Variable speed control of a centrifugal chiller using fuzzy logic
AssigneeYork International Corporation
InventorsGregory K. Beaverson, Russell P. Wueschinski, Craig N. Shores, John C. Hansen
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Abstract
To capacity control a refrigeration system including a compressor, a condenser, and an evaporator all connected in a closed refrigeration circuit, the compressor having a plurality of adjustable inlet guide vanes and driven by an internal combustion engine, signals indicating the condenser pressure; the evaporator pressure; the inlet guide vanes position; the engine speed; the chilled water discharge temperature; and the engine intake manifold pressure are processed by a microprocessor to continuously calculate a surface speed and to equalize engine speed and calculated surface speed utilizing a fuzzy logic algorithm.
Claims14
A capacity control system for a refrigeration system including a compressor, a condenser, and an evaporator all connected in a closed refrigeration circuit, the compressor having a plurality of adjustable inlet guide vanes and a prime mover connected to drive the compressor, said control system comprising:
- a first transducer for sensing condenser pressure to generate a first signal;
- a second transducer for serving evaporator pressure to generate a second signal;
- a third transducer for sensing the position of the inlet guide vanes to generate a third signal;
- a fourth transducer for sensing the actual speed of the prime mover to generate a fourth signal;
- a fifth transducer for sensing the temperature of chilled water discharged from the evaporator to generate a fifth signal;
- a sixth transducer for sensing the load of the prime mover to generate a sixth signal;
- and
- a microprocessor responsive to said first through sixth signals for continuously calculating a surface speed of the prime mover, and for controlling the actual speed of the prime mover to equal the calculated prime mover surface speed utilizing a fuzzy logic algorithm, wherein the prime mover comprises one of an internal combustion engine, an electric motor, and a steam turbine.
A method for controlling the capacity of a refrigeration system having a compressor, a condenser, and an evaporator all connected in a closed refrigeration circuit, the compressor having a plurality of adjustable inlet guide vanes and a prime mover connected to drive the compressor, wherein the prime mover is any one of an internal combustion engine, an electric motor and a steam turbine, said method comprising the steps of:
- generating a first signal representative of the condenser pressure;
- generating a second signal representative of the evaporator pressure;
- generating a third signal representative of the inlet guide vane position;
- generating a fourth signal representative of the prime mover speed;
- generating a fifth signal representative of the temperature of chilled water discharged from the evaporator;
- generating a sixth signal representative of the load of the prime mover;
- generating control signals in response to said first through sixth signals to continuously calculate a surface speed of the prime mover;
- and
- controlling prime mover speed to the calculated surface speed utilizing a fuzzy logic algorithm.
Dependencies are inferred from the claim text.