Journal of Textile Research ›› 2024, Vol. 45 ›› Issue (02): 206-213.doi: 10.13475/j.fzxb.20231004501

• Apparel Engineering • Previous Articles     Next Articles

Heat transfer simulation and parametric design of electric heating textile system

CHENG Ziqi1, LU Yehu1,2(), XU Jingxian1   

  1. 1. College of Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215021, China
    2. National Engineering Laboratory of Modern Silk, Suzhou, Jiangsu 215123, China
  • Received:2023-10-16 Revised:2023-11-01 Online:2024-02-15 Published:2024-03-29

RichHTML

23

PDF (PC)

89

Abstract:

Objective In order to ensure the thermal comfort and safety of users, it is necessary to investigate the performance of electric heating clothing. Electric heating textile system simulation can achieve precise simulation of heating components and explore the effect of various parameters on heating performance. This paper establishes a three-dimensional heat transfer model of an electrically heated fabric system including the skin layer to study the effects of environmental factors, heating temperature, and thermal resistance of the inner and outer layers of the clothing on skin temperature. Based on the influence relationship, a skin temperature prediction model is established.

Method A combination of electric heating clothing fabric was adopted, in which the heating component is a carbon nanomaterial heating film. The electric heating fabric system was numerically simulated using Comsol Multiphysics, considering the three heat transfer modes, which are conduction, convection, and radiation. The simulation involved the coupling of multiple physical fields. The effectiveness of the model was experimentally validated using an iSGHP thermal resistance tester and an MSR145 temperature humidity sensor.

Results The simulated experiment process obtained real-time temperature, and the simulated curve was compared with the experimental results, demonstrating a similar trend. At the beginning of the plate heating, the simulated heating rate was higher than the experimental value, and then the temperature gradually stabilized and approached the experimental value. There could be two reasons for this situation. 1. The heating temperature and heat flux of the simulation did not have a start-up time. In reality, it takes several seconds for the heating plate to reach the desired temperature, and when the temperature difference between the environment and the heating temperature is large, the heating time will be longer. Also, it takes a certain amount of time for the hot plate of the thermal resistance tester to reach the required power. 2. The simulation assumes that the fabric is thermally insulated on all sides, but it is difficult to achieve absolute thermal insulation in actual experiments, and there is still a small amount of heat exchange. A parametric study on the model is conducted in a steady state and three regions for skin temperature prediction are selected. Point A represents the skin temperature (Tska) beneath the midpoint of the heating detection area, domain B represents the average skin temperature (Tskb) beneath the rectangular region of the heating detection plate, and point C represents the skin temperature (Tskc) beneath the edge point of the heating detection plate. Then, the quantitative relationship between skin temperatures (Tska, Tskb, Tskc) and ambient temperature (Ta), wind velocity (Va), heating plate temperature (Th), as well as inner and outer clothing thermal resistances (I1, I2) was determined through regression analysis method. Based on this, a predictive model for skin temperature was established. For setting the comfort range of skin temperature, it was recommended to meet the following conditions simultaneously, i.e., the edge point temperature (Tskc) remains at 34 ℃, the skin temperature (Tska) in the heating detection area no more than 41 ℃, and the average skin temperature (Tskb) in the large heating no more than 37 ℃.

Conclusion A three-dimensional heat transfer model of an electrical heating fabric system, including the skin layer, has been established. The transient simulation results are compared with experimental data, showing a close similarity in temperature variation over time. The relative error between real-time and final temperatures is lower than 4%, indicating good agreement between simulated and experimental values. A parameterized study of the steady-state model is conducted based on the linear relationship between the skin temperatures of three regions and the ambient temperature, wind velocity, heating temperature of the heating element, and thermal resistances of the inner and outer layers of the clothing. A predictive model for skin temperature is developed. This skin temperature prediction model can be used to design the heating temperature and the inner and outer layers of the clothing based on the comfortable range of skin temperature under specific environmental conditions. Conversely, given the determined inner and outer layers of the clothing, the environmental conditions and heating temperature of the heating element can be determined based on the comfortable range of skin temperature. By predicting the post-dressing skin temperature, it is possible to assess thermal comfort and optimize clothing design accordingly.

