Heat transfer flow optimization device

After the process technology is selected, the energy consumption of hydrogenation unit is closely related to the process flow. The following examples illustrate several kinds of energy saving optimization approaches for hydrogenation units.

Heat transfer process optimization is an important method for process energy saving. Based on the full analysis of physical and chemical properties of logistics, heat exchange objectives and process constraints, it is necessary to reasonably match multiple material-energy flows to achieve the optimal scheme.

From the point of view of preheating of raw oil, the raw residue is filtered after being heated from 150℃ to 285℃ by four groups of heat exchangers. The main heating medium is hydroresidual oil, which is heated by reflux in the middle section of fractionator in the temperature range of 188~193℃, making full use of the heat of fractionator.

From the perspective of hydroresidual cooling, after the hydroresidual oil is extracted from the bottom of the fractionating tower, the heat at the highest temperature of 358~365℃ is used as the heat source of the reboiler of the diesel stripper,  then used to preheat the raw oil. The remaining heat is steam generated, and finally directly sent to the downstream catalytic cracking unit as hot discharge. When the catalytic cracking unit does not accept the hot material, the hot discharge is cooled by the air cooler and then sent to the tank farm.