scholarly journals Effects of Louvered Parameters on Exergetic Performance of Louvered Finned Solar Air Heater

2021 ◽  
Vol 39 (5) ◽  
pp. 1649-1658
Author(s):  
Subhash Chand ◽  
Prabha Chand
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Operating Conditions ◽  
High Mass ◽  
Solar Air Heater ◽  
Air Heater ◽  
Pitch Ratio ◽  
Exergy Performance

The aim of the present study to improve the performance of solar air heater because of low thermo-physical properties of air. In the current work, an attempt has been made to improve the performance of the heater by employing louvered fins to the absorber plate, as it not only enhances heat transfer coefficient but also improve heat transfer area. The effect of exergy performance on the geometrical parameters of louvered fin i.e., louvered angle, louvered pitch and louvered length has been studied and analyzed. The results are compared to plane solar air heater (PSAH) to evaluate the effectiveness of louvered finned solar air heater (LFSAH). The exergy efficiency of LFSAH is comparatively higher for all the operating conditions except for higher mass flow rate where it may even go below that of PSAH; possibly due to the higher pressure drop and more loss of exergy at high mass flow rate. In addition, the results conclude that for louvered parameters viz., louvered angle 20°, fin pitch to louvered pitch ratio 0.75 and louvered length to louvered pitch ratio 1.25, high exergy performance of SAH is obtained as compared to other louvered parameter values.

Investigation of the Thermal Performances of Flat, Finned, and v-Corrugated Plate Solar Air Heaters

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
A. E. Kabeel ◽  
A. Khalil ◽  
S. M. Shalaby ◽  
M. E. Zayed
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Convective Heat Transfer Coefficient ◽  
Operating Conditions ◽  
Experimental Results ◽  
Solar Air Heater ◽  
Outlet Temperature ◽  
Air Heater

In this research, the thermal performances of flat, finned, and v-corrugated plate solar air heaters were investigated experimentally. A solar air heater with single glass cover, single pass was designed and tested under prevailing weather conditions of Tanta city (30°43′ N, 31° E), Egypt. The solar air heater was designed to be easy to replace the absorber plate from one to another one. Comparisons between the temperature difference of air across the heater and thermal efficiencies of the flat, finned, and v-corrugated plate solar air heaters were presented. The effect of change in the mass flow rate of air on the outlet air temperature and the thermal efficiency of the heater were also studied when the mass flow rates were 0.062, 0.028, and 0.009 kg/s. The experimental results showed that the maximum value of outlet temperature of the v-corrugated plate solar air heater was 5 and 3.5 °C more than that of flat and finned plates when the mass flow rate was 0.062 kg/s, respectively. And, it increased to be 8 and 5.5 C when the mass flow rate was 0.009 kg/s. It is also indicated that the thermal efficiency of the v-corrugated solar air heater is 8–14.5% and 6–10.5% higher than that of the flat and finned plate heaters, respectively, when the mass flow rate was 0.062 kg/s under the considered configurations and operating conditions. The experimental results also indicated that the convective heat transfer coefficient of the v-corrugated heater reached up to 1.64 and 1.36 times than that of the flat and finned heaters, respectively, when the flow rate was 0.062 kg/s.

Data Analysis of 64 Rod Bundles Reflood Heat Transfer Experiment

2017 ◽  
Author(s):  
Lv Yufeng ◽  
Chen Yuzhou ◽  
Zhang Dongxu ◽  
Zhao Minfu ◽  
Duan Minghui
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Test Data ◽  
Mass Flow ◽  
Flow Rate ◽  
High Mass ◽  
Rod Bundles ◽  
Transfer Experiment ◽  
System Pressure ◽  
Injection Water

The test data of 64 rod bundles reflood heat transfer experiment performed by China Institute of Atomic Energy are analyzed. The heater rods are electrically powered and have a diameter of 9.5 mm and a length of 4.3 m arranged in a 8 × 8 array with a 12.6 mm pitch. The test parameter is in the range of 10–500 kg/(m2 · s) for injection water mass flux, 20–80°C for injection water temperature, 500–600°C for initial heater rod temperature, 0–1.1 kW/m for heating power, respectively. The system pressure is atmosphere pressure. Two kinds of spacer grids with and without mixing vanes are adopted to investigate their effect on heat transfer. The result shows that rod wall temperature downstream the spacer grid with mixing vanes is lower than that without mixing vanes, which indicates that the heat transfer is enhanced with mixing vanes. The rewetting velocity is nearly a constant under a certain test condition. The experimental values of rewetting velocity are compared with heat conduction controlled theories. At low mass flow rate, one-dimensional conduction gives agreement with experiment; while at high mass flow rate, the two-dimensional conduction theory is shown to be in agreement with experiment data. The RELAP5/ MOD3.3 reflood model is assessed against the test data. Comparison of code prediction and measured data indicates that the code predicts quench time relatively well but the peak rod temperature differs.

