Refrigeration plant and method of controlling a refrigeration plant
AssigneeDanfoss A/S
InventorsSven E. Thuesen, Klaus Gollnow
Life of this patent
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Abstract
The refrigeration plant disclosed herein includes an evaporator, a compressor connected to the outlet of the evaporator, a condenser connected to the outlet of the compressor, a controllable expansion valve connected to the outlet of the condenser and having its outlet connected to the evaporator and condenser pressure controls for providing at the least possible condenser pressure, the degree of opening of the expansion valve to obtain an optimum ratio between the condenser pressure and the evaporator evaporator performance. That is, the degree of opening of the expansion valve lies in a range giving the least possible condenser pressure.
Claims15
A refrigeration plant comprising an evaporator having an inlet and outlet, a compressor having an inlet and an outlet connected to the evaporator inlet, a condenser having an outlet and an inlet connected to the compressor outlet, a controllable expansion valve that is openable and closable, the expansion valve being connected to the outlet of the condenser and having an outlet connected to the evaporator and condenser pressure control means for controlling the condenser pressure in accordance with the degree of opening of the expansion valve to obtain an optimum ratio between the condenser pressure and the evaporator performance.
A method for controlling a refrigeration plant having a plurality of expansion valves connected in parallel, comprising evaporating a cooling medium in an evaporator, compressing the evaporated medium, liquefying the compressing medium and returning the liquefied medium through an adjustable opening expansion valve to the evaporator, characterized in that the condenser pressure is in dependence on the degree of opening of the expansion valve, comparing the degrees of the valve openings and controlling the condenser pressure in dependence on the largest degree of the openings of the expansion valve.
A method for controlling a refrigeration plant, comprising evaporating a cooling medium in an evaporator, compressing the evaporated medium, liquefying the compressed medium and returning the liquefied medium through an adjustable opening expansion valve to the evaporator, characterized in that the condenser pressure is in dependence on the degree of opening of the expansion valve, the degree of opening of the expansion valve being controlled in dependance of the superheating of the cooling medium in the evaporator, the controlling step setting in only after a predetermined minimum value of the degree of opening.
A method for controlling a refrigeration plant, comprising evaporating a cooling medium in an evaporator, compressing the evaporated medium, liquefying the compressed medium and returning the liquefied medium through an adjustable opening expansion valve to the evaporator, characterized in that the condenser pressure is in dependance on the degree of opening of the expansion valve, the degree of opening of the expansion valve being controlled in dependence of the superheating of the cooling medium in the evaporator, the controlling step setting in only a predetermined time after exceeding a predetermined minimum valve.
Dependencies are inferred from the claim text.