摘要
为了保证海水温度不影响LNG接收站开架式气化器（ORV）气化的LNG额定流量,ORV设计文件要求当海水温度低于5.5℃时,不得运行ORV,需改用浸没燃烧式气化器（SCV）;但由于SCV运行成本远远高于ORV,因此,如何在海水温度低于5.5℃时仍然能运行ORV便成了研究的重点。在海水低温条件下运行ORV的关键是确定ORV最小海水流量和最大LNG流量。因此,首先以ORV性能曲线为基础,确定其机械限定LNG流量和特定条件下ORV入口海水温度在2.5~5.5℃范围内的固有性能曲线,然后通过实验获得特定条件下入口海水温度在1.0~2.5℃范围内的试验性能曲线,进而分段建立特定条件下入口海水温度、LNG入口压力、最大LNG流量与最小海水流量间的计算模型,并由1st Opt软件采用多元非线性拟合确定模型系数,最后由能量守恒定律求解实际运行中的ORV最小海水流量和最大LNG流量,同时设计出了计算软件。实际运行结果表明该软件计算的最大相对误差仅为0.94%。在中国石油大连液化天然气有限公司LNG接收站的实际应用效果表明：在2012—2013年间,海水低温下ORV节能运行技术为该LNG接收站节约气化成本5 982万元。
Low temperatures of seawater may negatively affect the rated LNG flow of open rack vaporizer （ORV） in LNG terminals. The design documents of ORV specify that ORV should be replaced with submerged combustion vaporizer （SCV） when seawater temperature is below 5.5 ℃ . However, SCV involves much higher costs than ORV. Accordingly, how to maintain the proper functioning of ORV under seawater temperatures below 5.5 ℃ becomes a hot subject in researches. The key for operation of ORV at low temperatures of seawater is to determine the minimum seawater flow and the maximum LNG flow of ORV. For this purpose, ORV performance curves were used to determine the mechanically limited LNG flow and the inherent performance curves of ORV in temperatures of 2.5-5.5 ℃ under certain conditions. Then, the test performance curves in the range of inlet seawater under temperatures of 1.0-2.5 ℃ were obtained through exper- iments. The calculation model for inlet seawater temperatures, LNG inlet pressures, the maximum LNG flow and the minimum seawater flow under certain conditions is then built by sections. By using the 1 stOpt software, coefficients of the model were determined through multivariate nonlinear fitting. Finally, the maximum LNG fiow and the minimum seawater flow of ORV under actual operation conditions were clarified by using the energy conservation law, and the design software was also developed. Actual operations show that the maxi- mum relative error of the software is only 0.94%. Application in an LNG terminal of PetroChina Dalian LNG Co., Ltd. reveals that, from 2012 to 2013, the energy-saving operation technique of ORV under low seawater temperatures help to reduce the gasification cost by about RMB59.82 million yuan at the terminal.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2016年第5期106-114,共9页
Natural Gas Industry
关键词
ORV
海水低温
最小海水流量
最大LNG流量
能量守恒
计算模型
节能运行
LNG接收站
Open rack vaporizer （ORV）
Low temperature of seawater
Minimum seawater flow
Maximum LNG flow
Energy conservation law
Calculation model
Energy-saving operation
LNG terminal
