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Energy and exergy analysis of a ground source heat pump system with a slinky ground heat exchanger supported by nanofluid


This work contains the experimental analysis results in real environment conditions of the use of \(\hbox{Al}_2\hbox{O}_3\)-based nanofluid (NF) at different concentration ratios (0.1% and 0.2%) in a ground source heat pump (GSHP) system with a slinky ground heat exchanger (GHE). The energetic and exergic efficiencies of the system were investigated with the data obtained from the experimental results of base fluid (ethylene glycol (EG)-water) (EG volumetric ratio 25%) and NF with \(\hbox{Al}_2\hbox{O}_3\) concentration ratios of 0.1% and 0.2%. The exergetic model is obtained by applying energy and exergy equations for each system component. Exergetic efficiencies of the system components are evaluated separately and their potential for improvement is presented. According to the results of the energetic analysis, the overall system’s coefficient of performance (COP) values for the base fluid and NF with concentration ratios of 0.1% and 0.2% were 4.30, 4.38 and 4.34, respectively. These results show that NF contributes to system performance. However, an increase in system performance was not achieved due to the increase in NF concentration; on the contrary, a decrease in performance was observed. Exergetic efficiencies of the system for base fluid and NF with concentration ratios of 0.1% and 0.2% were 88.3%, 89.7% and 89.0%, respectively, for the heat pump unit, while these values were 78.7%, 79.3% and 79.0% for the entire system, respectively. The results show that the usage of NF with low concentration ratios increases the energetic and exergic efficiency of the system.

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\(\dot{m}\) :

Mass flow rate (\(\hbox{kg s}^{-1}\))

\(\dot{Q}\) :

Heat transfer rate (kW)

\(\dot{W}\) :

Rate of work or power (kW)

\(\dot{X}\) :

Exergy rate (kW)

\(\eta \) :


\(\phi \) :

Closed system exergy (\(\hbox{kJ kg}^{-1}\))

\(\psi \) :

Flow exergy (\(\hbox{kJ kg}^{-1}\))

\(\text {v}\) :

Velocity (\(\hbox{m s}^{-1}\))


Coefficient of performance


Economic lifetime

g :

Gravitational acceleration (\(\hbox{m s}^{-2}\))

h :

Specific enthalpy (\(\hbox{kJ kg}^{-1}\))

I :


i :

Discount rate

m :

Mass (kg)

O :

Operating costs

P :

Pressure (bar)

p :


S :

Entropy (\(\hbox{kJ K}^{-1}\))

s :

Specific entropy (\(\hbox{kJ kg}^{-1}\,\hbox{K}^{-1}\))

T :

Temperature (K or \(^\circ \hbox{C}\))


Total cost of ownership

U :

Internal energy (kJ)

u :

Specific internal energy (\(\hbox{kJ kg}^{-1}\))

V :

Volume (\(\hbox{m}^3\))

v :

Specific volume (\(\hbox{m}^3\,\hbox{kg}^{-1}\))

X :

Exergy (kJ)

z :

Height (m)


Reference (dead) state

a :


c :





Circulation pump


Capillary tube



e :




F :



Fan unit

H :



Heat pump





P :







  1. Emmi G, Zarrella A, De Carli M, Galgaro A. An analysis of solar assisted ground source heat pumps in cold climates. Energy Convers Manag. 2015;106:660–75.

    Article  Google Scholar 

  2. Etemoglu AB, Can M. Classification of geothermal resources in Turkey by exergy analysis. Renew Sustain Energy Rev. 2007;11:1596–606.

    Article  Google Scholar 

  3. Kavanaugh S, Rafferty K. Geothermal heating and cooling: design of ground-source heat pump systems. 2014;. p. 420.

  4. Naranjo-Mendoza C, Oyinlola MA, Wright AJ, Greenough RM. Experimental study of a domestic solar-assisted ground source heat pump with seasonal underground thermal energy storage through shallow boreholes. Appl Therm Eng. 2019;162:114218.

