JPH06194000A - Air conditioner - Google Patents

Abstract

PURPOSE:To prevent the deterioration of heat exchange performance of a heat exchanger as a condenser and evaporator by thermally separating by means of slits the heat exchanger into an upwind side half and a downwind side half in respect of fins. CONSTITUTION:A large number of heat transfer fins 8, which are parallelly disposed with specified spaces interposed between them, are respectively provided with separating slits 81 in their intermediate part, and rows of circular holes 80 for inserting the heat transfer pipes are provided in a longitudinal direction in such a manner as to sandwich the respective slits. Cooling medium pipes 9, in which cooling medium flows, are inserted through the holes 80 and vertically connected to the heat transfer fins 8. Upper and lower U-shaped cooling medium circuits are formed by use of heat transfer pipes of bends 10 connecting the cooling medium pipes 9. The cooling medium is distributed to the respective circuits by means of Y-shaped cooling medium distributors 12 provided at an inlet and outlet of a heat exchanger 3. Thus, unnecessary heat transfer between the two heat transfer circuits through the heat transfer fins 8 are prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner using a non-azeotropic mixed refrigerant as a working medium.

[0002]

2. Description of the Related Art A heat pump type air conditioner uses an indoor heat exchanger as an evaporator and an outdoor heat exchanger as a condenser during cooling, and uses an indoor heat exchanger as a condenser and an outdoor heat exchanger as an evaporator during cooling. To use as. In this case, the heat exchanger has a plurality of heat transfer tubes arranged in a zigzag manner as a whole so that a large number of fins are juxtaposed at predetermined intervals and are orthogonal to each other as shown in JP-A-3-194370. A cross fin tube type heat exchanger configured so as to penetrate therethrough is used.

In the cooling operation, the high-temperature and high-pressure non-azeotropic mixed refrigerant discharged from the compressor is cooled by air in the outdoor heat exchanger acting as a condenser to be condensed and liquefied, and this liquid refrigerant is decompressed in the decompressor. Then, it becomes a low-temperature gas-liquid two-phase refrigerant and flows into the indoor heat exchanger that functions as an evaporator. While passing through the indoor heat exchanger, the latent heat of vaporization is taken away by the heat exchange with the indoor air to evaporate, and the vaporized refrigerant is sucked into the compressor again to repeat the circulation.

At this time, when the non-azeotropic mixed refrigerant in the condenser is cooled to the dew point temperature determined by the mixing ratio, a large amount of the refrigerant component having a high boiling point begins to be condensed, and as the condensation progresses, the refrigerant component having a low boiling point is condensed. The ratio increases, and finally the liquid phase temperature determined by the mixing ratio is cooled and the entire amount is condensed. Therefore, the condensing temperature of the refrigerant drops considerably while passing through the heat transfer tube.

In the evaporator, the liquid-phase refrigerant having a large amount of the low-boiling-point refrigerant component evaporates at first by heating with air, and the liquid-refrigerant component having a high-boiling point also evaporates when further heated, which is determined by the mixing ratio. When heated to the dew point temperature, the whole amount becomes a vapor phase refrigerant. Therefore, the evaporation temperature of the refrigerant is
It rises considerably while passing through the heat transfer tubes.

[0006]

As described above, when the non-azeotropic mixed refrigerant is used as the working medium, the temperature of the refrigerant changes considerably during passing through the heat transfer tube in the case of condensation and the case of evaporation. Therefore, there is a large temperature difference between the heat transfer tube on the windward side and the heat transfer tube on the leeward side, and in particular, the temperature difference between the heat transfer tube near the refrigerant outlet and the heat transfer tube near the inlet. However, in the conventional heat exchanger, one set of fins is shared by the heat transfer pipes on the windward side and the heat transfer pipes on the leeward side, so that an unnecessary heat transfer phenomenon between the heat transfer pipes via the fins occurs. However, the heat exchange performance as a condenser and an evaporator is significantly deteriorated, and there is a problem that the heating performance and the cooling performance of the heat pump type air conditioner cannot be exhibited.

An object of the present invention is to provide a condenser and an evaporator due to an unnecessary heat transfer phenomenon between the heat transfer tubes on the upwind side and the heat transfer tubes on the leeward side caused by a temperature difference between the heat transfer tubes. By preventing the deterioration of heat exchange performance as
It is to provide a heat pump type air conditioner with significantly improved performance.

