数据中心用壳管式相变储能换热器的储能特性

doi:10.19799/j.cnki.2095-4239.2022.0741

摘要/Abstract

摘要：

针对相变储能换热器储/放能率低的问题，本工作设计了一种壳管式相变储能换热器，以相变温度为25 ℃的石蜡为储能材料，以水为传热流体，研究传热流体对换热器储能性能的影响。搭建了壳管式相变储能换热器的实验平台，并利用FLUENT软件对其进行三维瞬态建模，通过改变边界工况进行储能数值模拟，并对最优工况进行分析。研究结果表明：数值模拟不同传热流体温度和流速对蓄/放热过程的影响，传热流体温度与相变温度的差值越大，相变单元蓄/放热速率越快，平均储/放能率越大；温差增大5 ℃，平均储能率最大提高91%，平均放能率最大提高124%，但温差增大造成的不可逆?损失也越大；而在凝固过程中，由于相变材料内部自然对流的作用非常小，放热速率远低于蓄热速率，温差同为5 ℃时平均放能率仅为平均储能率的64%，温度差是主要影响因素。随着传热流体流速的增加，流体侧对流换热的加强会加快换热，加快熔化，但对壳管式换热器的平均储能率和?损失影响不大。综合考虑平均储/放能率和?损失，本研究中换热器性能最佳的蓄热工况为40 ℃，放热工况为10 ℃，流速工况为0.5 m/s，研究结果可为储能换热器在数据中心的应用提供一定参考。

关键词: 相变储能, 壳管式换热器, 数值模拟, 储能率, ?损失

Abstract:

Addressing the issue of low energy storage/discharge rates in phase-change energy storage heat exchangers, this paper presents a shell-and-tube type phase-change energy storage heat exchanger using paraffin as the energy storage material and water as the heat transfer fluid (HTF). The aim is to investigate the influence of HTF on the heat exchanger's energy storage performance. An experimental platform for the shell-and-tube type phase-change energy storage heat exchanger is constructed, and a three-dimensional transient model is developed using FLUENT software. By changing the boundary conditions, a numerical simulation of energy storage is performed to examine the effect of different HTF temperatures and flow rates on the energy charge/discharge process. The results of the study show that the larger the temperature difference between the HTF and the paraffin, the faster the heat charge/discharge rate. When the temperature difference increases by 5 ℃, the maximum increase of the average energy storage rate is 91%, and the maximum increase of the average energy discharge rate is 124% but with the penalty of irreversible exergy loss. Due to the very small natural convection within the phase change material, the heat discharge rate is much lower than the heat charge rate in the solidification process. With a temperature difference of 5 ℃, the average energy discharge is 64% of the average energy storage rate. The temperature difference is the main factor influencing the heat transfer performance. As the HTF flow rate increases, the strengthening of the convective heat transfer accelerates the heat transfer and melt rate. However, the impact on the average energy storage rate of the shell-and-tube heat exchanger and the exergy loss is insignificant. With balancing the average energy storage/discharge rate and exergy loss, this study's optimal heat exchanger performance was achieved with an HTF temperature of 40 ℃ for heat charge, an HTF temperature of 10 ℃ for heat discharge, and a flow rate condition of 0.5 m/s. This study provides valuable insights into applying energy storage heat exchangers in data centers.

Key words: phase change energy storage, shell-and-tube heat exchanger, numerical simulation, energy storage efficiency, exergy loss

中图分类号:

TK 02

彭子安, 段文超, 李杰, 孙小琴, 宋孟杰. 数据中心用壳管式相变储能换热器的储能特性[J]. 储能科学与技术, 2023, 12(6): 1765-1773.

Zian PENG, Wenchao DUAN, Jie LI, Xiaoqin SUN, Mengjie SONG. Energy storage characteristics of a shell-and-tube phase change energy storage heat exchanger for data centers[J]. Energy Storage Science and Technology, 2023, 12(6): 1765-1773.

