Parametric Investigation of Concentrating PV/T System With Spectral Filtering Utilizing a 2-D Model

2015 ◽  
Author(s):  
Nick Brekke ◽  
Todd Otanicar ◽  
Drew DeJarnette ◽  
Parameswar Harikumar
Keyword(s):  
Optical Filter ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Spectral Filtering ◽  
Temperature Variations ◽  
Cell Efficiency ◽  
Pv Cell ◽  
D Model ◽  
T System

Hybrid photovoltaic/thermal (PV/T) systems are continually being investigated, in particular the use of such systems in concentrating collectors as part of the ARPA-E FOCUS program. While many combined thermal and electrical models exist, most are limited to 0-D energy balance approaches or 1-D approaches where temperature variations through insulation, glazing and substrates are considered. Here, we develop a 2-D model for a concentrating PV/T system where the model accounts for temperature variations along the length of the collector. The proposed configuration consists of a GaAs cell laminated to an aluminum extrusion. The working fluid, a transparent high temperature heat transfer fluid with suspended nanoparticles, flows through the extrusion where it actively cools the PV cell before passing in front of the cell acting as an optical filter. The model includes PV cell efficiency, temperature, and bandgap dependence, a detail often neglected in prior works. This paper focuses on PV efficiency along the length of the system and outlet fluid temperature for both counter and parallel flow arrangements. Of particular interest here is the wavelength used in the design of the fluid filter and how changing the design impacts the exergetic efficiency and percent of exergy created as heat.

A Parametric Investigation of a Concentrating Photovoltaic/Thermal System With Spectral Filtering Utilizing a Two-Dimensional Heat Transfer Model

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Nick Brekke ◽  
Todd Otanicar ◽  
Drew DeJarnette ◽  
Parameswar Hari
Keyword(s):  
Heat Transfer ◽  
Optical Filter ◽  
Heat Transfer Model ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Transfer Model ◽  
Cell Efficiency ◽  
Photovoltaic Thermal System ◽  
Pv Cell ◽  
The Impact

A 2D heat transfer model of a hybrid photovoltaic/thermal (PV/T) system has been created. This paper investigates the impact of ideal filters to best accommodate for a nonuniform PV temperature along the length of the receiver. The proposed configuration consists of a GaAs cell laminated to an aluminum extrusion. The working fluid, a transparent high-temperature heat transfer fluid with suspended nanoparticles, flows through the hollow extrusion where it cools the PV cell before it is redirected in front of the cell acting as an optical filter. The model accounts for PV cell efficiency, temperature, and bandgap dependence, the details often neglected in prior works.

scholarly journals Experimental and Theoretical Analysis of a Linear Focus CPV/T System for Cogeneration Purposes

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2960 ◽  
Author(s):  
Carlo Renno
Keyword(s):  
Focal Length ◽  
Concentration Field ◽  
Operating Conditions ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Atmospheric Conditions ◽  
High Concentration ◽  
Environment Temperature ◽  
Temperature Levels ◽  
T System

The knowledge of the actual energy performances of a concentrating photovoltaic and thermal (CPV/T) system with a linear focus optics, allows to evaluate the possibility of adopting this type of system for cogeneration purposes. Hence, the main aim of this paper is the design, realization, setting and modeling of a linear focus CPV/T system in the high concentration field. An experimental linear focus CPV/T plant was created in order to determine its electrical and thermal performance under different working conditions in terms of environment temperature, sunny and cloudy conditions, focal length, etc. Moreover, a theoretical model of the linear focus CPV/T system was also studied. This model evaluates the temperatures of the working fluid that flows in the cooling circuit of the CPV/T system under several operating conditions. The temperatures of the triple junction (TJ) cells, experimentally evaluated referring to different solar radiation and atmospheric conditions, were considered as the input data for the model. The values of the fluid temperature, theoretically and experimentally determined, were thus compared with good agreement. The electrical production of the CPV/T system depends generally on the TJ cell characteristics and the concentration factor, while the thermal production is above all linked to the system configuration and the direct normal irradiance (DNI) values. Hence, in this paper the electric power obtained by the linear-focus CPV/T system was evaluated referring to the cogeneration applications, and it was verified if the TJ cell and the cooling fluid reach adequate temperature levels in this type of system, in order to match the electrical and the thermal loads of a user.

