Direct seawater cooling LNG liquefaction plants.
摘要
A historical survey of existing LNG plant experience with direct seawater cooling is presented and provides valuable insights for owners, operators, and engineers considering new plants and expansions. Material selection, corrosion and erosion rates, fouling, cleaning and water treatment are considered and comparisons drawn from reported plant owner experience. Proper design of direct seawater cooled, shell and tube heat exchangers is an important factor in reducing capital costs and maintenance costs, while boosting efficiency. The use of titanium low finned tubing and anti-vibration support structures is considered for refrigerant condensing and compressor cooler services. These newer technologies are applicable for grassroots plants in design phase, and also effective for retrofitting existing plants. Practical considerations must be made with regard to the availability of materials required for seawater heat exchangers. Titanium and nickel alloys are in high global demand at present, and an understanding of market supply and demand conditions is essential for the LNG plant developer. A practical overview of the titanium market is presented, including procurement strategies for long lead time materials.