Air conditioning apparatus

Abstract

An air conditioning apparatus has a refrigerant circuit configured as a result of plural indoor units being connected to an outdoor unit, and the air conditioning apparatus has a capacity controlling part and a target refrigerant temperature changing part. The capacity controlling part controls the air conditioning capacity of the outdoor unit in such a way that the evaporation or condensation temperature of refrigerant in the refrigerant circuit becomes a target evaporation or condensation temperature. The target refrigerant temperature changing part performs slow changing control that changes the target evaporation or condensation temperature in accordance with temperature differences between room and set temperatures and, in a case where the temperature differences have exceeded a threshold temperature difference and the number of the indoor units in operation has increased, performs fast changing control that forcibly changes the target evaporation or condensation temperature to a fast tracking evaporation or condensation temperature.

1 . An air conditioning apparatus equipped with a refrigerant circuit configured as a result of plural indoor units being connected to an outdoor unit, the air conditioning apparatus comprising:
 a capacity controlling part that controls an air conditioning capacity of the outdoor unit in such a way that an evaporation temperature or a condensation temperature of refrigerant in the refrigerant circuit becomes a target evaporation temperature or a target condensation temperature; and   a target refrigerant temperature changing part that performs slow changing control that changes the target evaporation temperature or the target condensation temperature in accordance with temperature differences between room temperatures of air conditioned spaces targeted by the indoor units and set temperatures that are target values of the room temperatures and, in a case where the temperature differences have exceeded a threshold temperature difference and the number of the indoor units in operation has increased, performs fast changing control that forcibly changes the target evaporation temperature or the target condensation temperature to a fast tracking evaporation temperature or a fast tracking condensation temperature.   
     
     
         2 . The air conditioning apparatus according to  claim 1 , wherein
 the air conditioning apparatus uses, as a condition for changing the target evaporation temperature or the target condensation temperature, a maximum value of the temperature differences between the room temperatures and the set temperatures among the indoor units in operation.   
     
     
         3 . The air conditioning apparatus according to  claim 1 , wherein
 the target refrigerant temperature changing part determines whether or not the slow changing control is necessary every time a first amount of waiting time passes and determines whether or not the fast changing control is necessary every time a second amount of waiting time shorter than the first amount of waiting time passes.   
     
     
         4 . The air conditioning apparatus according to  claim 1 , wherein
 the fast changing control has   powerful changing control by which the fast tracking evaporation temperature or the fast tracking condensation temperature is changed to a lowest evaporation temperature or a highest condensation temperature exceeding a maximum capacity evaporation temperature or a maximum capacity condensation temperature corresponding to a case where the air conditioning capacity of the outdoor unit is at 100% capacity and   quick changing control by which the fast tracking evaporation temperature or the fast tracking condensation temperature is changed to the maximum capacity evaporation temperature or the maximum capacity condensation temperature.