61 research outputs found
Dopamine restores reward prediction errors in old age
No full textSenescence affects the ability to utilize information about the likelihood of rewards for optimal decision-making. Using functional magnetic resonance imaging in humans, we found that healthy older adults had an abnormal signature of expected value, resulting in an incomplete reward prediction error (RPE) signal in the nucleus accumbens, a brain region that receives rich input projections from substantia nigra/ventral tegmental area (SN/VTA) dopaminergic neurons. Structural connectivity between SN/VTA and striatum, measured by diffusion tensor imaging, was tightly coupled to inter-individual differences in the expression of this expected reward value signal. The dopamine precursor levodopa (L-DOPA) increased the task-based learning rate and task performance in some older adults to the level of young adults. This drug effect was linked to restoration of a canonical neural RPE. Our results identify a neurochemical signature underlying abnormal reward processing in older adults and indicate that this can be modulated by L-DOPA
Energetic study of a residential building in Skutskär and savings proposal
No full textThis project consists on the Energy audit carried out on a residential building in Skutskär, property of the company Älvkarlebyhus, which is placed in the Älvkarleby municipality, belonging to Uppsala County in Sweden. The aim of the Energy audit is to obtain how much Energy is used, when is it used and how is it used. As well as the costs of the Energy use. The aim of the Energy audit also consists in reduces the Energy use applying efficiency measures. The audit carried out consist on identifying the heat losses and heat gains of the building, thus establishing an Energy balance that will reflect the Energy state of the building and finally propose some efficiency measures that could be applied. With this purpose, a strong method was developed in order to obtain as accurate results as possible. This method studies separately each component of the balance in order to get a better approach. The idea when working and present the results is to manage all the information in an easy way and present it in an easily understandable way for everyone, thus was used a spreadsheet. The expected results have been achieved; the difference between the heat losses and gains is of 0 MWh, which represents the balance 0 and all the values obtained are according to the experience values, which achieve the expected results. The total heat gain of the balance accounts for 1575,23 MWh. It is compounded by the District heating consumption which accounts 742,22 MWh that represents the 47 % of the heat gain and by the free heating which accounts for 832,79 MWh that represents the 53 %. The free heating is compounded by solar radiation which accounts for 643,36 MWh representing 41 % and for Internal heating which accounts for 189,43 MWh that represents 12 %. The total heat loss of the balance accounts for 1575,23 MWh. It is compounded by transmission losses which accounts for 875,46 MWh that represents 56 %, mechanical ventilation which accounts for 369,89 MWh that represents the 23 %, natural ventilation which account for 182,88 MWh that represents 12 % and hot tap water which account for 147 and represents 9 %. The efficiency measures will improve the Energy use in the buildings; especially in the cases were the Energy usage is too high, as in the case of transmission losses. Thus, the efficiency measures will be proposed mainly to alleviate the high values but also to improve other inefficient uses of the Energy. There are some efficiency measures proposed for every component of the balance and there is also some recommendation for the company in order to implement the most attractive ones, taking into account its profitability. These measures are only proposed and not studied deeply because of the main limitation of this thesis. Therefore, it is recommended to continue the study in order to examine and analyse deeply each measure, according to the energetic survey already done
Energy Optimization and Techno-economic assessment of an air source heat pump for sanity hot water production
No full text[EN] Nowadays there are in the market high performance air source heat pumps for sanitary hot
water production (SHW) and there is lot of research work for further increasing it. Nevertheless,
when installing those high-performance system coupled with a storage tank, until 30 % of the
global system energy efficiency (SPF4) can be spoiled. The indirect connection between the heat
pump and the storage tank has a big influence on the SPF4. However, after reviewing the
literature, it was found that none of the studies related to this topic was specifically addressing
this issue.
This work is focused on the indirect connection, which according to EN 1717:2000 is of
compulsory fulfilment to prevent pollution of potable water by backflow. The objective thus is
to determine the indirect connection with the highest possible energy efficiency, costeffectiveness,
and the lowest environmental cost. Moreover, an additional objective is to
determine the operating variables that make the system work in the optimal SPF4. Concluding
with two guides, one for the selection of the optimal case depending on the climate of the region
in the EU and another to select the optimal operation values of the HP to maximize the SPF4.
