Simulation & Analysis On Heat Exchanger Network Of Urumqi Oil Refinery Atmospheric-vacuum Distillation Unit

With the heat exchanger network (HEN) of the atmospheric-vacuum distillation No.2 in CNPC Urumqi refinery as the engineering background, flowsheet simulation and pinch analysis have been done with simulation software in the dissertation.Detail researches are summarized as follows:1) The simulation flowsheet of the HEN was established with PRO/II software on the basis of calibration data of the heat exchanger network,such as true boiling point of crude oil, engler curve of the products.2) An generalized computational procedure of"problem table algorithm"based on Excel VBA is developed, and solved the phase convertion in the calculation. The practical example was given.3) Basic data of hot and cold streams that transfer heat with each other in the process were extracted based on the simulation results. Heat exchanger network pinch analysis was carried out with the Aspen Pinch software and Excel VBA programme. Composite curves and grand composite curves were plotted under different HRAT. Comparing the results of two calculations, Excel VBA program has once again proven the feasibility and accuracy.4)The original HEN was analyzed based on the pinch technology. And taken the total annual cost as the objective function, the most appropriate HRAT of the original heat exchanger network was obtained. By adjusting HRAT, The original HEN was optimized. Based on pinch results of the comparison of uniform streaming and non-uniform streaming, influence of the splitting ratio on the pinch location of the HEN with splitting stream were studied.