Air-Conditioning/Hot-Water Supply System

Abstract

Provided is an air-conditioning/hot-water supply system having high operational efficiency. An internal heat exchanger ( 15 ) has: a primary heat transfer pipe ( 15 a ) for forming a part of the annular circuit of a refrigerant circuit ( 10 ) for air conditioning; and a secondary heat transfer pipe ( 15 b ) connected to piping (P) branched from the annular circuit through a pressure reduction device ( 16 ). The pressure reduction device ( 16 ) reduces the pressure of a first refrigerant flowing therein from the piping (P) depending on an operation mode and causes the first refrigerant, the pressure of which has been reduced, to flow toward the secondary heat transfer pipe ( 15 b ), thereby cooling the first refrigerant flowing through the primary heat transfer pipe ( 15 a ).

1 - 4 . (canceled) 
     
     
         5 . An air-conditioning/hot-water supply system comprising,
 a refrigerant circuit for air conditioning in which a first refrigerant circulates,   a refrigerant circuit for hot-water supply in which a second refrigerant circulates, and   a control device;   wherein   the refrigerant circuit for air conditioning includes a loop circuit in which a compressor for air conditioning, a four-way valve, an air-conditioning heat-source side heat exchanger, a first expansion valve, an intermediate heat exchanger capable of exchanging heat between the first refrigerant and the second refrigerant, an inside heat exchanger capable of cooling the first refrigerant, a second expansion valve, and an air-conditioned side heat exchanger are connected in order;
 the inside heat exchanger includes, 
 a primary-side heat transfer pipe constituting a portion of the loop circuit, and 
 a secondary-side heat transfer pipe connected to a branch pipe arrangement which branches off from the loop circuit through a decompression device; 
 when a cooling operation is performed, the control device controls the four-way valve such that the air-conditioning heat-source side heat exchanger functions as a condenser and the air-conditioned side heat exchanger functions as an evaporator, and causes the first refrigerant to be cooled in the inside heat exchanger, undergo pressure reduction in the second expansion valve, and flow into the air-conditioned side heat exchanger; and 
 when a heating operation is performed, the control device controls the four-way valve such that the air-conditioned side heat exchanger functions as a condenser and the air-conditioning heat-source side heat exchanger functions as an evaporator, and causes the first refrigerant to undergo pressure reduction in the second expansion valve and the first expansion valve in succession, and flow into the air-conditioning heat-source side heat exchanger. 
   
     
     
         6 . The air-conditioning/hot-water supply system according to  claim 5 , further comprising a plurality of indoor units each including the second expansion valve and the air-conditioned side heat exchanger, which is connected in series to the second expansion valve, where the plurality of indoor units are connected in parallel. 
     
     
         7 . The air-conditioning/hot-water supply system according to  claim 5 , wherein the decompression device is an expansion valve or a capillary tube. 
     
     
         8 . The air-conditioning/hot-water supply system according to  claim 7 , further comprising,
 a bypass pipe arrangement which connects a pipe arrangement connecting the primary-side heat transfer pipe in the inside heat exchanger and the second expansion valve and a pipe arrangement arranged on a discharge side of the compressor for air conditioning, and   an open-close means for causing the first refrigerant flowing out of the compressor for air conditioning to flow into the primary-side heat transfer pipe in the inside heat exchanger through the bypass pipe arrangement in a hot-water-supply operation mode.   
     
     
         9 . The air-conditioning/hot-water supply system according to  claim 5 , wherein, in a normal heating operation mode in which a heating operation is performed and a hot-water supply operation is not performed, the control device causes the first refrigerant having a pressure reduced in the second expansion valve to be cooled in the inside heat exchanger, further undergo pressure reduction in the first expansion valve, and flow into the air-conditioning heat-source side heat exchanger. 
     
     
         10 . The air-conditioning/hot-water supply system according to  claim 5 , wherein, in a heating-operation exhaust heat mode in which exhaust heat occurring in a heating operation is used for a hot-water supply operation, pressure reduction by the decompression device is not performed on the first refrigerant.