LNG Carrier

At Samsung, I worked on three LNG compressor projects that were used on LNG carriers: HDC, LDC, and an additional prototype, which was similar to LDC. These projects were important to me, since they were Samsung’s first line of LNG compressors and I participated in the assembly, which took place in South Korea.

We designed the boil-off gas compressors used to recover the unavoidable boil-off gas from the cargo tanks on LNG ships during voyage. Natural Gas has a very low energy density. The volume of Natural Gas in its liquid state is 600 times smaller than its volume in its gaseous state. Therefore, in order to be used efficiently as an energy source it needs to have its density increased by cooling it to cryogenic temperatures, which creates Liquified Natural Gas (LNG). On LNG carrier ships, this LNG is stored in well-insulated tanks in its liquid state. However, the heat transfer that occurs with the surroundings will cause some of this LNG to evaporate and become boil-off gas. Thus, this boil-off gas must be removed from the tanks to prevent excessive pressure build up.

Our team worked with the engineers in South Korea to design a complete HD and LD package within the typical constraints of a LNG ship's compressor room. I traveled to South Korea and visited the Samsung Techwin headquarters and Vendors in order to assist during initial assembly of the LD compressor.

Image source: http://www.wartsila.com

HDC (High Duty Compressor)

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Used to recirculate boil-off gas on LNG carriers and terminals, which transfers heated gas back to the cargo tank in order to warm it up. Some of the compressor specs for this project were: 
-single stage
-1 barA inlet: 2 barA discharge
-inlet temperature: -140ºC 
-cryogenic design conditions
-capacity : 34,000 m3/h 
-API 617 compliant

Source: http://energy.hanwhatechwin.com/customer/down_productfile.asp

LDC (Low Duty Compressor)

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Used as a boil-off gas compressor for converting the gas into fuel for the engine, and maintaining the cargo tank pressure. Some of the compressor specs for this project were: 
-3 stages
-1 barA inlet: 6.5 barA discharge 
-inlet temp : -140~ 40ºC
-cryogenic design conditions 
-capacity : 4,750 m3/h 
-API 617 compliant

Source: http://energy.hanwhatechwin.com/customer/down_productfile.asp

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