US 5,802,860 A · Refrigeration system

Abstract

A refrigeration system which controls subcooling by controlling the amount of refrigerant diverted from the condenser to the receiver based upon the difference in temperature between the phase change transition temperature of the refrigerant in the condenser and the liquid refrigerant temperature at the condenser output. Refrigerant is bled from the receiver to charge the system until the condenser pressure causes the difference between the phase change and liquid temperatures to exceed a predetermined value. A controller responds to this condition by simultaneously operating a bleed valve at the receiver inlet and a release valve at its outlet to draw refrigerant from the condenser into the receiver. As the condenser pressure drops, the difference between the phase change and liquid temperatures decreases toward the desired amount, and the cycle begins again.

Claims16

Dependent claims

A system for controlling the circulation of refrigerant through a refrigeration loop including an interconnected condenser and compressor to maintain a desired amount of subcooling of the refrigerant at the output of said condenser, said system comprising:

a receiver for containing refrigerant connected between said condenser and said compressor;
means operably associated with said loop for providing a temperature differential between said refrigerant at the output of said condenser and the phase change temperature of said refrigerant within said condenser;
said receiver connected to said loop by a valve for bleeding refrigerant from said receiver to said loop to increase said temperature differential as the volume of liquid refrigerant within said condenser increases;
and
controller means for diverting refrigerant from said condenser to said receiver when said temperature differential exceeds a predetermined value.

2 more elements

A refrigeration system for optimizing refrigerant subcooling in response to changes in ambient temperature, said system comprising:

a condenser exposed to said ambient temperature having an output;
a compressor having an input and an output, said compressor output being connected to said condenser;
an expansion valve connected between said condenser output and said compressor input;
a receiver connected between said condenser output and said compressor input;
a circuit connected between said receiver and said compressor for bleeding refrigerant from said receiver into said compressor input thereby increasing the volume of liquid refrigerant within said condenser;
a sensor for measuring the refrigerant pressure within said condenser;
a sensor for measuring the refrigerant temperature at said condenser output;
a sensor for measuring said ambient temperature;
and
controller means responsive to said sensors for diverting refrigerant from said condenser to said receiver,
said controller means calculating the phase change temperature of refrigerant within said condenser corresponding to said refrigerant pressure, diverting refrigerant from said condenser to said receiver when the temperature difference between said refrigerant temperature and said phase change temperature exceeds a value constituting the target subcooling, increasing said target subcooling value when the average difference between said refrigerant temperature and said ambient temperature is greater than a predetermined value for a first operating time period, and further decreasing said target subcooling value when said target subcooling value has remained unchanged for a second operating time period, said second operating time period being longer than said first operating time period.

8 more elements

Dependencies are inferred from the claim text.

Refrigeration system

Life of this patent

Refrigeration system

Life of this patent

Abstract

Claims16