JPH0749899B2 - Air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to improvement of an air conditioner provided with a plurality of refrigerant circulation systems, and more particularly to measures for reducing the facility capacity thereof.

(Prior Art) Conventionally, an air conditioner is provided with a refrigerant circulation system including a compressor, a heat source side heat exchanger, an expansion mechanism, and a use side heat exchanger. However, as disclosed in Japanese Patent Laid-Open No. 53-132842, for example, when a plurality of the above-mentioned refrigerant circulation systems are provided, air is satisfactorily air-conditioned even in a large room with a large air-conditioning load, and when one of the refrigerant circulation systems fails. In addition, the air conditioning operation is continued with the remaining refrigerant circulation system to ensure reliability against failure.

(Problems to be Solved by the Invention) By using an air conditioner provided with a plurality of refrigerant circulation systems as described above, a heat exchanger on the use side is arranged in each room on a predetermined floor of a high-rise building, for example. In the case of cooling and air-conditioning each room, the load of each heat exchanger on the use side is different for each room and changes with time due to the presence or absence of sunlight irradiation. Regarding the capacity of the compressor of the circulation system, it is necessary to select in advance the capacity value corresponding to the maximum value of each load during construction.

However, in that case, even if one of the refrigerant circulation systems is operating at the maximum capacity according to the load fluctuation in each usage-side heat exchanger, the other refrigerant circulation systems operate at intermediate capacity and Sometimes it is in a stopped state, and the effective utilization rate of the capacity is low when viewed from the total capacity of multiple refrigerant circulation systems,
As a result, there is a drawback that the installed capacity increases.

Similarly, in this type of air conditioner, at the same time as heating and air-conditioning a predetermined room in the winter season, for example, an electronic equipment room or the like in which a large number of electronic equipment (OA equipment) are arranged may be cooled and air-conditioned at a set low temperature value. If the amount of heat absorbed in the electronic equipment room is used as a heating heat source in the predetermined room during the simultaneous heating and cooling operation, the equipment capacity can be reduced accordingly.

The present invention has been made in view of such a point, and an object thereof is to provide a plurality of refrigerant circulation systems so that the cooling capacity can be compensated between the refrigerant circulation systems during the simultaneous cooling operation. At the same time, during the simultaneous operation of cooling and heating,
By using the amount of heat obtained from the room on the cooling side as a heating heat source, the capacity of each refrigerant circulation system can be selected as low as possible with a maximum capacity value to reduce the equipment capacity. It is in.

(Means for Solving Problems) In order to achieve the above object, in the present invention, during the simultaneous cooling operation, the degree of supercooling of the refrigerant of the other refrigerant circulation system is increased by the liquid refrigeration of one refrigerant circulation system. At the same time, the high pressure is lowered, and the cooling capacity of the other refrigerant circulation system is compensated accordingly. Further, at the time of simultaneous operation of cooling and heating, the heat quantity of the gas refrigerant is given to the liquid refrigerant of another refrigerant circulation system,
The so-called heat recovery operation is performed.

