## THERMAL SCIENCE

International Scientific Journal

### Thermal Science - Online First

online first only
### A new analytical method for defining the pump's power optimum of a water-to-water heat pump heating system using COP

**ABSTRACT**

This paper analyzes the energy efficiency of the heat pump and the complete heat pump heating system. Essentially, the maximum of the coefficient of performance - COPmax of the heat pump and the heat pump heating system are investigated and determined by applying a new analytical optimization procedure. The analyzed physical system consists of the water-to-water heat pump, circulation and well pump. In the analytical optimization procedure the "first derivative equal to zero" mathematical method is applied. The objective function is the coefficient of performance of the heat pump, and the heat pump heating system. By using the analytical optimization procedure and the objective function, as the result, the local and the total energy optimum conditions with respect to the mass flow rate of hot and cold water i.e. the power of circulation or well pump are defined.

**KEYWORDS**

PAPER SUBMITTED: 2016-11-10

PAPER REVISED: 2016-12-20

PAPER ACCEPTED: 2016-12-22

PUBLISHED ONLINE: 2017-01-14

- Granryd, E., Analytical expressions for optimum flow rates in evaporators condensers of heat pumping systems, International Journal of Refrigeration, Volume 33, Issue 7, November 2010, pp. 1211-1220.
- Sayyaadi, H., Amlashi, E. H., Amidpour, M., Multi-objective optimization of a vertical ground source heat pump using evolutionary algorithm, Energy Conversion and Management, 50 (2009), pp. 2035-2046.
- Esen, H., Turgut, E., Optimization of operating parameters of a ground coupled heat pump system by Taguchi method, Energy and Buildings, Volume 107, 15 November 2015, pp. 329-334.
- Mu, W., Wang, S., Pan, S., Shi, Y., Discussion of an Optimization Scheme for the Ground Source Heat Pump System of HVAC, Renewable Energy Resources and a Greener, Future Vol. VIII-13-3 2006, ESL-IC-06-11-315.
- Shi, Z., Li, Z., Thermo-economic Optimization of a Seawater Source Heat Pump System for Residential Buildings, Advanced Materials Research Online, 2011-10-07, ISSN: 1662-8985, Vols. 354-355, pp 794-797.
- Ahmadi, M. H., Ahmadi, M. A., Bayat, R., Ashouri, M., Feidt, M., Thermo-economic optimization of Stirling heat pump by using non-dominated sorting genetic algorithm, Energy Conversion and Management, 91 (2015), pp. 315-322.
- Go, G. H., Lee, S. R., Yoon, S., Kim, M. J., Optimum design of horizontal ground-coupled heat pump systems using spiral-coil-loop heat exchangers, Applied Energy, Volume 162, 15 January 2016, pp. 330-345
- Cui, W., Zhou, S., Liu, X., Optimization of design and operation parameters for hybrid ground-source heat pump assisted with cooling tower, Energy and Buildings, 99 (2015), 253-262
- Mokhtari, H., Hadiannasab, H., Mostafavi, M., Ahmadibeni, A., Determination of optimum geothermal Rankine cycle parameters utilizing coaxial heat exchanger, Energy, 102 (2016), pp. 260-275
- Takács J., Enhance of the efficiency of exploitation of geothermal energy, Proceedings, symposium EXPRES 2015, ISBN 978-86-82621-15-7, Subotica, pp. 46-49
- Wu, W., Shi, W., Wang, B., Li, X., Annual performance investigation and economic analysis of heating systems with a compression-assisted air source absorption heat pump, Energy Conversion and Management, Volume 98, 1 July 2015, pp. 290-302
- Dra ičević, S., Bojić, M., An energy optimization model for a combined heat and power production energy supply system with a heat pump, Proc. IMechE Vol. 223 Part A: J. Power and Energy, 2009, pp. 321-328
- Kalmár, F., Interrelation between glazing and summer operative temperature in buildings, International Review of Applied Sciences and Engineering, 7 (2016) 1, pp. 51-60 DOI: 10.1556/1848.2016.7.1.7
- Kalmár, F., Csomós, Gy., Lakatos, Á., Focus on renewable energy (energy policy) — Editorial, International Review of Applied Sciences and Engineering, 4 (1), 95-95 (2013)
- Kajtár, L., Kassai, M., Bánhidi, L., Computerized simulation of the energy consumption of air handling units. 2011, Energy and Buildings, ISSN 0378-7788, (45) pp. 54-59.
- Kassai, M., Ge, G., Simonson, C. J., Dehumidification performance investigation of liquid-to-air membrane energy exchanger system, Thermal Science, DOI: 10.2298/TSCI140816129K (2015).
- Nyers, J., Garbai, L., Nyers, A., A modified mathematical model of heat pump's condenser for analytical optimization, International J. Energy, Vol. 80, pp. 706-714, 1 February 2015. DOI:10.1016/j.energy.2014.12.028
- Nyers, J., Nyers, A., Hydraulic Analysis of Heat Pump's Heating Circuit using Mathematical Model, Proceedings-USB, 9th ICCC International Conferenc, ISBN 978-1-4799-0061-9, pp. 349-353, Tihany, Hungary, 2013
- Nyers, J., Nyers, A., COP of heating-cooling system with heat pump, Proceedings, EXPRES 2011, 3rd IEEE International Symposium on Exploitation of Renewable Energy Sources, Subotica, Serbia; 2011, pp. 17-21, Article number 5741809
- Nyers, J., Pek, Z., Mathematical model of heat pumps' coaxial evaporator with distributed parameters, Acta Polytechnica Hungarica, Volume 11, Issue 10, 2014, pp. 41-57