Experimental Study on Thermal Efficiency of Parabolic Trough Collector (PTC) Using Al2O3/H2O Nanofluid

2015 ◽  
Vol 787 ◽  
pp. 192-196
Author(s):  
E. Siva Reddy ◽  
R. Meenakshi Reddy ◽  
K. Krishna Reddy

Dispersing small amounts of solid nano particles into base-fluid has a significant impact on the thermo-physical properties of the base-fluid. These properties are utilized for effective capture and transportation of solar energy. This paper attempts key idea for harvesting solar energy by using alumina nanofluid in concentrating parabolic trough collectors. An experimental study is carried out to investigate the performance of a parabolic trough collector using Al2O3-H2O based nanofluid. Results clearly indicate that at same ambient, inlet temperatures, flow rate, concentration ratio etc. hike in thermal efficiency is around 5-10 % compared to the conventional Parabolic Trough Collector (PTC). Further, the effect of various parameters such as concentration ratio, receiver length, fluid velocity, volume fraction of nano particles has been studied. The different flow rates employed in the experiment are 2 ml/s, 4 ml/s and 6 ml/s. Volumetric concentration of 0.02%, 0.04% and 0.06% has been studied in the experiment. Surfactants are not introduced to avoid bubble formation. Tracking mode of parabolic trough collector is manual. Results also reveal that Al2O3-H2O based nanofluid has higher efficiency at higher flow rates.

Author(s):  
Aggrey Mwesigye ◽  
Zhongjie Huan ◽  
Josua P. Meyer

As parabolic trough systems with high concentration ratios become feasible, convective heat transfer enhancement is expected to play a significant role in improving the thermal and thermodynamic performance of these systems. In this paper, the thermal performances of a high concentration ratio system using three different types of nanofluids were investigated. A system with a geometric concentration ratio of 113 and a rim angle of 80° was used in this study. The nanofluids considered were copper-Therminol®VP-1, silver-Therminol®VP-1 and Al2O3-Therminol®VP-1 nanofluid. For each nanofluid, the volume fraction of the nanoparticles in the base fluid was varied from 0–6%. The numerical solution was obtained using a finite volume based computational fluid dynamics tool. Temperature dependent properties were used for both the base fluid and the nanoparticles. An actual receiver heat flux boundary condition obtained using Monte Carlo ray tracing was coupled to the computational fluid dynamics code to model the thermal performance of the receiver. Results show that for each nanofluid used, the thermal performance of the receiver improves significantly. The thermal efficiency increases by about 12.5%, 13.9% and 7.2% for the copper-Therminol®VP-1, silver-Therminol®VP-1 and Al2O3-Therminol®VP-1 nanofluids, respectively as the volume fraction increases from 0 to 6%. The thermal efficiency improvement with silver-Therminol®VP-1 was the highest of the considered nanofluids owing to the relatively higher thermal conductivity of silver.


Author(s):  
Aggrey Mwesigye ◽  
Josua P. Meyer

In this paper, the potential for improved thermal performance of a high concentration ratio parabolic trough solar energy system working with high thermal conductivity single-walled carbon nanotubes (SWCNTs) and Therminol®VP-1 nanofluid is numerically investigated. In the numerical analysis, the practical heat flux profiles expected for parabolic trough receivers were obtained using Monte-Carlo ray tracing and coupled with a computational fluid dynamics tool using user defined functions to investigate the thermal performance of the parabolic trough solar energy system. A parabolic trough system with a concentration ratio of 113 was considered in this study and heat transfer fluid inlet temperatures between 400 K and 650 K were used. The volume fraction of SWCNTs in the base fluid was in the range 0% to 2.5% and the flow rates used were in the range 0.82 to 69.41 m3/h. Results show improvements in the convective heat transfer performance and receiver thermal efficiency as well as a considerable reduction of the receiver thermal losses with increasing volume fractions. The heat transfer performance increases up to 64% while the thermal efficiency increases by about 4.4%. Higher increments are observed at low flow rates and inlet temperatures. The receiver thermodynamic performance also increases significantly with the use of nanofluids. Entropy generation rates reduce by about 30% for the range of parameters considered.


