Method and device for controlling a volume flow of a wetting fluid during adiabatic cooling

Abstract

In a method for controlling a volume flow of a wetting fluid during adiabatic cooling, an evaporation surface is wetted with the wetting fluid which flows therealong and air to be cooled and/or wetted is directed substantially transversely relative to the flow direction ( 15 ) of the wetting fluid the volume flow of the wetting fluid flowing over the evaporation surface is reduced after a predetermined period of wetting of the evaporation surface and, after the volume flow is reduced, temperatures (T 1 , T 2 ) and/or time/temperature gradients (ΔT 1 , ΔT 2 ) of the directed air are established at least at two different positions in the flow direction substantially parallel with the evaporation surface, with the volume flow of the wetting fluid being controlled in accordance with the established temperatures (T 1 , T 2 ) and/or time/temperature gradients (ΔT 1 , ΔT 2 ).

1 . Method for controlling a volume flow of a wetting fluid during adiabatic cooling, an evaporation surface being wetted with the wetting fluid which flows along the evaporation surface and the air to be cooled and/or to be wetted being directed substantially transversely relative to the flow direction of the wetting fluid over the evaporation surface,
 wherein   the volume flow of the wetting fluid flowing over the evaporation surface is reduced after a predetermined period of wetting of the evaporation surface and, after the volume flow is reduced, temperatures (T 1 , T 2 ) and/or time/temperature gradients (ΔT 1 , ΔT 2 ) of the air directed past the evaporation surface are established at least at two different positions in the flow direction of the wetting fluid substantially parallel with the evaporation surface, with the volume flow of the wetting fluid being controlled in accordance with the established temperatures (T 1 , T 2 ) and/or time/temperature gradients (ΔT 1 , ΔT 2 ).   
     
     
         2 . Method according to  claim 1 , wherein, in order to control the volume flow of the wetting fluid supplied to the evaporation surface, at least two temperatures (T 1 , T 2 ) which are established at different positions for one measurement time or at least two time/temperature gradients (ΔT 1 , ΔT 2 ) of the air which is directed past the evaporation surface, which time/temperature gradients (ΔT 1 , ΔT 2 ) are established at different positions, are compared. 
     
     
         3 . Method according to  claim 1  wherein the volume flow of the wetting fluid supplied to the evaporation surface is controlled in the event of a deviation of at least two temperatures (T 1 , T 2 ) established at different positions for one measurement time or at least two time/temperature gradients (ΔT 1 , ΔT 2 ) established at different positions in respect of the air directed past the evaporation surface. 
     
     
         4 . Method according to  claim 1 , wherein the volume flow of the wetting fluid supplied to the evaporation surface is reduced when the established temperatures (T 1 , T 2 ) or the established time/temperature gradients (ΔT 1 , ΔT 2 ) of the air directed past the evaporation surface are substantially identical at the at least two different positions in the flow direction of the wetting fluid and substantially transversely relative to the flow direction of the air to be cooled, or if the temperatures (T 1 , T 2 ) or time/temperature gradients (ΔT 1 , ΔT 2 ) established at least at two different positions in respect of the air directed past the evaporation surface indicate a temperature increase in the flow direction of the wetting fluid. 
     
     
         5 . Method according to  claim 1 , wherein the volume flow of the wetting fluid supplied to the evaporation surface is increased if the temperatures (T 1 , T 2 ) or time/temperature gradients (ΔT 1 , ΔT 2 ) established at the at least two different positions in respect of the air directed past the evaporation surface indicate a temperature increase counter to the flow direction of the wetting fluid. 
     
     
         6 . Method according to  claim 1 , wherein the wetting fluid is supplied for a predetermined period of time to the evaporation surface at a volume flow which is increased in comparison with the controlled volume flow. 
     
     
         7 . Method according to  claim 1 , wherein the evaporation surface is a surface of a contact wetter, past which the air to be cooled is directed, which surface can be wetted with wetting fluid. 
     
     
         8 . Method according to  claim 1 , wherein the evaporation surface is constructed as a pipe register of an air/fluid heat exchanger in which a heat transfer medium is directed through the pipe register for adiabatic cooling and the air to be wetted is directed around the pipe register, the outer surface of the pipe register being wetted with wetting fluid during cooling. 
     
     
         9 . Method according to  claim 1 , wherein the evaporation surface is in the form of part of an air/air plate heat exchanger in which cooling air is wetted with the wetting fluid before it is introduced into the air/air plate heat exchanger. 
     
     
         10 . Method according to  claim 1 , wherein the temperatures (T 1 , T 2 ) are established by means of corresponding temperature sensors, the temperature sensors for the comparison of established temperatures (T 1 , T 2 ) before the evaporation surface is wetted and before the adiabatic cooling being calibrated in such a manner that the temperature sensors have, before the wetting begins, a desired temperature difference in the flow direction of the wetting fluid. 
     
     
         11 . Device for controlling a volume flow of a wetting fluid during adiabatic cooling, which device has an evaporation surface which can be wetted with the wetting fluid provided by a wetting device and which can exchange heat during the adiabatic cooling and/or wetting with the air to be cooled and/or to be wetted, the volume flow of the wetting fluid which flows along the evaporation surface during cooling and/or wetting being controllable and the air to be cooled and/or to be wetted flowing substantially transversely relative to the flow direction of the wetting fluid and over the evaporation surface,
 wherein,   in order to control the volume flow of the wetting fluid, there are provided at least two temperature sensors which are arranged downstream of the evaporation surface in the flow direction of the wetting fluid and in relation to the flow direction of the air to be cooled.   
     
     
         12 . Device according to  claim 11 , characterized in that the evaporation surface is a surface of a contact wetter, which surface can be wetted with the wetting fluid, and in that the cooling of the air to be cooled is carried out in a direct adiabatic manner. 
     
     
         13 . Device according to  claim 11 , wherein the evaporation surface is in the form of a pipe register of an air/fluid heat exchanger, in which a heat transfer medium flows through the pipe register and the air to be cooled flows around the pipe register, the air/fluid heat exchanger having the wetting device by means of which the external surface of the pipe register can be wetted with the wetting fluid. 
     
     
         14 . Device according to  claim 11 , wherein the evaporation surface is in the form of part of an air/air plate heat exchanger, in which the air to be cooled exchanges its heat in an indirect adiabatic manner with cooling air which is wetted with the wetting fluid before it is introduced into the air/air plate heat exchanger. 
     
     
         15 . Device according to  claim 11 , wherein the at least two temperature sensors are arranged outside the air/air plate heat exchanger at the outlet side for the air to be cooled.