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Cooling System (cooling + system)
Selected AbstractsApplication of ozone treatment and pinch technology in cooling water systems design for water and energy conservationINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 6 2010A. Ataei Abstract Re-circulating cooling water systems offer the means to remove heat from a wide variety of industrial processes that generate excess heat. Such systems consist of a cooling tower and a heat-exchanger network that conventionally has a parallel configuration. However, reuse of water between different cooling duties allows cooling water networks to be designed in a series arrangement. This results in performance improvement and increased cooling tower capacity. In addition, by the integration of ozone treatment into the cooling tower, the cycle of concentration can be increased. The ozone treatment also dramatically reduces the blow-down that, in turn, is environmentally constructive. In this study, a new environmental-friendly and cost-effective design methodology for cooling water systems was introduced. Using this design methodology, Integrated Ozone Treatment Cooling System (IOTCS), achievement of minimum environmental impacts and total cost were afforded through a simultaneous integration of the cooling system components using an ozone treatment cooling tower and optimum heat-exchanger network configuration. Moreover, in the proposed method, the cooling tower optimum design was achieved through a mathematical model. The IOTCS design method is based upon a complex design approach using a combined pinch analysis and mathematical programming that provides an optimum heat-exchanger configuration while maximizing water and energy conservation and minimizing total cost. Related coding in MATLAB version 7.3 was used for the illustrative example to obtain optimal values in the IOTCS design method computations. The results of the recently introduced design methodology were compared with the conventional method. Copyright © 2009 John Wiley & Sons, Ltd. [source] Growth of ZnO single crystals by an induced nucleation from a high temperature solution of the ZnO-PbF2 systemCRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2007Xinhua Li Abstract To grow ZnO single crystals from a high temperature solution of the ZnO-PbF2 system, a gas cooling system was assembled at the bottom of the crucible to induce nucleation in the initial growth stage. The growth experiments were carried out in a homemade vertical Bridgman furnace and Pt crucible of 28 mm in diameter was used. The furnace temperature was set to 1100°C and the flow rate of the oxygen gas was optimized as 3.0 l/min. ZnO crystal up to 5,8mm in the thickness was obtained with the lowering rate of 0.3 mm/h. XRD patterns showed that the as-grown crystal was pure ZnO Wurtzite phase. The impurity ions were analyzed by the glow discharge mass spectroscopy (GDMS) as 390.0 ppm and 40.0 ppm for Pb2+ and F - , respectively. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Non-parametric,parametric model for random uncertainties in non-linear structural dynamics: application to earthquake engineeringEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 3 2004Christophe Desceliers Abstract This paper deals with the transient response of a non-linear dynamical system with random uncertainties. The non-parametric probabilistic model of random uncertainties recently published and extended to non-linear dynamical system analysis is used in order to model random uncertainties related to the linear part of the finite element model. The non-linearities are due to restoring forces whose parameters are uncertain and are modeled by the parametric approach. Jayne's maximum entropy principle with the constraints defined by the available information allows the probabilistic model of such random variables to be constructed. Therefore, a non-parametric,parametric formulation is developed in order to model all the sources of uncertainties in such a non-linear dynamical system. Finally, a numerical application for earthquake engineering analysis is proposed concerning a reactor cooling system under seismic loads. Copyright © 2003 John Wiley & Sons, Ltd. [source] Experimental study on flow characteristics of a sleeved jet into a main crossflowHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 1 2004H.L. Wu Abstract Experiments were carried out on the hydraulic mechanism of the thermal shock caused by cold jet injection at a T-junction with thermal sleeve in the reactor cooling system using digital particle imaging velocimetry (DPIV) technique to measure the flow in the main duct and in the annular space of the sleeve tube. The flow and vorticity characteristics were investigated at jet-to-crossflow velocity ratios of 0.5 to 4. There was a stream of discharge from the annular space at the rear part of the sleeve near the jet exit, which resulted in decreasing the influence of the jet on the downstream wall. The intensive vorticity in the near wake mainly originated from the shear layer vorticity of the jet and the annular discharge stream. The intensive vorticity soon broke down and dissipated, and further developed into the counterrotating vortex pair in the far wake. The flow in the annulus was closely dependent on R, and thermal protection of the sleeve would become evident at higher R. