跨临界压力下倾斜下降管内水的传热特性试验研究  

Experimental Study of the Heat Transfer Characteristics of Water in an Oblique Downcomer at a Trans-critical Pressure

作　　者：王思洋[1] 杨冬[1] 贾培英[2] 宋宝军[2] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,陕西西安710049 [2]哈尔滨锅炉厂有限责任公司高效清洁燃煤电站锅炉国家重点实验室,黑龙江哈尔滨150046

出　　处：《热能动力工程》2016年第5期113-117,156-157,共5页Journal of Engineering for Thermal Energy and Power

基　　金："十二五"国家科技支撑计划资助项目(2015BAAB03B01-01)

摘　　要：在压力11.5~28 MPa,质量流速450~1 550 kg/(m^2·s),外壁热负荷50~585 k W/m^2的工况范围内,对水平倾角为45°的倾斜下降光管内水的传热特性进行了试验研究。实验结果表明:倾斜下降管壁温沿管子周向分布不均匀。在亚临界压力区,倾斜下降管上下母线处的壁温有明显不同,壁温飞升时上下母线的临界干度差值较大。在近临界压力区,倾斜下降管内各母线处的壁温分布相似,壁温飞升时上下母线的干度差值很小。在超临界压力区,传热在拟临界焓值区得到强化,本研究工况下,压力的影响会改变热负荷的作用;在高焓值区,上母线处的壁温会有所降低。根据试验结果,得到了亚临界和近邻界压力区的临界干度关联式和超临界压力水的强制对流传热关联式。Experimentally studied were the heat transfer characteristics of water in an oblique bare downcomer with an inclination angle of 45 degrees at a pressure,a mass flow speed and an external wall heat load ranging from 11. 5 ~ 28 MPa,450- 1 550 kg /( m^2·s) and 50- 585 k W/m^2 respectively. The test results show that the wall temperature of the oblique downcomer features a non-uniform distribution along the circumferential direction of the tube. In the subcritical pressure zone,the wall temperature on the top and bottom surface of the oblique downcomer is obviously different and the dryness difference between the top and bottom surface of the oblique downcomer is comparatively big when the wall temperature soars. In the nearing critical pressure zone,the wall temperature distribution at various top and bottom surfaces of the oblique downcomer is similar and the dryness difference between the top and bottom surface of the oblique downcomer is very small when the wall temperature skyrockets. In the supercritical pressure zone,the heat transfer is intensified in the quasi-critical pressure zone and under some operating conditions,the influence of the pressure may change the action of the heat load. In the high enthalpy value zone,the wall temperature on the top surface of the oblique downcomer may somewhat decrease. On the basis of the test results,a critical dryness correlation formula in the subcritical and nearing critical pressure zone and an intensified convection heattransfer correlation formula at a supercritical pressure were obtained.

关 键 词：倾斜下降管 壁温 压力 热负荷 

分 类 号：TK124[动力工程及工程热物理—工程热物理]