AIR CONDITIONING APPARATUS

Description

FIELD

Techniques according to the present disclosure relate to air conditioning apparatuses.

BACKGROUND

A hot water heater has been known, the hot water heater including a refrigerant circuit where a refrigerant is circulated by operation of a compressor and a water circuit where water is circulated by operation of a water pump, the hot water heater having a heat exchanger provided to heat or cool the water by causing heat exchange between the refrigerant and the water, the hot water heater having an indoor radiator provided in the water circuit, the indoor radiator being for blowing air into a room to heat the room, the air having been heated by the water heated in the heat exchanger (Patent Literature 1). Specifically, the rotational speed of the compressor is controlled such that an outward temperature, which is a temperature of the water that flows into the indoor radiator, is at a target value, and the rotational speed of the water pump is controlled such that a difference between a return temperature, which is a temperature of the water that flows out from the indoor radiator, and the outward temperature is in a predetermined range. This technique enables water to be supplied to the indoor radiator, the water having an adequate flow rate, according to a heat radiation load on the indoor radiator. Furthermore, such a hot water heater is capable of cooling a room by an indoor radiator causing air to blow into the room, the air having been cooled by water cooled in a heat exchanger.

CITATION LIST

Patent Literature

• • Patent Literature 1: Japanese Laid-open Patent Publication No. 2007-287895

SUMMARY

Technical Problem

However, there is a problem that in a case where plurality of indoor radiators are provided in parallel in a water circuit of such a hot water heater, outward temperature adjustment in accordance with a heat radiation load on each of the plurality of indoor radiators is not possible, blowout air temperatures demanded of the respective plurality of indoor radiators are thus unable to be obtained, and comfort in rooms having the respective indoor radiators arranged therein is thus degraded.

Techniques disclosed herein have been achieved in view of these points and an object thereof is to provide an air conditioning apparatus enabling comfort to be improved.

Solution to Problem

According to an aspect of an embodiment, an air conditioning apparatus, includes a pump that circulates a heat medium in a heat medium circuit, a plurality of indoor heat exchangers provided in the heat medium circuit and provided in parallel with one another, a plurality of flow regulating valves respectively provided for the plurality of indoor heat exchangers, a plurality of heat medium temperature detection units respectively provided for the plurality of indoor heat exchangers, a heat source device that adjusts a temperature of the heat medium, and a control unit that: controls the pump such that the heat medium at a predetermined flow rate circulates through the heat medium circuit upon multiple unit operation having the heat medium flowing to the plurality of indoor heat exchangers, regards an indoor heat exchanger of the plurality of indoor heat exchangers as a largest heat load indoor heat exchanger, the indoor heat exchanger having a largest heat load among the plurality of indoor heat exchangers, calculates a largest heat load target flow rate on the basis of a heat load on the largest heat load indoor heat exchanger, controls the flow regulating valve of the plurality of flow regulating valves, the flow regulating valve corresponding to the largest heat load indoor heat exchanger, such that a flow rate of the heat medium flowing through the largest heat load indoor heat exchanger becomes equal to the largest heat load target flow rate, regards another indoor heat exchanger of the plurality of indoor heat exchangers as a residual heat load indoor heat exchanger, the another indoor heat exchanger being different from the largest heat load indoor heat exchanger, and controls the flow regulating valve of the plurality of flow regulating valves, the flow regulating valve corresponding to the residual heat load indoor heat exchanger, such that a flow rate of the heat medium flowing through the residual heat load indoor heat exchanger becomes equal to a residual heat load target flow rate calculated on the basis of a heat load on the residual heat load indoor heat exchanger and a temperature of the heat medium flowing into the largest heat load indoor heat exchanger, the temperature having been measured by the heat medium temperature detection unit corresponding to the largest heat load indoor heat exchanger.

Advantageous Effects of Invention

An air conditioning apparatus according to the disclosure enables comfort to be improved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a refrigerant circuit diagram illustrating an air conditioner provided with an air conditioning apparatus according to a first embodiment.

FIG. 2 is a block diagram illustrating an outdoor unit control device.

FIG. 3 is a diagram illustrating a pump target flow rate table.

FIG. 4 is a diagram illustrating a flow regulating valve target flow rate table.

FIG. 5 is a flowchart illustrating control operation.

FIG. 6 is a graph illustrating relations among water temperatures, heating capacities, and flow rates in an indoor heat exchanger.

DESCRIPTION OF EMBODIMENTS

Air conditioning apparatuses according to embodiments disclosed by the present application will hereinafter be described in detail by reference to the drawings. Techniques according to the present disclosure are not to be limited by the following description. Furthermore, in the following description, the same reference sign will be assigned to components that are the same and redundant description thereof will be omitted.

First Embodiment

An air conditioning apparatus according to a first embodiment is provided in an air conditioner 1, as illustrated in FIG. 1. FIG. 1 is a refrigerant circuit diagram illustrating the air conditioner 1 provided with the air conditioning apparatus according to the first embodiment. The air conditioner 1 includes an outdoor unit 2 and a plurality of indoor units 3-1 to 3-3. The outdoor unit 2 is installed outdoors. Of the plurality of indoor units 3-1 to 3-3, the first indoor unit 3-1 is installed in a first room of a plurality of rooms that are air conditioned by the air conditioner 1, the second indoor unit 3-2 is arranged in a second room, and the third indoor unit 3-3 is arranged in a third room.

The air conditioner 1 further includes a water circuit 4 (heat medium circuit). A water-refrigerant heat exchanger 5 (heat source device), a plurality of flow regulating valves 6-1 to 6-3, a plurality of indoor heat exchangers 7-1 to 7-3, and a pump 8 are connected to the water circuit 4 and water is circulated through the water circuit 4 by the pump 8 being driven. Of the plurality of indoor heat exchangers 7-1 to 7-3, the first indoor heat exchanger 7-1 is arranged inside the first indoor unit 3-1, the second indoor heat exchanger 7-2 is arranged inside the second indoor unit 3-2, and the third indoor heat exchanger 7-3 is arranged inside the third indoor unit 3-3.

The first flow regulating valve 6-1 of the plurality of flow regulating valves 6-1 to 6-3 is provided upstream of the first indoor heat exchanger 7-1. The second flow regulating valve 6-2 is provided upstream of the second indoor heat exchanger 7-2. The third flow regulating valve 6-3 is provided upstream of the third indoor heat exchanger 7-3. The first flow regulating valve 6-1 provided upstream of the first indoor heat exchanger 7-1 is arranged inside the first indoor unit 3-1 and is connected to the first indoor heat exchanger 7-1. The second flow regulating valve 6-2 provided upstream of the second indoor heat exchanger 7-2 is arranged inside the second indoor unit 3-2 and is connected to the second indoor heat exchanger 7-2. The third flow regulating valve 6-3 provided upstream of the third indoor heat exchanger 7-3 is arranged inside the third indoor unit 3-3 and is connected to the third indoor heat exchanger 7-3. The plurality of flow regulating valves 6-1 to 6-3 are connected in parallel with one another downstream from a water-refrigerant heat exchanger 19 via a branching pipe 11.

