窄通道欠热沸腾起始点计算模型的分析

Study on Calculation Model of Onset of Nucleate Boiling in Narrow Channels

欠热沸腾起始点(ONB)是窄通道内沸腾传热的关键转变点,直接关系到其后的流动传热特性。窄通道内ONB点的产生受很多因素影响,目前对其特征的把握尚不完善。运用B&R模型、苏顺玉经验关系式、潘良明模型和杨瑞昌模型对以水为工质的ONB热流密度进行分析比较,得出其与压力、质量流速和壁面温度的关系曲线,进而根据各计算模型的差异,提出主要影响因素的作用机理。

In the reactor engineering,narrow channels was used widely for its high power density,ex-ceptional heat transfer and actual engineering requirements.The point of Onset of Nucleate Boiling（ONB） is the key point of boiling heat transfer in narrow channels.The point of ONB can directly influence the fol-lowing flow and heat transfer characteristics in the reactor.Due to the special structure and complexity flow,the point of ONB in narrow channels are effected by many factors,which characteristics are not understood completely yet.Using BR model,Su Shun-yu model,Pan Liang-ming model and Yang Rui-chang model,the heat flux of onset of nucleate boiling is compared and analyzed by taking water as the medium.And then the relationships of the heat flux with pressure,mass flow and wall temperature are obtained.Based on the differences of each model,the mechanisms for the main influence factors are suggested..