梯级多孔介质强化管壳式相变储热器性能研究
|
摘要
本文采用数值模拟方法,针对套管式相变储热器内填充两级多孔介质的熔化过程特性强化开展研究,多孔介质孔隙率沿载热流体流动方向变化。分析了梯级多孔介质的孔隙率分布和各级所占的体积对熔化速率的影响;提出了一种适用于动态相变过程的温度场均匀性因子,揭示相变过程的换热强化物理机制。研究结果显示,当保证多孔介质总质量一定时,载热流体入口段的孔隙率和体积应该大于后一段,以保证较短的完全熔化时间;且入口段体积存在最优值,最优体积随着该段孔隙率的增加而减小。
In this study, numerical method was used to study the performance enhancement of melting characteristic of a shell-and-tube latent-heat storage unit enhanced by porous medium with graded porosity. Porous medium with two-stage porosity was inserted into phase change material,and the porosity varied along the flow direction of heat transfer fluid(HTF). The effects of the rates of porosity and volume of the first stage(at the entrance of HTF) to those of the second stage on the melting rate were investigated. A new evaluation index named as uniformity factor of temperature filed was proposed to reveal the mechanism of heat transfer enhancement for the dynamic process of solid-liquid phase change system. The results show that, when the total mass of porous medium is fixed, the porosity and volume of the first stage should be larger than that of the second stage to ensure a shorter total melting time. However, a higher volume of the first stage does not always bring a shorter total melting time. That is to say, there exists an optimal volume of the first stage, and this optimal volume depends on the porosity. The optimal volume of the first stage decreases with the increase of the porosity of the first stage.
In this study, numerical method was used to study the performance enhancement of melting characteristic of a shell-and-tube latent-heat storage unit enhanced by porous medium with graded porosity. Porous medium with two-stage porosity was inserted into phase change material,and the porosity varied along the flow direction of heat transfer fluid(HTF). The effects of the rates of porosity and volume of the first stage(at the entrance of HTF) to those of the second stage on the melting rate were investigated. A new evaluation index named as uniformity factor of temperature filed was proposed to reveal the mechanism of heat transfer enhancement for the dynamic process of solid-liquid phase change system. The results show that, when the total mass of porous medium is fixed, the porosity and volume of the first stage should be larger than that of the second stage to ensure a shorter total melting time. However, a higher volume of the first stage does not always bring a shorter total melting time. That is to say, there exists an optimal volume of the first stage, and this optimal volume depends on the porosity. The optimal volume of the first stage decreases with the increase of the porosity of the first stage.
引文
[1] ZHENG Zhangjing, XU Yang. A Novel System for Highpurity Hydrogen Production Based on Solar Thermal Cracking of Methane and Liquid-Metal Technology:Thermodynamic Analysis[J]. Energy Conversion and Management, 2018:157:562-574
[2] ZHENG Zhangjing, HE Yaling, LI Yinshi. An Entransy Dissipation-Based Optimization Principle for Solar Power Tower Plants[J]. Science China Technological Sciences,2014, 57(4):773-783
[3] Caliskan H, Dincer I, Hepbasli A. Thermodynamic Analyses and Assessments of Various Thermal Energy Storage Systems for Buildings[J]. Energy Conversion and Management, 2012, 62:109-122
[4] Zanganeh G, Commerford M, Haselbacher A, et al. Stabilization of the Outflow Temperature of a Packed-Bed Thermal Energy Storage by Combining Rocks with Phase Change Materials[J]. Applied Thermal Engineering, 2014,70(1):316-320
[5] LIU Ming, Saman W, Bruno F. Review on Storage Materials and Thermal Performance Enhancement Techniques for High Temperature Phase Change Thermal Storage Systems[J]. Renewable and Sustainable Energy Reviews,2012, 16(4):2118-2132
[6] Medrano M, Yilmaz M O, Nogues M, et al. Experimental Evaluation of Commercial Heat Exchangers for Use as PCM Thermal Storage Systems[J]. Applied Energy, 2009,86(10):2047-2055
[7] YANG Jialin, YANG Li.jun, XU Chao, et al. Experimental Study on Enhancement of Thermal Energy Storage with Phase-Change Material[J]. Applied Energy, 2016,169:164-176
