CFG能源桩用于混凝土路面除冰降温的试验研究
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摘要
利用试验场足尺水泥粉煤灰碎石(CFG)能源桩,对模型混凝土路面冬季防冻除冰与夏季降温防护技术进行了试验研究,意在探索一种节能、环保、高效和经济的道路路面工程安全与耐久新技术。桩及模型混凝土板内均安装聚乙烯塑料管作为换热管,能源桩、混凝土板内安装有温度应变传感器测量换热过程中相应位置的温度、应变变化,混凝土板进出口水温、混凝土板表面温度分别由温度计、红外测温仪量测。试验主要分析冬季条件下,单根、双根能源桩供热一块混凝土板,以及在夏季条件下,单根能源桩降温一块混凝土板时,管路流体、混凝土板、桩的温度变化以及由温度引起的混凝土板、桩的应力应变变化。试验结果表明:冬季工况下,单根、双根能源桩可以使一块混凝土板表面温度保持在0℃以上,除冰效果显著;夏季工况下,单根能源桩对混凝土板降温,试验组与对照组混凝土板表面温差最大约为9.4℃,降温效果明显。能源桩和模型混凝土板在换热过程中,因温度改变会导致桩身和混凝土板中产生附加温度应力。桩身附加温度应力对桩结构完整性和安全性不会造成影响,而混凝土路面板的附加温度应力则总是与被加热或降温前的应力叠加使其总应力幅值降低,有利于混凝土路面板的安全性和耐久性。试验过程仅使用水泵为换热管中的流体提供动力进行循坏,不消耗其他任何形式能量,运营维护成本较低。
This study was conducted to explore a new energy-saving, environment-friendly, highly efficient, and low-cost technique for increasing pavement safety and durability in the field of road engineering. It involved full-scale experiments on cementfly-ash gravel(CFG) piles that are used to deice a concrete pavement model to prevent frostbiting in winter, and cool the concrete pavement model, thereby preventing expansion, in summer. Polyethylene pipes were fixed in the piles and concrete pavement model; these pipes serve as heat exchange pipes. Thermal strain sensors were installed in the energy piles and concrete pavement model to monitor changes in temperature and strain during the heating-cooling process at corresponding positions. The temperature of the inlet/outlet water and surface of the concrete pavement model was measured using a thermometer and infrared thermometer, respectively. The experimental analyses focused primarily on the temperature change of water in the pipes, concrete pavement model, and piles, and the temperature-induced changes in stress/strain in the concrete pavement model and piles when the piles transfer heat to the concrete pavement model in winter or cool the concrete pavement model in summer. The experimental results indicate that: the piles, by transferring heat to the concrete pavement model in winter, are able to maintain the latter's surface temperature above 0 ℃, thus, proving the outstanding effects of deicing. In summer, the piles cool the concrete pavement model, and the maximum range of temperature difference is 9.4 ℃ between the experimental and control groups. During the heating or cooling process between the energy piles and concrete pavement model, the temperature change of the piles and concrete pavement model gives rise to additional thermal stresses. The additional thermal stress in the piles has no effect on their structural safety and integrity. The additional thermal stress in the concrete pavement model, superimposed on the stress before heating or cooling, always reduces the total stress, thereby increasing the safety and durability of the concrete pavement model. The power consumption in the heating or cooling system is dependent only on the use of a water pump. In the absence of any other source of energy consumption, the expenses due to operating and maintaining the system can be significantly low.
