Comparative Study on Parabolic Trough Collector by using Different Heat Transfer Fluids

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Krishna Mounica ◽  
Y.V. Hanumantha Rao ◽  
Vinay Atgur ◽  
G. Manavendra ◽  
B. Srinivasa Rao
Keyword(s):  
Heat Transfer ◽  
Mass Flow ◽  
Thermal Model ◽  
Heat Transfer Fluid ◽  
Parabolic Trough ◽  
Flow Rates ◽  
Parabolic Trough Collector ◽  
Heat Transfer Fluids ◽  
Mass Flow Rates ◽  
Simulation Results

In this paper the use of Syltherm-800 and Therminol-55 thermal oils in parabolic trough collector (PTC) is investigated with inlet temperatures of 375.35 K, 424.15 K, 470.65 K and 523.85 K and for mass flow rates of 4, 4.5 and 5 kg/sec. Analysis has been carried out using a thermal model and validated using the simulation results. Therminol-55 gives better heat transfer coefficient compared to Syltherm-800. Since Therminol-55 has higher specific heat and viscosity when compared to Syltherm-800, the use of Syltherm-800 as a heat transfer fluid in PTC is preferred. Better results are observed for temperature of 375.35 K and mass flow rate of 4 kg/sec.

scholarly journals Contribution to the Parametric Study of the Performance of A Parabolic Trough Collector

2021 ◽  
Vol 321 ◽  
pp. 02016
Author(s):  
Belkacem Bouali ◽  
Hanane-Maria Regue
Keyword(s):  
Heat Transfer ◽  
Mass Flow ◽  
Flow Rate ◽  
Optimal Operation ◽  
Heat Transfer Fluid ◽  
Parabolic Trough ◽  
Parabolic Trough Collector ◽  
Heat Transfer Fluids ◽  
Ansys Cfx ◽  
Different Seasons

This paper presents an analysis of the performance of a parabolic trough collector (PTC) according to some key operating parameters. The effects of the secondary reflector, the length and thickness of the absorber tube (receiver tube) and the flow rate of the heat transfer fluid (HTF) are investigated. The main objective is to determine an optimal operation, which improves the performance of a traditional PTC. The target variables are the temperature at the outlet of the tube, the amount of energy collected by the HTF and the efficiency of the system. The solar flux data concern the city of LAGHOUAT located in the south of Algeria. Four days in different seasons are considered. The optical analysis of the system is performed by using the open source SolTrace code. The output of this analysis is used as a boundary condition for the CFD solver. The conjugate heat transfer and the fluid flow through the absorber tube are simulated by using ANSYS-CFX solver. Water is considered as heat transfer fluids. The obtained results show that the use of a curved secondary reflector significantly improves the performance of the traditional PTC. As the thickness of the tube increases, the heat storage in the material increases, which increases the temperature at the exit of the tube and therefore the efficiency of the system. However, the length of the tube depends on the mass flow of the HTF and vice versa. To keep the efficiency constant by choosing another length, it is necessary to choose a mass flow rate proportional to the flow rate corresponding to the initial length.

Computational Study on Estimating the Surface Heat Transfer Coefficient of Absorber Tube in Solar Parabolic Trough Collector

2013 ◽  
Vol 446-447 ◽  
pp. 1546-1551
Author(s):  
Harshit Saxena ◽  
Arpit Santoki ◽  
Nimish Awalgaonkar ◽  
Arpan Jivani ◽  
Ganni Gowtham ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Solar Radiation ◽  
Computational Study ◽  
Surface Heat ◽  
Parabolic Trough ◽  
Flow Rates ◽  
Surface Heat Transfer Coefficient ◽  
Mass Flow Rates ◽  
The Given

Solar Parabolic Trough collectors are commonly used to harness the solar power for power generating applications involving high temperatures. In the given paper study we have made use of the SolTrace software which uses the Monte Carlo algorithm for finding out the radiation received on the absorber tube of the collector. The computational study was performed taking into account the solar radiation received at Vellore city in India (12.92oN, 79.13oE) as on 16th February 2013. Further a 3D model of the absorber tube used in the parabolic trough collector was created and meshed with the help of the Ansys Gambit software. The absorber tube which we considered for our study is made up of Stainless Steel AISI 302 material. The meshed model so created was then exported to the Ansys Fluent 6.3 software and simulations were performed for different mass flow rates of the fluid. The fluid which we used in the computational analysis study is Therminol 55. The temperature differences for different mass flow rates of the liquid passing through the absorber tube were found out and based on the temperature rise contours plots so obtained, we have plotted the surface heat transfer coefficient for the absorber tube. We also found out the static temperature contour plot for the fluid flowing through the given absorber tube taking into account the heat flux acting on the absorber tube due to the hourly and daily average solar radiation.

Application of the Transient Heat Transfer Measurement Technique Using TLC in a Network Configuration With Intersecting Circular Passages

2018 ◽  
Author(s):  
Anika Steurer ◽  
Rico Poser ◽  
Jens von Wolfersdorf ◽  
Stefan Retzko
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Mass Flow ◽  
Fluid Temperature ◽  
Thermochromic Liquid Crystal ◽  
Transfer Coefficients ◽  
Flow Rates ◽  
Flow Network ◽  
Mass Flow Rates ◽  
Time Information

The present study deals with the application of the transient thermochromic liquid crystal (TLC) technique in a flow network of intersecting circular passages as a potential internal turbine component cooling geometry. The investigated network consists of six circular passages with a diameter d = 20mm that intersect coplanar at an angle θ = 40°, the innermost in three, the outermost in one intersection level. Two additional non-intersecting passages serve as references. Such a flow network entails specific characteristics associated with the transient TLC method that have to be accounted for in the evaluation process: the strongly curved surfaces, the mixing and mass flow redistribution at each intersection point, and the resulting gradients between the wall and passage centerline temperatures. All this impedes the choice of a representative fluid reference temperature, which results in deviations using established evaluation methods. An alternative evaluation approach is introduced, which is supported by computational results obtained from steady-state three-dimensional RANS simulations using the SST turbulence model. The presented analysis uncouples local heat transfer coefficients from actually measured local temperatures but uses the time information of the thermocouples instead that represents the fluid temperature step change and evolution along the passages. This experimental time information is transferred to the steady-state numerical bulk temperatures, which are finally used as local references to evaluate the transient TLC experiments. As effective local mass flow rates in the passage sections are considered, the approach eventually allows for a conclusion whether heat transfer is locally enhanced due to higher mass flow rates or the intersection effects.

