微波谐振腔法测量蒸汽湿度时,谐振腔内壁面会沉积一层水膜和盐垢,计算在不同水膜和积盐厚度下谐振腔谐振频率的变化,进而分析介质沉积对蒸汽湿度测量的影响.研究结果表明：在水膜或积盐较薄时,其对湿度测量的影响较小,随着沉积介质厚度的增大其影响明显增加；相同水膜厚度时,湿蒸汽压力(温度)对测量结果的影响较小,且随着湿蒸汽压力(温度)的升高,水膜对测量结果的影响略有下降；沉积水膜对测量结果的影响要大于积盐影响,但在用于汽轮机排汽湿度测量时,谐振腔内壁沉积水膜厚度不到35μm,忽略水膜影响引起的湿度测量偏差不到1．262％.%During steam wetness measurement by microwave resonator,water film and salt will de-posit on the resonant cavity's inner surface.The effect of the deposited dielectric on the resonant frequency was analyzed,and its influence on the steam wetness measurement was also investiga-ted.The results show that:thinner film had less effect on the steam wetness measurement,but this effect aggravated with the film thickness;with the same water film thickness,the wet steam pressure (temperature)had little effects on resonant frequency,and the effect of water film on steam wetness measurement decreased slightly with an increase in wet steam pressure (tempera-ture);the effect of deposited water film on measurement was greater than the deposited sahow-ever,when this method was applied in the turbine's exhaust wetness measurement,the thickness of water film deposited on the resonator's inner surface was less than 3 5μm,and the deviation of wetness measurement was no more than 1.262%.
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