JP4774858B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner capable of performing a defrosting operation for defrosting frost adhering to an outdoor heat exchanger while heating is continued during a heating operation by a heat pump operation.

  Conventionally, the defrosting method of this type of heat pump type multi-type air conditioner has generally adopted a defrosting method in which the four-way valve is switched and the refrigerant of the refrigeration cycle is flowed in the reverse direction.

  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 the frost attached to the heat exchanger.

  In this defrosting method, since the indoor heat exchanger serves as an evaporator during defrosting, heating stops, so that 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 basic problem, an invention for performing a defrosting operation while continuing heating has been considered.

  FIG. 8 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, a four-way valve, an indoor heat exchanger, an expansion mechanism, and an outdoor heat exchanger are connected by a refrigerant circuit, the expansion mechanism and the outdoor heat in the refrigeration cycle Between the exchangers and between the suction side of the compressor, a refrigerant heating circuit having a refrigerant heater, and between the discharge side of the compressor, the outdoor heat exchanger and the four-way valve in the refrigeration cycle. A defrosting circuit to be connected, and when defrosting the outdoor heat exchanger during the heat pump operation of the refrigeration cycle, after the refrigerant heated by the refrigerant heater passes through the compressor, The flow through the indoor heat exchanger and the flow from the defrosting circuit to the flow through the outdoor heat exchanger are branched, and the flow of the branched refrigerant merges at the inlet of the refrigerant heating circuit, and again the refrigerant heater Thus the invention is configured is disclosed to be heated.

As taken up as a problem in the above invention, when performing defrosting operation of the outdoor unit when performing heat pump operation, it is possible to perform defrosting operation while continuing heating if the conditions are limited. Yes (see, for example, Patent Document 1).
JP-A-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 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 once, 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 being radiated by the indoor heat exchanger 110 merge, if the refrigerant pressure at the junction is higher than the refrigerant pressure after being defrosted, If the refrigerant flows through the heat exchanger and vice versa, the refrigerant will flow into the room, and the defrosting operation may not be performed while heating.

  In addition, since the refrigerant after being defrosted and the refrigerant radiated by the indoor heat exchanger 110 join together, refrigerant noise is likely to occur, and in order to solve the above pressure balance problem and refrigerant noise problem The case where a refrigerant merger is required can be considered.

  Moreover, since the refrigerant circulation amount increases and the pressure loss increases at the junction, it is necessary to increase the pipe diameter as a countermeasure, and there is a structural problem that the heater becomes large.

  In addition, when operating in the cooling circuit, the refrigerant heater 104 inside the pipe is normally in a state where the temperature of the refrigerant heater 104 is lowered by the low-pressure refrigerant, so that condensation tends to occur in the refrigerant heater 104. Even when refrigerant leaks due to failure of the way valve 108, condensation occurs in the refrigerant heater, and particularly when a heat transfer heater is used for the refrigerant heater, there is a big problem in the reliability and safety of the refrigerant heater. .

  Furthermore, when this technology is applied to a multi-type air conditioner, since there are multiple indoor units, the amount of heat released is large, and a phenomenon that a large amount of liquid refrigerant returns to the outdoor unit occurs or there are many encapsulated refrigerants. The problem is that it is difficult for the refrigerant to merge, the refrigerant noise, and the increase in size of the heater tend to be further deteriorated, so that it is difficult to heat the indoor side while defrosting, and the indoor unit has multiple rooms. Therefore, when the defrosting is performed, the refrigerant flow cannot be controlled, and the living environment is extremely deteriorated because the plurality of rooms cannot be heated.

  The present invention has been made in view of the above-described problems of the prior art, and can continue the heating operation in which the refrigeration cycle can be configured with a simple bypass circuit and the problem of refrigerant noise and pressure balance does not occur. An object of the present invention is to provide a multi-type air conditioner capable of defrosting operation.