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(1): 24,31, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10131 [source] Investigation of coolant flow distribution and the effects of cavitation on water pump performance in an automotive cooling systemINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 3 2009Kibum Kim Abstract Cavitation is a well-known phenomenon that causes performance losses in all kinds of hydraulic machinery, including automotive water pumps. The present study uses a coolant flow test rig to investigate cavitation in water pumps. The coolant flow rate was measured for various coolant temperatures and compositions. This study validates that cavitation occurs during the coolant warm-up period, in which coolant temperature is typically below 80°C. Cavitation was also related to a drop in the water pump inlet pressure and driving torque. Based on the results from this study, it can be concluded that cavitation is affected by coolant temperature, engine speed, and coolant composition. Furthermore, it is found that the use of an electric water pump is effective for minimizing the pressure drop and driving loss of the pump. Copyright © 2008 John Wiley & Sons, Ltd. [source] Comparison of evaporative inlet air cooling systems to enhance the gas turbine generated powerINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2007Mohammad Ameri Abstract The gas turbine performance is highly sensitive to the compressor inlet temperature. The output of gas turbine falls to a value that is less than the rated output under high temperature conditions. In fact increase in inlet air temperature by 1°C will decrease the output power by 0.7% approximately. The solution of this problem is very important because the peak demand season also happens in the summer. One of the convenient methods of inlet air cooling is evaporating cooling which is appropriate for warm and dry weather. As most of the gas turbines in Iran are installed in such ambient conditions regions, therefore this method can be used to enhance the performance of the gas turbines. In this paper, an overview of technical and economic comparison of media system and fog system is given. The performance test results show that the mean output power of Frame-9 gas turbines is increased by 11 MW (14.5%) by the application of media cooling system in Fars power plant and 8.1 MW (8.9%) and 9.5 MW (11%) by the application of fog cooling system in Ghom and Shahid Rajaie power plants, respectively. The total enhanced power generation in the summer of 2004 was 2970, 1701 and 1340 MWh for the Fars, Ghom and Shahid Rajaie power plants, respectively. The economical studies show that the payback periods are estimated to be around 2 and 3 years for fog and media systems, respectively. This study has shown that both methods are suitable for the dry and hot areas for gas turbine power augmentation. Copyright © 2007 John Wiley & Sons, Ltd. [source] Modelling of a pin-fin heat converter with fluid cooling for power semiconductor modulesINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 11 2003Igor Khorunzhii Abstract This paper presents a way to design a finite-element computer model of cooling system with a complicated geometry. The computer model is developed on the basis of a commercial software package ABAQUS. The steady state forced-convective fluid cooling of a pin-fin heat converter for power (,1 kW heat power) semiconductor module has been investigated on the basis of computer simulation. A phenomenological equation has been used for calculation of the local value of the heat transfer coefficient for the liquid-solid interface. The impacts of the thermal conductivity of the pin-fin sink material, volume flow rate of the cooling liquid and geometrical design of the pin-fin sink on the thermal resistance of the converter are shown. Copyright © 2003 John Wiley & Sons, Ltd. [source] Syndiotactic polystyrene: Process and applicationsADVANCES IN POLYMER TECHNOLOGY, Issue 3 2006Jürgen Schellenberg Abstract In this review, a summary is provided of the manufacturing process for syndiotactic polystyrene together with an overview of applications of syndiotactic polystyrenes, including selected examples of typical applications. The manufacturing process of syndiotactic polystyrene, consists of several basic sections: catalyst premix preparation, monomer treatment, polymerization reaction using a powder bed reactor together with an evaporative cooling system, devolatilization and extrusion, and finally finishing, including cooling and crystallization of the strands. This process is suitable for providing a wide range of syndiotactic polystyrenes comprising homopolymers, with a broad range of melt flow rates as well as copolymers of various comonomer contents, leading to products with various melting temperatures. Essential relationships and correlations of the separate process stages are demonstrated, in addition to useful analytical methods to control the process. These polymers' unique combination of heat resistance, chemical resistance, and electrical properties has led to their successful application in automotive, electrical and electronics, consumer and industrial uses. