Abstract:

Compared with the traditional high layout of LNG storage tanks, the low layout of LNG storage tank cap can save a lot of project construction cost, but it needs to consider the cap electric heat tracing. The advantages and disadvantages of parallel constant power and temperature self-limiting temperature are compared and analyzed. Combined with the thermal insulation and environmental data of 200 dam³ LNG storage tank cap structure in a coastal project, one-dimensional steady thermal conductivity method is used to calculate and analyze the heat tracing power needed for the cap, and then the appropriate electric tracing belt is selected.Then it compares and analyzes the traditional RTD temperature measurement control and optical fiber distributed temperature measurement schemes, analyzes the distribution circuit in the design of distribution and electricity consumption, design institute and supplier design division of labor, and finally gives the reference quantities of electrical design. It has reference significance for the design of electric heat tracing at the bottom of similar LNG tanks.

Key words: LNG storage tank, cap electrical heat tracing, parallel constant power, temperature self-regulating, temperature control

摘要：

相比传统高式布置液化天然气(LNG)储罐，低式储罐承台布置可以节省大量的建设成本，但需要考虑承台电伴热。对比分析了并联恒功率、并联自限温等几种方案的优缺点，结合某沿海项目200 dam³LNG储罐承台结构保温及环境数据，采用一维稳态导热法计算分析了承台所需要的伴热功率，进而选择合适的电伴热带。对比分析了传统RTD测温控制和光纤分布式测温方案，分析了设计中配电回路分配及用电消耗、设计院与供应商设计分工，给出电气设计参考工程量，对同类LNG罐底电伴热设计具有参考意义。

关键词: LNG储罐, 承台电伴热, 并联恒功率, 自限温, 温控