scholarly journals Assessment of thermal and electrical performance of BIPV façades using simplified simulations

2021 ◽  
Vol 2042 (1) ◽  
pp. 012081
Author(s):  
Romain Schindelholz ◽  
Mohammad Rahiminejad ◽  
Arnab Chatterjee ◽  
Dolaana Khovalyg
Keyword(s):  
Energy Use ◽  
Thermal Inertia ◽  
Visual Programming ◽  
Electrical Performance ◽  
Transfer Model ◽  
Complex Flow ◽  
Building Site ◽  
Electrical Efficiency ◽  
3D Cad ◽  
Wall Structures

Abstract Building integrated photovoltaic (BIPV) facades are a solution to consider when it comes to electricity generation on the building site. One of the main challenges attributes to this technology is finding the best trade-off between the electrical efficiency of BIPVs and the energy use of the building. This study aims to identify a scenario that yields the optimized results for electrical and thermal performance in a test building. Among the scenarios, the original wooden cladding in the test building is either replaced with PV panels or the PV modules are added to the existing facade. Rhinoceros 3D CAD software and its visual programming plugin Grasshopper are used to perform various simulations for both east-oriented and west-oriented façades with low and high thermal inertia wall structures. Although a complex flow phenomenon behind BIPVs is simplified in the 3D heat transfer model, relatively reliable results are obtained using the chosen simulation tool. It is observed that the east-faced BIPV facade in the test building has higher electrical efficiency. This could be attributed to the lower inertia of the east wall that allows easier propagation of heat through the structure.

Energy Saving Effect of Different Wall Structures Based on Intermittent Energy Use Characteristics in a Hot Summer and Cold Winter Zone

2016 ◽  
Author(s):  
Yanyan Zhu ◽  
Wei Li ◽  
Bin Zhou ◽  
David J. Kukulka
Keyword(s):  
Energy Use ◽  
Three Dimensional ◽  
Transfer Model ◽  
Cold Winter ◽  
Heating And Cooling ◽  
Living Space ◽  
Wall Structures ◽  
Insulation Thickness ◽  
Reduction Of Energy Consumption ◽  
Saving Effect

An analysis is performed for a typical residential living space with intermittent energy use in a hot summer and cold winter zone. Analysis performed in this study include a dynamic, three dimensional heat transfer model that examine the intermittent heating and cooling loads in a typical living space in Shanghai. Different wall structures (non-insulation structure, exterior insulation structure, or interior insulation structure) can have different influences on the energy efficiency in buildings. Results conclude that the interior insulation structure provides the largest reduction of energy consumption in buildings when compared to the other wall structures in a hot summer and cold winter zone. For the interior insulation structure in this study, the typical thermal insulation thickness is 0.03 m.

A 3D CAD model input pipeline for REFMUL3 full-wave FDTD 3D simulator

2021 ◽  
Vol 16 (11) ◽  
pp. C11013
Author(s):  
J.M. Santos ◽  
E. Ricardo ◽  
F.J. da Silva ◽  
T. Ribeiro ◽  
S. Heuraux ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Thermal Protection ◽  
Interface Problem ◽  
Cad Model ◽  
Fusion Plasma ◽  
3D Cad ◽  
Full Wave ◽  
Wall Structures ◽  
Design Cycle ◽  
Cad Models

Abstract The use of advanced simulation has become increasingly more important in the planning, design, and assessment phases of future fusion plasma diagnostics, and in the interpretation of experimental data from existing ones. The design cycle of complex reflectometry systems, such as the ones being planned for next generation machines (IDTT and DEMO), relies heavily on the results produced by synthetic diagnostics, used for system performance evaluation and prediction, both crucial in the design process decision making. These synthetic diagnostics need realistic representations of all system components to incorporate the main effects that shape their behavior. Some of the most important elements that are required to be well modelled and integrated in simulations are the wave launcher structures, such as the waveguides, tapers, and antennas, as well as the vessel wall structures and access to the plasma. The latter are of paramount importance and are often neglected in this type of studies. Faithfully modelling them is not an easy task, especially in 3D simulations. The procedure herein proposed consists in using CAD models of a given machine, together with parameterizable models of the launcher, to produce a description suited for Finite Difference Time Domain (FDTD) 3D simulation, combining the capabilities of real-world CAD design with the power of simulation. However, CAD model geometric descriptions are incompatible with the ones used by standard FDTD codes. CAD software usually outputs models in a tessellated mesh while FDTD simulators use Volumetric Pixel (VOXEL) descriptions. To solve this interface problem, we implemented a pipeline to automatically convert complex CAD models of tokamak vessel components and wave launcher structures to the VOXEL input required by REFMUL3, a full wave 3D Maxwell FDTD parallel code. To illustrate the full procedure, a complex reflectometry synthetic diagnostic for IDTT was setup, converted and simulated. This setup includes 3 antennas recessed into the vessel wall, for thermal protection, one for transmission and reception, and two just for reception.

