Comprehensive review on ideas, designs and current techniques in solar dryer for food applications.

Due to the expansion of residents, the consumption of non-renewable energy increased enormously, thus indirectly increasing pollution and affecting the surroundings. To reduce pollutions in the surroundings, it is recommended to choose non-conventional energy sources. By satisfying this, we can probably decrease the non-renewable sources of energy, by consuming the solar power in day-to-day life in the application of food drying process. In this review article, we have discussed the classification of solar dryer and the impact of design modifications performed in the components of solar dryer and assessed the various types of solar dryer performance, cost estimations and designs performed in solar dryer of food applications which were not discussed in the earlier research. The primary and critical task in designing the solar dryer is to achieve higher efficiency at minimum cost. Hence, proper analysis of drying application, selection of suitable components and suitable design must be carried out to attain efficient dryer. Considering these characteristics, this paper primarily focuses on the effective design parameters incorporated with various efficiency enhancement processes of the solar dryer in the applications of food drying techniques. Thus, this review paper delivers the various classifications, design parameters, performance enhancement methods, properties and valuable assets of solar dryer, which helps to develop the sustainable green eco-friendly environment most primarily, in the application of food drying process. This review article concreted the way for upcoming considerations and provided the techniques for the studies to convey the work for promoting method enhancements.

Performance and exergy analysis of solar-operated vacuum fan and external condenser integrated double-slope solar still using various nanofluids.

Productivity, distillate exergy, and energy efficiency of the conventional passive single-basin double-slope solar still is minimum, due to low evaporation and condensation rate. This research article attempts to increase the production rate, distillate exergy, and energy efficiency of the single-basin glasswool-insulated double-slope solar still by attaching novel solar-operated vacuum fan, external condenser and adding 0.1% volume concentration of copper oxide, aluminium oxide, and zinc oxide nanofluid. Inclusion of vacuum fan and external condenser enhances the production rate in the modified solar still. It is evident that as the vacuum fan exhales the vapour in the basin, the temperature of water in the basin and transparent glass are reduced significantly and so the vaporization amount increases considerably. It makes that a large amount of vapour is extracted by the vacuum fan and allowed to pass though the condenser, and therefore, the entire condensate of the solar still is increased significantly. To attain a comparative study, conventional and modified double-slope solar still of identical dimensions were developed utilizing aluminium and an experimental investigation carried out during the peak of summer. The inclusion of solar-operated vacuum fan and external condenser in the modified glasswool insulated double-slope solar still enhances the maximum energy efficiency, exergy efficiency, and cumulative production by 28.37%, 78.60%, and 64.29% due to enhancement in the evaporation rate of liquid in the solar still basin. Also, the addition of 0.1% volume concentration of copper oxide, aluminium oxide, and zinc oxide nanofluid in the conventional double-slope solar still possess the maximum increase in the energy efficiency and exergy efficiency by 20.96%, 18.01%, 10.76% and 52.53%, 38.52%, 30.35% as compared to conventional solar still without nanofluid. It is primarily due to increase in the thermal conductivity and radiative property of nanofluid. The result also signifies that the addition of 0.1% volume concentration of copper oxide, aluminium oxide, and zinc oxide nanofluid in the modified double-slope solar still possess the maximum enhancement in the energy efficiency and exergy efficiency by 21.33%, 19.36%, 17.03% and 50.11%, 36.82%, 23.75% as compared to modified solar still without nanofluid. Combined effect of using solar-operated vacuum fan, water cooled condenser, and 0.1% volume concentration of copper oxide, aluminium oxide, and zinc oxide nanofluid in the double-slope solar still enhances the maximum production rate and cumulative production by 59.26%, 55.56%, 51.85% and 96.43%, 82.14%, 75% as compared to conventional double-slope solar still. Among the three different nanofluids, the copper oxide nanofluid produced the highest cumulative production, energy efficiency, and exergy efficiency.

Review on phase change materials for solar energy storage applications.

The energy storage application plays a vital role in the utilization of the solar energy technologies. There are various types of the energy storage applications are available in the todays world. Phase change materials (PCMs) are suitable for various solar energy systems for prolonged heat energy retaining, as solar radiation is sporadic. This literature review presents the application of the PCM in solar thermal power plants, solar desalination, solar cooker, solar air heater, and solar water heater. Even though the availability and cost of PCMs are complex and high, the PCMs are used in most solar energy methods due to their significant technical parameters improvisation. This review's detailed findings paved the way for future recommendations and methods for the investigators to carry work for further system developments.

Comprehensive review on various parameters that influence the performance of parabolic trough collector.

Among the different kinds of renewable energy sources, solar energy plays a major role because it is safe and inexpensive at all times. Several techniques are developed for steam and electricity generation by solar energy, in which the parabolic trough collector is an advantageous method for generating steam and electricity. Different types of collectors for various temperatures, in which PTCs are used to produce medium temperature ranges using the readily available solar energy, were developed, produced, and tests. Many theoretical and experimental studies have been carried out to improvise parabolic trough collectors' optical and thermal characteristics. The modifications are reviewed in this paper to enhance the design modification, optical and thermal properties utilized in the collector. This analysis paper also elucidates the use of PTC desalination, various integrated parabolic trough collector methods for power generation, and the economic aspects of parabolic trough collector.