[8] LIU Zhenyu, YAO Yianpeng, WU Huiying. Numerical Modeling for Solid-Liquid Phase Change Phenomena in Porous Media:Shell-and-Tube Type Latent Heat Thermal Energy Storage[J]. Applied Energy, 2013, 112:1222-1232
[9] Atal A, Wang Y, Harsha M, et al. Effect of Porosity of Conducting Matrix on a Phase Change Energy Storage Device[J]. International Journal of Heat and Mass Transfer, 2016, 93:9-16
[10] Martinelli M, Bentivoglio F, Caron-Soupart A, et al. Experimental Study of a Phase Change Thermal Energy Storage with Copper Foam[J]. Applied Thermal Engineering, 2016, 101:247-261
[11] ZHENG Zhangjing, HE Yan, HE Yaling, et al. Numerical Optimization of Catalyst Configurations in a Solar Parabolic Trough Receiver-Reactor with Non-Uniform Heat Flux[J]. Solar Energy, 2015, 122:113-125
[12] ZHENG Zhangjing, XU Yang, HE Yaling. Thermal Analysis of a Solar Parabolic Trough Receiver Tube with Porous Insert Optimized by Coupling Genetic Algorithm and CFD[J]. Science China Technological Sciences, 2016,59(10):1475-1485
[13] XU Yang, REN Qinlong, ZHENG Zhangjing, et al. Evaluation and Optimization of Melting Performance for a Latent Heat Thermal Energy Storage Unit Partially Filled with Porous Media[J]. Applied Energy, 2017, 193:84-95
[14] ZHENG Zhangjing, LI Mingjia, HE Yaling. Thermal Analysis of Solar Central Receiver Tube with Porous Inserts and Non-Uniform Heat Flux[J]. Applied Energy,2017, 185:1152-1161
[15] XU Yang, LI Mingjia, ZHENG Zhangjing, et al. Melting Performance Enhancement of Phase Change Material by a Limited Amount of Metal Foam:Configurational Optimization and Economic Assessment[J]. Applied Energy,2018, 212:868-880
[16] ZHENG Zhangjing, LI Mingjia, HE Yaling. Optimiza-tion of Porous Insert Configurations for Heat Transfer Enhancement in Tubes Based on Genetic Algorithm and CFD[J]. International Journal of Heat and Mass Transfer,2015, 87:376-379
[17] YANG Jialin, YANG Lijun, XU Chao, et al. Numerical Analysis on Thermal Behavior of Solid-Liquid Phase Change within Copper Foam with Varying Porosity[J].International Journal of Heat and Mass Transfer, 2015,84:1008-1018
[18] TAO Yubing, YOU Yang, HE Yaling. Lattice Boltzmann Simulation on Phase Change Heat Transfer in Metal Foams/Paraffin Composite Phase Change Material[J].Applied Thermal Engineering, 2016, 93:476-485
[19] YANG Xiaohu, WANG Wenbin, YANG Chun, et al.Solidification of Fluid Saturated in Open-Cell Metallic Foams with Graded Morphologies[J]. International Journal of Heat and Mass Transfer, 2016, 98:60-69
[20] ZHANG Zhuqian, HE Xiande. Three-Dimensional Numerical Study on Solid-Liquid Phase Change within OpenCelled Aluminum Foam with Porosity Gradient[J]. Applied Thermal Engineering, 2017, 113:298-308
[21] ZHU Feng, ZHANG Chuan, GONG Xiaolu. Numerical Analysis on the Energy Storage Efficiency of Phase Change Material Embedded in Finned Metal Foam With Graded Porosity[J]. Applied Thermal Engineering, 2017,123:256-265
[22] Fluent Incorporated. User's Guide for Fluent/UNS and Rampant[R]. Fluent Incorporated, Lebanon, NH 03766,USA, 1996
[23]陶文铨.数值传热学[M].西安:西安交通大学出版社,2001 TAO Wenquan. Numerical Heat Transfer[M]. Xi'an:Xi'an Jiaotong University Press, 2001
[24] HE Yaling, ZHENG Zhangjing, DU Baocun et al., Experimental Investigation on Turbulent Heat Transfer Characteristics of Molten Salt in a Shell-and-Tube Heat Exchanger[J]. Applied Thermal Engineering, 2016, 108:1206-1213
[25] Lacroix M. Numerical Simulation of a Shell-and-Tube Latent Heat Thermal Energy Storage Unit[J]. Solar Energy,1993, 50(4):357-367
[2] ZHENG Zhangjing, HE Yaling, LI Yinshi. An Entransy Dissipation-Based Optimization Principle for Solar Power Tower Plants[J]. Science China Technological Sciences,2014, 57(4):773-783
[3] Caliskan H, Dincer I, Hepbasli A. Thermodynamic Analyses and Assessments of Various Thermal Energy Storage Systems for Buildings[J]. Energy Conversion and Management, 2012, 62:109-122
[4] Zanganeh G, Commerford M, Haselbacher A, et al. Stabilization of the Outflow Temperature of a Packed-Bed Thermal Energy Storage by Combining Rocks with Phase Change Materials[J]. Applied Thermal Engineering, 2014,70(1):316-320
