入口压力和空气流速对喷嘴成膜特性的影响
Influence of Inlet Pressure and Air Velocity on Film Forming Characteristics of Nozzles
宫传瑶 1何瑞 1卢昌燊 2丁玉栋2
作者信息
- 1. 东方电气集团东方汽轮机有限公司,四川 德阳 618000
- 2. 重庆大学 能源与动力工程学院,重庆 400030
- 折叠
摘要
为了研究冷却水入口压力和空气流速对喷嘴成膜特性的影响,以喷射式凝汽器喷嘴为研究对象,采用可视化实验方法对凝汽器喷嘴出口液膜的流动形态进行了拍摄,采用数字图像处理手段提取了液膜面积与喷射长度,并与数值模拟中不同的湍流模型的计算结果进行了对比,最终选取了Realizable k-ε湍流模型.基于Fluent求解器,耦合Realizable k-ε湍流模型与VOF方法,数值计算了凝汽器内部的流场.结果表明:当喷嘴入口压力从3 kPa升高到25 kPa时,布液板近壁面的速度随入口压力的升高逐渐增加,且液膜厚度也呈逐渐减小的趋势.对于DN15 和DN13 喷嘴,空气从静止状态变化到30m/s流速时液膜面积略微减小,空气流速从30m/s提高到150 m/s时液膜面积迅速减小.
Abstract
In order to study the influence of the cooling water inlet pressure and the air velocity on the nozzle film forming characteristics,taking the jet condenser nozzle as research object,the visualization experiment method was used to capture images of the liquid film flow pattern at the condenser nozzle out-let.Through digital image processing,the liquid film area and jet length were obtained,which was com-pared with the calculation results of various turbulence models in numerical simulations,and the Realiza-ble k-ε turbulence model was selected.The Fluent solver was used to combine the Realizable k-ε tur-bulence model with the VOF approach for numerical analysis of the flow field in the condenser.Results show that as the nozzle inlet pressure rises from 3 kPa to 25 kPa,the velocity near the wall of the liquid distribution plate increases steadily with the increase of the inlet pressure,while the liquid film thickness tends to decrease progressively.For DN15 and DN13 nozzles,the liquid film area reduces marginally when the air moves from a stationary condition to an air velocity of 30 m/s,and the liquid film area de-creases fast when the air velocity increases from 30 m/s to 150 m/s.
关键词
喷射式冷凝器/喷嘴/传热/入口压头/空气流速/铺展面积Key words
jet condenser/nozzle/heat transfer/inlet pressure/air velocity/spreading area引用本文复制引用
基金项目
东方电气集团科技项目资助(2020-154600)
出版年
2024
NETL
NSTL
万方数据