关键词: 加氢裂化, 高压换热流程, 火用分析, 流程模拟

Abstract: Based on a domestic hydrocracking unit, the high-pressure heat exchange network is simulated by using the simulation software of PRO/II, an exergy analysis is then presented by means of energy-grade-heat load (ε-Q) diagram and the bottlenecks in the heat exchange process are found. The analysis results show that the proportion of heat duty between recycle hydrogen and feed oil is unreasonable, thus the temperature of the recycle hydrogen at the furnace outlet is as high as 442℃, when it meets the 306℃ feed oil, an exergy loss of mixing comes to 1.304 MW. By readjusting the heat exchange sequence, the proportion of heat exchange capacity between recycle hydrogen and feed oil is optimized from the original 53.2% and 46.8% to 40.0% and 60.0%, respectively. After optimization, the energy recovery rate is increased, the load of furnace is reduced and reductions of exergy loss are obtained, which is 0.061 MW and 1.229 MW for heat exchanging and mixing, respectively.

Key words: hydrocracking, high-pressure heat exchange network, exergy analysis, process simulation