This study was conducted to explore a new energy-saving, environment-friendly, highly efficient, and low-cost technique for increasing pavement safety and durability in the field of road engineering. It involved full-scale experiments on cementfly-ash gravel(CFG) piles that are used to deice a concrete pavement model to prevent frostbiting in winter, and cool the concrete pavement model, thereby preventing expansion, in summer. Polyethylene pipes were fixed in the piles and concrete pavement model; these pipes serve as heat exchange pipes. Thermal strain sensors were installed in the energy piles and concrete pavement model to monitor changes in temperature and strain during the heating-cooling process at corresponding positions. The temperature of the inlet/outlet water and surface of the concrete pavement model was measured using a thermometer and infrared thermometer, respectively. The experimental analyses focused primarily on the temperature change of water in the pipes, concrete pavement model, and piles, and the temperature-induced changes in stress/strain in the concrete pavement model and piles when the piles transfer heat to the concrete pavement model in winter or cool the concrete pavement model in summer. The experimental results indicate that: the piles, by transferring heat to the concrete pavement model in winter, are able to maintain the latter's surface temperature above 0 ℃, thus, proving the outstanding effects of deicing. In summer, the piles cool the concrete pavement model, and the maximum range of temperature difference is 9.4 ℃ between the experimental and control groups. During the heating or cooling process between the energy piles and concrete pavement model, the temperature change of the piles and concrete pavement model gives rise to additional thermal stresses. The additional thermal stress in the piles has no effect on their structural safety and integrity. The additional thermal stress in the concrete pavement model, superimposed on the stress before heating or cooling, always reduces the total stress, thereby increasing the safety and durability of the concrete pavement model. The power consumption in the heating or cooling system is dependent only on the use of a water pump. In the absence of any other source of energy consumption, the expenses due to operating and maintaining the system can be significantly low.
引文
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[2] 余进华,李婕,袁铜森,等.路面积雪结冰清除技术综述[J].湖南交通科技,2016,42 (1):51-55. YU Jin-hua, LI Jie, YUAN Tong-sen, et al. Review of Techniques on Pavement Snow-melting and De-icing [J]. Hunan Communication Science and Technology, 2016, 42 (1): 51-55.
[3] FLINTSCH G W. Assessment of the Performance of Several Roadway Mixes Under Rain, Snow, and Winter Maintenance Activities [R]. Charlottesville: Virginia Polytechnic Institute & State University, 2004.
[4] SANZO D, HECNAR S J. Effects of Road De-icing Salt (NaCl) on Larval Wood Frogs (Rana Sylvatica) [J]. Environmental Pollution, 2006, 140: 247-256.
[5] CHEN M Y, WU S P, WANG H, et al. Study of Ice and Snow Melting Process on Conductive Asphalt Solar Collector [J]. Solar Energy Materials and Solar Cells, 2011, 95: 3241-3250.
[6] LOFGREN S. The Chemical Effects of Deicing Salt on Soil and Stream Water of Five Catchments in Southeast Sweden [J]. Water Air and Soil Pollution, 2001, 130 (1-4): 863-868.
[7] 赵方冉,杜拾妹,刘新琛,等.不同除冰工艺对机场水泥混凝土道面的损伤特性[J].交通运输工程学报.2015,15 (4):18-25. ZHAO Fang-ran, DU Shi-mei, LIU Xin-chen, et al. Damage Characteristics of Cement Concrete Pavement for Airfield Resulted from Different De-icing Techniques [J]. Journal of Traffic and Transportation Engineering, 2015, 15 (4): 18-25.
[8] HOPPE E J. Evaluation of Virginia's First Heated Bridge [R]. Charlottesville: Virginia Center for Transportation Innovation and Research, 2000.
[9] WON J, KIM C, LEE S, et al. Thermal Characteristics of a Conductive Cement-based Composite for a Snow-melting Heated Pavement System [J]. Composite Structures, 2014, 118: 106-111.
[10] PAN P, WU S P, XIAO Y, et al. A Review on Hydronic Asphalt Pavement for Energy Harvesting and Snow Melting [J]. Renewable & Sustainable Energy Review, 2015, 48: 624-634.
[11] XU H N, TAN Y Q. Modeling and Operation Strategy of Pavement Snow Melting Systems Utilizing Low-temperature Heating Fluids [J]. Energy, 2015, 80: 666-676.
[12] LAI Y, LIU Y, MA D X. Automatically Melting Snow on Airport Cement Concrete Pavement with Carbon Fiber Grille [J]. Cold Regions Science and Technology, 2014, 103: 57-62.
[13] WANG H J, LIU L B, CHEN Z H. Experimental Investigation of Hydronic Snow Melting Process on the Inclined Pavement [J]. Cold Regions Science and Technology, 2010, 63: 44-49.