An integrated system model in TRNSYS has been created based on Geot€ch European project,
analysing three different options of indirect connection: (i) coil heat exchanger, (ii) external heat
exchanger and (iii) double wall condenser. Cases that have been compared against the
conventional systems for SHW production: immersion electric heater and gas boiler. Resulting
in the double wall condenser case as the most efficient, cost-effective and least CO2 emitter
option. Regarding the techno-economic analysis, heat pump technology has been proved
profitable against the immersion electric heater but non-profitable against the gas boiler and
thus the breakeven price for the profitability of the HP over the gas case has been obtained.[ES] Actualmente existen en el mercado bombas de calor aerotérmicas para producción de agua
caliente sanitaria de muy altas prestaciones y además hay mucha labor de investigación para
obtener equipos con mejores prestaciones. En cambio, cuando estos equipos se instalan junto
con un sistema de almacenamiento térmico la eficiencia del sistema puede caer hasta un 30 %.
La conexión indirecta entre la bomba de calor y el sistema de almacenamiento tiene pues una
gran influencia en la eficiencia global del sistema y no hay ningún estudio específico acerca de
este tema en la literatura.
Este trabajo se centra en dicha conexión indirecta que de acuerdo con la EN 1717:2000 es de
obligado cumplimiento para prevenir la contaminación del agua de consumo por reflujo. El
objetivo es determinar la conexión indirecta con la eficiencia energética y rentabilidad más altas
y con los mínimos costes medioambientales. Además, otro objetivo adicional es el de determinar
los valores de operación que hacen trabajar al sistema en el punto de máxima eficiencia.
Concluyendo con 2 guías, una para la selección del caso de conexión indirecta óptima en función
del clima de la UE y otra para seleccionar los valores de operación de la bomba que maximizan
SPF4.
Tres opciones de conexión indirecta se han analizado: (i) intercambiador tipo coil,
(ii) intercambiador de calor externo y (iii) condensador de doble pared; desarrollado un modelo
integral del sistema en TRNSYS basado en el proyecto Europeo Geot€ch. Comparándolos frente
a los sistemas convencionales: calentador eléctrico y caldera de gas. Los resultados muestran la
opción del condensador de doble pared como la más eficiente, la más rentable y con el mínimo
coste medioambiental. Respecto al análisis tecno-económico, el sistema analizado resulta
rentable frente al calentador eléctrico, pero no rentable frente a la caldera de gas, por ello se
ha calculado el precio del gas a partir del cual la bomba de calor sería rentable[CA] Actualment existeixen en el mercat bombes de calor aerotèrmiques per a la producció d'aigua
calenta sanitària de altes prestacions i, a més a més, hi ha molta labor d'investigació per a obtenir
equips amb millors prestacions. En canvi, quan estos equips s'instal·len junt amb un sistema
d’emmagatzemament tèrmic, l'eficiència del sistema pot caure fins a un 30 %. La connexió
indirecta entre la bomba de calor i el sistema d'emmagatzemament té, doncs, una gran
influència en l'eficiència global del sistema i no hi ha cap estudi específic sobre este tema en la
literatura.
Este treball se centra en dita connexió indirecta que, d'acord amb l'EN 1717:2000, és de
compliment obligatori per a prevenir la contaminació de l'aigua de consum per reflux. L'objectiu
és determinar la connexió indirecta amb l'eficiència energètica i rendibilitat més altes i amb els
costos mediambientals mínims. A més, un altre objectiu addicional és el de determinar els valors
d'operació que fan treballar al sistema en el punt de màxima eficiència (SPF4). Concloent amb 2
guies, un per a la selecció del cas de connexió indirecta òptima depenent del clima de la UE i
altra per a seleccionar els valors d'operació de la bomba per a maximitzar SPF4.
