Analytical Solution of the Transient Heat Conduction in the Absorber Tube of a Parabolic Trough Solar Collector Under Quasi-Steady Conditions

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Roger Cundapí ◽  
Sara L. Moya ◽  
Octavio Cazarez
Keyword(s):  
Heat Conduction ◽  
Steady State ◽  
Analytical Solution ◽  
Solar Collector ◽  
Transient Heat Conduction ◽  
Step Function ◽  
Operating Conditions ◽  
Fluid Temperature ◽  
Parabolic Trough ◽  
Parabolic Trough Solar Collector

Abstract Temperature fields and their transient behaviors are essential subjects to be considered for modeling and design of absorber tubes in concentrated solar power plants. Both subjects have been addressed by various authors. However, the first subject has been primarily solved in the steady state. While the second has been solved by considering transient variations in the environmental or operating conditions, but with a heat conduction model in steady state. To the best of our knowledge, there are no analytical transient two-dimensional (2D) (r, φ) solutions involving nonuniform heat flux distribution (NUHFD) on the absorber tube of a parabolic trough solar collector (PTC). This study aims to obtain an analytical solution for the transient heat conduction in 2D of the absorber tube. The analytical solution was obtained using the method of separation of variables and the superposition principle. Two NUHFD functions were analyzed: a step function and a local concentration ratio (LCR) function. To the first function, the effect of the inlet fluid temperature and efficiency were also studied. The results agree with experimental and numerical results from the literature. The maximum average root-mean-square was near 6.4% for the step function, while the maximum average error was 1% for LCR function. The theoretical energy balances corroborate the validity of the analytical solution. The analytical solution could be useful to compare other theoretical studies (e.g., to prove new numerical schemes), to simulate other parameters of design, and to calibrate experimental tests. Even this work could be extended for nonlinear boundary conditions.

scholarly journals Analisa Efisiensi Prototype Solar Collector Jenis Parabolic Trough dengan Menggunakan Cover Glass Tube pada Pipa Absorber

2015 ◽  
Vol 4 (2) ◽  
pp. 26
Author(s):  
Hartamas Ridho Prasetyo
Keyword(s):  
Steady State ◽  
Solar Collector ◽  
Glass Tube ◽  
Parabolic Trough ◽  
Cover Glass ◽  
Parabolic Trough Solar Collector

Energi tidak dapat diciptakan maupun dimusnahkan, hanya dapat dikonversikan dari satu bentuk ke bentuk lainnya (Hukum Kekekalan Energi). Energi sangat penting dalam kehidupan sehari – hari khususnya energi listrik yang kebutuhan terhadap energi ini sangat besar sedangkan sebagian besar energi listrik dihasilkan dari sumber daya fosil yang mulai menipis jumlahnya. Ketergantungan akan minyak bumi untuk jangka panjang tidak dapat di pertahankan lebih lama jika pemakaian melebihi batas wajar. Dalam Tugas Akhir ini penulis melakukan analisa alat Parabolic Trough Solar Collector dengan memanfaatkan energi radiasi matahari, yang di awali adanya perancangan desain alat PTSC dengan material yang sudah di tentukan sebelumnya. Prototype tersebut hanya bisa dilakukan pengujian dengan posisi steady state atau diam antara jam 11.30 sampai dengan 12.30 siang. Dengan adanya penelitian tentang analisa performa pada alat tersebut, telah di dapatkan beberapa hasil nilai variabel yang signifikan dan berpengaruh besar dengan nilai performa alat tersebut.

scholarly journals A parabolic trough solar collector as a solar system for heating water: a study based on numerical simulation

2017 ◽  
Vol 2 (2) ◽  
pp. 29
Author(s):  
Mokhtar Ghodbane ◽  
Boussad Boumeddane
Keyword(s):  
Numerical Simulation ◽  
Solar Collector ◽  
Tap Water ◽  
Energy Balance Equation ◽  
Thermal Study ◽  
Fluid Temperature ◽  
Parabolic Trough ◽  
Heating Water ◽  
Small Model ◽  
Parabolic Trough Solar Collector

This paper is an optical and thermal study of a small model of a parabolic trough solar collector (CTP), which will be used to heat tap water in the winter at Guemar, El-Oued province, Algeria. A mathematical model drawn from the energy balance equation applied to the absorber tube, this model was solved by the finite difference method. A computer program was developed to solve our problem. MATLAB was used as a tool for numerical simulation where it is used to calculate dynamic shifts at the level of the absorbent tube. The results are very honorable and encouraging, where the thermal efficiency of the concentrator had passed 61%, and the fluid temperature had passed 343 K.

scholarly journals A Linear Parabolic Trough Solar Collector Performance Model

2007 ◽  
Author(s):  
Ming Qu ◽  
David H. Archer ◽  
Hongxi Yin
Keyword(s):  
Solar Collector ◽  
Incident Angle ◽  
Heating System ◽  
Performance Model ◽  
Operating Conditions ◽  
Ambient Conditions ◽  
Parabolic Trough ◽  
Fluid Properties ◽  
Solar Intensity ◽  
Parabolic Trough Solar Collector

A performance model has been programmed for a solar thermal collector based on a linear parabolic trough reflector focused on a coated absorber tube enclosed in an evacuated transparent tube: a Parabolic Trough Solar Collector (PTSC). This steady state, single dimensional model is based on fundamental material and energy balances together with heat transfer correlations programmed in the Engineering Equation Solver (EES). The model considers the effects of solar intensity, incident angle, collector dimensions, material properties, fluid properties, ambient conditions, and operating conditions on the performance of the PTSC. The model has been used to size system devices, to choose proper operating conditions, and to detect possible operating problems for the solar cooling and heating system for the Intelligent Workplace (IW) at Carnegie Mellon University (CMU) in Pittsburgh. The IW installed 52 - square meter PTSCs coupled with a 16 kW absorption chiller for space cooling and heating in August of 2006. The tests on PTSC performance are now being carried out. After the model is validated by experimental data of the tests, it will be further used to improve PTSC design and to optimize system operation and control for the IW.

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