Performance of a Ground-Source Heat Pump System and the Heat-Moisture Migration of Surrounding Soils in Karst Areas
Publication: Journal of Performance of Constructed Facilities
Volume 31, Issue 5
Abstract
In recent years, ground-source heat pumps (GSHPs) have been extensively used in engineering projects because of their ability to take advantage of geothermal energy and their subsequent benefits of energy saving and environmental protection. Significant progress has been made in understanding the heat exchange between ground heat exchangers (GHEs), and surrounding soils in a GSHP system. However, relatively fewer studies have been performed to investigate the influences of the moisture variations and seepage flow in the surrounding soils on the performances of the GSHP system. Karst formations extensively exist in many areas of southern China where the subtropical climate brings frequent precipitation, rich seepage water flow, and fluctuations in the groundwater table. All these factors pose huge challenges to the implementation of GSHP systems in these areas, which makes the heat exchange between GHEs and surrounding soils a coupled heat-moisture transport problem. No previous research has been dedicated to this topic. In order to understand the coupled heat-moisture transport process and its influences on the heat exchange between GHEs and surrounding soils in karst areas of southern China, a GSHP system was constructed in Guilin, Guangxi Province to monitor its performance under the combined influences of soil temperature and moisture changes. A data-acquisition system was set up to monitor the most relevant parameters of the system, such as temperature and moisture levels of the surrounding soils, climatic factors, groundwater table, and performance of the GSHP system. Three different operation-mode tests were used to simulate possible future applications under different scenarios. The test results were analyzed, from which some conclusions were drawn regarding the influences of the coupled heat-moisture migrations in karst areas on the performance of GSHP systems.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors are grateful for the financial support provided by National Natural Science Foundation of China (Grant Nos. 41502284, 51568014, and 41272358) and Natural Science Foundation of Guangxi Province of China (Grant No. 2013GXNSFBA019233).
References
Allen, R. G., Periera, L. S., Raes, D., and Smith, M. (1998). “Crop evapotranspiration: Guidelines for computing crop requirements.”, Food and Agriculture Organization of the United Nations, Rome.
Bose, J. E., Parker, J. D., and Mcquiston, F. C. (1985). “Design/data manual for closed-loop ground-coupled heat pump system.” American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Atlanta.
Bose, J. E., Smith, M. D., and Spitler, J. D. (2002). “Advances in ground source heat pump systems: An international overview.” Proc., 17th Int. Energy Agency Heat Pump Conf., China Architecture and Building Press, Beijing, 313–324.
Casasso, A., and Sethi, R. (2014). “Sensitivity analysis on the performance of a ground source heat pump equipped with a double U-pipe borehole heat exchanger.” Energy Procedia, 59, 301–308.
Chiasson, A. D., Rees, S. J., and Spitler, J. D. (2000). “A preliminary assessment of the effects of groundwater flow on closed-loop ground source heat pump systems.” ASHRAE Trans., 106(1), 380–393.
Del Col, D., Azzolin, M., Benassi, G., and Mantovan, M. (2014). “Experimental analysis of optimal operation mode of a ground source heat pump system.” Energy Procedia, 45, 1354–1363.
Diao, N. R., Li, Q. Y., and Fang, Z. H. (2004). “Heat transfer in ground heat exchangers with groundwater advection.” Int. J. Therm. Sci., 43(12), 1203–1211.
Gao, Q., Li, M., Yu, M., Spitler, J. D., and Yan, Y. Y. (2009). “Review of development from GSHP to UTES in China and other countries.” Renewable Sustainable Energy Rev., 13(6), 1383–1394.
Guo, Y. H., Zhang, G. Q., Zhou, J., Wu, J. S., and Shen, W. (2012). “A techno-economic comparison of a direct expansion ground-source and a secondary loop ground-coupled heat pump system for cooling in a residential building.” Appl. Therm. Eng., 35(1), 29–39.
İnallı, M., and Esen, H. (2004). “Experimental thermal performance evaluation of a horizontal ground-source heat pump system.” Appl. Therm. Eng., 24(14), 2219–2232.
İnallı, M., and Esen, H. (2005). “Seasonal cooling performance of a ground-coupled heat pump system in a hot and arid climate.” Renewable Energy, 30(9), 1411–1424.
Johnson, D. E., Johnson, J. R., Hilburn, J. L., and Scott, P. D. (1995). Basic electric circuit analysis, 5th Ed., Prentice-Hall, Upper Saddle River, NJ.
Kavanaugh, S. P. (1992). “Using existing standards to compare energy consumption of ground-source heat pumps with conventional equipment.” ASHRAE Transition, 98(2), 599–606.
Kavanaugh, S. P., and Rafferty, K. (1997). “Ground-source heat pumps: Design of geothermal system for commercial and institutional building.” American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Atlanta.
Leong, W. H., Tarnawski, V. R., and Aittomäki, A. (1998). “Effect of soil type and moisture content on ground heat pump performance.” Int. J. Refrig., 21(8), 595–606.
Li, X. G., Chen, Z. H., and Zhao, J. (2006). “Simulation and experiment on the thermal performance of U-vertical ground coupled heat exchanger.” Appl. Therm. Eng., 26(14), 1564–1571.