Tres opcions de connexió indirecta s'han analitzat: (i) intercanviador tipus coil, (ii) intercanviador
de calor extern i (iii) condensador de doble paret; desenvolupant un model integral del sistema
en TRNSYS basat en el projecte Europeu Geot€ch. Els casos analitzats s'han comparat davant
dels sistemes convencionals: calfador elèctric i caldera de gas. Els resultats mostren l'opció del
condensador de doble paret com la més eficient, la més rendible i amb el mínim cost
mediambiental. Respecte a l'anàlisi tecno-econòmic, el sistema analitzat resulta rendible davant
el calfador elèctric però no rendible enfront la caldera de gas, per això s'ha calculat el preu del
gas a partir del qual la bomba de calor seria rendibleMasip Sanchis, X. (2018). Energy Optimization and Techno-economic assessment of an air source heat pump for sanity hot water production. Universitat Politècnica de València. https://riunet.upv.es/handle/10251/108978TFG
Modeling, analysis and energy optimization of an air source heat pump system for SHW production
No full textIn order to fulfill with the European normative EN-1717:2000 regarding the general requirements of devices to prevent pollution of potable water by backflow, in those systems using a heat pump (HP) for the production of sanitary hot water (SHW), the coupling of the HP with the storage tank must be indirect. This paper will analyze three of the possible coupling configurations for the case of an air source heat pump system: (i) external brazed plate heat exchanger, (ii) coil heat exchanger inside the storage tank and (iii) double wall condenser at the heat pump. The system will be modeled using a dynamic simulation tool (TRNSYS). The aim of this work is to compare the energy performance of each configuration and to optimize its operation.The present work has been supported by the European Community Horizon 2020 Program for European Research and Technological Development (2014-2020) inside the framework of the project 656889 – GEOTeCH (Geothermal Technology for Economic Cooling and Heating), by the Generalitat Valenciana inside the program “Ayudas para la contratación de personal investigador en formación de carácter predoctoral (ACIF/2016/131)” and by the Ministerio de Educación, Cultura y Deporte inside the programme ‘Formación de Profesorado Universitario (FPU15/03476)’Masip Sanchis, X.; Cazorla-Marín, A.; Montagud- Montalvá, C.; Marchante-Avellaneda, J.; Corberán, JM. (2018). Modeling, analysis and energy optimization of an air source heat pump system for SHW production. Instituto de Ingeniería Energética. Universitat Politècnica de València. 1-7. https://riunet.upv.es/handle/10251/129634S1
Influence of the Thermal Energy Storage Strategy on the Performance of a Booster Heat Pump for Domestic Hot Water Production System Based on the Use of Low Temperature Heat Source
No full text[EN] Energy recovery from a low temperature heat source using heat pump technology is becoming a popular application. The domestic hot water demand has the characteristic of being very irregular along the day, with periods in which the demand is very intensive and long periods in which it is quite small. In order to use heat pumps for this kind of applications efficiently, the proper sizing and design of the water storage tank is critical. In this work, the optimal sizing of the two possible tank alternatives, closed stratified tank and variable-water-volume tank, is presented, and their respective performance compared, for domestic hot water production based on low temperature energy recovery in two potential applications (grey water and ultra-low temperature district heating). The results show that the efficiency of these kind of systems is very high and that variable-water-volume tanks allow a better use of the energy source, with an 8% higher exergy efficiency and around 3% better seasonal performance factor (SPF), being able to provide similar comfort levels with a smaller system size"Vicerectorado de Investigacion, Innovacion y Transferencia of the Universitat Politecnica de Valencia (Spain)" throught the project "REDUCCION DE LAS EMISIONES DE CO2 A ALTA TEMPERATURE A PARTIR DE LA RECUPERACION DE CALOR RESIDUAL MEDIANTE EL USO DE UNA BOMBA DE CALOR"with the reference SP20180039 from the program "Primeros proyectos de investigacion (PAID-06-18)".Masip, X.; Navarro-Peris, E.; Corberán, JM. (2020). Influence of the Thermal Energy Storage Strategy on the Performance of a Booster Heat Pump for Domestic Hot Water Production System Based on the Use of Low Temperature Heat Source. Energies. 