In order to achieve the above object, an air conditioner of the present invention includes a compressor, a four-way valve, a first flow divider, a plurality of indoor side heat exchangers, a second flow divider, an on-off valve, and an outdoor heat exchanger. A heat pump refrigeration cycle connected by a refrigerant circuit is mounted, and the plurality of indoor heat exchangers are connected to the outdoor unit by respective pipes, and the respective pipes are first and second shunts in the outdoor unit. In the air conditioner connected to a single pipe, the second shunt is provided with an expansion valve on each pipe on the indoor unit side, between the second shunt and the on-off valve, the four-way valve, and the A first bypass circuit connecting between the outdoor heat exchangers, a two-way valve and a refrigerant heater provided in the first bypass circuit, between the four-way valve and the first flow divider, Between the on-off valve and the outdoor heat exchanger, or between the compressor and the four-way valve When the on-off valve and the second bypass circuit for connecting the said chamber outer heat exchanger, e Bei a two-way valve provided in the second bypass circuit, before Symbol of the first bypass circuit by opening the two-way valve, after the refrigerant heated by the refrigerant heater and flow to the suction side of the compressor, and opening the two-way valve of the second bypass circuit, the refrigerant discharged from the compressor and it is characterized in that performing the defrosting operation flow before Symbol outdoor heat exchanger.

  The air conditioner of the present invention can perform defrosting while continuing the heating operation.

A first invention is a heat pump refrigeration cycle in which a compressor, a four-way valve, a first flow divider, a plurality of indoor heat exchangers, a second flow divider, an on-off valve, and an outdoor heat exchanger are connected by a refrigerant circuit. An air conditioner in which the plurality of indoor heat exchangers are connected to the outdoor unit by respective pipes, and the respective pipes are connected to a single pipe by the first and second flow dividers in the outdoor unit. The second shunt is provided with an expansion valve in each pipe on the indoor unit side, and the second shunt and the on-off valve, the four-way valve and the outdoor heat exchanger are connected. A first bypass circuit, a two-way valve and a refrigerant heater provided in the first bypass circuit, between the four-way valve and the first flow divider, the on-off valve and the outdoor heat exchanger Or between the compressor and the four-way valve, the on-off valve and the outdoor heat exchange A second bypass circuit for connecting the said second Bei example a two-way valve provided in the bypass circuit, by opening the two-way valve before Symbol first bypass circuit, the refrigerant heater in after the heated refrigerant and the flow to the suction side of the compressor, and opening the two-way valve of the second bypass circuit, the refrigerant discharged from the compressor flows before Symbol outdoor heat exchanger defrosting operation With this configuration, a high-temperature refrigerant can be allowed to flow in the outdoor heat exchanger while a high-temperature refrigerant is allowed to flow in the indoor heat exchanger, so that the defrosting operation is performed while performing the heating operation. Can be implemented.

  Further, since the defrosting operation is performed while heating is continued, no refrigerant noise is generated when the four-way valve is switched.

  Further, since the four-way valve is not switched during defrosting, the pressure fluctuation is small and the oil fluctuation of the compressor is small, so that the compressor can be operated with high reliability.

  In addition, since the defrosting circuit is performed outdoors even when the length of the connecting pipe becomes long, the compressor oil level in the defrosting operation by the pipe length does not decrease, and the compressor can be operated with high reliability even with long pipe products.

The second invention is equipped with a heat pump refrigeration cycle in which a compressor, a four-way valve, a first flow divider, a plurality of indoor heat exchangers, a second flow divider, and an outdoor heat exchanger are connected by a refrigerant circuit. In the air conditioner in which the plurality of indoor heat exchangers are connected to the outdoor unit by respective pipes, and the respective pipes are connected to a single pipe by the first and second shunts in the outdoor unit. An expansion valve is provided in each pipe on the indoor unit side of the two flow dividers, and between the second flow divider and the plurality of indoor heat exchangers and between the four-way valve and the outdoor heat exchanger. A first bypass circuit connected via a third shunt, a two-way valve and a refrigerant heater provided in the first bypass circuit, a space between the four-way valve and the first shunt, 2 between the shunt 2 and the outdoor heat exchanger, or between the compressor and the four-way valve, A second bypass circuit for connecting the said chamber outer heat exchanger and flow divider, the Bei example a two-way valve provided in the second bypass circuit, before SL two-way valve in the first bypass circuit by opening, after the refrigerant heated by the refrigerant heater and flow to the suction side of the compressor, and opening the two-way valve of the second bypass circuit, the refrigerant discharged from the compressor, before Symbol This is a defrosting operation that flows through the outdoor heat exchanger. By using this configuration, an outdoor heat exchanger is used while flowing a high-temperature refrigerant through the indoor heat exchanger using an expansion valve for refrigerant distribution. Moreover, since a high-temperature refrigerant | coolant can be poured, defrosting operation can be implemented, performing heating operation, without adding a new valve.