scholarly journals Thermal and Cost Analysis of a Multi-Pass Solar Air Heater with Reversed Absorber and Reflector

2020 ◽  
pp. 141-146
Keyword(s):  
Cost Analysis ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cost Effective ◽  
Solar Air Heater ◽  
Constant Mass ◽  
Air Heater ◽  
Effectiveness Model ◽  
Solar Intensity

Solar air heater is a major component of solar dryer. A model of multi pass solar air heater (MPSAH) with reversed absorber and reflector was developed. Exhaustive Study over the performance of MPSAH with and without reversed absorber and cost analysis was done. The performance curves show the effect of solar intensity on MPSAH with and without reversed absorber at constant mass flow. It was observed that the thermal efficiency of MPSAH is depending on solar intensity and losses when mass flow rate remain constant. At constant mass flow rate 26.90 gm/sec, the collector efficiency increased by 9% at average solar intensity 457w/m². Theoretical and experimental analysis showed close agreement. In addition the cost-effectiveness model has been used to examine the performance MPSAH with and without reverse absorbers. The air heaters annual cost (AC) estimation and annual power acquirement (AG) was analyze. The result is evidence for that multi-pass solar air heater with reverse absorbers and reflector is more cost-effective than multi-pass solar collectors without reverse absorber.

scholarly journals A Numerical Analysis of the Air-Cooling System of a Spark Ignition Aeronautical Engine

2020 ◽  
Vol 197 ◽  
pp. 06003
Author(s):  
Maria Faruoli ◽  
Annarita Viggiano ◽  
Paolo Caso ◽  
Vinicio Magi
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cooling System ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Air Cooling ◽  
Air Mass ◽  
Air Cooling System

It is well known that spark ignition internal combustion engines for aeronautical applications operate within a specific temperature range to avoid structural damages, detonations and loss of efficiency of the combustion process. An accurate assessment of the cooling system performance is a crucial aspect in order to guarantee broad operating conditions of the engine. In this framework, the use of a Conjugate Heat Transfer method is a proper choice, since it allows to estimate both the heat fluxes between the engine walls and the cooling air and the temperature distribution along the outer wall surfaces of the engine, and to perform parametric analyses by varying the engine operating conditions. In this work, the air-cooling system of a 4-cylinder spark ignition engine, designed by CMD Engine Company for aeronautical applications, is analysed in order to evaluate the amount of the air mass flow rate to guarantee the heat transfer under full load operating conditions. A preliminary validation of the model is performed by comparing the results with available experimental data. A parametric study is also performed to assess the influence of the controlling parameters on the cooling system efficiency. This study is carried out by varying the inlet air mass flow rate from 1.0 kg/s to 1.5 kg/s and the temperature of the inner wall surfaces of the engine combustion chambers from 390 K to 430 K.

scholarly journals Modeling and PSO optimization of Humidifier-Dehumidifier desalination

2018 ◽  
Vol 7 (1) ◽  
pp. 59 ◽  
Author(s):  
Mohammad Hossein Ahmadi ◽  
Mohammad Ali Afshar ◽  
Ali Naseri ◽  
Mokhtar Bidi ◽  
H. Hadiyanto
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Temperature Difference ◽  
Cooling Water ◽  
Decision Variable ◽  
Solar Air Heater ◽  
Air Heater ◽  
Output Ratio ◽  
Optimum Productivity

The aim of this study is modeling a solar-air heater humidification-dehumidification unit with applying particle swarm optimization to find out  the maximum gained output ratio with respect to the mass flow rate of water and air entering humidifier, mass flow rate of cooling water entering dehumidifier, width and length of solar air heater and terminal temperature difference (TTD) of dehumidifier representing temperature difference of inlet cooling water and saturated air to dehumidifier as its decision variable. A sensitivity analysis, furthermore, is performed to distinguish the effect of operating parameters including mass flow rate and streams’ temperature. The results showed that the optimum productivity decreases by decreasing the ratio of mass flow rate of water entering humidifier to air ones.Article History: Received: July 12th 2017; Revised: December 15th 2017; Accepted: 2nd February 2018; Available onlineHow to Cite This Article: Afshar, M.A., Naseri, A., Bidi, M., Ahmadi, M.H. and Hadiyanto, H. (2018) Modeling and PSO Optimization of Humidifier-Dehumidifier Desalination. International Journal of Renewable Energy Development, 7(1),59-64.https://doi.org/10.14710/ijred.7.1.59-64

scholarly journals Performance Analysis of Solar Desalination System for Improved Productivity by using Waste Heat of Household Chimney

2020 ◽  
Vol 8 (6) ◽  
pp. 3221-3225
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Brackish Water ◽  
Potable Water ◽  
Water Yield ◽  
Solar Air Heater ◽  
Water Tank ◽  
Conventional System ◽  
Air Heater

