WorldWideScience

Sample records for air cooled slagging

  1. NONEQUILIBRIUM SULFUR CAPTURE & RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

    Energy Technology Data Exchange (ETDEWEB)

    Bert Zauderer

    2003-04-21

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. The reacted particles impact and melt in the liquid slag layer on the combustor wall by the centrifugal force of the swirling combustion gases. Due to the low solubility of sulfur in slag, it must be rapidly drained from the combustor to limit sulfur gas re-evolution. Prior analyses and laboratory scale data indicated that for Coal Tech's 20 MMBtu/hour, air-cooled, slagging coal combustor slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to validate this sulfur-in-slag model in a group of combustor tests. A total of 36 days of testing on the combustor were completed during the period of performance of this project. This was more that double the 16 test days that were required in the original work statement. The extra tests were made possible by cost saving innovations that were made in the operation of the combustor test facility and in additional investment of Coal Tech resources in the test effort. The original project plan called for two groups of tests. The first group of tests involved the injection of calcium sulfate particles in the form of gypsum or plaster of Paris with the coal into the 20 MMBtu/hour-combustor. The second group of tests consisted of the entire two-step process, in which lime or limestone is co-injected with coal and reacts with the sulfur gas released during combustion to form calcium sulfate particles that impact and dissolve in the slag layer. Since this sulfur capture process has been validated in numerous prior tests in this combustor, the primary effort in the present project was on achieving the high slag flow rates needed to retain the sulfur in the slag.

  2. Physical Properties of Crushed Air-cooled Blast Furnace Slag and Numerical Representation of Its Morphology Characteristics

    Institute of Scientific and Technical Information of China (English)

    WANG Aiguo; DENG Min; SUN Daosheng; LI Bing; TANG Mingshu

    2012-01-01

    Physical properties and geometrical morphologies of crushed air-cooled blast furnace slag (SCR) and crushed limestone (LCR) were comparatively investigated.The shape,angularity,surface texture and internal pore structure of aggregate particles for different size and gradation were numerically represented by sphericity (ψ) and shape index (SI),angularity number (AN),index of aggregate particle shape and texture (IAPST),porosity and pore size,respectively.The results show that SCR is a porous and rough aggregate.Apparent density,void,water absorption and smashing index of SCR are obviously higher than those of LCR with the same gradation,respectively.However,bulk density of SCR is lower than that of LCR with the same gradation.SI,AN,IAPST and porosity of SCR are obviously higher than those of LCR with the same gradation,respectively.The smaller particle size of SCR,the larger of its AN,IAPST and porosity.

  3. Effect of Al2O3 mole fraction and cooling method on vitrification of an artificial hazardous material. Part 1: variation of crystalline phases and slag structures.

    Science.gov (United States)

    Kuo, Yi-Ming; Huang, Kuo-Lin; Wang, Chih-Ta; Wang, Jian-Wen

    2009-09-30

    This study investigated how Al ions affect slag structure. During vitrification, pure Al(2)O(3), CaO, and SiO(2) served as the encapsulation phases with the use of Al mol% as an operating parameter. All specimens with the same basicity (mass ratio of CaO to SiO(2)) of 2/3 were vitrified at 1400 degrees C and cooled by air cooling or water quenching. XRD was used to measure the volume fractions of crystalline and amorphous phases. In a non-Al environment, CaSiO(3) was formed in air-cooled and water-quenched slags. With the addition of Al(2)O(3), no crystalline phases were observed in water-quenched slags. With the increase of Al mol% in specimens, the Al ions in air-cooled slags initially acted as an intermediate linking one tetrahedron chain to another and reducing the amount of crystalline phase, then behaved as a network former making the slags amorphous, and finally replaced Si ions in silicate frames to generate a large amount of CaAl(2)Si(2)O(8). Air cooling improved the formation of crystallize structures with more leachable metal ions. A highly crystallized Al-framed structure is not suitable for encapsulating hazardous metals in vitrified slags. PMID:19428182

  4. Effect of High Cooling Rates on the Mineralogy and Hydraulic Properties of Stainless Steel Slags

    Science.gov (United States)

    Kriskova, Lubica; Pontikes, Yiannis; Pandelaers, Lieven; Cizer, Özlem; Jones, Peter Tom; Van Balen, Koen; Blanpain, Bart

    2013-10-01

    This article investigates the effect of chemical composition and cooling rate during solidification on the mineralogy and hydraulic properties of synthetic stainless steel slags. Three synthetic slags, covering the range of typical chemical composition in industrial practice, were subjected to high cooling rates, by melt spinning granulation or quenching in water, and to low cooling rates, by cooling inside the furnace. Both methods of rapid cooling led to volumetrically stable slags unlike the slow cooling which resulted in a powder-like material. Stabilized slags consisted predominantly of lamellar β-dicalcium silicate ( β-C2S) and Mg, Ca-silicates (merwinite and bredigite); the latter form the matrix at low basicity and are segregated along the C2S grain boundaries at high basicities. Slowly cooled slags consist of the γ-C2S polymorph instead of the β-C2S and of less Mg, Ca-silicates. Isothermal conduction calorimetry and thermogravimetric analysis indicate the occurrence of hydration reactions in the stabilized slags after mixing with water, while calcium silicate hydrates (C-S-H) of typical acicular morphology are identified by SEM. The present results demonstrate that the application of high cooling rates can result in a stable, environmental-friendly, hydraulic binder from stainless steel slags, rich in β-C2S, without the necessity of introducing any additions to arrest the β polymorph.

  5. Effect of the cooling rate on the phase composition and structure of copper matte converting slags

    Science.gov (United States)

    Selivanov, E. N.; Gulyaeva, R. I.; Udoeva, L. Yu.; Belyaev, V. V.; Pankratov, A. A.

    2009-08-01

    The effect of the cooling rate on the phase composition and microstructure of copper matte converting slags is studied by X-ray diffraction, combined thermogravimetry and calorimetry, mineragraphy, and electron-probe microanalysis. The compositions of oxide and sulfide phases are determined, and the forms of nonferrous metals in slags cooled at a rate of 0.3 and 900°C/s are revealed. At high cooling rates of the slags, iron silicate glass is shown to form apart from sulfide phases. Repeated heating of the slags leads to the development of devitrification, “cold” crystallization, and melting. A decrease in the cooling rate favors an increase in the grain sizes in oxides (magnetite, iron silicates) and sulfides (bornite-, sphalerite, and galena-based solid solutions).

  6. Application of finite difference techniques to the thermal analysis of the cooling of a slag casting

    International Nuclear Information System (INIS)

    It has been proposed to dispose of low grade radioactive waste by reducing it, through pyrolysis, to an inert slag. In this analysis, finite difference techniques are used to predict the cooling of a cylindrical slag casting which is initially in the molten state at 1425 C. The casting cools primarily by thermal radiation and the variation of physical properties with temperatures was included. Two mold designs were considered, a stainless steel mold and a stainless-steel mold with a silicon carbide lining. 4 refs

  7. Natural Flow Air Cooled Photovoltaics

    Science.gov (United States)

    Tanagnostopoulos, Y.; Themelis, P.

    2010-01-01

    Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. We performed experiments using a prototype based on three silicon photovoltaic modules placed in series to simulate a typical sloping building roof with photovoltaic installation. In this system the air flows through a channel on the rear side of PV panels. The potential for increasing the heat exchange from the photovoltaic panel to the circulating air by the addition of a thin metal sheet (TMS) in the middle of air channel or metal fins (FIN) along the air duct was examined. The operation of the device was studied with the air duct closed tightly to avoid air circulation (CLOSED) and the air duct open (REF), with the thin metal sheet (TMS) and with metal fins (FIN). In each case the experiments were performed under sunlight and the operating parameters of the experimental device determining the electrical and thermal performance of the system were observed and recorded during a whole day and for several days. We collected the data and form PV panels from the comparative diagrams of the experimental results regarding the temperature of solar cells, the electrical efficiency of the installation, the temperature of the back wall of the air duct and the temperature difference in the entrance and exit of the air duct. The comparative results from the measurements determine the improvement in electrical performance of the photovoltaic cells because of the reduction of their temperature, which is achieved by the naturally circulating air.

  8. Resistance of Alkali Activated Water-Cooled Slag Geopolymer to Sulphate Attack

    Directory of Open Access Journals (Sweden)

    S. A. Hasanein

    2011-06-01

    Full Text Available Ground granulated blast furnace slag is a finely ground, rapidly chilled aluminosilicate melt material that is separated from molten iron in the blast furnace as a by-product. Rapid cooling results in an amorphous or a glassy phase known as GGBFS or water cooled slag (WCS. Alkaline activation of latent hydraulic WCS by sodium hydroxide and/or sodium silicate in different ratios was studied. Curing was performed under 100 % relative humidity and at a temperature of 38°C. The results showed that mixing of both sodium hydroxide and sodium silicate in ratio of 3:3 wt.,% is the optimum one giving better mechanical as well as microstructural characteristics as compared with cement mortar that has various cement content (cement : sand were 1:3 and 1:2. Durability of the water cooled slag in 5 % MgSO4 as revealed by better microstructure and high resistivity-clarifying that activation by 3:3 sodium hydroxide and sodium silicate, respectively is better than using 2 and 6 % of sodium hydroxide.

  9. Experimental study on sulfur removal from ladle furnace refining slag in hot state by blowing Air

    Institute of Scientific and Technical Information of China (English)

    Li-hua Zhao; Lu Lin; Qi-fan Wu

    2016-01-01

    In view of the present problem of sulfur enrichment in the metallurgical recycling process of ladle furnace (LF) refining slag, a simple and efficient method of removing sulfur from this slag was proposed. The proposed method is compatible with current steelmaking processes. Sulfur removal from LF refining slag for SPHC steel (manufactured at a certain steel plant in China) by blowing air in the hot state was studied by using hot-state experiments in a laboratory. The FactSage software, a carbon/sulfur analyzer, and scanning electron micros-copy in conjunction with energy-dispersive X-ray spectroscopy were used to test and analyze the sulfur removal effect and to investigate factors influencing sulfur removal rate. The results show that sulfur ions in LF refining slag can be oxidized into SO2 by O2 at high tempera-ture by blowing air into molten slag; SO2 production was observed to reach a maximum with a small amount of blown O2 when the tem-perature exceeded 1350°C. At 1370°C and 1400°C, experimental LF refining slag is in the liquid state and exhibits good fluidity; under these conditions, the sulfur removal effect by blowing air is greater than 90wt% after 60 min. High temperature and large air flow rate are benefi-cial for removing sulfur from LF refining slag; compared with air flow rate, temperature has a greater strongly influences on the sulfur re-moval.

  10. Overview of Steel Slag Application and Utilization

    Directory of Open Access Journals (Sweden)

    Lim J.W.

    2016-01-01

    Full Text Available Significant quantities of steel slag are generated as waste material or byproduct every day from steel industries. Slag is produced from different types of furnaces with different operating conditions. Slag contains Ferrous Oxide, Calcium Oxide, Silica etc. Physical and chemical properties of slag are affected by different methods of slag solidification such as air cooled, steam, and injection of additives. Several material characterization methods, such as X-ray Diffraction (XRD, Scanned Electron Microscopy (SEM and Inductive Coupled Plasma (ICP-OES are used to determine elemental composition in the steel slag. Therefore, slags can become one of the promising materials in various applications such as in transportation industry, construction, cement production, waste water and water treatment. The various applications of steel slag indicate that it can be reused and utilized rather than being disposed to the landfill. This paper presents a review of its applications and utilization.

  11. Air cooled absorption chillers for solar cooling applications

    Science.gov (United States)

    Biermann, W. J.; Reimann, R. C.

    1982-03-01

    The chemical composition of a 'best' absorption refrigerant system is identified, and those properties of the system necessary to design hot water operated, air cooled chilling equipment are determined. Air cooled chillers from single family residential sizes into the commercial rooftop size range are designed and operated.

  12. Amorphous and crystalline blast furnace slag

    International Nuclear Information System (INIS)

    Full text: One of the by-products of iron production from a blast furnace is the slag, Generally 250-300 kg of slag is produced per ton of iron. Liquid blast furnace slag can either be cooled quickly by quenching in a granulator or more slowly in air. The air-cooled product is crushed and sized for use as an aggregate in concrete. The granulated slag is ground to form ground granulated slag, which is a cost-effective supplementary cementitious material. Blends of ground granulated slag and Portland cement produce a cementitious paste that is more resistant to chloride penetration than pastes made from the Portland cement alone. In this study neutron diffraction techniques were used to examine samples of air-cooled and granulated slags from Australian Steel Mill Services stock piles at Port Kembla. Sourced from the same blast furnace, the materials should be expected to posses similar elemental chemistry. The mineral compositions would be different due to the rate of cooling each slag was subjected to. Samples, 15 grams in mass, were mounted in a vanadium can and diffraction patterns were measured using the SLAD instrument on the Reactor R-2 at the Studvik Neutron Research Laboratory in Sweden. The diffraction patterns were transformed into radial distribution functions using the reverse Monte Carlo program, MCGR. The granulated slag showed no diffraction peaks while the air cooled slag showed a crystalline product that can be identified by x-ray diffraction. The radial distribution functions showed differences that were consistent with the granulated slag being amorphous and the air-cooled slag crystalline. Both slag samples showed peaks in the radial distribution function at 1.8 Angstroms and 2.8 Angstroms. The greatest anomaly was a feature about 2.5 Angstroms found only in the radial distribution function for the granulated slag. This demonstration showed that there are differences in the short range bonding between the two compounds. We are currently

  13. Lignite air-steam gasification in the fluidized bed of iron-containing slag catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, B.N.; Shchipko, M.L.; Golovin, Yu. [Inst. of Chemistry of Natural Organic Materials, Academgorodok, Krasnoyarsk (Russian Federation)

    1995-12-01

    The influence of fluidized bed of iron-containing slag particles on air-steam gasification of powdered Kansk-Achinsk lignite in entrained flow was studied in pilot installation with productivity about 60 kg per hour. Slag of Martin process and boiler slag were used as catalytic active materials until their complete mechanical attrition. Two following methods of catalytic gasification of lignite were compared: the partial gasification in stationary fluidized bed of slag particles with degree of fuel conversion 40-70% and complete gasification in circulating bed of slag particles. In the first case only the most reactive part of fuel is gasified with the simultaneously formation of porous carbon residue with good sorption ability. It was found the catalytic fluidized bed improves heat transfer from combustion to reduction zone of gas-generator and increases the rate of fuel conversion at the temperature range 900-1000{degrees}C. At these temperatures the degree of conversion is depended considerably on the duration time of fuel particles in the catalytic fluidized bed. The influence of catalytic fluidized bed height and velocity of reaction mixture on the temperature profiles in the gas-generator was studied. The optimal relationship was found between the fluidized bed height and velocity of flow which makes possible to produce the gas with higher calorific value at maximum degree of fuel conversion.

  14. Analogue experimental study on centrifugal-air blast granulation for molten slag

    International Nuclear Information System (INIS)

    Blast furnace slag is a by-product in iron and steel production process which has a high yield with extremely high discharge temperature. Aiming at energy and water saving as well as emission reduction, dry granulation technique appears to be a good application for the treatment of blast furnace slag. In this study, a granulation technique combining a high-speed rotating cup with air blast is proposed. The performance of this design was investigated by adopting a mixture of rosin and paraffin wax as the analogue of blast furnace slag. The effects of rotating speed of the atomizer, liquid flow rate and blast air flow rate on particle size, particle mass distribution and fiber mass fraction were studied. The effect of the function of air blast on the granulation performance was particularly discussed. The results showed that at a higher rotating speed and a smaller liquid flow rate, smaller particles can be easily obtained, yet the fiber mass fraction also increases. However, the increasing blast air leads to the increase of particle size and fiber mass fraction. For the operating conditions tested in this study, over 60% of total mass of particles fall within the size range of 0.5–1 mm, which means that the present system has a good performance in centrifugal granulation

  15. A Blast of Cool Air

    Science.gov (United States)

    2000-01-01

    Unable to solve their engineering problem with a rotor in their Orbital Vane product, DynEco Corporation turned to Kennedy Space Center for help. KSC engineers determined that the compressor rotor was causing a large concentration of stress, which led to cracking and instant rotor failure. NASA redesigned the lubrication system, which allowed the company to move forward with its compressor that has no rubbing parts. The Orbital Vane is a refrigerant compressor suitable for mobile air conditioning and refrigeration.

  16. Thermoelectric Air Cooling For Cars

    Directory of Open Access Journals (Sweden)

    Manoj S. Raut

    2012-05-01

    Full Text Available India is the second most populous country in the world with over 1.21billion people (estimated for April, 2011,more than sixth of the world’s population. India is projected to be world’s most populous country by 2025,surpassing china, its population exceeding 1.6 billion people by 2050.Comparing with the population there are 2.65 million cars sold in India as of march 2011.According to the society of Indian automotive manufacturer, annual car sales are projected to increase up to 5 million vehicles by 2015 and more than a 9 million by 2020.By 2050,the country is expected to top of the world in car volumes with approximately 611 million vehicles on the nation’s roads.The above data shows that, as the population increase the no. of vehicles also increase. Today, an automobile is a necessity for everyone. For a long or short journey people need car regard to thesafety, environment and most important comfort. Owing to these reasons, many vehicles are equipped with heating, ventilating and air conditioning system. In today’s world, no one feel comfortable in a vehicle without HVAC system. Therefore, HVAC becomes an integral part of human life. Today’s present HVAC system is very efficient and reliable but it has some demerits. It has been observed during the last two decades that the O3 –layer is slowly destroyed because of the refrigerant (CFC and HFC used for the refrigeration and air –conditioning purposes. The common refrigerant used is HFC’s which are leaked and slowly climb into the atmosphere. When they reach to O3 layer they act on O3 –molecules and the layer of O3 is destroyed.

  17. for an Internal Cooling Air System

    Directory of Open Access Journals (Sweden)

    Tadaharu Kishibe

    2000-01-01

    Full Text Available The swirling flow field in an internal cooling air system in which the fluid passes through an inducer, a hollow turbine shaft, and a cavity between two disks (referred to as a wheel space is solved using computational fluid dynamics and the pressure fluctuations on the hollow shaft wall surface are measured.

  18. Comparison of Air Cooled and Evaporatively Cooled Refrigerartion Systems – A Review Paper

    OpenAIRE

    V. V. Birangane; A.M.Patil

    2014-01-01

    The air cooled condensers are widely used as they are less costly and give satisfactory performance. But their performance is greatly affected by the temperature of cooling media which is ambient air. To deal this problem we can use water cooled condenser. But their cost and maintenance limit their use. The performance improvement of Air cooled condensers can be achieved by using evaporative cooling. This method may prove quiet effective and less costly. There are researchers ...

  19. On the Method of Air Jet Cooling in Green Manufacturing

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Green cooling is an important technology in green manufacturing. In the way of jetting, cooling airflow is used in the experiments of metal material cutting, by compari- son of the changes of some technological factors, such as cutting heat, surface finish, in the process of jet cooling, pour cooling and natural cooling, we can draw the conclusion that air jet cooling has a better cooling effect and green function. It can be widely used in both aditional and automatic green manufacturing.

  20. Floor cooling and air-cooling, the effects on thermal comfort or different cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Sijpheer, N.C.; Bakker, E.J.; Ligthart, F.A.T.M.; Opstelten, I.J. [ECN Energie in de Gebouwde Omgeving en Netten, Petten (Netherlands)

    2007-09-15

    One of the research areas of the Energy research Centre of the Netherlands (ECN) concerns the built environment. Several facilities to conduct research activities are at ECN's disposal. One of these facilities, are five research dwellings located on the premises of ECN. Measured data from these facilities together with weather data and computer models are used to evaluate innovative energy concepts and components in energy systems. Experiments with different cooling systems in ECN's research dwellings are executed to evaluate their effective influence on both energy use and thermal comfort. Influence of inhabitants' behaviour is taken into account in these experiments. The thermal comfort is indicated by the Predicted Mean Vote (PMV) as defined by P.O. Fanger. For this paper, the results of measurements with a floor cooling and air cooling system are assessed. Effects on the PMV measured during experiments with the two different cooling systems will be presented.

  1. Startup of air-cooled condensers and dry cooling towers at low temperatures of the cooling air

    Science.gov (United States)

    Milman, O. O.; Ptakhin, A. V.; Kondratev, A. V.; Shifrin, B. A.; Yankov, G. G.

    2016-05-01

    The problems of startup and performance of air-cooled condensers (ACC) and dry cooling towers (DCT) at low cooling air temperatures are considered. Effects of the startup of the ACC at sub-zero temperatures are described. Different options of the ACC heating up are analyzed, and examples of existing technologies are presented (electric heating, heating up with hot air or steam, and internal and external heating). The use of additional heat exchanging sections, steam tracers, in the DCT design is described. The need for high power in cases of electric heating and heating up with hot air is noted. An experimental stand for research and testing of the ACC startup at low temperatures is described. The design of the three-pass ACC unit is given, and its advantages over classical single-pass design at low temperatures are listed. The formation of ice plugs inside the heat exchanging tubes during the start-up of ACC and DCT at low cooling air temperatures is analyzed. Experimental data on the effect of the steam flow rate, steam nozzle distance from the heat-exchange surface, and their orientation in space on the metal temperature were collected, and test results are analyzed. It is noted that the surface temperature at the end of the heat up is almost independent from its initial temperature. Recommendations for the safe start-up of ACCs and DCTs are given. The heating flow necessary to sufficiently heat up heat-exchange surfaces of ACCs and DCTs for the safe startup is estimated. The technology and the process of the heat up of the ACC with the heating steam external supply are described by the example of the startup of the full-scale section of the ACC at sub-zero temperatures of the cooling air, and the advantages of the proposed start-up technology are confirmed.

  2. A study of occupant cooling by personally controlled air movement

    OpenAIRE

    Arens, Edward A.; Xu, T.; Miura, K; Zhang, H.; Fountain, M.; Bauman, Fred

    1997-01-01

    This study addresses the effectiveness of air movement cooling, an alternative to compressor-based cooling of the air itself. Subjects in an environmental chamber were exposed to a range of warm temperatures and allowed to adjust air movement to suit their individual preferences, while answering a series of questions about their comfort. Air movement was from the subject's side, in two modes of turbulent flow. The air speeds chosen by the subjects, and their subjective responses, are evaluate...

  3. Cooling Performance of ALIP according to the Air or Sodium Cooling Type

    International Nuclear Information System (INIS)

    ALIP pumps the liquid sodium by Lorentz force produced by the interaction of induced current in the liquid metal and their associated magnetic field. Even though the efficiency of the ALIP is very low compared to conventional mechanical pumps, it is very useful due to the absence of moving parts, low noise and vibration level, simplicity of flow rate regulation and maintenance, and high temperature operation capability. Problems in utilization of ALIP concern a countermeasure for elevation of internal temperature of the coil due to joule heating and how to increase magnetic flux density of Na channel gap. The conventional ALIP usually used cooling methods by circulating the air or water. On the other hand, GE-Toshiba developed a double stator pump adopting the sodium-immersed self-cooled type, and it recovered the heat loss in sodium. Therefore, the station load factor of the plant could be reduced. In this study, the cooling performance with cooling types of ALIP is analyzed. We developed thermal analysis models to evaluate the cooling performance of air or sodium cooling type of ALIP. The cooling performance is analyzed for operating parameters and evaluated with cooling type. 1-D and 3-D thermal analysis model for IHTS ALIP was developed, and the cooling performance was analyzed for air or sodium cooling type. The cooling performance for air cooling type was better than sodium cooling type at higher air velocity than 0.2 m/s. Also, the air temperature of below 270 .deg. demonstrated the better cooling performance as compared to sodium

  4. Air cooled turbine component having an internal filtration system

    Science.gov (United States)

    Beeck, Alexander R.

    2012-05-15

    A centrifugal particle separator is provided for removing particles such as microscopic dirt or dust particles from the compressed cooling air prior to reaching and cooling the turbine blades or turbine vanes of a turbine engine. The centrifugal particle separator structure has a substantially cylindrical body with an inlet arranged on a periphery of the substantially cylindrical body. Cooling air enters centrifugal particle separator through the separator inlet port having a linear velocity. When the cooling air impinges the substantially cylindrical body, the linear velocity is transformed into a rotational velocity, separating microscopic particles from the cooling air. Microscopic dust particles exit the centrifugal particle separator through a conical outlet and returned to a working medium.

  5. 铜冶炼炉渣缓冷技术研究与生产实践%Copper Smelting Slag Slow Cooling Technology Research and Practice

    Institute of Scientific and Technical Information of China (English)

    王国红

    2014-01-01

    Slow cooling process is widely used to recycle copper from slag in domestic copper smelter, which can improve copper recovery rate and adaptability of smelting furnace to raw material. After slow cooling slag beneficiation, copper concentrates return to the smelting system, tailings is to be as the raw material for cement production. In this article, the slow cooling process of copper smel-ting slag and the main problem in production practice are described, s the reasons are analyzed and solutions are proposed.%国内铜冶炼厂广泛采用缓冷工艺回收炉渣中铜,该工艺可以提高冶炼厂铜回收率和冶炼炉对原料的适应性。缓冷炉渣经过选矿后,铜精矿返回冶炼系统,尾矿作为生产水泥的原料。介绍了铜冶炼炉渣缓冷工艺及生产实践中存在的主要问题,进行了原因分析并提出了解决措施。

  6. Storage of HLW in engineered structures: air-cooled and water-cooled concepts

    International Nuclear Information System (INIS)

    A comparative study on an air-cooled and a water-cooled intermediate storage of vitrified, highly radioactive waste (HLW) in overground installations has been performed by Nukem and Belgonucleaire respectively. In the air-cooled storage concept the decay heat from the storage area will be removed using natural convection. In the water-cooled storage concept the decay heat is carried off by a primary and secondary forced-cooling system with redundant and diverse devices. The safety study carried out by Nukem used a fault tree method. It shows that the reliability of the designed water-cooled system is very high and comparable to the inherent, safe, air-cooled system. The impact for both concepts on the environment is determined by the release route, but even during accident conditions the release is far below permissible limits. The economic analysis carried out by Belgonucleaire shows that the construction costs for both systems do not differ very much, but the operation and maintenance costs for the water-cooled facility are higher than for the air cooled facility. The result of the safety and economic analysis and the discussions with the members of the working group have shown some possible significant modifications for both systems, which are included in this report. The whole study has been carried out using certain national criteria which, in certain Member States at least, would lead to a higher standard of safety than can be justified on any social, political or economic grounds

  7. 风水联合冷却冷渣器技术改造%Technological transformation of slag cooler with joint cooling of wind and water

    Institute of Scientific and Technical Information of China (English)

    曾建山; 闫贯峰; 李梅

    2011-01-01

    imed at the problem of the original slag cooler with joint cooling of wind and water during the operation in Ruiping Power Plant,based on the information and statistics of site investigation,targeted transformation is done,which basically solved the problem of high temperature slag,uncontrollable slag feed,easy leak of water-cooled set and other issues,and boiler efficiency can be increased by one percentage point by only reducing heat loss of physical ash.%针对瑞平电厂原风水联合冷却冷渣器运行过程中存在的问题,经过查找资料与现场数据统计,有针对性地对冷渣器进行改造,改造后的冷渣器基本解决了原来存在的排渣温度高、进渣量无法控制、进渣水冷套容易泄漏等问题,仅减少灰渣物理热损失一项,可提高锅炉热效率一个百分点。

  8. CO2 Extraction from Ambient Air Using Alkali-Metal Hydroxide Solutions Derived from Concrete Waste and Steel Slag

    Science.gov (United States)

    Stolaroff, J. K.; Lowry, G. V.; Keith, D. W.

    2003-12-01

    To mitigate global climate change, deep reductions in CO2 emissions are required in the coming decades. Carbon sequestration will play a crucial role in this reduction. Early adoption of carbon sequestration in low-cost niche markets will help develop the technology and experience required for large-scale deployment. One such niche may be the use of alkali metals from industrial waste streams to form carbonate minerals, a safe and stable means of sequestering carbon. In this research, the potential of using two industrial waste streams---concrete and steel slag---for sequestering carbon is assessed. The scheme is outlined as follows: Ca and Mg are leached with water from a finely ground bed of steel slag or concrete. The resulting solution is sprayed through air, capturing CO2 and forming solid carbonates, and collected. The feasibility of this scheme is explored with a combination of experiments, theoretical calculations, cost accounting, and literature review. The dissolution kinetics of steel slag and concrete as a function of particle size and pH is examined. In stirred batch reactors, the majority of Ca which dissolved did so within the first hour, yielding between 50 and 250 (mg; Ca)/(g; slag) and between 10 and 30 (mg; Ca)/(g; concrete). The kinetics of dissolution are thus taken to be sufficiently fast to support the type of scheme described above. As proof-of-concept, further experiments were performed where water was dripped slowly through a stagnant column of slag or concrete and collected at the bottom. Leachate Ca concentrations in the range of 15 mM were achieved --- sufficient to support the scheme. Using basic physical principles and numerical methods, the quantity of CO2 captured by falling droplets is estimated. Proportion of water loss and required pumping energy is similarly estimated. The results indicate that sprays are capable of capturing CO2 from the air and that the water and energy requirements are tractable. An example system for

  9. Creation of Air-Cooled Mn Series Bainitic Steels

    Institute of Scientific and Technical Information of China (English)

    FANG Hong-sheng; FENG Chun; ZHENG Yan-kang; YANG Zhi-gang; BAI Bing-zhe

    2008-01-01

    The development and mechanical performances of new type air-cooled Mn series bainitie steels including granular bainitie steels,FGBA/BG duplex steels,CFB/M duplex steels,medium carbon bainite/martensite steels,cast hainitic steels invented by the authors are summarized.The novel series of bainitie steels are alloyed with Mn,and several series bainitic duplex microstructures can be easily obtained under the condition of air cooling through unique composition design.The invented idea,the principle of alloying design,the strengthening mechanism,and the evolution of the microstructure of new type air-cooled Mn series bainitic steels are presented.Furthermore,the applications in different fields of these Mn series air-cooled bainitic steels with different strength level are also introdueed.It is suggested that the significance of the development of the air-cooled Mn series bainitic steel can be summarized as follows:reducing costs of both raw materials and production;good combination of strength and toughness;self-hardening with high bainitic hardenability by air cooling from hot working without additional quenching-tempering treatment or quenching procedure;large savings in energy resources;and reduced environmental pollution.

  10. Varying duty operation of air-cooled condenser units

    Science.gov (United States)

    Milman, O. O.; Kondratev, A. V.; Ptakhin, A. V.; Dunaev, S. N.; Kirjukhin, A. V.

    2016-05-01

    Results of experimental investigations of operation modes of air-cooled condensers (ACC) under design and varying duty conditions are presented. ACCs with varying cooling airflow rates under constant heat load and with constant cooling airflow under varying heat load are examined. Diagrams of heat transfer coefficients and condensation pressures on the heat load and cooling airflow are obtained. It is found that, if the relative heat load is in the range from 0.6 to 1.0 of the nominal value, the ACC heat transfer coefficient varies insignificantly, unlike that of the water-cooled surface condensers. The results of the determination of "zero points" are given, i.e., the attainable pressure in air-cooled condensing units (ACCU), if there is no heat load for several values of working water temperature at the input of water-jet ejectors and liquid ring vacuum pump. The results of the experimental determination of atmospheric air suction into the ACC vacuum system. The effect of additional air suctions in the steam pipe on ACCU characteristics is analyzed. The thermal mapping of ACC heat exchange surfaces from the cooling air inlet is carried out. The dependence of the inefficient heat exchange zone on the additional air suction into the ACC vacuum system is given. It is shown that, if there is no additional air suction into the ACC vacuum system, the inefficient heat exchange zone is not located at the bottom of the first pass tubes, and their portion adjacent to the bottom steam pipe works efficiently. Design procedures for the ACC varying duty of capacitors are presented, and their adequacy for the ACCU varying duty estimation is analyzed.

  11. Experimental Analysis Of 80 Tr Capacity Air Cooled Scroll Chiller Using R-22 & R-407c.

    OpenAIRE

    Mr. Bhikhu B,; Prof. Ronak Shah

    2014-01-01

    In air conditioning systems, chilled water is typically distributed to heat exchangers, or coils, in air handling units or other types of terminal devices which cool the air in their respective space(s), and then the water is recirculated back to the chiller to be cooled again. These cooling coils transfer sensible heat and latent heat from the air to the chilled water, thus cooling and usually dehumidifying the air stream. The experiment works on 80 TR capacity Air Cooled Scroll ...

  12. Preventing freezing of condensate inside tubes of air cooled condenser

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Jeong A; Hwang, In Hwan; Lee, Dong Hwan [Chonbuk Nat' l Univ., Jeonju (Korea, Republic of); Cho, Young Il [Drexel Univ., Philadelphia (United States)

    2012-08-15

    An air cooled condenser is a device that is used for converting steam into condensate by using ambient air. The air cooled condenser is prone to suffer from a serious explosion when the condensate inside the tubes of a heat exchanger is frozen; in particular, tubes can break during winter. This is primarily due to the structural problem of the tube outlet of an existing conventional air cooled condenser system, which causes the backflow of residual steam and noncondensable gases. To solve the backflow problem in such condensers, such a system was simulated and a new system was designed and evaluated in this study. The experimental results using the simulated condenser showed the occurrence of freezing because of the backflow inside the tube. On the other hand, no backflow and freezing occurred in the advanced new condenser, and efficient heat exchange occurred.

  13. Studying the effect of thermal and acid exposure on alkali activated slag Geopolymer

    OpenAIRE

    Khater H.M.

    2014-01-01

    This article reports a study about thermal stability as well as acid resistance of geopolymer materials prepared from Ground Granulated Blast Furnace Slag (GGBFS), Air Cooled Slag (ACS), Silica fume (SF) and cement kiln dust (CKD) using 6% (weight) of equal mix from alkaline sodium hydroxide and sodium silicate activators. Study of addition of ACS, SF and CKD as partial replacement of GGBFS is investigated so as to improve the mechanical and microstructural properties of geopolymer mixes. Com...

  14. Thermal computations for electronics conductive, radiative, and convective air cooling

    CERN Document Server

    Ellison, Gordon

    2010-01-01

    IntroductionPrimary mechanisms of heat flowConductionApplication example: Silicon chip resistance calculationConvectionApplication example: Chassis panel cooled by natural convectionRadiationApplication example: Chassis panel cooled only by radiation 7Illustrative example: Simple thermal network model for a heat sinked power transistorIllustrative example: Thermal network circuit for a printed circuit boardCompact component modelsIllustrative example: Pressure and thermal circuits for a forced air cooled enclosureIllustrative example: A single chip package on a printed circuit board-the proble

  15. Cool Colored Roofs to Save Energy and Improve Air Quality

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Levinson, Ronnen; Miller, William; Berdahl, Paul

    2005-08-23

    Urban areas tend to have higher air temperatures than their rural surroundings as a result of gradual surface modifications that include replacing the natural vegetation with buildings and roads. The term ''Urban Heat Island'' describes this phenomenon. The surfaces of buildings and pavements absorb solar radiation and become extremely hot, which in turn warm the surrounding air. Cities that have been ''paved over'' do not receive the benefit of the natural cooling effect of vegetation. As the air temperature rises, so does the demand for air-conditioning (a/c). This leads to higher emissions from power plants, as well as increased smog formation as a result of warmer temperatures. In the United States, we have found that this increase in air temperature is responsible for 5-10% of urban peak electric demand for a/c use, and as much as 20% of population-weighted smog concentrations in urban areas. Simple ways to cool the cities are the use of reflective surfaces (rooftops and pavements) and planting of urban vegetation. On a large scale, the evapotranspiration from vegetation and increased reflection of incoming solar radiation by reflective surfaces will cool a community a few degrees in the summer. As an example, computer simulations for Los Angeles, CA show that resurfacing about two-third of the pavements and rooftops with reflective surfaces and planting three trees per house can cool down LA by an average of 2-3K. This reduction in air temperature will reduce urban smog exposure in the LA basin by roughly the same amount as removing the basin entire onroad vehicle exhaust. Heat island mitigation is an effective air pollution control strategy, more than paying for itself in cooling energy cost savings. We estimate that the cooling energy savings in U.S. from cool surfaces and shade trees, when fully implemented, is about $5 billion per year (about $100 per air-conditioned house).

  16. Study on forced air convection cooling for electronic assemblies

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The slotted fin concept was employed to improve the air cooling performance of plate-fin in heat sinks.Numerical simulations of laminar heat transfer and flow pressure drop were conducted for the integral plate fin,discrete plate fin and discrete slotted fin heat sinks.It is found that the performance of the discrete plate fin is better than that of the integral continuum plate fin and the performance of slotted fin is better than that of the discrete plate fin at the same pumping power of the fan.A new type of heat sink characterized by discrete and slotted fin surfaces with thinner fins and smaller spaces between fins is then proposed.Preliminary computation shows that this type of heat sink may be useful for the next generation of higher thermal load CPUs.The limit of cooling capacity for air-cooling techniques was also addressed.

  17. Air cooling effect of fins on a Honda shine bike

    Directory of Open Access Journals (Sweden)

    Padhiyar Abhesinh J

    2015-05-01

    Full Text Available The main of aim of this work is to study various researches done in past to improve heat transfer rate of cooling fins by changing cylinder block fin geometry. Low rate of heat transfer through cooling fins is the main problem in this type of cooling. So efficiency of the engine is increase by increase the heat transfer. Examples of direct air cooling in modern automobiles are rare. The most common example is the commercials Automobile bike like a Honda Shine, Bajaj bike, Honda splendor etc. It is conclude about shape try to this fins is more effectively heat transfer in Honda shine bike compare to existing fins. After FEA Analysis it checking on fin whether efficiency of heat transfer increases or not. This work validation with Experimental and Mathematical.

  18. Optimal air-supply mode of hybrid system with radiant cooling and dedicated outdoor air

    Institute of Scientific and Technical Information of China (English)

    丁研; 田喆; 朱能

    2015-01-01

    The hybrid system with radiant cooling and dedicated outdoor air not only possesses high energy efficiency, but also creates a healthy and comfortable indoor environment. Indoor air quality will be improved by the dedicated outdoor air system (DOAS) and indoor thermal comfort can be enhanced by the radiant cooling system (RCS). The optimal air-supply mode of the hybrid system and the corresponding design approach were investigated. A full-scale experimental chamber with various air outlets and the ceiling radiant cooling panels (CRCP) was designed and established. The performances of different air-supply modes along with CRCPs were analyzed by multi-index evaluations. Preliminary investigations were also conducted on the humidity stratification and the control effect of different airflow modes to prevent condensation on CRCP. The overhead supply air is recommended as the best combination mode for the hybrid system after comprehensive comparison of the experiment results. The optimal proportion of CRCP accounting for the total cooling capacities in accord with specific cooling loads is found, which may provide valuable reference for the design and operation of the hybrid system.

  19. Waste heat recovery using looped heat pipes for air cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lamfon, N.J.; Akyurt, M.; Najjar, Y.S.H. (King Abdulaziz Univ., Jeddah (Saudi Arabia). Mechanical Engineering Dept.)

    1994-07-01

    A scheme is described for the recovery of waste heat from stacks of gas turbine engines and the utilization of recovered energy for the cooling of ambient air. Relationships are summarized for the modeling of components of the cooling system. Samples are presented from performance data that is predicted by the model. Effect of size and design of system components, as well as operational variables on system performance, are discussed. It is concluded that the single most significant variable in the design of the looped heat-pipe recovery and utilization system is the geometry of the exhaust pipe of the gas turbine engine. (author)

  20. Air Cooling for High Temperature Power Electronics (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Waye, S.; Musselman, M.; King, C.

    2014-09-01

    Current emphasis on developing high-temperature power electronics, including wide-bandgap materials such as silicon carbide and gallium nitride, increases the opportunity for a completely air-cooled inverter at higher powers. This removes the liquid cooling system for the inverter, saving weight and volume on the liquid-to-air heat exchanger, coolant lines, pumps, and coolant, replacing them with just a fan and air supply ducting. We investigate the potential for an air-cooled heat exchanger from a component and systems-level approach to meet specific power and power density targets. A proposed baseline air-cooled heat exchanger design that does not meet those targets was optimized using a parametric computational fluid dynamics analysis, examining the effects of heat exchanger geometry and device location, fixing the device heat dissipation and maximum junction temperature. The CFD results were extrapolated to a full inverter, including casing, capacitor, bus bar, gate driver, and control board component weights and volumes. Surrogate ducting was tested to understand the pressure drop and subsequent system parasitic load. Geometries that met targets with acceptable loads on the system were down-selected for experimentation. Nine baseline configuration modules dissipated the target heat dissipation, but fell below specific power and power density targets. Six optimized configuration modules dissipated the target heat load, exceeding the specific power and power density targets. By maintaining the same 175 degrees C maximum junction temperature, an optimized heat exchanger design and higher device heat fluxes allowed a reduction in the number of modules required, increasing specific power and power density while still maintaining the inverter power.

  1. Report of study 7.3: cooling and air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Russo, F.

    2000-07-01

    This report describes the results of the study carried out by the study group 7.3 in the triennium 1997-2000. The study was focused on industrial refrigeration and air conditioning for the large building utilising natural gas. The goal of this study, carried out in collaboration of the members of study group 7.3, was to analyse the markets of industrial refrigeration and air conditioning for large buildings to identify possibilities to increase the natural gas share in these sectors. The available technology in the two sectors of the market are described in a single section, i.e. the 'State of the art of the technology'. In this section, technical characteristics, applications, performances, new developments and others topics are discussed for absorbers, gas engines, gas turbines and fuel cells. In the 'Industrial Refrigeration' section an analysis of the present global market for the industrial sector is presented. Economics, advantages and barriers to gas units compared with the electrical units are discussed. Information on existing industrial plants, possible application options and new technology developments are described as well. The 'Air conditioning for the large building' section deals with offices, hotels, commercial buildings, hospitals and shopping centres with a cooling capacity of 350 kW or higher. It appears that the use of natural gas for cooling of large buildings has been increasing during the last decade, thanks to the greater availability of natural gas and the development of new technologies. A marketing survey of gas air-conditioning was carried out in cooperation with a group of Intergas Marketing. Based on the survey, the report describes the market position of natural gas relative to electricity. It provides the strategic prospects for further developing natural gas as a competitive option for air-conditioning of large buildings using a combination of state-of-the-art technologies. It is important to highlight

  2. Experimental and numerical study of open-air active cooling

    Science.gov (United States)

    Al-Fifi, Salman Amsari

    The topic of my thesis is Experimental and Numerical Study of Open Air Active Cooling. The present research is intended to investigate experimentally and Numerically the effectiveness of cooling large open areas like stadiums, shopping malls, national gardens, amusement parks, zoos, transportation facilities and government facilities or even in buildings outdoor gardens and patios. Our cooling systems are simple cooling fans with different diameters and a mist system. This type of cooling systems has been chosen among the others to guarantee less energy consumption, which will make it the most favorable and applicable for cooling such places mentioned above. In the experiments, the main focus is to study the temperature domain as a function of different fan diameters aerodynamically similar in different heights till we come up with an empirical relationship that can determine the temperature domain for different fan diameters and for different heights of these fans. The experimental part has two stages. The first stage is devoted to investigate the maximum range of airspeed and profile for three different fan diameters and for different heights without mist, while the second stage is devoted to investigate the maximum range of temperature and profile for the three different diameter fans and for different heights with mist. The computational study is devoted to built an experimentally verified mathematical model to be used in the design and optimization of water mist cooling systems, and to compare the mathematical results to the experimental results and to get an insight of how to apply such evaporative mist cooling for different places for different conditions. In this study, numerical solution is presented based on experimental conditions, such dry bulb temperature, wet bulb temperature, relative humidity, operating pressure and fan airspeed. In the computational study, all experimental conditions are kept the same for the three fans except the fan airspeed

  3. Temperature distribution in graphite during annealing in air cooled reactors

    International Nuclear Information System (INIS)

    A model for the evaluation temperature distributions in graphite during annealing operation in graphite. Moderated an-cooled reactors, is presented. One single channel and one dimension for air and graphite were considered. A numerical method based on finite control volumes was used for partioning the mathematical equations. The problem solution involves the use of unsteady equations of mass, momentum and energy conservation for air, and energy conservation for graphite. The source term was considered as stored energy release during annealing for describing energy conservation in the graphite. The coupling of energy conservation equations in air and graphite is performed by the heat transfer term betwen air and graphite. The results agree with experimental data. A sensitivity analysis shown that the termal conductivity of graphite and the maximum inlet channel temperature have great effect on the maximum temperature reached in graphite during the annealing. (author)

  4. Evaluating Fault Detection and Diagnostics Protocols Applied to Air-Cooled Vapor Compression Air-Conditioners

    OpenAIRE

    Yuill, David P.; Braun, James E.

    2012-01-01

    Fault detection and diagnostics (FDD) tools are being increasingly applied in air-conditioning systems. There are many different protocols used in these FDD tools, so an important question to ask is: how well do the protocols work? This paper describes the ongoing development of the first standardized method of evaluation for FDD protocols applied to air-cooled vapor compression air-conditioning systems. The general approach is to feed a library of data – including temperatures, pressures, an...

  5. Effect mechanism of air deflectors on the cooling performance of dry cooling tower with vertical delta radiators under crosswind

    International Nuclear Information System (INIS)

    Highlights: • A 3D numerical model was set for NDDCTV to study the effect of air deflectors. • The air deflectors improve the tower performance by 1.375 °C at uc = 6 m/s for a case. • The air deflectors reduce the air inflow deviation angle θd at most delta entries. • The reduced θd can improve the cooling performance of former deteriorated columns. • Both the radial inflow air velocity and θd impact the cooling performance of delta. - Abstract: To study the effect mechanism of air deflectors on dry cooling tower, a three dimensional numerical model was established, with full consideration of the delta structure. The accuracy and credibility of dry cooling tower numerical model were validated. By numerical model, the average air static pressure and the average radial inflow air velocity were computed and analyzed at delta air entry, sector air entry and exit faces. By the air inflow deviation angle θd, the effect of air deflectors on the aerodynamic field around tower was analyzed. The water exit temperatures of θ−1 columns, θ+2 columns and cooling sectors were also presented to clarify the effect of air deflectors. It was found that the air deflectors improved the aerodynamic field around cooling columns. The reduced air inflow deviation degree at delta entry improved the cooling performance of deteriorated columns. Referring to the radial inflow air velocity ura and the air inflow deviation degree at delta entry, the effect mechanism of air deflectors are clarified under crosswind

  6. Steady Thermal Field Simulation of Forced Air-cooled Column-type Air-core Reactor

    Institute of Scientific and Technical Information of China (English)

    DENG Qiu; LI Zhenbiao; YIN Xiaogen; YUAN Zhao

    2013-01-01

    Modeling the steady thermal field of the column-type air-core reactor,and further analyzing its distribution regularity,will help optimizing reactor design as well as improving its quality.The operation mechanism and inner insulation structure of a novel current limiting column-type air-core reactor is introduced in this paper.The finite element model of five encapsulation forced air-cooled column type air-core reactor is constructed using Fluent.Most importantly,this paper present a new method that,the steady thermal field of reactor working under forced air-cooled condition is simulated without arbitrarily defining the convection heat transfer coefficient for the initial condition; The result of the thermal field distribution shows that,the maximum steady temperature rise of forced air-cooled columntype air-core reactor happens approximately 5% to its top.The law of temperature distribution indicates:In the 1/3part of the reactor to its bottom,the temperature will rise rapidly to the increasing of height,yet the gradient rate is gradually decreasing; In the 5 % part of the reactor to its top,the temperature will drop rapidly to the increasing of height; In the part between,the temperature will rise slowly to the increasing of height.The conclusion draws that more thermal withstand capacity should be considered at the 5 % part of the reactor to its top to achieve optimal design solution.

  7. A fundamentally new approach to air-cooled heat exchangers.

    Energy Technology Data Exchange (ETDEWEB)

    Koplow, Jeffrey P.

    2010-01-01

    We describe breakthrough results obtained in a feasibility study of a fundamentally new architecture for air-cooled heat exchangers. A longstanding but largely unrealized opportunity in energy efficiency concerns the performance of air-cooled heat exchangers used in air conditioners, heat pumps, and refrigeration equipment. In the case of residential air conditioners, for example, the typical performance of the air cooled heat exchangers used for condensers and evaporators is at best marginal from the standpoint the of achieving maximum the possible coefficient of performance (COP). If by some means it were possible to reduce the thermal resistance of these heat exchangers to a negligible level, a typical energy savings of order 30% could be immediately realized. It has long been known that a several-fold increase in heat exchanger size, in conjunction with the use of much higher volumetric flow rates, provides a straight-forward path to this goal but is not practical from the standpoint of real world applications. The tension in the market place between the need for energy efficiency and logistical considerations such as equipment size, cost and operating noise has resulted in a compromise that is far from ideal. This is the reason that a typical residential air conditioner exhibits significant sensitivity to reductions in fan speed and/or fouling of the heat exchanger surface. The prevailing wisdom is that little can be done to improve this situation; the 'fan-plus-finned-heat-sink' heat exchanger architecture used throughout the energy sector represents an extremely mature technology for which there is little opportunity for further optimization. But the fact remains that conventional fan-plus-finned-heat-sink technology simply doesn't work that well. Their primary physical limitation to performance (i.e. low thermal resistance) is the boundary layer of motionless air that adheres to and envelops all surfaces of the heat exchanger. Within this

  8. Performance Prediction Method of CO2 Cycle for Air Cooling

    Science.gov (United States)

    Koyama, Shigeru; Xue, Jun; Kuwahara, Ken

    From the perspective of global environmental protection and energy-saving, the research and development on high-efficiency heat pump and refrigeration systems using environment-friendly refrigerants have become one of the most important issues in the air-conditioning and refrigeration sector. In the present work, a steady-state model of the CO2 transcritical cycle for air cooling, which consists of a rotary compressor, a fin-tube gas cooler,a fin-tube evaporator and an expansion valve, has been developed. The detailed model of fin-tube heat exchanger has been constructed by means of the finite volume method, in which the local heat transfer and flow characteristics are evaluated. It should be noted that the effects of the dew condensation generated on the cooling surface are considered in the evaporator model. As a calculation example, the effects of the indoor air wet-bulb temperature on the cycle performance have been examined with this developed simulator.

  9. Assessing and controlling corrosion in air-cooled condensers

    Energy Technology Data Exchange (ETDEWEB)

    Dooley, R. Barry [Structural Integrity Associates, Inc., Charlotte, NC (United States); Preez, Francois du [Eskom (South Africa); Aspden, J. Denis; Howell, Andrew G.

    2009-05-15

    An increasing number of air-cooled condensers (ACC) are being installed and operated on conventional and combined cycle plants worldwide. Unless understood and corrected, the corrosion associated with the ACC ducts and tube entries can become a major problem for operators of plant. Up to just a few years ago very little was known about the corrosion/ flow-accelerated corrosion (FAC) process. This paper starts to rectify the situation with a description of the corrosion/FAC process, a corrosion index and a relationship between the operating pH and the level of iron at the condensate pump discharge. (orig.)

  10. Slags from steel production: Properties and their utilization

    Directory of Open Access Journals (Sweden)

    J. Vlcek

    2013-07-01

    Full Text Available During steel production a considerable amount of slags is produced. In addition to its usual processing, as recycling in device for steel production and preparation of aggregates, it is also possible to apply less common slag processing ways. Depending on cooling mode of the steel slags these may show some binding properties. Geopolymer type binders can be prepared from the slag using alkali activators or the hydraulic properties of the dicalciumsilicate present in the slag can be induced by water. The paper summarizes present state of material utilisation of the steel slags with focus on emphasize of the possible sources of the slag volume instability. The influence of process of slag cooling on its phase composition is documented. It was also found that slags from real sources show different parameters compared to samples obtained for laboratory examination.

  11. Modeling and energy simulation of the variable refrigerant flow air conditioning system with water-cooled condenser under cooling conditions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yueming; Wu, Jingyi [Shanghai Jiao Tong University, Institute of Refrigeration and Cryogenics (China); Shiochi, Sumio [Daikin Industries Ltd. (Japan)

    2009-09-15

    As a new system, variable refrigerant flow system with water-cooled condenser (water-cooled VRF) can offer several interesting characteristics for potential users. However, at present, its dynamic simulation simultaneously in association with building and other equipments is not yet included in the energy simulation programs. Based on the EnergyPlus's codes, and using manufacturer's performance parameters and data, the special simulation module for water-cooled VRF is developed and embedded in the software of EnergyPlus. After modeling and testing the new module, on the basis of a typical office building in Shanghai with water-cooled VRF system, the monthly and seasonal cooling energy consumption and the breakdown of the total power consumption are analyzed. The simulation results show that, during the whole cooling period, the fan-coil plus fresh air (FPFA) system consumes about 20% more power than the water-cooled VRF system does. The power comparison between the water-cooled VRF system and the air-cooled VRF system is performed too. All of these can provide designers some ideas to analyze the energy features of this new system and then to determine a better scheme of the air conditioning system. (author)

  12. Air cooling of disk of a solid integrally cast turbine rotor for an automotive gas turbine

    Science.gov (United States)

    Gladden, H. J.

    1977-01-01

    A thermal analysis is made of surface cooling of a solid, integrally cast turbine rotor disk for an automotive gas turbine engine. Air purge and impingement cooling schemes are considered and compared with an uncooled reference case. Substantial reductions in blade temperature are predicted with each of the cooling schemes studied. It is shown that air cooling can result in a substantial gain in the stress-rupture life of the blade. Alternatively, increases in the turbine inlet temperature are possible.

  13. Smelting Oxidation Desulfurization of Copper Slags

    Institute of Scientific and Technical Information of China (English)

    LI Lei; HU Jian-hang; WANG Hua

    2012-01-01

    According to the mechanism of sulfur removal easily through oxidation, the process of smelting oxidation desulfurization of copper slags is studied, which supplies a new thinking for obtaining the molten iron of lower sulfur content by smelting reduction of copper slags. Special attention is given to the effects of the holding temperature, the holding time and CaF2, CaO addition amounts on the desulfurization rate of copper slags. The results indicate that the rate of copper slags smelting oxidation desulfurization depends on the matte mass transfer rate through the slag phase. After the oxidation treatment, sulfur of copper slags can be removed as SO2 efficiently. Amount of Ca2+ of copper slags affects the desulfurization rate greatly, and the slag desulfurization rate is reduced by adding a certain amount of CaF2 and CaO. Compared with CaF2, CaO is negative to slags sulfur removal with equal Ca2+ addition. Under the air flow of 0.3 U/min, the sulfur content of copper slags can be reduced to 0. 004 67% in the condition of the holding time of 3 min and the holding temperature of 1 500 ℃. The sulfur content of molten iron is reduced to 0. 000 8 % in the smelting reduction of treated slags, and the problem of high sulfur content of molten iron obtained by smelting reduction with copper slag has been successively solved.

  14. Experimental Analysis Of 80 Tr Capacity Air Cooled Scroll Chiller Using R-22 & R-407c.

    Directory of Open Access Journals (Sweden)

    Mr. Bhikhu B,

    2014-04-01

    Full Text Available In air conditioning systems, chilled water is typically distributed to heat exchangers, or coils, in air handling units or other types of terminal devices which cool the air in their respective space(s, and then the water is recirculated back to the chiller to be cooled again. These cooling coils transfer sensible heat and latent heat from the air to the chilled water, thus cooling and usually dehumidifying the air stream. The experiment works on 80 TR capacity Air Cooled Scroll Chiller systems. Vapour compression refrigeration cycle is used for cooling chilling water. Capacity of compressor is taken same for the different refrigerants used for experimental analysis. During experimental work used R-22 and R-407C as refrigerants. Theoretical COP of system with R- 22 refrigerant is 4.166 and actual COP is 2.227. For 80 TR capacity scroll air cooled chiller, theoretical COP of system with R-407c refrigerant is 3.465 and actual COP is 2.745 respectively. Based on the result analysis the same capacity of air cooling system with scroll compressor Actual COP of R-407C is higher than R-22. It means R-407C is also a alternative refrigerant for air cooled chilling system and also for HVAC system.

  15. Measures against the adverse impact of natural wind on air-cooled condensers in power plant

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The natural wind plays disadvantageous roles in the operation of air-cooled steam condensers in power plant.It is of use to take various measures against the adverse effect of wind for the performance improvement of air-cooled condensers.Based on representative 2×600 MW direct air-cooled power plant,three ways that can arrange and optimize the flow field of cooling air thus enhance the heat transfer of air-cooled condensers were proposed.The physical and mathematical models of air-cooled condensers with various flow leading measures were presented and the flow and temperature fields of cooling air were obtained by CFD simulation.The back pressures of turbine were calculated for different measures on the basis of the heat transfer model of air-cooled condensers.The results show that the performance of air-cooled condensers is improved thus the back pressure of turbine is lowered to some extent by taking measures against the adverse impact of natural wind.

  16. Preparation of Slag Wool by Integrated Waste-Heat Recovery and Resource Recycling of Molten Blast Furnace Slags: From Fundamental to Industrial Application

    OpenAIRE

    Dawei Zhao; Zuotai Zhang; Xulong Tang; Lili Liu; Xidong Wang

    2014-01-01

    The present paper investigated the process of the slag wool fabrication using high temperature blast furnace (BF) slag modified by coal ash (CA). The liquidus temperature and viscosity of the slag system with different mass ratios of BF slag and CA were measured through an inner cylinder rotation method. The approximate mass ratio used to fabricate the slag wool was therefore determined and slag wool was then successfully prepared with a high-speed air injection method in the laboratory. The ...

  17. Transient Performance of Air-cooled Condensing Heat Exchanger in Long-term Passive Cooling System during Decay Heat Load

    International Nuclear Information System (INIS)

    In the event of a 'loss of coolant accident'(LOCA) and a non-LOCA, the secondary passive cooling system would be activated to cool the steam in a condensing heat exchanger that is immersed in an emergency cooldown tank (ECT). Currently, the capacities of these ECTs are designed to be sufficient to remove the sensible and residual heat from the reactor coolant system for 72 hours after the occurrence of an accident. After the operation of a conventional passive cooling system for an extended period, however, the water level falls as a result of the evaporation from the ECT, as steam is emitted from the open top of the tank. Therefore, the tank should be refilled regularly from an auxiliary water supply system when the system is used for more than 72 hours. Otherwise, the system would fail to dissipate heat from the condensing heat exchanger due to the loss of the cooling water. Ultimately, the functionality of the passive cooling system would be seriously compromised. As a passive means of overcoming the water depletion in the tank, Kim et al. applied for a Korean patent covering the concept of a long-term passive cooling system for an ECT even after 72 hours. This study presents transient performance of ECT with installing air-cooled condensing heat exchanger under decay heat load. The cooling capacity of an air-cooled condensing heat exchanger was evaluated to determine its practicality

  18. Preliminary Design of KAIST Micro Modular Reactor with Dry Air Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Seung Joon; Bae, Seong Jun; Kim, Seong Gu; Lee, Jeong Ik [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    KAIST research team recently proposed a Micro Modular Reactor (MMR) concept which integrates power conversion unit (PCU) with the reactor core in a single module. Using supercritical CO{sub 2} as a working fluid of cycle can achieve physically compact size due to small turbomachinery and heat exchangers. The objective of this project is to develop a concept that can operate at isolated area. The design focuses especially on the operation in the inland area where cooling water is insufficient. Thus, in this paper the potential for dry air cooling of the proposed reactor will be examined by sizing the cooling system with preliminary approach. The KAIST MMR is a recently proposed concept of futuristic SMR. The MMR size is being determined to be transportable with land transportation. Special attention is given to the MMR design on the dry cooling, which the cooling system does not depend on water. With appropriately designed air cooling heat exchanger, the MMR can operate autonomously. Two types of air cooling methods are suggested. One is using fan and the other is utilizing cooling tower for the air flow. With fan type air cooling method it consumes about 0.6% of generated electricity from the nuclear reactor. Cooling tower occupies an area of 227 m{sup 2} and 59.6 m in height. This design is just a preliminary estimation of the dry cooling method, and therefore more detailed and optimal design will be followed in the next phase.

  19. Design guidelines for the forced-air cooling process of strawberries

    Energy Technology Data Exchange (ETDEWEB)

    Ferrua, M.J.; Singh, R.P. [Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616 (United States)

    2009-12-15

    The complex structure of the package systems currently used by the strawberry industry has prevented an efficient design of the forced-air cooling process. In this study, we investigated the mechanisms through which different design parameters affect the rate and uniformity of cooling, using a previously validated computational fluid dynamics model. The results indicated that the vent area has a significant effect on the cooling rate, but not on its uniformity. A design that reduces bypassing will not necessarily increase the cooling rate, because there is less bypass air to cool down the air exiting from each clamshell, so that the air entering the next clamshell becomes warmer. Periodic airflow reversal improves the rate and homogeneity of the cooling process. (author)

  20. 16 CFR Appendix H to Part 305 - Cooling Performance and Cost for Central Air Conditioners

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Cooling Performance and Cost for Central Air Conditioners H Appendix H to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC... RULEâ) Pt. 305, App. H Appendix H to Part 305—Cooling Performance and Cost for Central Air...

  1. Experimental feasibility study of radial injection cooling of three-pad radial air foil bearings

    Science.gov (United States)

    Shrestha, Suman K.

    Air foil bearings use ambient air as a lubricant allowing environment-friendly operation. When they are designed, installed, and operated properly, air foil bearings are very cost effective and reliable solution to oil-free turbomachinery. Because air is used as a lubricant, there are no mechanical contacts between the rotor and bearings and when the rotor is lifted off the bearing, near frictionless quiet operation is possible. However, due to the high speed operation, thermal management is one of the very important design factors to consider. Most widely accepted practice of the cooling method is axial cooling, which uses cooling air passing through heat exchange channels formed underneath the bearing pad. Advantage is no hardware modification to implement the axial cooling because elastic foundation structure of foil bearing serves as a heat exchange channels. Disadvantage is axial temperature gradient on the journal shaft and bearing. This work presents the experimental feasibility study of alternative cooling method using radial injection of cooling air directly on the rotor shaft. The injection speeds, number of nozzles, location of nozzles, total air flow rate are important factors determining the effectiveness of the radial injection cooling method. Effectiveness of the radial injection cooling was compared with traditional axial cooling method. A previously constructed test rig was modified to accommodate a new motor with higher torque and radial injection cooling. The radial injection cooling utilizes the direct air injection to the inlet region of air film from three locations at 120° from one another with each location having three axially separated holes. In axial cooling, a certain axial pressure gradient is applied across the bearing to induce axial cooling air through bump foil channels. For the comparison of the two methods, the same amount of cooling air flow rate was used for both axial cooling and radial injection. Cooling air flow rate was

  2. Evaluation of a Design Concept for the Combined Air-water Passive Cooling PAFS+

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sung Won; Kwon, Taesoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The APR+ system provides the Passive Auxiliary Feed-water System (PAFS) for the passive cooling capability. However, the current design requirement for working time for the PAFS is about 8 hours only. Thus, current working time of PAFS can not meet the required 72 hours cooling capability for the long term SBO situation. To meet the 72 hours cooling, the pool capacity should be almost 3∼4 times larger than that of current water cooling tank. In order to continue the PAFS operation for 72 hours, a new passive air-water combined cooling system is proposed. This paper provides the feasibility study on the combined passive air-water cooling system. Figure 1 and 2 show the conceptual difference of the PAFS and combined passive air-water cooling system, respectively. Simple performance evaluation of the passive air cooling heat exchanger has been conducted by the MARS calculation. For the postulated FLB scenario, 4800 heat exchanger tubes and 5 m/s air velocity are not sufficient to sustain the PCCT pool level for 72 hour cooling. Further works on the system design and performance enhancing plan are required to fulfill the 72 hours long term passive cooling.

  3. Slag Behavior in Gasifiers. Part II: Constitutive Modeling of Slag

    Energy Technology Data Exchange (ETDEWEB)

    Massoudi, Mehrdad [National Energy Technology Laboratory; Wang, Ping

    2013-02-07

    The viscosity of slag and the thermal conductivity of ash deposits are among two of the most important constitutive parameters that need to be studied. The accurate formulation or representations of the (transport) properties of coal present a special challenge of modeling efforts in computational fluid dynamics applications. Studies have indicated that slag viscosity must be within a certain range of temperatures for tapping and the membrane wall to be accessible, for example, between 1,300 °C and 1,500 °C, the viscosity is approximately 25 Pa·s. As the operating temperature decreases, the slag cools and solid crystals begin to form. Since slag behaves as a non-linear fluid, we discuss the constitutive modeling of slag and the important parameters that must be studied. We propose a new constitutive model, where the stress tensor not only has a yield stress part, but it also has a viscous part with a shear rate dependency of the viscosity, along with temperature and concentration dependency, while allowing for the possibility of the normal stress effects. In Part I, we reviewed, identify and discuss the key coal ash properties and the operating conditions impacting slag behavior.

  4. Simulation and Optimization of Air-Cooled PEMFC Stack for Lightweight Hybrid Vehicle Application

    Directory of Open Access Journals (Sweden)

    Jingming Liang

    2015-01-01

    Full Text Available A model of 2 kW air-cooled proton exchange membrane fuel cell (PEMFC stack has been built based upon the application of lightweight hybrid vehicle after analyzing the characteristics of heat transfer of the air-cooled stack. Different dissipating models of the air-cooled stack have been simulated and an optimal simulation model for air-cooled stack called convection heat transfer (CHT model has been figured out by applying the computational fluid dynamics (CFD software, based on which, the structure of the air-cooled stack has been optimized by adding irregular cooling fins at the end of the stack. According to the simulation result, the temperature of the stack has been equally distributed, reducing the cooling density and saving energy. Finally, the 2 kW hydrogen-air air-cooled PEMFC stack is manufactured and tested by comparing the simulation data which is to find out its operating regulations in order to further optimize its structure.