First and second thermodynamic law analyses applied to a solar dish collector

2014 ◽  
Vol 39 (4) ◽  
Author(s):  
Vahid Madadi ◽  
Touraj Tavakoli ◽  
Amir Rahimi
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Exergy Efficiency ◽  
Exergy Destruction ◽  
Flow Rates ◽  
Energy And Exergy ◽  
Mass Flow Rates

AbstractThe energy and exergy performance of a parabolic dish collector is investigated experimentally and theoretically. The effect of receiver type, inlet temperature and mass flow rate of heat transfer fluid (HTF), receiver temperature, receiver aspect ratio and solar radiation are investigated. To evaluate the effect of the receiver aperture area on the system performance, three aperture diameters are considered. It is deduced that the fully opened receivers have the greatest exergy and thermal efficiency. The cylindrical receiver has greater energy and exergy efficiency than the conical one due to less exergy destruction. It is found that the highest exergy destruction is due to heat transfer between the sun and the receivers and counts for 35 % to 60 % of the total wasted exergy. For three selected receiver aperture diameters, the exergy efficiency is minimum for a specified HTF mass flow rate. High solar radiation allows the system to work at higher HTF inlet temperatures. To use this system in applications that need high temperatures, in cylindrical and conical receivers, the HTF mass flow rates lower than 0.05 and 0.09 kg/s are suggested, respectively. For applications that need higher amounts of energy content, higher HTF mass flow rates than the above mentioned values are recommended.

scholarly journals Verification and Improving the Heat Transfer Model in Radiators in the Wide Change Operating Parameters

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6543
Author(s):  
Mieczysław Dzierzgowski
Keyword(s):  
Heat Transfer ◽  
Mass Flow ◽  
Water Mass ◽  
Heat Transfer Model ◽  
Operating Conditions ◽  
Transfer Model ◽  
Flow Rates ◽  
Wide Range ◽  
Different Types ◽  
Mass Flow Rates

Laboratory measurements and analyses conducted in a wide range of changes of water temperature and mass flow rate for different types of radiators allowed to provides limitations and assessment of the current radiators heat transfer model according to EN 442. The inaccuracy to determinate the radiator heat output according to EN 442, in case of low water mass flow rates may achieve up to 22.3% A revised New Extended Heat Transfer Model in Radiators NEHTMiRmd is general and suitable for different types of radiators both new radiators and radiators existing after a certain period of operation is presented. The NEHTMiRmd with very high accuracy describes the heat transfer processes not only in the nominal conditions—in which the radiators are designed, but what is particularly important also in operating conditions when the radiators water mass flow differ significantly from the nominal value and at the same time the supply temperature changes in the whole range radiators operating during the heating season. In order to prove that the presented new model NEHTMiRmd is general, the article presents numerous calculation examples for various types of radiators currently used. Achieved the high compatibility of the results of the simulation calculations with the measurement results for different types of radiators: iron elements (not ribbed), plate radiators (medium degree ribbed), convectors (high degree ribbed) in a very wide range of changes in the water mass flow rates and the supply temperature indicates that a verified NEHTMiRmd can also be used in designing and simulating calculations of the central heating installations, for the rational conversion of existing installations and district heating systems into low temperature energy efficient systems as well as to directly determine the actual energy efficiency, also to improve the indications of the heat cost allocators. In addition, it may form the basis for the future modification of the European Standards for radiator testing.

scholarly journals Investigation of energetic and exergetic performances of parabolic trough collector with using different heat transfer fluids

2019 ◽  
Vol 111 ◽  
pp. 01054 ◽  
Author(s):  
F. Mertkan Arslan ◽  
Hüseyin Günerhan
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Molten Salt ◽  
Sodium Nitrate ◽  
Potassium Nitrate ◽  
Parabolic Trough ◽  
Parabolic Trough Collector ◽  
Working Fluids ◽  
Selective Coating ◽  
Heat Transfer Fluids

In this study energetic and exergetic performances of parabolic trough collector is theoretically investigated by using 120 l/min synthetic ‘’Dowtherm A’’ oil , 1200 l/min Air at 100 bar (10 MPa) and 150 l/min molten salt which is mixture of 60 wt% sodium nitrate (NaNO3) and 40 wt% potassium nitrate (KNO3) which are widely used as heat transfer fluids. Fluids performance comparisons were performed with the LS-2 module, which is used with vacuum in annulus and Cermet as a selective coating. LS-2 module has 7.8 m receiver length and is 39 m2 aperture area. As a result, the maximum exergy efficiency of the molten salt, synthetic oil, Air to be 41.19% at 422 °C, 40.82% at 400 °C, 40.33% at 402 °C, respectively. The maximum exergy of air is higher than other working fluids up to 310 ° C but after about 310 ° C the exergy of the molten salt is higher than the others. The molten salt has the best energy efficiency at its operating temperatures (250 °C to 550 °C) than other working fluids.

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