High temperature heat recovery in refrigeration

Abstract

A high lift energy reclaiming circuit for use in a vapor compression refrigeration system, the circuit being interposed in the system between the compressor discharge line and the condenser inlet line. Refrigerant vapors discharged from the compressor are exposed to, and condensed into, a strong absorbent solution to develop temperatures within the mixture that are in excess of the saturation temperature of the discharge vapors. The mixture is brought into a heat exchanger where the high temperature energy is recovered by a heat reclaiming substance, such as water or the like. The diluted absorbent in the mixture is then separated from unabsorbed refrigerant vapors and the dilute solution flash cooled by expanding the solution to the inlet pressure of the compressor. The separated unabsorbed refrigerant vapors, which are still at or about saturation, are brought into thermal communication with the flash cooled solution in a concentrator where the unabsorbed refrigerant vapors are condensed, or partially condensed, to boil refrigerant from the dilute solution. This reconcentrated solution is recycled in the high lift circuit and the freed vapors delivered to the inlet of the compressor. All of the remaining unabsorbed refrigerant vapors not condensed to concentrate the dilute solution are passed on to a standard refrigeration condenser where they are condensed. The liquid condensate from this refrigeration condenser and the liquid condensate from the vessel in which the dilute solution is reconcentrated, the concentrator, are collected together in a common collection chamber, the float chamber, and together passed through an expansion device into the evaporator where the liquid refrigerant is again used as the evaporate to accomplish chilling in a conventional manner.

What is claimed is: .[.1. The method of developing a high temperature lift at the discharge of a compressor as employed in a vapor compression refrigeration system including 
     
        discharge to regulate the amount of energy consumed in absorption..]. 8. The method of developing a .[.high temperature lift.]. .Iadd.variable capacity heat reclaiming capability .Iaddend.in a refrigeration system employing a vapor compressor including exposing .[.a strong absorbent solution to the.]. refrigerant vapors discharged from the .[.vapor.]. compressor .[.to develop.]. .Iadd.to a concentrated absorbent solution wherein at least a portion of the refrigerant is absorbed by the solution diluting the solution and developing .Iaddend.a high temperature mixture which is at a temperature level above that of the discharge vapors .Iadd.normally discharged from the compressor, .Iaddend.   transferring the heat energy in the high temperature mixture to a heat reclaiming substance whereby the temperature of the reclaiming substance is raised to about that of the high temperature mixture,   separating the diluted solution from the unabsorbed vapors after heat transfer,   flash cooling the separated dilute solution by .[.exposing.]. .Iadd.throttling .Iaddend.the solution to the .[.low pressure.]. inlet .[.to.]. .Iadd.pressure of .Iaddend.the compressor,   placing the unabsorbed refrigerant vapors in thermal communication with the flash cooled solution to condense .Iadd.at least a portion of .Iaddend.the vapors whereby refrigerant is boiled from the solution thus reconcentrating the solution, .[.and.].   recirculating the reconcentrated solution to the compressor discharge for reuse.Iadd., and controlling the amount of reconcentrated solution that is recirculated in response to the temperature of the heat reclaiming substance, and   delivering the unabsorbed refrigerant to the refrigeration system after reconcentration of the solution and further condensing any vapors   
     
     
        remaining in the unabsorbed refrigerant. .Iaddend. .[.9.  The method of claim 8 further including the step of delivering the unabsorbed refrigerant to the refrigeration system after reconcentration of the solution and further condensing any vapors remaining therein whereby the refrigerant is placed in a condition for use in refrigeration..]. .[.10. The method of claim 9 further including the step of controlling the amount of reconstituted solution recirculated to the compressor discharge to regulate the amount of energy consumed in developing high temperatures in 
     
     
        the mixture..]. 11. The method of claim .[.10.]. .Iadd.8 .Iaddend.whereby energy consumed in developing the high temperature mixture is equal to or 
     
     
        less than the energy consumed in reconcentrating the dilute solution. 12. The method of claim .[.9.]. .Iadd.8 .Iaddend.wherein the refrigerant used in the refrigeration system is delivered to the inlet of the compressor where it is mixed with the refrigerant boiled from the 
     
     
        reconcentrated solution. 13. The method of claim 8 further including the step of preheating the reconstituted solution as it is being recirculated by placing the solution in heat transfer relation with the warmer dilute 
     
     
        solution prior to the dilute solution being flash cooled. 14. In a refrigeration system of the type including a condenser, an evaporator, an expansion mechanism for throttling refrigerant between the condenser and the evaporator, and a vapor compressor for raising the state of refrigerant vapors leaving the evaporator, the improvement comprising spray means for exposing the discharged vapors leaving the compressor to an absorbent solution to develop a high temperature mixture,   a heat exchanger for transferring heat energy from the mixture to a reclaiming substance,   separating means for separating unabsorbed refrigerant vapors from the diluted solution leaving the exchanger,   a concentrator interposed between the condenser and the separator through which the unabsorbed vapors pass from the separator to the condenser in heat transfer relation with a supply of solution contained therein, and   expansion means for flash cooling the separated diluted solution and delivering the solution to the supply of solution in said concentrator whereby heat energy is transferred from the vapors to the flash cooled solution to boil refrigerant therefrom thus reconcentrating the solution.   
     
