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Articles 1 - 18 of 18
Full-Text Articles in Mechanical Engineering
Development & Validation Of A Piv System For Obtaining Data From A Uasb Reactor, Camila D' Bastiani, Gerald Gallagher, David Kennedy, Anthony Reynolds
Development & Validation Of A Piv System For Obtaining Data From A Uasb Reactor, Camila D' Bastiani, Gerald Gallagher, David Kennedy, Anthony Reynolds
Conference Papers
Anaerobic digestion processes can generate energy in the form of biogas while treating organic wastewater. The efficiency of the treatment, and thus the generation of biogas, is closely linked to the type and design of the reactor, and the technology used. Granular anaerobic digestion technology offers advantages such as a higher loading rate and reduction of the space needed. However, the hydrodynamics inside this type of reactor can be complex due to the presence of solids (granules) and gas (biogas) phases along with the liquid phase (wastewater). This is one of the reasons why the study and optimization of reactors …
Economic Appraisal Of Hybrid Solar-Biomass Thermophotovoltaic Power Generation, C. M. Iftekhar Hussain Cmih, Aidan Duffy, Brian Norton
Economic Appraisal Of Hybrid Solar-Biomass Thermophotovoltaic Power Generation, C. M. Iftekhar Hussain Cmih, Aidan Duffy, Brian Norton
Conference Papers
The techno-economic parameters that influence the commercial deployment of hybrid thermophotovoltaic (TPV) solar power generation are determined using annual system simulations. It has been found that a TPV cell price of E5/cm2 or less together with a TPV operating temperature under 800°C is required for a hybrid solar–biomass TPV power plant to be economically competitive with the state-of-the-art hybrid solar–biomass Rankine cycle power plants.
The Feasibility Of Utilising Compressed Natural Gas As Part Of A Systematic Approach To Establishing The Necessary Groundwork For The Hydrogen Based Transport Economy, James Brunton, John Howlett, David Kennedy
The Feasibility Of Utilising Compressed Natural Gas As Part Of A Systematic Approach To Establishing The Necessary Groundwork For The Hydrogen Based Transport Economy, James Brunton, John Howlett, David Kennedy
Conference Papers
One key objective for vehicle manufacturers is to develop technology and infrastructure to facilitate the progression from combustion to conversion by the year 2050. In the short to medium term however, the combustion of fossil fuels such as petrol and diesel, coupled with advanced transmission innovations and emission control technology that are governed by strict Euro VI regulations appears to be the main path forward for the transport sector and the environment. This paper presents the feasibility of utilising the developing compressed natural gas network capabilities as part of a systematic approach to establishing the necessary groundwork for a hydrogen …
Available Work Rate Of A Reversible System Bounded By Constant Thermal Resistances Linked To Isothermal Reservoirs, Jim Mcgovern
Available Work Rate Of A Reversible System Bounded By Constant Thermal Resistances Linked To Isothermal Reservoirs, Jim Mcgovern
Conference Papers
Exergy analysis is based on the concept of an idealized, all-enclosing reference environment that has infinite heat capacity and thermal conductivity, and is in equilibrium. The actual surroundings of a real plant such as a heat engine, a heat pump or a refrigerator may differ significantly from the ideal. First law performance parameters and second law rational efficiency are examined. The concepts of finite time thermodynamics are applied in an attempt to refine the concept of T0, the environmental reference temperature, thereby making exergy analysis more reflective of reality.
A Simulation Analysis Of Photovoltaic Ac Module Integrated Converters In Parallel, Under Controlled Edge Shading Conditions, Lynette O'Callaghan, Mick Mckeever, Brian Norton
A Simulation Analysis Of Photovoltaic Ac Module Integrated Converters In Parallel, Under Controlled Edge Shading Conditions, Lynette O'Callaghan, Mick Mckeever, Brian Norton
Conference Papers
A DC and AC power simulation comparison of: a Photovoltaic (PV) array with a modular, parallel, AC converter configuration; and a series, string configuration with a central AC converter, is presented. The systems are simulated using a comprehensive range of edge shading scenarios and irradiance conditions. Power control and transformation circuitry must be designed for shade and module mismatch tolerance to prevent over-proportional power to shade losses, as average losses from Building Integrated PV (BIPV) systems are approximately 20 to 25%, due to shade, mismatch, differences in orientation and inclination, and temperature effects. 59.4% of the simulations showed gains in …
Analyse Du Comportement Réel Et De L'Optimisation Structurelle Des Cycles De Turbines À Gaz, Alexandru Dobrovicescu, Michel Feidt, Lavinia Grosu, Jim Mcgovern, Georgiana Tirca-Dragomirescu
Analyse Du Comportement Réel Et De L'Optimisation Structurelle Des Cycles De Turbines À Gaz, Alexandru Dobrovicescu, Michel Feidt, Lavinia Grosu, Jim Mcgovern, Georgiana Tirca-Dragomirescu
Conference Papers
L’article présente une étude comparative, basée sur l’analyse exégétique, de l’effet de non prise en considération du comportement réel de l’agent thermique et de l’utilisation des modèles simplifiés pour calculer les performances des cycles de turbines à gaz avec et sans récupération de chaleur. Un intérêt spécial a été réservé au processus de combustion et au transfert de chaleur dans le préchauffeur d’air. La variation des destructions et des pertes d’exergie par rapport à la variation des paramètres fonctionnels est présentée.
