带可调导叶离心压缩机变工况性能预测模型研究

Research of Off-design Performance Prediction Model of Centrifugal Compressor With Adjustable Guide Vane

分析了离心压缩机在导叶可调情况下的变工况工作过程,在选取合适的离心压缩机各种经验损失模型的基础上,结合无叶扩压段多变指数损失计算法,利用Matlab编写离心压缩机变导叶调节的变工况性能预测模型。通过迭代计算得到结果,将预测结果与数值模拟结果进行对比。发现压缩机性能在设计点时预测与模拟结果符合较好,偏离设计点越多误差越大,大流量处误差高于小流量范围内的误差。通过分析损失特点,利用流量系数对4种主要损失模型公式进行修正,修正后预测模型与数值模拟符合较好,精确度得到提高,大流量和大开度时误差稍大,但最大误差可控制在5%以内,预测模型能够准确地计算出离心压缩机级在不同导叶开度下的变工况性能。

In order to analyze off-design performance of the centrifugal compressor with adjustable guide vane, the suitable loss models of centrifugal compressor were choosen, and the loss of vaneless diffuser was calculated by polytropic coefficient. The performance prediction model of centrifugal compressor was programed by Matlab to analyze off-design performance of centrifugal compressor with adjustable guide vane. Comparing with the result of numerical simulation, the result of prediction model obtained by iterative calculation agree well at design point, but the error is growing as the difference between operating condition and design point increases. The error at big massflow is larger than small massflow. Through analyzing the loss characteristics, four main loss models were modified by flow coefficient. The result of prediction model modified match better with the result of numerical simulation. Precision is improved. The error is larger at big massflow and big opening, but the error can be controlled within the range of five percent. Prediction model can calculate the off-design performance of centrifugal compressor with adjustable guide vane exactly.