Preparation of 6N,7N High-Purity Gallium by Crystallization: Process Optimization

In this study, radial crystallization purification method under induction was proposed for preparing 6N,7N ultra-high purity gallium crystal seed. The effect of cooling temperature on the morphology of the crystal seed, as well as the cooling water temperature, flow rate, and the addition amount of crystal seed on the crystallization process was explored, and the best purification process parameters were obtained as follows: temperature of the crystal seed preparation, 278 K; temperature and flow rate of the cooling water, 293 K and 40 L·h−1, respectively; and number of added crystal seed, six. The effects of temperature and flow rate of the cooling water on the crystallization rate were investigated. The crystallization rate decreased linearly with increasing cooling water temperature, but increased exponentially with increasing cooling water flow. The governing equation of the crystallization rate was experimentally determined, and three purification schemes were proposed. When 4N crude gallium was purified by Scheme I, 6N high-purity gallium was obtained, and 7N high-purity gallium was obtained by Schemes II and III. The purity of high-purity gallium prepared by the three Schemes I, II, and III was 99.999987%, 99.9999958%, and 99.9999958%, respectively.

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Numerical Performance Investigation of Hybrid PV/Thermal System

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.19.28003 ◽

2018 ◽

Vol 7 (4.19) ◽

pp. 818

Author(s):

Kadhim K. Idan Al-Chlaihawi ◽

Dhafer A. Hamzah ◽

Ahmed K. Zarzoor ◽

Yousif M. Hasan

Keyword(s):

Solar Radiation ◽

Water Temperature ◽

Flow Rate ◽

Cooling Water ◽

Electrical Performance ◽

Flow Rates ◽

Electrical Efficiency ◽

Cooling Water Temperature ◽

Present Work Deal ◽

Numerical Performance

Promoting reduction of PV temperature plays crucial role in increasing electrical performance. The present work deal with different types of absorber shape for analysing heat transfer phenomena. Serpentine and spiral absorber are using to verify this purpose with different boundary conditions of inlet mass flow rate and inlet temperatures.The recent study was conducted to evaluate the effect of some operating and designing parameters such as solar radiation levels, flow rates, absorber shape and cooling water temperature on the performance of PVT system numerically. Performance of PVT system determined by thermal efficiency, electrical efficiency and the summation of both known as total or PVT efficiency. Solar radiation ranging from 500 W/m2 to1000 W/m2 was introduced and at each, flow rates of water ranging from 0.016 kg/s to 0.05 kg/s. The results show that the performance of PVT increases with a flow rate at all radiation levels. Also the spiral flow absorber gives a higher performance than serpentine absorber where the value of of spiral absorber is increased by about 5.2% compared to the value of serpentine absorber, on the other hand, the rate of heat loss ( decreased by about 10%.Increasing initial cooling water temperature degrades electrical efficiency of PVT system.

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Optimization of a New Phase Change Material Integrated Photovoltaic/Thermal Panel with The Active Cooling Technique Using Taguchi Method

Energies ◽

10.3390/en12061022 ◽

2019 ◽

Vol 12 (6) ◽

pp. 1022 ◽

Cited By ~ 13

Author(s):

Xiaohong Liu ◽

Yuekuan Zhou ◽

Chun-Qing Li ◽

Yaolin Lin ◽

Wei Yang ◽

...

Keyword(s):

Phase Change ◽

Water Temperature ◽

Mass Flow Rate ◽

Phase Change Material ◽

Flow Rate ◽

Cooling Water ◽

Optimal Combination ◽

Water Pipe ◽

Cooling Water Temperature ◽

Change Material

This paper investigates the energy performances of a hybrid system composed of a phase change materials-ventilated Trombe wall (PCMs-VTW) and a photovoltaic/thermal panel integrated with phase change material (PV/T-PCM). Equivalent overall output energy (QE) was proposed for energy performance evaluation regarding different energy forms, diversified conversions and hybrid thermal storages. This study focuses on parameters’ optimization of the PV/T-PCM system and parameters in the PCMs-VTW are kept optimal. Based on the experimentally validated numerical modelling, nine trial experiments have been conducted following Taguchi L9 (34) standard orthogonal array. The higher the better concept was implemented and the optimal combination of operating parameters was thereafter identified by using signal-to-noise (S/N) ratio and Analysis of Variance (ANOVA) method. The results show that QE is highly dependent on the mass flow rate, followed by the diameter of active cooling water pipe. However, the inlet cooling water temperature and the thickness of PCM have limited influence on QE. The optimal combination of each factor was identified as B3A3C2D1 (mass flow rate of 1 kg/s, diameter of water pipe of 0.6 m, inlet cooling water temperature of 15 °C and the thickness of PCM of 20 mm) with the highest QE of 20,700 kWh.

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Impact of the cold end operating conditions on energy efficiency of the steam power plants

Thermal Science ◽

10.2298/tsci100415066l ◽

2010 ◽

Vol 14 (suppl.) ◽

pp. 53-66 ◽

Cited By ~ 10

Author(s):

Mirjana Lakovic ◽

Mladen Stojiljkovic ◽

Slobodan Lakovic ◽

Velimir Stefanovic ◽

Dejan Mitrovic

Keyword(s):

