Development of Single Pebble Benchmark Ex. I-2A for IAEA UAM CRP With MOOSE

2018 ◽  
Author(s):  
Jinlin Niu ◽  
Lidong Wang ◽  
Jiong Guo ◽  
Fu Li
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer Coefficient ◽  
Object Oriented ◽  
Thermal Parameters ◽  
Maximum Temperature ◽  
Coolant Temperature ◽  
Simulation Environment ◽  
Helium Coolant ◽  
Solid Temperature ◽  
Shell Region

Ex. I-2a is Uncertainty Analysis in Modelling (UAM) of stand-alone thermal-hydraulics in steady state. It belongs to IAEA Coordinated Research Project (CRP). In this paper, the work is divided into two steps. Firstly, a single pebble model is developed based on Multiphysics Object Oriented Simulation Environment (MOOSE). The model includes two regions: homogeneous fuel region and shell region. One physical field is concerned: solid temperature field. The field is solved in a Jacobian-free Newton–Krylov (JFNK) way in the MOOSE framework. Secondly, perturbation of thermal parameters is done. In this paper, helium coolant temperature, convective heat transfer coefficient, power density and solid conductivity are the main thermal parameters which are concerned. Different kinds of perturbation of thermal parameters are conducted. Thus, variation of temperature profile across the pebble, Doppler temperature, moderator temperature and maximum temperature could be got.

Heat Transfer Characteristics of High Heat Generating Integrated Circuit Chips Cooled Using Liquid Cold Plate—A Combined Numerical and Experimental Study

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Naveen G. Patil ◽  
Tapano Kumar Hotta
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Integrated Circuit ◽  
Convective Heat Transfer Coefficient ◽  
High Heat ◽  
Vital Role ◽  
Maximum Temperature ◽  
Cold Plate ◽  
Error Band

Abstract This paper deals with the experimental and numerical investigations of seven integrated circuit (IC) chips cooled using the water flowing inside the cold plate at different flowrates. The study includes the supply of three different heat input cases under four different flowrates (0.063 kg/s, 0.125 kg/s, 0.25 kg/s, and 0.5 kg/s) to cool the high heat-generating IC chips mounted on the SMPS board at various positions. The optimal configuration (71-11-74-76-65-24-15) for the arrangement of the 7 IC chips is considered for the analysis. The numerical simulations are carried out using the commercial software ansys fluent (R-16) to support the experiments. Both the results (IC chips temperature) agree with each other in the error band of 8–14%. The smallest chip U6 attains the maximum temperature, as its heat attenuation rate is very high. The water flowing inside the cold plate absorbs the heat from the IC chips; by increasing the flowrate (Reynolds number increases), there is an increase in the convective heat transfer coefficient of the chips (Nusselt number increases) and ultimately cools these faster. A correlation is proposed for the Nusselt number of the chips with the Reynolds number of the flow. The results suggest that the liquid cold plate plays a vital role in the cooling of the IC chips and leads to better thermal management.

INFLUENCE OF HEAT TREATMENT OF MOUNTAIN MASSIVE ON TEMPERATURE MODE OF GEOTHERMAL CIRCULATION SYSTEM

2018 ◽  
pp. 44-50
Author(s):  
Yu. P. Morozov
Keyword(s):  
Heat Transfer ◽  
Operating Time ◽  
Fluid Motion ◽  
Coolant Temperature ◽  
Circulation System ◽  
Thermal Processes ◽  
Temperature Mode ◽  
Heat Influx ◽  
Stationary Heat Transfer

Based on the solution of the problem of non-stationary heat transfer during fluid motion in underground permeable layers, dependence was obtained to determine the operating time of the geothermal circulation system in the regime of constant and falling temperatures. It has been established that for a thickness of the layer H <4 m, the influence of heat influxes at = 0.99 and = 0.5 is practically the same, but for a thickness of the layer H> 5 m, the influence of heat inflows depends significantly on temperature. At a thickness of the permeable formation H> 20 m, the heat transfer at = 0.99 has virtually no effect on the thermal processes in the permeable formation, but at = 0.5 the heat influx, depending on the speed of movement, can be from 50 to 90%. Only at H> 50 m, the effect of heat influx significantly decreases and amounts, depending on the filtration rate, from 50 to 10%. The thermal effect of the rock mass with its thickness of more than 10 m, the distance between the discharge circuit and operation, as well as the speed of the coolant have almost no effect on the determination of the operating time of the GCS in constant temperature mode. During operation of the GCS at a dimensionless coolant temperature = 0.5, the velocity of the coolant is significant. With an increase in the speed of the coolant in two times, the error changes by 1.5 times.

Experimentation and modeling of convective heat transfer coefficient for evaporation of liquid foods in a pilot plant double effect

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Reyes Carlos Macedo y Ramírez ◽  
Jorge Fernando Vélez Ruiz
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Process Design ◽  
Food Industry ◽  
Convective Heat Transfer Coefficient ◽  
Double Effect ◽  
Sugar Solution ◽  
Convective Coefficient ◽  
Common Process ◽  
Predicted Values

Abstract Even though the evaporation is a common process in the food industry, there is scarce information about the convective coefficient evaluation as an important parameter for equipment and process design. A research on evaporation of sugar solution in a double effect was carried out. The experimental results obtained in this equipment, from the heat transfer and concentration processes are presented, a range of 2658–6091 W of heat flow was quantified implying computed values of 1431–3763 W/m2K for the convective coefficients and 1020–1815 W/m2K for the overall coefficient. The quantification of the convective coefficient, the fitting methodology and modeling were developed in order, to obtain the correspondent correlations. Then, from a set of several equations, two general relationships are proposed. Both correlations were applied to experimental and supposed data, finding a difference lower than 30% between the experimental and predicted values of the Nusselt number, that was considered as satisfactory.

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