Investigation Into The Possible Benefits Of A Refrigeration Based Intercooling System, Ronan Kierans, Jim Mcgovern
Investigation Into The Possible Benefits Of A Refrigeration Based Intercooling System, Ronan Kierans, Jim Mcgovern
Conference Papers
This paper describes findings from analysis and simulation in relation to the possible benefits of applying refrigeration based intercooling to the engine of a modern passenger car or haulage vehicle. Initial theoretical analysis showed that, depending on the engine specifications and the boost pressure level of the turbo/supercharger, the power improvement could range from 15–30% and there would be a similar improvement in torque. This meant a smaller engine could be used to do the work of a larger engine. The power required to run the refrigeration system, the space required and the charge air pressure drop due to its …
Thermodynamic Optimisation Of The Otto / Stirling Combined Cycle, Barry Cullen, Michel Feidt, Jim Mcgovern, Stoian Petrescu
Thermodynamic Optimisation Of The Otto / Stirling Combined Cycle, Barry Cullen, Michel Feidt, Jim Mcgovern, Stoian Petrescu
Conference Papers
Combined cycle systems are an established method for increasing primary energy efficiency of power generation systems. Some ongoing research is concerned with investigating the novel combined cycle system involving the Otto and Stirling thermodynamic cycles. The Otto cycle is to act as the topping cycle, with the Stirling cycle acting to recover heat from the exhaust for the purpose of additional power generation. The present work investigates the thermodynamic optimisation of the combined cycle system for the case of the engines operating under two imposed parametric constraints: 1) imposed heat addition to the Otto cycle, and 2) imposed maximum cycle …
Validation Of A Simulation Model For A Combined Otto And Stirling Cycle Power Plant, Jim Mcgovern, Barry Cullen, Michel Feidt, Stoian Petrescu
Validation Of A Simulation Model For A Combined Otto And Stirling Cycle Power Plant, Jim Mcgovern, Barry Cullen, Michel Feidt, Stoian Petrescu
Conference Papers
A project has been underway at the Technological University Dublin (DIT) to investigate the feasibility of a combined Otto and Stirling cycle power plant in which a Stirling cycle engine would serve as a bottoming cycle for a stationary Otto cycle engine. This type of combined cycle plant is considered to have good potential for industrial use. This paper describes work by DIT and collaborators to validate a computer simulation model of the combined cycle plant. In investigating the feasibility of the type of combined cycle that is proposed there are a range of practical realities to be faced and …
Preliminary Modelling Results For An Otto Cycle/Stirling Cycle Hybrid-Engine-Based Power Generation System, Barry Cullen, Jim Mcgovern, Michel Feidt, Stoian Petrescu
Preliminary Modelling Results For An Otto Cycle/Stirling Cycle Hybrid-Engine-Based Power Generation System, Barry Cullen, Jim Mcgovern, Michel Feidt, Stoian Petrescu
Conference Papers
This paper presents preliminary data and results for a system mathematical model for a proposed Otto Cycle / Stirling Cycle hybrid-engine-based power generation system. The system is a combined cycle system with the Stirling cycle machine operating as a bottoming cycle on the Otto cycle exhaust. The application considered is that of a stationary power generation scenario wherein the Stirling cycle engine operates as a waste heat recovery device on the exhaust stream of the Otto cycle engine. This paper is primarily concerned with the development of a model for a suitable Stirling cycle engine capable of running on the …
Development Of A Theoretical Decoupled Stirling Cycle Engine, Barry Cullen, Jim Mcgovern
Development Of A Theoretical Decoupled Stirling Cycle Engine, Barry Cullen, Jim Mcgovern
Conference Papers
The Stirling cycle engine is gaining increasing attention in the current energy market as a clean, quiet and versatile prime mover for use in such situations as solar thermal generation, micro cogeneration and other micro distributed generation situations. A theoretical Stirling cycle engine model is developed. Using a theoretical decoupled engine configuration in which working space swept volume, volume variation, phase angle and dead space ratio are controlled via a black-box electronic controller, a model is developed that is to be used as a tool for analysis of the ideal Stirling cycle engine and the limits on its real world …
Economic And Environmental Performance Analysis Of Pv Systems For Domestic Applications In Ireland, Lacour Ayompe, Aidan Duffy, Sarah Mccormack, Michael Conlon
Economic And Environmental Performance Analysis Of Pv Systems For Domestic Applications In Ireland, Lacour Ayompe, Aidan Duffy, Sarah Mccormack, Michael Conlon
Conference Papers
