Expansion device and refrigeration cycle apparatus

Abstract

Provided is an expansion device configured to form a refrigerant circuit using refrigerant containing a substance having such a property as to cause a disproportionation reaction, the expansion device including: a valve body having a cylindrical shape; and an expansion unit including a valve seat, the expansion unit being configured to vary an opening area by insertion of the valve body into the valve seat through movement of the valve body in an axial direction thereof, in which: a distal end portion of the valve body to be inserted into the expansion unit is formed to have an angle larger than 0 from a direction perpendicular to the axial direction of the valve body.

1 . An expansion device configured to form part of a refrigerant circuit circulating refrigerant, the expansion device comprising:
 a valve body having a cylindrical shape; and   an expansion unit including a valve seat, the expansion unit being configured to vary an opening area, through which a refrigerant mixture containing HFO-1123 passes, by insertion of the valve body into the valve seat through movement of the valve body in a valve axis direction,   wherein a distal end portion of the valve body to be inserted into the expansion unit is formed to have an angle larger than 0 from a direction perpendicular to the axial direction of the valve body.   
     
     
         2 . The expansion device of  claim 1 , wherein the distal end portion of the valve body has a conical shape or a polyhedral shape. 
     
     
         3 . The expansion device of  claim 1 , wherein the valve body is moved while rotating to vary the opening area. 
     
     
         4 . The expansion device of  claim 1 , wherein the angle is equal to or larger than 18 degrees. 
     
     
         5 . The expansion device of  claim 1 , wherein, when the angle is θ, cos(θ) is equal to or smaller than 0.95. 
     
     
         6 . (canceled) 
     
     
         7 . A refrigeration cycle apparatus, comprising a compressor, a first heat exchanger, the expansion device of  claim 1 , and a second heat exchanger connected by a refrigerant pipe to form a refrigerant circuit. 
     
     
         8 . The refrigeration cycle apparatus of  claim 7 , wherein refrigerant in a liquid state or refrigerant in a two-phase state is caused to flow into the expansion device. 
     
     
         9 . The refrigeration cycle apparatus of  claim 7 , wherein the refrigerant circuit is configured so that a direction of the refrigerant flowing through the expansion device in a case where the second heat exchanger acts as a condenser and a direction of the refrigerant flowing through the expansion device in a case where the second heat exchanger acts as an evaporator are opposite to each other. 
     
     
         10 . The refrigeration cycle apparatus of  claim 9 , wherein
 the expansion device has a structure in which an inflow direction of the refrigerant and an outflow direction of the refrigerant are approximately perpendicular to each other, and   the refrigerant is caused to flow into the expansion device in the axial direction of the valve body in any of the case where the second heat exchanger acts as the condenser and the case where the second heat exchanger acts as the evaporator.   
     
     
         11 . The refrigeration cycle apparatus of  claim 9 , wherein:
 the expansion device has a structure in which an inflow direction of the refrigerant and an outflow direction of the refrigerant are approximately perpendicular to each other; and   the refrigerant is caused to flow into the expansion device in the axial direction of the valve body when the second heat exchanger is caused to act as the evaporator and is caused to flow into the expansion device in a direction perpendicular to the axial direction of the valve body when the second heat exchanger is caused to act as the condenser.   
     
     
         12 . The refrigeration cycle apparatus of  claim 7 , further comprising:
 a plurality of indoor units, each configured to air-condition a space to be air-conditioned; and   one or a plurality of outdoor units.   
     
     
         13 . The refrigeration cycle apparatus of  claim 7 , wherein:
 the expansion device and the second heat exchanger are accommodated in each of a plurality of indoor units; and   the refrigerant is caused to flow into the expansion device in a direction perpendicular to the axial direction of the valve body when the second heat exchanger is caused to act as the condenser.   
     
     
         14 . The refrigeration cycle apparatus of  claim 7 , wherein the expansion device and the second heat exchanger are accommodated in a heat medium relay unit installable as a body independent of the one or a plurality of outdoor units and a plurality of indoor units at a position away from the one or the plurality of outdoor units and the plurality of indoor units.