Near-infrared measurement of water temperature near a 1-mm-diameter magnetic sphere and its heat generation rate under induction heating

2017 ◽  
Vol 122 (4) ◽  
pp. 044901 ◽  
Author(s):  
Naoto Kakuta ◽  
Keisuke Nishijima ◽  
Katsuya Kondo ◽  
Yukio Yamada
Keyword(s):  
Water Temperature ◽  
Heat Generation ◽  
Induction Heating ◽  
Near Infrared ◽  
Generation Rate ◽  
Heat Generation Rate ◽  
Infrared Measurement ◽  
Magnetic Sphere

scholarly journals A Simplified Calculation Method of Heat Source Model for Induction Heating

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2938 ◽  
Author(s):  
Hongbao Dong ◽  
Yao Zhao ◽  
Hua Yuan ◽  
Xiaocai Hu ◽  
Zhen Yang
Keyword(s):  
Heat Flux ◽  
Temperature Field ◽  
Heat Source ◽  
Heat Generation ◽  
Induction Heating ◽  
Generation Rate ◽  
Heat Generation Rate ◽  
Line Heating ◽  
Computation Efficiency ◽  
Computation Process

Line heating is used in forming the complex curve plates of ships, and this process is becoming integrated into automated tools. Induction heating equipment has become commonly used in automatic line heating. When applying automated equipment, it is necessary to calculate the relationship between the heating parameters and the temperature field. Numerical methods are primarily used to accomplish the calculations for induction heating. This computation process requires repeated iterations to obtain a stable heat generation rate. Once the heat generation rate changes significantly, a recalculation takes place. Due to the relative position of the coil and plate changes during heating, the grid needs to be frequently re-divided during computation, which dramatically increases the total computation time. In this paper, through an analysis of the computation process for induction heating, the root node that restricts the computation efficiency in the conventional electromagnetic-thermal computation process was found. A method that uses a Gaussian function to represent the heat flux was proposed to replace the electromagnetic computation. The heat flux is the input for calculating the temperature field, thus avoiding the calculation of the electromagnetic analysis during induction heating. Besides, an equivalence relationship for multi-coil was proposed in this paper. By comparing the results of the experiment and the numerical method, the proposed heat source model’s effectiveness was verified.

A novel heat generation acquisition method of cylindrical battery based on core and surface temperature measurements

2021 ◽  
pp. 1-17
Author(s):  
Xiaoli Yu ◽  
Qichao Wu ◽  
Rui Huang ◽  
Xiaoping Chen
Keyword(s):  
Surface Temperature ◽  
Heat Generation ◽  
Discharge Rate ◽  
Total Heat ◽  
Temperature Measurements ◽  
Generation Rate ◽  
Air Cooling ◽  
Heat Generation Rate ◽  
Environmental Chamber ◽  
Average Heat

Abstract Heat generation measurements of the lithium-ion battery are crucial for the design of the battery thermal management system. Most previous work uses the accelerating rate calorimeter (ARC) to test heat generation of batteries. However, utilizing ARC can only obtain heat generation of the battery operating under the adiabatic condition, deviating from common operation scenarios with heat dissipation. Besides, using ARC is difficult to measure heat generation of the high-rate operating battery because the battery temperature easily exceeds the maximum safety limit. To address these problems, we propose a novel method to obtain heat generation of cylindrical battery based on core and surface temperature measurements and select the 21700 cylindrical battery as the research object. Based on the method, total heat generation at 1C discharge rate under the natural convection air cooling condition in the environmental chamber is about 3.2 kJ, and the average heat generation rate is about 0.9 W. While these two results measured by ARC are about 2.2 kJ and 0.6 W. This gap also reflects that different battery temperature histories have significant impacts on heat generation. In addition, using our approach, total heat generation at 2C discharge rate measured in the environmental chamber is about 5.0 kJ, with the average heat generation rate being about 2.8 W. Heat generation results obtained by our method are approximate to the actual battery operation and have advantages in future applications.

Enhancement of Forced Convection Heat Transfer Using Twisted Heater With Exponential Heat Inputs

2013 ◽  
Author(s):  
Makoto Shibahara ◽  
Qiusheng Liu ◽  
Katsuya Fukuda
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Heat Generation ◽  
Swirling Flow ◽  
Generation Rate ◽  
Transient Heat Transfer ◽  
Heat Generation Rate ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Plate Heater

Forced convection transient heat transfer coefficients have been measured for nitrogen gas flowing over a twisted heater due to exponentially increasing heat inputs (Q0exp(t/τ)). And then, the effect of heater configuration on transient heat transfer by a twisted heater has been investigated comparing to that of the plate heater. In the experiment, the platinum ribbon with a thickness of 0.1 mm and a width of 4.0 mm was used as a test heater. For heat transfer enhancements in single-phase flow, it was twisted at the central part of the heater with an angle of 90 degrees with respect to the upper part of the heater. The heat generation rate was exponentially increased with a function of Q0exp(t/τ). The gas flow velocity ranged from 1 to 4 m/s for the gas temperatures of 313K. The periods of heat generation rate ranged from 46 ms to 17 s. The surface temperature difference and heat flux increased exponentially as the heat generation rate increased with the exponential function. The heat transfer coefficients for twisted heater have been compared to those of the plate heater. They were 24 % higher than those of the plate one. The geometric effect (twisted effect) of heater in this study showed an enhancement on the heat transfer coefficient. It was considered that the heat transfer coefficients are affected by the change in the flow due to swirling flow on the twisted heater. Finally, the empirical correlations for quasi-steady-state heat transfer and transient one have been obtained based on the experimental data.

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