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25:141,151, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20069 [source] Feasibility and Safety of Using an Esophageal Protective System to Eliminate Esophageal Thermal Injury: Implications on Atrial-Esophageal Fistula Following AF AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2009MAURICIO S. ARRUDA M.D. Background: Ablation for atrial fibrillation (AF) requires energy delivery in close proximity to the esophagus (Eso) which has accounted for the LA-Eso fistula, a rare but life-threatening complication. Purpose: We evaluated an Eso cooling system to protect the Eso during RF ablation. Methods and Results: An "in vitro" heart-Eso preparation was initially used to test a temperature-controlled fluid-circulating system (EPSac [esophageal protective system],RossHart Technologies Inc.) and an expandable compliant Eso sac during cardiac RF delivery (4 mm tip, perpendicular to the heart, 15 g pressure) at 25, 35, and 45 W, 100 ± 5 , for 30 seconds with the EPSac at 25, 15, 10, and 5°C. All cardiac lesions were transmural. Eso thermal injury could only be avoided with the EPSac at 10 and 5°C. The system was then tested in 6 closed chest dogs, each receiving 12 RFs (LA aiming at the Eso) for 30 seconds: without EPSac (control) at 35 W (1 dog); at 45 W with EPSac at 25°C (1 dog), 10°C (2 dogs), and 5°C (2 dogs). The EPSac volume was intentionally increased to displace the Eso toward the LA (2 dogs 5 and 10°C). Eso injured control and EPSac at 25°C; Eso spared EPSac at 5 and 10°C, without Eso displacement. Shallow external Eso injury noted when intentionally displacing the Eso toward the LA. Conclusions: The EPSac spares the Eso from collateral thermal injury. It requires circulating fluid at 5 or 10°C and a compliant sac to avoid displacement of the Eso. Its safety and efficacy remain to be demonstrated in patients undergoing AF ablation. [source] Formulation of sodium iodide (Na 123I) oral capsule,JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 5-6 2007A. Sattari Abstract Sodium iodide-123 (Na123I) is well known as a radioisotope that is used for studies of the thyroid and its metastases. 123I was produced from the reaction of 28 Mev protons with 99.99% enriched 124Xe by cyclotron. A home made target was installed and used for this purpose. The main part of the target contained target vessel, target windows and cooling system. In addition, some other part such as a cold finger, decay vessel, vacuum pump and four fingers were also designed and installed on the system. After bombardment, the production of 123I from 123Cs, the target was left for 6 hours and then rinsed with distilled water. A clear and colourless solution containing 123I was pumped to the hot cell. For adjusting the pH, sodium citrate buffer was used. The solution was added directly to the capsules which were already filled with inert powder. Each capsule contained 210 µCi Na123I. Quality control has shown 98% radiochemical and 99.96% radionuclide purity, with the yield of 2 mCi/µA. Quality control results had good accordance with the United States Pharmacopoeia. Copyright © 2007 John Wiley & Sons, Ltd. [source] High-Intensity Discharge Lamp with Mo,SiO2 Functionally Graded MaterialJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2006Ayumu Umemoto We show the invention of the new type of hermetically sealed high-intensity discharge lamps, made of Mo,SiO2 functionally graded material (FGM) as an electrode and a sealing component. In the case of high-intensity discharge lamps with Mo,SiO2 FGM (FGM lamp), the thermal expansion coefficient between Mo and SiO2 is functionally graded so that it tolerates a large number of heating cycles, with no cooling system required. Furthermore, lamps survive without breakage. The W electrode is totally separated from the lamp envelope by the FGM, so that no leakage of the luminous elements or gases takes place, when a large gas pressure exists inside a lamp. [source] Laser diodes semicircular side-pumped laser rod with a round-sharped outputLASER PHYSICS LETTERS, Issue 7 2006Y. X. Guo Abstract In order to keep the symmetric of the pump geometry and obtain a low-level, high quality laser output, the temperature of the side-pumped laser rod is more often be controlled by a water cooling system than a conduction cooling system in the diode-pumped solid-state lasers. But the use of the water cooling system increases the volume and decreases the mobility. To solve the confliction between the beam quality and the mobility of the laser system, a novel, compact and all-solid design of the pump structure is applied to the side-pumped laser system. The Nd:YAG rod is pumped by semicircular mounted LD arrays inthe pump module, and two pump modules are working together to compensate each other. Numerical calculation and experiment are performed, the output laser has a round-sharped beam with a beam waist of 5 mm and a divergence angle less than 7 mrad, and a maxim output pulse energy of 75.8 mJ is obtained under the working frequency of 20Hz, the slope efficiency