13(24):1-24. https://doi.org/10.3390/en13246576S12413242050 Long-Term Strategy https://ec.europa.eu/clima/policies/strategies/2050_enEnergy Consumption Buildings https://ec.europa.eu/energy/en/topics/energy-efficiency/buildingsEnergy Consumption in Households http://ec.europa.eu/eurostat/statistics-explained/index.php/Energy_consumption_in_householdshttps://www.google.com.hk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwip0ubH48ztAhUEMN4KHRmLA0kQFjABegQIAxAC&url=https%3A%2F%2Feur-lex.europa.eu%2FLexUriServ%2FLexUriServ.do%3Furi%3DOJ%3AL%3A2009%3A140%3A0016%3A0062%3Aen%3APDF&usg=AOvVaw10tSQ3SpiUkxpXKuCB6R0nCecchinato, L., Corradi, M., Fornasieri, E., & Zamboni, L. (2005). Carbon dioxide as refrigerant for tap water heat pumps: A comparison with the traditional solution. International Journal of Refrigeration, 28(8), 1250-1258. doi:10.1016/j.ijrefrig.2005.05.019Pitarch, M., Navarro-Peris, E., Gonzálvez-Maciá, J., & Corberán, J. M. (2017). Experimental study of a subcritical heat pump booster for sanitary hot water production using a subcooler in order to enhance the efficiency of the system with a natural refrigerant (R290). International Journal of Refrigeration, 73, 226-234. doi:10.1016/j.ijrefrig.2016.08.017Pitarch, M., Hervas-Blasco, E., Navarro-Peris, E., Gonzálvez-Maciá, J., & Corberán, J. M. (2017). Evaluation of optimal subcooling in subcritical heat pump systems. International Journal of Refrigeration, 78, 18-31. doi:10.1016/j.ijrefrig.2017.03.015Hervas-Blasco, E., Pitarch, M., Navarro-Peris, E., & Corberán, J. M. (2018). Study of different subcooling control strategies in order to enhance the performance of a heat pump. International Journal of Refrigeration, 88, 324-336. doi:10.1016/j.ijrefrig.2018.02.003Meggers, F., & Leibundgut, H. (2011). The potential of wastewater heat and exergy: Decentralized high-temperature recovery with a heat pump. Energy and Buildings, 43(4), 879-886. doi:10.1016/j.enbuild.2010.12.008Liu, L., Fu, L., & Jiang, Y. (2010). Application of an exhaust heat recovery system for domestic hot water. Energy, 35(3), 1476-1481. doi:10.1016/j.energy.2009.12.004Baek, N. C., Shin, U. C., & Yoon, J. H. (2005). A study on the design and analysis of a heat pump heating system using wastewater as a heat source. Solar Energy, 78(3), 427-440. doi:10.1016/j.solener.2004.07.009Bertrand, A., Aggoune, R., & Maréchal, F. (2017). In-building waste water heat recovery: An urban-scale method for the characterisation of water streams and the assessment of energy savings and costs. Applied Energy, 192, 110-125. doi:10.1016/j.apenergy.2017.01.096High Efficiency Heat Pump for Domestic Hot Water Generation http://docs.lib.purdue.edu/iracc%0Ahttp://docs.lib.purdue.edu/iracc/953Østergaard, P. A., & Andersen, A. N. (2018). Economic feasibility of booster heat pumps in heat pump-based district heating systems. Energy, 155, 921-929. doi:10.1016/j.energy.2018.05.076Fischer, D., Toral, T. R., Lindberg, K. B., Wille-Haussmann, B., & Madani, H. (2014). Investigation of Thermal Storage Operation Strategies with Heat Pumps in German Multi Family Houses. Energy Procedia, 58, 137-144. doi:10.1016/j.egypro.2014.10.420Han, Y. M., Wang, R. Z., & Dai, Y. J. (2009). Thermal stratification within the water tank. Renewable and Sustainable Energy Reviews, 13(5), 1014-1026. doi:10.1016/j.rser.2008.03.001Haller, M. Y., Haberl, R., Mojic, I., & Frank, E. (2014). Hydraulic Integration and Control of Heat Pump and Combi-storage: Same Components, Big Differences. Energy Procedia, 48, 571-580. doi:10.1016/j.egypro.2014.02.067Liu, F., Zhu, W., Cai, Y., Groll, E. A., Ren, J., & Lei, Y. (2017). Experimental performance study on a dual-mode CO2 heat pump system with thermal storage. Applied Thermal Engineering, 115, 393-405. doi:10.1016/j.applthermaleng.2016.12.095Castell, A., Medrano, M., Solé, C., & Cabeza, L. F. (2010). Dimensionless numbers used to characterize stratification in water tanks for discharging at low flow rates. Renewable Energy, 35(10), 2192-2199. doi:10.1016/j.renene.2010.03.020Armstrong, P., Ager, D., Thompson, I., & McCulloch, M. (2014). Domestic hot water storage: Balancing thermal and sanitary performance. Energy Policy, 68, 334-339. doi:10.1016/j.enpol.2014.01.012Hervás-Blasco, E., Navarro-Peris, E., & Corberán, J. M. (2019). Optimal design and operation of a central domestic hot water heat pump system for a group of dwellings employing low temperature waste heat as a source. Energy, 188, 115979. doi:10.1016/j.energy.2019.115979Next Generation of Heat Pumps Working with Natural Fluids (NxtHPG) http://www.nxthpg.eu/Transient Systems Simulation Homepage http://www.trnsys.comMasip, X., Cazorla-Marín, A., Montagud-Montalvá, C., Marchante, J., Barceló, F., & Corberán, J. M. (2019). Energy and techno-economic assessment of the effect of the coupling between an air source heat pump and the storage tank for sanitary hot water production. Applied Thermal Engineering, 159, 113853. doi:10.1016/j.applthermaleng.2019.11385
