Condensate-free outdoor air cooling unit

Abstract

A highly efficient condensate-free cooling unit functionally based on vapor-compression refrigeration cycle has been described. The condensate collected from the evaporator of the cooling unit is routed through a sub-cooling heat exchanger where it exchanges heat with the primary heat exchange medium emerging through the condenser of the cooling unit, thus, sub-cooling the primary heat exchange medium to a lower temperature before it enters the expansion valve. Emerging from the sub-cooling heat exchanger, the condensate flows through a condensate outlet pipe into multiple spray nozzles disposed over the condensate outlet pipe. The spray nozzles sprinkle the condensate over the hot air blown into the condenser to reduce its temperature. The cooling unit has a substantially higher coefficient of performance compared to the conventional cooling units utilizing vapor-compression refrigeration cycle, and eliminates the problems of condensate removal persistent in the art.

1 . A cooling unit employing vapor compression refrigeration cycle for cooling an ambient medium, the cooling unit comprising:
 an evaporator, including a plurality of heat exchange tubes adapted to carry a primary heat exchange medium, and arranged to receive a flow of an ambient medium;   a condensate pump positioned to route condensate from the evaporator;   a sub-cooling heat exchanger in fluid communication with the condensate pump; and   a plurality of spray nozzles in simultaneous fluid communication with the sub-cooling heat exchanger and positioned to spray condensate into the flow of the ambient medium.   
     
     
         2 . The cooling unit of  claim 1 , wherein the sub-cooling heat exchanger has a condensate inlet for a continuous inflow of the condensate therein, and a condensate outlet for a continuous outflow of the condensate therefrom. 
     
     
         3 . The cooling unit of  claim 2 , wherein the condensate outlet has a cross-sectional area preferably smaller than the cross-sectional area of the condensate inlet. 
     
     
         4 . The cooling unit of  claim 2 , wherein the condensate inlet is positioned at a higher elevation with respect to the condensate outlet. 
     
     
         5 . The cooling unit of  claim 2 , wherein the sub-cooling heat exchanger is in fluid communication with a condensate outlet pipe, the condensate outlet pipe having the spray nozzles mounted.thereon. 
     
     
         6 . The cooling unit of  claim 5 , wherein the condensate outlet pipe is provided with a set of perforations to fluidly communicate with the plurality of spray nozzles. 
     
     
         7 . The cooling unit of  claim 1 , wherein the sub-cooling heat exchanger has a primary heat exchange medium inlet for a continuous inflow of the primary heat exchange medium therein, and a primary heat exchange medium outlet for a continuous outflow of the primary heat exchange medium therefrom. 
     
     
         8 . The cooling unit of  claim 1 , wherein the primary heat exchange medium and the condensate are in thermal communication within the sub-cooling heat exchanger. 
     
     
         9 . The cooling unit of  claim 1 , wherein the sub-cooling heat exchanger is in fluid communication with least one of the plurality of spray nozzles. 
     
     
         10 . The cooling unit of  claim 1 , wherein the plurality of spray nozzles are arranged in a spaced array. 
     
     
         11 . The cooling unit of  claim 1 , wherein the plurality of spray nozzles are coupled to a condenser, and configured to continuously spray the condensate on air blown into the condenser. 
     
     
         12 . A method of increasing the coefficient of performance of a cooling unit utilizing vapor compression refrigeration cycle, the cooling unit including an evaporator, a compressor, a condenser and an expansion valve, the method comprising:
 collecting condensate from the evaporator;   routing condensate to a sub-cooling heat exchanger;   exchanging heat in the sub-cooling heat exchanger between the condensate and a primary heat exchange medium;   directing the condensate from the sub-cooling heat exchanger to a plurality of spray nozzles; and   sprinkling the condensate through the plurality of spray nozzles over air blown into the condenser.   
     
     
         13 . The method of  claim 12  wherein the cooling unit includes a compressor, and a condenser configured to receive a flow of an ambient medium, the method further comprising compressing the primary heat exchange medium within the compressor to a high-pressure value based at least on a set of parameters corresponding to the ambient medium. 
     
     
         14 . The method of  claim 13 , wherein the set of parameters includes a mass-flow rate value of the ambient medium flowing through the condenser. 
     
     
         15 . The method of  claim 13 , wherein the set of parameters include the corresponding average temperature values of the ambient medium entering and leaving the condenser. 
     
     
         16 . The method of  claim 12 , wherein the condensate remains in continuous thermal communication with a primary heat exchange medium within the sub-cooling heat exchanger. 
     
     
         17 . The method of  claim 12  further comprising directing the condensate through a condensate outlet pipe from the sub-cooling heat exchanger to the spray nozzles. 
     
     
         18 . The method of  claim 17  further comprising providing a set of perforations on the condensate outlet pipe to enable it being in simultaneous thermal communication with the plurality of spray nozzles.