That is, as a concrete solution means of the present invention, as shown in FIG. 1, a compressor (1), a heat source side heat exchanger (3), an expansion mechanism (11) and a utilization side heat exchanger (10) are used. It is premised on an air conditioner that is provided with a plurality of refrigerant circulation systems (17) and (20) and that performs an indoor cooling operation and a heating operation. Then, between the two predetermined refrigerant circulation systems (17) and (20), the heat transfer arranged on the downstream side of the heat source side heat exchanger (3) during cooling of one refrigerant circulation system (17 and 20). Heat exchanger (25 or
25 ') and the refrigerant on the downstream side of the heat source side heat exchanger (3) during cooling of the other refrigerant circulation system (20 or 17) is expanded by the expansion mechanism (26, 2).
The first refrigerant circuit (30 or 30), which is passed through the heat exchanger (25 or 25 ') for heat transfer via 6') and then returned to the compressor (1) of the other refrigerant circulation system (20 or 17). 30 ') and a first on-off valve (31) arranged in the first refrigerant circuit (30 or 30').
Or 31 ') and the refrigerant from the compressor (1) of the other refrigerant circulation system (20 or 17) to the heat transfer heat exchanger (25 or 25') and then the other refrigerant circulation. A second refrigerant circuit (32 or 32 ') returned to the downstream side of the heat source side heat exchanger (3) during cooling of the system (20 or 17), and the second refrigerant circuit (32 or 32)
A heat transfer device (34 or 34 ') including a second on-off valve (33 or 33') arranged in 32 ') is provided, and during the cooling operation by the two refrigerant circulation systems (17) and (20), By opening the first opening / closing valve (31 or 31 '), the cooling capacity of the other refrigerant circulation system (20 or 17) can be used to cool one refrigerant circulation system (17 or 31).
By making it possible to compensate for the cooling capacity of 20) and opening the second opening / closing valve (33 or 33 ') during simultaneous operation of cooling and heating by the two refrigerant circulation systems (17) and (20),
The configuration is such that the amount of heat in the cooling room can be used as a heating heat source.

(Operation) According to the present invention, in the present invention, in the simultaneous cooling operation, in each of the refrigerant circulation systems (17) and (20), the heat of the indoor air is absorbed in the utilization side heat exchanger (10) due to the circulation of the refrigerant. At the same time, this amount of heat is repeatedly radiated to the outside by the heat source side heat exchanger (3), and each room is satisfactorily cooled and air-conditioned.

Now, when a large cooling capacity is required in a predetermined refrigerant circulation system (for example, 17), the first opening / closing valve (31) is opened. As a result, a part of the liquid refrigerant on the downstream side of the heat source side heat exchanger (3) (condenser) of the other refrigerant circulation system (20) passes through the expansion mechanism (26) and the predetermined refrigerant circulation system (1).
The heat source side heat exchanger (3) (condenser) 7) flows to the heat transfer heat exchanger (25) on the downstream side. As a result, in the predetermined refrigerant circulation system (17), the liquid refrigerant condensed in the heat source side heat exchanger (3) is further transferred to the heat transfer heat exchanger (25).
Since it is cooled by the liquid refrigerant, the degree of supercooling of the refrigerant is increased, the high pressure is decreased, and the cooling capacity thereof is compensated to be high.

Further, during the simultaneous operation of cooling and heating, for example, the second opening / closing valve (33 ') is opened. As a result, a part of the gas refrigerant from the compressor (1) of the cooling side refrigerant circulation system (for example, 17) is partially converted into the heat source side heat exchanger (3) (evaporator of the heating side refrigerant circulation system (20). ) It flows to the heat transfer heat exchanger (25 ') on the upstream side. As a result, in the refrigerant circulation system (20) on the heating side, the liquid refrigerant from the heat exchanger (10) (condenser) on the use side receives heat from the gas refrigerant in the heat exchanger (25 ') for heat transfer. After passing through the heat source side heat exchanger (3) (evaporator), the amount of heat in the cooling side room is recovered as a heating heat source and radiated to the heating side room, so that the indoor heating and air conditioning is favorably performed. Therefore, each refrigerant circulation system (17),
The capacity of (20) can be selected so that the capacity value is as low as the compensation amount of the cooling capacity and the heat recovery amount, and the total equipment capacity can be reduced.

(Example) Hereinafter, the Example of this invention is described based on drawing.

FIG. 1 shows a refrigerant piping system of an air conditioner that air-conditions a large room on a predetermined floor such as a high-rise building. In the figure, (A)
Is an outdoor unit, (B) to (E) are a plurality (4) of indoor units arranged in a large room, and two predetermined indoor units (B) and (C) are the first chamber. And the other two indoor units (D) and (E) are placed in the second chamber.

