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.

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.

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 Feasibility Study of Freeze Recovery Options in Parabolic Trough Collector Plants Working with Molten Salt as Heat Transfer Fluid

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2340 ◽  
Author(s):  
Cristina Prieto ◽  
Alfonso Rodríguez-Sánchez ◽  
F. Ruiz-Cabañas ◽  
Luisa Cabeza
Keyword(s):  
Heat Transfer ◽  
Molten Salt ◽  
Molten Salts ◽  
Heat Transfer Fluid ◽  
Operational Experience ◽  
Parabolic Trough ◽  
Solar Salt ◽  
Parabolic Trough Collector ◽  
Overall Performance ◽  
Solar Field

Parabolic trough collector (PTC) technology is currently the most mature solar technology, which has led to the accumulation of relevant operational experience. The overall performance and efficiency of these plants depends on several components, and the heat transfer fluid (HTF) is one of the most important ones. Using molten salts as HTFs has the advantage of being able to work at higher temperatures, but it also has the disadvantage of the potential freezing of the HTF in pipes and components. This paper models and evaluates two methods of freeze recovery, which is needed for this HTF system design: Heat tracing in pipes and components, and impedance melting in the solar field. The model is used to compare the parasitic consumption in three molten salts mixtures, namely Solar Salt, HiTec, and HiTec XL, and the feasibility of this system in a freezing event. After the investigation of each of these subsystems, it was concluded that freeze recovery for a molten salt plant is possible.

scholarly journals State-of-the-art heat transfer fluids for parabolic trough collector

2020 ◽  
Vol 152 ◽  
pp. 119541 ◽  
Author(s):  
Yathin Krishna ◽  
M. Faizal ◽  
R. Saidur ◽  
K.C. Ng ◽  
Navid Aslfattahi
Keyword(s):  
Heat Transfer ◽  
State Of The Art ◽  
Parabolic Trough ◽  
Parabolic Trough Collector ◽  
Heat Transfer Fluids

Thermophysical Property Measurement of Nitrate Salt Heat Transfer Fluids

2011 ◽  
Author(s):  
Nathan P. Siegel ◽  
Robert W. Bradshaw ◽  
Joseph B. Cordaro ◽  
Alan M. Kruizenga
Keyword(s):  
Heat Transfer ◽  
Molten Salt ◽  
Thermophysical Property ◽  
Calcium Nitrate ◽  
System Level ◽  
Nitrate Salt ◽  
Parabolic Trough ◽  
Heat Transfer Fluids ◽  
Central Receiver ◽  
Salt Mixtures

Nitrate salts have been used for decades in the concentrating solar power industry as heat transfer fluids and thermal storage media. For most of this time these inorganic fluids have been restricted to use in central receiver platforms due to the useful working temperature range of the most widely researched formulation, a near eutectic mixture of sodium and potassium nitrate, which melts at 220°C and is stable in air to nearly 580°C. Recent research efforts have led to the development of nitrate salt mixtures that melt at lower temperatures and are suitable for use in parabolic trough systems. These mixtures include three or more components and generally have melting points in the range of 100°C, with stability in air up to 500°C. The design of parabolic trough systems that utilize molten salt heat transfer fluids is complicated by the fact that the properties of these fluids are considerably different from the organic heat transfer fluids that they may replace. In this paper we present measured thermophysical property data for several commercial and non-commercial molten salt mixtures that can be used in the system level design of parabolic trough and central receiver power plants. The data presented include heat capacity, density, thermal conductivity, viscosity, all as a function of temperature, along with melting point and thermal stability limits. Some properties, such as density, can be predicted by simple mixing rules. The dependence of viscosity was strongly influenced by the composition of the molten salts and, particularly, the proportion of calcium nitrate.

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