Minimizing the overall loss coefficient of flat plate solar collector using energy, entropy and exergy analysis

Author(s):  
Ponnusamy Sathyakala ◽  
Sai Sundara Krishnan Gangadharan ◽  
Balaji Kalaiarasu

In this paper, Energy, Entropy and Exergy (EEE) analysis of flat plate solar collector is studied through a mathematical model by considering the overall loss coefficient as a non-constant parameter. The overall loss coefficient is calculated by minimizing the top loss coefficient using Lagrange multiplier optimization technique and also by empirical formulas. Further, energy efficiency, entropy generation, exergy destruction and exergy efficiency of the flat plate solar collector are also determined for the both aforesaid overall loss coefficients. The exergy efficiency of the proposed model has been doubled, when compared with the experimental measurements in the earlier literature. Also, comparing the proposed methods, it is observed that exergy efficiency obtained by using the minimal top loss coefficient is reasonably high and it enhances the overall collector’s efficiency.

2012 ◽  
Vol 253-255 ◽  
pp. 760-765 ◽  
Author(s):  
Maryam Khademi ◽  
Farzad Jafarkazemi ◽  
Emad Ahmadifard ◽  
Saman Younesnejad

An increase in exergy efficiency of flat plate solar collector leads to a considerable improvement in collector’s performance. Different parameters influence the performance of collector. In this paper, Sequential Quadratic Programming (SQP) and Genetic Algorithm (GA) have been employed for optimizing exergy efficiency of the flat plate solar collector. Absorber plate area and mass flow rate of inlet water have been considered as optimization’s variables. The results show the possibility to reach higher exergy efficiency with lower absorber area and consequently lower price. Also it is obvious that SQP method performs optimization process with higher convergence speed but lower accuracy than GA.


Author(s):  
Ahmad Fudholi ◽  
Mariyam Fazleena Musthafa ◽  
Abrar Ridwan ◽  
Rado Yendra ◽  
Ari Pani Desvina ◽  
...  

<span lang="EN-US">Photovoltaic thermal (PVT) collectors convert solar radiation directly to both electrical and thermal energies. A PVT collector basiccaly combines the functions of a flat plate solar collector and those of a PV panel. This review presents thermodinamics fundamentals, descriptions, and previous works conducted on energy and exergy analysis of air based PVT collector. Studies in 2010 to 2018 of the energy and exergy analysis of air based PVT collectors are summarized. The energy and exergy efficiency of air based PVT collector ranges from 31% to 94% and 8.7% to 18%, respectively. In addition, flat plate solar collector is presented. Studies conducted on air based PVT collectors are reviewed.</span>


2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Yash Kashyap ◽  
Apurva Singh ◽  
Y. Raja Sekhar

In this study, the exergetic performance of a flat plate solar collector (FPSC) setup with ZnO-based ethylene glycol (EG)/water nanofluid as a working fluid has been evaluated against that of EG/water. As a passive means to augment the rate of heat transfer, internally grooved tubes of two different pitches (e = 0.43 and e = 0.44) have been examined and compared against the performance of plain tube. The mass flow rate was fixed at 0.015 kg/s and the volume fraction of ZnO nanoparticles is ф = 0.02% v/v. The results indicate an enhancement in exergy efficiency of 44.61% when using the grooved tube (e = 0.44) against plain tube without the nanofluid and 39.17% when nanofluid is used. Using the nanofluid enhanced the exergy efficiency of the FPSC by a maximum of 73.81%. Maximum exergy efficiency obtained was 5.95% for grooved tube (e = 0.44) with nanofluid as working fluid and is in good agreement with previous literature. Exergy destruction/irreversibility due to temperature differences and heat flow within the system has been reported. Sun-collector temperature difference accounts for nearly 86–94% of the irreversibility. The results for thermal efficiency of this experimental setup have been published and summarized in this study for reference.


2010 ◽  
Vol 31 (2) ◽  
pp. 45-62 ◽  
Author(s):  
Wiesław Zima ◽  
Piotr Dziewa

Mathematical modelling of heat transfer in liquid flat-plate solar collector tubesThe paper presents a one-dimensional mathematical model for simulating the transient processes which occur in the liquid flat-plate solar collector tubes. The proposed method considers the model of collector tube as one with distributed parameters. In the suggested method one tube of the collector is taken into consideration. In this model the boundary conditions can be time-dependent. The proposed model is based on solving the equation describing the energy conservation on the fluid side. The temperature of the collector tube wall is determined from the equation of transient heat conduction. The derived differential equations are solved using the implicit finite difference method of iterative character. All thermo-physical properties of the operating fluid and the material of the tube wall can be computed in real time. The time-spatial heat transfer coefficient at the working fluid side can be also computed on-line. The proposed model is suitable for collectors working in a parallel or serpentine tube arrangement. As an illustration of accuracy and effectiveness of the suggested method the computational verification was carried out. It consists in comparing the results found using the presented method with results of available analytic solutions for transient operating conditions. Two numerical analyses were performed: for the tube with temperature step function of the fluid at the inlet and for the tube with heat flux step function on the outer surface. In both cases the conformity of results was very good. It should be noted, that in real conditions such rapid changes of the fluid temperature and the heat flux of solar radiation, as it was assumed in the presented computational verification, do not occur. The paper presents the first part of the study, which aim is to develop a mathematical model for simulating the transient processes which occur in liquid flat-plate solar collectors. The experimental verification of the method is a second part of the study and is not presented in this paper. In order to perform this verification, the mathematical model would be completed with additional energy conservation equations. The experimental verification will be carry out in the close future.


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