Based on the petroleum processing units of a certain domestic refinery, the authors studied the appropriate cases for processing of Tahe medium gravity crude. The influence of three crude processing cases, including t...Based on the petroleum processing units of a certain domestic refinery, the authors studied the appropriate cases for processing of Tahe medium gravity crude. The influence of three crude processing cases, including the case for processing of crude slate blended with Tahe medium gravity crude, the case for separate processing and storing of individual crude oils, and the case for flash distillation of Tahe medium gravity crude coupled with separated processing of crude oils, on the products quality, stability of production operation and the overall techno-economic parameters was investigated. The study results have shown that the case for processing crude slate blended with Tahe medium gravity crude could lead to deterioration of the FCC products distribution, dramatic reduction of light distillates, significant surge of sulfur content in FCC naphtha, and increased specific consumption of FCC catalyst, indicating that this case was obviously not suited for processing the Tahe medium gravity crude. The case for separate processing and storing of individual crude oils, however, could increase the aggregate salable products ratio, but the frequent switchover of process streams could cause difficulty and hazards to the stabilization of refining operations, which could not be an ideal processing case. The case for flash distillation of Tahe medium gravity crude coupled with separate processing of crude oils featured the simplicity of process scheme, easiness for modification of process units, easy operation and a slight increase in the aggregate salable products ratio, making itself a suitable case for processing the Tahe medium gravity crude.展开更多
By extending the system's state variables,a novel predictive functional controller has been developed.The structure of this controller is similar to that of classical proportional integral(PI)optimal controller an...By extending the system's state variables,a novel predictive functional controller has been developed.The structure of this controller is similar to that of classical proportional integral(PI)optimal controller and in-cludes a control block that can perform a feed-forward control of future P-step set points.It considers both the state variables and the output errors in its cost function,which results in enhanced control performance compared with traditional state space predictive functional control(TSSPFC)methods that consider only the predictive output er-rors.The predictive functional controller(PFC)has been compared with TSSPFC in terms of tracking ability,dis-turbance rejection,and also based on its application to heavy oil coking equipment.The results obtained show the effectiveness of the controller.展开更多
In this paper, multi-refinery using the same heavy crude oils as raw materials is studied, while a new nonlinear model for mixed heavy crude distillation is proposed. In practical crude distillation operation, the dis...In this paper, multi-refinery using the same heavy crude oils as raw materials is studied, while a new nonlinear model for mixed heavy crude distillation is proposed. In practical crude distillation operation, the distillate yield and product distribution of distillation units are different due to their various equipment and operating parameters, even the same ratio of raw materials is provided, so different process models for multi-refinery planning is therefore required. For process modeling, the relationships between total yields and mixing ratio of different refineries were determined, which is combined with process simulation using production data. Then,the yields and properties of crude distillation unit(CDU) fractions were calculated with the use of true boiling point(TBP) curves and property curves respectively when the initial cutting temperatures were given. Finally,in order to maximize the economic benefit of distillation, the optimal product distribution and the best mixing ratio of crude oil were calculated under the constraints of different properties of fractions. Comparing to previous models, the proposed model takes the influence of different refinery parameters on production process into account, while avoiding the complex process for determining the cutting points, which is considered more efficient and more accurate with respect to heavy crude refinery. Model was successfully verified by a case study,allowing a significant improvement of the refinery profit to be achieved.展开更多
文摘Based on the petroleum processing units of a certain domestic refinery, the authors studied the appropriate cases for processing of Tahe medium gravity crude. The influence of three crude processing cases, including the case for processing of crude slate blended with Tahe medium gravity crude, the case for separate processing and storing of individual crude oils, and the case for flash distillation of Tahe medium gravity crude coupled with separated processing of crude oils, on the products quality, stability of production operation and the overall techno-economic parameters was investigated. The study results have shown that the case for processing crude slate blended with Tahe medium gravity crude could lead to deterioration of the FCC products distribution, dramatic reduction of light distillates, significant surge of sulfur content in FCC naphtha, and increased specific consumption of FCC catalyst, indicating that this case was obviously not suited for processing the Tahe medium gravity crude. The case for separate processing and storing of individual crude oils, however, could increase the aggregate salable products ratio, but the frequent switchover of process streams could cause difficulty and hazards to the stabilization of refining operations, which could not be an ideal processing case. The case for flash distillation of Tahe medium gravity crude coupled with separate processing of crude oils featured the simplicity of process scheme, easiness for modification of process units, easy operation and a slight increase in the aggregate salable products ratio, making itself a suitable case for processing the Tahe medium gravity crude.
基金Supported by the National Creative Research Groups Science Foundation of China (NCRGSFC 60421002)the National High Technology Research and Development Program of China (863 Program,2006AA04Z182).
文摘By extending the system's state variables,a novel predictive functional controller has been developed.The structure of this controller is similar to that of classical proportional integral(PI)optimal controller and in-cludes a control block that can perform a feed-forward control of future P-step set points.It considers both the state variables and the output errors in its cost function,which results in enhanced control performance compared with traditional state space predictive functional control(TSSPFC)methods that consider only the predictive output er-rors.The predictive functional controller(PFC)has been compared with TSSPFC in terms of tracking ability,dis-turbance rejection,and also based on its application to heavy oil coking equipment.The results obtained show the effectiveness of the controller.
文摘In this paper, multi-refinery using the same heavy crude oils as raw materials is studied, while a new nonlinear model for mixed heavy crude distillation is proposed. In practical crude distillation operation, the distillate yield and product distribution of distillation units are different due to their various equipment and operating parameters, even the same ratio of raw materials is provided, so different process models for multi-refinery planning is therefore required. For process modeling, the relationships between total yields and mixing ratio of different refineries were determined, which is combined with process simulation using production data. Then,the yields and properties of crude distillation unit(CDU) fractions were calculated with the use of true boiling point(TBP) curves and property curves respectively when the initial cutting temperatures were given. Finally,in order to maximize the economic benefit of distillation, the optimal product distribution and the best mixing ratio of crude oil were calculated under the constraints of different properties of fractions. Comparing to previous models, the proposed model takes the influence of different refinery parameters on production process into account, while avoiding the complex process for determining the cutting points, which is considered more efficient and more accurate with respect to heavy crude refinery. Model was successfully verified by a case study,allowing a significant improvement of the refinery profit to be achieved.