Inside the outdoor unit (A), two devices (H) and (I) having the same configuration are provided, and each device (H) and (I)
Includes a compressor (1), a four-way switching valve (2), an outdoor heat exchanger (3) as a heat source side heat exchanger, and an expansion mechanism (4) for heating operation. Each of (1) to (4) is connected to a refrigerant pipe (5) so that the refrigerant can flow therethrough. An inverter (7) is connected to the compressor (1), and the operating frequency of the compressor (1) is changed by the inverter (7) so that the capacity can be adjusted in multiple stages. On the other hand, each of the indoor units (B) to (E) has the same internal configuration, and inside thereof, an indoor heat exchanger (10) as a utilization side heat exchanger and an expansion mechanism (11) for cooling operation.
And each of the devices (10) and (11) has a refrigerant pipe (1
2) ... is connected so that the refrigerant can flow.

Thus, the indoor units (B), (C) of the first chamber are connected to each other in parallel by the refrigerant pipes (15), ..., And the outdoor unit (A) is connected by the other refrigerant pipes (16), (16). The refrigerant circulation system (17) for the first chamber is formed by being connected to one of the devices (H) such that the refrigerant can circulate. Similarly, the indoor units (D) and (E) of the second chamber are also connected in parallel to each other by the refrigerant pipes (18), while the other refrigerant pipes (19),
The refrigerant circulation system (20) for the second chamber is formed by the refrigerant (19) connected to the other device (I) of the outdoor unit (A) so that the refrigerant can circulate. In each of the refrigerant circulation systems (17) and (20), when the indoor cooling operation is performed, the four-way switching valve (2) is switched as indicated by the solid line to circulate the refrigerant as indicated by the solid line arrow so that the heat quantity of the indoor air is increased. The indoor heat exchanger (10) (evaporator) absorbs heat, and the outdoor heat exchanger (3) (condenser) repeatedly radiates the absorbed heat to the outside air to cool the room while heating the room. At times, the four-way switching valve (2) is switched as shown by the broken line to circulate the refrigerant as shown by the broken line arrow so that the heat quantity is exchanged in the opposite manner to heat the room.

Then, in the refrigerant circulation system (17) of the first chamber, on the downstream side of the outdoor heat exchanger (3) (condenser) during the cooling operation,
A double-tube heat transfer heat exchanger (25) is arranged. The heat exchanger (25) for heat transfer is an outdoor heat exchange during the cooling operation of the refrigerant circulation system (20) for the second chamber via the refrigerant pipe (27) in which the expansion mechanism (26) is interposed. The refrigerant circulation system (20) for the second chamber is connected to the downstream side of the condenser (3) (condenser) and through another refrigerant pipe (28).
The compressor (1) is connected to the suction side. Therefore, during the cooling operation, a part of the liquid refrigerant on the downstream side of the outdoor heat exchanger (3) (condenser) of the refrigerant circulation system (20) for the second chamber is transferred from the refrigerant pipe (27) to the expansion mechanism (36). After passing through the heat transfer heat exchanger (25), the second heat is passed through the refrigerant pipe (28).
A first refrigerant circuit (30) is configured to return to the suction side of the compressor (1) of the room refrigerant circulation system (20). In addition, an electromagnetic first on-off valve (31) for opening and closing the refrigerant pipe (28) is disposed in the middle of the refrigerant pipe (28) of the first refrigerant circuit (30). Furthermore, the heat transfer heat exchanger (25) includes a refrigerant pipe (28) to the suction side of the compressor (1) and another refrigerant pipe (29) branched from a terminal end of the refrigerant pipe (28). ) Is connected to the compressor (1) discharge side of the refrigerant circulation system (20) for the second chamber via
Both ends of the expansion mechanism (26) are bypassed by a refrigerant pipe (36) provided with a normally closed on-off valve (35). Therefore,
When the on-off valve (35) is in the open state, the gas refrigerant from the compressor (1) of the refrigerant circulation system (20) for the second chamber is circulated to the heat exchanger (25) for heat transfer, and then the refrigerant. A second refrigerant circuit (32) is configured to return to the upstream side of the outdoor heat exchanger (3) during the heating operation of the refrigerant circulation system (20) for the second chamber via the pipe (27). Then, in the middle of the refrigerant pipe (29) of the second refrigerant circuit (32), the refrigerant pipe (2
A second on-off valve (33) for opening and closing 9) is arranged. As described above, the heat transfer device (34) is configured to transfer the heat quantity of the second chamber refrigerant circulation system (20) to the first chamber refrigerant circulation system (17).