Optimal design and operation of a multi-variable heat pump system for sanitary hot water production
No full textAccording to the European Commission, buildings are nowadays responsible for the 40 % of the
energy consumption and 36 % of CO2 emissions in Europe, corresponding the gross of the energy
consumption to the air-conditioning and sanitary hot water (SHW) production systems. Within
the introduction of the Near Zero Energy Buildings (NZEB) concept, the percentage of the energy
consumption of SHW production systems is expected to dramatically increase. Therefore, in order
to reduce the energy usage for SHW production in the residential sector, it will be key the use of
highly energy efficient technologies as well as good design, installation procedures, and operation
strategies carried out in the facilities.
This research work is framed in a H2020 European project titled Geot€ch `GEOthermal
Technology for economic Cooling and Heating¿ whose aim is to develop a multi-variable heat
pump system solution for heating, cooling and SHW production, making the best use of hybrid
HP and control technologies.
The present work is focused on optimizing the design and operation of such a multi-variable HP
system when it works for SHW production. In this context, it is not only important to maximise
the HP efficiency but also to minimize the system efficiency losses that appear when coupling the
HP to the storage tank. In order to fulfil with the European normative EN-1717:2000 regarding
the general requirements of devices to prevent pollution of potable water by backflow, the
coupling of the HP with the storage tank must be indirect.
An integrated system model in TRNSYS has been created in order to analyse three different
options of indirect coupling: (i) coil heat exchanger inside the storage tank, (ii) external brazed
plate heat exchanger and (iii) double wall condenser at the HP. The aim of this work is not only
to select the optimal type of HP coupling but also to optimize the system operation for three
representative climates existing around Europe. Results conclude that up to 30% of the system
energy efficiency can be spoiled either by not selecting the optimal type of coupling or not making
the system work under optimal operating conditions.The present work has been supported by the Ministerio de Educación, Cultura y Deporte inside
the programme ‘Formación de Profesorado Universitario (FPU15/03476)’Masip Sanchis, X.; Cazorla-Marín, A.; Montagud- Montalvá, C.; Marchante-Avellaneda, J.; Corberán, JM. (2019). Optimal design and operation of a multi-variable heat pump system for sanitary hot water production. Universidad de Castilla-La Mancha. 61-71. https://riunet.upv.es/handle/10251/129321S617
Modelling and energy analysis of a dual source heat pump system in an office building
No full textThis paper presents the modelling and energy analysis of a dual source heat pump system for the
production of heating, cooling and domestic hot water (DHW) in buildings.
The research work was carried out in the framework of the Geot€ch project ‘GEOthermal Technology for
economic Cooling and Heating’. The Geot€ch project, funded by the European commission within the H2020
program, is a four years’ duration project which demonstrates the next generation of ground source heat pump
systems with a high energy efficiency but also with lower system costs with respect to those already existing in
the market. To this end, one of the objectives of the project is the design of an efficient and comparative low cost
‘plug& play’ system for providing the heating, cooling and DHW needs in three demonstration sites located in
Italy, the United Kingdom and the Netherlands respectively.
In this context, an innovative dual source heat pump has been developed, which is capable of making optimal
use of ground or air environmental heat sources according to operating and climate conditions. On the other
hand, in order to reduce the costs of the installation, a new more efficient technology of coaxial borehole heat
exchangers will be developed within the framework of the project. The project started on May 2015 and it is still
ongoing.