[5] LIU Ming, Saman W, Bruno F. Review on Storage Materials and Thermal Performance Enhancement Techniques for High Temperature Phase Change Thermal Storage Systems[J]. Renewable and Sustainable Energy Reviews,2012, 16(4):2118-2132
[6] Medrano M, Yilmaz M O, Nogues M, et al. Experimental Evaluation of Commercial Heat Exchangers for Use as PCM Thermal Storage Systems[J]. Applied Energy, 2009,86(10):2047-2055
[7] YANG Jialin, YANG Li.jun, XU Chao, et al. Experimental Study on Enhancement of Thermal Energy Storage with Phase-Change Material[J]. Applied Energy, 2016,169:164-176
[8] LIU Zhenyu, YAO Yianpeng, WU Huiying. Numerical Modeling for Solid-Liquid Phase Change Phenomena in Porous Media:Shell-and-Tube Type Latent Heat Thermal Energy Storage[J]. Applied Energy, 2013, 112:1222-1232
[9] Atal A, Wang Y, Harsha M, et al. Effect of Porosity of Conducting Matrix on a Phase Change Energy Storage Device[J]. International Journal of Heat and Mass Transfer, 2016, 93:9-16
[10] Martinelli M, Bentivoglio F, Caron-Soupart A, et al. Experimental Study of a Phase Change Thermal Energy Storage with Copper Foam[J]. Applied Thermal Engineering, 2016, 101:247-261
[11] ZHENG Zhangjing, HE Yan, HE Yaling, et al. Numerical Optimization of Catalyst Configurations in a Solar Parabolic Trough Receiver-Reactor with Non-Uniform Heat Flux[J]. Solar Energy, 2015, 122:113-125
[12] ZHENG Zhangjing, XU Yang, HE Yaling. Thermal Analysis of a Solar Parabolic Trough Receiver Tube with Porous Insert Optimized by Coupling Genetic Algorithm and CFD[J]. Science China Technological Sciences, 2016,59(10):1475-1485
[13] XU Yang, REN Qinlong, ZHENG Zhangjing, et al. Evaluation and Optimization of Melting Performance for a Latent Heat Thermal Energy Storage Unit Partially Filled with Porous Media[J]. Applied Energy, 2017, 193:84-95
[14] ZHENG Zhangjing, LI Mingjia, HE Yaling. Thermal Analysis of Solar Central Receiver Tube with Porous Inserts and Non-Uniform Heat Flux[J]. Applied Energy,2017, 185:1152-1161
[15] XU Yang, LI Mingjia, ZHENG Zhangjing, et al. Melting Performance Enhancement of Phase Change Material by a Limited Amount of Metal Foam:Configurational Optimization and Economic Assessment[J]. Applied Energy,2018, 212:868-880
[16] ZHENG Zhangjing, LI Mingjia, HE Yaling. Optimiza-tion of Porous Insert Configurations for Heat Transfer Enhancement in Tubes Based on Genetic Algorithm and CFD[J]. International Journal of Heat and Mass Transfer,2015, 87:376-379
[17] YANG Jialin, YANG Lijun, XU Chao, et al. Numerical Analysis on Thermal Behavior of Solid-Liquid Phase Change within Copper Foam with Varying Porosity[J].International Journal of Heat and Mass Transfer, 2015,84:1008-1018
[18] TAO Yubing, YOU Yang, HE Yaling. Lattice Boltzmann Simulation on Phase Change Heat Transfer in Metal Foams/Paraffin Composite Phase Change Material[J].Applied Thermal Engineering, 2016, 93:476-485
[19] YANG Xiaohu, WANG Wenbin, YANG Chun, et al.Solidification of Fluid Saturated in Open-Cell Metallic Foams with Graded Morphologies[J]. International Journal of Heat and Mass Transfer, 2016, 98:60-69
[20] ZHANG Zhuqian, HE Xiande. Three-Dimensional Numerical Study on Solid-Liquid Phase Change within OpenCelled Aluminum Foam with Porosity Gradient[J]. Applied Thermal Engineering, 2017, 113:298-308
[21] ZHU Feng, ZHANG Chuan, GONG Xiaolu. Numerical Analysis on the Energy Storage Efficiency of Phase Change Material Embedded in Finned Metal Foam With Graded Porosity[J]. Applied Thermal Engineering, 2017,123:256-265
[22] Fluent Incorporated. User's Guide for Fluent/UNS and Rampant[R]. Fluent Incorporated, Lebanon, NH 03766,USA, 1996
[23]陶文铨.数值传热学[M].西安:西安交通大学出版社,2001 TAO Wenquan. Numerical Heat Transfer[M]. Xi'an:Xi'an Jiaotong University Press, 2001
[24] HE Yaling, ZHENG Zhangjing, DU Baocun et al., Experimental Investigation on Turbulent Heat Transfer Characteristics of Molten Salt in a Shell-and-Tube Heat Exchanger[J]. Applied Thermal Engineering, 2016, 108:1206-1213
[25] Lacroix M. Numerical Simulation of a Shell-and-Tube Latent Heat Thermal Energy Storage Unit[J]. Solar Energy,1993, 50(4):357-367