초록 ▼

A method and apparatus for controlling the capacity of a multi-stage cooling system is disclosed. The system of the invention utilizes a plurality of commonly piped compressors having common suction load wherein at least one compressor being a variable speed compressor, means for establishing a sing

A method and apparatus for controlling the capacity of a multi-stage cooling system is disclosed. The system of the invention utilizes a plurality of commonly piped compressors having common suction load wherein at least one compressor being a variable speed compressor, means for establishing a single predetermined cooling stage “cut-in”pressure and a single predetermined cooling stage “cut-out”pressure, a plurality of condenser fans and a microprocessor based control means for controlling the operation of the system.

대표청구항 ▼

A refrigeration system having in a closed loop connection a compressor for compressing a refrigerant, condensing means for condensing the compressed refrigerant from the compressor and discharging the condensed refrigerant at a discharge pressure into an outlet of said condensing means, said system

A refrigeration system having in a closed loop connection a compressor for compressing a refrigerant, condensing means for condensing the compressed refrigerant from the compressor and discharging the condensed refrigerant at a discharge pressure into an outlet of said condensing means, said system further comprising: (a) a pre-selected number of condenser fans, at least one condenser fan being adapted to operate between a maximum and a minimum operating speed; (b) discharge pressure selection means for establishing a first and second discharge pressure range, each said discharge pressure range having an upper and a lower limit, the first discharge pressure range being associated with the variable speed fan and the second discharge pressure range being associated with the remaining fans; (c) detection means for sensing the discharge pressure and for cooperating with the discharge pressure selection means to provide an increase speed signal when the discharge pressure exceeds the upper limit of the first discharge pressure range, a decrease speed signal when the discharge pressure falls below the lower limit of the first discharge pressure range, an increase capacity signal when the discharge pressure exceeds the upper limit of the second discharge pressure range and when the variable speed fan is operating at the maximum speed, and a decrease capacity signal when the discharge pressure falls below the lower limit of the second pressure range and when the variable speed fan is operating at the minimum speed; and (d) selection means for receiving the increase speed and decrease speed signals and in respective response thereto increasing and decreasing the speed of the variable speed fan, and for receiving the increase capacity and decrease capacity signals and in respective response thereto energizing and deenergizing a fan of the refrigeration compressor system.