Operation of air-cooling CHP generating unit under the effect of natural wind

摘要

The influences of natural wind on the thermo-fluid performance of 300 MW air-cooling combined heat and power (CHP) generating unit were investigated both numerically and experimentally. The CHP unit operated with only partial air cooling condensers (ACCs) in work under the winter chill environment. The physico-mathematical model was established for air flow and temperature fields of air-cooling island, in which only natural convection was considered while the axial flow fans of ACCs stopped. Variations of heat rate of ACCs with natural wind direction and speed were acquired. The results indicated that the heat rate varied significantly both with hot plume recirculation and reversed air flow to ACCs caused by natural wind. However, different from the normal operated air cooling power generating unit, the total heat rate of ACCs might increase due to the reversed flow for all axial flow fans stopped. Based on the observations, a case study was executed for the CHP unit with partial power generating load under natural wind conditions. The optimal operating schemes of the ACCs, as well as the rotating speed of the axial flow fans under various ambient wind conditions were obtained to satisfy heat supply of urban heating network, and also to maintain economic operation of the CHP unit. The numerical results were verified by the experiments. (C) 2016 Elsevier Ltd. All rights reserved.