  5. COMMISION DEBUGGING OF AIR-COOLED ISLAND SYSTEMS FOR 600 MW AIR-COOLED UNITS%600 MW空冷机组空冷岛的调试

    Institute of Scientific and Technical Information of China (English)

    杨海生; 李路江; 吴瑞涛; 刘春报; 刘红霞

    2009-01-01

    The problems appeared in commission debugging of the air-cooled island systems for two 600 MW air-cooled units of Guodian Longshan Power Generation Co Ltd,such as undue fast vacuum drop in air-cooled island during start-up of said units after their shutdown in winter, the rapid rise of back-pressure in said air-cooled isrand due to full-load operation of all cooling air fans and air-leakage in the steam seal system, etc. , have been analysed, and corresponding preventive measures a-dopted for above-mentioned problems in the commission debugging process being given. Regarding to a part of problems, which hadn't been solved in debugging, some concrete recommendations have been put forward.%对国电河北龙山发电有限公司2×600 MW空冷机组空冷岛的调试中出现的问题进行了分析,如冬季停机后起动空冷岛真空下降过快,全部空冷风机全负荷运转,汽封系统漏空气空冷岛背压急剧上升等,给出了调试中对上述问题采取的相关防范措施,并对调试中部分未能解决的问题,提出了具体建议.

  6. Control of cooling processes with forced-air aimed at efficiency energetic and the cooling time of horticultural products

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Joao Carlos Teles Ribeiro da; Mederos, Barbara Janet Teruel [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola

    2008-07-01

    The application of cooling technologies for the conservation of horticultural products is one of the stages the Cold Chain. In Brazil particularly, as a country with tropical climate with average high temperature almost all year, the application of these technologies is very important because the shelf-life of fresh horticultural products, with quality that the market demands, is directly related to temperature. In particular, the systems of forced air cooling operate according to the flow of air predetermined in the project according to the quantity of product to cool. When actual conditions differ from considerations of the project, as to the quantity of product, a situation very common in agricultural properties and packing houses, the fan will continue providing the nominal flow rate, causing alteration of the cost-benefit relation of process. This project aims at the development of a micro-processing equipment (output current of 4 to 20 mA) to control the rotational speed of the motor of the fan systems, air forced through an inverter of frequency. The objective is development of a Man-Machine Interface, based on an algorithm, which, through the introduction of mass product data and the automatic acquisition of data from temperature of the product and the camera, is calculated the cooling time. The rotation of the engine fan will be amended automatically, to maintain air flow with a proper cost-benefit, in connection with the reduction of cooling time, energy consumption, for the increasing the shelf life of products. (author)

  7. Citywide Impacts of Cool Roof and Rooftop Solar Photovoltaic Deployment on Near-Surface Air Temperature and Cooling Energy Demand

    Science.gov (United States)

    Salamanca, F.; Georgescu, M.; Mahalov, A.; Moustaoui, M.; Martilli, A.

    2016-10-01

    Assessment of mitigation strategies that combat global warming, urban heat islands (UHIs), and urban energy demand can be crucial for urban planners and energy providers, especially for hot, semi-arid urban environments where summertime cooling demands are excessive. Within this context, summertime regional impacts of cool roof and rooftop solar photovoltaic deployment on near-surface air temperature and cooling energy demand are examined for the two major USA cities of Arizona: Phoenix and Tucson. A detailed physics-based parametrization of solar photovoltaic panels is developed and implemented in a multilayer building energy model that is fully coupled to the Weather Research and Forecasting mesoscale numerical model. We conduct a suite of sensitivity experiments (with different coverage rates of cool roof and rooftop solar photovoltaic deployment) for a 10-day clear-sky extreme heat period over the Phoenix and Tucson metropolitan areas at high spatial resolution (1-km horizontal grid spacing). Results show that deployment of cool roofs and rooftop solar photovoltaic panels reduce near-surface air temperature across the diurnal cycle and decrease daily citywide cooling energy demand. During the day, cool roofs are more effective at cooling than rooftop solar photovoltaic systems, but during the night, solar panels are more efficient at reducing the UHI effect. For the maximum coverage rate deployment, cool roofs reduced daily citywide cooling energy demand by 13-14 %, while rooftop solar photovoltaic panels by 8-11 % (without considering the additional savings derived from their electricity production). The results presented here demonstrate that deployment of both roofing technologies have multiple benefits for the urban environment, while solar photovoltaic panels add additional value because they reduce the dependence on fossil fuel consumption for electricity generation.

  8. Citywide Impacts of Cool Roof and Rooftop Solar Photovoltaic Deployment on Near-Surface Air Temperature and Cooling Energy Demand

    Science.gov (United States)

    Salamanca, F.; Georgescu, M.; Mahalov, A.; Moustaoui, M.; Martilli, A.

    2016-04-01

    Assessment of mitigation strategies that combat global warming, urban heat islands (UHIs), and urban energy demand can be crucial for urban planners and energy providers, especially for hot, semi-arid urban environments where summertime cooling demands are excessive. Within this context, summertime regional impacts of cool roof and rooftop solar photovoltaic deployment on near-surface air temperature and cooling energy demand are examined for the two major USA cities of Arizona: Phoenix and Tucson. A detailed physics-based parametrization of solar photovoltaic panels is developed and implemented in a multilayer building energy model that is fully coupled to the Weather Research and Forecasting mesoscale numerical model. We conduct a suite of sensitivity experiments (with different coverage rates of cool roof and rooftop solar photovoltaic deployment) for a 10-day clear-sky extreme heat period over the Phoenix and Tucson metropolitan areas at high spatial resolution (1-km horizontal grid spacing). Results show that deployment of cool roofs and rooftop solar photovoltaic panels reduce near-surface air temperature across the diurnal cycle and decrease daily citywide cooling energy demand. During the day, cool roofs are more effective at cooling than rooftop solar photovoltaic systems, but during the night, solar panels are more efficient at reducing the UHI effect. For the maximum coverage rate deployment, cool roofs reduced daily citywide cooling energy demand by 13-14 %, while rooftop solar photovoltaic panels by 8-11 % (without considering the additional savings derived from their electricity production). The results presented here demonstrate that deployment of both roofing technologies have multiple benefits for the urban environment, while solar photovoltaic panels add additional value because they reduce the dependence on fossil fuel consumption for electricity generation.

  9. Air Corrosivity in U.S. Outdoor-Air-Cooled Data Centers is Similar to That in Conventional Data Centers

    Energy Technology Data Exchange (ETDEWEB)

    Coles, Henry C.; Han, Taewon; Price, Phillip N.; Gadgil, Ashok J.; Tschudi, William F.

    2011-07-17

    There is a concern that environmental-contamination caused corrosion may negatively affect Information Technology (IT) equipment reliability. Nineteen data centers in the United States and two in India were evaluated using Corrosion Classification Coupons (CCC) to assess environmental air quality as it may relate IT equipment reliability. The data centers were of two basic types: closed and outside-air cooled. A closed data center provides cool air to the IT equipment using air conditioning in which only a small percent age of the recirculation air is make-up air continuously supplied from outside to meet human health requirements. An outside-air cooled data center uses outside air directly as the primary source for IT equipment cooling. Corrosion measuring coupons containing copper and silver metal strips were placed in both closed and outside-air cooled data centers. The coupons were placed at each data center (closed and outside-air cooled types) with the location categorized into three groups: (1) Outside - coupons sheltered, located near or at the supply air inlet, but located before any filtering, (2) Supply - starting just after initial air filtering continuing inside the plenums and ducts feeding the data center rooms, and (3) Inside located inside the data center rooms near the IT equipment. Each coupon was exposed for thirty days and then sent to a laboratory for a corrosion rate measurement analysis. The goal of this research was to investigate whether gaseous contamination is a concern for U.S. data center operators as it relates to the reliability of IT equipment. More specifically, should there be an increased concern if outside air for IT equipment cooling is used To begin to answer this question limited exploratory measurements of corrosion rates in operating data centers in various locations were undertaken. This study sought to answer the following questions: (1) What is the precision of the measurements (2) What are the approximate statistical

  10. Cooling Performance Characteristics on Mobile Air-Conditioning System for Hybrid Electric Vehicles

    OpenAIRE

    Ho-Seong Lee; Moo-Yeon Lee

    2013-01-01

    This study investigates the cooling performance characteristics of the mobile air-conditioning system using R744 (CO2) for the hybrid electric vehicle as an alternative to both the R-134a and the conventional air-conditioning system. The developed air-conditioning system is operated with an electric driven compressor in the battery driving mode and a belt driven compressor in the engine driving mode. The cooling performance characteristics of the developed system have been analyzed by experim...

  11. Optimum design of bipolar plates for separate air flow cooling system of PEM fuel cells stacks

    Science.gov (United States)

    Franco, Alessandro

    2015-12-01

    The paper discusses about thermal management of PEM fuel cells. The objective is to define criteria and guidelines for the design of the air flow cooling system of fuel cells stacks for different combination of power density, bipolar plates material, air flow rate, operating temperature It is shown that the optimization of the geometry of the channel permits interesting margins for maintaining the use of separate air flow cooling systems for high power density PEM fuel cells.

  12. The Experimental Study of Water Cooled Electrode Used in Slag Wool Insulation Furnace%矿渣棉保温炉用水冷电极的实验研究

    Institute of Scientific and Technical Information of China (English)

    唐洋洋; 袁守谦; 王旭; 马栓

    2015-01-01

    Electrode consumpted seriously in slag wool production, prolong smelting time and reducing the productivity.This paper put forward a water cooled electrode in slag wool production to reducing consumption of electrode consumption, 12 groups oxidation experiments of water cooled electrode is conducted under laboratory conditions, it shows 1 h pure graphite quality loss ratio is 6.67%, and the quality loss of graphite in water cooled electrode corresponding maximum rate reached to 3.808×10-2%.%矿渣棉生产电极消耗严重,延长了冶炼时间且降低生产率,设计出矿渣棉生产用水冷电极来降低电极消耗。在实验室条件下进行12组水冷电极氧化实验,1h纯石墨质量损失比为6.67%,而水冷电极相应的石墨端质量损失率最大达到3.808×10-2%。

  13. Discussion on Feasibility and Economy of 1000-MW Ultra-Supercritical Air-Cooling Unit

    Institute of Scientific and Technical Information of China (English)

    Zhu Jun; Wang Yunze; Jin Wen

    2007-01-01

    @@ Based on analysis on types and features of domestically made 1000-MW large ultra supercritical steam turbine and 600-MW air cooling steam turbine,the author puts forward that 1000-MW ultra supercritical air-cooling turbine can be assembled with high and medium pressure cylinder modules of 1000-MW ultra-supercritical steam turbine and low-pressure cylinder module of 600-MW tow-cylinder and tow-exhaust air-cooling turbine.In addition,the economy of the assembled turbine is discussed, and designing considerations and issues need to be furtherstudied are proposed as well.

  14. Influence of Different Vortex Generators on Heat Transfer in Direct Air-Cooled Condensers

    Institute of Scientific and Technical Information of China (English)

    ZHOU Guobing; YANG Laishun

    2012-01-01

    With the capacity of air cooling turbines increasing, the air-cooled steam condenser has been developed to the single fiat tube. Fig.1 shows the studied single-row wavy-finned flat tube. Vortex generators are more and more used in oil and chemical industry, power generation, and refrigeration industry in the heat exchanger. The analyses are performed to investigate the effect of vortex generators on pressure drop and heat transfer of single-row wavy-finned fiat tubes of direct air-cooled condensers.

  15. Experimental evaluation of a direct air-cooled lithium bromide-water absorption prototype for solar air conditioning

    OpenAIRE

    González-Gil, A.; Izquierdo, M.; Marcos, J.D.; Palacios, E.

    2011-01-01

    Abstract A new direct air-cooled single-effect LiBr-H2O absorption prototype is described and proposed for use in solar cooling. As distinguishing aspects, it presents: an adiabatic absorber using flat-fan sheets; an air-cooling system that directly refrigerates both the condenser and the absorber and; the possibility of being operated also as a double-effect unit. A solar facility comprising a 48m2 field of flat-plate collectors was used to test the single-effect operation mode of...

  16. Experimental results of a direct air-cooled ammonia–lithium nitrate absorption refrigeration system

    International Nuclear Information System (INIS)

    Absorption thermal cooling systems driven by renewable energy are a viable option in order to reduce fossil fuel consumption and the associated emissions. This work shows the results of an air cooled absorption cooling prototype working with an ammonia–lithium nitrate mixture at high ambient temperatures. An absorption refrigeration system was designed and built. The prototype is a one stage ammonia–lithium nitrate air cooled chiller. The experimental system was instrumented to evaluate each component. This paper shows the operation conditions in the experimental unit as well as some of the heat loads encountered at different operating conditions. The system was operated successfully at ambient temperatures in the range of 25–35 °C. A series of test showed that even at ambient temperatures it can be operated at evaporator temperatures below 10 °C producing chilled water for air conditioning applications such as radiative cooling panels. The system proved to stabilize very quickly and no risk of crystallization was encountered so the first results are promising in order to continue with the development of a more advanced prototype. - Highlights: •Experimental results of a direct air-cooled ammonia–lithium nitrate system. •The prototype is a one stage ammonia–lithium nitrate air cooled chiller. •The absorption system was operated successfully at ambient temperatures. •Cooling loads of 4.5 kW were reached in the chilled water side

  17. Performance analysis of solar air cooled double effect LiBr/H2O absorption cooling system in subtropical city

    International Nuclear Information System (INIS)

    Highlights: • The meteorological data during the working period of air conditioning was measured. • The suitable working range of collector temperature of system was gotten. • The characteristic of hourly and monthly total efficiency of system were obtained. • The yearly performance of system was calculated. - Abstract: Due to the absence of cooling tower and independent on water, the air cooled solar double effect LiBr/H2O absorption cooling system is more convenient to be used in commercial building and household use. The performance with collector temperature is an important field for such system. The paper mainly deals with the performance with collector temperature for the solar air cooled double effect LiBr/H2O absorption cooling system in subtropical city. The parameters of system are: aperture area of collector array is 27 m2, tilted angle of collector with respect to the horizontal plane is 20 toward to south evaporator temperature is 5 °C and the cooling capacity is 20 kW. The simulation is based on the meteorological data of monthly typical day which was summarized from a year round measured data. A corresponding parametric model was developed. The hourly and average performance with the collector temperature for monthly typical day was obtained and discussed. It was found that the suitable working range of inlet temperature of collector is 110–130 °C to improve performance and lower the risk of crystallization. The difference of hourly total efficiency in 9:00–16:00 is less, and the monthly total efficiency from May to October is approximate. The yearly performance of system including total efficiency, cooling capacity per area of collector and solar fraction was given. Furthermore, the effect of effectiveness of heat exchanger and pressure drop on total efficiency and solar fraction was studied and compared. The paper can serve as a preliminary investigation of solar air cooled double effect LiBr/H2O absorption cooling system in

  18. Craft-joule project: air-cooled water LiBr absorption cooling machine of low capacity for air conditioning (ACABMA)

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, A; Castro, J; Perez Segarra, C.D [Universitat Politecnica de Catalunya, Barcelona (Spain); Lucena, M.A [Instituto Nacional de Tecnica Aeroespecial (Spain)] (and others)

    2000-07-01

    The ACABMA (Air-Cooled water-LiBr Absorption cooling Machine of low capacity for Air- conditioning) project is a Craft-Joule Project within the framework of the Non Nuclear Energy Programme Joule III coordinated by the Centre Technologic de Transferencia de Calor (CTTC). The basic objective of this project is the development of a new air-cooled absorption cooling machine for air-conditioning, in the low power sector market. Making use of water-LiBr technology together with the air-cooling feature, it is possible to reach a better relationship between quality (in terms of performance, ecology, etc.) and price of such absorption machines, than the ones existing on the market. Air-cooling instead of water cooling saves installation costs specially in small systems and removes the demand for cooling water (an important aspect in Southern-European countries), thus increasing the possible application range. The main interest for the SME proposers is to take advantage of the increasing cooling demand in Europe, specially in southern countries. Another point of interest for the SME proposers is the development of a cheaper cooling and heating system in terms of energy and installation costs. In this moment the solar cooling systems are approx. 30% more expensive than the conventional ones. A cheaper absorption machine due to the air-cooling feature together with the possibility of energy savings due to low generator temperatures, that allow the absorption machine for solar applications or waste heat, will lead to solar cooling and heating systems more competitive to the conventional ones. In order to achieve the above mentioned goal, the following step are necessary and will be carried out in this project: i)solution of the air-cooling of the water-LiBr machine, the main problem that up to now has not allowed commercialization, ii)reduction of the size of the air-cooled elements of the machine in order to reduce the machine costs, iii)development of an efficient control

  19. Cooling Rates of Humans in Air and in Water: An Experiment

    Science.gov (United States)

    Bohren, Craig F.

    2012-12-01

    In a previous article I analyzed in detail the physical factors resulting in greater cooling rates of objects in still water than in still air, emphasizing cooling of the human body. By cooling rate I mean the rate of decrease of core temperature uncompensated by metabolism. I concluded that the "correct ratio for humans is closer to 2 than to 10." To support this assertion I subsequently did experiments, which I report following a digression on hypothermia.

  20. Dehumidifying Air for Cooling & Refrigeration: Nanotechnology Membrane-based Dehumidifier

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-10-01

    Broad Funding Opportunity Announcement Project: Dais is developing a product called NanoAir which dehumidifies the air entering a building to make air conditioning more energy efficient. The system uses a polymer membrane that allows moisture but not air to pass through it. A vacuum behind the membrane pulls water vapor from the air, and a second set of membranes releases the water vapor outside. The membrane’s high selectivity translates into reduced energy consumption for dehumidification. Dais’ design goals for NanoAir are the use of proprietary materials and processes and industry-standard installation techniques. NanoAir is also complementary to many other energy saving strategies, including energy recovery.

  1. Analysis of nocturnal air temperature in districts using mobile measurements and a cooling indicator

    Science.gov (United States)

    Leconte, François; Bouyer, Julien; Claverie, Rémy; Pétrissans, Mathieu

    2016-08-01

    The urban heat island phenomenon is generally defined as an air temperature difference between a city center and the non-urbanized rural areas nearby. However, this description does not encompass the intra-urban temperature differences that exist between neighborhoods in a city. This study investigates the air temperature dynamics of neighborhoods for meteorological conditions that lead to important urban heat island amplitude. Local climate zones (LCZs) have been determined in Nancy, France, and mobile screen-height air temperature measurements are performed using an instrumented vehicle. Initially, hourly measurements are performed within four different LCZs. These results show that air temperature within LCZ demonstrates a nocturnal cooling in two phases, i.e., a first phase between 1 to 3 h before sunset and 3 to 5 h after sunset, and a second phase from 3 to 5 h after sunset to sunrise. During phase 1, neighborhoods exhibit different cooling rate values and air temperature gaps develop between districts, while during phase 2, cooling rates tend to be analogous. Then, a larger meteorological data set is used to investigate these two phases for a selection of 13 LCZs. Normalized cooling rates are calculated between daytime measures and nighttime measures in order to quantify the air temperature dynamics of the studied areas during phase 1. Considering this indicator, three groups are emerging: LCZ compact midrise and open midrise with mean normalized cooling rate values of 0.09 h -1 LCZ large lowrise and open lowrise/sparsely built with mean normalized cooling rate values of 0.011 h -1 LCZ low plants with mean normalized cooling rate values of 0.014 h -1 Results indicate that the relative position of LCZ within the conurbation does not drive air temperature dynamics during phase 1. In addition, measures performed during phase 2 tend to illustrate that cooling rates are similar to all LCZ during this period.

  2. Comparison of different air supply and cooling systems in pig fattening houses; Vergleich von Zuluftfuehrungs- und Kuehlungssystemen in der Schweinemast

    Energy Technology Data Exchange (ETDEWEB)

    Threm, Joachim; Gallmann, Eva; Jungbluth, Thomas [Hohenheim Univ. (Germany). Fachgebiet Verfahrenstechnik der Tierhaltungssysteme; Pflanz, Wilhelm [Bildungs- und Wissenszentrum LSZ, Boxberg (Germany). Referat Haltungssysteme, Stallbau, Stallklima, Biogas

    2011-07-01

    There is a need for research regarding the optimization of air supply and of air cooling systems of livestock houses for fatteners. A decision support project for the German Ministry of Agriculture has been established to investigate such technologies on a research farm and under practical conditions. Since April 2011, on the research farm Landesanstalt fuer Schweinezucht (LSZ Boxberg) measurements on three air supply and cooling system are carried out: Underfloor air inlet and supply, cooling pad and high pressure evaporative indoor air cooling. First results show differences concerning the parameters temperature, differential pressure and air velocity. (orig.)

  3. Design considerations and experimental observations for the TAMU air-cooled reactor cavity cooling system for the VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Sulaiman, S. A., E-mail: shamsulamri@tamu.edu; Dominguez-Ontiveros, E. E., E-mail: elvisdom@tamu.edu; Alhashimi, T., E-mail: jbudd123@tamu.edu; Budd, J. L., E-mail: dubaiboy@tamu.edu; Matos, M. D., E-mail: mailgoeshere@gmail.com; Hassan, Y. A., E-mail: yhasssan@tamu.edu [Department of Nuclear Engineering, Texas A and M University, College Station, TX, 77843-3133 (United States)

    2015-04-29

    The Reactor Cavity Cooling System (RCCS) is a promising passive decay heat removal system for the Very High Temperature Reactor (VHTR) to ensure reliability of the transfer of the core residual and decay heat to the environment under all off-normal circumstances. A small scale experimental test facility was constructed at Texas A and M University (TAMU) to study pertinent multifaceted thermal hydraulic phenomena in the air-cooled reactor cavity cooling system (RCCS) design based on the General Atomics (GA) concept for the Modular High Temperature Gas-Cooled Reactor (MHTGR). The TAMU Air-Cooled Experimental Test Facility is ⅛ scale from the proposed GA-MHTGR design. Groundwork for experimental investigations focusing into the complex turbulence mixing flow behavior inside the upper plenum is currently underway. The following paper illustrates some of the chief design considerations used in construction of the experimental test facility, complete with an outline of the planned instrumentation and data acquisition methods. Computational Fluid Dynamics (CFD) simulations were carried out to furnish some insights on the overall behavior of the air flow in the system. CFD simulations assisted the placement of the flow measurement sensors location. Preliminary experimental observations of experiments at 120oC inlet temperature suggested the presence of flow reversal for cases involving single active riser at both 5 m/s and 2.25 m/s, respectively and four active risers at 2.25 m/s. Flow reversal may lead to thermal stratification inside the upper plenum by means of steady state temperature measurements. A Particle Image Velocimetry (PIV) experiment was carried out to furnish some insight on flow patterns and directions.

  4. Cooling energy efficiency and classroom air environment of a school building operated by the heat recovery air conditioning unit

    International Nuclear Information System (INIS)

    The recently-built school buildings have adopted novel heat recovery ventilator and air conditioning system. Heat recovery efficiency of the heat recovery facility and energy conservation ratio of the air conditioning unit were analytically modeled, taking the ventilation networks into account. Following that, school classroom displacement ventilation and its thermal stratification and indoor air quality indicated by the CO2 concentration have been numerically modeled concerning the effects of delivering ventilation flow rate and supplying air temperature. Numerical results indicate that the promotion of mechanical ventilation rate can simultaneously boost the dilution of indoor air pollutants and the non-uniformity of indoor thermal and pollutant distributions. Subsequent energy performance analysis demonstrates that classroom energy demands for ventilation and cooling could be reduced with the promotion of heat recovery efficiency of the ventilation facility, and the energy conservation ratio of the air conditioning unit decreases with the increasing temperatures of supplying air. Fitting correlations of heat recovery ventilation and cooling energy conservation have been presented. - Highlights: • Low energy school buildings and classroom environment. • Heat recovery facility operating with an air conditioning unit. • Displacement ventilation influenced by the heat recovery efficiency. • Energy conservation of cooling and ventilation through heat recovery. • Enhancement of classroom environment with reduction of school building energy

  5. Numerical simulation on internal and external flow field of a SCAL indirect air cooling tower

    Institute of Scientific and Technical Information of China (English)

    TIAN Songfeng; CHAI Yanqin; XIANG Tongqiong; ZHOU Guangsha

    2014-01-01

    According to the actual size of cooling tube bundle and the arrangement of cooling triangle of a surface condenser aluminum exchangers (SCAL)natural draft cooling tower,the geometric model of heat transfer elements at the tower bottom was established.On the basis of the RNG k-εturbulence model and porous medium model,three-dimensional numerical simulation was carried out for the inner and external flow field of the air cooling tower,to investigate the influence of environmental conditions on the tower's operation performance.The results show that,with an increase in ambient wind speed,the inlet air speed at windward side of the tower increases gradually,while that at crosswind side and lee side decreases and tends to be obvious;the tower ventilation rate and outlet air speed increases at first and then decreases,and their maximum values appear when the wind speed is 2 m/s.

  6. Correlation of Cooling Data from an Air-Cooled Cylinder and Several Multicylinder Engines

    Science.gov (United States)

    Pinkel, Benjamin; Ellerbrock, Herman H , Jr

    1940-01-01

    The theory of engine-cylinder cooling developed in a previous report was further substantiated by data obtained on a cylinder from a Wright r-1820-g engine. Equations are presented for the average head and barrel temperatures of this cylinder as functions of the engine and the cooling conditions. These equations are utilized to calculate the variation in cylinder temperature with altitude for level flight and climb. A method is presented for correlating average head and barrel temperatures and temperatures at individual points on the head and the barrel obtained on the test stand and in flight. The method is applied to the correlation and the comparison of data obtained on a number of service engines. Data are presented showing the variation of cylinder temperature with time when the power and the cooling pressure drop are suddenly changed.

  7. Separation of Iron Droplets From Titania Bearing Slag

    Institute of Scientific and Technical Information of China (English)

    WANG Ming-yu; LOU Tai-ping; ZHANG Li; SUI Zhi-tong

    2008-01-01

    Owing to smelting vanadium-titanium magnetite ore, the amount of iron entrainment in slag as droplets is far higher than that in conventional BF slag. However, the iron droplets can be easily settled by blowing air into the molten slag. The results show that more than 80% of iron droplets in titania bearing slag can be settled and separated after treatment. The temperature rise of molten slag during the oxidizing process and the decreased viscosity caused by the component change of slag as well as air stirring in slag both accelerate the iron droplets settling. The vanadium content in the settled iron droplets and the original iron droplets was obtained by chemical analysis. The possible reason for the increased vanadium in the settled iron droplets was discussed by thermodynamic principles.

  8. 风冷式干除渣系统设备故障分析及处理%Analysis and treatment of equipment faults in air-cooled and dry deslagging system

    Institute of Scientific and Technical Information of China (English)

    何宏; 鲁术全

    2012-01-01

    针对风冷式干除渣设备在应用中出现闸斗堵焦,碎渣机上部蓬焦,清扫链脱轨,碎渣机易损件、斗提机链条和提斗使用周期短等问题,通过对故障原因进行分析,提出了改造方案及措施。改造结果表明:风冷式干除渣系统运行的稳定性、安全性和使用寿命均得到了提高,取得了良好的效果。%Aiming at the problems of the lock hopper coke block, the upper part of slag crusher covered with coke, the cleaning chain disorbition, and the short use cycle such as wearing parts of slag crusher, chain of bucket conveyer and bucket in the application of air-cooled and dry deslagging equipment, analyzes the causation of faults, puts forward improvement schemes and measures. The result shows that after the technical improvement, the stability, safety and service life of the air-cooled and dry deslagging system were promoted, which obtains better effect.

  9. An experimental investigation on air-side performances of finned tube heat exchangers for indirect air-cooling tower

    Directory of Open Access Journals (Sweden)

    Du Xueping

    2014-01-01

    Full Text Available A tremendous quantity of water can be saved if the air cooling system is used, comparing with the ordinary water-cooling technology. In this study, two kinds of finned tube heat exchangers in an indirect air-cooling tower are experimentally studied, which are a plain finned oval-tube heat exchanger and a wavy-finned flat-tube heat exchanger in a cross flow of air. Four different air inlet angles (90°, 60 °, 45°, and 30° are tested separately to obtain the heat transfer and resistance performance. Then the air-side experimental correlations of the Nusselt number and friction factor are acquired. The comprehensive heat transfer performances for two finned tube heat exchangers under four air inlet angles are compared. For the plain finned oval-tube heat exchanger, the vertical angle (90° has the worst performance while 45° and 30° has the best performance at small ReDc and at large ReDc, respectively. For the wavy-finned flat-tube heat exchanger, the worst performance occurred at 60°, while the best performance occurred at 45° and 90° at small ReDc and at large ReDc, respectively. From the comparative results, it can be found that the air inlet angle has completely different effects on the comprehensive heat transfer performance for the heat exchangers with different structures.

  10. Use of local convective and radiant cooling at warm environment: effect on thermal comfort and perceived air quality

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Duszyk, Marcin; Krejcirikova, Barbora;

    2012-01-01

    compared to without cooling. The acceptability of the thermal environment was similar for all cooling devices. The acceptability of air movement and PAQ increased when the local cooling methods were used. The best results were achieved with personalized ventilation and cooling fan. The improvement in PAQ...

  11. Power boost of gas turbines by inlet air cooling

    Energy Technology Data Exchange (ETDEWEB)

    White, C.; Raghu, S. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Mechanical Engineering; Giannotti, G.; Giannotti, H. [Giannotti Associates, Bellport, NY (United States)

    1996-12-31

    The design of a power boost system for an existing gas turbine unit using a direct spray evaporative spray cooling method is described in this paper. Experiments were conducted to determine the extent of cooling possible by this method, droplet size requirements and spray water requirements. Although up to 4.9% of power boost is theoretically possible at the design conditions of 32.2 C (90 F) and 60% relative humidity, various other constraints limit the actual power boost to about 3.8% of the nominal power. For small values of the wet-bulb depression (less than about 5 C or 10 F), the required droplet sizes for complete evaporation become so small (of the order of 5--10 microns with high flow rates) that production of them at the required flow rates is a challenging task.

  12. Performance and economic enhancement of cogeneration gas turbines through compressor inlet air cooling

    Science.gov (United States)

    Delucia, M.; Bronconi, R.; Carnevale, E.

    1994-04-01

    Gas turbine air cooling systems serve to raise performance to peak power levels during the hot months when high atmospheric temperatures cause reductions in net power output. This work describes the technical and economic advantages of providing a compressor inlet air cooling system to increase the gas turbine's power rating and reduce its heat rate. The pros and cons of state-of-the-art cooling technologies, i.e., absorption and compression refrigeration, with and without thermal energy storage, were examined in order to select the most suitable cooling solution. Heavy-duty gas turbine cogeneration systems with and without absorption units were modeled, as well as various industrial sectors, i.e., paper and pulp, pharmaceuticals, food processing, textiles, tanning, and building materials. The ambient temperature variations were modeled so the effects of climate could be accounted for in the simulation. The results validated the advantages of gas turbine cogeneration with absorption air cooling as compared to other systems without air cooling.

  13. Overview of direct air free cooling and thermal energy storage potential energy savings in data centres

    International Nuclear Information System (INIS)

    In the last years the total energy demand of data centres has experienced a dramatic increase which is expected to continue. This is why data centres industry and researchers are working on implementing energy efficiency measures and integrating renewable energy to overcome energy dependence and to reduce operational costs and CO2 emissions. The cooling system of these unique infrastructures can account for 40% of the total energy consumption. To reduce the energy consumption, free cooling strategies are used more and more, but so far there has been little research about the potential of thermal energy storage (TES) solutions to match energy demand and energy availability. Hence, this work intends to provide an overview of the potential of the integration of direct air free cooling strategy and TES systems into data centres located at different European locations. For each location, the benefit of using direct air free cooling is evaluated energetically and economically for a data centre of 1250 kW. The use of direct air free cooling is shown to be feasible. This does not apply the TES systems by itself. But when using TES in combination with an off-peak electricity tariff the operational cooling cost can be drastically reduced. - Highlights: • The total annual hours for direct air free cooling in data centres are calculated. • The potential of TES integration in data centres is evaluated. • The implementation of TES to store the ambient air cold is not recommended. • TES is feasible if combined with redundant chillers and off-peak electricity price. • The cooling electricity cost is being reduced up to 51%, depending on the location

  14. A passive decay heat removal system for LWRs based on air cooling

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, Hiroyasu, E-mail: mochizki@u-fukui.ac.jp [Research Institute of Nuclear Engineering, University of Fukui, 1-2-4 Kanawa-cho, Tsuruga, Fukui 914-0055 (Japan); Yano, Takahiro [Graduate School of Engineering, University of Fukui, 1-2-4 Kanawa-cho, Tsuruga, Fukui 914-0055 (Japan)

    2015-05-15

    Highlights: • A passive decay heat removal system for LWRs is discussed. • An air cooler model which condenses steam is developed. • The decay heat can be removed by air coolers with forced convection. • The dimensions of the air cooler are proposed. - Abstract: The present paper describes the capability of an air cooling system (ACS) to remove decay heat from a core of LWR such as an advanced boiling water reactor (ABWR) and a pressurized water reactor (PWR). The motivation of the present research is the Fukushima severe accident (SA) on 11 March 2011. Since emergency cooling systems using electricity were not available due to station blackout (SBO) and malfunctions, many engineers might understand that water cooling was not completely reliable. Therefore, a passive decay heat removal (DHR) system would be proposed in order to prevent such an SA under the conditions of an SBO event. The plant behaviors during the SBO are calculated using the system code NETFLOW++ for the ABWR and PWR with the ACS. Two types of air coolers (ACs) are applied for the ABWR, i.e., a steam condensing air cooler (SCAC) of which intake for heat transfer tubes is provided in the steam region, and single-phase type of which intake is provided in the water region. The DHR characteristics are calculated under the conditions of the forced air circulation and also the natural air convection. As a result of the calculations, the decay heat can be removed safely by the reasonably sized ACS when heat transfer tubes are cooled with the forced air circulation. The heat removal rate per one finned heat transfer tube is evaluated as a function of air flow rate. The heat removal rate increases as a function of the air flow rate.

  15. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing

    Energy Technology Data Exchange (ETDEWEB)

    Liapis, Ioannis, E-mail: iliapis@sidenor.vionet.gr [AEIFOROS SA, 12th km Thessaloniki-Veroia Rd, PO Box 59, 57008 Ionia, Thessaloniki (Greece); Papayianni, Ioanna [Laboratory of Building Materials, Department of Civil Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2015-02-11

    Highlights: • Addition of 10% perlite decreases specific weight of the slag by approx. 7.5%. • Slag-crucible interaction and thin coating layer result in variations in XRF. • XRD shows high glass content and smaller crystalline sizes due to rapid cooling. • SEM shows higher homogeneity and lower crystallisation for SiO{sub 2}/CaO-rich samples. • Physical properties (LA, PSV, AAV) of modified slag show limited deterioration. - Abstract: Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector.

  16. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing

    International Nuclear Information System (INIS)

    Highlights: • Addition of 10% perlite decreases specific weight of the slag by approx. 7.5%. • Slag-crucible interaction and thin coating layer result in variations in XRF. • XRD shows high glass content and smaller crystalline sizes due to rapid cooling. • SEM shows higher homogeneity and lower crystallisation for SiO2/CaO-rich samples. • Physical properties (LA, PSV, AAV) of modified slag show limited deterioration. - Abstract: Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector

  17. Observations of convective cooling in the tropical tropopause layer in AIRS data

    Directory of Open Access Journals (Sweden)

    H. Kim

    2004-11-01

    Full Text Available We investigate the impact of convection on the thermal structure of the Tropical Tropopause Layer (TTL. We use temperature profiles measured by the Atmospheric Infrared Sounder (AIRS onboard the Aqua satellite, and the time evolution of local convection determined by the National Centers for Environmental Protection/Aviation Weather Center (NCEP/AWS half-hourly infrared global geostationary composite. The observations demonstrate that the TTL is cooled by convection, in agreement with previous observations and model simulations. By using a global data set, we are able to investigate the variations in this convective cooling by season and region. The estimated cooling rate during active convection is 7.5~9 K/day. While we cannot unambiguously identify the cause of this cooling, our analysis suggests that radiative cooling is likely not an explanation.

  18. Observations of convective cooling in the tropical tropopause layer in AIRS data

    Science.gov (United States)

    Kim, H.; Dessler, A. E.

    2004-11-01

    We investigate the impact of convection on the thermal structure of the Tropical Tropopause Layer (TTL). We use temperature profiles measured by the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite, and the time evolution of local convection determined by the National Centers for Environmental Protection/Aviation Weather Center (NCEP/AWS) half-hourly infrared global geostationary composite. The observations demonstrate that the TTL is cooled by convection, in agreement with previous observations and model simulations. By using a global data set, we are able to investigate the variations in this convective cooling by season and region. The estimated cooling rate during active convection is 7.5~9 K/day. While we cannot unambiguously identify the cause of this cooling, our analysis suggests that radiative cooling is likely not an explanation.

  19. Experimental Study of Air Conditioning Unit of Evaporative Cooling Assisted Mechanical Refrigeration

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiang; XU Fang-cheng; WU Jun-mei

    2009-01-01

    The evaporative cooling,which assists the refrigeration machinery air-conditioning systems test-rig,has been designed.Its structure and working principle were described,and the performance test was con-ducted and analyzed.The test shows that making full use of the evaporative cooling"free cooling" in Spring and Autumn seasons can fully meet the requirements of air-conditioned comfort through the switch of the function in different seasons.Taking into account the evaporative cooling fan and pump energy consumption,compared with the traditional mechanical refrigeration system,more than 80 percent of energy can be saved,and the ener-gY efficiency ratio of the Unit(EER) is as high as 7.63.Using the two stages of indirect evaporative cooling to pre-cool the new wind in summer,under the conditions of the same air supply temperature requirements,0.83 kg/s chilled water saved can be equivalent to the traditional mechanical refrigeration system,and when the newwind ratio up to 50 percent.more than 10 percent load was reduced in mechanical refrigeration system.The overall EER increased about 35 percent.

  20. Experimental tests on the air cooling of the CLIC vertex detector

    CERN Document Server

    Duarte Ramos, Fernando; Nuiry, Francois-Xavier

    2016-01-01

    The strict requirements in terms of material budget for the inner region of the CLIC detector concept require the use of a dry gas for the cooling of the respective sensors. This, in conjunction with the compactness of the inner volumes, poses several challenges for the design of a cooling system that is able to fulfil the required detector specifications. This note summarizes the results obtained from experimental tests on the air cooling of the CLIC vertex detector as well as their comparison with the corresponding computational fluid dynamics simulations.

  1. STOCHASTIC ANALYSIS OF AN AIR CONDITION COOLING SYSTEM MODEL

    Directory of Open Access Journals (Sweden)

    Punam Phartyal

    2011-01-01

    Full Text Available The present study deals with the stochastic analysis of a real existing industrial systemmodel of a central air-condition (AC system. The system consists of three different subsystemsnamely- Air Blower, Compressor, water pump. All these subsystems are arranged in seriesnetwork. Transition probabilities as well as the recurrence relations for various reliability andcost effective measures are developed. Failure time distributions of all the subsystems are takenas exponential whereas repair time distributions are general. By using regenerative pointtechnique we have obtained various measures of system effectiveness such as –Reliability,MTSF, Availability, Busy period of repairman and Net expected profit. The results are alsodrawn in a particular case when repair time distributions are assumed as exponentials.

  2. Drag and Cooling with Various Forms of Cowling for a "Whirlwind" Radial Air-Cooled Engine I

    Science.gov (United States)

    Weick, Fred E

    1930-01-01

    This report presents the results of an investigation undertaken in the 20-foot Propeller Research Tunnel at Langley Field on the cowling of radial air-cooled engines. A portion of the investigation has been completed, in which several forms and degrees of cowling were tested on Wright "Whirlwind" J-5 engine mounted in the nose of a cabin fuselage. The cowlings varied from the one extreme of an entirely exposed engine to the other in which the engine was entirely inclosed. Cooling tests were made and each cowling modified, if necessary, until the engine cooled approximately as satisfactorily as when it was entirely exposed. Drag tests were then made with each form of cowling, and the effect of the cowling on the propulsive efficiency determined with a metal propeller. The propulsive efficiency was found to be practically the same with all forms of cowling. The drag of the cabin fuselage with uncowled engine was found to be more than three times as great as the drag of the fuselage with engine removed and nose rounded. The conventional forms of cowling, in which at least the tops of the cylinder heads and valve gear are exposed, reduce the drag somewhat, but the cowling entirely covering the engine reduces it 2.6 times as much as the best conventional one. The decrease in drag due to the use of spinners proved to be almost negligible. The use of the cowling completely covering the engine seems entirely practical as regards both cooling and maintenance under service conditions. It must be carefully designed, however, to cool properly. With cabin fuselages its use should result in a substantial increase in high speed over that obtained with present forms of cowling on engines similar in contour to the J-5. (author)

  3. Performance of introducing outdoor cold air for cooling a plant production system with artificial light

    Directory of Open Access Journals (Sweden)

    Jun eWang

    2016-03-01

    Full Text Available The commercial use of a plant production system with artificial light (PPAL is limited by its high initial construction and operation costs. The electric-energy consumed by heat pumps, applied mainly for cooling, accounts for 15-35% of the total electric-energy used in a PPAL. To reduce the electric-energy consumption, an air exchanger with low capacity (180 W was used for cooling by introducing outdoor cold air. In this experiment, the indoor air temperature in two PPALs (floor area: 6.2 m2 each was maintained at 25ºC and 20ºC during light and dark periods, respectively, for lettuce production. In one PPAL (PPALe, an air exchanger (air flow rate: 250 m3 h-1 was used along with a heat pump (cooling capacity: 3.2 kW to maintain the indoor air temperature at the set-point. The other PPAL (PPALc with only a heat pump (cooling capacity: 3.2 kW was used for reference. Effects of introducing outdoor cold air on energy use efficiency, coefficient of performance (COP, electric-energy consumption for cooling and growth of lettuce were investigated. The results show that: when the air temperature difference between indoor and outdoor ranged from 20.2°C to 30.0°C: 1 the average energy use efficiency of the air exchanger was 2.8 and 3.4 times greater than the COP of the heat pumps in the PPALe and PPALc, respectively; 2 hourly electric-energy consumption in the PPALe reduced by 15.8-73.7% compared with that in the PPALc; 3 daily supply of CO2 in the PPALe reduced from 0.15 kg to 0.04 kg compared with that in the PPALc; 4 no significant difference in lettuce growth was observed in both PPALs. The results indicate that using air exchanger to introduce outdoor cold air should be considered as an effective way to reduce electric-energy consumption for cooling with little effects on plant growth in a PPAL.

  4. Prediction of Air Flow and Temperature Distribution Inside a Yogurt Cooling Room Using Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    A Surendhar

    2015-01-01

    Full Text Available Air flow and heat transfer inside a yogurt cooling room were analysed using Computational Fluid Dynamics. Air flow and heat transfer models were based on 3D, unsteady state, incompressible, Reynolds-averaged Navier-Stokes equations and energy equations. Yogurt cooling room was modelled with the measured geometry using 3D design tool AutoCAD. Yogurt cooling room model was exported into the flow simulation software by specifying properties of inlet air, yogurt, pallet and walls of the room. Packing material was not considered in this study because of less thickness (cup-0.5mm, carton box-1.5mm and negligible resistance created in the conduction of heat. 3D Computational domain was meshed with hexahedral cells and governing equations were solved using explicit finite volume method. Air flow pattern inside the room and the temperature distribution in the bulk of palletized yogurt were predicted. Through validation, the variation in the temperature distribution and velocity vector from the measured value was found to be 2.0oC (maximum and 30% respectively. From the simulation and the measured value of the temperature distribution, it was observed that the temperature was non-uniform over the bulk of yogurt. This might be due to refrigeration capacity, air flow pattern, stacking of yogurt or geometry of the room. Required results were achieved by changing the location of the cooling fan.

  5. Heat recovery in air conditioning systems in frost-free season with using adiabatic cooling. Capacities overview

    Directory of Open Access Journals (Sweden)

    S.V. Chuduk

    2011-01-01

    Full Text Available In article the review of the information on possibilities of use of recuperators of heat is presented for the warm period of year for air-conditioning system. Aim of heat exchanger work in frost-free season is indirect cooling of incoming air before its input into maintainable premises. It is possible if exhaust air is cooled before its input into heat exchanger . In the article the operational principle of air conditioning system with using of adiabatic air cooling is considered. The data concerned system functioning depending on parameters of microclimate in maintainable premises are given.

  6. Comparison of immersed liquid and air cooling of NASA's Airborne Information Management System

    Science.gov (United States)

    Hoadley, A. W.; Porter, A. J.

    1992-01-01

    The Airborne Information Management System (AIMS) is currently under development at NASA Dryden Flight Research Facility. The AIMS is designed as a modular system utilizing surface mounted integrated circuits in a high-density configuration. To maintain the temperature of the integrated circuits within manufacturer's specifications, the modules are to be filled with Fluorinert FC-72. Unlike ground based liquid cooled computers, the extreme range of the ambient pressures experienced by the AIMS requires the FC-72 be contained in a closed system. This forces the latent heat absorbed during the boiling to be released during the condensation that must take within the closed module system. Natural convection and/or pumping carries the heat to the outer surface of the AIMS module where the heat transfers to the ambient air. This paper will present an evaluation of the relative effectiveness of immersed liquid cooling and air cooling of the Airborne Information Management System.

  7. A Novel kind of Air Cooling Bainite Nitriding Steel and Plasma Nitriding Test

    Institute of Scientific and Technical Information of China (English)

    LI Xin-sheng; LIANG Shu-rong

    2004-01-01

    In order to avoid serious distortion and cracking that may occur with nitrided parts while quenching and tempering, a novel kind of air cooling bainite nitriding steel consisting of Ct, Mo, Mn and Si was developed. After normalized and high temperature tempered, the tested steel has satisfactory strength, toughness and microstructure as well as good nitriding properties.

  8. Generation IV nuclear energy system initiative; air-cooled option RCCS studies and NSTF preparation

    International Nuclear Information System (INIS)

    The work documented in this report is a follow-on to the FY 2010 work reported on the air-cooled RCCS design of the General Atomics (GA) Modular High Temperature Gas-cooled Reactor (MHTGR). This workscope focused on confirming the scaling laws selected to design the scaled experiments in the large-scale Argonne National Laboratory (ANL) Natural Convection Shutdown Heat Removal Test Facility (NSTF) and on sensitivity studies to evaluate the effect of the modeling approximations made in FY 2010 on the models developed for the experiment design supporting analysis. In addition design support analyses were performed to evaluate NSTF configuration modifications proposed to enhance instrumentation performance. The objectives were to: (a) update and confirm the scaling relations to be used in modifying the existing NSTF facility into a scaled model of the GA-MHTGR air-cooled RCCS; and (b) provide an analytical basis for the NSTF modifications needed to conduct scaled experimental simulations of this RCCS. In summary, the scaling evaluation updated the basis that the air-cooled RCCS can be simulated at the ANL NSTF facility at a prototypic scale in the lateral direction and about half scale in the vertical direction. The density behavior of air was modified. A parallel track approach was taken with both RELAP5 system evaluations and STAR-CCM+ computational fluid dynamic (CFD) evaluations carried out as the set of instrumentation configurations were detailed.

  9. Feasibility Study Of Maisotsenko Indirect Evaporative Air Cooling Cycle In Iran

    Directory of Open Access Journals (Sweden)

    Rezaee Vahid

    2015-06-01

    Full Text Available This paper presents energy and exergy analysis of air cooling cycle based on novel Maisotsenko indirect evaporative cooling cycle. Maisotsenko cycle (M-cycle provides desired cooling condition above the dew point and below the wet bulb temperature. In this study, based on average annual temperature, The Iran area is segmented into eleven climates. In energy analysis, wet-bulb and dew point effectiveness, cooling capacity rate and in exergy analysis, exergy input rate, exergy destruction rate, exergy loss, exergy efficiency, exergetic COP and entropy generation rate for Iran's weather conditions in the indicated climates are calculated. Moreover, a feasibility study based on water evaporation rate and Maisotsenko cycle was presented. Energy and exergy analysis results show that the fifth, sixth, seventh and eighth climates are quite compatible and Rasht, Sari, Ramsar and Ardabile cities are irreconcilable with the Maisotsenko cycle.

  10. Preliminary Analysis on Heat Removal Capacity of Passive Air-Water Combined Cooling Heat Exchanger Using MARS

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung-Sin; Jeon, Seong-Su; Hong, Soon-Joon [FNC Tech, Yongin (Korea, Republic of); Bae, Sung-Won; Kwon, Tae-Soon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Current design requirement for working time of PAFS heat exchanger is about 8 hours. Thus, it is not satisfied with the required cooling capability for the long term SBO(Station Black-Out) situation that is required to over 72 hours cooling. Therefore PAFS is needed to change of design for 72 hours cooling. In order to acquirement of long terms cooling using PAFS, heat exchanger tube has to be submerged in water tank for long time. However, water in the tank is evaporated by transferred heat from heat exchanger tubes, so water level is gradually lowered as time goes on. The heat removal capacity of air cooling heat exchanger is core parameter that is used for decision of applicability on passive air-water combined cooling system using PAFS in long term cooling. In this study, the development of MARS input model and plant accident analysis are performed for the prediction of the heat removal capacity of air cooling heat exchanger. From analysis result, it is known that inflow air velocity is the decisive factor of the heat removal capacity and predicted air velocity is lower than required air velocity. But present heat transfer model and predicted air velocity have uncertainty. So, if changed design of PAFS that has over 4.6 kW heat removal capacity in each tube, this type heat exchanger can be applied to long term cooling of the nuclear power plant.

  11. Experimental and numerical analysis of air and radiant cooling systems in offices

    DEFF Research Database (Denmark)

    Corgnati, S. P.; Perino, M.; Fracastoro, G. V.;

    2009-01-01

    , for example in offices with high thermal loads. This study was performed by means of CFD simulations previously validated through an experimental campaign performed in a full scale test room, simulating a typical two-desk office equipped with an all air mixing ventilation system. The numerical studies were......This paper analyses office cooling systems based on all air mixing ventilation systems alone or coupled with radiant ceiling panels. This last solution may be effectively applied to retrofit all air systems that are no longer able to maintain a suitable thermal comfort in the indoor environment...

  12. Influence of thermal flow field of cooling tower on recirculation ratio of a direct air-cooled system for a power plant

    Institute of Scientific and Technical Information of China (English)

    Zhao Wanli; Liu Peiqing

    2008-01-01

    In order to get thermal flow field of direct air-cooled system,the hot water was supplied to the model of direct air-cooled condenser(ACC).The particle image velocimetery(PIV)experiments were carried out to get thermal flow field of a ACC under different conditions in low velocity wind tunnel,at the same time,the recirculation ratio at cooling tower was measured,so the relationship between flow field characteristics and recirculation ratio of cooling tower can be discussed.From the results we can see that the flow field configuration around cooling tower has great effects on average recirculation ratio under cooling tower.The eddy formed around cooling tower is a key reason that recireulation pro-duces.The eddy intensity relates to velocity magnitude and direction angle,and the configuration of eddy lies on the ge-ometry size of cooling tower.So changing the flow field configuration around cooling tower reasonably can decrease recir-culation ratio under cooling tower,and heat dispel effect of ACC can also be improved.

  13. Indoor Air Quality Assessment in a Radiantly Cooled Tropical Building: a Case Study

    Directory of Open Access Journals (Sweden)

    Qi Jie KWONG

    2015-10-01

    Full Text Available Background: Many studies have been conducted to assess the indoor air quality (IAQ of buildings throughout the world because it is closely related to comfort, safety and work productivity of occupants. However, there is still lack of available literature about IAQ in tropical buildings that apply radiant cooling systems in conditioning the indoor air.Methods: This paper reports the results obtained from an IAQ audit that was conducted in a new radiantly cooled building in Malaysia, by focusing on the IAQ and thermal comfort parameters.Results: It was identified that the measured concentration levels for the five indoor air contaminants (CO, CO2, TVOC, formaldehyde and respirable particulates were within the threshold limit values (TLVs specified in the IAQ guidelines. Besides, no significant difference was found between the contaminant levels in each floor of the studied building, and a majority of the respondents did not encounter any form of physical discomfort. There is a risk of condensation problem, judging from the measured RH level.Conclusion: An increase of airflow rate and more dehumidification work in the studied building can be made to improve IAQ and prevention of condensation problem. Nevertheless, these schemes should be implemented carefully to avoid occupants’ discomfort. Relocation of workstations was suggested, especially for the lower floors, which had higher occupancy levels. Keywords: Indoor air quality (IAQ, Radiant cooling systems, IAQ audit, Indoor air contaminants, Condensation 

  14. Power Enhancement of Gas Turbine Plant by Intake Air Fog Cooling

    Directory of Open Access Journals (Sweden)

    J. P. Yadav

    2012-08-01

    Full Text Available Performance of gas turbine significantly depends upon the ambient air temperature and mass flow rate. During summer season the density of the air decreases which affects the mass flow rate and ultimately the power output of a gas turbine is reduced. In order to overcome this situation several techniques are already in the practice and one of the most effective and economical is adopting the inlet fog cooling which basically enhances the power output of the machine. The cooling of ambient air by fog cooling up to wet bulb temperature increases the mass flow rate on account of increase in air density, as a result it ultimately increases the power output of a gas turbine. Fogging is applied with consideration of relative humidity of ambient air not only during summer season but also during dry days of summer season in order to increase the power output of gas turbine. This paper describes the effect on percentage enhancement of power output adopting various fuel options with low and high humidity ambient conditions. The results indicate the potential increase in the power output up to 14�20It is also observed that the total cost of power production increases due to increase in fuel consumption on account of enhanced power output. Thus, the optimum operating parameters are required for taking advantage of power augmentation ensuring that it does not lead to excessive increase in fuel cost.

  15. Experimental Investigation and Optimization of Air-Water SprayImpingement Cooling to Enhance Heat Transfer

    Directory of Open Access Journals (Sweden)

    Santosh Kumar Nayak

    2016-02-01

    Full Text Available The current research focused with the optimization of the heat flux from the surface of a hot steel test plate by air atomized water spray cooling. The air atomized water spray cooling experimental setup was designed and fabricated at School of Mechanical Engineering KIIT University, Odisha, India to investigate the role of various process parameters to enhance the heat flux from the surface of the heated steal specimen. The dimensions of test specimen used in the experiment were 120 mm X 120 mm, having different thickness of 4 mm, 6 mm and 8 mm. The effect of the process parameters such as thickness of the test plate, nozzle to plate distance, air and water pressure for removal of heat flux were optimized. The optimization of the controlling parameters was carried out by using the response surface method (RSM. A new correlation was developed for optimization of the surface heat flux.

  16. Air-conditioning and antibiotics: Demand management insights from problematic health and household cooling practices

    International Nuclear Information System (INIS)

    Air-conditioners and antibiotics are two technologies that have both been traditionally framed around individual health and comfort needs, despite aspects of their use contributing to social health problems. The imprudent use of antibiotics is threatening the capacity of the healthcare system internationally. Similarly, in Australia the increasing reliance on air-conditioning to maintain thermal comfort is contributing to rising peak demand and electricity prices, and is placing an inequitable health and financial burden on vulnerable heat-stressed households. This paper analyses policy responses to these problems through the lens of social practice theory. In the health sector, campaigns are attempting to emphasise the social health implications of antibiotic use. In considering this approach in relation to the problem of air-conditioned cooling and how to change the ways in which people keep cool during peak times, our analysis draws on interviews with 80 Australian households. We find that the problem of peak electricity demand may be reduced through attention to the social health implications of air-conditioned cooling on very hot days. We conclude that social practice theory offers a fruitful analytical route for identifying new avenues for research and informing policy responses to emerging health and environmental problems. - Highlights: • Over-use of antibiotics and air-conditioning has social health implications. • Focusing on financial incentives limits the potential of demand management programs. • Explaining peak demand to households shifts the meanings of cooling practices. • Emphasising the social health implications of antibiotics and air-conditioning may resurrect alternative practices. • Analysing policy with social practice theory offers insights into policy approaches

  17. A basic condition-based maintenance strategy for air-cooled turbine generators

    Energy Technology Data Exchange (ETDEWEB)

    Laird, T; Griffith, G [Mechanical Dynamics and Analysis LLC, Generator Repair Services, Sunset Hills, MO (United States); Hoof, M. [Univ. of Applied Sciences, High Voltage and Power Systems Lab, Kaiserslautern (Germany)

    2005-07-01

    Generator components require regular maintenance to prevent failures. It is important to detect degradation of critical generator components such as stator windings, stator core, rotor windings, rotor retaining rings, generator bearings and high voltage bushings which are all exposed to high stresses. The methods of using condition-based maintenance (CBM) for turbine generators was discussed with particular focus on the maintenance strategy for air-cooled generators. Higher unit rated air-cooled machines typically designed as hydrogen-cooled machines are being used more frequently by the power industry to reduce costs. Since more compact machines are being built to reduce material costs, thermal and electrical design stresses have increased, resulting in higher utilization of the machines and reduced long-term reliability in service. It was noted that CBM will not completely eliminate all forced outage situations, but will greatly reduce their occurrence and will help avoid catastrophic machine situations. This paper outlined basic maintenance strategies for nuclear power plants, major utilities including fossil-fuel power plants, and minor utilities including industrial power plant producers. The economic strategy for air-cooled turbine generators was outlined with reference to unit condition assessment, trending assessed condition of major generator components, and unknown component weaknesses. The CBM maintenance can be applied to all types of power producers that can benefit from an improved, low cost maintenance strategy. Detailed knowledge of the unit design, operational weakness, cost of maintenance and operational capabilities is needed in order to conduct a reliable assessment. 19 refs., 2 figs.

  18. Properties of the Carrol system and a machine design for solar-powered, air cooled, absorption space cooling

    Science.gov (United States)

    1981-05-01

    The name Carrol was selected as a convenient shorthand designation for a prime candidate chemical system comprising ethylene glycol-lithium bromide as an absorbent mixture with water as a refrigerant. The instrumentation, methods of handling data and numerical results from a systematic determination of Carrol property data required to design an air cooled absorption machine based on this chemical system are described. These data include saturation temperature, relative enthalpy, density, specific heat capacity, thermal conductivity, viscosity and absorber film heat transfer coefficient as functions of solution temperature and Carrol concentration over applicable ranges. For each of the major components of the absorption chiller, i.e., generator, chiller, absorber, condenser, heat exchanger, purge and controls, the report contains an assembly drawing and the principal operating characteristics of that component.

  19. Cooling, freezing and heating with the air cycle: air as the ultimate green refrigerant

    OpenAIRE

    Verschoor, M.J.E.

    2000-01-01

    Due to the recent concern about the damage that CFCs cause to the environment (ozone layer, global warming) and the absence of commonly acceptable alternative refrigerants, the search for alternative refrigeration concepts is going on. Air as refrigerant in the Joule-Brayton cycle (air cycle) is one of the most natural refrigerants, and it meets all criteria for a refrigerant being environmentally benign. For this reason the air cycle is one of the most promising long-term alternatives for re...

  20. Experimental investigation of thermal comfort and air quality in an automobile cabin during the cooling period

    Science.gov (United States)

    Kilic, M.; Akyol, S. M.

    2012-08-01

    The air quality and thermal comfort strongly influenced by the heat and mass transfer take place together in an automobile cabin. In this study, it is aimed to investigate and assess the effects of air intake settings (recirculation and fresh air) on the thermal comfort, air quality satisfaction and energy usage during the cooling period of an automobile cabin. For this purpose, measurements (temperature, air velocity, CO2) were performed at various locations inside the cabin. Furthermore, whole body and local responses of the human subjects were noted while skin temperatures were measured. A mathematical model was arranged in order to estimate CO2 concentration and energy usage inside the vehicle cabin and verified with experimental data. It is shown that CO2 level inside of the cabin can be greater than the threshold value recommended for the driving safety if two and more occupants exist in the car. It is also shown that an advanced climate control system may satisfy the requirements for the air quality and thermal comfort as well as to reduce the energy usage for the cooling of a vehicle cabin.

  1. Investigation of Freeze-Linings in Copper-Containing Slag Systems: Part I. Preliminary Experiments

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Hayes, Peter C.; Jak, Evgueni

    2013-06-01

    Slag freeze-linings are increasingly used in industrial pyrometallurgical processes to insure that furnace integrity is maintained in aggressive high-temperature environments. Most previous studies of freeze-linings have analyzed the formation of slag deposits based solely on heat-transfer models. The focus of the present research is to determine the impact of slag chemistry and local process conditions on the microstructures, thickness, stability, and heat-transfer characteristics of the frozen deposit at steady-state conditions. The formation of the freeze-linings is studied under controlled laboratory conditions using an air-cooled "cold-finger" technique for Cu-Fe-Si-Al-O slag at equilibrium with metallic copper relevant to the industrial copper smelting processes. The phase assemblages and microstructures of the deposits formed in the cold-finger experiments differ significantly from those expected from phase equilibrium considerations. The freeze-lining deposits have been found, in general, to consist of several layers. Starting from the cold finger, these layers consist of glass; glass with microcrystalline precipitates; closed crystalline layer; and open crystalline layer. Even at steady-state conditions, there was no primary phase sealing layer of delafossite [Cu2O · (Al, Fe)2O3] present at the deposit/liquid interface—these observations differ markedly from those expected from phase equilibrium considerations. The findings have significant practical implications, and potential for the improved design and operation of industrial metallurgical furnaces.

  2. Cooling, freezing and heating with the air cycle: air as the ultimate green refrigerant

    NARCIS (Netherlands)

    Verschoor, M.J.E.

    2000-01-01

    Due to the recent concern about the damage that CFCs cause to the environment (ozone layer, global warming) and the absence of commonly acceptable alternative refrigerants, the search for alternative refrigeration concepts is going on. Air as refrigerant in the Joule-Brayton cycle (air cycle) is one

  3. The design of an air-cooled metallic high temperature radial turbine

    Science.gov (United States)

    Snyder, Philip H.; Roelke, Richard J.

    1988-01-01

    Recent trends in small advanced gas turbine engines call for higher turbine inlet temperatures. Advances in radial turbine technology have opened the way for a cooled metallic radial turbine capable of withstanding turbine inlet temperatures of 2500 F while meeting the challenge of high efficiency in this small flow size range. In response to this need, a small air-cooled radial turbine has been designed utilizing internal blade coolant passages. The coolant flow passage design is uniquely tailored to simultaneously meet rotor cooling needs and rotor fabrication constraints. The rotor flow-path design seeks to realize improved aerodynamic blade loading characteristics and high efficiency while satisfying rotor life requirements. An up-scaled version of the final engine rotor is currently under fabrication and, after instrumentation, will be tested in the warm turbine test facility at the NASA Lewis Research Center.

  4. JT8D revised high-pressure turbine cooling and other outer air seal program

    Science.gov (United States)

    Gaffin, W. O.

    1979-01-01

    The JT8D high pressure turbine was revised to reduce leakage between the blade tip shrouds and the outer air seal, and engine testing was performed to determine the effect on performance. The addition of a second knife-edge on the blade tip shroud, the extension of the honeycomb seal land to cover the added knife-edge and an existing spoiler on the shroud, and a material substitution in the seal support ring to improve thermal growth characteristics are included. A relocation of the blade cooling air discharge to insure adequate cooling flow is required. Significant specific fuel consumption and exhaust gas temperature improvements were demonstrated with the revised turbine in sea level and simulated altitude engine tests. Inspection of the revised seal hardware after these tests showed no unusual wear or degradation.

  5. JT8D revised high-pressure turbine cooling and other outer air seal program

    Energy Technology Data Exchange (ETDEWEB)

    Gaffin, W.O.

    1979-03-20

    The JT8D high pressure turbine was revised to reduce leakage between the blade tip shrouds and the outer air seal, and engine testing was performed to determine the effect on performance. The addition of a second knife-edge on the blade tip shroud, the extension of the honeycomb seal land to cover the added knife-edge and an existing spoiler on the shroud, and a material substitution in the seal support ring to improve thermal growth characteristics are included. A relocation of the blade cooling air discharge to insure adequate cooling flow is required. Significant specific fuel consumption and exhaust gas temperature improvements were demonstrated with the revised turbine in sea level and simulated altitude engine tests. Inspection of the revised seal hardware after these tests showed no unusual wear or degradation.

  6. Modeling the forced-air cooling process of fresh strawberry packages, Part I: Numerical model

    Energy Technology Data Exchange (ETDEWEB)

    Ferrua, M.J.; Singh, R.P. [Department of Biological and Agricultural Engineering, University of California at Davis, One Shields Avenue, Davis, CA 95616 (United States)

    2009-03-15

    A numerical analysis of the forced-air cooling process of retail packages of strawberries was performed by solving the conservation equations of mass, momentum and energy within the system. The results showed that the heterogeneity of the cooling process is largely influenced by the structure and design of the packaging system (individual clamshell packages and trays). On average 75 {+-} 2% of the total airflow forced through the system bypassed the clamshells, and 46 {+-} 5% of the flow rate forced through clamshells bypassed the strawberries. After 1 h of cooling, the average-fruit-temperature per clamshell ranged from 2.4 C to 8.3 C between the first and last clamshells along the main flow direction. Within these clamshells, the maximum differences in the volume-average temperature of individual fruits reached 3.5 C and 5.1 C, respectively. The results show the potential use of this numerical approach as a design tool to optimize the forced-air cooling process of horticultural products. (author)

  7. Forced Convective Air Cooling from Electronic Component Arrays in a Parallel Plate Channel

    Institute of Scientific and Technical Information of China (English)

    D.Y.Cai; Y.P.Gan; 等

    1994-01-01

    This paper discusses air forced convection heat transfer from inline protruding elements arranged in eight rows.The streamwise and spanwise spacings between elements were varied using a splitter plate that can be positioned at three different modular configurations.A set of empirical formulas was presented to correlate the experimental data for the design of air cooling systems.Arrays of componets with one odd-size module have been tested also.Experimental results show that blocks near the entrance and behind the odd-size module have improved performance compared with uniform arrangements.Accordingly,temperature sensitive components are suggested to be arranged in these locations.

  8. Observations of convective cooling in the tropical tropopause layer in AIRS data

    OpenAIRE

    Kim, H.; A. E. Dessler

    2004-01-01

    International audience We investigate the impact of convection on the thermal structure of the Tropical Tropopause Layer (TTL). We use temperature profiles measured by the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite, and the time evolution of local convection determined by the National Centers for Environmental Protection/Aviation Weather Center (NCEP/AWS) half-hourly infrared global geostationary composite. The observations demonstrate that the TTL is cooled by convecti...

