Many external factors significantly influence the operating capacity of an LNG plant. Among these factors, variations in ambient temperature have major impacts on LNG productions, and are outside the operators' control. Design margins should be included to counter the effects of temperature variations. However, although required, overly generous design margins can result in inefficient utilization of plant facilities and hurt the overall project economics. The goal of this paper is to present a systematic approach to address this issue. Much attention has been paid to the handling of meteorological data. Recently the authors presented a new methodology to simplify the conversion of monthly average temperatures to temperature distribution and exceedance functions. The converted functions are more suitable for design purposes because the LNG plant capacity is directly related to ambient temperatures, but only weakly related to calendar days. This presentation builds on the previous work and continues to develop strategies to mitigate the impacts. Firstly, common industry practices are categorized and their pros and cons discussed. Then, an example based on realistic scenarios is shown as illustration. Finally, a roadmap is presented as useful guidelines leading to optimal selections. It should be recognized that the optimal choice is highly project-specific, depending on many factors, such as severity of temperature variations, contractual terms, and availability of additional gas supplies for production make-up. The optimal solutions for two projects are rarely identical.
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