Development of Thermomechanical Coupled Numerical Model for Energy Slab

Sangwoo Park; Hangseok Choi; Seokjae Lee

doi:10.7843/kgs.2024.40.1.55

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2024 Vol.40, Issue 1 Preview Page

Development of Thermomechanical Coupled Numerical Model for Energy Slab 에너지 슬래브의 열-역학적 수치해석 모델 개발

29 February 2024. pp. 55-63

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Abstract

In this study, a thermomechanical numerical model was developed to evaluate the stability of energy slabs. First, a wall-type energy slab was installed in a residential underground parking lot, and thermal performance tests were conducted. Based on the tests, a numerical thermohydraulics model of the energy slab was developed to accurately simulate the thermal behavior in thermal performance tests. Finally, utilizing the temperature data acquired using the developed model, a thermomechanical numerical model of the energy slab was established. The thermomechanical model was then used to simulate the thermal stresses induced by operating the energy slab. The results demonstrated a maximum thermal stress of 5,300 kPa, which highlights the need to utilize cement mortar with sufficient tensile strength to realize stable operation of the energy slab.

Keywords

Energy slab

Ground heat exchanger (GHEX)

Numerical model

Thermal performance test (TPT)

Thermal stress

본 연구에서는 에너지 슬래브의 안정성을 검토하기 위해 열-역학적 수치해석 모델을 개발하였다. 먼저, 주거용 건물 지하주차장에 벽체형 에너지 슬래브를 설치한 뒤 현장 열성능 평가시험(Thermal performance test, TPT)을 수행하였다. 이를 기반으로 현장 열성능 평가시험의 열-수리학적 거동을 정교하게 모사할 수 있는 에너지 슬래브의 열-수리학적 수치해석 모델을 개발하였다. 마지막으로, 열-수리학적 모델을 통해 도출된 시간-온도 데이터를 기반으로 에너지 슬래브의 열-역학적 수치해석 모델을 개발하였다. 개발된 모델을 기반으로 에너지 슬래브의 운용에 따른 열응력을 산정한 결과 최대 5,300kPa의 열응력이 발생하였으며, 이는 에너지 슬래브의 안정적인 운용을 위해 충분한 인장강도가 확보된 시멘트 몰탈 활용이 필요하다는 것을 시사한다.

References

Asadi, I., Shafigh, P., Hassan, Z. F. B. A., and Mahyuddin, N. B. (2018), Thermal Conductivity of Concrete-A Review, Journal of Building Engineering, Vol.20, pp.81-93. 10.1016/j.jobe.2018.07.002

Boënnec, O. (2008), Shallow Ground Energy Systems, Proceedings of the Institution of Civil Engineers-Energy, Vol.161, No.2, pp.57-61. 10.1680/ener.2008.161.2.57

Chen, X., Wu, S., and Zhou, J. (2013), Influence of Porosity on Compressive and Tensile Strength of Cement Mortar, Construction and Building Materials, Vol.40, pp.869-874. 10.1016/j.conbuildmat.2012.11.072

Choi, J. M. (2012), Heating and Cooling Performance of a Ground Coupled Heat Pump System with Energy-slab, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol.24, No.2, pp.196-203. 10.6110/KJACR.2012.24.2.196

Comsol, A. B. (2018), Heat Transfer Module User's Guide, COMSOL Multiphysics R, Stockholm, Sweden, 5.

Delage, P. (2013), On the Thermal Impact on the Excavation Damaged Zone around Deep Radioactive Waste Disposal, Journal of Rock Mechanics and Geotechnical Engineering, Vol.5, No.3, pp.179-190. 10.1016/j.jrmge.2013.04.002

Desmedt, J., Van Bael, J., Hoes, H., and Robeyn, N. (2012), Experimental Performance of Borehole Heat Exchangers and Grouting Materials for Ground Source Heat Pumps, International Journal of Energy Research, Vol.36, No.13, pp.1238-1246. 10.1002/er.1898

Gim, Y. S., Ryu, H. G., and Choi, S. H. (2019), A Study on Service Development of Geothermal Energy Supply Diffusion Using Open Data, J of Air-Conditioning and Refrigeration Enginnering, Vol.31, No.7, pp.302-311. 10.6110/KJACR.2019.31.7.302

Hamdhan, I. N. and Clarke, B. G. (2010, April), Determination of Thermal Conductivity of Coarse and Fine Sand Soils, In Proceedings of world geothermal congress (pp.1-7).

