Gas compressor

Patent metadata

Field	Value
Publication number	US-10030646-B2
Application number	US-201615099809-A
Country	US
Kind code	B2
Filing date	Apr 15, 2016
Priority date	Oct 16, 2012
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

A gas compressor includes a compressor unit having a compressor body for compressing gas and an electricity-generation device generating electricity by obtaining a driving force by vaporizing a working fluid utilizing exhaust heat generated by a compressing action in the compressor body and expanding the working fluid so as to utilize the power generated by the electricity-generation device as a power source, and includes a switch device switching between power from the electricity generation device and power from a commercial power supply to supply power to the power consumption equipment, and a control device detecting an electricity-generation amount or a value correlative to the electricity generation amount and switching between the powers by the switch device, thereby generating the power using exhaust heat as a heat source to surely drive an auxiliary machine by a simple configuration regardless of a shortage of the electricity generation amount.

First claim

What is claimed is:

1. A gas compressor including a compressor unit having a compressor body for compressing a gas and an electricity generation device for generating electricity by obtaining a driving force by vaporizing a working fluid utilizing exhaust heat generated by compressing action in the compressor body and expanding the working fluid and utilizing power generated by the electricity generation device as a power supply of power consumption equipment in the gas compressor, comprising:
a switch device for switching between the power generated by the electricity generation device and power obtained from a commercial power supply to supply the power to the power consumption equipment, and
a control device for detecting an electricity generation amount of the electricity generation device or a value correlative to the electricity generation amount and making the switch device switch between the power generated by the electricity generation device and the power obtained from the commercial power supply on the basis of at least one of the electricity generation amount and the correlative value, wherein
the control device controls the switch device on the basis of a time elapsed after activation of the compressor.

2. The gas compressor according to claim 1 , wherein
the gas compressor is an oil-cooled gas compressor including an oil separator for separating oil from the compressed gas discharged from the compressor body, a gas pipe for sending the compressed gas from which the oil has been separated by the oil separator to a demander and an oil pipe for returning the oil separated by the oil separator to the compressor, and
the power generation device configures a Rankine cycle by including an exhaust heat recovery heat exchanger for exchanging heat between the oil flowing through the oil pipe and the working fluid to cool the oil and to heat and vaporize the working fluid, an expander which is driven by expanding the working fluid vaporized by the exhaust heat recovery heat exchanger, a condenser for cooling and condensing the working fluid from the expander, and a circulating pump for supplying the working fluid condensed by the condenser to the exhaust heat recovery heat exchanger, and includes an electric generator driven by the expander to generate electricity.

3. The gas compressor according to claim 2 , further comprising:
an air-cooled heat exchanger for cooling the oil flowing through the oil pipe; and
a cooling fan for sending cooling air to the air-cooled heat exchanger, wherein
the exhaust heat recovery heat exchanger is disposed upstream of the air-cooled heat exchanger.

4. The gas compressor according to claim 3 , wherein
the air-cooled heat exchanger is adapted to cool also the compressed gas flowing through the gas pipe, and the exhaust heat recovery heat exchanger is adapted to recover heat also from the compressed gas flowing through the gas pipe.

5. The gas compressor according to claim 4 , further comprising:
a discharge temperature sensor for detecting a temperature of the compressed gas discharged from the compressor body;
an oil outlet temperature sensor for detecting a temperature of the gas gone out of the exhaust heat recovery heat exchanger, and
a gas outlet temperature sensor for detecting a temperature of the compressed gas gone out of the exhaust heat recovery heat exchanger.

6. The gas compressor according to claim 3 , wherein
the power consumption equipment is a fan motor for driving the cooling fan.

7. The gas compressor according to claim 6 , wherein
the electric generator is a DC generator, the number of rotations of the fan motor for driving the cooling fan is controlled by supplying the power from the commercial power supply to the fan motor via an inverter, also DC power generated by the electricity generation device is supplied to the inverter, and the switch device for switching between the power generated by the electricity generation device and the power obtained from the commercial power supply so as to supply the power to the fan motor is incorporated into the inverter.

8. The gas compressor according to claim 7 , wherein
the control device controls the number of rotations of the cooling fan via the inverter on the basis of the temperature of the oil detected by the oil outlet temperature sensor such that the temperature of the oil reaches a predetermined temperature or a temperature within a predetermined temperature range.

9. The gas compressor according to claim 8 , wherein
the condenser of the electricity generation device is cooled with air sent from the cooling fan, a number of rotations of the cooling fan for the condenser is also controlled by the inverter, the inverter generates two frequencies so as to individually control the numbers of rotations of the cooling fan for the air-cooled heat exchanger and the cooling fan for the condenser, and the cooling fan for the condenser is controlled on the basis of the temperature of the oil detected by the oil outlet temperature sensor.

10. The gas compressor according to claim 2 , wherein
the condenser of the electricity generation device is cooled with air sent from the cooling fan, and the power consumption equipment is a fan motor for driving the cooling fan.

11. The gas compressor according to claim 10 , wherein
the electric generator is a DC generator, the number of rotations of the fan motor for driving the cooling fan is controlled by supplying the power from the commercial power supply to the fan motor via an inverter, also DC power generated by the electricity generation device is supplied to the inverter, and the switch device for switching between the power generated by the electricity generation device and the power obtained from the commercial power supply so as to supply the power to the fan motor is incorporated into the inverter.

12. The gas compressor according to claim 11 , further comprising:
an oil outlet temperature sensor for detecting the temperature of oil gone out of the exhaust heat recovery heat exchanger, wherein
the number of rotations of the cooling fan for the condenser is controlled by the inverter such that the temperature detected by the oil outlet temperature sensor reaches a predetermined temperature or a temperature within a predetermined temperature range.

13. The gas compressor according to claim 1 , wherein
the electricity generation device configures a Rankine cycle by including an exhaust heat recovery heat exchanger for exchanging heat between the compressed gas compressed by the compressor body and the working fluid to cool the compressed gas and to heat and vaporize the working fluid, an expander driven by expanding the working fluid vaporized by the exhaust heat recovery heat exchanger, a condenser for cooling and condensing the working fluid sent from the expander and a circulating pump for supplying the working fluid condensed by the condenser to the exhaust heat recovery heat exchanger, and includes an electric generator driven by the expander to generate electricity.

14. The gas compressor according to claim 13 , wherein
the power generator is a DC generator, and DC power generated by the DC generator is supplied to the power consumption equipment via an AC converter.

15. The gas compressor according to claim 13 , wherein
the compressor unit includes an air-cooled heat exchanger for cooling the compressed gas compressed by the compressor body and discharged, and a cooling fan for sending cooling air to the air-cooled heat exchanger, and the power consumption equipment is a fan motor for driving the cooling fan.

16. The ga

Assignees

• Hitachi Industry Equipment Systems Co Ltd

Inventors

• Yamamoto Kentaro
• Kamiya Yuji
• Takano Masahiko

Classifications

• F04B17/03

  driven by electric motors · CPC title

• F04B49/06 Primary

  Control using electricity (regulating by means of floats actuating electric switches F04B49/04) · CPC title

• F04B35/04

  the means being electric · CPC title

• F01K15/00

  Adaptations of plants for special use {(F01K7/02 takes precedence)} · CPC title

• F01K13/02 Primary

  Controlling, e.g. stopping or starting · CPC title