Solar Radiation Heat Research Articles

Analisa Kinerja Mesin Pengering Buah Pinang Tenaga Hibrid

The purpose of this study was to determine the performance of a hybrid dryer by combining the utilization of solar energy (solar dryer) and biomass power sources. Utilization of solar thermal energy sources by maximizing solar heat radiation sources which are absorbed directly into the drying chamber in the form of a transparent house with ventilation holes for fresh air to enter and moist air to exit. This process will produce hot air circulation (convection) in the drying chamber continuously so that the process of evaporation of water from the material being dried is faster. The temperature of the hybrid dryer with a sun source without the test material was 56º C. In the hybrid dryer test with a biomass combustion power source without the test material, the maximum temperature was 46 º C with a stable temperature of 40 º C. In the hybrid dryer test with a solar power source with the material test with a drying rate for 6 hours of drying there was a reduction in the mass of areca nut by 19%. The performance of the hybrid drying machine is better when the temperature is controlled with a setting temperature of 60º C. The average drying rate of areca nut from the hybrid dryer is 1 kg/hour

Thermal decomposition of δ-MoN and ε-Fe2N synthesized under concentrated solar radiation in NH3 gas stream

Decomposition temperatures of δ-MoN and ε-Fe2N synthesized with flowing NH3 gas under concentrated solar radiation heating were evaluated by Differential Scanning Calorimetry (DSC) in Argon (Ar) gas environment. The measured decomposition temperature of δ-MoN and ε-Fe2N were dependent on the solar synthesis conditions, particularly either NH3 or N2 gas flow rate at temperature. Sample containing δ-MoN showed two exothermic peaks around 680 and 900 °C, attributed to the reactions of δ-phase into γ-single-phase and (γ+β)-two-phase Mo2N, respectively, attributed to the dissociation reaction of δ-phase into γ-single phase and the dissociation reaction of γ-phase into metallic M saturated with N, respectively. Decomposition of ε-Fe2N took place into γ’-Fe4N in two steps occurring at 606 and 660 °C, respectively. When N2 instead of ammonia (NH3) gas was used, complete dissociation of γ’-Fe4N into Fe took place at around 610 °C. Full decomposition of γ’-Fe4N into metallic α-Fe(N) was corroborated by X-ray diffraction (XRD) analysis.

Thermo-physical properties of liquids and gases over a heated rotating disk

The motivation of this study arises due to huge occurrence of rotating disk in field of real-world processes like rotational air cleaner, turbomachinery, centrifugal pumps, aerospace engineering and chemical engineering. A numerical investigation is undertaken to study the thermo-physical properties of Newtonian fluid flow over a strongly heated rotating disk with temperature dependent viscosity. The solar radiative heat flux is considered in the heat equation. The temperature dependent viscosity and thermo-physical properties are assumed to explore the flow behavior. Numerical solutions of the converted boundary layer equations are then achieved by using fifth order Rung-Kutta Fehlberg integration approach with a shooting method. The attained results are discussed for mean flow profiles and physical interpretations of the problem are given through graphs and tables. It is observed that temperature dependence viscosity for liquids ranges to decrease the base flow profiles, whilst the gaseous viscosity nature has the opposite impact. The mass diffusion coefficient creates enhancement in concentration field. Moreover, correlations are plotted graphically in terms of temperature, concentration, and viscosity.