     
         5. The apparatus of claim 14 further including a circulating pump for moving the reconcentrated solution from the concentrator to the spray 
     
     
        means. 16. The apparatus of claim 14 having further means for exposing the flash cooled solution in the concentrator to the inlet of the compressor to allow the heat energy transferred from the vapors to sustain the 
     
     
        boiling of refrigerant from the solution. 17. The apparatus of claim 15 including a control means for regulating the amount of solution moving 
     
     
        between the concentrator and the spray means. 18. A .[.high temperature.]. .Iadd.variable capacity heat reclaiming .Iaddend.circuit .[.operatively connected between the discharge region of.]. .Iadd.for use with a refrigeration system having .Iaddend.a vapor compressor and a condenser .[.in a refrigeration system to act upon refrigerant moving therebetween.]. including a concentrator having a supply area for collecting and storing an absorbent solution .[.and flow means to bring refrigerant moving between the compressor and the condenser into thermal communication with the solution.].,   pump means for delivering solution from the concentrator into the vapor discharge region of the compressor wherein at least some of the vapors are absorbed by the solution to .[.raise the temperature of the discharge.]. .Iadd.develop a high temperature mixture of refrigerant and absorbent solution, .Iaddend.   heat .[.exchange.]. .Iadd.exchanger .Iaddend.means for transferring heat energy in the high temperature mixture to a heat reclaiming substance,   means to separate the dilute solution leaving the heat exchanger from the unabsorbed refrigerant vapors .[.prior to the refrigerant vapors through the concentrator to the condenser, and.]. .Iadd.in the mixture of refrigerant and absorbent solution, .Iaddend.   expansion means for flash cooling the separated dilute solution and delivering the solution into the supply region of the concentrator.Iadd., .Iaddend.   .[.whereby the unabsorbed vapors passing through the concentrator are condensed therein.]. .Iadd.first flow means to bring the unabsorbed refrigerant vapors into thermal communication with the supply of solution contained in the concentrator .Iaddend.to boil refrigerant from the solution .Iadd.and at least partly condense the unabsorbed refrigerant vapors, and   second flow means for delivering the unabsorbed refrigerant to the condenser after reconcentration of the solution to further condense any   
     
     
        vapors remaining in the unabsorbed refrigerant. .Iaddend. 19. The apparatus of claim 18 wherein the supply area of the concentrator is connected to the inlet of the compressor whereby refrigerant boiled from 
     
     
        the solution is drawn into the compressor. 20. The apparatus of claim 19 further including control means for regulating the amount of solution delivered from the concentrator into the discharge region of the 
     
     
        compressor. 21. The apparatus of claim 20 wherein the amount of solution delivered into the compressor discharge region is regulated so that the amount of energy stored in the vapors consumed in absorption is less than or equal to the amount of energy consumed in reconcentration of the 
     
     
        solution. 22. The apparatus of claim 18 including further means for transferring heat energy from the dilute solution separated from the refrigerant vapors and the reconcentrated solution pumped to the compressor discharge region prior to the dilute solution being flash 
     
     
        cooled. 23. The apparatus of claim 18 wherein the heat exchange means is a counterflow heat exchanger for raising the temperature of the reclaiming substance close to that of the high temperature mixture. .[.24. Apparatus for developing a high lift in a vapor compression refrigeration system to raise the temperature of the energy rejected therefrom including means for introducing an absorbent into the vapor discharge of the compressor whereby at least some of the vapors are absorbed and condensed to raise the temperature of the mixture above the normal discharge temperature,   heat exchange means for transferring heat energy from the high temperature mixture to a heat reclaiming substance, and   means for placing the unabsorbed refrigerant vapors in thermal communication with the dilute solution after heat transfer to   
     
     
        reconcentrate said solution..]. .Iadd.25.  The apparatus of claim 14 further including means for exposing the flash cooled solution in the concentrator to the inlet of the compressor to allow the heat energy transferred from the vapors to sustain the boiling of refrigerant from the solution,   means for controlling the amount of reconcentrated solution recirculated to the compressor discharge in response to the temperature of the heat reclaiming substance, and   an absorbent solution heat exchanger for transferring heat from the dilute absorbent solution prior to the dilute solution being cooled to the cooler reconcentrated solution as it is being recirculated to the compressor discharge. .Iaddend.