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Considering the global fuel crisis, countries have made it imperative to exploit solar energy correctly, which has emerged as the most significant renewable energy source in recent times. Utilizing solar energy to heat the water appropriately to reduce global energy consumption is a challenge most countries face. Research has, therefore, been done extensively to maximize the performance of solar water heating through various applications. Several methods were enumerated and applied in this review study to determine how to enhance the performance of solar water heaters. Eleven techniques for improvement were identified. They are as follows: using nanofluid with phase change material; improving the collector design; coating; lowering the inlet water temperature; switching to a combined system in place of the conventional gas heating system; utilizing a dual glass cover; utilizing the upstream delta wing; utilizing the evacuated tube collector; utilizing the heat exchanger; utilizing the photovoltaic glass unit; and integrating the solar water heater and tubular lighting device into one unit. According to the essential results, using an absorption cooling system with solar power resulted in 34% electricity savings. The absorption system was enhanced, and the COP was raised to 2.75 by implementing the solar water heating system. Solar heating systems combined with PCM achieved the highest efficiency rating of 65%. The dryer system's CO2 emissions were lowered by about 34% when adding a solar collector. The solar water heater's thermal efficiency was increased by 22.53% by a CuO/H2O nanofluid. [ABSTRACT FROM AUTHOR]

The requirement of getting continuous electricity at low cost is essential but challenging. Especially in the undeveloped countries there is no sufficient electricity for the people to do their daily regular works. In order to overcome this problem different renewable energy sources are sought and being explored. One of the approaches is to have a cooking system that is energized from the solar power, not directly using a solar cooker but by storing the energy in the form of heat that can be utilized as per requirement. This paper reports the design and fabrication of an alternative system to generate heat using solar radiation. This chulha is helpful in effective heating with the help of solar radiations at lower costs. A cooking technology is presented consisting of a solar panel directly connected to an electric heater inside of a well‐insulated chamber. An insulated container with fixed amount of oil is heated up. The heat is found to be retained in the chamber even after sun set which is sufficient for heating water for making tea. The possible causes of temperature drop and possible remedy has been pointed out and discussed in this paper. [ABSTRACT FROM AUTHOR]

The performance characteristics of a novel solar water desalination system has been investigated experimentally. The desalination unit consisted of a square basin-pyramid solar still coupled with a solar heater. Different DI water based mono and hybrid nanofluids were prepared using CuO and GO nanoparticles following the two-step method. DI water when employed as the heat transfer fluid in the system, improved the distillate water yield by about 28.80% relative to the conventional solar still. Out of all the considered CuO mono-nanofluids, the 1.0 wt.% concentration resulted in the maximum increment of about 78.80% in the distillate water yield followed by 1.5 wt.% (62.05%) and 0.5 wt.% (53.30%) respectively. Utilizing the CuO+GO hybrid nanofluid, resulted in maximum increment of about 127.46% at 25:75 nanoparticle proportion followed by, 50:50 (101.33%) and 75:25 (89.30%) respectively, while employing the 1.0 wt.% GO mono-nanofluid, resulted in an increment of about 54.93% in the distillate water yield. The pumping power of the prepared nanofluids was found to be the function of their concentration. Hence, the performance index was evaluated for all the tested heat transfer fluids followed by an economic analysis of all the considered cases. The purity of the produced distilled water was also assessed by comparing with the Bureau of Indian Standards. Finally, the study proposed the best suitable heat transfer fluid for the investigated system and suggested the possible futuristic research objectives. [ABSTRACT FROM AUTHOR]

