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The world is presently confronted with the twin crisis of fossil fuel depletion and environmental degradation. Indiscriminate extraction and lavish consumption of fossil fuels have led to reduction in underground based carbon resources. The search for an alternative fuel, which promises a harmonious correlation with sustainable development, energy conservation, management, efficiency, and environmental...
The objectives of this study are (a) development of optimized regression and ANN (artificial neural network) models for EEC (electrical energy consumption) forecasting based on several optimization methodologies, (b) examination of the effects of different historical data types on accuracy of EEC forecasting, and (c) long-term EEC forecasting for Iran and the U.S. as developing and developed economies,...
In this paper, thermodynamic calculations of nozzle governing stage are taken based on APROS (Advanced Process Simulation), and verify through the comparison of experiment table data. The influence of partial admission on pressure ratio within the governing stage is also analyzed. The results show that partial admission not only leads to partial admission losses, but also makes an impact on pressure...
Barriers to energy efficiency have been extensively discussed in the energy literature, but little is known about positive drivers. This paper investigates the role of top managers and more specifically of top operations managers on the adoption of energy-efficiency practices, based on 5779 energy efficiency recommendations made to 752 small and medium-sized manufacturing firms under the US Department...
This work for the first time uses a three-dimensional multi-physics model to optimize the performance of three kinds of two-stage TECs, connected electrically in series, in parallel, and separated, respectively. The optimizations are performed for the two-stage TEC with 30 thermoelectric elements. The number ratio and current ratio are searched to reach the optimal cooling capacity, COP, and maximum...
Concerning food security, China has launched non-grain fuel ethanol projects with potential land. However, there are concerns and facts, such as feedstock price rise, regarding its implications on quantity of food supply and food price. The study aims to better understand the impacts of expanding non-grain fuel ethanol on food price, supply and consumption using a CGE (computable general equilibrium)...
To explain the time dependence of cell voltage in CWS (coal water slurry) electrolysis, the effects of three coal types along with graphite, CWS concentration and catalysts on cell voltage are examined. Results show that the overall cell voltage for CWS electrolysis is lowered as coal rank decreases. The four overall types carbonaceous material show successive reductions in Uθ + η for CWS electrolysis...
The problems aided with wind turbine noise have been one of the more studied environmental influence areas in wind energy engineering. Noise levels can be measured, but, similar to other environmental attentions, the public's perception of the noise impact of wind turbines is in part a subjective determination. The author investigated in this work the aerodynamic acoustics of one type of the VAWT...
This paper presents an updated historic oil production analysis as well as an updated future oil production forecast for Norway and Denmark. Previous forecasts conducted by academic and official agencies using a variety of methodologies are contrasted and their accuracy examined. The bottom-up field-by-field methodology is found to be precise in the short-term, as it deviates by less than 1% from...
A comparative study is performed to obtain the energy performance of four different photovoltaic module technologies, when they are exposed to the same real sun conditions over a one-year period under the meteorological conditions of Southern Spain. Modules of thin film technologies were analysed: amorphous silicon (a-Si), tandem structure of amorphous silicon and microcrystalline silicon (a-Si/μc-Si)...
Energy and exergy performance of adsorption storage system was studied experimentally for residential application. A fin-coated heat exchanger was adopted for a sorption bed to quicken the charging process. When the regeneration temperature was 70 °C, ambient temperature was 30 °C, HTF (heat transfer fluid) inlet temperature for the adsorption bed was 30 °C, results showed that the heat ESD (energy...
A two-dimensional cross-flow tube bank heat exchanger arrangement problem with internal laminar flow is considered in this work. The objective is to optimize the arrangement of tubes and find the most favorable geometries, in order to simultaneously maximize the rate of heat exchange while obtaining a minimum pressure loss. A systematic study was performed involving a large number of simulations....
This study aims at comparing the performance of honeycomb type adsorbent beds (or desiccant wheels) for air dehumidification with various solid desiccant wall materials, from a viewpoint of system operation. A mathematical model is proposed and validated to predict the cyclic behaviors of the cycling beds or wheels. The influences of regeneration air temperature, process air temperature, and humidity...
We report a LDC (load duration curve) method to determine the optimum size of CHP (combined heat and power) units. The method gives the appropriate capacity graphically from the LDC of a building's heating demand. The method can be applied to the most common CHP units that are connected to the electrical grid, installed with thermal storage and auxiliary heat sources, and operated by a traditional...
Direct liquid-immersion cooling of solar cells using dimethyl silicon oil is proposed as a heat dissipation solution for linear CPV (concentrating photovoltaic) systems. To reduce the liquid holdup, a narrow rectangular channel receiver was designed and its heat transfer performance was investigated experimentally at an energy flux ratio of 9.1 suns. Long-term stability of mono-crystalline concentrator...
In this work an estimation and comparison of the technical and sustainable potentials of EGS (Enhanced Geothermal Systems) in Europe is presented. The temperatures at depths of (3500–9500) m were firstly calculated from the available data of temperatures at surface, 1000 m and 2000 m depth, and heat flow. Next the available thermal energy stored in each 1000 m thick layer along the considered depths...
In this experimental research, the exergy recovery from a DI Diesel engine is investigated where a turbocharged OM314 DIMLER diesel engine was tested at various engine speeds (1200, 1400, 1600, 1800 and 2000 rpm) and torques (20, 40, 60, 80 and 100 N m). For this aim, a double pipe heat exchanger with counter current flow is used in the exhaust of engine. As an important outcome, by increasing the...
The mineral carbonation of FGD (flue gas desulfurization) gypsum was carried out through CO2 sorption into ammonia solution containing FGD gypsum. High-purity calcium carbonate was precipitated from DCC (dissolved calcium carbonate) solution which was extracted during the induction period. The factors affecting the preparation of pure calcium carbonate were examined under the following conditions:...
The index of TFEE (total-factor energy efficiency) is used to assess the level of energy consumption to produce economic output (GDP (gross domestic product)) based on multi factors input, which is superior to conventional energy efficiency evaluation regarded as a partial-factor energy efficiency index. The objective of this study is to provide the changes of TFEE at sector and provincial level and...
MES (multi-energy systems) whereby electricity, heat, cooling, fuels, transport, and so on optimally interact with each other at various levels (for instance, within a district, city or region) represent an important opportunity to increase technical, economic and environmental performance relative to “classical” energy systems whose sectors are treated “separately” or “independently”. This performance...
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