Numerical Optimization of a Cogenerating Parabolic Solar Collector Receiver

2008 ◽  
Author(s):  
Catalina Gonzalez ◽  
Jinny Rhee
Keyword(s):  
Heat Transfer ◽  
Solar Energy ◽  
Solar Collector ◽  
Photovoltaic Cells ◽  
Electricity Consumption ◽  
Photovoltaic System ◽  
Working Fluid ◽  
Electrical Efficiency ◽  
Solar Systems ◽  
Electricity Costs

The motivation for this study comes from the need for a clean, renewable energy source, which is greater now more than ever to reduce the country’s dependence on fossil fuels. Cogenerating solar systems can provide heat and electricity for many industrial applications such as power generation and absorption refrigeration systems. For example, data centers that run on conventional refrigeration systems are one of the largest electricity consumers in the nation, accounting for 1.2% of the total electricity consumption in 2005. This electricity consumption, almost half of which is used to run the data center’s air conditioning units, translates to $2.7 billion in electricity costs for that year. Using cogenerating solar systems for these types of applications could represent a significant amount of savings in electricity costs. The objective of this paper is to numerically optimize a receiver for a cogenerating photovoltaic and thermal parabolic solar collector that will produce both heat and electricity. The solar cogeneration system studied will convert solar energy into both heat and electricity by using a combination of photovoltaic cells, a parabolic trough thermal collector, and water as the liquid heat exchanger on the photovoltaic cells. The peak electrical efficiency of the multi-junction gallium arsenide Spectrolab photovoltaic cells used in this study is about 32%, with the rest of the solar energy being absorbed as heat. These temperature gains in the cells can lead to a decrease in efficiency. However, in cogenerating systems, water is used as a working fluid to remove heat from the photovoltaic cells, thus aiding in increasing the electrical efficiency of the photovoltaic system as well as increasing the thermal energy gained from the solar thermal collector. The numerical analysis for this project will use Flotherm, a CFD tool used to solve fluid and thermal problems. A single-phase water cooled square duct receiver subjected to non-uniform heating will be analyzed in Flotherm to determine the optimal parameters for the best convection heat transfer between the working fluid and the photovoltaic cells. To enhance the heat transfer between photovoltaic cells and working fluid, the inner surface of the receiver tube receiving the heat flux will be improved by adding fins to increase heat transfer and induce turbulent flow. The initial receiver design will be compared with other receivers to determine the optimal design. Results will be presented parametrically for a range of flow rates and receiver geometry.

scholarly journals The Impact of Application of Photovoltaic Cells for Bus Ecological Properties / Wpływ Zastosowania Ogniw Fotowoltaicznych Na Ekologiczność Autobusu Miejskiego

2012 ◽  
Vol 22 (1) ◽  
pp. 159-170
Author(s):  
Jerzy Merkisz ◽  
Paweł Fuc ◽  
Maciej Bajerlein ◽  
Piotr Lijewski ◽  
Łukasz Rymaniak ◽  
...  
Keyword(s):  
Solar Energy ◽  
Public Transport ◽  
Environmental Performance ◽  
Photovoltaic Cells ◽  
Urban Traffic ◽  
Photovoltaic System ◽  
Relative Influence ◽  
Gas Analyzer ◽  
Measurement Systems ◽  
The Impact

Abstract The paper presents discusses the application of photovoltaic cells and provides information on solar energy in Poland. Article presents examples of research emission two buses, one of them was equipped with additional auxiliary photovoltaic system. Measurements was carried out in on-road, in urban traffic - bus line public transport. For measurement was used mobile gas analyzer included in Portable Emissions Measurement Systems (PEMS). The results have been developed in such a way as to determine the relative influence of the system implemented on the total environmental performance of the vehicle.