This research investigates the performance of hybrid nanofluids in solar heating systems, focusing on heat transfer effectiveness and thermodynamic irreversibility. Solar energy is widely favored for its eco-friendly nature, but traditional operating fluids in solar heaters lack sufficient thermal conductivity. To address this issue, modified fluids called nanofluids have been developed. This study proposes a novel approach that combines nanofluids and turbulators to evaluate solar system performance. ANSYS FLUENT 18.0 solver is employed, utilizing the iterative time advancement technique for solving the set of equations. Entropy generation analysis is employed as a promising methodology. Aluminum-oxide nanoparticles are examined for their impact on heat transfer, pressure drop, and entropy generation in a rib channel at Re= 20,000. To enhance heat transfer, the effects of angled-ribs are assessed using the thermal enhancement factor, which considers heat transfer rate and friction factor. Results indicate that triangular-shaped ribs exhibit superior thermal performance. Furthermore, the study investigates the influence of nanofluid volume fraction and heat flux distribution on Nusselt number, pressure drop, thermal performance factor, and entropy generation. Increasing the nanofluid fraction enhances the Nusselt number, pressure drop, and performance evaluation criterion (PEC). Based on the results of a quantitative analysis, it can be concluded that 4% nanoparticle volume fraction results in an increase of 4.6%, 11.63%, and 18.5% in Nusselt number in triangular and rectangular channels without teeth and with teeth, respectively. Additionally, a positive heat flux gradient improves heat transfer and reduces entropy generation, suggesting that adjusting the boundary condition can enhance energy and exergy efficiency. Overall, this study demonstrates the benefits of entropy generation analysis for assessing thermal systems and implementing hybrid nanofluids with turbulators in solar heating, contributing valuable insights to sustainable energy technologies.

The study presents a comprehensive thermal performance analysis of a U-pipe Evacuated Tube Solar Collector (U-ETSC) system, integrated with Phase Change Material (PCM), for satisfying water demand in domestic applications. The innovative approach of incorporating PCM aims to enhance the system's efficiency during night or off-sunny hours, addressing a common limitation in solar heater systems. The research primarily focuses on the impact of varying mass flow rates of the heat transfer fluid (HTF) on the thermal dynamics of the system. Experimental results reveal that as the mass flow rates of HTF increase from 0.5 to 1 and then to 1.5 liters per minute, there is a notable change in the phase transition times of the PCM. Specifically, the melting time of the PCM is increased by 13% and 16% for the respective flow rates, suggesting a delayed response in energy absorption. Conversely, the solidification time of the PCM is reduced by 16% and 18% respectively, indicating a faster release of stored thermal energy. This behavior underscores the PCM's significant role in stabilizing the system's thermal output during varying solar intensities. The findings of this study highlight the potential of integrating PCM in U-ETSC systems to achieve a more consistent and reliable supply of hot water for domestic purposes, especially during periods when solar irradiance is low or absent.

Conventional flat plate solar air collectors have advantages such as low cost and simple design. However, their thermal efficiency is lower than that of other designs. The thermal efficiency of these collectors can be increased by detailed examination of parameters such as the shape, size, arrangement and material of the air duct. In this study, it is aimed to improve the thermal efficiency of solar air collectors. The effect of louver baffles, which were not previously used in solar air collectors, on thermal efficiency was investigated numerically via computational fluid dynamics. Three different solar air collectors with flat plates, segmented baffles, and louver baffles were compared in terms of thermal efficiency. In addition, pressure drops in solar air collectors were investigated. The mass flow rate of the air in all collectors is assumed to be 0.04 kg/s. Analyzes were carried out between 09:00 and 16:00. The thermal efficiency values obtained during the day for solar air collectors with flat plate, segmented baffles and louver baffles are 27.66%–56.35%, 29.57%–58.82% and 30.09%–59.47%, respectively. The daily thermal efficiency values obtained for solar air collectors with flat plate, segmented baffles and louver baffles are 46.98%, 49.18% and 49.87%, respectively. The pressure drop for solar air collectors with flat plate, segmented baffles and louver baffles were found to be 4.62, 18.82 and 5.96 Pa, respectively. Based on the data obtained from this study, louver baffles are recommended for use in solar heating applications due to their high thermal efficiency and low pressure drop. [ABSTRACT FROM AUTHOR]