A 3-D Model Simulation of High Temperature Solar Cavity Receiver

2017 ◽  
Author(s):  
Huayi Feng ◽  
Yanping Zhang ◽  
Chongzhe Zou
Keyword(s):  
Heat Transfer ◽  
Radiation Intensity ◽  
Large Scale ◽  
Model Simulation ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Outlet Temperature ◽  
Fluid Temperature ◽  
Heat Transfer Efficiency ◽  
Direct Normal Irradiance

In this paper, a 3-D numerical model is proposed to investigate the capability of generating high operating temperature for a modified solar cavity receiver in large-scale dish Stirling system. The proposed model aims to evaluate the influence of radiation intensity on the cavity receiver performance. The properties of the heat transfer fluid in the pipe and heat transfer losses of the receiver are investigated by varying the direct normal irradiance from 400W/m2 to 1000W/m2. The temperature of heat transfer fluid, as well as the effect of radiation intensity on the heat transfer losses have been critically presented and discussed. The simulation results reveal that the heat transfer fluid temperature and thermal efficiency of the receiver are significantly influenced by different radiation flux. With the increase of radiation intensity, the efficiency of the receiver will firstly increase, then drops after reaching the highest point. The outlet working fluid temperature of the pipe will be increased consistently. The results of the simulations show that the designed cylindrical receiver used in dish Stirling system is capable to achieve the targeted outlet temperature and heat transfer efficiency, with an acceptable pressure drop.

A Numerical Model for Off-Design Performance Calculation of Parabolic Trough Based Solar Power Plants

2010 ◽  
Author(s):  
Andrea Giostri ◽  
Claudio Saccilotto ◽  
Paolo Silva ◽  
Ennio Macchi ◽  
Giampaolo Manzolini
Keyword(s):  
Heat Transfer ◽  
Numerical Model ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Design Calculation ◽  
Fluid Temperature ◽  
Parabolic Trough ◽  
Design Algorithm ◽  
Energy Balances ◽  
Steam Cycle

The paper deals with the development and testing of an innovative code for the performance prediction of solar trough based CSP plants in off-design conditions. The code is developed in MS Visual Basic 6.0 with Excel as user interface. The proposed code originates from a previously presented algorithm for on-design sizing and cost estimation of the solar field lay-out, as well as of the main components of the plant, including connecting piping and the steam cycle. Off-design calculation starts from data obtained through the on-design algorithm and considers steady-state situations. Both models are implemented in the same software, named PATTO (PArabolic Trough Thermodynamic Optimization), which is very flexible: the optical-thermal model of collectors can simulate different kinds of parabolic trough systems in commerce, including a combination of various mirrors, receivers and supports. The code is also flexible in terms of working fluid, temperature and pressure range, and can also simulate direct steam generation plants (DSG). Regarding the power block, a conventional steam cycle with super-heater, eventually a re-heater section, and up to seven regenerative bleedings is adopted. The off-design model calculates thermal performance of collectors taking into account proper correlations for convective heat transfer coefficients, considering also boiling regime in DSG configurations. Solar plant heat and mass balances and performances at off-design conditions are estimated by accounting for the constraints imposed by the available heat transfer areas in heat exchangers and condenser, as well as the characteristic curve of the steam turbine. The numerical model can be used for a single calculation in a specific off-design condition, as well as for a whole year estimation of energy balances with an hourly resolution. The model is tested towards real applications and reference values found in literature; in particular, focusing on SEGS VI plant in the USA and SAM® code. Annual energy balances with ambient condition taken from TMY3 database are obtained, showing good accuracy of predicted performances. The code potentiality in the design process reveals twofold: it can be used for plant optimization in feasibility studies; moreover it is useful to find the best control strategy of a plant, especially the mass flow of heat transfer fluid in each operating condition.

scholarly journals Review of water-nanofluid based photovoltaic/thermal (PV/T) systems

2019 ◽  
Vol 9 (1) ◽  
pp. 134 ◽  
Author(s):  
Nur Farhana Mohd Razali ◽  
Ahmad Fudholi ◽  
Mohd Hafidz Ruslan ◽  
Kamaruzzaman Sopian
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Solar Energy ◽  
Optical Filter ◽  
Heat Transfer Fluid ◽  
Nanoparticles Concentration ◽  
Improve Heat Transfer ◽  
New Generation ◽  
To Receive ◽  
T System

