Experimental Demonstrations and Optimal Design Conditions of Snow-Melting System Using Geothermal and Solar Energy
Experimental Demonstrations and Optimal Design Conditions of Snow-Melting System Using Geothermal and Solar Energy
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DOI：
10.1115/ht2009-88181
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
Nirou Nagai;S. Miyamoto;T. Tsuda;Shinya Yamahata
中科院分区：
文献类型：
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作者：
Nirou Nagai;S. Miyamoto;T. Tsuda;Shinya Yamahata
作者提出并开发了利用地热和太阳能的融雪系统。夏季，太阳热能从路面储存到地下桩基。在冬天，地下的热量被用来融化路面上的雪。该系统应用于规模较小（小于1000平方米）的停车场和桥梁。并编制了数值模拟程序，对系统温度场进行预测，对系统性能进行评价。该方案仅在较小规模的试验区进行了实验数据验证。此外，在给定路面面积和融雪能力（平均热流密度）的情况下，很难确定桩径、桩长、桩数等合适的设计条件。本文旨在对该系统进行较大规模（大于1000 m2）的演示，并在给定路面面积和能力下获得系统的最优设计条件。将地热和太阳能融雪系统应用于大型停车场和桥梁。这两个地点都在实际使用中，这意味着汽车有时会在桥上停放和行驶。得到的系统温度场和融雪情况的实验数据表明，数值模拟程序能够较好地预测系统性能和温度场，尽管程序中存在一些简化。为探讨优化设计条件，通过改变桩径、桩长、桩数及桩距、散热管间距及桩径、循环水流量、路面面积等参数进行数值模拟。这些参数都会影响系统的性能。仿真结果表明，桩径、桩长和桩数决定的桩表面积是决定融雪能力的主要参数。即在给定路面和融雪能力的情况下，通过仿真结果可以得到所需的桩表面积，从而在考虑埋桩成本的情况下进行桩的系统设计。ASME版权所有©2009
The authors have been proposed and developed snow-melting system using geothermal and solar energy. In summer, solar heat is stored into underground from road surface to underground piles. In winter, the underground heat is utilized to melt snow on the road surface. This system was applied to parking lots and bridges of relatively small scale (less than 1000 m2 ). Numerical simulation program was also developed to predict temperature field of the system and to evaluate system performance. This program was verified by experimental data only for relatively small scale test area. In addition, appropriate design conditions, such as pile diameter, length and number, can not be easily estimated when road surface area and ability (average heat flux) of snow-melting are given. This paper aims to demonstrate the system for relatively large scale (larger than 1000 m2 ), and to obtain optimal design conditions of the system at given road surface area and ability. The snow-melting system using geothermal and solar energy was applied to a parking lot and a bridge of large scale. Both sites were under practical use which means cars were sometimes parked and run over the bridge. Obtained experimental data of temperature field of the system and snow melting situation show that numerical simulation program predicted system performance and temperature field adequately even though the program contains several simplifications. To discuss the optimal design conditions, numerical simulation was conducted by changing the following parameters: diameter, length, number and pitch of piles, pitch and diameter of heat dissipation pipe, flow rate of circulating water, road surface area. All these parameters are considered to affect system performance. The simulation results revealed that pile surface area determined by diameter, length and number of piles is the dominant parameter for deciding snow-melting ability. Namely, when road surface and snow-melting ability are given, necessary pile surface area can be obtained from the simulation results, and system design of piles becomes possible with considering cost for embedding piles.Copyright © 2009 by ASME