is 35.8%. (© 2006 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Blood Flow in Snake Infrared Organs: Response-Induced Changes in Individual VesselsMICROCIRCULATION, Issue 2 2007RICHARD C. GORIS ABSTRACT Objective: In the past the microkinetics of blood flow in the infrared pit organs of pit vipers has been studied with Doppler flowmetry using various infrared stimuli such as a human hand or soldering iron at various distances, lasers of various wavelengths, etc. Quick-acting variations in blood flow were recorded, and interpreted as a cooling mechanism for avoiding afterimage in the infrared receptors. However, the Doppler measurements provided only the summation of blood flow in a number of vessels covered by the sensing probe, but did not give data on flow in individual vessels. Methods: In the present work the authors introduced into the bloodstream of Gloydius and Trimeresurus pit vipers fluorescent microspheres labeled with fluorescein isothiocyanate (FITC) contained in a solution of FITC-dextran in physiological saline. They observed the passage of the microspheres through individual pit organ vessels with a fluorescent microscope to which was attached a high-speed video camera and image intensifier. Output of the camera was recorded before, during, and after stimulus with a 810-nm diode laser. Recording was done at 250 frames/s on high-speed video apparatus and downloaded to a hard disk. Disk files were loaded into proprietary software and particles were tracked and average velocities calculated. The data were then tested for significance by ANOVA with post hoc tests. Results: A significant (p < .05) increase in blood velocity was found at the focal point of the stimulus laser, but not anywhere removed from this point. Proximal severing of the pit sensory nerves caused degeneration of the pit receptor terminals and abolished stimulus-induced blood flow changes, but did not affect normal blood flow. Conclusions: The authors conclude that the receptors themselves are directly and locally controlling the smooth muscle elements of the blood vessels, in response to heating of the receptors by infrared radiation. They speculate that the heavy vascularization constitutes a cooling system for the radiation-encoding receptors, and further that the agent of control may be a volatile neuromediator such as nitric oxide. [source] Analysis of SR thermal load studied by FEAPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2007Abstract This work deals with analysis of the thermal effects and inherent mechanical deformations under absorption of the X-ray beam heat. The work is motivated by recent research concentrated on the development of optics for high-flux synchrotron radiation sources. We present the analyses of the static thermal load effects on the surface deformation field for a monocrystalline silicon target, which is the basic material for crystal X-ray optics. The surface and bulk thermal load induces the gradient of temperature and mechanical deformations of the target that are affecting the reflection and diffraction properties of the target. The paper presents the finite-element analyses (FEA) and simulation results of mechanical deformation of flat and slotted silicon targets. The hints for improved target geometry and physical limits for an actual cooling system can be obtained from the presented analyses. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] 900-MHz Nonthermal Atmospheric Pressure Plasma Jet for Biomedical ApplicationsPLASMA PROCESSES AND POLYMERS, Issue 3-4 2010Jun Choi Abstract A portable microwave-excited atmospheric pressure plasma jet (APPJ) using a coaxial transmission line resonator is introduced for applications of plasma biomedicine. Its unique feature includes the portability and no need for matching network and cooling system with high power efficiency, operating at 900,MHz with low ignition power less than 2.5,W in argon at atmospheric pressure. The temperature at the downstream of the APPJ stays less than 47,°C (,320,K) during 5,min of continuous operation. The optical emission spectrum of the APPJ shows various reactive radicals such as OH, NO, and O which are responsible for biomedicine. The APPJ was applied to investigate the acceleration of blood coagulation, which occurred within 20,s of plasma treatment in vitro and within 1,min in vivo. This is significantly faster than the natural coagulation. [source] Laser Hair Removal with Alexandrite versus Diode Laser Using Four Treatment Sessions: 1-Year ResultsDERMATOLOGIC SURGERY, Issue 11 2001Sorin Eremia MD Background. Laser hair removal is the treatment of choice for hypertrichosis. The two most commonly used hair removal lasers are compared. Objective. To present the results of a comparative study examining the role of wavelength, fluence, spot size, pulse width, and cooling systems on long-term results after a series of four laser hair removal treatments using the 755 nm alexandrite and 800,810 nm diode lasers. Methods. The axillae of 15 untanned, type I,V patients were treated side by side four times at 4- to 6-week intervals with a 755 nm, 3-msec pulse width, cryogen spray-equipped alexandrite laser and an 800 nm, variable pulse width, cooled