Helium charged refrigerator

Abstract

A helium charged refrigerator is capable of cooling a refrigerator box to a temperature of 6° C. (43° F.) and the freezer compartment to a temperature of −9° C. (15° F.) when the ambient is at a temperature of 43° C. (110° F.). The total cubic area cooled is greater than or equal to six cubic feet. The unit includes a condenser, an evaporator, a liquid ammonia tube, and a gas heat exchanger. The liquid ammonia tube includes two vertical sections. The second section is downstream of the first and is noncontiguous with the heat exchanger so that no heat is exchanged between flowable fluids flowing in the second vertical section and in the heat exchanger. The heat exchanger includes modifications to its inner and outer tubes to produce an increase in surface area of the corresponding surface.

1 . A refrigerator having a diffusion-absorption refrigeration assembly that uses helium as a diffusion gas, the refrigeration assembly comprising, a condenser, an evaporator, a liquid ammonia tube, and a gas heat exchanger, wherein the liquid ammonia tube comprising a first vertical section with an inlet, and a second vertical section downstream of the first. 
     
     
         2 . A refrigerator according to  claim 1 , wherein the second vertical section of the liquid ammonia tube being noncontiguous with said heat exchanger, wherein no heat is exchanged between flowable fluids flowing in said second vertical section and in said heat exchanger. 
     
     
         3 . A refrigerator according to  claim 1 , wherein said liquid ammonia tube further comprising an intermediate section downstream of the second vertical section, said intermediate section being contiguous with said heat exchanger, wherein heat is exchanged between flowable fluids flowing in said intermediate section and in said heat exchanger. 
     
     
         4 . A refrigerator according to  claim 3 , wherein said liquid ammonia tube further comprising a freezer section upstream of the intermediate section, said freezer section being contiguous with said heat exchanger, wherein heat is exchanged between flowable fluids flowing in said freezer section and in said heat exchanger. 
     
     
         5 . A refrigerator according to  claim 4 , wherein the second vertical section of the liquid ammonia tube being noncontiguous with said heat exchanger, wherein no heat is exchanged between flowable fluids flowing in said second vertical section and in said heat exchanger. 
     
     
         6 . A refrigerator having a diffusion-absorption refrigeration assembly that uses helium as a diffusion gas, the refrigeration assembly comprising, a condenser, an evaporator, a liquid ammonia tube, and a gas heat exchanger, wherein the liquid ammonia tube comprising a first vertical section with an inlet, and a second vertical section downstream of the first, said refrigerator having a freezer box defining a first cubic area, and a refrigerator box defining a second cubic area, the sum of said first and second cubic areas being equal to or greater than six cubic feet, wherein said assembly being capable of cooling the refrigerator box to a temperature of 6° C. (43° F.) and the freezer compartment to a temperature of −9° C. (15° F.) when the ambient is at a temperature of 43° C. (110° F.). 
     
     
         7 . A refrigerator according to  claim 6 , wherein the heat exchanger includes inner and outer tubes, said inner tube having an outer surface, and said outer tube having an inner surface, said outer and inner surfaces each being shaped to produce an increase in surface area of the corresponding surface. 
     
     
         8 . A refrigerator having a diffusion-absorption refrigeration assembly that uses helium as a diffusion gas, the refrigeration assembly comprising, a condenser, an evaporator, a liquid ammonia tube, a gas heat exchanger, wherein the liquid ammonia tube comprising a first vertical section with an inlet, and a second vertical section downstream of the first, said refrigerator having a freezer box defining a first cubic area, and a refrigerator box defining a second cubic area, the sum of said first and second cubic areas being equal to or greater than six cubic feet, wherein said assembly being capable of cooling the refrigerator box to a temperature of 6° C. (43° F.) and the freezer compartment to a temperature of −9° C. (15° F.) when the ambient is at a temperature of 43° C. (110° F.), wherein the second vertical section of the liquid ammonia tube being noncontiguous with said heat exchanger, wherein no heat is exchanged between flowable fluids flowing in said second vertical section and in said heat exchanger. 
     
     
         9 . A refrigerator according to  claim 8 , wherein the heat exchanger includes inner and outer tubes, said inner tube having an outer surface, and said outer tube having an inner surface, said outer and inner surfaces each having serrations to produce an increase in surface area of the corresponding surface. 
     
     
         10 . A refrigerator according to  claim 9 , wherein said liquid ammonia tube further comprising an intermediate section downstream of the second vertical section, said intermediate section being contiguous with said heat exchanger, wherein heat is exchanged between flowable fluids flowing in said intermediate section and in said heat exchanger. 
     
     
         11 . A refrigerator according to  claim 10 , wherein the second vertical section of the liquid ammonia tube being noncontiguous with said heat exchanger, wherein no heat is exchanged between flowable fluids flowing in said second vertical section and in said heat exchanger. 
     
     
         12 . A refrigerator having a diffusion-absorption refrigeration assembly that uses helium as a diffusion gas, the refrigeration assembly comprising, a condenser, an evaporator, a liquid ammonia tube, and a gas heat exchanger, wherein the gas heat exchanger comprising an inner tube having and outer diameter of between about 14 and about 16 millimeters and an outer tube having an outer diameter of between about 25 and 27 millimeters, said refrigerator having a freezer box defining a first cubic area, and a refrigerator box defining a second cubic area, the sum of said first and second cubic areas being equal to or greater than six cubic feet, wherein said assembly being capable of cooling the refrigerator box to a temperature of 6° C. (43° F.) and the freezer compartment to a temperature of −9° C. (15° F.) when the ambient is at a temperature of 43° C. (110° F.). 
     
     
         13 . A refrigerator according to  claim 12 , wherein the liquid ammonia tube comprising a first vertical section with an inlet, and a second vertical section downstream of the first, wherein the second vertical section being noncontiguous with said heat exchanger, wherein no heat is exchanged between flowable fluids flowing in said second vertical section and in said heat exchanger. 
     
     
         14 . A refrigerator according to  claim 13 , wherein said liquid ammonia tube further comprising an intermediate section downstream of the second vertical section, said intermediate section being contiguous with said heat exchanger, wherein heat is exchanged between flowable fluids flowing in said intermediate section and in said heat exchanger. 
     
     
         15 . A refrigerator according to  claim 14 , wherein said liquid ammonia tube further comprising a freezer section upstream of the intermediate section, said freezer section being contiguous with said heat exchanger, wherein heat is exchanged between flowable fluids flowing in said freezer section and in said heat exchanger. 
     
     
         16 . A refrigerator according to  claim 15 , wherein said inner tube of the heat exchanger includes an outer surface, and said outer tube includes an inner surface, said outer and inner surfaces each having serrations to produce an increase in surface area of the corresponding surface.