LDPE装置乙烯等熵增压过程关键安全问题研究

为评估超高压聚乙烯(LDPE)装置乙烯压缩过程的失控风险,采用ASPEN等对乙烯等熵增压过程热效应进行了系统性研究。研究表明,乙烯分解速率随温度升高呈指数型增长,分解爆炸的最大压力为初始压力的3.5倍。工况条件下乙烯一级等熵压缩至250 MPa时的绝热温升为724℃,50 MPa为增压梯度的关键变化点。采用两次六级的形式进行增压,2个压缩机的绝热温升降分别为390,101℃。乙烯泄放过程的冲击波会使界面侧空气压缩升温,空气等熵压缩至1 MPa时温度可达到400℃。在乙烯增压过程中应综合考虑压缩级数与热效应,并严格控制绝热温升。

Study on Key Safety Issues of Ethylene Isentropic Pressurization Process in LDPE Plant

In order to evaluate the risk of ethylene compression process of LDPE equipment,ASPEN was applied to systematically study the thermal effect of ethylene isentropic pressurization.Studies had shown that the decomposition rate of ethylene increased exponentially with the increase of temperature,and the maximum pressure of the decomposition explosion was 3.5 times to the initial pressure.Under working conditions,the adiabatic temperature rise was up to 724℃.When ethylene was compressed to 250 MPa by the one-stage isentropic compression,50 MPa was the key change point of the pressure gradient.When ethylene was compressed by two-stage process,the adiabatic temperature were respectively 390℃and 101℃.The shock wave in the ethylene release process made the air compress and heat up,and the temperature can reach 400℃when the air was isentropically compressed to 1 MPa.In the process of ethylene pressurization,the compression stages and thermal effects should be considered comprehensively,and the adiabatic temperature rise should be strictly controlled.