Micro-leak detection system of reliquefication system for ship
Disclosed herein is a micro-leak detection system of a reliquefaction system for ships. The micro-leak detection system includes: a reliquefaction system reliquefying boil-off gas generated from a liquefied gas stored in a storage tank in a ship by recovering cold heat from the boil-off gas in a heat exchanger, compressing the boil-off gas, and cooling the compressed boil-gas in the heat exchanger through heat exchange with refrigerant circulated along a refrigerant circulation line; a heater heating the boil-off gas to be supplied from the storage tank to the heat exchanger through heat exchange with an antifreeze liquid; and a micro-leak detection device connected to a drain port through which a remaining liquid is drained from the heater and detecting small leaks in the heater.
1 . A micro-leak detection system of a reliquefaction system for ships, comprising:
a reliquefaction system reliquefying boil-off gas generated from a liquefied gas stored in a storage tank of a ship by recovering cold heat from the boil-off gas in a heat exchanger, compressing the boil-off gas, and cooling the compressed boil-off gas in the heat exchanger through heat exchange with a refrigerant circulated along a refrigerant circulation line;
a heater heating the boil-off gas to be supplied from the storage tank to the heat exchanger through heat exchange with an antifreeze liquid; and
a micro-leak detection device connected to a drain port through which a remaining liquid is drained from the heater and detecting small leaks in the heater.
2 . The micro-leak detection system according to claim 1 , wherein the micro-leak detection device comprises:
a connection tube fastened to the drain port and extending downwards therefrom; and
a leak detection unit provided to the connection tube to detect the presence of the liquid discharged from the drain port.
3 . The micro-leak detection system according to claim 2 , wherein the micro-leak detection device further comprises:
a first shut-off valve disposed on the connection tube at an inlet side of the leak detection unit;
a second shut-off valve disposed on the connection tube at an outlet side of the leak detection unit; and
a tube plug disposed at a lower end of the connection tube.
4 . The micro-leak detection system according to claim 3 , wherein the first shut-off valve is operated in a normally open state and the second shut-off valve is operated in a normally closed state, and, during maintenance of the heater, the second shut-off valve is opened to drain the remaining liquid from the heater.
5 . The micro-leak detection system according to claim 3 , wherein the leak detection unit is a sight glass to visually detect the presence of the liquid discharged from the drain port.
6 . The micro-leak detection system according to claim 3 , wherein the leak detection unit is a liquid level detector to detect and measure the liquid discharged from the drain port.
7 . The micro-leak detection system according to claim 1 , ny wherein the heat exchanger is provided as a cryogenic heat exchanger, and the heater is provided as a shell-tube heat exchanger.