[14] TANAKA O, YAMAKAGE H, OGUSHI T, et al. Snow Melting Using Heat Pipes [J]. Advances in Heat Pipe Technology, 1982: 11-23.
[15] LUND J W. Pavement Snow Melting [R]. Klamath Falls: Oregon Institute of Technology, 2001.
[16] YU W B, YI X, GUO M, et al. State of the Art and Practice of Pavement Anti-icing and De-icing Techniques [J]. Sciences in Cold and Arid Regions, 2014, 6 (1): 14-21.
[17] OZSOY A,YILDIRIM R. Prevention of Icing with Ground Source Heat Pipe: A Theoretical Analysis for Turkey's Climatic Conditions [J]. Cold Regions Science and Technology, 2016, 125: 65-71.
[18] WANG X Y, ZHU Y L, ZHU M Z, et al. Thermal Analysis and Optimization of an Ice and Snow Melting System Using Geothermy by Super-long Flexible Heat Pipes [J]. Applied Thermal Engineering, 2017, 112: 1353-1363.
[19] BRANDL H. Energy Foundations and Other Thermo-active Ground Structures [J]. Géotechnique, 2006, 56 (2): 81-122.
[20] 桂树强,程晓辉,张志鹏.地源热泵桩基与钻孔埋管换热器换热性能比较[J].土木建筑与环境工程,2013,35(3):151-156. GUI Shu-qiang, CHENG Xiao-hui, ZHANG Zhi-peng. Comparative Analysis of Heat Exchange Performance of Energy Piles and Borehole Heat Exchangers in GSHP System [J]. Journal of Civil, Architectural & Environmental Engineering, 2013, 35 (3): 151-156.
[21] 桂树强,程晓辉.能源桩换热过程中结构响应原位试验研究[J].岩土工程学报,2014,36(6):1087-1094. GUI Shu-qiang, CHENG Xiao-hui. In-situ Tests on Structural Responses of Energy Piles During Heat Exchanging Process [J]. Chinese Journal of Geotechnical Engineering, 2014, 36 (6): 1087-1094.
[22] 郭红仙,李翔宇,程晓辉.能源桩热响应测试的模拟及适用性评价[J].清华大学学报:自然科学版,2015,55(1):14-20. GUO Hong-xian, LI Xiang-yu, CHENG Xiao-hui. Simulation and Applicability of Thermal Response Tests in Energy Piles [J]. Journal Tsinghua University: Science & Technology, 2015,55 (1): 14-20.
[23] 李翔宇,郭红仙,程晓辉.能源桩温度分布的试验与数值研究[J].土木工程学报,2016,49(4):102-110. LI Xiang-yu, GUO Hong-xian, CHENG Xiao-hui. Experimental and Numerical Study on Temperature Distribution in Energy Piles [J]. China Civil Engineering Journal, 2016, 49 (4): 102-110.
[24] YOU S, CHENG X H, GUO H X, et al. In-situ Experimental Study of Heat Exchange Capacity of CFG Pile Geothermal Exchangers [J]. Energy and Buildings, 2014, 79: 23-31.
[25] YOU S, CHENG X H, GUO H X, et al. Experimental Study on Structural Response of CFG Energy Piles [J]. Applied Thermal Engineering, 2016, 96: 640-651.
[26] JEONG S, LIM H, LEE J K, et al. Thermally Induced Mechanical Response of Energy Piles in Axially Loaded Pile Groups [J]. Applied Thermal Engineering, 2014, 71: 608-615.
[27] MIMOUNI T, LALOUI L. Behaviour of a Group of Energy Piles [J]. Canadian Geotechnical Journal, 2015, 52: 1913-1929.
[28] NG C W W, SHI C, GUNAWAN A, et al. Centrifuge Modelling of Heating Effects on Energy Pile Performance in Saturated Sand [J]. Canadian Geotechnical Journal, 2015, 52: 1045-1057.
[29] LALOUI L, DONNA A D. Understanding the Behaviour of Energy Geo-structures [J]. Proceedings of ICE-Civil Engineering, 2011, 164 (4): 184-191.
