余热排出泵小破口失水事故空化特性数值分析

发布时间：2019-07-23 18:51

【摘要】：为研究小破口失水事故工况下余热排出泵内部空化流动特性,基于Rayleigh-Plesset方程的混合物均相流空化模型和剪切应力运输SST湍流模型,对余热排出泵高温高压环境下叶轮内空化流动进行全流道数值计算。根据计算结果获得了余热排出泵小破口严重事故工况下扬程和效率的衰减曲线及空化发生的初始压力,捕捉到泵内空化的发生、发展过程。研究结果表明:当环境压力降低至大约1.15 MPa时,叶片吸力面进水边靠近前盖板处开始出现空泡,随着环境压力的降低,空泡分布区域及空泡体积分数不断扩大;当压力降低至1.143 MPa时,叶轮内部最大空泡体积分数达到50.17%,严重空化时,叶片工作面会有空泡聚集并造成叶轮流道严重堵塞致使泵扬程急剧下降。通过分析空化发生的状况得出空化发生的初始压力,为余热排出泵的设计提供一定的参考。
[Abstract]:In order to study the cavitation flow characteristics of waste heat discharge pump under the condition of small break water loss accident, the cavitation flow in impeller under high temperature and high pressure environment was calculated based on the mixture homogeneous flow cavitation model and shear stress transport SST turbulence model based on Rayleigh-Plesset equation. According to the calculation results, the attenuation curve of head and efficiency and the initial pressure of cavitation under the condition of small break and serious accident of waste heat discharge pump are obtained, and the occurrence and development process of cavitation in the pump are captured. The results show that when the ambient pressure decreases to about 1.15 MPa, the cavitation begins to appear at the inlet edge of the suction surface near the front cover plate. With the decrease of the environmental pressure, the cavitation distribution area and the volume fraction of the cavitation increase. When the pressure is reduced to 1.143 MPa, the maximum cavitation volume fraction in the impeller reaches 50.17%. When the impeller is seriously cavitation, there will be cavitation accumulation in the blade working face and serious blockage of the blade rotation path, resulting in a sharp decrease in the pump head. The initial pressure of cavitation is obtained by analyzing the occurrence of cavitation, which provides a certain reference for the design of waste heat discharge pump.
【作者单位】：江苏大学流体机体机械工程技术研究中心;
【基金】：国家科技支撑计划资助项目(2011BAF14B04Z) 国家自然科学基金重点资助项目(51239005);国家自然科学基金资助项目(51349004)
【分类号】：TL364.4

【相似文献】