Refrigeration system with electrically controlled expansion valve

Claim 1

An energy-efficient refrigeration system comprising: an electrically controlled thermal expansion valve disposed in refrigerant system piping so as to control flow of refrigerant in said refrigeration system; and an expansion valve controller coupled to said thermal expansion valve to provide a control signal thereto, said controller comprising a refrigerant flow sensing device coupled to said refrigeration system to sense a flow control temperature corresponding to refrigerant temperature at a flow measurement site, whereby said thermal expansion valve selectively controls refrigerant flow in said refrigeration system in response to said controller; said thermal expansion valve comprising an orifice chamber, a variable-sized orifice through which the system refrigerant passes, a thermal expansion medium, and a heating element thermally coupled to said thermal expansion medium, said thermal expansion medium comprising a refrigerant-filled elastomer material disposed within said orifice chamber such that the size of said orifice corresponds to the volume of said refrigerant-filled elastomer material, said volume being determined by the pressure of said thermal expansion medium, the volume of said thermal expansion medium being responsive to energy supplied by said heating element.