Techno-economic evaluation of a solar assisted combined heat pump – Organic Rankine Cycle system

Simulation of a solar assisted combined heat pump – Organic rankine cycle system

“…The heat injection could lead to a reduced borehole depth or an increased COP at the beginning of the next heating period by counteracting the thermal degradation of the ground. These benefits are discussed in detail in another work by the authors [13].…”

“…All levels used by the evolutionary algorithm as well as the resulting deviations to the reference level, on which one annual simulation takes about 28 h, which clearly is not reasonable for an optimization, are presented in the tables of Appendix B. The uncertainties are not only based on the simulations of this work but include the ones of another study by the authors focusing on the techno-economic evaluation of the system [13].…”

“…This indicates that the benefits of recharging the ground during ORC mode on the electricity consumption are marginal although at Ankara and Denver about 50% of the amount of extracted heat is reinjected. The reinjection nonetheless would reduce the necessary borehole length by countering the long-term thermal degradation of the ground, an effect which is described in detail in [13].…”

“…Further savings are expected from a reduced borehole length and from the fact, that changes of the solar fluid, resulting from an aging due to a stagnation of the solar loop, are not necessary. A detailed discussion of the economic viability is given in [13].…”

“…The total efficiencies can be increased by the use of evacuated tube collectors. A comparison of the economic feasibility of flat-plate collectors and evacuated tube collectors is conducted in [13].…”