Air-conditioning apparatus

Abstract

An air-conditioning apparatus includes a heat source-side unit including a compressor that compresses a refrigerant and a heat source-side heat exchanger, a plurality of use-side units each including a use-side heat exchanger, and a plurality of intermediate heat exchangers connected to the heat source-side unit and to the use-side units. A target determination device detects condensation status of each of the use-side units and determines whether to perform condensation suppression control. The use-side unit determined by the target determination means to be subjected to the condensation suppression control is connected to an intermediate heat exchanger for adjustment. A refrigerant circuit control device controls a temperature of the refrigerant flowing into the intermediate heat exchanger for adjustment so that the heat medium temperature T of the heat medium flowing into at least one use-side unit enters a predetermined target set temperature range.

1 . An air-conditioning apparatus comprising:
 a heat source-side unit including a compressor that compresses a refrigerant and a heat source-side heat exchanger that exchanges heat between air and the refrigerant;   a plurality of use-side units each including a use-side heat exchanger that exchanges heat between air and a heat medium;   a plurality of intermediate heat exchangers connected to the heat source-side unit via a refrigerant pipe and connected to the use-side units via a heat medium pipe, and configured to exchange heat between the refrigerant and the heat medium;   a heat medium flow switching device configured to switch combinations of connection between each of the use-side units and a corresponding one of the intermediate heat exchangers;   a target determination device configured to detect a condensation state of each of the use-side units and determine whether to perform condensation suppression control for suppressing condensation with respect to each of the use-side units;   a temperature sensor configured to detect, as a heat medium temperature, a temperature of the heat medium flowing into at least one use-side unit of the use-side units determined by the target determination device to be subjected to the condensation suppression control;   a heat medium circuit control device configured to control the heat medium flow switching device so as to connect the at least one use-side unit of the use-side units determined by the target determination device to be subjected to the condensation suppression control to an intermediate heat exchanger for adjustment assigned for the condensation suppression control among the plurality of intermediate heat exchangers; and   a refrigerant circuit control device configured to control a temperature of the refrigerant flowing into the intermediate heat exchanger for adjustment so that the heat medium temperature detected by the temperature sensor falls within a predetermined target set temperature range.   
     
     
         2 . The air-conditioning apparatus of  claim 1 , further comprising a refrigerant expansion device configured to expand or depressurize the refrigerant flowing into the intermediate heat exchanger for adjustment,
 wherein the refrigerant circuit control device controls the temperature of the refrigerant by controlling an amount of expansion of the refrigerant expansion device.   
     
     
         3 . The air-conditioning apparatus of  claim 2 ,
 wherein the refrigerant circuit control device controls the refrigerant expansion device so as to keep the heat medium temperature within the target set temperature range, when the heat medium temperature is within the target set temperature range.   
     
     
         4 . The air-conditioning apparatus of  claim 1 ,
 wherein the heat source-side unit is configured to perform a heating operation and a cooling operation,   the air-conditioning apparatus further comprises a refrigerant flow switching device configured to switch a flow path of the refrigerant flowing into the intermediate heat exchanger for adjustment to a heating flow path for the heating operation and to a cooling flow path for the cooling operation, and   the refrigerant circuit control device controls the temperature of the refrigerant flowing into the intermediate heat exchanger for adjustment by causing the refrigerant flow switching device to switch the flow path of the intermediate heat exchanger for adjustment.   
     
     
         5 . The air-conditioning apparatus of  claim 4 ,
 wherein the refrigerant circuit control device causes the refrigerant flow switching device to set the flow path of the refrigerant flowing into the intermediate heat exchanger for adjustment to the heating flow path when the heat medium temperature is lower than the target set temperature range.   
     
     
         6 . The air-conditioning apparatus of  claim 4 ,
 wherein the refrigerant circuit control device causes the refrigerant flow switching device to set the flow path of the refrigerant flowing into the intermediate heat exchanger for adjustment to the cooling flow path when the heat medium temperature is higher than the target set temperature range.   
     
     
         7 . The air-conditioning apparatus of  claim 1 , further comprising:
 an inlet temperature sensor configured to detect a temperature of air sucked into each of the use-side units; and   an inlet humidity sensor configured to detect humidity of the air sucked into each of the use-side units,   wherein the target determination device detects the condensation status on a basis of the inlet temperature detected by the inlet temperature sensor and the inlet humidity detected by the inlet humidity sensor, so as to determine whether to perform the condensation suppression control.   
     
     
         8 . The air-conditioning apparatus of  claim 1 , further comprising:
 an inlet temperature sensor configured to detect a temperature of air sucked into each of the use-side unit;   an inlet humidity sensor configured to detect humidity of the air sucked into each of the use-side unit; and   a dew point calculation device configured to calculate a dew point on a basis of the inlet temperature detected by the inlet temperature sensor and the inlet humidity detected by the inlet humidity sensor,   wherein the refrigerant circuit control device sets the predetermined target set temperature range on a basis of the dew point calculated by the dew point calculation device.   
     
     
         9 . The air-conditioning apparatus of  claim 8 ,
 wherein the refrigerant circuit control device detects a maximum dew point which is a highest dew point among the dew points of the at least one use-side unit of the use-side units determined to be subjected to the condensation suppression control, and sets the predetermined target set temperature range on a basis of the detected maximum dew point.   
     
     
         10 . The air-conditioning apparatus of  claim 1 , further comprising:
 a flow rate control device configured to control a flow rate of the heat medium flowing through the intermediate heat exchanger for adjustment and the use-side units,   wherein the heat medium circuit control device is configured to control the flow rate control device, and   controls the flow rate control device so that the heat medium temperature falls within the predetermined target set temperature range.