Processes and systems for monitoring and controlling refrigeration energy comsumption

Abstract

Methods and systems include, using a monitoring system, initiating a control logic configured to control a production control system pertaining to a refrigeration system connected to a plurality of production trains. The method may include obtaining a plurality of production parameters; calculating, using the plurality of production parameters, an isentropic efficiency value for the primary compressor if the production flow rate is less than a production threshold; comparing each of the plurality of isentropic efficiency values; determining from the comparing each of the plurality of isentropic efficiency values, a primary compressor having a lowest isentropic efficiency value; selecting the respective primary compressor having the lowest isentropic efficiency value. The method may include, using a production control system, shutting down the selected primary compressor.

What is claimed is: 
     
         1 . A method for monitoring and controlling energy consumption of a refrigeration system operatively connected to a plurality of production trains, the method comprising:
 using a monitoring system,
 initiating a control logic configured to control a production control system pertaining to the refrigeration system,
 wherein the plurality of production trains includes a production flow therethrough, 
 wherein each of the production trains respectively comprises a primary compressor comprising a first recycle valve; 
 
 for each production train:
 obtaining a plurality of production parameters, wherein one of the plurality of production parameters comprises a production flow rate; 
 determining whether the production flow rate is less than a production threshold; 
 calculating, using the plurality of production parameters, an isentropic efficiency value for the primary compressor if the production flow rate is less than a production threshold; 
 
 comparing each of the plurality of isentropic efficiency values; 
 determining from the comparing each of the plurality of isentropic efficiency values, a primary compressor having a lowest isentropic efficiency value,
 wherein the lowest isentropic efficiency value is one of the plurality of isentropic efficiency values that is quantitatively smallest compared to all other isentropic efficiency values; 
 
 selecting the respective primary compressor having the lowest isentropic efficiency value; and 
   using the production control system:
 reducing the production flow to the one of the plurality of production trains which includes the selected primary compressor; 
 redirecting the production flow from the one of the plurality of production trains including the selected primary compressor to at least one other of the plurality of production trains; 
 opening the first recycle valve of the selected primary compressor to fully opened; and 
 shutting down the selected primary compressor. 
   
     
     
         2 . The method of  claim 1 , wherein the plurality of production parameters further comprises:
 a recycle valve opening measurement, and   a driver power value;   calculating, using the recycle valve opening measurement and the driver power value, the isentropic efficiency value.   
     
     
         3 . The method of  claim 2 , further comprises:
 determining the driver power value, using the monitoring system, from at least a measured voltage, a measured current, and a power factor.   
     
     
         4 . The method of  claim 1 , further comprises:
 wherein each of the plurality of production trains comprises a secondary compressor comprising a second recycle valve,   closing the second recycle valve of the secondary compressor of the production train having the selected primary compressor.   
     
     
         5 . The method of  claim 4 , further comprises:
 shutting down, using the production control system, the secondary compressor of the production train having the selected primary compressor;   using the monitoring system,
 deselecting the primary compressor having the lowest isentropic for shutdown if the secondary compressor of the production train having the selected primary compressor is already shutdown, 
 selecting the respective primary compressor with next lowest isentropic efficiency value; 
   shutting down, using the production control system, the selected primary compressor.   
     
     
         6 . The method of  claim 1 , further comprises:
 wherein the monitoring system comprises a user interface,   initiating, using the monitoring system, the control logic from input from the user interface.   
     
     
         7 . The method of  claim 1  wherein the production threshold is 1450 million standard cubic feet per day (mmscfd). 
     
     
         8 . The method of  claim 1 , further comprises, using the monitoring system:
 calculating a cooling duty of the refrigeration system for liquefying the production fluids;   determining whether the cooling duty is greater than a cooling threshold;   deselecting the selected primary compressor.   
     
     
         9 . The method of  claim 1 , further comprises:
 optimizing energy consumption of the refrigeration system,   wherein optimizing energy consumption reduces carbon dioxide emissions.   
     
     
         10 . The method of  claim 1 , further comprises:
 redistributing production flow equally among the plurality of production trains that are not the production train having the lowest isentropic value.   
     
     
         11 . A system for monitoring and controlling energy consumption of a refrigeration system operatively connected to a plurality of production trains, the system comprising:
 a monitoring system configured to:
 initiate a control logic configured to control a production control system pertaining to the refrigeration system,
 wherein the plurality of production trains includes a production flow therethrough, 
 wherein each of the production trains respectively comprises a primary compressor comprising a first recycle valve; 
 
 for each production train:
 obtain a plurality of production parameters, wherein one of the plurality of production parameters comprises a production flow rate; 
 determine whether the production flow rate is less than a production threshold; 
 calculate, using the plurality of production parameters, an isentropic efficiency value for the primary compressor if the production flow rate is less than a production threshold; 
 
 compare each of the plurality of isentropic efficiency values; 
 determine from the comparing each of the plurality of isentropic efficiency values,
 a primary compressor having a lowest isentropic efficiency value, 
 wherein the lowest isentropic efficiency value is one of the plurality of isentropic efficiency values that is quantitatively smallest compared to all other isentropic efficiency values; 
 
 select the respective primary compressor having the lowest isentropic efficiency value; and 
   the production control system configured to:
 reduce the production flow to the one of the plurality of production trains which includes the selected primary compressor; 
 redirect the production flow from the one of the plurality of production trains including the selected primary compressor to at least one other of the plurality of production trains; 
 open the first recycle valve of the selected primary compressor to fully opened; and 
 shut down the selected primary compressor. 
   
     
     
         12 . The system of  claim 11 ,
 wherein the plurality of production parameters further comprises:
 a recycle valve opening measurement, and 
 a driver power value; 
   wherein the monitoring system is configured to:
 calculate, using the recycle valve opening measurement and the driver power value, the isentropic efficiency value. 
   
     
     
         13 . The system of  claim 12 , wherein the monitoring system is configured to determine the driver power value from at least a measured voltage, a measured current, and a power factor. 
     
     
         14 . The system of  claim 11 ,
 wherein each of the plurality of production trains comprises a secondary compressor comprising a second recycle valve,   wherein the production control system is configured to close the second recycle valve of the secondary compressor of the production train having the selected primary compressor.   
     
     
         15 . The system of  claim 14 ,
 wherein the production control system is configured to:
 shut down the secondary compressor of the production train having the selected primary compressor; 
   wherein the monitoring system is configured to:
 deselect the primary compressor having the lowest isentropic for shutdown if the secondary compressor of the production train having the selected primary compressor is already shutdown, 
 select the respective primary compressor with next lowest isentropic efficiency value; 
   wherein the production control system is further configured to shut down the selected primary compressor.   
     
     
         16 . The method of  claim 11 ,
 wherein the monitoring system comprises a user interface,   wherein the monitoring system is configured to initiate the control logic from input from the user interface.   
     
     
         17 . The system of  claim 11  wherein the production threshold is 1450 million standard cubic feet per day (mmscfd). 
     
     
         18 . The system of  claim 11 , wherein the monitoring system is configured to:
 calculate a cooling duty of the refrigeration system for liquefying the production fluids;   determine whether the cooling duty is greater than a cooling threshold;   deselect the selected primary compressor.   
     
     
         19 . The system of  claim 11 ,
 wherein the monitoring system is configured to optimize energy consumption of the refrigeration system,   wherein optimizing energy consumption reduces carbon dioxide emissions.   
     
     
         20 . The method of  claim 1 , wherein the production control system is configured to redistribute production flow equally among the plurality of production trains that are not the production train having the lowest isentropic value.