In recent years，with the growing of polyethylene production，the flash explosion accidents occurring in polyethylene production enterprise and the other polyolefin production enterprise grows. The flash explosion accidents not only has caused a certain economic loss, but also has seriously affected the normal production of the enterprise. To avoid the repetition of similar accidents, this project puts CNPC DuShanZi petrochemical company ethylene plant as the research object, the main risk of subsequent system are analyzed in detail, and safety acceptability of subsequent are Systematically analyzed through the experimental simulation and theoretical analysis and calculation, then puts forward corresponding technical measures to ensure the safety of subsequent system.

Through experiment simulation, theoretical analysis and calculation, find that the polyethylene particle size and the presence of combustible gases such as ethylene is an important factor influencing the properties of polyethylene powder explosion, and explosion properties of powders are closely related to powder electrostatic discharge form. Comprehensive research and analysis shows that the spark discharge and brush discharge with propagation form will result in the ignition source of dust explosion .There is no need to change air transportation to nitrogen protection in the existing production conditions, only increasing some anti-static measures can ensure the security of the subsequent system.

This research achievement of the project has the following innovation points:

(1)Simultaneously consider the polyethylene particle size and the combustible gases influencing the properties of polyethylene powder explosion;

(2) The minimum ignition energy of powders, maximum energy provided by different types of electrostatic discharge and powder electrostatic simulation results are made a comprehensive comparative analysis, systematically evaluate the safety of subsequent system of polyethylene production device, and put forward corresponding countermeasures and measures.

The project method can use as risk assessment on subsequent system of polyolefin production enterprises, and make up for the current limitations of safety assessment on subsequent system of polyolefin production device, and is an innovation of the risk analysis for subsequent system of polyolefin production device. The application of the research achievement of this project in polyolefin production enterprises can undertake risk assessment on the subsequent system, determine the corresponding risk degree, and put forward effective preventive measures, so as to solve the flash explosion problems occurring in polyolefin plant of petrochemical industry for many years, ensure enterprises run smoothly, safely, long cycle.

The project was identified by the Ministry of Education organization in 2007, research results have been applied in CNPC DuShanZi petrochemical company, and the application effect is good, the comprehensive economic benefit of the project was 180 million RMB in 2007.