This work deals with the analysis of the proposed innovative humidification-dehumidification (HD) desalination unit in which waste hot air of kitchen chimney has been used for heating brackish water. The proposed system is configured with solar air heater also, thus both heated air and heated water has been used to improve the water yield of desalination unit compared to conventional system. Mathematical modeling of propose unit based on energy balance of flat plate air heater, humidifier, dehumidifier and brackish water tank has been used to evaluate the effect of operating condition. Potable water yield found to increase (with highest productivity of 6.5 kg/day) when mass flow rate of process air increases from 0.6 kg/min to 3 kg/min. Strong dependency of water mass flow rate has also been found as productivity increases (with maximum value of 6.7 kg/day and 7.5 kg/day) by increasing the mass flow rate of brackish water in humidifier and cold water in dehumidifier respectively. The higher initial temperature of brackish water also found beneficial as it increases productivity. Finally, the thermal performance of desalination unit has been evaluated in terms of Gain in Output Ratio and comparison has been made with conventional system. The higher GOR of the proposed system ensures the better utilization of thermal energy in potable water production.

scholarly journals Mathematical Modelling of Single Glazed and Double Glazed Solar Air Heater

2021 ◽  
Vol 10 (3) ◽  
pp. 34-42
Author(s):  
Bhawna Agrawal ◽  
Pallavi Agrawal ◽  
Suman Agrawal
Keyword(s):  
Solar Radiation ◽  
Mathematical Modelling ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Winter Season ◽  
Solar Air Heater ◽  
Counter Flow ◽  
Heat Gain ◽  
Air Heater

This paper focuses on Mathematical Modelling of Single Glazed and Double Glazed Solar air heater (SAH) which is special kind of heat exchanger that transfers thermal energy from the solar radiation to the fluid flowing inside of the collector. The most potential applications of SAH is the supply of hot air for heating of buildings, to maintain a comfortable environment especially in the winter season, air preheating, desiccant refrigeration, and drying of vegetables, fruits, meat, textile and marine products. Solar radiation intensity is less in the morning that increase gradually till noon and again decrease from noon to evening. During simulations it is observed that the heat gain is directly proportional to the mass flow rate. It is maximum for the counter flow SAH and is least for transpired solar air heater. The efficiency of the SAH is directly proportional to mass flow rate. The thermal efficiency is maximum for the counter flow SAH, The useful heat gain increases is highest in the clear days of summer month particularly in the month of April-May and lowest in the cloudy days of winter month particularly in the month of December. The results are in conformation with theoretical aspects.

scholarly journals Numerical Simulation of Solar Air Heater using Paraffin Wax-Aluminum Compound as Phase Changing Material

2021 ◽  
Vol 3 (2) ◽  
pp. 49-55
Author(s):  
Atul Kumar ◽  
Prabhakar Bhandari ◽  
K.S. Rawat
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Paraffin Wax ◽  
Solar Air Heater ◽  
Outlet Temperature ◽  
Freezing Time ◽  
Aluminum Compound ◽  
Air Heater ◽  
Aluminium Powder

This paper presents a theoretical investigation of solar air heater using phase change material (PCM). PCM used in present configuration is homogenous mixture of paraffin wax with Aluminium powder. The purpose of using Aluminium powder with paraffin wax is to increase the thermal conductivity. PCM mixtures are encapsulated in cylinders and are used as solar absorbers. Using MATLAB program, the effect of different parameters is studied. It has been observed that with increase in mass flow rate, air outlet temperature decreases and freezing time of cylinder decreases. However, at constant mass flow rate, with increase in cylinder radius, air temperature decreases and while freezing time increase sharply. The different parameters have  to be chosen such that performance of solar air heater can be optimized.

Influence of twisted tape fins on heat transfer and friction factor characteristics for impinging jet solar air heater

2021 ◽  
pp. 095440892199528
Author(s):  
MM Matheswaran ◽  
TV Arjunan ◽  
Mukesh K Sahu
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Impinging Jet ◽  
Operating Conditions ◽  
Design Parameters ◽  
Twisted Tape ◽  
Solar Air Heater ◽  
Air Heater ◽  
Twist Ratio ◽  
Pitch Ratio

In this work, an experimental study was carried out to investigate the enhancement of heat transfer and friction factor characteristics of an impinging jet solar air heater integrated with twisted tape fins. During the analysis, the Reynolds number fin design parameters namely twist ratio (Y), and pitch ratio (py) are varied from 3500 –13500, 5.5–9.5, and 0.1–0.3, respectively. During the experimentation, the constant heat flux of 1000 W/m2 was maintained on the absorber plate. From the results, it was observed that the heat transfer rate increases while increasing the twist ratio up to 7.5 and further increase in twist ratio diminishes the performance. It was also concluded that the rise in pitch ratio (py) deteriorates the rate of heat transfer. The present work enhances the heat transfer and friction factor by the maximum of 1.9 and 1.81 times as compared with the conventional jet impingement solar air heater at identical operating conditions.

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