Development of Numerical Simulation Method to Evaluate Heat Transfer Performance of Air Around Fuel Debris: Part 1 — Effect of the Debris Shape

2017 ◽  
Author(s):  
Susumu Yamashita ◽  
Shinichiro Uesawa ◽  
Hiroyuki Yoshida
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Free Convection ◽  
Simulation Method ◽  
Air Cooling ◽  
Atmospheric Conditions ◽  
Analysis Method ◽  
Simulation Code ◽  
Convection And Heat Transfer ◽  
Multi Phase

Fuel debris retrieval in atmospheric conditions is proposed as one candidate in the Fukushima Daiichi NPS since it can suppress generation of the contaminated water. However, there are unknowns and uncertainties to evaluate the air cooling performance of the fuel debris. Solving the problems, we have been developing the air-cooling analysis method for accumulated debris in the pedestal. A numerical simulation code JUPITER, which is based on a CFD technics and treats a multi-phase, multi-component thermal-hydraulics, is used as the basis of the method. We preliminary evaluated the effect of debris shapes and heat source conditions on free convection and heat transfer in the simplified structure of the pedestal region using the JUPITER. As a result, it was confirmed that the flow pattern of the free convection in the pedestal clearly differs with debris shapes and a correlation exists between the temperature distribution and the velocity fluctuation around the debris surface.

Calculation and Design Method Study of the Coil-Wound Heat Exchanger

2014 ◽  
Vol 1008-1009 ◽  
pp. 850-860 ◽  
Author(s):  
Zhou Wei Zhang ◽  
Jia Xing Xue ◽  
Ya Hong Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
Design Method ◽  
Fluid Velocity ◽  
Exchange Process ◽  
Three Dimensional ◽  
Simulation Method ◽  
Physical Parameters ◽  
Numerical Result

A calculation method for counter-current type coil-wound heat exchanger is presented for heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of wound bundles. By controlling the inlet fluid velocity varying in coil-wound heat exchanger to program and calculate the iterative process. The calculation data is analyzed by comparison of numerical result and the unit three dimensional pipe bundle model was built. Studies show that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration in coil-wound heat exchanger. This method can be applied to the physical modeling and heat transfer calculation of pipe bundles in coil wound heat exchanger, program to calculate the complex heat transfer changing with velocity and other parameters, and optimize the overall design and calculation of spiral bundles.

Numerical Simulation Study on Thermal-Hydraulic Performances of Vehicular Radiator Heat Transfer Units

2012 ◽  
Vol 538-541 ◽  
pp. 2061-2066
Author(s):  
Yang Zheng ◽  
Bao Lan Xiao ◽  
Wei Ming Wu ◽  
Xiao Li Yu ◽  
Guo Dong Lu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Cooling System ◽  
Experimental Testing ◽  
Orthogonal Experiment ◽  
Simulation Method ◽  
Manufacturing Cost ◽  
Performance Simulation ◽  
Factor Study ◽  
Testing Cost

A radiator is one of the most important components in vehicular cooling system whose excellent fluid flow and heat transfer characteristics guarantees the engine operations. The calculation workload for performance simulation of a whole radiator is too huge due to its size. Experimental study is the conventional method to study radiator performance. This paper put forward a numerical simulation method and radiator heat transfer units were taken as study objects. Orthogonal experiment method was adopted to arrange multi-factor and multi-level calculation schemes. 23 samples with different fin parameters were simulated to investigate their thermal-hydraulic performances. Compared with experimental testing, this method greatly reduced sample manufacturing cost and testing cost, and offered data support for the effect factor study of radiator heat transfer units.

The Effect Analysis of Fin Arrangement on Thermal Hydraulic Performance of a Vehicular Cooler

2013 ◽  
Vol 712-715 ◽  
pp. 1600-1604
Author(s):  
Jing Zhao ◽  
Bao Lan Xiao ◽  
Wei Ming Wu ◽  
Xiao Li Yu ◽  
Guo Dong Lu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Fluid Flow ◽  
Design Process ◽  
Simulation Method ◽  
Effect Analysis ◽  
Performance Requirements ◽  
Flow And Heat Transfer ◽  
Stability Structure ◽  
Safety And Stability

The excellent thermal hydraulic performances of coolers are the foundations of vehicular safety and stability. Structure, material, fin type and arrangement all have important effects on the thermal hydraulic performances. Numerical simulation method was adopted in this paper to investigate the effect of fin arrangement. The fluid flow and heat transfer performances were contrasted and analyzed under two different fin arrangements. It was found that fin arrangement effected thermal hydraulic performances severely and during the design process of a cooler, the performance requirements could be met through adjusting fin arrangements.

