Refrigerating cycle device and air conditioner

Abstract

A compressor for compressing a refrigerant containing a substance having a double bond, a condenser for condensing the refrigerant by heat exchange, expanding means for decompressing the condensed refrigerant, and an evaporator for evaporating the decompressed refrigerant by heat exchange are connected by piping so as to configure a refrigerant circuit through which the refrigerant is circulated, and control means is provided for controlling an operation of the refrigerant circuit so that a pressure of the refrigerant in the refrigerant circuit becomes less than a critical pressure of the substance having the double bond.

1 . A refrigerating cycle device, wherein
 a compressor for compressing a refrigerant containing a substance having a double bond;   a condenser for condensing said refrigerant by heat exchange;   expanding means for decompressing the condensed refrigerant; and   an evaporator for evaporating said decompressed refrigerant by heat exchange are connected by piping so as to constitute a refrigerant circuit through which said refrigerant is circulated, and   control means is provided for controlling an operation of said refrigerant circuit so that a pressure of said refrigerant in the refrigerant circuit becomes less than a critical pressure of said substance having the double bond to prevent said refrigerant from becoming a supercritical state to destroy the double bond of said refrigerant.   
     
     
         2 . A refrigerating cycle device, wherein
 a compressor for compressing a refrigerant containing a substance having a double bond;   a condenser for condensing said refrigerant by heat exchange;   expanding means for decompressing the condensed refrigerant; and   an evaporator for evaporating said decompressed refrigerant by heat exchange are connected by piping so as to constitute a refrigerant circuit through which said refrigerant is circulated, and   control means is provided for controlling operations of means constituting said refrigerant circuit so that a value of a pressure of said refrigerant in the refrigerant circuit becomes a pressure value or less set on the basis of the lowest critical pressure in the substance constituting said refrigerant.   
     
     
         3 . The refrigerating cycle device of  claim 1 , further comprising
 high-pressure side pressure detecting means disposed at a position anywhere in a flow passage from an outlet side of said compressor to an inlet of said expanding means and transmitting a signal on the basis of a detected pressure, wherein   said control means lowers a compressor frequency of said compressor or stops said compressor if said control means determines that the pressure value on the basis of a signal of said high-pressure side pressure detecting means is larger than a first pressure value.   
     
     
         4 . The refrigerating cycle device of  claim 1 , further comprising
 pressure storage means for storing values of a plurality of pressures relating to detection of said high-pressure side pressure detecting means for a predetermined period of time, wherein   said control means calculates a value of a pressure after the predetermined time on the basis of the values of said plurality of pressures as a forecast value, and if said control means judges that said forecast value is larger than a second pressure value, said control means controls operations of means constituting said refrigerant circuit.   
     
     
         5 . The refrigerating cycle device of  claim 1 , further comprising
 blowing means for blowing air to be heat-exchanged with said refrigerant to said condenser and/or said evaporator, wherein   said control means controls an operation of said blowing means.   
     
     
         6 . The refrigerating cycle device of  claim 1 , wherein
 in the refrigerating cycle device in which a plurality of said condensers are connected in parallel,   said control means controls operations of means constituting said refrigerant circuit so as to lower a pressure of the refrigerant in said refrigerant circuit before refrigerant supply to at least one of said condensers is stopped or substantially at the same time as the stop.   
     
     
         7 . The refrigerating cycle device of  claim 6 , wherein
 said control means lowers a compressor frequency in said compressor so as to lower the refrigerant pressure in said refrigerant circuit.   
     
     
         8 . The refrigerating cycle device of  claim 1 , wherein
 in the refrigerating cycle device in which a plurality of flow-rate control means including said expanding means for adjusting a flow rate of said refrigerant in said refrigerant circuit is disposed in said refrigerant circuit,   said control means executes control such that at least one of the flow-rate control means is opened if a space between at least two flow-rate control means is judged to be in a sealed state.   
     
     
         9 . The refrigerating cycle device of  claim 8 , wherein
 pressure detecting means for transmitting a signal on the basis of a detected pressure is disposed between said plurality of flow-rate control means; and   said control means judges a sealed state of said piping on the basis of the signal from the pressure detecting means between said flow-rate control means.   
     
     
         10 . The refrigerating cycle device of  claim 8 , wherein said control means executes control to open at least either of said flow-rate control means after a predetermined time has elapsed since the judgment of said sealed state. 
     
     
         11 . An air conditioner, wherein cooling/heating for a target space is performed by the refrigerating cycle device of  claim 1 . 
     
     
         12 . The refrigerating cycle device of  claim 2 , further comprising
 high-pressure side pressure detecting means disposed at a position anywhere in a flow passage from an outlet side of said compressor to an inlet of said expanding means and transmitting a signal on the basis of a detected pressure, wherein   said control means lowers a compressor frequency of said compressor or stops said compressor if said control means determines that the pressure value on the basis of a signal of said high-pressure side pressure detecting means is larger than a first pressure value.   
     
     
         13 . The refrigerating cycle device of  claims 2 , further comprising
 pressure storage means for storing values of a plurality of pressures relating to detection of said high-pressure side pressure detecting means for a predetermined period of time, wherein   said control means calculates a value of a pressure after the predetermined time on the basis of the values of said plurality of pressures as a forecast value, and if said control means judges that said forecast value is larger than a second pressure value, said control means controls operations of means constituting said refrigerant circuit.   
     
     
         14 . The refrigerating cycle device of  claim 2 , further comprising
 blowing means for blowing air to be heat-exchanged with said refrigerant to said condenser and/or said evaporator, wherein   said control means controls an operation of said blowing means.   
     
     
         15 . The refrigerating cycle device of  claim 2 , wherein
 in the refrigerating cycle device in which a plurality of said condensers are connected in parallel,   said control means controls operations of means constituting said refrigerant circuit so as to lower a pressure of the refrigerant in said refrigerant circuit before refrigerant supply to at least one of said condensers is stopped or substantially at the same time as the stop.   
     
     
         16 . The refrigerating cycle device of  claim 15 , wherein
 said control means lowers a compressor frequency in said compressor so as to lower the refrigerant pressure in said refrigerant circuit.   
     
     
         17 . The refrigerating cycle device of  claim 2 , wherein
 in the refrigerating cycle device in which a plurality of flow-rate control means including said expanding means for adjusting a flow rate of said refrigerant in said refrigerant circuit is disposed in said refrigerant circuit,   said control means executes control such that at least one of the flow-rate control means is opened if a space between at least two flow-rate control means is judged to be in a sealed state.   
     
     
         18 . The refrigerating cycle device of  claim 17 , wherein
 pressure detecting means for transmitting a signal on the basis of a detected pressure is disposed between said plurality of flow-rate control means; and   said control means judges a sealed state of said piping on the basis of the signal from the pressure detecting means between said flow-rate control means.   
     
     
         19 . The refrigerating cycle device of  claim 17 , wherein
 said control means executes control to open at least either of said flow-rate control means after a predetermined time has elapsed since the judgment of said sealed state.   
     
     
         20 . An air conditioner, wherein cooling/heating for a target space is performed by the refrigerating cycle device of  claim 2 .