The performance of water heating systems must be evaluated considering energy consumption and efficiency in storing and distributing hot water, together with building and climate characteristics. This work aims to analyse the performance of different water heating systems compared to electric showers, which are widely used in Brazil. Systems with individual gas heaters and solar heaters with electric backup and gas backup were analysed in multi-family buildings. In addition, the influence of thermal insulation of hot water pipes was verified. The analyses were conducted using the EnergyPlus programme, considering three Brazilian cities with different climates: Curitiba, Brasília, and Belém. The results showed that solar heaters are a low primary energy consumption alternative, especially if combined with gas heaters. However, electric showers are the most efficient option for larger buildings and cold-climate cities, where thermal losses in distribution are more significant. Monthly, an electric shower can save up to 1.82 kWh/m2 of electricity compared to a solar heating system with an electric backup. The insulation has a limited influence on the performance of short-length pipes (temperature difference less than 0.3 °C in the instantaneous gas system). For longer pipes, the absence of insulation significantly reduces the shower temperature (up to 2.47 °C in solar heating systems), mainly in cold-climate locations. It is concluded that the most suitable water heating system should be determined according to the climate and characteristics of the buildings, such as the size and length of the pipe. [ABSTRACT FROM AUTHOR]

Solar stills are used in distant and arid areas to convert brackish or salty water into potable water fit for human use in a simple, affordable, and effective manner. Even when PCM materials are used, typical solar systems still have minimal production per day. In this study, experimental tests were carried out in order to increase the performance of a single-slope solar still combined with PCM material (paraffin wax) and a solar-powered electric heater. Two identical single-slope solar stills were designed, fabricated, and tested under the same climatic conditions during the summer and spring seasons of 2021 in Al-Arish, Egypt. The first is a conventional solar still (CVSS), and the other is also a conventional still but with PCM and an electric heater (CVSSWPCM). Several parameters were measured during the experiments, including sun intensity, meteorological aspects, cumulative freshwater production, average glass, and water temperatures and PCM temperature. The improved solar still was evaluated at different operating temperatures and was compared to the conventional traditional one. There were four cases studied: one case without a heater (paraffin wax only) and three other cases with a heater operating at 58 °C, 60 °C, and 65 °C, respectively. The experimental results revealed that activating the heater inside the paraffin wax increased daily production (i) in the spring by 2.38, 2.66, and 3.1 times and (ii) and in the summer by 2.2, 2.39, and 2.67 times at the three above-mentioned temperatures respectively (when compared to the traditional still). In addition, the maximum rate of daily freshwater production was achieved at paraffin wax temperature of 65 °C in both spring and summer (Case 5). Finally, the economic evaluation of the modified solar still was carried out according to cost per litre. The modified solar still with a heater operating at 65 °C has a higher exergoeconomic value than the traditional one. The maximum CO2 mitigation in cases 1 and 5 was approximately 28 tons and 160 tons, respectively. [ABSTRACT FROM AUTHOR]

Concentrated collectors offer a broad variety of solar energy uses, including heating, cooling, power production, and water desalination. This study was conducted to construct and test a concentrated parabolic solar dish water heater. The aperture size of the dish is 4.556m², and a copper absorber has a surface area of 0.2278m², a volume of 0.015m³, and a concentrating ratio of 20. The water is heated up to 120°C at a solar radiation intensity of 700W/m² and a 20°C ambient temperature. The absorber's stagnation temperature reached 246°C in roughly 1500 seconds. The thermal efficiency of the system was found to be 46%. [ABSTRACT FROM AUTHOR]

This analysis focused on investigating thermal storage behaviour on phase change material along with Al2O3 as an additive. The experimental investigation was performed by three set temperature points, i.e. 40οC, 50οC and 60οC with the mass circulation rate through the tank of 5 kg/min, 3 kg/min and 2 kg/min. The forced circulation method was used to circulate the liquid, water was used as a working medium and Al2O3 as nano particle. Paraffin acts a phase change material to conduct the experimental procedure. The combination of paraffin with Al2O3 improves the latent heat storage of the material. The performance, with respect to charging and discharging of the material, was investigated and it was observed that the temperature location point of 50οC shows the best results in terms of charging and discharging phenomena, compared to other two temperature location points. During the process of charging, the maximum rate of heat transfer can be achieved by Al2O3 nanofluids. Paraffin along with Al2O3 are characterized by the best thermal storage behaviour during the latent heat storage at charging process and dissipation of heat during discharge process. The rapid cooling comparison for three set location points has been studied and best solidification was achieved at the point of 60οC,; this is due to the rapid cooling at higher elevation temperatures. The energy that was stored in thermal form is to be transferred with the aid of heat exchanger, a special type heat exchanger employed in this analysis to transfer the heat. From this analysis it is concluded that paraffin with Al2O3 are characterized by the best performance in terms of the charging and discharging phenomenon.

