The vehicle loading system of the liquid type material has a long use history in the petroleum chemical industry, and it is still a kind of universal and essential system. Typical liquid material vehicle quantitative loading system is composed by the liquid material storage tank, material conveying material pump, pipeline and loading platform and other facilities. In the previous loading operation, the operation worker mainly through the simple instrument to observe the date (liquid level inspection rule), plus manual operation, the degree of automation is very low. This paper take Ningbo oil deport Engineering project gasoline, diesel vehicle loading stack station project as the background, This research from the actual situation is as follows:(1) After the analysis and research, the characteristics of the loading process are summarized. The control object and the control objective of the quantitative loading system are defined, and the practical needs of enterprises and customers are considered. Design and research of automatic loading control system for user. First, I research the quantitative loading control system based on quantitative loading controller, second I research of the loading control system based on DCS. Considering the advantages and disadvantages of the two systems in practical application, a modified loading system is proposed, which can be used in the field operation to complete the quantitative loading control, and to complete the advanced load control algorithm. (2) Based on the analysis of loading process and electro hydraulic valve characteristics, this paper research the relationship between the load flow and the loading capacity, and gives the control method of the loading control. The influence of the "water hammer" phenomenon in the loading operation is reduced by using the electro-hydraulic valve multistage opening and closeing. Through the research on the influence factors of the loading precision, the mathematical expression of the self setting program is designed, which makes the system adapt to all kinds of environment and improve the accuracy of loading.This paper gives the overall design scheme, hardware configuration, and the improvement of the loading algorithm for automatic quantitative loading control system. The acquisition, processing and controlling function of field signal are realized. The system has the function of remote control, alarm monitoring, historical trend curve query, report printing and so on. |