The pump 8 is arranged inside the outdoor unit 2. The pump 8 is connected to the plurality of indoor heat exchangers 7-1 to 7-3 via a joining pipe 12. The water-refrigerant heat exchanger 19 is arranged inside the outdoor unit 2 and is connected to the pump 8 via piping.

The pump 8 supplies water, which is supplied from the indoor heat exchangers 7-1 to 7-3 via the joining pipe 12, to the water-refrigerant heat exchanger 19 and circulates the water through the water circuit 4. The water-refrigerant heat exchanger 19 causes heat exchange between the water supplied from the pump 8 and a refrigerant. The branching pipe 11 divides the water that has undergone the heat exchange by the water-refrigerant heat exchanger 19 to the plurality of flow regulating valves 6-1 to 6-3. The first flow regulating valve 6-1 regulates the flow rate of water flowing in the first indoor heat exchanger 7-1. The second flow regulating valve 6-2 regulates the flow rate of water flowing in the second indoor heat exchanger 7-2. The third flow regulating valve 6-3 regulates the flow rate of water flowing in the third indoor heat exchanger 7-3.

The water-refrigerant heat exchanger 19 is connected to a refrigerant circuit 14. The refrigerant circuit 14 includes a compressor 15, a four-way valve 16, an outdoor heat exchanger 17, an expansion valve 18, and the water-refrigerant heat exchanger 19 (heat medium-refrigerant heat exchanger). The refrigerant circuit 14 further includes a suction pipe 21 and a discharge pipe 22. The compressor 15 includes a rotor, the rotor rotates, and a gas phase refrigerant supplied to the compressor 15 via the suction pipe 21 is thereby compressed and the compressed gas phase refrigerant is thereby discharged to the discharge pipe 22. The larger the rotational speed, at which the rotor rotates per unit time, the larger the amount of the refrigerant discharged by the compressor 15 per unit time.

The four-way valve 16 is connected to the suction pipe 21 and the discharge pipe 22, and is connected to the compressor 15 via the suction pipe 21 and the discharge pipe 22. The four-way valve 16 is also connected to the outdoor heat exchanger 17 via a refrigerant pipe and is connected to the water-refrigerant heat exchanger 19 via a refrigerant pipe. The four-way valve 16 includes a valve body, the refrigerant circuit 14 is switched to a heating cycle by the valve body being arranged at a heating position, and the refrigerant circuit 14 is switched to a cooling cycle by the valve body being arranged at a cooling position. When the refrigerant circuit 14 has been switched to the heating cycle, the discharge pipe 22 is connected to the water-refrigerant heat exchanger 19 via the four-way valve 16 and the outdoor heat exchanger 17 is connected to the suction pipe 21 via the four-way valve. When the refrigerant circuit 14 has been switched to the cooling cycle, the discharge pipe 22 is connected to the outdoor heat exchanger 17 via the four-way valve 16 and the water-refrigerant heat exchanger 19 is connected to the suction pipe 21 via the four-way valve 16.

The expansion valve 18 is connected to the outdoor heat exchanger 17 via a refrigerant pipe. The water-refrigerant heat exchanger 19 is connected to the expansion valve 18 via a refrigerant pipe.

The air conditioner 1 further includes an outward temperature sensor 23, a return temperature sensor 24, a plurality of room temperature sensors 25-1 to 25-3, and a plurality of water temperature sensors 26-1 to 26-3 (a plurality of heat medium temperature detection units). The outward temperature sensor 23 is arranged inside the outdoor unit 2 and measures a temperature of water flowing from the water-refrigerant heat exchanger 19 to the branching pipe 11. The return temperature sensor 24 is arranged inside the outdoor unit 2 and measures a temperature of water supplied from the pump 8 to the water-refrigerant heat exchanger 19.

Of the plurality of room temperature sensors 25-1 to 25-3, the first room temperature sensor 25-1 is arranged inside the first indoor unit 3-1, the second room temperature sensor 25-2 is arranged inside the second indoor unit 3-2, and the third room temperature sensor 25-3 is arranged inside the third indoor unit 3-3. The first room temperature sensor 25-1 measures a temperature of the first room where the first indoor unit 3-1 is installed. The second room temperature sensor 25-2 measures a temperature of the second room where the second indoor unit 3-2 is installed. The third room temperature sensor 25-3 measures a temperature of the third room where the third indoor unit 3-3 is installed.

Of the plurality of water temperature sensors 26-1 to 26-3, the first water temperature sensor 26-1 is arranged inside the first indoor unit 3-1, the second water temperature sensor 26-2 is arranged inside the second indoor unit 3-2, and the third water temperature sensor 26-3 is arranged inside the third indoor unit 3-3. The first water temperature sensor 26-1 measures a temperature of water supplied to the first indoor heat exchanger 7-1. The second water temperature sensor 26-2 measures a temperature of water supplied to the second indoor heat exchanger 7-2. The third water temperature sensor 26-3 measures a temperature of water supplied to the third indoor heat exchanger 7-3.

The air conditioner 1 further includes a plurality of indoor unit control devices 27-1 to 27-3 and an outdoor unit control device 28 (control unit). Of the plurality of indoor unit control devices 27-1 to 27-3, the first indoor unit control device 27-1 is arranged inside the first indoor unit 3-1, the second indoor unit control device 27-2 is arranged inside the second indoor unit 3-2, and the third indoor unit control device 27-3 is arranged inside the third indoor unit 3-3. The first indoor unit control device 27-1 controls the first indoor unit 3-1, the second indoor unit control device 27-2 controls the second indoor unit 3-2, and the third indoor unit control device 27-3 controls the third indoor unit 3-3. The plurality of indoor unit control devices 27-1 to 27-3 have each been electrically connected to the outdoor unit control device 28 and transmit information for controlling the air conditioner 1 to one another.

The outdoor unit control device 28 is arranged inside the outdoor unit 2. FIG. 2 is a block diagram illustrating the outdoor unit control device 28. The outdoor unit control device 28 includes a storage device 31 and a CPU 32 (central processing unit). The storage device 31 stores a computer program installed on the outdoor unit control device 28, and information used by the CPU 32. By executing the computer program installed on the outdoor unit control device 28, the CPU 32 obtains information from the outward temperature sensor 23, the return temperature sensor 24, and the plurality of indoor unit control devices 27-1 to 27-3, and controls the plurality of flow regulating valves 6-1 to 6-3, the pump 8, the compressor 15, and the four-way valve 16.

