臺灣博碩士論文加值系統

地下淺層溫能空氣熱交換器(earth air heat exchanger)是一種使用穩定的地下溫度做為熱傳主體的低耗能外氣通風技術。無論是透過理論或是現地實驗，在全世界有非常多針對地下空氣熱交換器的研究，但在台灣，以現地實驗為主軸的研究可說是近乎為零。因此本論文主要由現地實驗方式出發，分別針對土壤式空氣熱交換器與水式空氣熱交換器進行研究。針對土壤式空氣熱交換器所進行的實驗主要設施包括了七支50m長、直徑為0.25m並埋於3m深度的PVC空氣管道，以及可提供6800 m3/h送風量之離心式風機，通風時間則設定為在11:00至13:00間啟動系統進行通風。研究結果顯示，土壤式空氣熱交換器的全年加熱潛力高於冷卻潛力，而中午間歇式的操作方式則可有效利用較多的冷卻潛力。於2015年5月至2016年1月間的最大冷卻、除溼熱傳率為40kW，加熱熱傳率為15kW。透過本論文所開發、可計算時間效應與質量傳輸的計算模式，發現操作持續時間的選擇及空氣濕度比對熱傳量影響很大。本研究藉由回歸分析方式提出了針對操作時間及濕度比對交換係數(exchange coefficient)影響的計算公式，可用來進行熱傳量的估計。進一步為了提高地下空氣熱交換器的性能，本論文並針對了以水為主體的水式地下空氣熱交換器進行了實驗研究，主要對象包括了水平放置於充填水的建築地下筏式基礎裡的四支PVC空氣管道，管道平均長度為40m，管徑為0.2m，通風量為1460 m3/h。研究結果顯示，在1.3m深度的筏基水具有與2m以下土壤深度相近的冷卻潛力，而透過對建築周圍土地進行表面處理應可使水溫更加穩定，以期增加冷卻潛力。實際運轉測試表明，出口空氣溫度可有效趨近筏基水的溫度，在接近夏季氣候的測試亦可提供1.5 kg/hour至2.8 kg/hour之除溼量，而冷卻熱傳量為3.36 kW及3.66kW。本論文亦提出了針對水式地下空氣熱交換器的簡化模型，可做為尺寸分析使用。最後，針對兩種系統的回收年限分析顯示，經過適當的尺寸設計，兩系統的回收年限可分別為：土壤式為5年，水式為4年。

The earth air heat exchanger (EAHE) is a low-energy ventilation technique using the stable temperature of the earth. In the past decade, many experimental studies deal with the performance evaluation of EAHE system worldwide; however, in Taiwan these kinds of in-situ applications are still not available. This thesis presents a systemic approach to the analysis of two EAHE systems with different heat transfer media: water and soil. The soil-based systems were studied by means of long-term monitoring in Nantou, Taiwan, and analytical simulation. The experimental setup for the soil-based EAHE consists of seven parallel PVC pipes with 50m length and 0.25m diameter, buried at 3m depth beneath the ground surface, and a centrifugal fan with airflow rate of 6800m3/h. The operating strategy is to turn on the fan at 11:00 and turn off at 13:00. The results demonstrate that the annual acceptable cooling potential of soil-based earth-air heat exchanger may lower than the heating potential, but the midday intermittent operating can reach the maximum use of the cooling potential. The maximum total heat transfer rate ranged from -15 kW for heating, humidify, to about 40 kW for cooling, or dehumidify, during the period from May 2015 to January 2016. This thesis also develops an analytical model counting into the time delay effect and air humidity ratio. Through the analytical investigation, it was concluding that the effect of operating duration and latent heat exchange on performance is significant because they influence not only the temperature changes with time but also the exchange coefficient of soil. Intending to calculate the effect, dimensionless correlations were developed. Furthermore, to develop alternative efficient heat transfer media of earth air heat exchanger, an investigation for water-based system was also conducted in this thesis by an in-situ experiment in Yilan, Taiwan. The objective for the water-based EAHE consists of four air pipes with 40m length, 0.2m diameter, immersed in the water-filled raft foundation of a three stories building. A centrifugal fan with airflow rate of 1460 m3/h circulating the air into the system. The investigation shows that the cooling potential of the water beneath a building of 1.3m during spring season was close to that of ground soil at 2 m depth or deeper. The effect of changing the media around the air pipe of EAHE is significant. In addition, a suitable treatment of the ground surface is also important to avoid extra heat added into the water in the foundation. The in-situ experiment in three selected dates showed the air temperature could be dampened close to the average water temperature in the foundation. The ability of dehumidification was around 1.5 kg/hour and 2.8 kg/hour during hot season, and the averages of total heat transfer rate in hot weather was 3.36kW and 3.66kW, which was approximately equal to 1RT. In order to carry out the dimensioning of water-based EAHE, an analytical model was developed. Finally, the thermal and economic comparison between water and soil EAHE was presented, indicating that the water-based EAHE costs less than the soil-based one. The evaluated ROI periods are 4 years for water-based EAHE and 5 years for soil-based EAHE. The initial costs have huge effect on the ROI period, therefore an appropriate dimensioning was recommended in real application.

