- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Thermocells for Hybrid Photovoltaic/Thermal Systems
摘要： The photovoltaic conversion e?ciency of solar cells is highly temperature dependent and decreases with increasing temperature. Therefore, the thermal management of solar cells is crucial for the e?cient utilization of solar energy. We fabricate a hybrid photovoltaic/thermocell (PV/T) module by integrating a thermocell directly into the back of a solar panel and explore the feasibility of the module for its practical implementation. The proposed PV/T hybrid not only performs the cooling of the solar cells but also produces an additional power output by converting the heat stored in the solar cell into useful electric energy through the thermocell. Under illumination with an air mass of 1.5 G, the conversion e?ciency of the solar cell can improve from 13.2% to 15% by cooling the solar cell from 61 ?C to 34 ?C and simultaneously obtaining an additional power of 3.53 μW/cm2 from the thermocell. The advantages of the PV/T module presented in this work, such as the additional power generation from the thermocell as well as the simultaneous cooling of the solar cells and its convenient installation, can lead to the module’s importance in practical and large-scale deployment.
关键词： photovoltaic,carbon nanotube,ferric/ferrous cyanide,thermal management,thermocell
更新于2025-09-23 15:19:57
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Nanofibrous Kevlar Aerogel Films and Their Phase-Change Composites for Highly Efficient Infrared Stealth
摘要： Infrared (IR) stealth is essential not only in high technology and modern military but also in fundamental material science. However, effectively hiding targets and rendering them invisible to thermal infrared detectors have been great challenges in past decades. Herein, flexible, foldable, and robust Kevlar nanofiber aerogel (KNA) films with high porosity and specific surface area were fabricated first. The KNA films display excellent thermal insulation performance and can be employed to incorporate with phase-change materials (PCMs), such as polyethylene glycol, to fabricate KNA/PCM composite films. The KNA/PCM films with high thermal management capability and infrared emissivity comparable to that of various backgrounds demonstrate high performance in IR stealth in outdoor environments with solar illumination variations. To further realize hiding hot targets from IR detection, combined structures constituted of thermal insulation layers (KNA films) and ultralow IR transmittance layers (KNA/PCM) are proposed. A hot target covered with this combined structure becomes completely invisible in infrared images. Such KNA/PCM films and KNA?KNA/PCM combined structures hold great promise for broad applications in infrared thermal stealth.
关键词： thermal management,aerogel,phase-change materials,free-standing films,Kevlar nanofibers,infrared stealth
更新于2025-09-19 17:15:36
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Spectrally selective approaches for passive cooling of solar cells: A review
摘要： Waste heat is generated in solar cells during the daytime because they operate with a limited electrical efficiency. Moreover, the generated heat increases the solar cells’ operating temperature, and this has an adverse effect on their electrical efficiency. Therefore, numerous cooling methods have been developed to cool solar cells, such as forced air/water flow, hybrid photovoltaic/thermal system, and phase change material based photovoltaic application. Recently, a novel concept of changing the solar cells’ spectral response to both sunlight and thermal radiation has been proposed and developed to provide a passive cooling method for solar cells, which has drawn much attention from materials science to engineering fields. In this paper, the recent advancements of such a spectrally selective approach to passively cool solar cells, including radiative cooling of solar cells and full-spectrum thermal management of solar cells are reviewed, analyzed, and discussed from fundamental principles to detailed demonstration. Furthermore, the technical challenges involved in developing this new cooling technology are discussed. This paper is devoted to give a systematic introduction to a new passive cooling technology for solar cells by controlling the spectral property of solar cells, aiming to open a new opportunity for solar cells’ cooling.
