Air conditioning system

Abstract

An air conditioning system including a variable speed compressor configured to operator at faster and slower speeds. The system includes an evaporator and a thermal expansion valve for regulating the flow of a refrigerant from the compressor to the evaporator. The system includes a flow restricting device in a flow path from the thermal expansion valve to the evaporator thereby increasing the efficiency of the system when the compressor is operating at slower speeds.

1 . An air conditioning system comprising:
 an evaporator containing refrigerant, wherein the evaporator is configured to exchange heat with a surrounding environment;   a metering device for regulating the flow of refrigerant into the evaporator, wherein the metering device is configured to regulate the flow into the evaporator based, at least in part, on the pressure sensed in a flow path to the evaporator;   a compressor for compressing refrigerant and providing liquid refrigerant to the metering device;   wherein the system is configured so that refrigerant flowing from the metering device into the evaporator passes through a flow restricting device located in the flow path.   
     
     
         2 . The system of  claim 1 , wherein the compressor is a variable speed compressor. 
     
     
         3 . The system of  claim 2 , wherein the speed of the compressor is regulated based on an available power supply. 
     
     
         4 . The system of  claim 1 , wherein the metering device includes a thermal expansion valve. 
     
     
         5 . The system of  claim 4 , wherein the thermal expansion valve includes a needle valve. 
     
     
         6 . The system of  claim 1 , wherein the metering device is controlled based on, at least in part, a temperature sensed at an outlet of the evaporator. 
     
     
         7 . The system of  claim 1 , wherein the flow restricting device comprises a throttle valve in the refrigerant flow path from the thermal expansion valve to the evaporator. 
     
     
         8 . The system of  claim 1 , wherein the flow restricting device comprises an orifice. 
     
     
         9 . An air conditioning system including a variable speed compressor configured to operate at faster and slower speeds, an evaporator and a thermal expansion valve for regulating the flow of a refrigerant from the compressor to the evaporator, wherein the thermal expansion valve is configured to control the flow of the refrigerant into the evaporator based on a temperature sensed at the outlet of the evaporator and a pressure sensed at the inlet to the evaporator; wherein the system includes a flow restricting device in a flow path from the thermal expansion valve to the evaporator thereby increasing the efficiency of the system when the compressor is operating at slower speeds. 
     
     
         10 . The system of  claim 9 , wherein the flow restriction device is configured to throttle flow to the evaporator so that when the compressor is operating at faster speeds refrigerant flow to the evaporator is not restricted.