誌謝 i
中文摘要 iii
ABSTRACT iv
CONTENTS vi
LIST OF FIGURES ix
LIST OF TABLES xiii
NOMENCLATURE xiv
Chapter 1 Introduction 1
1.1 Earth-to-Air Heat Exchanger 2
1.2 Literature Review 3
1.2.1 Soil-Based Earth-Air Heat Exchanger 4
1.2.2 In-Situ Studies of Soil-based Earth-Air Heat Exchanger 19
1.2.3 Water-Based Earth-Air Heat Exchanger 20
1.3 Objectives and Outline 22
Chapter 2 Soil Based Earth-Air Heat Exchanger 25
2.1 Theoretical Background 25
2.1.1 Conductive Heat Transfer 25
2.1.2 Forced Convective heat transfer 26
2.1.3 Underground Soil Temperature Profile 27
2.2 In-Situ Experimental Analysis 28
2.2.1 Experimental Setup 29
2.2.2 Measuring Setup 32
2.2.3 Experimental Uncertainty 33
2.3 Heat and Moisture Transfer Model of EAHE 34
2.3.1 Governing Equations of Temperature 36
2.3.2 Formulation of Coupled Heat and Moisture Transfer 38
2.3.3 Solution of Steady-State Part 41
2.3.4 Solution of Harmonic Part 46
2.4 Results 50
2.4.1 Experimental Results 50
2.4.2 Validation of Analytical Model with Experimental Data 59
2.4.3 Analytical Results 63
2.4.4 Correlation of Exchange Coefficient for EAHE 81
2.4.5 Guidelines for pipe length selection 83
2.5 Summary 85
Chapter 3 Water-based Earth-Air Heat Exchanger 87
3.1 Theoretical Background 87
3.2 In-Situ Experimental Analysis 89
3.3 Analysis Model of Raft Foundation Integrated EAHE 92
3.3.1 Simplified Thermal Analysis 92
3.3.2 Wall Temperature of Reservoir 97
3.3.3 Thermal Resistance 98
3.4 Results 99
3.4.1 Experimental Results 99
3.4.2 Validation and Case study of Analytical Model 105
3.5 Comprehensive Comparison with Soil-Based EAHE 108
3.5.1 Thermal Aspect 108
3.5.2 Economic Aspect 109
3.6 Summary 113
Chapter 4 Conclusions and Outlook 115
REFERENCES 117
APPENDIX 125

[1]K. Voss, and M. Kramp, “Zero-Energy/Emission-Buildings – Terms, Definitions and Building Pratice,” CESB 2007, Prague, 2007.
[2]P. Hollmuller, and B. Lachal, “Air–soil heat exchangers for heating and cooling of buildings - Design guidelines,” Applied Energy, vol. 119, pp. 476 – 487, 2014.
[3]C. Arkar, and S. Medved, “Free cooling of a building using PCM heat storage integrated into the ventilation system,” Solar Energy, vol. 81, 2007.
[4]L. Ozgener, “A review on the experimental and analytical analysis of earth to air heat exchanger (EAHE) systems in Turkey,” Renewable and Sustainable Energy Reviews, Vol.15, pp.4483– 4490, 2011
[5]F. Al-Ajmi, D. L. Loveday, and V. I. Hanby, “The cooling potential of earth-air heat exchangers for domestic buildings in a desert climate,” Building and Environment, vol. 41, no. 3, pp. 235–244, 2006.
[6]A. Tzaferis, D. Liparakis, M. Santamouris, and A. Argiriou, “Analysis of the accuracy and sensitivity of eight models to predict the performance of earth-to-air heat exchangers,” Energy and Buildings, vol. 18, no. 1, pp. 35–43, 1992.
