1,721,178 research outputs found
Parabolic trough photovoltaic/thermal collectors. Part II: Dynamic simulation of a solar trigeneration system
No full textOptimizing renewable energy integration in new districts: Power-to-X strategies for improved efficiency and sustainability
No full textTo achieve optimal renewable energy self-sufficiency in new districts, it's crucial to efficiently manage surplus electricity or heat. One effective approach is ‘sector coupling,’ which increases self-consumption by redirecting excess energy via heat pumps (Power-to-Heat) or producing hydrogen (Power-to-Gas). Integrating electric vehicles and storage solutions (Power-to-Power) further enhances system flexibility. Moreover, the implementation of energy communities offers not just an uptick in self-consumption but also encourages consumers to embrace renewable energy technologies. This study evaluates the integration of renewable energy within urban districts through ‘sector coupling’ strategies, aiming to enhance self-sufficiency and consumption by managing surplus electricity and heat. Focusing on a renovated district in Southern Italy, it compares Power-to-X strategies—such as Power-to-Heat, Power-to-Gas, and Power-to-Power—in terms of their impact on primary energy usage, CO2 emissions, and financial costs. Dynamic simulations show these strategies can reduce CO2 emissions by 30 % and energy use by 20 % on average, offering valuable insights for urban energy planning and policy
Parabolic Trough Photovoltaic/ Thermal Collectors. Part II: Dynamic Simulation of a Solar Trigeneration System
No full textDesign and dynamic simulation of a novel polygeneration system fed by vegetable oil and by solar energy
No full textIn this paper the integration of vegetable oil-fed reciprocating engines with solar thermal collector is investigated, seeking to design a novel polygeneration system producing: electricity, space heating and cooling and domestic hot water, for a university building located in Naples (Italy), assumed as case study. The polygeneration system is based on the following main components: concentrating parabolic trough solar collector, double-stage LiBr–H2O absorption chiller and a reciprocating engine fed by vegetable oil. The engine operates at full load producing electrical energy which is in part consumed by the building lights and equipments, in part used by the system passive loads and the rest is eventually sold to the grid. In fact, the engine is grid connected in order to perform a convenient net metering. The system was designed and then simulated by means of a zero-dimensional transient simulation model, developed using the TRNSYS software. The simulation tool developed by the authors allows one to analyze the results for different time basis (minutes, days, weeks, months and years), from both energetic and economic points of view. The economic results show that the system under investigation is profitable, especially if properly funded
Thermoeconomic optimazation of the condenser in a vapour compression heat pump
No full textIn the paper, the design optimisation of a heat exchanger is discussed, using a thermoeconomic approach. The
investigation is referred to the tube-in-tube condenser of a conventional vapour-compression heat pump, with a twophase
refrigerant flowing in the inner tube and a single-phase fluid flowing in the annulus. A cost function to be minimised
is introduced, defined as the sum of two contributions: (i) the amortisation cost of the condenser, related to the
heat exchange area;(ii) the operating cost of the electric-driven heat pump in which the heat exchanger will work,
depending on the overall exergy destruction rate in the system. In the paper, this latter contribution is related to the
local irreversibility rate in the condenser, using the so-called structural approach. The optimal trade-off between
amortisation and operating cost is therefore investigated, by minimising the above-mentioned cost function. A
numerical example is discussed, in which, for a commercial heat exchanger, the design improvements needed to obtain
a cost-optimal configuration are investigated. The analysis is carried out for three different refrigerants: R22, R134a
and R410A
Parametric Exergy Analysis of a Tubular Solid Oxide Fuel Cell (SOFC) stack through Finite-Volume Model
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Optimal control of polygeneration systems including photovoltaic/thermal collectors and solar assisted heat pumps
No full textOptimizing storage capacity in 100 % renewable electricity supply: A GIS-based approach for Italy
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