Experimental investigation of an active inclined solar panel absorber solar still - Energy and Exergy analysis

2021 ◽  
Author(s):  
Mohamed Thalib Mohamed Rafeek ◽  
Vimala Muthu ◽  
Muthu Manokar Athikesavan ◽  
Ravishankar Sathyamurthy ◽  
Abd Elnaby Kabeel
Keyword(s):  
Mass Flow ◽  
Average Energy ◽  
Electrical Energy ◽  
Exergy Efficiency ◽  
Solar Panel ◽  
Water Yield ◽  
Flow Rates ◽  
Pv Panel ◽  
Energy And Exergy ◽  
Mass Flow Rates

Abstract The objective of the current study is to investigate the performance of the Inclined Solar Panel Basin Still (ISPBS) incorporated with a Spiral Tube Collector (STC) for various mass flow rates of water (mf). The maximum potable water yield of 8.1, 6.9 and 6.1 kg is obtained for different mass flow rates of 1.8, 3.2 and 4.7 kg/hr in each instance. Also, for mf values of 1.8, 3.2 and 4.7 kg per hour, the daily average energy and exergy efficiency of the ISPBS is recorded to be 47.9, 39.3 and 31.02 % and 9.8, 7.9 and 5.6 % in each instance. The average electrical, energy and exergy efficiency of the PV panel is noted to be 6.5, 7.1 and 7.5 %, 15.67, 17.1 and 18.04 % and 20.03, 22.21 and 23.36 % for mf values of 1.8, 3.2 and 4.7 kg/hr in each instance. The rise in mf causes a drop in the fresh water production yield, thermal, exergy and overall thermal effectiveness and an enhancement in the power production of the panel, electrical, thermal, exergy and overall exergy efficiency of the system.

First and second thermodynamic law analyses applied to a solar dish collector

2014 ◽  
Vol 39 (4) ◽  
Author(s):  
Vahid Madadi ◽  
Touraj Tavakoli ◽  
Amir Rahimi
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Exergy Efficiency ◽  
Exergy Destruction ◽  
Flow Rates ◽  
Energy And Exergy ◽  
Mass Flow Rates

AbstractThe energy and exergy performance of a parabolic dish collector is investigated experimentally and theoretically. The effect of receiver type, inlet temperature and mass flow rate of heat transfer fluid (HTF), receiver temperature, receiver aspect ratio and solar radiation are investigated. To evaluate the effect of the receiver aperture area on the system performance, three aperture diameters are considered. It is deduced that the fully opened receivers have the greatest exergy and thermal efficiency. The cylindrical receiver has greater energy and exergy efficiency than the conical one due to less exergy destruction. It is found that the highest exergy destruction is due to heat transfer between the sun and the receivers and counts for 35 % to 60 % of the total wasted exergy. For three selected receiver aperture diameters, the exergy efficiency is minimum for a specified HTF mass flow rate. High solar radiation allows the system to work at higher HTF inlet temperatures. To use this system in applications that need high temperatures, in cylindrical and conical receivers, the HTF mass flow rates lower than 0.05 and 0.09 kg/s are suggested, respectively. For applications that need higher amounts of energy content, higher HTF mass flow rates than the above mentioned values are recommended.

scholarly journals An experimental study of solar thermal system with storage for domestic applications

2018 ◽  
Vol 12 (4) ◽  
pp. 4098-4116
Author(s):  
M. Abid ◽  
B. A. A. Yousef ◽  
M. E. Assad ◽  
A. Hepbasli ◽  
K. Saeed
Keyword(s):  
Heat Exchanger ◽  
Mass Flow ◽  
Solar Collector ◽  
Exergy Efficiency ◽  
Solar Thermal ◽  
Secondary Circuit ◽  
Water Heating ◽  
Flow Rates ◽  
Energy And Exergy ◽  
Mass Flow Rates

Building sector consumes a greater portion of energy for heating and cooling applications. The utilization of fossil fuels for space and water heating in buildings cause a negative effect on the environment by producing larger CO2. In this study solar thermal water heating system for building application have been analyzed from the first and second law perspectives of thermodynamics considering various scenarios and water consumption pattern. The solar flat collector is very commonly used to extract energy from sunlight. Therefor energy and exergy efficiency curves for the solar flat collector were presented. The energetic and exergetic values for the system were calculated based on the experimental values for the overall system, the heat exchanger and the pumps using the approach of exergetic product/fuel basis. The greatest and lowest relative irreversibility’s occurred at the solar collector and the heat exchanger with values of 85.73% and 2.45%, respectively, and the system overall exergy efficiency was determined to be 20.28%. The energy and exergy efficiencies of the solar collector were analyzed at three different cases depending on the mass flow rates in the solar collector and the secondary circuit of the system. Three different mass flow rates were applied to the inlet of the secondary circuit to observe the efficiency effect on the solar collector circuit. This study can assist in selecting a proper solar collector and storage size for buildings of various capacity and possible improvement in the design of the system components.