[7]V. P. Kabashnikov, L. N. Danilevskii, V. P. Nekrasov, and I. P. Vityaz, “Analytical and numerical investigation of the characteristics of a soil heat exchanger for ventilation systems,” International Journal of Heat and Mass Transfer, vol. 45, no. 11, pp. 2407–2418, 2002.
[8]G. Mihalakakou, M. Santamouris, J. O. Lewis, and D. N. Asimakopoulos, “On the application of the energy balance equation to predict ground temperature profiles,” Solar Energy, vol. 60, no. 3-4, pp. 181–190, 1997.
[9]P. Hollmuller, “Analytical characterisation of amplitude-dampening and phase-shifting in air/soil heat-exchangers,” International Journal of Heat and Mass Transfer, vol. 46, no. 22, pp. 4303–4317, 2003.
[10]H. Ben Jmaa Derbel and O. Kanoun, “Investigation of the ground thermal potential in tunisia focused towards heating and cooling applications,” Applied Thermal Engineering, vol. 30, no. 10, pp. 1091–1100, 2010.
[11]O. Ozgener, L. Ozgener, and J. W. Tester, “A practical approach to predict soil temperature variations for geothermal (ground) heat exchangers applications,” International Journal of Heat and Mass Transfer, vol. 62, no. 1, pp. 473–480, 2013.
[12]M. De Paepe and A. Janssens, “Thermo-hydraulic design of earth-air heat exchangers,” Energy and Buildings, vol. 35, no. 4, pp. 389–397, 2003.
[13]M. Cucumo, S. Cucumo, L. Montoro, and A. Vulcano, “A one-dimensional transient analytical model for earth-to-air heat exchangers, taking into account condensation phenomena and thermal perturbation from the upper free surface as well as around the buried pipes,” International Journal of Heat and Mass Transfer, vol. 51, no. 3-4, pp. 506–516, 2008.
[14]J. Pfafferott, “Evaluation of earth-to-air heat exchangers with a standardised method to calculate energy efficiency,” Energy and Buildings, vol. 35, no. 10, pp. 971–983, 2003.
[15]A. De Jesus Freire, J. L. C. Alexandre, V. B. Silva, N. D. Couto, and A. Rouboa, “Compact buried pipes system analysis for indoor air conditioning,” Applied Thermal Engineering, vol. 51, no. 1-2, pp. 1124–1134, 2013.
[16]K. H. Lee and R. K. Strand, “The cooling and heating potential of an earth tube system in buildings,” Energy and Buildings, vol. 40, no. 4, pp. 486–494, 2008.
[17]F. Al-Ajmi, D. L. Loveday, and V. I. Hanby, “The cooling potential of earth-air heat exchangers for domestic buildings in a desert climate,” Building and Environment, vol. 41, no. 3, pp. 235–244, 2006.
[18]G. Mihalakakou, M. Santamouris, D. Asimakopoulos, and I. Tselepidaki, “Parametric prediction of the buried pipes cooling potential for passive cooling applications,” Solar Energy, vol. 55, no. 3, pp. 163–173, 1995.
[19]A. S. Dhaliwal and D. Y. Goswami, Heat Transfer Analysis Environment Control Using an Underground Air Tunnel, ASME Solar Energy Division, Las Vegas, Nev, USA, 1984.
[20]B. K. Shingari, “Earth tube heat exchanger,” Poultry International, vol. 34, no. 14, pp. 92–97, 1995.
[21]V. P. Sethi and S. K. Sharma, “Thermal modeling of a greenhouse integrated to an aquifer coupled cavity flow heat exchanger system,” Solar Energy, vol. 81, no. 6, pp. 723–741, 2007.
[22]X. Li, J. Zhao, and Q. Zhou, “Inner heat source model with heat and moisture transfer in soil around the underground heat exchanger,” Applied Thermal Engineering, vol. 25, no. 10, pp. 1565–1577, 2005.
[23]V. Badescu, “Simple and accurate model for the ground heat exchanger of a passive house,” Renewable Energy, vol. 32, no. 5, pp. 845–855, 2007.
[24]A. Sehli, A. Hasni, and M. Tamali, “The potential of earth-air heat exchangers for low energy cooling of buildings in South Algeria,” Energy Procedia, vol. 18, pp. 496–506, 2012.
[25]P. Tittelein, G. Achard, and E. Wurtz, “Modelling earth-to-air heat exchanger behaviour with the convolutive response factors method,” Applied Energy, vol. 86, no. 9, pp. 1683–1691, 2009.