Liao, Y. L., and Yu, P. H. (1994). “The microstructure and generalized model of red clay.” J. Eng. Geol., 2(1), 27–37.
Liao, Y. L., Zhu, L. J., and Zhou, X. H. (2001). “Research on the inert pore in soils and its physical-mechanical property.” Geotech. Invest. Surv., 1, 5–8.
Liu, C. H., Zhou, D., and Wu, H. (2011). “Measurement and prediction of temperature effects of thermal conductivity of soils.” Chin. J. Geotech. Eng., 33(12), 1877–1886.
Liu, J. R., Huang, G. B., Huang, X. L., and Liang, Y. C. (2001). “Discussion on the evolution of different types of regional tropical karst landform in Guangxi.” Carsologica Sinica, 20(4), 247–252.
Lund, J. W., Freeston, D. H., and Boyd, T. L. (2011). “Direct utilization of geothermal energy 2010 worldwide review.” Geothermics, 40(3), 159–180.
Man, Y., Yang, H. X., Wang, J. G., and Fang, Z. H. (2012). “In situ operation performance test of ground coupled heat pump system for cooling and heating provision in temperate zone.” Appl. Energy, 97, 913–920.
Martin, P. E. (1990). “A design and economic sensitivity study of single-pipe horizontal ground-coupled heat pump systems.” ASHRAE Trans., 96(1), 634–642.
Montagud, C., Corberán, J. M., Montero, A., and Urchueguía, J. F. (2011). “Analysis of the energy performance of a ground source heat pump system after five years of operation.” Energy Build., 43(12), 3618–3626.
Montagud, C., Corberán, J. M., and Montero, Á. (2014). “In situ optimization methodology for the water circulation pumps frequency of ground source heat pump systems.” Energy Build., 68, 42–53.
Omer, A. M. (2008). “Ground-source heat pumps systems and applications.” Renewable Sustainable Energy Rev., 12(2), 344–371.
Pahud, D., and Matthey, B. (2001). “Comparison of the thermal performance of double U-pipe borehole heat exchangers measured in situ.” Energy Build., 33(5), 503–507.
Qu, S. L., Ge, X., Liu, Y. M., and Yu, Q. (2011). “Testing and analysis of thermal performance of ground source heat pump system.” Procedia Environ. Sci., 11, 566–572.
Sarbu, I., and Sebarchievici, C. (2014). “General review of ground-source heat pump systems for heating and cooling of buildings.” Energy. Build., 70, 441–454.
Sebarchievici, C., and Sarbu, I. (2015). “Performance of an experimental ground-coupled heat pump system for heating, cooling and domestic hot-water operation.” Renewable Energy, 76, 148–159.
Self, S. J., Reddy, B. V., and Rosen, M. A. (2013). “Geothermal heat pump systems: Status review and comparison with other heating options.” Appl. Energy, 101, 341–348.
Shao, N. C. (2001). “Some problems about piezometric tube.” Dam Obs. Geotech. Tests, 25(5), 6–7.
Spilker, E. H. (1998). “Ground-coupled heat pump loop design using thermal conductivity testing and the effect of different backfill materials on vertical bore length.” ASHRAE Trans., 104(1B), 775–787.
Tang, A. M., Cui, Y. J., and Le, T. T. (2008). “A study on the thermal conductivity of compacted bentonites.” Appl. Clay Sci., 41(3), 181–189.
Yang, H., Cui, P., and Fang, Z. (2010a). “Vertical-borehole ground-coupled heat pumps: A review of models and systems.” Appl. Energy, 87(1), 16–27.
Yang, L., Lam, J. C., and Tsang, C. L. (2008). “Energy performance of building envelopes in different climate zones in China.” Appl. Energy, 85(9), 800–817.
Yang, W., Zhou, J., Xu, W., and Zhang, G. Q. (2010b). “Current status of ground-source heat pumps in China.” Energy Policy, 38(1), 323–332.
Yang, W. B., and Zhang, S. S. (2014). “Research status and key problem of underground thermal unbalance of ground coupled heat pump operated in districts with unbalanced cooling and heating load.” Fluid Mach., 42(1), 80–87.
Yao, R. M., Li, B. Z., and Steemers, K. (2005). “Energy policy and standard for built environment in China.” Renewable Energy, 30(13), 1973–1988.
Zeng, Z. T. (2014). “Research on heat and moisture migration of red clay and its influence on heat transfer performance of ground source heat pump system in karst region.” Guangxi Univ., Guangxi, China.
Zhao, Y. L., Zeng, Z. T., Lu, H. B., and Ge, R. D. (2013). “Review and prospect of heat and moisture migration mechanism and mechanical behavior of soil in shallow geothermal energy exploitation.” J. Eng. Geol., 21(2), 222–227.
Zhu, H. F., and Du, Z. Y. (2011). “Effects of the ground heat balance of ground coupled heat pump system on ecological environment.” Energy Energy Convers., 7, 4–6.
Information & Authors
Information
Published In
Journal of Performance of Constructed Facilities
Volume 31 • Issue 5 • October 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Dec 29, 2015
Accepted: Jan 13, 2017
Published ahead of print: Mar 26, 2017
Published online: Mar 27, 2017
Discussion open until: Aug 27, 2017
Published in print: Oct 1, 2017
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.