物理模型及边界条件对直流蒸发管两相流不稳定性边界影响研究
|
摘要
本文研究不同边界条件及物理模型对两相流不稳定性边界的影响。采用RELAP5程序模拟直流蒸发管内的两相流不稳定性实验工况,对计算程序和模型进行验证,分析恒定流量及恒定压降两种边界条件、并联管数量、轴向功率分布形式和传热管热容等不同边界条件和物理模型对不稳定性边界的影响。结果表明:恒定压降边界条件下,单根管、2根并联管和多根并联管的不稳定性边界差别小于5%;恒定流量边界条件下,多根并联管不稳定性边界和2根并联管相比差别小于5%,而与单根管不稳定性边界的差别则超过100%;并联管根数相同时,恒定流量边界条件的稳定性好于恒定压降边界条件;沿流动方向(轴向)功率递增分布时,系统稳定性好于沿流动方向功率均匀分布,沿流动方向功率均匀分布时,系统稳定性好于沿流动方向功率递减分布;当管壁厚度为0～20 mm时,管壁热容对不稳定性边界几乎没有影响。
The effects of different boundary conditions and physical models on two-phase flow instability boundary were studied in this paper. In order to verify the code and model, the RELAP5 code was used to simulate two-phase flow instability experiments in once-through evaporation tube. Then the influences of constant flow rate and constant pressure drop boundary conditions, the number of parallel tubes, the axial power distribution patterns and the heat capacity of the heat transfer tubes on the instability boundary were analyzed. The results show that the instability boundary differences among single tube, two tubes and multiple tube models are less than 5% under constant pressure drop boundary conditions. Under constant flow rate boundary conditions, the instability boundary of multiple tube models differs from that of two tubes model by less than 5%, while the instability boundary of single tube model differs from that of two tubes models by more than 100%. When the numbers of parallel tubes in the models are the same, the stability of the model with the constant flow rate boundary conditions is better than that with the constant pressure drop boundary conditions. The stability of the system with increasing power distribution along the flow direction(axial direction) is better than that with uniform power distribution, and the stability of the system with uniform power distribution along the flow direction is better than that with decreasing power distribution. When the wall thickness varies from 0 to 20 mm, the wall heat capacity has little effect on the instability boundary.
The effects of different boundary conditions and physical models on two-phase flow instability boundary were studied in this paper. In order to verify the code and model, the RELAP5 code was used to simulate two-phase flow instability experiments in once-through evaporation tube. Then the influences of constant flow rate and constant pressure drop boundary conditions, the number of parallel tubes, the axial power distribution patterns and the heat capacity of the heat transfer tubes on the instability boundary were analyzed. The results show that the instability boundary differences among single tube, two tubes and multiple tube models are less than 5% under constant pressure drop boundary conditions. Under constant flow rate boundary conditions, the instability boundary of multiple tube models differs from that of two tubes model by less than 5%, while the instability boundary of single tube model differs from that of two tubes models by more than 100%. When the numbers of parallel tubes in the models are the same, the stability of the model with the constant flow rate boundary conditions is better than that with the constant pressure drop boundary conditions. The stability of the system with increasing power distribution along the flow direction(axial direction) is better than that with uniform power distribution, and the stability of the system with uniform power distribution along the flow direction is better than that with decreasing power distribution. When the wall thickness varies from 0 to 20 mm, the wall heat capacity has little effect on the instability boundary.
引文
[1] BOURE J A, BERGLES A E, TONG L S. Review of two-phase flow instability[J]. Nuclear Engineering and Design, 1973, 25(2): 165-192.
[2] LAHEY R T, PODOWSKI M Z. On the analysis of various instabilities in two-phase flows[J]. Multiphase Science & Technology, 1989, 4(1-4): 183-370.
[3] MA Y, LI X, WU X. Thermal-hydraulic characteristics and flow instability analysis of an HTGR helical tube steam generator[J]. Annals of Nuclear Energy, 2014, 73(1): 484-495.
[4] HIRAYAMA M, UMEKAWA H, OZAWA M. Parallel-channel instability in natural circulation system[J]. Multiphase Science & Technology, 2006, 18(4): 305-333.
[5] 马越,李晓伟,吴莘馨. 垂直上升管内对流沸腾瞬态数值模拟及其两相流不稳定性预测[J]. 原子能科学技术,2013,47(12):2 249-2 253. MA Yue, LI Xiaowei, WU Xinxin. Transient numerical simulation and two-phase flow instability prediction of convective boiling in vertical up-flow tube[J]. Atomic Energy Science and Technology, 2013, 47(12): 2 249-2 253(in Chinese).