<span lang="EN-US">Solar energy is secure, clean, and available on earth throughout the year. The PV/T system is a device designed to receive solar energy and convert it into electric/thermal energy. Nanofluid is a new generation of heat transfer fluid with promising higher thermal conductivity and improve heat transfer rate compared with conventional fluids. In this review, the recent studies of PV/T using nanofluid is discussed regarding basic concept and theory PV/T, thermal conductivity of nanofluid and experimentally and theoretically study the perfromance of PV/T using nanofluid. A review of the literature shows that many studies have evaluated the potential of nanofluid as heat transfer fluid and optical filter in the PV/T system. The preparations of nanofluid play an essential key for high stability and homogenous nanofluid for a long period. The thermal conductivity of nanofluid is depending on the size of nanoparticles, concentration and preparation of nanofluids.</span>

Experimental Study of the Influence of Light Intensity on Solar ORC Power Generation System

2015 ◽  
Author(s):  
Yuping Wang ◽  
Lei Tang ◽  
Yiwu Weng
Keyword(s):  
Power Generation ◽  
Light Intensity ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Fluid Temperature ◽  
System Efficiency ◽  
Generation System ◽  
Thermoelectric Efficiency ◽  
Turn Point ◽  
Power Generation System

A low temperature (<393K) solar Organic Rankine Cycle (ORC) power generation experimental facility was designed and built. The heat pipe evacuated tubular collector was selected as the solar collector. A scroll expander was used as the expander and the working fluid was R600a. The influence of light intensity variation on system performance has been studied. The results indicate that the system efficiency and thermoelectric efficiency of the experimental facility can reach to 2.2% and 4.4%, respectively. The thermoelectric efficiency and power decrease with the decrease of the heat transfer fluid temperature. There is a turn point in the variation of these performance parameters at high flow rate. The heat transfer fluid temperature at the turn point is about 75°C at the working fluid flow rate of 200L/h. The system efficiency decreases with the decrease of light intensity. There is a turn point light intensity Itpi. The system efficiency varies slowly when the light intensity is higher than Itpi. The experimental results are of great significance for the new design of low temperature solar ORC power generation system.

Performance Analysis of Photovoltaic Thermal (PVT) Panels Considering Thermal Parameters

2016 ◽  
Author(s):  
W. J. A. Jayasuriya ◽  
A. U. C. D. Athukorala ◽  
A. T. D. Perera ◽  
M. P. G. Sirimanna ◽  
R. A. Attalage
Keyword(s):  
Wind Speed ◽  
Performance Analysis ◽  
Mass Flow ◽  
Flow Analysis ◽  
Operating Conditions ◽  
Solar Irradiation ◽  
Heat Transfer Fluid ◽  
Design Parameters ◽  
Working Fluid ◽  
Fluid Temperature

Solar PVT panels are getting popular for wider spectrum of applications for concurrent heat and power generation (CHP). These panels can provide the heating demand of buildings while generating electricity which becomes ideal for building applications of urban energy systems. Energy flow analysis of such panels and performance analysis of such systems becomes essential to design PVT systems matching with the operating conditions. A number of studies have used both theoretical and experimental methods to optimize PVT. However, this task is challenging due to interrelation of CHP production based on two different phenomena where classical optimization methods cannot be applied directly. Hence basic performance analysis considering primary design parameters plays a major role. In this study, a computational model is developed to evaluate sensitivity of design, operating and climatic parameters for a hybrid PVT system and to analyze the performances of PVT for five different design configurations. Five main configurations of the PVT system are considered based on the heat transfer fluid and the arrangements of glass and tedlar layers of PVT collector. This study presents comprehensive performance analysis conducted to evaluate the sensitivity of mass flow rate and working fluid temperature for the five different design configurations of PVT panels. Results show that glass-tedlar water collector performs better when compared to other configurations. Subsequently, the sensitivity of wind speed and solar irradiation is evaluated. The behavior of thermal and electrical efficiencies is analyzed at different wind speed and solar irradiation levels for a range of mass flow rates and working fluid temperatures. Important conclusions on the performance of PVT panels are given based on this detailed analysis.

Numerical Analysis of a Photovoltaic-Thermal Solar Collector With PCM Embedded in Highly Conductive Porous Material

2021 ◽  
Author(s):  
Vivek R. Pawar ◽  
Mahbube K. Siddiki ◽  
Sarvenaz Sobhansarbandi
Keyword(s):  
Porous Metal ◽  
Melting Rate ◽  
Heat Energy ◽  
Electrical Performance ◽  
Heat Transfer Fluid ◽  
Back Surface ◽  
Pv System ◽  
Pv Panel ◽  
Pv Cell ◽  
T System