  9. Effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding.

    Science.gov (United States)

    Secilmis, Asli; Bulbul, Mehmet; Sari, Tugrul; Usumez, Aslihan

    2013-01-01

    The neodymium/yttrium-aluminum-garnet (Nd/YAG) laser has been suggested to repair broken prostheses in the mouth. This study investigated the effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding. Three intact human maxillary molars were prepared for full-veneer crown. For each tooth, dentin thicknesses in mesiobuccal cusp was 2, 3, or 4 mm. Twenty dies were duplicated from each of the prepared teeth. For metal copings with 0.5-mm thickness, wax patterns were prepared with dip wax technique directly onto each of dies. All patterns were sprued and invested. The castings were made using a nickel-chromium alloy (Nicromed Premium, Neodontics). A hole with 0.5-mm diameter was prepared on the mesiobuccal cusp of each crown. The Nd/YAG laser (9.85 W; 1 Hz repetition rate; fluence, 1.230 J/cm(2); Fidelis Plus 3, Fotona) was used for welding with or without air cooling (n = 10). The temperature rise was measured in pulpal chamber with a J-type thermocouple wire that was connected to a data logger. Differences between start and highest temperature reading were taken, and temperature rise values were compared using two-way analysis of variance and Tukey's honestly significant difference tests (α = .05). Pulpal temperature rise varied significantly depending on the dentin thickness and air cooling (p 0.05); however, pulpal temperature rise was the lowest for 4-mm dentin thickness group (p Laser welding on base metal castings with Nd/YAG laser can be applied with air cooling to avoid temperature rises known to adversely affect pulpal health when dentin thickness is 2 or 3 mm. PMID:22562450

  10. Performance Study of Adsorption Cooling Cycle for Automotive Air-conditioning

    OpenAIRE

    Ali, Syed Muztuza; Chakraborty, Anutosh

    2015-01-01

    Exhaust gas from automobile can be used to drive adsorption cooling based air conditioning system for the vehicle cabin. This study describes the thermodynamic framework of a two stage indirect exhaust heat recovery system of automotive engine and an effective lumped parameter model to simulate the dynamic behaviors of an adsorption chiller that ranges from the transient to the cyclic steady states. Silica gel and water are used as adsorbent-adsorbate pair. The adsorption chiller model is dev...

  11. Investigation of heat exchanger inclination in forced-draught air-cooled heat exchangers

    OpenAIRE

    Kennedy, I.J.; Spence, S.W.T.; Spratt, G.R.; Early, J. M.

    2013-01-01

    The purpose of this study is to determine the influence of inclining the heat exchanger relative to the fan in a forced draught air-cooled heat exchanger. Since inclination increases plenum depth, the effect of inclination is also compared with increasing plenum depth without inclination. The experimental study shows that inclination improves thermal performance by only 0.5%, when compared with a baseline non-inclined case with a shallow plenum. Similarly, increasing plenum depth without incl...

  12. Development and application of low Reynolds number turbulence models for air-cooled electronics

    OpenAIRE

    Dhinsa, Kulvir Kaur

    2006-01-01

    Semiconductors are at the heart of electronic devices such as computers, mobile phones, avionics systems, telecommunication racks, etc. Power dissipation from semiconductor devices is continuing to increase due to the growth in the number of transistors on the silicon chip as predicted by Moore's Law. Thermal management techniques, used to dissipate this power, are becoming more and more challenging to design. Air cooling of electronic components is the preferred method for many designs where...

  13. Silicagel-water adsorption cooling prototype system for mobile air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    De Boer, R.; Smeding, S.F.; Mola, S. [ECN Efficiency and Infrastructure, Petten (Netherlands)

    2009-09-15

    A prototype adsorption cooling system was developed for the purpose of on-board test of mobile air conditioning driven by waste heat from the engine. The system was designed, constructed and first tested in the laboratory of ECN. The performance under various static operating conditions was determined in the laboratory. The system can produce 2 kW of chilling power with a COP of 0.4. The prototype was afterward installed in the Fiat Grande Punto demonstration car by CRF. The system was connected to the heating and cooling systems of the car and tested. The performance in the car was comparable to the performance in the lab, indicating that system integration was successful. A waste heat driven adsorption cooling system can be applied for comfort cooling purposes in a car. The amount of waste heat that is freely available in the engine coolant circuit as well as its temperature level is sufficient to drive the adsorption cooling system and to produce enough cold to keep comfortable interior temperatures.

  14. Experimental study of condensate subcooling with the use of a model of an air-cooled condenser

    Science.gov (United States)

    Sukhanov, V. A.; Bezukhov, A. P.; Bogov, I. A.; Dontsov, N. Y.; Volkovitsky, I. D.; Tolmachev, V. V.

    2016-01-01

    Water-supply deficit is now felt in many regions of the world. This hampers the construction of new steam-turbine and combined steam-and-gas thermal power plants. The use of dry cooling systems and, specifically, steam-turbine air-cooled condensers (ACCs) expands the choice of sites for the construction of such power plants. The significance of condensate subcooling Δ t as a parameter that negatively affects the engineering and economic performance of steam-turbine plants is thereby increased. The operation and design factors that influence the condensate subcooling in ACCs are revealed, and the research objective is, thus, formulated properly. The indicated research was conducted through physical modeling with the use of the Steam-Turbine Air-Cooled Condenser Unit specialized, multipurpose, laboratory bench. The design and the combined schematic and measurement diagram of this test bench are discussed. The experimental results are presented in the form of graphic dependences of the condensate subcooling value on cooling ratio m and relative weight content ɛ' of air in steam at the ACC inlet at different temperatures of cooling air t ca ' . The typical ranges of condensate subcooling variation (4 ≤ Δ t ≤ 6°C, 2 ≤ Δ t ≤ 4°C, and 0 ≤ Δ t ≤ 2°C) are identified based on the results of analysis of the attained Δ t levels in the ACC and numerous Δ t reduction estimates. The corresponding ranges of cooling ratio variation at different temperatures of cooling air at the ACC inlet are specified. The guidelines for choosing the adjusted ranges of cooling ratio variation with account of the results of experimental studies of the dependences of the absolute pressure of the steam-air mixture in the top header of the ACC and the heat flux density on the cooling ratio at different temperatures of cooling air at the ACC inlet are given.

  15. Flame burn protection: assessment of a new, air-cooled fireproof garment.

    Science.gov (United States)

    Eldad, Arieh; Salmon, Ashi Y; Breiterman, Semion; Chaouat, Malka; BenBassat, Hannah

    2003-08-01

    A new, air-cooled fireproof garment for tank crewmen was assessed regarding its efficacy for burn protection. A pig model was developed with a flame infliction instrument specially designed for this experiment. This pneumatic tool can initiate eight simultaneous flame injuries where the distance of skin from burn source and exposure time are adjustable. In the study, 1,000 degrees C, 5-second exposure flame burns were inflicted upon anesthetized pigs. Full-thickness injuries were caused to exposed animals or to animals that were protected by the single layer of old type Nomex protective garments. On day 21, the original burn size diminished to 42.3% +/- 6.3% and 41.2% +/- 7.9%, respectively. When the animals were dressed with the new type of air-cooled Nomex, only small and superficial burns could be detected when the air compressor was operating, and moderate burns were demonstrated when the compressor was not working. On day 21, postburn original burn size was diminished to 1.9% +/- 1.9% and to 17% +/- 6.5%, respectively. Quantitative burn wound histology followed the same trends with almost normal skin architecture after 7 days in the air-inflated new garments, moderate pathology, and an advanced wound healing process in the affected area when the compressor was not working and severe damage with only initial wound healing in the exposed skin or the areas that were protected by old type, single-layered fireproof garments. This new type of air-cooled fireproof garment was significantly better than the old garment under the experiment condition and seems to be very promising in burn prevention among tank crewmen. PMID:12943032

  16. Open absorption system for cooling and air conditioning using membrane contactors - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R.; Dorer, V. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland)

    2008-07-01

    Air conditioning systems based upon the open absorption principle, essentially an absorption device operating at atmospheric pressure, have been proposed and investigated at many instances in the past eighty years. Their potential for improving energy efficiency is clearly recognized in the earliest research reports. By the mid 1950ies, solar thermal energy was being applied to drive open absorption-based air conditioning systems. For several reasons, however, the open absorption technology was not mature enough to take place in the mainstream. In the past two decades, vigorous efforts have been undertaken to reverse this situation, but success continued to elude, despite the fact that the main problems, such as corrosion, aerosols in the supply air, etc., have been identified. This report details the work and the main results from the MemProDEC Project. In this project innovative solutions were proposed, and successfully investigated, for the corrosion problem and the improvement of efficiency of the absorption process, in particular a new method to cool a very compact absorber. The practically uniform flow distribution for all three streams in the absorber (air, water and desiccant) warrants the contact of the air to be dehumidified with the desiccant over the whole surface of exchange (across a porous membrane). This, together with the cooling with water in counter flow to the air, are the key factors for the excellent effectiveness of the absorber. As the results show, the dehydration effectiveness of the prototype absorber is up to 150 % higher than that previously obtained by others. The solutions developed for compactness and modularity represent an important step in the way to flexible manufacturing, i.e. using a single element size to assemble autonomous air handling units of various nominal capacities. And although the manufacturing methods of the individual elements require improvement, namely by avoiding adhesive bonding, the choice of materials and the

  17. Dynamic models of heating and cooling coils with one-dimensional air distribution

    Science.gov (United States)

    Wang, Zijie; Krauss, G.

    1993-06-01

    This paper presents the simulation models of the plate-fin, air-to-water (or water vapour) heat exchangers used as air-heating or air-cooling and dehumidifying coils in the HVAC (Heating, Ventilation and Air-Conditioning) systems. The thermal models are used to calculate the heat exchange between distributing air and coil pipes and outlet temperatures of air and heat or chilled fluid. The aerodynamic models are used to account for the pressure drop of the air crossing the coil tubes. They can also be used to optimize the structures of such coils. The models are based on principal laws of heat and mass conservation and fluid mechanics. They are transparent and easy to use. In our work, a coil is considered as an assembly of numbers of basic elements in which all the state variables are unique. Therefore we can conveniently simulate the coils with different structures and different geometric parameters. Two modular programs TRNSYS (Transient System Simulation) and ESACAP are utilized as supporting softwares which make the programming and simulation greatly simplified. The coil elements and a real coil were simulated. The results were compared with the data offered by the manufacturer (company SOFICA) and also with those obtained using critical methods such as NTU method, etc. and good agreement is attained.

  18. Dynamic Models of Heating and Cooling Coils with One—Dimensional Air Distribution

    Institute of Scientific and Technical Information of China (English)

    WangZijie; G.Krauss

    1993-01-01

    This paper presents the simulation models of the plate-fin,air-to-water(or water vapour) heat exchangers used as air-heating or air-cooling and dehumidifying colis in the HVAC(Heating,Ventilation and AIr-Conditioning)systems.The thermal models are used to calculate the heat exchange between distributing air and coil pipes and outlet temperatures of air and heat or chilled fluid.The aerodynamic models are used to account for the pressure drop of the air crossing the coil tubes,They can also be used to optimize the structres of such coils.The models are based on principal laws of teat and mass conservation and fluid mechanics.They are transparent and easy to use.In our work,a coil is considered as an assembly of numbers of basic elements in which all the state variables are unique.Therefore we can conveniently simulate the coils with different structures and different geometric parameters.Two modular programs TRNSYS(Transient System Simulation)and ESACAP are utilized as supporting softwares which make the programming and simulation greatly simplified.The coil elements and a real coil were simulated.The results were compared with the data offered by the manufacturer(company SOFICA) and also with those obtained using critical methods such as NTU method ,etc.and good agreement is attained.

  19. Experimental investigation of the influence of the air jet trajectory on convective heat transfer in buildings equipped with air-based and radiant cooling systems

    DEFF Research Database (Denmark)

    Le Dreau, Jerome; Heiselberg, Per; Jensen, Rasmus Lund

    2015-01-01

    -state and dynamic conditions. With the air-based cooling system, a dependency of the convective heat transfer on the air jet trajectory has been observed. New correlations have been developed, introducing a modified Archimedes number to account for the air flow pattern. The accuracy of the new correlations has been......The complexity and diversity of airflow in buildings make the accurate definition of convective heat transfer coefficients (CHTCs) difficult. In a full-scale test facility, the convective heat transfer of two cooling systems (active chilled beam and radiant wall) has been investigated under steady...... evaluated to±15%. Besides the study with an air-based cooling system, the convective heat transfer with a radiant cooling system has also been investigated. The convective flow at the activated surface is mainly driven by natural convection. For other surfaces, the complexity of the flow and the large...

  20. Methodology for uncertainty calculation of net total cooling effect estimation for rating room air conditioners and packaged terminal air conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor [Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica, Pereira (Colombia); University of Liege, Campus du Sart Tilman, Bat: B49, P33, B-4000 Liege (Belgium)

    2009-09-15

    This article presents the general procedure for uncertainty calculation of net total cooling effect estimation for rating room air conditioners and packaged terminal air conditioners, by means of measurements carried out in a test bench specially designed for this purpose. The uncertainty analysis presented in this work looks for establishing a confidence degree or certainty of experimental results. It is particularly important considering that international standards related to this type of analysis are too ambiguous when treating this subject. The uncertainty analysis is on the other hand an indispensable requirement to international standard ISO 17025 [ISO, 2005. International Standard. 17025. General Requirement to Test and Calibration Laboratories Competences. International Organization for Standardization, Geneva.], which must be applied to obtain the required quality levels according to the Word Trade Organization WTO. (author)

  1. Thermodynamic analysis of a novel air-cooled non-adiabatic absorption refrigeration cycle driven by low grade energy

    International Nuclear Information System (INIS)

    Graphical abstract: To improve the performance of the air-cooled type absorption refrigeration, a novel non-adiabatic absorber has been applied in the cycle. Simulation results show that low grade energy is applicable for NH3/NaSCN and NH3/LiNO3 absorption refrigeration system under air cooling condition and relatively high system performance can be obtained. - Highlights: • We analyze an absorption refrigeration cycle driven by low grade energy. • Working fluids thermophysical property correlations are corrected. • Influence of non-adiabatic absorber on system performance is investigated. • We propose system operation parameters under air-cooled condition. - Abstract: An air-cooled type absorption refrigeration cycle using ammonia–lithium nitrate and ammonia–sodium thiocyanate solutions as working fluids are thermodynamically studied in this paper. In the case of many occasions especially small cooling capacity occasion where water cooling is restricted or inconvenient, application of conventional adiabatic absorbers in air-cooled type absorption refrigeration system has been studied by many investigators. Comparing to the adiabatic absorber, a novel air-cooled non-adiabatic absorber is applied to the absorption refrigeration system in this study to improve system performance. It is shown that, system performance has a significant improvement when temperatures of rich ammonia solution at the outlet of absorber decrease under the effect of the heat dissipation capacity of the non-adiabatic absorber. Another advantage is that heat load of the system heat exchangers including generator, solution heat exchanger and air-cooler, decreases with the solution temperature decrease at the outlet of the absorber under the same system cooling capacity condition, which brings benefits to the system cost reduction. Variation of system performance and other system operation parameters with generator temperature, absorption temperature and absorption efficiency has

  2. Effects of Using Wind Guiding Nets to Improve Prevailing Ambient Wind on Direct Air-cooled Condensers

    Institute of Scientific and Technical Information of China (English)

    YANG Jianguo; LIU Da; ZHANG Zhaoying; JU Xiaoli

    2012-01-01

    Prevailing ambient wind is the main reason that causes inlet flow rate (air mass flow rate) decreasing and air flowing backward to the air-cooled condenser fans upward to the wind, hence a set of wind guiding nets is designed to improve the detrimental effect. Fig. 1 shows four typical units of a 1000MW direct air-cooled condenser (DACC) and a set of wind guiding nets installed under its edge upward to the ambient wind. As shown in Fig. 2, the fan inlet flow rate decreases as the prevailing ambient wind velocity increasing, especially for the first two units upward to the wind.

  3. Fruchill – the frugal fridge : Cool refrigerators with cold outside air to cut peak demand for electricity

    OpenAIRE

    Steffner, Ylva

    2015-01-01

    To use electricity, especially during peak demand periods, to cool fridges makes cold air seem as an overlooked resource for reducing the electrical energy spent on operating household refrigerators. This thesis investigates whether an automatic device for supplementary cooling of a fridge using cold outside air can be retrofitted to a fridge in order to save energy. Prototypes were constructed to facilitate iterative optimization resulting in a POC design that reduces the energy consumption ...

  4. Transfair. An air method of floor heating and cooling; Transfair. Procede de chauffage et de rafraichissement par le sol a air

    Energy Technology Data Exchange (ETDEWEB)

    Desvouas, C. [Tarnsfair TTR, 77 - Perthes en Gatinais (France)

    1997-12-31

    This paper presents the `Transfair` method which consists in the use of air instead of water in heating and cooling systems. This presentation comprises 4 parts. Part 1 is a general presentation of the activities of the French TTR company which has developed the Transfair method and its realizations in industrial space heating and in chemical industry (refrigeration units for sulfuric acid). Part 2 is a comparative evaluation of equivalent water and air systems in order to emphasize the advantages of air cooling systems (simplicity and reliability). Part 3 is a presentation of a software for the optimization of the dimensioning of components and investment costs of industrial air space heating systems. Part 4 is a presentation of the feasibility study of a floor cooled by air circulation and with a self-balancing of circuits confirmed by flow rate measurements. (J.S.)

  5. Conjugate Heat transfer Analysis of helical fins with airfoil crosssection and its comparison with existing circular fin design for air cooled engines employing constant rectangular cross-section

    OpenAIRE

    Ashwin Shridhar; Asokan Ram Deepak

    2015-01-01

    Air Cooled Engines have been used in a variety of applications, ranging from airplanes to motorbikes and even stationary or portable engines. Since modern automobiles and airplanes use engines delivering more power, they have to be cooled more efficiently due to which a more complex water cooling system is used for cooling engines with large displacements. Hence air cooling is becoming a thing of the past, especially in the aviation sector due to the advent of more efficient gas t...

  6. Comfort air temperature influence on heating and cooling loads of a residential building

    Science.gov (United States)

    Stanciu, C.; Șoriga, I.; Gheorghian, A. T.; Stanciu, D.

    2016-08-01

    The paper presents the thermal behavior and energy loads of a two-level residential building designed for a family of four, two adults and two students, for different inside comfort levels reflected by the interior air temperature. Results are intended to emphasize the different thermal behavior of building elements and their contribution to the building's external load. The most important contributors to the building thermal loss are determined. Daily heating and cooling loads are computed for 12 months simulation in Bucharest (44.25°N latitude) in clear sky conditions. The most important aspects regarding sizing of thermal energy systems are emphasized, such as the reference months for maximum cooling and heating loads and these loads’ values. Annual maximum loads are encountered in February and August, respectively, so these months should be taken as reference for sizing thermal building systems, in Bucharest, under clear sky conditions.

  7. Thermal investigation of lithium-ion battery module with different cell arrangement structures and forced air-cooling strategies

    International Nuclear Information System (INIS)

    Highlights: • Three-dimensional CFD model with forced air cooling are developed for battery modules. • Impact of different air cooling strategies on module thermal characteristics are investigated. • Impact of different model structures on module thermal responses are investigated. • Effect of inter-cell spacing on cell thermal characteristics are also studied. • The optimal battery module structure and air cooling strategy is recommended. - Abstract: Thermal management needs to be carefully considered in the lithium-ion battery module design to guarantee the temperature of batteries in operation within a narrow optimal range. This article firstly explores the thermal performance of battery module under different cell arrangement structures, which includes: 1 × 24, 3 × 8 and 5 × 5 arrays rectangular arrangement, 19 cells hexagonal arrangement and 28 cells circular arrangement. In addition, air-cooling strategies are also investigated by installing the fans in the different locations of the battery module to improve the temperature uniformity. Factors that influence the cooling capability of forced air cooling are discussed based on the simulations. The three-dimensional computational fluid dynamics (CFD) method and lumped model of single cell have been applied in the simulation. The temperature distributions of batteries are quantitatively described based on different module patterns, fan locations as well as inter-cell distance, and the conclusions are arrived as follows: when the fan locates on top of the module, the best cooling performance is achieved; the most desired structure with forced air cooling is cubic arrangement concerning the cooling effect and cost, while hexagonal structure is optimal when focus on the space utilization of battery module. Besides, the optimized inter-cell distance in battery module structure has been recommended

  8. Thermal-economic optimization of an air-cooled heat exchanger unit

    International Nuclear Information System (INIS)

    Thermodynamic modeling and optimal design of an air-cooled heat exchanger (ACHE) unit are developed in this study. For this purpose, ε–NTU method and mathematical relations are applied to estimate the fluids outlet temperatures and pressure drops in tube and air sides. The main goal of this study is minimizing of two conflicting objective functions namely the temperature approach and the minimum total annual cost, simultaneously. For this purpose, fast and elitist non-dominated sorting genetic-algorithm (NSGA-II) is applied to minimize the objective functions by considering ten design parameters. In addition, a set of typical constraints, governing on the ACHE unit design, is subjected to obtain more practical optimum design points. Furthermore, sensitivity analysis of change in the objective functions, when the optimum design parameters vary, is conducted and the degree of each parameter on conflicting objective functions has been investigated. Finally, a selection procedure of the best optimum point is introduced and final optimum design point is determined. -- Highlights: ► Multi-objective optimization of air-cooled heat exchanger. ► Considering ten new design parameters in this type of heat exchanger. ► A detailed cost function is used to estimate the heat exchanger investment cost. ► Presenting a mathematical relation for optimum total cost vs. temperature approach. ► The sensitivity analysis of parameters in the optimum situation

  9. Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

    Directory of Open Access Journals (Sweden)

    Zhengqi Guo

    2016-04-01

    Full Text Available In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of copper and iron.

  10. Modelling of cooled-ceiling air-conditioning systems: Influences on indoor environment and energy consumption. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Niu, J.

    1994-06-14

    The contents presented in this thesis consist of four principal parts: (1) the critical review of turbulence CFD (Computational Fluid Dynamics) techniques and their application in building air flow study, and the experimental evaluation of the widely used k-epsilon turbulence model for in-room air flow situations; (2) the development of a thermodynamic mathematical model for cooled-ceiling air-conditioning systems, and the enhancement of an existing computer code ACCURACY, and the experimental validation of the convective parameters involved in the models; (3) the combined use of building dynamic simulation and CFD technique for the investigation of thermal comfort and ventilation effectiveness performance of three typical air-conditioning systems, the air-panel type cooled-ceiling (ACC) system, and the water-panel type cooled ceiling (CC) system; and (4) the use of the dynamic model coupled with air-handling-unit (AHU) and primary equipment models to simulate the annual energy consumption of CC systems and all-air systems and to estimate thermal performances of some passive cooling schemes, especially the evaporative free-cooling scheme. The review of the state-of-the-art of turbulence modeling shows that the k-epsilon turbulence model still remains the most-widely used engineering model.

  11. Soil Stabilisation Using Ground Granulated Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Ashish Kumar Pathak

    2014-05-01

    Full Text Available Stabilisation is a broad sense for the various methods employed and modifying the properties of a soil to improve its engineering performance and used for a variety of engineering works. In today‟s day soil stabilisation is the major problem for civil engineers, either for construction of road and also for increasing the strength or stability of soil and reduces the construction cost. In this thesis the soil are stabilised by ground granulated blast furnace slag (GGBS and this material is obtained from the blast furnace of cement plant, which is the byproduct of iron (from ACC plant, sindri. It is generally obtained in three shaped one is air cooled, foamed shaped and another is in granulated shaped. The use of by-product materials for stabilisation has environmental and economic benefits. Ground granulated blast furnace slag (GGBS material is used in the current work to stabilise soil (clay. The main objectives of this research were to investigate the effect of GGBS on the engineering property (optimum moisture content and maximum dry density, plastic limit, liquid limit, compaction, unconfined compressive strength, triaxial and California bearing ratio test of the soil and determine the engineering properties of the stabilised.

  12. Air conditioning using an air-cooled single effect lithium bromide absorption chiller: results of a trial conducted in Madrid in August 2005

    OpenAIRE

    Izquierdo, M.; Lizarte, R.; Marcos, J.D.; Gutiérrez, G.

    2008-01-01

    Air conditioning using an air-cooled single effect lithium bromide absorption chiller: results of a trial conducted in Madrid in August 2005 correspondence: Corresponding author. Tel.: + 34 91 871 32 48; fax: + 34 91 871 32 48. (Izquierdo, M.) (Izquierdo, M.) Instituto de Ciencias de la Construccion Eduardo Torroja (CSIC) c/Serrano Galvache 4 - 28033 Madrid--> - SPAIN (Izquierdo, M.) SPAIN (Izquierdo, M.)...

  13. Open absorption system for cooling and air conditioning using membrane contactors. 2006 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R. [Materials Science and Technology (EMPA), Abteilung Bautechnologien, Duebendorf (Switzerland)

    2006-11-15

    This illustrated annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of an open absorption system for cooling and air-conditioning. The report reviews the construction of a first prototype and the manufacture of its components. The conceptual design of this new type of air handling unit (AHU), operating with a liquid desiccant, is discussed. The AHU is to be autonomous and the system will not require additional mechanical refrigeration. It is to be thermally driven at temperatures below 80 {sup o}C. Waste heat sources, solar collectors, district heating plants and co-generation systems are targeted as providers of thermal energy at this temperature level. Work carried out is reported on, including that on two-stream membrane contactors.

  14. Characterization of Francisella species isolated from the cooling water of an air conditioning system.

    Science.gov (United States)

    Gu, Quan; Li, Xunde; Qu, Pinghua; Hou, Shuiping; Li, Juntao; Atwill, Edward R; Chen, Shouyi

    2015-01-01

    Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems.

  15. Characterization of Francisella species isolated from the cooling water of an air conditioning system.

    Science.gov (United States)

    Gu, Quan; Li, Xunde; Qu, Pinghua; Hou, Shuiping; Li, Juntao; Atwill, Edward R; Chen, Shouyi

    2015-01-01

    Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems. PMID:26413079

  16. Optimization of fog inlet air cooling system for combined cycle power plants using genetic algorithm

    International Nuclear Information System (INIS)

    In this research paper, a comprehensive thermodynamic modeling of a combined cycle power plant is first conducted and the effects of gas turbine inlet fogging system on the first and second law efficiencies and net power outputs of combined cycle power plants are investigated. The combined cycle power plant (CCPP) considered for this study consist of a double pressure heat recovery steam generator (HRSG) to utilize the energy of exhaust leaving the gas turbine and produce superheated steam to generate electricity in the Rankine cycle. In order to enhance understanding of this research and come up with optimum performance assessment of the plant, a complete optimization is using a genetic algorithm conducted. In order to achieve this goal, a new objective function is defined for the system optimization including social cost of air pollution for the power generation systems. The objective function is based on the first law efficiency, energy cost and the external social cost of air pollution for an operational system. It is concluded that using inlet air cooling system for the CCPP system and its optimization results in an increase in the average output power, first and second law efficiencies by 17.24%, 3.6% and 3.5%, respectively, for three warm months of year. - Highlights: • To model the combined cycle power plant equipped with fog inlet air cooling method. • To conduct both exergy and economic analyses for better understanding. • To conduct a complete optimization using a genetic algorithm to determine the optimal design parameters of the system

  17. Study on Air Intake and Cooling System for Marine Diesel Engine

    Directory of Open Access Journals (Sweden)

    Su Shaohui

    2013-09-01

    Full Text Available Regarding the power, the efficiency and the discharge questions of the low-speed diesel engine, this article studied emphatically the Miller cycle, the analysis technology for the air intake system, and the matching technology for the intake and the exhaust. On the foundation of the twin inlet structure the paper analyzed the intake swirl control area and its influence to the gas charging efficiency, proposed the design scheme for the invariable intake swirl control system. By matching reasonably the intake, the exhaust, and the injection process of the diesel engine, the combustion process is further optimized to satisfy the target request for the complete machine’s power, fuel oil efficiency and emission. Aiming at the high-power low-speed marine diesel engine, the paper analyzes the impact of the diesel engine’s cooling to the power, economy and NOx’s emission, studies the variable flow control method and system of the diesel engine cooling water and proposes the scheme setting up the intercooler system and the body cooling system independently in the diesel engine. The results show that the methods and systems are better to improve the engine power, reduce the fuel consumption and NOx’s emission.    

  18. Design of a Prototype EHD Air Pump for Electronic Chip Cooling Applications

    International Nuclear Information System (INIS)

    This paper presents the design, optimization and fabrication of an EHD air pump intended for high-power electronic chip cooling applications. Suitable high-voltage electrode configurations were selected and studied, in terms of the characteristics of the generated electric field, which play an important role in ionic wind flow. For this purpose, dedicated software is used to implement finite element analysis. Critical design parameters, such as the electric field intensity, wind velocity, current flow and power consumption are investigated. Two different laboratory prototypes are fabricated and their performances experimentally assessed. This procedure leads to the fabrication of a final prototype, which is then tested as a replacement of a typical fan for cooling a high power density electronic chip. To assist towards that end, an experimental thermal testing setup is designed and constructed to simulate the size of a personal computer's CPU core of variable power. The parametric study leads to the fabrication of experimental single-stage EHD pumps, the optimal design of which is capable of delivering an air flow of 51 CFM with an operating voltage of 10.5 kV. Finally, the theoretical and experimental results are evaluated and potential applications are proposed. (plasma technology)

  19. The performance of a mobile air conditioning system with a water cooled condenser

    Science.gov (United States)

    Di Battista, Davide; Cipollone, Roberto

    2015-11-01

    Vehicle technological evolution lived, in recent years, a strong acceleration due to the increased awareness of environmental issues related to pollutants and climate altering emissions. This resulted in a series of international regulations on automotive sector which put technical challenges that must consider the engine and the vehicle as a global system, in order to improve the overall efficiency of the system. The air conditioning system of the cabin, for instance, is the one of the most important auxiliaries in a vehicle and requires significant powers. Its performances can be significantly improved if it is integrated within the engine cooling circuit, eventually modified with more temperature levels. In this paper, the Authors present a mathematical model of the A/C system, starting from its single components: compressors, condenser, flush valve and evaporator and a comparison between different refrigerant fluid. In particular, it is introduced the opportunity to have an A/C condenser cooled by a water circuit instead of the external air linked to the vehicle speed, as in the actual traditional configuration. The A/C condenser, in fact, could be housed on a low temperature water circuit, reducing the condensing temperature of the refrigeration cycle with a considerable efficiency increase.

  20. STUDY ON AIR INGRESS MITIGATION METHODS IN THE VERY HIGH TEMPERATURE GAS COOLED REACTOR (VHTR)

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh

    2011-03-01

    An air-ingress accident followed by a pipe break is considered as a critical event for a very high temperature gas-cooled reactor (VHTR). Following helium depressurization, it is anticipated that unless countermeasures are taken, air will enter the core through the break leading to oxidation of the in-core graphite structure. Thus, without mitigation features, this accident might lead to severe exothermic chemical reactions of graphite and oxygen. Under extreme circumstances, a loss of core structural integrity may occur along with excessive release of radiological inventory. Idaho National Laboratory under the auspices of the U.S. Department of Energy is performing research and development (R&D) that focuses on key phenomena important during challenging scenarios that may occur in the VHTR. Phenomena Identification and Ranking Table (PIRT) studies to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important (Oh et al. 2006, Schultz et al. 2006). Consequently, the development of advanced air ingress-related models and verification and validation (V&V) requirements are part of the experimental validation plan. This paper discusses about various air-ingress mitigation concepts applicable for the VHTRs. The study begins with identifying important factors (or phenomena) associated with the air-ingress accident by using a root-cause analysis. By preventing main causes of the important events identified in the root-cause diagram, the basic air-ingress mitigation ideas can be conceptually derived. The main concepts include (1) preventing structural degradation of graphite supporters; (2) preventing local stress concentration in the supporter; (3) preventing graphite oxidation; (4) preventing air ingress; (5) preventing density gradient driven flow; (4) preventing fluid density gradient; (5) preventing fluid temperature gradient; (6) preventing high temperature. Based on the basic concepts listed above, various air

  1. Experimental evaluation of dry/wet air-cooled heat exchangers. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, S.G.; Gruel, R.L.; Huenefeld, J.C.; Eschbach, E.J.; Johnson, B.M.; Kreid, D.K.

    1982-08-01

    The ultimate goal of this project was to contribute to the development of improved cooling facilities for power plants. Specifically, the objective during FY-81 was to experimentally determine the thermal performance and operating characteristics of an air-cooled heat exchanger surface manufactured by the Unifin Company. The performance of the spiral-wound finned tube surface (Unifin) was compared with two inherently different platefin surfaces (one developed by the Trane Co. and the other developed by the HOETERV Institute) which were previously tested as a part of the same continuing program. Under dry operation the heat transfer per unit frontal area per unit inlet temperature difference (ITD) of the Unifin surface was 10% to 20% below that of the other two surfaces at low fan power levels. At high fan power levels, the performances of the Unifin and Trane surfaces were essentially the same, and 25% higher than the HOETERV surface. The design of the Unifin surface caused a significantly larger air-side pressure drop through the heat exchanger both in dry and deluge operation. Generally higher overall heat transfer coefficients were calculated for the Unifin surface under deluged operation. They ranged from 2.0 to 3.5 Btu/hr-ft/sup 2/-/sup 0/F as compared to less than 2.0 Btu hr-ft/sup 2/-/sup 0/F for the Trane and HOETERV surfaces under similar conditions. The heat transfer enhancement due to the evaporative cooling effect was also measureably higher with the Unifin surface as compared to the Trane surface. This can be primarily attributed to the better wetting characteristics of the Unifin surface. If the thermal performance of the surfaces are compared at equal face velocities, the Unifin surface is as much as 35% better. This method of comparison accounts for the wetting characteristics while neglecting the effect of pressure drop. Alternatively the surfaces when compared at equal pressure drop essentially the same thermal performance.

  2. Experimental study of the air-atomized spray cooling of high-temperature metal

    International Nuclear Information System (INIS)

    An experimental study of heat transfer between a hot metallic surface and water droplets sprayed by a commercial flat pattern air-atomized spray nozzle was conducted. A lattice grid was used to measure the local spray density (Q) along the horizontal (X) and vertical (Y) axes of the local spray region. By measuring the temperature evolution inside the test plate, the surface heat flux was calculated by the inverse heat conduction problem. In the case of no obvious run-off flow on the surface, the temperature TCHF and heat flux qCHF at the critical heat flux (CHF) point increased with Q. Besides, the values of TLeid and qLeid for the Leidenfrost point also showed similar variation. When V = 1.11 × 10−5 m3 s−1, the CHF points at locations around the spray center were forced to transfer to higher surface temperature, due to the run-off water flow from the spray center. Based on the results obtained, mathematical correlations were proposed, signifying the dependence of heat flux in different boiling regimes for water flow rates V ≤ 0.83 × 10−5 m3 s−1. The results obtained in this study will provide a theoretical basis for predicting the temperature of the cold-rolled strip during the spray-cooling process and for designing the cooling process. - Highlights: • Air-atomized water spray cooling of a very high temperature surface was studied. • Correlations of heat flux in different boiling regimes were established. • CHF shifted to higher surface temperature due to the serious run-off water flow

  3. Simulation and performance enhancement of the air cooling system in a DC/AC power converter station

    Energy Technology Data Exchange (ETDEWEB)

    Lozowy, R.; El-Shaboury, A.; Soliman, H.; Ormiston, S. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Mechanical and Manufacturing Engineering

    2010-07-01

    This study analyzed the flow structure and heat transfer in a large 3-dimensional domain with turbulence, mixed convection, an impinging jet, and flow over heated blocks. The objective was to better understand turbulent mixed-convection cooling of heat-generating bodies in 3-dimensional enclosures, which is important to industry. The cooling of 2 thyristor valve halls was simulated. Each valve hall housed 3 towers that contained electronics used in DC/AC power conversion. The simulation results included the magnitudes of the net air flows for all the inter-block gaps and the maximum temperature in each gap. A parametric study was also performed to investigate the effects of the air inlet location, size and aspect ratio. The effects of the air injection angle on cooling effectiveness was also examined. The study showed that for fixed inlet mass flow rate, significant improvement in the cooling effectiveness can be obtained by changing the injection angle of the inlet air jet, the location of the inlet grill, or the size of the inlet grill. It was concluded that these study results may be relevant to other applications, such as the design of power transformers, the design of cooling systems for spent nuclear fuel and computer server cooling racks. 13 refs., 12 figs.

  4. Solidification of stainless steel slag by accelerated carbonation.

    Science.gov (United States)

    Johnson, D C; MacLeod, C L; Carey, P J; Hills, C D

    2003-06-01

    On exposure to carbon dioxide (CO2) at a pressure of 3 bars, compacts formed from pressed ground slag, and 12.5 weight percent water, were found to react with approximately 18% of their own weight of CO2. The reaction product formed was calcium carbonate causing the slag to self-cement. Unconfined compressive strengths of 9MPa were recorded in carbonated compacts whereas strengths of < 1 MPa were recorded in non-carbonated slag compacts. As molten stainless steel slag containing dicalcium silicate (C2S) cools it can undergo several phase transitions. The final transformation from the beta-polymorph to gamma-C2S is accompanied by a volume change that causes the slag to self-pulverise or 'dust'. As a consequence of this the fine grained portion of the slag contains more of this phase whilst the coarser particles of the slag contain more of the calcium magnesium silicates that contribute the bulk of the waste. The fine fraction (< 125 microm) of the slag when ground is found to react to the same extent as the ground bulk slag and produces compacts with equivalent strength. A coarser fraction (4-8 mm) when ground to a similar grading does not react as extensively and produces a weaker product. Additions of ordinary Portland cement (OPC) at 5 and 10 percent by weight did not alter the degree of reaction during carbonation of the bulk slag or ground fine fraction, however the strength of the 4-8 mm fraction was increased by this change. PMID:12868521

  5. Conjugate heat transfer investigation on the cooling performance of air cooled turbine blade with thermal barrier coating

    Science.gov (United States)

    Ji, Yongbin; Ma, Chao; Ge, Bing; Zang, Shusheng

    2016-08-01

    A hot wind tunnel of annular cascade test rig is established for measuring temperature distribution on a real gas turbine blade surface with infrared camera. Besides, conjugate heat transfer numerical simulation is performed to obtain cooling efficiency distribution on both blade substrate surface and coating surface for comparison. The effect of thermal barrier coating on the overall cooling performance for blades is compared under varied mass flow rate of coolant, and spatial difference is also discussed. Results indicate that the cooling efficiency in the leading edge and trailing edge areas of the blade is the lowest. The cooling performance is not only influenced by the internal cooling structures layout inside the blade but also by the flow condition of the mainstream in the external cascade path. Thermal barrier effects of the coating vary at different regions of the blade surface, where higher internal cooling performance exists, more effective the thermal barrier will be, which means the thermal protection effect of coatings is remarkable in these regions. At the designed mass flow ratio condition, the cooling efficiency on the pressure side varies by 0.13 for the coating surface and substrate surface, while this value is 0.09 on the suction side.

  6. Numerical study by large-eddy simulation on effects and mechanism of air-cooling enhancing technologies

    International Nuclear Information System (INIS)

    Learning from the lessons of the Fukushima Daiichi nuclear incident in which a long-term station black-out occurred, we have been developing an air-cooling system for boiling water reactors that can operate without electricity for a virtually indefinite time. Improvement in the heat transfer performance of air-cooling is key to the development of the air-cooling system. We developed air-cooling enhancing technologies for the air-cooling system by using heat transfer fins, turbulence-enhancing ribs and a micro-fabrication surface. In our previous study, the performance of these air-cooling enhancing technologies was evaluated by heat transfer tests using a single pipe of the air-cooling heat exchanger. To achieve further improvement of the heat transfer performance, it is important to understand the mechanism of the air-cooling enhancing technologies. In this study, we used the numerical analysis which is based on the filtered incompressible Navier-Stokes equation and the filtered energy equation with the large-eddy simulation in order to investigate the effects and the mechanism of the developed air-cooling enhancing technologies. We found that the analysis results agreed well with the experimental results and the empirical formula results. The heat transfer enhancement mechanism of the heat transfer fin is due to an increase in the heat transfer area. Due to a decrease in the flow velocity at the base of the fins, the increase in the Nusselt number was approximately 15% smaller than the estimated value from the area increase. In the heat transfer enhancement by the turbulence-enhancing ribs, the unsteady behavior of the large-scale vortex generated by the flow separation plays an important role. The enhancement ratio of the Nusselt number by the micro-fabrication surface can be explained by the apparent thermal conductivity. The Nusselt number was increased 4-8% by the micro-fabrication surface. The effect of the micro-fabrication surface is increased by applying

  7. Preparation of Slag Wool by Integrated Waste-Heat Recovery and Resource Recycling of Molten Blast Furnace Slags: From Fundamental to Industrial Application

    Directory of Open Access Journals (Sweden)

    Dawei Zhao

    2014-05-01

    Full Text Available The present paper investigated the process of the slag wool fabrication using high temperature blast furnace (BF slag modified by coal ash (CA. The liquidus temperature and viscosity of the slag system with different mass ratios of BF slag and CA were measured through an inner cylinder rotation method. The approximate mass ratio used to fabricate the slag wool was therefore determined and slag wool was then successfully prepared with a high-speed air injection method in the laboratory. The effect of mBF/m ratio, slag temperature for injection and air pressure on the preparation of slag wool was systematically investigated. The mechanical and thermal properties were also studied to confirm the long-term working conditions of the slag wool. An industry-scale slag wool production application was established. The energy consumption and the pollutant generation, were analyzed and compared with the traditional production method, which indicated a 70% reduction in energy consumption and a 90% pollution emission decrease.

  8. The effect of ambient air condition on heat transfer of hot steel plate cooled by an impinging water jet

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Pil Jong; Choi, Hae Won [Research Institute of Industrial Science and Technology, Pohang (Korea, Republic of); Lee, Sung Hong [Busan National Univ., Busan (Korea, Republic of)

    2003-05-01

    It has been observed that the cooling capacity of an impinging water jet is affected by the seasonal conditions in large-scale steel manufacturing processes. To confirm this phenomenon, cooling experiments utilizing a hot steel plate cooled by a laminar jet were conducted for two initial ambient air temperatures (10 .deg. C and 40 .deg. C) in a closed chamber, performing an inverse heat conduction method for quantitative comparison. This study reveals that the cooling capacity at an air temperature of 10 .deg. C is lower than the hear extracted at 40 .deg. C. The amount of total extracted heat at 10 .deg. C is 15% less than at 40 .deg. C. These results indicate the quantity of water vapor, absorbed until saturation, affects the mechanism of boiling heat transfer.

  9. Cooling rates of living and killed chicken and quail eggs in air and in helium-oxygen gas mixture.

    Science.gov (United States)

    Tazawa, H; Turner, J S; Paganelli, C V

    1988-01-01

    1. In a helium atmosphere, heat is dissipated from a surface 3.5 times faster than it is in air. Eggs in a helium-oxygen atmosphere cool only 1.4 times faster than they cool in air. This signifies that internal resistance to heat flow is a significant factor in the cooling rates of eggs. 2. Heat flow occurs inside an egg in two ways: by conduction through the tissues and in flowing blood. Killing an embryo stops the latter, but not the former. Eggs cool more slowly after they have been killed, signifying that blood flow can be an important component in an egg's internal flows of heat. 3. Blood flow should be a relatively more important component of heat flow in large eggs than in small eggs. The difference in conductance between living and killed eggs is larger in 60 g chicken eggs than it is in 10 g quail eggs. PMID:2900113

  10. Energy Performance of Water-based and Air-based Cooling Systems in Plus-energy Housing

    DEFF Research Database (Denmark)

    Andersen, Mads E.; Schøtt, Jacob; Kazanci, Ongun Berk;

    2016-01-01

    -space, and air-to-water heat pump vs. ground heat exchanger as cooling source) on the system energy performance were investigated while achieving the same thermal indoor conditions. The results show that the water-based floor cooling system performed better than the air-based cooling system in terms of energy......Energy use in buildings accounts for a large part of the energy use globally and as a result of this, international building energy performance directives are becoming stricter. This trend has led to the development of zero-energy and plus-energy buildings. Some of these developments have led...... to certain issues regarding thermal indoor environments, such as overheating. Thermal comfort of occupants should not be sacrificed for energy efficiency but rather, these should be achieved simultaneously. Although the priority should be to minimize the cooling demand during the design, this is not always...

  11. Modeling the forced-air cooling process of fresh strawberry packages, Part III: Experimental validation of the energy model

    Energy Technology Data Exchange (ETDEWEB)

    Ferrua, M.J.; Singh, R.P. [Department of Biological and Agricultural Engineering, University of California at Davis, One Shields Avenue, Davis, CA 95616 (United States)

    2009-03-15

    The aim of this study was to validate a mathematical model previously developed for predicting the cooling rate of individual packages of strawberries (clamshells) during an industrial forced-air cooling application. The differences between the predicted and experimental profiles of the average-fruit temperature per clamshell were less than 0.7 C (within the limits of the experimental uncertainty). The 7/8th cooling time of individual clamshells was predicted within less than 3% of the experimental value. In addition, the local performance of the model and its capability to predict the strawberry moisture loss were qualitatively analyzed. The moisture loss was predicted between 73% and 88% of the experimental value. The predicted temperature profile of individual fruits and airflow within clamshells followed the general trends experimentally determined. Finally, the results corroborated that the transport phenomena during force-air cooling applications can be modeled by decoupling the momentum transport from the transport of energy and mass. (author)

  12. Effect of the Heat Treatment on the Chromium Partition in CaO-MgO-SiO2-Cr2O3 Synthetic Slags

    Science.gov (United States)

    Albertsson, Galina Jelkina; Teng, Lidong; Engström, Fredrik; Seetharaman, Seshadri

    2013-12-01

    Mg-spinel phase is known to be important for control of Cr leaching from Cr-containing slags. The objective of the present study is to get an understanding of the phase relationships in the CaO-MgO-SiO2-Cr2O3 system with a view to control the precipitation of Cr-spinel in the slag phase. The equilibrium phases in CaO-MgO-SiO2-Cr2O3 slag system in the range of 1673 K to 1873 K (1400 °C to 1600 °C) have been investigated experimentally and compared with the results from thermodynamic calculations. The slag compositions close to the industrial slag systems were chosen. The Cr2O3 and MgO contents in the slag were fixed to be 6 and 8 wt pct, respectively. The basicity (CaO/SiO2) of the slag was varied in the range of 1.0 to 2.0. The slags were synthesized at a pre-determined oxygen partial pressure (10-4) or air (2.13 × 104 Pa) at a temperature above the liquidus temperature. The samples were then soaked at targeted temperatures for 24 hours in controlled atmosphere in order to achieve the equilibrium state before quenching in water. Four different heat-treatment regimes (defined as Ia, Ib, II.a and II.b) in Section II-D) were used in the present experiments. The lower oxygen partial pressure was maintained by a suitable mixture of CO and CO2 gases. Phases present and their compositions in the quenched slags were studied using scanning electron microscopy coupled with energy-dispersive spectroscopy and X-ray diffraction techniques. The chromium content in the phases present was analyzed using wavelength-dispersive spectrometer. The experimental results obtained are compared with the calculation results from Factsage software. The size of spinel crystals increased drastically after slow-cooling from 1873 K (1600 °C) followed by annealing at 1673 K (1400 °C) for 24 hours (heating regimes II) compared to samples being quenched directly after soaking at 1873 K (1600 °C) (heating regime I.a). It was found that the amount of foreign elements in the spinel phase, and

  13. An open reversed Brayton cycle with regeneration using moist air for deep freeze cooled by circulating water

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Shaobo [Guangdong Ocean University, College of Engineering, East Jiefang Rd. No. 40, Xiashan, Zhanjiang, Guangdong 524006 (China); Northwestern Polytechnical University, School of Aeroengine and Thermal Power Engineering, Xi' an, Shaanxi 710072 (China); Zhang, Hefei [Northwestern Polytechnical University, School of Aeroengine and Thermal Power Engineering, Xi' an, Shaanxi 710072 (China)

    2009-01-15

    This paper presents an open reversed Brayton cycle with regeneration using moist air for deep freeze cooled by circulating water, and proves its feasibility through performance simulation. Pinch technology is used to analyze the cooling of the wet air after compressor and the water used for cooling wet air after compressor. Its refrigeration depends mainly on the sensible heat of air and the latent heat of water vapor, its performance is more efficient than a conventional air-cycle, and the utilization of turbo-machinery makes it possible. The adoption of this cycle will make deep freeze easily and reduce initial cost because very low temperature, about -55 C, air is obtained. The sensitivity analysis of coefficient of performance to the efficiency of compressor and the efficiency of compressor, and the results of the cycle are also given. The simulation results show that the COP of this system depends on the temperature before turbine, the efficiency of compressor and the efficiency of compressor, and varies with the wet bulb temperature of the outdoor air. Humid air is a perfect working fluid for deep freeze with no cost to the user. (author)

  14. Cooling air flow in high-shelved storage rooms; Die Kuehlluftstroemung in Hochregallagern

    Energy Technology Data Exchange (ETDEWEB)

    Doege, K. [Institut fuer Luft- und Kaeltetechnik gGmbH, Dresden (Germany); Ehle, A. [Institut fuer Luft- und Kaeltetechnik gGmbH, Dresden (Germany)

    1995-12-31

    Operation of high-shelved storage rooms requires strict observation of specified temperatures and refrigerating capacities. However, the geometric and thermal conditions prevailing in the individual case make it difficult to estimate air flow behaviour and resultant temperatures. In designing the new high-shelved storage rooms of Langnese Iglo, therefore, a computer programme named ResCUE was used to model and numerically calulate non-isothermal room air flows. Specific tasks were to determine the influence of cooling air distribution, building geometry, arrangement of outlets, and internal heat sources on velocity and temperature fields and to pinpoint the consequences of the great height of the storage rooms. (orig./HW) [Deutsch] Fuer den Betrieb von Hochregallagern ist die Einhaltung vorgegebener Temperaturen und Kuehlleistungen von besonderer Bedeutung. Aufgrund der geometrischen und thermischen Randbedingungen sind jedoch die Stroemungsverhaeltnisse und Termperturen zunaechst schwer abschaetzbar. Deshalb wurde fuer die neuen Hochregallager von Langnese Iglo die nichtisotherme Raumluftstroemung modelliert und mit dem Computerprogramm ResCUE numerisch berechnet. Untersucht wurden der Einfluss der Kuehlluftverteilung, der Gebaeudegeometrie, der Anordnung der Austrittsoeffnungen und der inneren Waermequellen auf die Geschwindigkeits- und Temperaturfelder sowie die Konsequenzen aus der grossen Hoehe des Hochregallagers. (orig./HW)

  15. Studying the effect of thermal and acid exposure on alkali activated slag Geopolymer

    Directory of Open Access Journals (Sweden)

    Khater H.M.

    2014-04-01

    Full Text Available This article reports a study about thermal stability as well as acid resistance of geopolymer materials prepared from Ground Granulated Blast Furnace Slag (GGBFS, Air Cooled Slag (ACS, Silica fume (SF and cement kiln dust (CKD using 6% (weight of equal mix from alkaline sodium hydroxide and sodium silicate activators. Study of addition of ACS, SF and CKD as partial replacement of GGBFS is investigated so as to improve the mechanical and microstructural properties of geopolymer mixes. Compressive strength and SEM were utilized in these studies. Materials were prepared using water/binder of 0.30 at 38°C and 100% RH. Results showed that geopolymer materials prepared using alkali activated slag exhibit large changes in compressive strength with increasing the firing temperature from 300 to 1000°C and exhibit an enhancement in thermal stability as compared to concrete specimens. Materials prepared by replacing GGBFS by 15% ACS resist thermal deterioration up to 1000°C. It was suggested to be suitable for refractory insulation applications as well as for production of nuclear concrete reactors. On the other hand, geopolymer mixes exhibit low stability upon subjecting to different concentration from the mix of nitric and hydrochloric acid in equal ratio (1:1. Current studies of geopolymer microstructure were focused on the morphology as well as the relationship between compositions and mechanical properties.

  16. Slag analysis with laser-induced breakdown spectrometry.

    Science.gov (United States)

    Kraushaar, M; Noll, R; Schmitz, H U

    2003-10-01

    Laser-induced breakdown spectrometry (LIBS) has been applied for multi-elemental analysis of slag samples from a steel plant. In order to avoid the time-consuming step of sample preparation, the liquid slag material can be filled in special probes. After cooling of the liquid slag and solidification, the samples can be analyzed with LIBS. Chemical analysis of slag is an essential input parameter used for numerical simulations to control liquid steel processing. The relative variation range of element concentrations in slag samples from steel production can amount to up to 30%. A multivariate calibration model is used to take into account matrix effects caused by these varying concentrations. By optimizing the measuring parameters as well as the calibration models, an agreement between the standard X-ray fluorescence (XRF) analysis and LIBS analysis in terms of the coefficient of determination r2 of 0.99 for the main analytes CaO, SiO2, and Fetot of converter slag samples was achieved. The average repeatability of the LIBS measurement for these elements in terms of the relative standard deviation of the determined concentration is improved to less than 1.0%. With these results, the basis is established for future on-line applications of LIBS in the steel-making industry for slag analysis. PMID:14639759

  17. A method for calculation of forces acting on air cooled gas turbine blades based on the aerodynamic theory

    Directory of Open Access Journals (Sweden)

    Grković Vojin R.

    2013-01-01

    Full Text Available The paper presents the mathematical model and the procedure for calculation of the resultant force acting on the air cooled gas turbine blade(s based on the aerodynamic theory and computation of the circulation around the blade profile. In the conducted analysis was examined the influence of the cooling air mass flow expressed through the cooling air flow parameter λc, as well as, the values of the inlet and outlet angles β1 and β2, on the magnitude of the tangential and axial forces. The procedure and analysis were exemplified by the calculation of the tangential and axial forces magnitudes. [Projekat Ministarstva nauke Republike Srbije: Development and building the demonstrative facility for combined heat and power with gasification

  18. The phenomenon of evaporative cooling from a humid surface as an alternative method for air-conditioning

    Directory of Open Access Journals (Sweden)

    E. Velasco Gomez, F.C. Rey Martinez, A. Tejero Gonzalez

    2010-01-01

    Full Text Available The phenomenon of evaporative cooling is a common process in nature, whose applications for cooling air are being used since the ancient years. In fact, it meets this objective with a low energy consumption, being compared to the primary energy consumption of other alternatives for cooling, as it is simply based in the phenomenon of reducing the air temperature by evaporating water on it. This process can be an interesting alternative to conventional systems in these applications where no very low temperatures are needed, like the case of air-conditioning during the summer. However, the risk of contamination by legionnaire’s disease, commonly related to evaporative cooling systems, has led in recent years to the substitution of these devices in the industry by less-efficient systems, like the case of cooling towers or evaporative condensers substituted by air-condensing refrigerating processes. Therefore, these systems based in the evaporative cooling are rarely used for cooling buildings. To reduce this risk, evaporative cooling is produced from humid surfaces, in such a way that water evaporates due to the difference of vapor pressure between the surface and the air, and thus minimizing the generation of aerosols, responsible for the spread of legionnaire disease. Aerosols are nevertheless produced in conventional systems where water is sprayed or directly in contact with the stream of air; and the problem worsens if the water, which is recirculated, has been still in any moment or its temperature is adequate for the bacteria proliferation. This paper aims to introduce the thermodynamic basis in which the process is based, as well as the commercial evaporative systems and the problem associated to legionnaire’s disease in this kind of systems. Furthermore, three different experimental devices based in evaporative cooling are described, which have been designed and manufactured in the Thermal Engineering Research Group of the University of

  19. Thermal Characteristics of Air-Water Spray Impingement Cooling of Hot Metallic Surface under Controlled Parametric Conditions

    Institute of Scientific and Technical Information of China (English)

    Santosh Kumar Nayak; Purna Chandra Mishra

    2016-01-01

    Experimental results on the thermal characteristics of air-water spray impingement cooling of hot metallic surface are presented and discussed in this paper.The controlling input parameters investigated were the combined air and water pressures,plate thickness,water flow rate,nozzle height from the target surface and initial temperature of the hot surface.The effects of these input parameters on the important thermal characteristics such as heat transfer rate,heat transfer coefficient and wetting front movement were measured and examined.Hot flat plate samples of mild steel with dimension 120 mm in length,120 mm breadth and thickness of 4 mm,6 mm,and 8 mm respectively were tested.The air assisted water spray was found to be an effective cooling media and method to achieve very high heat transfer rate from the surface.Higher heat transfer rate and heat transfer coefficients were obtained for the lesser i.e,4 mm thick plates.Increase in the nozzle height reduced the heat transfer efficiency of spray cooling.At an inlet water pressure of 4 bar and air pressure of 3 bar,maximum cooling rates 670℃/s and average cooling rate of 305.23℃/s were achieved for a temperature of 850℃ of the steel plate.

  20. Thermal characteristics of air-water spray impingement cooling of hot metallic surface under controlled parametric conditions

    Science.gov (United States)

    Nayak, Santosh Kumar; Mishra, Purna Chandra

    2016-06-01

    Experimental results on the thermal characteristics of air-water spray impingement cooling of hot metallic surface are presented and discussed in this paper. The controlling input parameters investigated were the combined air and water pressures, plate thickness, water flow rate, nozzle height from the target surface and initial temperature of the hot surface. The effects of these input parameters on the important thermal characteristics such as heat transfer rate, heat transfer coefficient and wetting front movement were measured and examined. Hot flat plate samples of mild steel with dimension 120 mm in length, 120 mm breadth and thickness of 4 mm, 6 mm, and 8 mm respectively were tested. The air assisted water spray was found to be an effective cooling media and method to achieve very high heat transfer rate from the surface. Higher heat transfer rate and heat transfer coefficients were obtained for the lesser i.e, 4 mm thick plates. Increase in the nozzle height reduced the heat transfer efficiency of spray cooling. At an inlet water pressure of 4 bar and air pressure of 3 bar, maximum cooling rates 670°C/s and average cooling rate of 305.23°C/s were achieved for a temperature of 850°C of the steel plate.

  1. Air-Cooled Heat Exchanger for High-Temperature Power Electronics: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Waye, S. K.; Lustbader, J.; Musselman, M.; King, C.

    2015-05-06

    This work demonstrates a direct air-cooled heat exchanger strategy for high-temperature power electronic devices with an application specific to automotive traction drive inverters. We present experimental heat dissipation and system pressure curves versus flow rate for baseline and optimized sub-module assemblies containing two ceramic resistance heaters that provide device heat fluxes. The maximum allowable junction temperature was set to 175 deg.C. Results were extrapolated to the inverter scale and combined with balance-of-inverter components to estimate inverter power density and specific power. The results exceeded the goal of 12 kW/L and 12 kW/kg for power density and specific power, respectively.

  2. A passive air-cooled dry storage facility for vitrified high-level wastes

    International Nuclear Information System (INIS)

    A conceptual design of air-cooled dry storage vault facility for vitrified high-level waste (HLW) canisters is developed for a site in northern Japan. The facility is designed for the reception and unloading of shielded seagoing transportation casks of vitrified HLW canisters, for the inspection of these canisters, and for their temporary storage for a period of up to 50 years. The waste is to be at least 9 years old when received, and the facility will be capable of storing up to 2,500 canisters. This paper provides a conceptual design to identify construction requirements, materials, and space requirements that are unique to the vitrified HLW storage facility. It also identifies the types of special systems and equipment needed in such a facility

  3. Manufacturing surface hardened components of 42CrMo4 by water-air spray cooling

    Energy Technology Data Exchange (ETDEWEB)

    Gretzki, T.; Krause, C.; Frolov, I.; Hassel, T.; Nicolaus, M.; Bach, F.W. [Inst. of Materials Science, Leibniz Univ. Hannover, Garbsen (Germany); Kaestner, M.; Abo-Namous, O.; Reithmeier, E. [Inst. of Measurement and Control Engineering, Leibniz Univ. Hannover (Germany); National Metallurgical Academy of Ukraine, Dniepropetrovsk (Ukraine)

    2009-12-15

    By employing integrated heat-treatment using forging heat, a significant shortening of the process chain is attained for manufacturing precision forged components with considerable savings in time and energy. With the aid of water-air spray cooling, surface hardening and tempering can be carried out without, at the same time, reheating the component following quenching. In this work, geometric models of splines and single cylinder crankshafts (both made of 1.7225) were surface hardened and tempered using a purpose-built rotating spray unit The obtained hardness, microstructures and their distortions were investigated. To optically and spatially detect the components, fringe and shadow projection systems were employed. In a second research topic, the influence of the spray parameters on the component's distortion was investigated. For both components; the splined shaft and the crankshaft geometries, it was possible to carry out successful surface heat-treatments using these processes. (orig.)

  4. Structural Design and Preliminary Evaluation of a Lightweight, Brazed, Air-Cooled Turbine Rotor Assembly

    Science.gov (United States)

    Meyer, Andre J., Jr.; Morgan, William C.

    1958-01-01

    A lightweight turbine rotor assembly was devised, and components were evaluated in a full-scale jet engine. Thin sheet-metal airfoils were brazed to radial fingers that were an integral part of a number of thin disks composing the turbine rotor. Passages were provided between the disks and in the blades for air cooling. The computed weight of the assembly was 50 percent less than that of a similar turbine of normal construction used in a conventional turbojet engine. Two configurations of sheet-metal test blades simulating the manner of attachment were fabricated and tested in a turbojet engine at rated speed and temperature. After 8-1/2 hours of operation pieces broke loose from the tip sections of the better blades. Severe cracking produced by vibration was determined as the cause of failure. Several methods of overcoming the vibration problem are suggested.

  5. Contingency power for small turboshaft engines using water injection into turbine cooling air

    Science.gov (United States)

    Biesiadny, Thomas J.; Berger, Brett; Klann, Gary A.; Clark, David A.

    1987-01-01

    Because of one engine inoperative requirements, together with hot-gas reingestion and hot day, high altitude takeoff situations, power augmentation for multiengine rotorcraft has always been of critical interest. However, power augmentation using overtemperature at the turbine inlet will shorten turbine life unless a method of limiting thermal and mechanical stresses is found. A possible solution involves allowing the turbine inlet temperature to rise to augment power while injecting water into the turbine cooling air to limit hot-section metal temperatures. An experimental water injection device was installed in an engine and successfully tested. Although concern for unprotected subcomponents in the engine hot section prevented demonstration of the technique's maximum potential, it was still possible to demonstrate increases in power while maintaining nearly constant turbine rotor blade temperature.

  6. Contingency power for a small turboshaft engine by using water injection into turbine cooling air

    Science.gov (United States)

    Biesiadny, Thomas J.; Klann, Gary A.

    1992-01-01

    Because of one-engine-inoperative (OEI) requirements, together with hot-gas reingestion and hot-day, high-altitude take-off situations, power augmentation for multiengine rotorcraft has always been of critical interest. However, power augmentation by using overtemperature at the turbine inlet will shorten turbine life unless a method of limiting thermal and mechanical stress is found. A possible solution involves allowing the turbine inlet temperature to rise to augment power while injecting water into the turbine cooling air to limit hot-section metal temperatures. An experimental water injection device was installed in an engine and successfully tested. Although concern for unprotected subcomponents in the engine hot section prevented demonstration of the technique's maximum potential, it was still possible to demonstrate increases in power while maintaining nearly constant turbine rotor blade temperature.

  7. Experimental study of gas engine driven air to water heat pump in cooling mode

    International Nuclear Information System (INIS)

    Nowadays a sustainable development for more efficient use of energy and protection of the environment is of increasing importance. Gas engine heat pumps represent one of the most practicable solutions which offer high energy efficiency and environmentally friendly for heating and cooling applications. In this paper, the performance characteristics of gas engine driven heat pump used in water cooling were investigated experimentally without engine heat recovery. The effects of several important factors (evaporator water inlet temperature, evaporator water volume flow rate, ambient air temperature, and engine speed) on the performance of gas engine driven heat pump were studied in a wide range of operating conditions. The results showed that primary energy ratio of the system increased by 22.5% as evaporator water inlet temperature increased from 13 oC to 24 oC. On the other hand, varying of engine speed from 1300 rpm to 1750 rpm led to decrease in system primary energy ratio by 13%. Maximum primary energy ratio has been estimated with a value of two over a wide range of operating conditions.

  8. Performance Estimation of Supercritical Co2 Micro Modular Reactor (MMR) for Varying Cooling Air Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Yoonhan; Kim, Seong Gu; Cho, Seong Kuk; Lee, Jeong Ik [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2015-05-15

    A Small Modular Reactor (SMR) receives interests for the various application such as electricity co-generation, small-scale power generation, seawater desalination, district heating and propulsion. As a part of SMR development, supercritical CO2 Micro Modular Reactor (MMR) of 36.2MWth in power is under development by the KAIST research team. To enhance the mobility, the entire system including the power conversion system is designed for the full modularization. Based on the preliminary design, the thermal efficiency is 31.5% when CO2 is sufficiently cooled to the design temperature. A supercritical CO2 MMR is designed to supply electricity to the remote regions. The ambient temperature of the area can influence the compressor inlet temperature as the reactor is cooled with the atmospheric air. To estimate the S-CO2 cycle performance for various environmental conditions, A quasi-static analysis code is developed. For the off design performance of S-CO2 turbomachineries, the experimental result of Sandia National Lab (SNL) is utilized.

  9. The induction of water to the inlet air as a means of internal cooling in aircraft-engine cylinders

    Science.gov (United States)

    Rothrock, Addison M; Krsek, Alois, Jr; Jones, Anthony W

    1943-01-01

    Report presents the results of investigations conducted on a full-scale air-cooled aircraft-engine cylinder of 202-cubic inch displacement to determine the effects of internal cooling by water induction on the maximum permissible power and output of an internal-combustion engine. For a range of fuel-air and water-fuel ratios, the engine inlet pressure was increased until knock was detected aurally, the power was then decreased 7 percent holding the ratios constant. The data indicated that water was a very effective internal coolant, permitting large increases in engine power as limited by either knock or by cylinder temperatures.