关键词： Radiative cooling,Thermal management,Spectrally selective filter,Solar cells,Passive cooling,Thermal radiation
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE International Conference on Consumer Electronics - Taiwan (ICCE-TW) - YILAN, Taiwan (2019.5.20-2019.5.22)] 2019 IEEE International Conference on Consumer Electronics - Taiwan (ICCE-TW) - Maximum Power Point Tracking of Photovoltaic System Based on Reinforcement Learning
摘要： Chip designers place on-chip thermal sensors to measure local temperatures, thus preventing thermal runaway situations in many-core processing architectures. However, the quality of the thermal reconstruction is directly dependent on the number of placed sensors, which should be minimized, while guaranteeing full detection of all the worst case temperature gradient. In this paper, we present an entire framework for the thermal management of complex many-core architectures, such that we can precisely recover the thermal distribution from a minimal number of sensors. The proposed sensor placement algorithm is guaranteed to reduce the impact of noisy measurements on the reconstructed thermal distribution. We achieve signi?cant improvements compared to the state of the art, in terms of both computational complexity and reconstruction precision. For example, if we consider a 64 cores systems-on-chip with 64 noisy sensors (s2 ? 4), we achieve an average reconstruction error of 1:5(cid:2) C, that is less than half of what previous state-of-the-art methods achieve. We also study the practical limits of the proposed method and show that we do not need realistic workloads to learn the model and ef?ciently place the sensors. In fact, we show that the reconstruction error is not significantly increased if we randomly generate the power-traces of the components or if we have just a part of the correct workload.
关键词： thermal monitoring,thermal management,Sensor placement
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Can Bad Solar Cells Make a PV Module More Efficient?
摘要： Chip designers place on-chip thermal sensors to measure local temperatures, thus preventing thermal runaway situations in many-core processing architectures. However, the quality of the thermal reconstruction is directly dependent on the number of placed sensors, which should be minimized, while guaranteeing full detection of all the worst case temperature gradient. In this paper, we present an entire framework for the thermal management of complex many-core architectures, such that we can precisely recover the thermal distribution from a minimal number of sensors. The proposed sensor placement algorithm is guaranteed to reduce the impact of noisy measurements on the reconstructed thermal distribution. We achieve signi?cant improvements compared to the state of the art, in terms of both computational complexity and reconstruction precision. For example, if we consider a 64 cores systems-on-chip with 64 noisy sensors (s2 ? 4), we achieve an average reconstruction error of 1:5(cid:2) C, that is less than half of what previous state-of-the-art methods achieve. We also study the practical limits of the proposed method and show that we do not need realistic workloads to learn the model and ef?ciently place the sensors. In fact, we show that the reconstruction error is not signi?cantly increased if we randomly generate the power-traces of the components or if we have just a part of the correct workload.
关键词： thermal management,thermal monitoring,Sensor placement
更新于2025-09-19 17:13:59
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Investigation of functionally graded metal foam thermal management system for solar cell
摘要： Concentrated photovoltaic cell (CPV) is a solar energy harvesting device that converts solar energy into electrical energy. However, the performance and efficiency of the CPV are heavily dependent on the temperature. Besides, nonuniformity of temperature distribution on the CPV will lead to thermal aging and affects the cycle life. Hence, an effective cooling system is required to remove excess heat generated to ensure that the CPV operates at optimum operating temperature with minimum variation of temperature. Metal foam is a new class of material that possesses huge potential for thermal management. In this study, a functionally graded metal foam is proposed for the CPV thermal management system. Computational thermal fluid dynamic analysis is conducted to investigate the effect of porosity and pore density on the flow field and thermal performance of the aluminum foam heat sink. The investigation results revealed that 10 PPI functionally graded aluminum foam heat sink with two stages of porosity gradient 0.794 and 0.682 produced the lowest pressure drop and highest thermal performance. Temperature difference of 3.9°C was achieved for a solar cell with total heat generation of 900 W under water mass flow rate of 20 gs?1.
关键词： metal foam,thermal management system,concentrator photovoltaic,functionally graded metal foam,CFD model
更新于2025-09-19 17:13:59
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Non-Curing Thermal Interface Materials with Graphene Fillers for Thermal Management of Concentrated Photovoltaic Solar Cells
摘要： Temperature rise in multi-junction solar cells reduces their e?ciency and shortens their lifetime. We report the results of the feasibility study of passive thermal management of concentrated multi-junction solar cells with the non-curing graphene-enhanced thermal interface materials. Using an inexpensive, scalable technique, graphene and few-layer graphene ?llers were incorporated in the non-curing mineral oil matrix, with the ?ller concentration of up to 40 wt% and applied as the thermal interface material between the solar cell and the heat sink. The performance parameters of the solar cells were tested using an industry-standard solar simulator with concentrated light illumination at 70× and 200× suns. It was found that the non-curing graphene-enhanced thermal interface material substantially reduces the temperature rise in the solar cell and improves its open-circuit voltage. The decrease in the maximum temperature rise enhances the solar cell performance compared to that with the commercial non-cured thermal interface material. The obtained results are important for the development of the thermal management technologies for the next generation of photovoltaic solar cells.
