JPH0798166A - Air-conditioner - Google Patents

Abstract

PURPOSE:To improve the heat exchanging efficiency of an air-conditioner and enable fast defrosting to be carried out without using any specific defrosting device. CONSTITUTION:The inlet port 17a for refrigerant in a heat exchanger 7 used as at least an evaporator is provided on the downstream side of the air flow passing through the heat exchanger 7 due to the rotation of a fan 19, and the outlet port 17b for refrigerant is provided on the upstream side. The air- conditioner has a heating mode in which the fans 15, 19 and a compressor 1 are on and the flow of refrigerant is made an opposing flow flowing from the downstream side inlet port 17a of the heat exchanger 7 toward the outlet 17b on the upstream side, and a defrosting mode in which the fans 15, 19 are off, the compressor 1 is on and the flow of refrigerant is made an opposing flow directed in the same direction as that in the heating mode in which the refrigerant flows from the downstream side inlet port 17a of the heat exchanger 7 to the upstream side outlet port 17b.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Generally, a heat pump type air conditioner is composed of a compressor, an indoor heat exchanger, a pressure reducing device and an outdoor heat exchanger, and in the heating mode, the indoor heat exchanger is used as a condenser. Use the outdoor heat exchanger as an evaporator. In the cooling mode, the indoor heat exchanger is used as an evaporator, the outdoor heat exchanger is used as a condenser, and a single refrigerant is used as the refrigerant circulating in the refrigeration cycle.

[0003]

In recent years, CFCs, which are a single refrigerant, have been abolished from the place where they adversely affect the earth, and instead, non-azeotropic mixed refrigerants for substitution have been considered promising. .

In the evaporator in the refrigerating mode, the non-azeotropic mixed refrigerant becomes the refrigerant vapor while the refrigerant liquid maintains the vapor-liquid equilibrium.
During this time, the evaporation temperature has a temperature gradient that gradually increases. In the condenser, the opposite is true, and the condensation temperature gradually decreases. On the other hand, air loses heat in the evaporator and becomes low temperature, and heat is obtained in the condenser and becomes high temperature. Table 1 shows a summary of these temperature relationships.

[0005]

[Table 1] In the refrigeration mode using this non-azeotropic mixed refrigerant, countercurrent heat exchange is performed to utilize the characteristic that the temperature of the phase change depends on the concentration to make the refrigerant heat with the cold fluid or heating fluid. Exchange loss can be reduced and the coefficient of performance can be improved. The countercurrent method is that the inlet of the refrigerant is the most downwind row and the outlet is the most upwind row with respect to the air flow.
This is a case where the refrigerant is arranged so as to sequentially flow from the leeward row to the leeward row. The opposite case is called a parallel flow system, and the efficiency is improved so that the heat exchanger is in the counter flow in the cooling mode and the heating mode.
No. 115945 is known.

However, in the evaporator, in the air conditioner using the non-azeotropic mixed refrigerant having a temperature gradient in which the temperature gradually increases from the inlet side to the outlet side, the counterflow or parallel flow pure air flow is used. In addition to the heat transfer phenomenon heat exchange rate, for example, by frost formation growing on the inlet fins of the evaporator,
The amount of ventilation between fins decreases, and it is necessary to consider the heat exchange rate due to the reduction in ventilation. The heat exchange rate due to this frost is not taken into consideration in JP-A-59-115945, and a special defrosting device is required to perform defrosting.

[0007] Therefore, the present invention provides an air conditioner capable of improving the heat exchange rate in a pure heat transfer phenomenon and rapidly defrosting without using a special defrosting device. The purpose is to do.

[0008]

In order to achieve the above object, the present invention comprises a compressor, an indoor heat exchanger, a pressure reducing device and an outdoor heat exchanger. As a condenser, while using the outdoor heat exchanger as an evaporator, during the cooling mode, the indoor heat exchanger as an evaporator, the outdoor heat exchanger as a condenser and the refrigerant circulating in the refrigeration cycle, non- In the air conditioner using the azeotropic mixed refrigerant, at least the inlet side of the refrigerant of the heat exchanger used as the evaporator, the leeward side with respect to the air flow passing through the heat exchanger by the rotation of the fan, of the refrigerant. While the outlet side is provided on the windward side, respectively, the fan and the compressor are turned on, and the heating mode operation is such that the flow of the refrigerant is a counterflow from the leeward inlet side of the heat exchanger toward the windward outlet side. fan With the defrosting mode operation in which the compressor is turned on, the flow of the refrigerant is counter-current so as to flow in the same direction as in the heating mode from the leeward inlet side of the heat exchanger to the leeward outlet side. There is.