  10. Slag characterization and removal using pulse detonation for coal gasification. Quarterly research report, July 1--September 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Huque, Z.; Mei, D.; Biney, P.O.; Zhou, J.; Ali, M.R.

    1996-10-25

    Boiler slagging and fouling as a result of inorganic impurities in combustion gases being deposited on heat transfer tubes have caused severe problems in coal-fired power plant operation. These problems are fuel, system design, and operating condition dependent. Conventional slag and ash removal methods include the use of in situ blowing or jet-type devices such as air or steam soot blowers and water lances. Pulse detonation technology for the purpose of removing slag and fouling deposits in coal-fired utility power plant boilers offers great potential. The detonation wave technique based on high impact velocity with sufficient energy and thermal shock on the slag deposited on gas contact surfaces offers a convenient, inexpensive, yet efficient and effective way to supplement existing slag removal methods. These detonation waves have been demonstrated experimentally to have exceptionally high shearing capability important to the task of removing slag and fouling deposits. Several tests have been performed with single shot detonation wave at University of Texas at Arlington to remove the slag deposit. To hold the slag deposit samples at the exit of detonation tube, two types of fixture was designed and fabricated. They are axial arrangement and triangular arrangement. The slag deposits from the utility boilers have been used to prepare the slag samples for the test. The experimental results show that the single shot detonation wave is capable of removing the entire slag (types of slag deposited on economizer, and air-heater, i.e., relatively softer slags) and 30% of the reheater slag (which is harder) even at a distance of 6 in. from the exit of a detonation engine tube. Wave strength and slag orientation also have different effects on the chipping off of the slag. The annual report discusses about the results obtained in effectively removing the slag.

  11. An experimental investigation of the air entrainment in the shutdown cooling system during mid-loop operation

    International Nuclear Information System (INIS)

    An experimental study on the air entrainment phenomena during mid-loop operation has been performed for Ulchin 3 and 4 nuclear power plant (UCN 3 and 4). The UCN 3 and 4 is the standard Combustion Engineering (CE) System 80, two-loop, 2825 MWt pressurized water reactor which is currently under construction in Korea. This study was undertaken by Korea Atomic Energy Research Institute to provide a basis for modification of CE system 80 design which has relatively small mid-loop operating range, and to investigate the impact of the air entrainment on the shutdown cooling pump. A 1/4 scale model test was performed for two shutdown cooling suction nozzle configurations, with and without bellmouth entry, to obtain data relative to air ingestion and vortex formation at the shutdown cooling suction nozzle during mid-loop operation. The test model size was determined based on Froude number corresponding to that which occurs in plants by considering that the Weber number and Reynolds number are large enough to ensure that liquid surface tension and viscosity would not significantly affect the vortex formation. An empirical correlation between the flow rate and the critical submergence was obtained with respect to the Froude number. The impact of the air entrainment of the pump was also investigated to select parameters for plant operators to monitor the onset of air entrainment into shutdown cooling system (SCS). Effects of the bellmouth entry on the critical submergence were also investigated. (author)

  12. Evaporative and sorptive cooling. Possibilities and limitations in air treatment.; Evaporativ och sorptiv kylning. Moejligheter och begraensningar vid luftbehandling

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, T. [Chalmers Univ. of Techn., Goeteborg (Sweden). Dept. of Building Services Engineering

    2001-10-01

    A primary demand for a good indoor climate in a building is that temperature and humidity are maintained at comfortable levels, regardless of the prevailing outdoor climate. Some buildings often have a heat surplus for a great part of the year due to internal activities, even in climates with moderate ambient temperatures. This heat surplus has to be removed in order to fulfil the specified requirements on the indoor climate. The focus in this report is on possibilities and limitations using evaporative and desiccant cooling to satisfy the cooling demands in such buildings. Today the most common technical solution is to use a compressor refrigeration system for air-conditioning. As a result of the greenhouse effect and the ozone depletion debate, the prerequisites for compressor refrigeration systems have been changed. Evaporative cooling is an interesting alternative to conventional compressor refrigeration systems. However, the use of evaporative cooling presupposes all-air systems. The use of such a system will also, to a large extent, be limited by ambient conditions as well as the settled demands on the indoor climate. High outdoor humidity levels have great influence on the supply-air temperature achievable, i.e., cooling loads possible to meet. One way to considerably reduce the influence of these limitations is to use desiccant cooling, i.e., to dehumidify the ambient air before the evaporative stages. In this report, a general methodology to describe possibilities and limitations for evaporative and desiccant cooling, is presented. The major advantage of this methodology is that it may give rise to an increased understanding of these processes and, hence, be a guide to a proper dimensioning.

  13. Forecasting Cool Season Daily Peak Winds at Kennedy Space Center and Cape Canaveral Air Force Station

    Science.gov (United States)

    Barrett, Joe, III; Short, David; Roeder, William

    2008-01-01

    The expected peak wind speed for the day is an important element in the daily 24-Hour and Weekly Planning Forecasts issued by the 45th Weather Squadron (45 WS) for planning operations at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The morning outlook for peak speeds also begins the warning decision process for gusts ^ 35 kt, ^ 50 kt, and ^ 60 kt from the surface to 300 ft. The 45 WS forecasters have indicated that peak wind speeds are a challenging parameter to forecast during the cool season (October-April). The 45 WS requested that the Applied Meteorology Unit (AMU) develop a tool to help them forecast the speed and timing of the daily peak and average wind, from the surface to 300 ft on KSC/CCAFS during the cool season. The tool must only use data available by 1200 UTC to support the issue time of the Planning Forecasts. Based on observations from the KSC/CCAFS wind tower network, surface observations from the Shuttle Landing Facility (SLF), and CCAFS upper-air soundings from the cool season months of October 2002 to February 2007, the AMU created multiple linear regression equations to predict the timing and speed of the daily peak wind speed, as well as the background average wind speed. Several possible predictors were evaluated, including persistence, the temperature inversion depth, strength, and wind speed at the top of the inversion, wind gust factor (ratio of peak wind speed to average wind speed), synoptic weather pattern, occurrence of precipitation at the SLF, and strongest wind in the lowest 3000 ft, 4000 ft, or 5000 ft. Six synoptic patterns were identified: 1) surface high near or over FL, 2) surface high north or east of FL, 3) surface high south or west of FL, 4) surface front approaching FL, 5) surface front across central FL, and 6) surface front across south FL. The following six predictors were selected: 1) inversion depth, 2) inversion strength, 3) wind gust factor, 4) synoptic weather pattern, 5) occurrence of

  14. Fibre-coupled air-cooled high-power diode laser systems

    Science.gov (United States)

    Bartoschewski, Daniel; Meinschien, Jens; Fornahl, Udo

    2008-02-01

    applications demanding more power. Our measurements show the potential for direct air-cooled laser systems with 100 Watt power out of the fibre.

  15. 风冷式与水冷式单元空调机组的对比%Comparison between air-cooled and water-cooled unitary air conditioners

    Institute of Scientific and Technical Information of China (English)

    赵丽

    2012-01-01

    从不同方面比较了风冷式和水冷式单元空调机组的优缺点,包括机组能效比、名义工况冷源综合制冷性能系数、机房面积以及对总体建筑环境的影响.指出了对于大型会展建筑中冷热负荷具有临时性的空调区域,分散式风冷单元空调机组有较好的发展前景.%Compares the advantages and disadvantages of air-cooled and water-cooled unitary air conditioners from different aspects including the unit EER, the overall nominal working condition refrigerating coefficient of performance, the area of machine room, and the influence on the building environment. Points out that to the areas in convention and exhibition buildings with temporary cooling/ heating loads, there will be a better prospect for the decentralized air-cooled unitary air conditioners.

  16. Characteristic Evaluation on the Cooling Performance of an Electrical Air Conditioning System Using R744 for a Fuel Cell Electric Vehicle

    OpenAIRE

    Moo-Yeon Lee; Hong-Phil Won; Ho-Seong Lee

    2012-01-01

    The objective of this study was to investigate the cooling performance characteristics of an electrical air conditioning system using R744 as an alternative of R-134a for a fuel cell electric vehicle. In order to analyze the cooling performance characteristics of the air conditioning system using R744 for a fuel cell electric vehicle, an electrical air conditioning system using R744 was developed and tested under various operating conditions according to both inlet air conditions of the gas c...

  17. Durability of zirconia thermal-barrier ceramic coatings on air-cooled turbine blades in cyclic jet engine operation

    Science.gov (United States)

    Liebert, C. H.; Jacobs, R. E.; Stecura, S.; Morse, C. R.

    1976-01-01

    Thermal barrier ceramic coatings of stabilized zirconia over a bond coat of Ni Cr Al Y were tested for durability on air cooled turbine rotor blades in a research turbojet engine. Zirconia stabilized with either yttria, magnesia, or calcia was investigated. On the basis of durability and processing cost, the yttria stabilized zirconia was considered the best of the three coatings investigated.

  18. LF炉精炼废渣循环利用的研究进展%The Development of Research on Recycling of LF Spent Slag

    Institute of Scientific and Technical Information of China (English)

    吕宁宁; 于景坤; 苏畅

    2011-01-01

    由于LF炉精炼废渣带来的堆放占地和环境污染等问题日益突出,因此,开展精炼废渣循环利用的研究对企业的节能减排具有重要意义。从熔融态和固态两方面分析了精炼废渣循环利用的研究现状及目前存在的问题。提出去硫是今后精炼废渣循环利用研究的关键,处理熔融态废渣时可选择将废渣倒入其他容器中,然后再吹入空气将渣中的硫脱除;对于固态废渣,可通过控制碱度和冷却方式使渣中的硫以CaS的形式存在继而采用水化和氧化的方法将硫去除。%The problems of the land occupation and the pollution of environment caused by discarding the LF spent slag are becoming serious.Therefore,it is important to study the recycling of LF spent slag.This paper analyzed the research status of recycling of LF spent slag and the major problems with the melting and solid state.It is considered that the focus of future research is to remove the sulfur containing in LF spent slag;the molten spent slag should be poured into other vessel and the sulfur in the molten spent slag would be removed by blowing air directly into it.It would be available to remove sulfur from solid spent slag by means of hydration and oxidation on condition that the slag had been dealed with a certain basicity and cooling method and the sulfur in slag had been existing with the form of CaS.

  19. Interim Report: Air-Cooled Condensers for Next Generation Geothermal Power Plants Improved Binary Cycle Performance

    Energy Technology Data Exchange (ETDEWEB)

    Daniel S. Wendt; Greg L. Mines

    2010-09-01

    As geothermal resources that are more expensive to develop are utilized for power generation, there will be increased incentive to use more efficient power plants. This is expected to be the case with Enhanced Geothermal System (EGS) resources. These resources will likely require wells drilled to depths greater than encountered with hydrothermal resources, and will have the added costs for stimulation to create the subsurface reservoir. It is postulated that plants generating power from these resources will likely utilize the binary cycle technology where heat is rejected sensibly to the ambient. The consumptive use of a portion of the produced geothermal fluid for evaporative heat rejection in the conventional flash-steam conversion cycle is likely to preclude its use with EGS resources. This will be especially true in those areas where there is a high demand for finite supplies of water. Though they have no consumptive use of water, using air-cooling systems for heat rejection has disadvantages. These systems have higher capital costs, reduced power output (heat is rejected at the higher dry-bulb temperature), increased parasitics (fan power), and greater variability in power generation on both a diurnal and annual basis (larger variation in the dry-bulb temperature). This is an interim report for the task ‘Air-Cooled Condensers in Next- Generation Conversion Systems’. The work performed was specifically aimed at a plant that uses commercially available binary cycle technologies with an EGS resource. Concepts were evaluated that have the potential to increase performance, lower cost, or mitigate the adverse effects of off-design operation. The impact on both cost and performance were determined for the concepts considered, and the scenarios identified where a particular concept is best suited. Most, but not all, of the concepts evaluated are associated with the rejection of heat. This report specifically addresses three of the concepts evaluated: the use of

  20. Energy flow and thermal comfort in buildings: Comparison of radiant and air-based heating & cooling systems

    DEFF Research Database (Denmark)

    Le Dréau, Jérôme

    and standing positions. Besides this comparative study of different terminals, the relation between cooling system and internal convective flow has also been investigated experimentally. The comparison with existing models pointed out the specificity of existing correlations and the limitation of their range...... of application. Because of differences in the air jet trajectory, existing correlations tend to overestimate the convective flow, especially at the ceiling. Two approaches have thus been tested to better account for the air flow pattern in the definition of convective heat transfer coefficients (CHTC......Heating and cooling terminals can be classified in two main categories: convective terminals (e.g air conditioning, active chilled beam, fan coil) and radiant terminals. The two terminals have different modes of heat transfer: the first one is mainly based on convection, whereas the second one...

  1. Performance of an air-cooled steam condenser for a waste-to-energy plant over its whole operating range

    International Nuclear Information System (INIS)

    Research highlights: → Performance of ACSC are strongly affected by environmental conditions. → A mathematical model was developed for predicting performance of ACSC. → The relation between the air temperature and the maximum heat rate was achieved. -- Abstract: In this work the behaviour of an air-cooled steam condenser (ACSC), installed in a waste-to-energy heat recovery plant, has been analysed under various environmental conditions. The analysis has been carried out by using a mathematical model developed by the authors. For an ACSC, the bottom heat sink is represented by the environmental air, hence the fluctuations of the environmental air temperature undoubtedly affect the performance of the device. Because of the constancy of the temperature on the condensing steam side, the mathematical model is based on the direct application of LMTD (log-mean temperature difference) method. It provides the relation between the air temperature and the volumetric air flow rate, and the main cycle operating parameters. An analysis of the on-site electrical demand has been also performed, which shows that a net benefit is achievable by increasing the air-cooled steam condenser units from six to eight.

  2. Conceptual design of passive containment cooling system with air holdup tanks in the concrete containment of improved APR+

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Byong Guk; NO, Hee Cheon, E-mail: hcno@kaist.ac.kr

    2014-02-15

    Highlights: • Conceptual design of passive containment cooling system (PCCS) based on APR+ is proposed. • Decay heat removal rate is to be maximized by introducing air holdup tanks (AHT). • Only air is transported into the AHT decreasing air mass fraction near HXs inside containment and increasing heat transfer rates. • Large AHT volume gives significantly higher heat removal rate. • External HXs have merits over in-tube HXs for long term cooling. - Abstract: The accident of the Fukushima nuclear power plant emphasized passive systems against prolonged station blackout. This paper aims at conceptual design of passive containment cooling system (PCCS) based on APR+, an advanced PWR developed in Korea with passive auxiliary feedwater system (PAFS). In the design, decay heat removal rate is to be maximized by introducing air holdup tanks (AHT). The AHT is an isolated space disposed above IRWST and is connected to the containment free space by vent lines through IRWST water and PAFS heat exchangers (HXs), where steam generated by decay heat is condensed. Since a lot of steam is condensed through in-tube HXs and IRWST water, air is mainly transported into the AHT decreasing air mass fraction near HXs inside containment and increasing heat transfer rates. Several design options (AHT volume, flow distribution in vent lines, HX types) are evaluated via scoping analysis. The scoping analysis had proved that AHT (>10% containment volume) decreased the required number of PCCS HXs to be installed less than a half, failure of valves caused marginal increase in HXs to be installed, and external HXs had merits over in-tube HXs for long term cooling.

  3. Legionella detection and subgrouping in water air-conditioning cooling tower systems in Kuwait.

    Science.gov (United States)

    Al-Matawah, Qadreyah; Al-Zenki, Sameer; Al-Azmi, Ahmad; Al-Waalan, Tahani; Al-Salameen, Fadila; Hejji, Ahmad Ben

    2015-07-01

    The main aim of the study was to test for the presence of Legionnaires' disease-causing microorganisms in air-conditioned buildings in Kuwait using molecular technologies. For this purpose, 547 samples were collected from 38 cooling towers for the analysis of Legionella pneumophila. These samples included those from water (n = 178), air (n = 231), and swabs (n = 138). Out of the 547 samples, 226 (41%) samples were presumptive positive for L. pneumophila, with L. pneumophila viable counts in the positive water samples ranging from 1 to 88 CFU/ml. Of the Legionella culture-positive samples, 204 isolates were examined by latex agglutination. These isolates were predominately identified as L. pneumophila serogroup (sg) 2-14. Using the Dresden panel of monoclonal antibodies, 74 representatives isolates were further serogrouped. Results showed that 51% of the isolates belonged to serogroup 7 followed by 1 (18%) and 3 (18%). Serogroups 4 (4%) and 10 (7%) were isolated at a lower frequency, and two isolates could not be assigned to a serogroup. These results indicate the wide prevalence of L. pneumophila serogroup 7 as the predominant serogroup at the selected sampling sites. Furthermore, the 74 L. pneumophila (sg1 = 13; sg3 = 13; sg4 = 3; sg7 = 38; sg10 = 5; sgX = 2) isolates were genotyped using the seven gene protocol sequence-based typing (SBT) scheme developed by the European Working Group for Legionella Infections (EWGLI). The results show that Legionella isolates were discriminated into nine distinct sequence typing (ST) profiles, five of which were new to the SBT database of EWGLI. Additionally, all of the ST1 serogroup 1 isolates were of the OLDA/Oxford subgroup. These baseline data will form the basis for the development of a Legionella environmental surveillance program and used for future epidemiological investigations.

  4. Novel single-double-effect LiBr-H₂O absorption prototype with a highly efficient direct air-cooled adiabatic absorber: characterization, simulation and experimental results

    OpenAIRE

    González Gil, Arturo

    2011-01-01

    Due to unsustainable growth of air conditioning market, a great interest in solar cooling technologies has emerged. The coincidence between availability of solar irradiation and peaks of cooling demand makes solar cooling a very attractive option to replace conventional refrigeration machines based on electricity. What is more, solar cooling systems normally use natural refrigerants that are not harmful to the environment. However, an improvement of the current technology is needed for solar ...

  5. Enhancement and performance evaluation for heat transfer of air cooling zone for reduction system of sponge titanium

    Science.gov (United States)

    Wang, Wenhao; Wu, Fuzhong; Jin, Huixin

    2016-05-01

    Since the magnesiothermic reduction employed in current sponge titanium is a highly exothermic reaction, the TiCl4 feed rate is carried out slowly to keep a suitable temperature in reduction reactor, which accounts for an extremely low level of productivity and energy efficiency. In order to shorten the production cycle and improve the energy efficiency, an enhancing scheme is proposed to enhance the heat transfer of air cooling zone for reduction system. The air cooling zone and enhancing scheme are firstly introduced. And then, the heat transfer characteristics of cooling zone are obtained by theoretical analysis and experimental date without enhancing scheme. Finally, the enhancement is analyzed and evaluated. The results show that the fitting results of heat transfer coefficients can be used to evaluate the heat transfer enhancement of cooling zone. Heat sources temperatures have a limited decreasing, heat transfer rate increases obviously with the enhanced cooling, and the TiCl4 feed rate can be increased significantly by 9.61 %. And the measured and calculated results are good enough to meet the design requirements.

  6. Impacts of Ventilation Ratio and Vent Balance on Cooling Load and Air Flow of Naturally Ventilated Attics

    Directory of Open Access Journals (Sweden)

    Zhigang Shen

    2012-08-01

    Full Text Available The impacts of ventilation ratio and vent balance on cooling load and air flow of naturally ventilated attics are studied in this paper using an unsteady computational fluid dynamics (CFD model. Buoyancy-driven turbulent ventilations in attics of gable-roof residential buildings are simulated for typical summer conditions. Ventilation ratios from 1/400 to 1/25 combined with both balanced and unbalanced vent configurations are investigated. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively insensitive to the variations in ventilation ratio and vent configuration. The predicted temperature fields are characterized by thermal stratification, except for the soffit regions. It is demonstrated that an increase in ventilation ratio will reduce attic cooling load. Compared with unbalanced vent configurations, balanced attic ventilation is shown to be the optimal solution in both maximizing ventilating flow rate and minimizing cooling load for attics with ventilation ratio lower than 1/100. For attics with ventilation ratios greater than 1/67, a configuration of large ridge vent with small soffit vent favors ventilating air flow enhancement, while a configuration of small ridge vent with large soffit vent results in the lowest cooling energy consumption.

  7. Heat transfer enhancement using air-atomized spray cooling with water-Al2O3 nano-fluid

    International Nuclear Information System (INIS)

    The study deals with the air-atomized spray cooling using nano-fluid as the cooling media for high heat flux applications. The nano-fluid has been prepared by commercial Al2O3 particles of diameter less than 13 nm and water. Heat transfer study has been carried out on a pre-heated steel specimen of dimensions 100 mm x 100 mm x 6 mm. The initial temperature of the plate which was subjected to air-atomized spray cooling was over 900 deg. C. Various coolants consisting of 0.1% volumetric concentration of water -Al2O3 mixture, with or without a dispersing agent (surfactant) were used for the study. The dispersing agents used are sodium dodecyl sulphate (SDS) and polyoxyethylene (20) sorbitan monolaurate (Tween 20). Inverse heat conduction software INTEMP has been used for estimating the surface heat flux and temperatures taking into account the measured internal temperature histories by the thermocouples during the cooling process. The results obtained using nano-fluid coolants are compared with that of the results where pure water (filtered potable water) is used as a coolant. The analyses reveal that the cooling rate, critical heat flux and heat transfer coefficients are significantly enhanced when nano-fluids are used as coolants in air-atomized spray process. Also, the nano-fluid coolants with dispersing agent shows a better enhancement of heat transfer over that of the nano-fluid without the dispersing media. The nano-fluid with dispersing agent Tween 20 is found more effective than that of its counterpart. Overall, the percentage enhancement in cooling rate of all these nano-fluids compared with pure water (filtered potable water) is 10.2% for water-Al2O3, 18.6% for water-Al2O3-SDS, and up to 32.3% for water-Al2O3 -Tween 20. (authors)

  8. A novel trapezoid fin pattern applicable for air-cooled heat sink

    Science.gov (United States)

    Chen, Chien-Hung; Wang, Chi-Chuan

    2015-11-01

    The present study proposed a novel step or trapezoid surface design applicable to air-cooled heat sink under cross flow condition. A total of five heat sinks were made and tested, and the corresponding fin patterns are (a) plate fin; (b) step fin (step 1/3, 3 steps); (c) 2-step fin (step 1/2, 2 steps); (d) trapezoid fin (trap 1/3, cutting 1/3 length from the rear end) and (e) trapezoid fin (trap 1/2, cutting 1/2 length from the rear end). The design is based on the heat transfer augmentation via (1) longer perimeter of entrance region and (2) larger effective temperature difference at the rear part of the heat sink. From the test results, it is found that either step or trapezoid design can provide a higher heat transfer conductance and a lower pressure drop at a specified frontal velocity. The effective conductance of trap 1/3 design exceeds that of plate surface by approximately 38 % at a frontal velocity of 5 m s-1 while retains a lower pressure drop of 20 % with its surface area being reduced by 20.6 %. For comparisons exploiting the overall thermal resistance versus pumping power, the resultant thermal resistance of the proposed trapezoid design 1/3, still reveals a 10 % lower thermal resistance than the plate fin surface at a specified pumping power.

  9. Enhanced cooling in mono-crystalline ultra-thin silicon by embedded micro-air channels

    KAUST Repository

    Ghoneim, Mohamed T.

    2015-12-11

    In today’s digital world, complementary metal oxide semiconductor (CMOS) technology enabled scaling of bulk mono-crystalline silicon (100) based electronics has resulted in their higher performance but with increased dynamic and off-state power consumption. Such trade-off has caused excessive heat generation which eventually drains the charge of battery in portable devices. The traditional solution utilizing off-chip fans and heat sinks used for heat management make the whole system bulky and less mobile. Here we show, an enhanced cooling phenomenon in ultra-thin (>10 μm) mono-crystalline (100) silicon (detached from bulk substrate) by utilizing deterministic pattern of porous network of vertical “through silicon” micro-air channels that offer remarkable heat and weight management for ultra-mobile electronics, in a cost effective way with 20× reduction in substrate weight and a 12% lower maximum temperature at sustained loads. We also show the effectiveness of this event in functional MOS field effect transistors (MOSFETs) with high-κ/metal gate stacks.

  10. Enhanced cooling in mono-crystalline ultra-thin silicon by embedded micro-air channels

    Directory of Open Access Journals (Sweden)

    Mohamed T. Ghoneim

    2015-12-01

    Full Text Available In today’s digital world, complementary metal oxide semiconductor (CMOS technology enabled scaling of bulk mono-crystalline silicon (100 based electronics has resulted in their higher performance but with increased dynamic and off-state power consumption. Such trade-off has caused excessive heat generation which eventually drains the charge of battery in portable devices. The traditional solution utilizing off-chip fans and heat sinks used for heat management make the whole system bulky and less mobile. Here we show, an enhanced cooling phenomenon in ultra-thin (>10 μm mono-crystalline (100 silicon (detached from bulk substrate by utilizing deterministic pattern of porous network of vertical “through silicon” micro-air channels that offer remarkable heat and weight management for ultra-mobile electronics, in a cost effective way with 20× reduction in substrate weight and a 12% lower maximum temperature at sustained loads. We also show the effectiveness of this event in functional MOS field effect transistors (MOSFETs with high-κ/metal gate stacks.

  11. Enhanced cooling in mono-crystalline ultra-thin silicon by embedded micro-air channels

    Science.gov (United States)

    Ghoneim, Mohamed T.; Fahad, Hossain M.; Hussain, Aftab M.; Rojas, Jhonathan P.; Torres Sevilla, Galo A.; Alfaraj, Nasir; Lizardo, Ernesto B.; Hussain, Muhammad M.

    2015-12-01

    In today's digital world, complementary metal oxide semiconductor (CMOS) technology enabled scaling of bulk mono-crystalline silicon (100) based electronics has resulted in their higher performance but with increased dynamic and off-state power consumption. Such trade-off has caused excessive heat generation which eventually drains the charge of battery in portable devices. The traditional solution utilizing off-chip fans and heat sinks used for heat management make the whole system bulky and less mobile. Here we show, an enhanced cooling phenomenon in ultra-thin (>10 μm) mono-crystalline (100) silicon (detached from bulk substrate) by utilizing deterministic pattern of porous network of vertical "through silicon" micro-air channels that offer remarkable heat and weight management for ultra-mobile electronics, in a cost effective way with 20× reduction in substrate weight and a 12% lower maximum temperature at sustained loads. We also show the effectiveness of this event in functional MOS field effect transistors (MOSFETs) with high-κ/metal gate stacks.

  12. Air-cooled gas turbine cycles – Part 1: An analytical method for the preliminary assessment of blade cooling flow rates

    International Nuclear Information System (INIS)

    It is well known that, for a given compressor technology, gas turbine efficiency increases with the turbine inlet temperature (TIT): both modern aeronautical and land-based gas turbines operate at very high temperatures (1500–2000K) –and correspondingly high pressure ratios. As the TIT increases, the heat transferred from the expanding gas to the turbine blade also increases, and the need to extend the operational life make it necessary to adopt internal air cooling to reduce blade creep, oxidation and low-cycle fatigue. The cooling medium is usually air extracted from the high-pressure compressor stages, and since this extraction decreases the thermal efficiency and power output of the engine, it is important to bleed the minimum amount of coolant to attain a prescribed maximum material temperature in the blade with the maximum possible uniformity (lower thermal stresses): thence the need to properly model the cooling system for a given turbine blade geometry under realistic engine operating conditions. In the preliminary design of the first statoric and rotoric blading, it is essential for designers to rely on simple models that often neglect the small scales effects on the external flows and also by force adopt a much simplified treatment of the internal ones, and as a result attain a substantially lower degree of approximation than that offered by more complex and expensive numerical simulations. The goal in the design of a lumped model is therefore to make it both sufficiently general and accurate to analyze blade shapes and cooling channels structures that can be further refined by means of more accurate, but also more computationally intensive, models. This paper presents a simple, globally lumped thermodynamic model of blade cooling whose most important feature is its being analytical, so that the solution is devoid of numerical approximations and leads to closed-form expressions that can be easily manipulated to accommodate for different process

  13. A Blended Cement Containing Blast Furnace Slag and Phosphorous Slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Blended cement containing blast furnace slag(BFS) and phosphorous slag(PS) is a new kind of cement.The total content of blended materials could increase if two additives were used. Using the same admixtures, the properties of the blended cement with 70% additives could reach the standard of 525-grade slag cement according to GB.The strength of cement with 80% additives could reach the standard of 425-grade slag cement.The tests of strength, pore structure,hydration products,inhibiting alkali-aggregate reaction, resistance to sulfate corrosion of BFS-PSC were performed.

  14. Resfriamento de banana-prata com ar forçado Forced-air cooling of banana

    Directory of Open Access Journals (Sweden)

    BÁRBARA TERUEL

    2002-04-01

    Full Text Available Este trabalho apresenta as curvas de resfriamento de banana-prata (Musa balbisiana Colla e os valores do tempo de meio e sete oitavos de resfriamento, partindo do cálculo da Taxa Adimensional de Temperatura. Os frutos foram resfriados num sistema com ar forçado a 7ºC, umidade relativa de 87,6±3,8%, e velocidade do ar entre 1 e 0,2 m/s. Aplicou-se um delineamento experimental inteiramente casualizado, usando um esquema fatorial 2x2 (dois fluxos de ar (fatores e duas embalagens (níveis, para um nível de significância de 10%. Os fluxos de ar foram 1.933 a 1.160 m³/h, e as embalagens se diferenciaram pela porcentagem de área de abertura disponível para a ventilação (40 e 3,2%. Foi constatada uma diferença significativa no tempo de resfriamento, tanto quando aplicadas as duas taxas de ar como quando usadas as duas embalagens. O menor tempo de resfriamento foi atingido no tratamento que combinou a maior taxa de ar (1.933 m³/h com a embalagem de maior área de aberturas (40%. O maior tempo de resfriamento foi atingido no tratamento que combinou a menor taxa de ar (1160 m³/h com a embalagem de 3,2% de área efetiva de abertura. Os resultados obtidos demonstram que o tempo de resfriamento depende, em grande medida, da taxa de ar e do tipo de embalagem usada. O tempo de resfriamento variou em média entre 117 a 555 min, dependendo do tratamento aplicado. Não se constatou diferença significativa nas perdas de massa entre os diferentes tratamentos.This work presents the cooling curves for bananas Prata, (Musa balbisiana Colla, and determinates half-cooling and seven-eight cooling times and the cooling rate. Bananas were kept in a cold room with a forced-air system at 7ºC and RH = 87.6±3.8%. The experiment was conducted in a 2x2 factorial design, to test the effects of two flow rates (factors of air passing through the product, and two types of boxes (levels. The statistical analysis was performed at p<0.10. The air flow rates were 1933

  15. PHOSPHORUS REMOVAL USING STEEL SLAG

    Institute of Scientific and Technical Information of China (English)

    Y.Z. Lan; S. Zhang; J.K. Wang; R. W. Smith

    2006-01-01

    Steel slag is a byproduct produced in large amounts in the steel-making process. It is an important resource that can be effectively utilized. An experiment was described in which steel slag was tested as an adsorbent for the removal of phosphorus from waste water. Phosphorus removal depended on the amount of steel slag added, the pH value, the contact time, and the initial concentration. Under laboratory conditions when the added slag was 7.5g/L, the contact time 2h, and the pH value was equivalent to 6.5, over 99% of the phosphorus was removed; the experimental data on steel slag adsorption of phosphorus in the water fitted the Freundlich isotherm model. Steel slag was found to be very effective in adsorbing phosphorus.

  16. Experimental study of the heat transfers and passive cooling potential of a ventilated plenum designed for uniform air distribution

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Lessing, Julian

    2016-01-01

    suspended ceiling to uniformly distribute the supply air to the occupied zone. This, in effect, increases the thermal mass of the room because the upper slab of the room no longer is isolated from the occupied zone. In this study, the cooling potential of a diffuse ceiling ventilation system....... The established heat transfer coefficient is used for analysis of the cooling performance of the system in dynamic building simulation program which showed that during peak summer days, the scenario with ventilated plenum would exhibit temperatures in the occupied zone approx. 1-1.5 °C lower than the baseline...... with unventilated plenum. In conclusion this study disclosed the mean heat transfer of the plenum with an inlet jet of approx. 1.2-0.4 m/s and temperature differences of 0.5-4.5 °C and showed that ventilation supply through the plenum can be used to augment the night cooling potential....

  17. Modeling the forced-air cooling process of fresh strawberry packages, Part II: Experimental validation of the flow model

    Energy Technology Data Exchange (ETDEWEB)

    Ferrua, M.J.; Singh, R.P. [Department of Biological and Agricultural Engineering, University of California at Davis, One Shields Avenue, Davis, CA 95616 (United States)

    2009-03-15

    The aim of this study was to validate a previously developed mathematical model for predicting the airflow behavior within individual packages of strawberries (clamshells) during forced-air cooling applications. The model was validated by using a non-intrusive flow measurement technique (PIV). The use of PIV required the development of a simplified transparent system that reproduces the packaging structure of typical retail clamshells. The validation was achieved by comparing the velocity field predicted by the model within this system against experimental data. The model not only predicted the main flow features, but also the location of steep acceleration within the packed structure voids. This work shows that, assuming that the momentum transport can be decoupled from the transport of energy and mass during forced-air cooling applications, the steady-state Navier-Stokes equations can accurately predict the airflow within individual clamshells of strawberries. (author)

  18. EFFECT OF GASOLINE - ETHANOL BLENDS ON PERFORMANCE AND EMISSION CHARACTERISTICS OF A SINGLE CYLINDER AIR COOLED MOTOR BIKE SI ENGINE

    Directory of Open Access Journals (Sweden)

    A. SAMUEL RAJA

    2015-12-01

    Full Text Available This paper investigates the effect of using gasoline-ethanol (GE blends on performance and exhaust emission of a four stroke 150 cc single cylinder air cooled spark ignition (SI engine, without any modifications. Experiments were conducted at part load and different engine speeds ranging from 3000 to 5000 rpm, without and with catalytic converter. Ethanol content was varied from 5 percentage to 20 percentage by volume and four different blends (E5, E10, E15 and E20 were tested. Fuel consumption, engine speed, air fuel ratio, exhaust gas temperature and exhaust emissions were measured during each experiment. Brake thermal efficiency (ηb,th, volumetric efficiency (ηvol, brake specific fuel consumption (BSFC and excess air factor were calculated for each test run. Brake specific fuel consumption, volumetric efficiency and excess air factor increased with ethanol percentage in the blend. Carbon monoxide (CO, hydrocarbon (HC and oxides of nitrogen (NOx emissions decreased with blends.

  19. Experimental und numerical investigations on cooling efficiency of Air-Mist nozzles on steel during continuous casting

    Science.gov (United States)

    Arth, G.; Taferner, M.; Bernhard, C.; Michelic, S.

    2016-07-01

    Cooling strategies in continuous casting of steel can vary from rapid cooling to slow cooling, mainly controlled by adjusting the amount of water sprayed onto the surface of the product. Inadequate adjustment however can lead to local surface undercooling or reheating, leading to surface and inner defects. This paper focuses on cooling efficiency of Air-Mist nozzles on casted steel and the experimental and numerical prediction of surface temperature distributions over the product width. The first part explains the determination of heat transfer coefficients (HTC) on laboratory scale, using a so called nozzle measuring stand (NMS). Based on measured water distributions and determined HTC's for air-mist nozzles using the NMS, surface temperatures are calculated by a transient 2D-model on a simple steel plate, explained in the second part of this paper. Simulations are carried out varying water impact density and spray water distribution, consequently influencing the local HTC distribution over the plate width. Furthermore, these results will be interpreted with regard to their consequence for surface and internal quality of the cast product. The results reveal the difficulty of correct adjustment of the amount of sprayed water, concurrent influencing water distribution and thus changing HTC distribution and surface temperature.

  20. Design sensitivity analysis of using various in-tube condensation correlations for an air-cooled condenser for ORCs

    OpenAIRE

    Kaya, Alihan; Lazova, Marija; De Paepe, Michel

    2015-01-01

    The study is related to the evaluation of using 19 condensation heat transfer correlations in an annular finned horizontal round tube V-shaped air-cooled condenser design problem for a representative low-temperature waste heat recovery Organic Rankine Cycle (ORC) case. The condensation is realized through cold air provided by the fan suction at a mass flow rate of 90,35 kg/s, whereas the working fluid mass flow rate is 7,8 kg/s. The considered condensation temperature is 40°C which correspond...

  1. Experimental study of convective heat transfer during cooling with low air velocity in a stack of objects

    Energy Technology Data Exchange (ETDEWEB)

    Ben Amara, Sami; Laguerre, Onrawee [Cemagref - Refrigeration Processes Engineering Research Unit, parc de Tourvoie, BP 44, 92163 cedex, Antony (France); Flick, Denis [National Agronomic Institute - INAPG, 16 rue Claude Bernard, 75231 cedex 05, Paris (France)

    2004-12-01

    During cooling with low air velocity (u{<=}0.2 m.s{sup -1}) of a stack of foodstuffs (a few centimeters dimension), the radiation and conduction between products can be of the same order of magnitude as convection. A method was developed to quantify these various transfer modes. The experiment was carried out using an in-line spherical arrangement; however, the same methodology can be applied to other product shapes. The results confirm that the heat transfers by radiation and conduction cannot be neglected. In addition, the convective heat transfer coefficient varies not only with air velocity but also with the product position in the stack. (authors)

  2. THERAPEUTIC OF SKIN AGING WITH CARBON DIOXIDE LASER SKIN RESURFACING AND COMBINATION WITH AIR COOLING

    Directory of Open Access Journals (Sweden)

    NKA Maya Damayanti

    2013-12-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 So far, a lot of people who want their face skin always looks young though age continued to grow. It cannot be denied that aging will occur in everyone although some faster or later occur. Various ways were developed by scientists to fix this issue. Laser Skin Resurfacing (LSR technique to tighten facial skin is a procedure that is popular among the public and the practice of medicine. CO2 LSR technique is still a gold standard was used. Pain during surgery can be reduced when this technique was combined with air cooling. In addition, the adverse effects of post-operative might be tolerated.   /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  3. Design sensitivity analysis of a plate-finned air-cooled condenser for waste heat recovery ORCs

    OpenAIRE

    Kaya, Alihan; Lazova, Marija; De Paepe, Michel

    2015-01-01

    The study is related to the design sensitivity analysis of a plate-finned tube bundle V-shaped air-cooled condenser design problem for a range of representative low-temperature waste heat recovery Organic Rankine Cycle (ORC) cases. An iterative design model is implemented which reveals the thermodynamic and geometric design error margins that occur when different in-tube prediction methods are used. 19 condensation heat transfer correlations are used simultaneously within arrays of geometric ...

  4. Refractories Utilizability for Slagging Gasifiers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Slagging coal gasification process became a highlight of coal chemical industry in China during the last decade. Refractory lining's life of slagging gasifiers is one of the most critical factors for a cost -effective operation. The paper introduces current status of coal gasification in China, lining structure of slagging gasifiers and performance of refractory lining. It also summarizes the major factors impacting on refractory wear in slagging coal gasifiers in four Chinese chemical plants, based on ten years of industrial experience. The utilizability is discussed in terms of cost -effectiveness of high chromia refractories and possibility of the alternatives.

  5. Stainless steel denitriding with slag

    International Nuclear Information System (INIS)

    Calculation and experimental methods were used to investigate the process of titanium nitride formation when alloying chromium nickel stainless steels with titanium. At common concentrations of titanium and nitrogen, titanium nitrides were observed to be precipitated from the melt into slag in amounts of 0.1% and more. The laboratory study of the slag influence of the process of steel refining from titanium nitrides showed that the slag containing calcium, aluminium and magnesium oxides is favourable to the denitriding of steel. In addition, the possibility of direct transition of dissolved nitrogen from the metal into the slag is revealed. 7 refs., 1 fig., 2 tabs

  6. Influence of Inlet Air Dry-Bulb and Wet-Bulb Temperature on Cooling Effect in Spraying Cooling Tower%喷雾冷却塔进塔干湿球温度对冷却效果的影响

    Institute of Scientific and Technical Information of China (English)

    路建岭; 吴培浩; 余鹏

    2011-01-01

    According to the principle of atoraization cooling, a 80t/h experimental counter-flow no-padding spraying cooling tower was established. And through four experimental conditions the influence of the inlet air dry-bulb /wet-bulb temperature on cooling effect in spraying cooling tower was analyzed. The results showed; when inlet air dry-bulb temperature increased by 2℃, the cooling range reduced by only 0.2℃ and the cooling efficiency only reduced by 3.2% , when inlet air wet-bulb temperature increased by 1. 8℃, the cooling range reduced by 0.8℃ and the cooling efficiency reduced by about 13.4% , which showed that the inlet air wet - bulb temperature had a larger impact on the cooling effect than that of the inlet air dry-bulb temperature in spraying cooling tower.%根据雾化冷却原理,建立了80t/h试验用逆流式无填料喷雾冷却塔,并通过4个工况的试验分析了进塔空气干湿球温度对喷雾冷却塔冷却效果的影响,结果表明:当进塔空气干球温度增加2℃时,冷却温差仅减小0.2℃,冷却效率仅减小0.8%;当进塔空气湿球温度增大1.8℃时,冷却温差减小0.8℃,冷却效率减小13.4%;进塔空气湿球温度对喷雾冷却塔的冷却效果影响较大.

  7. 3-Dimensional numerical study of cooling performance of a heat sink with air-water flow through mini-channel

    Science.gov (United States)

    Majumder, Sambit; Majumder, Abhik; Bhaumik, Swapan

    2016-07-01

    The present microelectronics market demands devices with high power dissipation capabilities having enhanced cooling per unit area. The drive for miniaturizing the devices to even micro level dimensions is shooting up the applied heat flux on such devices, resulting in complexity in heat transfer and cooling management. In this paper, a method of CPU processor cooling is introduced where active and passive cooling techniques are incorporated simultaneously. A heat sink consisting of fins is designed, where water flows internally through the mini-channel fins and air flows externally. Three dimensional numerical simulations are performed for large set of Reynolds number in laminar region using finite volume method for both developing flows. The dimensions of mini-channel fins are varied for several aspect ratios such as 1, 1.33, 2 and 4. Constant temperature (T) boundary condition is applied at heat sink base. Channel fluid temperature, pressure drop are analyzed to obtain best cooling option in the present study. It has been observed that as the aspect ratio of the channel decreases Nusselt number decreases while pressure drop increases. However, Nusselt number increases with increase in Reynolds number.

  8. Energy and Exergy Performances of Air-Based vs. Water-Based Heating and Cooling Systems: A Case Study of a Single-Family House

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    energy and exergy inputs to the system, energy and exergy inputs to the auxiliary components were also studied. Both heating and cooling cases were considered and three climatic zones were studied; Copenhagen (Denmark), Yokohama (Japan), and Ankara (Turkey). The analysis showed that the water......-based radiant heating and cooling system performed better than the air-based system both in terms of energy and exergy input to the heating/cooling plant. The relative benefits of the water-based system over the air-based system vary depending on the climatic zone. The air-based system also requires higher...

  9. An experimental investigation of an air cooling scheme for removing environmentally imposed heat loads from the multiplicity and vertex detector's main enclosure

    International Nuclear Information System (INIS)

    This report presents a summary of an experimental investigation of a closed loop air cooling system designed to control the temperature and humidity in the main enclosure of the multiplicity and vertex detector (MVD). Measurements of the cooling air flow rate, the humidity levels inside and outside of the MVD, and the cooling air temperatures were used to assess the performance of the system and to characterize the system limitations and potential assembly problems. The results of the study indicate that several design changes are needed in the final design to meet the temperature and humidity operating requirements. A thorough set of design change recommendations that satisfy these operating criteria completes this report

  10. Preferred Air Velocity and Local Cooling Effect of desk fans in warm environments

    DEFF Research Database (Denmark)

    Simone, Angela; Olesen, Bjarne W.

    2013-01-01

    . Besides, higher air velocities and personal control increase the acceptability of the indoor environment at higher air temperatures with a limited energy consumption compared to full air conditioning during summer seasons in warmer countries. Comparing the study with Danish subjects with previous findings...... with Chinese subjects showed that subjects used to warmer climate could accept higher air velocities and felt less uncomfortable....

  11. Energy and Exergy Analysis for Improving the Energy Performance of Air-Cooled Liquid Chillers by Different Condensing-Coil Configurations

    Directory of Open Access Journals (Sweden)

    Tzong-Shing Lee

    2012-03-01

    Full Text Available This study constructed a parameter analysis for improving the energy performance of air-cooled water chillers by altering the angle configuration of the condenser coils. The mathematical models for energy and exergy analyses of the individual components and overall system of air-cooled water chillers are presented. This study investigated the potential enhancement of performance efficiency in air-cooled chillers and the energy conversion efficiency of each component, in order to determine how the angle configuration of condenser coils influences chiller performance. This study found that the overall performance of an air-cooled chiller could be improved by approximately 3.4%, and the total irreversibility could be reduced by approximately 2.7%. With each 1% increase in average wind speed over the condenser coils, the overall performance of an air‑cooled chiller was found to be enhanced by approximately 0.43%, and its total irreversibility was reduced by approximately 0.35%. The results of this study can be effectively applied to air-cooled condenser units, and can provide an important basis of reference for developing and enhancing the energy efficiency of air-cooled chillers.

  12. Pyrochemical recovery of plutonium from calcium fluoride reduction slag

    Science.gov (United States)

    Christensen, D.C.

    A pyrochemical method of recovering finely dispersed plutonium metal from calcium fluoride reduction slag is claimed. The plutonium-bearing slag is crushed and melted in the presence of at least an equimolar amount of calcium chloride and a few percent metallic calcium. The calcium chloride reduces the melting point and thereby decreases the viscosity of the molten mixture. The calcium reduces any oxidized plutonium in the mixture and also causes the dispersed plutonium metal to coalesce and settle out as a separate metallic phase at the bottom of the reaction vessel. Upon cooling the mixture to room temperature, the solid plutonium can be cleanly separated from the overlying solid slag, with an average recovery yield on the order of 96 percent.

  13. Hybrid radiator cooling system

    Energy Technology Data Exchange (ETDEWEB)

    France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

    2016-03-15

    A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

  14. A hybrid thermal management system for lithium ion batteries combining phase change materials with forced-air cooling

    International Nuclear Information System (INIS)

    Highlights: • Heat accumulation in PCM causes failures of passive thermal management systems. • The introduction of forced air convection improves the reliability of PCMs. • Temperature distribution in the hybrid system remains uniform. • Active cooling and PCMs play separate roles in battery thermal management. • Numerical results agree with experiment data and give theoretic insights. - Abstract: Passive thermal management systems using phase change materials (PCMs) provides an effective solution to the overheating of lithium ion batteries. But this study shows heat accumulation in PCMs caused by the inefficient cooling of air natural convection leads to thermal management system failures: The temperature in a battery pack operating continuously outranges the safety limit of 60 °C after two cycles with discharge rate of 1.5 C and 2 C. Here a hybrid system that integrates PCMs with forced air convection is presented. This combined system successfully prevents heat accumulation and maintains the maximum temperature under 50 °C in all cycles. Study on airspeed effects reveals that thermo-physical properties of PCMs dictate the maximum temperature rise and temperature uniformity in the battery pack, while forced air convection plays a critical role in recovering thermal energy storage capacity of PCMs. A numerical study is also carried out and validated with experiment data, which gives theoretic insights on thermo-physical changes in this hybrid battery thermal management system

  15. Prediction of cold start hydrocarbon emissions of air cooled two wheeler spark ignition engines by simple fuzzy logic simulation

    Directory of Open Access Journals (Sweden)

    Samuel Raja Ayyanan

    2014-01-01

    Full Text Available The cold start hydrocarbon emission from the increasing population of two wheelers in countries like India is one of the research issues to be addressed. This work describes the prediction of cold start hydrocarbon emissions from air cooled spark ignition engines through fuzzy logic technique. Hydrocarbon emissions were experimentally measured from test engines of different cubic capacity, at different lubricating oil temperature and at different idling speeds with and without secondary air supply in exhaust. The experimental data were used as input for modeling average hydrocarbon emissions for 180 seconds counted from cold start and warm start of gasoline bike engines. In fuzzy logic simulation, member functions were assigned for input variables (cubic capacity and idling rpm and output variables (average hydrocarbon emission for first 180 seconds at cold start and warm start. The knowledge based rules were adopted from the analyzed experimental data and separate simulations were carried out for predicting hydrocarbon emissions from engines equipped with and without secondary air supply. The simulation yielded the average hydrocarbon emissions of air cooled gasoline engine for a set of given input data with accuracy over 90%.

  16. Water cooling system for an air-breathing hypersonic test vehicle

    Science.gov (United States)

    Petley, Dennis H.; Dziedzic, William M.

    1993-01-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  17. Windblown fugitive dust emissions from smelter slag

    Science.gov (United States)

    Sanderson, R. Steven; McKenna Neuman, Cheryl; Boulton, J. Wayne

    2014-06-01

    The waste products of mining and smelter operations contain fine particles that, when stored in stockpiles and tailings ponds, are subject to aerodynamic forces that may result in their suspension and transport within boundary layer air flows. The accuracy of atmospheric dispersion models such as AERMOD depends strongly upon suitable inputs for the emission rate that generally must be either measured or estimated from suitable analogues. Measurements of the emission rate of PM10 from smelter slag, based on wind tunnel experiments using the control volume method, are reported in this study and compared with vertical flux values obtained using a finite difference approximation. As compared to natural soils, the dust coatings on slag fragments are rapidly depleted during wind events so that the temporal aspect is important to capture in any consideration of the emission rate. At low wind speeds, vertical flux measurements underestimate the emission rate, but otherwise the agreement is excellent. Comparison with field measurements obtained at the smelter site reveals a degree of overlap with the laboratory data. As a general rule, PM10 emission from smelter slag by aerodynamic entrainment alone is several orders of magnitude lower than published fluxes of total suspended particulate (TSP) emitted from natural soil surfaces for which saltation bombardment is recognized to play a key role in the ejection of dust.

  18. Cryogenic Cooling System for Zero-Venting Storage of Supercritical Air Packs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Supercritical air at cryogenic temperature is an attractive source of breathing air because of its very high density and low pressure. However, heat leak into the...

  19. Computational Study of Air/Mist Impinging Jets Cooling Effectiveness under Various Curvature Models

    OpenAIRE

    Cheng, Peng; Yao, Guofeng; Chen, Wei; Li, Bin; Li, Junlou; Xu, Tao; Yu, Zhenglei; Ma, Long

    2014-01-01

    Efficiency is one of the most important parameters in evaluating the performance of a gas turbine engine by increasing the turbine inlet temperature, which could increase the gas turbine cycle’s efficiency. In order to increase the turbine inlet temperature significantly, an advanced cooling system needs to be researched and developed. This paper will establish a double chamber model simulating mist impingement cooling under typical gas turbine operating conditions of high temperature and pre...

  20. Characteristic Evaluation on the Cooling Performance of an Electrical Air Conditioning System Using R744 for a Fuel Cell Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Moo-Yeon Lee

    2012-05-01

    Full Text Available The objective of this study was to investigate the cooling performance characteristics of an electrical air conditioning system using R744 as an alternative of R-134a for a fuel cell electric vehicle. In order to analyze the cooling performance characteristics of the air conditioning system using R744 for a fuel cell electric vehicle, an electrical air conditioning system using R744 was developed and tested under various operating conditions according to both inlet air conditions of the gas cooler and evaporator and compressor speed. The cooling capacity and coefficient of performance (COP forcooling of the tested air conditioning system were up to 6.4 kW and 2.5, respectively. In addition, the electrical air conditioning system with R744 using an inverter driven compressor showed better performance than the conventional air conditioning system with R-134a under the same operating conditions. The observed cooling performance of the developed electrical air conditioning system was found to be sufficient for cooling loads under various real driving conditions for a fuel cell electric vehicle.

  1. Assessment of the forced air-cooling performance for cylindrical lithium-ion battery packs: A comparative analysis between aligned and staggered cell arrangements

    International Nuclear Information System (INIS)

    An appropriate cell arrangement plays significant role to design a highly efficient cooling system for the lithium-ion battery pack. This paper performs a comparative analysis of thermal performances on different arrangements of cylindrical cells for a LiFePO4 battery pack. A thermal model for the battery pack is developed and is solved in couple with the governing equations of fluid flow in the numerical simulations. The experiments for model validation are conducted on a single cell of the battery pack with forced-air cooling system. The effects of longitudinal and transverse spacing on the cooling performances are analyzed for the battery pack with the aligned and the staggered arrays. Under a specified flow rate of cooling air, the maximum temperature rise is proportional to the longitudinal interval for the staggered arrays, while it is in inverse for the aligned arrangement. Increasing the transverse interval leads to the increase of the battery temperature rise for both aligned and staggered arrangements. By trade-off the design requirements (maximum temperature rise, temperature uniformity, power requirement and cooling index), an appropriate solution in term of the optimal combination of the longitudinal interval, transverse interval, and air inlet width is obtained for the aligned arrangement. - Highlights: • Forced air-cooling performance for cylindrical lithium-ion battery is evaluated. • Thermal performances for aligned and staggered cell arrangements are compared. • Geometric optimization is investigated for the battery air-cooling system

  2. Improved Performance of an Air Cooled Condenser (ACC) Using SPX Wind Guide Technology at Coal-Based Thermoelectric Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Ken Mortensen

    2010-12-31

    This project added a new airflow enhancement technology to an existing ACC cooling process at a selected coal power plant. Airflow parameters and efficiency improvement for the main plant cooling process using the applied technology were determined and compared with the capabilities of existing systems. The project required significant planning and pre-test execution in order to reach the required Air Cooled Condenser system configuration for evaluation. A host Power Plant ACC system had to be identified, agreement finalized, and addition of the SPX ACC Wind Guide Technology completed on that site. Design of the modification, along with procurement, fabrication, instrumentation, and installation of the new airflow enhancement technology were executed. Baseline and post-modification cooling system data was collected and evaluated. The improvement of ACC thermal performance after SPX wind guide installation was clear. Testing of the improvement indicates there is a 5% improvement in heat transfer coefficient in high wind conditions and 1% improvement at low wind speed. The benefit increased with increasing wind speed. This project was completed on schedule and within budget.

  3. Comparative analysis of steady state heat transfer in a TBC and functionally graded air cooled gas turbine blade

    Indian Academy of Sciences (India)

    Nilanjan Coomar; Ravikiran Kadoli

    2010-02-01

    Internal cooling passages and thermal barrier coatings (TBCs) are presently used to control metal temperatures in gas turbine blades. Functionally graded materials (FGMs), which are typically mixtures of ceramic and metal, have been proposed for use in turbine blades because they possess smooth property gradients thereby rendering them more durable under thermal loads. In the present work, a functionally graded model of an air-cooled turbine blade with airfoil geometry conforming to the NACA0012 is developed which is then used in a finite element algorithm to obtain a non-linear steady state solution to the heat equation for the blade under convection and radiation boundary conditions. The effects of external gas temperature, coolant temperature, surface emissivity changes and different average ceramic/metal content of the blade on the temperature distributions are examined. Simulations are also carried out to compare cooling effectiveness of functionally graded blades with that of blades having TBC. The results highlight the effect of including radiation in the simulation and also indicate that external gas temperature influences the blade heat transfer more strongly. It is also seen that graded blades with about 70% ceramic content can deliver better cooling effectiveness than conventional blades with TBC.

  4. Utilization of copper slag as a cementitious material in reactive powder concrete

    OpenAIRE

    Edwin, Romy Suryaningrat; De Schepper, Mieke; Gruyaert, Elke; De Belie, Nele

    2015-01-01

    This research studies the use of copper slag from a plant in Belgium as a cementitious material in reactive powder concrete (RPC). The quickly cooled granulated copper slag (QCS) was ground intensively using a planetary ball mill. A lower water-to-binder ratio of 0.18 was chosen for the RPC in this study. Various concrete and cement paste samples were produced with increasing copper slag contents from 0 to 20 wt% in steps of 5 wt%. Particle size distribution (PSD) and specific surface area (S...

  5. A review on the thermal hydraulic characteristics of the air-cooled heat exchangers in forced convection

    Indian Academy of Sciences (India)

    Ankur Kumar; Jyeshtharaj B Joshi; Arun K Nayak; Pallippattu K Vijayan

    2015-05-01

    In this paper, a review is presented on the experimental investigations and the numerical simulations performed to analyze the thermal-hydraulic performance of the air-cooled heat exchangers. The air-cooled heat exchangers mostly consist of the finned-tube bundles. The primary role of the extended surfaces (fins) is to provide more heat transfer area to enhance the rate of heat transfer on the air side. The secondary role of the fins is to generate vortices, which help in enhancing the mixing and the heat transfer coefficient. In this study, the annular and plate fins are considered, the annular fins are further divided into four categories: (1) plane annular fins, (2) serrated fins, (3) crimped spiral fins, (4) perforated fins, and similarly for the plate fins, the fin types are: (1) plain plate fins, (2) wavy plate fins, (3) plate fins with DWP, and (4) slit and strip fins. In Section 4, the performance of the various types of fins is presented with respect to the parameters: (1) Reynolds number, (2) fin pitch, (3) fin height, (4) fin thickness, (5) tube diameter, (6) tube pitch, (7) tube type, (8) number of tube rows, and (9) effect of dehumidifying conditions. In Section 5, the conclusions and the recommendations for the future work have been given.

  6. Influence of a Cooled Ceiling on Indoor Air Quality in a Displacement Ventilated Room Examined by Means of Computational Fluid Dynamics

    DEFF Research Database (Denmark)

    Brohus, Henrik

    The influence of a cooled ceiling on the air quality in a displacement ventilated room is examined by means of CFD. The objective of the study is to examine how the flow field in a displacement ventilated room is influenced when a cooled ceiling removes a major part of the total heat I9ad......, and in particular to examine the effect on the contaminant distribution and the indoor air quality. The simulations shovy that the inclusion of a cooled ceiling has a significant impact on the flow field but only a minor influence on the personal exposure in this study...

  7. Radiation Heat Transfer Effect on Thermal Sizing of Air-Cooling Heat Exchanger of Emergency Cooldown Tank

    International Nuclear Information System (INIS)

    An attempt has begun to extend the life time of emergency cooldown tank (ECT) by Korea Atomic Energy Research Institute (KAERI) researchers. Moon et al. recently reported a basic concept upon how to keep the ECT in operation beyond 72 hours after an accident occurs without any active corrective actions for the postulated design basis accidents. When the SMART (System-integrated Modular Advanced Reac-Tor) received its Standard Design Approval (SDA) for the first time in the world, hybrid safety systems are applied. However, the passive safety systems of SMART are being enforced in response to the public concern for much safer reactors since the Fukushima accident occurred. The ECT is a major component of a passive residual heat removal system (PRHRS), which is one of the most important systems to enhance the safety of SMART. It is being developed in a SMART safety enhancement project to contain enough cooling water to remove a sensible heat and a decay heat from reactor core for 72 hours since an accident occurs. Moon et al. offered to install another heat exchanger above the ECT and to recirculate an evaporated steam into water, which enables the ECT to be in operation, theoretically, indefinitely. An investigation was made to determine how long and how many tubes were required to meet the purpose of the study. In their calculation, however, a radiation heat transfer effect was neglected. The present study is to consider the radiation heat transfer for the design of air-cooling heat exchanger. Radiation heat transfer is normally ignored in many situations, but this is not the case for the present study. Kim et al. conducted thermal sizing of scaled-down ECT heat exchanger, which will be used to validate experimentally the basic concept of the present study. Their calculation is also examined to see if a radiation heat transfer effect was taken into consideration. The thermal sizing of an air-cooling heat exchanger was conducted including radiation heat transfer

  8. Kinetics of Copper Reduction from Molten Slags

    OpenAIRE

    Tesfaye, Fiseha

    2009-01-01

    The objective of this thesis was to study the process of reduction of cuprous oxide by carbon from copper flash smelting slags. The flash smelting and slag cleaning processes are described in the introductory part. The studies are focused on the slag cleaning process in the three - electrode electric furnace (EF), where components of the slag reduce to matte and EF slag in a periodic batch process. Parametric values of different variables (surface energy, density, viscosity, and equilibri...

  9. Crystallization of synthetic coal-petcoke slag mixtures simulating those encountered in entrained bed slagging gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Jinichiro Nakano; Seetharaman Sridhar; Tyler Moss; James Bennett; Kyei-Sing Kwong [National Energy Technology Laboratory, Pittsburgh, PA (United States)

    2009-09-15

    Commercial entrained bed slagging gasifiers use a carbon feedstock of coal, petcoke, or combinations of them to produce CO and H{sub 2}. These carbon sources contain mineral impurities that liquefy during gasification and flow down the gasification sidewall, interacting with the refractory linear and solidifying in the cooler zones of the gasifier. Proper slag flow is critical to good gasifier operation. A hot-stage confocal scanning laser microscope (CSLM) was used to analyze the kinetic behavior of slag crystallization for a range of synthetic coal-petcoke mixtures. On the basis of the observed precipitation during cool down studies in the 1200-1700{sup o}C temperature range, a time-temperature-transformation (TTT) diagram was created. The crystallization studies were conducted with a CO/CO{sub 2} (=1.8) corresponding to a gasification PO{sub 2} of approximately 10-8 atm at 1500{sup o}C. Ash chemistries were chosen such that they correspond to coal-petcoke feedstock mixtures with coal ash amounts of 0, 10, 30, 50, 70, and 100% (by weight), with the balance being petcoke ash. The TTT diagram exhibited two crystallization areas, one above and one below 1350{sup o}C. At the nose of the higher temperature curves, karelianite (V{sub 2}O{sub 3}) crystallization occurred and was fastest for a 30% coal-petcoke ash mixture. The second nose was located below 1350{sup o}C and had spinel-type phases that formed at 1200{sup o}C, in which preferred atomic occupation at the octahedral and tetrahedral sites varied depending upon the ash composition. At 1200{sup o}C, an Al-rich spinel formed for 100% coal slag and a Fe-rich spinel formed in petcoke-enriched slags. The addition of petcoke ash to coal ash promoted crystallization in the slag, with additional crystalline phases, such as V-rich spinel, forming at the lower temperatures. These phases were not predicted using commercially available databases. 30 refs., 18 figs.

  10. Discussions on Energy Saving of Air-Cooled Compressed Air-Conditioning Unit%风冷压缩单元式空调器节能探讨

    Institute of Scientific and Technical Information of China (English)

    冯璐; 陆黎明

    2012-01-01

    Analyzes the operating principle of air-cooled air conditioner,put forward two types of modular units produced hot water and room refrigeration in order to increase the comprehensive usage efficiency of energy and conserve the building energy.%从分析风冷压缩单元式空调器的制冷原理入手,提出了两种空气源热泵热水模块+空气源压缩制冷模块机,为提高能源综合利用效率、节约建筑能耗提供了一定的实践思路。

  11. Precipitation of α2 Phase in α+β Solution-Treated and Air-cooled Ti-Al-Sn-Zr-Mo-Si-Nd Alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A series of Ti-Al-Sn-Zr-Mo-Si-Nd alloys with various content of Al were solution treated in α+β phase field and air-cooled.The precipitation of α2 phase in cooling was investigated by transmission electron microscopic analysis.The precipitation characteristic of α2 phase was discussed. The precipitation of α2 phase would proceed by the nucleation and growth of α2 phase dependent on the diffusion of Al atoms. And a comparison on the difference of precipitation of α2 phase was carried out under the conditions of air-cooling and quenching in water.The investigation showed that the air-cooling and even quenching could supply enough time for the precipitation and growth of α2 phase when Al content reached a certain value even though far away from the stoichiometric composition of TisAl.

  12. Modeling, numerical simulation and experimental verification of the unsteady cooling of a solid body in quiescent ambient air

    Energy Technology Data Exchange (ETDEWEB)

    Campo, Antonio [Department of Mechanical Engineering, The University of Vermont, Burlington, VT 05405 (United States); Salazar, Abraham [Department of Mechanical Engineering, University of Kentucky, Lexington, KY 40506 (United States); Rebollo, Daniel [Instituto de Mecanica Aplicada, Universidad Nacional de San Juan, 5400 San Juan (Argentina)

    2004-07-01

    The scope of the present article is two-fold. Firstly, to conduct an experiment to provide the temperature-time history of the cooling of a hot ball bearing in quiescent ambient air. Secondly, to predict the temporal variation of the bearing under the hypothesis of natural convection, radiation or natural convection coexists with radiation for a non-vanishing total hemispherical emissivity of the surface of the bearing. Numerical solutions of the three governing nonlinear lumped heat equations were carried out with a Runge-Kutta-Fehlberg (RKF45) algorithm accounting for automatic step size control. The experimental data was obtained with chrome steel ball bearings of diameter 0.953 cm (7/16 in) heated in an electric oven to a pre-set temperature. The heated bearing was exposed later to ambient air at atmospheric temperature and pressure. (orig.)

  13. Modeling, numerical simulation and experimental verification of the unsteady cooling of a solid body in quiescent ambient air

    Science.gov (United States)

    Campo, Antonio; Salazar, Abraham; Rebollo, Daniel

    The scope of the present article is two-fold. Firstly, to conduct an experiment to provide the temperature-time history of the cooling of a hot ball bearing in quiescent ambient air. Secondly, to predict the temporal variation of the bearing under the hypothesis of natural convection, radiation or natural convection coexists with radiation for a non-vanishing total hemispherical emissivity of the surface of the bearing. Numerical solutions of the three governing nonlinear lumped heat equations were carried out with a Runge-Kutta-Fehlberg (RKF45) algorithm accounting for automatic step size control. The experimental data was obtained with chrome steel ball bearings of diameter 0.953 cm (7/16 in) heated in an electric oven to a pre-set temperature. The heated bearing was exposed later to ambient air at atmospheric temperature and pressure.

  14. Air-liquid solar collector for solar heating, combined heating and cooling, and hot water subsystems

    Science.gov (United States)

    1978-01-01

    A collection of quarterly reports consisting of the installation and layout design of the air collector system for commercial applications, completion of the preliminary design review, detailed design efforts, and preparation of the verification test plan are given. Performance specifications and performance testing of a prototype model of a two manifold, 144 tube air collector array is presented.

