Oil-cooled gas compressor

摘要

An oil-cooled gas compressor provided with: a compressor body (3); an oil separator (6) that separates out oil from a compressed gas; a gas pipe (8) for sending the compressed gas, from which oil has been separated out by the oil separator, to a user; and an oil pipe (7) for returning, to the compressor, the oil separated out by the oil separator. The following are also provided: an air-cooled heat exchanger (13) for cooling the aforementioned oil; a controllable-speed cooling fan (14) for blowing cooling air at said air-cooled heat exchanger; and a waste-heat-recovery heat exchanger (10), provided upstream of the air-cooled heat exchanger, for recovering heat from the oil flowing through the abovementioned oil pipe. The speed of the cooling fan is controlled so as to bring the temperature of the compressed gas discharged from the compressor body to within a prescribed range. This makes it possible both to recover waste heat from the oil heated by being used to cool the compressor, and to suppress compressor temperature fluctuations even if the load on the waste-heat-recovery equipment varies.

主权项

1. An oil-cooled gas compressor comprising: a compressor body; an oil separator separating out oil from compressed gas discharged from said compressor body; a gas pipe for sending, to a user, the compressed gas separated from the oil by said oil separator; and an oil pipe for returning, to said compressor, the oil separated by said oil separator, the oil-cooled gas compressor further comprising:
an air-cooled heat exchanger for cooling the oil flowing through said oil pipe; a cooling fan with a controllable rotational frequency for sending cooling wind to said air-cooled heat exchanger; a waste-heat-recovery heat exchanger, being provided upstream of said air-cooled heat exchanger, in which the oil flowing is heat-exchanged with cooling fluid flowing for recovering heat from the oil flowing through said oil pipe; and a discharge temperature sensor detecting temperature of the compressed gas discharged from said compressor body, wherein the rotational frequency of said cooling fan is controlled in a manner such that temperature of the compressed gas discharged from said compressor body falls within a prescribed range in accordance with the temperature detected by said discharge temperature sensor, and wherein said air-cooled heat exchanger also cools compressed gas flowing through said gas pipe, and said waste-heat-recovery heat exchanger also recovers heat from the compressed gas flowing through said gas pipe.