange capacity can be sufficiently improved. As a result, the heat exchanger can be effectively reduced in size and cost.

(Embodiment 3) FIGS. 3 to 5 show the configuration and effects of a heat exchanger according to Embodiment 3 of the present invention.

This embodiment is different from the first and second embodiments described above.
Unlike the heat exchanger, a cross fin coil type heat exchanger is adopted. In the cross fin coil heat exchanger, the liquid-phase refrigerant at the inlet of the heat transfer tube is branched and extracted once, and then again in the heat transfer tube. The composition of the refrigerant is changed by merging the refrigerant with the air, and the refrigerant and the external air flow are caused to flow in a counter-current state.

In the figure, reference numeral 1 denotes a cross fin coil type heat exchanger. The cross fin coil type heat exchanger 1 has a plurality of heat transfer tubes 2, 2.
Are fitted and fixed at a predetermined fin pitch, and tube plates 7, 7 are provided at both ends thereof.

The plurality of heat transfer tubes 2, 2... Are a refrigerant inlet 5a of a refrigerant inflow tube and a refrigerant outlet 6a of a refrigerant outflow tube.
Each part is connected to a connection pipe to a condenser and a compressor.
They are arranged side by side in a pair, and their front and rear ends are connected integrally with each other via a U-shaped connecting pipe in a mutually communicating state.
They are juxtaposed in two rows with their vertical positions slightly changed in the thickness direction.

Of the two rows of heat transfer pipe groups that communicate with each other, the heat transfer pipe 2 at the lowermost end of the downstream row of the air flow is the refrigerant inflow pipe, and the heat transfer pipe 2 at the lowermost end of the upstream row of the air flow is the same. The non-azeotropic refrigerant flowing into the heat transfer pipe 2 serving as the refrigerant inflow pipe is configured to flow in the direction of the heat transfer pipe 2 serving as the refrigerant outflow pipe as opposed to the air flow as illustrated in the drawing. ing.

A connection pipe 5 for connecting the heat transfer pipe 2 at the lowermost end of the air flow downstream row, which is the above-mentioned refrigerant inflow pipe, to a condenser (not shown) is connected to the air which serves as a refrigerant inflow pipe via a gas-liquid separator 3. It is connected to the refrigerant inlet 5a of the heat transfer tube 2 at the lowermost end of the downstream row. Then, the liquid refrigerant separated by the gas-liquid separator 3 is supplied from the gas-liquid separator 3 to the downstream stream heat transfer tubes 2, 2,.
A liquid refrigerant branch pipe 5b that branches and supplies the mixture through the mixer 4 to the downstream side row intermediate portion 2a of the...

Therefore, the lower end of the heat transfer tube 2 at the lower end of the air flow downstream row, which is the refrigerant inflow pipe, enters the heat transfer tube 2 from the refrigerant inlet 5a, and from the liquid refrigerant branch pipe 5b to the downstream side of the air flow downstream row. The non-azeotropic refrigerants supplied and merged to the intermediate portion respectively flow in the heat exchanger 1 in the two rows of heat transfer tubes 2, 2. The heat is efficiently exchanged with the air by flowing while facing the airflow in the side direction, and then the refrigerant flows out from the refrigerant outlet 6a of the heat transfer pipe 2 at the lowermost end of the airflow upstream side row, which is the refrigerant outflow pipe, to the compressor side via the connection pipe. Spilled to.

In this case, as described above, in the present embodiment, the liquid refrigerant is separated by the gas-liquid separator 3 at the refrigerant inlet 5a of the heat transfer tube 2 which is the refrigerant inflow tube of the heat exchanger 1. Branch once, and then again on the downstream heat transfer tube 2,
It is made to join in the middle of 2 ...

Therefore, the heat transfer tubes 2, 2,...
The composition of the non-azeotropic refrigerant in the medium changes, the high-boiling components are reduced, and the gas-liquid equilibrium temperature is lowered, so that the average temperature difference can be increased and the heat exchange capacity can be improved.

