A sensitivity-coefficients method for predicting thermal performance of natural draft wet cooling towers under crosswinds

Abstract

• A sensitivity-coefficients method for predicting performance of NDWCTs is proposed. • Both the environmental and operating parameters are considered in this method. • The relationships between the coefficients and the parameters are obtained. • This method can predict the performance of NDWCTs under crosswinds accurately. The thermal performance of natural draft wet cooling tower (NDWCT), which can be evaluated through the Merkel number and outlet water temperature, is greatly affected by the environmental crosswinds and has important impact on the economical and safe operation of power plant. Previous studies on the impact of crosswinds were mainly based on two methods include numerical simulation and experimental research, which caused high economical and time costs. This study proposes a sensitivity-coefficient method for predicting thermal performance of NDWCT under different conditions. This method consists of two processes. First, according to the principle of aerodynamic and thermal balance, the performance parameters are iteratively calculated under windless condition. Next, based on the above results, the prediction method for thermal performance under crosswinds, in which two sensitivity coefficients, namely α 3 and α 4 are introduced, is proposed by combining theoretical analysis and experimental research. Using the proposed method, the performance parameters of a practical NDWCT are predicted, and the error between the predicted values and the measured or numerical values meets the accuracy requirements. Therefore, this method can conveniently and accurately analyze the change in NDWCT thermal performance under variable working conditions.