JP2007107853A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner performing defrosting operation while continuing heating operation. <P>SOLUTION: This air conditioner is provided with a heat pump type freezing cycle, in which a compressor 1, a four-way valve 2, an indoor heat exchanger 3, a decompressor 4, and an outdoor heat exchanger 5 are connected mutually by a refrigerant circuit, and a bypass circuit 6 making connection between the indoor heat exchanger 3 and the decompressor 4 and between the four-way valve 2 and the outdoor heat exchanger 5 connected to the freezing cycle. A refrigerant heating two-way valve 7 and a refrigerant heater 8 are arranged in the bypass circuit 6. When an outside air temperature detected by an outside air temperature detection means is lower than a predetermined temperature, the refrigerant heating two-way valve 7 in the bypass circuit 6 is opened, and bypass operation is carried out so that a refrigerant heated by the refrigerant heater 8 is made to flow toward the suction side of the compressor 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is an air conditioner that does not require a defrosting operation in which heating capacity is improved at a low outside air temperature and heating is performed by a refrigerant heater during a heating operation by a heat pump operation, and frost adhering to an outdoor heat exchanger is melted. It relates to the device.

  Conventionally, this type of heat pump air conditioner heating operation control system generally switches the four-way valve and melts the refrigerant in the refrigeration cycle in the reverse direction to melt frost adhering to the outdoor heat exchanger at low temperatures. The defrosting method is used.

  That is, in the defrosting operation, the flow direction of the refrigerant is the same as that during cooling, and a high-temperature and high-pressure refrigerant is passed through the outdoor heat exchanger to melt frost adhering to the heat exchanger. In this defrosting method, since the indoor heat exchanger becomes an evaporator during defrosting, there is a basic problem that the temperature of the room in the room is lowered and a feeling of cold air is felt.

  As a countermeasure to this problem, an invention for performing a defrosting operation while continuing heating has been considered. FIG. 4 is a configuration diagram of a refrigeration cycle of a conventional air conditioner.

  As shown in the figure, in a heat pump refrigeration cycle in which a compressor 101, a four-way valve 102, an indoor heat exchanger 110, an expansion mechanism 105, and an outdoor heat exchanger 103 are connected by a refrigerant circuit, the expansion in the refrigeration cycle is performed. A refrigerant heating circuit having a refrigerant heater 104 connected between the mechanism 105 and the outdoor heat exchanger 103 and the suction side of the compressor 101, a discharge side of the compressor 101 in the refrigeration cycle, and the outdoor A defrosting circuit that connects between the heat exchanger 103 and the four-way valve 102, and is heated by the refrigerant heater 104 when defrosting the outdoor heat exchanger 103 during heat pump operation of the refrigeration cycle. After the refrigerant having passed through the compressor 101, the outdoor heat exchanger 103 is flowed from the flow through the indoor heat exchanger 110 and the circuit for defrosting. Is branched into a flow through the flow of these branched refrigerant joined at the inlet of the refrigerant heating circuit, it discloses an invention that is configured to be heated by the refrigerant heater 104 again.

As taken up as a problem in the above invention, when performing a defrosting operation of the outdoor unit when performing a heat pump operation, it is possible to perform the defrosting operation while continuing the heating if conditions are determined. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 11-182994

  However, this refrigeration cycle system has the following problems.

  In this refrigeration cycle, when the defrosting operation is performed, the two-way valve 109a is opened, and the refrigerant discharged from the compressor 101 flows between the outdoor heat exchanger 103 and the four-way valve 102. The two-way valve 106 is necessary so that the hot gas refrigerant to be defrosted does not flow to the compressor 101 suction side.

The two-way valve 106 is connected to the suction side of the compressor 101, and in order to reduce the pressure loss during cooling and heating operation, the two-way valve 106 having a large diameter is adopted, which makes the two-way valve very expensive. End up. In addition, the two-way valve 108 is opened from the heat pump operation to switch to the refrigerant heating operation, and the refrigerant flow in the outdoor heat exchanger 103 is reversed in the method of performing the defrosting operation. Must be closed at one end, and a two-way valve 107 is required at the inlet of the outdoor heat exchanger 103. Therefore, this refrigeration cycle requires as many as four two-way valves, which is a complicated and expensive method.

  In addition, since the refrigerant after being defrosted and the refrigerant after radiating heat in the indoor heat exchanger 110 merge, if the refrigerant pressure at the junction is higher than the pressure of the refrigerant after being defrosted, If the refrigerant flows through the outdoor heat exchanger and the other way around, the refrigerant will flow into the indoor side, and there may be a case where the defrosting operation cannot be performed while heating.