Similarly, a double-tube heat transfer heat exchanger (25 ′) is disposed downstream of the outdoor heat exchanger (3) of the second-chamber refrigerant circulation system (20) during the cooling operation. In the heat exchanger (25 ') for heat transfer, a part of the liquid refrigerant on the downstream side of the outdoor heat exchanger (3) during the cooling operation of the refrigerant circulation system (17) for the first chamber is connected to the refrigerant pipe ( 27 ′) to expansion mechanism (2
After passing through the heat transfer heat exchanger (25 ') through 6'), the compressor (1) suction of the refrigerant circulation system (17) for the first chamber through the refrigerant pipe (28 '). I tried to put it back to the side
The refrigerant circuit (30 ') is connected, and an electromagnetic first on-off valve (31') is arranged in the middle of the refrigerant pipe (28 ') of the first refrigerant circuit (30'). . Further, when the on-off valve (35 ') bypassing the expansion mechanism (26') of the first refrigerant circuit (30 ') is opened, the refrigerant circulation system (17) for the first chamber.
The heat exchanger (2) for transferring heat from the compressor (1) in the second chamber through the refrigerant pipe (29 ') in the refrigerant circulation system (20) for the second chamber.
After being circulated in 5 '), it is returned to the upstream side of the outdoor heat exchanger (3) during the heating operation of the refrigerant circulation system (17) for the first chamber via the refrigerant pipe (27'). Second refrigerant circuit (3
2 ') is configured and the second refrigerant circuit (3
The second opening / closing valve (33 ') is provided in the middle of the refrigerant pipe (29') on the discharge side of the compressor (1) of 2 '). Due to the above, the refrigerant circulation system for the first chamber ( Second, the amount of heat that 17) has
A heat transfer device (34 ') is configured to be transferred to the room refrigerant circulation system (20).

Thus, the two inverters (7), (7) and the two first opening / closing valves (31), (3) of the outdoor unit (A) are
1 '), second on-off valves (33), (33') and on-off valves (3
The operations of 5) and (35 ') are controlled by a controller (not shown) having a built-in CPU or the like.

The controller is related to the control of the inverter (7),
A set of indoor units (B) and (C) on the first chamber side,
A thermo signal is received from each of the indoor units (D) and (E) on the second room side, and a frequency setting signal of an appropriate value is output to the corresponding inverter (7) according to the thermo signal. As shown in FIG. 2, when the temperature signal is a hold signal in which the room temperature is within the range of ± 0.5 ° C. with respect to the room temperature target value (room temperature setting value) T ₀ , the frequency setting signal value is held as it is, The thermo signal is the hold upper limit value (T ₀ +0.5
In the case of an up signal having a small differential Δt with respect to (° C), the frequency setting signal value is increased by one step, and in the case of a down signal having a small differential Δt with respect to the hold lower limit value (T ₀ -0.5 ° C). , The frequency setting signal value is lowered by one step, and the operating frequency of the compressor (1) in the refrigerant circulation system (17), (20) corresponding to the thermo signal is set as the frequency corresponding to the frequency setting signal, and its capacity is set. For example
It has a function to control in 5 steps of 100, 75, 50, 25, 0%.

Next, the inverter (7) by the controller,
The operation control of (7) and the first on-off valves (31), (31 '), that is, the control during the simultaneous cooling operation of the two chambers will be described based on the control flow of FIG. After the start, in step S ₁ , the value of the thermo signal of the refrigerant circulation system (17) on the first chamber side is determined, and when the capacity of the compressor (1) belonging to the system does not need to be changed.
HOLD Sometimes, immediately proceeds to subsequent step S _11, and performing control for coolant circulation system of the second chamber side (20).

