3 stage cooling and defrosting system using quick-freezing chamber, freezing chamber, and refrigerating chamber

Abstract

The present invention relates to a system for cooling a quick-freezing chamber at −40 to −30° C., a freezing chamber at −20 to −15° C., a refrigerating chamber at 0 to 5° C., and the like and an energy-saving defrosting system for defrosting the quick-freezing chamber, the freezing chamber, and the refrigerating chamber using condensed waste heat.

1 . A 3 stage cooling and energy saving defrosting system using −40˜-30° C. of quick-freezing chamber, −20˜-15° C. of freezing chamber, and 0˜5° C. of refrigerating chamber, comprising the 3 stage cooling steps of:
 1) −40˜-30° C. of quick-freezing step in quick-freezing chamber, wherein the liquid phase refrigerant sprayed from electronic valve (S 3 ) away from condenser after 2 step compression is evaporated and then the ultra lower temperature of liquid phase refrigerant sequentially is further evaporated until the quick-freezing chamber to be lower than −40° C.; 
 2) −20˜-15° C. of freezing step in freezing chamber, wherein the refrigerant injected from electronic valve (R 1 ) after recovery from quick-freezing chamber is evaporated after closing electronic valve (V 1 ), and the liquid phase refrigerant sprayed from electronic valve (S 2 ) away from condenser can be further evaporated until the freezing chamber to be −20° C.; and 
 3) 0˜5° C. of refrigerating step in refrigerating chamber, wherein the refrigerant injected from electronic valve (R 2 ) after recovery from quick-freezing chamber and/or freezing chamber is evaporated after closing electronic valve (V 2 ), and the liquid phase refrigerant sprayed from electronic valve (S 1 ) away from condenser can be further evaporated until the refrigerating chamber to be 0° C. 
 
     
     
         2 . The 3 stage cooling and defrosting system according to  claim 1 , wherein the structure of 3 stage cooling system comprises
 1) a multi ( 2 ) step compressor comprising a lower step compressor for compressing the vapor phase refrigerant to be medium pressure, an inter-cooler for cooling the refrigerant until the saturation temperature corresponding to medium pressure, and a higher step compressor for compressing the cooled refrigerant to be high pressure and high temperature of vapor phase refrigerant;   2) a condenser for condensing the high pressure and high temperature vapor phase refrigerant from compressor to be liquid phase refrigerant;   3) a quick-freezing evaporator for quick-freezing the chamber using liquid phase refrigerant from condenser;   4) a freezing evaporator for freezing the chamber using liquid phase refrigerant from condenser and/or vapor phase refrigerant recovered from quick-freezing chamber; and   5) a refrigerating evaporator for refrigerating the chamber using liquid phase refrigerant from condenser and/or vapor phase refrigerant recovered from quick-freezing chamber and/or freezing chamber.   
     
     
         3 . The 3 stage cooling and defrosting system according to  claim 1 , wherein said 3 stage cooling system comprising the steps of:
 1) −40˜-30° C. of quick-freezing step in quick-freezing chamber, wherein the low temperature of liquid phase refrigerant sprayed from expansion valve ( 1 ) passing through electronic valve (a, b) away from condenser after 2 step compression is evaporated until the quick-freezing chamber to be −25° C., and then the ultra lower temperature of liquid phase refrigerant sprayed from expansion valve ( 2 ) sequentially is evaporated until the quick-freezing chamber to be lower than −40° C.;   2) −20˜-15° C. of freezing step in freezing chamber, wherein the vapor phase refrigerant injected from electronic valve ( 7 ) after recovery from quick-freezing chamber is evaporated, and the low temperature of liquid phase refrigerant sprayed from electronic valve ( 4 ) passing through electronic valve (c, d) away from condenser is evaporated until the freezing chamber to be −20° C.; and   3) 0˜5° C. of refrigerating step in refrigerating chamber, wherein the vapor phase refrigerant injected from electronic valve ( 8 ) after recovery from quick-freezing chamber and/or freezing chamber is evaporated, and the low temperature of liquid phase refrigerant sprayed from electronic valve (e, f) away from condenser is evaporated until the refrigerating chamber to be 0° C.   
     
     
         4 . The 3 stage cooling and defrosting system according to  claim 3 , wherein if the temperature of recovered refrigerant from quick-freezing chamber is higher than −20° C. in 2nd freezing step, the liquid phase refrigerant is injected and evaporated for freezing the chamber after opening electronic valve (c) and manual valve (e), while the liquid phase refrigerant is injected and evaporated for refrigerating the chamber after opening electronic valve (e) and manual valve ( 5 ), if the temperature of recovered refrigerant from quick-freezing chamber and/or freezing chamber is higher than 0° C. in 3rd refrigerating step. 
     
     
         5 . The 3 stage cooling and defrosting system according to  claim 1 , wherein upon selecting the normal operation or the defrosting operation by control panel;
 in normal operation, the cooling system is operated and circulated after suspending circulation pump [ 5 ] for defrosting with closing check valve (V 7 ), wherein the wasted heat energy emitted from external condenser [ 2 ] is received and stored in the waste heat storage tank [ 4 ], after heat exchange between external condenser and brine until the temperature of brine becomes to be 30˜40° C.,   while in defrosting operation, the defrosting system is started and operated by restarting and operating circulation pump [ 5 ] with opening check valve (V 7 ) after suspending the operation of cooling system, wherein 30˜40° C. of heated brine stored in the waste heat storage tank [ 4 ] is supplied into brine pipe for removing a frost present outer surface of evaporator [ 3 ] and 4˜15° C. of brine is circulated and recovered to waste heat storage tank [ 4 ].   
     
     
         6 . The 3 stage cooling and defrosting system according to  claim 5 , wherein
 if the temperature of brine in waste heat storage tank [ 4 ] is lower than 40° C. in normal operation, another route of 3 way valve [ 6 ] is open for supplying the heat energy from high temperature of vapor refrigerant directly to the waste heat storage tank [ 4 ] by closing normal circulation route of vapor phase refrigerant,   while 3 way valve [ 6 ] is open for normal circulation route, if the temperature of brine in waste heat storage tank [ 4 ] is higher than 40° C., 3 way valve [ 6 ] is open for ordinary route.   
     
     
         7 . The 3 stage cooling and defrosting system according to  claim 2 , wherein said 3 stage cooling system comprises the steps of:
 1) −40˜-30° C. of quick-freezing step in quick-freezing chamber, wherein the low temperature of liquid phase refrigerant sprayed from expansion valve ( 1 ) passing through electronic valve (a, b) away from condenser after 2 step compression is evaporated until the quick-freezing chamber to be −25° C., and then the ultra lower temperature of liquid phase refrigerant sprayed from expansion valve ( 2 ) sequentially is evaporated until the quick-freezing chamber to be lower than −40° C.;   2) −20˜-15° C. of freezing step in freezing chamber, wherein the vapor phase refrigerant injected from electronic valve ( 7 ) after recovery from quick-freezing chamber is evaporated, and the low temperature of liquid phase refrigerant sprayed from electronic valve ( 4 ) passing through electronic valve (c, d) away from condenser is evaporated until the freezing chamber to be −20° C.; and   3) 0˜5° C. of refrigerating step in refrigerating chamber, wherein the vapor phase refrigerant injected from electronic valve ( 8 ) after recovery from quick-freezing chamber and/or freezing chamber is evaporated, and the low temperature of liquid phase refrigerant sprayed from electronic valve (e, f) away from condenser is evaporated until the refrigerating chamber to be 0° C.