scholarly journals A Thermal Management Strategy for Electronic Devices Based on Moisture Sorption-Desorption Processes

Joule ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 435-447 ◽  
Author(s):  
Chenxi Wang ◽  
Lingji Hua ◽  
Hongzhi Yan ◽  
Bangjun Li ◽  
Yaodong Tu ◽  
...  
2021 ◽  
Vol 13 (14) ◽  
pp. 7865
Author(s):  
Mohammed Mahedi Hasan ◽  
Nikos Avramis ◽  
Mikaela Ranta ◽  
Andoni Saez-de-Ibarra ◽  
Mohamed El Baghdadi ◽  
...  

The paper presents use case simulations of fleets of electric buses in two cities in Europe, one with a warm Mediterranean climate and the other with a Northern European (cool temperate) climate, to compare the different climatic effects of the thermal management strategy and charging management strategy. Two bus routes are selected in each city, and the effects of their speed, elevation, and passenger profiles on the energy and thermal management strategy of vehicles are evaluated. A multi-objective optimization technique, the improved Simple Optimization technique, and a “brute-force” Monte Carlo technique were employed to determine the optimal number of chargers and charging power to minimize the total cost of operation of the fleet and the impact on the grid, while ensuring that all the buses in the fleet are able to realize their trips throughout the day and keeping the battery SoC within the constraints designated by the manufacturer. A mix of four different types of buses with different battery capacities and electric motor specifications constitute the bus fleet, and the effects that they have on charging priority are evaluated. Finally, different energy management strategies, including economy (ECO) features, such as ECO-comfort, ECO-driving, and ECO-charging, and their effects on the overall optimization are investigated. The single bus results indicate that 12 m buses have a significant battery capacity, allowing for multiple trips within their designated routes, while 18 m buses only have the battery capacity to allow for one or two trips. The fleet results for Barcelona city indicate an energy requirement of 4.42 GWh per year for a fleet of 36 buses, while for Gothenburg, the energy requirement is 5 GWh per year for a fleet of 20 buses. The higher energy requirement in Gothenburg can be attributed to the higher average velocities of the bus routes in Gothenburg, compared to those of the bus routes in Barcelona city. However, applying ECO-features can reduce the energy consumption by 15% in Barcelona city and by 40% in Gothenburg. The significant reduction in Gothenburg is due to the more effective application of the ECO-driving and ECO-charging strategies. The application of ECO-charging also reduces the average grid load by more than 10%, while shifting the charging towards non-peak hours. Finally, the optimization process results in a reduction of the total fleet energy consumption of up to 30% in Barcelona city, while in Gothenburg, the total cost of ownership of the fleet is reduced by 9%.


2021 ◽  
Vol 17 (0) ◽  
Author(s):  
Randeep Singh ◽  
Jason Velardo ◽  
Mohammad Shahed Ahamed ◽  
Masataka Mochizuki ◽  
Abhijit Date ◽  
...  

Author(s):  
Jinwei Chen ◽  
Yuanfu Li ◽  
Huisheng Zhang ◽  
Zhenhua Lu

Abstract The SOFC performance and lifetime highly depend on the operation condition, especially the SOFC operation temperature. The temperature fluctuation causes thermal stress in electrodes and electrolyte ceramics. On the other hand, it also needs to maintain a sufficiently high temperature to enable the efficient transport of oxygen ions across the electrolyte. Therefore, it is necessary to design an effective SOFC temperature management system to guarantee safe and efficient operation. In this paper, a two-side temperature control method is proposed to avoid the temperature difference between anode and cathode. Therefore, the SOFC thermal management system includes two control loops. The anode inlet temperature and cathode inlet temperature are controlled by blowers adjusting the recirculated flow rate. In addition, the control performance of the proposed SOFC thermal management system is compared with one-side temperature control systems. The results show that both anode control loop and cathode control loop are essential to get a better control performance. The SOFC would operate with less efficiency with only anode temperature control. On the other hand, the safety problem would occur with only cathode temperature control. The temperature gradient would be more than the upper limit at a part load condition. Therefore, the SOFC thermal management strategy with anode and cathode temperature control loops is feasible for the SOFC-GT system.


2018 ◽  
Vol 31 (7) ◽  
pp. 767-777
Author(s):  
Gopal Krishna Singh Khagokpam ◽  
Sudipta Halder

Miniaturization of electronic devices with more computing power has created a challenging set of aspects in thermal management. Present work is based on phase change materials microsphere and its incorporation in the epoxy network to develop a new class of potting material facilitating thermal management for miniaturized electronic devices. A facile and scalable method was implemented to synthesize paraffin wax microspheres (PMPs). It was dispersed into a room temperature curing epoxy network to fabricate the epoxy composite with high latent heat of fusion and high thermal stability. PMPs obtained have spherical morphology with an average diameter of approximately 5 µm. The PMP/epoxy composite can store 34.34 and 49.3 J g−1 of latent heat energy at 30 and 40 wt% PMP loading, respectively. Leakage test reveals that leaching declined as the size of PMP is reduced. Incorporation of PMP into the epoxy network reduces the compressive strength, but still resilient enough to protect electronic devices. This is an added advantage over the potential to mitigate the issue of hot spot in electronic devices as demonstrated by infrared thermography. The application of such composite is not limited only as electronic potting materials but also has the potential for other thermal energy storage applications.


Author(s):  
Yafei Yin ◽  
Min Li ◽  
Wei Yuan ◽  
Xiaolian Chen ◽  
Yuhang Li

Flexible electronics, as a relatively new category of device, exhibit prodigious potential in many applications, especially in bio-integrated fields. It is critical to understand that thermal management of certain kinds of exothermic flexible electronics is a crucial issue, whether to avoid or to take advantage of the excessive temperature. A widely adaptable analytical method, validated by finite-element analysis and experiments, is conducted to investigate the thermal properties of exothermic flexible electronics with a heat source in complex shape or complex array layout. The main theoretical strategy to obtain the thermal field is through an integral along the complex curve source region. The results predicted by the analytical model enable accurate control of temperature and heat flow in the flexible electronics, which may help in the design and fabrication of flexible electronic devices in the future.


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