Modeling, Testing, and Evaluation of a Building-Integrated Photovoltaic-Thermal Collector

2009 ◽  
Author(s):  
Charles D. Corbin ◽  
Michael J. Brandemuehl
Keyword(s):  
Heat Transfer ◽  
Thermal Efficiency ◽  
Low Cost ◽  
Convection Heat Transfer ◽  
Calibration Error ◽  
Transfer Model ◽  
Transfer Coefficients ◽  
Electrical Efficiency ◽  
Building Integrated Photovoltaic ◽  
Low Efficiency

The performance of Building-Integrated Photovoltaic-Thermal (BIPV/T) collector is examined in this study. A full scale-test collector is monitored over several weeks in the summer of 2008 and measured data is used to calibrate a heat transfer model implemented in a common scientific computing software package. Following calibration, error between experimental measurements and the calibrated model outputs is within the limits of measurement uncertainty. Collector simulations are constructed to examine thermal efficiency, the effectiveness of the collector as a night-sky radiator, the effect of heat collection on electrical efficiency, the effect of two common exterior convection coefficients on collector performance, and the effect of eliminating the air gap between the PV and absorber surfaces. Overall collector thermal efficiency is relatively low compared to existing collectors. However, the potential low cost of the system could allow larger collector areas to compensate for low efficiency, especially in warm climates. Combined thermal and electrical efficiency can be as high as 34%. Additional analysis also indicates that the predicted thermal performance is highly dependent on the thermal resistance between the PV cells and the absorber plate and is sensitive to assumptions regarding wind-driven convection heat transfer coefficients.

scholarly journals Numerical Performance Investigation of Hybrid PV/Thermal System

2018 ◽  
Vol 7 (4.19) ◽  
pp. 818
Author(s):  
Kadhim K. Idan Al-Chlaihawi ◽  
Dhafer A. Hamzah ◽  
Ahmed K. Zarzoor ◽  
Yousif M. Hasan
Keyword(s):  
Solar Radiation ◽  
Water Temperature ◽  
Flow Rate ◽  
Cooling Water ◽  
Electrical Performance ◽  
Flow Rates ◽  
Electrical Efficiency ◽  
Cooling Water Temperature ◽  
Present Work Deal ◽  
Numerical Performance

Promoting reduction of PV temperature plays crucial role in increasing electrical performance. The present work deal with different types of absorber shape for analysing heat transfer phenomena. Serpentine and spiral absorber are using to verify this purpose with different boundary conditions of inlet mass flow rate and inlet temperatures.The recent study was conducted to evaluate the effect of some operating and designing parameters such as solar radiation levels, flow rates, absorber shape and cooling water temperature on the performance of PVT system numerically. Performance of PVT system determined by thermal efficiency, electrical efficiency and the summation of both known as total or PVT efficiency. Solar radiation ranging from 500 W/m2 to1000 W/m2 was introduced and at each, flow rates of water ranging from 0.016 kg/s to 0.05 kg/s. The results show that the performance of PVT increases with a flow rate at all radiation levels. Also the spiral flow absorber gives a higher performance than serpentine absorber where the value of  of spiral absorber is increased by about 5.2% compared to the value of serpentine absorber, on the other hand, the rate of heat loss ( decreased by about 10%.Increasing initial cooling water temperature degrades electrical efficiency of PVT system.  

scholarly journals A Calculation Model to Estimate the Electrical Performance of a Photovoltaic Panel

2021 ◽  
Vol 65 (2-4) ◽  
pp. 256-263
Author(s):  
Mario A. Cucumo ◽  
Vittorio Ferraro ◽  
Dimitrios Kaliakatsos ◽  
Francesco Nicoletti ◽  
Albino Gigliotti
Keyword(s):  
Experimental Data ◽  
Mechanical Energy ◽  
Electrical Power ◽  
Calculation Model ◽  
Electrical Performance ◽  
Photovoltaic Panel ◽  
Electrical Efficiency ◽  
The Mean ◽  
Set Up ◽  
The University

In this study, the thermal and electrical modeling of a photovoltaic panel is performed to evaluate its temperature profiles, electrical efficiency and the electrical power supplied. The energy balance equations under transient conditions of all the layers that make up the panel are discretized by the finite difference technique and solved with the implicit method. The results are validated with experimental data provided by an experimental set-up located on the roof of a building of the Department of Mechanical, Energy and Management Engineering (DIMEG) of the University of Calabria. The comparison with the experimental data allows us to see an excellent approximation of the distribution of temperatures inside the panel and in particular of the photovoltaic cells, accurately evaluating the effect on electrical efficiency and the electrical power supplied. The validation was performed with reference to a clear winter day and a clear summer day. The mean square error was about 1.5°C on the panel temperature and about 3 W on the electrical power (1.2% of the maximum power).