  According to a third aspect of the invention, in particular, the first bypass circuit of the second aspect of the invention is provided in each of the plurality of circuits between the plurality of indoor heat exchangers and the second shunt, The system bypass circuit is provided with a two-way valve and a refrigerant heater. With this configuration, a plurality of indoor heat exchangers can be heated by heating the refrigerant with the respective refrigerant heaters. While flowing a high-temperature refrigerant through the inner heat exchanger, a high-temperature refrigerant can also flow through the outdoor heat exchanger, and the defrosting operation can be performed while performing the heating operation.

  In addition, since the first bypass circuit provided with the refrigerant heater is separately mounted for a plurality of indoor units, the heating capacity can be sufficiently performed according to the indoor unit side, and the load of each room The optimal heater can be operated accordingly.

  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 conditioner according to the present invention. In the figure, an outdoor unit 20 includes a compressor 1, a four-way valve 2, a first flow divider 3, expansion valves 6 and 7, a second flow divider 8, an on-off valve 9, an outdoor heat exchanger 10, 1 bypass circuit 30, refrigerant heating two-way valve 11, refrigerant heater 12, second bypass circuit 40, two-way valve 13 of the second bypass circuit, outdoor blower (not shown) are mounted. .

  The indoor units 21 and 22 are provided with indoor heat exchangers 4 and 5 and an indoor fan (not shown).

  Next, FIG. 4 is a control block diagram according to the present invention, and FIG. 5 is a time chart showing the behavior when the control is operated.

  In FIG. 4, the defrosting start judgment is made by the defrosting start judging means 50 on the outdoor unit side 20, and when it is judged that the defrosting is started, the compressor operating means 51, the refrigerant heating two-way valve opening / closing means 52, the defrosting two The defrosting operation is performed by the way valve opening / closing means 53, the expansion valve opening varying means 54, the outdoor fan operating means 55, the four-way valve switching means 56, and the heater heater operation stopping means 57 performing the operations shown in FIG.

  At this time, the defrosting start signal is received from the outdoor unit 20 by the defrosting start signal receiving means 58 in the indoor units 21 and 22, and the indoor fan (not shown) is controlled by the indoor fan operating means 59 from the judgment of the defrosting operation. To do.

  Specifically, as shown in FIG. 5, when the start of defrosting is determined, the heating operation by the heat pump in step 1 is shifted to the heating operation by the refrigerant heating operation in step 2. At this time, the refrigerant heating two-way valve 11 is turned on and controlled in the opening direction.

The defrosting two-way valve 13 is kept closed, and the heater heater 12 is turned on to perform the refrigerant heating operation. At this time, the on-off valve 9 remains open, and the expansion valves 6 and 7 maintain the normal opening degree of the heating operation. Since the four-way valve 2 continues heating, it does not switch even during defrosting in the heating circuit.

  Moreover, since an internal fan continues heating, it does not stop. The outside fan continues to operate.

  Next, at step 3, the compressor operating frequency is changed to a value for defrosting, and the refrigerant heating two-way valve 11 is left open.

  Further, the two-way valve 13 for defrosting is opened, and the heater 12 is continuously turned on to perform the refrigerant heating operation and the defrosting operation.

  Further, the on-off valve 9 is closed, and the expansion valves 6 and 7 are shifted to the opening for defrosting.

  Also, the outside fan stops operating.

  And in step 4, it returns to the operation before defrosting with the completion of defrosting.

  Furthermore, it returns to normal heat pump heating operation after step 5.

  Although the operation frequency of the compressor is changed in the first embodiment, the defrosting operation can be performed by continuing heating even with a constant speed compressor.