As described above, when the high-boiling component is reduced by once branching the non-azeotropic refrigerant in the gas-liquid two-phase region on the heat exchanger inlet side, the high-boiling component is reduced. As a result, the gas-liquid equilibrium temperature is lowered, and as described above, the average temperature difference with the air when the external airflow to the heat exchanger 1 is used as the counterflow can be increased, thereby improving the heat exchange capacity. (See FIG. 5). Further, it is possible to prevent a decrease in the amount of heat exchange due to a decrease in refrigerant performance.

As a result, according to the heat exchanger of the present embodiment, the deterioration of the refrigerant performance due to the phase change of the non-azeotropic refrigerant can be reduced as much as possible, and the effective heat exchange capacity of the heat exchanger can be reduced. Can be secured.

Further, it is not necessary to increase the size and cost of the heat exchanger.

(Embodiment 4) FIGS. 6 to 8 show the configuration of a heat exchanger according to Embodiment 4 of the present invention.

In this embodiment, a cross fin coil type heat exchanger is employed as in the third embodiment, and in the cross fin coil type heat exchanger, The present invention is characterized in that, after the gas refrigerant is once branched and extracted, the refrigerant composition is changed by being joined again to the outlet of the heat transfer tube, and the refrigerant and the heat fluid are caused to flow in a counterflow state.

In the figure, reference numeral 1 denotes a cross fin coil type heat exchanger. The cross fin coil type heat exchanger 1 has a plurality of heat transfer tubes 2, 2.
Are fitted and fixed at a predetermined fin pitch, and tube plates 7, 7 are provided at both ends thereof.

Are connected to the refrigerant inlet 5a of the refrigerant inflow pipe and the refrigerant outlet 6 of the refrigerant outflow pipe.
The part a is connected to the connecting pipes for the condenser and the compressor, respectively, while the two parts are vertically arranged side by side in a pair, and their front and rear ends are connected in a U-shape. They are integrally connected in a mutually communicating state via a pipe, and they are arranged side by side in a two-row state by slightly changing the vertical position in the left-right thickness direction.

Of the two rows of heat transfer pipe groups that communicate with each other, the heat transfer pipe 2 at the lowermost end of the downstream row of the air flow is the refrigerant inflow pipe, and the heat transfer pipe 2 at the lowermost end of the upstream row of the air flow is the same. The non-azeotropic refrigerant flowing into the heat transfer pipe 2 serving as the refrigerant inflow pipe is configured to flow in the direction of the heat transfer pipe 2 serving as the refrigerant outflow pipe as opposed to the air flow as illustrated in the drawing. ing.

A connection pipe to a condenser (not shown) is directly connected to the refrigerant inlet 5a of the heat transfer pipe 2 at the lowermost end of the air flow downstream row as the refrigerant inflow pipe, and the pressure is reduced through a pressure reducing valve. A condensed refrigerant is supplied. On the other hand, a gas-liquid separator 9 is provided at an intermediate portion 2b of the heat transfer tubes 2, 2,... In the air flow upstream row, and a gas refrigerant branch pipe 6b extends from the gas-liquid separator 9. The downstream end thereof is connected via a mixer 8 to the refrigerant outlet 6a of the heat transfer tube 2 at the lowermost end of the air flow upstream side row, which is the refrigerant inflow tube. Then, the gas refrigerant in the gas-liquid two-phase refrigerant in the middle of the heat transfer tubes 2, 2,... In the air flow upstream row is branched and extracted, and merges with the most downstream refrigerant outlet 6a. .

In this manner, the condensed refrigerant and the gaseous refrigerant supplied in the middle of the two most upstream heat transfer tubes and the two rows of heat transfer tubes 2, 2,... As shown in the figure, the heat is efficiently exchanged with the air by flowing in the direction opposite to the air flow in the heat transfer tubes 2, 2... And gradually evaporates. The refrigerant is discharged from the refrigerant outlet 6 a of the heat transfer tube 2 and the mixer 8 to the compressor via the connection pipe 6.