Key words: electrically heated textile system, heat transter simulation, skin temperature, prediction model, parameter design

CLC Number: 

  • TM925.63

Tab. 1

Physical parameters of materials"

材料
编号		 材料
名称		 厚度/
mm		 密度/
(kg·m-3)		 比热容/
(J·(kg·
K)-1)		 导热系数/
(W·(m·
K)-1)
h1 服装外层
组合织物		 20.478 19.5 1 340 0.052 738
h3 加热片 0.310 540.9 1 340 0.037 805
h4 服装内层 0.116 489.3 1 340 0.011 016

Fig. 1

Schematic diagram of geometric modeling. (a) Cross-section; (b) Top view"

Fig. 2

Grid independence testing"

Fig. 3

Comparison between experimental and simulated values at various heating temperature"

Tab. 2

Comparison between experimental and simulated data"

加热温
度/℃		 测温
点		 平均相对
误差/%		 最终实验
温度/℃		 最终模拟
温度/℃		 最终温度相
对误差/%
38 1 2.15 37.6 37.7 0.15
2 3.10 39.7 40.3 1.42
3 1.85 37.6 37.9 0.85
45 1 1.28 38.8 38.9 0.15
2 3.81 45.7 46.2 0.99
3 1.89 39.1 39.6 1.32
50 1 1.09 39.9 39.8 0.13
2 1.28 49.9 51.1 2.32
3 1.28 40.4 41.0 1.55

Tab. 3

Parameter settings"

参数
设置		 环境温度
Ta/℃		 风速Va/
(m·s-1)		 加热片温度
Th/℃		 服装热阻/
(m2·℃·W-1)
外层 内层
设置
范围		 -10~
10 [9,22]		 0.1~
2.6 [9]		 35~
55		 0.2~
0.7 [23]		 0.004~
0.4 [23]
设置
步长		 5 0.625 5 0.125 0.099

Fig. 4

Three dimensional relationship diagram between heating temperature and thermal resistance of inner and outer fabric layers"

Tab. 4

Thermal resistance relationship between inner and outer layers of clothing"

加热温度/℃ 服装内外层热阻关系式
35 I 1 = 0.783 ? 89 - 1.138 ? 37 I 2 ( I 2 ∈ ( 0,0.078 ? 1 ) )
36 I 1 = 0.783 ? 26 - 1.138 ? 37 I 2 ( I 2 ∈ ( 0,0.058 ? 0 ) )
37 I 1 = 0.782 ? 62 - 1.138 ? 37 I 2 ( I 2 ∈ ( 0,0.037 ? 9 ) )
38 I 1 = 0.781 ? 99 - 1.138 ? 37 I 2 ( I 2 ∈ ( 0,0.017 ? 8 ) )

Fig. 5

Three-dimensional relationship diagram among heating temperature, ambient temperature and wind speed"