Kim, D., Kim, G., Kim, D., and Baek, H. (2017), Experimental and Numerical Investigation of Thermal Properties of Cement-based Grouts Used for Vertical Ground Heat Exchanger, Renewable Energy, Vol.112, pp.260-267. 10.1016/j.renene.2017.05.045

Lee, C., Park, S., Choi, H. J., Lee, I. M., and Choi, H. (2016), Development of Energy Textile to Use Geothermal Energy in Tunnels, Tunnelling and Underground Space Technology, Vol.59, pp.105-113. 10.1016/j.tust.2016.06.014

Lee, S., Han, T. H., Park, S., Hwang, C., and Choi, H. (2023), Thermal Performance Design and Analysis Method for Energy Cast-in-place Piles (E-CIPs) Installed in Diaphragm Walls, Energy and Buildings, 296, p.113372. 10.1016/j.enbuild.2023.113372

Lee, S., Park, S., Kang, M., and Choi, H. (2018), Field Experiments to Evaluate Thermal Performance of Energy Slabs with Different Installation Conditions, Applied Sciences, Vol.8, No.11, p.2214. 10.3390/app8112214

Lee, S., Park, S., Won, J., and Choi, H. (2021), Influential Factors on Thermal Performance of Energy Slabs Equipped with an Insulation Layer, Renewable Energy, Vol.174, pp.823-834. 10.1016/j.renene.2021.04.090

Moon, C. E. and Choi, J. M. (2015), Heating Performance Characteristics of the Ground Source Heat Pump System with Energy-piles and Energy-slabs, Energy, Vol.81, pp.27-32. 10.1016/j.energy.2014.10.063

Park, S., Lee, D., Lee, S., Chauchois, A., and Choi, H. (2017), Experimental and Numerical Analysis on Thermal Performance of Large-diameter Cast-in-place Energy Pile Constructed in Soft Ground, Energy, Vol.118, pp.297-311. 10.1016/j.energy.2016.12.045

Park, S., Lee, S., Oh, K., Kim, D., and Choi, H. (2018), Engineering Chart for Thermal Performance of Cast-in-place Energy Pile Considering Thermal Resistance, Applied Thermal Engineering, Vol.130, pp.899-921. 10.1016/j.applthermaleng.2017.11.065

Romagnoli, C., Zerbini, S., Lago, L., Richter, B., Simon, D., Domenichini, F., Elmi, C., and Ghirotti, M. (2003), Influence of Soil Consolidation and Thermal Expansion Effects on Height and Gravity Variations, Journal of Geodynamics, Vol.35, No.4-5, pp.521-539. 10.1016/S0264-3707(03)00012-7

Singh, S. B., Munjal, P., and Thammishetti, N. (2015), Role of Water/cement Ratio on Strength Development of Cement Mortar, Journal of Building Engineering, Vol.4, pp.94-100. 10.1016/j.jobe.2015.09.003

Waples, D. W. and Waples, J. S. (2004), A Review and Evaluation of Specific Heat Capacities of Rocks, Minerals, and Subsurface Fluids. Part 1: Minerals and Nonporous Rocks, Natural Resources Research, Vol.13, pp.97-122. 10.1023/B:NARR.0000032647.41046.e7

Zhao, J., Li, Y., and Wang, J. (2016), A Review on Heat Transfer Enhancement of Borehole Heat Exchanger, Energy Procedia, Vol.104, pp.413-418. 10.1016/j.egypro.2016.12.070

Information

Publisher :The Korean Geotechnical Society
Publisher(Ko) :한국지반공학회
Journal Title :Journal of the Korean Geotechnical Society
Journal Title(Ko) :한국지반공학회 논문집
Volume : 40
No :1
Pages :55-63
Received Date : 2024-01-31
Revised Date : 2024-02-07
Accepted Date : 2024-02-08
DOI :https://doi.org/10.7843/kgs.2024.40.1.55

Journal of the Korean Geotechnical Society ISSN:1229-2427(Print) 2288-646X(Online) 한국지반공학회 논문집

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