[30] BALBAY A, ESEN M. Temperature Distributions in Pavement and Bridge Slabs Heated by Using Vertical Ground-source Heat Pump Systems [J]. Acta Scientiarum, 2013, 35 (4): 677-685
[31] 李翔宇.基于试验与数值模拟的桩基埋管地下换热器设计分析[D]. 北京:清华大学,2015. LI Xiang-yu. Analysis and Design Method for Pile Heat Exchangers Based on In-situ Test and Numerical Simulation [D]. Beijing: Tsinghua University, 2015.
[32] GB 50010—2010,混凝土结构设计规范 [S]. GB 50010—2010, Code for Design of Concrete Structure [S].
[2] 余进华,李婕,袁铜森,等.路面积雪结冰清除技术综述[J].湖南交通科技,2016,42 (1):51-55. YU Jin-hua, LI Jie, YUAN Tong-sen, et al. Review of Techniques on Pavement Snow-melting and De-icing [J]. Hunan Communication Science and Technology, 2016, 42 (1): 51-55.
[3] FLINTSCH G W. Assessment of the Performance of Several Roadway Mixes Under Rain, Snow, and Winter Maintenance Activities [R]. Charlottesville: Virginia Polytechnic Institute & State University, 2004.
[4] SANZO D, HECNAR S J. Effects of Road De-icing Salt (NaCl) on Larval Wood Frogs (Rana Sylvatica) [J]. Environmental Pollution, 2006, 140: 247-256.
[5] CHEN M Y, WU S P, WANG H, et al. Study of Ice and Snow Melting Process on Conductive Asphalt Solar Collector [J]. Solar Energy Materials and Solar Cells, 2011, 95: 3241-3250.
[6] LOFGREN S. The Chemical Effects of Deicing Salt on Soil and Stream Water of Five Catchments in Southeast Sweden [J]. Water Air and Soil Pollution, 2001, 130 (1-4): 863-868.
[7] 赵方冉,杜拾妹,刘新琛,等.不同除冰工艺对机场水泥混凝土道面的损伤特性[J].交通运输工程学报.2015,15 (4):18-25. ZHAO Fang-ran, DU Shi-mei, LIU Xin-chen, et al. Damage Characteristics of Cement Concrete Pavement for Airfield Resulted from Different De-icing Techniques [J]. Journal of Traffic and Transportation Engineering, 2015, 15 (4): 18-25.
[8] HOPPE E J. Evaluation of Virginia's First Heated Bridge [R]. Charlottesville: Virginia Center for Transportation Innovation and Research, 2000.
[9] WON J, KIM C, LEE S, et al. Thermal Characteristics of a Conductive Cement-based Composite for a Snow-melting Heated Pavement System [J]. Composite Structures, 2014, 118: 106-111.
[10] PAN P, WU S P, XIAO Y, et al. A Review on Hydronic Asphalt Pavement for Energy Harvesting and Snow Melting [J]. Renewable & Sustainable Energy Review, 2015, 48: 624-634.
[11] XU H N, TAN Y Q. Modeling and Operation Strategy of Pavement Snow Melting Systems Utilizing Low-temperature Heating Fluids [J]. Energy, 2015, 80: 666-676.
[12] LAI Y, LIU Y, MA D X. Automatically Melting Snow on Airport Cement Concrete Pavement with Carbon Fiber Grille [J]. Cold Regions Science and Technology, 2014, 103: 57-62.
[13] WANG H J, LIU L B, CHEN Z H. Experimental Investigation of Hydronic Snow Melting Process on the Inclined Pavement [J]. Cold Regions Science and Technology, 2010, 63: 44-49.
[14] TANAKA O, YAMAKAGE H, OGUSHI T, et al. Snow Melting Using Heat Pipes [J]. Advances in Heat Pipe Technology, 1982: 11-23.
[15] LUND J W. Pavement Snow Melting [R]. Klamath Falls: Oregon Institute of Technology, 2001.
[16] YU W B, YI X, GUO M, et al. State of the Art and Practice of Pavement Anti-icing and De-icing Techniques [J]. Sciences in Cold and Arid Regions, 2014, 6 (1): 14-21.