As described above, in the present embodiment, the gas refrigerant in the non-azeotropic refrigerant is branched and extracted by the gas-liquid separator 9 in the middle of the heat transfer tube of the heat exchanger 1, and then joined again at the outlet of the heat transfer tube. I try to make it.

Accordingly, the composition of the refrigerant in the middle of the heat transfer tube 2 changes, the low-boiling components decrease, and the gas-liquid equilibrium temperature rises, so that the average temperature difference with the air can be increased. Ability can be improved.

As described above, when the low-boiling component is reduced by branching the non-azeotropic refrigerant in the gas-liquid two-phase region in the middle of the heat transfer tube to reduce the low-boiling component, the low-boiling component is reduced. The gas-liquid equilibrium temperature rises, the average temperature difference with air when the heat exchanger is used as the direct counterflow can be increased, and the heat exchange capacity can be improved (FIG. 8).
reference). Further, it is possible to prevent a decrease in the amount of heat exchange due to a decrease in refrigerant performance.

As a result, according to the heat exchanger of the present embodiment, the deterioration of the refrigerant performance due to the phase change of the non-azeotropic refrigerant can be reduced as much as possible, and the heat exchange capacity of the heat exchanger is secured. Can be achieved.

Further, it is not necessary to increase the size and cost of the heat exchanger.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a heat exchanger according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a heat exchanger according to Embodiment 2 of the present invention.

FIG. 3 is a side view showing a configuration of a heat exchanger according to Embodiment 3 of the present invention.

FIG. 4 is a refrigerant circuit diagram of the heat exchanger.

FIG. 5 is a Mollier chart showing the heat exchange capacity of the heat exchanger.

FIG. 6 is a side view showing a configuration of a heat exchanger according to Embodiment 4 of the present invention.

FIG. 7 is a refrigerant circuit diagram of the heat exchanger.

FIG. 8 is a Mollier chart showing the heat exchange capacity of the heat exchanger.

[Explanation of symbols]

1 is a heat exchanger, 2 is a heat transfer tube, 3 is a gas-liquid separator, 4 is a mixer, 5 is a connection pipe to a condenser, 5a is a refrigerant inlet, 6 is a connection pipe to a compressor, and 8 is a mixer. , 9 is a gas-liquid separator, 10
Is a thermal fluid pipe, and 11a and 11b are refrigerant pipes.

Claims (4)

[Claims] 1. A heat exchanger comprising a heat transfer tube which forms a part of a refrigerant circuit and exchanges heat with another fluid, employs a non-azeotropic refrigerant as a refrigerant, and transfers the non-azeotropic refrigerant to the heat transfer tube. A heat exchanger, wherein a liquid phase component branching / joining circuit is provided for branching once at an inlet portion and joining again in a gas-liquid two-phase region in the middle of the heat transfer tube. 2. A heat exchanger comprising a heat transfer tube forming a part of a refrigerant circuit and exchanging heat with another fluid, wherein a non-azeotropic refrigerant is adopted as a refrigerant, and the non-azeotropic refrigerant is supplied to the heat transfer tube. A heat exchanger comprising a gas-phase component branching / joining circuit in which a gas-phase refrigerant is branched once in a gas-liquid two-phase region on the way, and joined again at the outlet of the heat transfer tube. 3. A heat transfer pipe having a double pipe structure of a heat exchange fluid pipe through which a heat exchange fluid flows and a refrigerant pipe through which a non-azeotropic refrigerant flows, wherein the non-azeotropic refrigerant flowing through the refrigerant pipe is The heat exchanger according to claim 1, wherein the heat exchanger flows so as to face a heat exchange fluid flowing in the heat exchange fluid pipe. 4. The heat transfer tubes are arranged in a plurality of rows from the downstream side to the upstream side of the air flow, and the non-azeotropic refrigerant flowing in the heat transfer tubes flows in opposition to the external air flow. The heat exchanger according to claim 1.