  Furthermore, when the cooling circuit is operated, the inside of the piping of the refrigerant heater 104 is stabilized with the low-pressure refrigerant, and the temperature of the refrigerant heater 104 is decreased. Therefore, when the dew condensation occurs on the refrigerant heater 104 or the two-way valve 108 breaks down, the refrigerant Even when leakage occurs, condensation occurs in the refrigerant heater, and there is a big problem in the reliability and safety of the refrigerant heater.

  The present invention has been made in view of such problems of the prior art, and the refrigeration cycle can be configured with a simple bypass circuit, and defrosting operation for melting frost adhering to the outdoor heat exchanger is unnecessary. Then, it aims at providing the air conditioning apparatus which enables continuation of heating operation.

  In order to solve the above-described conventional problems, an air conditioner of the present invention includes a compressor, a four-way valve, an indoor heat exchanger, a decompressor, a refrigerant circuit connecting the outdoor heat exchanger, and an outside air temperature detecting means. The refrigerant circuit includes a bypass circuit that connects the indoor heat exchanger and the decompressor, the four-way valve, and the outdoor heat exchanger, and a refrigerant heating two-way valve provided in the bypass circuit. And a refrigerant heater, and when the detected value of the outside air temperature detecting means is smaller than a predetermined value, the refrigerant heating two-way valve is opened, and the refrigerant heated by the refrigerant heater is sucked into the compressor It is possible to exhibit a high heating capacity even at low outside temperatures due to the combined effect of heat absorption from the outside air by the outdoor heat exchanger and the refrigerant heater.

  According to the present invention, during the heating operation by the heat pump operation, there is no need for the defrosting operation to improve the heating capability at the low outdoor temperature and to continue the heating by the refrigerant superheater and to melt the frost adhering to the outdoor heat exchanger. An air conditioner can be realized.

  A first invention includes a refrigerant circuit in which a compressor, a four-way valve, an indoor heat exchanger, a decompressor, and an outdoor heat exchanger are connected, and an outside air temperature detecting means, and the refrigerant circuit includes the indoor heat exchanger, A bypass circuit connecting between the pressure reducer, the four-way valve, and the outdoor heat exchanger; a refrigerant heating two-way valve provided in the bypass circuit; and a refrigerant heater, and detecting the outside air temperature When the detection value of the means is smaller than a predetermined value, the two-way valve for heating the refrigerant is opened, and the refrigerant heated by the refrigerant heater is caused to flow into the suction side of the compressor. Sometimes, by using heat absorption from the outside air by the outdoor heat exchanger and heat absorption by the refrigerant heater by the first bypass circuit in combination, it is possible to exhibit a high heating capacity even at a low outside temperature.

  The second invention is characterized in that the decompressor is an electromagnetic expansion valve, and is in a state close to closing or closing during heating operation, and does not absorb heat in the outdoor heat exchanger. The defrosting operation for melting the frost adhering to the container becomes unnecessary, and the heating operation can be continued.

  A third invention is characterized in that a two-way valve is connected in series with a pressure reducer, and the two-way valve is closed during heating operation, and since no heat is absorbed by the outdoor heat exchanger, A defrosting operation for melting the frost attached to the heat exchanger is unnecessary, and the heating operation can be continued.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of an air-conditioning apparatus according to heating operation control of the air-conditioning apparatus according to the first embodiment of the present invention. In FIG. 1, an outdoor unit 20 includes a compressor 1, a four-way valve 2, a decompressor 4, an outdoor heat exchanger 5, a bypass circuit 6, a refrigerant heating two-way valve 7, and an outdoor fan 19. The indoor unit 18 is provided with the indoor heat exchanger 3 and the indoor blower 17.

  About the heating operation control of the air conditioning apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, a bypass circuit 6 that connects between the indoor heat exchanger 3 and the pressure reducer 4 connected to the refrigeration cycle, and between the four-way valve 2 and the outdoor heat exchanger 5 is provided. 7 and the refrigerant heater 8 are provided. When the outside air temperature is detected by the outside air temperature detecting means and the outside air temperature becomes lower than a predetermined temperature, the refrigerant heating two-way valve 7 of the bypass circuit 6 is opened to produce the refrigerant. A bypass operation 7 is performed to flow the refrigerant heated by the heater 8 to the suction side of the compressor 1.

