Mathematical Formulation of Cooling Water Flow Rates for High Speed Continuous Slab Caster

1981 ◽  
Vol 103 (2) ◽  
pp. 318-327
Author(s):  
Y. P. Singh
Keyword(s):  
Water Flow ◽  
High Speed ◽  
Cooling Water ◽  
Least Square ◽  
Continuous Steel ◽  
Slab Caster ◽  
Flow Rates ◽  
Cooling Flow ◽  
Steel Slab ◽  
Steel Cast

In high speed continuous steel slab castings machine, the partially solidified strand emerging out from the bottomless mold is cooled to complete solidification by means of water sprays arranged through its metallurgical length. The cooling water flow rates are dependent on slab size, grade of steel cast, working length of mold, casting speed, water pressure, spray nozzles and their location in the strand support system of the caster. In this paper an analytical method to predict the spray cooling water flow rates is presented. A least square polynomial is found which best describes extensive data of cooling flow rates obtained from high speed continuous steel slab caster at Linz, Austria. Polynomial curves for various slab sizes, grades of steel cast and casting speeds have been determined using the actual water flow rates data and the developed least square technique. The technique developed in this paper is general and can be used for determination of cooling flow rates of any type of continuous steel casting machine.

scholarly journals Comparison of Optimization-Regulation Algorithms for Secondary Cooling in Continuous Steel Casting

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 237
Author(s):  
Michal Brezina ◽  
Tomas Mauder ◽  
Lubomir Klimes ◽  
Josef Stetina
Keyword(s):  
Convergence Rate ◽  
Water Flow ◽  
Steel Casting ◽  
Casting Process ◽  
Continuous Steel Casting ◽  
Continuous Steel ◽  
Cooling Zone ◽  
Secondary Cooling ◽  
Flow Rates ◽  
Secondary Cooling Zone

The paper presents the comparison of optimization-regulation algorithms applied to the secondary cooling zone in continuous steel casting where the semi-product withdraws most of its thermal energy. In steel production, requirements towards obtaining defect-free semi-products are increasing day-by-day and the products, which would satisfy requirements of the consumers a few decades ago, are now far below the minimum required quality. To fulfill the quality demands towards minimum occurrence of defects in secondary cooling as possible, some regulation in the casting process is needed. The main concept of this paper is to analyze and compare the most known metaheuristic optimization approaches applied to the continuous steel casting process. Heat transfer and solidification phenomena are solved by using a fast 2.5D slice numerical model. The objective function is set to minimize the surface temperature differences in secondary cooling zones between calculated and targeted surface temperatures by suitable water flow rates through cooling nozzles. Obtained optimization results are discussed and the most suitable algorithm for this type of optimization problem is identified. Temperature deviations and cooling water flow rates in the secondary cooling zone, together with convergence rate and operation times needed to reach the stop criterium for each optimization approach, are analyzed and compared to target casting conditions based on a required temperature distribution of the strand. The paper also contains a brief description of applied heuristic algorithms. Some of the algorithms exhibited faster convergence rate than others, but the optimal solution was reached in every optimization run by only one algorithm.

Research and Application of Dynamic Secondary Cooling Control System for a Continuous Steel Billet Caster

2012 ◽  
Vol 572 ◽  
pp. 404-409
Author(s):  
Zun Peng ◽  
Wen Hao Hu ◽  
Yan Ping Bao ◽  
Min Wang ◽  
Li Qiang Zhang ◽  
...  
Keyword(s):  
Water Flow ◽  
Cooling System ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Cooling Water ◽  
Transfer Model ◽  
Secondary Cooling ◽  
Billet Temperature ◽  
Flow Rates ◽  
Billet Caster

A two-dimensional heat-transfer model for transient simulation of a billets caster is presented. Its accuracy is verified through measured billet temperature and shell thickness. Billets temperature and solidification are computed by this model as a function of time varying casting speed, secondary cooling water flow rates and temperature, billet cross section, steel grade, and pouring and ambient temperatures. A control methodology and algorithm suitable for online control of 5 strands billet continuous casting machine is integrated in this model. The ability of this model to control the surface temperature profile is demonstrated through dynamic and precise adjustment of secondary cooling water flow rates. This secondary cooling system has been applied to a billet caster in Hangzhou Steel Corporation.

Effect of cooling water flow rates on local temperatures and heat transfer of casting dies

2004 ◽  
Vol 148 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Henry Hu ◽  
Fang Chen ◽  
Xiang Chen ◽  
Yeou-li Chu ◽  
Patrick Cheng
Keyword(s):  
Heat Transfer ◽  
Water Flow ◽  
Cooling Water ◽  
Flow Rates

Study on the Thermal Characteristics of a Motorized Spindle Unit

2012 ◽  
Vol 479-481 ◽  
pp. 2546-2550
Author(s):  
Teng Qing Wu ◽  
Heng Liu ◽  
Min Qing Jing ◽  
Hong Wei Fan
Keyword(s):  
Water Flow ◽  
Heat Generation ◽  
High Performance ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Thermal Characteristics ◽  
Motorized Spindle ◽  
Flow Rates ◽  
Cooling Water Flow Rate ◽  
Spindle Unit

Heat generation and heat transfer of motorized spindle unit are studied in this paper, including heat generation of built-in motor and rolling bearings, heat conduction, convection and radiation between spindle components. By modeling a FEM model of a high performance motorized grinding spindle, thermal characteristics simulation of the spindle unit is completed. The thermal characteristics under different spindle speeds, different cooling water flow rates and different forced air flow rates are simulated. The numerical results show that spindle speed and cooling water flow rate have significant influences on thermal characteristics of motorized spindle unit. These results are useful to guide the design and verification of motorized spindle unit.