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参考文献 19

1	MA X W, ZHANG Q, ZOU S K. An experimental and numerical study on the thermal performance of a loop thermosyphon integrated with latent thermal energy storage for emergency cooling in a data center[J]. Energy, 2022, 253: doi:10.1016/j.energy.2022.123946.
2	LIU L J, ZHANG Q, ZHAI Z Q, et al. State-of-the-art on thermal energy storage technologies in data center[J]. Energy and Buildings, 2020, 226: doi: 10.1016/j.enbuild.2020.110345.
3	JACOB R, BRUNO F. Review on shell materials used in the encapsulation of phase change materials for high temperature thermal energy storage[J]. Renewable and Sustainable Energy Reviews, 2015, 48: 79-87.
4	李洋, 王彩霞, 宗军, 等. 不同形式相变储热换热器的对比分析[J]. 储能科学与技术, 2019, 8(2): 347-356.
	LI Y, WANG C X, ZONG J, et al. A comparative analysis of different heat exchangers containing phase change materials[J]. Energy Storage Science and Technology, 2019, 8(2): 347-356.
5	孟强, 陈梦东, 胡晓, 等. 管内熔融盐强制对流传热的数值模拟[J]. 储能科学与技术, 2019, 8(3): 544-550.
	MENG Q, CHEN M D, HU X, et al. Numerical simulation of forced convective heat transfer of molten salt in tubes[J]. Energy Storage Science and Technology, 2019, 8(3): 544-550.
6	ABDULATEEF A M, MAT S, ABDULATEEF J, et al. Geometric and design parameters of fins employed for enhancing thermal energy storage systems: A review[J]. Renewable and Sustainable Energy Reviews, 2018, 82: 1620-1635.
7	WANG C, WANG S, CHENG X X, et al. Research progress and performance improvement of phase change heat accumulators[J]. Journal of Energy Storage, 2022, 56: doi: 10.1016/j.est.2022.105884.
8	HAN G S, DING H S, HUANG Y, et al. A comparative study on the performances of different shell-and-tube type latent heat thermal energy storage units including the effects of natural convection[J]. International Communications in Heat and Mass Transfer, 2017, 88: 228-235.
9	DING C, PEI J C, WANG S N, et al. Evaluation and comparison of thermal performance of latent heat storage units with shell-and-tube, rectangular, and cylindrical configurations[J]. Applied Thermal Engineering, 2023, 218: doi: 10.1016/j.applthermaleng.2022. 119364.
10	CAO X L, YUAN Y P, XIANG B, et al. Effect of natural convection on melting performance of eccentric horizontal shell and tube latent heat storage unit[J]. Sustainable Cities and Society, 2018, 38: 571-581.
11	刘丽辉, 张航, 彭子安, 等. 板式相变储能换热器的性能优化[J]. 储能科学与技术, 2021, 10(5): 1745-1752.
	LIU L H, ZHANG H, PENG Z A, et al. Energy storage optimization of a plate-type phase change heat exchanger[J]. Energy Storage Science and Technology, 2021, 10(5): 1745-1752.
12	张云婷, 云和明, 张艳玲, 等. 壳管式相变蓄热装置的数值模拟[J]. 制冷与空调(四川), 2013, 27(4): 329-334.
	ZHANG Y T, YUN H M, ZHANG Y L, et al. The numerical simulation of shell and tube phase-change heat storage device[J]. Refrigeration & Air Condition, 2013, 27(4): 329-334.
13	ASHRAE T. 9.9: Thermal Guidelines for Liquid Cooled Data Processing Environments [R]. American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), White Paper, 2011.
14	DZHONOVA-ATANASOVA D, GEORGIEV A, NAKOV S, et al. Compact thermal storage with phase change material for low-temperature waste heat recovery—Advances and perspectives[J]. Energies, 2022, 15(21): doi: 10.3390/en15218269.
15	NEDJAR B. An enthalpy-based finite element method for nonlinear heat problems involving phase change[J]. Computers & Structures, 2002, 80(1): 9-21.
16	MIRANDA FUENTES J, JOHANNES K, KUZNIK F, et al. Melting with convection and radiation in a participating phase change material[J]. Applied Energy, 2013, 109: 454-461.
17	卢沛, 罗向龙, 陈健勇, 等. 板式换热器及其热力系统的运行特性和高级(火用)分析[J]. 化工学报, 2021, 72(S1): 512-519.
	LU P, LUO X L, CHEN J Y, et al. Operating characteristics and advanced exergy analysis of plate heat exchangers and their thermal system[J]. CIESC Journal, 2021, 72(S1): 512-519.
18	SUN B Z, LIU Z Z, JI X, et al. Thermal energy storage characteristics of packed bed encapsulating spherical capsules with composite phase change materials[J]. Applied Thermal Engineering, 2022, 201: doi: 10.1016/j.applthermaleng.2021. 117659.
19	EBRAHIMI K, JONES G F, FLEISCHER A S. A review of data center cooling technology, operating conditions and the corresponding low-grade waste heat recovery opportunities[J]. Renewable and Sustainable Energy Reviews, 2014, 31: 622-638.

