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Energy Recovery (energy + recovery)
Selected AbstractsFatigue life expenditure assessment and countermeasure for turbine blades due to harmonic excitations of slip energy recovery drivesEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 8 2009Jong-Ian Tsai Abstract The long-term effect of noncharacteristic harmonic currents arising from a slip energy recovery drive (SERD) on the fatigue life expenditure in turbine-generator blades is presented in this paper. Since the SERD converter can be rated at a fraction of a motor due to its static converter cascade with the wound-rotor and with high efficiency characteristics, still the feedwater pumps (FPs) in a few power plants are driven by such an induction motor (IM) drive. However, because the frequencies of the three main harmonic terms of the recovery currents are subsynchronous and offer a probability distribution due to the adjustable speed operation, a systematic fatigue estimation approach was devised by the author to investigate the long-term impact for the low-pressure (LP) turbine blades. From the simulation results, it was found that such a long-term harmonic excitation becomes a cause of turbine blade failure for single generator connected to the SERD system, even though the amplitude of these harmonic currents is normal. By the effect analysis of uncertainty, the countermeasure for the turbine integrity was then found. Copyright © 2008 John Wiley & Sons, Ltd. [source] Optimization study of large-scale low-grade energy recovery from conventional Rankine cycle power plantsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 12 2010K. M. Mohamed Abstract This study evaluates large-scale low-grade energy recovery (LS-LGER) from a conventional coal-fired Rankine cycle (RC) as a ,green' option to offsetting the cost of treating pollution. An energy and exergy analysis of a reference generating station isolates the key areas for investigation into LS-LGER. This is followed by a second law analysis and a detailed optimization study for a revised RC configuration, which provides a conservative estimate of the possible energy recovery. Cycle optimization based on specific power output, and including compact heat exchanger designs, indicates plant efficiency improvements (with high-capacity equipment) of approximately 2 percentage points with reduced environmental impact. Copyright © 2009 John Wiley & Sons, Ltd. [source] Life cycle assessment of a PPV plant applied to an existing SUW management systemINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2003Francesco Di Maria Abstract The huge amount of wastes produced by modern and developed countries involves important aspects of economical, social and technical fields and also of the environment. For this reason, different technologies have been proposed for trying to reduce the impact of waste management and disposal. Generally waste management system consists of different steps like selective collection, recycling and reuse operation, energy recovery from waste and landfilling. A new technology proposed for thermal waste treatment is the plasma pyrolysis vetrification (PPV). This system seems to have interesting perspective due to the possibility of thermal treatment of dangerous slag or waste producing inactivate vetrified substances that can be landfilled or used as building materials with no impact on the environment. In this study, the effect of the application of a PPV plant on an existing waste management system was evaluated with a life cycle assessment (LCA) analysis. All the activities connected to the existing system have been carefully analysed by collecting a large quantity of experimental data. Some assumptions have been made, in particular, on the PPV plant performance. LCA analysis results illustrate how the environmental benefits arising from the adoption of the new technology, concerns only few aspects of the whole system. Copyright © 2003 John Wiley & Sons, Ltd. [source] Heating and cooling energy recovery for an HVAC system: Economic analysis for the Italian climateINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 8 2001Adolfo Palombo Abstract In this paper the economic analysis of the energy recovery in all-outdoor-air HVAC systems for the Italian climate is performed. The energy recovery device considered here is the same for both heating and cooling periods. During the summer season, the energy saving is achieved by evaporative cooling. The performances of the hybrid innovative HVAC system and the traditional system are calculated hour by hour by following the test reference year (TRY) profile. Such analysis is carried out taking into account simultaneously, the trend of some climatic indexes computed in order to (i) better understand the influence of climate on the HVAC system behaviour, (ii) obtain a swift feasibility analysis of the energy recovery system and (iii) perform a rough operating cost estimate of the traditional HVAC system. Copyright © 2001 John Wiley & Sons, Ltd. [source] Strategies for Meeting EU End-of-Life Vehicle Reuse/Recovery TargetsJOURNAL OF INDUSTRIAL ECOLOGY, Issue 4 2006Paulo Ferrão Summary Disposal of end-of-life vehicles (ELVs) is a relatively new focus of the European policy community. Technical requirements for car design and minimum reuse and recovery rates for end-of-life vehicles are the subject of a recent European Union directive on ELVs. This directive is expected to induce changes in the infrastructure required for ELV processing, and presents a substantial challenge to maintaining such an infrastructure as economically viable. This paper assesses current and emerging ELV recycling technologies, in order to provide guidelines for the development of future ELV recycling strategies. Emphasis is given to technologies dedicated to automobile shredder residue (ASR) recovery, as an alternative/complement to more labor-intensive dismantling activities. The ultimate goal is to develop a vision of the type of ASR processing technology that could emerge in the future. The analysis is based on a model developed to simulate ELV processing infrastructures, and shredding data are taken from full-scale experiments. The results obtained show that ASR mechanical separation and recycling technologies may enable more extensive recycling and contribute to achieving European Union recycling targets, and can thus be considered as far more promising than technologies based on energy recovery. [source] Application of thermally sprayed coatings of the type WC/CoCr in reverse osmosis processes for seawater desalinationMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 11 2008A. Dwars Abstract Seawater desalination based on the reverse osmosis process requires a variety of hydraulic systems. The material concepts of these hydraulic systems are designed to reliably resist the corrosive properties of seawater and brine as well as the tribological loads. Strong tribological loads typically occur during the start-up and shutdown of multi-stage high-pressure pumps. Thermally sprayed coatings can be used to increase the wear resistance and also the tribological properties of bearings. Also in pressure exchangers for energy recovery, high tribological loads occur on the surfaces of rotors which operate with a clearance gap of 40,100 µm. Today, thermally sprayed coatings are used for the surface protection of these rotors. To resist the various tribological loads, the material pairs are optimized for each case. Thermally sprayed coatings with high surface hardness have proven to be particularly successful. A coating system, based on a CoCr matrix, has been developed especially for these applications. [source] Treatment of cow-waste slurry by a microbial fuel cell and the properties of the treated slurry as a liquid manureANIMAL SCIENCE JOURNAL, Issue 6 2006Hiroshi YOKOYAMA ABSTRACT Resource recycling and the proper treatment of animal waste to reduce its environmental impact are currently important issues for the livestock industry. A microbial fuel cell (MFC), a new type of bioreactor, is expected to play roles in both waste-water purification and energy recovery. However, the generation of electricity from cow waste has not yet been examined. In this study, using an MFC, we examined the possibility of generating electricity from dairy-cow waste slurry, and analyzed the properties of the treated slurry as liquid manure for resource recycling. The MFC treatment of the slurry generated electricity in a dose-dependent manner, and the maximum power output by the MFC from a 1 g of chemical oxygen demand/L slurry was 0.34 mW/m2. After the MFC treatment, 84% of the biological oxygen demand in the slurry was removed and three essential fertilizer elements (nitrogen, phosphorus, and potassium) were retained at 84, 70, and 91% levels, respectively. The amount of ammonia nitrogen in the slurry, as an element of fast-release fertilizer, was increased by 1.9-fold. Although the treated slurry displayed properties that made it preferable as liquid manure, further studies to improve the electrical power output by the MFC are required for practical use. 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