The performance of water heating systems must be evaluated considering energy consumption and efficiency in storing and distributing hot water, together with building and climate characteristics. This work aims to analyse the performance of different water heating systems compared to electric showers, which are widely used in Brazil. Systems with individual gas heaters and solar heaters with electric backup and gas backup were analysed in multi-family buildings. In addition, the influence of thermal insulation of hot water pipes was verified. The analyses were conducted using the EnergyPlus programme, considering three Brazilian cities with different climates: Curitiba, Brasília, and Belém. The results showed that solar heaters are a low primary energy consumption alternative, especially if combined with gas heaters. However, electric showers are the most efficient option for larger buildings and cold-climate cities, where thermal losses in distribution are more significant. Monthly, an electric shower can save up to 1.82 kWh/m2 of electricity compared to a solar heating system with an electric backup. The insulation has a limited influence on the performance of short-length pipes (temperature difference less than 0.3 °C in the instantaneous gas system). For longer pipes, the absence of insulation significantly reduces the shower temperature (up to 2.47 °C in solar heating systems), mainly in cold-climate locations. It is concluded that the most suitable water heating system should be determined according to the climate and characteristics of the buildings, such as the size and length of the pipe.

Solar power is considered as the most essential renewable energy in human life, particularly for daily activities. The application of solar water heater is significantly able to reduce the electric load of water heating so that this method is indirectly able to save energy needs. The biggest challenge is increasing the energy density of warm water storage. The best storage medium is paraffin, but it is constrained by the low thermal conductivity of the paraffin and also the wrapping media. This study focuses on efforts to improve thermal conductivity of paraffin as a heat storage medium by using nickel mixture at a ratio (volume) of 10 - 50%. Samples of paraffin and nickel paraffin mixture are inserted into the wrapper of aluminum 6063 material and then tested for heat absorption and release process. The best heat absorption is shown by the sample with the most nickel content, while in the heat release process the best performing sample is shown with a nickel mixture between 2040%. These results are directly related to the power rate of each sample. The results of this study can be used as a reference for increasing the thermal capacity of warm water storage from solar water heaters.

This analysis focused on investigating thermal storage behaviour on phase change material along with Al2 O3 as an additive. The experimental investigation was performed by three set temperature points, i.e. 40 °C, 50 °C and 60 °C with the mass circulation rate through the tank of 5 kg/min, 3 kg/min and 2 kg/min. The forced circulation method was used to circulate the liquid, water was used as a working medium and Al2 O3 as nano particle. Paraffin acts a phase change material to conduct the experimental procedure. The combination of paraffin with Al2 O3 improves the latent heat storage of the material. The performance, with respect to charging and discharging of the material, was investigated and it was observed that the temperature location point of 50 °C shows the best results in terms of charging and discharging phenomena, compared to other two temperature location points. During the process of charging, the maximum rate of heat transfer can be achieved by Al2 O3 nanofluids. Paraffin along with Al2 O3 are characterized by the best thermal storage behaviour during the latent heat storage at charging process and dissipation of heat during discharge process. The rapid cooling comparison for three set location points has been studied and best solidification was achieved at the point of 60 °C; this is due to the rapid cooling at higher elevation temperatures. The energy that was stored in thermal form is to be transferred with the aid of heat exchanger, a special type heat exchanger employed in this analysis to transfer the heat. From this analysis it is concluded that paraffin with Al2 O3 are characterized by the best performance in terms of the charging and discharging phenomenon. [ABSTRACT FROM AUTHOR]

Abstract The study of controlled methods of cocoa fermentation on a small scale is important to assess the maintenance of heat generated in the last days of fermentation. The research aimed to study the impact of spontaneous fermentation in controlled fermentation systems on the quality and acceptability of fermented cocoa beans. A 2×3 complete factorial design used different controlled fermentation systems (jacket system, solar heater and wooden box) and pulp reduction as variables. Samples were analyzed for fermentation index and volatile aroma composition profile using Headspace-Solid Phase Microextraction (HS-SPME) and Gas Chromatography-Mass Spectrometry (GC-MS). The profile of volatile compounds is evaluated for the studied variables using a multivariate Principal Components Analysis (PCA). The results showed increasing fermentation times in the jacket system seeing that it raised the fermentation rate and accelerated it to five days of fermentation combined with pulp reduction. The PCA analysis showed differences in the chemical composition of volatile compounds that were mainly associated with the reduction of the pulping process than the type of controlled system in four days of fermentation.