The outdoor unit control device 28 executes each of a plurality of functions, according to the computer program installed on the outdoor unit control device 28. The outdoor unit control device 28 includes, as the plurality of functions, a four-way valve control unit 33, a compressor control unit 34, a pump control unit 35, and a flow regulating valve control unit 36. The four-way valve control unit 33 controls the four-way valve 16 such that the refrigerant circuit 14 is switched to the heating cycle or the cooling cycle, according to the air conditioner 1 being operated by a user. The compressor control unit 34 controls the compressor 15 such that a refrigerant at an adequate flow rate circulates through the refrigerant circuit 14. The pump control unit 35 controls the pump 8 such that water at an adequate flow rate circulates through the water circuit 4. The flow regulating valve control unit 36 controls the plurality of flow regulating valves 6-1 to 6-3 such that water at an adequate flow rate flows through each of the plurality of flow regulating valves 6-1 to 6-3.

The storage device 31 further stores a pump target flow rate table 37 and a flow regulating valve target flow rate table 38. FIG. 3 is a diagram illustrating the pump target flow rate table 37. The pump target flow rate table 37 has a plurality of combinations associated with a plurality of single unit operation target flow rates 43, the plurality of combinations each being a combination of one of a plurality of temperature differences 41 and one of a plurality of outward temperatures 42. Specifically, the larger the temperature difference 41, the larger the single unit operation target flow rate 43 set, and the lower the outward temperature 42, the larger the single unit operation target flow rate 43 set. FIG. 4 is a diagram illustrating the flow regulating valve target flow rate table 38. The flow regulating valve target flow rate table 38 includes a plurality of combinations each being a combination of: a capacity 46 associated with a water temperature 45; and a water flow rate 47.

Operation executed by the air conditioner 1 includes cooling operation, heating operation, and control operation.

Cooling Operation

The cooling operation is executed, for example, when the air conditioner 1 is operated by a user for execution of the cooling operation. When the air conditioner 1 executes the cooling operation, the outdoor unit control device 28 controls the four-way valve 16 to switch the refrigerant circuit 14 to the cooling cycle. The outdoor unit control device 28 controls the compressor 15 to compress a low-pressure gas phase refrigerant supplied to the compressor 15 via the suction pipe 21. The low-pressure gas phase refrigerant is compressed by the compressor 15 and turned into a high-pressure gas phase refrigerant. The compressor 15 further discharges the high-pressure gas phase refrigerant to the discharge pipe 22. The high-pressure gas phase refrigerant discharged to the discharge pipe 22 is supplied to the outdoor heat exchanger 17 by the refrigerant circuit 14 having been switched to the cooling cycle.

The outdoor heat exchanger 17 causes heat exchange between the high-pressure gas phase refrigerant supplied from the four-way valve 16 and the outside air. In the outdoor heat exchanger 17, the high-pressure gas phase refrigerant condenses and turns into a high-pressure liquid phase refrigerant in a supercooled state, by radiating heat to the outside air. That is, when the air conditioner 1 executes the cooling operation, the outdoor heat exchanger 17 functions as a condenser. The high-pressure liquid phase refrigerant that has flown out from the outdoor heat exchanger 17 is supplied to the expansion valve 18.

The expansion valve 18 adjusts the flow rate of the refrigerant flowing to the water-refrigerant heat exchanger 19 from the outdoor heat exchanger 17 and decompresses the high-pressure liquid phase refrigerant supplied from the outdoor heat exchanger 17. The high-pressure liquid phase refrigerant is decompressed by the expansion valve 18 and turned into a low-pressure gas liquid two phase refrigerant. The low-pressure gas liquid two phase refrigerant that has flown out from the expansion valve 18 is supplied to the water-refrigerant heat exchanger 19.

The water-refrigerant heat exchanger 19 causes heat exchange between the low-pressure gas liquid two phase refrigerant supplied from the expansion valve 18 and water circulating through the water circuit 4. The low-pressure gas liquid two phase refrigerant is evaporated by being heated in the water-refrigerant heat exchanger 19 and is turned into a low-pressure gas phase refrigerant. That is, when the air conditioner 1 executes the cooling operation, the water-refrigerant heat exchanger 19 functions as an evaporator. The low-pressure gas phase refrigerant that has flown out from the water-refrigerant heat exchanger 19 is supplied to the four-way valve 16. The low-pressure gas phase refrigerant supplied to the four-way valve 16 is supplied to the suction pipe 21 by the refrigerant circuit 14 having been switched to the cooling cycle, and is sucked into the compressor 15 via the suction pipe 21.

Heating Operation

The heating operation is executed, for example, when the air conditioner 1 is operated by a user for execution of the heating operation. When the air conditioner 1 executes the heating operation, the outdoor unit control device 28 controls the four-way valve 16 to switch the refrigerant circuit 14 to the heating cycle. The outdoor unit control device 28 controls the compressor 15 to compress a low-pressure gas phase refrigerant supplied to the compressor 15 via the suction pipe 21. The low-pressure gas phase refrigerant is compressed by the compressor 15 and turned into a high-pressure gas phase refrigerant. The compressor 15 further discharges the high-pressure gas phase refrigerant to the discharge pipe 22. The high-pressure gas phase refrigerant discharged to the discharge pipe 22 is supplied to the water-refrigerant heat exchanger 19 by the refrigerant circuit 14 having been switched to the heating cycle.

The water-refrigerant heat exchanger 19 causes heat exchange between the high-pressure gas phase refrigerant supplied from the four-way valve 16 and water circulating through the water circuit 4. In the water-refrigerant heat exchanger 19, the high-pressure gas phase refrigerant turns into a high-pressure liquid phase refrigerant in a supercooled state, by radiating heat to the water. That is, when the air conditioner 1 executes the heating operation, the water-refrigerant heat exchanger 19 functions as a condenser. The high-pressure liquid phase refrigerant that has flown out from the water-refrigerant heat exchanger 19 is supplied to the expansion valve 18.

The expansion valve 18 adjusts the flow rate of the refrigerant flowing to the outdoor heat exchanger 17 from the water-refrigerant heat exchanger 19 and decompresses the high-pressure liquid phase refrigerant supplied from the water-refrigerant heat exchanger 19. The high-pressure liquid phase refrigerant is decompressed by the expansion valve 18 and turned into a low-pressure gas liquid two phase refrigerant. The low-pressure gas liquid two phase refrigerant that has flown out from the expansion valve 18 is supplied to the outdoor heat exchanger 17.

The outdoor heat exchanger 17 causes heat exchange between the low-pressure gas liquid two phase refrigerant supplied from the expansion valve 18 and the outside air. The low-pressure gas liquid two phase refrigerant is heated in the outdoor heat exchanger 17 and is turned into a low-pressure gas phase refrigerant. That is, when the air conditioner 1 executes the heating operation, the outdoor heat exchanger 17 functions as an evaporator. The low-pressure gas phase refrigerant that has flown out from the outdoor heat exchanger 17 is supplied to the four-way valve 16. The low-pressure gas phase refrigerant supplied to the four-way valve 16 is supplied to the suction pipe 21 by the refrigerant circuit 14 having been switched to the heating cycle, and is sucked into the compressor 15 via the suction pipe 21.

