scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Study on Effect of Number of Transparent Covers and Refractive Index on Performance of Solar Water Heater

01 Sep 2014-Vol. 2014, pp 1-11
TL;DR: In this article, an attempt has been made to optimize the number of transparent covers and refractive index to improve the optical efficiency and thermal efficiency for the collector, which is one of the important applications in solar thermal system.
Abstract: Liquid flat plate collector (solar flat plate collector) is one of the important applications in solar thermal system. The development in solar photovoltaic is an emerging challenge for the solar thermal system. In the current work an attempt has been made to optimize the number of transparent covers and refractive index to improve the optical efficiency and thermal efficiency for the collector. Performance of the liquid flat plate collector at VIT University Vellore has been simulated numerically for January 21st at an interval of half an hour with different numbers of transparent covers (0–3) and different refractive index values ranging from 1.1 to 1.7. The formulation and solutions are developed with simple software Microsoft Office Excel to result the performance characteristics. The result shows that the efficiency of the flat plate collector increases with an increase in number of covers and decreases after an optimum number of covers. It also decreases with an increase in refractive index. The combination of optimum number (two) and lower refractive index (1.1) results improved useful heat.

Content maybe subject to copyright    Report

Citations
More filters
Journal ArticleDOI
TL;DR: In this paper, an attempt has been made to consolidate the global trends and practices that has been underwent incorporating Phase change materials (PCMs) in solar thermal systems in order to enhance the performance of the solar heating systems by acting as thermal storage batteries.
Abstract: Solar thermal systems (STSs) are gaining boom in the globalized market since last two decades to combat the menace of global warming. Considerable research has been carried out in the field of solar thermal system for efficiency enhancement. Improvement in terms of efficiency and performance would make solar thermal systems a better option for replacing the conventional energy systems. Phase change Materials (PCMs) have emerged as an alternative to enhance the performance of the solar heating systems by acting as thermal storage batteries. In this review article an attempt has been made to consolidate the global trends and practices that has been underwent incorporating Phase change materials (PCMs) in solar thermal systems. Research on PCM based solar cooker has found to be extinct. PCM based PCM based high temperature power plant applications are on current trends of research. Application of phase change materials for low, medium and high temperature solar thermal systems are comprehensively reviewed and discussed in this article. As well the environmental benefits in terms decline in CO2 emission, due to the use of STS in day-today life and the economic analysis of PCM based STS in terms of cost and payback period is presented.

117 citations

Journal Article
TL;DR: In this article, a double glaze system was introduced and optimized the space between the absorber plate to glass cover (1) and glass cover were considered to analyze the overall top loss heat transfer coefficient (U t ).
Abstract: Solar energy can be converted into useful energy in the form of thermal energy. One of the most efficient methods is to harvesting heat energy by using solar flat plate collector. The function of solar collector is to heat water from the atmospheric temperature. The heated water can be used for domestic and industrial applications etc. The efficiency of the solar collector is depend with many parameters such as  number of glass cover, wind velocity, space  between absorber plate to the glass cover and overall top loss heat transfer coefficient out of which top loss heat transfer coefficient top loss (U t ) plays an important role for design of solar collector. Taking this point under consideration the present work is to reduce the overall top loss heat transfer coefficient and improve the collector efficiency. A double glaze system was introduced and optimized the space between the absorber plate to glass cover (1) and glass cover (2)were considered to analysis the overall top loss heat transfer coefficient (U t ). The single and double glazing solar flat plate collectors were fabricated with same dimensions and installed at a latitude angle of 12 degree facing towards N-S direction. The experiment has been carried out between 10.00 AM to 4.00 PM with thermosyphon principle. The result shows that the efficiency of double glazing is higher compared to single glazing system with same solar intensity. The higher efficiency has obtained because of the overall top loss heat transfer coefficient was reduced in double glazing system. However, the efficiency of collector is not constant; it varies with wind velocity, convective, radiative heat transfer coefficient and solar intensity.Â

27 citations

Journal ArticleDOI
TL;DR: In this paper, a novel gravity-based passive solar tracking mechanism is proposed to minimize the tracking load and error by controlling in dripping rate or filling rate of liquid in the gravity system.