This paper first describes the characteristics of the dual source heat pump designed in the project. Then, in order
to assist both in the optimal design and energy optimization of the operation of the system, a model of the
‘plug&play’ system in TRNSYS including all the integrated system components (dual source heat pump, ground
source heat exchanger, air conditioning and DHW hydraulic loops) is presented for the demo site located in the
Netherlands. Finally, the paper presents an analysis of the system operation as well as a first energy assessment
in order to identify key control strategies needed to optimize the seasonal energy performance of the system.The present work has been supported by the European Community Horizon 2020 Program for European Research
and Technological Development (2014-2020) inside the framework of the project 656889 – GEOTeCH (Geothermal
Technology for Economic Cooling and Heating) and by the Generalitat Valenciana inside the program “Ayudas para
la contratación de personal investigador en formación de carácter predoctoral (ACIF/2016/131)”.Corberán, JM.; Cazorla-Marín, A.; Marchante-Avellaneda, J.; Montagud- Montalvá, C.; Masip Sanchis, X. (2017). Modelling and energy analysis of a dual source heat pump system in an office building. Università di Bologna. 1-10. https://riunet.upv.es/handle/10251/129393S11
Impairment-Aware Routing in Translucent Spectrum-Sliced Elastic Optical Path Networks
No full textSpectrum-sliced elastic optical path (SLICE) technology offers a more flexible bandwidth allocation in optical networks than wavelength division multiplexing. It allows different connections to be served via different modulation formats. However, as with any optical network, the optical signal may be susceptible to signal impairments, especially when the signal traverses over long distances. The degree of impairment may differ per modulation type, but in any case must be taken into account. If impairment levels get too high, the signal needs to be regenerated by regenerators placed selectively (due to cost considerations) inside the network. In this paper we study the impairment-aware dynamic routing and subcarrier allocation problem in translucent SLICE networks. We propose an impairment-aware routing algorithm that tries to balance traffic flows evenly across the network to reduce the blocking probability. We consider two cases, namely (1) a modulation will be selected that is used by the entire connection, and (2) the modulation can beNetwork Architectures and Services (NAS) GroupElectrical Engineering, Mathematics and Computer Scienc
Advantages of straw-bale in the building sector and a case study
No full text[EN] Straw presents several benefits when considering it for the construction sector in substitution
of conventional materials. Not only has lower embodied energy and density, but also has
valuable thermal properties for passive construction. Using rice-straw bales for construction
could reduce the current waste-management problem for the city, saving costs for the material
supply in the construction sector while providing better building and air-quality for the city.
This research compiles different studies addressing the issue of using straw-bales for the
construction, concluding with the main advantages of this material for professional building.
The study also presents a monitored case study constructed in Villareal (Spain) using
prefabricated modules of straw-bales. The study also comprises a detailed dynamic energy
simulation with Energy Plus, and the detail of the calibration of the model.This work is framed inside the Chair of Urban Energy Transition of the city of València in the
Universitat Politècnica de València and from the Institute for Energy Engineering.
We thank the cooperative OKAMBUVA.Masip, X.; Reverte, V.; Prades-Gil, C.; Barceló Ruescas, F. (2020). Advantages of straw-bale in the building sector and a case study. Faculty of Mechanical Engineering and Naval Architecture, Zagreb. 1-13. https://riunet.upv.es/handle/10251/179349S11
Comparison of Transcritical and Subcritical Heat Pump Systems for Domestic Hot Water Production in Energy Recovery Applications
No full textWater-to-Water heat pump (WtWHP) is an efficient alternative to the current technologies used in Domestic Hot Water (DHW) production. However, this application is characterized by high secondary temperature lifts and irregular demands that define critically its design. In order to maximize the efficiency, transcritical cycles coupled to stratified storage tank has been the preferred solution. Nevertheless, recently subcritical cycles with a subcooling control system has been also considered also as a promising alternative because of the cost with the right desing the efficiencies could be in the range of transcritical system. The objective of this work is to compare the performance of both heat pump systems for DHW production in a heat recovery application where there is no restriction in the low temperature energy source availability. This situation could correspond to a source coming from sewage water or a system of low temperature district heating. The comparison has been made for the optimum configuration of both system which has implied the definition of the proper control strategy, proper sizing of the WtWHP and the tank and incorporation of a primary recovery heat exchanger in order to compare both systems in what is considered as the optimum working conditions. Results show that while both systems are able to operate with similar SCOPs, the CO2 system is more sensitive to water temperature lifts variations and temperature of the heat source than the propane WtWHP resulting in lower performances
- …