When the air conditioner 1 executes the cooling operation or the heating operation, the outdoor unit control device 28 further controls the pump 26 to supply water supplied from the joining pipe 12 to the water-refrigerant heat exchanger 19 and circulate the water through the water circuit 4. The water that has undergone the heat exchange with the refrigerant in the water-refrigerant heat exchanger 19 is supplied to the plurality of flow regulating valves 6-1 to 6-3 via the branching pipe 11. The first flow regulating valve 6-1 regulates the flow rate of the refrigerant flowing from the branching pipe 11 into the first indoor heat exchanger 7-1 and regulates the flow rate of the water flowing through the first indoor heat exchanger 7-1. The second flow regulating valve 6-2 regulates the flow rate of the refrigerant flowing from the branching pipe 11 into the second indoor heat exchanger 7-2 and regulates the flow rate of the water flowing through the second indoor heat exchanger 7-2. The third flow regulating valve 6-3 regulates the flow rate of the refrigerant flowing from the branching pipe 11 into the third indoor heat exchanger 7-3 and regulates the flow rate of the water flowing through the third indoor heat exchanger 7-3.

The first indoor heat exchanger 7-1 causes heat exchange between the water flowing through the first indoor heat exchanger 7-1 and the air in the first room. The first indoor unit control device 27-1 controls the first indoor unit 3-1 to: blow out the air that has undergone the heat exchange with the water in the first indoor heat exchanger 7-1, into the first room at an airflow determined on the basis of a user's operation; and air condition the first room. The second indoor heat exchanger 7-2 causes heat exchange between the water flowing through the second indoor heat exchanger 7-2 and the air in the second room. The second indoor unit control device 27-2 controls the second indoor unit 3-2 to: blow out the air that has undergone the heat exchange with the water in the second indoor heat exchanger 7-2, into the second room at an airflow determined on the basis of a user's operation; and air condition the second room. The third indoor heat exchanger 7-3 causes heat exchange between the water flowing through the third indoor heat exchanger 7-3 and the air in the third room. The third indoor unit control device 27-3 controls the third indoor unit 3-3 to: blow out the air that has undergone the heat exchange with the water in the third indoor heat exchanger 7-3, into the third room at an airflow determined on the basis of a user's operation; and air condition the third room. The water that has flown through the plurality of indoor heat exchangers 7-1 to 7-3 is supplied to the pump 8 via the joining pipe 12.

Control Operation

The control operation is continually executed when the heating operation or cooling operation is being executed. FIG. 5 is a flowchart illustrating the control operation. A user operates the first indoor unit 3-1 to stop the first indoor unit 3-1 when the user does not want to air condition the first room. A user operates the first indoor unit 3-1 to set a first set temperature on the first indoor unit 3-1 when the user wants to air condition the first room. A user operates the second indoor unit 3-2 similarly to the first indoor unit 3-1 to stop the second indoor unit 3-2 or set a second set temperature on the second indoor unit 3-2. A user operates the third indoor unit 3-3 similarly to the first indoor unit 3-1 to stop the third indoor unit 3-3 or set a third set temperature on the third indoor unit 3-3.

The first indoor unit control device 27-1 obtains a first room temperature measured by the first room temperature sensor 25-1 from the first room temperature sensor 25-1 and obtains a first water temperature measured by the first water temperature sensor 26-1 from the first water temperature sensor 26-1. On the basis of the first set temperature and the first room temperature, the first indoor unit control device 27-1 calculates a first requested temperature range. The first requested temperature range indicates a temperature range of water to be supplied to the first indoor heat exchanger 7-1 when the first indoor unit 3-1 air conditions the first room to the first set temperature. Furthermore, the first requested temperature range is included in a temperature range specific to the first indoor heat exchanger 7-1. The specific temperature range indicates a temperature range of water that is able to be supplied to the first indoor heat exchanger 7-1, and specifically, an upper limit of the first requested temperature range is lower than an upper limit of the temperature range of the water that is able to be supplied to the first indoor heat exchanger 7-1 and a lower limit of the first requested temperature range is higher than a lower limit of this temperature range. The first requested temperature range has a range specific to each of the plurality of indoor units 3-1 to 3-3, according to the volume and heat transfer performance, for example, of the indoor heat exchanger. Similarly to the first indoor unit control device 27-1, the second indoor unit control device 27-2 obtains a second room temperature from the second room temperature sensor 25-2, obtains a second water temperature from the second water temperature sensor 26-2, and calculates a second requested temperature range. Similarly to the first indoor unit control device 27-1, the third indoor unit control device 27-3 obtains a third room temperature from the third room temperature sensor 25-3, obtains a third water temperature from the third water temperature sensor 26-3, and calculates a third requested temperature range.

When the cooling operation or heating operation is being executed, the outdoor unit control device 28 obtains information on whether or not the plurality of indoor units 3-1 to 3-3 have been stopped, from the plurality of indoor unit control devices 27-1 to 27-3, and determines whether multiple unit operation is being executed or single unit operation is being executed (Step S1). In the multiple unit operation, two or more of the plurality of indoor units 3-1 to 3-3 are in operation, and water is flowing through indoor heat exchangers (hereinafter, referred to as operating indoor heat exchangers) of the plurality of indoor heat exchangers 7-1 to 7-3, the indoor heat exchangers corresponding to the two or more indoor units in operation. In the single unit operation, only a singly operating indoor unit that is one of the plurality of indoor units 3-1 to 3-3 has not been stopped, and other indoor units of the plurality of indoor units 3-1 to 3-3 have been stopped, the other indoor units being different from the singly operating indoor unit. That is, in the single unit operation, water is flowing through only a singly operating indoor heat exchanger of the plurality of indoor heat exchangers 7-1 to 7-3, the singly operating indoor heat exchanger having been provided in the singly operating indoor unit, and water is not flowing through the other indoor heat exchangers of the plurality of indoor heat exchangers 7-1 to 7-3, the other indoor heat exchangers being different from the singly operating indoor heat exchanger. When two or more operating indoor units of the plurality of indoor units 3-1 to 3-3 have not been stopped, the outdoor unit control device 28 determines that the multiple unit operation is being executed in the air conditioner 1 (Step S1, Yes). When only one of the plurality of indoor units 3-1 to 3-3 is in operation, the outdoor unit control device 28 determines that the single unit operation is being executed in the air conditioner 1 (Step S1, No).