关键词： thermal management,solar cells,non-curing thermal interface materials,graphene
更新于2025-09-16 10:30:52
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[IEEE 2019 13th International Conference on Signal Processing and Communication Systems (ICSPCS) - Gold Coast, Australia (2019.12.16-2019.12.18)] 2019 13th International Conference on Signal Processing and Communication Systems (ICSPCS) - Comparison of Modulation Methods for Visible Light Communication System Using Organic LED
摘要： Chip designers place on-chip thermal sensors to measure local temperatures, thus preventing thermal runaway situations in many-core processing architectures. However, the quality of the thermal reconstruction is directly dependent on the number of placed sensors, which should be minimized, while guaranteeing full detection of all the worst case temperature gradient. In this paper, we present an entire framework for the thermal management of complex many-core architectures, such that we can precisely recover the thermal distribution from a minimal number of sensors. The proposed sensor placement algorithm is guaranteed to reduce the impact of noisy measurements on the reconstructed thermal distribution. We achieve signi?cant improvements compared to the state of the art, in terms of both computational complexity and reconstruction precision. For example, if we consider a 64 cores systems-on-chip with 64 noisy sensors (s2 ? 4), we achieve an average reconstruction error of 1:5(cid:2) C, that is less than half of what previous state-of-the-art methods achieve. We also study the practical limits of the proposed method and show that we do not need realistic workloads to learn the model and ef?ciently place the sensors. In fact, we show that the reconstruction error is not significantly increased if we randomly generate the power-traces of the components or if we have just a part of the correct workload.
关键词： thermal monitoring,thermal management,Sensor placement
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 69th Electronic Components and Technology Conference (ECTC) - Las Vegas, NV, USA (2019.5.28-2019.5.31)] 2019 IEEE 69th Electronic Components and Technology Conference (ECTC) - Additive Laser Metal Deposition Onto Silicon for Enhanced Microelectronics Cooling
摘要： We previously demonstrated how the Sn3Ag4Ti alloy can robustly bond onto silicon via selective laser melting (SLM). By employing this technology, thermal management devices (e.g., micro-channels, vapor chamber evaporators, heat pipes) can be directly printed onto the electronic package (silicon die) without using thermal interface materials. Under immersion two-phase cooling (pool boiling), we compare the performance of three chip cooling methods (conventional heat sink, bare silicon die and additively manufactured metal micro-fins) under high heat flux conditions (100 W/cm2). Heat transfer simulations show a significant reduction in the chip temperature for the silicon micro-fins. Reduction of the chip operating temperature or increase in clock speed are some of the advantages of this technology, which results from the elimination of thermal interface materials in the electronic package. Performance and reliability aspects of this technology are discussed through experiments and computational models.
关键词： Performance and Reliability,Thermal Management,Laser Metal Deposition,Additive Manufacturing,Electronic Cooling
更新于2025-09-16 10:30:52
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Thermal Management of GaN-on-Si High Electron Mobility Transistor by Copper Filled Micro-Trench Structure
摘要： Self-heating effect is a major limitation in achieving the full performance potential of high power GaN power devices. In this work, we reported a micro-trench structure fabricated on the silicon substrate of an AlGaN/GaN high electron mobility transistor (HEMT) via deep reactive ion etching, which was subsequently filled with high thermal conductive material, copper using the electroplating process. From the current-voltage characteristics, the saturation drain current was improved by approximately 17% with the copper filled micro-trench structure due to efficient heat dissipation. The iDS difference between the pulse and DC bias measurement was about 21% at high bias VDS due to the self-heating effect. In contrast, the difference was reduced to approximately 8% for the devices with the implementation of the proposed structure. Using Micro-Raman thermometry, we showed that temperature near the drain edge of the channel can be lowered by approximately ~22 °C in a HEMT operating at ~10.6 Wmm?1 after the implementation of the trench structure. An effective method for the improvement of thermal management to enhance the performance of GaN-on-Silicon HEMTs was demonstrated.
关键词： thermal management,high electron mobility transistor,self-heating effect,copper filled micro-trench,GaN-on-Si
更新于2025-09-16 10:30:52