Turbo refrigerator and startup control method therefor
AssigneeMitsubishi Heavy Industries Thermal Systems, Ltd.
InventorsYoshie Togano, Kenji Ueda, Yasushi Hasegawa
Life of this patent
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Abstract
In order to reduce the effect on a compressor caused by foaming in an oil tank, a control unit for controlling an oil pump starts the oil pump before a compressor is started (SA1), starts the compressor (SA4) when an oil supply differential pressure P satisfies a compressor startup condition during a reference time Tas from the starting of the oil pump (“Yes” in SA3), and extends the operation of the oil pump for a prescribed time without starting the compressor (Step SA5) when the compressor startup condition is not satisfied (“No” in SA3).
Claims10
A centrifugal chiller comprising:
- a compressor which compresses a refrigerant;
- a condenser which condenses the refrigerant compressed by the compressor;
- an expansion valve which expands a liquid refrigerant introduced from the condenser;
- an evaporator which evaporates the refrigerant expanded by the expansion valve;
- an oil tank which stores a lubricant to be supplied to the compressor;
- an oil pump which supplies the lubricant in the oil tank to the compressor;
- and
- a control unit which controls the oil pump,
- wherein the control unit includes
- a processor, and
- a memory storing a program that, when executed by the processor, causes the processor to perform operations, the operations including,
- starting the oil pump before the compressor starts,
- when a reference period elapses from the startup of the oil pump, starting the compressor in a case where an oil supply differential pressure which is a differential pressure between an inlet-side pressure of the compressor and a pressure in the oil tank satisfies a compressor startup condition and extending an operation of the oil pump for a predetermined period without starting the compressor in a case where the oil supply differential pressure does not satisfy the compressor startup condition.
A startup control method for a centrifugal chiller including a compressor which compresses a refrigerant, a condenser which condenses the refrigerant compressed by the compressor, an expansion valve which expands a liquid refrigerant introduced from the condenser, an evaporator which evaporates the refrigerant expanded by the expansion valve, an oil tank which stores a lubricant to be supplied to the compressor, and an oil pump which supplies the lubricant in the oil tank to the compressor,
- the method comprising:
- starting the oil pump before starting the compressor;
- and
- starting the compressor in a case where an oil supply differential pressure which is a differential pressure between an inlet-side pressure of the compressor and a pressure in the oil tank satisfies a compressor startup condition and extending an operation of the oil pump for a predetermined period without starting the compressor in a case where the oil supply differential pressure does not satisfy the compressor startup condition, when a reference period elapses from the startup of the oil pump.
Dependencies are inferred from the claim text.