On the other hand, sometimes UP increasing the capacity of the compressor (1) in step S _1, first to determine the capability state of the compressor (1) which belongs to the system in step S _2, 100% during operation (during full load) If not, the stage increases the capacity by one step UP a frequency setting signal at the step S _3. Also, at full load
If YES, 'to determine the state of the first on-off valve (31 in Step S ₄ first on-off valve (31)' in the case of YES) is in the open state, a portion of the liquid refrigerant other in order to be prevented from circulating in the coolant circulation system (20) increases the cooling capacity of the self-system (17), the first on-off valve in step S ₅ (31 ') for closing control. When the first on-off valve (31 ') is in the closed state, the refrigerant circulating system of the second chamber side (20) of the compressor capacity state of (1) determined in the step S _6, the capacitance value There when not in full load condition, in order to effectively utilize the cooling capacity of the coolant circulation system of the second chamber side (20), the refrigerant circulating system of the second chamber side at step S ₇ (20) of the compressor (1 ) Is further increased by one step, the first opening / closing valve (31) is controlled to be opened, and a part of the liquid refrigerant is circulated in the own system (17) through the first refrigerant circuit (30). To step S ₁₁ .

On the other hand, at the time of DOWN for reducing the capacity of the compressor (1) in step S ₁ , the state of the first on-off valve (31) is determined in step S ₈ , and if YES in the open state, the cooling capacity Since the compensation is being received, the first opening / closing valve (31) is controlled to be closed in step S ₉ and the compressor of the refrigerant circulation system (20) on the first chamber side is first released in order to cancel the capacity compensation. The capacity of (1) is controlled to decrease by one step, and the process proceeds to step S ₁₁ . Also,
First on-off valve (31) is in a closed state, if not the ability compensation state, and one step reduction control capacity of the own system (17) of the compressor at step S ₁₀ (1), in step S ₁₁ move on.

Then, in the step S ₁₁ and later, until the subsequent step S _20, performs volume control and the on-off valve control of the same compressor (1) to the coolant circulation system of the second chamber side (17) And return.

Therefore, according to the control flow of FIG. 3, the capacity of the compressor (1) of one refrigerant circulation system (17 or 20) is the maximum capacity during the simultaneous cooling operation of both refrigerant circulation systems (17) and (20). If the compressor (1) of the other refrigerant circulation system (20 or 17) has a margin of capacity in the above demand, the compressor (1) of the other refrigerant circulation system (20 or 17) The capacity is controlled to increase by one step and the first on-off valve (31 or 31 ')
Is controlled so that the cooling capacity of one refrigerant circulation system (17 or 20) can be compensated by the cooling capacity of the other refrigerant circulation system (20 or 17).

In addition, the controller is configured such that, during simultaneous operation of cooling and heating, the second opening / closing valve (3) corresponding to the heat transfer heat exchanger (25 ′ or 25) provided in the refrigerant circulation system (20 or 17) on the heating side is provided.
Both the 3'or 33) and the on-off valve (35 'or 35) are controlled to be opened, and the compressor (1) of the cooling side refrigerant circulation system (17 or 20)
Part of the gas refrigerant from the above is circulated to the heating side heat transfer heat exchanger (25 'or 25) through the second refrigerant circuit (32' or 32) to absorb heat from the cooling side room. The heat quantity is applied to the heating-side refrigerant circulation system (20 or 17). In this case, when the on-off valve (35 'or 35) is closed, the refrigerant flows through the expansion mechanism (26' or 26) and exhibits the same effect as the above, but the on-off valve (35 'or 35' It is preferable to control the opening of 35) because the resistance can be reduced and the heat transfer amount can be increased. Further, the expansion mechanism (26 'or 26) and the on-off valve (35' or 35) may be constituted by one electric expansion valve and used in common. Also, when the high pressure of the refrigerant circulation system on the cooling operation side becomes lower than a predetermined value (for example, 13.5 kg / cm ² ) during the simultaneous operation of cooling and heating, the rotation speed (air volume) of the outdoor blower fan When the high pressure of the refrigerant circulation system on the heating side rises to another predetermined value (for example, 22 kg / cm ² ) or more, it also has a function of reducing the air volume of the outdoor blower fan.

