Optimal Synthesis And Operation Of Multi-cycle Utility System Optimization Problem

The synthesis and operation optimization of utility systems are very important to process industry to save energy and get economic profit as much as possible. This dissertation has carried out systematic research on the synthesis and operation planning problem of utility systems for multi-periods operation with varying demands. The main research includes:(1) Apply a general mixed-integer optimization model for multi-periods synthesis and operation planning problem(MSOP) to utility systems and then obtain the PM model. For feasible mathematic solving, this PM model has been reformulated.(2) Aiming at the characters of the multi-periods operation planning problem for utility systems and the difficulties encountered when use the standard Branch-and-Bound algorithm, the thought of accelerating is adopted and the accelerated Branch-and-Bound algorithm is introduced. The solution space is decreased and the computational costs are reduced and the ability of searching optimal solution is enhanced. Through two examples, the validity of the algorithm has been proved.(3) For the multi-periods synthesis and operation planning problem of utility systems(PM), the combination load will show exponential growth with the number of units and periods. Usual algorithms can not achieve optimal solution in reasonable time. To overcome this problem, the Bilevel Decomposition Method is introduced. With the method the PM problem is divided into two subproblems to solve, thus computational costs are reduced and the size of problems solvable is increased. With two examples of different size the algorithm has been tested for it's applicability and validity.