  15. Phenomenology of deflagration and detonation of hydrogen-air mixtures in water cooled nuclear power plants

    International Nuclear Information System (INIS)

    This paper summarizes fundamentals of the flammability of the hydrogen-air mixtures and hydrogen-air containing added steam or other inerting agent. The flammability behaviour of such gaseous mixtures is described with reference to physical and chemical conditions close enough to those expected in the containment of a nuclear reactor during a LOCA

  16. Performance and evaluation of gas engine driven rooftop air conditioning equipment at the Willow Grove (PA) Naval Air Station. Interim report, 1992 cooling season

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, P.R.; Conover, D.R.

    1993-05-01

    In a field evaluation conducted for the US Department of Energy (DOE) Office of Federal Energy Management Program (FEMP), the Pacific Northwest Laboratory (PNL) examined the performance of a new US energy-related technology under the FEMP Test Bed Demonstration Program. The technology was a 15-ton natural gas engine driven roof top air conditioning unit. Two such units were installed on a naval retail building to provide space conditioning to the building. Under the Test Bed Demonstration Program, private and public sector interests are focused to support the installation and evaluation of new US technologies in the federal sector. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) with DOE were the American Gas Cooling Center, Philadelphia Electric Company, Thermo King Corporation, and the US Naval Air Station at Willow Grove, Pennsylvania. Equipment operating and service data as well as building interior and exterior conditions were secured for the 1992 cooling season. Based on a computer assessment of the building using standard weather data, a comparison was made with the energy and operating costs associated with the previous space conditioning system. Based on performance during the 1992 cooling season and adjusted to a normal weather year, the technology will save the site $6,000/yr in purchased energy costs. An additional $9,000 in savings due to electricity demand ratchet charge reductions will also be realized. Detailed information on the technology, the installation, and the results of the technology test are provided to illustrate the advantages to the federal sector of using this technology. A history of the CRADA development process is also reported.

  17. Prediction of thermal behaviors of an air-cooled lithium-ion battery system for hybrid electric vehicles

    Science.gov (United States)

    Choi, Yong Seok; Kang, Dal Mo

    2014-12-01

    Thermal management has been one of the major issues in developing a lithium-ion (Li-ion) hybrid electric vehicle (HEV) battery system since the Li-ion battery is vulnerable to excessive heat load under abnormal or severe operational conditions. In this work, in order to design a suitable thermal management system, a simple modeling methodology describing thermal behavior of an air-cooled Li-ion battery system was proposed from vehicle components designer's point of view. A proposed mathematical model was constructed based on the battery's electrical and mechanical properties. Also, validation test results for the Li-ion battery system were presented. A pulse current duty and an adjusted US06 current cycle for a two-mode HEV system were used to validate the accuracy of the model prediction. Results showed that the present model can give good estimations for simulating convective heat transfer cooling during battery operation. The developed thermal model is useful in structuring the flow system and determining the appropriate cooling capacity for a specified design prerequisite of the battery system.

  18. Understanding Slag Freeze Linings

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Hayes, Peter C.; Jak, Evgueni

    2014-09-01

    Slag freeze linings, the formation of protective deposit layers on the inner walls of furnaces and reactors, are increasingly used in industrial pyrometallurgical processes to ensure that furnace integrity is maintained in these aggressive, high-temperature environments. Most previous studies of freeze-linings have analyzed the formation of slag deposits based solely on heat transfer considerations. These thermal models have assumed that the interface between the stationary frozen layer and the agitated molten bath at steady-state deposit thickness consists of the primary phase, which stays in contact with the bulk liquid at the liquidus temperature. Recent experimental studies, however, have clearly demonstrated that the temperature of the deposit/liquid bath interface can be lower than the liquidus temperature of the bulk liquid. A conceptual framework has been proposed to explain the observations and the factors influencing the microstructure and the temperature of the interface at steady-state conditions. The observations are consistent with a dynamic steady state that is a balance between (I) the rate of nucleation and growth of solids on detached crystals in a subliquidus layer as this fluid material moves toward the stagnant deposit interface and (II) the dissolution of these detached crystals as they are transported away from the interface by turbulent eddies. It is argued that the assumption that the interface temperature is the liquidus of the bulk material represents only a limiting condition, and that the interface temperature can be between T liquidus and T solidus depending on the process conditions and bath chemistry. These findings have implications for the modeling approach and boundary conditions required to accurately describe these systems. They also indicate the opportunity to integrate considerations of heat and mass flows with the selection of melt chemistries in the design of future high temperature industrial reactors.

  19. Integration of thermal insulation coating and moving-air-cavity in a cool roof system for attic temperature reduction

    International Nuclear Information System (INIS)

    Highlights: • A novel integrated cool roof system for attic temperature reduction is introduced. • 13 °C temperature reduction achieved due to its efficient heat transfer mechanism. • Aluminium tube cavity of the roof is able to reduce the attic temperature. • This positive result is due to its efficient heat reflection and hot air rejection. • Thermal insulation coating incorporates the usage of eggshell waste as bio-filler. - Abstract: Cool roof systems play a significant role in enhancing the comfort level of occupants by reducing the attic temperature of the building. Heat transmission through the roof can be reduced by applying thermal insulation coating (TIC) on the roof and/or installing insulation under the roof of the attic. This paper focuses on a TIC integrated with a series of aluminium tubes that are installed on the underside of the metal roof. In this study, the recycled aluminium cans were arranged into tubes that act as a moving-air-cavity (MAC). The TIC was formulated using titanium dioxide pigment with chicken eggshell (CES) waste as bio-filler bound together by a polyurethane resin binder. The thermal conductivity of the thermal insulation paint was measured using KD2 Pro Thermal Properties Analyzer. Four types of cool roof systems were designed and the performances were evaluated. The experimental works were carried out indoors by using halogen light bulbs followed by comparison of the roof and attic temperatures. The temperature of the surrounding air during testing was approximately 27.5 °C. The cool roof that incorporated both TIC and MAC with opened attic inlet showed a significant improvement with a reduction of up to 13 °C (from 42.4 °C to 29.6 °C) in the attic temperature compared to the conventional roof system. The significant difference in the results is due to the low thermal conductivity of the thermal insulation paint (0.107 W/mK) as well as the usage of aluminium tubes in the roof cavity that was able to transfer

  20. Technical and economic assessment of the use of ammonia expanders for energy recovery in air-cooled power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, S.G.; Hane, G.J.; Johnson, B.M.

    1982-07-01

    Binary cycle power plants have been the subject of much discussion among engineers and scientists for nearly 100 years. Current economic and environmental concerns have stimulated new interest and research. Ammonia has been recommended by other studies as the leading contender for use as simply the heat rejection medium in an air-cooled power plant. This study investigates the technical feasibility and economic potential of including an expander in the heat rejection system of an air-cooled power plant. The expander would be used during certain parts of the year to increase the total output of the power plant. Five different plant locations (Miami, San Francisco, Bakersfield, Chicago, Anchorage) were investigated to show the effect which climate has on the economic potential of this ammonia bottoming cycle. The study shows that the expected energy costs for the bottoming cycle only will be less than 50 mills/kWh for any of the five plant locations. This cost assumes that an ammonia phase-change heat rejection system is already a part of the existing plant. The colder climates of Chicago and Anchorage demonstrate an even smaller energy cost of less than 15 mills/kWh. Further investigation of the concept is merited to substantiate these costs and determine the needed technology.

  1. Experimental Study of Air Distribution and Ventilation Effectiveness in a Room with a Combination of Different Mechanical Ventilation and Heating/Cooling Systems

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.; Simone, Angela; Krajcik, Michal;

    2011-01-01

    , in this study, been experimentally tested. The studies on a displacement ventilation system show lower vertical air temperature differences and higher ventilation effectiveness when it is combined with a floor heating system. With floor cooling, the displacement ventilation system should be designed...... with a higher supply air temperature. Furthermore, the buoyancy flows from warm or cold windows and occupants influence the airflow pattern and increase the mixing of supply air into the occupied zone....

  2. Impacts of dynamic interactions on the predicted thermal performance of earth–air heat exchangers for preheating, cooling and ventilation of buildings

    OpenAIRE

    Gan, Guohui

    2015-01-01

    Earth–air tunnel ventilation is an energy efficient ventilation technique that makes use of relatively stable soil temperature in shallow ground for preheating and cooling of supply air to a building. During operation, an earth–air heat exchanger interacts with the soil and atmosphere and the performance varies with the soil and atmospheric conditions. A computer program has been developed for modelling of coupled heat and moisture transfer in soil and for simulation of the dynamic thermal pe...

  3. Heat Transfer and Observation of Droplet-Surface Interactions During Air-Mist Cooling at CSP Secondary System Temperatures

    Science.gov (United States)

    Huerta L., Mario E.; Mejía G., M. Esther; Castillejos E., A. Humberto

    2016-04-01

    Air-mists are key elements in the secondary cooling of modern thin steel slab continuous casters. The selection of water, W, and air, A, flow rates, and pressures in pneumatic nozzles open up a wide spectrum of cooling possibilities by their influence on droplet diameter, d, droplet velocity, v, and water impact flux, w. Nonetheless, due to the harsh environment resulting from the high temperatures and dense mists involved, there is very little information about the correlation between heat flux extracted, - q, and mist characteristics, and none about the dynamics of drop-wall interactions. For obtaining both kinds of information, this work combines a steady-state heat flux measuring method with a visualization technique based on a high-speed camera and a laser illumination system. For wall temperatures, T w, between ~723 K and ~1453 K (~450 °C and ~1180 °C), which correspond to film boiling regime, it was confirmed that - q increases with increase in v, w, and T w and with decrease in d. It should be noticed, however, that the increase in w generally decreases the spray cooling effectiveness because striking drops do not evaporate efficiently due to the interference by liquid remains from previous drops. Visualization of the events happening close to the surface also reveals that the contact time of the liquid with the surface is very brief and that rebounding, splashing, sliding, and levitation of drops lead to ineffective contact with the surface. At the center of the mist footprint, where drops impinge nearly normal to the surface those with enough momentum establish intimate contact with it before forming a vapor layer that pushes away the remaining liquid. Also, some drops are observed sliding upon the surface or levitating close to it; these are drops with low momentum which are influenced by the deflecting air stream. At footprint positions where oblique impingement occurs, frequently drops are spotted sliding or levitating and liquid films flowing in

  4. 中厚板气雾冷却模型及控制系统%Air-mist cooling model and control system in heavy plate plant

    Institute of Scientific and Technical Information of China (English)

    冉瑞生; 彭燕华; 何立

    2014-01-01

    In order to online control air-mist cooling device,an air-mist cooling control model and a set of online control system have been developed for an air-mist cooling device in a heavy plate plant. With the analysis of the cooling process and the investigation of the boundary conditions,the cooling model has been built. Based on the production process of air-mist cooling and the feature of air-mist cooling device,a set of automatic control system has been built. The model and the system have been applied to a heavy plate plant,the results show that the need of online automatic control is satisfied, and the cooling rate and the temperature precision expected are reached.%为了对气雾冷却过程进行在线自动控制,针对某中厚板厂的气雾冷却装置,开发了一套气雾冷却控制模型及在线控制系统。在对冷却过程做传热分析及充分考虑边界条件的基础上建立气雾冷却模型,并根据气雾冷却的生产流程及设备特点,开发了自动控制系统。该套模型和控制系统已应用到某中板厂生产现场,应用结果表明,该系统实现了气雾冷却的在线自动控制,冷却速度和温度控制精度达到工艺要求。

  5. Modelling the thermodynamic performance of a concentrated solar power plant with a novel modular air-cooled condenser

    International Nuclear Information System (INIS)

    This paper aims at developing a novel air-cooled condenser for concentrated solar power plants. The condenser offers two significant advantages over the existing state-of-the-art. Firstly, it can be installed in a modular format where pre-assembled condenser modules reduce installation costs. Secondly, instead of using large fixed speed fans, smaller speed controlled fans are incorporated into the individual modules. This facility allows the operating point of the condenser to change and continuously maximise plant efficiency. A thorough experimental analysis was performed on a number of prototype condenser designs. This analysis investigated the validly and accuracy of correlations from literature in predicting the thermal and aerodynamic characteristics of different designs. These measurements were used to develop a thermodynamic model to predict the performance of a 50 MW CSP (Concentrated Solar Power) plant with various condenser designs installed. In order to compare different designs with respect to the specific plant capital cost, a techno-economic analysis was performed which identified the optimum size of each condenser. The results show that a single row plate finned tube design, a four row, and a two row circular finned tube design are all similar in terms of their techno-economic performance and offer significant savings over other designs. - Highlights: • A novel air cooled condenser for CSP (Concentrated Solar Power) applications is proposed. • A thorough experimental analysis of various condenser designs was performed. • Heat transfer and flow friction correlations validated for fan generated air flow. • A thermodynamic model to calculate CSP plant output is presented. • Results show the proposed condenser design can continually optimise plant output

  6. Physical and Mathematical Modeling of Thin Steel Slab Continuous Casting Secondary Cooling Zone Air-Mist Impingement

    Science.gov (United States)

    de León B., Melecio; Castillejos E., A. Humberto

    2015-10-01

    This study is an attempt to unveil the fluid dynamic phenomena occurring during interaction of air-mists with the surface of the steel strand during its pass through the continuous casting secondary cooling system. Air-mists generated under conditions of practical interest are studied while impacting on a vertical wall at room temperature. Experimentally a spatial multiple-counting technique based on capturing instantaneous double-exposure shadowgraphs is used to visualize the internal structure of mists at distances between 0 and 4 mm from the wall. Analysis of single exposure images allows determination of size distributions of primary (impinging) and secondary (ejecting) drops and of fluctuating thickness of water films formed on the wall surface. Besides, examination of image pairs enables measurement of velocity and trajectory angles of both kinds of drops. These results aided in the formulation and validation of a transient, turbulent, 3D, multiphase fluid dynamic model for simulating impinging air-mists. The model is based on KIVA-3V and for simulating the airborne mist region it solves the continuity equations—mass, momentum, turbulence quantities—for the air coupled with the equation of motion for drops sampled randomly from distributions assumed to govern their size and volume flux at the nozzle orifice. While for the impingement region submodels are established to estimate the results of drop/wall interaction, i.e., the dynamics of secondary drops and water films formed by the impingement of primary drops. The model forecasts reasonably well the random distributions of diameters, velocities, trajectory angles, and Weber numbers of both kind of drops moving near the wall. Additionally, it predicts well the average thickness of the water film and the important effect that air nozzle pressure has on the normal impinging velocity of drops; high pressures result in large drop velocities favoring intimate contact with the surface.

  7. High-Temperature Air-Cooled Power Electronics Thermal Design: Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Waye, Scot [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-08-01

    Power electronics that use high-temperature devices pose a challenge for thermal management. With the devices running at higher temperatures and having a smaller footprint, the heat fluxes increase from previous power electronic designs. This project overview presents an approach to examine and design thermal management strategies through cooling technologies to keep devices within temperature limits, dissipate the heat generated by the devices and protect electrical interconnects and other components for inverter, converter, and charger applications. This analysis, validation, and demonstration intends to take a multi-scale approach over the device, module, and system levels to reduce size, weight, and cost.

  8. Thermal-Hydraulic Analysis of an Experimental Reactor Cavity Cooling System with Air. Part I: Experiments; Part II: Separate Effects Tests and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Corradin, Michael [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Anderson, M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Muci, M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Hassan, Yassin [Texas A & M Univ., College Station, TX (United States); Dominguez, A. [Texas A & M Univ., College Station, TX (United States); Tokuhiro, Akira [Univ. of Idaho, Moscow, ID (United States); Hamman, K. [Univ. of Idaho, Moscow, ID (United States)

    2014-10-15

    This experimental study investigates the thermal hydraulic behavior and the heat removal performance for a scaled Reactor Cavity Cooling System (RCCS) with air. A quarter-scale RCCS facility was designed and built based on a full-scale General Atomics (GA) RCCS design concept for the Modular High Temperature Gas Reactor (MHTGR). The GA RCCS is a passive cooling system that draws in air to use as the cooling fluid to remove heat radiated from the reactor pressure vessel to the air-cooled riser tubes and discharged the heated air into the atmosphere. Scaling laws were used to preserve key aspects and to maintain similarity. The scaled air RCCS facility at UW-Madison is a quarter-scale reduced length experiment housing six riser ducts that represent a 9.5° sector slice of the full-scale GA air RCCS concept. Radiant heaters were used to simulate the heat radiation from the reactor pressure vessel. The maximum power that can be achieved with the radiant heaters is 40 kW with a peak heat flux of 25 kW per meter squared. The quarter-scale RCCS was run under different heat loading cases and operated successfully. Instabilities were observed in some experiments in which one of the two exhaust ducts experienced a flow reversal for a period of time. The data and analysis presented show that the RCCS has promising potential to be a decay heat removal system during an accident scenario.

  9. Investigations of Stabilization of Cr in Spinel Phase in Chromium-Containing Slags

    OpenAIRE

    Jelkina Albertsson, Galina

    2011-01-01

    The influence of basicity, heat treatment as well as different oxygen partial pressures on the phase relationships in the CaO-MgO-SiO2-Cr2O3 slags was studied with a view to control the precipitation of Cr-spinel in the slag phase. The equilibrium phases in CaO-MgO-SiO2-Cr2O3 slag system in the range on 1673-1873 K have been investigated under low oxygen partial pressure as well as in as air atmosphere. In low oxygen partial pressure experiments, a suitable mixture of CO and CO2 was used to c...

  10. Kinetics of the dissolution of zinc sulfide in an oxidizing slag

    Science.gov (United States)

    Gupta, Suresh K.

    1990-10-01

    A new concept has been developed for the production of zinc from zinc and complex zinc concentrates. It is a two-stage process involving oxidation of zinc sulfide to oxide and dissolution into slag and the fuming of zinc from the slag by injecting carbonaceous materials into it to produce zinc vapors which can be subsequently condensed in a lead-splash condenser such as those used in the Imperial Smelting Process (ISP). In this paper, the effects of the quantity of air, temperature, and concentrate feed rate have been discussed on the production of zinc-rich slag, which is the first stage of the proposed process.

  11. Preliminary design review package on air flat plate collector for solar heating and cooling system

    Science.gov (United States)

    1977-01-01

    Guidelines to be used in the development and fabrication of a prototype air flat plate collector subsystem containing 320 square feet (10-4 ft x 8 ft panels) of collector area are presented. Topics discussed include: (1) verification plan; (2) thermal analysis; (3) safety hazard analysis; (4) drawing list; (5) special handling, installation and maintenance tools; (6) structural analysis; and (7) selected drawings.

  12. Experimental study of an air-source heat pump for simultaneous heating and cooling - Part 2: Dynamic behaviour and two-phase thermosiphon defrosting technique

    International Nuclear Information System (INIS)

    Highlights: → Experimental study of an air-source heat pump for simultaneous heating and cooling. → Operating sequences alternating between heating, cooling and simultaneous modes. → Validation of the high pressure control system. → Validation of the non-penalizing two-phase thermosiphon defrosting sequence. - Abstract: This article presents the concepts of an air-source heat pump for simultaneous heating and cooling (HPS) designed for hotels and smaller residential, commercial and office buildings in which simultaneous needs in heating and cooling are frequent. The main advantage of the HPS is to carry out simultaneously space heating and space cooling with the same energy input. Ambient air is used as a balancing source to run a heating or a cooling mode. The second advantage is that, during winter, energy recovered by the subcooling of the refrigerant is stored at first in a water tank and used subsequently as a cold source at the water evaporator to improve the average performance and to carry out defrosting of the air evaporator using a two-phase thermosiphon. Unlike conventional air-source heat pumps, defrosting is carried out without stopping the heat production. A R407C HPS prototype was built and tested. The basic concepts of the HPS are detailed in part1 of this article . Its performance on defined operating conditions corresponds to the data given by the selection software of the compressor manufacturer. In the present part of this article, the operation of the high pressure control system, the transitions between heating, cooling and simultaneous modes and the defrosting sequence are analysed and validated experimentally.

  13. Air-Cooled Stack Freeze Tolerance Freeze Failure Modes and Freeze Tolerance Strategies for GenDriveTM Material Handling Application Systems and Stacks Final Scientific Report

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, David, W.

    2012-02-14

    Air-cooled stack technology offers the potential for a simpler system architecture (versus liquid-cooled) for applications below 4 kilowatts. The combined cooling and cathode air allows for a reduction in part count and hence a lower cost solution. However, efficient heat rejection challenges escalate as power and ambient temperature increase. For applications in ambient temperatures below freezing, the air-cooled approach has additional challenges associated with not overcooling the fuel cell stack. The focus of this project was freeze tolerance while maintaining all other stack and system requirements. Through this project, Plug Power advanced the state of the art in technology for air-cooled PEM fuel cell stacks and related GenDrive material handling application fuel cell systems. This was accomplished through a collaborative work plan to improve freeze tolerance and mitigate freeze-thaw effect failure modes within innovative material handling equipment fuel cell systems designed for use in freezer forklift applications. Freeze tolerance remains an area where additional research and understanding can help fuel cells to become commercially viable. This project evaluated both stack level and system level solutions to improve fuel cell stack freeze tolerance. At this time, the most cost effective solutions are at the system level. The freeze mitigation strategies developed over the course of this project could be used to drive fuel cell commercialization. The fuel cell system studied in this project was Plug Power's commercially available GenDrive platform providing battery replacement for equipment in the material handling industry. The fuel cell stacks were Ballard's commercially available FCvelocity 9SSL (9SSL) liquid-cooled PEM fuel cell stack and FCvelocity 1020ACS (Mk1020) air-cooled PEM fuel cell stack.

  14. Technology Development on Waste Heat Recovery of Little Water Quenching Method for BF Slag%高炉炉渣微水淬法余热回收技术开发

    Institute of Scientific and Technical Information of China (English)

    邱润强; 许征鹏

    2014-01-01

    The waste heat recovery technology of BF slag was developed by Shandong Jiuyang Group. The technology is consisted of collecting middle pressure saturated steam changed by evaporated cooling water, getting circulating hot air used of wind cooling, again recovered waste heat by waste heat boiler. The recyclable heat quantity of ton of iron is 257.7 MJ, the comprehensive recovery ratio can reach 87%, and the process can save of water consumption 7-9 t every ton of slag compared with the traditional water quenching slag process.%山东九羊集团有限公司开发了高炉炉渣余热回收技术,将绝大部分冷却水蒸发为中压饱和蒸汽进行收集,然后采用风冷工艺获得热循环空气,通过余热锅炉再次回收余热,吨铁可回收热量257.7 MJ,综合回收率可达87%,与传统的水淬工艺相比吨渣可节约用水7~9t。

  15. Experimental study of an air-source heat pump for simultaneous heating and cooling - Part 1: Basic concepts and performance verification

    International Nuclear Information System (INIS)

    This article presents the concepts of an air-source heat pump for simultaneous heating and cooling (HPS) designed for hotels and smaller residential, commercial and office buildings in which simultaneous needs in heating and cooling are frequent. The main advantage of the HPS is to carry out simultaneously space heating and space cooling with the same energy input. Ambient air is used as a balancing source to run a heating or a cooling mode. The second advantage is that, during winter, energy recovered by the subcooling of the refrigerant is stored at first in a water tank and used subsequently as a cold source at the water evaporator to improve the average performance and to carry out defrosting of the air evaporator using a two-phase thermosiphon. Unlike conventional air-source heat pumps, defrosting is carried out without stopping the heat production. A R407C HPS prototype was built and tested. Its performance on defined operating conditions corresponds to the data given by the selection software of the compressor manufacturer. The operation of the high pressure control system, the transitions between heating, cooling and simultaneous modes and the defrosting sequence were validated experimentally and are presented in the second part of this article .

  16. UTILIZATION OF ELECTRIC STEEL­SMELTING SLAGS

    Directory of Open Access Journals (Sweden)

    A. I. Pankovets

    2013-01-01

    Full Text Available There are not enough of production facilities on crushing of newly-formed slag due to increase of production volume on steel smelting. The tendencies of slag-processing at OAO «BMZ» are considered.

  17. Design of Air-Cooled Beam Dump for Extraction Line of PS Booster

    CERN Document Server

    Perillo-Marcone, A; Venturi, V; Antonakakis, T; Vlachoudis, V; Nowak, E; Mason, G; Battistin, M; Czapski, M; Sgobba, S

    2013-01-01

    A new beam dump has been designed, which withstands the future proton beam extracted from the Proton Syncrotron Booster (PSB) at CERN, consisting of up to 1E14 protons per pulse at 2 GeV after its upgrade in 2018/2019. In order to be able to efficiently release the deposited heat, the new dump will be made out of a single cylindrical block of a copper alloy and cooled by forced ventilation. In order to determine the energy density distribution deposited by the beam in the dump, Monte Carlo simulations were performed using FLUKA, and thermomechanical analyses carried out by importing the energy density into Ansys. In addition, CFD simulations of the airflow were carried out in order to accurately estimate the heat transfer convection coefficient on the surface of the dump. This paper describes the design process and highlights the constraints of integrating a new dump for increased beam power into the existing facility.

  18. Check valve slam caused by air intrusion in emergency cooling water system

    International Nuclear Information System (INIS)

    Waterhammer pressures were experienced during periodic starting of Residual Heat Removal (RHR) pumps at a nuclear plant. Prior to an analytical investigation careful analysis performed by plant engineers indicated that the spring effect of entrapped air in a heat exchanger resulted in water hammer due to check valve slam following flow reversal. In order to determine in more detail the values of pertinent parameters controlling this water hammer a hydraulic transient analysis was performed of the RHR piping system, including essential elements such as the pump, check valve, and heat exchanger. Using characteristic torque and pressure loss curves the motion of the check valve was determined. By comparing output of the water hammer analysis with site recordings of pump discharge pressure the computer model was calibrated, allowing for a realistic estimate of the quantity of entrapped air in the heat exchanger. (author)

  19. Improving the energy efficiency of refrigeration plants by decreasing the temperature difference in air-cooled condensers

    Science.gov (United States)

    Shishov, V. V.; Talyzin, M. S.

    2015-09-01

    The electric energy consumption efficiency is estimated in comparing the real refrigeration machine cycle with the theoretical inverse Carnot cycle. The potential for saving electricity in using aircooled condensers with different values of temperature difference is shown. A procedure for calculating a refrigerating system with the evaporation temperature equal to -10°C, which corresponds at this temperature level to the thermal load of a standard supermarket, is described. The calculation was carried out taking into account the annual profile of temperatures in the indicated locality and based on the possibility of adjusting the condenser capacity for maintaining constant condensation temperature. The payback period in case of using condensers with different values of temperature difference is calculated; for example, in using condensers with a temperature difference of less than 15 K, the payback period will be less than one year. Decreasing the temperature difference results, on one hand, in a larger annual consumption of electric energy by the condenser fans, and on the other hand, it results in a lower condensation pressure, which leads to a smaller annual consumption of energy by the compressor unit. As a result, the total amount of energy consumed by the refrigeration system decreases so that despite a higher cost of condensers designed to operate at lower values of temperature difference, it becomes possible to achieve the above-mentioned payback period. Additionally, the payback period in case of using an air-cooled microchannel aluminum condenser was calculated: in case of using such a condenser with a temperature difference of 8 K instead of the condenser with the temperature difference equal to 15 K, the payback period will be less than half a year. Recommendations for designing new refrigeration systems equipped with air-cooled condensers are given.

  20. Viscosity estimation for slags containing calcium fluoride

    Institute of Scientific and Technical Information of China (English)

    Qifeng Shu; Jiayun Zhang

    2005-01-01

    Based on recently published experimental data, the Riboud model was modified for viscosity estimation of the slags containing calcium fluoride. The estimated values were in good agreement with measured data. Reasonable estimation can be achieved using the modified Riboud model for mould fluxes and ESR (eletro slag remelting) slags. Especially for ESR slags, the modified Riboud model can provide much more precise values than the original Riboud model.

  1. Coal Slag Attack-A Review

    Institute of Scientific and Technical Information of China (English)

    GUO Zongqi

    2004-01-01

    Although slagging coal gasifiers have served the commercial systems of electricity and chemical fertilizer productions for more than ten years, refractory service life still is a critical factor for gasifier availability. Some investigations were attracted, focusing on coal slag attack on high chromia refractories. A general introduction is made in order to have further understanding about slag corrosion in coal gasification environment. Microstructural deterioration and wear process of high chromia refractory in slagging gasifiers are discussed.

  2. A mathematical model for predicting the performance of the solar energy assisted hybrid air conditioning system, with one-rotor six-stage rotary desiccant cooling system

    International Nuclear Information System (INIS)

    Highlights: • The desiccant wheels used honeycombed silica gel six-stage rotary desiccant cooling system was studied. • The mathematical model has been validated with the experimental data. • The optimal rotation speed increases with increasing the inlet temperature of the regeneration air. - Abstract: A mathematical model for predicting the performance of solar energy assisted hybrid air conditioning system (SEAHACS) is presented. The honeycombed silica gel desiccant wheel is used in this study. One-rotor six-stage rotary desiccant cooling system, (two-stage dehumidification process, two-stage pre-cooling process and two-stage regeneration process) are realized by only one wheel. Three air streams are involved in the present system. The mathematical model has been validated with the experimental data. The range of regeneration air inlet temperature changed from 65 to 140 °C, area ratio of process air to regeneration air change from 1 to 3.57, regeneration air inlet velocity from 1.5 to 5.5 m/s have been examined for a range of rotation speed from 6 to 20 rev/h. The optimization of these parameters is conducted based on the moisture removal capacity D, relative moisture removal capacity, dehumidification coefficient of performance and thermal coefficient of performance. At last, the influences of these main parameters on optimal rotation speed are discussed

  3. PERFORMANCE OF PULVERIZED SLAG-SUBSTITUTED CEMENT

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The Portland cement is equivalently substituted by slag micropowders with various specific areas. The workability,activity and acid-corrosion resistance of the slag-substituted cements are investigated,the activation of gypsum is discussed,also the porosity and pore distribution of mortars of the slag micropowders cement are determined by mercury intrusion porosimetry.

  4. Exergetic analysis of a double stage LiBr-H{sub 2}O thermal compressor cooled by air/water and driven by low grade heat

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, M. [Instituto C.C. Eduardo Torroja (CSIC), Edificacion y Habitabilidad, Madrid (Spain); Venegas, M.; Garcia, N. [Universidad Carlos III de Madrid (Spain). Departamento de Ingenieria Termica y Fluidos; Palacios, E. [Universidad Politecnica de Madrid (Spain). Departamento de Mecanica Industrial

    2005-05-01

    In the present paper, an exergetic analysis of a double stage thermal compressor using the lithium bromide-water solution is performed. The double stage system considered allows obtaining evaporation temperatures equal to 5{sup o} C using solar heat coming from flat plate collectors and other low grade thermal sources. In this study, ambient air and water are alternatively used as cooling fluids without crystallization problems up to condensation-absorption temperatures equal to 50 {sup o}C. The results obtained give the entropy generated, the exergy destroyed and the exergetic efficiency of the double stage thermal compressor as a function of the absorption temperature. The conclusions obtained show that the irreversibilities generated by the double stage thermal compressor will tend to increase with the absorption temperature up to 45 {sup o}C. The maximum value corresponds to 1.35 kJ kg{sup -}1{sup K-1}. The entropy generated and the exergy destroyed by the air cooled system are higher than those by the water cooled one. The difference between the values increases when the absorption temperature increases. For an absorption temperature equal to 50 {sup o}C, the air cooled mode generates 14% more entropy and destroys 14% more exergy than the water cooled one. Also, the results are compared with those of previous studies for single and double effect air cooled and water cooled thermal compressors. The conclusions show that the double stage system has about 22% less exergetic efficiency than the single effect one and 32% less exergetic efficiency than the double effect one. (author)

  5. Cooler than air. Evaporative cooling makes it possible; Kuehler als die Luft erlaubt.. Verdunstungskuehlung macht's moeglich

    Energy Technology Data Exchange (ETDEWEB)

    Sturies, Hubert [EVAPCO Europe GmbH, Meerbusch (Germany)

    2009-09-15

    The contribution outlines the variants of evaporation cooling aggregates that are commercially available. It should be mentioned that cooling towers of 200 kW to 20 MW can be constructed in serial production. Over 20 MW, modular cooling towers comprised of cooling cells are used that can be assembled on site. (orig.)

  6. Numerical simulation of 3-D temperature distribution of the flame tube of the combustion chamber with air film cooling

    Science.gov (United States)

    Chang, Haiping; Huang, Taiping; Chen, Wanbing

    1996-01-01

    The wall temperature distribution of the flame tube of the combustion chamber is strongly affected by the combustion, radiation and flow. The interaction of these influential factors forms a coupling system. In this paper, a new method, which is different from the previous methods, has been developed for calculating the temperature distribution of the flame tube wall together with the flow field inside and outside the flame tube. In the calculation, the combustion, heat radiation, cooling air film and injection stream mixing inside the flame tube as well as the secondary air flowing outside the flame tube have been simulated. The calculation, in this paper, uses the SIMPLE algorithm, the k - ɛ turbulence model and the auto-adjustable damping method. By using this method, the 3-D temperature distribution of the flame tube wall of the combustion chamber of an aeroengine has been simulated successfully. The calculation results are compared to the experimental data. The error of wall temperature is less than 10%.

  7. Experimental analysis of secondary flow in turbines (with cooling air ejection). Final report; Experimentelle Analyse der Sekundaerstroemungen in Turbinen (mit Kuehlluftausblasung). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Langowsky, C. [ed.; Weyer, H.B.

    1997-09-01

    Film cooling is an effective method of blade surface cooling. To satisfy not only the thermal but also the aerodynamic demand of minimum loss production the detailed knowledge of the interaction between the cooling air and the main flow is necessary. In this work the effect of cooling air ejection on the aerodynamics of the cascade flow and its loss production is studied experimentally with varied Blowing ratios and locations. Furthermore the mixing process of the cooling air jets among the influence of the secondary flow is investigated. To be able to analyse the different superimposed effects (radial pressure gradient, secondary flow) various measurement techniques are used. By means of additional numerical flow simulations origins of the experimental indicated effects could be figured out. (orig.) [Deutsch] Filmkuehlung ist eine wirkungsvolle Methode zur Kuehlung der aeusseren Schaufeloberflaeche. Um neben den thermischen auch den aerodynamischen Anspruechen nach einer minimalen Verlustproduktion zu genuegen, ist die genaue Kenntnis der wechselseitigen Beeinflussung von ausgeblasener Kuehlluft und Hauptstroemung notwendig. Gegensteand der vorliegenden Arbeit ist die experimentelle Untersuchung der Auswirkungen der Kuehlluftausblasung auf die Aerodynamik der Hauptstroemung eines filmgekuehlten Turbinenstators und auf dessen Verlustproduktion bei Variation des Ausblaseortes und der Ausblaserate. Desweiteren wurde die Mischungscharakteristik der Kuehlluftstrahlen unter besonderer Beruecksichtigung des Einflusses der Sekundaerstroemung studiert. Um die unterschiedlichen Wirkungen sich ueberlagernder Einfluesse (radialer Druckgradient, Sekundaerstroemung) analysieren zu koennen, wurden verschiedene Messtechniken eingesetzt. Begleitende numerische Simulationen der Stroemungsvorgaenge ermoeglichten Aussagen zu den Ursachen der experimentell aufgedeckten Effekte. (orig.)

  8. Slags in steel making; Kuonat teraeksen valmistuksessa

    Energy Technology Data Exchange (ETDEWEB)

    Haerkki, J.; Paeaetalo, M.; Karhu, P.; Jauhiainen, A.; Alamaeki, P.; Koski-Laine, S.; Ollila, J. [Oulu Univ. (Finland). Dept. of Process Engineering

    1996-12-31

    At the first step of the project all stages of the steelmaking processes were viewed from the blast furnace to the continuous casting. Slag knowledge of each processes were collected into a guide, which is meant to help both production and research. At the same time the essential problems caused by slags in steelmaking were focused. At the second step the focus of this slag-project were transferred into the desulphurization, converter, ladle and tundish slags. Wide slag knowledge has been divided into smaller parts and applied versatile into the steelmaking process taking into account the metallurgical, economical and qualitative aspects. (orig.) SULA 2 Research Programme; 13 refs.

  9. Comparative Cooling Season Performance of Air Distribution Systems in Multistory Townhomes

    Energy Technology Data Exchange (ETDEWEB)

    Poerschke, A. [IBACOS, Inc., Pittsburgh, PA (United States); Beach, R. [IBACOS, Inc., Pittsburgh, PA (United States); Beggs, T. [IBACOS, Inc., Pittsburgh, PA (United States)

    2016-08-26

    IBACOS investigated the performance of a small-diameter high velocity heat pump system compared to a conventional system in a new construction triplex townhouse. A ductless heat pump system also was installed for comparison, but the homebuyer backed out because of aesthetic concerns about that system. In total, two buildings, having identical solar orientation and comprised of six townhomes, were monitored for comfort and energy performance. Results show that the small-diameter system provides more uniform temperatures from floor to floor in the three-story townhome. No clear energy consumption benefit was observed from either system. The builder is continuing to explore the small-diameter system as its new standard system to provide better comfort and indoor air quality. The homebuilder also explored the possibility of shifting its townhome product to meet the U.S. Department of Energy Challenge Home National Program Requirements.

  10. Study on cementitious properties of steel slag

    Directory of Open Access Journals (Sweden)

    Zhu G.

    2013-01-01

    Full Text Available The converter steel slag chemical and mineral components in China’s main steel plants have been analysed in the present paper. The electronic microscope, energy spectrum analysis, X-ray diffraction analysis confirmed the main mineral compositions in the converter slag. Converter slag of different components were grounded to obtain a powder with specific surface area over 400m2/kg, making them to take place some part of the cement in the concrete as the admixture and carry out the standard tests. The results indicate that the converter slag can be used as cementitious materials for construction. Furthermore, physical mechanic and durability tests on the concrete that certain amount of cement be substituted by converter steel slag powder from different steel plants are carried out, the results show that the concrete with partial substitution of steel slag powder has the advantages of higher later period strength, better frost resistance, good wear resistance and lower hydration heat, etc. This study can be used as the technical basis for “Steel Slag Powder Used For Cement And Concrete”, “Steel Slag Portland Cement”, “Low Heat Portland Steel Slag Cement”, “Steel Slag Road Cement” in China, as well as a driving force to the works of steel slag utilization with high-value addition, circular economy, energy conservation and discharge reduction in the iron and steel industry.

  11. Effect of Coal Properties and Operation Conditions on Flow Behavior of Coal Slag in Entrained Flow Gasifiers: A Brief Review

    Energy Technology Data Exchange (ETDEWEB)

    Wang,Ping; Massoudi, Mehrdad

    2011-01-01

    Integrated gasification combined cycle (IGCC) is a potentially promising clean technology with an inherent advantage of low emissions, since the process removes contaminants before combustion instead of from flue gas after combustion, as in a conventional coal steam plant. In addition, IGCC has potential for cost-effective carbon dioxide capture. Availability and high capital costs are the main challenges to making IGCC technology more competitive and fully commercial. Experiences from demonstrated IGCC plants show that, in the gasification system, low availability is largely due to slag buildup in the gasifier and fouling in the syngas cooler downstream of the gasification system. In the entrained flow gasifiers used in IGCC plants, the majority of mineral matter transforms to liquid slag on the wall of the gasifier and flows out the bottom. However, a small fraction of the mineral matter (as fly ash) is entrained with the raw syngas out of the gasifier to downstream processing. This molten/sticky fly ash could cause fouling of the syngas cooler. Therefore, it is preferable to minimize the quantity of fly ash and maximize slag. In addition, the hot raw syngas is cooled to convert any entrained molten fly slag to hardened solid fly ash prior to entering the syngas cooler. To improve gasification availability through better design and operation of the gasification process, better understanding of slag behavior and characteristics of the slagging process are needed. Slagging behavior is affected by char/ash properties, gas compositions in the gasifier, the gasifier wall structure, fluid dynamics, and plant operating conditions (mainly temperature and oxygen/carbon ratio). The viscosity of the slag is used to characterize the behavior of the slag flow and is the dominating factor to determine the probability that ash particles will stick. Slag viscosity strongly depends on the temperature and chemical composition of the slag. Because coal has varying ash content and

  12. Comparative Cooling Season Performance of Air Distribution Systems in Multistory Townhomes

    Energy Technology Data Exchange (ETDEWEB)

    Poerschke, Andrew [IBACOS Inc., Pittsburgh, PA (United States); Beach, Rob [IBACOS Inc., Pittsburgh, PA (United States; Beggs, Timothy [IBACOS Inc., Pittsburgh, PA (United States

    2016-08-01

    IBACOS investigated the performance of a small-diameter high velocity heat pump system compared to a conventional system in a new construction triplex townhouse. A ductless heat pump system also was installed for comparison, but the homebuyer backed out because of aesthetic concerns about that system. In total, two buildings, having identical solar orientation and comprised of six townhomes, were monitored for comfort and energy performance. Results show that the small-diameter system provides more uniform temperatures from floor to floor in the three-story townhome. No clear energy consumption benefit was observed from either system. The builder is continuing to explore the small-diameter system as its new standard system to provide better comfort and indoor air quality. The homebuilder also explored the possibility of shifting its townhome product to meet the U.S. Department of Energy Challenge Home National Program Requirements. Ultimately, the builder decided that adoption of these practices would be too disruptive midstream in the construction cycle. However, the townhomes met the ENERGY STAR Version 3.0 program requirements.

  13. Slag cement matrix for immobilisation of spent organic ion exchange resins from nuclear power plants

    International Nuclear Information System (INIS)

    The spent IX resins from nuclear power reactors are highly active solid wastes generated during operations of water cooled nuclear power plants. Direct immobilisation of spent IX resins in slag cement matrix was investigated. Slag cement matrix formulations were optimised for mixed, K+ and borate resins by evaluating leaching characteristics, porosity, hydraulic conductivity etc. The 137cesium leaching characteristics of slag cement matrices developed in this study gave the average leach rates of the order of 10-4 g/cm2/d and leachability indices of 8.4 to 9.6. The 137cesium behaviour was in accordance with the porosity and hydraulic conductivity of matrix. The laboratory study revealed that these tests can be effectively used to shortlist cement matrix formulations for long term 137cesium leach tests. The results showed that slag cement matrix can be satisfactorily used to immobilise spent resins arising from PHWR and PWR/VVER type reactors. The selected formulations were successfully deployed to prepare full size (200 litre) slag cement matrix block incorporating 100 litres of mixed IX resins. The compressive strengths of core drilled samples were 64 to 118 kg/cm2 which satisfactorily meet the safety requirements. The study has shown that the slag cement matrix has potential to replace the polymer matrix making treatment of spent IX resins cost effective. (author)

  14. Effect of oxidization on enrichment behavior of TiO2 in titanium-bearing slag

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Due to the dispersed distribution of the titanium component in various mineral phases and very fine grain size, it is difficult to recover the titanium component from the slag. In order to utilize titanium resources, selective enriching and selective growing of the titanium component from the molten slag is expected. In this paper, the selection of the best titanium enrichment phase and the effect of oxidization on the enrichment of titanium by blowing air into the molten slag were studied. The results showed that through oxidizing the slag, the content of the perovskite phase increases while that of the other titanium-bearing mineral phases decreases until they disappear. Most titania resources were enriched into the perovskite phase and increase in size. The process of enrichment and growth is easily carried out.

  15. Difference in BOF Slag Splashing in US and China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Some differences in slag splashing between BOF steel works in USand China were investigated. The slag composition, melting point, and mineralogical phases of final slags from both countries were studied. The control of slag superheat is important to an effective slag coating.

  16. Improving Vortex Generators to Enhance the Performance of Air-Cooled Condensers in a Geothermal Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Manohar S. Sohal

    2005-09-01

    This report summarizes work at the Idaho National Laboratory to develop strategies to enhance air-side heat transfer in geothermal air-cooled condensers such that it should not significantly increase pressure drop and parasitic fan pumping power. The work was sponsored by the U.S. Department of Energy, NEDO (New Energy and Industrial Technology Development Organization) of Japan, Yokohama National University, and the Indian Institute of Technology, Kanpur, India. A combined experimental and numerical investigation was performed to investigate heat transfer enhancement techniques that may be applicable to largescale air-cooled condensers such as those used in geothermal power applications. A transient heat transfer visualization and measurement technique was employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements were obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that included four tube rows in a staggered array. Heat transfer and pressure drop measurements were also acquired in a separate multiple-tube row apparatus in the Single Blow Test Facility. In addition, a numerical modeling technique was developed to predict local and average heat transfer for these low-Reynolds number flows, with and without winglets. Representative experimental and numerical results were obtained that reveal quantitative details of local finsurface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. Heat transfer and pressure-drop results were obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500. The winglets were of triangular (delta) shape with a 1:2 or 1:3 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface heat transfer results indicate a significant level of heat transfer enhancement (in terms of

  17. 风冷热泵模块机在别墅空调系统中的应用%Application of Air-cooled Heat Pump Module in the Air Conditioning System of the Villa

    Institute of Scientific and Technical Information of China (English)

    钱华梅

    2014-01-01

    Combining with an engineering application,the air-cooled heat pump unit and the frequency VRV air conditioning system are compared. The reason of small air-cooled heat pump unit being widely used in air conditioning system of villas is concluded. At last we discusses some problems should be paid attention to in the air-cooled heat pump unit designing and installing process of household central air conditioning system.%本文结合某工程实例进行了风冷热泵模块机和变频多联机空调系统的对比,得出了小型风冷热泵机组在别墅等家用空调系统中广泛应用的原因,探讨风冷热泵模块机在家用中央空调系统设计施工过程中应该注意的几点问题。

  18. Evaluation on chemical stability of lead blast furnace (LBF) and imperial smelting furnace (ISF) slags.

    Science.gov (United States)

    Yin, Nang-Htay; Sivry, Yann; Guyot, François; Lens, Piet N L; van Hullebusch, Eric D

    2016-09-15

    The leaching behavior of Pb and Zn from lead blast furnace (LBF) and imperial smelting furnace (ISF) slags sampled in the North of France was studied as a function of pHs and under two atmospheres (open air and nitrogen). The leaching of major elements from the slags was monitored as a function of pH (4, 5.5, 7, 8.5 and 10) under both atmospheres for different slag-water interaction times (1 day and 9 days). The leaching results were coupled with a geochemical model; Visual MINTEQ version 3.0, and a detailed morphological and mineralogical analysis was performed on the leached slags by scanning and transmission electron microscopy (SEM and TEM). Significant amounts of Ca, Fe and Zn were released under acidic conditions (pH 4) with a decrease towards the neutral to alkaline conditions (pH 7 and 10) for both LBF and ISF slags. On the other hand, Fe leachability was limited at neutral to alkaline pH for both slags. The concentrations of all elements increased gradually after 216 h compared to initial 24 h of leaching period. The presence of oxygen under open-air atmosphere not only enhanced oxidative weathering but also encouraged formation of secondary oxide and carbonate phases. Formation of carbonates and clay minerals was suggested by Visual MINTEQ which was further confirmed by SEM & TEM. The hydration and partial dissolution of hardystonite, as well as the destabilization of amorphous glassy matrix mainly contributed to the release of major elements, whereas the spinel related oxides were resistant against pH changes and atmospheres within the time frame concerned for both LBF and ISF slags. The total amount of Pb leached out at pH 7 under both atmospheres suggested that both LBF and ISF slags are prone to weathering even at neutral environmental conditions. PMID:27240207

  19. Mechanism of Mineral Phase Reconstruction for Improving the Beneficiation of Copper and Iron from Copper Slag

    Science.gov (United States)

    Guo, Zhengqi; Zhu, Deqing; Pan, Jan; Zhang, Feng

    2016-09-01

    To maximize the recovery of iron and copper from copper slag, the modification process by adding a compound additive (a mixture of hematite, pyrite and manganous oxide) and optimizing the cooling of the slag was studied. The phase reconstruction mechanism of the slag modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that the synergy between the burnt lime and the compound additive promotes the generation of target minerals, such as magnetite and copper matte. In addition, the multifunctional compound additive is able to improve the fluidity of the molten slag, which facilitates the coalescence and growth of fine particles of the target minerals. As a result, the percentage of iron distributed in the form of magnetite increased from 32.9% to 65.1%, and that of the copper exiting in the form of metallic copper and copper sulfide simultaneously increased from 80.0% to 90.3%. Meanwhile, the grains of the target minerals in the modified slag grew markedly to a mean size of over 50 μm after slow cooling. Ultimately, the beneficiation efficiency of copper and iron was improved because of the ease with which the target minerals could be liberated.

  20. BEM/FDM Conjugate Heat Transfer Analysis of a Two-dimensional Air-cooled Turbine Blade Boundary Layer

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A coupled boundary element method (BEM) and finite difference method (FDM) are applied to solve conjugate heat transfer problem of a two-dimensional air-cooled turbine blade boundary layer. A loosely coupled strategy is adopted, in which each set of field equations is solved to provide boundary conditions for the other. The Navier-Stokes equations are solved by HIT-NS code. In this code, the FDM is adopted and is used to resolve the convective heat transfer in the fluid region. The BEM code is used to resolve the conduction heat transfer in the solid region. An iterated convergence criterion is the continuity of temperature and heat flux at the fluid-solid interface. The numerical results from the BEM adopted in this paper are in good agreement with the results of analyrical solution and the results of commercial code, such as Fluent 6.2. The BEM avoids the complicated mesh needed in other computation method and saves the computation time. The results prove that the BEM adopted in this paper can give the same precision in numerical results with less boundary points. Comparing the conjugate results with the numerical results of an adiabatic wall flow solution, it reveals a significant difference in the distribution of metal temperatures. The results from conjugate heat transfer analysis are more accurate and they are closer to realistic thermal environment of turbines.

  1. Accelerated ageing of an EAF black slag by carbonation and percolation for long-term behaviour assessment.

    Science.gov (United States)

    Gurtubay, L; Gallastegui, G; Elias, A; Rojo, N; Barona, A

    2014-07-01

    The efficient reuse of industrial by-products, such as the electric arc furnace (EAF) black slag, is still hindered by concern over their long-term behaviour in outdoor environments. The aim of this study was to develop an accelerated ageing method to simulate the long-term natural carbonation of EAF slag exposed to the elements. The degree of carbonation achieved in a freshly produced slag after accelerated ageing and in a slag used on a fifteen-year-old unpaved road was very similar. The influence of particle size on accelerated carbonation was assessed, with it being concluded that the slag sample with a particle size bigger than 5-6 mm underwent slight carbonation over time when it was exposed to CO2. The accelerated ageing procedure based on percolating a previously carbonated water solution through the slag column allowed gradual leaching with simulated acid rain, as well as providing information about the gradual and total chemical release from the slag. Three classification groups were established according to the release rate of the determined elements. The joint use of the accelerated carbonation method and the percolation test is proposed as a useful tool for environmental risk assessment concerning the long-term air exposure of EAF black slag.

  2. Effect of MgO and MnO on Phosphorus Utilization in P-Bearing Steelmaking Slag

    Science.gov (United States)

    Lin, Lu; Bao, Yan-Ping; Wang, Min; Li, Xiang

    2016-04-01

    In order to recycle the phosphorus in P-bearing converter slag and make it used as slag phosphate fertilizer, the effect of MgO and MnO in P-bearing steelmaking slag on phosphorus existence form, P2O5 solubility and magnetic separation behavior were researched systematically. The results show that the phosphorus in slag is mainly in the form of n2CaO · SiO2-3CaO · P2O5 (for short nC2S-C3P) solid solution in the P-rich phase for CaO-SiO2-FetO-P2O5-X (X stands for MgO and MnO, respectively). And the increasing of MgO and MnO content has no influence on precipitation of nC2S-C3P solid solution in slag, MnO and MgO mainly enter into RO phase and base phase to form MnFe2O4 and MgFe2O4, which has little effect on the P2O5 content of P-rich phase, so which has little effect on the degree of phosphorus enrichment and phosphorus occurrence form of the P-bearing slag. And adding MgO and MnO into CaO-SiO2-P2O5-Fe2O3 slag system can break the complex net structure formed by Si-O on certain degree, and also hinder the precipitation of β-Ca3(PO4)2 crystal with low citric acid solubility during the melting-cooling process. Therefore, adding appropriate MgO and MnO content into slag can improve the slag P2O5 solubility, but the effect of different amounts of MgO and MnO on the P2O5 solubility has little difference. Meanwhile, adding MgO and MnO into slag can improve the metallization of slag and magnetism of iron-rich phase, make the magnetic substances content increase and separation of phosphorus and iron incomplete, so it is adverse to phosphorus resources recovery from P-bearing slag by magnetic separation method. In order to recycle the phosphorus in P-bearing converter slag, the MgO and MnO content in the P-bearing slag should be controlled in the steelmaking process.

  3. A Brief Review of Viscosity Models for Slag in Coal Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Massoudi, Mehrdad; Wang, Ping

    2011-11-01

    Many researchers have defined the phenomenon of 'slagging' as the deposition of ash in the radiative section of a boiler, while 'fouling' refers to the deposition of ash in the convective-pass region. Among the important parameters affecting ash deposition that need to be studied are ash chemistry, its transport, deposit growth, and strength development; removability of the ash deposit; heat transfer mechanisms; and the mode of operation for boilers. The heat transfer at the walls of a combustor depends on many parameters including ash deposition. This depends on the processes or parameters controlling the impact efficiency and the sticking efficiency. For a slagging combustor or furnace, however, the temperatures are so high that much of the coal particles are melted and the molten layer, in turn, captures more particles as it flows. The main problems with ash deposition are reduced heat transfer in the boiler and corrosion of the tubes. Common ways of dealing with these issues are soot blowing and wall blowing on a routine basis; however, unexpected or uncontrolled depositions can also complicate the situation, and there are always locations inaccessible to the use of such techniques. Studies have indicated that slag viscosity must be within a certain range of temperatures for tapping and the membrane wall to be accessible, for example, between 1300 C and 1500 C, the viscosity is approximately 25 Pa {center_dot} s. As the operating temperature decreases, the slag cools and solid crystals begin to form. In such cases the slag should be regarded as a non-Newtonian suspension, consisting of liquid silicate and crystals. A better understanding of the rheological properties of the slag, such as yield stress and shear-thinning, are critical in determining the optimum operating conditions. To develop an accurate heat transfer model in any type of coal combustion or gasification process, the heat transfer and to some extent the rheological properties

  4. Design and Calculation of Air-cooled Condenser Used in Power Station%电站空冷凝汽器设计计算

    Institute of Scientific and Technical Information of China (English)

    侯霄艳; 张向南; 常春梅; 解德甲; 孙振; 姚立影

    2016-01-01

    以某火力发电厂新建300 MW发电项目直接空冷凝汽装置为工程实例,采用A字形结构框架空冷器,将扁钢管钎焊蛇形铝翅片管作为空冷凝汽器的核心传热元件,应用数学解析方法进行了工艺设计计算,可为直接空冷凝汽器的设计计算提供参考。%Taking the 300 MW power generation project of a thermal power plant for example,a direct air-cooled condenser needs to be designed.A-shaped structure frame air cooler was adopt-ed ,flat steel pipe brazed with S-shaped aluminum fin was used as heat transfer element and math-ematics method was introduced to compute the direct air-cooled condenser.It will provide refer-ence for design and calculation of the direct air-cooled condenser.

  5. Simulation of past exposure in slag wool production.

    Science.gov (United States)

    Fallentin, B; Kamstrup, O

    1993-08-01

    A survey of the working conditions at a Danish slag wool production factory during the early technological phase in the 1940s is presented. No exposure data, however, are available for that period. So, a full-scale simulation of the past production of slag wool has been performed. Air monitoring was carried out in the working area around the cupola furnace. The aim was to measure exposure to air pollutants other than fibres. Such exposure might have confounded a possible association between lung cancer and exposure to fibres, in the early technological phase of slag wool production. The simulation experiment demonstrated exposure to PAH, a known lung carcinogen. The effect of other concurrent exposures is difficult to assess. Time-weighted average concentrations of particulate material ranged between 12.9 and 49.1 mg m-3 at the upper decks around the cupola. Corresponding concentrations of the dominant metals zinc and lead were 4.4-22.7 mg Zn m-3 and 0.9-4.7 mg Pb m-3. Significant concentrations of PAH up to 269 micrograms PAH m-3 (4 micrograms BaP m-3) occurred during ignition of the cupola furnace. The carbon monoxide level reached 270 ppm also during ignition.

  6. Simulation of past exposure in slag wool production.

    Science.gov (United States)

    Fallentin, B; Kamstrup, O

    1993-08-01

    A survey of the working conditions at a Danish slag wool production factory during the early technological phase in the 1940s is presented. No exposure data, however, are available for that period. So, a full-scale simulation of the past production of slag wool has been performed. Air monitoring was carried out in the working area around the cupola furnace. The aim was to measure exposure to air pollutants other than fibres. Such exposure might have confounded a possible association between lung cancer and exposure to fibres, in the early technological phase of slag wool production. The simulation experiment demonstrated exposure to PAH, a known lung carcinogen. The effect of other concurrent exposures is difficult to assess. Time-weighted average concentrations of particulate material ranged between 12.9 and 49.1 mg m-3 at the upper decks around the cupola. Corresponding concentrations of the dominant metals zinc and lead were 4.4-22.7 mg Zn m-3 and 0.9-4.7 mg Pb m-3. Significant concentrations of PAH up to 269 micrograms PAH m-3 (4 micrograms BaP m-3) occurred during ignition of the cupola furnace. The carbon monoxide level reached 270 ppm also during ignition. PMID:8379619

  7. Petroleum coke slags :characterization and dissolution

    OpenAIRE

    Lu, Jun

    1997-01-01

    Slags are crystalline to vitreous by-product materials generated in many high temperature industrial processes. This study presents a general technique for the identification of the phases present in petroleum coke gasification slags. documents the phase assemblages and textures, and finally determines the dissolution of vanadium from these slags as part of the considerations of potential resource reclamation. The general identification procedure utilizes (1) recognition of separa...

  8. Performance analysis on a solar-powered air-cooled two-staged water ejector cooling system%风冷太阳能双级水喷射制冷空调系统性能分析

    Institute of Scientific and Technical Information of China (English)

    卢苇; 郑立星; 陈洪杰

    2011-01-01

    The performance was analyzed for a solar-powered air-cooled two-staged water ejector cooling system that rated cooling capacity is 12.3 Kw. The cooling capacity of the proposed system increases with the rising of indoor temperature and the enhancement of solar irradiance, while decreases with the rising of the ambient temperature. The COP has similar changing trend with that of the cooling capacity except that it increases rapidly with the enhancement of solar irradiance firstly and then become stable when the solar irradiance exceeding a certain value. The cooling capacity is 7.7~32 Kw and the COP is 0.082~0.107 under the normal operating conditions with indoor temperature over 27℃, ambient temperature below 38 ℃. And solar irradiance surpassing 500 W/m2.%对额定制冷量为12.3kW的风冷太阳能双级水喷射制冷空调系统进行了变工况性能分析.该系统的制冷量随室内温度升高而增大,随环境温度升高而减小,随太阳辐照度增强而增大;COP的变化与制冷量的变化类似,所不同的是COP随着太阳辐照度的增强先迅速增大,当太阳辐照度增大到一定程度后,COP基本保持稳定.在室内温度不低于27℃,室外温度不高于38℃,太阳辐照度不低于500 W/m2的条件下,系统的制冷量为7.7~32 kW,COP为0.082~0.107.

  9. Investigations of Air-Cooled Turbine Rotors for Turbojet Engines. 1: Experimental Disk Temperature Distribution in Modified J33 Split-Disk Rotor at Speeds up to 6000 RPM

    Science.gov (United States)

    Schramm, Wilson B.; Ziemer, Robert R.

    1952-01-01

    An experimental investigation is being conducted at the Lewis laboratory to establish general principles for the design of noncritical turbine rotor configurations. This investigation includes evaluation of cooling effectiveness, structural stability, cooling-air flow distribution characteristics, and methods of supplying cooling air to the turbine rotor blades. Prior to design of a noncritical rotor, a standard turbine rotor of a commerical turbojet engine was split in the plane of rotation and machined to provide a passage for distributing cooling air to the base of each blade. The rotor was fitted with nontwisted, hollow, aircooled blades containing nine tubes in the coolant passage. In the investigation reported herein, the modified turbine rotor operated successfully up to speeds of 6000 rpm with ratios of cooling-air to combustion-gas flow as low as 0.02. The disk temperatures observed at these conditions were below 450 0 F when cooling air at 100 F was used from the laboratory air system. The calculated disk temperatures based on the correlation method presented for rated engine conditions were well below 1000 F at a cooling-air flow ratio of 0.02, which is considered adequate for a noncritical rotor. An appreciable difference in temperature level existed between the forward and rear disks. This temperature difference probably introduced undesirable disk stress distributions as a result of the relative elongations of the two disks. This investigation was terminated at 6000 rpm so that slight changes in the engine configuration could be made to relieve this condition.

  10. The Sulfide Capacity of Iron Oxide-Rich Slags

    Science.gov (United States)

    Motlagh, M.

    1988-03-01

    The relationship between the sulfide capacity of slags rich in iron oxide and the sulfur partition ratio between the metal and slag is strongly related to the slag's iron oxide concentration. For slags containing little or no lime, this relationship is linear for a constant concentration of iron oxide in the slag. The effect of silica on changes in the sulfide capacity of slags rich in iron oxide is similar to that of basic steel-making slags, particularly at low activity of silica in slag.

  11. The influence of water/air cooling on collateral tissue damage using a diode laser with an innovative pulse design (micropulsed mode)-an in vitro study.

    Science.gov (United States)

    Beer, F; Körpert, W; Buchmair, A G; Passow, H; Meinl, A; Heimel, P; Moritz, A

    2013-05-01

    Since the diode laser is a good compromise for the daily use in dental offices, finding usage in numerous dental indications (e.g., surgery, periodontics, and endodontics), the minimization of the collateral damage in laser surgery is important to improve the therapeutical outcome. The aim of this study was to investigate the effect of water/air cooling on the collateral thermal soft tissue damage of 980-nm diode laser incisions. A total of 36 mechanically executed laser cuts in pork liver were made with a 980-nm diode laser in micropulsed mode with three different settings of water/air cooling and examined by histological assessment to determine the area and size of carbonization, necrosis, and reversible tissue damage as well as incision depth and width. In our study, clearly the incision depth increased significantly under water/air cooling (270.9 versus 502.3 μm-test group 3) without significant changes of incision width. In test group 2, the total area of damage was significantly smaller than in the control group (in this group, the incision depth increases by 65 %). In test group 3, the total area of damage was significantly higher (incision depth increased by 85 %), but the bigger part of it represented a reversible tissue alteration leaving the amount of irreversible damage almost the same as in the control group. This first pilot study clearly shows that water/air cooling in vitro has an effect on collateral tissue damage. Further studies will have to verify, if the reduced collateral damage we have proved in this study can lead to accelerated wound healing. Reduction of collateral thermal damage after diode laser incisions is clinically relevant for promoted wound healing.

  12. 浅谈直接空冷机组凝结水精处理系统%On cooled water condensate polishing system of direct air-cooled machine team

    Institute of Scientific and Technical Information of China (English)

    郭丽鹏

    2009-01-01

    The paper analyzes water features of cooled water by direct air-cooled machine team and problems that may be exist, and then it points out necessity of establishing condensate polishing system, it also proposes several suggestions for condensate polishing system that being used in our nation nowadays, so as to optimize the condensate polishing system.%通过对直接空冷机组凝结水水质特点和可能存在的问题进行分析,指出设置凝结水精处理的必要性,就目前国内采用的凝结水精处理系统提出几点建议,以达到优化凝结水精处理系统的目的.

  13. Effect of alumina short fiber and air-cooling processing on solidification microstructure and tensile properties of Al2O3/Al-15Si composites

    Institute of Scientific and Technical Information of China (English)

    张学习; 王德尊; 姚忠凯

    2002-01-01

    The effect of microstructure variation by addition of alumina short fiber and optimization of tensile properties by air-cooling processing in Al2O3/Al-15Si composites were studied. The results show that in Al-15Si alloy matrix composites with 14% and 30%(volume fraction) fiber, the primary silicon is hardly refined, but the eutectic silicon is effectively refined and granulated. Granulation of some eutectic silicon mainly happens in fiber segregation areas. Refining and granulation of the eutectic silicon are related to the physical constraint arising from the fiber. After the 30%Al2O3/Al-15Si composite was remelted and air-cooled, the number of the eutectic silicon on the surface of the fiber increases, which results in the improvement of fiber/matrix interface and tensile properties for the as-cast composite. Air-cooling processing may be reliable for the optimization of the microstructure and properties of fiber reinforced hypereutectic Al-15Si alloy composites.

  14. Steel desulphurization with synthetic slag

    Directory of Open Access Journals (Sweden)

    Heput, T.

    2007-02-01

    Full Text Available Generally speaking, sulphur is considered a harmful element for steel quality, reason why all the technological steps are being taken in order to eliminate it from the metal bath. This paper deals with the influence of the chemical composition, on the slag quantity and of the bath stirring condition upon the desulphurization process in the casting ladle by treatment with synthetic slag. The experiments were made at an open-hearth plant with the steel tapping in two ladles (the desulphurization was made with synthetic slag at one ladle while the other one was considered standard and at the electric steel plant and for the synthetic slag formation a mix was used, made, according to several receipts, of: lime (50-75%, fluorine (0-17%, bauxite (0-32% and aluminous slag (8-22%. The data were processed in the calculation programs EXCEL and MATLAB, which resulted in a series of correlations between the desulphurization degree and the chemical composition of the slag, respectively the slag quantity both for the charges bubbled with Argon and the unbubbled ones.

