Evaluation of Optical Transmissivity of Transparent Materials on the Performance of Solar Flat Plate Collectors

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Saboor Shaik ◽  
Manvendra Bhardwaj ◽  
Somya Agarwal ◽  
Raja Sekhar Yendaluru ◽  
Md. Hasanuzzaman ◽  
...  
Keyword(s):  
Flat Plate ◽  
Thermal Efficiency ◽  
Tamil Nadu ◽  
Optical Efficiency ◽  
Heating Systems ◽  
High Iron ◽  
Thermal Energy Conversion ◽  
Acrylic Glass ◽  
Selection Of ◽  
Peak Summer

Abstract The energy gain of domestic solar water heating systems is determined by solar to thermal energy conversion and glazing optical efficiency. For this study, solar transmission properties of different transparent glazing materials such as acrylic, low-iron, medium-iron, and high-iron glasses were measured. The collector thermal efficiency under natural convection mode was compared for different transparent covers determined by numerical simulation using the Hottel–Whillier–Bliss equation. The low-iron glass (LiG-12 mm) has 16.3% and 20% higher thermal efficiency than medium- (MiG-12 mm) and high-iron glasses (HiG-12 mm), respectively, for a peak summer day. The effect of glass thickness on thermal performance is noteworthy in glasses than in acrylic glass sheets. Low-iron content glass with 6 mm thickness has the highest thermal and optical efficiency of 63.2% and 75.65%, respectively, for the collector optimum tilt for Vellore city in Tamil Nadu, India. The results are useful in the selection of glass covers for energy-efficient solar flat plate collectors.

scholarly journals An experimental study of the thermal performance of the square and rhombic solar collectors

2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 487-494 ◽  
Author(s):  
Aminreza Noghrehabadi ◽  
Ebrahim Hajidavaloo ◽  
Mojtaba Moravej ◽  
Ali Esmailinasab
Keyword(s):  
Experimental Study ◽  
Flat Plate ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Performance ◽  
Thermal Efficiency ◽  
Solar Collectors ◽  
Heating Systems ◽  
Solar Water Heating

Solar collectors are the key part of solar water heating systems. The most widely produced solar collectors are flat plate solar collectors. In the present study, two types of flat plate collectors, namely square and rhombic collectors are experi?mentally tested and compared and the thermal performance of both collectors is investigated. The results show both collectors have the same performance around noon (?61%), but the rhombic collector has better performance in the morning and afternoon. The values for rhombic and square collectors are approximately 56.2% and 53.5% in the morning and 56.1% and 54% in the afternoon, respectively. The effect of flow rate is also studied. The thermal efficiency of rhombic and square flat plate collectors increases in proportion to the flow rate. The results indicated the rhombic collector had better performance in comparison with the square collector with respect to the mass-flow rate.

scholarly journals Development of Thermal Performance Metrics for Direct Gas-Fired Circulating Heaters

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 588
Author(s):  
Benjamin C. Smith ◽  
Brett C. Ramirez ◽  
Steven J. Hoff
Keyword(s):  
Mass Flow ◽  
Measurement System ◽  
Thermal Efficiency ◽  
Performance Metrics ◽  
Standardized Test ◽  
Flow System ◽  
Standard Test ◽  
Testing System ◽  
Measurement Systems ◽  
Selection Of

Many climate-controlled agricultural buildings use direct gas-fired circulating heaters (DGFCH) for supplement heat. There is no standardized test to calculate thermal efficiency for these heaters. This study aimed to develop a measurement system and analytical analysis for thermal efficiency, quantify the measurement uncertainty, and assess economics of DGFCH efficiency. The measurement system developed was similar to the ASHRAE 103 standard test stand with adaptations to connect the apparatus to the DGFCH. Two different propane measurement systems were used: input ratings < 30 kW used a mass flow system and input ratings > 30 kW used a volumetric gas meter. Three DGFCHs (21.9, 29.3, 73.3 kW) were tested to evaluate the system. Thermal efficiencies ranged from 92.4% to 100.9%. The resulting uncertainty (coverage factor of 2; ~95% Confidence Interval) ranged from 13.1% to 30.7% for input ratings of 56.3 to 11.4 kW. Key sources of uncertainty were propane and mass flow of air measurement. The economic impact of 1% difference in thermal efficiency ranged from USD $61.3 to $72.0 per heating season. Refinement of the testing system and procedures are needed to reduce the uncertainty. The application of this system will aid building designers in selection of DGFCHs for various applications.

Comparative Thermodynamics for Brayton and Rankine Cycles

1990 ◽  
Vol 112 (1) ◽  
pp. 94-99 ◽  
Author(s):  
E. W. Beans
Keyword(s):  
Thermodynamic Model ◽  
Thermal Efficiency ◽  
Unit Volume ◽  
Work Conditions ◽  
Comparison Analysis ◽  
Independent Variables ◽  
Equal Work ◽  
Maximum Work ◽  
Cycle Temperature ◽  
Selection Of

The thermal efficiency, work per unit mass, and work per unit volume of the simple Rankine and Brayton cycles are expressed in terms of seven independent variables using a simplified thermodynamic model. By requiring equal efficiency, equal work conditions, and the same maximum cycle temperature for both cycles, two necessary relationships are established between the seven independent variables. These two relationships along with two maximum work conditions produce a method for comparing required and selected properties. These comparisons provide useful guidelines for the selection of the cycle and cycle fluids. The comparison analysis shows that for a given application the more attractive cycle is strongly dependent upon the fluids selected.

scholarly journals Dryland Farmers on Climate Resilient Practices – An Adoption Study at an Industrialized Taluk of Tamil Nadu

