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In this paper, the effect of hydrogen (H2) addition on the pollutant emissions of an IDF (inverse diffusion flame) burning LPG (liquefied petroleum gas) has been studied. Pollutant emission behavior was intensively investigated at fuel lean condition, and CO2, CO, HC, and NOx emitted from the flame were measured with their emission indices reported. HC and CO emissions are highly dependent on overall...
A fluctuating inflow around the surface of rotor blade in the spanwise direction presents a more significant challenge in the performance of wind turbine. In this paper, three-dimensional (3D) experimental and computational investigations of a straight-bladed VAWT (Vertical Axis Wind Turbine) are proposed and analyzed with two straight blades. In wind tunnel experiments, LDV (Laser Doppler Velocimeter)...
This paper proposes a novel framework for modeling electricity loads; it can be used for both forecasting and analysis. The framework combines the EnKF (ensemble Kalman filter) technique with shrinkage/multiple regression methods. First, SSMs (state-space models) are used to model the load structure, and then the EnKF is used for the estimation. Next, shrinkage/multiple linear regression methods are...
Nanocrystalline MgH2 powders were synthesized by reactive ball milling of elemental Mg powders milled for 200 h under a high hydrogen gas pressure of 50 bar. The end-product obtained after 200 h of milling was contaminated (∼2.3 wt.%) with the materials (Fe–12Cr stainless steel). In order to improve the hydrogenation/dehydrogenation kinetics of metal hydride powders, the as-synthesized MgH2 was doped...
Experiments on the performance of ground-source heat exchangers using short residential foundation piles were performed in Saga, Japan. U-tube, double-tube, and multitube heat exchangers were installed in the ground to depths of 20 m. Water was used as the working fluid. Temperatures were measured on pipe walls, pile walls, and in the ground. From the measured data, thermal resistances of pipes, grout,...
In this work, hydrate-based CO2 removal from a CH4/CO2 mixture was studied. CH4/CO2 led to faster hydrate formation than pure CH4, because the existence of CO2 resulted in easier hydrate nucleation. Kinetic separation of CO2 was observed in the CH4/CO2 hydrate formation with different initial CO2 proportions (1.83–27.76%) due to the higher CO2 affinity of formation of hydrates. However, the initial...
Constructal theory is introduced into the hot metal yield maximization of the blast furnace in this paper. Generalized constructal optimization of a blast furnace is performed for a specified total raw material cost. The optimal distribution of each raw material cost in the total cost, namely “generalized optimal construct”, is obtained. Besides, the optimal charge composition of the blast furnace...
Due to the rapid development of renewable energy and waste energy recovery, absorption energy storage is an important technology with promising future. However, because most researches focus on working fluid flow rather than energy flow used in electric power systems, it is hard to analyze the entire systems as a whole. This contribution introduces the electrical circuit analogy to analyze absorption...
The lift to drag ratio is the most determining factor in power efficiency of wind conversion systems such as wind turbines. The lift to drag ratio can be enhanced considerably using circulating airfoil shapes. In this research, the NACA0021 airfoil is modified and manufactured to form a treadmill like circulating shape. Aerodynamic performance of the treadmill shape is computationally and experimentally...
In recent years, haze becomes a choking problem in northern China in winter. A HRV (heat recovery ventilator) is an effective device to provide clean indoor environment by supplying fresh outdoor air to residential and commercial buildings, but the HRV system must be combined with an air filter to remove the fine particular matter of the outdoor air. There is limited information regarding this integrated...
For efficient thermal management in the building under hot weather condition a new paraffin composition as suitable PCM is needed. Several notable attributes of paraffin wax including thermo-physical properties, open air atmospheric condition, economy, and environmental amiability make them suitable PCM for incorporation in the building. Thus, new PCM with massive storage of heat or cold in a specific...
In this study, we explored the effects of different design strategies on final and primary energy use for production and operation of a newly constructed apartment building. We analysed alternatives of the building “As built” as well as to energy efficiency levels of the Swedish building code and passive house criteria. Our approach is based on achieving improved versions of the building alternatives...
We explore theoretically a thermodynamic heat-engine concept that has the potential of attaining a high efficiency and power density relative to competing solutions, while having a simple construction with few moving parts and dynamic seals, allowing low capital and operating costs, and long lifetimes. Specifically, an unsteady heat-engine device within which a working fluid undergoes a power cycle...
Hydraulic turbines are designed for the given values of head, discharge and speed but mostly operate at off designed head and discharge values. Due to variation in head, operating parameters like speed and discharge coefficients are changed affecting the flow and efficiency characteristics of turbine. This makes customary to assess the turbine performance at different operating parameters. Pelton...
The gasification of MSW (municipal solid wastes) using CO2 as a gasifying agent has been object of growing interest in recent years. Although quite limited, studies have shown that CO2 can behave as a catalyst and accelerate the thermal cracking of volatiles as well as minimize tar formation, and even give a positive contribute to environment. Despite these promising features, it is still necessary...
In this paper, ceria was proposed as a candidate material of membrane reactor for solar fuel production. A thermodynamic model of the membrane reactor system based on ceria with heat recovery was established and solar-to-fuel efficiency of both inert gas-assisted and pump-assisted CO2 splitting was calculated under a broad range of conditions. For system using inert gas, gas heat recovery is the determining...
A thermally stable and self-sustainable portable energy conversion system is designed using low temperature thin film SOFCs (solid oxide fuel cells). Hydrogen and air gases are fed into this system, which is successfully operated at 319 °C. Each cell, comprised of Pt (anode)/YSZ-GDC-YSZ/Pt (cathode), is manufactured using sputtering and atomic layer deposition, and the area of a single cell is 2.56 cm...
The global economy has witnessed a concurrent rise in oil prices and agricultural commodities prices and this has generated interest in understanding the energy-food nexus. Many studies have attributed the rise in agricultural commodity prices to the role of world oil prices. Similar to global oil prices, South Africa experienced a surge in agricultural commodity prices from 2004 and reached a peak...
This paper presents a new framework for congestion management utilizing a reliability model of demand response resources under the smart grid environment. Demand response resources modeling is highly appertaining to uncertainty of customer's behavior. Interval data which is a core deliverable of advanced metering infrastructure, is essential for customers to participate in demand response events....
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