[1] REAZUDDIN M, DAIVA M. Progress in flexible electronic textile for heating application: a critical review[J]. Materials, 2021, 14(21): 17-18.
doi: 10.3390/ma14010017
[2] WANG F, GAO C. Protective clothing: managing thermal stress[M]. Cambridge: Woodhead Publishing, 2014: 282-283.
[3] 庄梅玲, 张晓枫. 电热服的热性能评价[J]. 青岛大学学报(工程技术版), 2004, 19(2): 54-58.
ZHUANG Meiling, ZHANG Xiaofeng. Heat performance evaluation of electric heating garment[J]. Journal of Qingdao University (Engineering & Technology Edition), 2004, 19(2): 54-58.
[4] SORA S, HAE-HYUN C, BIN Y, et al. Evaluation of body heating protocols with graphene heated clothing in a cold environment[J]. International Journal of Clothing Science and Technology, 2017, 29(6): 830-844.
doi: 10.1108/IJCST-03-2017-0026
[5] 丁波, 李健, 牛子璇, 等. 电加热服装发热元件的组合设计与评价[J]. 纺织导报, 2022(5): 93-97.
DING Bo, LI Jian, NIU Zixuan, et al. Combination design and evaluation of heating elements for electrically heated gar-ments[J]. China Textile Leader, 2022(5): 93-97.
[6] SONG W, LAI D, WANG F. Evaluating the cold protective performance (CPP) of an electrically heated garment (EHG) and a chemically heated garment (CHG) in cold environments[J]. Fibers and Polymers, 2015, 16(12): 2689-2697.
doi: 10.1007/s12221-015-5409-4
[7] WANG F, GAO C, HOLMER I. Effects of air velocity and clothing combination on heating efficiency of an electrically heated vest (EHV): a pilot study[J]. Occup Environ Hyg, 2010, 7(9): 501-505.
[8] PARK H, HWANG S, LEE J, et al. Impact of electrical heating on effective thermal insulation of a multi-layered winter clothing system for optimal heating efficiency[J]. International Journal of Clothing Science and Technology, 2016, 28(2): 254-264.
[9] 吴黛唯, 李红彦, 戴艳阳, 等. 加热装置在防寒服中的位置及其热效用[J]. 纺织学报, 2020, 41(6): 118-124.
WU Daiwei, LI Hongyan, DAI Yanyang, et al. Thermal function effectiveness and location of heating device in cold protective clothing[J]. Journal of Textile Research, 2020, 41(6): 118-124.
doi: 10.1177/004051757104100206
[10] 徐新宇, 王云仪. CFD数值模拟在着装人体传热研究中的应用进展[J]. 纺织导报, 2021(9): 74-78.
XÜ Xinyu, WANG Yunyi. Application of CFD numerical simulation in heat transfer research of dressed human body[J]. China Textile Leader, 2021(9): 74-78.
[11] 李雅芳. 基于镀银纱线的加热织物制备及其热力学性能研究与仿真[D]. 天津: 天津工业大学, 2017:117-118.
LI Yafang. Preparation and study of thermal property in heating fabric based on silver-plated yarn[D]. Tianjin: Tiangong University, 2017:117-118.
[12] 陈扬, 杨允出, 张艺强, 等. 电加热服装中加热片与织物组合体的稳态热传递模拟[J]. 纺织学报, 2018, 39(5): 49-55.
CHEN Yang, YANG Yunchu, ZHANG Yiqiang, et al. Simulation of steady heat transfer on fabrics system embedded with heating unit in electrically heated clothing[J]. Journal of Textile Research, 2018, 39(5): 49-55.
doi: 10.1177/004051756903900109
[13] 谢艳杰. 电加热服热性能仿真分析研究[D]. 北京: 北京服装学院, 2021:49-50.
XIE Yanjie. Research on simulation analysis of thermal performance of electric heating clothing[D]. Beijing: Beijing Institute of Fashion Technology, 2021:49-50.
[14] LI X, KUAI B, TU X, et al. Three-dimensional analysis model of electric heating fabrics considering the skin metabolism[J]. Journal of Engineered Fibers and Fabrics, 2021, 16: 3-4.
[15] 刘鸣茗. 基于皮肤组织模型的热功能服装传热性能模拟分析[D]. 杭州: 浙江理工大学, 2021:43-44.
LIU Mingming. Study and prediction of heat transfer performance of thermal textile considering the skin tissue[D]. Hangzhou: Zhejiang Sci-Tech University, 2021:43-44.
[16] WANG F, KANG Z, ZHOU J. Model validation and parametric study on a personal heating clothing system (PHCS) to help occupants attain thermal comfort in unheated buildings[J]. Building and Environment, 2019, 162: 2-9.
[17] HUANG Q, XING G, YANG F, et al. Modelling and experimental study on electrically heating garment to enhance personal thermal comfort[C]//ADIGUZEL O, BRAZHNIKOV A, GU K, et al. 2020 International Conference on New Energy, Power and Environmental Engineering. Xiamen: IOP Publishing Ltd, 2021, 696(1): 4-11.
[18] 张渭源. 服装舒适性与功能[M]. 北京: 中国纺织出版社, 2005:35-36.
ZHANG Weiyuan. Clothing comfort and function[M]. Beijing: China Textile & Apparel Press, 2005: 35-36.
[19] 陶文铨. 传热学[M]. 5版. 北京: 高等教育出版社, 2019: 5-11.