In this study, the energy analysis of a solar air heater with an absorber plate made of different obstacles was made. Absorber plate of the solar air heater was created with porous steel wool. Three different absorber plates were used for the experimental study. Complex plate (Type I) was used as the first type of absorber plate, less complex plate (Type II) as the second type absorber plate, and flat plate (Type III) the third type absorber plate. On these plates, which are manufactured as three different absorber plates, steel wools are placed in a complex and less complex way. One absorber plate was left empty. In the experiments, the mass-flow rate of the air passing through the air passage channels was taken as 0.05 kg/s and 0.025 kg/s, and the optimum flow rate was found as 0.05 kg/s. In order to make heater efficiency calculations, heater inlet temperature, outlet temperature, absorber plate temperature, ambient temperature and solar radiation values were measured. Efficiency values for different absorber plate were found between 23% and 74%. [ABSTRACT FROM AUTHOR]

In present paper, CFD technique is used to investigate the thermal efficiency of square shape protruded roughened absorber plate used in solar air heater. A 3-D CFD model of solar air heater with sixteen geometrical arrangements of roughness is analyzed under varying Reynolds number from 4000 to 20000 by using RNG k-epsilon method under transient conditions. The dimensionless geometrical parameters (P/e and e/D) having values vary from 38.8 to 61.1 and 0.016 to 0.036, respectively. The simulated results from the present study is further used to calculate the thermal efficiency of actual solar air heater with the help of computer program. Maximum enhancement in the value of performance parameters like, thermal efficiency, Nusselt number and friction factor are at minimum value of geometrical parameters (P/e) of 38.8 and at higher e/D value of 0.036. Design plot has been also proposed in order to design square shape protruded roughened solar air heater. [ABSTRACT FROM AUTHOR]

The solar heater is a system that generates hot water by converting solar energy to thermal energy. In these last few years, various ways have been developed to gather this natural energy. However, they can not be able to store the energy when the sun disappears. In this study, thermal system based on phase change materials that improves the hot water production and stores thermal energy is proposed. In order to describe phase change materials and considers the effects of inclination angle on the production and storing thermal energy a numerical study has been carried out using the ANSYS-Fluent software. In addition, details concerning the choice of calculation range, mesh size, boundary conditions and turbulence model have been provided. The numerical results have been compared with previous data that was very promising. [ABSTRACT FROM AUTHOR]

A novel system that applied fogging as a desalination technique was recently published, which could be considered a further development of the humidification-dehumidification desalination system (HDH), that provides an advantage through its ability to desalinate high salinity levels. This involves spraying hot saline water at high pressure vertically upwards, creating a mist instead of large water droplets. This increases productivity since the fine mist facilitates evaporation and the low-saline mist can go upwards more than the large high-salinity droplets. However, experiments showed that this methodology, in terms of productivity, performance and cost, was between other technologies. It was noted that the performance of this system peaked at ~39 %. Therefore, in this paper, an exergy analysis of the system is presented to determine the location of the highest exergy destruction and also highlight its comparative feasibility. The results indicated that the exergetic efficiency of the system reached 17.3 % while the main source of irreversibility is the fogging process itself (~75 %). Additionally, increasing the water temperature from 33 to 76 °C increased the exergetic efficiency of the fogger from 4 % to 20 %. Therefore, the authors recommend using a combination of humidification and atomization via nozzles of larger orifices with different spraying angles. • An energy and exergy analysis of a novel fog desalination system is performed. • System energetic efficiency reached 38.95 %. • System performance reached 17.3 % for exergy efficiency. • Fogging process is the main source for irreversibility • System feasibility may be enhanced by extracting salt after fogging process. [ABSTRACT FROM AUTHOR]