2021 ◽  
Vol 9 (2) ◽  
Author(s):  
P. Muruganantham ◽  
◽  
Balaji Dhanapal ◽  

Renewable energy is one of the cleaner energy generation strategies practiced all over the world to reduce environmental impacts and waste based on current sustainability in economic practices. Solar energy is one kind of renewable sources of energy practiced for different application. The thermal storage system in solar energy is one of the least practiced methods in research, and the utilization of solar energy in the thermal application is attaining higher responses and is quite possible. In this paper, solar heat generation is attained by solar parabolic trough collector using phase change materials. The ideology behind this research is to develop a thermal energy storage system using solar collectors and phase change materials. A composition mixture of MgCl2. 6H2O phase change materials used as the fluid medium in trough collector and thermal efficiency of the material is evaluated. For effective optimization, an imperialist competitive algorithm is used for optimizing the thermal efficiency of the solar collectors. The thermal efficiency of the collector is numerically experimented in the running platform of Mat Lab and executed in terms of heat gain, heat loss, and thermal efficiency of the parabolic trough collector, respectively. The efficiency of the proposed framework is 85%, and the current framework just has 80% efficiency. The heat loss in the proposed framework is lower than that of the current system, distinguished as 4200 W and 4520 W, respectively. It is shown from the research study that the proposed PCM composition is an optimal method for generating heat energy in solar parabolic trough collectors.


Author(s):  
Aggrey Mwesigye ◽  
Zhongjie Huan ◽  
Josua P. Meyer

In this paper, the thermal performance of a high concentration ratio parabolic trough system and the potential for improved thermal performance using Syltherm800-CuO nanofluid were investigated and presented. The parabolic trough system considered in this study has a concentration ratio of 113 compared with 82 in current commercial systems. The heat transfer fluid temperature was varied between 350 K and 650 K and volume fractions of nanoparticle were in the range 1–6%. Monte-Carlo ray tracing was used to obtain the actual heat flux on the receiver’s absorber tube. The obtained heat flux profiles were subsequently coupled with a computational fluid dynamics tool to investigate the thermal performance of the receiver. From the study, the results show that with increased concentration ratios, receiver thermal performance degrades, with both the receiver heat loss and the absorber tube circumferential temperature differences increasing, especially at low flow rates. The results further show that the use of nanofluids significantly improves receiver thermal performance. The heat transfer performance increases up to 38% while the thermal efficiency increases up to 15%. Significant improvements in receiver thermal efficiency exist at high inlet temperatures and low flow rates.


2017 ◽  
Vol 867 ◽  
pp. 191-194
Author(s):  
Anbu Manimaran Sukanta ◽  
M. Niranjan Sakthivel ◽  
Gopalsamy Manoranjith ◽  
Loganathan Naveen Kumar

Solar Energy is one of the forms of Renewable Energy that is available abundantly. This work is executed on the enhancement of the performance of solar parabolic trough collector using Intensified Ray Convergence System (IRCS). This paper distinguishes between the performance of solar parabolic trough collector with continuous dual axis tracking and a fixed solar parabolic trough collector (PTC) facing south (single axis tracking). The simulation and performance of the solar radiations are visualized and analyzed using TRACEPRO 6.0.2 software. The improvement in absorption of solar flux was found to be enhanced by 39.06% in PTC using dual axis tracking, absorption of solar flux increases by 52% to 200% in PTC receiver using perfect mirror than PTC using black chrome coating.


Solar Energy ◽  
2016 ◽  
Vol 134 ◽  
pp. 180-192 ◽  
Author(s):  
Jean-Louis Bouvier ◽  
Ghislain Michaux ◽  
Patrick Salagnac ◽  
Thiebaut Kientz ◽  
Dominique Rochier

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