Accumulator and refrigeration cycle apparatus

Abstract

An accumulator includes a container where refrigerant is accumulated, an inflow pipe for flow of refrigerant into the container, an outflow pipe for flow of refrigerant out of the container, an oil return portion provided with an opening for suction of oil, and a decompressing pipe to decompress refrigerant. In the accumulator, the decompressing pipe and the oil return portion are arranged on the outflow pipe.

1 . An accumulator provided between an evaporator of a refrigeration cycle apparatus and a refrigerant suction side of a compressor of the refrigeration cycle apparatus, the accumulator comprising:
 a container where refrigerant is accumulated;   an inflow pipe for flow of refrigerant into the container;   an outflow pipe for flow of refrigerant out of the container;   an oil return portion provided with an opening for suction of oil; and   a decompressing apparatus to decompress refrigerant, wherein   the decompressing apparatus and the oil return portion are arranged on the outflow pipe in the container.   
     
     
         2 . The accumulator according to  claim 1 , wherein
 the decompressing apparatus is composed of a decompressing pipe smaller in diameter than the outflow pipe, and   the decompressing pipe and the oil return portion are arranged in an order of the decompressing pipe and the oil return portion on the outflow pipe in a direction of flow of refrigerant.   
     
     
         3 . The accumulator according to  claim 1 , wherein
 the oil return portion comprises a first oil return portion and a second oil return portion,   the decompressing apparatus is composed of a decompressing pipe smaller in diameter than the outflow pipe, and   the first oil return portion, the second oil return portion, and the decompressing pipe are arranged in an order of the first oil return portion, the decompressing pipe, and the second oil return portion on the outflow pipe in a direction of flow of refrigerant.   
     
     
         4 . The accumulator according to  claim 1 , wherein
 the decompressing apparatus is composed of a second expansion valve an opening of which is adjustable, and   the second expansion valve and the oil return portion are arranged in an order of the second expansion valve and the oil return portion on the outflow pipe in a direction of flow of refrigerant.   
     
     
         5 . A refrigeration cycle apparatus comprising:
 the accumulator according to claim  4 ;   the compressor;   a first heat exchanger;   a second heat exchanger;   a first expansion valve;   a first sensor to measure a discharge superheat of refrigerant discharged from the compressor; and   a control device to control an opening of the second expansion valve, wherein   when the second heat exchanger functions as the evaporator, refrigerant sequentially flows through the compressor, the first heat exchanger, the first expansion valve, the second heat exchanger, and the accumulator, and   the control device controls the opening of the second expansion valve in accordance with the discharge superheat of refrigerant calculated from a value obtained by the first sensor.   
     
     
         6 . A refrigeration cycle apparatus comprising:
 the accumulator according to claim  4 ;   the compressor;   a first heat exchanger;   a second heat exchanger;   a first expansion valve;   a second sensor to measure a state of oil in the compressor; and   a control device to control an opening of the second expansion valve, wherein   when the second heat exchanger functions as the evaporator, refrigerant sequentially flows through the compressor, the first heat exchanger, the first expansion valve, the second heat exchanger, and the accumulator, and   the control device controls the opening of the second expansion valve in accordance with the state of oil detected by the second sensor.   
     
     
         7 . A refrigeration cycle apparatus comprising:
 the accumulator according to claim  4 ;   the compressor;   a first heat exchanger;   a second heat exchanger;   a first expansion valve;   a third sensor to measure a suction superheat of refrigerant that flows into the accumulator; and   a control device to control an opening of the first expansion valve and the second expansion valve, wherein   when the second heat exchanger functions as the evaporator, refrigerant sequentially flows through the compressor, the first heat exchanger, the first expansion valve, the second heat exchanger, and the accumulator, and   after the control device receives a signal to stop the compressor, the control device increases the opening of the second expansion valve as compared with the opening before the compressor is stopped, and controls the opening of the first expansion valve in accordance with the suction superheat of refrigerant calculated from a value obtained by the third sensor.   
     
     
         8 . A refrigeration cycle apparatus comprising:
 the accumulator according to  claim 1 ;   the compressor;   a first heat exchanger;   a second heat exchanger; and   a first expansion valve, wherein   when the second heat exchanger functions as the evaporator, refrigerant sequentially flows through the compressor, the first heat exchanger, the first expansion valve, the second heat exchanger, and the accumulator.