Refrigerating apparatus using non-azeotropic mixed refrigerant

Abstract

A refrigerating apparatus using a non-azeotropic mixed refrigerant may include a compressor operable in a continuous operation mode and configured to compress the non-azeotropic mixed refrigerant, a condenser configured to condense the refrigerant compressed by the compressor, an expander configured to expand the refrigerant condensed by the condenser, and an evaporator configured to evaporate the refrigerant expanded by the expander. A pressure difference (ΔP) of the non-azeotropic mixed refrigerant has a value included in a range of 340 kPa<ΔP<624.7 kPa. Therefore, reliability of components, such as a piston, in the refrigerating apparatus using the non-azeotropic mixed refrigerant may be further improved.

1 . A refrigerating apparatus including a non-azeotropic mixed refrigerant, the refrigerating apparatus comprising:
 a compressor operable in a continuous operation mode and to compress the non-azeotropic mixed refrigerant;   a condenser to condense the non-azeotropic mixed refrigerant compressed by the compressor;   an expander to expand the non-azeotropic mixed refrigerant condensed by the condenser; and   an evaporator to evaporate the non-azeotropic mixed refrigerant expanded by the expander, wherein a pressure difference (ΔP) of the non-azeotropic mixed refrigerant is in a range of 340 kPa<ΔP<624.7 kPa.   
     
     
         2 . The refrigerating apparatus according to  claim 1 , wherein a condensing pressure (Pd) of the non-azeotropic mixed refrigerant is in a range of 393.4 kPa<Pd<745.3 kPa. 
     
     
         3 . The refrigerating apparatus according to  claim 1 , wherein an evaporation pressure (Ps) of the non-azeotropic mixed refrigerant is in a range of 53.5 kPa<Ps<120.5 kPa. 
     
     
         4 . The refrigerating apparatus according to  claim 1 , wherein, in the continuous operation mode, the compressor is controlled to operate even when an interior temperature of the refrigerating apparatus is in a target temperature range. 
     
     
         5 . The refrigerating apparatus according to  claim 1 , wherein the compressor comprises a linear compressor. 
     
     
         6 . The refrigerating apparatus according to  claim 5 , wherein the linear compressor comprises:
 a shell including a suction inlet;   a cylinder disposed in the shell to define a refrigerant compression space;   a frame coupled to an outer side of the cylinder;   a piston to reciprocate within the cylinder;   a discharge valve movably coupled to the cylinder to selectively discharge the non-azeotropic mixed refrigerant compressed in the refrigerant compression space; and   a passage that extends into a space between the cylinder and the frame and through which at least a portion of the non-azeotropic mixed refrigerant discharged from the discharge valve flows.   
     
     
         7 . The refrigerating apparatus according to  claim 6 , wherein the cylinder comprises:
 a cylinder body including at least one nozzle; and   
       a cylinder flange that extends radially outward from the cylinder body. 
     
     
         8 . The refrigerating apparatus according to  claim 7 , wherein the frame comprises:
 a frame body that surrounds the cylinder body;   a recessed portion which receives the cylinder flange; and   a seating portion that faces a seating surface of the cylinder flange.   
     
     
         9 . The refrigerating apparatus according to  claim 8 , wherein the passage comprises a first passage between an outer circumferential surface of the cylinder flange and an inner circumferential surface of the recessed portion. 
     
     
         10 . The refrigerating apparatus according to  claim 9 , wherein the passage comprises a second passage between the seating surface of the cylinder flange and a seating surface of the frame. 
     
     
         11 . The refrigerating apparatus according to  claim 10 , wherein the passage comprises a third passage that extends into a space between an outer circumferential surface of the cylinder body and an inner circumferential surface of the frame body. 
     
     
         12 . The refrigerating apparatus according to  claim 5 , wherein the linear compressor comprises:
 a cylinder including a cylinder stepped portion on an inner circumferential surface thereof;   a piston to reciprocate within the cylinder and including a piston stepped portion on an outer circumferential surface thereof, wherein a low pressure is formed between the piston stepped portion and the cylinder stepped portion when the piston moves in a first direction and a high pressure is formed between the piston stepped portion and the cylinder stepped portion when the piston moves in a second direction;   an oil suction passage to allow oil to flow between the cylinder stepped portion and the piston stepped portion; and   an oil discharge passage to allow the oil between the cylinder stepped portion and the piston stepped portion to be discharged outside of the cylinder.   
     
     
         13 . The refrigerating apparatus according to  claim 1 , wherein the non-azeotropic mixed refrigerant comprises a first hydrocarbon that is isobutane and a second hydrocarbon that is propane. 
     
     
         14 . The refrigerating apparatus according to  claim 13 , wherein the isobutane has a weight ratio of 76%≤isobutane≤87%. 
     
     
         15 . A refrigerating apparatus including a non-azeotropic mixed refrigerant, the refrigerating apparatus comprising:
 a linear compressor to compress the non-azeotropic mixed refrigerant;   a condenser to condense the non-azeotropic mixed refrigerant compressed by the compressor;   an expander to expand the non-azeotropic mixed refrigerant condensed by the condenser; and   an evaporator to evaporate the non-azeotropic mixed refrigerant expanded by the expander, wherein a pressure difference (ΔP) of the non-azeotropic mixed refrigerant is in a range of 340 kPa<ΔP<624.7 kPa.   
     
     
         16 . The refrigerating apparatus according to  claim 15 , wherein the linear compressor comprises:
 a piston that reciprocates; and   a cylinder to guide the piston, wherein the non-azeotropic mixed refrigerant of high pressure compressed by the piston is guided to an inner surface of the cylinder to cause an outer surface of the piston to be spaced from the inner surface of the cylinder.   
     
     
         17 . The refrigerating apparatus according to  claim 15 , wherein the non-azeotropic mixed refrigerant comprises at least two hydrocarbons, the at least two hydrocarbons comprising:
 at least one first hydrocarbon having an evaporation temperature of −12° C. or more at 1 bar; and   at least one second hydrocarbon having an evaporation temperature of −50° C. or more and less than −12° C. at 1 bar, and wherein a gliding temperature difference is 4° C. or more.   
     
     
         18 . The refrigerating apparatus according to  claim 17 , wherein a weight ratio of the at least one first hydrocarbon is 50% or more. 
     
     
         19 . The refrigerating apparatus according to  claim 15 , wherein the linear compressor comprises:
 a piston that reciprocates to compress the non-azeotropic mixed refrigerant; and   a cylinder to guide the piston, wherein oil pumped by a pressure difference of the non-azeotropic mixed refrigerant is present at contact surfaces between the piston and the cylinder.   
     
     
         20 . A refrigerating apparatus including a non-azeotropic mixed refrigerant, the refrigerating apparatus comprising:
 a compressor to compress the non-azeotropic mixed refrigerant;   a condenser to condense the non-azeotropic mixed refrigerant compressed by the compressor;   an expander to expand the non-azeotropic mixed refrigerant condensed by the condenser; and   an evaporator to evaporate the non-azeotropic mixed refrigerant expanded by the expander and to provide cold air to an inner space of the refrigerating apparatus, wherein the compressor is selectively operable in an intermittent operation mode and a continuous operation mode, and wherein in the continuous operation mode, the compressor is controlled to operate continuously even when a temperature of the inner space of the refrigerating apparatus is within a target temperature range.