[26]V. Bansal, R. Misra, G. D. Agrawal, and J. Mathur, “Performance analysis of earth-pipe-air heat exchanger for winter heating,” Energy and Buildings, vol. 41, no. 11, pp. 1151–1154, 2009
[27]V. Bansal, R. Misra, G. D. Agrawal, and J. Mathur, “Performance analysis of earth-pipe-air heat exchanger for summer cooling,” Energy and Buildings, vol. 42, no. 5, pp. 645–648, 2010.
[28]V. Bansal, R. Mishra, G. D. Agarwal, and J. Mathur, “Performance analysis of integrated earth-air-tunnel-evaporative cooling system in hot and dry climate,” Energy and Buildings, vol. 47, pp. 525–532, 2012.
[29]V. Bansal, R. Misra, G. D. Agrawal, and J. Mathur, “Performance evaluation and economic analysis of integrated earth-air-tunnel heat exchanger-evaporative cooling system,” Energy and Buildings, vol. 55, pp. 102–108, 2012.
[30]V. Bansal, R. Misra, G. D. Agarwal, and J. Mathur, “‘Derating Factor’ new concept for evaluating thermal performance of earth air tunnel heat exchanger: a transient CFD analysis,” Applied Energy, vol. 102, pp. 418–426, 2013.
[31]R. Misra, V. Bansal, G. D. Agrawal, J. Mathur, and T. K. Aseri, “CFD analysis based parametric study of derating factor for Earth Air Tunnel Heat Exchanger,” Applied Energy, vol. 103, pp. 266–277, 2013.
[32]V. Bansal, R. Misra, G. D. Agarwal, and J. Mathur, “Transient effect of soil thermal conductivity and duration of operation on performance of Earth Air Tunnel Heat Exchanger,” Applied Energy, vol. 103, pp. 1–11, 2013.
[33]H. Wu, S. Wang, and D. Zhu, “Modelling and evaluation of cooling capacity of earth-air-pipe systems,” Energy Conversion and Management, vol. 48, no. 5, pp. 1462–1471, 2007.
[34]J. Vaz, M. A. Sattler, E. D. Dos Santos, and L. A. Isoldi, “Experimental and numerical analysis of an earth-air heat exchanger,” Energy and Buildings, vol. 43, no. 9, pp. 2476–2482, 2011.
[35]T. Mnasri, R. B. Younès, A. Mazioud, and J. F. Durastanti, “FVM-BEM method based on the Green''s function theory for the heat transfer problem in buried co-axial exchanger,” Comptes Rendus—Mecanique, vol. 338, no. 4, pp. 220–229, 2010.
[36]V. Khalajzadeh, M. Farmahini-Farahani, and G. Heidarinejad, “A novel integrated system of ground heat exchanger and indirect evaporative cooler,” Energy and Buildings, vol. 49, pp. 604–610, 2012.
[37]A. Flaga-Maryanczyka, J. Schnotale, J. Radon, and K. Was, “Experimental measurements and CFD simulation of a ground source heat exchanger operating at a cold climate for a passive house ventilation system,” Energy and Buildings, vol. 68, pp. 562–570, 2014.
[38]L. Ramírez-Dávila, J. Xamán, J. Arce, G. Álvarez, and I. Hernández-Pérez, “Numerical study of earth-to-air heat exchanger for three different climates,” Energy and Buildings, vol. 76, pp. 238–248, 2014.
[39]G. Mihalakakou, “On the heating potential of a single buried pipe using deterministic and intelligent techniques,” Renewable Energy, vol. 28, no. 6, pp. 917–927, 2003.
[40]V. Badescu and D. Isvoranu, “Pneumatic and thermal design procedure and analysis of earth-to-air heat exchangers of registry type,” Applied Energy, vol. 88, no. 4, pp. 1266–1280, 2011.
[41]R. Kumar, A. R. Sinha, B. K. Singh, and U. Modhukalya, “A design optimization tool of earth-to-air heat exchanger using a genetic algorithm,” Renewable Energy, vol. 33, no. 10, pp. 2282–2288, 2008.
[42]R. Kumar, S. C. Kaushik, and S. N. Garg, “Heating and cooling potential of an earth-to-air heat exchanger using artificial neural network,” Renewable Energy, vol. 31, no. 8, pp. 1139–1155, 2006.
