Simulation And Analysis About Cold Energy Utilization Of Liquefied Natural Gas Based On Aspen Plus

With the development of Chinese level of industrialization, energy demand is increasingly prominent. Natural gas exploitation in our country is rapidly, in order to facilitate storage and transportation, natural gas is liquefied in cryogenic LNG, when it supplies to users, LNG should be gasified. The gasification process emits large amounts of cold energy, if we don’t use this part of the cold energy, it will be a large wasteful of energy, and it will be cold pollution. Therefore, it is very necessary to study of LNG cold energy utilization.On the basis of the study LNG cold energy utilization, this article elaborated LNG cold energy evaluation methods, and analyzed the factors of the cold exergy. Then introduced the different utilization of LNG cold energy.And analysis the principles of air separation unit(ASU) and cold storage systems, then based on different principle of systems build LNG cold energy for ASU and cold storage systems.Using Aspen Plus simulation LNG cold energy used for ASU systems and cold storage system with using sequential modular approach. According to the simulation results, Analysis the factors Influencing of ASU, extraction ratio of liquid nitrogen and outlet pressure of nitrogen compressor, and get optimum working conditions. Using software to simulate the traditional way of electric refrigeration for cold storage systems and compare with the new system, obtain the advantages of LNG cold energy used for the system.According to the actual situation of Dalian and the Dalian LNG terminal region, simulate the ASU system and cold storage systems with different temperatures of inlet and outlet of the LNG heat exchangers. Using the method of exergy calculate the loss of LNG heat exchanger, to establish a data base for the cascade use. According to the above results, the paper establishs cascade utilization system of ASU-cold cascades.Compare LNG consumption and electric power consumption with different temperatures of inlet and outlet of the LNG heat exchangers. And using exergy method calculates the loss of LNG heat exchanger and the loss of one ton LNG. Finally, get the best point of the temperature.