Air-conditioning apparatus

Abstract

An air-conditioning apparatus includes a heat medium temperature adjustment operation mode in which when the temperature of a heat medium falls outside a predetermined temperature range while a compressor and a pump are kept stopped, the compressor and the pump are driven to cause an intermediate heat exchanger to exchange heat between a refrigerant and the heat medium so that the heat medium is heated or cooled to have a temperature that falls within the temperature range.

1 . An air-conditioning apparatus including
 a refrigeration cycle circuit including a compressor, a heat source side heat exchanger, at least one expansion valve, and a plurality of intermediate heat exchangers connected to one another via refrigerant pipes, the intermediate heat exchangers being configured to exchange heat between a refrigerant and a heat medium, and   a heat medium circulation circuit including the intermediate heat exchangers, a pump configured to convey the heat medium, and a plurality of use side heat exchangers, each use side heat exchanger being connected to the intermediate heat exchangers and the pump via heat medium pipes to form the heat medium circulation circuit in which the plurality of use side heat exchangers are parallel to each other,   wherein the apparatus is provided with   a heat medium temperature adjustment operation mode in which when a temperature of the heat medium falls outside a predetermined temperature range while the compressor and the pump are kept stopped, the compressor and the pump are driven to cause the intermediate heat exchangers to exchange heat between the refrigerant and the heat medium so that the heat medium is heated or cooled to have a temperature that falls within the predetermined temperature range;   the apparatus comprising:   a temperature sensor configured to detect the temperature of the heat medium;   a control device configured to control the compressor and the pump based on at least a detection result obtained by the temperature sensor to perform the heat medium temperature adjustment operation mode; and   a plurality of channel switching valves located in portions of the heat medium circulation circuit corresponding to an inlet and an outlet of the heat medium in each of the plurality of the use side heat exchangers, and configured to switch a passage of the heat medium having passed through the plurality of intermediate heat exchangers to one of the plurality of use side heat exchangers,   wherein the control device controls the channel switching valve such that the heat medium is supplied from at least two of the plurality of intermediate heat exchangers to the corresponding ones of the plurality of use side heat exchangers, and mixes, through the channel switching valve, a stream of the heat medium supplied from one of the plurality of intermediate heat exchangers to the corresponding one of the plurality of use side heat exchangers with a stream of the heat medium supplied from another one of the plurality of intermediate heat exchangers to the corresponding one of the plurality of use side heat exchangers, and   the control device performs at least one of   a control operation in which when the detection result obtained by the temperature sensor is higher than the temperature range, the control device causes a corresponding one of the plurality of intermediate heat exchangers to function as an evaporator and cools the heat medium passing through a corresponding one of the plurality of intermediate heat exchangers, and   a control operation in which when the detection result obtained by the temperature sensor is lower than the temperature range, the control device causes a corresponding one of the plurality of intermediate heat exchangers to function as a radiator and heats the heat medium passing through a corresponding one of the plurality of intermediate heat exchangers.   
     
     
         2 - 3 . (canceled) 
     
     
         4 . The air-conditioning apparatus of  claim 1 , wherein
 when the detection result obtained by the temperature sensor a predetermined time after driving of the compressor and the pump is higher than a temperature obtained by adding an antihunting constant to a lower limit of the temperature range and is not higher than an upper limit of the temperature range, the control device stops the compressor and the pump.   
     
     
         5 . (canceled) 
     
     
         6 . The air-conditioning apparatus of  claim 1 , wherein
 when the detection result obtained by the temperature sensor a predetermined time after driving of the compressor and the pump is lower than a temperature obtained by subtracting an antihunting constant from an upper limit of the temperature range and is not lower than a lower limit of the temperature range, the control device stops the compressor and the pump.   
     
     
         7 . The air-conditioning apparatus of  claim 1 , wherein
 the control device   opens the channel switching valve to ensure a circulation channel of the heat medium before or concurrently with driving of the pump, and   causes the heat medium to circulate between at least one of the plurality of intermediate heat exchangers and a corresponding one of the plurality of use side heat exchangers.   
     
     
         8 . The air-conditioning apparatus of  claim 1 , further comprising:
 an outdoor-air temperature sensor configured to detect an outdoor-air temperature, wherein   the control device   calculates an average temperature of outdoor air in a predetermined period of time based on a detection result obtained by the outdoor-air temperature sensor, and   determines an upper limit and a lower limit of the temperature range based on the calculated average temperature.