Method for providing a refrigerant medium in a secondary cycle

Abstract

A method for providing a refrigerant medium having a controlled flow temperature in a secondary cycle ( 20 ), wherein the refrigerant medium in the secondary cycle ( 20 ) takes up heat from one or more process coolers ( 22 ) and then gives off heat to primary water in a primary cycle ( 10 ) before it flows back to the process coolers ( 22 ), wherein at least two primary heat exchangers ( 12, 14 ) are present for cooling the refrigerant medium, in addition a bypass line ( 26 ) in the secondary cycle ( 20 ) branches off after exit from the process coolers ( 22 ) for bypassing the primary heat exchangers ( 12, 14 ), and the temperature in the secondary cycle ( 20 ) in the flow to the process coolers ( 22 ) is controlled via the setting of the bypass stream.

1 . A method for providing a refrigerant medium having a controlled flow temperature in a secondary cycle ( 20 ), wherein the refrigerant medium in the secondary cycle ( 20 ) takes up heat from one or more process coolers ( 22 ) and then gives off heat to primary water in a primary cycle ( 10 ) before it flows back to the process coolers ( 22 ), wherein at least two primary heat exchangers ( 12 ,  14 ) are present for cooling the refrigerant medium, in addition a bypass line ( 26 ) in the secondary cycle ( 20 ) branches off after exit from the process coolers ( 22 ) for bypassing the primary heat exchangers ( 12 ,  14 ), and the temperature in the secondary cycle ( 20 ) in the flow to the process coolers ( 22 ) is controlled via the setting of the bypass stream. 
     
     
         2 . The method according to  claim 1 , wherein number and dimensioning of the primary heat exchangers ( 12 ,  14 ) are designed for a high load case, and in a low load case the refrigeration capacity of the primary cycle ( 10 ) is adapted by shutting off one or more of the primary heat exchangers ( 12 ,  14 ), wherein at least one primary heat exchanger remains in operation. 
     
     
         3 . The method according to  claim 2 , wherein the capacity is adapted in such a manner that the pressure drop of the primary water across the primary heat exchangers ( 12 ,  14 ) in operation is in each case at least 300 mbar, preferably at least 800 mbar. 
     
     
         4 . The method according to  claim 1 , wherein the primary heat exchangers ( 12 ,  14 ) are designed for a maximally permissible temperature difference between primary water intake and primary water outlet. 
     
     
         5 . The method according to  claim 1 , wherein the primary heat exchangers ( 12 ,  14 ) are connected in parallel both on the part of the primary cycle ( 10 ) and also on the part of the secondary cycle ( 20 ). 
     
     
         6 . The method according to  claim 1 , wherein the primary heat exchangers ( 12 ,  14 ) are plate heat exchangers or tube-bundle heat exchangers, in particular sealed or welded plate heat exchangers. 
     
     
         7 . Apparatus for carrying out the method according to  claim 1 , comprising one or more process coolers ( 22 ) in the secondary cycle ( 20 ) and also at least one temperature sensor in the flow to the process coolers ( 22 ), wherein at least two primary heat exchangers ( 12 ,  14 ) are present in which the refrigerant medium of the secondary cycle ( 20 ) can release heat to the primary water of the primary cycle ( 10 ), in addition, a bypass line ( 26 ) is present which, in the secondary cycle ( 20 ), branches off after exit from the process coolers ( 22 ) for bypassing the primary heat exchangers ( 12 ,  14 ) and is provided with an actuator, using which the temperature in the secondary cycle ( 20 ) is controllable in the flow to the process coolers ( 22 ). 
     
     
         8 . The apparatus according to  claim 7 , wherein the primary heat exchangers ( 12 ,  14 ) are connected in parallel not only on sides of the primary cycle ( 10 ) but also on sides of the secondary cycle ( 20 ).