Preparation and solar thermochemical properties analysis of NiFe2O4@SiC/ @Si3N4 for high-performance CO2-splitting

The solar-driven thermochemical CO2-to-CO conversion is an effective way to achieve the mission of carbon peaking and carbon neutrality. However, synthesizing porous reacting materials with excellent thermal stability, hardness and long-term cyclic stability, oxygen exchange capacity, and higher CO2-to-CO conversion are the most important challenges associated with the thermochemical CO2-splitting approach and technological upscaling to large-scale applications. This study presented the development of NiFe2O4 oxygen carriers, the synthesis method of SiC and Si3N4 supports, and solar-to-fuel processing of the newly prepared materials through CO2-splitting under a highly concentrated solar radiative heat flux. The newly synthesized NiFe2O4@SiC porous redox material resulted in higher solar energy absorption and CO2 conversion capability with an instantaneous CO production of 410 μmol/g and direct CO2-to-CO conversion rate of 18.1 % at 1073–1273 K reaction temperature. The media composite of NiFe2O4@SiC exhibited high-temperature thermal changes, good thermochemical reaction stability, and a higher CO production rate through six redox cycles compared to NiFe2O4@Si3N4 porous reacting material. The high oxidation potential and remarkably solar radiative heat flux absorption and thermochemical CO2-splitting capacities of the newly developed materials were demonstrated through experimental analysis. The synergistic effect of the oxygen carriers (NiFe2O4) and substrate materials including SiC and Si3N4 skeletons for CO2-splitting is highlighted. This study provided comprehensive and novel experimental insights that can be used as guidance for theoretical research and application in CO2 conversion into high-value-added energy products.

Modeling cloud properties over the 79 N Glacier (Nioghalvfjerdsfjorden, NE Greenland) for an intense summer melt period in 2019

AbstractLong believed to be insignificant, melt activity on the Northeast Greenland Ice Stream (NEGIS) has increased in recent years. Summertime Arctic clouds have the potential to strongly affect surface melt processes by regulating the amount of radiation received at the surface. However, the cloud effect over Greenland is spatially and temporally variable and high‐resolution information on the northeast is absent. This study aims at exploring the potential of a high‐resolution configuration of the polar‐optimized Weather Research & Forecasting Model (PWRF) in simulating cloud properties in the area of the Nioghalvfjerdsfjorden Glacier (79 N Glacier). Subsequently, the model simulations are employed to investigate the impact of Arctic clouds on the surface energy budget and on surface melting during the extensive melt event at the end of July 2019. Compared to automatic weather station (AWS) measurements and remote‐sensing data (Sentinel‐2A and the Moderate Resolution Imaging Spectroradiometer, MODIS), PWRF simulates cloud properties with sufficient accuracy. It appears that peak melt was caused by an increase in solar radiation and sensible heat flux (SHF) in response to a blocking anticyclone and foehn winds in the absence of clouds. Cloud warming over high‐albedo surfaces helped to precondition the surface and prolonged the melting as the anticyclone abated. The results are sensitive to the surface albedo and suggest spatiotemporal differences in the cloud effect as snow and ice properties change over the course of the melting season. This demonstrates the importance of including high‐resolution information on clouds in analyses of ice sheet dynamics.

Energy, economic analysis and mathematical modelling of mixed-mode solar drying of potato slices with thermal storage loaded V-groove collector: Application to Maghreb region

This research aims to study the thermodynamic and economic feasibility of a mixed-type solar dryer of potato chips equipped with a V-corrugated solar collector and loaded with a heat storage system in the Maghreb region of North Africa. The thermodynamic, economic assessment and environmental impact of deploying the solar dryer were investigated. For, this reason a mix-mode solar dryer with V- groove collector loaded with granite bed as thermal storage was developed at the Faculty of Sciences and Techniques of Tangier, Morocco. Drying of the potato chips took 4.5 h at a collector efficiency of 60.08%. Solar radiation heat contributed 78.18% of energy utilization while the granite bed thermal storage contributed 21.82%. The effectiveness of energy utilization embodied in specific energy consumption was determined as 6.109 kWh/kg and the specific moisture extraction rate was deduced as 0.1637kg/kWh. Wang/Singh and Midilli/Kucuk models presented the best kinetic models for predicting the potato drying kinetic in the mixed-type dryer and open sun drying, respectively. Using the solar dryer in the Maghreb country of Morocco can save $69.58 to $698.5 on running costs with a payback period of 0.179–1.744 years at a usage rate of 10–100%. Environmental impact assessment showed the dryer can limit up to 163 tons of CO2 from the atmosphere at the current usage.

