以某新建300万t/a渣油加氢裂化装置为例，对冷低压分离器不同的操作压力及分馏塔进料加热炉炉前是否设置闪蒸罐从而对装置的操作费用、能耗、投资的影响进行了分析、对比。通过模拟分析发现，将冷低压分离器操作压力由0.20 MPa提高至1.35 MPa、并设置分馏塔进料加热炉炉前闪蒸罐，能耗（折标油）降低600.33 kg/h，操作费用降低1 546.11万元/a，一次性投资费用降低364万元。综合对比能耗、投资及操作费用，适当提高冷低压分离器的压力并设置分馏炉前闪蒸罐的流程更具优势。

Taking a newly constructed 3 million tons/year residual oil hydrocracking plant as an example, the influences of different operating pressures in the cold low pressure separator and whether the flash tank in front of the fractionating tower feed heating furnace is set or not on the operating cost, energy consumption and investment of the plant are analyzed and compared.Through the simulation analysis, it is found that the energy consumption is reduced by 600.33 kg of standard oil per hour, the operating cost is reduced by RMB 15.461 1 million per year, and the one-time investment cost is reduced by RMB 3.64 million after the operating pressure at the cold low pressure separator rises from 0.20 MPa(G) to 1.35 MPa(G), and a flash tank is set in front of the feed heating furnace for the fractionation tower.Through analysis on energy consumption, investment and operating costs, the process that appropriately increases the pressure at cold low pressure separator and sets a flash tank is more advantageous.