Energy Efficiency ◽

Power Plant ◽

Water Temperature ◽

Flow Rate ◽

Power Plants ◽

Cooling Water ◽

Operating Conditions ◽

Steam Boiler ◽

Steam Power ◽

Cooling Water Temperature

The conventional steam power plant working under the Rankine Cycle and the steam condenser as a heat sink and the steam boiler as a heat source have the same importance for the power plant operating process. Energy efficiency of the coal fired power plant strongly depends on its turbine-condenser system operation mode. For the given thermal power plant configuration, cooling water temperature or/and flow rate change generate alterations in the condenser pressure. Those changes have great influence on the energy efficiency of the plant. This paper focuses on the influence of the cooling water temperature and flow rate on the condenser performance, and thus on the specific heat rate of the coal fired plant and its energy efficiency. Reference plant is working under turbine-follow mode with an open cycle cooling system. Analysis is done using thermodynamic theory, in order to define heat load dependence on the cooling water temperature and flow rate. Having these correlations, for given cooling water temperature it is possible to determine optimal flow rate of the cooling water in order to achieve an optimal condensing pressure, and thus, optimal energy efficiency of the plant. Obtained results could be used as useful guidelines in improving existing power plants performances and also in design of the new power plants. This article has been corrected. Link to the correction <a href="http://dx.doi.org/10.2298/TSCI151102198E">10.2298/TSCI151102198E</a>

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The Research of Cooling Water Temperature and Flow Rate Control System Based on Heat Transfer and Neural Network

2015 Fifth International Conference on Instrumentation and Measurement, Computer, Communication and Control (IMCCC) ◽

10.1109/imccc.2015.143 ◽

2015 ◽

Author(s):

Meng Lingling ◽

Qian Xuefei

Keyword(s):

Neural Network ◽

Heat Transfer ◽

Control System ◽

Water Temperature ◽

Flow Rate ◽

Rate Control ◽

Cooling Water ◽

Cooling Water Temperature ◽

Flow Rate Control

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Separation of HCl/water mixture using air gap membrane distillation, Taguchi optimization and artificial neural network

Chemical Product and Process Modeling ◽

10.1515/cppm-2020-0078 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Sarita Kalla ◽

Rakesh Baghel ◽

Sushant Upadhyaya ◽

Kailash Singh

Keyword(s):

Water Temperature ◽

Flow Rate ◽

Cooling Water ◽

Membrane Distillation ◽

Air Gap ◽

Water Mixture ◽

Feed Flow Rate ◽

Ann Model ◽

Cooling Water Temperature ◽

Feed Temperature

AbstractThe aim of this paper is to analyze the performance of the air gap membrane distillation (AGMD) process for the separation of HCl/Water mixture first by applying Taguchi optimization approach and second by developing an artificial neural network (ANN) model. The experimental data which are fed as input to the above approaches are collected from the fabricated AGMD lab-scale setup using poly-tetra-fluoro-ethylene membrane of 0.22 µm pore size. The process input variables considered are bulk feed temperature, feed flow rate, air gap thickness, cooling water temperature and cooing water flow rate and AGMD performance index is the total permeate flux. The optimum operating condition is found to be at feed temperature 50 °C, air gap thickness 7 mm, cooling water temperature 5 °C and feed flow rate 10 lpm. Analysis of variance test is carried out for both Taguchi and ANN models. Regression model has also been developed for the comparison between experimental and model predicted data. The developed ANN model has been found well fitted with experimental data having R2 value of 0.998. Based on the calculated percentage of contribution of each input parameter on the AGMD permeate flux, it can be concluded that feed temperature and air gap thickness have highest weightage whereas feed flow rate and cooling water temperature have moderate effects. Predictive ability of the developed ANN model is further checked with 2D contour plot. The distinctive feature of the paper is the development of the Taguchi experimental design and ANN model and then consequently integration of both Taguchi and ANN has been carried out to optimized the developed ANN model parameters.

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Analysis of Cooling Water Temperature Impact on Computing Performance and Energy Consumption

2020 IEEE International Conference on Cluster Computing (CLUSTER) ◽

10.1109/cluster49012.2020.00027 ◽

2020 ◽

Author(s):

Jorji Nonaka ◽

Toshihiro Hanawa ◽

Fumiyoshi Shoji

Keyword(s):

Energy Consumption ◽

Water Temperature ◽

Cooling Water ◽

Cooling Water Temperature ◽

Temperature Impact ◽

Computing Performance

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Reduction of CO2 Emissions in Steelmaking by Means of Utilization of Steel Plant Waste Heat to Stabilize Seasonal Cooling Water Temperature

Sustainability ◽

10.3390/su13115957 ◽

2021 ◽

Vol 13 (11) ◽

pp. 5957

Author(s):

Tomas Mauder ◽

Michal Brezina

Keyword(s):

Continuous Casting ◽

Water Temperature ◽

Co2 Emissions ◽

Waste Heat ◽

Cooling Water ◽

Main Idea ◽

Casting Process ◽

Spray Cooling ◽

Steel Plant ◽

Cooling Water Temperature

Production of overall CO2 emissions has exhibited a significant reduction in almost every industry in the last decades. The steelmaking industry is still one of the most significant producers of CO2 emissions worldwide. The processes and facilities used at steel plants, such as the blast furnace and the electric arc furnace, generate a large amount of waste heat, which can be recovered and meaningfully used. Another way to reduce CO2 emissions is to reduce the number of low-quality steel products which, due to poor final quality, need to be scrapped. Steel product quality is strongly dependent on the continuous casting process where the molten steel is converted into solid semifinished products such as slabs, blooms, or billets. It was observed that the crack formation can be affected by the water cooling temperature used for spray cooling which varies during the year. Therefore, a proper determination of the cooling water temperature can prevent the occurrence of steel defects. The main idea is based on the utilization of the waste heat inside the steel plant for preheating the cooling water used for spray cooling in the Continuous Casting (CC) process in terms of water temperature stabilization. This approach can improve the quality of steel and contribute to the reduction of greenhouse gas emissions. The results show that, in the case of billet casting, a reduction in the cooling water consumption can be also reached. The presented tools for achieving these goals are based on laboratory experiments and on advanced numerical simulations of the casting process.

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