[0008]

An air conditioner according to the present invention is constructed by inserting a heat transfer tube into a heat transfer fin having a plurality of circular holes arranged in parallel and inserting the heat transfer tube at a right angle through the circular holes. An air conditioner having a plurality of cross fin type heat exchangers and a refrigeration cycle for a non-azeotropic mixed refrigerant comprising a compressor, a four-way valve, and a pressure reducer, wherein the heat exchanger is a wind of a heat transfer fin. It is characterized in that the upper half and the leeward half are thermally separated by a slit.

[0009]

In the present invention, since the windward half and the leeward half of the heat transfer fin are thermally separated by the slit, an unnecessary heat transfer phenomenon occurs between the heat transfer tubes via the fin. Therefore, the heat exchange performance as the condenser and the evaporator is improved, and the performance of the heat pump type air conditioner having the refrigeration cycle for non-azeotropic mixed refrigerant is significantly improved.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An air conditioner of the present invention will be described based on the embodiments shown in FIGS.

FIG. 1 is a side view of a cross fin type indoor heat exchanger, FIG. 2 is a side view of a cross fin type outdoor heat exchanger, and FIG.
Is a plan view of a heat transfer fin, and FIG. 4 shows a refrigeration cycle of a heat pump type air conditioner according to the present invention.

The refrigeration cycle is constructed so that the refrigerant compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the pressure reducer 4 and the indoor heat exchanger 5 are connected by a refrigerant pipe so that the refrigerant circulates inside. . In FIG. 5, the arrow 18 indicates the flow direction of the refrigerant during the cooling operation, and the arrow 19 indicates the flow direction of the refrigerant during the heating operation.

During cooling operation (during heating operation), the compressor 1
Compresses the refrigerant gas sent from the indoor heat exchanger 5 (outdoor heat exchanger 3) through the four-way valve 2, and the high-temperature high-pressure refrigerant gas is four-wayed as shown by an arrow 18 (arrow 19). It discharges to the outdoor heat exchanger 3 (indoor heat exchanger 5) through the valve 2. The outdoor heat exchanger 3 (indoor heat exchanger 5) acts as a condenser, and the refrigerant gas that has flowed into the outdoor heat exchanger 3 (indoor heat exchanger 5) passes through the blower 6 (blower 7). It is condensed and liquefied by exchanging heat with the outdoor (indoor) air passing through the outside. The indoor heat exchanger 5 (outdoor heat exchanger 3) acts as an evaporator, and is a low-temperature gas-liquid two-phase refrigerant 18 (19) that is decompressed by the pressure reducer 4 and flows into the indoor heat exchanger (outdoor heat exchanger). Is heat-exchanged with the indoor (outdoor) air flowing outside through the blower 6 (blower 7) to form a refrigerant gas. At this time, the cooled (heated) air is discharged into the room for cooling (heating). After passing through the indoor heat exchanger 5 (outdoor heat exchanger 3), the refrigerant gas returns to the compressor 1 through the four-way valve 2 and is compressed again and circulated.

The outdoor heat exchanger 3 has the structure shown in FIG. In FIG. 1, an arrow 20 indicates the passage direction of air to the heat exchanger 3. Reference numeral 8 denotes a large number of heat transfer fins juxtaposed at predetermined intervals. The heat transfer fin 8 is provided with a separation slit 81 at an intermediate portion as shown in FIG. The circular hole array 80 is bored along the longitudinal direction. Reference numeral 9 is a refrigerant pipe which is inserted and joined to the heat transfer fin 8 at a right angle through a circular hole 80 and through which a refrigerant flows.
Reference numeral 0 is a bend for connecting the refrigerant pipes, and the heat transfer pipe group connected by the bend causes the U-shaped refrigerant circuit to move up and down by two.
The circuit is configured. The Y-shaped refrigerant distributor 12 provided at the inlet and outlet of the heat exchanger divides the refrigerant into the respective circuits.

The indoor heat exchanger 5 has the structure shown in FIG. In FIG. 2, the arrow 21 indicates the passage direction of air to the heat exchanger 5. A T-shaped refrigerant shunt 11 for diverting the refrigerant is arranged in the middle of the heat exchanger, and a U-shaped refrigerant circuit is vertically arranged in the heat exchanger via the T-shaped refrigerant shunt 11. The circuit is configured.