When it has been determined that the air conditioner 1 is executing the multiple unit operation (Step S1, Yes), the outdoor unit control device 28 controls the pump 8 to circulate water through the water circuit 4 at a predetermined flow rate that has been determined beforehand according to the number of indoor units connected thereto, such that the flow rate of the water circulating through the water circuit 4 does not change (Step S2). A flow rate is set as the predetermined flow rate in this control, the flow rate not resulting in deficiency of capacity even in a case where rated capacity is demanded of all of the plurality of indoor units 3-1 to 3-3.

Subsequently, the outdoor unit control device 28 calculates temperature differences for the indoor units executing the operation, calculates, on the basis of the temperature differences, target flow rates for the respective indoor units executing the operation, and controls the plurality of flow regulating valves 6-1 to 6-3 according to the target flow rates (Step S3). Specifically, the outdoor unit control device 28 firstly calculates a heat load on any indoor unit executing target flow rate operation. A case where all of the plurality of indoor units 3-1 to 3-3 are executing the operation will be described as an example. On the basis of the first room temperature of the plurality of room temperatures and the first set temperature of the plurality of set temperatures, a first heat load of a plurality of heat loads is calculated, the first room temperature having been obtained from the first indoor unit control device 27-1, the first set temperature having been obtained from the first indoor unit control device 27-1. The first heat load indicates a heat load on the first indoor heat exchanger 7-1 and corresponds to a capacity needed when the first indoor unit 3-1 air conditions the first room to the first set temperature, and the larger an absolute value of a first temperature difference, the larger the first heat load, the first temperature difference resulting from subtraction of the first set temperature from the first room temperature. The outdoor unit control device 28 calculates a second heat load and a third heat load of the plurality of heat loads, for example, similarly to the first heat load. The second heat load indicates a heat load on the second indoor heat exchanger 7-2 and the third heat load indicates a heat load on the third indoor heat exchanger 7-3.

The outdoor unit control device 28 regards the indoor heat exchanger having the largest heat load among the plurality of heat loads as a largest load indoor heat exchanger. The outdoor unit control device 28 obtains a first target flow rate (a largest heat load target flow rate) on the basis of the largest heat load. The first target flow rate is a water flow rate needed in the indoor heat exchanger with the largest load, and the larger the largest heat load, the larger the first target flow rate stored in the storage device 31 beforehand. The outdoor unit control device 28 controls a largest load flow regulating valve of the plurality of flow regulating valves 6-1 to 6-3 such that the flow rate of water flowing to the largest load indoor heat exchanger becomes equal to the first target flow rate, the largest load flow regulating valve having been provided in the largest load indoor heat exchanger.

Furthermore, the outdoor unit control device 28 obtains an outward temperature measured by the outward temperature sensor 23 from the outward temperature sensor 23. The outdoor unit control device 28 calculates a second target flow rate (residual heat load target flow rate) on the basis of a heat load of the plurality of heat loads and the outward temperature, by referring to the flow regulating valve target flow rate table 38 for an operating indoor heat exchanger (residual heat load indoor heat exchanger) of the plurality of indoor heat exchangers 7-1 to 7-3, the operating indoor heat exchanger being different from the largest load indoor heat exchanger, the heat load being on the operating indoor heat exchanger. More specifically, the outdoor unit control device 28 selects a water temperature closest to the outward temperature from the plurality of water temperatures 45 (selects a higher water temperature in a case where there are two closest water temperatures), selects a capacity closest to the heat load on the operating indoor heat exchanger from some capacities of the plurality of capacities 46, these capacities corresponding to the water temperature selected, and selects a water flow rate associated with the selected capacity from the plurality of water flow rates 47. The second target flow rate is equal to this selected water flow rate. The second target flow rate is smaller than the first target flow rate, and the larger the heat load on the operating indoor heat exchanger, the larger the second target flow rate. The outdoor unit control device 28 controls an operating load flow regulating valve of the plurality of flow regulating valves 6-1 to 6-3 such that the flow rate of water flowing to the operating indoor heat exchanger become equal to the second target flow rate, the operating load flow regulating valve having been provided in the operating indoor heat exchanger.

Subsequently, on the basis of the plurality of requested temperature ranges (the first requested temperature range to the third requested temperature range), the outdoor unit control device 28 calculates a temperature control range. An upper limit of the temperature control range indicates a lowest temperature of upper limits of the plurality of requested temperature ranges and a lower limit of the temperature control range indicates a highest temperature of lower limits of the plurality of requested temperature ranges. On the basis of the largest heat load and the temperature control range, the outdoor unit control device 28 calculates a multiple unit operation target outward temperature. The multiple unit operation target outward temperature is included in the plurality of requested temperature ranges, the larger the largest heat load when the cooling operation is being executed, the lower the multiple unit operation target outward temperature, and the larger the largest heat load when the heating operation is being executed, the higher the multiple unit operation target outward temperature. On the basis of the multiple unit operation target outward temperature, the outdoor unit control device 28 calculates a multiple unit operation target compressor rotational speed. The multiple unit operation target compressor rotational speed is calculated so that the temperature (outward temperature) of water flowing from the water-refrigerant heat exchanger 19 to the branching pipe 11 becomes equal to the multiple unit operation target outward temperature when the rotational speed of the compressor 15 is equal to the multiple unit operation target compressor rotational speed. The outdoor unit control device 28 controls the compressor 15 such that the rotational speed of the compressor 15 becomes equal to the multiple unit operation target compressor rotational speed (Step S4).

FIG. 6 is a graph illustrating relations among water temperatures, heating capacities, and water flow rates in an indoor heat exchanger. A heating capacity corresponding to a water temperature and a water flow rate indicates a heating capacity demonstrated when, under predetermined conditions, a temperature of water flowing to the indoor heat exchanger is equal to that water temperature and a flow rate of water that flows to the indoor heat exchanger per unit time is equal to that water flow rate. An example of these conditions include a temperature in a room where an indoor unit provided with the indoor heat exchanger is installed, and an airflow of the air blown into the room, the air having been adjusted in temperature by the indoor heat exchanger. In a case where the multiple unit operation is being executed in the air conditioner 1 and the flow rates of water flowing to the plurality of indoor heat exchangers 7-1 to 7-3 are not adjusted according to the heat loads on the plurality of indoor heat exchangers 7-1 to 7-3, the water temperature, the heating capacity, and the water flow rate may not agree with the relations represented by the graph in FIG. 6, the air conditioning capacities at the plurality of indoor units 3-1 to 3-3 may thus be too large or too small, and comfort may thus be degraded.

