Loading and unloading of compressors in a cooling system

Abstract

A system and method of loading and unloading a compressor in a cooling system. The method includes detecting a temperature, determining a compressor should be turned on/off to supply/stop supplying cooling based on the temperature, turning the compressor on/off, and opening/closing a plurality of valves when the compressor is turned on/off.

1 . A method of loading and unloading a compressor in a cooling system, the method comprising:
 detecting a temperature;   determining a compressor should be turned on to supply cooling based on the temperature;   determining a point in time when the impact of turning on a motor of the compressor is minimized using point-on-wave analysis; and   turning on the compressor at about the determined point in time.   
     
     
         2 . The method of  claim 1 , further comprising determining a compressor should be turned off to stop supplying cooling based on the detected temperature;
 determining a second point in time when the impact of turning off the motor of the compressor is minimized using point-on-wave analysis; and   turning off the compressor at about the determined second point in time.   
     
     
         3 . The method of  claim 2 , further comprising closing a compressor intake valve and a compressor output valve when the compressor is turned off. 
     
     
         4 . The method of  claim 1 , further comprising opening a compressor intake valve and a compressor output valve when the compressor is turned on. 
     
     
         5 . The method of  claim 1 , wherein the cooling system is a residential air conditioner. 
     
     
         6 . The method of  claim 1 , wherein the power to the compressor is applied by closing a DC contactor. 
     
     
         7 . The method of  claim 1 , further comprising anticipating that cooling will be required, wherein the compressor is turned on prior to a set-point temperature being reached. 
     
     
         8 . The method of  claim 1 , wherein the compressor is one of a plurality of compressors for the cooling system, and the acts of  claim 1  are performed for loading each of the plurality of compressors. 
     
     
         9 . The method of  claim 1 , further comprising opening an evaporator valve when the compressor is turned on and closing the evaporator valve when the compressor is turned off. 
     
     
         10 . A method of loading and unloading a compressor in a cooling system, the method comprising:
 detecting a temperature;   determining a compressor should be turned on to supply cooling based on the temperature;   turning on the compressor; and   opening a plurality of valves when the compressor is turned on.   
     
     
         11 . The method of  claim 10 , wherein the plurality of valves includes a compressor intake valve and a compressor outlet valve. 
     
     
         12 . The method of  claim 10 , further comprising
 determining the compressor should be turned off to stop supplying cooling based on the temperature;   turning off the compressor;   closing the plurality of valves when the compressor is turned off.   
     
     
         13 . The method of  claim 10 , wherein the plurality of valves includes a compressor intake valve and a compressor outlet valve. 
     
     
         14 . The method of  claim 10 , wherein a pressure across the compressor is maintained when the compressor is off by the closing of the plurality of valves. 
     
     
         15 . A cooling system, the system comprising:
 a compressor;   a temperature sensor configured to provide an indication of a temperature;   a compressor intake valve coupled to an input of the compressor;   a compressor output valve coupled to an output of the compressor; and   a controller coupled to the compressor, the temperature sensor, the compressor intake valve, and the compressor output valve, the controller configured to
 receive the indication of the temperature from the temperature sensor, 
 determine that the compressor should be turned off to stop providing cooling based on the indication of temperature received from the temperature sensor, 
 turn off the compressor, 
 close the compressor intake valve, and 
 close the compressor output valve, 
 wherein closing the compressor intake valve and the compressor output valve maintains a pressure of refrigerant across the compressor while the compressor is off. 
   
     
     
         16 . The method of  claim 15 , the controller is further configured to determine a point in time when an impact on the motor is minimized using point-on-wave analysis, and to turn on the compressor at the determined point in time. 
     
     
         17 . The cooling system of  claim 15 , wherein the controller is further configured to
 determine that the compressor should be turned on to provide cooling based on the indication of temperature received from the temperature sensor,   turn on the compressor,   open the compressor intake valve, and   open the compressor output valve.   
     
     
         18 . The cooling system of  claim 15 , wherein the compressor is a scroll compressor. 
     
     
         19 . The cooling system of  claim 15 , wherein the temperature sensor is a thermostat. 
     
     
         20 . The cooling system of  claim 15 , wherein the cooling system includes a plurality of compressors, and the controller is configured to perform the acts for each compressor of the plurality of compressors.