Dynamic optimal design of a power generation system utilizing industrial waste heat considering parameter fluctuations of exhaust gas

The industrial waste heat parameters, like flow rate and temperature, usually fluctuate in a certain range due to the variation of upstream industrial process. However, the heat recovery systems are usually designed not under the fluctuation range but under a specific point, therefore, the most reasonable design condition of the waste heat should be estimated based on the fluctuation ranges. A single pressure waste heat recovery system was studied in this paper. Static models were developed for system design and dynamic models were established to simulate the system transient performance when the temperature or flow rate of exhaust gas fluctuates. Systems designed at different exhaust gas parameters were operated under the same fluctuation condition to find out which one could generate the maximum net power. The fluctuations of temperature and flow rate of exhaust gas were studied separately. The results show that systems designed at the upper boundary of fluctuation range of exhaust gas could generate more power. In the case of temperature fluctuation of exhaust gas, the optimal turbine inlet pressure obtained by dynamic analysis is 7.9% lower than that of static analysis. It is 4.6% higher than that of static analysis in the case of flow rate fluctuation.