1,720,968 research outputs found
Optimal control of polygeneration systems including photovoltaic/thermal collectors and solar assisted heat pumps
No full textFinite volume model of a flat plate cogenerative collector: thermodynamic and experimental analysis
No full textClimate Characterization and Energy Efficiency in Container Housing: Analysis and Implications for Container House Design in European Locations
No full textThe present study investigates the energy efficiency of different container house configurations across thirty European locations. By employing Heating Degree Days (HDDs) and Cooling Degree Days (CDDs), the research delves into climatic zone exploration, providing a simplified climatic classification for residential purposes and comparing it with the K & ouml;ppen-Geiger model. The authors use specific hourly climatic data for each location, obtained through dynamic simulations with TRNSYS v.18 software. Initially, the CDDs are calculated by using different base temperatures (comfort temperatures that minimize energy demand) tailored to the specific conditions of each case. Then, the thermal loads of container houses are evaluated in different climatic scenarios, establishing a direct correlation between climatic conditions and the energy needs of these innovative and modular housing solutions. By comparing stacked and adjacent modular configurations in container housing, particularly in post-disaster scenarios, the study underscores the importance of adaptive design to optimize energy efficiency. The analysis conducted by the authors has allowed them to propose a climate characterization model based on HDDs, CDDs, and solar irradiance, obtaining an effective novel correlation with the K & ouml;ppen-Geiger classification, especially in extreme climates. The present model emerges as a powerful tool for climate characterization in residential applications, offering a new perspective for urban planning and housing design. Furthermore, the results reveal a significant correlation between climate classification and the specific energy needs of container houses, emphasizing the direct influence of regional climatic characteristics on energy efficiency, particularly in small-sized dwellings such as container houses
Thermoeconomic analyis of a solar assisted heat pump based on photovoltaic/thermal solar collectors
No full textEnergetic performance of a low-cost PhotoVoltaic/Thermal (PVT) collector with and without thermal insulation
No full textOptimization of a novel polygeneration system integrating photovoltaic/thermal collectors, solar assisted heat pump, adsorption chiller and electrical energy storage
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Transient simulation of a photovoltaic/thermal collector heating system for outdoor swimming pools
No full textThe outdoor swimming pools are subjected to energy losses by evaporation, convection and radiation to the surrounding environment and conduction through the walls and the bottom of the pool. The losses associated with the evaporation phenomena are the most consistent ones and they are strictly related to the velocity of the air that flows over the water table. The thermal behavior of the pool depends on the meteorological conditions of the site and on the use and occupancy of the pool. The pool is often heated in order to ensure suitable comfort conditions for swimmers. During the night hours without swimming pool cover, the evaporation phenomenon will continue to exist and it will depend only on the conditions of the environment. The scope of this work is to simulate the dynamic energy behavior of an existing outdoor swimming pool located in Naples and its surrounding environment to properly size a photovoltaic thermal panels plant (PV/T). In PV/T systems, electric energy is produced by a conventional photovoltaic panel (PV), while the absorber, placed under it, conveys the thermal energy developed by the photovoltaic effect in a heat transfer fluid. In this way, the electrical efficiency of the PV panel rises because it is continuously cooled and simultaneously there is a low-temperature heat production. In the specific case, the electricity produced is intended to meet the electrical user loads while the low enthalpy heat is used to heat the pool water. In the simulation model, the energy losses of the pool, the variability of thermohygrometric conditions of the environment and the production of the PV/T plant are simultaneously taken into account. The system was dynamically simulated in TRNSYS environment, implementing appropriate models for the simulation of heat transfer and evaporation in the swimming pool. The model allows one to evaluate all the energy flows on whatever time basis. In particular, the tool calculates thermal and electrical energy produced by the PVT. Similarly, the model calculates the thermal demand of the swimming pool for heating purposes and for domestic hot water. Results showed that the use of PVT systems allows one to dramatically reduce the energy consumption of swimming pools
Energy and economic analysis of energy savings measures in a swimming pool centre by means of dynamic simulations
No full textSport centres thermal demand is extremely high due to the large amount of sanitary hot water production. Therefore, energy savings actions must be performed in order to optimize system efficiency. In this framework, the present paper investigates the possibility to perform an energy rehabilitation of an indoor swimming pool centre by means of solar thermal collectors and heat pump technologies integrated with the existing plant. The case study consists of a university indoor swimming pool centre located in Naples, South of Italy. A dynamic simulation model is developed by TRNSYS software (Thermal Energy System Specialists, LLC, Madison, WI, USA). An experimental investigation is also performed in order to calibrate the swimming pool thermal model and the space conditioning equipment operation. Real data concerning the thermal demand of the centre are implemented and the dynamic behaviour of the swimming pool occupants is also considered. The proposed technical solutions are analysed from an energy and economic point of view. A parametric analysis aiming at determining the effect of the size of the solar field on the system performance is performed. The comparison outlines that the best energy and economic performance is achieved by evacuated solar thermal collectors. In particular, the Simple Pay Back (SPB) period results about 14 years without incentives and it decreases to 5 years considering the Italian incentive policy. For an evacuated collector field of 150 m2, the SPB without incentive results below 9 years
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