熔点/℃	导热系数 /[W/(m·℃)]	黏度 /[kg/(m·s)]	比热容 /[J/(kg·℃)]	密度/(kg/m³)		相变潜热 /(kJ/kg)
熔点/℃	导热系数 /[W/(m·℃)]	黏度 /[kg/(m·s)]	比热容 /[J/(kg·℃)]	固相	液相	相变潜热 /(kJ/kg)
25	0.2	0.0027	2000	880	770	230

[1]	见禹, 陈宝明, 朱彭真, 李坤. 含梯度孔密度骨架石蜡方腔相变传热特性[J]. 储能科学与技术, 2023, 12(6): 1968-1980.
[2]	禹永帅, 刘永峰, 裴普成, 张璐, 姚圣卓. 阴极相对湿度对PEMFC电解质水含量及性能的影响[J]. 储能科学与技术, 2023, 12(6): 1755-1764.
[3]	陈育新, 杨家沐, 李东博, 练成, 刘洪来. 圆柱形锂离子电池真空干燥过程的数值模拟[J]. 储能科学与技术, 2023, 12(6): 1957-1967.
[4]	胡健, 任育杰, 杜金魁, 刘元, 刘丹. 含相变储能的风/光/热电联产综合能源系统优化调度[J]. 储能科学与技术, 2023, 12(3): 968-975.
[5]	胡自锋, 徐耀祖, 段振云, 商向东, 徐景久. 新型蓄热体结构蓄热过程分析[J]. 储能科学与技术, 2023, 12(1): 165-171.
[6]	葛苏槿, 张龙, 杨晓华, 单文豪, 徐广强. 冷风送风方式对储能电池簇降温效果影响的模拟[J]. 储能科学与技术, 2023, 12(1): 150-154.
[7]	崔婷婷, 王燕. 基于LBM的多孔介质无机复合相变材料储能特性[J]. 储能科学与技术, 2023, 12(1): 61-68.
[8]	李琳, 王宇, 钱雯艳, 李东旭. 脂肪酸相变储能板性能及控温效果模拟[J]. 储能科学与技术, 2023, 12(1): 247-254.
[9]	唐奡, 严川伟. 液流电池模拟仿真研究现状与展望[J]. 储能科学与技术, 2022, 11(9): 2866-2878.
[10]	冯国会, 王天雨, 王刚. 封装方式对相变水箱蓄放热性能影响模拟分析[J]. 储能科学与技术, 2022, 11(7): 2161-2176.
[11]	叶文兰, 赵明, 胡明禹, 田扬. 管束式相变蓄热器的蓄放热性能分析[J]. 储能科学与技术, 2022, 11(7): 2151-2160.
[12]	李仲博, 汉京晓, 王成成, 杨慧, 杨娜, 尹少武, 王立, 童莉葛, 唐志伟, 丁玉龙. 热化学反应器放热过程模拟及参数影响规律[J]. 储能科学与技术, 2022, 11(7): 2133-2140.
[13]	吴小凌, 周涛, 刘钰照, 杜艳平, 陈会平, 李顺. 基于空气紊流的中空底孔微柱阵列设计及强化散热数值研究[J]. 储能科学与技术, 2022, 11(6): 1980-1987.
[14]	甘露雨, 陈汝颂, 潘弘毅, 吴思远, 禹习谦, 李泓. 锂电池安全性多尺度研究策略：实验与模拟方法[J]. 储能科学与技术, 2022, 11(3): 852-865.
[15]	薛洁, 张军, 杜昭, 胡汝坤, 杨肖虎. 新型平底型相变蓄热器蓄热性能的数值模拟[J]. 储能科学与技术, 2022, 11(12): 3855-3861.