海洋核平台的等高差非能动安全壳冷却系统运行中容易发生流动不稳定现象,同时非能动系统的惯性导致事故初期自然循环换热不足。相变材料具有大潜热和等温吸热特性,因此被用于提升非能动系统的性能。本研究通过建立耦合相变材料的等高差非能动安全壳冷却系统的Apros仿真模型,对比分析了耦合相变材料前后对自然循环换热管内的运行特性和换热特性的影响规律。结果显示,耦合相变材料后能够有效降低自然循环阻力,换热管顶部的自然循环阻力峰值从1510 Pa降低至1310 Pa,下降幅度超过13%。相变材料可以使管内对流传热系数更快到达峰值,加快自然循环的建立和稳定,缓解了事故初期自然循环换热不足的问题。

Passive containment cooling systems for offshore nuclear platforms with equal-height differences are prone to flow instability during operation, while the inertia of the passive system leads to insufficient natural circulation of heat exchange in the early stages of an accident. Phase change materials(PCMs) have large latent heat and isothermal heat absorption properties, and are therefore used to enhance the performance of passive systems. In this study, the Apros simulation model of the passive containment cooling system with equal-height difference coupled with PCMs is established, and the effects of the coupled PCMs on the operating characteristics and heat exchange characteristics in the natural circulation heat transfer tube before and after the coupled PCMs are comparatively analyzed. The results show that the coupled PCMs can effectively reduce the natural circulation resistance, and the peak natural circulation resistance at the top of the heat transfer tube is reduced from 1510 Pa to 1310 Pa, with a decrease of more than 13%. The PCMs can make the convective heat transfer coefficient in the tube reach the peak value faster, accelerate the establishment and stabilization of the natural circulation, and alleviate the problem of insufficient heat exchange in the natural circulation at the beginning of the accident.

TQ021.3

国家自然科学基金（U24B2011）