• A developed hybrid system combines reverse osmosis technology and solar stills. • A developed system integrated with photovoltaic/thermal and solar water heaters. • Photovoltaic cooling improved the electrical power output by 24.1% on average. • Reverse osmosis water recovery improved by 46% with energy savings of 38.34%. • The productivity of solar distiller improved by 98.32%. Energy and freshwater are the most prioritized needs for any nation nowadays, especially for arid areas. Giving attention to renewable energy sources like solar energy is a must towards a cleaner environment and a world with no need of temporary sources like fossil fuels. Also, a solution to lower the power requirements and costs of desalination hybrid systems should be investigated to overcome the water problem. The present study aims to design and build a novel hybrid desalination plant working with the highest productivity and lowest power consumption. This was done by incorporating a reverse osmosis desalination unit with the conventional solar distiller. The photovoltaic/thermal collectors were utilized to produce electricity as well as a heating unit in addition to the evacuated tube solar collectors, to preheat the hybrid desalination plant feed water. The results presented that the use of photovoltaic/thermal panels and evacuated tube solar collectors as preheating units improved water recovery by 46% and reduced power consumption by 38.34% for the small reverse osmosis unit but the salt rejection decreased by 4%. Cooling the photovoltaic panel increased its electricity production by 24.1% on average. Moreover, the combination of the solar distiller with the reverse osmosis unit on the feed line represents the best configuration which improves the solar distiller's productivity by 98.32% as compared to separate solar distillers. The cost of freshwater produced is 0.719 $/ m 3 which is cost competitive compared to previous solar desalination systems. [ABSTRACT FROM AUTHOR]

Employing rough surfaces and nanofluids in solar heater ducts are recognized as effective techniques to improve thermal performances of these devices. In this paper, the second law of thermodynamics analysis is performed for nanofluid turbulent flow in a solar heater duct with rib roughness on the absorber plate. The effects of different parameters including rib height, rib wedge angle, rib pitch, Reynolds number, and nanofluid concentration on thermal and frictional irreversibilities are investigated. The results indicated that the thermal entropy generation decreases about 11.1% by using nanofluid with concentration of 0.04. The frictional and thermal entropy generations decrease by increasing the rib pitch. Moreover, the thermal entropy decreases about 21.05% by increasing the rib height in the range of 0.025-0.033 for Re = 3200. Finally, it is found that the thermal entropy generation decreases by increasing the wedge angle of the rib. [ABSTRACT FROM AUTHOR]

Solar thermal water heating systems have been developed to replace conventional heating. Therefore, the design of a parabolic cylinder collector-type solar heating unit with a coil-shaped heater (absorber) has been carried out. The cylindrical collector is made of an aluminum plate covered with a reflective sticker and the base is insulated, having a diameter, height, length, and position of the focal point 150, 60, 200, and 22.4 cm, respectively. The coil water heater of 3/8-inch diameter copper pipe having a diameter, pitch, and length of 20, 3, and 200 cm, respectively. The concentration ratio between collector area and heating pipe area (absorber) is 3.6. The results of heating trials conducted from 10:00 to 16:00 WIT, in Duplo to 100 liters of water circulated through the heating pipe at a speed of 0.017 kg/sec, indicate that heating is affected by fluctuations in radiation intensity. Thermal efficiency is inversely proportional to heating time. the lower the time when the difference between the temperature of the incoming and outgoing water gets smaller, or in other words in the evening the water temperature approaches a steady state. The achieved maximum water-heating temperature is 53C in the average radiation range during the test is 687-693 W/m2.

The effects of simultaneous implementation of corrugated walls and nanoparticles upon the performance of solar heaters are investigated. Triangular and sinusoidal wall profiles along with varying concentration of nanoparticles are analyzed. The multi-phase mixture and the SST κ-ω models are used to simulate turbulent nanofluid flows inside the corrugated channels. The staggered computational grid is employed for storing the velocity and pressure terms at cell faces and cell center, respectively. The governing equations are first discretized by employing a second-order upwind differencing technique and are then solved by means of pressure-based finite volume approach. The convergence criterion is also presented for the validation of obtained results. The effects of wall profiles and nanoparticle concentration on the pertinent parameters including Nusselt number, pressure drop, performance evaluation criterion (PEC), and thermal and frictional irreversibilities are studied. This reveals that, in general, the triangular duct features superior heat transfer and inferior hydraulic characteristics in comparison with the sinusoidal duct. It is demonstrated that as long as the base fluid (water) is used the highest value of PEC corresponds to the straight duct. Yet, by introducing nanofluids the PEC values of the corrugated ducts exceed those of the straight duct. The analysis further shows that on the basis of the performance evaluation criterion, the sinusoidal duct appears to be a better choice in comparison with the triangular duct. However, the situation is reversed when thermodynamic irreversibilities are considered. It is argued that vortex formation in the two investigated wavy walls and shear layer developed in the triangular case are the essential physical reasons for the observed thermal, hydraulic and entropic behaviors. [ABSTRACT FROM AUTHOR]