    Article  Google Scholar 

  5. Alshehri F, Beck S, Ingham D, Ma L, Pourkashanian M. Techno-economic analysis of ground and air source heat pumps in hot dry climates. J Build Eng. 2019;26:100825.

    Article  Google Scholar 

  6. Esen H, Inalli M, Esen M. Technoeconomic appraisal of a ground source heat pump system for a heating season in eastern Turkey. Energy Convers Manag. 2006;47:1281–97.

    Article  Google Scholar 

  7. Lei Y, Tan H, Li Y. Technical-economic evaluation of ground source heat pump for office buildings in China. Energy Procedia. 2018;152:1069–78.

    Article  Google Scholar 

  8. Seo Y, Seo UJ, Kim JH. Economic feasibility of ground source heat pump system deployed in expressway service area. Geothermics. 2018;76:220–30.

    Article  Google Scholar 

  9. Yin P, Pate M, Battaglia F. In-field performance evaluation and economic analysis of residential ground source heat pumps in heating operation. J Build Eng. 2019;26:100932.

    Article  Google Scholar 

  10. Council European Geothermal Energy. EGEC Geothermal Market Report. 2018;2019.

  11. Chiam HW, Azmi WH, Usri NA, Mamat R, Adam NM. Thermal conductivity and viscosity of Al2O3 nanofluids for different based ratio of water and ethylene glycol mixture. Exp Therm Fluid Sci. 2017;81:420–9.

    Article  CAS  Google Scholar 

  12. Goudarzi K, Jamali H. Heat transfer enhancement of \(\text{ Al}_{2}\text{ O}_{3}\)-EG nanofluid in a car radiator with wire coil inserts. Appl Therm Eng. 2017;118:510–7.

    Article  CAS  Google Scholar 

  13. Fotukian SMM, Esfahany MN, Nasr Esfahany M. Experimental investigation of turbulent convective heat transfer of dilute gamma-\(\text{ Al}_{2}\text{ O}_{3}\)/water nanofluid inside a circular tube. Int J Heat Fluid Flow. 2010;31:606–12.

    Article  CAS  Google Scholar 

  14. Hung YH, Teng TP, Teng TC, Chen JH. Assessment of heat dissipation performance for nanofluid. Appl Therm Eng. 2012;32:132–40.

    Article  CAS  Google Scholar 

  15. Krishnakumar TS, Viswanath SP, Varghese SM, Prakash MJ. Experimental studies on thermal and rheological properties of \(\text{ Al}_{2}\text{ O}_{3}\)-ethylene glycol nanofluid. Int J Refrig. 2018;89:122–30.

    Article  CAS  Google Scholar 

  16. Moghaieb HS, Abdel-Hamid HM, Shedid MH, Helali AB. Engine cooling using \(\text{ Al}_{2}\text{ O}_{3}\)/water nanofluids. Appl Therm Eng. 2017;115:152–9.

    Article  CAS  Google Scholar 

  17. Peyghambarzadeh SM, Hashemabadi SH, Hoseini SM, Seifi Jamnani M. Experimental study of heat transfer enhancement using water/ethylene glycol based nanofluids as a new coolant for car radiators. Int Commun Heat Mass Transf. 2011;38:1283–90.

    Article  CAS  Google Scholar 

  18. Syam Sundar L, Kirubeil A, Punnaiah V, Singh MK, Sousa ACM. Effectiveness analysis of solar flat plate collector with \(\text{ Al}_{2}\text{ O}_{3}\) water nanofluids and with longitudinal strip inserts. Int J Heat Mass Transf. 2018;127:422–35.

    Article  CAS  Google Scholar 

  19. Kulkarni DP, Das DK, Vajjha RS. Application of nanofluids in heating buildings and reducing pollution. Appl Energy. 2009;86:2566–73.