[6] AMBROSINI W, FERRERI J C. Analysis of basic phenomena in boiling channel instabilities with different flow models and numerical schemes[C]//International Conference on Nuclear Engineering. [S. l.]: [s. n.], 2006: 889-900.
[7] 付文,李晓伟,吴莘馨,等. 并联直流蒸发管内两相流密度波不稳定性研究[J]. 工程热物理学报,2014,35(3):576-580. FU Wen, LI Xiaowei, WU Xinxin, et al. Investigation on two-phase flow density wave instability in parallel once-through evaporatiom tubes[J]. Journal of Engineering Thermophysics, 2014, 35(3): 576-580(in Chinese).
[8] MARCO C, ANTONIO C, DAVIDE P, et al. RELAP5/MOD3.3 study on density wave instabilities in single channel and two parallel channels[J]. Progress in Nuclear Energy, 2012, 56(4): 15-23.
[9] XIA G, PENG M, GUO Y. Research of two-phase flow instability in parallel narrow multi-channel system[J]. Annals of Nuclear Energy, 2012, 48(48): 1-16.
[10] 王芊. 垂直上升管内汽液两相流不稳定性的实验研究与数值计算[D]. 西安:西安交通大学,1989.
[11] TAKITANI K, TAKEMURA T. Density wave instability in once-through boiling flow system, Ⅰ[J]. Journal of Nuclear Science & Technology, 1978, 15(5): 355-364.
[12] GUO Y, HUANG J, XIA G, et al. Experiment investigation on two-phase flow instability in a parallel twin-channel system[J]. Annals of Nuclear Energy, 2010, 37(10): 1 281-1 289.
[2] LAHEY R T, PODOWSKI M Z. On the analysis of various instabilities in two-phase flows[J]. Multiphase Science & Technology, 1989, 4(1-4): 183-370.
[3] MA Y, LI X, WU X. Thermal-hydraulic characteristics and flow instability analysis of an HTGR helical tube steam generator[J]. Annals of Nuclear Energy, 2014, 73(1): 484-495.
[4] HIRAYAMA M, UMEKAWA H, OZAWA M. Parallel-channel instability in natural circulation system[J]. Multiphase Science & Technology, 2006, 18(4): 305-333.
[5] 马越,李晓伟,吴莘馨. 垂直上升管内对流沸腾瞬态数值模拟及其两相流不稳定性预测[J]. 原子能科学技术,2013,47(12):2 249-2 253. MA Yue, LI Xiaowei, WU Xinxin. Transient numerical simulation and two-phase flow instability prediction of convective boiling in vertical up-flow tube[J]. Atomic Energy Science and Technology, 2013, 47(12): 2 249-2 253(in Chinese).
[6] AMBROSINI W, FERRERI J C. Analysis of basic phenomena in boiling channel instabilities with different flow models and numerical schemes[C]//International Conference on Nuclear Engineering. [S. l.]: [s. n.], 2006: 889-900.
[7] 付文,李晓伟,吴莘馨,等. 并联直流蒸发管内两相流密度波不稳定性研究[J]. 工程热物理学报,2014,35(3):576-580. FU Wen, LI Xiaowei, WU Xinxin, et al. Investigation on two-phase flow density wave instability in parallel once-through evaporatiom tubes[J]. Journal of Engineering Thermophysics, 2014, 35(3): 576-580(in Chinese).
[8] MARCO C, ANTONIO C, DAVIDE P, et al. RELAP5/MOD3.3 study on density wave instabilities in single channel and two parallel channels[J]. Progress in Nuclear Energy, 2012, 56(4): 15-23.
[9] XIA G, PENG M, GUO Y. Research of two-phase flow instability in parallel narrow multi-channel system[J]. Annals of Nuclear Energy, 2012, 48(48): 1-16.
[10] 王芊. 垂直上升管内汽液两相流不稳定性的实验研究与数值计算[D]. 西安:西安交通大学,1989.
[11] TAKITANI K, TAKEMURA T. Density wave instability in once-through boiling flow system, Ⅰ[J]. Journal of Nuclear Science & Technology, 1978, 15(5): 355-364.
[12] GUO Y, HUANG J, XIA G, et al. Experiment investigation on two-phase flow instability in a parallel twin-channel system[J]. Annals of Nuclear Energy, 2010, 37(10): 1 281-1 289.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |