Refrigeration device with adaptive automatic defrosting and corresponding defrosting method

Abstract

A refrigeration device including a thermally-insulated housing enclosing an inner chamber to be cooled and an evaporator for cooling the chamber. The evaporator is arranged in an air passage communicating with the chamber through openings in a wall separating the evaporator from the chamber. A control device controls a heating device to heating the evaporator to defrost the evaporator. The air flow through the air passage is measured by a measuring device arranged in the air passage or opening to provide a signal representative of the air flow. When the measured air flow falls below a threshold value, the control device operates the heating device to defrost the evaporator.

1 - 10 . (canceled)  
   
   
       11 . A refrigeration device, comprising: 
 a thermally insulating housing;    said thermally insulating housing enclosing an inner chamber;    said thermally insulating housing enclosing an evaporator arranged in an air passage separated from and communicating with said inner chamber;    a heating device for heating said evaporator;    a control circuit for controlling the operation of said heating device;    a measuring device arranged in said air passage to provide a measured signal representative of the air flow through said air passage; and    said control circuit coupled to said measuring device air flow signal, said control circuit enabled to bring said heating device into operation when the recorded air flow signal falls below a predetermined threshold value.    
   
   
       12 . The refrigeration device according to  claim 11 , wherein said measuring device includes a body driven to move by said air flow in said passage and a sensor to record the movement of said body indicative of the air flow speed and said control circuit determines a fall below said threshold value when the recorded air flow speed falls below said threshold value.  
   
   
       13 . The refrigeration device according to  claim 11 , wherein said measuring device includes an elastic element which can be deflected from a rest position by said air flow in said passage and a sensor to record the deflection of said element indicative of the air flow speed and said control circuit determines a fall below said threshold value when the recorded deflection falls below said threshold value.  
   
   
       14 . The refrigeration device according to  claim 11 , wherein said measuring device includes a pressure sensor to measure a dynamic air pressure in said passage indicative of the air flow speed and said control circuit determines a fall below the threshold value when said recorded pressure rises above said threshold value.  
   
   
       15 . The refrigeration device according to  claim 11 , wherein said measuring device includes two temperature sensors which are thermally differently closely coupled to at least one of a heat source and a sink and the air in said passage indicative of the air flow speed and said control circuit determines a fall below the threshold value when the difference between the temperatures recorded by the two sensors exceeds said threshold value.  
   
   
       16 . The refrigeration device according to  claim 15 , wherein said heat sink is said evaporator.  
   
   
       17 . The refrigeration device according to  claim 16 , including a first one of said temperature sensors arranged directly in contact with said evaporator.  
   
   
       18 . The refrigeration device according to  claim 17 , wherein said first temperature sensor arranged on an area of said evaporator which is capable of icing up.  
   
   
       19 . The refrigeration device according to  claim 18 , including the second one of said temperature sensors arranged on an output of said passage.  
   
   
       20 . A method for controlling the defrosting of an evaporator in refrigeration device, said refrigeration device comprising a thermally insulating housing; said thermally insulating housing enclosing an inner chamber; said thermally insulating housing enclosing an evaporator arranged in an air passage separated from and communicating with said inner chamber; a heating device for heating said evaporator; and 
 a control circuit for controlling the operation of said heating device; said method comprising the following steps:    estimating an air flow through said air passage in which said evaporator ( 7 ) is arranged; and    triggering a defrosting process when the estimated air flow falls below a predetermined threshold value.