Therefore, in the above embodiment, during the cooling operation of both refrigerant circulation systems (17) and (20), the respective compressors (1),
In the case of (1), the operation is controlled by each controller based on the corresponding thermo signal, and when the cooling load of the corresponding first and second chambers is large, the capacity value also increases and the cooling load is small. In the case of, the air conditioner is reduced, and the large room is satisfactorily cooled and air-conditioned.

Now, in the simultaneous cooling operation of the indoor units (B) and (C) on the first room side and the indoor units (D) and (E) on the second room side, when the magnitude of the cooling load is different, for example, First
The capacity value of the compressor (1) of the refrigerant circulation system (17) on the room side is required to be more than full load, and the intermediate capacity value (for example, 50% capacity value etc.) of the refrigerant circulation system (20) on the second room side. As an example, the compressor (1) having the intermediate capacity value is controlled by the controller, the capacity value is further increased, and the first on-off valve (31) is controlled to be opened. As a result, a part of the liquid refrigerant on the downstream side of the outdoor heat exchanger (3) (condenser) of the refrigerant circulation system (20) on the second chamber side moves to the expansion mechanism (26) in the first refrigerant circuit (30). Through the heat transfer heat exchanger (25) of the first chamber-side refrigerant circulation system (17), and then through the first refrigerant circuit (30).
Returning to the compressor (1) suction side of 0) is repeated. As a result, in the refrigerant circulation system (17) on the first chamber side, the refrigerant liquefied in the outdoor heat exchanger (3) (condenser) is further circulated to the heat transfer heat exchanger (25) to be the liquid refrigerant. Because it is cooled in
As shown in the Mollier diagram of FIG. 4, the degree of supercooling of the refrigerant is increased, the high pressure is decreased, and the enthalpy in the refrigerant circulation system (17) on the first chamber side is increased.
The cooling capacity is increased accordingly. Therefore, the maximum capacity of the own refrigerant circulation system can be suppressed to a low level as much as the capacity is compensated by the other refrigerant circulation system, and the total equipment capacity can be reduced, and the initial cost and the running cost can be reduced. On the other hand, the refrigerant circulation system (2
0) when the maximum capacity or more is required, when the cooling capacity of the refrigerant circulation system (17) on the first chamber side is small,
This time, conversely, the cooling capacity of the refrigerant circulation system (17) on the first chamber side compensates for the cooling capacity of the refrigerant circulation system (20) on the second chamber side.

In addition, for example, when the first room is an electronic equipment room and the second room is an air-conditioned room that requires air conditioning for occupants, heating operation is performed in the refrigerant circulation system (20) inside the air-conditioned room during the winter season. A cooling operation is performed in the refrigerant circulation system (17) on the electronic equipment room side. In this case, the second on-off valve (33 ') and the on-off valve (3
5 ′) and are controlled to open by the controller. As a result, a part of the amount of heat absorbed in the electronic equipment room is generated by the gas refrigerant from the compressor (1) of the refrigerant circulation system (17) for heat transfer in the refrigerant circulation system (20) inside the air conditioning room. After flowing through the exchanger (25 ') to radiate heat, the second refrigerant circuit (32')
Outdoor heat exchanger (3) (condenser) of its own system (17) via
Return to the downstream side. As a result, in the refrigerant circulation system (20) inside the air-conditioned room, a part of the liquid refrigerant from the indoor heat exchanger (10) (condenser) is transferred to the heat transfer heat exchanger (25 ') from the gas refrigerant to generate heat. After receiving and evaporating, it flows to the outdoor heat exchanger (3) (evaporator), so that the heat quantity in the electronic equipment room is recovered in the refrigerant circulation system (20) inside the air conditioning room and used as a heating heat source in the air conditioning room. Since it is used, the equipment capacity of the refrigerant circulation system (20) inside the air-conditioned room can be further reduced accordingly.