9 citations

Journal ArticleDOI
TL;DR: In this article , the authors present a comprehensive review and consolidates numerous advanced cavity receivers for linear concentrators and discuss the influence of different design and operating parameters on the performance of the receiver or the entire concentrator.

3 citations

Dissertation
01 Jan 2015

1 citations


Cites background from "Study on Effect of Number of Transp..."

  • ...Therefore, the rays change from visible range to infrared range to which the glass acts as opaque resulting in low solar radiation transmission [13]....

    [...]

  • ...this absorption, reflection, and transmissivity of solar radiation through the transparent cover reduces the transmissivityabsorptivity(τα) product[13]....

    [...]

References
More filters
Journal ArticleDOI
TL;DR: In this paper, the effect of the zinc precursor type, the aging of the starting solution, the substrate temperature and a vacuum-annealing treatment on the electrical, morphological, structural and optical properties was studied, in order to obtain conductive and transparent zinc oxide thin films.

2,780 citations

Book
13 Jan 2009
TL;DR: The revision of the hallmark text on solar energy has been done keeping in mind the current scenario in solar energy requirements as discussed by the authors.As a result the book is updated with the energy scenario and the various applications of solar energy being used today.
Abstract: The revision of this text hallmark text on Solar Energy has been done keeping in mind the current scenario in Solar Energy requirements. As a result the book is updated with the energy scenario and the various applications of solar energy being used today. Numerous new topics comparison tables solved and unsolved problems, have been added and changes have been made to cater to the changing requirements of the students. In all it is the most updated and comprehensive yet concise book on the subject.

582 citations


"Study on Effect of Number of Transp..." refers background in this paper

  • ...(10) In the above formula A, B, C [10] are constant whose values are determined on a monthly basis, these values change for every month depending on the season....

    [...]

  • ...The first step in the numerical calculation [10] is to find the declination for day number using the below formula, the day number indicates the day of the year from day 1 to day 365, to the corresponding date....

    [...]

Journal ArticleDOI
TL;DR: The most promising solutions are based on the principle of mixing bulk material with air on a subwavelength scale in order to obtain the very low effective refractive indices suitable as anti-reflection (AR) coatings for glazing as discussed by the authors.

68 citations


"Study on Effect of Number of Transp..." refers methods in this paper

  • ...[4] worked with the ways to Hindawi Publishing Corporation Journal of Renewable Energy Volume 2014, Article ID 757618, 11 pages http://dx....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the effects of absorption of solar radiation on inner and outer surface temperatures and consequently on convective and radiative heat transfer coefficients have been studied over a wide range of independent variables.

54 citations


"Study on Effect of Number of Transp..." refers background in this paper

  • ...Akhtar and Mullick [8] studied the effect of absorption of solar radiation in glass cover....

    [...]

Journal ArticleDOI
TL;DR: In this paper, a flat-plate solar collector with a black absorber considering the glass cover as an absorbing-emitting media is presented, where the optical constants of a clear glass window are analyzed as a non-gray plane-parallel medium subjected to solar and thermal irradiations.

49 citations


"Study on Effect of Number of Transp..." refers background in this paper

  • ...Khoukhi and Maruyama [6] calculated the instantaneous efficiency of solar collector in steady state by dividing the energy that reaches the absorber by the radiative heat flux at the outside surface of the glass cover and compared with the classical approach in which the top loss coefficient U t is assumed to be a linear function of the temperature difference between the plate and the surroundings....

    [...]

  • ...Khoukhi and Maruyama [6] calculated the instantaneous efficiency of solar collector in steady state by dividing the energy that reaches the absorber by the radiative heat flux at the outside surface of the glass cover and compared with the classical approach in which the top loss coefficient 𝑈 𝑡 is assumed to be a linear function of the temperature difference between the plate and the surroundings....

    [...]