摘要
【目的】探究相变蓄热器不同布置方式对相变过程的影响,进一步分析多管蓄热器的简化方式。【方法】基于焓-孔隙率法建立管壳式石蜡蓄热器蓄释热过程计算模型,研究卧式、立式布置下单管外石蜡的相变过程,并分别对比单管、多管蓄热器顺排及周期性错排等对其蓄释热过程的影响。【结果】卧式单管蓄热时长比立式缩短了18%,但二者释热时长相差不大;与蓄热过程不同,释热过程以热传导为主要传热方式,因此相对缓慢,释热时长相比蓄热时长增加了20%以上。多管蓄热器蓄释热过程所需时长略大于单管蓄热器,但其增加时长均未超过10%,蓄释热速率曲线基本与单管一致。通过进一步研究发现,当多管蓄热器中每根管周围包裹的石蜡体积及包裹方式相同时,不同排布方式不会对蓄释热过程产生较大影响。【结论】相比立式布置,卧式布置可有效提升单管外石蜡的熔化速度,且蓄热过程的强化效果相比释热过程更明显。此外,在分析多管蓄热器蓄释热过程性能时,可采用单管或部分周期性管道进行简化。
[Objectives]The influence of different placements of phase change heat exchangers on the phase change process was investigated,and the simplified mode of multi-tube heat exchangers was further analyzed.[Methods]Based on the enthalpy-porosity method,a calculation model for the melting and solidification process of the shell-and-tube paraffin heat exchanger was established,and the phase change process of paraffin outside the single-tube was investigated under horizontal and vertical placements.The effects of single-tube heat exchanger and multi-tube heat exchanger with straight and staggered rows on the melting and solidification process were compared,respectively.[Results]Full melting time of horizontal single-tube heat exchanger is 18%shorter than that of vertical,but the difference of full solidification time between the two is not significant.Unlike the melting process,the solidification process uses heat conduction as the main mode of heat transfer,so it is relatively slow,and the full solidification time is increased by more than 20%compared to the same period of full melting time.The time required for the melting and solidification process of multi-tube heat exchanger is slightly longer than that of the single-tube heat exchanger,but its increase in time is not more than 10%,and its melting and solidification rate curve is basically consistent with that of single-tube.Through further study,it is found that when the volume of paraffin wraps around each tube in the multi-tube heat exchanger and the wrapping method is the same,different arrangement methods of the multi-tube heat exchanger would not affect the melting and solidification process.[Conclusions]Compared with the vertical placement,the horizontal placement can effectively enhance the melting rate of paraffin outside the single-tube,and the enhancement effect of the melting process is more obvious than that of the solidification process.In addition,when analyzing the performance of the melting and solidification process of the multi-tube heat exchange
作者
屠楠
刘家琛
徐静
方嘉宾
马彦花
TU Nan;LIU Jiachen;XU Jing;FANG Jiabin;MA Yanhua(School of Mechanical and Electrical Engineering,Xi’an Polytechnic University,Xi’an 710600,Shaanxi Province,China;School of Chemical Engineering and Technology,Xi’an Jiaotong University,Xi’an 712000,Shaanxi Province,China;School of Mechanical and Electrical Engineering,Yunnan Agricultural University,Kunming 650500,Yunnan Province,China)
出处
《发电技术》
CSCD
2024年第3期508-516,共9页
Power Generation Technology
基金
陕西省重点研究计划项目(2022GXLH-01-08)
陕西省秦创原“科学家+工程师”队伍建设项目(2022KXJ-179)
中国电力建设股份有限公司研究中心定向资助计划(DJ-PTZX-2021-03)。
关键词
太阳能
相变蓄热器
释热
传热
数值模拟
solar energy
phase change heat exchanger
heat release
heat transfer
numerical simulation