When the multiple unit operation is being executed in the air conditioner 1, the flow rates of water flowing to the plurality of indoor heat exchangers 7-1 to 7-3 are adjusted according to the heat loads on the plurality of indoor heat exchangers 7-1 to 7-3, and capacities of the plurality of indoor heat exchangers 7-1 to 7-3 are thereby able to be made equal to capacities according to the heat loads on the plurality of indoor heat exchangers 7-1 to 7-3. That is, the plurality of flow regulating valves 6-1 to 6-3 are able to be controlled in the air conditioner 1 such that relations among water temperatures, flow rates, and heat loads for the plurality of indoor heat exchangers 7-1 to 7-3 generally agree with the relations among the water temperatures, water flow rates, and heating capacities represented by the graph in FIG. 6. Therefore, the air conditioner 1 enables the refrigerant to be prevented from circulating too much or too little through each of the plurality of indoor heat exchangers 7-1 to 7-3. As a result, the plurality of indoor units 3-1 to 3-3 enable adequate air conditioning and improvement of comfort.

When it has been determined that the air conditioner 1 is executing the single unit operation (Step S1, No), the outdoor unit control device 28 regards one operating indoor unit of the plurality of indoor heat exchangers 7-1 to 7-3 as a singly operating indoor heat exchanger. The outdoor unit control device 28 controls the plurality of flow regulating valves 6-1 to 6-3 such that a singly operating flow regulating valve of the plurality of flow regulating valves 6-1 to 6-3 is fully opened and stopped flow regulating valves of the plurality of flow regulating valves 6-1 to 6-3 are fully closed, the singly operating flow regulating valve corresponding to the singly operating indoor heat exchanger, the stopped flow regulating valves being flow regulating valves different from the singly operating flow regulating valve (Step S5).

Subsequently, the outdoor unit control device 28 calculates a target flow rate of the singly operating indoor unit and controls the pump 8 according to the target flow rate (Step S6). Specifically, the outdoor unit control device 28 obtains an outward temperature from the outward temperature sensor 23 first.

Subsequently, the outdoor unit control device 28 obtains a return temperature measured by the return temperature sensor 24 from the return temperature sensor 24. On the basis of the outward temperature and the return temperature, the outdoor unit control device 28 calculates a temperature difference. The temperature difference is equal to a value resulting from subtraction of the return temperature from the outward temperature.

The outdoor unit control device 28 refers to the pump target flow rate table 37 and calculates a single unit operation target flow rate on the basis of the outward temperature and the temperature difference for the singly operating indoor heat exchanger. More specifically, the outdoor unit control device 28 selects, from the plurality of temperature differences 41 in the pump target flow rate table 37, a temperature difference closest to the temperature difference obtained, and selects a value closest to the current outward temperature from the plurality of outward temperatures 42. The single unit operation target flow rate is equal to a single unit operation target flow rate from the plurality of single unit operation target flow rates 43, the single unit operation target flow rate having been associated with a combination of the selected temperature difference and outward temperature. The outdoor unit control device 28 controls the pump 8 such that a flow rate, at which the pump 8 circulates water through the water circuit 4, becomes equal to the single unit operation target flow rate (Step S6).

On the basis of a heat load on the singly operating indoor heat exchanger, the outdoor unit control device 28 calculates a single unit operation target outward temperature. When the cooling operation is being executed, the larger the heat load on the singly operating indoor heat exchanger, the lower the single unit operation target outward temperature, and when the heating operation is being executed, the larger the heat load on the singly operating indoor heat exchanger, the higher the single unit operation target outward temperature. On the basis of the single operation target outward temperature, the outdoor unit control device 28 calculates a single unit operation target compressor rotational speed. The single unit operation target compressor rotational speed is calculated so that the temperature (outward temperature) of water flowing from the water-refrigerant heat exchanger 19 to the branching pipe 11 becomes equal to the single unit operation target outward temperature when the rotational speed of the compressor 15 is equal to the single unit operation target compressor rotational speed. The outdoor unit control device 28 controls the compressor 15 such that the rotational speed of the compressor 15 becomes equal to the single unit operation target compressor rotational speed (Step S7).

When the single unit operation is being executed in the air conditioner 1, adjustment of the flow rate of water flowing to the singly operating indoor heat exchanger enables the pump 8 to be controlled such that relations among water temperatures, water flow rates, and heating capacities at the singly operating indoor heat exchanger agree with the relations among the water temperatures, the water flow rates, and the heating capacities represented by the graph in FIG. 6, the adjustment being in accordance with a temperature difference and an outward temperature for the singly operating indoor heat exchanger. Therefore, the air conditioner 1 enables the refrigerant to be prevented from circulating too much or too little through the singly operating indoor heat exchanger. As a result, the singly operating indoor unit enables adequate air conditioning and improvement of comfort. Furthermore, the air conditioner 1 enables reduction of the flow rate in the pump 8 without needlessly increasing the flow rate in the pump 8 when the heat load on the singly operating indoor heat exchanger is small and thus enables reduction in consumption of electricity.

Effects of Air Conditioning Apparatus of First Embodiment

The air conditioning apparatus according to the first embodiment includes the pump 8, the plurality of indoor heat exchangers 7-1 to 7-3, the plurality of flow regulating valves 6-1 to 6-3, the plurality of water temperature sensors 26-1 to 26-3, the water-refrigerant heat exchanger 19, and the outdoor unit control device 28. The pump 8 circulates water through the water circuit 4. The plurality of indoor heat exchangers 7-1 to 7-3 are provided in parallel with one another in the water circuit 4. The plurality of flow regulating valves 6-1 to 6-3 are provided respectively for the plurality of indoor heat exchangers 7-1 to 7-3. The plurality of water temperature sensors 26-1 to 26-3 are provided respectively for the plurality of indoor heat exchangers 7-1 to 7-3. The water-refrigerant heat exchanger 19 adjusts the temperature of water that circulates through the water circuit 4.

Upon the multiple unit operation, in which water flows through the plurality of indoor heat exchangers 7-1 to 7-3, the outdoor unit control device 28 controls the pump 8 such that water at a predetermined flow rate circulates through the water circuit 4. Upon the multiple unit operation, the outdoor unit control device 28 further calculates the first target flow rate on the basis of the largest value of heat loads on the plurality of indoor heat exchangers 7-1 to 7-3. The outdoor unit control device 28 controls the largest load flow regulating valve of the plurality of flow regulating valves 6-1 to 6-3 such that the flow rate of water flowing through the largest load indoor heat exchanger of the plurality of indoor heat exchangers 7-1 to 7-3 becomes equal to the first target flow rate, the largest load indoor heat exchanger having the largest heat load, the largest load flow regulating valve having been provided in the largest load indoor heat exchanger. Upon the multiple unit operation, the outdoor unit control device 28 calculates the second target flow rate on the basis of the heat load on another indoor heat exchanger of the plurality of indoor heat exchangers 7-1 to 7-3 and the temperature of water flowing into the largest load indoor heat exchanger, the other indoor heat exchanger being different from the largest load indoor heat exchanger, the temperature having been measured by the largest load water temperature sensor of the plurality of water temperature sensors 26-1 to 26-3, the largest load water temperature sensor having been provided in the largest load indoor heat exchanger. The outdoor unit control device 28 controls the other flow regulating valve of the plurality of flow regulating valves 6-1 to 6-3 such that the flow rate of water flowing through the other indoor heat exchanger becomes equal to the second target flow rate, the other flow regulating valve having been provided in the other indoor heat exchanger.

