Heating, Ventilation, and Air-Conditioning Systems and Methods

Abstract

A heating, ventilation, and air-conditioning (“HVAC”) system for use with a refrigerant. The HVAC system includes a compressor, a condenser, an expansion device, an evaporator, and a separator. The compressor is operable to compress the refrigerant. The condenser is positioned downstream of the compressor and operable to condense the refrigerant. The expansion device is positioned downstream of the condenser and operable to reduce a pressure of the refrigerant flowing therethrough. The evaporator is positioned downstream of the expansion device and operable to vaporize the refrigerant from the expansion device. The separator is positioned downstream of the expansion device and operable to separate the refrigerant into liquid refrigerant and gaseous refrigerant. The gaseous refrigerant from the separator and the liquid refrigerant from the separator are combined prior to being compressed by the compressor.

What is claimed is: 
     
         1 . A heating, ventilation, and air-conditioning (“HVAC”) system for use with a refrigerant, the HVAC system comprising:
 a compressor operable to compress the refrigerant; 
 a first heat exchanger positioned downstream of the compressor while the HVAC system is operating in a cooling mode, the first heat exchanger operable to condense the refrigerant; 
 a separator positioned downstream of the first heat exchanger in the cooling mode, the separator being operable to separate the refrigerant into liquid refrigerant and gaseous refrigerant; 
 a second heat exchanger positioned downstream of the separator in the cooling mode; and 
 a refrigerant bypass in fluid communication with the separator and bypassing the second heat exchanger, 
 wherein the separator is operable in the cooling mode to flow the separated gaseous refrigerant through the refrigerant bypass and flow the separated liquid refrigerant through the second heat exchanger, and 
 wherein the separated gaseous refrigerant and the refrigerant from the second heat exchanger are combined prior to being compressed by the compressor. 
 
     
     
         2 . The system of  claim 1 , wherein the second heat exchanger further comprises intermediate bypass points. 
     
     
         3 . The system of  claim 1 , further comprising a fan operable to blow air over the compressor. 
     
     
         4 . The system of  claim 1 , further comprising a receiver. 
     
     
         5 . The system of  claim 1 , further comprising an expansion device comprising a valve. 
     
     
         6 . The system of  claim 1 , wherein the separator is valve, vortex, coalescing, or gravity separator. 
     
     
         7 . The system of  claim 1 , wherein bypassed separated gaseous refrigerant further comprises no superheat. 
     
     
         8 . The system of  claim 7 , wherein the separated gaseous refrigerant comprising no superheat results in reducing a suction temperature of the combined refrigerant flowing into the compressor and a discharge temperature of the combined refrigerant leaving the compressor. 
     
     
         9 . The system of  claim 1 , wherein the second heat exchanger is:
 positioned upstream of the compressor in the cooling mode; and   configured to evaporate the separated liquid refrigerant prior to being combined with the bypassed separated gaseous refrigerant from the separator.   
     
     
         10 . A method of operating an HVAC system, the method comprising:
 condensing high-pressure refrigerant in a first heat exchanger of the HVAC system in a cooling mode;   reducing the pressure of the high-pressure refrigerant exiting the first heat exchanger to a low-pressure refrigerant;   separating the low-pressure refrigerant into a liquid refrigerant and a gaseous refrigerant in a separator of the HVAC system;   flowing the separated liquid refrigerant to a second heat exchanger;   evaporating the separated liquid refrigerant in the second heat exchanger in the cooling mode;   bypassing the separated gaseous refrigerant from the second heat exchanger through a refrigerant bypass;   combining the separated gaseous refrigerant with the refrigerant from the second heat exchanger prior to being compressed by a compressor; and   compressing the combined separated gaseous refrigerant and the refrigerant from the second heat exchanger with a compressor of the HVAC system.   
     
     
         11 . The method of  claim 10 , further comprising bypassing refrigerant evaporated in the second heat exchanger from flowing through a remaining portion of the second heat exchanger using an intermediate bypass point within the second heat exchanger. 
     
     
         12 . The method of  claim 11 , further comprising combining the evaporated refrigerant bypassed through the intermediate bypass point with the separated gaseous refrigerant. 
     
     
         13 . The method of  claim 12 , further comprising bypassing the combined evaporated refrigerant flows from the second heat exchanger. 
     
     
         14 . The method of  claim 10 , wherein the separated gaseous refrigerant comprises no superheat. 
     
     
         15 . The method of  claim 10 , wherein bypassing the separated gaseous refrigerant from the second heat exchanger further comprises reducing a suction temperature of the combined separated gaseous refrigerant and refrigerant from the second heat exchanger entering the compressor and a discharge temperature of the combined refrigerant leaving the compressor due to the separated gaseous refrigerant comprising no superheat. 
     
     
         16 . The method of  claim 10 , wherein bypassing the separated gaseous refrigerant from the second heat exchanger further comprises reducing a discharge temperature of the combined separated gaseous refrigerant and refrigerant from the second heat exchanger leaving the compressor due to the separated gaseous refrigerant comprising no superheat. 
     
     
         17 . The method of  claim 10 , wherein bypassing the separated gaseous refrigerant further comprises reducing a pressure drop of the refrigerant in the second heat exchanger. 
     
     
         18 . The method of  claim 10 , further comprising blowing air over the compressor to cool the compressor. 
     
     
         19 . The method of  claim 10 , wherein the separator is valve, vortex, coalescing, or gravity separator.