Solar Engineering Of Thermal Processes

Several simplified design procedures for solar energy systems require monthly average meteorological data. Monthly average daily totals of the solar radiation incident on a horizontal surface are available. However, radiation data on tilted surfaces, required by the design procedures, are generally not available. A simple method of estimating the average daily radiation for each calendar month on surfaces facing directly towards the equator has been presented by Liu and Jordan [1]. This method is verified with experimental measurements and extended to allow calculation of monthly average radiation on surfaces of a wide range of orientations.

Calculation of monthly average insolation on tilted surfaces

Comparison of Support Vector Machine and Extreme Gradient Boosting for predicting daily global solar radiation using temperature and precipitation in humid subtropical climates: A case study in China

Solar water heating (SWH) systems have a widespread usage and applications in both domestic and industrial sectors. According to Renewable Energy Policy Network data (2010), 70 million houses worldwide were reported to be using SWH systems. Solar water heating is not only environmentally friendly but requires minimal maintenance and operation cost compared to other solar energy applications. SWH systems are cost effective with an attractive payback period of 2–4 years depending on the type and size of the system. Extensive research has been performed to further improve the thermal efficiency of solar water heating. This paper presents a detailed review exclusively on the design aspects of SWH systems. The first part of the paper provides a consolidated summary on the development of various system components that includes the collector, storage tank and heat exchanger. The later part of this paper covers the alternative refrigerant technology and technological advancements in improving the performance as well as the cost effectiveness of the SWH system.

Recent advances in the solar water heating systems: A review

A comprehensive review on solar cookers

Estimation of solar radiation and optimum tilt angles for south-facing surfaces in Humid Subtropical Climatic Region of India

Computation of glass-cover temperatures and top heat loss coefficient of flat-plate solar collectors with double glazing

Approximate method for computation of glass cover temperature and top heat-loss coefficient of solar collectors with single glazing

This study demonstrates the performance comparison of the models to estimate monthly mean diffuse solar radiation on a horizontal surface for Humid-Subtropical Climatic Region of India. Meteorological data (global and diffuse solar radiation) were observed for the city of Aligarh (27.89°N, 78.08°E) at the Heat Transfer and Solar Energy Laboratory, Department of Mechanical Engineering, Aligarh Muslim University, Aligarh. The mean global, beam and diffuse solar radiation values for Aligarh were observed as 22.12 MJ/m2-day, 14.20 MJ/m2-day and 7.92 MJ/m2-day respectively. The mean values of sky-clearness index, diffuse fraction and diffusion coefficient were found to be 0.69, 0.37 and 0.25, respectively. The region exhibits abundant potential for solar energy utilization with favorable sky conditions. Diffuse solar radiation models with single input parameter (in the form of global solar radiation) were analyzed for suitability of estimation. 100 typical models were selected from the literature which correlated diffuse fraction (ratio of horizontal diffuse to global solar radiation) to sky-clearness index (ratio of global to extraterrestrial solar radiation). The objective here was to find the most precise model which is suitable to assess diffuse solar radiation in the region considered. Distinctive statistical evaluation of the models was performed in terms of well-known statistical indicators. Further, the scaled values of statistical indicators were used to calculate Global Performance Indicator (GPI). GPI of the selected models lied in the range of from −4.2987 to 2.6606 with the highest value representing the best performing model. Models were subsequently ranked in order of descending GPI. This study helps to recognize the significance of diffuse solar radiation models where the absence of required equipment as well as high cost of operation and maintenance represents a critical barrier for measurement. The outcomes of the present study are valuable for locations within the developing countries and remote areas with similar climatic conditions.

Comparison of empirical models to estimate monthly mean diffuse solar radiation from measured data: Case study for humid-subtropical climatic region of India

Naiem Akhtar

Papers

Estimation of solar radiation and optimum tilt angles for south-facing surfaces in Humid Subtropical Climatic Region of India

Computation of glass-cover temperatures and top heat loss coefficient of flat-plate solar collectors with double glazing

Approximate method for computation of glass cover temperature and top heat-loss coefficient of solar collectors with single glazing

Comparison of empirical models to estimate monthly mean diffuse solar radiation from measured data: Case study for humid-subtropical climatic region of India

Estimation of diffuse solar radiation in humid-subtropical climatic region of India: Comparison of diffuse fraction and diffusion coefficient models