    En general, el azufre es considerado un elemento nocivo para la calidad del acero y, por eso, en la práctica, se toman todas las medidas de orden tecnológico para su eliminación del baño metálico. En este trabajo se analiza la influencia de la composición química, de la cantidad de escoria y del estado de agitación del baño sobre el proceso de desulfuración en la cuchara para fundir por tratamiento con escoria sintética. Los experimentos se han realizado en una acería evacuando el acero en dos ollas (en una cuchara se efectuó la desulfuración con escoria sintética y a la otra se consideró como patrón y en un acería eléctrica y para la formación de la escoria sintética se utilizó una mezcla producida según muchas recetas, formada por: cal (50-75%, fluorina (0-17%, bauxita (0-32% y escoria aluminosa (8-22%. Los datos han sido procesados en los programas de c

  15. Valorization of electric arc furnace primary steelmaking slags for cement applications.

    Science.gov (United States)

    Kim, Hyung-Seok; Kim, Kee-Seok; Jung, Sung Suk; Hwang, Jin Ill; Choi, Jae-Seok; Sohn, Il

    2015-07-01

    To produce supplementary cementitious materials from electric arc furnace (EAF) slags, FeO was reduced using a two-stage reduction process that included an Al-dross reduction reaction followed by direct carbon reduction. A decrease in FeO was observed on tapping after the first-stage reduction, and further reduction with a stirred carbon rod in the second-stage reduction resulted in final FeO content below 5wt%, which is compatible with cement clinker applications. The reduced electric arc furnace slags (REAFS) mixed with cement at a unit ratio exhibited physical properties comparable to those of commercialized ground granulated blast furnace slags (GGBFS). Confocal laser scanning microscopy (CLSM) was used to obtain fundamental information on the cooling characteristics and conditions required to obtain amorphous REAFS. REAFS can be applied in cement mixtures to achieve the hydraulic properties needed for commercial use.

  16. Radiological significance of coal, slag and fly ash samples from the Eastern Black Sea region

    International Nuclear Information System (INIS)

    This work presents a study of natural radioactivity levels in coal and its combustion residues (fly ash and slag) used in the houses in Black Sea Region, Turkey. Coal, fly ash and slag samples were provided from different locations of the region and analyzed by gamma spectroscopy using a high-purity germanium detector (HPGe). Also, chemical analyses of these samples were carried out using energy dispersive X-ray fluorescence spectrometer. The mean 226Ra activity concentrations in coal, slag and fly ash were measured as 83, 99 and 38 Bq kg-1, respectively. The mean 232Th activity concentrations in coal, slag and fly ash were measured as 108, 113 and 50 Bq kg-1, respectively. The mean 40K activity concentrations in coal, slag and fly ash were found to be 366, 381 and 204 Bq kg-1, respectively. The potential radiological hazards associated to these materials were evaluated by calculating the radium equivalent activity (Raeq), the air absorbed gamma dose rate (D), the annual effective dose rate (AED), the external hazard index (Hex) and internal hazard index (Hin) and compared with the internationally accepted or reference values. The mean Raeq values of the coal, fly ash and slag samples were lower than the recommended maximum values 370 Bq kg-1 by the Organization for Economic Cooperation and Development (OECD). The overall mean outdoor terrestrial gamma air absorbed dose rate in coal, fly ash and slag samples are 119, 129 and 62 nGy h-1 and the corresponding outdoor annual effective doses are 0.60, 0.32 and 0.64 mSv y-1, which is higher than the worldwide average (0.07 mSv y-1), respectively. Moreover, the enrichment factors relative to the input coal are calculated for the radionuclide contents observed. Calculated enrichment factor values for 226Ra and 232Th were found 1.14 and 1.01, respectively. (orig.)

  17. The use of blast furnace slag

    Directory of Open Access Journals (Sweden)

    V. Václavík

    2012-10-01

    Full Text Available The paper presents the results of experimental research that dealt with the substitution of finely ground blast furnace slag for Portland cement in the course of simple concrete manufacturing. Physical and mechanical properties of experimental concrete mixtures based on finely ground blast furnace slag were observed.

  18. Design and Preparation of Steel Slag SMA

    Institute of Scientific and Technical Information of China (English)

    WU Shao-peng; YANG Wen-feng; XUE Yong-jie; LIN Zhen-hua

    2003-01-01

    On the basis of the characteristics of high rigidity and excellent friction resistance,a new kind of steel slag SMA (stone matrix asphalt) concrete was designed and prepared.The main processes include aggregate gradation,performance analysis of steel slag before and after aging,preparation methods and properties test of steel slag SMA.The experimental results indicate that the index of steel slag's activation is less than 1 percent,the dynamic stability is 5699 times/mm,and both the residual stability and ratio of frozen splitting strength are more than 80 percent;the friction factor and structure depth are 67.1% and 0.7mm respectively.These results show the steel slag SMA is superior to the common asphalt concrete and SMA that uses common aggregate.

  19. Combined current and temperature mapping in an air-cooled, open-cathode polymer electrolyte fuel cell under steady-state and dynamic conditions

    Science.gov (United States)

    Meyer, Q.; Ronaszegi, K.; Robinson, J. B.; Noorkami, M.; Curnick, O.; Ashton, S.; Danelyan, A.; Reisch, T.; Adcock, P.; Kraume, R.; Shearing, P. R.; Brett, D. J. L.

    2015-11-01

    In situ diagnostic techniques provide a means of understanding the internal workings of fuel cells so that improved designs and operating regimes can be identified. Here, for the first time, a combined current density and temperature distributed measurement system is used to generate an electro-thermal performance map of an air-cooled, air-breathing polymer electrolyte fuel cell stack operating in an air/hydrogen cross-flow configuration. Analysis is performed in low- and high-current regimes and a complex relationship between localised current density, temperature and reactant supply is identified that describes the way in which the system enters limiting performance conditions. Spatiotemporal analysis was carried out to characterise transient operations in dead-ended anode/purge mode which revealed extensive current density and temperature gradients.

  20. Comparative Study on Heat Dissipation Performance of Liquid Cooling and Air Cooling Technology of Airborne Chassis%机载机箱液冷与风冷技术的散热性能对比研究

    Institute of Scientific and Technical Information of China (English)

    赵波

    2015-01-01

    随着机载机箱内部的热密度越来越高以及安装空间的有限性,对机箱的散热性能和外形尺寸也提出了更高的要求. 首先分析了强迫风冷的散热方式,其次运用Flotherm软件对液冷机箱的散热性能进行了仿真验证,结果表明液冷机箱能更好地满足高热流密度的散热要求和结构外形要求.%With heat density inside the airborne cabinet rapidly improves higher and higher, and considering the limited instal-lation space, we propose higher request to the heat dissipation and the boundary dimension of cabinet. In this paper, we firstly introduce the heat dissipation pattern of forced-air cooling, and then use the software FLOTHERM to conduct simulation veri-fication on the heat dissipation performance of the liquid-cooled chassis. The results show that liquid-cooled chassis can bet-ter satisfies requirements on aspects of the heat dissipation and the structure appearance of high heating flux density.

  1. Valorisation of electric arc furnace steel slag as raw material for low energy belite cements.

    Science.gov (United States)

    Iacobescu, R I; Koumpouri, D; Pontikes, Y; Saban, R; Angelopoulos, G N

    2011-11-30

    In this paper, the valorisation of electric arc furnace steel slag (EAFS) in the production of low energy belite cements is studied. Three types of clinkers were prepared with 0 wt.% (BC), 5 wt.% (BC5) and 10 wt.% (BC10) EAFS, respectively. The design of the raw mixes was based on the compositional indices lime saturation factor (LSF), alumina ratio (AR) and silica ratio (SR). The clinkering temperature was studied for the range 1280-1400°C; firing was performed at 1380°C based on the results regarding free lime and the evolution of microstructure. In order to activate the belite, clinkers were cooled fast by blown air and concurrent crushing. The results demonstrate that the microstructure of the produced clinkers is dominated by belite and alite crystals, with tricalcium aluminate and tetracalcium-alumino-ferrite present as micro-crystalline interstitial phases. The prepared cements presented low early strength development as expected for belite-rich compositions; however the 28-day results were 47.5 MPa, 46.6 MPa and 42.8 MPa for BC, BC5 and BC10, respectively. These values are comparable with OPC CEMI 32.5 N (32.5-52.5 MPa) according to EN 197-1. A fast setting behaviour was also observed, particularly in the case of BC10, whereas soundness did not exceed 1mm.

  2. Development and Evaluation of an Externally Air-Cooled Low-Flow torch and the Attenuation of Space Charge and Matrix Effects in Inductively Coupled Plasma Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Praphairaksit, N.

    2000-09-12

    An externally air-cooled low-flow torch has been constructed and successfully demonstrated for applications in inductively coupled plasma mass spectrometry (ICP-MS). The torch is cooled by pressurized air flowing at {approximately}70 L/min through a quartz air jacket onto the exterior of the outer tube. The outer gas flow rate and operating RF forward power are reduced considerably. Although plasmas can be sustained at the operating power as low as 400 W with a 2 L/min of outer gas flow, somewhat higher power and outer gas flows are advisable. A stable and analytical useful plasma can be obtained at 850 W with an outer gas flow rate of {approximately}4 L/min. Under these conditions, the air-cooled plasma produces comparable sensitivities, doubly charged ion ratios, matrix effects and other analytical merits as those produced by a conventional torch while using significantly less argon and power requirements. Metal oxide ion ratios are slightly higher with the air-cooled plasma but can be mitigated by reducing the aerosol gas flow rate slightly with only minor sacrifice in analyte sensitivity. A methodology to alleviate the space charge and matrix effects in ICP-MS has been developed. A supplemental electron source adapted from a conventional electron impact ionizer is added to the base of the skimmer. Electrons supplied from this source downstream of the skimmer with suitable amount and energy can neutralize the positive ions in the beam extracted from the plasma and diminish the space charge repulsion between them. As a result, the overall ion transmission efficiency and consequent analyte ion sensitivities are significantly improved while other important analytical aspects, such as metal oxide ion ratio, doubly charged ion ratio and background ions remain relatively unchanged with the operation of this electron source. This technique not only improves the ion transmission efficiency but also minimizes the matrix effects drastically. The matrix-induced suppression

  3. Hydrothermal synthesis of xonotlite from carbide slag

    Institute of Scientific and Technical Information of China (English)

    Jianxin Cao; Fei Liu; Qian Lin; Yu Zhang

    2008-01-01

    Carbide slag was used as the calcareous materials for the first time to prepare xonotlite via dynamic hydrothermal synthesis.The effects of influential factors including different calcination temperatures,pretreatment methods of the carbide slag and process param-eters of hydrothermal synthesis on the microstructure and morphology of xonotlite were explored using XRD and SEM techniques.The results indicate that the carbide slag after proper calcination could be used to prepare pure xonotlite;and different calcination tern-peratures have little effect on the crystallinity of synthesized xonotlitc,but have great impact on the morphology of secondary particles.The different pretreatment methods of the carbide slag pose great impact on the crystallinity and morphology of secondary particles of xonotlite.Xonotlite was also synthesized from pure CaO under the salne experimental conditions as that prepared from calcined carbide slag for comparison.Little amount of impurities in carbide slag has no effect on the mechanism of hydrothermal synthesizing xonotlite from carbide slag.

  4. Analysis and Design of a Dish/Stirling System for Solar Electric Generation with a 2.7 kW Air-Cooled Engine

    Directory of Open Access Journals (Sweden)

    Beltrán-Chacón R.

    2012-01-01

    Full Text Available This paper presents a mathematical modeling, simulation and design of a solar power system of a parabolic dish with an air-cooled Stirling engine of 2.7 kW. The model used for the solar concentrator, the cavity and the Stirling engine were successfully validated against experimental data. Based on a parametric study, the design of the components of the engine is carried out. The study shows that as system capacity increases, the overall efficiency is limited by the power required by the fan, since the design of the cooler needs greater amounts of heat removal by increasing the air flow without affecting the internal conditions of the process (mass flow of working gas and internal dimensions of the same. The system was optimized and achieves an overall efficiency of solar to electric energy conversion of 26.7%. This study shows that the use of an air-cooled Stirling engine is potentially attractive for power generation at low capacities.

  5. The Effect of Vegetation Coverage and Greenhouse Area on the Performance of an Earth-to-Air Heat Exchanger in Cooling Mode of Greenhouse

    Directory of Open Access Journals (Sweden)

    M Mohammadi Mogharreb

    2013-02-01

    Full Text Available The underground temperature at a depth of about three to four meters is almost constant during the year. As a result in summer the underground is cooler than the ambient temperature. This potential is considered for greenhouse cooling by using an Earth-to-Air Heat Exchanger (EAHE. In this research the effects of two parameters were investigated: a the area of greenhouse in three levels of 9, 18, 27 m2 and b the percent of vegetation coverage inside the greenhouse in three levels of 0%, 50%, 100% on the performance of EAHE. The experimental design was factorial experiment in a randomized complete block design. The parameters of greenhouse’s inside temperature, thermal energy exchange and coefficient of performance (COP were considered in cooling mode. As one of the remarkable results it was observed that the closed loop utilization of the system was infeasible in cooling mode. This was mainly due to the occurrence of vapor distillation inside the underground pipes and hence the blockages of the air flow. Also the effect of area and the percent of vegetation coverage were significant on the performance of EAHE. The highest average temperature difference between the temperature of testimonial greenhouse and the temperature of greenhouse was observed in treatment of 100% vegetation coverage and 9 m2 floor area which was measured as 9.6°C. The least average temperature difference in the treatment without vegetation coverage and 27 m2 floor area was measured as 5.2 °C. Considering thermal energy exchange in cooling greenhouse with open loop, the best treatment determined for EAHE in this research was the one with 9 m2 floor area and 100% of vegetation coverage.

  6. Coexistence Theory of Slag Structure and Its Application to Calculation of Oxidizing Capability of Slag Melts

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculation of oxidizing capabilities of slag melts in combination with the coexistence theory of slag structure.For slag melts containing basic oxides FeO and MnO, their oxidizing capabilities can be expressed by NFetO=NFeO+6NFe2O3, while for slag melts containing basic oxides CaO, MgO, etc., in addition to FeO and MnO, their oxidizing capabilities can be given as NFetO=NFeO+6NFe2O3+8NFe3O4.

  7. The Effect of Slag on the Effectiveness of Phosphorus Removal from Ferrous Alloys Containing Carbon, Chromium and Nickel

    Directory of Open Access Journals (Sweden)

    Kawecka-Cebula E.

    2016-03-01

    Full Text Available The aim of this study was to determine the impact of slag composition on phosphorus removal from ferrous solutions containing carbon, chromium and nickel. Additions of cryolite, Na3AlF6, were applied for better fluxing and higher phosphate capacity of the slag. An X-ray analysis of final slags formed during dephosphorization of ferrous solutions containing chromium and nickel with CaO-CaF2 or CaO-CaF2-Na3AlF6 mixtures of different chemical compositions was carried out. The equilibrium composition of the liquid and the solid phase while cooling the slags from 1673K to 298K was computed using FactSage 6.2 software. The performed equilibrium computations indicated that the slags were not entirely liquid at those temperatures. The addition of cryolite causes a substantial increase of the liquid phase of the slag. It also has a favourable effect on the dephosphorization grade of hot metal. The obtained results were statistically processed and presented in the form of regression equations.

  8. Investigation of Bubble-Slag Layer Behaviors with Hybrid Eulerian-Lagrangian Modeling and Large Eddy Simulation

    Science.gov (United States)

    Li, Linmin; Li, Baokuan

    2016-08-01

    In ladle metallurgy, bubble-liquid interaction leads to complex phase structures. Gas bubble behavior, as well as the induced slag layer behavior, plays a significant role in the refining process and the steel quality. In the present work, a mathematical model using the large eddy simulation (LES) is developed to investigate the bubble transport and slag layer behavior in a water model of an argon-stirred ladle. The Eulerian volume of fluid model is adopted to track the liquid steel-slag-air free surfaces while the Lagrangian discrete phase model is used for tracking and handling the dynamics of discrete bubbles. The bubble coalescence is considered using O'Rourke's algorithm to solve the bubble diameter redistribution and bubbles are removed after leaving the air-liquid interface. The turbulent liquid flow that is induced by bubble-liquid interaction is solved by LES. The slag layer fluactuation, slag droplet entrainment and spout eye open-close phenomenon are well revealed. The bubble diameter distribution and the spout eye size are compared with the experiment. The results show that the hybrid Eulerian-Lagrangian-LES model provides a valid modeling framework to predict the unsteady gas bubble-slag layer coupled behaviors.

  9. Thermal–economic–environmental analysis and multi-objective optimization of an ice thermal energy storage system for gas turbine cycle inlet air cooling

    International Nuclear Information System (INIS)

    In this study, a mathematical model of an ice thermal energy storage (ITES) system for gas turbine cycle inlet air cooling is developed and thermal, economic, and environmental (emissions cost) analyses have been applied to the model. While taking into account conflicting thermodynamic and economic objective functions, a multi-objective genetic algorithm is employed to obtain the optimal design parameters of the plant. Exergetic efficiency is chosen as the thermodynamic objective while the total cost rate of the system including the capital and operational costs of the plant and the social cost of emissions, is considered as the economic objective. Performing the optimization procedure, a set of optimal solutions, called a Pareto front, is obtained. The final optimal design point is determined using TOPSIS decision-making method. This optimum solution results in the exergetic efficiency of 34.06% and the total cost of 28.7 million US$ y−1. Furthermore, the results demonstrate that inlet air cooling using an ITES system leads to 11.63% and 3.59% improvement in the output power and exergetic efficiency of the plant, respectively. The extra cost associated with using the ITES system is paid back in 4.72 years with the income received from selling the augmented power. - Highlights: • Mathematical model of an ITES system for a GT cycle inlet air cooling is developed. • Exergetic, economic and environmental analyses were performed on the developed model. • Exergy efficiency and total cost rate were considered as the objective functions. • The total cost rate involves the capital, maintenance, operational and emissions costs. • Multi-objective optimization was applied to obtain the Pareto front

  10. 空冷风机桥架疲劳寿命分析%Analysis of fatigue life for air-cooling fan bridges

    Institute of Scientific and Technical Information of China (English)

    徐亚洲; 白国良

    2013-01-01

    Based on the in-situ tested vibration responses of an air-cooling fan bridge,the dynamic analysis is performed with modulation amplitude disturbing force model of draught fans.Rainflow method is used to count stress cycles and the fatigue load spectrum of air-cooling fan bridges is then programmed combined with investigation results of running frequencies of different operation modes per year.Fatigue damage to the air-cooling fan bridge is calculated in terms of Miner' s cumulative damage rule and design p-S-N curve.After giving the damage threshold corresponding to fatigue failure,the predicted fatigue life of the fan bridge is longer than the designed service life.Furthermore,the fatigue life slightly decreases as effects of mean stress are taken into consideration by Goodman' s,Gerber' s and Soderberg' s models.%基于现场实测风机桥架振动响应,采用风机调幅扰力模型进行结构动力响应分析.根据不同工况下疲劳危险点的名义应力时程,采用雨流计数法和各工况年运行频次调查结果编制疲劳载荷谱.通过Miner损伤累积准则和p-S-N关系对风机桥架进行疲劳损伤分析,给定疲劳破坏的损伤阈值,所得疲劳寿命满足设计使用年限的要求.采用Goodman、Gerber和Soderberg模型考虑平均应力影响时的疲劳寿命略有降低.

  11. Modeling 2m air temperatures over mountain glaciers: Exploring the influence of katabatic cooling and external warming

    OpenAIRE

    Ayala, A.; Pellicciotti, Francesca; J. M. Shea

    2015-01-01

    Air temperature is one of the most relevant input variables for snow and ice melt calculations. However, local meteorological conditions, complex topography, and logistical concerns in glacierized regions make the measuring and modeling of air temperature a difficult task. In this study, we investigate the spatial distribution of 2 m air temperature over mountain glaciers and propose a modification to an existing model to improve its representation. Spatially distributed meteorological data f...

  12. Energy conservation on large air-conditioned buildings: use of evaporative roof cooling in hot and dry climates

    Energy Technology Data Exchange (ETDEWEB)

    Sodha, M.S.; Sawhney, R.L.; Deshmukh, M.K.

    Energy conservation potential of the evaporative roof cooling technique for a cinema house in a composite climate (characterized by Delhi) has been evaluated. Thermal loads due to heat conduction through the building envelope, the required ventilation and the occupants have been taken into account. Life-cycle-cost analysis has been employed to evaluate the cost effectiveness of this energy conservation technique. It is seen that evaporative cooling on the roof leads to a net saving of 14% in the initial investment and 17% in the annual cost.

  13. The numerical analysis of natural convective heat transfer around a pin-fin of air cooling module for electronic packaging applications

    International Nuclear Information System (INIS)

    In present study, the natural convective heat transfer around a pin-fin of an air cooling module for electronic devices was numerically analyzed with change of pin-fin shapes. The cross-sectional shape of the pin-fin was changed from the square(the reference shape) to the long rectangle with same cross-sectional area and height. The Nusselt numbers of outside surfaces of the pin-fin array was much higher than those of the inside surfaces. Of six case tests, the rectangle pin-fin which its aspect ratio was 2.56 had the best heat transfer performance.

  14. Pressure drop and heat transfer in the sodium to air heat exchanger tube banks on advanced sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    A numerical study was performed to investigate the thermal and hydraulic characteristics and build up design model of the AHX (sodium-to-air heat exchanger) unit of a sodium-cooled fast reactor. Helical-coiled tube banks in the AHX were modeled as porous media and simulated heat and momentum transfer. Two-dimensional flow characteristic appeared at the most region of AHX annulus. Pressure drop and heat transfer coefficient for rectangular, parallelogram and staggered tube banks as the main components of the AHX were evaluated and compared with Zhukauskas empirical correlations. (author)

  15. Radiation dose contribution from coal-slag from the Ajka region used as structural building material

    Energy Technology Data Exchange (ETDEWEB)

    Somali, J.; Kanyar, B.; Lendvai, Z.; Nemeth, C.; Bodnar, R. [Veszpremi Egyetem, Veszprem (Hungary). Radiokemia Tanszek

    1997-10-01

    A significant dose contribution on the population could be derived from coal slags used as material in buildings. Extremely high natural activities are measured in the coal slag from the region of Ajka, Hungary. The main conclusions based on the results of the monitoring of the gamma-dose rate and the radon concentration in the air in nearly 240 houses are as follows: (1) for individuals, such as children, spending a long time at home (19.2 h/day) the external annual dose is 1.7-4.5 mSv; (2) in the majority of houses with local slag the estimated annual average value of indoor-radon concentration was above 400 Bq/m{sup 3}, and in several cases there were buildings with values over 1200 Bq/m{sup 3}. In these cases the internal annual dose of the dwellers can be estimated between 6-20 mSv; (3) due to the elevated gamma-exposure and the radon concentration in the dwellings the total annual dose was estimated as 8-24 mSv, more than 5-10 times the world average value; and (4) some of the houses were built after the 1960s, when the use of slags from the region of Ajka as building material was already banned by the authorities. In addition to the regulations an effective radiological control should be introduced and a practice for testing the use of slag as building material.

  16. Study of Air Filters in Evaporative Cooling Ventilation and Air-conditioning Unit Used in Power Plants%发电厂蒸发冷却通风空调机组空气过滤器的探讨

    Institute of Scientific and Technical Information of China (English)

    张鑫; 黄翔; 董晓杰

    2015-01-01

    通过对空气过滤器过滤机理、过滤材料以及分类的介绍,并根据蒸发冷却通风空调机组在发电厂中的应用现状,阐释了科学合理选用空气过滤器的重要性。提出为了减缓室外环境中污染物对直接(间接)蒸发冷却器换热性能的影响,应正确选择空气过滤器的类别和级数。%The air filtration theory, air filtration material and classification of air filters are introduced. Based on the current situation of evaporative cooling ventilation and air-conditioning unit used in power plants, these give a explanation of the importance of choose air filters scientifically. In order to slow the effect of evaporative cooler’s heat exchange performance by pollutant in outdoor, the classification and stage of air filters should choose correctly.

  17. Selective Precipitation and Concentrating of Perovskite Crystals from Titanium-Bearing Slag Melt in Supergravity Field

    Science.gov (United States)

    Gao, Jintao; Zhong, Yiwei; Guo, Zhancheng

    2016-08-01

    Selective precipitation and concentrating of perovskite crystals from titanium-bearing slag melt in the supergravity field was investigated in this study. Since perovskite was the first precipitated phase from the slag melt during the cooling process, and a greater precipitation quantity and larger crystal sizes of perovskite were obtained at 1593 K to 1563 K (1320 °C to 1290 °C), concentrating of perovskite crystals from the slag melt was carried out at this temperature range in the supergravity field, at which the perovskite transforms into solid particles while the other minerals remain in the liquid melt. The layered structures appeared significantly in the sample obtained by supergravity treatment, and all the perovskite crystals moved along the supergravity direction and concentrated as the perovskite-rich phase in the bottom area, whereas the molten slag concentrated in the upper area along the opposite direction, in which it was impossible to find any perovskite crystals. With the gravity coefficient of G = 750, the mass fraction of TiO2 in the perovskite-rich phase was up to 34.65 wt pct, whereas that of the slag phase was decreased to 12.23 wt pct, and the recovery ratio of Ti in the perovskite-rich phase was up to 75.28 pct. On this basis, an amplification experimental centrifugal apparatus was exploited and the continuous experiment with larger scale was further carried out, the results confirming that selective precipitation and concentrating of perovskite crystals from the titanium-bearing slag melt by supergravity was a feasible method.

  18. 冰蓄冷技术应用于燃气轮发电机进气冷却%Economic and Technology Analysis of Application of Ice Thermal Storage Technology to Inlet-air of Gas-turbine Cooling

    Institute of Scientific and Technical Information of China (English)

    曾淼; 叶水泉; 董兴杰; 陈永林

    2002-01-01

    Gas-turbine is constant flow engine, its power is direct proportion of air mass flow. Reducing the inlet-airtemperature will increase the output of gas-turbine. This paper analyzed the feasibility of the application of ice-thernal storagetechnology to inlet-air of gas-turbine cooling. It concludes that this application is feasible on both technology and economicsides.

  19. Settling of copper drops in molten slags

    Science.gov (United States)

    Warczok, A.; Utigard, T. A.

    1995-02-01

    The settling of suspended metal and sulfide droplets in liquid metallurgical, slags can be affected by electric fields. The migration of droplets due to electrocapillary motion phenomena may be used to enhance the recovery of suspended matte/metal droplets and thereby to increase the recovery of pay metals. An experimental technique was developed for the purpose of measuring the effect of electric fields on the settling rate of metallic drops in liquid slags. Copper drops suspended in CaO-SiO2-Al2O3-Cu2O slags were found to migrate toward the cathode. Electric fields can increase the settling rate of 5-mm-diameter copper drops 3 times or decrease the settling until levitation by reversal of the electric field. The enhanced settling due to electric fields decreases with increasing Cu2O contents in the slag.

  20. Electroreduction Kinetics for Molten Oxide Slags

    Institute of Scientific and Technical Information of China (English)

    GAO Yun-ming; CHOU Kuo-chih; GUO Xing-min; WANG Wei

    2007-01-01

    The oxygen-ion conductor, the reducing agent, and the molten oxide slag containing electroactive matter were used as constituent of a galvanic cell. Metal was directly electroreduced from molten slag using a short-circuit galvanic cell. The following galvanic cell was assembled in the present experiment: graphite rod, [O]Fe-C saturated|ZrO2(MgO)|Cu(l)+(FeO)(slag), and molybdenum wire. The FeO electroreduction reaction was studied through measuring short circuit current by controlling factors such as temperature, the FeO content in molten slags, and the external circuit resistance. An overall kinetics model was developed to describe the process of FeO electroreduction. It was found that the modeled curves were in good agreement with the experimental values. The new oxide reduction method in the metallurgy with controlled oxygen flow was proposed and the metallurgical theory with controlled oxygen flow was developed.

  1. Dissolution of alumina in stainless steelmaking slags

    Energy Technology Data Exchange (ETDEWEB)

    Divakar, M.; Lahiri, A.K. [Indian Inst. of Science, Bangalore (India). Dept. of Metallurgy; Goernerup, M. [Uddeholm Technology AB (Sweden)

    2001-02-01

    Dissolution of alumina in stainless steelmaking slags was studied by conducting laboratory scale experiments on typical slags in the temperature range 1823-1923 K. The mechanism of dissolution was studied under the actual steelmaking conditions where several phenomena such as simultaneous reduction of chromium, iron and vanadium oxides by carbon, in-situ gas generated due to the reduction, foam/emulsion formation occur. The kinetics of alumina dissolution are studied under the influence of the above mentioned phenomena. (orig.)

  2. The use of blast furnace slag

    OpenAIRE

    Václavík, Vojtěch; Dirner, Vojtech; Dvorský, Tomáš; Daxner, J.

    2012-01-01

    The paper presents the results of experimental research that dealt with the substitution of fi nely ground blast furnace slag for Portland cement in the course of simple concrete manufacturing. Physical and mechanical properties of experimental concrete mixtures based on fi nely ground blast furnace slag were observed. Rad predstavlja rezultate eksperimentalnog istraživanja koja se bave mogućnostima primjene fi nozrnate troske iz visoke peći za Portland cement u jednostavnoj proiz...

  3. Sulfide capacities of fayalite-base slags

    Science.gov (United States)

    Simeonov, S. R.; Sridhar, R.; Toguri, J. M.

    1995-04-01

    The sulfide capacities of fayalite-base slags were measured by a gas-slag equilibration technique under controlled oxygen and sulfur potentials similar to those encountered in the pyrometallurgical processing of nonferrous metals. The oxygen pressure range was from 10-9.5 to 10-11 MPa and the sulfur pressure range from 10-3 to 10-4.5 MPa, over a temperature range of 1473 to 1623 K. The slags studied were FeO-SiO2 at silica saturation and those with addition of CaO, MgO, and Al2O3 to determine their effect on sulfide capacities. For these slags, the sulfide capacities were found to vary from 10-3.3 to 10-5. The sulfide capacities increased with increasing temperature from 1473 to 1623 K. A comparison of the reported plant data on sulfur content of industrial slags shows good agreement with the present experimental results. The present data will be useful in estimating metal losses in slag due to metal sulfide entrainment in nonferrous smelters.

  4. Calculation of sulfide capacities of multicomponent slags

    Science.gov (United States)

    Pelton, Arthur D.; Eriksson, Gunnar; Romero-Serrano, Antonio

    1993-10-01

    The Reddy-Blander model for the sulfide capacities of slags has been modified for the case of acid slags and to include A12O3 and TiO2 as components. The model has been extended to calculate a priori sulfide capacities of multicomponent slags, from a knowledge of the thermodynamic activities of the component oxides, with no adjustable parameters. Agreement with measurements is obtained within experimental uncertainty for binary, ternary, and quinary slags involving the components SiO2-Al2O3-TiO2-CaO-MgO-FeO-MnO over wide ranges of composition. The oxide activities used in the computations are calculated from a database of model parameters obtained by optimizing thermodynamic and phase equilibrium data for oxide systems. Sulfur has now been included in this database. A computing system with automatic access to this and other databases has been developed to permit the calculation of the sulfur content of slags in multicomponent slag/metal/gas/solid equilibria.

  5. Theoretical analysis of the performance of different cooling strategies with the concept of cool exergy

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    for the ventilation system being outdoor air vs. air from the crawl-space, and air-to-water heat pump vs. ground heat exchanger as cooling source) on system exergy performance were investigated. It is crucial to minimize the cooling demand because it is possible to use a wide range of heat sinks (ground, lake, sea-water......The whole chains of exergy flows for different cooling systems were compared. The effects of cooling demand (internal vs. external solar shading), space cooling method (floor cooling vs. air cooling with ventilation system), and the availability of a nearby natural heat sink (intake air......, etc.) and indoor terminal units, only with a minimized demand. The water-based floor cooling system performed better than the air-based cooling system; when an air-to-water heat pump was used as the cooling source, the required exergy input was 28% smaller for the floor cooling system. The auxiliary...

  6. Development of Fine-Grained, Low-Carbon Bainitic Steels with High Strength and Toughness Produced Through the Conventional Hot-Rolling and Air-Cooling

    Science.gov (United States)

    Dhua, Sanjay Kumar; Sarkar, Partha Pratim; Saxena, Atul; Jha, Bimal Kumar

    2016-09-01

    Low-carbon bainitic steels have created enormous interest among scientists across the world in the past few decades because of their high strength, toughness, and weldability replacing the conventional quenched and tempered medium-carbon steels. Three experimental steels with varying alloy additions were made in a 100-kg laboratory induction furnace and cast into 100-mm-diameter cylindrical ingots. These ingots were hot-rolled and air-cooled to 6-mm plates in an experimental rolling mill with selected thermomechanical parameters. Steels processed through this process provided an ultrafine low-carbon bainitic microstructure with maximum yield strength (YS) and ultimate tensile strength (UTS) 575 and 705 MPa, respectively. The Charpy impact toughness of the experimental steels was excellent, and at 253 K (-20 °C), it varied from 114 to 170 Joules. Cu-B-added steel was found to give an optimum combination of strength, YS-575 MPa, and toughness, 114 J at 253 K (-20 °C). Thus, fine-grained, low-carbon bainitic steels could be developed with a proper combination of alloying elements and thermomechanical parameters even by air-cooling.

  7. The evaporative cooling air conditioning system comfort%浅谈蒸发冷却空调系统的舒适性

    Institute of Scientific and Technical Information of China (English)

    丁秀娟

    2014-01-01

    This paper introduces the influence of temperature,humidity,wind speed on human thermal comfort,and gives three kinds of factors on the coef icient of thermal comfort of human body,that the humidity and wind speed for evaporative cooling air conditioning system influence on thermal comfort is,in contrast to the proper occasion but made up for the evaporation cooling air conditioning system of high humidity,high wind speed defect.%本文介绍了温度,湿度,风速对人体热舒适的影响,并给出三种因素对人体热舒适的影响系数,认为湿度和风速对于蒸发冷却空调系统来说对热舒适的影响不大,相反在适当的场合反而弥补了蒸发冷却空调系统湿度较高,风速过大的缺陷。

  8. Design Report for the ½ Scale Air-Cooled RCCS Tests in the Natural convection Shutdown heat removal Test Facility (NSTF)

    Energy Technology Data Exchange (ETDEWEB)

    Lisowski, D. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Farmer, M. T. [Argonne National Lab. (ANL), Argonne, IL (United States); Lomperski, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Kilsdonk, D. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Bremer, N. [Argonne National Lab. (ANL), Argonne, IL (United States); Aeschlimann, R. W. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-06-01

    The Natural convection Shutdown heat removal Test Facility (NSTF) is a large scale thermal hydraulics test facility that has been built at Argonne National Laboratory (ANL). The facility was constructed in order to carry out highly instrumented experiments that can be used to validate the performance of passive safety systems for advanced reactor designs. The facility has principally been designed for testing of Reactor Cavity Cooling System (RCCS) concepts that rely on natural convection cooling for either air or water-based systems. Standing 25-m in height, the facility is able to supply up to 220 kW at 21 kW/m2 to accurately simulate the heat fluxes at the walls of a reactor pressure vessel. A suite of nearly 400 data acquisition channels, including a sophisticated fiber optic system for high density temperature measurements, guides test operations and provides data to support scaling analysis and modeling efforts. Measurements of system mass flow rate, air and surface temperatures, heat flux, humidity, and pressure differentials, among others; are part of this total generated data set. The following report provides an introduction to the top level-objectives of the program related to passively safe decay heat removal, a detailed description of the engineering specifications, design features, and dimensions of the test facility at Argonne. Specifications of the sensors and their placement on the test facility will be provided, along with a complete channel listing of the data acquisition system.

  9. Acid slag injection into the blast furnace tuyere zone

    Energy Technology Data Exchange (ETDEWEB)

    Haerkki, J.; Tervola, K. [Oulu Univ. (Finland). Dept. of Process Engineering

    1996-12-31

    The possibility of acid slag injection and its effect on the slag formation and on the melting behaviour of the charge materials are studied in the present work. The work is partly based on the literature evaluating the slag formation, slag properties and the basic slag injection. The possibility of acid slag injection is first examined by studying changes in the composition of the primary slag if the share of the acid slag component (Kostamus pellet/RR) of the charge material is lowered. Phase diagrams and viscosity charts are used to evaluate the viscosity, and solidus/liquidus temperature in the slag phase. The share of the slag phase of the pellet is evaluated by calculating the amount of the acid slag injection. The injection rate of some injectants is also examined. The primary slag formed of the sinter and the coke ash is in liquid form and its viscosity is close to the viscosity of the blast furnace slag. It is possible that the liquid slag phase can be formed in the blast furnace without the presence of the acid pellet because the melting point and the viscosity of the slag is lowered by alkalies, sulfur and the dissolved ironoxide of the slag. If high SiO{sub 2} content materials alone are used for injection there is a risk that the slag phase of the tuyere zone becomes too viscous. Olivine and some iron containing components such as fayalite are possible injection material. More information is needed to evaluate the effect of acid slag injection on the operation of the blast furnace. (orig.) SULA 2 Research Programme; 2 refs.

  10. Tool for Forecasting Cool-Season Peak Winds Across Kennedy Space Center and Cape Canaveral Air Force Station

    Science.gov (United States)

    Barrett, Joe H., III; Roeder, William P.

    2010-01-01

    The expected peak wind speed for the day is an important element in the daily morning forecast for ground and space launch operations at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The 45th Weather Squadron (45 WS) must issue forecast advisories for KSC/CCAFS when they expect peak gusts for >= 25, >= 35, and >= 50 kt thresholds at any level from the surface to 300 ft. In Phase I of this task, the 45 WS tasked the Applied Meteorology Unit (AMU) to develop a cool-season (October - April) tool to help forecast the non-convective peak wind from the surface to 300 ft at KSC/CCAFS. During the warm season, these wind speeds are rarely exceeded except during convective winds or under the influence of tropical cyclones, for which other techniques are already in use. The tool used single and multiple linear regression equations to predict the peak wind from the morning sounding. The forecaster manually entered several observed sounding parameters into a Microsoft Excel graphical user interface (GUI), and then the tool displayed the forecast peak wind speed, average wind speed at the time of the peak wind, the timing of the peak wind and the probability the peak wind will meet or exceed 35, 50 and 60 kt. The 45 WS customers later dropped the requirement for >= 60 kt wind warnings. During Phase II of this task, the AMU expanded the period of record (POR) by six years to increase the number of observations used to create the forecast equations. A large number of possible predictors were evaluated from archived soundings, including inversion depth and strength, low-level wind shear, mixing height, temperature lapse rate and winds from the surface to 3000 ft. Each day in the POR was stratified in a number of ways, such as by low-level wind direction, synoptic weather pattern, precipitation and Bulk Richardson number. The most accurate Phase II equations were then selected for an independent verification. The Phase I and II forecast methods were

  11. Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins

    International Nuclear Information System (INIS)

    The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial

  12. Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, S.G.; Kreid, D.K.; Johnson, B.M.

    1981-01-01

    The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial.

  13. 发电厂直接空冷凝汽器的新型防冻监测系统设计%Design of Novel Anti-freezing Monitoring System for Direct Air Cooled Condenser in Power Plant

    Institute of Scientific and Technical Information of China (English)

    国建刚; 贾杰; 田振宇

    2014-01-01

    This paper analyzes tube bundle structure of A-type tower and its operating principle in direct air cooled condenser; it indicates that the lower end of downstream tube buddle is easier to freeze than that of upstream tube buddle in air cooled condenser. The utilization of temperature field online monitoring system of A-type tower tube bundles in direct air cooled condenser can effectively monitor freezing of air cooled con-denser. Finally, this paper expounds design and implementation scheme of temperature field online monitoring system of A-type tube bundles in direct air cooled condenser.%对直接空冷凝汽器A型塔管束结构及工作原理进行了分析,指出空冷凝汽器顺流管束的下端比逆流管束更容易结冰。采用空冷凝汽器温度场在线监测系统,可以有效监测空冷凝汽器冻结问题的发生,详细介绍了在线监测系统的设计方案。

  14. Fly ash, basic slag and Glenbrook slag toxicity in cattle

    Energy Technology Data Exchange (ETDEWEB)

    Dewes, H.F.; McLeay, L.M.; Harfoot, C.G.

    1995-06-01

    In case studies of two herds of dairy cattle, a herd of 270 Friesian cows and heifers and a herd of 256 Jersey cows and heifers experienced high death rates and a protracted course of illness when fly ash was broadcast as a fertiliser over the farms at a rate of about 1 tonne per hectare. The onset of weakness, lassitude and diarrhoea in the cattle first appeared within 4-5 days and both fertility and milk fat production fell off dramatically. In the following 7 months, 51 animals died in the Friesian herd and a similar death rate and performance losses occurred in the Jersey herd. Emaciation and hepatic fibrosis were consistently reported from autopsies. Heavy metal poisoning was eliminated from the possible diagnosis. The slags and fly ash used as fertiliser had several features in common. They contained 29-40% calcium as calcium oxide, 15-35 grams of iron per kg, they were all extremely alkaline and concentrations of lead and arsenic were low. The effect of adding fly ash to rumen contents in vitro was to raise the pH to greater than 7.2, at which point fermentation was markedly reduced.

  15. Decalcification resistance of alkali-activated slag

    Energy Technology Data Exchange (ETDEWEB)

    Komljenovic, Miroslav M., E-mail: miroslav.komljenovic@imsi.rs [Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030 Belgrade (Serbia); Bascarevic, Zvezdana, E-mail: zvezdana@imsi.bg.ac.rs [Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030 Belgrade (Serbia); Marjanovic, Natasa, E-mail: natasa@imsi.bg.ac.rs [Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030 Belgrade (Serbia); Nikolic, Violeta, E-mail: violeta@imsi.bg.ac.rs [Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030 Belgrade (Serbia)

    2012-09-30

    Highlights: Black-Right-Pointing-Pointer The effects of decalcification on properties of alkali-activated slag were studied. Black-Right-Pointing-Pointer Decalcification was performed by concentrated NH{sub 4}NO{sub 3} solution (accelerated test). Black-Right-Pointing-Pointer Portland-slag cement (CEM II/A-S 42.5 N) was used as a benchmark material. Black-Right-Pointing-Pointer Decalcification led to strength decrease and noticeable structural changes. Black-Right-Pointing-Pointer Alkali-activated slag showed significantly higher resistance to decalcification. - Abstract: This paper analyses the effects of decalcification in concentrated 6 M NH{sub 4}NO{sub 3} solution on mechanical and microstructural properties of alkali-activated slag (AAS). Portland-slag cement (CEM II/A-S 42.5 N) was used as a benchmark material. Decalcification process led to a decrease in strength, both in AAS and in CEM II, and this effect was more pronounced in CEM II. The decrease in strength was explicitly related to the decrease in Ca/Si atomic ratio of C-S-H gel. A very low ratio of Ca/Si {approx}0.3 in AAS was the consequence of coexistence of C-S-H(I) gel and silica gel. During decalcification of AAS almost complete leaching of sodium and tetrahedral aluminum from C-S-H(I) gel also took place. AAS showed significantly higher resistance to decalcification in relation to the benchmark CEM II due to the absence of portlandite, high level of polymerization of silicate chains, low level of aluminum for silicon substitution in the structure of C-S-H(I), and the formation of protective layer of polymerized silica gel during decalcification process. In stabilization/solidification processes alkali-activated slag represents a more promising solution than Portland-slag cement due to significantly higher resistance to decalcification.

  16. Application of aggregate air-cooling system in concrete production of lock%骨料风冷系统在船闸混凝土生产中的应用

    Institute of Scientific and Technical Information of China (English)

    涂伟成; 丁碧珍; 蒋华东; 刘松

    2015-01-01

    在富春江船闸扩建改造工程风冷系统实际施工过程中,对粗骨料、拌合水、混凝土出机口温度以及浇筑温度进行实时监测,研究风冷骨料及制冷水系统的冷却能力,以指导后期施工。%According to the actual construction process of air cooling system of the Fuchun river lock expansion and improving project,through the real-time monitoring of coarse aggregate,mixing water,the concrete mixer outlet temperature and pouring temperature,this article gives a comprehensive study on the cooling capacity of the air-cooling aggregate and its cooling water system,to provide guidance for the later construction.

  17. Cooled snubber structure for turbine blades

    Science.gov (United States)

    Mayer, Clinton A; Campbell, Christian X; Whalley, Andrew; Marra, John J

    2014-04-01

    A turbine blade assembly in a turbine engine. The turbine blade assembly includes a turbine blade and a first snubber structure. The turbine blade includes an internal cooling passage containing cooling air. The first snubber structure extends outwardly from a sidewall of the turbine blade and includes a hollow interior portion that receives cooling air from the internal cooling passage of the turbine blade.

  18. Heat pump control method based on direct measurement of evaporation pressure to improve energy efficiency and indoor air temperature stability at a low cooling load condition

    International Nuclear Information System (INIS)

    Highlights: • New heat pump control method was developed. • Experimental investigation on performance of heat pump with various control method. • New control method appeared to improve the stability of indoor air temperature. • New control method appeared to have a potential to reduce power consumption. - Abstract: The control systems of conventional heat pumps have an input of refrigerant temperature at the evaporator outlet to maintain superheat at proper level. In order to develop a control method that can be used to achieve better indoor thermal comfort and energy efficiency at a low cooling load condition than the current control method, a new method of the evaporation pressure control based on the evaporator outlet pressure reading (EPCP) was developed. The changes in the stability of indoor air temperature and power consumption were measured while changing the compressor frequency in accordance with the new control method. Compared with the evaporation pressure control based on the evaporator outlet temperature reading, the EPCP control method appeared to improve the stability of room air temperature or occupant thermal comfort significantly

  19. DOAS, Radiant Cooling Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Hastbacka, Mildred; Dieckmann, John; Bouza, Antonio

    2012-12-01

    The article discusses dedicated outdoor air systems (DOAS) and radiant cooling technologies. Both of these topics were covered in previous ASHRAE Journal columns. This article reviews the technologies and their increasing acceptance. The two steps that ASHRAE is taking to disseminate DOAS information to the design community, available energy savings and the market potential of radiant cooling systems are addressed as well.

  20. 火电机组直接空冷系统优化设计方法研究%Optimal Design Method of Direct Air-cooling System for Thermal Power Plants

    Institute of Scientific and Technical Information of China (English)

    张晓鲁; 汪建平; 孙锐; 董建勋; 詹扬; 柴靖宇

    2011-01-01

    与采用湿冷系统相比,火电机组采用空冷系统将增加工程投资和运行费用.对空冷系统进行优化设计十分重要,可提高空冷机组的整体经济性.该文提出了基于年费用最小的直接空冷系统优化设计方法,对设计气温、初始温差(initial temperature difference,ITD)等参数的选择、空冷凝汽器管型、空冷风机等选型及系统热力计算、空气阻力计算等进行了分析和讨论.以直接空冷系统国产化示范工程600MW火电机组空冷系统为例说明了该方法的应用.该方法已应用于36台300和600 MW火电机组国产化直接空冷系统的设计,并被采纳用于编制国家有关设计标准.%Thermal power plants using air-cooling system increase project capital investment and operating costs compared to those using water-cooling system, so the optimal design of the air-cooling system is very important and can improve the overall economics of the air-cooling power plants. The optimal design method of direct air-cooling system was proposed based on minimizing the annual expenses. The selection of the design temperature, initial temperature difference (ITD), the air cooler tube type and air cooling fan, the calculation of heat transfer and air resistance were analyzed and discussed. The direct air-cooling system of one 600 MW thermal unit as the localization demonstration project was used as an example to illustrate the application of the optimal design method. The method has been applied to direct air-cooling system design of 36 300 MW and 600 MW domestic thermal units, and is incorporated into the relevant national design standards.

  1. Osmundiron, cleaved iron bars and slags (Osmundjern, kloder og kalotslagger)

    DEFF Research Database (Denmark)

    Buchwald, Vagn Fabritius

    1996-01-01

    Investigation of so-called Osmund iron, iron bars and slags from iron production in the medieval ages.......Investigation of so-called Osmund iron, iron bars and slags from iron production in the medieval ages....

  2. The impact of different cooling strategies on urban air temperatures: the cases of Campinas, Brazil and Mendoza, Argentina

    Science.gov (United States)

    Alchapar, Noelia Liliana; Cotrim Pezzuto, Claudia; Correa, Erica Norma; Chebel Labaki, Lucila

    2016-07-01

    This paper describes different ways of reducing urban air temperature and their results in two cities: Campinas, Brazil—a warm temperate climate with a dry winter and hot summer (Cwa), and Mendoza, Argentina—a desert climate with cold steppe (BWk). A high-resolution microclimate modeling system—ENVI-met 3.1—was used to evaluate the thermal performance of an urban canyon in each city. A total of 18 scenarios were simulated including changes in the surface albedo, vegetation percentage, and the H/W aspect ratio of the urban canyons. These results revealed the same trend in behavior for each of the combinations of strategies evaluated in both cities. Nevertheless, these strategies produce a greater temperature reduction in the warm temperate climate (Cwa). Increasing the vegetation percentage reduces air temperatures and mean radiant temperatures in all scenarios. In addition, there is a greater decrease of urban temperature with the vegetation increase when the H/W aspect ratio is lower. Also, applying low albedo on vertical surfaces and high albedo on horizontal surfaces is successful in reducing air temperatures without raising the mean radiant temperature. The best combination of strategies—60 % of vegetation, low albedos on walls and high albedos on pavements and roofs, and 1.5 H/W—could reduce air temperatures up to 6.4 °C in Campinas and 3.5 °C in Mendoza.

  3. Ultrasonic methodology measurement of two-phase (air-water) flows in cooling systems of nuclear reactor

    International Nuclear Information System (INIS)

    An ultrasonic methodology is proposed for the measurement for two phase (air-water) flow parameters. Ultrasonic backscattered signals were used to analyze the following parameters: average number of bubbles, interfacial area and void fraction. The results show a strong correlation between the parameters and the ultrasonic power signal obtained. (author)

  4. 蒸发冷却空调在水力发电厂的应用分析%Application Analysis of Evaporative Cooling Air Conditioning in the of Hydraulic Power Plant

    Institute of Scientific and Technical Information of China (English)

    许玉忠

    2012-01-01

    This paper introduces the basic principle of evaporative cooling air conditioning,expounds the direct evaporation cooling and indirect evaporative cooling process.Combining the design procedures analyzes the evaporative cooling air conditioning in the advantages of application of hydraulic power plant,and gives the evaporative cooling air conditioning in hydraulic power plants examples of application,explains the operation process and actually using the use effect,and introduces the evaporative cooling technology application in some of the new development of hydropower plant.Evaporative cooling air is conditioning in line with the economy,the green,the energy saving of the low carbon development requirements,and compared to traditional mechanical refrigeration and air conditioning,is more suitable for use in areas of the hydropower station,and has widely application prospect.%本文介绍了蒸发冷却空调的基本原理,阐述了直接蒸发冷却和间接蒸发冷却过程。结合设计规程分析了蒸发冷却空调在水力发电厂应用的优势,给出了蒸发冷却空调在水力发电厂的应用实例,说明了其实用的运行流程及使用效果,并介绍了蒸发冷却技术在水电厂应用的一些新发展。分析得出蒸发冷却空调符合经济、绿色、节能的低碳发展要求,和传统机械制冷空调相比,更适合在适宜地区的水电厂使用,且应用前景广泛。

  5. Process-integrated slag treatment; Prozessintegrierte Schlackebehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Koralewska, R.; Faulstich, M. [Technische Univ., Garching (Germany). Lehrstuhl fuer Wasserguete- und Abfallwirtschaft

    1998-09-01

    The present study compares two methods of washing waste incineration slag, one with water only, and one which uses additives during wet deslagging. The presented aggregate offers ideal conditions for process-integrated slag treatment. The paper gives a schematic description of the integrated slag washing process. The washing liquid serves to wash out the readily soluble constituents and remove the fines, while the additives are for immobilising heavy metals in the slag material. The study is based on laboratory and semi-technical trials on the wet chemical treatment of grate slag with addition of carbon dioxide and phosphoric acid. [Deutsch] Die dargestellten Untersuchungen beziehen sich auf den Vergleich zwischen einer Waesche der Muellverbrennungsschlacke mit Wasser und unter Zugabe von Additiven im Nassentschlacker. In diesem Aggregat bieten sich optimale Voraussetzungen fuer eine prozessintegrierte Schlackebehandlung. Die Durchfuehrung der integrierten Schlackewaesche wird schematisch gezeigt. Durch die Waschfluessigkeit sollen die leichtloeslichen Bestandteile ausgewaschen und die Feinanteile ausgetragen sowie durch die Additive zusaetzlich die Schwermetalle im Schlackematerial immobilisiert werden. Dazu erfolgten Labor- und halbtechnische Versuche zur nasschemischen Behandlung der Rostschlacken unter Zugabe von Kohlendioxid und Phosphorsaeure. (orig./SR)

  6. ENHANCEMENT OF STRUCTURAL FOAM MATERIALS BY INCORPORATION OF GASIFIER SLAG

    Energy Technology Data Exchange (ETDEWEB)

    Olin Perry Norton; Ronald A. Palmer; W. Gene Ramsey

    2006-03-15

    As advanced gasification technology is increasingly adopted as an energy source, disposal of the resulting slag will become a problem. We have shown that gasifier slag can be incorporated into foamed glass, which is currently being manufactured as an abrasive and as an insulating material. The slag we add to foamed glass does not simply act as filler, but improves the mechanical properties of the product. Incorporation of gasifier slag can make foamed glass stronger and more abrasion resistant.

  7. Chromium reduction from slag on electromelting of stainless steel

    International Nuclear Information System (INIS)

    Specific features of chromium reduction from the slag on electromelting of stainless steel type Kh18N10T according to one- or two-slag procedure were studied. It was shown that one-slag melting technology allows double decrease of chromium losses in the form of incompletely reduced oxides. This occurs due to additional chemical reactions between metal and slag on their combined pouring into the ladle. 1 ref.; 3 figs

  8. Exergy analysis of a novel air-cooled non-adiabatic absorption refrigeration cycle with NH3–NaSCN and NH3–LiNO3 refrigerant solutions

    International Nuclear Information System (INIS)

    Graphical abstract: A methodology based on the second law of thermodynamic has been carried out in the analysis of an air-cooled type ammonia/salt absorption refrigeration system. Simulation results show that Low grade energy is applicable for NH3/NaSCN and NH3/LiNO3 absorption refrigeration system under air cooling condition and relatively high exergetic efficiency can be obtained. - Highlights: • We analyze an absorption refrigeration cycle driven by low grade energy. • Modified Methodology in entropy calculation is presented. • New exergy calculation method of ammonia/salt solution is presented. • Exergy analysis under air-cooled condition is carried out. • Influence of non-adiabatic absorber to exergetic efficiency is analyzed. - Abstract: This paper presents a methodology of exergy analysis for ammonia-lithium nitrate and ammonia-sodium thiocyanate absorption refrigeration cycle which applies a novel air-cooled type non-adiabatic absorber to improve both the coefficient of performance and exegetic efficiency of the system under air cooling condition. A modified entropy calculation method for NH3/NaSCN and NH3/LiNO3 solutions is presented in this literature and different results are obtained comparing to previous research. In addition to the variation of solution temperature and pressure from specific working state to the reference state, the variation of solution concentration, which was always neglected by previous researchers in ammonia/salt solution exergy calculation, has been taken into account while analyzing the least potential of ammonia/salt solution for doing useful work, and a corresponding approach for specific exergy calculation is presented. The effects of generator temperature, absorber outlet temperature, absorber efficiency and other system parameters on system exergetic efficiency have been discussed in this study. Analysis results indicate that relatively high system performance can be obtained by air-cooled type ammonia

  9. An Approach to the Integrated Design of PCM-Air Heat Exchangers Based on Numerical Simulation: A Solar Cooling Case Study

    Directory of Open Access Journals (Sweden)

    Pablo Dolado

    2015-10-01

    Full Text Available A novel technique of design of experiments applied to numerical simulations is proposed in this paper as a methodology for the sizing and design of thermal storage equipment integrated in any specific application. The technique is carried out through the response surfaces in order to limit the number of simulation runs required to achieve an appropriate solution. Thus, there are significant savings on the time spent on the design as well as a potential cost saving on the experimentation if similarity relationships between the prototype and the model are met. The technique is applied here to a previously developed and validated numerical model that simulates the thermal behavior of a phase change material-air heat exchanger. The incorporation of the thermal energy storage unit is analyzed in the case of a solar cooling application, improving the system coefficient of performance. The economic viability is mainly conditioned by the price of the macroencapsulated phase change material.

  10. Research on cooling effectiveness in stepped slot film cooling vane

    Science.gov (United States)

    Li, Yulong; Wu, Hong; Zhou, Feng; Rong, Chengjun

    2016-06-01

    As one of the most important developments in air cooling technology for hot parts of the aero-engine, film cooling technology has been widely used. Film cooling hole structure exists mainly in areas that have high temperature, uneven cooling effectiveness issues when in actual use. The first stage turbine vanes of the aero-engine consume the largest portion of cooling air, thereby the research on reducing the amount of cooling air has the greatest potential. A new stepped slot film cooling vane with a high cooling effectiveness and a high cooling uniformity was researched initially. Through numerical methods, the affecting factors of the cooling effectiveness of a vane with the stepped slot film cooling structure were researched. This paper focuses on the cooling effectiveness and the pressure loss in different blowing ratio conditions, then the most reasonable and scientific structure parameter can be obtained by analyzing the results. The results show that 1.0 mm is the optimum slot width and 10.0 is the most reasonable blowing ratio. Under this condition, the vane achieved the best cooling result and the highest cooling effectiveness, and also retained a low pressure loss.

  11. Study on natural convection heat transfer in a vertical enclosure of double coaxial cylinder. Cooling by natural circulation of air

    International Nuclear Information System (INIS)

    To investigate a heat transfer characteristic in a vertical cavity between the pressure vessel and the cooling panel of a high-temperature engineering test reactor (HTTR), we carried out an experiment of natural convection coupled with thermal radiation in a vertical enclosure of a double coaxial cylinder. Rayleigh number based on the width of the double coaxial cylinder was set to be 5.6x105 d 8. A heat transfer coefficient of natural convection coupled with thermal radiation was obtained as function of Rayleigh number, aspect ratio of the enclosure, and the temperature of the hot and cold surface. We also carried out the numerical analysis using a heat transfer and fluid flow analytical code, which is named FLUENT/UNS. The numerical results of the temperature distribution in the apparatus showed good agreement with the experimental ones. (J.P.N.)

  12. Study on natural convection heat transfer in a vertical enclosure of double coaxial cylinder. Cooling by natural circulation of air

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Youjie [Institute on Nuclear Energy Technology, Tsinghua Univ., Beijing (China); Takeda, Tetsuaki; Inaba, Yoshitomo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    2000-11-01

    To investigate a heat transfer characteristic in a vertical cavity between the pressure vessel and the cooling panel of a high-temperature engineering test reactor (HTTR), we carried out an experiment of natural convection coupled with thermal radiation in a vertical enclosure of a double coaxial cylinder. Rayleigh number based on the width of the double coaxial cylinder was set to be 5.6x10{sup 5} < Ra{sub d} < 1.04x10{sup 8}. A heat transfer coefficient of natural convection coupled with thermal radiation was obtained as function of Rayleigh number, aspect ratio of the enclosure, and the temperature of the hot and cold surface. We also carried out the numerical analysis using a heat transfer and fluid flow analytical code, which is named FLUENT/UNS. The numerical results of the temperature distribution in the apparatus showed good agreement with the experimental ones. (J.P.N.)

  13. Performance and evaluation of gas-engine-driven split-system cooling equipment at the Willow Grove Naval Air Station

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, P.R.; Schmelzer, J.R.

    1997-01-01

    DOE`s Federal Energy Management Program supports efforts to reduce energy use and associated expenditures within the federal sector; one such effort, the New Technology Demonstration Program (NTDP)(formerly the Test Bed Demonstration program), seeks to evaluate new energy saving US technologies and secure their more timely adoption by the federal government. This report describes the field evaluation conducted to examine the performance of a 15-ton natural-gas-engine- driven, split-system, air-conditioning unit. The unit was installed at a multiple-use building at Willow Grove Naval Air Station, a regular and reserve training facility north of Philadelphia, and its performance was monitored under the NTDP.

  14. The Selection of Water Switch in the Water-cooled Air conditioner%水冷空调中水流开关的选用

    Institute of Scientific and Technical Information of China (English)

    王彦川; 王晨光

    2015-01-01

    With the increasing of large and medium public buildings, the water system air conditioning solution is widely used in centralized HVAC buildings, due to its bigger cooling capacity and higher EER. As the necessary com-ponents on water cooled equipment, the use and selection of water switches is in a tremendous difference, due to the various awareness from different manufacturers. Through the deeply analysis and summary about water switch’s op-erating status, this paper will sum up a professional method for selection.%随着大中型公共建筑的越来越多,水冷空调因其较大的制冷量和较高的能效比,被人们广泛应用在集中式暖通建筑上。水流开关作为水冷空调上必备的元器件,其使用及选型原则因空调设备生产厂家的理解而千差万别,本文通过对水流开关运行状态的实际分析和总结,归纳出一种较为科学的水流开关选用方法。

  15. Evaluation of an Absorption Heat Pump to Mitigate Plant Capacity Reduction Due to Ambient Temperature Rise for an Air-Cooled Ammonia and Water Cycle: Preprint

    International Nuclear Information System (INIS)

    Air-cooled geothermal plants suffer substantial decreases in generating capacity at increased ambient temperatures. As the ambient temperature rises by 50 F above a design value of 50 F, at low brine-resource temperatures, the decrease in generating capacity can be more than 50%. This decrease is caused primarily by increased condenser pressure. Using mixed-working fluids has recently drawn considerable attention for use in power cycles. Such cycles are more readily amenable to use of absorption ''heat pumps.'' For a system that uses ammonia and water as the mixed-working fluid, this paper evaluates using an absorption heat pump to reduce condenser backpressure. At high ambient temperatures, part of the turbine exhaust vapor is absorbed into a circulating mixed stream in an absorber in series with the main condenser. This steam is pumped up to a higher pressure and heated to strip the excess vapor, which is recondensed using an additional air-cooled condenser. The operating conditions are chosen to reconstitute this condensate back to the same concentration as drawn from the original system. We analyzed two power plants of nominal 1-megawatt capacity. The design resource temperatures were 250 F and 300 F. Ambient temperature was allowed to rise from a design value of 50 F to 100 F. The analyses indicate that using an absorption heat pump is feasible. For the 300 F resource, an increased brine flow of 30% resulted in a net power increase of 21%. For the 250 F resource, the increase was smaller. However, these results are highly plant- and equipment-specific because evaluations must be carried out at off-design conditions for the condenser. Such studies should be carried out for specific power plants that suffer most from increased ambient temperatures

  16. Non-isothermal Crystallization Kinetics of Spinels in Vanadium Slag with High CaO Content

    Science.gov (United States)

    Zhou, Wang; Xie, Bing; Tan, Wen-Feng; Diao, Jiang; Zhang, Xie; Li, Hong-Yi

    2016-09-01

    This paper investigated the non-isothermal crystallization kinetics of the spinel crystals in vanadium slags containing high CaO content. Experiments were performed in combination with theoretical calculation to address this issue, and statistical analyses based on the Crystal Size Distribution theory. The results indicate that low cooling rate and high CaO content benefit the growth of spinel crystals. The growth mechanism is revealed to be controlled by interface reactions and diffusion at the cooling rates of 5 K/min and 15 K/min, respectively. However, at higher temperatures (>1673 K), the growth of spinel crystals is controlled by nucleation. While the temperature is decreased to 1523 K at the cooling rate of 5 K/min, the mean diameter of spinel crystals could reach 36.44 μm. Experimental results combining with theoretical reveal that low cooling rate benefits spinels growth, especially for the interval of 1523 K-1200 K.

  17. Investigation of the Freeze-Lining Formed in an Industrial Copper Converting Calcium Ferrite Slag

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Jansson, Jani; Taskinen, Pekka; Hayes, Peter C.; Jak, Evgueni

    2014-06-01

    Pyrometallurgical coppermaking processes are operated under intensive reaction conditions; high process temperatures and vigorous bath agitation is used to increase the kinetics of reactions and to achieve high smelter throughput. Slag freeze-lining reactor wall protection is a widely used technology in coppermaking processes, such as flash smelting and converting reactors. Freeze-linings mitigate and resist the effects of thermal and chemical attack by aggressive slags. In this laboratory-based study, a water-cooled probe "cold finger" technique has been used to investigate freeze-lining formation with calcium ferrite slags in equilibrium with metallic copper; the slag composition reflects that used in the industrial copper flash converting furnace of Rio Tinto—Kennecott Utah Copper. The effects of probe immersion times on the thickness and microstructures in the freeze-lining deposits have been investigated. A range of complex oxide solutions and copper-containing phases have been found in the deposits. The phase assemblages formed from the industrial calcium ferrite slag in the steady-state deposit are very complex and information on the phase equilibria of the multi-component systems with addition of minor elements may not be available. Subsolidus and subliquidus phase equilibria in the Cu-Ca-Fe-O system at metallic copper saturation along with interpolated temperature across the deposit, microstructural changes and compositional trends in the phases in the deposit have been used to understand the formation and characteristics of the phases in the steady-state freeze-lining. Also, it has been shown that under steady-state conditions a dense sealing layer consisting primarily of the spinel primary phase is formed at the deposit/liquid interface; however, the interface temperature is below the liquidus temperature. The findings of the study have potentially important implications for the operation of the converting furnace and the design of freeze linings in

  18. Code-to-code comparison for analysing the steady-state heat transfer and natural circulation in an air-cooled RCCS using GAMMA+ and Flownex

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, P.G., E-mail: pgr@mtechindustrial.com [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X 6001, Potchefstroom (South Africa); Toit, C.G. du [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X 6001, Potchefstroom (South Africa); Jun, J.S.; Noh, J.M. [Korea Atomic Energy Research Institute, Daedeok-daero 989-111, Yuseong-gu, Daejeon (Korea, Republic of)

    2015-09-15

    Highlights: • The GAMMA+ and Flownex codes are used in the analyses of the air-cooled RCCS system. • Radiation heat transfer comprises the bulk of the total rate of heat transfer. • It is possible to obtain reverse flow through the RCCS standpipes. • It has been found that the results obtained with the two codes are in good agreement. • RCCS remain functional for very high blockage ratios thus supporting the safety case. - Abstract: The GAMMA+ and Flownex codes are both based on a one-dimensional flow network modelling approach and both can account for any complex network of different heat transfer phenomena occurring simultaneously. However, there are notable differences in some of the detail modelling aspects, such as the way in which the convection in the reactor cavity is represented. Despite this, it was found in the analyses of the air-cooled RCCS system that the results provided by the two codes compare very well if similar input values are used for the pressure drop coefficients, heat transfer coefficients and view factors. The results show that the radiation heat transfer comprises the bulk of the total rate of heat transfer from the RPV surface. It is also shown that it is possible to obtain a stable and sustainable steady-state operational condition where the flow is in the reverse direction through the RCCS standpipes, resulting in excessively high values for the concrete wall temperature. It is therefore crucial in the design to ensure that such a flow reversal will not occur under any circumstances. In general the good comparison between the two codes provides confidence in the ability of both to correctly solve the fundamental conservation and heat transfer relations in an integrated manner for the complete RCCS system. Provided that appropriate input values are available, these codes can therefore be used effectively to evaluate the integrated performance of the system under various operating conditions. It is shown here that the RCCS

  19. Electrochemistry of oxygen ion transport in slag

    Institute of Scientific and Technical Information of China (English)

    鲁雄刚; 丁伟中; 李福燊; 李丽芬; 周国治

    2002-01-01

    A systematic experiment relating to the electrochemistry of oxygen ion transport in slag has been studied in lab.An equivalent circuit has been used to describe ion transfer between metal and slag in this paper and a kinetic model with electrochemical characteristic representing oxygen ion immigration has been worked out.The different experimental phenomena can be explained generally by this model.It can be seen that the theoretical results are in good agreement with experiments.The comparison of experimental data with model calculation proved that the electrochemical model is right.

