Energy and exergy analysis of a ground source heat pump system for a public building in Wuhan, China under different control strategies

Abstract This paper presents the energy and exergy studies of a ground source heat pump (GSHP) system for a public building in Wuhan, China under five different control strategies to improve the system performance. Original system was under manual operation with constant frequency heat pump, constant speed circulation pumps, and constant water flow rate. The five control strategies were: 1) Automatic ON/OFF control based on Building Load Ratio (BLR); 2) Optimum circulation flow rate control; 3) Optimum ON/OFF control with variable speed heat pump units; 4) Variable flow control by adjusting valve position; 5) Variable flow control by variable speed pumps. The results of the system exergy efficiency, exergy loss, COP, and energy consumption under different operation scenarios are presented. By comparing original operation with the best case (scenario five), it is found that during cooling and heating season, the system exergy efficiency was improved from 9.0% to 10.4% and from 6.1% to 6.9%; exergy loss dropped by 31% and 51%; COP increased from 3.2 to 3.7 and from 2.7 to 3.8; and energy consumption was reduced by 37% and 60%, respectively.

[1]  Van D Baxter,et al.  Exergy analysis of a two-stage ground source heat pump with a vertical bore for residential space conditioning under simulated occupancy , 2015 .

[2]  Y. Bi,et al.  Comprehensive exergy analysis of a ground-source heat pump system for both building heating and cooling modes , 2009 .

[3]  Birol Kılkış,et al.  Exergy metrication of radiant panel heating and cooling with heat pumps , 2012 .

[4]  Van D Baxter,et al.  Exergy and Energy analysis of a ground-source heat pump for domestic water heating under simulated occupancy conditions , 2013 .

[5]  Radu Zmeureanu,et al.  Exergy analysis of variable air volume systems for an office building , 2009 .

[6]  Donal Finn,et al.  Generalised water flow rate control strategy for optimal part load operation of ground source heat pump systems , 2015 .

[7]  Majid Amidpour,et al.  Multi-objective optimization of a vertical ground source heat pump using evolutionary algorithm , 2009 .

[8]  Arif Hepbasli,et al.  Application of conventional and advanced exergy analyses to evaluate the performance of a ground-source heat pump (GSHP) dryer used in food drying , 2014 .

[9]  Arif Hepbasli,et al.  Exergetic modeling and assessment of solar assisted domestic hot water tank integrated ground-source heat pump systems for residences , 2007 .

[10]  Murat Ozturk,et al.  Energy and exergy analysis of a combined ground source heat pump system , 2014 .

[11]  Per Fahlén,et al.  Capacity-controlled ground source heat pumps in hydronic heating systems , 2007 .

[12]  Arif Hepbasli,et al.  A comparative study on exergetic assessment of two ground-source (geothermal) heat pump systems for residential applications , 2007 .

[13]  S. P. Lohani,et al.  Comparison of energy and exergy analysis of fossil plant, ground and air source heat pump building heating system , 2010 .

[14]  Per Lundqvist,et al.  A descriptive and comparative analysis of three common control techniques for an on/off controlled Ground Source Heat Pump (GSHP) system , 2013 .

[15]  Jorg Thöming,et al.  Thermoeconomic optimization of vertical ground-source heat pump systems through nonlinear integer programming , 2014 .

[16]  Michele De Carli,et al.  A simulation-based analysis of variable flow pumping in ground source heat pump systems with different types of borehole heat exchangers: A case study , 2017 .

[17]  Olcay Kincay,et al.  Exergoenvironmental and exergoeconomic analyses of a vertical type ground source heat pump integrated wall cooling system , 2016 .

[18]  Zhenjun Ma,et al.  Optimal design of vertical ground heat exchangers by using entropy generation minimization method and genetic algorithms , 2014 .

[19]  Onder Ozgener,et al.  Exergoeconomic analysis of a solar assisted ground-source heat pump greenhouse heating system , 2005 .

[20]  Arif Hepbasli,et al.  A study on modeling and performance assessment of a heat pump system for utilizing low temperature geothermal resources in buildings , 2007 .

[21]  Guoqiang Zhang,et al.  Exergy analysis of a novel CHP–GSHP coupling system , 2016 .

[22]  Umberto Lucia,et al.  Ground-source pump system for heating and cooling: Review and thermodynamic approach , 2017 .

[23]  Olcay Kincay,et al.  Exergy, exergoenvironmental and exergoeconomic evaluation of a heat pump-integrated wall heating system , 2016 .

[24]  Ryozo Ooka,et al.  Theoretical analysis on ground source heat pump and air source heat pump systems by the concepts of cool and warm exergy , 2014 .

[25]  Arif Hepbasli,et al.  Energy and exergy analysis of a ground source (geothermal) heat pump system , 2004 .

[26]  Mostafa Nejatolahi,et al.  Thermodynamic and thermoeconomic optimization of a cooling tower-assisted ground source heat pump , 2011 .

[27]  Sara Cosentino,et al.  Second law analysis of horizontal geothermal heat pump systems , 2016 .

[28]  Davide Del Col,et al.  Energy efficiency in a ground source heat pump with variable speed drives , 2015 .

[29]  Costantino Carlo Mastino,et al.  Energy and exergy analysis of a geothermal heat pump air conditioning system , 2015 .

[30]  Arif Hepbasli,et al.  Exergoeconomic evaluation of a ground-source heat pump food dryer at varying dead state temperatures , 2017 .