化工学报 ›› 2020, Vol. 71 ›› Issue (S1): 98-105.DOI: 10.11949/0438-1157.20191189

• 流体力学与传递现象 • 上一篇    下一篇

换热器结构优化与换热性能评价指标研究

刘秀峰1(),张诗2(),周志杰2,郑浩2,王成泽2,时红远3,李梦杰3   

  1. 1.海军装备部驻武汉地区军事代表局驻武汉地区军事代表室,湖北 武汉 430000
    2.中国舰船研究设计中心,湖北 武汉 430000
    3.西安交通大学热流科学与工程教育部重点实验室,陕西 西安 710049
  • 收稿日期:2019-10-11 修回日期:2019-10-26 出版日期:2020-04-25 发布日期:2020-04-25
  • 通讯作者: 张诗
  • 作者简介:刘秀峰(1970—),男,硕士,高级工程师,693284153@qq.com

Study on structure optimization of heat exchanger and evaluation index of heat transfer performance

Xiufeng LIU1(),Shi ZHANG2(),Zhijie ZHOU2,Hao ZHENG2,Chengze WANG2,Hongyuan SHI3,Mengjie LI3   

  1. 1.Military Representation Office of Military Representative Bureau of Naval Equipment Department in Wuhan Area, Wuhan 430000, Hubei, China
    2.China Ship Development and Design Center, Wuhan 430000, Hubei, China
    3.MOE Key Laboratory of Thermal Fluid Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, China
  • Received:2019-10-11 Revised:2019-10-26 Online:2020-04-25 Published:2020-04-25
  • Contact: Shi ZHANG

摘要:

某运载器中冷却器存在若干问题:壳侧压力损失较大;采用的弓形折流板结构使得壳侧工质呈现出Z字形流动,在折流板后易形成流动死区,促使壳侧结垢,使得换热器总传热性能降低。提出了两种针对壳侧结构的强化换热设计方案。方案一为减少弓形折流板数量、增加折流板间距;方案二为采用螺旋折流板替换原有的弓形折流板。为验证文中采用的热力设计方法的准确性,根据文献中的实验结果针对弓形折流板和螺旋折流板管壳式换热器热力设计方法进行了验证,结果表明文中采用的热力设计方法得到的计算数据与实验结果的偏差在37%以内,满足工程设计需求。优化方案根据优化参数不同,其优化结果有所不同,基本存在以下规律:优化设计可使换热器管壳两侧总压降减小,但同时其换热性能也下降。因此,需要一个综合指标来进行评价。文中提出以换热量Q与换热器流动阻力引起功耗的比值作为综合性能评价指标。该指标表示换热系统克服换热器流动阻力消耗单位泵功下的换热量,其值越大,单位泵功下换热量越高,经济性越好。经过计算发现最优方案相对原始方案,综合评价指标提高了约22.2%。

关键词: 传热, 换热器, 设计, 实验验证, 评价指标, 优化

Abstract:

There are some problems in the cooler of a launch vehicle. Firstly, the pressure loss of the shell side is large. Secondly, the segmental baffle structure makes the working substance flow in Z-shape. It is easy to form a dead zone behind the baffle, which promotes scaling on the shell side and reduces the overall heat transfer performance of the heat exchanger. Two heat transfer enhancement schemes for shell-side structures are proposed in this paper. The first scheme is to reduce the number of segmental baffles and increase the baffle spacing. The second scheme is to replace the original baffles with helical baffles. In order to verify the accuracy of the thermodynamic design method adopted in this paper, the thermodynamic design method of segmental baffle and helical baffle shell-and-tube heat exchangers are verified according to the experimental results in literature. The results show that the deviation between the experimental results and the calculated data obtained by the thermodynamic design method in this paper is within 37%, which meets engineering requirement. According to different optimization parameters, the optimization results are different. There is basically a following rule: the optimal design can reduce the total pressure drop on both shell and tube sides of heat exchanger, but its heat transfer performance decreases at the same time. Therefore, a comprehensive index is needed for evaluation. In this paper, the ratio of heat transfer Q to power consumption caused by flow resistance of heat exchanger is proposed as a comprehensive performance evaluation index. This index indicates that exchanging heat quantity obtained by heat transfer system per unit pump power. The larger the value, the better the economy. After calculation, it is found that the comprehensive evaluation index of the optimal scheme is increased by about 22.2% compared with the original scheme.

Key words: heat transfer, heat exchanger, design, experimental validation, evaluation index, optimization

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