摘要
为探究单面加热窄矩形通道内,单相自然循环对流传热特性,进行了实验压力为0.2 MPa和0.3 MPa,入口欠热度范围为35~60 K,加热功率范围为30~90 kW/m^2的单相对流传热实验。实验结果表明,对流换热系数与Gnielinski公式符合较好,92%的实验数据与公式的相对误差在20%以内。引入斯坦顿数(St),对数据分析发现:自然循环流动中,实验段入口欠热度及加热功率对换热能力有明显影响,换热能力随着入口欠热度的增加而减小,随着加热功率的增加而变大。在窄矩形通道内的向上自然循环流动中,通过提高入口欠热度而导致的浮升力增加会引起同向对流,从而使换热减弱;单面加热条件下,提高加热功率引起的横向热驱动力增加会使传热得到强化。
To investigate the heat transfer characteristic of single-phase natural circulation flow in a one-side heating narrow rectangular channel, experiments were performed at pressures of 0. 2 and 0. 3 MPa, at an inlet sub-cooling temperature from 35 K to 60 K, and heat flux from 30 kW/m2 to 90 kW/m2. Experimental results indicate that the heat transfer coefficient agrees with the predictions of the Gnielinski correlation, and 92% of the experimental results are within a ± 20% error range of the correlation predictions. The heat transfer performance was investigated by introducing the Stanton number. The heat transfer coefficient increased with an increase in heat flux and a decrease in inlet sub-cooling. For upward natural circulation flow in a narrow rectangular channel, the increase in buoyancy induced by increasing the inlet sub-cooling resulted in the relaminarization effect, leading to a passive effect on heat transfer. However, the increase in thermal driven force induced by increasing heat flux makes the boundary layer unstable, thereby enhancing heat transfer.
作者
田春平
阎昌琪
曹夏昕
王建军
田旺盛
戴斌
TIAN Chunping;YAN Changqi;CAO Xiaxin;WANG Jianjun;TIAN Wangsheng;DAI Bin(National Defense Key Discipline Laboratory on Nuclear Safety and Simulation Technology, Harbin Engineering University, Harbin 150001, China)
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
北大核心
2017年第10期1554-1559,共6页
Journal of Harbin Engineering University
基金
国家自然科学基金项目(11675045)
中央高校基本科研业务费专项资金-博士研究生科研创新基金项目(HEUGIP201715)
关键词
窄矩形通道
自然循环
对流换热系数
斯坦顿数
局部对流
欠热度
浮升力
层流化
横向热驱动力
narrow rectangular channel
natural circulation
convective heat transfer coefficient
Stanton number
local convection
subeooling
buoyancy
laminarization
transverse thermally driven force