Heat pump apparatus and operation method for heat pump apparatus

Abstract

This description relates to a heat pump and a method of using the heat pump. The heat pump includes a hydraulic compressor that compresses a heat medium, an oil separation and recovery device that separates oil from the heat medium discharged from the compressor and returns the separated oil to the compressor, a condenser that liquefies the heat medium compressed in the compressor, a decompression device that decompresses the heat medium liquefied in the condenser, and an evaporator that causes the heat medium to absorb heat. An intake temperature control, unit capable of controlling the temperature of the heat medium taken into the compressor is on the intake side of the compressor.

1 . A heat pump apparatus in which a hydraulic compressor that compresses gas to be compressed that is at a temperature equal to or higher than a normal temperature, an oil separation and recovery device that separates oil from the gas discharged from the compressor and returns the separated oil to the compressor, a condenser that liquefies the gas compressed in the compressor for heat dissipation, a decompression device that decompresses the gas liquefied in the condenser, and an evaporator that causes the liquefied gas decompressed in the decompression device to absorb heat and be evaporated are connected in series in a gas circulation path and the gas is circulated in those devices,
 wherein a hydrocarbon converted into a gaseous state by heating is used as the gas to be compressed that is taken into the compressor, a temperature sensor detects a discharge temperature and the compressor is set to be capable of compressing the gas at a compression ratio at which the discharge temperature becomes 150 to 200° C.,   the heat pump apparatus further comprising:   a heat exchanger provided at the intake side of the compressor,   a heating unit for heating the gas,   a bypass circuit formed to bypass the heat exchanger; and   an intake temperature control unit which controls the temperature of the hydrocarbon taken into the compressor by adjusting operation of the heat exchanger and adjusting a bypass amount of the bypass circuit,   wherein the heating control of the heating unit is performed by the intake temperature control unit so that the hydrocarbon is controlled by heating to a gaseous state.   
     
     
         2 . The heat pump apparatus according to  claim 1 , wherein the gas to be compressed is a C4-C7 hydrocarbon refrigerant, and the hydrocarbon is heated by the intake temperature control unit to a temperature of 60 to 100° C. and used as the gas to be taken into the compressor. 
     
     
         3 . The heat pump apparatus according to  claim 1 , comprising:
 a temperature sensor which detects the discharge temperature of the compressor, wherein   a command is issued to the intake temperature control unit and the intake temperature of the hydrocarbon taken into the compressor is controlled so that a target temperature of the temperature sensor is set to 150 to 200° C. and a detected value of the temperature sensor is the target temperature.   
     
     
         4 . The heat pump apparatus according to  claim 1 ,
 wherein the heat pump apparatus further comprises a bypass valve of which an opening degree is adjusted and provided at the bypass circuit and   wherein the hydrocarbon taken into the compressor is controlled by heating to be in a gaseous state by adjusting the opening degree of the bypass valve.   
     
     
         5 . An operation method for a heat pump apparatus in which a hydraulic compressor that compresses a gas to be compressed that is at a temperature equal to or higher than a normal temperature, an oil separation and recovery device that separates oil from the gas discharged from the compressor and returns the separated oil to the compressor, a condenser that liquefies the gas compressed in the compressor for heat dissipation, a decompression device that decompresses the gas liquefied in the condenser, and an evaporator that causes the liquefied gas decompressed in the decompression device to absorb heat and be evaporated are connected in series in a gas circulation path and the gas is circulated in those devices,
 wherein a hydrocarbon converted into a gaseous state by heating is used as the gas to be compressed that is taken into the compressor, a temperature sensor detects a discharge temperature of the gas or a part having a temperature equal to the discharge temperature and the compressor is set to be capable of compressing the gas at a compression ratio at which a discharge temperature becomes 150 to 200° C., and   wherein controlling by heating performed by means of   a heat exchanger provided at the intake side of the compressor, a bypass circuit formed to bypass the heat exchanger, and a heating unit for heating the gas, adjustment of operation of the heat exchanger and adjustment of a bypass amount of the bypass circuit are performed and the temperature of the hydrocarbon taken into the compressor is controlled by heating to maintain the hydrocarbon in a gaseous state.   
     
     
         6 . The operation method for a heat pump apparatus according to  claim 5 , wherein the hydrocarbon is heated by the heating unit to a temperature equal to or higher than a boiling point at an intake pressure of the compressor before the compressor is operated.