The operation of this embodiment constructed as described above will be described with reference to FIGS.

In the cooling operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger through the inlet pipe 16. The refrigerant that has flowed into the outdoor heat exchanger is Y
The U-shaped refrigerant circuit is divided into two upper and lower parts through the U-shaped refrigerant distributor 12. At this time, the non-azeotropic mixed refrigerant in the condenser is
When cooled to the dew point temperature determined by the mixing ratio by heat exchange with the external air, condensation with a large amount of refrigerant components with a high boiling point begins, and the condensation ratio of the refrigerant components with a low boiling point increases as the condensation progresses, and finally, depending on the mixing ratio. It is cooled to the determined liquidus temperature and the whole amount is condensed. Therefore, the condensation temperature of the refrigerant in the heat transfer tube forming the U-shaped refrigerant circuit is considerably lowered while passing through the heat transfer tube. Therefore, the temperature difference between the heat transfer pipe on the windward side and the heat transfer pipe on the leeward side sandwiching the slit 81, particularly the temperature difference between the heat transfer pipe near the refrigerant outlet and the heat transfer pipe near the inlet becomes large. However, in the present invention, since the windward half and the leeward half of the heat transfer fin are thermally separated by the slit 81, an unnecessary heat transfer phenomenon between the both heat transfer tubes via the fin occurs. Since it can be prevented from occurring, the heat exchange performance as the condenser is improved.

The condensed and liquefied refrigerant passes through the decompressor 4 and expands into a low-temperature and low-pressure atomized gas-liquid two-phase refrigerant and flows into the indoor heat exchanger 5 which functions as an evaporator. The gas-liquid two-phase refrigerant that has flowed in from the refrigerant inlet pipe 11 arranged in the center of the indoor heat exchanger is divided into two directions, up and down, through the T-shaped flow divider 11 provided in the heat exchanger to form a U-shape. The refrigerant flows into the heat transfer tube group forming the refrigerant circuit. In the indoor heat exchanger acting as an evaporator, the liquid phase refrigerant having a large amount of the low boiling point refrigerant component is first evaporated by heating with air, and the liquid refrigerant component having the high boiling point is also evaporated when further heated, When heated to the dew point temperature determined by the mixing ratio, the entire amount becomes a vapor phase refrigerant. Therefore, the evaporation temperature of the refrigerant rises considerably while passing through the heat transfer tube. Therefore, as in the case of the outdoor heat exchanger acting as a condenser, the temperature difference between the heat transfer pipes on the windward side and the heat transfer pipes on the leeward side, especially between the heat transfer pipe near the refrigerant outlet and the heat transfer pipe near the inlet. Although the temperature difference between the heat transfer fins becomes large, since the windward half and the leeward half of the heat transfer fins are thermally separated by the slit 81, it is unnecessary between the heat transfer tubes via the fins. Since it is possible to prevent the occurrence of various heat transfer phenomena, the heat exchange performance as the evaporator is improved.

The operation during the cooling operation has been described above. However, during heating, the indoor heat exchanger functions as a condenser and the outdoor heat exchanger functions as an evaporator, as opposed to the cooling operation, as shown in FIG.

The operation during the heating operation will be described below. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the indoor heat exchanger 5 through the inlet pipe 14. The refrigerant that has flowed into the indoor heat exchanger is divided into two upper and lower U-shaped refrigerant circuits via the Y-shaped refrigerant distributor 12. At this time,
The non-azeotropic mixed refrigerant in the condenser is cooled to the dew point temperature determined by the mixing ratio by heat exchange with room air,
Condensation with a large amount of the refrigerant component having a high boiling point starts, and the condensation ratio of the refrigerant component with a low boiling point increases as the condensation proceeds, and finally the liquid component is cooled to a liquid phase temperature determined by the mixing ratio and the whole amount is condensed. Therefore, the condensation temperature of the refrigerant in the heat transfer tube forming the U-shaped refrigerant circuit is considerably lowered while passing through the heat transfer tube. Therefore, the temperature difference between the heat transfer pipe on the windward side and the heat transfer pipe on the leeward side sandwiching the slit 81, particularly the temperature difference between the heat transfer pipe near the refrigerant outlet and the heat transfer pipe near the inlet becomes large. However, in the present invention, since the windward half and the leeward half of the heat transfer fins are thermally separated by the slit 81, an unnecessary heat transfer phenomenon between the heat transfer tubes via the fins. The heat exchange performance as a condenser is improved because it can be prevented from occurring. Two U
The refrigerant condensed through the V-shaped refrigerant circuit merges again via the T-shaped refrigerant distributor 11 and is further cooled in the heat transfer tube to become a supercooled liquid refrigerant, which flows out from the outlet pipe 13.