Towards Higher Micro Gas Turbine Efficiency and Flexibility: Humidified MGTS — A Review

2017 ◽  
Author(s):  
Ward De Paepe ◽  
Marina Montero Carrero ◽  
Svend Bram ◽  
Alessandro Parente ◽  
Francesco Contino
Keyword(s):  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Waste Heat ◽  
Electrical Performance ◽  
Small Scale ◽  
Major Drawback ◽  
Electrical Efficiency ◽  
Micro Gas Turbine ◽  
Turbine Efficiency ◽  
Cycle Efficiency

Micro Gas Turbines (mGTs) offer several advantages for small-scale Combined Heat and Power (CHP) production compared to their main competitors, the Internal Combustion Engines (ICEs), such as low vibration level, cleaner exhaust and less maintenance. The major drawback is their lower electrical efficiency, which makes them economically less attractive and explains their low market penetration. Next to improving the efficiency of the components of the traditional recuperated mGT, shifting towards more innovative cycles may help enhancing the performance and the flexibility of mGTs. One interesting solution is the introduction of water in the mGT cycle — either as auto-raised steam or hot liquid —, preheated with the waste heat from the exhaust gases. The so-called humidification of the mGT cycle has the potential of increasing the electrical performance and flexibility of the mGT, resulting in a higher profitability. However, despite the proven advantages of mGT humidification, only few of these engines have been experimentally tested and up to now, no cycle is commercially available. With this paper, we give a comprehensive review of the literature on research and development of humidified mGTs: we examine the effect of humidification both on the improvement of the cycle efficiency and flexibility and on the performance of the specific mGT components. Additionally, we will present the different possible layouts, both focusing on the numerical and experimental work. Finally, we pinpoint the technological challenges that need to be overcome for humidified mGTs to be viable. In conclusion, humidification of mGT cycles offers great potential for enhancing the cycle’s electrical efficiency and flexibility, but further research is necessary to make the technology commercially available.

The Influence of Wall Structures to Air Conditioner Energy Consumption Based on the Characteristics of Intermittent and Loculose Energy Use

2012 ◽  
Vol 256-259 ◽  
pp. 2656-2661 ◽  
Author(s):  
Jin Li ◽  
Xiao Qian Qian ◽  
Yao Tai Zhu
Keyword(s):  
Energy Consumption ◽  
Energy Use ◽  
Transient State ◽  
Air Conditioner ◽  
External Insulation ◽  
Wall Structures ◽  
Part Time ◽  
Numerical Computing ◽  
Computing Method ◽  
Better Than

In some areas like south of China, energy is used in part time of the 24 hours and part space of the buildings, that is the characteristics of intermittent and loculose energy use. The energy consumption of the air conditioner can be calculated from the transient state with the help of numerical computing method. Among different wall configurations of self-insulation, internal insulation and external insulation walls, it shows that self-insulation and internal insulation walls performs better than external insulation walls in energy saving. The energy stored by walls which account for the most part of the energy consumption can be sharply reduced in the configurations of self-insulation, internal insulation walls.

Performance Analysis of a Combination System of Concentrating PV/T Collector and TEGs

2013 ◽  
Author(s):  
Xinqiang Xu ◽  
Siyi Zhou ◽  
Mark Meyers ◽  
Bahgat G. Sammakia ◽  
Bruce Murray
Keyword(s):  
Hybrid System ◽  
Seebeck Effect ◽  
Electrical Performance ◽  
Peltier Effect ◽  
Accurate Estimation ◽  
Transfer Model ◽  
Cooling Channel ◽  
Cell Array ◽  
Matching Problem ◽  
Te Modules

Thermoelectric modules utilize available temperature differences to generate electricity by the Seebeck effect. The current study investigates the merits of employing thermoelectrics to harvest additional electric energy instead of just cooling concentrating photovoltaic (CPV) modules by heat sinks (heat extractors). One of the attractive options to convert solar energy into electricity efficiently is to laminate TE modules between CPV modules and heat extractors to form a CPV-TE/thermal hybrid system. In order to perform an accurate estimation of the additional electrical energy harvested, a coupled field model is developed to calculate the electrical performance of TE devices, which incorporates a rigorous interfacial energy balance including the Seebeck effect, the Peltier effect, and Joule heating, and results in better predictions of the conversion capability. Moreover, a 3D multiphysics computational model for the hybrid concentrating PV-TE/thermal (CPV-TE/T) water collector system consisting of a solar concentrator, 10 serially-connected GaAs/Ge PV cells, 300 couples of bismuth telluride TE modules, and a cooling channel with heat-recovery capability, is implemented by using the commercial FE–tool COMSOL™. A conjugate heat transfer model is used, assuming laminar flow through the cooling channel. The performance and efficiencies of the hybrid system are analyzed. As compared with the traditional PV/T system, a comparable thermal efficiency and a higher 8% increase of the electrical efficiency can be observed through the PV-TE hybrid system. Additionally, with the identical convective surface area and cooling flow rate in both configurations, the PV-TE/T hybrid system yields higher PV cell temperatures but more uniform temperature distributions across the cell array, which thus eliminates the current matching problem; however, the higher cell temperatures lower the PV module’s fatigue life, which has become one of the biggest challenges in the PV-TE hybrid system.