[43]J. Vaz, M. A. Sattler, R. da S. Brum, E. D. dos Santos, L. A. Isoldi, "An experimental study on the use of Earth-Air Heat Exchangers(EAHE)," Energy and Buildings, Vol. 72, pp. 122–131, 2014
[44]J. Zhao, H. Wang, X. Li, and C. Dai, “Experimental investigation and theoretical model of heat transfer of saturated soil around coaxial ground coupled heat exchanger,” Applied Thermal Engineering, vol. 28, no. 2-3, pp. 116–125, 2008.
[45]H. Breesch, A. Bossaer, and A. Janssens, “Passive cooling in a low-energy office building,” Solar Energy, vol. 79, no. 6, pp. 682–696, 2005.
[46]J.-U. Lee, T. Kim, and S.-B. Leigh, “Applications of building-integrated coil-type ground-coupled heat exchangers—Comparison of performances of vertical and horizontal installations,” Energy and Buildings, vol. 93, pp. 99–109, 2015.
[47]Y. Hamada, H. Saitoh, M. Nakamura, H. Kubota, and K. Ochifuji, “Field performance of an energy pile system for space heating,” Energy and Buildings, vol. 39, no. 5, pp. 517–524, 2007.
[48]J. Gao, X. Zhang, J. Liu, K. S. Li, and J. Yang, “Thermal performance and ground temperature of vertical pile-foundation heat exchangers: A case study,” Applied Thermal Engineering, vol. 28, no. 17-18, pp. 2295–2304, 2008.
[49]D. Bozis, K. Papakostas, and N. Kyriakis, “On the evaluation of design parameters effects on the heat transfer efficiency of energy piles,” Energy and Buildings, vol. 43, no. 4, pp. 1020–1029, 2011.
[50]Jalaluddin, A. Miyara, K. Tsubaki, S. Inoue, and K. Yoshida, “Experimental study of several types of ground heat exchanger using a steel pile foundation,” Renewable Energy, vol. 36, no. 2, pp. 764–771, 2011.
[51]H. Park, S.-R. Lee, S. Yoon, and J.-C. Choi, “Evaluation of thermal response and performance of PHC energy pile: Field experiments and numerical simulation,” Applied Energy, vol. 103, pp. 12–24, 2013.
[52]C. Cheng, Y. Liu, and C. Ting, “An urban drought-prevention model using raft foundation and urban reservoir,” Building Services Engineering Research and Technology, vol. 30, no. 4, pp. 343–355, 2009.
[53]A.-M. Gustafsson, L. Westerlund, and G. Hellström, “CFD-modelling of natural convection in a groundwater-filled borehole heat exchanger,” Applied Thermal Engineering, vol. 30, no. 6-7, pp. 683–691, 2010.
[54]A.-M. Gustafsson and L. Westerlund, “Multi-injection rate thermal response test in groundwater filled borehole heat exchanger,” Renewable Energy, vol. 35, no. 5, pp. 1061–1070, 2010.
[55]Y. Nam and H.-B. Chae, “Numerical simulation for the optimum design of ground source heat pump system using building foundation as horizontal heat exchanger,” Energy, vol. 73, pp. 933–942, 2014.
[56]ASHRAE, ANSI/ASHRAE Standard 62.1-2010. Ventilation for acceptable indoor air quality. 2010, American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc.: Atlanta, GA
[57]J.A. Heyns, D.G. Kröger, “Experimental investigation into the thermal-flow performance characteristics of an evaporative cooler,” Applied Thermal Engineering, vol. 30, pp. 492–498, 2010.
[58]Fast Fourier transform, http://www.mathworks.com/help/matlab/ref/fft.html, The MathWorks, Inc.
[59]M. Frigo, and S. G. Johnson. "FFTW: An Adaptive Software Architecture for the FFT." Proceedings of the International Conference on Acoustics, Speech, and Signal Processing. Vol. 3, 1998, pp. 1381–1384.
[60]P. Hollmuller, B. Lachal, "Air–soil heat exchangers for heating and cooling of buildings: Design guidelines, potentials and constraints, system integration and global energy balance," Applied Energy, Vol. 119, pp. 476–487, 2014
[61]Y. A. Cengel and A. J. Ghajar, Heat and Mass Transfer: Fundamentals and Applications. McGraw-Hill Education, fifth ed., 2015.
[62]ASHRAE Handbook 2005, Fundamentals (SI), “PSYCHROMETRICS,” American Society of Heating and, Refrigerating and Air-conditioning Engineer, Ch.6, pp.6.1–4.10, 2005.