渐缩型混合室引射式低压加热器的特性分析

Characteristic Analysis of a Low-pressure Ejector Heater with Tapered Mixing Chamber

将常规引射式低压加热器的圆柱形混合室改为渐缩型混合室,研发了一种新的渐缩型混合室引射式低压加热器,通过理论计算分析了进口参数和喉部直径对该装置加热和升压性能的影响,并将出口水温与试验结果进行了比较.结果表明:在蒸汽压力不变时,增大入水压力,加热器出口温度下降,出口压力升高,并均呈减缓趋势;当入水参数不变时,增大蒸汽压力,加热器引射系数增大,出口温度升高,但蒸汽流量对出口压力影响不大;增大混合室喉部面积可以降低出口压力,有利于提高加热器变工况运行下加热性能和实际运行的稳定性.

A new low-pressure ejector heater has been developed by changing the cylindrical mixing chamber of conventional low-pressure ejector heaters into tapered shape.Based on theoretical calculation,the influence of inlet parameters and throat size on heating and pressure-boosting performance of the heater has been analyzed,while a comparison of outlet water temperature performed between calculated and experimental data.Results show that in case of a constant steam pressure,the outlet temperature of heater reduces and the outlet pressure rises gradually with rising inlet pressure of water;in case of constant parameters of inlet water,both the ejecting coefficient and outlet temperature of heater increases with rising steam pressure,but the outlet pressure is little affected by the steam flow;the outlet pressure can be reduced by raising the throat size of mixing chamber,which will be benefit for improvement of heating performance and operation stability of heaters,under variable working conditions.