Research On The Key Control Scheme Of Diesel Hydrogenation Unit

Diesel oil hydrogenation technology is an effective means of diesel desulfurization, in and abroad. The sulfur, nitrogen and other elements in the crude oil are removed by hydrogenation in the hydrogenation unit, and the combustion performance of the product is more stable with the addition of sixteen alkanes. Diesel hydrogenation device is an important device for oil refining enterprises, its operation is in hydrogen and high pressure and temperature conditions, it’s necessary to monitor the production process, so as to ensure the long-term stable operation of hydrogenation unit.Firstly, the technological process of Luoyang Petrochemical 2.6million tons per year diesel hydrogenation unit was introduced. Then described the effects of process parameters on the hydrogenation reaction. Analyzed the effect of reaction temperature on the reaction depth, reaction rate, product quality and yield. Aimed at the shortage of the existing control schemes of reaction temperature in diesel hydrogenation unit, the Smith furnace outlet temperature cascade control scheme and Dahlin-Smith cascade control scheme have been proposed. By theoretical research and simulation results analyzing, the results show that the Dahlin-Smith cascade control scheme can achieve a better control effect.Secondly, the role of circulating hydrogen and recycle hydrogen compressor in the device and the importance of stable operation to the device was described. Then analyzed the causes and the harm of surge to this unit and device. The anti-surge control scheme of centrifugal compressor of circulating hydrogen in diesel hydrogenation unit was studied, The more suitable control line of compressor anti surge and the compressor anti surge control scheme have been proposed to the actual production situation. Under the condition of fixed speed and variable speed, the simulation and comparison of the control system to the existing PID control system are carried out, the results show that fuzzy anti surge control system can achieve better control effect:reduced the working of the compressor, prevented the hydrogen partial pressure fluctuation caused by excessive circulating hydrogen, reduced the consumption of hydrogen and avoided the waste of energy.After the researches and improvements on diesel and hydrogen device key link control scheme, the more suitable control scheme of the heating furnace and a circulating hydrogen compressor anti surge to the production and operation situation were obtained. Thus can provide convenience for the efficient production and operation control of the device, and can also provide reference for the control of large time delay plant and centrifugal compressor in other chemical plant.