Method and device for controlling a refrigeration system with a plurality of chillers in an arrangement or network

Abstract

A method for controlling a refrigeration system comprising a plurality of chillers in an arrangement or network, at least some of which differ from each other in performance characteristics with respect to cooling capacity or power to be provided, electrical power consumed and cooling water temperature, comprising the steps of a) detecting a requested target cooling capacity and a current cooling water temperature; b) determining the available cooling capacity of the chillers in the network on the basis of the respective capacity characteristics and the detected current cooling water temperature; c) determining the possible combinations of chillers that can provide the required target cooling capacity; d) selecting, from the possible combinations of chillers and based on their respective performance characteristics, the combination that provides the highest overall efficiency; and e) operating the chillers of the selected combination.

1 . A method for controlling a refrigeration system with a plurality of refrigerating machines in a network, wherein at least some of the plurality of refrigerating machines differ from one another in performance characteristics, wherein the performance characteristics include at least one of cooling capacity, power which can be provided, electrical power consumed, or cooling water temperature, the method comprising:
 a) detecting a requested target cooling capacity and a current cooling water temperature;   b) determining an available cooling capacity of a plurality of chillers in the network based on the cooling capacity performance characteristic and the detected current cooling water temperature;   c) determining one or more possible combinations of the plurality of chillers configured to provide the requested target cooling capacity;   d) selecting, from the one or more possible combinations of the plurality of chillers and based on their respective performance characteristics, a combination configured to provide the highest overall efficiency; and   e) operating the plurality of chillers of the selected combination.   
     
     
         2 . The method according to  claim 1 , further comprising:
 upon a change in the requested target cooling capacity or the detected current cooling water temperature, repeating steps c) to e).   
     
     
         3 . The method according to  claim 1 , wherein the operation of the plurality of chillers of the selected combination is controlled by adjusting the cooling capacity of the respective chiller. 
     
     
         4 . The method according to  claim 1 , wherein the adjustment of the hot water mass flow supplied to the respective chiller is carried out by controlling a feed pump in a respective hot water circuit. 
     
     
         5 . The method according to  claim 1 , wherein in the step of selecting the combination, if several chillers with the same output characteristic are present in the combination, that combination is selected with the chiller with the same output characteristic which has the lowest number of operating hours. 
     
     
         6 . The method according to  claim 1 , wherein in the step of selecting the combination, that combination is selected which has the lowest number of chillers to be operated. 
     
     
         7 . The method according to  claim 1 , wherein in the step of selecting the combination, that combination is selected which requires the smallest number of machine starts. 
     
     
         8 . The method according to  claim 1 , wherein the steps a) to e) are carried out centrally by a main chiller in the network, wherein the main chiller controls remaining chillers in the network as auxiliary or assist chillers. 
     
     
         9 . The method according to  claim 8 , wherein the main chiller in the network also controls peripheral devices of the refrigeration system. 
     
     
         10 . The method according to  claim 8 , wherein the main chiller in the network also monitors malfunctions of the plurality of chillers of the network. 
     
     
         11 . (canceled) 
     
     
         12 . An apparatus for controlling a refrigeration system comprising:
 a plurality of chillers in an arrangement or network, wherein the plurality of chillers have different performance characteristics, wherein the performance characteristics include at least one of cooling capacity, power to be provided, electrical power consumer, or cooling water temperature, wherein the apparatus is configured to:
 a) detect a requested target cooling capacity and a current cooling water temperature; 
 b) determining an available cooling capacity of the plurality of chillers in the network based on the cooling capacity performance characteristic and the detected current cooling water temperature; 
 c) determining one or more possible combinations of the plurality of chillers configured to provide the requested target cooling capacity; 
 d) selecting, from the one or more possible combinations of the plurality of chillers and based on their respective performance characteristics, a combination configured to provide the highest overall efficiency; and 
 e) operating the plurality chillers of the selected combination. 
   
     
     
         13 . The method according to  claim 3 , wherein the cooling capacity of the respective chiller is adjusted based on a hot water mass flow supplied to the respective chiller. 
     
     
         14 . The method according to  claim 8 , wherein main chiller includes the highest capacity of the plurality of chillers present in the network. 
     
     
         15 . The method according to  claim 9 , wherein the peripheral devices of the refrigeration system include at least one of a re-cooling device or a free-cooling device.