Refrigeration system and method of operating the same

Abstract

A refrigeration system comprises a condenser, an evaporator, and a plurality of compressors in fluid communication. The plurality of compressors has a current run pattern with a current run capacity. The refrigeration system further comprises a controller operable to control the plurality of compressors. One method of operating the refrigeration system includes, at the controller, determining whether to increase or decrease the current run capacity and, when an increase or decrease in the current run capacity is required, creating a new run pattern to replace the current run pattern.

What is claimed is:  
     
         1 . A method of controlling a refrigeration system comprising 
 a condenser, an evaporator, and a plurality of compressors in fluid communication, and    a controller operable to control the plurality of compressors, the method comprising the acts of: 
 at the controller, 
 controlling the plurality of compressors with a current run pattern and resulting in a current run capacity;  
 determining whether to increase or decrease the current run capacity; and  
 when an increase or decrease in the current run capacity is required, creating a new run pattern to replace the current run pattern.  
 
   
     
     
         2 . A method as set forth in  claim 1  wherein the method further comprises the act of monitoring run times for the plurality of compressors, and wherein the creating a new run pattern is based in part on the monitored run times.  
     
     
         3 . A method as set forth in  claim 1  wherein the refrigeration system further includes a suction group and wherein the suction group includes the plurality of compressors.  
     
     
         4 . A method as set forth in  claim 3  wherein the refrigeration system further includes a second suction group including a second plurality of compressors, wherein the controller is operable to control the second plurality of compressors, and wherein the method further comprises: 
 controlling the second plurality of compressors with a second current run pattern and resulting in a second current run capacity  
 determining whether to increase or decrease the second current run capacity for the second suction group; and  
 when an increase or decrease in the second current run capacity is required, creating a second new run pattern to replace the second current run pattern.  
 
     
     
         5 . A method as set forth in  claim 4  wherein the method further comprises the act of monitoring run times for the second plurality of compressors, and wherein the creating a second new run pattern is based in part on the monitored run times for the second plurality of compressors.  
     
     
         6 . A method as set forth in  claim 1  wherein the suction group includes a plurality of operable compressors and at least one inoperable compressor, and wherein the new run pattern is selected from the group of operable compressors.  
     
     
         7 . A method as set forth in  claim 1  wherein creating a new run pattern comprises 
 determining a total capacity for the plurality of compressors,  
 determining a percentage of the total capacity for each compressor,  
 determining a current run capacity for the plurality of compressors, and  
 determining a next available run capacity percentage combination for the plurality of compressors.  
 
     
     
         8 . A method as set forth in  claim 7  wherein the plurality of compressors includes a plurality of operable compressors and at least one inoperable compressor, and wherein the determining acts are performed for the operable compressors.  
     
     
         9 . A method as set forth in  claim 2  wherein creating a new run pattern comprises 
 determining a total capacity for the plurality of compressors,  
 determining a percentage of the total capacity for each compressor,  
 determining a current run capacity for the plurality of compressors, and  
 determining a next available run capacity percentage combination for the plurality of compressors.  
 
     
     
         10 . A method as set forth in  claim 9  wherein creating a new run pattern comprises 
 prior to determining a next available run capacity percentage combination, determining a plurality of capacity percentage combinations; and  
 optimizing the next run pattern if the next available run capacity percentage combination results in two compressor combinations having the same run capacity percentage.  
 
     
     
         11 . A method of controlling a refrigeration system comprising 
 a condenser, an evaporator, and a plurality of compressors in fluid communication, and    a controller operable to control the plurality of compressors, the method comprising the acts of: 
 at the controller, 
 controlling the plurality of compressors with a current run pattern and resulting in a current run capacity;  
 determining a total capacity for the plurality of compressors;  
 determining a percentage of the total capacity for each compressor;  
 determining a next available run capacity percentage; and  
 determining a new run pattern to replace the current run pattern, the new run pattern including the next available run capacity percentage.  
 
   
     
     
         12 . A method as set forth in  claim 11  wherein the method further comprises determining a current run capacity percentage for the plurality of compressors, determining whether to increase the current run capacity, and wherein the next available run capacity percentage is greater than the current run capacity percentage when the current run capacity percentage is less than one hundred percent.  
     
     
         13 . A method as set forth in  claim 11  wherein the method further comprises determining a current run capacity percentage for the plurality of compressors, determining whether to decrease the current run capacity, and wherein the next available run capacity percentage is less than the current run capacity percentage when the current run capacity percentage is greater than zero percent.  
     
     
         14 . A method as set forth in  claim 11  wherein the method further comprises the act of monitoring run times for the plurality of compressors, and wherein determining a new run pattern includes creating a new run pattern based on the monitored run times.  
     
     
         15 . A method as set forth in  claim 11  wherein the plurality of compressors includes a plurality of operable compressors and at least one inoperable compressor, and wherein the determining acts are performed for the operable compressors.