Numerical Simulation of High-Temperature Air Direct-Ignition of Pulverized Coal

2005 ◽  
Author(s):  
Z. Z. Kang ◽  
B. M. Sun ◽  
Y. H. Guo ◽  
W. Zhang ◽  
H. Q. Wei
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
High Temperature ◽  
Simulation Method ◽  
Pulverized Coal ◽  
Inlet Velocity ◽  
Operation Optimization ◽  
Structure Improvement ◽  
Simulation Results ◽  
Direct Ignition

Numerical simulation method is employed in this article to investigate various high-temperature air direct-ignition processes of pulverized coal (PC). Several important factors are analyzed, which are the inlet velocity of primary air flow, PC concentration and the velocity and temperature of high temperature air. The flow, combustion and heat transfer in high temperature air oil-free ignition burner can also be obtained from the simulation results, which are in accordance with the experimental data. The research provides guidance for structure improvement and operation optimization of burner.

The Numerical Simulation Research on Heat Exchanging Enhancement and Structural Optimization of the Flue Gas Heat Transfer of Mixed Arrangement Irregular Heat-Pipe

2013 ◽  
Vol 781-784 ◽  
pp. 2770-2774
Author(s):  
De Fan Qing ◽  
Deng Qiang Yan
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Pipe ◽  
Flue Gas ◽  
Simulation Method ◽  
Inlet Temperature ◽  
Equivalent Diameter ◽  
The Third ◽  
Heat Transfer Efficiency ◽  
Line Spacing

The mixed arrangement irregular heat-pipe flue gas heat transfer was researched, using numerical simulation method. The irregular heat-pipe: triangle heat pipe; square heat pipe. The heat pipe equivalent diameter of flue gas heat transfer is 20 mm, the speed of inlet flue gas is 11 m/s, the inlet temperature of flue gas is 500 K. the results show mixed arrangement irregular heat-pipe can enhance heat exchanging, the optimal parameters of mixed arrangement structure in the condition of given working condition: the first row is triangle heat pipe, the second row is circular heat pipe, the third row is triangle heat pipe, row 4 is square heat pipe, the line spacing of the first row and second is 40 mm, the line spacing of the second and third row is 40 mm, the line spacing of the third row and the fourth row is 35 mm, and the row spacing of the tube is 40 mm. the heat transfer efficiency of the optimized irregular heat-pipe-exchanger raised 40 ~ 60%.

Utilization of Cold-Flow Numerical Simulation With Overset Grid Method in Development Process of Aeroengine Combustor

2010 ◽  
Author(s):  
Mitsumasa Makida ◽  
Naoki Nakamura ◽  
Osamu Nozaki
Keyword(s):  
Numerical Simulation ◽  
Development Process ◽  
Grid Method ◽  
Simulation Method ◽  
Simulation Methods ◽  
Overset Grid ◽  
Simulation Code ◽  
Screening Process ◽  
Cold Flow ◽  
Overset Grid Method

In the TechCLEAN project of JAXA, a combustor for a small aircraft engine has been developed. The combustor was tuned to show the behavior of the Rich-Lean combustion through combustion tests under atmospheric and practical conditions. In the development process of the combustor, numerical simulation methods were also utilized as analysis tools to accelerate the development of the combustor. To use in the screening process of the combustor design, we focused on cost-effective simulation methods and adopted the cold-flow RANS simulation code UPACS which has been developed in JAXA. And to simplify the treatment of calculation grids of the combustor with complicated configuration, we also utilized combination of the overset grid method with the attached multi-block grid method. This simulation method was applied to three phases in the combustor development process; first to the analysis of the combustor configuration to adjust the overall pressure loss, secondly to the analysis of flame stability, and thirdly to the tuning of air flow ratio to optimize emission characteristics of full annular combustors. Finally, the full annular combustor was successively tuned to reduce NOx emissions to 38.1% of the ICAO CAEP4 standard under ICAO LTO cycles, also sustaining basic performances as an aircraft combustor.

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