In a case where the plurality of indoor units 3-1 to 3-3 are in operation in the air conditioning apparatus and the flow rates of water flowing to the plurality of indoor heat exchangers 7-1 to 7-3 are not adjusted according to the heat loads on the plurality of indoor heat exchangers 7-1 to 7-3, the air conditioning capacities may become too large or too small and comfort may thus be degraded. The air conditioning apparatus according to the first embodiment enables: adjustment of the flow rates of water flowing to the plurality of indoor heat exchangers 7-1 to 7-3, the adjustment being in accordance with the heat loads on the plurality of indoor heat exchangers 7-1 to 7-3; prevention of too much or too little air conditioning by each of the plurality of indoor units 3-1 to 3-3; and improvement of comfort.

Furthermore, the water-refrigerant heat exchanger 19 in the air conditioning apparatus according to the first embodiment has the refrigerant circuit 14 including the compressor 15 and the water-refrigerant heat exchanger 19 that causes heat exchange between water and the refrigerant, and the refrigerant circulates through the refrigerant circuit 14. Upon the single unit operation, in which water flows to only one singly operating indoor heat exchanger of the plurality of indoor heat exchangers 7-1 to 7-3, the outdoor unit control device 28 calculates the single unit operation target flow rate on the basis of the heat load on the singly operating indoor heat exchanger. The outdoor unit control device 28 controls the pump 8 such that the flow rate of water flowing to the singly operating indoor heat exchanger becomes equal to the single unit operation target flow rate. Upon the single unit operation, the outdoor unit control device 28 further controls the compressor 15 such that the compressor rotational speed of the compressor 15 becomes equal to the single unit operation target compressor rotational speed calculated on the basis of the heat load on the singly operating indoor heat exchanger. Upon the multiple unit operation, the outdoor unit control device 28 controls the compressor 15 such that the compressor rotational speed becomes equal to the multiple unit operation target compressor rotational speed calculated on the basis of the largest heat load. The air conditioning apparatus according to the first embodiment enables: control of the compressor 15 of the water-refrigerant heat exchanger 19 such that the refrigerant does not circulate through the refrigerant circuit 14 too much or too little; prevention of too much or too little air conditioning by the plurality of indoor units 3-1 to 3-3; and improvement of comfort.

Furthermore, the air conditioning apparatus according to the first embodiment further includes the storage device 31, the outward temperature sensor 23, and the return temperature sensor 24. The storage device 31 stores the pump target flow rate table 37 and the flow regulating valve target flow rate table 38. The pump target flow rate table 37 has the plurality of combinations associated with the plurality of single unit operation target flow rates, the plurality of combinations each being a combination of a temperature difference and a heat load. The flow regulating valve target flow rate table 38 has the plurality of combinations associated with the plurality of water flow rates 47, the plurality of combinations each being a combination of a heat load and a temperature. The outward temperature sensor 23 measures the temperature of water that has been adjusted in temperature by the water-refrigerant heat exchanger 19. The return temperature sensor 24 measures the temperature of water that has flown out from the plurality of indoor heat exchangers 7-1 to 7-3.

Upon the single unit operation, the outdoor unit control device 28 calculates the single unit operation target flow rate corresponding to the combination of the outward temperature measured by the outward temperature sensor 23 and the temperature difference between the outward temperature and the return temperature measured by the return temperature sensor 24, by referring to the pump target flow rate table 37, the single unit operation target flow rate being from the plurality of single unit operation target flow rates 43. Upon the multiple unit operation, the outdoor unit control device 28 calculates the second target flow rate corresponding to the combination of the heat load on the other indoor heat exchanger and the outward temperature by referring to the flow regulating valve target flow rate table 38, the second target flow rate being from the plurality of water flow rates 47. The air conditioning apparatus according to the first embodiment enables: calculation of the single unit operation target flow rate and the second target flow rate in a short period of time; and improvement of comfort.

Furthermore, the air conditioning apparatus according to the first embodiment further includes the plurality of indoor units 3-1 to 3-3 respectively including the plurality of indoor heat exchangers 7-1 to 7-3. The first indoor unit 3-1 of the plurality of indoor units 3-1 to 3-3 includes the first room temperature sensor 25-1 that measures a temperature in the room where the first indoor unit 3-1 is installed. The outdoor unit control device 28 calculates, on the basis of the room temperature measured by the first room temperature sensor 25-1 and a set temperature set on the first indoor unit 3-1, a heat load on the first indoor heat exchanger 7-1 of the plurality of indoor heat exchangers 7-1 to 7-3, the first indoor heat exchanger 7-1 having been provided in the first indoor unit 3-1. Upon the single unit operation, the outdoor unit control device 28 calculates the single unit operation target outward temperature on the basis of the heat load on the singly operating indoor heat exchanger, and calculates the single unit operation target compressor rotational speed so that the outward temperature becomes equal to the single unit operation target outward temperature. Upon the multiple unit operation, the outdoor unit control device 28 calculates the multiple unit operation target outward temperature on the basis of the heat load on the largest load indoor heat exchanger, and calculates the multiple unit operation target compressor rotational speed so that the outward temperature becomes equal to the multiple unit operation target outward temperature. In the air conditioning apparatus according to the first embodiment, the single unit operation and the multiple unit operation have different methods of controlling the outward temperature, the compressor 15 of the water-refrigerant heat exchanger 19 is able to be controlled in both a case where the single unit operation is being executed and a case where the multiple unit operation is being executed, too much or too little air conditioning by the plurality of indoor units 3-1 to 3-3 is able to be prevented, and comfort is able to be improved.

In the above described air conditioning apparatus according to the first embodiment, the second target flow rate is calculated by use of the flow regulating valve target flow rate table 38, but the second target flow rate may be calculated without the use of the flow regulating valve target flow rate table 38. Furthermore, in the above described air conditioning apparatus according to the first embodiment, the single unit operation target flow rate is calculated by use of the pump target flow rate table 37, but the single unit operation target flow rate may be calculated without the use of the pump target flow rate table 37.

Second Embodiment

An air conditioning apparatus according to a second embodiment is the same as the above described air conditioning apparatus according to the first embodiment except that the outdoor unit control device 28 of the air conditioning apparatus according to the first embodiment described above calculates a second target flow rate and a single unit operation target flow rate by using equations without using the pump target flow rate table 37 and the flow regulating valve target flow rate table 38. That is, a water capacity Qw of each target indoor heat exchanger of the plurality of indoor heat exchangers 7-1 to 7-3 is generally expressed by the following Equation 1 using a specific heat capacity of water Cpw, an entrance water temperature TwL, an exit water temperature TwR, and a water flow rate Gw.