[0009]

According to such an air conditioner, for example, in the heating mode operation, the high-temperature / high-pressure refrigerant vapor discharged from the compressor first enters the indoor heat exchanger through the four-way valve,
It radiates heat to indoor air and condenses. The condensed refrigerant is decompressed by the decompression device to become low temperature and low pressure, and absorbs heat from the outdoor air in the outdoor heat exchanger to be vaporized. The vaporized refrigerant is sucked into the compressor, becomes high-temperature and high-pressure vapor again, and repeats the heating cycle.

During this heating cycle, since the refrigerant has a counterflow relationship with the airflow from the leeward inlet side to the leeward outlet side, efficient heat exchange can be performed.

On the other hand, when the defrosting mode operation is started, the compressor is turned on and the fan is turned off, and the refrigerant has the same flow as in the heating mode operation. Therefore, the high temperature refrigerant flows from the inlet side, so that the inlet side region The frost that frosted on the fins can be quickly thawed. In this case, defrosting is possible without using a special defrosting device.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings of FIGS.

FIG. 2 shows refrigerants such as R32 and R134.
The refrigerating cycle of the air conditioning apparatus A using the non-azeotropic mixed refrigerant of a is shown. The air conditioner A includes a compressor 1, an indoor heat exchanger 3, a decompression device 5, and an outdoor heat exchanger 7. By switching the four-way valve 9, the refrigerant discharged from the compressor 1 is shown by a solid line. A refrigeration cycle can be obtained which goes to the indoor heat exchanger 3 side as shown by the arrow and to the outdoor heat exchanger 7 side as shown by the solid line arrow in FIG. 3, and switching control corresponding to the operation mode becomes possible. ing.

The indoor heat exchanger 3 comprises a continuous heat transfer tube 11 and fins 13 provided at a predetermined pitch. One end of the heat transfer tube 11 is connected to the four-way valve 9 and the other end is connected to the pressure reducing device 5, respectively. Then, as shown in FIG. 2, in the heating mode, the refrigerant flows as indicated by the solid arrow, thereby functioning as a condenser. Further, as shown in FIG. 3, in the cooling mode, it functions as an evaporator by flowing as shown by the solid arrow, and the rotation of the fan 15 causes the air flow to flow between the fins 13 and 13 as shown by the arrow. It's flowing.

The outdoor heat exchanger 7 is composed of a continuous heat transfer tube 17 and fins 18 provided at a predetermined pitch. One end of the heat transfer tube 17 is connected to the four-way valve 9 and the other end is connected to the pressure reducing device 5, respectively. Then, as shown in FIG. 2, in the heating mode, the refrigerant flows as indicated by the solid arrow, thereby functioning as an evaporator. Further, as shown in FIG. 3, in the cooling mode, the refrigerant flows as indicated by the solid line arrow to function as a condenser, and the rotation of the fan 19 causes the air flow to move to the fins 1 as indicated by the arrow.
It flows between the windshield 8 and the fin 18 from the windward side a toward the leeward side b.

An independent first control circuit 21 and second control circuit 23 are connected in an X-shape to the circuit on the side of the outdoor heat exchanger 7,
The first control circuit 21 is provided with a first opening / closing valve 25, and the second control circuit 23 is provided with a second opening / closing valve 27. Further, the third opening / closing valves 29, 29 are provided in the circuits between both connecting portions of the first and second control circuits 21, 23, respectively, and the first, second, third opening / closing valves 25, 27 are provided. , 29 are the operation unit 31 for the cooling mode operation and the operation unit 3 for the heating mode operation
3. The open / close control can be performed according to the operation of the operation unit 35 in the defrosting mode operation.

During the cooling mode operation 31 as shown in FIG. 3, the first and second opening / closing valves 25 and 27 are open and the third opening / closing valve 2 is opened.
While 9, 29 are closed, the compressor 1 and each fan 15, 1 are closed.
9 is in the ON operation state, which is a refrigeration cycle in which the refrigerant flows as indicated by the solid arrow.

In this refrigeration cycle, the outdoor heat exchanger 7 can obtain a counterflow to the airflow from the refrigerant inlet 17a side on the leeward b side to the refrigerant outlet 17b side on the upwind a side. There is.

During the heating mode operation 33, as shown in FIG. 2, the first and second opening / closing valves 25 and 27 are closed and the third opening / closing valve 2 is opened.
9, 29 are open, while the compressor 1 and each fan 15, 1
9 is in the operating state of ON, and the refrigeration cycle indicated by the solid arrow.

In this refrigeration cycle, the outdoor heat exchanger 7 is adapted to obtain a counterflow with respect to the air flow, which flows from the refrigerant inlet 17a side on the leeward b side to the outlet 17b side on the upwind a side. .

In the defrosting mode operation 35, as shown in FIG. 1, the first and second opening / closing valves 25 and 27 are closed and the third opening / closing valve 2 is opened.
9, 29 are open, compressor 1 is on, each fan 1
Reference numerals 5 and 19 are in an off state, which is a refrigeration cycle in which a refrigerant flows as indicated by a solid arrow.