  As described above, in the present embodiment, the bypass operation 7 is performed in which the refrigerant heating two-way valve 7 of the bypass circuit 6 is opened and the refrigerant heated by the refrigerant heater 8 flows to the suction side of the compressor 1. Thus, at the time of heating operation, it is possible to exhibit high heating capability even at low outside air temperature by using both the heat absorption from the outside air by the outdoor heat exchanger and the heat absorption by the refrigerant heater by the bypass circuit.

(Embodiment 2)
FIG. 2 is a configuration diagram of the air conditioner according to the heating operation control of the air conditioner according to the second embodiment of the present invention. In FIG. 2, the outdoor unit 20 includes a compressor 1, a four-way valve 2, a decompressor 4, an outdoor heat exchanger 5, a bypass circuit 6, a refrigerant heating two-way valve 7, and an outdoor fan 19. The indoor unit 18 is provided with the indoor heat exchanger 3 and the indoor blower 17. Here, the decompressor is the electromagnetic expansion valve 10. About the heating operation control of the air conditioning apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, a bypass circuit 6 is provided to connect between the indoor heat exchanger 3 and the pressure reducer 4 connected to the refrigeration cycle, and between the four-way valve 2 and the outdoor heat exchanger 5, and the bypass circuit 6 has a two-way valve for heating the refrigerant. 7 and the refrigerant heater 8 are provided. When the outside air temperature is detected by the outside air temperature detecting means and the outside air temperature becomes lower than a predetermined temperature, the refrigerant heating two-way valve 7 of the bypass circuit 6 is opened to produce the refrigerant. A bypass operation 7 is performed to flow the refrigerant heated by the heater 8 to the suction side of the compressor 1, and the electromagnetic expansion valve 10 is closed or closed to close.

As described above, in the present embodiment, the bypass operation 7 is performed in which the refrigerant heating two-way valve 7 of the bypass circuit 6 is opened and the refrigerant heated by the refrigerant heater 8 flows to the suction side of the compressor 1. At the same time, the electromagnetic expansion valve 10 is closed or closed close to the closed state, so that only the heat absorption by the refrigerant heater 8 by the bypass circuit is used during heating operation, and high heating capability can be exhibited even at low outside temperatures. In addition, the heating operation is continued by heat absorption by the refrigerant heater 8 and the work of the compressor 1, and heat is not absorbed by the outdoor heat exchanger, so that the frost attached to the outdoor heat exchanger is removed. The frost operation is unnecessary, and the heating operation can be continued for a long time. In addition, if the heater part of the refrigerant | coolant heater 8 is a heat generating body, a shape and a system will not ask | require.

  As described above, the air-conditioning apparatus of the present invention can perform the defrosting operation while performing the heating operation, and thus can be applied to an air-conditioning apparatus in a cold district where the outdoor temperature is very low.

Configuration diagram of the air-conditioning apparatus according to Embodiment 1 of the present invention. The block diagram of the air conditioning apparatus of Embodiment 2 of this invention The block diagram of the air conditioning apparatus of Embodiment 3 of this invention Configuration diagram of conventional air conditioner

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Pressure reducer 5 Outdoor heat exchanger 6 Bypass circuit 7 Two-way valve for refrigerant heating 8 Refrigerant heater 10 Electromagnetic expansion valve 11 Two-way valve 12 Pressure reducer for refrigerant heating 13 Heater Heater 14 Refrigerant passage pipe section 15 Heat storage section 17 Indoor fan 18 Indoor unit 19 Outdoor fan 20 Outdoor unit

Claims (3)

A compressor circuit, a four-way valve, an indoor heat exchanger, a decompressor, a refrigerant circuit connected to the outdoor heat exchanger, and an outside air temperature detecting means, and the refrigerant circuit is between the indoor heat exchanger and the decompressor. A bypass circuit connecting between the four-way valve and the outdoor heat exchanger, a refrigerant heating two-way valve and a refrigerant heater provided in the bypass circuit, and a detection value of the outside air temperature detecting means is predetermined. An air conditioner configured to open the refrigerant heating two-way valve when the value is smaller than the value so that the refrigerant heated by the refrigerant heater flows into the suction side of the compressor. The air conditioner according to claim 1, wherein the decompressor is an electromagnetic expansion valve, and is in a state close to closing or closing during heating operation. The air conditioner according to claim 1, wherein a two-way valve is connected in series with the decompressor, and the two-way valve is closed during heating operation.

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