摘要：AbstractFossil fuel power plants dominate the energy structure in China. However, the water scarcity, in Southeast/Southwest China, results in the development of the dry cooling power plants. Direct air cooling condenser (DACC) is appealing for its water saving ability. In DACC, the exhaust steam is cooled and condensed to water by the air flow, which is provided by the fan array at the cost of electricity. There exists a varying optimal exhaust steam pressure under different air temperatures and loads. The static model of the turbine-DACC system is built to quantify the influences of the air temperatures and loads. An on-line optimization is used here to set the reference value of the exhaust steam pressure for the turbine-DACC system for economic operation. The objective is to maximize the net power production while satisfying the constraints on the safety pressure and the available air flowrate. The optimization is conducted in a model 660MW power plant selected on a random summer/winter day. The hourly optimal exhaust steam pressure and the operation instructions are calculated as the reference values for the control layer. The optimization results show that the optimal exhaust steam pressure may be too close to the safety limits in winter, suggesting the safety also to be considered in the optimization. In summer, the DACC system cannot satisfy the condensation load sometimes. Thus, a complementary cooling method, for example, the wet cooling, is needed to reduce the burden on the DACC system.
关键词：KeywordsDirect air cooling condenserTurbine variationsCondensation pressure optimizationCooling fan array