Abstract Solar photovoltaic (PV) system harness the energy from the sunlight and convert into clean electricity to power homes and businesses. During an operation the solar panels get hot, the electrons inside the solar cells pick up that extra heat energy which puts them in a more excited state and when they are already excited, they have less room to absorb the energy from sunlight. As a result, electrical performance of a PV system reduces with increase in solar cell temperature. Efficiency of PV panels can be retained by establishing a hybrid PV-Thermal (PV-T) system. In this study, container filled with phase change material (PCM) embedded in porous metal is attached to back surface of the PV cell. As well as, to extract the excess heat from the PV cell, water is used as a heat transfer fluid (HTF) with constant mass flow rate of 30 kg/hr. During the simulation melting rate of PCM, amount of latent heat energy stored, thermal, electrical and overall efficiencies of the PV panel is studied and compared with the conventional PV-T system. The results show the enhanced melting fraction of PCM by 6% and 8% for the PV-T/PCM/Cu and PV-T/PCM/Al system, respectively compared with PV-T/PCM system. Moreover, in comparison with the conventional PV-T system, the overall efficiency of the PV-T/PCM/Cu and PV-T/PCM/Al is increased by 10.62% and 8.80%, respectively.

Integration Between Gas Turbines and Concentrated Parabolic Trough Solar Power Plants

2012 ◽  
Author(s):  
Roberto Cipollone ◽  
Andrea Cinocca
Keyword(s):  
Gas Turbines ◽  
Power Plants ◽  
Solar Power ◽  
Electrical Energy ◽  
Energy Generation ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Parabolic Trough ◽  
Solar Power Plants

Parabolic Trough Concentrating Solar Power plants (PT-CSP) technology has the capability to give, in the mean future, a strong contribution to the electrical energy generation. In the long term, inside a new framework of relationships concerning energy production, many aspects would justify a significant contribution to the phase out of fossil sources use. The paper concerns about a theoretical modeling aimed at improving the performances of CSP which approaches the energy generation from a system point of view. Thanks to it, the attention is focused on the use of gases as heat transfer fluid inside the solar receivers and on the possibility to use it as working fluid inside unconventional gas turbines for a direct electricity generation. The success of this concept is related to the possibility to increase the fluid temperature above the actual maximum values: this requires that the receiver efficiency has to be recalculated as a function of the fluid temperature. An innovative integration between the solar field and the gas turbine power plant, modified in order to maximize thermal energy conversion, is discussed.

scholarly journals Theoretical and Experimental Evaluation of the Working Fluid Temperature Levels in a CPV/T System

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3077
Author(s):  
Carlo Renno
Keyword(s):  
Thermal Energy ◽  
Integrated System ◽  
Hot Water ◽  
Experimental Comparison ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Cooling Fluid ◽  
Operation Conditions ◽  
Temperature Levels ◽  
T System

A linear focus Concentrator Photovoltaic and Thermal (CPV/T) system can match the thermal demands of a user. The evaluation of the cooling fluid temperature levels of a CPV/T system is fundamental to understand if this system is capable of satisfying the typical thermal requirements of a residential user (heating, cooling and domestic hot water). First, an experimental line-focus CPV/T system, realized in the Laboratory of Applied Thermodynamics of the University of Salerno (Italy), has allowed to determine the cooling fluid temperature at the CPV/T system outlet. Successively, the cooling fluid temperatures, experimentally obtained, have been compared with the same temperatures calculated by means of a theoretical model under the same operation conditions. A deviation in terms of the percentage relative error between theoretical and experimental results included between about 0.5% and 5%, has been found. The goodness of the theoretical–experimental comparison in terms of the temperature of the operation fluid at the CPV/T system outlet has represented a fundamental point to evaluate theoretically, by means of the TRNSYS software, the other levels of temperature of an integrated system, constituted by CPV/T system, thermal tank and user, for different temporal scenarios (hourly, weekly, monthly and yearly). The input data of the TRNSYS model are: Direct Normal Irradiance (DNI), Triple-Junction (TJ) cell temperature and environmental conditions. A tank model is also adopted to satisfy the thermal energy demand peaks, and the temperature stratification in the tank linked to the CPV/T system, as function of the height, is obtained in winter and summer. It is important to define these thermal levels to verify if a CPV/T system is capable to satisfy the residential user energy demands or a thermal energy integration is necessary in some periods of the year. A good stratification has been noted in the summer season, with temperature values that are variable between about 40 and 90 °C. From April to October, the tank average temperature is generally resulted about 10 °C higher than the temperature required by the fluid sent to the residential user, and a very low integration is then necessary. It has been verified that the CPV/T system covers a large part of the thermal energy needs of the residential user during the year; the coverage is limited only in the winter months.

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