Qw = Cpw × ( TwL - TwR ) × Gw ( 1 )

The entrance water temperature TwL indicates a temperature of water supplied to the target indoor heat exchanger. The exit water temperature TwR indicates a temperature of water flowing out from the target indoor heat exchanger. The water flow rate Gw indicates a flow rate of water flowing per unit time to the target indoor heat exchanger. Furthermore, the air capacity Qa of the target indoor heat exchanger is generally expressed by the following Equation 2 using a specific heat capacity of air Cpa, the entrance water temperature TwL, an indoor intake temperature Ta, a heat exchanger temperature efficiency ε, and an airflow Ga.

Qa = Cpa × ( TwL - Ta ) × ε × Ga ( 2 )

The indoor intake temperature Ta indicates a temperature in a room where the target indoor unit has been installed, the target indoor unit being where the target indoor heat exchanger of the plurality of indoor units 3-1 to 3-3 has been provided. The heat exchanger temperature efficiency ε indicates a value specific to the target indoor heat exchanger and is a function of the water flow rate Gw. The airflow Ga indicates an airflow, at which the target indoor unit blows air into the room, the air having been adjusted in temperature by the target indoor heat exchanger.

Upon the multiple unit operation, the outdoor unit control device 28 calculates the water flow rate Gw as the second target flow rate by reversely calculating Equations 1 and 2 so that the water capacity Qw and the air capacity Qa generally agree with the heat load on the target indoor heat exchanger. Upon the single unit operation, the outdoor unit control device 28 calculates the water flow rate Gw as the single unit operation target flow rate by reversely calculating Equations 1 and 2 so that the water capacity Qw and the air capacity Qa generally agree with the heat load on the singly operating indoor heat exchanger.

The air conditioning apparatus according to the second embodiment enables the plurality of flow regulating valves 6-1 to 6-3 and the pump 8 to be controlled similarly to the above described air conditioning apparatus according to the first embodiment even in a case where the second target flow rate and the single unit operation target flow rate are calculated by use of equations without the use of the pump target flow rate table 37 and the flow regulating valve target flow rate table 38. Therefore, similarly to the above described air conditioning apparatus according to the first embodiment, the air conditioning apparatus according to the second embodiment enables comfort to be improved. Furthermore, by using the pump target flow rate table 37 and the flow regulating valve target flow rate table 38, the above described air conditioning apparatus according to the first embodiment does not need to reversely calculate Equations 1 and 2, and thus enables calculation of the second target flow rate and the single operation target flow rate in a shorter period of time as compared to the air conditioning apparatus according to the second embodiment.

The plurality of water temperature sensors 26-1 to 26-3 have been provided in the above described air conditioning apparatuses according to the embodiments but the plurality of water temperature sensors 26-1 to 26-3 may be omitted. Water temperatures measured by the plurality of water temperature sensors 26-1 to 26-3 are generally equal to an outward temperature measured by the outward temperature sensor 23. Therefore, the air conditioning apparatuses may use an outward temperature measured by the outward temperature sensor 23 instead of water temperatures measured by the plurality of water temperature sensors 26-1 to 26-3 if the plurality of water temperature sensors 26-1 to 26-3 have been omitted. Furthermore, the above described air conditioning apparatuses according to the embodiments have the outward temperature sensor 23 provided therein, but the outward temperature sensor 23 may be omitted. The air conditioning apparatuses may use a water temperature measured by any of the plurality of water temperature sensors 26-1 to 26-3 instead of an outward temperature measured by the outward temperature sensor 23 if the outward temperature sensor 23 has been omitted. In such a case also, similarly to the above described air conditioning apparatuses according to the embodiments, an air conditioning apparatus enables comfort to be improved.

The water-refrigerant heat exchanger 19 of the air conditioning apparatuses according to the embodiments described above heats and cools water circulating through the water circuit 4, but the water-refrigerant heat exchanger 19 may be replaced by another heat source device that does not cool but only heats the water circulating through the water circuit 4. In such a case also, similarly to the air conditioning apparatuses according to the embodiments described above, an air conditioning apparatus enables comfort to be improved.

Water circulates through the water circuit 4 of the air conditioning apparatuses according to the embodiments described above, but a heat medium different from water may circulate therethrough. Examples of the heat medium include antifreeze. Similarly to the air conditioning apparatuses according to the embodiments described above, even if a heat medium different from water circulates through a water circuit 4, an air conditioning apparatus enables comfort to be improved.

The air conditioning apparatuses according to the embodiments described above are provided with the plurality of indoor units 3-1 to 3-2 that blow air into the rooms, but the plurality of indoor units 3-1 to 3-2 may be replaced by other a plurality of terminals. Examples of these terminals include floor heating devices that heat the rooms by adjusting temperatures of the floors. In such a case also, similarly to the air conditioning apparatuses according to the first embodiment described above, an air conditioning apparatus enables comfort to be improved.

Embodiments have been described above, but the embodiments are not to be limited by what has been described above. Furthermore, the components described above include those readily supposed by persons skilled in the art, those that are substantially the same, and those of so-called equivalent scope. Furthermore, the components described above may be combined as appropriate. Furthermore, without departing from the gist of the embodiments, at least one of various omissions, substitutions, and modifications of the components may be made.

REFERENCE SIGNS LIST

• • 1 AIR CONDITIONER
  • 3-1 to 3-3 INDOOR UNITS
  • 4 WATER CIRCUIT (HEAT MEDIUM CIRCUIT)
  • 5 WATER-REFRIGERANT HEAT EXCHANGER (HEAT SOURCE DEVICE)
  • 6-1 TO 6-3 FLOW REGULATING VALVES
  • 7-1 TO 7-3 INDOOR HEAT EXCHANGERS
  • 8 PUMP
  • 14 REFRIGERANT CIRCUIT
  • 15 COMPRESSOR
  • 19 WATER-REFRIGERANT HEAT EXCHANGER (HEAT MEDIUM-REFRIGERANT HEAT EXCHANGER)
  • 23 OUTWARD TEMPERATURE SENSOR
  • 24 RETURN TEMPERATURE SENSOR
  • 25-1 TO 25-3 ROOM TEMPERATURE SENSORS
  • 26 PUMP
  • 26-1 TO 26-3 WATER TEMPERATURE SENSORS (HEAT MEDIUM TEMPERATURE DETECTION UNITS)
  • 28 OUTDOOR UNIT CONTROL DEVICE (CONTROL UNIT)
  • 37 PUMP TARGET FLOW RATE TABLE
  • 38 FLOW REGULATING VALVE TARGET FLOW RATE TABLE