A Comparative Investigation of Two Types of MHPA Flat-Plate Solar Air Collector Based on Exergy Analysis

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
T. T. Zhu ◽  
Y. H. Diao ◽  
Y. H. Zhao ◽  
C. Ma ◽  
T. Y. Wang ◽  
...  
Keyword(s):  
Flat Plate ◽  
Mass Flow ◽  
Exergy Analysis ◽  
Comparative Investigation ◽  
Exergy Efficiency ◽  
High Mass ◽  
Condenser Section ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Low Mass

In this study, a comparative investigation of two types of microheat pipe array (MHPA) flat-plate solar air collectors (FPSAC) based on exergy analysis has been conducted. The thermal performance of MHPA-type solar air collectors (SACs) with two different shaped fins is experimentally evaluated. A detailed parametric study is also conducted to examine the effects of various fins, operation parameters, and inlet air temperature at different mass flow rates on thermal and exergy efficiencies. Results indicated that using V-shaped slotted fins at the specified range of mass flow rates can enhance exergy efficiency. Exergy efficiency can be considered as the main criterion to evaluate the performance of MHPA FPSACs. Attaching V-shaped slotted fins on the condenser section of MHPA is more effective than attaching rectangular fins at high mass flow rates. By contrast, the latter is more effective than the former at low mass flow rates.

scholarly journals Designing of a New Type Air-Water Cooled Photovoltaic Collector

2020 ◽  
Vol 14 (1) ◽  
pp. 41-45
Author(s):  
Erhan Arslan ◽  
Azim Doğuş Tuncer ◽  
Meltem Koşan ◽  
Ekin Can Dolgun ◽  
Mustafa Aktaş
Keyword(s):  
Mass Flow ◽  
Electrical Energy ◽  
High Heat ◽  
Working Fluid ◽  
Flow Mode ◽  
Flow Rates ◽  
Hot Air ◽  
High Heat Transfer ◽  
Mode 2 ◽  
Mass Flow Rates

The importance of photovoltaic-thermal (PV / T) collector systems in renewable energy technologies is increasing for combined hybrid electrical heat applications. The efficiency of photovoltaic (PV) systems varies between 5-20%. On average, 15% of the solar radiation coming to the PV panel surface is converted to electrical energy and the remainder is lost. In this study, a PV/T collector was designed using two different fluids simultaneously and its efficiency was calculated numerically. PV/T collector systems are specifically designed for agricultural production and their advantages are discussed. In this study, numerical calculations of PV/T collector with a different design have been made. The results were compared with reference to another experimental study. Two different working fluids (air and water) were used in the calculations. The system where air is used as working fluid is called Mode 1 and the system where water is used is called Mode 2. It is aimed to achieve high heat transfer by using water pipes, air ducts and fins placed under PV panels. In this way, it is aimed to produce a more stable hot air and water. In addition, in order to investigate the effect of flow on the yield, different flow rates were calculated. As a result of the theoretical analyses and calculations made in consideration of literature, the total efficiencies of air flow mode (Mode 1) were calculated as 43.2%, 46,2% and 48.7% at 0.0067 kg/s, 0.0072 kg/s and 0.0077 kg/s mass flow rates, respectively. For water flow mode (Mode 2), these values computed as 52.81%, 53.83% and 55.04% at 0.023 kg/s, 0.036 kg/s and 0.054 kg/s mass flow rates, respectively. It was found that PV / T collector efficiency increased with increasing end flow. Designed collector system is preferable in terms of effective use of energy and it can be easily applicable in processes such as hot air-water preparation, drying and greenhouse heating.

scholarly journals Performance analysis of a novel integrated photovoltaic–thermal system by top-surface forced circulation of water

Clean Energy ◽  
2020 ◽  
Author(s):  
Md Arman Arefin ◽  
Mohammad Towhidul Islam ◽  
Mohammad Zunaed ◽  
Khodadad Mostakim
Keyword(s):  
No Value ◽  
Forced Circulation ◽  
Pv Panel ◽  
Photovoltaic Thermal System ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Mass Flow Rates ◽  
Overall Efficiency ◽  
The Individual ◽  
Over The Top

Abstract Almost 80–90% of energy is wasted as heat (provides no value) in a photovoltaic (PV) panel. An integrated photovoltaic–thermal (PVT) system can utilize this energy and produce electricity simultaneously. In this research, through energy and exergy analysis, a novel design and methodology of a PVT system are studied and validated. Unlike the common methods, here the collector is located outside the PV panel and connected with pipes. Water passes over the top of the panel and then is forced to the collector by a pump. The effects of different water-mass flow rates on the PV panel and collector, individual and overall efficiency, mass loss, exergetic efficiency are examined experimentally. Results show that the overall efficiency of the system is around five times higher than the individual PV-panel efficiency. The forced circulation of water dropped the panel temperature and increased the panel efficiency by 0.8–1% and exergy by 0.6–1%, where the overall energy efficiency was ~81%.

scholarly journals Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Tobias Blanke ◽  
Markus Hagenkamp ◽  
Bernd Döring ◽  
Joachim Göttsche ◽  
Vitali Reger ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Laminar Flow ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Circular Ring ◽  
Flow Conditions ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Pipe Radius

AbstractPrevious studies optimized the dimensions of coaxial heat exchangers using constant mass flow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar flow types. In contrast, in this study, flow conditions in the circular ring are kept constant (a set of fixed Reynolds numbers) during optimization. This approach ensures fixed flow conditions and prevents inappropriately high or low mass flow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic effort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass flow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellström’s borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefficients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy difference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy flux and hydraulic effort. The Reynolds number in the circular ring is instead of the mass flow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54% of the outer pipe radius for laminar flow and 60% for turbulent flow scenarios. Net-exergetic optimization shows a predominant influence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth’s thermal properties and the flow type. Conclusively, coaxial geothermal probes’ design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics.

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