118,298 research outputs found
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
Optimizing 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 textEnergetic and economic analysis of integrated systems for municipal solid waste management
No full textSYNOPSIS: In order to solve the problem represented by Municipal Solid Waste (MSW) management, it is now common to utilise an integrated management scheme. Integrated systems for MSW management are extremely complex. However, they also represent a very interesting potential resource, from both energy and economic viewpoints. Thus, proper planning of the integrated cycle as a whole is of fundamental importance. This paper focuses on the development of a model for the analysis and optimisation of integrated cycles for MSW treatment. This objective is pursued through an assessment of the entire MSW life cycle. An application is also presented, in the form of a case-study of the Italian Region of Campania, which appears to be of particular interest, due to the recent start of a new regional plan for waste treatment, recycling and disposal. © 2004 Taylor & Francis Group, LLC
Design and parametric optimization of an organic rankine cycle powered by solar energy
No full textThis study presents the simulation and performance analysis of a regenerative and superheated Organic Rankine Cycle (ORC). To this scope, anew simulation model has been developed. The model is based on zero-dimensional energy and mass balances for all the components of the system. Shell and tube heat expanders with single shell and double tube pass have been chosen. Pump and expander have been considered only form a thermodynamic point of view, with constant compressor and expansion efficiency. The simulations havebeen carried out in order to find different optimization criteria to use as preliminary design tools,especially for the organic fluid choice and the heat exchanger design. Firstly, the ORC performances have been evaluated for different organic medium, varying the temperature of the heat source. The global efficiency of the plant, the net electric power generation and the volumetric expansion ratio has been considered as evaluation parameters. The simulation results show that two hydrocarbons demonstrate good performance for low, medium and high heat source, namely Isobutene, n-Butene; R245fa can add to them for the exploitation of heat source up to 170°C. Additional simulations have been carried out to discover an optimization criterion for the heat exchanger design. The plant performances have been first evaluated varying one by one the following parameters: tube length, tube number and shell diameter. Then a global optimization was also performed using the Golden Search technique. The total cost of the plant has been considered as objective functions. With respect to the objective function, higher the boiling heat transfer area higher the electric power generation and the economical benefit. The optimal configuration, compared to the initial one, shows an increase of incomes and mechanical power equal to 60.1 and 48.2% respectively, against a decrease of global efficiency equal to 10.9%
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