scholarly journals Estimation of Needleleaf Canopy and Trunk Temperatures and Longwave Contribution to Melting Snow

2017 ◽  
Vol 18 (2) ◽  
pp. 555-572 ◽  
Author(s):  
K. N. Musselman ◽  
J. W. Pomeroy
Keyword(s):  
Energy Balance ◽  
Radiative Transfer ◽  
Thermal Inertia ◽  
Longwave Radiation ◽  
Ambient Air ◽  
Balance Model ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Individual Tree ◽  
Energy Balance Approach

AbstractA measurement and modeling campaign evaluated variations in tree temperatures with solar exposure at the edge of a forest clearing and how the resulting longwave radiation contributed to spatial patterns of snowmelt energy surrounding an individual tree. Compared to measurements, both a one-dimensional (1D) energy-balance model and a two-dimensional (2D) radial trunk heat transfer model that simulated trunk surface temperatures and thermal inertia performed well (RMSE and biases better than 1.7° and ±0.4°C). The 2D model that resolved a thin bark layer better simulated daytime temperature spikes. Measurements and models agreed that trunk surfaces returned to ambient air temperature values near sunset. Canopy needle temperatures modeled with a 1D energy-balance approach were within the range of measurements. The radiative transfer model simulated substantial tree-contributed snow surface longwave irradiance to a distance of approximately one-half the tree height, with higher values on the sun-exposed sides of the tree. Trunks had very localized and substantially lower longwave energy influence on snowmelt compared to that of the canopy. The temperature and radiative transfer models provide the spatially detailed information needed to develop scaling relationships for estimating net radiation for snowmelt in sparse and discontinuous forest canopies.

Performance Analysis of a Combination System of Concentrating Photovoltaic/Thermal Collector and Thermoelectric Generators

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Xinqiang Xu ◽  
Siyi Zhou ◽  
Mark M. Meyers ◽  
Bahgat G. Sammakia ◽  
Bruce T. Murray
Keyword(s):  
Hybrid System ◽  
Seebeck Effect ◽  
Electrical Performance ◽  
Peltier Effect ◽  
Accurate Estimation ◽  
Transfer Model ◽  
Cooling Channel ◽  
Cell Array ◽  
Matching Problem ◽  
Te Modules

Thermoelectric (TE) modules utilize available temperature differences to generate electricity by the Seebeck effect. The current study investigates the merits of employing thermoelectrics to harvest additional electric energy instead of just cooling concentrating photovoltaic (CPV) modules by heat sinks (heat extractors). One of the attractive options to convert solar energy into electricity efficiently is to laminate TE modules between CPV modules and heat extractors to form a CPV-TE/thermal (CPV-TE/T) hybrid system. In order to perform an accurate estimation of the additional electrical energy harvested, a coupled-field model is developed to calculate the electrical performance of TE devices, which incorporates a rigorous interfacial energy balance including the Seebeck effect, the Peltier effect, and Joule heating, and results in better predictions of the conversion capability. Moreover, a 3D multiphysics computational model for the HCPV-TE/T water collector system consisting of a solar concentrator, 10 serially connected GaAs/Ge photovoltaic (PV) cells, 300 couples of bismuth telluride TE modules, and a cooling channel with heat-recovery capability, is implemented by using the commercial FE–tool Comsol Multiphysics®. A conjugate heat transfer model is used, assuming laminar flow through the cooling channel. The performance and efficiencies of the hybrid system are analyzed. As compared with the traditional photovoltaic/thermal (PV/T) system, a comparable thermal efficiency and a higher 8% increase of the electrical efficiency can be observed through the PV-TE hybrid system. Additionally, with the identical convective surface area and cooling flow rate in both configurations, the PV-TE/T hybrid system yields higher PV cell temperatures but more uniform temperature distributions across the cell array, which thus eliminates the current matching problem; however, the higher cell temperatures lower the PV module's fatigue life, which has become one of the biggest challenges in the PV-TE hybrid system.

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