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Energy storage is important for renewable energy systems. Compressed air storage is an attractive alternative to pumped water storage. It is suitable for use with wind-energy systems. We have studied a system consisting of a wind turbine, compressor, storage tank, and air-lift pump. The output power and capacity factor were accurately determined. Characteristics of the air-lift pump were investigated...
A finite-difference procedure is presented for solving unsteady, three-dimensional heat-transfer problems for cooling buildings by the use of cold water flowing within regularly arranged pipes embedded in the ceiling slab. Our procedure is based on solution of the three differential equations for heat conduction within the ceiling slab, convection cooling with water and the indoor energy balance...
In order to counter worsening air pollution in Turkey caused by increasing energy demands, an experimental study has been undertaken at the TUBITAK-Marmara Research Centre to determine possibilities of using energy-friendly plant sweet sorghum as an alternative fuel. The fuel properties of sweet sorghum have been compared with those of various Turkish lignites in terms of emission of polluting gases...
Solar energy was utilized as a clean renewable heat source for operation of a multi-stage flash (MSF) distillation system in Benghazi to produce distilled water. The optimum T h for operation of the MSF system with a typical flat-plate collector is 80°C; 1 m 2 of a flat-plate collector produces annually 8.2 m 3 of distilled water at T h = 80°C. When 1 m 2 ...
The most common sea water desalination systems available today are described. These are divided into two broad categories, namely, direct and indirect collection systems. In the former, solar energy is absorbed and used in the same piece of equipment whereas in the latter, two separate sub-systems are used, one for solar energy conversion and one for desalination. Various systems are analysed with...
We address the fundamental problem of determining the optimal history (regime of operation) of a battery so that the work output is maximum. The essential features of the problem are: (i) the life of the battery is constrained, (ii) the battery has an internal resistance through which it can lose its charge even at open circuit, and (iii) the battery is connected to an electric motor with finite...
The effect of water film cooling of the glass cover on the efficiency of a single-basin still has been investigated numerically. Proper use of the film-cooling parameters may increase the still efficiency by up to 20%. On the other hand, a poor combination of these parameters leads to a significant reduction in efficiency. The presence of the cooling film neutralizes the effect of wind speed on...
A recently developed thermal energy recycling unit operating under forced air circulation was attached to a conventional, basin-type solar still to enhance overall still productivity. In this unit, a relatively large fraction of the latent heat of condensation of the distillate is utilized to preheat and evaporate the feedstock. The system performance was tested in the laboratory using a solar simulator...
This paper examines the technologies, energy use and environmental pollution of brickmaking in China. China's brick industry is characterized by its enormous size and large number of small producers with outdated technologies. More than 90% of the bricks are fired in annular kilns with coal as the predominant fuel, resulting in substantial SO 2 , CO 2 and other air emissions. Based...
The feasibility of effective cooling using two solid-gas reactors has been tested experimentally with a low-power machine. The ambient temperature was 313 K. The power output of the reactors has been determined as a function of cooling temperature for air conditioning and refrigeration. REfrigeration requires a heat-transfer fluid temperature of 273 K, while air conditioning of buildings requires...
An IRWTHS may be treated as a combined cycle of a finite-size irreversible Carnot heat engine driving an irreversible Carnot refrigerator. This system is analyzed using finite-time thermodynamics. The combined effects of finite-rate heat transfer and internal dissipation on optimal performance have been investigated.
The weaknesses of the traditional measure of national output are well known and, in recent years, efforts to find more appropriate alternatives have intensified. One such methodology is the PPP approach which may capture the real value of the GDP. In general, this approach raises the incomes of developing countries by a substantial amount, and this has serious implications for energy indicators on...
To mitigate global warming, we have proposed the GLAD (Gas-Lift Advanced Dissolution) system for CO 2 release into deep seawater. It is an inverse-J pipeline set in the sea at a depth of 200-400m. CO 2 bubbles injected into the pipe form a buoyant plume and dissolve into the seawater as they rise. This dense solution is released from the other side of the pipe. The feasibility...
The mitigation of atmospheric greenhouse gas emissions is important for minimizing the anthropogenic contributions to climate change. These concerns have led to the investigation of many technologies and strategies for mitigation, both in the U.S. and abroad. One technology explored at ANL is integrated gasification combined cycle (IGCC) power generation, which is based on extraction of CO 2...
Data needed for evaluation of ocean CO 2 -sequestering technologies include the solubility of CO 2 and density of CO 2 hydrate at 30 MPa. Theses were measured using a high-pressure facility suitable for simulating pressure and temperature conditions 3000 m beneath the ocean surface. The solubility decreases linearly with decreasing water temperature, which is opposite to...
Catalytic reduction of CO 2 with H 2 was studied on Ni/SiO 2 , Ni 1-x Cu x /SiO 2 (x =0.05-0.9) and Cu/SiO 2 in a closed circulating reaction system in order to obtain a highly active and selective catalyst for CO formation. The yield of CO from CO 2 + H 2 on Cu/SiO 2 was about 60% and its selectivity was 97%...
A theoretical investigation has been conducted into the effect of hydrates on the instability of liquid CO 2 jets in the deep ocean. It is shown that the effect of hydrates on instability of a liquid CO 2 jet depends on the relative magnitudes of the hydrate-formation time, t f , at which the CO 2 -seawater interface is covered entirely with hydrates and of the jet-breakup...
The cyanobacterium Anacystis nidulans R2 is a photosynthetic procaryote grown only under inorganic carbon conditions. We studied cell-growth (CO 2 -removal) characteristics of this strain, cultivated photoautotrophically at 30°C in 1.1 dm 3 in airlift bioreacters. The highest growth rate of 0.046 h -1 was achieved when the culture was illuminated at 8 klx and sparged...
Microscopic observations of the liquid CO 2 -water-CO 2 -hydrate system were conducted to measure both the interfacial tensions in these phases and the strength of the CO 2 -hydrate film. Measurements on hanging drops revealed that the interfacial tension between liquid CO 2 and water decreased slightly as the temperature was raised from 266.3 to 284.9 K, and that...
We propose a new and innovative gas-turbine system using fuel-rich hydrogen combustion, which we call a chemical gas-turbine system. It involves a fuel-rich hydrogen-air combustor as a major component. We have focused on a coaxial diffusion flame under normal pressure. The effects of equivalence ratio and swirl number have been investigated by measuring temperature profiles, gas compositions, and...
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