[17] OZSOY A,YILDIRIM R. Prevention of Icing with Ground Source Heat Pipe: A Theoretical Analysis for Turkey's Climatic Conditions [J]. Cold Regions Science and Technology, 2016, 125: 65-71.
[18] WANG X Y, ZHU Y L, ZHU M Z, et al. Thermal Analysis and Optimization of an Ice and Snow Melting System Using Geothermy by Super-long Flexible Heat Pipes [J]. Applied Thermal Engineering, 2017, 112: 1353-1363.
[19] BRANDL H. Energy Foundations and Other Thermo-active Ground Structures [J]. Géotechnique, 2006, 56 (2): 81-122.
[20] 桂树强,程晓辉,张志鹏.地源热泵桩基与钻孔埋管换热器换热性能比较[J].土木建筑与环境工程,2013,35(3):151-156. GUI Shu-qiang, CHENG Xiao-hui, ZHANG Zhi-peng. Comparative Analysis of Heat Exchange Performance of Energy Piles and Borehole Heat Exchangers in GSHP System [J]. Journal of Civil, Architectural & Environmental Engineering, 2013, 35 (3): 151-156.
[21] 桂树强,程晓辉.能源桩换热过程中结构响应原位试验研究[J].岩土工程学报,2014,36(6):1087-1094. GUI Shu-qiang, CHENG Xiao-hui. In-situ Tests on Structural Responses of Energy Piles During Heat Exchanging Process [J]. Chinese Journal of Geotechnical Engineering, 2014, 36 (6): 1087-1094.
[22] 郭红仙,李翔宇,程晓辉.能源桩热响应测试的模拟及适用性评价[J].清华大学学报:自然科学版,2015,55(1):14-20. GUO Hong-xian, LI Xiang-yu, CHENG Xiao-hui. Simulation and Applicability of Thermal Response Tests in Energy Piles [J]. Journal Tsinghua University: Science & Technology, 2015,55 (1): 14-20.
[23] 李翔宇,郭红仙,程晓辉.能源桩温度分布的试验与数值研究[J].土木工程学报,2016,49(4):102-110. LI Xiang-yu, GUO Hong-xian, CHENG Xiao-hui. Experimental and Numerical Study on Temperature Distribution in Energy Piles [J]. China Civil Engineering Journal, 2016, 49 (4): 102-110.
[24] YOU S, CHENG X H, GUO H X, et al. In-situ Experimental Study of Heat Exchange Capacity of CFG Pile Geothermal Exchangers [J]. Energy and Buildings, 2014, 79: 23-31.
[25] YOU S, CHENG X H, GUO H X, et al. Experimental Study on Structural Response of CFG Energy Piles [J]. Applied Thermal Engineering, 2016, 96: 640-651.
[26] JEONG S, LIM H, LEE J K, et al. Thermally Induced Mechanical Response of Energy Piles in Axially Loaded Pile Groups [J]. Applied Thermal Engineering, 2014, 71: 608-615.
[27] MIMOUNI T, LALOUI L. Behaviour of a Group of Energy Piles [J]. Canadian Geotechnical Journal, 2015, 52: 1913-1929.
[28] NG C W W, SHI C, GUNAWAN A, et al. Centrifuge Modelling of Heating Effects on Energy Pile Performance in Saturated Sand [J]. Canadian Geotechnical Journal, 2015, 52: 1045-1057.
[29] LALOUI L, DONNA A D. Understanding the Behaviour of Energy Geo-structures [J]. Proceedings of ICE-Civil Engineering, 2011, 164 (4): 184-191.
[30] BALBAY A, ESEN M. Temperature Distributions in Pavement and Bridge Slabs Heated by Using Vertical Ground-source Heat Pump Systems [J]. Acta Scientiarum, 2013, 35 (4): 677-685
[31] 李翔宇.基于试验与数值模拟的桩基埋管地下换热器设计分析[D]. 北京:清华大学,2015. LI Xiang-yu. Analysis and Design Method for Pile Heat Exchangers Based on In-situ Test and Numerical Simulation [D]. Beijing: Tsinghua University, 2015.
[32] GB 50010—2010,混凝土结构设计规范 [S]. GB 50010—2010, Code for Design of Concrete Structure [S].