  20. Dynamic simulation of the air-cooled decay heat removal system of the German KNK-II experimental breeder reactor

    International Nuclear Information System (INIS)

    A Dump Heat Exchanger and associated feedback control system models for decay heat removal in the German KNK-II experimental fast breeder reactor are presented. The purpose of the controller is to minimize temperature variations in the circuits and, hence, to prevent thermal shocks in the structures. The basic models for the DHX include the sodium-air thermodynamics and hydraulics, as well as a control system. Valve control models for the primary and intermediate sodium flow regulation during post shutdown conditions are also presented. These models have been interfaced with the SSC-L code. Typical results of sample transients are discussed

  1. Limitation of Sulfide Capacity Concept for Molten Slags

    Science.gov (United States)

    Jung, In-Ho; Moosavi-Khoonsari, Elmira

    2016-04-01

    The sulfide capacity concept has been widely used in pyrometallurgy to define sulfur removal capacities of slags. Typically, the sulfide capacity is considered to be a unique slag property depending only on temperature regardless of partial pressures of oxygen and sulfur. In the present study, it is demonstrated that sulfide capacities of slags in particular those of Na2O-containing slags can vary with partial pressures of oxygen and sulfur due to large solubility of sulfide in Na2O-containing slag systems.

  2. Research on Hydration of Steel Slag Cement Activated with Waterglass

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper studied the hydration and strength influence factors of Steel Slag Cement (SSC),such as the quantity of steel slag and slag and the dosage of additive.The results show that:(a) In the process of hydration of SSC,steel slag and slag activate each other;(b) Waterglass's structure forms the preliminary skeleton of SSC,and the hydration products of SSC link or fill in the skeleton;(c) Sodium in waterglass is the catalytic and its concentration does not change in the process of hydration.(d) Structure of activation is a significant factor to the property of SSC.

  3. Tool for Forecasting Cool-Season Peak Winds Across Kennedy Space Center and Cape Canaveral Air Force Station (CCAFS)

    Science.gov (United States)

    Barrett, Joe H., III; Roeder, William P.

    2010-01-01

    Peak wind speed is important element in 24-Hour and Weekly Planning Forecasts issued by 45th Weather Squadron (45 WS). Forecasts issued for planning operations at KSC/CCAFS. 45 WS wind advisories issued for wind gusts greater than or equal to 25 kt. 35 kt and 50 kt from surface to 300 ft. AMU developed cool-season (Oct - Apr) tool to help 45 WS forecast: daily peak wind speed, 5-minute average speed at time of peak wind, and probability peak speed greater than or equal to 25 kt, 35 kt, 50 kt. AMU tool also forecasts daily average wind speed from 30 ft to 60 ft. Phase I and II tools delivered as a Microsoft Excel graphical user interface (GUI). Phase II tool also delivered as Meteorological Interactive Data Display System (MIDDS) GUI. Phase I and II forecast methods were compared to climatology, 45 WS wind advisories and North American Mesoscale model (MesoNAM) forecasts in a verification data set.

  4. Numerical Simulation of 3—D Temperature Distribution of the Flame Tube of the Combustion Chamber with Air Film COoling

    Institute of Scientific and Technical Information of China (English)

    ChangHaiping; HuangTaiping; 等

    1996-01-01

    The wall temperature distribution of the flame tube of the combustion chamber is strongly affected by the combustion,radiation and flow.The interaction of these influential factors froms a coupling system.In this paper,a new method,which is different from the previous methods,has been developed for calcuating the temperature distribution of the flame tube wall together with the flow field inside and outside the flame tube,In the calculation.the combustion,heat radiation,cooling air film and injection stream mixing inside the flame tube as well as the secondary air flowing outside the flame tube have been simulated.The calculation,in this paper,uses the SIMPLE algorithm,the κ-εturbulence model and the auto-adjustable damping method .By using this method ,the 3-D temperature distribution of the floame tube wall of the combustion chamber of an aeroengine has been simulated successfully.The calculation results are compared to the experimetal data.The error of wall temperature is less than 10%.

  5. The use of SHS-process slag for the preparation of foundry sand

    Science.gov (United States)

    Safronov, N.; Kharisov, L.

    2015-06-01

    The article presents the construction of a linear approximation of the response function (strength of molding sand on tensile strength and air permeability) in a given area by changing the investigated factors for which charge makeup of SHS-cast iron obtaining process and content of the slag product of this process in the molding mixture were used. The analysis of regression coefficients significance of the objective function was done to identify the most important input parameters.

  6. Thermodynamic properties of chromium bearing slags and minerals. A review

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Yanping; Holappa, L.

    1996-12-31

    In this report, the thermodynamic properties of chromium bearing slags and minerals were reviewed based on the available information in the literature. It includes the analysing methods for oxidation state of chromium in slags, oxidation state of chromium and activities of chromium oxides in slags and minerals. The phase diagrams of chromium oxide systems and chromium distributions between slag and metal phases are also covered ill this review. Concerning the analysing methods, it was found that most of the available approaches are limited to iron free slag systems and the sample preparation is very sensitive to the analysing results. In silicate slags under reducing atmosphere, divalent and trivalent chromium co-exist in the slags. It is agreed that the fraction of divalent chromium to total chromium increases with higher temperature, lower slag basicity and oxygen potential. For the slags under oxidising atmosphere, trivalent, pentavalent and hexavalent states were reported to be stable. The activities of CrO and CrO{sub 1.5} were concluded to have positive deviation from ideal solution. Slag basicity has a positive effect and temperature has a negative effect on the activities of chromium oxides. The phase diagrams of the Cr-O, binary, and ternary chromium containing oxide systems have been examined systematically. The analysis shows that the data on the quaternary and quinary systems are insufficient, and require further investigation. The most important features of the chromium containing silicate slags are the large miscibility gaps and the stability of the chromite spinel. (orig.) (76 refs.)

  7. Research and development of blasting abrasive made of steelmaking slag

    Institute of Scientific and Technical Information of China (English)

    TANG Oujing

    2015-01-01

    This study focuses on the development of a new type of nonmetallic steelmaking slag abrasive.The performance,processing,and application of steelmaking slag as a nonmetallic abrasive are introduced.The chemical composition,hardness,crushing value,and particle gradation of steelmaking slag are analyzed.A processing method for steelmaking slag as a blasting abrasive is suggested and evaluated.Compared with conventional abrasives such as copper ore sand and cast iron shot,processed steelmaking slag exhibits similar performance and can satisfy abrasive technical requirements.The derusting effect provided by steelmaking slag for a ship deck can reach the Sa2.0 level,and its recyclability is higher than that of copper ore sand.The derusting performance of steelmaking slag is similar to that of copper ore,and it can thus be used in repairing ship decks.

  8. 77 FR 25901 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Removal of the 1980...

    Science.gov (United States)

    2012-05-02

    ... area for TSP, and the Atlantic Cement Company (now Lafarge North America) was re-permitted in 2001... County. Hot metal slag from Bethlehem Steel's blast furnace that is not processed by the Atlantic Cement Company's (now LaFarge North America) granulated slag cement plant is allowed to cool before being sent...

  9. Air

    Science.gov (United States)

    ... house) Industrial emissions (like smoke and chemicals from factories) Household cleaners (spray cleaners, air fresheners) Car emissions (like carbon monoxide) *All of these things make up “particle pollution.” They mostly come from cars, trucks, buses, and ...

  10. Mechanisms of phosphate removal from aqueous solution by blast furnace slag and steel furnace slag

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We report the adsorption of phosphate and discuss the mechanisms of phosphate removal from aqueous solution by burst furnace slag (BFS) and steel furnace slag (SFS). The results show that the adsorption of phosphate on the slag was rapid and the majority of adsorption was completed in 5~10 min. The adsorption capacity of phosphate by the slag was reduced dramatically by acid treatment. The relative contribution of adsorption to the total removal of phosphate was 26%~28%. Phosphate adsorption on BFS and SFS follows the Freundlich isotherm, with the related constants ofk 6.372 and 1/n 1.739 for BFS, and ofk 1.705 and 1/n 1.718 for SFS. The pH and Ca2+ concentration were decreased with the addition of phosphate, suggesting the formation of calcium phosphate precipitation. At pH 2.93 and 6.93, phosphate was desorbed by about 36%~43% and 9%~11%, respectively.These results indicate that the P adsorption on the slag is not completely reversible and that the bond between the slag particles and adsorbed phosphate is strong. The X-ray diffraction (XRD) patterns of BFS and SFS before and after phosphate adsorption verify SFS is related to the formation of phosphate calcium precipitation and the adsorption on hydroxylated oxides. The results show that BFS and SFS removed phosphate nearly 100%, indicating they are promising adsorbents for the phosphate removal in wastewater treatment and pollution control.

  11. 组合式空调机组供冷量测量的不确定度评定%Uncertainty evaluation of cooling capacity measurement of modular air handling units

    Institute of Scientific and Technical Information of China (English)

    陆宏觉

    2011-01-01

    介绍了空调机组供冷量的测试方法.并在对某机组供冷量实测的基础上,详细分析了水侧及空气侧供冷量测量的不确定度及其主要来源.结果表明,供冷量测量不确定度的主要因素是进出风干、湿球温度和进出水温度及水流量.%Presents the test methods of cooling capacity of the air handling units. Based on the cooling capacity measurement of an actual unit, analyses the uncertainty and main sources in detail. As a result, theuncertainty of cooling capacity measurement results mainly from the dry-bulb and wet-bulb temperature of entering and leaving air, temperature of entering and leaving water and water flow rate.

  12. Characteristic analysis on variable working condition of direct air-cooled condenser for 600 MW thermal power unit%600MW火电机组直接空冷凝汽器变工况特性分析

    Institute of Scientific and Technical Information of China (English)

    刘振盛

    2012-01-01

    针对直接空冷凝汽器运行中存在的问题。通过对空冷凝汽器变工况计算,找出了环境温度、迎面风速、汽轮机排汽量变化对汽轮机背压、发电标准煤耗率的影响关系。结果表明:空冷凝汽器的运行工况与设计工况差别较大,用户应在变工况下合理确定空冷凝汽器运行方式。%Aiming at the problem of direct air-cooled condenser inactual operation, through the Calculation in variable working condition of air-cooled condenser, finds out the influence relations of the environment temperature, the head-on wind speed and the change of quantity discharged of the steam turbine for the back pressure of the steam turbine and standard coal loss rate of the power generation. The result shows that the difference of operation and design working conditions of air-cooled condenser is very great, user should determine in reason the operation way of air-cooled condenser in variable working condition.

  13. Nieuwe wapens in de slag om groen

    NARCIS (Netherlands)

    Vreke, J.

    2010-01-01

    Groen verliest in en rond steden vaak de slag. Burgers vinden groene gebieden belangrijk, ze stimuleren beweging, bevorderen de integratie en maken huizen meer waard. Toch kiezen bestuurders uiteindelijk vaak toch voor ‘rood’ omdat dat geld en prestige oplevert. In deze bijdrage wordt verslag gedaan

  14. 自然冷却与真空冷却对蛋糕货架期的影响%Effect of Natural Air Cooling and Vacuum Pre-cooling on Shelf Life of Cake

    Institute of Scientific and Technical Information of China (English)

    崔诚; 李保国; 管骁

    2011-01-01

    为考察冷却方法对蛋糕货架期的影响,进行了自然冷却与真空冷却蛋糕的实验研究.比较了经两种方法冷却后,在不同贮藏温度条件(4℃、15℃、25℃、37℃)下,微生物随贮藏时间的变化规律.发现微生物数量随贮藏时间的延长而增加,微生物生长速率随贮藏温度的升高而增大.根据不同贮藏温度条件下蛋糕中微生物随时间的变化,拟合得到微生物生长的动力学初级模型.并运用Arrhenius方程分别建立了蛋糕真空冷却后贮藏过程中菌落总数、霉菌数量与贮藏温度、时间之间动力学二级模型.结合动力学模型,推导出了真空冷却蛋糕的货架期预测模型.研究结果表明,所建立的蛋糕货架期预测模型其预测误差小于12%,可用于预测蛋糕的货架期.%The influence of vacuum pre-cooling cake on the shelf life was analyzed and compared with natural air cooling. The changes of total number of bacteria and moulds in cakes during storage at different temperatures(4℃, 15℃, 25 ℃, 37 ℃) were analyzed. Results showed that the total microbial count of cake was increased with prolonged storage time, and there was an increase in microbial growth rate as storage temperature rose. Primary kinetic models were obtained by analyzing the changes of microbial count in cakes. Kinetic models were developed for total number of colonies and moulds as a function of storage time and temperature based on Arrhenius equation. Mathematic models for predicting the shelf life of cake were obtained based on the kinetic models. It shows that relative error between prediction by the model for the shelf life of cake and observed shelf life is less than 12%, which indicates that this model could be used for predicting the shelf life of cakes.

  15. Design and Development of Intracavity Optical Parametric Oscillator-based Eye Safe Laser Operating at 20 Hz without Forced Air Cooling

    Directory of Open Access Journals (Sweden)

    Atul Bhardwaj

    2013-12-01

    Full Text Available In this paper we report the design and development of an electro-optically Q-switched diode pumped Nd:YAG laser with intracavity optical parametric oscillator, generating ~ 5 ns laser pulses of ~8 mJ energy at eye safe wavelength of 1534 nm. A Z-shaped laser resonator has been designed with porro prism end reflector in Q-switch arm containing RTP Q-Switch and a suitably oriented waveplate. The gain arm consists of a Ø3 x 72 mm Nd: YAG laser rod, pumped from one side by 3 x 5 bar laser diode array stack emitting total optical peak power of 740 W at 804 nm at 38 °C. Thermoelectric coolers (TECs have been employed to maintain the optimum temperature of laser diode arrays and the combined heat load from the pump chamber and TECs is distributed over the system base plate with embedded heat pipes. Such cooling mechanism has eliminated the requirement of fins and fans in the laser system. Eye safe radiation is out-coupled through intra cavity KTA OPO (5 x 5 x 20 mm3 placed in the gain arm. Laser was operated at 20 Hz for several duty cycles of 10 min on and 10 min off and output energy remained stable within ±0.5 mJ without any forced air/liquid cooling.Defence Science Journal, 2013, 63(6, pp.599-605, DOI:http://dx.doi.org/10.14429/dsj.63.5759

  16. Air

    International Nuclear Information System (INIS)

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  17. Alternative Room Cooling System

    Directory of Open Access Journals (Sweden)

    Md. Fazle Rabbi

    2015-06-01

    Full Text Available The rapidly growing population results in an increasing demand for much more residential and commercial buildings, which leads to vertical growth of the buildings and needs proper ventilation of those buildings. Natural air ventilation system is not sufficient for conventional building structures. Hence fans and air-conditioners are must to meet the requirement of proper ventilation as well as space conditioning. Globally building sector consumes largest energy in heating, cooling, ventilation and space conditioning. This load can be minimized by the application of solar chimney and modification in building structure for heating, cooling, ventilation and space conditioning. Passive solar cooling is a subject of interest to provide cooling by using the sun, a powerful energy source. This is done for ensuring human comfort in hot climates. ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers defines Comfort as ‘that state of mind which expresses satisfaction with the thermal environment.’ The present paper describes the development of a solar passive cooling system, which can provide thermal cooling throughout the summer season in hot and humid climates. The constructed passive system works on natural convection mode of air. Such system reduces the inside temperature of up to 5°C from the atmospheric temperature. Temperature can further be reduced by the judicious use of night ventilation.

  18. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing.

    Science.gov (United States)

    Liapis, Ioannis; Papayianni, Ioanna

    2015-01-01

    Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector.

  19. TRIGENERATION - A highly energy efficient source for heating, domestic hot water preparation, electricity and air cooling systems for tertiary sector

    International Nuclear Information System (INIS)

    The general concerns relating to sustainable energy development have led to the implementation of certain solutions at the international level that have increased both energy generation and energy consuming processes efficiency. In our country the first steps in this direction have been carried out by the private companies that, after having analyzed the income increase and costs diminishing, have come to the conclusion that a reliable way to save money would be the rational use of the energy resources for utilities. A favorable consequence was the synergetic effect of the measures meant to increase energy efficiency for the energy generation and consumption processes that are also accompanied by benefit effects on the environmental impact by reduction CO2 emissions. One of the solutions making the utmost of primary energy is the combined heat and power production (co-generation) that has significantly developed in our country within the energy sector as a whole. Co-generation may be considered environmentally friendly because it saves fuel on the one hand and, technologically, generates less emissions as compared to the separate generation of heat and power, on the other hand. The most favorable applications of co-generation at a medium and small scale are in the tertiary sector (hotels, hospitals, and office buildings) where heat consumption is usually high enough and is accompanied by relatively constant electricity consumption. By corroborating the above mentioned facts relating to local cogeneration installation utilization with those relating to the increased need for cooling in the tertiary buildings, a concept named 'TRI-GENERATION' in specialized literature has occurred, representing, in fact, utilization of cogeneration installations for supplying energy to the electricity, heat and cold consumer. Thus, the cogeneration installation utilization time will be practically prolonged over the entire duration of a year a fact that has extremely favorable

  20. Synthesis and heavy metal immobilization behaviors of slag based geopolymer.

    Science.gov (United States)

    Yunsheng, Zhang; Wei, Sun; Qianli, Chen; Lin, Chen

    2007-05-01

    In this paper, two aspects of studies are carried out: (1) synthesis of geopolymer by using slag and metakaolin; (2) immobilization behaviors of slag based geopolymer in a presence of Pb and Cu ions. As for the synthesis of slag based geopolymer, four different slag content (10%, 30%, 50%, 70%) and three types of curing regimes (standard curing, steam curing and autoclave curing) are investigated to obtain the optimum synthesis condition based on the compressive and flexural strength. The testing results showed that geopolymer mortar containing 50% slag that is synthesized at steam curing (80 degrees C for 8h), exhibits higher mechanical strengths. The compressive and flexural strengths of slag based geopolymer mortar are 75.2 MPa and 10.1 MPa, respectively. Additionally, Infrared (IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques are used to characterize the microstructure of the slag based geopolymer paste. IR spectra show that the absorptive band at 1086 cm(-1) shifts to lower wave number around 1007 cm(-1), and some six-coordinated Als transforms into four-coordination during the synthesis of slag based geopolymer paste. The resulting slag based geopolymeric products are X-ray amorphous materials. SEM observation shows that it is possible to have geopolymeric gel and calcium silicate hydrate (C-S-H) gel forming simultaneously within slag based geopolymer paste. As for immobilization of heavy metals, the leaching tests are employed to investigate the immobilization behaviors of the slag based geopolymer mortar synthesized under the above optimum condition. The leaching tests show that slag based geopolymer mortar can effectively immobilize Cu and Pb heavy metal ions, and the immobilization efficiency reach 98.5% greater when heavy metals are incorporated in the slag geopolymeric matrix in the range of 0.1-0.3%. The Pb exhibits better immobilization efficiency than the Cu in the case of large dosages of heavy metals.

  1. Distribution of Bi Between Slags and Liquid Copper

    Science.gov (United States)

    Chen, Chunlin; Wright, Steven

    2016-06-01

    The distribution of Bi between liquid copper and calcium ferrite slag containing 24 wt pct CaO, iron silicate slag with 25 wt pct SiO2, and calcium iron silicate slags was measured at 1573 K (1300 °C) under controlled CO-CO2 atmosphere. The experimental results showed that bismuth distribution is affected by the oxygen partial pressure, and bismuth is likely to exist in slags in the 2+ oxidation state, i.e., as BiO. The distribution ratio between calcium ferrite slag and metal was found to be close to that of iron silicate slag. The Bi distribution ratio was found to decrease with increasing SiO2 and Al2O3 content in slag. Increasing temperature was found to decrease the Bi distribution ratio between slag and metal. Using the measured equilibrium data on Bi content of the metal and slag and composition dependence of the activity of Bi in liquid copper, the activity and hence activity coefficient of BiO in the slag was calculated. The close value of activity coefficient of BiO in both slags at the same oxygen partial pressure indicates that the CaO-BiO and SiO2-BiO interactions are likely to be at the same level, or the FeO x -BiO interaction is the predominant interaction for BiO in the slag. Therefore at a constant FeO x content in the slag, the CaO-BiO and SiO2-BiO interactions doesn't affect γ_{{BiO}} significantly.

  2. Comparison between predicted duct effectiveness from proposed ASHRAE Standard 152P and measured field data for residential forced air cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Siegel, Jeffrey A.; McWilliams, Jennifer A.; Walker, Iain S.

    2002-04-01

    The proposed ASHRAE Standard 152P ''Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems'' (ASHRAE 2002) has recently completed its second public review. As part of the standard development process, this study compares the forced air distribution system ratings provided by the public review draft of Standard 152P to measured field results. 58 field tests were performed on cooling systems in 11 homes in the summers of 1998 and 1999. Seven of these houses had standard attics with insulation on the attic floor and a well-vented attic space. The other four houses had unvented attics where the insulation is placed directly under the roof deck and the attic space is not deliberately vented. Each house was tested under a range of summer weather conditions at each particular site, and in some cases the amount of duct leakage was intentionally varied. The comparison between 152P predicted efficiencies and the measured results includes evaluation of the effects of weather, duct location, thermal conditions, duct leakage, and system capacity. The results showed that the difference between measured delivery effectiveness and that calculated using proposed Standard 152P is about 5 percentage points if weather data, duct leakage and air handler flow are well known. However, the accuracy of the standard is strongly dependent on having good measurements of duct leakage and system airflow. Given that the uncertainty in the measured delivery effectiveness is typically also about 5 percentage points, the Standard 152P results are acceptably close to the measured data.

  3. Boundary conditions for heat transfer and evaporative cooling in the trachea and air sac system of the domestic fowl: a two-dimensional CFD analysis.

    Directory of Open Access Journals (Sweden)

    Nina S Sverdlova

    Full Text Available Various parts of the respiratory system play an important role in temperature control in birds. We create a simplified computational fluid dynamics (CFD model of heat exchange in the trachea and air sacs of the domestic fowl (Gallus domesticus in order to investigate the boundary conditions for the convective and evaporative cooling in these parts of the respiratory system. The model is based upon published values for respiratory times, pressures and volumes and upon anatomical data for this species, and the calculated heat exchange is compared with experimentally determined values for the domestic fowl and a closely related, wild species. In addition, we studied the trachea histologically to estimate the thickness of the heat transfer barrier and determine the structure and function of moisture-producing glands. In the transient CFD simulation, the airflow in the trachea of a 2-dimensional model is evoked by changing the volume of the simplified air sac. The heat exchange between the respiratory system and the environment is simulated for different ambient temperatures and humidities, and using two different models of evaporation: constant water vapour concentration model and the droplet injection model. According to the histological results, small mucous glands are numerous but discrete serous glands are lacking on the tracheal surface. The amount of water and heat loss in the simulation is comparable with measured respiratory values previously reported. Tracheal temperature control in the avian respiratory system may be used as a model for extinct or rare animals and could have high relevance for explaining how gigantic, long-necked dinosaurs such as sauropoda might have maintained a high metabolic rate.

  4. Turbine airfoil with ambient cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Jr, Christian X.; Marra, John J.; Marsh, Jan H.

    2016-06-07

    A turbine airfoil usable in a turbine engine and having at least one ambient air cooling system is disclosed. At least a portion of the cooling system may include one or more cooling channels configured to receive ambient air at about atmospheric pressure. The ambient air cooling system may have a tip static pressure to ambient pressure ratio of at least 0.5, and in at least one embodiment, may include a tip static pressure to ambient pressure ratio of between about 0.5 and about 3.0. The cooling system may also be configured such that an under root slot chamber in the root is large to minimize supply air velocity. One or more cooling channels of the ambient air cooling system may terminate at an outlet at the tip such that the outlet is aligned with inner surfaces forming the at least one cooling channel in the airfoil to facilitate high mass flow.

  5. Leaching of heavy metals from steelmaking slags

    Directory of Open Access Journals (Sweden)

    Gomes, J. F. P

    2006-12-01

    Full Text Available Leaching tests with EAF and Ladle slags were performed, using a flow through test and the standard batch test DIN 38414-S4. The previous method was used to simulate the leaching behaviour of steel slags under landfill. The chemical analysis of the leachates during this period shows, in general, for both types of slag, an increase of heavy metal releases with ageing. Standard test method DIN 38414-S4 was used to evaluate leachability of heavy metals by water in unprocessed slags. After more than one year of trials, slag samples submitted to these trials presented very low total leaching levels. The most extracted elements are calcium and magnesium. Nevertheless, in flow-through test, calcium and magnesium leached from solid slags are below 0.5% and all other metals below 0.1%. Leachates obtained with DIN 38414-S4 present, as expected, higher leaching values; however, these are inferior to 5 % (Ca and 1% (other elements.

    Este articulo contiene los resultados obtenidos en ensayos de lixiviación de escorias de acero (horno electrico y cuchara ejecutados siguiendo la metodologia de flujo dinámico así como el ensayo normalizado DIN 38414-S4. El primer ensayo intenta simular el comportamiento de lixiviación de las escorias en vertedero. Para las escorias ensayadas se han complementado los ensayos con el análisis químico de los lixiviados y se ha verificado un aumento de la liberación de metales pesados. El ensayo DIN 38414-S4 se ha utilizado para evaluar la lixiviación por agua de metales pesados, en muestras de escorias originales. Despues de un año de ensayos, se han observado niveles muy bajos de lixiviación. Los elementos mas lixiviados han sido calcio y magnesio. No obstante, en los ensayos de flujo dinámico, el calcio y el magnesio lixiviados de las escorias sólidas era menor de 0,5% y el resto de los otros metales era inferior a 0,1%. Los lixiviados obtenidos con el ensayo DIN 38414-S4 presentan, como era de esperar, valores

  6. Control system for forced-air cooling of horticultural products Sistema de controle para o resfriamento com ar forçado de produtos hortícolas

    Directory of Open Access Journals (Sweden)

    João C. T. R. da Silva

    2011-01-01

    Full Text Available This work is a study of the implementation of a classical controller using a tuning method referred to as IMC (Internal Model Control and aimed at the reduction of electrical energy consumption by the appropriate relation between energy consumption and the cooling time with forced air. The supervisory system installed was able to manipulate the variable of frequency of the signal power of the exhaust fan engine (forced air module, to accelerate or decelerate the loss of heat from the product to be cooled by airflow variation that passes through the mass of the produce. The results demonstrated a reduction in energy consumption from 64% and an increase of only 8% in the cooling time to the system using PI/IMC (Proportional - Integral with IMC tuning method compared with the system in its operating nominal condition. This PI/IMC control may be implemented directly in a frequency converter, without the need to purchase a computer or PLC (programmable logic controller to run the dedicated application, increasing its economical viability.Este trabalho consiste no estudo da implementação de um controlador clássico utilizando o método de sintonia denominado por Controle de Modelo Interno, visando à redução do consumo de energia elétrica que decorra na adequada relação entre este consumo e o tempo de resfriamento do processo de resfriamento com ar forçado de produtos hortícolas. Para isto, o sistema supervisório instalado manipulou a variável de frequência do sinal de alimentação do motor de indução trifásico do exaustor (módulo de ar forçado, para acelerar ou desacelerar a perda de calor do produto a ser resfriado por intermédio da variação da vazão de ar que perpassava a massa deste produto. Obteve-se como resultado uma redução no consumo de energia elétrica de 64% e um acréscimo de apenas 8% no tempo de resfriamento para o sistema utilizando um controle proporcional e integral associado ao método de sintonia promovido

  7. Methodologies for estimating air emissions from three non-traditional source categories: Oil spills, petroleum vessel loading and unloading, and cooling towers. Final report, October 1991-March 1993

    International Nuclear Information System (INIS)

    The report discusses part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plan (SIP) area source methodologies and to develop appropriate emissions estimation methodologies and emission factors for a group of these source categories. Based on the results of the identification and characterization portions of this research, three source categories were selected for methodology and emission factor development: oil spills, petroleum vessel loading and unloading, and cooling towers. The report describes the category selection process and presents emissions estimation methodologies and emission factor data for the selected source categories. The discussions for each category include general background information, emissions generation activities, pollutants emitted, sources of activity and pollutant data, emissions estimation methodologies and data issues. The information used in these discussions was derived from various sources including available literature, industrial and trade association publications and contracts, experts on the category and activity, and knowledgeable federal and state personnel

  8. Electron cooling

    Science.gov (United States)

    Meshkov, I.; Sidorin, A.

    2004-10-01

    The brief review of the most significant and interesting achievements in electron cooling method, which took place during last two years, is presented. The description of the electron cooling facilities-storage rings and traps being in operation or under development-is given. The applications of the electron cooling method are considered. The following modern fields of the method development are discussed: crystalline beam formation, expansion into middle and high energy electron cooling (the Fermilab Recycler Electron Cooler, the BNL cooler-recuperator, cooling with circulating electron beam, the GSI project), electron cooling in traps, antihydrogen generation, electron cooling of positrons (the LEPTA project).

  9. Stochastic Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Blaskiewicz, M.

    2011-01-01

    Stochastic Cooling was invented by Simon van der Meer and was demonstrated at the CERN ISR and ICE (Initial Cooling Experiment). Operational systems were developed at Fermilab and CERN. A complete theory of cooling of unbunched beams was developed, and was applied at CERN and Fermilab. Several new and existing rings employ coasting beam cooling. Bunched beam cooling was demonstrated in ICE and has been observed in several rings designed for coasting beam cooling. High energy bunched beams have proven more difficult. Signal suppression was achieved in the Tevatron, though operational cooling was not pursued at Fermilab. Longitudinal cooling was achieved in the RHIC collider. More recently a vertical cooling system in RHIC cooled both transverse dimensions via betatron coupling.

  10. Assessment of steam generator slagging and slag removal with water guns

    Energy Technology Data Exchange (ETDEWEB)

    Bude, F.; Schettler, H.; Weidlich. H.G.

    1983-09-01

    This paper discusses combustion parameters and slag buildup on heating surfaces in brown coal fired steam generators. At the Berlin steam generator plant (GDR), the influence of slagging on heat transfer in a combustion chamber is calculated according to the method of A.M. Gurwitsch (1950). Combustion properties are further assessed with the approximation method according to B. Weiser (1976), for which nomograms have been developed. For the prediction of brown coal slagging behavior, four ash and slag analyses are described and compared. Slag removal from heating surfaces in various 815 t/h steam generators is carried out by 36 back-acting blowers, distributed over all 4 sides of the combustion chamber. These blowers, however, are not capable of complete cleaning of the heating surfaces. An automated and electrically operated water jet gun (type EWL 1) was, therefore, developed. It can be installed in all steam generator sizes including those with very large combustion chambers. The performance of the EWL 1 is evaluated with graphs. Four water guns are sufficient for periodic combustion chamber cleaning of 1,000 t/h steam generators. (9 refs.)

  11. Outcomes of experimental researches on stainless steel decontamination from radioactive contamination using electric slag remelting method

    International Nuclear Information System (INIS)

    Full text: Institute of Atomic Energy prepared and conducted the experiments the purpose of researching a possibility of applying of stainless steel electric slag remelting for its decontamination from radioactive contamination. The activities were conducted at participating of the specialists of Kurgan State University, Kurgan (Russian Federation). A stand, which includes the electroslag furnace (power - 150 kW, current - to 3000 A) and auxiliary equipment (the system of common and special ventilation, system of remote control, system of parameters measuring and registering and others) was created to conduct the experiments. The properties of slag compositions were researched in the course of experiments preparation. Oxide (CaO-Al2O3 - CaO-SiO2 - MgO-B2O3) and fluoride-oxide (CaF2-SiO2 - MgF2-SiO2) slag systems and some their modifications were chosen to research physical and chemical properties. Physical and chemical properties of the slag systems were experimentally researched and it included: measuring of surface tension using the method of maximum pressure in a gas bubble (at the same time density was measured); measuring of slag alloys electrical conductivity; measuring of melt volt-ampere characteristics. The flue tubes of high temperature reactor gas cooling KET technological channels were chosen as a source of radioactive contaminated stainless steel. This reactor is meant for testing of the fuel pin and FA of the nuclear pulse propulsion. Decontamination effect for all the remelted flue tubes was indirectly confirmed by the outcomes of measuring of radioactive radiation dose rate of the materials, extracted of the crystallizer after experiments finishing. The outcomes of the experiments show that the following processes pass at electroslag remelting of radioactively contaminated steel: uranium extraction from steel; uranium transfer from steel to slag; saving or insignificant modification of steel initial composition; radionuclides deposing on the special

  12. Reduction Kinetics of Electric Arc Furnace Oxidizing Slag by Al-Fe Alloy

    Science.gov (United States)

    Lee, Jaehong; Oh, Joon Seok; Lee, Joonho

    2016-09-01

    Effects of temperature and slag basicity on the reduction rate of iron oxide in molten synthetic electric arc furnace oxidizing slag by Al-40 wt.%Fe alloy was investigated. An alloy sample was dropped into molten slag in an MgO crucible. When the initial slag temperature was 1723 K, there was no reduction. However, when the initial slag temperature was 1773 K and the slag basicity was 1.1, the reduction was initiated and the temperature of the slag rapidly increased. When the slag basicity was 1.1, increasing the initial slag temperature from 1773 K to 1823 K increases the reaction rate. As the slag basicity increased from 1.1 to 1.4 at 1773 K, the reaction rate increased. From SEM analysis, it was found that an Al2O3 or a spinel phase at the slag-metal interface inhibited the reaction at a lower temperature and a lower slag basicity.

  13. A Site Simulation Test on Compressed Air Blowers for Ash Fouling of Air Cooled Condensers%空冷凝汽器积灰干式吹扫系统现场实验研究

    Institute of Scientific and Technical Information of China (English)

    赵波; 马士全; 胡亚才; 杨善让; 张纲; 张宏宇; 张海林; 蒋静江; 刘志超; 王文忠; 洪海清

    2013-01-01

    直冷系统以节水率达69%~84%而在燃煤电站得到广泛应用。但在风沙大的干旱地区,若清洗不及时,空冷凝汽器则因积灰而使排汽背压升高8 kPa甚或以上,机组煤耗因而升高10~15 g/(kW⋅h),污染排放亦随之增大,而及时清洗所需的水资源又为环境所限。对此,该文设计了一种以压缩空气代替高压除盐水的干式吹扫系统,并在某600 MW直冷机组单排翅片管空冷凝汽器上进行了两种清洗方式的比较实验。文中介绍了干式吹扫系统的构成、实验内容及结果,拟定了吹扫效果评价方法,建立了灰垢热阻与排汽背压的定量关联,并据以比较了干式吹扫与水洗在同一清洗周期内累计清洗效果。结果表明:干式吹扫年节水量为1.47 kg/m2,累计平均背压降低1.7 kPa ,机组发电煤耗降低约2.5g/(kW⋅h),实现了节水、节能和减排共赢。%Direct air cooling (DAC) system has been widely applied in coal-fired power plants for its water-saving rate of 69%~84%. However, in arid regions with large sandstorm, the exhaust pressure of steam turbine will be raised by 8kPa or more because of the ash fouling of air cooled condenser (ACC). If it is not timely cleaned, the coal consumption of unit would elevate above 10~15 g/(kW⋅h) and the pollution emissions increases in the meantime. But the water consumption for timely cleaning is restricted by environmental conditions. To solve the incompatible contradiction, a novel compressed air blower (CAB) system was designed to clean the ash fouling for ACC in this paper, that is, the compressed air will entirely replace desalted water as cleaning medium for the new system. The main body of this paper includes the basic components of the CAB system, the content and results of a site simulation test (SST) for CAB under multi-operation conditions on an ACC of 600MW DAC unit, the blowing evaluation indexes proposed, and the quantitative correlation

  14. Investigation on the Potentials of Cupola Furnace Slag in Concrete

    Directory of Open Access Journals (Sweden)

    Stephen Adeyemi Alabi

    2013-12-01

    Full Text Available The compressive strength of the concrete designed using blast cupola furnace slag and granulated cupola slag as a coarse aggregate and partial replacement for cement was investigated. A series of experimental studies were conducted involve concrete production in two stages. The first stage comprised of normal aggregate concrete (NAC produced with normal aggregates and 100% ordinary Portland cement (OPC. Meanwhile, the second stage involved production of concrete comprising of cupola furnace slag an aggregates with 100% ordinary Portland cement (OPC and subsequently with 2%, 4%, 6%, 8% and 10% cementitious replacement with granulated cupola furnace slag that had been grounded and milled to less than 75 µm diameter. The outcomes of compressive strength test conducted on the slag aggregate concrete (SAC with and without granulated slag cementitious replacement were satisfactory compared to normal aggregate concretes (NAC.

  15. Optimization of Blended Mortars Using Steel Slag Sand

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new kind of mortar made of ground granulated blast-furnace slag (GGBFS), gypsum,clinker and steel slag sand (<4.75 mm) was developed. The ratio of steel slag sand to GGBFS was 1:1 and the amount of gypsum was 4% by weight while the dosage of clinker ranged from 0% to 24%. The optimization formulation of such mortar was studied. The content of steel slag sand should be less than 50% according to the volume stability of blended mortar, and the dosage of clinker is about 10% based on the strength development.Besides strength, the hydration heat, pore structure and micro pattern of blended mortar were also determined.The experimental results show the application of steel slag sand may reduce the dosage of cement clinker and increase the content of industrial waste product such as GGBFS, and the clinker is also a better admixture for blended mortar using steel slag sand.

  16. Reduction of chromium oxide from slags

    Directory of Open Access Journals (Sweden)

    Gutiérrez-Paredes, J.

    2005-12-01

    Full Text Available Experimental and theoretical work were performed to estimate the effect of slag basicity and amount of reducing agents on the reduction of chromium oxide from the slag which interacted with molten steel at 1,600 °C. The slag system contained CaO, MgO, SiO2, CaF2 and Cr2O3 together with Fe-alloys (Fe-Si and Fe-Si-Mg. The CaF2 and MgO contents in the slags were 10 mass % each; Cr2O3 was 25%. The amount of the ferroalloys ranged from 12.5 to 50 g per 100 g of slag. The (CaO+MgO/SiO2 ratio was held at 1 and 2. The Cr yield was determined using both Fe-alloys as reducing agents. Some estimations were made to determine the theoretical effect of temperature, slag basicity, (CaO+MgO/SiO2, and amount of reducing agents in the slag on the chromium recovery. The FACT (Facility for the Analysis of Chemical Thermodynamics computational package is used to determine the equilibrium between the slag and molten steel.

    En el presente trabajo se realiza un estudio teórico y experimental para determinar el efecto de la basicidad de la escoria y la cantidad de agentes reductores sobre la reducción de óxidos de cromo contenidos en la escoria, la cual está en contacto con acero líquido a 1.600 °C. La escoria se prepara con los reactivos CaO, MgO, SiO2, CaF2 y ferroaleaciones (Fe-Si y Fe-Si-Mg. Los contenidos de CaF2 y MgO en la escoria son de 10 %, cada uno, y el de Cr2O3 es 25 %. La cantidad de la ferroaleación varía de 12,5 a 50 g por cada 100 g de escoria. La relación (CaO+MgO/SiO2 tiene los valores de 1 y 2. Se determina la eficiencia de recuperación de cromo empleando los dos tipos de ferroaleaciones. Se realizaron cálculos para determinar el efecto teórico de la temperatura, la basicidad de la escoria, (CaO+MgO/SiO2, y la cantidad de agentes reductores sobre la reducci

  17. Electrochemical Method to Accelerate Metal-Slag Reaction

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The electrochemical nature of reaction between melt and slag in a closed system was worked out. Experimental results demonstrated that both the rate and reaction extent increase when the electronic conductor or voltage was applied between melt and slag. The bigger the contact area of the conductor with melts is, the faster the reaction rate is. With the increase of applied voltage which is beneficial for electron's migration between metal and slags, the rate and extent of reaction increase.

  18. Effect of the chemical composition of slag on its foamability in an electric arc furnace

    Science.gov (United States)

    Kozhukhov, A. A.

    2015-06-01

    The problems of foaming electric furnace slags are considered. The role of the physicochemical properties of slag during its foaming in electric arc furnaces is studied. The regions of slag foaming in an electric arc furnace are determined. Based on the derived relations between the chemical composition of slag and its foamability, one can choose a rational path of slag formation to ensure good slag foaming in the course of electrosmelting of steel.

  19. The definition of cool

    Energy Technology Data Exchange (ETDEWEB)

    Nichiporuk, A.

    2005-05-01

    A new air cooling system at Agnico-Eagle's LaRonde mine, located in the Abitibi Region of Quebec is described. The new system serves a mine operating at 7,250 plus feet level. The system is installed at the surface; it utilizes ammonia to cool water, which cools the air. The system consists of four compressors which lower the temperature of the ammonia to minus 2 degrees C. Water, which at this temperature is 14 degrees, and ammonia pass through a plate heat exchanger simultaneously, however, without coming into contact with each other. The heat transfer that occurs causes the water's temperature to drop to 2 degrees C. The total volume of water cooled is 220 litres per second. The system is capable of reducing 636,000 cfm of air from 30 degrees C to 6 degrees C, to which 214,000 cfm of non-cooled air is added. This mixture, which is maintained at approximately 8 degrees C throughout the summer season, is sent underground to the deepest parts of the mine. The system runs from June to September, depending on the weather. In the evenings, when the temperature dips to around four to five degrees C, the water is shut down and side doors are opened to prevent the water from freezing.

  20. Thermochemistry of calcium oxide and calcium hydroxide in fluoride slags

    Science.gov (United States)

    Chattopadhyay, S.; Mitchell, A.

    1990-08-01

    Calcium oxide activity in binary CaF2-CaO and ternary CaF2-CaO-Al2O3 and CaF2-CaO-SiO2 slags has been determined by CO2-slag equilibrium experiments at 1400 °C. The carbonate ca-pacity of these slags has also been computed and compared with sulfide capacity data available in the literature. The similarity in trends suggests the possibility of characterizing carbonate capacity as an alternative basicity index for fluoride-base slags. Slag-D2O equilibrium experi-ments are performed at 1400°C with different fluoride-base slags to determine water solubility at two different partial pressures of D2O, employing a new slag sampling technique. A novel isotope tracer detection technique is employed to analyze water in the slags. The water solubility data found show higher values than the previous literature data by an order of magnitude but show a linear relationship with the square root of water vapor partial pressure. The activity of hydroxide computed from the data is shown to be helpful in estimating water solubility in in-dustrial electroslag remelting (ESR) slags.

  1. Process of Re-Resourcing of Converter Slag

    Institute of Scientific and Technical Information of China (English)

    GAO Jin-tao; LI Shi-qi; ZHANG Yan-ting; ZHANG Yan-ling; CHEN Pei-yu; SHEN Ping

    2011-01-01

    The process of "re-resourcing of converter slag" was put forward based on the analysis of the existing steel slag treatment process.The converter slag obtained from Jinan steel plant was studied.After grinding,the slag contained 3.3% of iron particles,54.84% of magnetic part(wTFe=20%),and 41.84% of non-magnetic part,which could be used for making cement directly.At a temperature below 1000 ℃,the non-magnetic Fe2O3 in the slag could be efficiently reduced to magnetic iron by pure H2 and CO.The slag after precise reduction had high degree of dispersion and did not get sintered,which provided an optimum condition for the separation of iron and impurities.To separate the slag and enrich the iron after reduction,the laboratory-scale device of magnetic separation was designed and made.The process of slag re-resourcing,which included magnetic sorting,precise reduction,magnetic separation,and removal of free calcium oxide(f-CaO),was proposed to obtain iron-rich magnetic materials and cement adulterant materials.Through this process,33 kg iron particles,150 kg iron-rich material and 700 kg cement could be obtained in each ton slag.Besides,this process to recycle converter slag had a lower energy and material consumption and no pollutant emission.

  2. Evaluation of copper slag blast media for railcar maintenance

    Science.gov (United States)

    Sagers, N. W.; Finlayson, Mack H.

    1989-06-01

    Copper slag was tested as a blasting substitute for zirconium silicate which is used to remove paint from railroad cars. The copper slag tested is less costly, strips paint faster, is produced near the point of need, provides a good bonding surface for paint, and permits the operator to work in a more comfortable position, i.e., standing nearly erect instead of having to crouch. Outdoor blasting with the tested Blackhawk (20 to 40 mesh) copper slag is also environmentally acceptable to the State of Utah. Results of tests for the surface erosion rate with copper slag blasting are included.

  3. Chemical, Mineralogical, and Morphological Properties of Steel Slag

    Directory of Open Access Journals (Sweden)

    Irem Zeynep Yildirim

    2011-01-01

    Full Text Available Steel slag is a byproduct of the steelmaking and steel refining processes. This paper provides an overview of the different types of steel slag that are generated from basic-oxygen-furnace (BOF steelmaking, electric-arc-furnace (EAF steelmaking, and ladle-furnace steel refining processes. The mineralogical and morphological properties of BOF and electric-arc-furnace-ladle [EAF(L] slag samples generated from two steel plants in Indiana were determined through X-Ray Diffraction (XRD analyses and Scanning Electron Microscopy (SEM studies. The XRD patterns of both BOF and EAF(L slag samples were very complex, with several overlapping peaks resulting from the many minerals present in these samples. The XRD analyses indicated the presence of free MgO and CaO in both the BOF and EAF(L slag samples. SEM micrographs showed that the majority of the sand-size steel slag particles had subangular to angular shapes. Very rough surface textures with distinct crystal structures were observed on the sand-size particles of BOF and EAF(L slag samples under SEM. The characteristics of the steel slag samples considered in this study are discussed in the context of a detailed review of steel slag properties.

  4. Energy effective approach for activation of metallurgical slag

    Science.gov (United States)

    Mazov, I. N.; Khaydarov, B. B.; Mamulat, S. L.; Suvorov, D. S.; Saltikova, Y. S.; Yudin, A. G.; Kuznetsov, D. V.

    2016-01-01

    The paper presents results of investigation of the process of mechanical activation of metallurgical slag using different approaches - ball milling and electromagnetic vortex apparatus. Particle size distribution and structure of mechanically activated slag samples were investigated, as well as energetic parameters of the activation process. It was shown that electromagnetic vortex activation is more energy effective and allows to produce microscale milled slag-based concrete using very short treatment time. Activated slag materials can be used as clinker-free cement in civilian and road construction, providing ecology-friendly technology and recycling of high-tonnage industrial waste.

  5. Durability of Alkali Activated Blast Furnace Slag

    Science.gov (United States)

    Ellis, K.; Alharbi, N.; Matheu, P. S.; Varela, B.; Hailstone, R.

    2015-11-01

    The alkali activation of blast furnace slag has the potential to reduce the environmental impact of cementitious materials and to be applied in geographic zones where weather is a factor that negatively affects performance of materials based on Ordinary Portland Cement. The scientific literature provides many examples of alkali activated slag with high compressive strengths; however research into the durability and resistance to aggressive environments is still necessary for applications in harsh weather conditions. In this study two design mixes of blast furnace slag with mine tailings were activated with a potassium based solution. The design mixes were characterized by scanning electron microscopy, BET analysis and compressive strength testing. Freeze-thaw testing up to 100 freeze-thaw cycles was performed in 10% road salt solution. Our findings included compressive strength of up to 100 MPa after 28 days of curing and 120 MPa after freeze-thaw testing. The relationship between pore size, compressive strength, and compressive strength after freeze-thaw was explored.

  6. Artificial neural network model to predict slag viscosity over a broad range of temperatures and slag compositions

    Energy Technology Data Exchange (ETDEWEB)

    Duchesne, Marc A. [Chemical and Biological Engineering Department, University of Ottawa, 161 Louis Pasteur, Ottawa, Ont. (Canada); CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario (Canada); Macchi, Arturo [Chemical and Biological Engineering Department, University of Ottawa, 161 Louis Pasteur, Ottawa, Ont. (Canada); Lu, Dennis Y.; Hughes, Robin W.; McCalden, David; Anthony, Edward J. [CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario (Canada)

    2010-08-15

    Threshold slag viscosity heuristics are often used for the initial assessment of coal gasification projects. Slag viscosity predictions are also required for advanced combustion and gasification models. Due to unsatisfactory performance of theoretical equations, an artificial neural network model was developed to predict slag viscosity over a broad range of temperatures and slag compositions. This model outperforms other slag viscosity models, resulting in an average error factor of 5.05 which is lower than the best obtained with other available models. Genesee coal ash viscosity predictions were made to investigate the effect of adding Canadian limestone and dolomite. The results indicate that magnesium in the fluxing agent provides a greater viscosity reduction than calcium for the threshold slag tapping temperature range. (author)

  7. 急冷风速对建陶辊道窑急冷段内气体流动影响的数值模拟%Numerical Simulation of Inlfuence of Air-splat cooling Velocity on Gas-lfow in Splat Cooling Zone of Roller Hearth Kiln

    Institute of Scientific and Technical Information of China (English)

    童剑辉; 冯青

    2016-01-01

    本文采用计算流体动力学(CFD)Fluent软件,构建了辊道窑急冷段三维物理模型,并采用非结构化四面体网格对模型进行网格划分,选择标准K-两方程湍流模型,设置边界条件,对辊道窑急冷段内气体流动进行数值模拟,研究了急冷风速对急冷段内气体流动的影响。结果表明:增加急冷风速可减小管内风速和喷风小孔风速各自沿管长方向的差别,从而使管内急冷风温度沿管长方向分布更趋近均匀,同时也使沿管长方向相应各处的温度更低。适当增加急冷风速有助于加强砖坯与急冷风之间的对流换热,提高砖坯的冷却速率。但急冷风速增加过大时,会使气流速度沿窑宽方向相差较大,导致窑内宽两侧有较大温差,极可能使制品产生风裂或色差等烧成缺陷。%For the numerical simulation study on the inlfuence of air-splat cooling velocity on gas-lfow in the splat cooling zone of roller hearth kiln, the 3D physical model was constructed and meshed with tetrahedral grid by using CFD Fluent software. The standard K- two-equation turbulent lfow model was selected and the boundary conditions were set. The results show that increasing air-splat cooling velocity contributes to reduced difference of the velocity of air-splat cooling in tube as well as of air spraying from tiny holes along the length of tubes, which makes the temperature distribution of air-splat cooling in tube more even and the temperature of the corresponding location along the length of tubes lower. The appropriate increase of air-splat cooling velocity also can enhance the convection heat transfer between green bricks and air-splat cooling and further increase the cooling rate of green bricks, while an unreasonable rise in air-splat cooling velocity can cause the more serious difference in gas-lfow velocity distribution along the width of kiln. Consequently, the more difference in temperature between both

  8. Absorption of water vapour in the falling film of water-(LiBr + LiI + LiNO{sub 3} + LiCl) in a vertical tube at air-cooling thermal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bourouis, Mahmoud; Valles, Manel; Medrano, Marc; Coronas, Alberto [Centro de Innovacion Tecnologica en Revalorizacion Energetica y Refrigeracion, CREVER, Universitat Rovira i Virgili, Autovia de Salou, s/n, 43006, Tarragona (Spain)

    2005-05-01

    In air-cooled water-LiBr absorption chillers the working conditions in the absorber and condenser are shifted to higher temperatures and concentrations, thereby increasing the risk of crystallisation. To develop this technology, two main problems are to be addressed: the availability of new salt mixtures with wider range of solubility than water-LiBr, and advanced absorber configurations that enable to carry out simultaneously an appropriate absorption process and an effective air-cooling. One way of improving the solubility of LiBr aqueous solutions is to add other salts to create multicomponent salt solutions. The aqueous solution of the quaternary salt system (LiBr + LiI + LiNO{sub 3} + LiCl) presents favourable properties required for air-cooled absorption systems: less corrosive and crystallisation temperature about 35 K lower than that of water-LiBr.This paper presents an experimental study on the absorption of water vapour over a wavy laminar falling film of an aqueous solution of (LiBr + LiI + LiNO{sub 3} + LiCl) on the inner wall of a water-cooled smooth vertical tube. Cooling water temperatures in the range 30-45 C were selected to simulate air-cooling thermal conditions. The results are compared with those obtained in the same experimental set-up with water-LiBr solutions.The control variables for the experimental study were: absorber pressure, solution Reynolds number, solution concentration and cooling water temperature. The parameters considered to assess the absorber performance were: absorber thermal load, mass absorption flux, degree of subcooling of the solution leaving the absorber, and the falling film heat transfer coefficient.The higher solubility of the multicomponent salt solution makes possible the operation of the absorber at higher salt concentration than with the conventional working fluid water-LiBr. The absorption fluxes achieved with water-(LiBr + LiI + LiNO{sub 3} + LiCl) at a concentration of 64.2 wt% are around 60 % higher than

  9. Analysis of the Air Motion Flow Field in the Air Duct of an Air-cooled Steam Turbine Generator Rotor%空冷汽轮发电机转子风道中气体运动流场分析

    Institute of Scientific and Technical Information of China (English)

    吴德义

    2009-01-01

    In the light of the features of rotors running at a high speed,analyzed was the air moving status in the air duct of the rotors with a numerical calculation model being established.The analytic results show that the air motion in the rotor air duct is the result of a joint action of the fan and rotor high speed rotation.With the ventilation structure of a suction type air-cooled turbogenerator serving as an example,a rotor rotating at a speed of 3 000 r/min can increase the air admission quantity of the air duct from 0.14 kg/s to 0.21 kg/s,and the influence of the rotor rotation on the air motion in the air duct must be taken into account.The inviscid version should be chosen for a viscid model.A comparison of model test results of the rotor air duct outlet air speed with the numerical simulation ones under same conditions indicates that the numerical simulation ones are in agreement with relevant engineering practice.A rational calculation model for the air motion flow field in the air duct of the rotors shall be as follows:the suction type fan and the inlet of the air duct of the rotor are used as the inlet and outlet boundary conditions,the rotor rotation is considered in the fluid boundary condition,the relative coarseness coefficient and constants in the wall boundary conditions which reflect the surface coarseness of the tube walls shall be K_s~+=500~1000 and C_k=1.0 respectively.An inviscid model would be chosen for the viscous model.The calculation model in question can be used to analyze the air motion flow field in the rotor air duct of the air-cooled turbogenerator.%针对转子高速转动的特点,分析了转子风道气体运动状态,建立了数值计算模型.分析结果表明,转子风道气体运动是由风扇和转子高速转动共同作用的结果,以吸入式空冷汽轮发电机通风结构为例,转子以3 000 r/min转速绕轴高速转动可以使风道中进风量由0.14 kg/s增加到0.21 kg/s,必须考虑转子转动对风道中

  10. Foamability of stainless steelmaking slags in an EAF

    Science.gov (United States)

    Kerr, James John

    Foaming in electric furnace steelmaking is desirable to allow for a longer arc and subsequently higher power operation in order to reduce the tap to tap time and consequently increase productivity. Stainless steelmaking slags do not foam as well as carbon steelmaking slags. To produce foam, the foamability or foam index of a slag and the gas generation rate must be adequate. The possible causes for the poor foamability of stainless steelmaking slags were examined in this research. Specifically the foam index of a simulated stainless steelmaking slag containing chrome oxide was measured and the rate at which carbon reacts with Cr2O3, CrO, and FeO was also measured. The experimental results show that the foam index of stainless steelmaking slags is comparable to carbon steelmaking slags provided that the amount of solid chrome oxide particles or complexes is not excessive. This indicates the low foamability is not due to a poor foam index. Gas is normally generated by cycling carbon into the slag, which produces CO by reducing oxides in the slag. The experimental results demonstrate that the reaction rate of carbon with CrO dissolved in the slag and hence the generation of CO is significantly slower than for the reaction rate of carbon with FeO dissolved in slags. Therefore, the lack of FeO or other reducible oxides in stainless steelmaking slags is a primary reason for the poor foamability. Experimental results indicate that limestone, nickel oxide, calcium nitrate, and waste oxide briquettes generate gas at sufficient rates to induce foaming when added to the stainless steelmaking slag. Heat transfer most likely controls the rate of CO2 generated by limestone and NiO reduction is controlled by mass transfer of NiO to the carbon in the slag. WOBs generate gas very rapidly due to intimate mixing of the carbon and iron oxides at unit activity. Calcium nitrate generates gas by dissociation and heat transfer likely controls the dissociation rate. Simple models are

  11. The Optimization of Air Cooling Platform in the Waste Incineration Plants%直接空冷垃圾焚烧电厂的数值模拟计算分析

    Institute of Scientific and Technical Information of China (English)

    陈芹; 张冬洁; 许向阳

    2011-01-01

    With a wide range of application and the safe operation of the air cooling technology in a large thermal power plants, more and more waste incineration plants in the northern water scarcity region tend to use air cooling technology. Because the differences of the waste incineration plants and power plants in the form and air-cooled plant layout in the size of the island, we can not apply a simple air-cooled power plant technology, with the situation on the ground of waste incineration plant in Dalian and to use numerical simulation at this plant, in order to provide a theoretical reference at the designed of waste incineration plant in the latter.%随着空冷技术在大型火力电厂上的广泛应用和安全运行,越来越多的在北方缺水地区建设的垃圾焚烧电厂,倾向于采用空冷技术,由于垃圾焚烧电厂与火力发电厂在厂房布置形式和空冷岛大小的差异,导致我们并不能简单的套用火力发电厂的空冷技术,在结合大连垃圾焚烧电厂的实地情况,并对该电厂进行空冷技术的数值模拟计算,为后期垃圾焚烧电厂的设计提供理论参考。

  12. Comparison and Analysis on Heating Performance of Evaporative Cooling Heat Pump Unit and Air Cooled Heat Pump Unit%蒸发冷却式热泵机组与风冷热泵机组制热性能对比分析

    Institute of Scientific and Technical Information of China (English)

    张勇; 李志明; 张结良; 黄锐坚

    2015-01-01

    A new application of heat pump technology, evaporative cooling heat pump, was proposed in order to overcome the drawback of the heat losses of conventional air cooled heat pump units during frosting and defrosting. The experimental results show that the average heating capacities of air cooled heat pump unit decrease seriously at low ambient temperatures. At –2 oC ambient temperature, the average heating capacity is 53%of the nominal heating capacity. At ambient temperatures lower than 3 oC, the average heating capacity of the evaporative cooling heat pump unit is higher than that of the air cooled heat pump unit.%本文介绍了一种新的热泵技术应用形式——蒸发冷却式热泵,可以克服传统风冷热泵在结霜、融霜情况下热量的损失。试验结果表明:在低环境温度下,风冷热泵机组的平均制热量衰减较为严重;在环境温度-2℃时,风冷热泵的平均制热量只有名义制热工况热量的约53%;在环境温度低于3℃时,蒸发冷却式热泵机组提供的平均制热量高于风冷热泵的平均制热量。

  13. 蒸发冷却式热泵机组与风冷热泵机组制热性能对比分析%Comparison and Analysis on Heating Performance of Evaporative Cooling Heat Pump Unit and Air Cooled Heat Pump Unit

    Institute of Scientific and Technical Information of China (English)

    张勇; 李志明; 张结良; 黄锐坚

    2015-01-01

    A new application of heat pump technology, evaporative cooling heat pump, was proposed in order to overcome the drawback of the heat losses of conventional air cooled heat pump units during frosting and defrosting. The experimental results show that the average heating capacities of air cooled heat pump unit decrease seriously at low ambient temperatures. At –2 oC ambient temperature, the average heating capacity is 53%of the nominal heating capacity. At ambient temperatures lower than 3 oC, the average heating capacity of the evaporative cooling heat pump unit is higher than that of the air cooled heat pump unit.%本文介绍了一种新的热泵技术应用形式——蒸发冷却式热泵,可以克服传统风冷热泵在结霜、融霜情况下热量的损失。试验结果表明:在低环境温度下,风冷热泵机组的平均制热量衰减较为严重;在环境温度-2℃时,风冷热泵的平均制热量只有名义制热工况热量的约53%;在环境温度低于3℃时,蒸发冷却式热泵机组提供的平均制热量高于风冷热泵的平均制热量。

  14. Effect of SiO2 on the Crystallization Behaviors and In-Mold Performance of CaF2-CaO-Al2O3 Slags for Drawing-Ingot-Type Electroslag Remelting

    Science.gov (United States)

    Shi, Cheng-Bin; Li, Jing; Cho, Jung-Wook; Jiang, Fang; Jung, In-Ho

    2015-10-01

    The crystallization characteristics of CaF2-CaO-Al2O3 slags with varying amounts of SiO2 were experimentally studied. The effects of slag crystallization behaviors on the horizontal heat transfer and lubrication performance in drawing-ingot-type electroslag remelting (ESR) were also evaluated in terms of as-cast ingots surface quality and drawing-ingot operation. The results show that increasing SiO2 addition from 0 to 6.8 mass pct strongly suppresses the crystallization of ESR type CaF2-CaO-Al2O3 slags. The crystallization temperature of the studied slags decreases with the increase in SiO2 addition. The liquidus temperatures of the slags also show a decreasing trend with increasing SiO2 content. In CaF2-CaO-Al2O3-(SiO2) slags, faceted 11CaO·7Al2O3·CaF2 crystals precipitate first during continuous cooling of the slag melts, followed by the formation of CaF2 at lower temperatures. 11CaO·7Al2O3·CaF2 was confirmed to be the dominant crystalline phase in the studied slags. CaF2-CaO-Al2O3 slags with a small amount of SiO2 addition are favorable for providing sound lubrication and horizontal heat transfer in mold for drawing-ingot-type ESR, which consequently bring the improvement in the surface quality of ESR ingot and drawing-ingot operating practice as demonstrated by plant trials.

  15. Evaluation of Active Cooling Systems for Non-Residential Buildings

    OpenAIRE

    M.A. Othuman Mydin

    2014-01-01

    Cooling systems are an essential element in many facets of modern society including cars, computers and buildings. Cooling systems are usually divided into two types: passive and active. Passive cooling transfers heat without using any additional energy while active cooling is a type of heat transfer that uses powered devices such as fans or pumps. This paper will focus on one particular type of passive cooling: air-conditioning systems. An air-conditioning system is defined as controlled air...

  16. Phase analytical studies of industrial copper smelting slags. Part I: Silicate slags

    Science.gov (United States)

    Rüffler, R.; Dávalos, J.

    1998-12-01

    The pyrometallurgical extraction of copper from sulfide ore concentrates is determined by the behaviour of the associated iron during smelting. Hence, 57Fe Mössbauer spectroscopy is an attractive tool for studying the phases in silicate slags from German and Chilean smelting plants. Other methods used were ore microscopy, electron microprobe analysis, and X-ray powder diffraction.

  17. Micronutrient availability from steel slag amendment in pine bark substrates

    Science.gov (United States)

    Steel slag is a byproduct of the steel industry that can be used as a liming agent, but also has a high mineral nutrient content. While micronutrients are present in steel slag, it is not known if the mineral form of the micronutrients would render them available for plant uptake. The objective of...

  18. China Customs Removed the Import Tax on Titanium Slag

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>The long waited solution to the problem relating to the import of titanium slag has finally resolved. According to China Customs report, the import of titanium slag no longer requires tax payment as from January 1, 2007. This decision will help with the healthy development of China’s titanium industry and increase China’s competitiveness in the international marketplace.

  19. Sulfide capacity of high alumina blast furnace slags

    Science.gov (United States)

    Shankar, Amitabh; Görnerup, Märten; Seetharaman, S.; Lahiri, A. K.

    2006-12-01

    Sulfide capacities of high alumina blast furnace slags were experimentally determined using the gas-slag equilibration technique. Two different slag systems were considered for the current study, namely, CaO-SiO2-MgO-Al2O3 quaternary and CaO-SiO2-MgO-Al2O3-TiO2 quinary system. The liquid slag was equilibrated with the Ar-CO-CO2-SO2 gas mixture. Experiments were conducted in the temperature range of 1773 to 1873 K. The effects of temperature, basicity, and the MgO and TiO2 contents of slags on sulfide capacity were studied. As expected, sulfide capacity was found to increase with the increase in temperature and basicity. At the higher experimental temperature, titania decreases the sulfide capacity of slag. However, at the lower temperature, there was no significant effect of titania on the sulfide capacity of slag. Sulfide capacity increases with the increase in MgO content of slag if the MgO content is more than 5 pct.

  20. A ceramographic evaluation of chromia refractories corroded by slag

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, Alton H.; Chinn, Richard E.

