Refrigeration unit with air humidity monitoring

Abstract

A refrigeration appliance includes a storage chamber, an evaporator that cools the storage chamber, and a processing unit configured to assign values for the air humidity in the storage chamber and an evaporation temperature of the evaporator to one another, at a given temperature of the storage chamber, under the assumption that the absolute water vapor content of the air of the storage chamber is the same as that of water-vapor-saturated air at the evaporation temperature. This assignment makes it possible on one hand to estimate the relative air humidity in the storage chamber on the basis of the temperatures, and on the other hand to control the air output temperature, at constant temperature in the storage chamber, in order to influence the air humidity therein.

1 - 10 . (canceled) 
     
     
         11 . A refrigeration appliance, comprising:
 a storage chamber;   an evaporator for cooling said storage chamber; and   a processing unit configured to assign values for air humidity in said storage chamber and an evaporation temperature of said evaporator to one another at a defined temperature of said storage chamber, under an assumption that an absolute water vapor content of air in said storage chamber equals an absolute water vapor content of water vapor-saturated air at the evaporation temperature.   
     
     
         12 . The refrigeration appliance according to  claim 11 , which further comprises:
 sensors for measuring the temperature of said storage chamber and the evaporation temperature;   said processing unit being configured to estimate the air humidity by assignment to a defined value of the evaporation temperature; and   a display instrument connected to said processing unit for displaying an estimated air humidity.   
     
     
         13 . The refrigeration appliance according to  claim 11 , which further comprises:
 an operating element for setting the air humidity in said storage chamber as a set point variable;   said processing unit being connected to said operating element and being configured to estimate a target value of the evaporation temperature by assignment to a defined value of the air humidity and to align a real evaporation temperature of said evaporator with the target value.   
     
     
         14 . The refrigeration appliance according to  claim 13 , which further comprises a compressor having a mass throughput being used by said processing unit to control the evaporation temperature of said evaporator. 
     
     
         15 . The refrigeration appliance according to  claim 13 , which further comprises at least one throttle valve connected in series with said evaporator, said at least one throttle valve having an opening cross section being used by said processing unit to control the evaporation temperature of said evaporator. 
     
     
         16 . The refrigeration appliance according to  claim 11 , wherein the evaporation temperature is higher for a high defined value than for a low defined value of the air humidity, at a defined temperature of said storage chamber. 
     
     
         17 . The refrigeration appliance according to  claim 11 , which further comprises a fan with a controllable throughput for circulating air between said evaporator and said storage chamber. 
     
     
         18 . The refrigeration appliance according to  claim 17 , wherein the refrigeration appliance is a no-frost appliance. 
     
     
         19 . The refrigeration appliance according to  claim 17 , wherein said fan has a throughput being higher for a high defined value of air humidity than for a low defined value of air humidity, at a defined temperature of said storage chamber. 
     
     
         20 . A method for estimating a relative air humidity in a refrigeration appliance or a household refrigerator having a storage chamber and an evaporator for cooling the storage chamber, the method comprising the following steps:
 a) measuring a temperature of the storage chamber;   b) measuring an evaporation temperature of the evaporator; and   c) calculating a relative humidity of air at the temperature of the storage chamber, while an absolute moisture content of the air in the storage chamber is equal to an absolute moisture content of water vapor-saturated air at the evaporation temperature.   
     
     
         21 . A method for operating a refrigeration appliance or a household refrigerator having a storage chamber and an evaporator for cooling the storage chamber, the method comprising the following steps:
 a′) determining a set point temperature of the storage chamber;   b′) determining a set point air humidity of the storage chamber; and   c′) setting an evaporation temperature of the evaporator to cause an absolute moisture content of water vapor-saturated air at an evaporation temperature to be equal to an absolute moisture content of air having the set point air humidity at the set point temperature.