The Optimization Of Cool-End System In Coal-Fired And Wet Cooling Unit

This paper has made a systematic analysis that studying the operation characteristics and performance parameters for the subsystem and equipments relating to cool-end system, analyzing respective influencing factors, and building mathematical model, for optimizing cool-end system in the coal-fired and wet cooling unit from operation and design. Firstly, for the operation system, the optimal pressure of condenser and optimal operation mode of circulating water pump is analysed. According to common maximum income method, based on second law of thermodynamics, the maximum income method considering exergy loss of condenser is proposed in this paper. In this method, the value of exergy loss in the process of steam condensation is considered for the objective function, which reflect the conservation of amout and the depreciation of quality for the process of energy utilization. Using the above two methods and combining with actual operation data of 300MW unit of northeast, the optimal results of the maximum income method considering exergy loss of condenser is more scientific and comprehensive than the common one in view of the energy analysis. Secondly, based on heat balance model of condenser and circulating water system and combining with operation characteristics of subsystem and equipments relating to cool-end system to establish mathematic model, the total annual cost is chosen as objective function for design optimization of condenser to satisfy the technology and economy need of the safe and stable condition at long time. The objective function mainly considers disposable materials of condenser, cooling water consumption, and consumption electric of circulating water pump. Genetic Algorithm Theories are choosed for optimization analysis. And the optimal results give some guiding significance for economical operation and performance optimization of cool-end system.