Jet pump and air conditioner

Abstract

A jet pump includes a discharge outlet configured to discharge refrigerant in which relatively high pressure refrigerant and relatively low pressure refrigerant are mixed, a diffuser disposed coaxially with the discharge outlet in an upstream side of the discharge outlet, the diffuser including an inside diameter which gradually reduces in size away from the discharge outlet, a suction hole following from a minimum diameter portion of the diffuser in an upstream side of the minimum diameter portion, disposed coaxially with the discharge outlet, and to which the lower pressure refrigerant is guided, a high pressure refrigerant path configured to guide the high pressure refrigerant to the diffuser, and a nozzle portion configured to eject the high pressure refrigerant from the high pressure refrigerant path into the diffuser in a downstream side of the minimum diameter portion.

1 . A jet pump, comprising:
 a discharge outlet configured to discharge refrigerant in which relatively high pressure refrigerant and relatively low pressure refrigerant are mixed;   a diffuser disposed coaxially with the discharge outlet in an upstream side of the discharge outlet, the diffuser including an inside diameter which gradually reduces in size away from the discharge outlet;   a suction hole following from a minimum diameter portion of the diffuser in an upstream side of the minimum diameter portion, disposed coaxially with the discharge outlet, and to which the lower pressure refrigerant is guided;   a high pressure refrigerant path configured to guide the high pressure refrigerant to the diffuser; and   a nozzle portion configured to eject the high pressure refrigerant from the high pressure refrigerant path into the diffuser in a downstream side of the minimum diameter portion.   
     
     
         2 . The jet pump according to  claim 1 , comprising:
 a tubular nozzle outside member and a tubular nozzle inside member disposed inside the nozzle outside member in a radial direction, wherein   the discharge outlet is formed in one end portion of the nozzle outside member,   the suction hole is formed in the nozzle inside member, and   each of the high pressure refrigerant path and the nozzle portion is formed between the nozzle outside member and the nozzle inside member.   
     
     
         3 . The jet pump according to  claim 2 , wherein
 the nozzle inside member includes a nozzle tube section, and the nozzle portion is formed between the nozzle tube section and the nozzle outside member.   
     
     
         4 . The jet pump according to  claim 3 , wherein
 the nozzle portion includes a plurality of nozzle recesses disposed in a circumferential direction of the nozzle inside member.   
     
     
         5 . The jet pump according to  claim 4 , wherein
 the nozzle portion includes a convex portion which has contact with an inner circumference of the nozzle outside member and extends in a longitudinal direction of the nozzle tube section,   the nozzle recesses and the convex portion are alternately disposed in an outer circumferential face of the nozzle tube section in a circumferential direction, and   the nozzle recesses extend in an axial direction of the diffuser.   
     
     
         6 . The jet pump according to  claim 2 , wherein
 the diffuser includes a first diffuser formed in an inner face of the one end portion of the nozzle outside member and a second diffuser formed in an inner circumferential portion of a leading end of the nozzle inside member on the discharge outlet side, the second diffuser including a diameter which gradually reduces toward the suction hole from an opening of a leading end.   
     
     
         7 . The jet pump according to  claim 6 , wherein
 the nozzle portion ejects the high pressure refrigerant into the diffuser between the first diffuser and the second diffuser.   
     
     
         8 . The jet pump according to  claim 6 , wherein
 the nozzle inside member includes a nozzle tube section, and the nozzle portion is formed between the nozzle tube section and the nozzle outside member, and   the second diffuser is formed in an inner circumferential face of the nozzle tube section.   
     
     
         9 . The jet pump according to  claim 6 , wherein
 the nozzle inside member includes a nozzle tube section, and the nozzle portion is formed between the nozzle tube section and the nozzle outside member,   the nozzle outside member includes a tube insertion hole connected to a minimum diameter portion of the first diffuser, and   the nozzle tube section is inserted into the tube insertion hole, and the nozzle portion is formed between the nozzle tube section and an inner circumference of the tube insertion hole.   
     
     
         10 . The jet pump according to  claim 6 , wherein
 an angle of an inner circumference of the second diffuser relative to an axis of the diffuser is the same as an angle of an inner circumference of the first diffuser relative to an axis of the diffuser.   
     
     
         11 . The jet pump according to  claim 1 , wherein
 the diffuser includes in a position on the discharge outlet side of the nozzle portion an inlet portion having a constant inside diameter in an axial direction.   
     
     
         12 . The jet pump according to  claim 11 , wherein
 a length L 1  of the inlet portion in the axial direction satisfies a relationship of L 1 ≦3D where a diameter of the suction hole is D.   
     
     
         13 . An air conditioner having the jet pump according to  claim 1  disposed in a downstream side of an expansion value in a refrigerating cycle having a compressor, a condenser, the expansion valve, and an evaporator, comprising
 a first evaporator and a second evaporator as the evaporator, wherein 
 refrigerant which has passed through the expansion valve is branched into a first guiding branch and a second guiding branch, 
 the first guiding branch is connected to an entrance side of the first evaporator via a capillary, 
 an exit side of the first evaporator is connected to the suction hole of the jet pump, 
 the second guiding branch is connected to the high pressure refrigerant path of the jet pump, 
 the discharge outlet is connected to an entrance side of the second evaporator, 
 an exit side of the second evaporator is connected to an entrance side of the compressor, and 
 the refrigerant which has passed through the first evaporator is sucked into the diffuser from the suction hole by a driving flow formed by ejecting of the refrigerant which has passed through the expansion value into the diffuser from the nozzle portion.