Numerical Simulation Of LTL Natural Gas Liquefaction Process And Its Heat Exchanger

Liquefied natural gas has obvious advantage in the storage and transportation. The consumption of natural gas is increasing by the growing proportion of in energy consumption structure. Nowadays, the increasingly fierce market competition require liquefied natural gas equipment and liquefaction process to be low energy consumption, less investment, reliable, easy to maintain. The establishment of new process and system simulation and optimization analysis has become an important technology. In this paper, aiming at today's background, new gas process is proposed and the new simulation optimization analysis for process will be started. Meanwhile, finite element analysis for key component of the system is carried on.Firstly, the current widely used LNG process will be gotten a more comprehensive comparative analysis and overviewed on performances, working principle, liquefaction costs, plant size and etc, then a new liquefied program will be proposed, meanwhile, the base mathematical model of each module will be initially established under the relevant theory of thermodynamics, providing the theoretical basis and methods for follow-up process simulation.Secondly, LTL and LTL / MR liquefaction gas process are simulated. Two new cryogenic gas liquefaction process programs are put forward, through initializing parameter, the process is simulated and compared between the two key parameters. The several LNG heat exchanger of LTL / MR liquefaction process system is analyzed on performance, then the curve of heat load is gotten, UA and the temperature, the direction of operation and adjustment are determined .Thirdly, from the thermodynamic point of view, a new natural gas liquefaction process were analyzed, a number of important process parameters on the system are discussed. The entire process is optimized analyzed with optimizer, the gas flow is 56720kmol/h, the system consumes is more than 0.284kw/m3.Fourthly, three LNG heat exchangers are analyzed from the thermodynamic point of view, the heat exchanger working fluid enthalpy, and the UA value of heat flux and exergy loss are impacted by Temperature, pressure and component sub-rate change. The key LNG heat exchanger's head finite element model of system is created, the temperature distribution and thermal stress distribution of head are obtained, the temperature between heat exchanger core body and the four corners is highest, the lowest temperature is on the inner surface which connect pipe and head, the maximum thermal stress is194MPa.