In the above embodiment, the capacity of the compressor (1) is controlled to increase / decrease by the inverter (7). However, the capacity can be controlled not only by the unload mechanism but also by the capacity not controlled by the unload mechanism. In this case, in the simultaneous cooling operation state, when the compressor of one refrigerant circulation system is stopped, this compressor may be operated to compensate for the cooling capacity of the other refrigerant circulation system.

(Effect of the invention) As described above, according to the air conditioner of the present invention,
In the simultaneous cooling operation, when the capacity equal to or more than the maximum capacity is required for a predetermined refrigerant circulation system, the degree of supercooling of the predetermined refrigerant circulation system is increased by the liquid refrigerant of the other refrigerant circulation system. At the same time, the high pressure is reduced to compensate the cooling capacity, and at the time of simultaneous operation of cooling and heating, heat is recovered from the room on the cooling side and used as the heating heat source, so the maximum capacity of each refrigerant circulation system is made as low as possible. While suppressing, the room can be comfortably cooled and air-conditioned according to the load, and the facility capacity can be effectively reduced, and the initial cost and running cost can be reduced.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a refrigerant piping system diagram of an air conditioner having two refrigerant circulation systems, FIG. 2 is an explanatory diagram of a thermo signal, and FIG. 3 shows operation of a controller. FIG. 4 is a flowchart, and FIG. 4 is a Mollier diagram showing how the cooling capacity in the refrigerant circulation system is compensated. (A) ... outdoor unit, (B) to (G) ... indoor unit, (1) ... compressor, (3) ... outdoor heat exchanger,
(10) …… Indoor heat exchanger, (17), (20) …… Refrigerant circulation system, (25), (25 ′) …… Heat transfer heat exchanger, (2
6), (26 ') ... expansion mechanism, (30), (30') ... first refrigerant circuit, (31), (31 ') ... first on-off valve, (3
2), (32 ') ... Second refrigerant circuit, (33), (33') ...
… Second on-off valve, (34), (34 ′) …… Heat transfer device.

Claims (1)

[Claims] 1. A plurality of refrigerant circulation systems (17), (20) comprising a compressor (1), a heat source side heat exchanger (3), an expansion mechanism (11) and a use side heat exchanger (10). An air conditioner that performs an indoor cooling operation and an indoor heating operation, and is provided between two predetermined refrigerant circulation systems (17) and (20) during cooling of one refrigerant circulation system (17 or 20). A heat exchanger (25 or 25 ') for heat transfer arranged on the heat source side heat exchanger (3) downstream side;
The heat exchanger (25 or 25 ') for heat transfer of the refrigerant on the downstream side of the heat source side heat exchanger (3) during cooling of the other refrigerant circulation system (20 or 17) through the expansion mechanism (26, 26'). ) And a first refrigerant circuit (30 or 30 ') which returns to the compressor (1) of the other refrigerant circulation system (20 or 17) and is arranged in the first refrigerant circuit (30 or 30') First on-off valve (31 or 31 ')
And the refrigerant from the compressor (1) of the other refrigerant circulation system (20 or 17) is transferred to the heat transfer heat exchanger (25 or 2).
5 ') and then the other refrigerant circulation system (20 or 1
2) Returning to the heat source side heat exchanger (3) downstream side during cooling in 7)
The refrigerant circuit (32 or 32 ') and the second refrigerant circuit (32 or 3)
The heat transfer device (34 or 34 ') including the second on-off valve (33 or 33') arranged in 2 ') is provided, and during the cooling operation by the two refrigerant circulation systems (17) and (20), By opening the first opening / closing valve (31 or 31 '), the cooling capacity of the other refrigerant circulation system (20 or 17) can be used to cool one refrigerant circulation system (17 or 31).
In addition to making it possible to compensate for the cooling capacity of 20), by opening the second on-off valve (33 or 33 ') during simultaneous operation of cooling and heating by the two refrigerant circulation systems (17) and (20), An air conditioner characterized in that the amount of heat can be used as a heating heat source.