  Further, the rotational speed of the indoor fan may be fixed or may vary.

  Further, the rotational speed of the indoor fan may be fixed or may vary.

  In the first embodiment, one end of the first bypass circuit is connected between the four-way valve and the outdoor heat exchanger, but is connected between the four-way valve and the suction side of the compressor. Also good.

Further, one end of the second bypass circuit is connected between the four-way valve and the first flow divider, but the same effect can be obtained also between the first flow divider and the indoor heat exchanger. .
(Embodiment 2)
Next, Embodiment 2 will be described with reference to FIGS.

  In FIG. 2, when it is determined to start defrosting, as shown in FIG. 6, the heating operation by the heat pump in step 1 is shifted to the defrosting operation by the refrigerant heating operation in step 2. At this time, the refrigerant heating two-way valve 11 is turned on and controlled in the opening direction.

  The defrosting two-way valve 13 is kept closed, and the heater heater 12 is turned on to perform the refrigerant heating operation. At this time, the expansion valves 6 and 7 are closed. Since the four-way valve 2 continues heating, it does not switch even during defrosting in the heating circuit.

  Moreover, since an internal fan continues heating, it does not stop. The outside fan continues to operate.

  Next, at step 3, the operating frequency of the compressor is changed to a value for defrosting and the refrigerant heating two-way valve 11 is left open.

Further, the two-way valve 13 for defrosting is opened, and the heater 12 is continuously turned on to perform the refrigerant heating operation and the defrosting operation. The expansion valves 6 and 7 are closed. Also, the outside fan stops operating.

  And in step 4, it returns to the operation before defrosting with the completion of defrosting.

  Furthermore, it returns to normal heat pump heating operation after step 5.

  Although the operation frequency of the compressor is changed in the first embodiment, the defrosting operation can be performed by continuing heating even with a constant speed compressor.

  Further, the rotational speed of the indoor fan may be fixed or may vary.

  The heater part of the refrigerant heater may be of any shape and method as long as it is a heating element.

  In the second embodiment, one end of the first bypass circuit is connected between the four-way valve and the outdoor heat exchanger, but is connected between the four-way valve and the suction side of the compressor. Also good.

  Further, one end of the second bypass circuit is connected between the four-way valve and the first flow divider, but the same effect can be obtained also between the first flow divider and the indoor heat exchanger. .

(Embodiment 3)
Next, Embodiment 3 will be described with reference to FIG. 3 and FIG.

  In FIG. 3, when the start of defrosting is determined, as shown in the time chart of FIG. 7, the process proceeds from the heating operation by the heat pump in step 1 to the defrosting operation by the refrigerant heating operation in step 2. At this time, the refrigerant heating two-way valves 15 and 16 are turned on and controlled in the opening direction.

  Further, the two-way defrosting valve 13 is kept closed, and the heaters 17 and 18 are turned on to perform the refrigerant heating operation. At this time, the expansion valves 6 and 7 are closed. Since the four-way valve 2 continues heating, it does not switch even during defrosting in the heating circuit.

  Moreover, since an internal fan continues heating, it does not stop. The outside fan continues to operate.

  Next, in step 3, the operating frequency of the compressor is changed to a value for defrosting, and the refrigerant heating two-way valves 15 and 16 are left open.

  The defrosting two-way valve 13 is opened, and the heaters 17 and 18 are continuously turned on to perform the refrigerant heating operation. The expansion valves 6 and 7 are closed. Also, the outside fan stops operating.

  And in step 4, it returns to the operation before defrosting with the completion of defrosting.

  Furthermore, it returns to normal heat pump heating operation after step 5.

  Although the operation frequency of the compressor is changed in the first embodiment, the defrosting operation can be performed by continuing heating even with a constant speed compressor.

  Further, the rotational speed of the indoor fan may be fixed or may vary.

In the third embodiment, one end of the first bypass circuit is connected between the four-way valve and the outdoor heat exchanger, but is connected between the four-way valve and the suction side of the compressor. Also good.

  Further, one end of the second bypass circuit is connected between the four-way valve and the first flow divider, but the same effect can be obtained also between the first flow divider and the indoor heat exchanger. .

