Method of controlling a device including hilsch-ranque vortex tubes

Abstract

A method of controlling a device for air conditioning ( 80 ) or cooling by refrigeration ( 10 ) or heating the interior of a sealed chamber ( 12 ), the device ( 10, 80 ) including at least one compressed air source ( 16, 30 ) which supplies at least one Hilsch-Ranque tube ( 24 ), called “vortex” tube, with compressed air at an injection pressure (P inj ), is characterized in that a tapered relief valve ( 48 ) of the tube ( 24 ) is preset so that the first (FC) and second (FF) fractions of cold and hot air are constant while the method is running and in that it includes a step (E 3, C 4 ) for controlling the compressed air injection pressure (P inj ). A device for implementing such a method is also described.

1 . Method of controlling a device for air conditioning ( 80 ) or cooling by refrigeration ( 10 ) or heating the interior of a sealed chamber ( 12 ), the device ( 10 ,  80 ) comprising at least one compressed air source ( 16 ,  30 ) which supplies at least one Hilsch-Ranque tube ( 24 ), called “vortex” tube, with compressed air at an injection pressure (P inj ), the Hilsch-Ranque vortex tube ( 24 ) comprising:
 at least one tangential orifice ( 40 ) for injecting compressed air into the Hilsch-Ranque vortex tube ( 24 ) which is arranged close to a first end ( 36 ) of the Hilsch-Ranque vortex tube, the injected air forming a first incoming stream of swirling air ( 44 ) towards a second end ( 38 ) of the Hilsch-Ranque vortex tube;   a tapered relief valve ( 48 ) which partially blocks off a first expulsion orifice ( 46 ) of the second end ( 38 ) of the Hilsch-Ranque vortex tube so that a first fraction (FC) of the incoming hot air stream ( 44 ) is expelled outside the chamber ( 12 ) while a second fraction (FF) of the air stream is reflected towards the first end ( 36 ) of the Hilsch-Ranque vortex tube forming a second concentric swirling air stream ( 52 ) inside the first swirling stream ( 44 ), the reflected air stream ( 52 ) being cooled by heat exchange with the incoming air stream ( 44 );   a “cold” outlet orifice ( 56 ) for the reflected air ( 52 ) which is arranged at the first end ( 36 ) of the Hilsch-Ranque vortex tube so as to allow the second fraction (FF) of the cold air stream ( 52 ) to leave inside the chamber ( 12 );   characterized in that the tapered relief valve ( 48 ) is preset so that the first (FC) and second (FF) fractions of air are constant while the method is running and in that it comprises a step (E 3 , C 4 ) for controlling the compressed air injection pressure (P inj ).   
   
   
       2 . Control method according to  claim 1 , characterized in that the outlet temperature (θ SF ) of the cold air stream is controlled by acting only on the injection pressure (P inj ) of the air into the Hilsch-Ranque vortex tube ( 24 ) according to a predetermined control law (EQ7). 
   
   
       3 . Control method according to  claim 1 , characterized in that it comprises a step (C 2 ) for calculating the outlet temperature (θ SF ) of the cold air stream prior to the step for controlling the injection pressure (C 4 ) during which said outlet temperature (θ SF ) is calculated by subtracting a predetermined constant value from the compressed air injection temperature (θ inj ),
 and in that it comprises a step for correcting (C 3 ) the calculated cold air stream outlet temperature (θ SF ), which is triggered when said outlet temperature (θ SF ) during the preliminary calculation step (C 2 ) is less than a minimum temperature (θ min ) and during which the outlet temperature (θ SF ) is corrected so as to be greater than or equal to said minimum temperature (θ min ).   
   
   
       4 . Control method according to  claim 3 , characterized in that the compressed air source ( 16 ) is an air compressor which sucks in ambient air from outside the chamber ( 12 ), and in that the injection temperature (θ inj ) is proportional to the external temperature (θ ext ) of the chamber ( 12 ). 
   
   
       5 . Control method according to  claim 4 , characterized in that the chamber ( 12 ) is a passenger compartment of a motor vehicle in which the air conditioning device ( 80 ) is installed and in that the air compressor ( 16 ) is driven by the heat engine of the motor vehicle through the intermediary of a hydraulic pump and a hydraulic motor. 
   
   
       6 . Control method according to  claim 2 , characterized in that the injection pressure (P inj ) is controlled by pulses at an injection pressure (P inj ) which is predetermined, the duration (t) of each pulse being determined in such a way that the chamber ( 12 ) is maintained at a setpoint temperature (θ c ). 
   
   
       7 . Method according to  claim 6 , characterized in that the duration (t) of each pulse is determined as a function of the ambient temperature inside the chamber (θ int ), of the injection temperature of compressed air into the Hilsch-Ranque vortex tube (θ inj ), and of the setpoint temperature (θ c ). 
   
   
       8 . Control method according to  claim 7 , characterized in that the duration (t) of each pulse is determined by taking into account the balance (EQ1) between:
 the sum of the heat losses (Q dep ) through the walls of the chamber ( 12 ) per time unit and the quantity of heat to be removed (Q ref ) to cool the air inside the chamber ( 12 ) to the setpoint temperature (θ c ), and   the quantity of heat (Q m,af ) likely to be absorbed by the cold air leaving each Hilsch-Ranque vortex tube ( 24 ) for said time unit.   
   
   
       9 . Method according to  claim 7 , characterized in that the air is dried by drying means ( 60 A,  60 B) before its injection into each Hilsch-Ranque vortex tube ( 24 ) so that its dew point is less than the air outlet temperature (θ SF ). 
   
   
       10 . Device ( 10 ,  80 ) for implementing the method according to  claim 1 , characterized in that it comprises a plurality of Hilsch-Ranque vortex tubes ( 24 ) which are fed in parallel by at least one common compressed air source ( 16 ,  30 ) and in that each Hilsch-Ranque vortex tube ( 24 ) includes a tapered relief valve ( 48 ) that can be adjusted only manually. 
   
   
       11 . Method according to  claim 8 , characterized in that the air is dried by drying means ( 60 A,  60 B) before its injection into each Hilsch-Ranque vortex tube ( 24 ) so that its dew point is less than the air outlet temperature (θ SF ).