夹点技术在延迟焦化换热网络中的应用

某石化企业处理量为1.20 Mt/a的延迟焦化装置存在较大的节能潜力，应用夹点技术对其能量利用进行分析与优化。首先确定换热网络夹点位置和能量目标，消除违背夹点规则的换热，然后对优化后换热网络的热负荷回路进一步优化，提高原料渣油进炉温度，并得到最终换热网络。研究结果表明，改造后的换热网络取得了显著的经济效益，年节省能耗11.89×104 GJ，改造总投资77.82万元，年增经济效益457.70万元，投资回收期为2个月。夹点技术对延迟焦化装置的节能降耗、经济效益的提高有着十分重要的理论和现实意义。

PINCH TECHNOLOGY APPLICATION IN DELAYED COKING HEAT EXCHANGE NETWORK

There was a considerable energy saving potential in the delayed coking unit with a capacity of 1.20 Mt/a in a petrochemical plant. The heat exchanger network (HEN) of the delayed coking unit is analyzed and optimized by pinch technology. After obtaining the pinch point and energy targets, the pinch technology was applied to eliminate the heat exchange which violates the pinch rules. The optimized HEN was further optimized to cancel the problematic heat exchanger loop and raise the inlet temperature of the vacuum residue (VR) before entering the heating furnace, resulting in a final optimized HEN. Consequently, the modified HEN has achieved remarkable economic benefits by decreasing energy consumption of 11.89×104 GJ, which indicates that energy saving of this proposal can bring additional benefits of 4.577 0 million Yuan/a. The payback period of investment is 2 months with a total reconstructive investment of 0.778 2 million Yuan. The pinch technology for energy saving of delayed coking unit and the improvement of economic benefits has very important theoretical and practical significance.