  As described above, since the air conditioner of the present invention can perform the defrosting operation while performing the heating operation, the outdoor temperature is extremely high while maintaining the living environment of the multiple rooms of the multi-type air conditioner at a high level. It can also be applied to an air conditioner in a low temperature cold area.

Configuration diagram of the air-conditioning apparatus of Embodiment 1 of the present invention Configuration diagram of an air-conditioning apparatus according to Embodiment 2 of the present invention Configuration diagram of an air-conditioning apparatus according to Embodiment 3 of the present invention Control block diagram of the present invention Time chart of Embodiment 1 of the present invention Time chart of Embodiment 2 of the present invention Time chart of Embodiment 3 of the present invention Configuration of conventional air conditioner

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 1st flow divider 4 Indoor side heat exchanger 5 Indoor side heat exchanger 6 Expansion valve 7 Expansion valve 8 2nd flow divider 9 On-off valve 10 Outdoor heat exchanger 11 2 for refrigerant | coolant heating One-way valve 12 Heater 13 Two-way valve for defrosting 14 Third flow divider 15 Two-way valve for refrigerant heating 16 Two-way valve for refrigerant heating 17 Heater 18 Heater 20 Outdoor unit 21 Indoor unit 22 Indoor unit 30 First Bypass circuit 40 Second bypass circuit

Claims (3)

A heat pump refrigeration cycle in which a compressor, a four-way valve, a first flow divider, a plurality of indoor heat exchangers, a second flow divider, an on-off valve, and an outdoor heat exchanger are connected by a refrigerant circuit is installed. In the air conditioner in which the indoor side heat exchanger is connected to the outdoor unit through respective pipes, and each of the pipes is connected to a single pipe through the first and second flow dividers in the outdoor unit, The first bypass circuit is provided with an expansion valve in each pipe on the indoor unit side of the chamber, and connects between the second flow divider and the on-off valve, and between the four-way valve and the outdoor heat exchanger. And a two-way valve and refrigerant heater provided in the first bypass circuit, between the four-way valve and the first flow divider, between the on-off valve and the outdoor heat exchanger, or Connecting between the compressor and the four-way valve, and between the on-off valve and the outdoor heat exchanger A second bypass circuit, said Bei example a two-way valve provided in the second bypass circuit, before Symbol by opening the two-way valve in the first bypass circuit, the refrigerant heated by the refrigerant heater after flow to the suction side of the compressor, said opening the two-way valve in the second bypass circuit, characterized by performing the defrosting operation to flow a refrigerant discharged from the compressor, before Symbol outdoor heat exchanger Air conditioner. A heat pump refrigeration cycle in which a compressor, a four-way valve, a first flow divider, a plurality of indoor heat exchangers, a second flow divider, and an outdoor heat exchanger are connected by a refrigerant circuit; In the air conditioner in which the heat exchanger is connected to the outdoor unit by each pipe, and the respective pipes are connected to the single pipe by the first and second flow dividers in the outdoor unit, the interior of the second shunt On the machine side, each pipe is provided with an expansion valve, and a third flow divider is provided between the second flow divider and the plurality of indoor heat exchangers and between the four-way valve and the outdoor heat exchanger. A first bypass circuit connected through the two-way valve and the refrigerant heater provided in the first bypass circuit, between the four-way valve and the first flow divider, a second flow divider, and the Between the outdoor heat exchanger, or between the compressor and the four-way valve, the second shunt and the A second bypass circuit for connecting the outer heat exchanger, the second Bei example a two-way valve provided in the bypass circuit, by opening the two-way valve before Symbol first bypass circuit, after flow of the refrigerant heated by the refrigerant heating heater to the intake side of the compressor, and opening the two-way valve of the second bypass circuit, the refrigerant discharged from the compressor, before Symbol outdoor heat exchanger An air conditioner that performs a defrosting operation. A first bypass circuit is provided for each of the plurality of circuits between the plurality of indoor heat exchangers and the second shunt, and two-way valves and refrigerant heating are provided in the bypass circuits of the respective systems. The air conditioner according to claim 2, further comprising a heater.

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