    Article  CAS  Google Scholar 

  20. Chandrasekar M, Suresh S, Chandra Bose A. Experimental studies on heat transfer and friction factor characteristics of \(\text{ Al}_{2}\text{ O}_{3}\)/water nanofluid in a circular pipe under laminar flow with wire coil inserts. Exp Therm Fluid Sci. 2010;34:122–30.

    Article  CAS  Google Scholar 

  21. Albadr J, Tayal S, Alasadi M. Heat transfer through heat exchanger using \(\text{ Al}_{2}\text{ O}_{3}\) nanofluid at different concentrations. Case Stud Therm Eng. 2013;1:38–44.

    Article  Google Scholar 

  22. Darzi AAR, Farhadi M, Sedighi K. Heat transfer and flow characteristics of \(\text{ Al}_{2}\text{ O}_{3}\)-water nanofluid in a double tube heat exchanger. Int Commun Heat Mass Transf. 2013;47:105–12.

    Article  CAS  Google Scholar 

  23. Kim S, Tserengombo B, Choi SH, Noh J, Huh S, Choi B, et al. Experimental investigation of heat transfer coefficient with \(\text{ Al}_{2}\text{ O}_{3}\) nanofluid in small diameter tubes. Appl Therm Eng. 2019;146:346–55.

    Article  CAS  Google Scholar 

  24. Kim S, Song H, Yu K, Tserengombo B, Choi SH, Chung H, et al. Comparison of CFD simulations to experiment for heat transfer characteristics with aqueous \(\text{ Al}_{2}\text{ O}_{3}\) nanofluid in heat exchanger tube. Int Commun Heat Mass Transf. 2018;95:123–31.

    Article  CAS  Google Scholar 

  25. Fujii H, Nishi K, Komaniwa Y, Chou N. Numerical modeling of slinky-coil horizontal ground heat exchangers. Geothermics. 2012;41:55–62.

    Article  Google Scholar 

  26. Habibi M, Hakkaki-Fard A. Evaluation and improvement of the thermal performance of different types of horizontal ground heat exchangers based on techno-economic analysis. Energy Convers Manag. 2018;171:1177–92.

    Article  Google Scholar 

  27. Kapıcıoğlu A, Esen H. Experimental investigation on using \(\text{ Al}_{2}\text{ O}_{3}\)/ethylene glycol-water nano-fluid in different types of horizontal ground heat exchangers. Appl Therm Eng. 2019;165:114559.

    Article  Google Scholar 

  28. Kim MJ, Lee SR, Yoon S, Go GH. Thermal performance evaluation and parametric study of a horizontal ground heat exchanger. Geothermics. 2016;60:134–43.

    Article  Google Scholar 

  29. Yoon S, Lee SR, Go GH. Evaluation of thermal efficiency in different types of horizontal ground heat exchangers. Energy Build. 2015;105:100–5.

    Article  Google Scholar 

  30. Congedo PM, Colangelo G, Starace G. CFD simulations of horizontal ground heat exchangers: a comparison among different configurations. Appl Therm Eng. 2012;33–34:24–32.

    Article  Google Scholar 

  31. Diglio G, Roselli C, Sasso M, Jawali Channabasappa U. Borehole heat exchanger with nanofluids as heat carrier. Geothermics. 2018;72:112–23.

    Article  Google Scholar 

  32. Esen H, Inalli M, Esen M, Pihtili K. Energy and exergy analysis of a ground-coupled heat pump system with two horizontal ground heat exchangers. Build Environ. 2007;42:3606–15.

    Article  Google Scholar 

  33. Menberg K, Heo Y, Choi W, Ooka R, Choudhary R, Shukuya M. Exergy analysis of a hybrid ground-source heat pump system. Appl Energy. 2017;204:31–46.

    Article  Google Scholar 

  34. Deymi-Dashtebayaz M, Maddah S, Goodarzi M, Maddah O. Investigation of the effect of using various HFC refrigerants in geothermal heat pump with residential heating applications. J Therm Anal Calorim. 2020;141:361–72.