The liquid refrigerant discharged from the indoor heat exchanger expands through the pressure reducer 4 to become a low-temperature low-pressure atomized gas-liquid two-phase refrigerant and flows into the outdoor heat exchanger 5 which functions as an evaporator. . The gas-liquid two-phase refrigerant that has flowed in from the refrigerant inlet pipe 17 arranged in the central portion of the outdoor heat exchanger is divided into two upper and lower U-shaped refrigerant circuits via the Y-shaped refrigerant distributor 12. At this time, in the outdoor heat exchanger acting as an evaporator, the liquid-phase refrigerant having a large amount of the low-boiling-point refrigerant component is first evaporated by heating with air, and the liquid refrigerant component having the high-boiling point is also evaporated when further heated. When heated to the dew point temperature determined by the mixing ratio, the entire amount becomes a vapor phase refrigerant. Therefore, the evaporation temperature of the refrigerant rises considerably while passing through the heat transfer tube. Therefore, as in the case of the indoor heat exchanger acting as a condenser, the temperature difference between the heat transfer pipes on the windward side and the heat transfer pipes on the leeward side, especially between the heat transfer pipes near the refrigerant outlet and the heat transfer pipes near the inlet. Although the temperature difference between the heat transfer fins becomes large, since the windward half and the leeward half of the heat transfer fins are thermally separated by the slit 81, it is unnecessary between the heat transfer tubes via the fins. Since it is possible to prevent the occurrence of various heat transfer phenomena, the heat exchange performance as the evaporator is improved.

In the present invention, since the windward half and the leeward half of the heat transfer fin are thermally separated by the slit,
Since it is possible to prevent unnecessary heat transfer phenomenon between both heat transfer tubes via the fins, heat exchange performance as a condenser and an evaporator is improved, and a refrigeration cycle for non-azeotropic mixed refrigerant is provided. The performance of the heat pump type air conditioner is significantly improved.

In the heat transfer fin shown in this embodiment, as shown in FIG. 3, the slit 80 is formed over the entire length along the longitudinal direction of the fin, but the windward half and the leeward half are heated. A partial slit 81 may be provided as shown in FIG.

[0024]

According to the present invention, since the windward half and the leeward half of the heat transfer fins are thermally separated by the slits, an unnecessary heat transfer phenomenon between the heat transfer tubes via the fins is achieved. As a result, the heat exchange performance as the condenser and the evaporator is improved, and the cooling and heating performance of the heat pump type air conditioner having the refrigeration cycle for the non-azeotropic mixed refrigerant can be significantly improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an outdoor heat exchanger of an air conditioner according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an indoor heat exchanger of an air conditioner according to a second embodiment of the present invention.

FIG. 3 is a plan view of heat transfer fins of the heat exchanger according to the embodiment of the present invention.

FIG. 4 is a system diagram of a refrigeration cycle of an air conditioner according to an embodiment of the present invention.

FIG. 5 is a plan view of a heat transfer fin showing a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor, 3 ... Outdoor heat exchanger, 4 ... Decompressor, 8 ... Heat transfer fin, 9 ... Heat transfer tube, 81 ... Slit part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mari Uchida 502 Jinritsucho, Tsuchiura City, Ibaraki Prefecture, Hiritsu Seisakusho Co., Ltd. (72) Inventor Hiroshi Kogure 800 Tomita, Ohira Town, Shimotsuga-gun, Tochigi Hitachi, Ltd. Living Equipment Division

Claims (1)

[Claims] 1. A plurality of cross fin type heat exchangers configured by inserting and joining heat transfer tubes at right angles to the heat transfer fins having a plurality of circular holes arranged in parallel, An air conditioner having a refrigeration cycle for a non-azeotropic mixed refrigerant consisting of a compressor, a four-way valve, and an expansion mechanism, wherein the heat exchanger comprises:
An air conditioner characterized in that the windward half and the leeward half of the heat transfer fin are separated by a slit.