Method and apparatus for controlling the removal of heat from the condenser in a refrigeration system
AssigneeYork International Corporation
InventorsCurtis C. Crane, John F. Judge
Life of this patent
Estimating the term…
Abstract
This invention increases efficiency of a refrigeration system by maximizing the cooling of the condenser and reducing unnecessary work done by the compressor. In air cooled systems it will also increase the stability of the fans by reducing fan cycling. The fan controller will utilize an algorithm that will consider the following inputs: oil pressure, compressor suction pressure, expansion valve position, compressor loading, last compressor loading change, and current fan stage. The algorithm uses fuzzy logic to characterize the inputs and generates an output that controls the system cooling fans.
Claims37
A refrigeration system that circulates a refrigerant through a closed loop having a high pressure side extending from a compressor, through a condenser, to a flow-restricting expansion device, and a low pressure side extending between the expansion device, through an evaporator, to the compressor, further comprising:
- a variable capacity cooling system to cool refrigerant in the condenser;
- a controller that monitors the pressure associated with the low side of the system;
- and
- wherein the controller adjusts the variable capacity cooling based on that pressure, while maintaining an acceptable pressure in the low pressure side of the system using fuzzy logic principles.
A refrigeration system that circulates a refrigerant through a closed loop having a high pressure side extending from a compressor, through a condenser, to a flow-restricting expansion device, and a low pressure side extending between the expansion device, through an evaporator, to the compressor, the system comprising:
- a variable capacity cooling system to cool refrigerant in the condenser;
- and
- a controller that monitors the pressure associated with the low side of the system and at least one of a lubrication oil pressure for the compressor and a difference in pressure associated with a return oil line and the compressor and adjusts the variable capacity cooling based on the monitored pressures while maintaining an acceptable pressure in the low pressure side of the system and an acceptable pressure associated with the lubrication oil for the compressor.
A method for controlling a refrigeration system that circulates a refrigerant through a closed loop having a high pressure side extending from a compressor, through a condenser, to a flow-restricting expansion device, and a low pressure side extending between the expansion device, through an evaporator, to the compressor, the method comprising:
- monitoring system pressure on the and low side of the system;
- and
- periodically increasing cooling of the refrigerant in the condenser toward the maximum possible level as long as the low pressure side of the system exceeds a minimum threshold value.
A refrigeration system that circulates a refrigerant through a closed loop having a high pressure side extending from a compressor, through a condenser, to a flow-restricting expansion device, and a low pressure side extending between the expansion device, through an evaporator, to the compressor, further comprising:
- a variable capacity cooling system to cool refrigerant in the condenser;
- and
- a controller to monitor pressures associated with the high and low sides of the system and the amount of superheat in the refrigerant applied to the compressor;
- wherein the controller adjusts the variable capacity cooling system to lower the pressure associated with the high side of the system by increasing cooling of refrigerant in the condensor toward or at the maximum level, while maintaining an acceptable pressure differential between the high pressure side of the system and the low pressure side of the system and an acceptable amount of superheat in the refrigerant applied to the compressor.
A refrigeration system that circulates a refrigerant through a closed loop having a high pressure side extending from a compressor, through a condenser, to an adjustable flow-restricting expansion device, and a low pressure side extending between the expansion device, through an evaporator, to the compressor, further comprising:
- a variable capacity cooling system to cool refrigerant in the condenser;
- and
- a controller to monitor pressures associated with the high and low side of the system and an amount of superheat in the refrigerant applied to the compressor;
- wherein the controller adjusts at least one of the variable capacity cooling system and the adjustable flow-restricting expansion device to lower the pressure associated with the high side of the system, while maintaining an acceptable pressure differential between the high pressure side of the system and the low pressure side of the system and an acceptable amount of superheat in the refrigerant applied to the compressor.
A method for controlling a refrigeration system that circulates a refrigerant through a closed loop having a high pressure side extending from a compressor, through a condenser, to a flow-restricting expansion device, and a low pressure side extending between the expansion device, through an evaporator, to the compressor, the method comprising:
- monitoring system pressure on the high side and low side of the system;
- monitoring superheat of the refrigerant in the low pressure side of the system;
- and
- periodically increasing cooling of the refrigerant in the condenser toward the maximum possible level as long as the superheat of the refrigerant in the low pressure side of the system exceeds a minimum threshold value and a refrigerant pressure differential between the high and low pressure sides of the system exceeds a minimum threshold value.
Dependencies are inferred from the claim text.