Search results for "Boiler"

Introducing exergy analysis in life cycle assessment: A case study

2018

Life Cycle Assessment (LCA) is a methodology for assessing the potential environmental aspects associated with a product or service along its life cycle. However, in the case of energy technologies, it is suggested that the LCA of a product encompasses also further aspects other than environmental aspects and primary energy calculations. In particular, to optimize the reduction of raw materials during the whole life cycle, it is important to introduce the assessment of the irreversibility, applying the exergy analysis. In this paper, an integrated approach of exergy analysis and LCA is proposed, developing the Life-cycle quality index able to suggest potential exergy inefficiencies and the …

Towards controlling PCDD/F production in a multi-fuel fired BFB boiler using two sulfur addition strategies. Part I: Experimental campaign and results

2014

Abstract Levels of PCDD/F production in a 140 MW th bubbling fluidized bed boiler were measured. The boiler uses solid recovered fuel, bark and sludge. Homologue distribution patterns suggest the de novo mechanism is the main pathway for the generation of dioxin and furans in the post combustion zones of the boiler. Two modes of sulfur addition were tested to induce the deactivation of Cu which has been identified as the prime catalyst of this mechanism. First, S-pellet promoted Cu sulfation as supported by aerosol sampling data and resulted in a decrease in PCDD/F levels. The second approach was adding sulfur through peat; this resulted in an increase in PCDD/F concentration. Factors such …

Constructal law optimization of a boiler

2017

The paper aims at the optimization of the design of a biomass boiler under the inspiration of the Constructal Law by Bejan. The boiler is of the smoke tubes typology, fuel being biomass pellets. The smoke tubes are 16 and are placed in a staggered configuration. A model is built in MATLAB environment, based on empirical correlations and the mean log temperature methodology. The analysis is based on the development of a wide parametric analysis that involves variations of diameters, numbers and positioning of the tubes. Results are based on the concept of the overall performance coefficient methodology and investigate both the pressure drops variation and the thermal power generated in the d…

A Constructal Law optimization of a boiler inspired by Life Cycle thinking

2018

Abstract The aim of the paper is to explore how design optimization contributes to a technology's ecological evolution. The article develops this concept through an application of Constructal Law, used to account for the “evolution” of technologies design (configuration, shape, structure, pattern, rhythm), and Life Cycle Assessment (LCA), used for quantifying the environmental impacts of the design choices. The combination of both methods assesses how technology evolution affects the environment during its life, extending the concept of evolution of design. The study is applied to a case study of a real biomass boiler. The study analyses basic case and a series of alternative scenarios opti…

Online mass flow prediction in CFB boilers with explicit detection of sudden concept drift

2010

Fuel feeding and inhomogeneity of fuel typically cause fluctuations in the circulating fluidized bed (CFB) process. If control systems fail to compensate the fluctuations, the whole plant will suffer from dynamics that is reinforced by the closed-loop controls. This phenomenon causes reducing efficiency and the lifetime of process components. In this paper we address the problem of online mass flow prediction, which is a part of control. Particularly, we consider the problem of learning an accurate predictor with explicit detection of abrupt concept drift and noise handling mechanisms. We emphasize the importance of having domain knowledge concerning the considered case and constructing the…

Preliminary Thermo-Mechanical Design of the Once Through Steam Generator and Molten Salt Intermediate Heat Exchanger for EU DEMO

2020

The European DEMOnstration power plant (DEMO) is considered to be the nearest-term fusion reactor capable of producing several hundred MWs of net electricity, operating with a closed tritium fuel-cycle (achieving the tritium self-sufficiency), and qualifing technological solutions for a fusion power plant with different breeding blanket (BB) concepts that are under investigation. The BB is a key component for the development of the DEMO plant design and, in particular, of those systems having the responsibility to remove the plasma-generated thermal power and its conversion in the electrical energy. This study deals with the preliminary thermo-mechanical design of the heat exchangers and st…

Sensitivity Analysis of the MASLWR Helical Coil Steam Generator Using TRACE

2011

Accurate simulation of transient system behavior of a nuclear power plant is the goal of systems code calculations, and the evaluation of a code's calculation accuracy is accomplished by assessment and validation against appropriate system data. These system data may be developed either from a running system prototype or from a scaled model test facility, and characterize the thermal hydraulic phenomena during both steady state and transient conditions. The identification and characterization of the relevant thermal hydraulic phenomena, and the assessment and validation of thermal hydraulic systems codes, has been the objective of multiple international research programs. The validation and…

ONLINE GAMBLING CONTRACTS AS NEW FRONTIERS OF INTERNATIONAL CONSUMER TRANSACTIONS

2016

The Protection of the Weaker Parties in the Platform Economy

2018

Known by many names – platform, sharing, peer-to-peer (p2p), collaborative economy, and so on - entirely new business models have emerged in recent years, whereby online platforms use digital technologies to connect distinct groups of users in order to facilitate transactions for the exchange of assets and services. This dramatic shift in business organisation and market structure has opened an intense debate on the persisting need for those regulatory measures that typically protect the weaker party in bilateral business-to-consumer transactions. Widespread calls for a more “levelled playing field” makes a strong argument for reconsidering the scope of regulation and delegating regulatory …

Electrical hybrid heat pumps assisted by natural gas boilers: a review

2022

In this paper, a comprehensive review is performed on hybrid systems using electrical Heat Pumps for Heating, Ventilation & Air Conditioning systems and Domestic Hot Water production using case studies from 2016 to 2022. This work particularly focuses on studies that investigated systems with electrical Heat Pumps assisted by a gas boiler. Some studies that considered the exploitation of renewable energy sources, but not as a whole sub-stitute for fossil sources, have also been included. In particular, the analysis investigated the layouts of the systems by considering the type and the size of the components, the control methods applied (by distinguishing rule-based control methods and …