Method for Estimating the Heat Load Imposed on a Cryogenic Refrigerator, Associated Program Product, and Method for Controlling the Refrigerator

Abstract

The invention relates to a method for estimating a heat load imposed on a cryogenic refrigerator, to an associated computer program product, and to a method for controlling the cooling power output by said refrigerator. As the refrigerator ( 1, 1 ′) includes a phase separator ( 40, 40 ′) comprising a bath ( 41, 41 ′) of refrigerant, the method for estimating the heat load imposed on said refrigerator includes a step in which said heat load is estimated using a program executed by a computer, said program being based on a mass balance carried out on the phase separator for expressing variations in the time drift of the height of the bath of refrigerant in the phase separator.

1 . A method for estimating a thermal load applied to a cryogenic refrigerator comprising a phase separator containing a bath of liquid refrigerant, in which this thermal load is estimated using a computer program, said program being based on a mass balance performed on the phase separator allowing the variation in the time derivative of the height of the bath of liquid refrigerant in the phase separator to be expressed. 
     
     
         2 . The method as claimed in  claim 1 , in which the thermal load applied to the cryogenic refrigerator is a variable thermal load. 
     
     
         3 . The method as claimed in  claim 1 , in which the variable thermal load applied to the cryogenic refrigerator is pulsed. 
     
     
         4 . The method as claimed in  claim 1 , in which a step is provided for determining appropriate variables of the cryogenic refrigerator, representing the variation in the time derivative of the height of the bath of liquid refrigerant in the phase separator, before the step of estimating the thermal load using the computer program. 
     
     
         5 . The method as claimed in  claim 1 , in which, the cryogenic refrigerator comprising a valve at the inlet of the phase separator, said appropriate variables comprise at least the degree of opening of the valve, the temperature upstream of the valve and their respective time derivatives, and the thermal load. 
     
     
         6 . The method as claimed in  claim 4 , in which the computer program comprises a step in which the data relating to the variation in the time derivative of the height of the bath of liquid refrigerant in the phase separator are filtered. 
     
     
         7 . A method for regulating the cryogenic refrigerator subjected to a thermal load, in which the thermal load applied to the refrigerator is estimated using the method as claimed in  claim 1 , and then at least one operating parameter of the refrigerator is regulated depending on the value of the thermal load estimated beforehand. 
     
     
         8 . The method as claimed in  claim 7 , in which the regulating step is implemented by modifying the degree of opening of the valve of the refrigerator, said valve being located at the inlet of the phase separator. 
     
     
         9 . A computer program product comprising programming code instructions for implementing a method as claimed in  claim 1 .