Title:
BOIL-OFF GAS RELIQUEFACTION SYSTEM, METHOD FOR DISCHARGING LUBRICATING OIL IN BOIL-OFF GAS RELIQUEFACTION SYSTEM, AND ENGINE FUEL SUPPLY METHOD
Document Type and Number:
WIPO Patent Application WO/2019/027067
Kind Code:
A1
Abstract:
Disclosed is a method for discharging lubricating oil in a system for reliquefying boil-off gas by compressing the boil-off gas by means of a compressor, subjecting the compressed boil-off gas to heat exchange with the pre-compression state boil-off gas in a heat exchanger, and thus cooling same, and decompressing, by means of a decompressing device, the fluid cooled by the heat exchange. The method for discharging lubricating oil is characterized in that: the boil-off gas used as a refrigerant in the heat exchanger may be supplied to the heat exchanger via a first supply line; the boil-off gas used as a refrigerant in the heat exchanger may be supplied to the compressor via a second supply line; the boil-off gas before being used as a refrigerant in the heat exchanger may be supplied to the compressor by bypassing the heat exchanger via a bypass line; a bypass valve for controlling fluid flow and opening/closing is installed on the bypass line; a first valve for controlling fluid flow and opening/closing is installed at the front end of the heat exchanger on the first supply line; a second valve for controlling fluid flow and opening/closing is installed at the rear end of the heat exchanger on the second supply line; and the compressor comprises at least one oil-lubricated cylinder. The method for discharging lubricating oil comprises the steps of: 2) opening the bypass valve and closing the first valve and the second valve; 3) compressing, by means of the compressor, the boil-off gas before being used as a refrigerant in the heat exchanger by having the boil-off gas pass the bypass line; and 4) transferring one portion or all of the boil-off gas compressed by the compressor to the heat exchanger. By means of the boil-off gas of which the temperature has risen by being compressed by the compressor, condensed or coagulated lubricating oil may be discharged by being melted or by having the viscosity thereof decreased.
Inventors:
LEE JOON CHAE (KR)
CHOI DONG KYU (KR)
LYU SUNG KAK (KR)
JANG JAE HYEOUNG (KR)
CHOI DONG KYU (KR)
LYU SUNG KAK (KR)
JANG JAE HYEOUNG (KR)
Application Number:
PCT/KR2017/008376
Publication Date:
February 07, 2019
Filing Date:
August 03, 2017
Export Citation:
Assignee:
DAEWOO SHIPBUILDING & MARINE (KR)
International Classes:
B63B25/16; B63H21/38; F17C6/00; F17C9/02; F17C13/00
Foreign References:
| KR20170010427A | 2017-01-31 | |||
| KR20150067094A | 2015-06-17 | |||
| KR20170031426A | 2017-03-21 | |||
| KR20160062300A | 2016-06-02 | |||
| KR20150001600A | 2015-01-06 |
Attorney, Agent or Firm:
AIP PATENT & LAW FIRM (KR)
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