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Solar court yard is a court yard that includes a solar thermal equipment, as the solar cheap heater of construction materials, Fimsol, that costs 2 to 6 USD /m2 and has a 10% of thermal efficiency. Is evaluated energetically and economically a solar heater Fimsol, is characterized its environmental impact and its perspectives of domestic and industrial applications, as well as thermal support of solar dryers. [ABSTRACT FROM AUTHOR]

The proposal of a thermal solar system to heat water in the Hospital service is the fundamental objective of the present work, which had the aim of carry out a study on the employment of renewable energy sources to increase the energy efficiency and the quality of the hospitable service. The methodology used to select the proposed system took in consideration the rules of thumbs offered by several international organizations as RETScreen, SODEANS and Swisscontact, different computer software were employed. This project, with an approximate initial cost of $37 200, allows to obtain an annual electric energy saving of 190 MW.h and it contribute a net annual greenhouse gas emission reduction equivalent to 440 barrels of crude oil not consumed.

A comprehensive numerical study is performed on the fluid flow and heat transfer within a porous solar heater. The effects of porous material on the heat transfer enhancement and pressure drop are presented in details. Also, the attention is focused on the effects of several parameters on the combined convection–radiation heat transfer and flow structures. Volume averaged equations are applied to simulate the transport phenomena within the porous substrate. Furthermore, the regular continuity, momentum, and energy equations are used in the clear fluid region. These equations are discretized using the control volume technique. It is found that the Nusselt number increases by inserting the porous substrate to the heater. These augmentations are up to 3, 4.4 and 5.9 times for δ = 1/3, 2/3 and 1, respectively at Da = 10 - 2 . Also, the pressure drop increases with an increase in the porous layer thickness and decrease in the Darcy number. [ABSTRACT FROM AUTHOR]

In this study, a novel liquid desiccant air conditioning/drying cum desalination system is proposed employing Maisotsenko cycle-based indirect contact cooler in the dehumidifier and membrane-based indirect contact regenerator instead of the conventional structured packing-based dehumidifier and structured packing based direct contact regenerator. The liquid desiccant selected for the present investigation is lithium chloride (LiCl). A thermal model is developed to predict the performance of the above-mentioned conventional and novel systems. The developed model has been validated with the experimental data available in the literature and found to match well with a maximum possible error of ±9.7%. Depending upon the developed model, a performance comparison of conventional and novel systems and performance assessment of novel air conditioning/drying cum desalination system is carried out. From the performance assessment, it is observed that for the given operating range, coefficient of performance (COP) varies from 0.75–0.81 and 0.85–0.92 for conventional and novel systems, respectively that are intended for air conditioning application whereas system efficiency varies from 50%–55% and 70%–75% for conventional and novel systems, respectively which are meant for drying application. Further, it is also found that the novel system has 18% more COP and 27% higher system efficiency compared to the conventional system designated for air conditioning and drying applications, respectively. Moreover, from the novel air conditioning/drying cum desalination system, the maximum amount of freshwater obtained as a by-product from the atmospheric air is about 4.62 LPM. The proposed system has multipurpose applications such as building space cooling, drying food products, and extraction of pure water from ambient air. [Display omitted] • Proposed M-cooler integrated novel air conditioning/drying cum desalination system • Developed thermal model for performance analyses of conventional and novel systems • Novel air conditioning/drying system COP/efficiency is about 0.92/74%, respectively • Novel system COP/efficiency is 18%/27% higher than conventional system • Maximum possible pure water extraction rate from novel system is about 4.62 LPM [ABSTRACT FROM AUTHOR]