TAO Wenquan. Heat transfer[M]. 5th ed. Beijing: Higher Education Press, 2009: 5-11.
[20] 崔鹏. 高蓬松纤维集合体保温性检测机理与应用[D]. 上海: 东华大学, 2011: 46-48.
CUI Peng. The principle and application of test of warm performance of high buoyancy fibrous porous mate-rials[D]. Shanghai: Donghua University, 2011:46-48.
[21] 戈强胜, 谭伟新, 王向钦, 等. 远红外纺织品评价指标研究[J]. 中国纤检, 2018(6): 132-134.
GE Qiangsheng, TAN Weixin, WANG Xiangqin, et al. The index research for the evaluation of the far infrared radiated textiles[J]. China Fiber Inspection, 2018(6): 132-134.
[22] 顾心清, 李荣杰, 李亿光, 等. 92海军舰艇艇员防寒服保暖性能人体试验评价[J]. 海军医学杂志, 2000(1): 17-20.
GU Qiangsheng, LI Rongjie, LI Yiguang, et al. Evaluation of thermal insulation of mark 92 cold weather clothing for navy ship's crew[J]. Journal of Navy Medicine, 2000(1): 17-20.
[23] 周浩. 人体皮肤温度影响因素实验研究[D]. 西安: 西安建筑科技大学, 2013:10-11.
ZHOU Hao. Experimental study on the influence factors of human skin temperature[D]. Xi'an: Xi'an University of Architecture and Technology, 2013:10-11.
[1] DONG Zhijia, GUO Yanyuqiu, LIU Haisang, YAO Sihong. Structural design and realization of warp-knitted fully formed hollow maillot [J]. Journal of Textile Research, 2023, 44(12): 130-137.
[2] WANG Zhongyu, SU Yun, WANG Yunyi. Development of personal comfort models based on machine learning and their application prospect in clothing engineering [J]. Journal of Textile Research, 2023, 44(05): 228-236.
[3] DU Jihui, SU Yun, LIU Guangju, TIAN Miao, LI Jun. Research and design of temperature-control intelligent thermal gloves with wearing comfort [J]. Journal of Textile Research, 2023, 44(04): 172-178.
[4] WU Jiaqing, WANG Yiting, HE Xinxin, GUO Yafei, HAO Xinmin, WANG Ying, GONG Yumei. Influence of blending ratio on mechanical properties of bio-polyamide 56 staple fiber/cotton blended yarn [J]. Journal of Textile Research, 2023, 44(03): 49-54.
[5] YU Xuezhi, ZHANG Mingguang, CAO Jipeng, ZHANG Yue, WANG Xiaoyan. Influence of twist on quality indexes of polyamide/cotton blended yarns [J]. Journal of Textile Research, 2023, 44(01): 106-111.
[6] CHEN Ying, SONG Zetao, ZHENG Xiaohui, JIANG Yan, CHANG Suqin. Study on cooling performance of evaporative cooling garment [J]. Journal of Textile Research, 2022, 43(11): 141-147.
[7] ZHENG Wenjie, ZHANG Aidan. Lightness prediction method for shaded satin fabrics based on image reconstruction of light and shadow [J]. Journal of Textile Research, 2022, 43(05): 97-103.
[8] ZHANG Zhaohua, CHEN Zhirui, LI Luyao, XIAO Ping, PENG Haoran, ZHANG Yuhan. Airflow sensitivity of local human skin and its influencing factors [J]. Journal of Textile Research, 2021, 42(12): 125-130.
[9] WANG Lijun, MA Ximing, DING Yinjia, CHEN Chengyi. Influence of wind speed on moisture resistance of single-layer and double-layer combined sportswear knit fabrics [J]. Journal of Textile Research, 2021, 42(07): 151-157.
[10] NIU Mengyu, PAN Shuwen, DAI Hongqin, LÜ Kaimin. Relationship between thermal-moist comfort of medical protective clothing and human fatigue [J]. Journal of Textile Research, 2021, 42(07): 144-150.
[11] YANG Yang, YU Xin, ZHANG Weijing, ZHANG Peihua. Evaluation method and prediction model establishment of cooling performance of knitted fabrics [J]. Journal of Textile Research, 2021, 42(03): 95-101.
[12] ZHANG Xiaoxia, LIU Fengkun, MAI Wei, MA Chongqi. Prediction of loom efficiency based on BP neural network and its improved algorithm [J]. Journal of Textile Research, 2020, 41(08): 121-127.
[13] HUANG Qianqian, LI Jun. Research progress on mechanism of human thermal sensation under ambient temperature step change [J]. Journal of Textile Research, 2020, 41(04): 188-194.
[14] ZHENG Qing, WANG Hongfu, KE Ying, LI Shuang. Design and evaluation of cooling clothing by phase change materials for miners [J]. Journal of Textile Research, 2020, 41(03): 124-129.
[15] ZHOU Jie, MA Qiurui. Application of BP neural network in prediction of shapewear pressure [J]. Journal of Textile Research, 2019, 40(04): 111-116.
Viewed
Full text


Abstract

Cited
  Shared   
  Discussed   
No Suggested Reading articles found!
京ICP备14006648号
Copyright 2021 © Editorial office of Journal of Textile Research
Supported by Beijing Magtech Co.Ltd