    2001-01-01

    This paper describes the ceramographic preparation of Cr{sub 2}O{sub 3}-Al{sub 2}O{sub 3} refractory bricks and subsequent microstructural analysis to determine the corrosive effects of molten slag. The porous and friable nature of the brick, especially after exposure to the slag or its individual components, presented some problems in the preparation.

  1. Interactions of Refractory Materials with Molten Gasifier Slags

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Jimichiro; Sridhar, Seetharaman; Kwong, Kye-Sing; Bennett, James; Moss, Tyler

    2011-04-01

    The current study focuses on the analysis of sessile-drop interfacial reactions between two synthetic slags (based on average ash chemistries of coal and petcoke feedstock) and two refractory materials (90 wt% Cr{sub 2}O{sub 3}–10 wt% Al{sub 2}O{sub 3} and 100 wt% Al{sub 2}O{sub 3}), using a Confocal Scanning Laser Microscope (CSLM). Ground slag samples (less than 325 mesh) were placed at specific microstructure locations on refractory substrates and heated to 1500 °C in an atmosphere of CO/CO{sub 2} gas mixture (volume ratio = 1.8), using a gold-image heating chamber. Cross-sections of the slag/refractory interface indicated unique slag penetration into preferred areas of the refractory and grain dissolution into the slag which promoted spalling of the refractory. Initially, the slag attacked both grain boundaries and fine microstructure areas, freeing alumina grains into the slag. The formation of VO{sub x}-based crystalline material in the petcoke slag was found to alter the liquid composition. Chemical spalling of Cr-containing crystal layer also facilitated degradation of the refractory.

  2. Interactions of refractory materials with molten gasifier slags

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, J.; Sridhar, S.; Bennett, J.; Kwong, K.S.; Moss, T. [US DOE, Albany, OR (United States)

    2011-04-15

    The current study focuses on the analysis of sessile-drop interfacial reactions between two synthetic slags (based on average ash chemistries of coal and petcoke feedstock) and two refractory materials (90 wt% Cr2O{sub 3}-10 wt% Al{sub 2}O{sub 3} and 100 wt% Al{sub 2}O{sub 3}), using a Confocal Scanning Laser Microscope (CSLM). Ground slag samples (less than 325 mesh) were placed at specific microstructure locations on refractory substrates and heated to 1500 {sup o}C in an atmosphere of CO/CO{sub 2} gas mixture (volume ratio = 1.8), using a gold-image heating chamber. Cross-sections of the slag/refractory interface indicated unique slag penetration into preferred areas of the refractory and grain dissolution into the slag which promoted spalling of the refractory. Initially, the slag attacked both grain boundaries and fine microstructure areas, freeing alumina grains into the slag. The formation of VOx-based crystalline material in the petcoke slag was found to alter the liquid composition. Chemical spalling of Cr-containing crystal layer also facilitated degradation of the refractory.

  3. Space Characteristics of Exhaust Plume Recirculation Flow Ratios for Air-Cooled Condensers at Ambient Winds%风场影响下直接空冷系统热风回流率的空间分布特性

    Institute of Scientific and Technical Information of China (English)

    杨立军; 杜小泽; 杨勇平

    2011-01-01

    Ambient winds may lead to the worsened exhaust plume recirculation flows and the deteriorated heat transfer performances of the air-cooled condensers in a power plant.It can be of use for the design and operation of the direct dry cooling system to investigate the space characteristics of the exhaust plume recirculation flow ratios for the air-cooled condensers at ambient winds.On the basis of the representative 2×600 MW direct dry cooling power plant,the flow and temperature fields of the cooling air are presented and the exhaust plume recirculation flow ratios of the air-cooled condensers and condenser cells are calculated by using the numerical simulation.The results show that the exhaust plume recirculation flows are enhanced owing to the increase of the wind speeds and vary widely with the wind directions.The wind blowing from the main buildings is most unfavorable for the exhaust plume recirculation flows.The exhaust plume recirculation flow ratios present space-dependent characteristics and the conspicuous differences are presented among the condenser cells at various locations.The upwind condenser cells generally have more disadvantageous plume recirculation flows.%环境风场影响下,电站直接空冷系统热风回流加剧,传热性能恶化。掌握风场作用下直接空冷系统热风回流率的空间分布特性,可为空冷系统的设计和运行提供理论依据。以典型2×600 MW直接空冷电站为例,通过数值模拟获得了冷却空气流场和温度场,分别计算了空冷岛和各个空冷单元的热风回流率。计算结果表明,随环境风速增加,空冷岛热风回流率升高,并随风向发生显著变化,炉后来风时空冷岛热风回流最为严重。空冷单元热风回流率呈现空间分布特性,风场不同区域空冷单元热风回流存在显著差异,处于风场上游空冷单元通常具有更大的热风回流率。

  4. Phosphate enrichment mechanism in CaO-SiO2-FeO-Fe2O3-P2O5 steelmaking slags with lower binary basicity

    Science.gov (United States)

    Li, Jin-yan; Zhang, Mei; Guo, Min; Yang, Xue-min

    2016-05-01

    The addition of silica to steelmaking slags to decrease the binary basicity can promote phosphate enrichment in quenched slag samples. In this study, we experimentally investigated phosphate enrichment behavior in CaO-SiO2-FeO-Fe2O3-P2O5 slags with a P2O5 content of 5.00% and the binary basicity B ranging from 1.0 to 2.0, where the (%Fe t O)/(%CaO) mass percentage ratio was maintained at 0.955. The experimental results are explained by the defined enrichment degree R_{C_2 S - C_3 P} of solid solution 2CaO·SiO2-3CaO·P2O5 (C2S-C3P), where R_{C_2 S - C_3 P} is a component of the developed ion and molecule coexistence theory (IMCT)- N i model for calculating the mass action concentrations N i of structural units in the slags on the basis of the IMCT. The asymmetrically inverse V-shaped relation between phosphate enrichment and binary basicity B was observed to be correlated in the slags under applied two-stage cooling conditions. The maximum content of P2O5 in the C2S-C3P solid solution reached approximately 30.0% when the binary basicity B was controlled at 1.3.

  5. Properties of Foamed Mortar Prepared with Granulated Blast-Furnace Slag

    Directory of Open Access Journals (Sweden)

    Xiao Zhao

    2015-01-01

    Full Text Available Foamed mortar with a density of 1300 kg/m3 was prepared. In the initial laboratory trials, water-to-cement (w/c ratios ranging from 0.54 to 0.64 were tested to determine the optimal value for foamed mortar corresponding to the highest compressive strength without compromising its fresh state properties. With the obtained optimal w/c ratio of 0.56, two types of foamed mortar were prepared, namely cement-foamed mortar (CFM and slag-foamed mortar (SFM, 50% cement was replaced by slag weight. Four different curing conditions were adopted for both types of foamed mortar to assess their compressive strength, ultrasonic pulse velocity (UPV and thermal insulation performance. The test results indicated that utilizing 50% of slag as cement replacement in the production of foamed mortar improved the compressive strength, UPV and thermal insulation properties. Additionally, the initial water curing of seven days gained higher compressive strength and increased UPV values as compared to the air cured and natural weather curing samples. However, this positive effect was more pronounced in the case of compressive strength than in the UPV and thermal conductivity of foamed mortar.

  6. Survey of materials and corrosion performance in dry cooling applications

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.B.; Pratt, D.R.; Zima, G.E.

    1976-03-01

    The report presented summarizes aqueous and air-side corrosion aspects of candidate materials in dry cooling applications. The applications include piping, condensers, louvers, structures, and the air-cooled surfaces.

  7. Slag-Resistance of MgAlON Spinel

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The slag-resistance and microstructural changes after the slag tests of MgAlON spinel containing different amount of nitrogen were studied by means of crucible slag-resistant experiment, SEM and EDS in the work. The results show that the slag-resistance of MgAlON is dependent on the nitrogen content, and the optimum amount is 2.88%. The structure is not changed although the grains have been permeated by some silicon, calcium and iron. A glass phase which contained nitrogen formed in the metamorphic layer. The glass can improve the ability of the slag-resistance of MgAlON because of its higher viscosity.

  8. Chemical and mineralogical characterizations of a copper converter slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A copper converter slag was examined chemically and mineralogically to determine its existing phases, in particular those containing Co and Cu. The slag consists predominantly of fayalite and magnetite, together with some glass,chalcocite, and metallic copper. Copper is entrapped in the slag mostly as chalcocite and metallic copper, as well as trace copper oxide. There was no indication of any independent Co mineral in the slag, but Co was found to be enriched in fayalite and megnetite as solid solution, although Co was detected in all the phases of the slag by SEM-EDX (scanning electron microscopy equipped with model EDAX-9100 energy dispersive spectrometer) and WDS (model WDX-2A X-ray wave-length dispersive spectrometer).

  9. Roles of Mineralogical Phases in Aqueous Carbonation of Steelmaking Slag

    Directory of Open Access Journals (Sweden)

    Huining Zhang

    2016-05-01

    Full Text Available Mineralogical phases of steelmaking slags have significant influences on the carbonation of the slags. In this paper, the effects of temperature and reaction time on the conversion of calcium-related phases and the carbonation degree of a slag sample were studied. The experimental conditions were a liquid-to-solid ratio of 20 mL/g, a carbon dioxide flow rate of 1 L/min and a slag particle size of 38–75 μm. The results show that the optimum carbonation temperature and reaction time are 60 °C and 90 min, respectively, and calcite phase content is about 26.78% while the conversion rates of Ca3Al2O6, CaSiO3, Ca2SiO4 and free CaO are about 40%, 42.46%, 51% and 100%, respectively, and the carbon dioxide sequestration efficiency is about 170 g/kg slag.

  10. 600MW火电机组空冷技术的研发与工程示范%Research and demonstration of direct air-cooling system for 600 MW fossil-fired power plants

    Institute of Scientific and Technical Information of China (English)

    张晓鲁; 汪建平; 胡振岭

    2011-01-01

    Considering the characteristics of water resources distribution, the needs of power industry development in China and foreign monopoly of air-cooling technologies,independen research and development of air-cooling technologies for fossil-fired power plants is very necessary and significant.Through test and research, simulation and calculation, process and equipment development,industrial experiment and demonstration project, the key technologies of air-cooling system were studied, the design and operation technologies of air-cooling system were grasped,the key equipment was developed and the demonstration project was completed.The demonstration project shows that the technical indicators of the air-cooling system have been reached or exceeded the design requirements.Part of the research results have been ncorporated into relevant national design standards.The technologies have been applied in 23 fossil-fired units of 600 MW or above in China.%鉴干我国资源分布的特点、电力工业的发展需要和国外对空冷技术垄断的实际情况,自主研究开发火电厂空冷技术十分必要且意义重大.通过试验研究、模拟计算、工艺开发、设备研制、工业试验、工程示范等方法和手段,进行空冷系统关键技术研究,掌握了空冷系统设计技术和运行技术,研制了空冷系统关键设备,完成了工程示范.工程示范结果表明,空冷系统各项技术指标达到或超过设计要求.部分研究成果已编人国家有关设计标准.项目所研发的技术已应用于国内23台600 M W以上容量的火电机组.

  11. Effect of TiO2 Content on the Crystallization Behavior of Titanium-Bearing Blast Furnace Slag

    Science.gov (United States)

    Hu, Meilong; Wei, Ruirui; Yin, Fangqing; Liu, Lu; Deng, Qingyu

    2016-09-01

    The content of TiO2 has an important influence on both the basic structure and the crystallization behavior of titanium-bearing blast furnace (BF) slag. The results of thermodynamic calculations show that, when the mass content of TiO2 is smaller than 25%, CaTiO3 increases as the content of TiO2 increases. However, when the TiO2 content is more than 25%, the CaTiO3 content decreases and TiO2 gradually increases. The results of a confocal laser scanning microscopy (CLSM) experiment show that, when the TiO2 mass content is 10%, Ca2MgSi2O7 and Ca2Al2SiO7 are the main crystallized phases resulting from the molten slag. Furthermore, when the TiO2 mass content is 20%, CaMgSi2O6, Ca(Ti,Mg,Al)(Si,Al)2O7 and dendrite CaTiO3 are the crystallized phases, while when the TiO2 mass content increases to 30%, CaTiO3 is the sole phase. The discrepancy between the CLSM results and the thermodynamic calculations occurs mainly due to the high melting point of the titanium-bearing BF slag. During the cooling process for the molten slag, CaTiO3 is crystallized first, due to its high crystallization temperature. Furthermore, the molten slag is solidified in its entirety before the other phases crystallize.

  12. An optimization study on transesterification catalyzed by the activated carbide slag through the response surface methodology

    International Nuclear Information System (INIS)

    Highlights: • New catalyst material for biodiesel production. • New utilization approach of waste carbide slag. • Detailed characterization of carbide slag used as transesterification catalyst. • Optimal parameters for biodiesel production obtained by response surface methodology. • Effect of impurities on catalytic activity of carbide slag in transesterification. - Abstract: After activated at 850 °C under air condition, calcium hydroxide and calcium carbonate in carbide slag are transformed into calcium oxide. The prepared transesterification catalyst, labeled as CS-850, gains surface area of 8.00 m2 g−1, functional groups of vanishing O−C−O and O−H bonds, surface morphology of tenuous branch and porous structure and basic strength of 9.8 < H– < 15.0. From aspects of the molar ratio of methanol to oil (γ), the catalyst added amount (ζ) and the reaction temperature (Tr), transesterification catalyzed by CS-850 is optimized through the Box–Behnken design of the response surface methodology (BBD–RSM). A quadratic polynomial model is preferred for transesterification efficiency prediction with coefficient of determination (R2) of 0.9815. The optimal parameters are predicted to be γ = 13.8, ζ = 6.7% and Tr = 60 °C with the efficiency of 94.70% and validated by experimental value of 93.83%. Meanwhile, γ is demonstrated to be the most significant variable for the minimum p-value. Besides, CS-850 performs acceptable reusability and for the fifth time reusage, efficiency of 82.61% could still be supplied. Aluminium oxide is proved to have the greatest effect on the catalytic activity of CS-850 among other small quality oxides. Physicochemical properties of the purified biodiesel meet American Society for Testing and Material (ASTM) standard

  13. Compressor ported shroud for foil bearing cooling

    Science.gov (United States)

    Elpern, David G.; McCabe, Niall; Gee, Mark

    2011-08-02

    A compressor ported shroud takes compressed air from the shroud of the compressor before it is completely compressed and delivers it to foil bearings. The compressed air has a lower pressure and temperature than compressed outlet air. The lower temperature of the air means that less air needs to be bled off from the compressor to cool the foil bearings. This increases the overall system efficiency due to the reduced mass flow requirements of the lower temperature air. By taking the air at a lower pressure, less work is lost compressing the bearing cooling air.

  14. 24 CFR 3280.511 - Comfort cooling certificate and information.

    Science.gov (United States)

    2010-04-01

    ... such air conditioners are rated at 0.3 inch water column static pressure or greater for the cooling air... following shall be supplied in the Comfort Cooling Certificate: Air Conditioner Manufacturer Air Conditioner... Conditioner Manufacturer Certified Capacity ___ BTU/Hr. in accordance with the appropriate Air......

  15. Progress in Slag Foaming in Metallurgical Processes

    Science.gov (United States)

    Zhu, Tai Xi; Coley, K. S.; Irons, G. A.

    2012-08-01

    Professor Fruehan has been a pioneer in the fundamental understanding of slag foaming in ironmaking and steelmaking processes. Although considerable progress has been made in our understanding of the phenomena, there are still unanswered questions regarding the mechanisms in industrial processes and how to control them. At McMaster University, we have been working on conditions that are relevant to foaming in electric arc furnaces (EAFs) where these phenomena are central to modern EAF practices. This work will be reviewed and put in the context of what is known from a fundamental standpoint.

  16. 风冷冷热水机组测试系统的优化改进%Optimization of the Test System for Air-Cooled and Cold/Hot Water Unit

    Institute of Scientific and Technical Information of China (English)

    田杰; 余晓明; 李萌; 忍继斌; 张强

    2016-01-01

    在原有实验系统的基础上,对风冷冷热水机组进行优化设计,并针对常规系统中余热存在浪费的现象,以及制冷机和空气加热器同时工作造成极大能源浪费的问题进行了优化改进。为了节省风冷冷热水机组性能测试试验室的耗电量,提出了一种新型试验室节能改进设计方案,即在工况机组上增设热回收器回收利用高温高压气体,以期达到节能目的。%The air-cooled and cold/hot water unit is optimized with the original experiment system. Both the waste heat in the general system and the serious energy waste while refrigerators and air heaters operate together, are improved. In order to save the power consumption of performance testing laboratory for air -cooled and cold/hot water unit, this paper presents a new type of energy saving improvement solution for laboratory design installing the heat reclaiming device on the operated unit to recovery air of high temperature and high pressure, and achieve the goal of energy saving.

  17. 600MW直接空冷机组热力系统的(火用)分析与评价%Exergy Analysis and Assessment on Thermodynamic System of 600MW Direct Air-cooled Unit

    Institute of Scientific and Technical Information of China (English)

    蒋爱华; 蒋琪琳; 杜金魁; 余煌

    2011-01-01

    In order to reveal mechanisms of the irreversible exergy loss of the thermodynamic system of a direct air-cooled unit and explore the energy saving potential, exergy analysis and energy-saving assessment were performed to the thermodynamic system of a 600MW direct air-cooled unit.The results show that: the exergy efficiency of 600MW direct aircooled units is 39.08%, the total exergy loss accounts for 60.92%.The exergy loss coefficient of the condenser of the unit is 6.11% , and the same item of water cooled units of the same capacity is only 2.23% , so some energy-saving measures must be taken for the condenser to improve exergy efficiency of direct air-cooling units.%为揭示直接空冷机组热力系统的不可逆(火用)损失的机理和挖掘其节能潜力,对600MW直接空冷机组的热力系统进行了(火用)分析和节能评价.结果表明:600MW直接空冷机组的目的(火用)效率为39.08%,总损失占60.92%.凝汽器的(火用)损系数为6.11%,而相同容量水冷机组的凝汽器(火用)损系数仅为2.23%,因此,必须对凝汽器采取节能措施,提高直接空冷机组的整体(火用)效率.

  18. Study on aluminothermic reduction of V2O5: effect of slag chemistry

    International Nuclear Information System (INIS)

    Vanadium alloys are promising candidate materials for structural components of fusion reactors because of their superior high temperature thermal and physical properties, low cross section to neutrons, low activation properties and good resistance against neutron irradiation. Increased level of interstitial impurities like O and N in vanadium is known to have several detrimental effects on the workability and weldability of alloys. Activation consideration also place limitation on N content. In the present study, systematic work is done with the use of modern analytical techniques to better understand the science of the thermit process of vanadium so that it can be applied efficiently at bigger scale. In literature, generally CaO is used as a fluxing agent, to minimize excess heat and also for good slag metal separation in aluminothermy. Normally heat sinks are added in order to control the heat of reaction. This study shows that apart from the quantity, it is the nature of heat sink/flux, which plays an important role in controlling the heat of reaction, which subsequently result in better yield and quality of the product. Effect of various parameters like amount of heat sink/flux, nature of heat sink, excess aluminum and particle size of Al has been studied. Heat sink materials/ fluxes were added to control the vigorous nature of the reaction and a corresponding increase in slag volume (resulting in thicker slag layer) was also intended. Increased slag volume was expected to decrease the interaction of air with the molten metal thereby resulting in minimization of nitrogen in the final metal. This aspect is examined in detail in the present work. It will help in better understanding of the process as far as the contribution of nitrogen in thermit from air and starting material. In general, during the aluminothermic reduction, MgO walled reactors is used, but in this study it is shown that substantial amount of MgO also participate in the aluminothermy. The role

  19. The Change and Performance Analysis of Peak Load Cooling System Used in 600MW Direct Air Cooling Unit%600MW直接空冷机组加装尖峰冷却装置改造及性能分析

    Institute of Scientific and Technical Information of China (English)

    樊小朝; 党岳; 史瑞静; 李凤婷; 蒋高峰

    2013-01-01

    The higher operating vacuum pressure of air-cooled power plant greatly affects the safety and power output of steam turbine in summer,so the method of reducing air temperature by peak load cooling system in used.The tide over summer capacity of air cooled condenser can also be improved by this method.This paper states on peak load spray humidification changed in Datang Binchang power generation Co.Ltd.We are contrast and analysis direct air-cooled vacuum after the peak load spray humidification used in different load and different temperature in summer.The vacuum press reduce 4.9kPa,5.1 kPa,3.3kPa in different loading of 600MW,550MW,500MW and different temperature of 26℃ ~31 ℃.The higher efficiency of spray humidification in 550 ~ 600MW,the efficiency will lower in small loading and high air-cooled vacuum; lastly,we are estimate the economy efficiency in full loading of steam turbine.%为解决空冷发电厂夏季高背压运行影响汽轮机安全问题,保证机组的出力,直接空冷机组都采用了尖峰冷却装置,以提高直接空冷机组渡夏能力.介绍大唐彬长电厂机组空冷尖峰喷淋装置的改造,并针对夏季高温时段,不同负荷、不同环境温度下,投运尖峰冷却装置后机组真空的变化进行了对比分析;结果表明,机组在600MW、550MW、500MW负荷运行且环境温度26℃~31℃时,机组的背压分别下降4.9kPa、5.1kPa、3.3kPa.机组在550MW~ 600MW运行时,投运尖峰冷却装置效率最高,负荷越低,背压越低时,投运尖峰冷却装置效率越低;最后对机组在满负荷运行情况下所取得的经济效益进行了评估.

  20. 40 CFR Table 4 to Subpart F of... - Organic Hazardous Air Pollutants Subject to Cooling Tower Monitoring Requirements in § 63.104

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Organic Hazardous Air Pollutants... STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry Pt. 63, Subpt. F,...

  1. Vanadium bioavailability in soils amended with blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Maja A., E-mail: maja.larsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Baken, Stijn, E-mail: stijn.baken@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Smolders, Erik, E-mail: erik.smolders@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Cubadda, Francesco, E-mail: francesco.cubadda@iss.it [Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161 (Italy); Gustafsson, Jon Petter, E-mail: jon-petter.gustafsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Division of Land and Water Resources Engineering, KTH Royal Institute of Technology, Brinellvägen 28, 100 44 Stockholm (Sweden)

    2015-10-15

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg{sup −1}) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment.

  2. On the Dissolution Behavior of Sulfur in Ternary Silicate Slags

    Science.gov (United States)

    Kang, Youn-Bae; Park, Joo Hyun

    2011-12-01

    Sulfur dissolution behavior, in terms of sulfide capacity ( C S), in ternary silicate slags (molten oxide slags composed of MO - NO - SiO2, where M and N are Ca, Mn, Fe, and Mg), is discussed based on available experimental data. Composition dependence of the sulfur dissolution, at least in the dilute region of sulfur, may be explained by taking into account the cation-anion first-nearest-neighbor (FNN) interaction (stability of sulfide) and the cation-cation second-nearest-neighbor (SNN) interaction over O anion (oxygen proportions in silicate slags). When the Gibbs energy of a reciprocal reaction MO + NS = MS + NO is positive, the sulfide capacity of slags with virtually no SiO2 or low SiO2 concentration decreases as the concentration of MO increases. However, in some slags, as SiO2 concentration increases, replacing NO by MO at a constant SiO2 concentration may increase sulfide capacity when the basicity of NO is less than that of MO. This phenomenon is observed as rotation of iso- C S lines in ternary silicate slags, and it is explained by simultaneous consideration of the stability of sulfide and oxygen proportions in the silicate slags. It is suggested that a solution model for the prediction of sulfide capacity should be based on the actual dissolution mechanism of sulfur rather than on the simple empirical correlation.

  3. UTILIZATION OF LIGHTWEIGHT MATERIALS MADE FROM COAL GASIFICATION SLAGS

    Energy Technology Data Exchange (ETDEWEB)

    Vas Choudhry; Stephen Kwan; Steven R. Hadley

    2001-07-01

    The objective of the project entitled ''Utilization of Lightweight Materials Made from Coal Gasification Slags'' was to demonstrate the technical and economic viability of manufacturing low-unit-weight products from coal gasification slags which can be used as substitutes for conventional lightweight and ultra-lightweight aggregates. In Phase I, the technology developed by Praxis to produce lightweight aggregates from slag (termed SLA) was applied to produce a large batch (10 tons) of expanded slag using pilot direct-fired rotary kilns and a fluidized bed calciner. The expanded products were characterized using basic characterization and application-oriented tests. Phase II involved the demonstration and evaluation of the use of expanded slag aggregates to produce a number of end-use applications including lightweight roof tiles, lightweight precast products (e.g., masonry blocks), structural concrete, insulating concrete, loose fill insulation, and as a substitute for expanded perlite and vermiculite in horticultural applications. Prototypes of these end-use applications were made and tested with the assistance of commercial manufacturers. Finally, the economics of expanded slag production was determined and compared with the alternative of slag disposal. Production of value-added products from SLA has a significant potential to enhance the overall gasification process economics, especially when the avoided costs of disposal are considered.

  4. Phosphorus removal by electric arc furnace steel slag and serpentinite.

    Science.gov (United States)

    Drizo, Aleksandra; Forget, Christiane; Chapuis, Robert P; Comeau, Yves

    2006-05-01

    Electric arc furnace (EAF) steel slag and serpentinite were tested in columns either alone or mixed with limestone to determine their capacity to remove phosphorus (P) from a solution containing initially 20mg P/L (for 114 days) than 400mg P/L (for 21 days). EAF steel slag was nearly 100% efficient due to specific P adsorption onto metal hydroxides and precipitation of hydroxyapatite. Serpentinite also showed a good performance that decreased with time, adsorption appearing to be the dominant mechanism for P removal. Mixing limestone with these two materials did not improve their performance and in the case of serpentinite, it actually even decreased it. In 114 days of experimentation, serpentinite alone and the mixture of serpentinite and limestone removed 1.0mg P/g while in 180 days of experimentation, EAF steel slag and the mixture of slag and limestone removed an average of 2.2mg P/g, without attaining their maximum P removal potential. The void hydraulic retention time (HRTv) was a key factor for growing hydroxyapatite crystals and had a significant effect on P removal efficiency by EAF steel slag. A temporary increase in HRTv caused by clogging resulted in an increase in EAF steel slag efficiency (from 80% to almost 100%) towards the end of investigation. Results from this study indicate that the use of EAF steel slag in constructed wetlands or filter beds is a promising solution for P removal via adsorption and precipitation mechanisms.

  5. Utilizing steel slag in environmental application - An overview

    Science.gov (United States)

    Lim, J. W.; Chew, L. H.; Choong, T. S. Y.; Tezara, C.; Yazdi, M. H.

    2016-06-01

    Steel slags are generated as waste material or byproduct every day from steel making industries.The potential environmental issues which are related with the slag dump or reprocessing for metal recovery are generally being focused in the research. However the chemistry and mineralogy of slag depends on metallurgical process which is able to determine whether the steel slag can be the reusable products or not. Nowadays, steel slag are well characterized by using several methods, such as X-ray Diffraction, ICP-OES, leaching test and many more. About the industrial application, it is mainly reused as aggregate for road construction, as armour stones for hydraulic engineering constructions and as fertilizers for agricultural purposes. To ensure the quality of steel slag for the end usage, several test methods are developed for evaluating the technical properties of steel slag, especially volume stability and environmental behaviour. In order to determine its environmental behaviour, leaching tests have been developed. The focus of this paper however is on those applications that directly affect environmental issues including remediation, and mitigation of activities that negatively impact the environment.

  6. Comparison of possibilities the blast furnace and cupola slag utilization by concrete production

    OpenAIRE

    D. Baricová; A. Pribulová; P. Demeter

    2010-01-01

    In process of pig iron and cast iron production secondary raw materials and industrial wastes are formed The most abundant secondaryproduct originating in these processes are furnace slag. Blast furnace slag and cupola furnace slag originates from melting of gangue parts of metal bearing materials, slag forming additions and coke ash. In general, slag are compounds of oxides of metallic and non-metallic elements, which form chemical compounds and solutions with each other and also contain sma...

  7. 自然工质风冷太阳能双级喷射中低温空调制冷系统的设计及性能分析%Design and performance analysis of solar-powered air-cooled two-staged ejector cooling systems with natural refrigerants for middle and low temperature purpose

    Institute of Scientific and Technical Information of China (English)

    卢苇; 陈洪杰; 杨林; 曹聪

    2012-01-01

    依据中低温空调温度要求,分别以水、氨、R290和R600a为工质,设计了额定制冷量为10kW的风冷太阳能双级喷射制冷系统并对其进行变工况性能分析.在获得相同制冷量和室内温度的条件下,水系统最省材料,其次是氨和R290系统,且二者相当,R600a系统最耗材.4种工质系统均具有较强的变工况性能;综合考虑环境温度和太阳辐照度的影响,各系统制冷能力相当.水系统的COP较其他系统的高,且在低太阳辐照度时更明显;其余3个系统COP从高到低依次为氨、R290、R600a.在太阳辐照度较弱地区,使用水喷射制冷系统更合理.%According to the requirement of middle and low temperature air conditioning,the solar-powered air-cooled two-staged ejector cooling system with rated cooling capacity of 10 kW is designed,using water,ammonia,R290 and R600a as working fluids separately. The performance is analyzed. At certain cooling capacity and indoor temperature,the water system is the most material-saving system,followed by the ammonia and R290 ones with equivalent consumption,and the R600a system is the most material-consuming one. The four systems have relatively perfect off-design performance and their cooling capacities are almost the same on comprehensive consideration of the influences of ambient temperature and solar irradiance. Among the four systems,the water system presents higher COP value,the effect of which is more obvious under weaker solar irradiance,followed by ammonia system,R290 and R600a systems. A solar-powered air-cooled ejector refrigeration system with water as working fluid is more suitable for use in the regions with relatively weak solar irradiance.

  8. Simulation and Experiment on Air-Cooled Thermal Energy Management of Lithium-Ion Power Batteries%锂电池热管理中空气冷却效果的实验与模拟

    Institute of Scientific and Technical Information of China (English)

    张江云; 张国庆; 张磊; 饶中浩

    2011-01-01

    把空冷方法用于商业磷酸铁锂电池以分析强化传热效果。对商用磷酸铁锂电池进行15~35A的放电测试,并根据实验数据对单一电池的温度分布进行了数值模拟。分析和模拟了空气横掠2个和3个电池情况下的冷却效果。实验和模拟的结果表明:在0~30A电流放电的情况下,空气冷却对电池热管理具有积极作用。在放电电流小于30A的情况下时,电池的最大温度低于50℃,但是电池间的温差仍然高于5℃。在放电电流大于30A的情况,仅仅通过空气冷却不能使电池和电池组内温度均匀分布,即不能满足电池散热的需求。%The air-cooled methods were used for cooling commercial LiFePO4 batteries to illustrate the effect of heat transfer enhancement. The commercial LiFePO4 batteries were tested at 15-35 A. The temperature distribution in a single battery was numerical ly simulated according to the experiment al data. Air flow across two and three batteries was simulated to illustrate the air-cooled effect. Experiment al and simulation results show that air-coola has a positive significance for the battery thermal management at discharging currents of 0-30 A. For discharging currents less than 30 A, the peak temperature in batteries is less than 50 ℃, while the temperature difference between batteries is still more than 5 ℃. When the discharging current is higher than 30 A, air-cooling for batteries and battery packs can not guarantee evenly temperature distribution, not being able to meet the regui re ment of batteriy heat dissipation.

  9. 往复流散热方式的锂离子电池热管理%Thermal Management of Lithium-ion Battery with Reciprocating Air-flow Cooling Mode

    Institute of Scientific and Technical Information of China (English)

    梁波; 欧阳陈志; 刘燕平; 毛聪; 唐思绮; 江清柏

    2014-01-01

    For solving the problem of the temperature unevenness among individual cells in battery module affecting service performance and lifespan of battery, a reciprocating air-flow cooling mode is adopted in this paper, with which the direction of cooling air flow is reversed periodically to reduce the temperature gradient in battery a-long air-flow direction in conventional cooling mode with unidirectional air flow. The results show that with recipro-cating flow cooling mode, the temperature evenness of battery increases by 12. 1% and 62. 4% respectively under 1C and 13. 33 C discharge current rates, so the service performance and safety of battery greatly improved with its service life extended. In addition, an optimization is also carried out on three parameters affecting heat dissipation performance, i. e. the velocity and temperature of air flow at inlet and reversal frequency, with the law of their in-fluence on the highest temperature and temperature difference of battery revealed.%为解决电池模块内部单体电池间的温度不均匀性而影响电池的使用性能和寿命的问题,本文中采用了一种往复流冷却方式,使冷却空气流动方向周期性逆转,以降低单向流空气冷却方式时单体电池沿空气流方向的温度梯度。结果表明,采用往复流冷却方式后,在1C和13.33C放电倍率下,电池温度均匀性分别提高了12.1%和62.4%,电池模块的使用性能和安全性得到改善,电池使用寿命得以提高。同时,文中还利用计算流体动力学虚拟试验与正交优化相结合,对影响往复流散热性能的往复流入口的速度与温度和往复周期3个参数进行了优化,并揭示了它们对电池最高温度和温差的影响规律。

  10. 家用水冷式空调的运行特性实验研究%Experimental Research on the Operational Characteristics of Domestic Water-cooled Air-conditioners

    Institute of Scientific and Technical Information of China (English)

    陈华; 黄耀坤

    2011-01-01

    The operational characteristics of domestic water-cooled air-conditioners were studied through the experiment. The relationship between the performance of the system and the changes of indoor and outdoor conditions and cooling water flow rate was presented. The research will be useful to provide theoretical support for the product development.%通过实验,研究了家用水冷式空调的运行特性。探讨了室外环境温度、室外相对湿度、室内温度、室内负荷、室内显热比及冷却水流量等参数的变化对系统性能带来的影响,有助于进一步了解系统的运行规律,为产品的开发提供一定理论支持。

  11. Boron removal from molten silicon using sodium-based slags

    Institute of Scientific and Technical Information of China (English)

    Yin Changhao; Hu Bingfeng; Huang Xinming

    2011-01-01

    Slag refining,as an important option for boron removal to produce solar grade silicon (SOG-Si) from metallurgical grade silicon (MG-Si),has attracted increasing attention.In this paper,Na2CO3-SiO2 systems were chosen as the sodium-based refining slag materials for boron removal from molten silicon.Furthermore,the effect of Al2O3 addition for boron removal was studied in detail,which showed that an appropriate amount of Al2O3 can help retention of the basicity of the slags,hence improving the boron removal rate.

  12. Deoxidation and slag treatment of liquid steel. 1. Fundamental analysis

    International Nuclear Information System (INIS)

    By means of thermodynamic calculations and of special computer programs one determined the composition of nonmetallic inclusions (NI) developing in Kh18N9 stainless steel depending on alternative method of deoxidation by silicon, aluminium and titanium. One showed predominance of NI belonging to aluminium oxide base solid solution quality; one calculated oxygen partial pressure exerted on substances that corresponded to compositions of the selected slags under 1973 and 2273 K. One determined temperatures of liquidus surface of the mentioned slags and showed that four from mine slags under 1873 K turned to be liquid and homogeneous ones

  13. Cool contrails

    OpenAIRE

    U. Schumann

    2012-01-01

    Contrails are cirrus clouds which warm or cool the Earth depending on flight route and weather. Hence, the climate impact of aviation can be minimised by avoiding warming contrails and allowing for cooling contrails by proper weather dependent route selection. This article summarises recent research results on this topic.

  14. Desalting a process cooling water using nanofiltration

    NARCIS (Netherlands)

    Radier, R.G.J.; Oers, van C.W.; Steenbergen, A.; Wessling, M.

    2001-01-01

    The cooling water system of a chemical plant of Akzo Nobel is a partly open system. The site is located at the North Sea. The air in contact with the cooling water contains seawater droplets dissolving and increasing the chloride concentration. The cooling water contains chromate to protect the inst

  15. Heat Harmful Mine Air Cooling and Waste Heat Utilization System Design%热害矿井空气能系统降温与废热提级利用系统设计

    Institute of Scientific and Technical Information of China (English)

    邓宝; 张辉; 韩伟超; 孙永东; 姜志坡; 石银飞

    2014-01-01

    针对目前热害矿井在开采过程中存在的危害,各国针对存在热害的矿井采取了不同的防治措施,并且取得了一定效果,但是其系统的投资与运行费用较高。提出一种利用空气能系统对矿井进行降温的新模式,结合平顶山大庄矿矿井基本情况,对机电硐室进行空气能制冷降温与废热提级利用系统设计,并对主要设备进行了选型。最后与传统冷水机组制冷降温系统进行比较,空气能系统具有显著的经济效益。研究成果为企业节能减排方案的选择提供了参考和依据。%Countries having heat damage mines have adopted different prevention measures against the existing hazards in the mining process. Although some effects have been achieved, the investment and operation costs are extremely high. This paper presents a new model of using air energy system to cool the mines. Based on the general situation of Pingdingshan Dazhuang Mine, this paper designs upgraded mechanical and electrical air cooling chamber and waste heat utilization system, as well as selects the major equipment. Finally after making a comparison with conventional chiller refrigeration cooling system, it concludes that the air-source system has a significant advantage economically. The study provides a reference for energy saving and pollution reduction of the enterprises.

  16. A Research on Safety Design of 18650 Power Battery System Based on Air Cooling Mode%基于风冷模式的18650动力电池系统安全性设计研究

    Institute of Scientific and Technical Information of China (English)

    裴锋; 符兴锋

    2015-01-01

    18650 power battery system based on air cooling internal circulation structure is designed in accordance with operating requirement of an electric passenger vehicle, and structural safety, thermal management safety, flame retardant and insulation safety are studied and analyzed. Based on test data, and also in combination with theoretical calculation formula, 18650 power battery heat generation calculation model is built, and flow field of battery air cooling internal circulation system is analyzed and calculated, design of battery pack internal flow field is optimized according to simulation results. Safety of 18650 power battery system based on air cooling mode is proved by vehicle test and low temperature heating equilibrium test.%针对某纯电动乘用车的使用要求,设计了基于风冷内循环结构的18650动力电池系统,研究和分析了18650动力电池的结构安全性、热管理安全性和阻燃与绝缘安全性.以该18650动力电池的试验数据为基础,结合理论计算公式,建立了18650动力电池的生热仿真计算模型,对电池风冷内循环系统的流场进行了分析计算,根据仿真计算结果优化了电池箱内部流场设计.通过实车试验和低温加热均衡试验,验证了基于风冷模式的18650动力电池系统的安全性.

  17. Research advances in forced air pre-cooling for fruits and vegetables in China%我国果蔬差压预冷方法分析

    Institute of Scientific and Technical Information of China (English)

    张中芳; 邓超; 裴文伟

    2013-01-01

      介绍了果蔬差压预冷的原理、组成、分类及影响因素,综述了近几年差压式预冷方法及设备的研究进展,提出了压差预冷技术推广的建议及今后的发展方向。%Introduced the principle composition, classification and factors of pressure pre-cooling of fruit and vegetable, reviewed the research of pressure pre-cooling technology and equipment in recent years, put forward the recommendations to promote and the development of future direction for pressure pre-cooling technology.

  18. Modeling and Simulation of a Water- cooled Central Air Conditioning System Based on Trnsys%基于Trnsys的水冷型中央空调系统建模与仿真

    Institute of Scientific and Technical Information of China (English)

    胡玮; 陈立定

    2011-01-01

    In this paper,a water-cooled central air conditioning system of a building in Guangzhou is taken for an example to establish the simulation models of one of the building's layers and its central air conditioning systems, on the basis of a controlled and uncontrolled cases, the energy consumption is analyzed. The simulation results from the two models show that there is a great space of energy-saving of central air conditioning system. This model is mainly used to study some properties of the central air conditioning and is of great significance to energy-saving optimal control of central air conditioning.%以广州某大厦水冷型中央空调系统为例子,利用Trnsys建立了大厦某层的多区域建筑及其中央空调系统能耗仿真模型,在此基础上分析加控制和不加控制2种情况下中央空调能耗情况.由2种模型的仿真结果可知中央空调具有很大的节能空间.模型主要用于研究中央空调运行的一些性质,对中央空调的节能优化控制具有重要的意义.

  19. Investigations of Air-cooled Turbine Rotors for Turbojet Engines II : Mechanical Design, Stress Analysis, and Burst Test of Modified J33 Split-disk Rotor / Richard H. Kemp and Merland L. Moseson

    Science.gov (United States)

    Kemp, Richard H; Moseson, Merland L

    1952-01-01

    A full-scale J33 air-cooled split turbine rotor was designed and spin-pit tested to destruction. Stress analysis and spin-pit results indicated that the rotor in a J33 turbojet engine, however, showed that the rear disk of the rotor operated at temperatures substantially higher than the forward disk. An extension of the stress analysis to include the temperature difference between the two disks indicated that engine modifications are required to permit operation of the two disks at more nearly the same temperature level.

  20. 1000MW直接空冷机组凝结水泵配置方案探讨%Discussion on Configuration Scheme of Condensate Pump of a 1 000 MW Direct Air-cooling Unit

    Institute of Scientific and Technical Information of China (English)

    胡训栋; 曲宁; 高振宝

    2012-01-01

    针对1000MW直接空冷机组的凝绪水泵配置方案进行论述,对提出的多个方案进行技术经济比较分析.给出凝结水泵的配置建议。%This paper is intended to discuss condensate pump configuration scheme of a 1 000 MW direct air-cooling unit, proposes a number of options for the analysis of technical and economic comparison, and recommends configuration of condensate pump.

  1. Activity of Reducing Steel Slag of EAF

    Institute of Scientific and Technical Information of China (English)

    GUO Chinhsiang; HWANG Chaolung; LIN Tingyi

    2011-01-01

    Reducing steel slag (RSS) was mainly acquired from five electric-arc furnace (EAF)steelmaking plants (among them, the products of two plants were carbon steel and those of other plants were stainless steel) for research tests. The chemical properties, compound compositions, activities and contents of main expansive compounds were tested. The results showed that the field sampled RSS had a very high crystallinity and hydraulicity with main chemical compositions close to those of Portland cement. It can be known from the study that in case of C/S ratio higher than 2.0, the main compound compositions are C2S, C3S, C2F and f-CaO. However, after the RSS was stored for six months, an obvious variation occurred with potential pre-hydration in RSS, where the SO3 content was slightly reduced and the compressive activity index was obviously higher than that at the 28th day.

  2. Numerical Investigation of Slag Behavior for RSRM

    Science.gov (United States)

    Liaw, P.; Chen, Y.-S.; Shang, H.; Shih, M.; Doran, D.; Stewart, E.

    1996-01-01

    It is known that the flow field of the redesigned solid rocket motor (RSRM) is very complicated due to the complex characteristics of turbulent multi-phase flow, chemical reaction, particle combustion, evaporation, breakup and agglomeration etc. It requires multi-phase calculations, chemical reaction simulation, and particle combustion, evaporation, and breakup models to obtain a better understanding of thermophysics for the RSRM design using numerical methods. Also, the slag buildup due to the molten particles is another factor affecting the performance of the RSRM. To achieve this goal, the volume of fluid (VOF) method is used to capture the free surface motion so as to simulate the accumulation of the molten particles (slag) of the RSRM. A finite rate chemistry model is used to simulate the chemical reaction effects. For multi-phase calculations, the Hermsen combustion model is used for the aluminum particle combustion analysis and the Taylor Analogy Breakup (TAB) model is used for the particle breakup analysis. An interphase mas-exchange model introduced by Spalding is used for the evaporation calculation. The particle trajectories are calculated using a one-step implicit method for several groups of particle sizes by which the drag forces and heat fluxes are then coupled with the gas phase equations. The preliminary results predicted a reasonable physical simulation of the particle effects using a simple two dimensional solid rocket motor configuration. It shows that the AL/AL2O3 particle sizes are reduced due to the combustion, evaporation, and breakup. The flow field is disturbed by the particles. Mach number distributions in the nozzle are deformed due to the effect of particle concentrations away from the center line.

  3. The behavior of sulfur in industrial pyrometallurgical slags

    Science.gov (United States)

    Nagamori, Meguru

    1994-08-01

    Dissolution of sulfur in industrial slags, even at such a low level as 1 mass% S or so, increases the solubility of certain valuable metals by an order of magnitude. The phenomenon is accounted for in terms of Flood-Førland-Grjotheim's model for dianionic salt solutions, whereas its rigorous analysis requires the digaseous Gibbs-Duhem integration. In the research described here, the distribution of sulfur among gas, slag, and metallic iron phases in the bath smelting of iron ore was computer-simulated based on a two-sites model coupled with sulfide capacity data. The solubilities of Ag, Cu, Co, and Ni in industrial slags are reviewed by applying the sulfidic-oxidic dissolution model to copper-matte smelting, nickel-slag cleaning (Falconbridge, Canada), and the imperial smelting process for zinc and lead (Hachinohe, Japan).

  4. Properties of Industrial Slag as Fine Aggregate in Concrete

    Directory of Open Access Journals (Sweden)

    A. Ananthi

    2015-04-01

    Full Text Available The main objective of this paper is to use the industrial waste such as bottom ash and Weld Slag (WS as the partial replacement for fine aggregates in concrete. This paper presents the chemical analysis and strength properties of industrial solid waste such as bottom ash, weld slag 1 (WS 1 and weld slag 2 (WS 2. Their chemical compositions were identified by X-ray powder diffraction (XRD analysis. The qualitative and quantitative elemental analysis of the bottom ash and weld slag was recognized by energy dispersive X-ray analysis and their morphology were studied by Scanning Electron Microscope (SEM. The compressive strength of concrete with 10% replacement of fine aggregate to the industrial waste shows higher strength than the normal concrete and hence this industrial waste can be used as fine aggregate in concrete.

  5. Characterization of structure and thermophysical properties of three ESR slags

    Science.gov (United States)

    Plotkowski, A.; deBarbadillo, J.; Krane, Matthew J. M.

    2016-07-01

    The structure and properties of electroslag remelting (ESR) slags were characterized. Slags samples of three compositions were obtained from industrial remelting processes at Special Metals Corporation and from casting in a laboratory vacuum induction melter. The structure of the slag samples was observed using optical and electron microscopy, and phases were identified and their relative amounts quantified using X-ray diffraction. Laser flash thermal diffusivity, density, and differential scanning calorimetry measurements for specific heat were performed to determine the bulk thermal conductivity of the samples. Sample porosity was measured as a function of depth using a serial sectioning technique, and a onedimensional computational model was developed to estimate the thermal conductivity of the fully dense slags. These results are discussed in context with previous studies, and opportunities for future research are identified. AFRL Case Number: 88ABW-2015-1871.

  6. Experimental Investigation and Modeling of Copper Smelting Slags

    Science.gov (United States)

    Starodub, Konstantin; Kuminova, Yaroslava; Dinsdale, Alan; Cheverikin, Vladimir; Filichkina, Vera; Saynazarov, Abdukahhar; Khvan, Alexandra; Kondratiev, Alex

    2016-10-01

    Effective extraction of copper from sulfide ores requires careful operation of a copper smelter, which in turn depends very much on chemistry of the feed and resulted slag and matte. For example, chemical composition of copper smelting slags has to be in a certain range to ensure that their properties are within specific limits. Disobeying these rules may lead to complications in smelting operation, poor quality of the copper products, and premature shutdown of the copper smelter. In the present paper the microstructure and phase composition of slags from the Almalyk copper flash smelter were investigated experimentally and then modeled thermodynamically to evaluate potential ways of improvement and optimization of the copper smelting process and its products. The slag samples were taken at different stages of the copper smelting process: on slag tapping, after slag transportation to a deposition site, and at the site. Experimental investigation included the XRD, XRF, and SEM techniques, which were also confirmed by the traditional wet chemistry analysis. Thermodynamic modeling was carried out using thermochemical software package MTDATA, which enables thermodynamic and physical properties of the matte, slag, and gas phases to be calculated in a wide range of temperatures, pressures, and chemical compositions. In addition, slag viscosities and corresponding matte settling rates were estimated using the modified Urbain and Utigard-Warczok models, and the Hadamard-Rybczynski equation, respectively. It was found that the copper content in the slags may vary significantly depending on the location of slag sampling. Cu was found to be present as sulfide particles, almost no Cu was found to be dissolved in the slag. Analysis of microstructure and phase composition showed that major phase found in the samples is fayalite, while other phases are complex spinels (based on magnetite), different sulfides, and a glass-like phase. Thermodynamic calculations demonstrated the

  7. Experimental Investigation and Modeling of Copper Smelting Slags

    Science.gov (United States)

    Starodub, Konstantin; Kuminova, Yaroslava; Dinsdale, Alan; Cheverikin, Vladimir; Filichkina, Vera; Saynazarov, Abdukahhar; Khvan, Alexandra; Kondratiev, Alex

    2016-07-01

    Effective extraction of copper from sulfide ores requires careful operation of a copper smelter, which in turn depends very much on chemistry of the feed and resulted slag and matte. For example, chemical composition of copper smelting slags has to be in a certain range to ensure that their properties are within specific limits. Disobeying these rules may lead to complications in smelting operation, poor quality of the copper products, and premature shutdown of the copper smelter. In the present paper the microstructure and phase composition of slags from the Almalyk copper flash smelter were investigated experimentally and then modeled thermodynamically to evaluate potential ways of improvement and optimization of the copper smelting process and its products. The slag samples were taken at different stages of the copper smelting process: on slag tapping, after slag transportation to a deposition site, and at the site. Experimental investigation included the XRD, XRF, and SEM techniques, which were also confirmed by the traditional wet chemistry analysis. Thermodynamic modeling was carried out using thermochemical software package MTDATA, which enables thermodynamic and physical properties of the matte, slag, and gas phases to be calculated in a wide range of temperatures, pressures, and chemical compositions. In addition, slag viscosities and corresponding matte settling rates were estimated using the modified Urbain and Utigard-Warczok models, and the Hadamard-Rybczynski equation, respectively. It was found that the copper content in the slags may vary significantly depending on the location of slag sampling. Cu was found to be present as sulfide particles, almost no Cu was found to be dissolved in the slag. Analysis of microstructure and phase composition showed that major phase found in the samples is fayalite, while other phases are complex spinels (based on magnetite), different sulfides, and a glass-like phase. Thermodynamic calculations demonstrated the

  8. An experimental system for thermal performance test of large-scale air-cooling towers%大型间接空冷机组空冷塔热力性能实验系统

    Institute of Scientific and Technical Information of China (English)

    席新铭; 郭永红; 杜小泽; 杨立军; 杨勇平

    2014-01-01

    On the basis of a 600 MW indirect air cooling unit,an experimental system for large-scale air-coo-ing tower was designed by means of the similarity principles,with a proportion of 1 to 30.This system con-sists of modeling air cooling tower,air cooling modeling radiator,heat load power control system and data collection system.During the experiment,the heat load can be regulated by the control system,according to the parameters'value and experimental purpose.The calculation shows the measurement error of heat transfer coefficient of this experimental system is less than 20%.Through this system,the flow and heat transfer characteristics at inside and outside of the dry-cooling tower under various environmental condi-tions can be measured.Moreover,the correlations of flow and heat transfer of air-cooled heat exchanger and the off-design performance of the indirect dry cooling system can be obtained.The hot plume recirculation flows,anti-freezing in winter and the thermo-hydraulic performances for stack and tower integration design can be investigated using this experimental system.The design principle,basic parameters and measuring errors were analyzed.%以某600 MW间接空冷机组的空冷塔为原型,按1∶30的比例,根据相似原理设计了1套自然环境条件下大型间接空冷塔的实验系统。该系统由模型空冷塔、空冷模型散热器、散热热负荷控制系统及数据采集系统等组成。实验期间可根据数值大小及实验目的利用控制系统调整热负荷。对实验数据计算及分析,表明:该空冷塔实验系统的换热系数测量误差小于20%;利用该实验系统,可获得不同环境气象条件下,空冷塔内部空气流场特性,以及散热负荷的空间分布规律;可进行间接空冷系统热空气回流、冬季防冻及烟塔合一条件下塔内气体流动传热机理的研究。

  9. Hydration and properties of sodium sulfate activated slag

    OpenAIRE

    A.M. Rashad; Bai, Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China); Basheer, P. A. M.; Milestone, N.B.; Collier, N.C.

    2013-01-01

    Interest in alkali-activated slag as a construction material is increasing, primarily due to its environmentally friendly nature. Although strong alkaline activators, such as sodium hydroxide and sodium silicate solution, are preferred for high strength, none of them exists naturally and their manufacturing process is quite energy intensive. Whilst sodium sulfate (NaSO ) can be obtained from natural resources, the early strength of NaSO activated slag is usually low. In this paper, the effect...

  10. Desulfurization ability of refining slag with medium basicity

    Science.gov (United States)

    Yu, Hui-xiang; Wang, Xin-hua; Wang, Mao; Wang, Wan-jun

    2014-12-01

    The desulfurization ability of refining slag with relative lower basicity ( B) and Al2O3 content ( B = 3.5-5.0; 20wt%-25wt% Al2O3) was studied. Firstly, the component activities and sulfide capacity ( C S) of the slag were calculated. Then slag-metal equilibrium experiments were carried out to measure the equilibrium sulfur distribution ( L S). Based on the laboratorial experiments, slag composition was optimized for a better desulfurization ability, which was verified by industrial trials in a steel plant. The obtained results indicated that an MgO-saturated CaO-Al2O3-SiO2-MgO system with the basicity of about 3.5-5.0 and the Al2O3 content in the range of 20wt%-25wt% has high activity of CaO ( a CaO), with no deterioration of C S compared with conventional desulfurization slag. The measured L S between high-strength low-alloyed (HSLA) steel and slag with a basicity of about 3.5 and an Al2O3 content of about 20wt% and between HSLA steel and slag with a basicity of about 5.0 and an Al2O3 content of about 25wt% is 350 and 275, respectively. The new slag with a basicity of about 3.5-5.0 and an Al2O3 content of about 20wt% has strong desulfurization ability. In particular, the key for high-efficiency desulfurization is to keep oxygen potential in the reaction system as low as possible, which was also verified by industrial trials.

  11. Study of Chromium Oxide Activities in EAF Slags

    Science.gov (United States)

    Yan, Baijun; Li, Fan; Wang, Hui; Sichen, Du

    2016-02-01

    The activity coefficients of chromium in Cu-Cr melts were determined by equilibrating liquid copper with solid Cr2O3 in CO-CO2 atmosphere. The temperature dependence of the activity coefficients of chromium in Cu-Cr melts could be expressed as lg γ_{Cr}(s)^{0} = { 3 2 5 9( ± 1 8 6} )/T - 0. 5 9( { ± 0. 1} ). Based on the above results, the activities of bivalent and trivalent chromium oxide in some slags at 1873 K (1600 °C) were measured. The slags were equilibrated with Cu-Cr melts under two oxygen partial pressures ( {p_{O}_{ 2} }} } = 6.9 × 10-4 and 1.8 × 10-6 Pa, respectively). The morphology of the quenched slags and the solubility of chromium oxide in the melts were investigated by EPMA, SEM, and XRD. Under both oxygen partial pressures, the slags were saturated by the solid solution MgAl2- x Cr x O4- δ . At the low oxygen partial pressure (1.8 × 10-6 Pa), the content of Cr in the liquid phase varied from 0.4 to 1.6 mass pct with the total Cr content in the slags increasing from 1.3 to 10.8 mass pct. At the high oxygen partial pressure (6.9 × 10-4 Pa), the content of Cr in the liquid phase decreased to the level of 0.2 to 0.6 mass pct. Both the activities of CrO and Cr2O3 in slag were found to increase approximately linearly with the increase of the total Cr content in slag. While the oxygen partial pressure had minor effect on the activity of Cr2O3 in the slag, it had significant effect on the activity of CrO.

  12. Investigation on the Potentials of Cupola Furnace Slag in Concrete

    OpenAIRE

    Stephen Adeyemi Alabi; Joseph O. Afolayan

    2013-01-01

    The compressive strength of the concrete designed using blast cupola furnace slag and granulated cupola slag as a coarse aggregate and partial replacement for cement was investigated. A series of experimental studies were conducted involve concrete production in two stages. The first stage comprised of normal aggregate concrete (NAC) produced with normal aggregates and 100% ordinary Portland cement (OPC). Meanwhile, the second stage involved production of concrete comprising of cupola furnace...

  13. Potential benefits of cool roofs on commercial buildings. Conserving energy, saving money, and reducing emission of greenhouse gases and air pollutants

    International Nuclear Information System (INIS)

    Cool roofs - roofs that stay cool in the sun by minimizing solar absorption and maximizing thermal emission - lessen the flow of heat from the roof into the building, reducing the need for space cooling energy in conditioned buildings. Cool roofs may also increase the need for heating energy in cold climates. For a commercial building, the decrease in annual cooling load is typically much greater than the increase in annual heating load. This study combines building energy simulations, local energy prices, local electricity emission factors, and local estimates of building density to characterize local, state average, and national average cooling energy savings, heating energy penalties, energy cost savings, and emission reductions per unit conditioned roof area. The annual heating and cooling energy uses of four commercial building prototypes - new office (1980+), old office (pre-1980), new retail (1980+), and old retail (pre-1980) - were simulated in 236 US cities. Substituting a weathered cool white roof (solar reflectance 0.55) for a weathered conventional gray roof (solar reflectance 0.20) yielded annually a cooling energy saving per unit conditioned roof area ranging from 3.30 kWh/m2 in Alaska to 7.69 kWh/m2 in Arizona (5.02 kWh/m2 nationwide); a heating energy penalty ranging from 0.003 therm/m2 in Hawaii to 0.14 therm/m2 in Wyoming (0.065 therm/m2 nationwide); and an energy cost saving ranging from USD 0.126/m2 in West Virginia to USD 1.14/m2 in Arizona (USD 0.356/m2 nationwide). It also offered annually a CO2 reduction ranging from 1.07 kg/m2 in Alaska to 4.97 kg/m2 in Hawaii (3.02 kg/m2 nationwide); an NOx reduction ranging from 1.70 g/m2 in New York to 11.7 g/m2 in Hawaii (4.81 g/m2 nationwide); an SO2 reduction ranging from 1.79 g/m2 in California to 26.1 g/m2 in Alabama (12.4 g/m2 nationwide); and an Hg reduction ranging from 1.08 μg/m2 in Alaska to 105 μg/m2 in Alabama (61.2 μg/m2 nationwide). Retrofitting 80% of the 2.58 billion square meters of

  14. Applicability of Carbonated Electric Arc Furnace Slag to Mortar

    International Nuclear Information System (INIS)

    Authors have been studying the absorption of CO2 in the steelmaking slag. In this study, an application of the electric arc furnace slag after the carbonation to admixture of mortar was investigated with the JIS (A6206-1997) method for ground granulated blast-furnace slag for concrete. The percent flows for the test mortar were smaller than that for the standard mortar. The percent flow of the carbonated slag whose average particle size of more than approximately 4 μm increased with an increase in the average size of the particles. Because the compressive strengths of the test mortar cured for 91 days were almost the same as those cured 28 days, the slag after the carbonation was thought not to have self-hardening property for a medium and long term. The compressive strength for the test mortar was almost unchanged within a range of approximately 2 to 7 μm of the average particle size, and it in this range was highest. The activity indexes for the test mortar prepared with the slag after the carbonation ranged from approximately 40 to 60%.

  15. Applicability of Carbonated Electric Arc Furnace Slag to Mortar

    Science.gov (United States)

    Yokoyama, S.; Arisawa, R.; Hisyamudin, M. N. N.; Murakami, K.; Maegawa, A.; Izaki, M.

    2012-03-01

    Authors have been studying the absorption of CO2 in the steelmaking slag. In this study, an application of the electric arc furnace slag after the carbonation to admixture of mortar was investigated with the JIS (A6206-1997) method for ground granulated blast-furnace slag for concrete. The percent flows for the test mortar were smaller than that for the standard mortar. The percent flow of the carbonated slag whose average particle size of more than approximately 4 μm increased with an increase in the average size of the particles. Because the compressive strengths of the test mortar cured for 91 days were almost the same as those cured 28 days, the slag after the carbonation was thought not to have self-hardening property for a medium and long term. The compressive strength for the test mortar was almost unchanged within a range of approximately 2 to 7 μm of the average particle size, and it in this range was highest. The activity indexes for the test mortar prepared with the slag after the carbonation ranged from approximately 40 to 60 %.

  16. Chloride ion transport performance in slag mortar under fatigue loading

    Institute of Scientific and Technical Information of China (English)

    WANG CaiHui; SUN Wei; JIANG JinYang; HAN JianDe; YE BangTu

    2012-01-01

    The transport performance of chloride ion in slag cement mortar was investigated experimentally.In the self-designed experiment,fatigue loading was coupled simultaneously with ion transportation process,the diffusion law of chloride ion was obtained by titration and the AE (acoustic emission) technique was employed to detect the real-time damage distribution in the mortar specimen.The results for fatigue stress levels of 0.3,0.4 and 0.5 and slag contents of 0,10%,30% and 50% showed that fatigue loading accelerated the diffusion of chloride ion in mortar and the acceleration effect increased with the increase in stress levels.Slag addition was found to improve anti-chloride ion erosion performance effectively with the best substitution level at 30%,because the inhibition effect of slag on chloride ion diffusion diminished when the slag content exceeded 30%.The comparative experiments indicated that dynamic load has a significant effect on the transport performance of chloride ion in slag cement mortar.

  17. Reuse of steel slag in bituminous paving mixtures.

    Science.gov (United States)

    Sorlini, Sabrina; Sanzeni, Alex; Rondi, Luca

    2012-03-30

    This paper presents a comprehensive study to evaluate the mechanical properties and environmental suitability of electric arc furnace (EAF) steel slag in bituminous paving mixtures. A variety of tests were executed on samples of EAF slag to characterize the physical, geometrical, mechanical and chemical properties as required by UNI EN specifications, focusing additionally on the volumetric expansion associated with hydration of free CaO and MgO. Five bituminous mixtures of aggregates for flexible road pavement were designed containing up to 40% of EAF slag and were tested to determine Marshall stability and indirect tensile strength. The leaching behaviour of slag samples and bituminous mixtures was evaluated according to the UNI EN leaching test. The tested slag showed satisfactory physical and mechanical properties and a release of pollutants generally below the limits set by the Italian code. Tests on volume stability of fresh materials confirmed that a period of 2-3 months is necessary to reduce effects of oxides hydration. The results of tests performed on bituminous mixtures with EAF slag were comparable with the performance of mixtures containing natural aggregates and the leaching tests provided satisfactory results. PMID:22305201

  18. Modelization of cooling system components

    International Nuclear Information System (INIS)

    In the site evaluation study for licensing a new nuclear power facility, the criteria involved could be grouped in health and safety, environment, socio-economics, engineering and cost-related. These encompass different aspects such as geology, seismology, cooling system requirements, weather conditions, flooding, population, and so on. The selection of the cooling system is function of different parameters as the gross electrical output, energy consumption, available area for cooling system components, environmental conditions, water consumption, and others. Moreover, in recent years, extreme environmental conditions have been experienced and stringent water availability limits have affected water use permits. Therefore, modifications or alternatives of current cooling system designs and operation are required as well as analyses of the different possibilities of cooling systems to optimize energy production taking into account water consumption among other important variables. There are two basic cooling system configurations: - Once-through or Open-cycle; - Recirculating or Closed-cycle. In a once-through cooling system (or open-cycle), water from an external water sources passes through the steam cycle condenser and is then returned to the source at a higher temperature with some level of contaminants. To minimize the thermal impact to the water source, a cooling tower may be added in a once-through system to allow air cooling of the water (with associated losses on site due to evaporation) prior to returning the water to its source. This system has a high thermal efficiency, and its operating and capital costs are very low. So, from an economical point of view, the open-cycle is preferred to closed-cycle system, especially if there are no water limitations or environmental restrictions. In a recirculating system (or closed-cycle), cooling water exits the condenser, goes through a fixed heat sink, and is then returned to the condenser. This configuration

  19. Application of Water-cooled Multi Air Conditioning System in Steel Plant Building%水冷多联空调系统在炼钢厂房中的应用

    Institute of Scientific and Technical Information of China (English)

    刘贵琦

    2012-01-01

    A 150-ton converter project has been built in a large northern steel mill,and a four-story integrated building for assistance will also be built.This integrated building will adopt water-cooled multi air conditioning system.Compared with other commercial or public buildings,its system does not need cooling tower,but need circling cooling water in steel plant.%北方某大型钢厂新建一座150吨转炉项目,其中将建设一栋四层炼钢综合楼作为其炼钢厂房的辅助配套工程,该综合楼采用水冷多联空调系统做为其部分空调设计。与常规的水冷多联系统不同,该系统不单独设置冷却塔,而采用炼钢生产中的循环冷却水作为空调冷热源,达到了节能环保的目的,并大幅地降低了初期投资。

  20. Experimental Study on A New Type of Air-cooled Brake Drum's Braking Performance%自助风冷型制动鼓制动性能试验研究

    Institute of Scientific and Technical Information of China (English)

    赵悟; 杜木伟; 刘晨敏; 沈建军; 于宥源

    2013-01-01

    The structure and cooling mechanisms of a new type of air-cooled brake drum are introduced. Contrast test of temperature rising, brake torque and rotation speed are conducted by the inertia brake tester JF122C between the new type of air-cooled brake drum and the original brake drum. Meanwhile the strength and stiffness of the holes-drilled new type one are analyzed. The result of the contrast test proves that, compared with the original, the average maximum temperature of the new type of air-cooled brake drum is reduced by about 15℃, its average brake torque doesn't change much, and the initial revolving speed and declining trend of every test are alike, the strength and stiffness degrade little, i.e the new type of brake drum greatly improves heat radiating performance of the brake system while maintaining braking safety.%介绍了新型风冷式制动鼓的结构和降温机理.针对新型风冷式制动鼓和原车制动鼓,在JF122C惯性制动试验台上进行了制动鼓温升、制动力矩和转速对比试验,并分析了钻小孔后的新型制动鼓的强度和刚度.试验结果表明,与原车制动鼓相比,新型风冷式制动鼓平均最高温度降低约15℃,平均制动力矩没有明显改变,制动初始转速及下降趋势一致,强度和刚度也未下降.即新型制动豉在保证制动安全性的前提下,较好地改善了制动系统的散热性能.