- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Direct Fluid Cooling of Concentrator Photovoltaics for Hybrid Photovoltaic-Solar Thermal Energy Conversion
摘要： A spectrum-splitting photovoltaic module is developed for hybrid photovoltaic-solar thermal energy conversion using direct fluid cooling (DFC) of partially transmissive concentrator photovoltaic cells. The waste heat generated in photovoltaic cells can be more efficiently extracted by flowing a heat transfer fluid in direct contact with both sides of the cells. The module also acts as a beam splitter, dividing the incident light into two parts. Photons with higher energy than the bandgap of the cells are absorbed in cells, while photons with lower energy are passed through the infrared-transmissive module to a thermal receiver. Optical modeling (experimental) shows 63.2% (34.3%) out-of-band transmittance through the cell regions and 90.4% (89.0%) full spectrum transmittance through the surrounding bypass region. Thermal modelling verifies the direct cooling fluid method is an effective way to maintain cell temperature < 110℃. Electrical power conversion efficiency in a first prototype module is 79% of the bare cell efficiency. Fluid flow characterization shows laminar flow. The modules are currently undergoing field testing.
关键词： hybrid CPV/T system,active cooling,silicone oil heat transfer fluid,CPV
更新于2025-09-23 15:21:01
-
Theoretical and Numerical Study of a Photovoltaic System with Active Fluid Cooling by a Fully-Coupled 3D Thermal and Electric Model
摘要： The paper deals with the three-dimensional theoretical and numerical investigation of the electrical performance of a Photovoltaic System (PV) with active fluid cooling (PVFC) in order to increase its efficiency in converting solar radiation into electricity. The paper represents a refinement of a previous study by the authors in which a one-dimensional theoretical model was presented to evaluate the best compromise, in terms of fluid flow rate, of net power gain in a cooled PV system. The PV system includes 20 modules cooled by a fluid circulating on the bottom, the piping network, and the circulating pump. The fully coupled thermal and electrical model was developed in a three-dimensional geometry and the results were discussed with respect to the one-dimensional approximation and to experimental tests. Numerical simulations show that a competitive mechanism between the power gain due to the cell temperature reduction and the power consumption of the pump exists, and that a best compromise, in terms of fluid flow rate, can be found. The optimum flow rate can be automatically calculated by using a semi-analytical approach in which irradiance and ambient temperature of the site are known and the piping network losses are fully characterized.
关键词： thermal–electrical model,solar energy,photovoltaic modules,active cooling,computational fluid dynamics (CFD)
更新于2025-09-16 10:30:52
-
Influence of cooling on edge effects in laser forming
摘要： Edge effects in laser forming influence the possible tolerances that can be achieved with laser forming. Edge effects arise due to uneven temperature profiles along the laser scan line. It has been suggested that an increased cooling rate can minimize the occurrence of edge effects. This work will examine the effect of increased cooling to reduce edge effects. The height profile along the laser scan line is reported and compared for different levels of cooling using experiments and simulations. The results show that increased cooling has no impact on the edge effects.
关键词： Laser forming,Edge effects,Active cooling
更新于2025-09-12 10:27:22
-
Thermal and optical performance characteristics of a spatial light modulator with high average power picosecond laser exposure applied to materials processing applications
摘要： A spatial light modulator (SLM) addressed with Computer Generated Holograms (CGH’s) can create structured light fields when an incident laser beam is diffracted by a phase CGH. The power handling limitations of SLMs based on a liquid crystal layer have always been of some concern. Now, with careful engineering of chip thermal management, we present the detailed optical phase and temperature response of a liquid cooled SLM exposed to picosecond laser average powers up to 220W at 1064nm – new knowledge critical for determining device performance at high laser powers. SLM chip temperature rose linearly with incident laser exposure, increasing by only 5°C at 220W incident power, measured with a thermal imaging camera. Thermal response time with continuous exposure was 1-2 seconds. The optical phase response with incident power approaches 2π radians with average powers up to 130W while above this power, liquid crystal thickness variations limit phase response to just over π radians. These remarkable performance characteristics show that liquid crystal based SLM technology is highly robust when efficiently cooled. High speed, multi-beam plasmonic surface micro-structuring at a coverage rate of 8cm2s-1 is achieved on polished metal surfaces at 25W exposure, while diffractive multi-beam surface ablation on stainless steel at an ablation rate of ～4mm3min-1 is demonstrated with average power 100W. Continuous exposure for many hours exceeding 100W laser power did not result in any detectable drop in diffraction efficiency hence no permanent changes in SLM phase response characteristics have been observed This research work will help to accelerate the use of liquid crystal SLMs for both scientific and ultra-high throughput laser-materials micro-structuring applications.
关键词： Spatial light modulator,active cooling,high average power picosecond laser,high power laser micro-machining
更新于2025-09-12 10:27:22
-
Integrative passive and active cooling system using PCM and nanofluid for thermal regulation of concentrated photovoltaic solar cells
摘要： An integration of passive and active cooling systems for thermal regulation of concentrated photovoltaic (CPV) solar system has been developed and modeled. A heat storage battery of phase change material (PCM) is combined with a closed loop water cooling system in the developed design. A two dimensional model has been developed for the simulation of the CPV layers with the integrated cooling system. Results have been investigated to evaluate the thermal and electrical performances of the system components and the entire system. Further investigations have been conducted to study the effects of different arrangements of the PCM plates in the water tank on the system performances. Enhancing the system performance by using nanofluid as heat transfer fluid (HTF) was also evaluated. Results showed that the proposed system achieves 60% reduction in the CPV average temperature compared to the conventional direct PCM-PV and water-cooling individual systems. At 10 concentration ratio (CR) and 0.01 m/s HTF velocity, the cell temperature does not exceed 78 °C. Moreover, the PCM maximum temperature is kept below the degradation temperature limit. The effect of the PCM plates’ arrangements in the water tank on the system performance is negligible. Using nanofluid as HTF enhancer increases the CPV efficiency by 2.7% and reduces the PV maximum temperature and the PCM melting time by 4 °C and 12%, respectively.
关键词： Concentrated photovoltaic,Integrative passive-active cooling system,PCM,Thermal regulation,Nanofluid
更新于2025-09-12 10:27:22