中间热交换器二次侧流量分配及阻力特性试验研究

Study on Flow Distribution and Resistance Characteristics of Secondary Side of Intermediate Heat Exchanger

中间热交换器是液态金属钠冷反应堆堆芯和蒸汽发生器之间进行热交换的重要设备。由于管束众多,理论计算难以得到准确的流量分配情况及阻力特性参数。针对上述问题,以某型中间热交换器为原型,在1∶1模型上开展了流量分配及阻力特性试验,获得了不同流量分配结构的流量分配因子以及二次侧中心下降段、换热管段等局部结构的阻力系数。结果表明,锥形盘和无流量分配结构会导致外层流量明显偏高;而孔板结构会降低外层流量分配因子,使流量分配更均匀。二次侧中心下降段、换热管段的阻力系数随雷诺数(Re)的增加而略微降低。二次侧下封头的阻力系数从大到小依次为锥形盘、孔板2、孔板1、无流量分配结构,总阻力系数的变化也满足这一规律。研究结果为中间热交换器的优化设计提供数据支持。

Intermediate heat exchanger is an important equipment for heat exchange between liquid-sodium cooled fast reactor core and steam generator.Due to the large number of tube bundles,it is difficult to get accurate flow distribution and resistance characteristic parameters by theoretical calculation.In order to solve the above problems,an intermediate heat exchanger was taken as a prototype,and the flow distribution and resistance characteristics tests were carried out on a 1∶1 model.The flow distribution factors of different flow distribution structures and the resistance coefficients of local structures such as the central descending section of the secondary side and the heat exchange tube section were obtained.The results show that the conical plate and no flow-distribution structure will lead to the high outer flow.The orifice plate structure can reduce the outer flow distribution factor and make the flow distribution more uniform.The resistance coefficients of the central descending section and the heat exchange tube section of the secondary side decrease slightly with the increase of Reynolds number(Re).The resistance coefficient of the secondary side lower head from large to small is conical plate,orifice plate 2,orifice plate 1,no flow distribution structure,and the change of the total resistance coefficient also follows this law.The research results can provide data support for the optimization design of intermediate heat exchanger.