2020 ◽  
pp. 169-177
Author(s):  
D. Alagu Niranjan ◽  
Dipak Kumar Bose
Keyword(s):  
Correlation Analysis ◽  
Tamil Nadu ◽  
Survey Design ◽  
Conservation Tillage ◽  
Primary Data ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Adoption Study ◽  
Planting Materials ◽  
Selection Of

Aims: To study the adoption of climate resilient practices by the farmers in the dryland region. Study Design: Cross-sectional survey design was used for the present descriptive study. Place and Duration of Study: The study was conducted in Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad (Prayagraj) during the year of 2018 and for the period of 6 months. Methodology: The study used direct interview method with the subjects using a structured and pre-tested interview schedule for primary data collection in the sampled area which is an industrialized taluk of Tamil Nadu. The selection of area was purposeful, whereas, selection of villages was random and 15 respondents form each village was convenient. The collected data was tabulated and interpreted using descriptive statistics and correlation analysis. Results: The results of the study suggest that there is a poor adoption level of climate resilient practices existing among the dryland farmers. While, some of the practices like incorporation of residues in to soil instead of burning, brown and green manuring, conservation tillage, temperature tolerant varieties, farm machinery custom hiring centre, location specific intercropping systems, crop rotation, usage of better planting materials, prophylaxis, custom hiring centre and weather based insurance were adopted to some extent. Though there was no specific intervention to sensitize on these practices, adoption of above mentioned practices were found which could be due to the passive adaptation by the farmers of the locality over years. And the results of correlation analysis revealed that there is a significant relationship between adoption of climate resilient practices and variables like the respondents’ education, exposure to mass media exposure, contacts with extension agents, innovativeness level, risk orientation and scientific orientation at 0.01% level of significance. Conclusion: The results of the study will definitely help in evaluating government projects (as baseline) like National Initiative on Climate Resilient Agriculture, and strengthening programme planning and implementation in climate change.

scholarly journals Determining the Effect of Inlet Flow Conditions on the Thermal Efficiency of a Flat Plate Solar Collector

Fluids ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 67 ◽  
Author(s):  
Mohammad Alobaid ◽  
Ben Hughes ◽  
Andrew Heyes ◽  
Dominic O’Connor
Keyword(s):  
Flat Plate ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Maximum Temperature ◽  
Inlet Temperature ◽  
Flow Conditions ◽  
Riser Pipe ◽  
Computational Fluid Dynamics Cfd ◽  
Flat Plate Solar Collector ◽  
Feed Temperature

The main objective of this study was to investigate the effect of inlet temperature (Tin) and flowrate ( m ˙ ) on thermal efficiency ( η t h ) of flat plate collectors (FPC). Computational Fluid Dynamics (CFD) was employed to simulate a FPC and the results were validated with experimental data from literature. The FPC was examined for high and low level flowrates and for inlet temperatures which varied from 298 to 373 K. Thermal efficiency of 93% and 65% was achieved at 298 K and 370 K inlet temperature’s respectively. A maximum temperature increase of 62 K in the inlet temperature was achieved at a flowrate of 5 × 10−4 kg/s inside the riser pipe. Tin and m ˙ were optimised in order to achieve the minimum required feed temperature for a 10 kW absorption chiller.

Experimental Studies on the Thermal Performance of the Balcony-Type Flat-Plate Solar Water Heater

2014 ◽  
Vol 953-954 ◽  
pp. 111-114
Author(s):  
Sheng Xian Wei ◽  
Fen E Hu ◽  
Dong Yu Li ◽  
Hui Li
Keyword(s):  
Water Temperature ◽  
Flat Plate ◽  
Temperature Rise ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Water Heating ◽  
Solar Water Heating ◽  
Solar Water ◽  
Daily Water Temperature ◽  
Daily Water

Based on the test methods for solar water heating systems, the unsteady thermal efficiency, the daily thermal efficiency and the daily water temperature rise of the balcony-type solar water heating system with a flat-plate solar collector fixed at a large tilt angle (≥60o) have been discussed by the experimental test in Kunming. The results indicate that the average daily thermal efficiencies of the solar collector installed at 60o, 70o, 80o and 90o are around 0.35, 0.39, 0.34 and 0.40. The intercept and the slope of the unsteady thermal efficiency equations are about 0.36~0.44 and 1.62~4.01W·°C-1·m-2. The average daily water temperature rise is 25.2°C, 20.1°C, 18.2°C and 17.4°C for the solar collector fixed at 60o, 70o, 80o and 90o.

Design of power converters for induction heating applications taking advantage of wide-bandgap semiconductors

2017 ◽  
Vol 36 (2) ◽  
pp. 483-488 ◽  
Author(s):  
Oscar Lucia ◽  
Hector Sarnago ◽  
José M. Burdio
Keyword(s):  
Induction Heating ◽  
Wide Bandgap ◽  
Power Supplies ◽  
Disruptive Technology ◽  
Content Type ◽  
Heating Systems ◽  
Future Design ◽  
Bandgap Semiconductors ◽  
Heating Technology ◽  
Selection Of

Purpose Wide-bandgap (WBG) semiconductors have emerged as a disruptive technology in the power electronics sphere. This paper aims to analyse and discuss the importance for induction heating systems and gives some examples and highlights some future design trends and perspectives. Design/methodology/approach The benefits of WBG semiconductors are reviewed with a special emphasis on induction heating applications. Findings WBG devices enable the design of higher-performance induction heating power supplies. A significant selection of the reported converters is discussed, highlighting the benefits of this technology. Originality/value This paper highlights the benefits of WBG semiconductors and their potential to change and improve induction heating technology in the next years.

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