sapphire window-equipped diode laser. Each patient was pretested and treated with the maximum fluence tolerated at the largest spot size available for each laser (12 mm round/113 mm2 for the alexandrite and 9 mm for the diode). Results. Evaluations were done at 3, 6, 9, and 12 months after the last treatment. Twelve-month results with the alexandrite and diode lasers achieved 85% versus 84% hair reduction. The fact that tan avoidance was strictly followed permitted the use of relatively high fluences (25,30+ J/cm2) even in type IV patients. For most patients, four treatment sessions using high fluences (30,40 J/cm2) with relatively large spot sizes (12 mm round for the 755 nm alexandrite and 9 mm for the 800 nm diode) resulted in 12-month hair reductions in the 90% range. Conclusion. Both the alexandrite and diode lasers in this 12-month study produced excellent long-term hair reductions. [source] Energy Conservation in Urban AreasIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 1 2008Hideharu Sugihara Member Abstract This article outlines the energy conservation measures in the civilian sector from a few different viewpoint regarding energy conservation in cities. First, the energy consumption trends in the business and residential sectors are discussed, focusing the importance of energy conservation measures in applications such as home heating, water heating and specific power demand. Second, as a measure to reduce energy demand itself, energy conservation by way of applying heat insulating materials to buildings and changing the life style of residents is considered. And from the viewpoint of improving the energy system efficiency, additionally discussed here are the measures to improve the efficiency of each energy equipment such as air-conditioners and co-generation equipment, and the characteristics of District heating and cooling systems such as the local energy infrastructures. Lastly, from the knowledge obtained through model analyses by the authors, a scheme is recommended that would be one of the most efficient city-energy schemes where the energy systems including heat pumps, co-generators or equipment using solar power are utilized for their best-suited applications for business and residential customers. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Comparison of evaporative inlet air cooling systems to enhance the gas turbine generated powerINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2007Mohammad Ameri Abstract The gas turbine performance is highly sensitive to the compressor inlet temperature. The output of gas turbine falls to a value that is less than the rated output under high temperature conditions. In fact increase in inlet air temperature by 1°C will decrease the output power by 0.7% approximately. The solution of this problem is very important because the peak demand season also happens in the summer. One of the convenient methods of inlet air cooling is evaporating cooling which is appropriate for warm and dry weather. As most of the gas turbines in Iran are installed in such ambient conditions regions, therefore this method can be used to enhance the performance of the gas turbines. In this paper, an overview of technical and economic comparison of media system and fog system is given. The performance test results show that the mean output power of Frame-9 gas turbines is increased by 11 MW (14.5%) by the application of media cooling system in Fars power plant and 8.1 MW (8.9%) and 9.5 MW (11%) by the application of fog cooling system in Ghom and Shahid Rajaie power plants, respectively. The total enhanced power generation in the summer of 2004 was 2970, 1701 and 1340 MWh for the Fars, Ghom and Shahid Rajaie power plants, respectively. The economical studies show that the payback periods are estimated to be around 2 and 3 years for fog and media systems, respectively. This study has shown that both methods are suitable for the dry and hot areas for gas turbine power augmentation. Copyright © 2007 John Wiley & Sons, Ltd. [source] Water Use by Thermoelectric Power Plants in the United States,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2007Xiaoying Yang Abstract:, Thermoelectric power generation is responsible for the largest annual volume of water withdrawals in the United States although it is only a distant third after irrigation and industrial sectors in consumptive use. The substantial water withdrawals by thermoelectric power plants can have significant impacts on local surface and ground water sources, especially in arid regions. However, there are few studies of the determinants of water use in thermoelectric generation. Analysis of thermoelectric water use data in existing steam thermoelectric power plants shows that there is wide variability in unitary thermoelectric water use (in cubic decimeters per 1 kWh) within and among different types of cooling systems. Multiple-regression models of unit thermoelectric water use were developed to identify significant determinants of unit thermoelectric water use. The high variability of unit usage rates indicates that there is a significant potential for water conservation in existing thermoelectric power plants. [source] | ||||||||||||||||||||||