Oil-cooled gas compressor

Patent metadata

Field	Value
Publication number	US-10001124-B2
Application number	US-201615237990-A
Country	US
Kind code	B2
Filing date	Aug 16, 2016
Priority date	Aug 27, 2010
Publication date	Jun 19, 2018
Grant date	Jun 19, 2018

Abstract

An oil-cooled gas compressor provided with a compressor body, an oil separator that separates out oil from a compressed gas, a gas pipe for sending the compressed gas, from which oil has been separated out by the oil separator, to a user, and an oil pipe for returning, to the compressor, the oil separated out by the oil separator. An air-cooled heat exchanger for cooling the aforementioned oil, a controllable-speed cooling fan for blowing cooling air at said air-cooled heat exchanger, and a waste-heat-recovery heat exchanger, provided upstream of the air-cooled heat exchanger, for recovering heat from the oil flowing through the abovementioned oil pipe, are also provided. 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. It is 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.

First claim

What is claimed is:

1. A gas compressor comprising:
a compressor body;
a gas pipe for sending, to a user, the compressed gas;
an air-cooled heat exchanger for cooling the compressed gas flowing through said gas pipe;
a cooling fan capable of controlling rotational frequency for sending cooling wind to said air-cooled heat exchanger;
a waste-heat-recovery heat exchanger provided upstream of said air-cooled heat exchanger for recovering heat from the compressed gas flowing through said gas pipe;
an oil separator separating out oil from the compressed gas discharged from said compressor body; and
an oil pipe for returning, to said compressor, the oil separated by said oil separator; 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;
the gas pipe sends the compressed gas to a user from the oil separator;
the air-cooled heat exchanger also cools the oil flowing through said oil pipe; and
the waste-heat-recovery heat exchanger also recovers heat from the oil flowing through said oil pipe.

2. The gas compressor according to claim 1 , further comprising:
an oil bypass pipe for flowing the oil exiting from upstream of said waste-heat-recovery heat exchanger to said air-cooled heat exchanger without flowing the oil to said waste-heat-recovery heat exchanger; and
an oil change-over valve changing over the oil from the oil separator between flow to said waste-heat-recovery heat exchanger and flow to said oil bypass pipe.

3. A gas compressor comprising:
a compressor body;
a gas pipe for sending, to a user, the compressed gas;
an air-cooled heat exchanger for receiving the compressed gas flowing through said gas pipe and cooling the compressed gas flowing through said gas pipe;
a cooling fan capable of controlling rotational frequency for sending cooling wind to said air-cooled heat exchanger; and
a waste-heat-recovery heat exchanger provided upstream of said air-cooled heat exchanger for recovering heat from the compressed gas flowing through said gas pipe; 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.

4. The gas compressor according to claim 3 , further comprising:
a gas bypass pipe for flowing the compressed gas exiting from upstream of said waste-heat-recovery heat exchanger to said air-cooled heat exchanger; and
a gas change-over valve changing over the compressed gas in said gas pipe between flow to said waste-heat-recovery heat exchanger and flow to said gas bypass pipe.

5. The gas compressor according to claim 3 , wherein
said waste-heat-recovery heat exchanger is connected to a circulation pipe for guiding fluid from an external waste-heat-recovery equipment and returning the fluid subjected to heat exchange to said waste-heat-recovery equipment; and
the circulation pipe includes a running water detecting sensor.

6. The gas compressor according to claim 5 , further comprising:
a controller controlling the oil change-over valve based on running water information detected by said running water detecting sensor.

7. The gas compressor according to claim 3 , wherein
said waste-heat-recovery heat exchanger is connected to a circulation pipe for guiding fluid from an external waste-heat-recovery equipment and returning the fluid subjected to heat exchange to said waste-heat-recovery equipment; and
said circulation pipe includes a temperature sensor.

8. The gas compressor according to claim 7 , further comprising:
a controller controlling said oil change-over valve based on temperature information from said temperature sensor provided at said circulation pipe.

9. The gas compressor according to claim 7 , wherein
a plurality of said waste-heat-recovery equipment are parallelly connected to said circulation pipe, and are selectively connected based on the temperature information from said temperature sensor.

Assignees

• Hitachi Industry Equipment Systems Co Ltd

Inventors

• Takano Masahiko
• Tanaka Hideharu

Classifications

• F04C18/16

  with helical teeth, e.g. chevron-shaped, screw type {(for non-parallel axes of movement F04C18/48)} · CPC title

• F04C2240/81

  Sensor, e.g. electronic sensor for control or monitoring · CPC title

• F05B2260/20

  Heat transfer, e.g. cooling · CPC title

• F04C2270/195

  Controlled or regulated · CPC title

• F04C29/04 Primary

  Heating; Cooling (of machines or engines in general F01P); Heat insulation (heat insulation in general F16L59/00) · CPC title