Designing a novel solar-assisted heat pump system with modification of a thermal energy storage unit

2019 ◽  
Vol 233 (5) ◽  
pp. 588-603 ◽  
Author(s):  
Mustafa Aktaş ◽  
Meltem Koşan ◽  
Erhan Arslan ◽  
Azim Doğuş Tuncer
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Heat Pump ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Collector ◽  
Working Fluid ◽  
Storage Unit ◽  
Heating Systems ◽  
Energy Storage Unit

The integrated usage of solar energy systems, heat pump applications, and thermal energy storage units is an effective way for heating systems due to their sustainability and stability in operations. In this study, a novel direct solar-assisted heat pump with thermal energy system has been designed which uses the solar collector as the evaporator of the heat pump. Besides, two-dimensional transient numeric analyses have been conducted for the thermal energy storage unit using the ANSYS Fluent 16.2 commercial software package. With this direct system, the heat required for heating systems is supplied from the condenser with the heat received from the solar collector of the working fluid. For an effective and high performance system, the solar collector is designed as a double-pass which provided superheating of the working fluid. It is aimed to store the surplus energy from the solar energy in the thermal energy storage unit and to operate the system continuously and efficiently in both sunny and overcast weather conditions. Furthermore, the system has been analyzed theoretically and the results show that coefficient of performance may improve. As a result, this newly designed system can be successfully applied for thermal applications.

Performance Optimization and Parametric Analysis of a Class of Solar-Driven Heat Engines

2010 ◽  
Author(s):  
Houcheng Zhang ◽  
Lanmei Wu ◽  
Guoxing Lin
Keyword(s):  
Heat Transfer ◽  
Heat Loss ◽  
Performance Optimization ◽  
Solar Collector ◽  
Heat Engine ◽  
Working Fluid ◽  
Convection Heat ◽  
Combined System ◽  
Heat Engines ◽  
Internal Irreversibility

A class of solar-driven heat engines is modeled as a combined system consisting of a solar collector and a unified heat engine, in which muti-irreversibilities including not only the finite rate heat transfer and the internal irreversibility, but also radiation-convection heat loss from the solar collector to the ambience are taken into account. The maximum overall efficiency of the system, the optimal operating temperature of the solar collector, the optimal temperatures of the working fluid and the optimal ratio of heat transfer areas are calculated by using numerical calculation method. The influences of radiation-convection heat loss of the collector and internal irreversibility on the cyclic performances of the solar-driven heat engine system are revealed. The results obtained in the present paper are more general than those in literature and the performance characteristics of several solar-driven heat engines such as Carnot, Brayton, Braysson and so on can be directly derived from them.

scholarly journals Numerical simulation of concentrating solar collector P2CC with a small concentrating ratio

2012 ◽  
Vol 16 (suppl. 2) ◽  
pp. 471-482 ◽  
Author(s):  
Velimir Stefanovic ◽  
Sasa Pavlovic ◽  
Marko Ilic ◽  
Nenad Apostolovic ◽  
Dragan Kustrimovic
Keyword(s):  
Mathematical Model ◽  
Fluid Flow ◽  
Solar Radiation ◽  
Solar Energy ◽  
Radiation Intensity ◽  
Solar Collector ◽  
Numerical Procedure ◽  
Working Fluid ◽  
Flow Rates ◽  
Solar Radiation Intensity

Solar energy may be practically utilized directly through transformation into heat, electrical or chemical energy. A physical and mathematical model is presented, as well as a numerical procedure for predicting thermal performances of the P2CC solar concentrator. The demonstrated prototype has the reception angle of 110? at concentration ratio CR = 1.38, with the significant reception of diffuse radiation. The solar collector P2CC is designed for the area of middle temperature conversion of solar radiation into heat. The working fluid is water with laminar flow through a copper pipe surrounded by an evacuated glass layer. Based on the physical model, a mathematical model is introduced, which consists of energy balance equations for four collector components. In this paper, water temperatures in flow directions are numerically predicted, as well as temperatures of relevant P2CC collector components for various values of input temperatures and mass flow rates of the working fluid, and also for various values of direct sunlight radiation and for different collector lengths. The device which is used to transform solar energy to heat is referred to as solar collector. This paper gives numerical estimated changes of temperature in the direction of fluid flow for different flow rates, different solar radiation intensity and different inlet fluid temperatures. The increase in fluid flow reduces output temperature, while the increase in solar radiation intensity and inlet water temperature increases output temperature of water. Furthermore, the dependence on fluid output temperature is determined, along with the current efficiency by the number of nodes in the numerical calculation.

