Actuating unit for a heat exchanger, heat exchanger, and a method for controlling a heat exchanger

Abstract

A control unit for a heat exchanger is programmed to receive information on an ambient temperature, an ambient humidity, an amount of water of a wetting device for wetting the heat exchanger and a number of rotations of a ventilator of the heat exchanger and to calculate an amount of spray water based on the information and set the wetting device to wet the heat exchanger with the calculated amount of spray water.

1 . A control unit for a heat exchanger, the control unit being programmed to receive information on an ambient temperature, an ambient humidity, an amount of water of a wetting device for wetting the heat exchanger and a number of rotations of a ventilator of the heat exchanger and to calculate an amount of spray water based on the information and set the wetting device to wet the heat exchanger with the calculated amount of spray water. 
     
     
         2 . The control unit in accordance with  claim 1 , wherein the control unit is programmed to receive information on at least one of a geodetic level and the calculated amount of spray water, representing an estimated value for an amount of evaporation. 
     
     
         3 . The control unit in accordance with  claim 1 , wherein the control unit is programmed to to calculate a cost function based on a parameter and to set the heat exchanger to minimize the cost function. 
     
     
         4 . The control unit in accordance with  claim 3 , wherein the parameter is at least one of a water price for the wetting device and an electricity price for the ventilator. 
     
     
         5 . The control unit in accordance with  claim 1 , wherein the control unit is programmed to set a target number of rotations of the ventilator. 
     
     
         6 . The control unit in accordance with  claim 1 , wherein the control unit is programmed to set the wetting device with a PI regulator. 
     
     
         7 . A heat exchanger comprising the control unit in accordance with  claim 1 . 
     
     
         8 . The heat exchanger in accordance with  claim 7 , comprising
 a module including a plurality of transfer elements and a plurality of heat exchanger fins connected to the transfer elements in a heat conducting manner and forming an air passage, and a ventilator configured to generate an air flow in the air passage, the wetting device being arranged at the heat exchanger and configured to wet the heat exchanger with a wetting fluid.   
     
     
         9 . The heat exchanger in accordance with  claim 7 , further comprising a control device associated with the ventilator, configured to receive a target number of rotations from the control unit, and configured to set the target number of rotations at the ventilator. 
     
     
         10 . The heat exchanger in accordance with  claim 7 , wherein the wetting device is configured to wet at least one of the module, the transfer elements, the heat exchanger fins and a wetting mat with liquid. 
     
     
         11 . A method of regulating a heat exchanger, comprising:
 calculating, with a control unit, an amount of spray water based on an ambient temperature, an ambient humidity, an amount of water of a wetting device for wetting the heat exchanger and a number of rotations of a ventilator of the heat exchanger; and   setting, with a control unit, the wetting device such that the heat exchanger is wetted with the calculated amount of spray water.   
     
     
         12 . The method in accordance with  claim 11 , further comprising, in a first mode of operation, setting the ventilator to a maximum target number of rotations, and setting the wetting device to a maximum amount of spray water. 
     
     
         13 . The method in accordance with  claim 12 , wherein, in a second mode of operation, the calculating the amount of spray water includes calculating an estimated value for an amount of evaporation. 
     
     
         14 . The method in accordance with  claim 11 , further comprising, in a third mode of operation, calculating a cost function based on a parameter and setting the heat exchanger to minimize the cost function. 
     
     
         15 . The method in accordance with  claim 11 , wherein calculating the amount of spray water based on at least one of a geodetic level and a mode of operation of the heat exchanger is derived in dependence on a liquefaction temperature.