    Article  CAS  Google Scholar 

  35. Qiao Z, Long T, Li W, Zeng L, Li Y, Lu J, et al. Performance assessment of ground-source heat pumps (GSHPs) in the Southwestern and Northwestern China: In situ measurement. Renew Energy. 2020;153:214–27.

    Article  Google Scholar 

  36. Serageldin AA, Sakata Y, Katsura T, Nagano K. Performance enhancement of borehole ground source heat pump using single U-tube heat exchanger with a novel oval cross-section (SUO) and a novel spacer. Sustain Energy Technol Assess. 2020;42:100805.

    Google Scholar 

  37. Zhou K, Mao J, Li Y, Hua Z. Comparative study on thermal performance of horizontal ground source heat pump systems with Dirichlet and Robin boundary conditions on ground surface. Energy Convers Manag. 2020;225:113469.

    Article  Google Scholar 

  38. Zhao W, Zhang Y, Chen X, Su W, Li B, Fu Z. Experimental heating performances of a ground source heat pump (GSHP) for heating road unit. Energy Convers Manag X. 2020;7:100040.

    Google Scholar 

  39. Du R, Jiang DD, Wang Y, Wei Shah K. An experimental investigation of CuO/water nanofluid heat transfer in geothermal heat exchanger. Energy Build. 2020;227:110402.

    Article  Google Scholar 

  40. Rostami S, Aghaei A, Hassani Joshaghani A, Mahdavi Hezaveh H, Sharifpur M, Meyer JP. Thermal-hydraulic efficiency management of spiral heat exchanger filled with Cu-ZnO/water hybrid nanofluid. J Therm Anal Calorim 2020;1–14.

  41. The World Health Organization. Housing, energy and thermal comfort. World Health Organization Regional Office for Europe; 2007; Denmark.

  42. Lohani SP, Schmidt D. Comparison of energy and exergy analysis of fossil plant, ground and air source heat pump building heating system. Renew Energy. 2010;35:1275–82.

    Article  Google Scholar 

  43. Çengel YA, Boles MA. Thermodynamics an engineering approach, vol. 978;2013.

  44. Kotas TJ. The exergy method of thermal plant analysis, vol. 296. 1985.

  45. Hepbasli A, Akdemir O. Energy and exergy analysis of a ground source (geothermal) heat pump system. Energy Convers Manag. 2004;45:737–53.

    Article  Google Scholar 

  46. Holman JP. Experimental methods for engineers. 2011.

  47. Duangthongsuk W, Wongwises S. An experimental study on the heat transfer performance and pressure drop of \(\text{ TiO}_{2}\)-water nanofluids flowing under a turbulent flow regime. Int J Heat Mass Transf. 2010;53:334–44.

    Article  CAS  Google Scholar 

  48. Sajid MU, Ali HM. Recent advances in application of nanofluids in heat transfer devices: a critical review. Renew Sustain Energy Rev. 2019;103:556–92.

    Article  CAS  Google Scholar 

  49. Li Y, Xie HQ, Yu W, Li J. Investigation on heat transfer performances of nanofluids in solar collector. 2011;89:122–30.

  50. Akbulut U, Acikgoz O, Kincay O, Karakoc TH. Exergetic analysis of a vertical ground-source heat pump system with wall heating/cooling. In: Progress in exergy, energy, and the environment. 2014;305–312.

  51. Ozgener O, Hepbasli A. Experimental performance analysis of a solar assisted ground-source heat pump greenhouse heating system. Energy Build. 2005;37:101–10.

    Article  Google Scholar 

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This work is supported by the Scientific Research Projects of Sivas Cumhuriyet University (CUBAP) under project no: TEKNO-025 and partially supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under project no: 118M140.

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Correspondence to Abdullah Kapicioglu.

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Kapicioglu, A. Energy and exergy analysis of a ground source heat pump system with a slinky ground heat exchanger supported by nanofluid. J Therm Anal Calorim 147, 1455–1468 (2022).

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