scholarly journals Heat transfer in a low latitude flat-plate solar collector

2012 ◽  
Vol 16 (2) ◽  
pp. 583-591
Author(s):  
C.O.C. Oko ◽  
S.N. Nnamchi
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Solar Collector ◽  
Design Parameters ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Port Harcourt ◽  
Collector Efficiency ◽  
One Year ◽  
Flat Plate Solar Collector

Study of rate of heat transfer in a flat-plate solar collector is the main subject of this paper. Measurements of collector and working fluid temperatures were carried out for one year covering the harmattan and rainy seasons in Port Harcourt, Nigeria, which is situated at the latitude of 4.858oN and longitude of 8.372oE. Energy balance equations for heat exchanger were employed to develop a mathematical model which relates the working fluid temperature with the vital collector geometric and physical design parameters. The exit fluid temperature was used to compute the rate of heat transfer to the working fluid and the efficiency of the transfer. The optimum fluid temperatures obtained for the harmattan, rainy and yearly (or combined) seasons were: 317.4, 314.9 and 316.2 [K], respectively. The corresponding insolation utilized were: 83.23, 76.61 and 79.92 [W/m2], respectively, with the corresponding mean collector efficiency of 0.190, 0.205 and 0.197 [-], respectively. The working fluid flowrate, the collector length and the range of time that gave rise to maximum results were: 0.0093 [kg/s], 2.0 [m] and 12PM - 13.00PM, respectively. There was good agreement between the computed and the measured working fluid temperatures. The results obtained are useful for the optimal design of the solar collector and its operations.

Study on Heat Transfer Characteristics of Loop Heat Pipe for Solar Collector

2012 ◽  
Author(s):  
Shota Sato ◽  
Shigeki Hirasawa ◽  
Tsuyoshi Kawanami ◽  
Katsuaki Shirai
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Rate ◽  
Solar Collector ◽  
Transfer Rate ◽  
Thermal Conductance ◽  
Filling Ratio ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Single Tube

We experimentally study the thermal conductance of single-tube and loop heat pipes for a solar collector. The evaporator of the heat pipe is 1 m long, 6 mm in diameter and has 30° inclination. The thermal conductance is defined as the heat transfer rate divided by the temperature difference between the evaporator-wall and the condenser-wall. Effects of heat transfer rate, saturation temperature of the working fluid, liquid filling ratio, inclination angle, and position of the evaporator on the thermal conductance are examined. We found that the thermal conductance of the 30°-inclined loop heat pipe with an upper-evaporator is 40–50 (W/K), which is 1.8 times higher than that of the vertical loop type and 3 times higher than that of the single-tube type. Thus, the inclined loop heat pipe is preferable for a solar collector. There is an optimum liquid filling ratio. When the liquid filling ratio is too small, a dry-out portion appears in the evaporator. When the liquid filling ratio is too large, the liquid flows in the condenser to decrease heat transfer area. Also we numerically analyze the thermal conductance of a vertical loop heat pipe.

scholarly journals Investigation of Performance of Solar Flat and Curved Plate Collectors through Numerical Simulations

2021 ◽  
Vol 40 (1) ◽  
pp. 66-74
Author(s):  
Luqman Ahmed Pirzada ◽  
Xiaoli Wu . ◽  
Qaiser Ali ◽  
Asif Khateeb .
Keyword(s):  
Solar Energy ◽  
Flat Plate ◽  
Solar Collector ◽  
Numerical Study ◽  
Hot Water ◽  
Working Fluid ◽  
Solar Panels ◽  
Modeling Tools ◽  
Design Work ◽  
Flat Plate Collector

