Seasonal performance assessment of a dual source heat pump system for heating, cooling and domestic hot water production

Abstract

In order to contribute to a global CO 2 emissions reduction in 2020, the increase in the use of highly efficient heat pumps for heating, cooling and domestic hot water production in buildings is very recommendable. In this direction, Ground Source Heat Pump (GSHP) systems are generally recognized as one of the most energy-efficient compared to air source heat pump systems. However, this strongly depends on the temperature evolution of the air and the ground during the year, which also depends on the geographical location of the system. Therefore, an optimal system from the energy point of view apparently would be the one that is able to switch from one source to the other in order to operate the heat pump with the highest efficiency. In this context, a new Dual Source Heat Pump (DSHP) unit for heating, cooling and production of domestic hot water, was developed and manufactured in the framework of a H2020 European project called GEOT€CH (Geothermal Technology for €conomic Cooling and Heating

Energy Analysis and Cost-Effective Design Solutions for a Dual-Source Heat Pump System in Representative Climates in Europe

“…A novel "plug-and-play" DSHP, capable of working in eleven operating modes, was designed and modeled in TRNSYS, which is described by Corberán et al in the following study [25]. Another work, by Cazorla-Marín et al, in which the integrated DSHP system was adapted to three different locations in Spain (Valencia, Madrid, Bilbao), analyzed the percentage of operation of the DSHP under each of the selected working modes [26]. An extension to this study, where an office building with the DSHP unit is simulated for three different European cities with representative climates-Strasbourg (average climate), Athens (warmer climate), and Stockholm (colder climate)-concluded that in warmer climates the use of DSHP is not as profitable as in cold climates, as the air is used to satisfy only 4% of the thermal energy demand [27].…”

“…Another work, by Cazorla-Marín et al, in which the integrated DSHP system was adapted to three different locations in Spain (Valencia, Madrid, Bilbao), analyzed the percentage of operation of the DSHP under each of the selected working modes [26]. An extension to this study, where an office building with the DSHP unit is simulated for three different European cities with representative climates-Strasbourg (average climate), Athens (warmer climate), and Stockholm (colder climate)-concluded that in warmer climates the use of DSHP is not as profitable as in cold climates, as the air is used to satisfy only 4% of the thermal energy demand [27]. Another work by Cazorla-Marín et al consisted of the implementation of a coaxial borehole heat exchanger TRNSYS type into the previously developed DSHP model, which allowed for both short-and mid-term simulations [28].…”

“…Another work by Cazorla-Marín et al consisted of the implementation of a coaxial borehole heat exchanger TRNSYS type into the previously developed DSHP model, which allowed for both short-and mid-term simulations [28]. The most recent study regarding this DSHP pump unit, where different optimization strategies were tested using data from the demo site in Amsterdam, was presented at the 8th Iberian-American Congress of Refrigeration Science and Technology [29].…”

“…This research work complements the studies developed in GEOTeCH's framework. While the energy performance of the modeled DSHP is analyzed in detail in the previously mentioned publications [26,27], both studies assumed the same BHE size for all analyzed locations. In addition, the long-term energy assessment was excluded from the analysis, as the system performance was examined in only one year of operation.…”

“…In addition, the long-term energy assessment was excluded from the analysis, as the system performance was examined in only one year of operation. Additionally, the energy assessment conducted in the latest work [29], in which various strategies for the DSHP system optimization are analyzed, is focused on only one climatic condition. Moreover, while in the previously described study [22] the DSHP system performance is analyzed under different climatic conditions, the simulated exemplary building has the same insulation parameters for each climate, and the unique constructive typology was not considered for each location specified in the study.…”