The optimal manipulation of cooling water flow rates in a heat exchanger network

2001 ◽  
Vol 34 (25) ◽  
pp. 511-516
Author(s):  
Jin-Kyeong Kim ◽  
Bomsock Lee ◽  
Euy Soo Lee ◽  
Gyeongbeom Yi
Keyword(s):  
Heat Exchanger ◽  
Water Flow ◽  
Cooling Water ◽  
Heat Exchanger Network ◽  
Flow Rates

Hydraulic model of a water cooling system in a chemical plant

1988 ◽  
Vol 53 (4) ◽  
pp. 788-806
Author(s):  
Miloslav Hošťálek ◽  
Jiří Výborný ◽  
František Madron
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Cooling Water ◽  
Graph Algorithm ◽  
Automatic Generation ◽  
Hydraulic Calculation ◽  
Return Flow ◽  
Flow Rates ◽  
Pressure Losses ◽  
Controlled Flow

Steady state hydraulic calculation has been described of an extensive pipeline network based on a new graph algorithm for setting up and decomposition of balance equations of the model. The parameters of the model are characteristics of individual sections of the network (pumps, pipes, and heat exchangers with armatures). In case of sections with controlled flow rate (variable characteristic), or sections with measured flow rate, the flow rates are direct inputs. The interactions of the network with the surroundings are accounted for by appropriate sources and sinks of individual nodes. The result of the calculation is the knowledge of all flow rates and pressure losses in the network. Automatic generation of the model equations utilizes an efficient (vector) fixing of the network topology and predominantly logical, not numerical operations based on the graph theory. The calculation proper utilizes a modification of the model by the method of linearization of characteristics, while the properties of the modified set of equations permit further decrease of the requirements on the computer. The described approach is suitable for the solution of practical problems even on lower category personal computers. The calculations are illustrated on an example of a simple network with uncontrolled and controlled flow rates of cooling water while one of the sections of the network is also a gravitational return flow of the cooling water.

scholarly journals Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Air Flow ◽  
Bubble Diameter ◽  
Diameter Ratio ◽  
Experimental Measurements ◽  
Cfd Model ◽  
Flow Rates ◽  
Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

Effect of Heat Sink Structure Improvement on Heat Dissipation Performance in High Heat Flux

2016 ◽  
Author(s):  
Zhuo Cui
Keyword(s):  
Heat Resistance ◽  
Water Flow ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Convection Heat Transfer ◽  
Cooling Water ◽  
High Heat Flux ◽  
Pin Fin ◽  
Pin Fins ◽  
Pin Fin Arrays

This paper presents the effects of heat dissipation performance of pin fins with different heat sink structures. The heat dissipation performance of two types of pin fin arrays heat sink are compared through measuring their heat resistance and the average Nusselt number in different cooling water flow. The temperature of cpu chip is monitored to determine the temperature is in the normal range of working temperature. The cooling water flow is in the range of 0.02L/s to 0.15L/s. It’s found that the increase of pin fins in the corner region effectively reduce the temperature of heat sink and cpu chip. The new type of pin fin arrays increase convection heat transfer coefficient and reduce heat resistance of heat sink.

Experimental Characterization of a Modified Airlift Pump

2014 ◽  
Author(s):  
Afshin Goharzadeh ◽  
Keegan Fernandes
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
High Speed ◽  
Water Flow Rate ◽  
High Speed Photography ◽  
Two Phase ◽  
Inner Diameter ◽  
Airlift Pump ◽  
Flow Map ◽  
Churn Flow

This paper presents an experimental investigation on a modified airlift pump. Experiments were undertaken as a function of air-water flow rate for two submergence ratios (ε=0.58 and 0.74), and two different riser geometries (i) straight pipe with a constant inner diameter of 19 mm and (ii) enlarged pipe with a sudden expanded diameter of 19 to 32 mm. These transparent vertical pipes, of 1 m length, were submerged in a transparent rectangular tank (0.45×0.45×1.1 m3). The compressed air was injected into the vertical pipe to lift the water from the reservoir. The flow map regime is established for both configurations and compared with previous studies. The two phase air-water flow structure at the expansion region is experimentally characterized. Pipeline geometry is found to have a significant influence on the output water flow rate. Using high speed photography and electrical conductivity probes, new flow regimes, such as “slug to churn” and “annular to churn” flow, are observed and their influence on the output water flow rate and efficiency are discussed. These experimental results provide fundamental insights into the physics of modified airlift pump.

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