Solar energy is radiant light as a form of thermal heat energy which can be obtained and used by means of a variety of solar apparatus. As apparatus the flat and curved plate solar collector is specifically designed for assembling solar energy as a solar water heater system. The designing potency of this collector lone can generate medium level hot water from radiant sunlight source via absorbed plates. Standard type flat and curved plates solar collector plates are mostly used in remote coldest regions of the world where hot water is consumed for commercial and domestic purposes. These types of solar collector Plates can cheaply be manufactured compared to other solar panels like solar Shingles, Polycrystalline Solar Panels, Mono-crystalline Solar Panels, and Thin Film Solar Panels. For future work, this proposed pre-design is recommended for fabrication. A numerical study was carried-out on eight city locations in China by tracing their horizontal and vertical longitudinal, latitudinal lines noting the date, time and sunlight feeding of temperatures in the Celsius scale with the help of simulation and modeling tools like CFD, ANSYS FLUENT software, mesh geometry tools, and by using the Navier-Stokes and Continuity equations by fluid flow discharge rate, mass flow, water temperature and dropping of temperature, radiation working mechanisms, dimensions of water flowing tubes and absorber plates, density, the velocity of water as the working fluid, the viscosity of water in a cold and hot state as a process of Pre-design. Work also focuses on the comparison between flat plate collector and curved plate collector radiant sunlight absorption, As end result it is found the Curved plate collector produces 22% more elevated heat of outgoing water than flat plate collector.

scholarly journals A Linear Hybrid Concentrated Photovoltaic Solar Collector: A Methodology Proposal of Optical and Thermal Analysis

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8155
Author(s):  
Eduardo Venegas-Reyes ◽  
Naghelli Ortega-Avila ◽  
Manuel I. Peña-Cruz ◽  
Omar J. García-Ortiz ◽  
Norma A. Rodríguez-Muñoz
Keyword(s):  
Heat Transfer ◽  
Hot Spots ◽  
Solar Collector ◽  
Concentration Ratio ◽  
Photovoltaic Cells ◽  
Photovoltaic Cell ◽  
Radiative Flux ◽  
Electrical Performance ◽  
Optimal Receiver

The photovoltaic cell surface in linear hybrid concentrated solar collectors receives non-uniform radiative flux, causing additional thermal stress due to hot spots and reducing its electrical performance and durability. The current study proposes a parametric methodology to determine the optimal receiver displacement required in a linear Cassegrain-type hybrid solar collector. The aim was to achieve a minimal non-uniformity distribution and a high radiative flux over the photovoltaic cells, considering optical errors close to real environment conditions and analyzing the heat transfer to determine the electrical and thermal efficiencies. The developed methodology was applied to analyze a case study with a receiver width of 0.125 m and rim angle of 80° and using a commercial silicon photovoltaic cell that supports up to 7000 W/m2. After applying the methodology, a hybrid solar collector with a concentration ratio of 13.0 and receiver displacement of 0.14 m is recommended. As a result, 5728 W/m2 of average radiative flux with non-uniformity lower than 4% was achieved. Thus, thanks to the proposed configuration, a low non-uniformity and high radiative flux were achieved, benefiting the photovoltaic cells’ life while improving their operation.

scholarly journals Entropy Generation and Thermal Analysis of Nanofluid Flow Inside the Evacuated Tube Solar Collector

2021 ◽  
Author(s):  
S. Mojtaba Tabarhoseini ◽  
M. Sheikholeslami
Keyword(s):  
Heat Transfer ◽  
Entropy Generation ◽  
Solar Collector ◽  
Base Fluid ◽  
Pure Water ◽  
Working Fluid ◽  
Distribution Analysis ◽  
Nanoparticle Dispersion ◽  
Evacuated Tube Solar Collector ◽  
Evacuated Tube

Abstract In the current investigation, the thermal and thermodynamic behavior of a buoyancy-driven evacuated tube solar collector has undergone precise evaluation, and the efficacy of nanoparticle dispersion in the base fluid has been scrutinized using computational fluid dynamics based on the finite volume method. The natural convection process was analyzed in different vertical sections of the absorber tube. The temperature and velocity distributions of water as the conventional working fluid and the nanofluid were compared at various cutting planes along the tube during the simulation time. In this problem, CuO nanoparticles with optimum thermal properties were suspended in the base fluid. According to the surveyed results, the temperature distribution analysis illustrates that the mean temperature of the tank experiences more enhancement when the nanofluid is used. The comparison of the heat transfer coefficient between two simulated cases shows the competency of utilizing CuO/water nanofluid in the thermal performance improvement of the collector. The results related to entropy generation assessment show that the irreversibility owing to fluid friction rises when the nanofluid is applied during the flow time. In contrast, the entropy generation of pure water owing to heat transfer surpasses the case with nanofluid.

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