scholarly journals Thermal analysis of a parabolic trough solar collector with synthetic oil as working fluid using a computational tool

2020 ◽  
pp. 1-9
Author(s):  
Ernesto ENCISO-CONTRERAS ◽  
Alejo Jesús DE LA CRUZ ◽  
Guillermo Irving ALCOCER ◽  
Juan Gabriel BARBOSA-SALDAÑA
Keyword(s):  
Thermal Analysis ◽  
Mass Flow ◽  
Solar Irradiance ◽  
Liquid State ◽  
Solar Collector ◽  
Working Fluid ◽  
Computational Tool ◽  
Parabolic Trough ◽  
Synthetic Oil ◽  
Parabolic Trough Solar Collector

This work describes the use of a computational tool to assess a previously built parabolic trough solar collector (PTC) that uses a working fluid in liquid state. This work is focused on the thermal analysis of a PTC collector considering two common used synthetic oils: Syltherm 800 and Therminol VP1. The designing characteristics of the commercial LS3 solar collector was selected and as solar resource, the solar irradiance that reaches Mexico City was used with twelve monthly average values along the year. The computational tool provides thermal and flow data for every synthetic oil and for every solar irradiance value used. The most important data computed is the mass flow, which is obtained through iterative processes until the necessary value is found, in order to satisfy the working fluid final temperature for the synthetic oil, once the optimum mass flow value is found, the collector thermal parameters are computed, such as: heat gain, heat losses, thermal efficiency, and the temperatures for the absorber and coating tubes. The computational tool can assess any PTC collector with any working fluid in liquid state, and the data obtained can be used to improve of modify the design of the collector for a better performance.

Thermodynamic Analysis of an Integrated Solar-Based Cooling System in UAE

2014 ◽  
Author(s):  
Mohamed Gadalla ◽  
Amani Al Hammadi
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Solar Irradiance ◽  
Solar Collector ◽  
Cooling System ◽  
Constant Mass ◽  
Parabolic Trough ◽  
Energy And Exergy ◽  
Parabolic Trough Solar Collector

Renewable energy resource is considered by many developed and developing countries as a promising and a cost effective candidate to provide energy. The operation of cooling systems in the United Arab Emirates (UAE) have some operating problems especially in summer such as severe grid dependent, excessive energy consumption, high emissions and high costs. So, more economically and environmentally friendly HVAC systems are desired to provide the required electricity demands for cooling loads while saving energy and having low emissions to the environment. In this paper, a parabolic trough solar collector is integrated with a triple effect absorption cooling system for sustainable development. A computer code is developed using Engineering Equation Solver (EES) software to obtain all required thermodynamic properties of water-lithium bromide (H2O/LiBr) solution and to optimize all operating parameters and carry out all detailed energy and exergy analyses for a 10 kW cooling capacity. In addition, the parabolic trough solar collector (PTSC) is also designed for the required cooling load and its overall dynamic behavior is also investigated. The solar irradiance available in the UAE on a monthly basis is used in the analysis of a PTSC-based HVAC cooling system. Energetic and exergetic efficiencies of the PTSC for every month are also evaluated under different operating conditions. The Overall monthly energy and exergy efficiencies of the integrated PTSC-based HVAC system for a constant mass flow rate of Therminol-66 and concentration ratio are calculated. The dynamic variation of the coefficient of performance of the integrated system with the solar irradiance and mass flow rate of the oil are also evaluated. Results show that both energetic and exergetic COPs are decreased with increasing the solar irradiance for a constant mass flow rate of oil and constant concentration ratio. It is found that increasing the mass flow rate of the oil from 0.1 to 0.5 kg/s results in decreasing the energetic COP from 2.15 to 1.98 and the exergetic COP from 2.05 to 1.93.

Influence of Dimensionless Parameter on De-Ionized Water-alumina Nanofluid Based Parabolic Trough Solar Collector

2020 ◽  
Vol 13 (3) ◽  
pp. 206-221
Author(s):  
Vijayan Gopalsamy ◽  
Karunakaran Rajasekaran ◽  
Logesh Kamaraj ◽  
Siva Sivasaravanan ◽  
Metin Kok
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Dimensionless Parameter ◽  
Parabolic Trough ◽  
Alumina Nanofluid ◽  
Parabolic Trough Solar Collector

Background: Aqueous-alumina nanofluid was prepared using magnetic stirrer and ultrasonication process. Then, the prepared nanofluid was subjected to flow through the unshielded receiver of the parabolic trough solar collector to investigate the performance of the nanofluid and the effects of the dimensionless parameter were determined. Methods: The experimental work has been divided into two sections. First, the nanofluid was prepared and tested for its morphology, dimensions, and sedimentation using X-Ray Diffraction and Raman shift method. Then, the nanofluids of various concentrations from 0 to 4.0% are used as heat transfer fluid in unshielded type collector. Finally, the effect of the dimensionless parameter on the performance was determined. Results: For the whole test period, depending upon the bulk mean temperature, the dimensionless parameters such as Re and Nu varied from 1098 to 4552 & 19.30 to 46.40 for air and 2150 to 7551 & 11.11 to 48.54 for nanofluid. The enhancement of thermal efficiency found for 0% and 4.0% nanoparticle concentrations was 32.84% for the mass flow rate of 0.02 kg/s and 13.26% for the mass flow rate of 0.06 kg/s. Conclusion: Re and Nu of air depend on air velocity and ambient temperature. Re increased with the mass flow rate and decreased with concentration. Heat loss occurred by convection mode of heat transfer. Heat transfer coefficient and global efficiency increased with increased mass flow rate and volume fraction. The thermal efficiency of both 0% and 4.0% concentrations became equal for increased mass flow rate. It has been proven that at high mass flow rates, the time available to absorb the heat energy from the receiver is insufficient.

Determination of Parabolic Trough Solar Collector Efficiency Using Nanofluid: A Comprehensive Numerical Study

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Hamidreza Khakrah ◽  
Amir Shamloo ◽  
Siamak Kazemzadeh Hannani
Keyword(s):  
Renewable Energy ◽  
Solar Collector ◽  
Volume Fraction ◽  
Numerical Study ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Parabolic Trough ◽  
Metallic Nanoparticle ◽  
Velocity Magnitude ◽  
Parabolic Trough Solar Collector

Due to significant reduction in fossil fuel sources, several researches have been conducted recently to explore modern sources of renewable energy. One of the major fields in the category of renewable energy harnessing devices is parabolic trough solar collector (PTC). Several parameters have effect on the overall efficiency of the PTCs. As the effect of these parameters is coupled to each other, a comprehensive investigation is necessary. In the present study, a numerical analysis is performed to examine the efficiency of PTCs via variation of several governing parameters (e.g., wind velocity magnitude, nanoparticles volume fraction, inlet temperature, and reflector's orientation). A detailed set of absorber, reflector, and protection glass in addition to the surrounding environment is modeled to capture sufficiently accurate data. The working fluid is assumed to be nanofluid to inspect the advantage of metallic nanoparticle addition to the base fluid. The Monte Carlo radiation tracing method is utilized to calculate the solar gain on the absorber tube. According to the obtained results, the efficiencies are reduced by 1–3% by rotating the reflector by 30 deg relative to wind direction. Moreover, 14.3% and 12.4% efficiency enhancement is obtained by addition of 5% volume fraction of Al2O3 to the base synthetic oil for horizontal and rotated reflectors, respectively.

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