Pulsating fluid cooling with frequency control

Abstract

A pulsating fluid cooling device comprising a transducer ( 1 ) for generating a pulsating fluid flow and a fluid guiding structure ( 3 ) for directing the pulsating flow towards an object ( 4 ) to be cooled. The device further comprises a sensor ( 7 ) for detecting at least one variable external to the transducer, a feedback path ( 6 ) for providing a feedback signal 5 indicative of this variable, and control circuitry ( 5 ) arranged to receive the feedback signal and generate a frequency control signal based on said feedback, for controlling a working frequency of the transducer. By providing the control circuitry with information about the conditions at the object, the frequency can be controlled based on actual performance. The performance can be 10 optimized in terms of the measured variable. For example, if the feedback signal includes information about the temperature change of the object, the control circuitry can be arranged to select a working frequency that results in optimal cooling.

1 . A pulsating fluid cooling device comprising a transducer for generating a pulsating fluid flow and a fluid guiding structure for directing the pulsating flow towards an object ( 4 ) to be cooled, the cooling device comprising:
 a sensor for detecting at least one variable external to the transducer,   a feedback path for providing a feedback signal indicative of the variable, and   control circuitry arranged to receive the feedback signal and generate a frequency control signal based on said feedback, for controlling a working frequency of the transducer.   
   
   
       2 . The cooling device according to  claim 1 , wherein said variable relates to conditions at the object ( 4 ) to be cooled. 
   
   
       3 . The cooling device according to  claim 2 , wherein said variable relates to one of a temperature change of the object, a fluid flux in a vicinity of the object and a fluid velocity in a vicinity of the object. 
   
   
       4 . The cooling device according to  claim 1 , wherein the control circuitry includes a voltage controlled oscillator. 
   
   
       5 . The cooling device according to  claim 1 , wherein the control circuitry includes:
 a combination unit for combining a first signal indicative of the phase of the voltage across the transducer and a second signal indicative of the phase of the current through the transducer, so as to generate a phase difference signal, and   a control unit for generating said frequency control signal based on this phase difference signal.   
   
   
       6 . The cooling device according to  claim 1 , wherein the working frequency is the resonance frequency or the anti-resonance frequency of the device. 
   
   
       7 . A method for cooling an object ( 4 ) by generating said pulsating fluid flow and directing said fluid flow towards said object ( 4 ), said method characterized by:
 detecting at least one variable external to the transducer,   providing a feedback signal indicative of this variable, and   generating a frequency control signal based on said feedback, and   using said control signal to control a working frequency of the transducer.   
   
   
       8 . The method according to  claim 7 , wherein said variable relates to conditions at the object to be cooled. 
   
   
       9 . The method according to  claim 8 , wherein said variable relates to one of a temperature change of the object, a fluid flux in a vicinity of the object and a fluid velocity in a vicinity of the object. 
   
   
       10 . The method according to  claim 7 , wherein the working frequency is the resonance frequency or the anti-resonance frequency of the device.