Long-term monthly average daily solar radiation values on horizontal surfaces at 20 locations in Ireland were used to model the performance of a 1.72 kWp grid-connected PV system. Global solar radiation on horizontal surfaces varied between 865.1 and 1,127.9 kWh/m2/yr with a mean of 947.9 kWh/m2/yr. Annual energy yields varied between 869 and 1,156 960 kWh/kWp with a mean of 960 kWh/kWp. The capacity factor for the PV system varied between 9.9 and 13.2% while the mean was 11.0%. System cost parameters, long-term annual average electricity domestic rate cost escalation were used to calculate the Net Present Value (NPV), cost …
Modelling And Simulation Of A Biomass Gasification-Solid Oxide Fuel Cell Combined Heat And Power Plant Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy
Modelling And Simulation Of A Biomass Gasification-Solid Oxide Fuel Cell Combined Heat And Power Plant Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy
Conference Papers
In this paper the operation and performance of a high temperature solid oxide fuel cell (SOFC) stack on biomass syn-gas from a demonstration biomass gasification combined heat and power (CHP) plant is investigated. The objective of this work is to develop a computer simulation model of a biomass-SOFC CHP system, flexible enough for use in industry, capable of predicting system performance under various operating conditions and using diverse fuels. The biomass gasifier is of the dual fluidised bed (DFB) type with steam as the gasifying agent and is operated at atmospheric pressure. The tubular SOFC configuration, developed by Siemens Power …
Simulation Of A Circulating Fluidised Bed Biomass Gasifier Using Aspen Plus: A Performance Analysis, Wayne Doherty, Anthony Reynolds, David Kennedy
Simulation Of A Circulating Fluidised Bed Biomass Gasifier Using Aspen Plus: A Performance Analysis, Wayne Doherty, Anthony Reynolds, David Kennedy
Conference Papers
In the near future biomass gasification is likely to play an important role in energy production and conversion. Its application has great potential in the context of climate change mitigation, increasing efficiency and energy security. Atmospheric circulating fluidised bed (CFB) technology was selected for the current study. An original computer simulation model of a CFB biomass gasifier was developed using ASPEN Plus (Advanced System for Process ENgineering Plus). It is based on Gibbs free energy minimisation and the restricted equilibrium method was used to calibrate it against experimental data. This was achieved by specifying the temperature approach for the gasification …
Exergetic Cost Analysis Of A Mechanical Exergy Recycle, Jim Mcgovern
Exergetic Cost Analysis Of A Mechanical Exergy Recycle, Jim Mcgovern
Conference Papers
A mechanical plant that involves an exergy recycle is presented for analysis. It consists of gearboxes and a fluid coupling. There is one input of shaft power to the plant and there are three separate outputs of shaft power. An exergetic cost analysis approach is outlined and applied to the plant.
A Virtual-System Concept For Exergy Analysis Of Flow Network Plant; Part I: Principles, Jim Mcgovern, Francis O'Toole
A Virtual-System Concept For Exergy Analysis Of Flow Network Plant; Part I: Principles, Jim Mcgovern, Francis O'Toole
Conference Papers
A new type of virtual system, named a flow constraint system (FCS), is proposed to facilitate, clarify, and simplify exergy analyses of plant that involve material flow networks. The need for the virtual system is outlined and the concept is demonstrated by applying it to a CHP steam cycle. The FCS concept allows the physical constraints on the exergy interactions associated with flow streams to be taken into account fully. It also simplifies the treatment of bifurcations in material flows and considerably reduces the need for absolute exergy evaluations. The new concept follows from the work already published by the …
A Virtual-System Concept For Exergy Analysis Of Flow Network Plant; Part Ii: Exergetic And Exergonomic Analysis Illustration, Jim Mcgovern, Francis O'Toole
A Virtual-System Concept For Exergy Analysis Of Flow Network Plant; Part Ii: Exergetic And Exergonomic Analysis Illustration, Jim Mcgovern, Francis O'Toole
Conference Papers
This paper is a continuation of Part I — Principles, to which it refers extensively. The virtual system concept and the methodology introduced in Part I are illustrated by means of a numerical example. This is an exergetic and exergoeconomic analysis of the CHP steam plant that was described in Part I without operating values and parameters. Matrix methods developed by Valero et al. (1986) are adapted to the new concept. It is shown that these methods are made simpler and less subjective. Bond-graph-type diagrams for exergetic and economic costs are presented.
Heat Pump Research Programme At University College Dublin (1976), Seamus Timoney, Jim Mcgovern
Heat Pump Research Programme At University College Dublin (1976), Seamus Timoney, Jim Mcgovern
Conference Papers
This paper describes heat pump research at University College Dublin in 1976 relating to an air-to-air heat pump. The plant under test and its instrumentation are described and some measured performance data are presented. A heat pump simulation program is described. A theoretical comparison of refrigerants 12, 22 and 502 is presented with graphs of performance parameters as a function of operating conditions.