In this refrigeration cycle, the refrigerant is the refrigerant inlet 17a of the outdoor heat exchanger 7 in which the air flow has stopped.
It flows from the side toward the outlet 17b side.

According to the air conditioner thus constructed, during the cooling operation, the high temperature and high pressure refrigerant vapor discharged from the compressor 1 enters the outdoor heat exchanger 7 through the four-way valve 9 and becomes the outdoor air. It dissipates heat and condenses. The condensed refrigerant is decompressed by the decompression device 5, becomes low temperature and low pressure, and absorbs heat from the indoor air in the indoor heat exchanger 3 to be vaporized. The vaporized refrigerant is sucked into the compressor 1, becomes high-temperature and high-pressure vapor again, and the refrigeration cycle is repeated. On the other hand, during the heat pump heating operation, the high-temperature, high-pressure refrigerant vapor discharged from the compressor 1 first enters the indoor heat exchanger 3 via the four-way valve 9 and radiates heat to indoor air to be condensed. The condensed refrigerant is decompressed by the decompression device 5, and the low temperature
The pressure becomes low and the outdoor heat exchanger 7 absorbs heat from the outdoor air and vaporizes. The vaporized refrigerant is sucked into the compressor 1, and the high temperature
It becomes high-pressure steam and repeats the heating cycle.

At the time of this heating mode operation 33, in the outdoor heat exchanger 7, the refrigerant is the inlet 17a on the leeward side a.
Since it is a counterflow from the side toward the outlet 17b, efficient heat exchange is performed.

In this heating mode operation 33, when the outside air temperature is low and frost is generated on the fins 18 around the refrigerant inlet 17a side, the defrosting mode operation 35 is started.

At this time, the fans 15 and 19 are in the off state, heat exchange is not performed by the air flow, and as shown in FIG.
The refrigerant has the same flow as in the heating mode operation 33, and the high temperature refrigerant flows toward the refrigerant inlet 17a side, so that defrosting can be performed quickly.

As shown in FIG. 4, the first, second and third
Instead of the on-off valves 25, 27, 29, check valves 37, 39,
The same effect can be expected by adopting 40, 40. Although not shown, a four-way valve may be used to obtain a circuit configuration that allows the functions of the first, second, and third on-off valves 25, 27, 29, 29 to be obtained.

Although this embodiment has been described on the outdoor heat exchanger 7 side, it may be provided on the indoor heat exchanger 3 side in addition to the outdoor heat exchanger 7.

[0029]

As described above, according to the present invention, since the heat exchanger can be used as the counter flow in accordance with the operation mode, the efficiency of heat exchange can be improved and the efficiency can be improved. Further, it is possible to quickly remove frost without newly providing a special defrosting device.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a refrigeration cycle in a defrosting mode implementing the present invention.

FIG. 2 is an explanatory diagram showing a refrigeration cycle in a heating mode.

FIG. 3 is an explanatory diagram showing a refrigeration cycle in a cooling mode.

FIG. 4 is a block diagram showing an operation unit and an air conditioner for cooling, heating, and defrosting mode operation.

FIG. 5 is a view in which the first, second, and third on-off valves are replaced with check valves.
Explanatory drawing similar to FIG.

[Explanation of symbols]

 1 Compressor 3 Indoor heat exchanger 5 Decompressor 7 Outdoor heat exchanger 9 Four-way valve 15, 19 Fan 17a Inlet side 17b Outlet side 21 First control circuit 23 Second control circuit 25 First on-off valve 27 Second on-off valve 29 3rd on-off valve

Claims (1)

[Claims] 1. A compressor, an indoor heat exchanger, a decompression device, and an outdoor heat exchanger. In the heating mode, the indoor heat exchanger is used as a condenser and the outdoor heat exchanger is used as an evaporator. In the cooling mode, the indoor heat exchanger is used as an evaporator, the outdoor heat exchanger is used as a condenser, and the refrigerant circulating in the refrigeration cycle is an air conditioner using a non-azeotropic mixed refrigerant, at least the evaporator. The refrigerant inlet side of the heat exchanger used as, the leeward side with respect to the air flow passing through the heat exchanger by the rotation of the fan, the refrigerant outlet side is provided on the windward side, while the fan and the compressor are Heating mode operation in which the flow of the refrigerant is turned on so that the flow of the refrigerant is a counterflow from the leeward inlet side of the heat exchanger toward the windward outlet side, the fan is turned off, the compressor is turned on, and the refrigerant flow is changed to the heat Wind of exchanger An air conditioner comprising: a defrosting mode operation in which a counterflow is performed in the same direction as in a heating mode from a lower inlet side to a windward outlet side.