Design and evaluation of renewable energies-based multi-generation system for hydrogen production, freshwater and cooling

In this study, a new combination of a multi-generation system based on solar energy is presented and studied from the perspective of energy and exergy. The system includes parabolic trough solar collectors (PTSCs) to collect solar radiant heat, and storage tanks to keep the system operational at all hours of the day (considering three operating modes for the system according to the intensity of solar radiation during the day). Also, a geothermal energy system has been coupled with this system to improve its usability. In this system it was tried to use most of the dissipated heat. The system includes solar parts, a regenerative organic Rankine cycle (RORC), two organic Rankine cycle (ORC), three humidification-dehumidification (HDH) desalination cycles, and a single-effect absorption chiller (SE-ARC). The system was studied from a thermodynamic view point, and for these three modes, the energetic efficiency index of the entire system was calculated to be 121.9, 57.28, and 77.68, respectively, while the exergetic efficiency index of the entire system was calculated as 7.696, 3.374, and 4.922, respectively. The highest amount of fresh water and hydrogen production occurs in solar mode and for cooling load in storage mode, which are equal to 6.068, 3.569 and 538.7, respectively. Compared to similar studies, the efficiency of the system has improved due to the better utilization of the dissipated heat as well as the use of geothermal energy. It was also concluded that the highest destruction rate exergy among all the components of the system occurs in PTSC in solar and solar with storage mode and in the storage mode evaporator 1 has the most exergy damage, which is equal to: 1275, 4233 and 390.4 kW, respectively.

Solar radiation over a roof in the presence of temperature-dependent thermal conductivity of a Casson flow for energy saving in buildings

Non-Newtonian Casson fluid has great importance in biomechanics, processing of polymer, and industries. Therfore,in the current study, the solar radiation effects onCasson fluid flow and heat transfer over an exponentially stretching sheet in the presence of the influence of the temperature-dependent thermal conductivity are investigated. The propsoed mechanism is given a mathematical form in terms of partial differential equations. Using appropriate similarity variables for similar solutions, a set of partial differential equations are then reduced into set of ordinary differential equations. The solutions of transformed equations are determined by employing the MATLAB built-in function bvp4c. The solutions of velocity distribution, temperature field, and concentration profile are computed against sundry parameters and portryed in graphs. The skin friction, heat transfer rate, and mass transfer rate versus pertinent parameters are displayed in tables. The numerical outcomes show that as Casson parameter β and radiation parameter N are augmented velocity field rises and reduces with increasing values of Prandtl number Pr and thermal conductivity variation parameter γ. The temperature of fluid is enhaced as N is raised and revese trend is noted for increasing values of β, Pr, and γ. Concentration profile grows well with augmentation in N and γ and reverse behavior is observed for augmenting values of β and Pr. A comparision of present and existing results is given to validate of current solutions.

Diurnal Variation Mechanisms of the Zonal Shear Line Inducing Anomalous Heavy Precipitation Over the Tibetan Plateau in Boreal Summer

AbstractThe Tibetan Plateau (TP) is one of the regions with the most remarkable diurnal variations in the global atmosphere. The zonal shear line (ZSL) is the primary synoptic system inducing precipitation over the TP in boreal summer. It is of great significance in studying its diurnal variation. This study objectively identified and composited 11 ZSL cases inducing anomalous heavy precipitation based on the ERA5 hourly reanalysis datasets from June to August during 1980–2019. The diurnal variation characteristics and mechanisms of ZSL’s intensity were explored based on the composited ZSL. Results suggest that the intensity of ZSL has significant diurnal variation, reaching the peak at midnight (about 23 Local Solar Time). The dynamical and thermal structures near the ZSL both show significant diurnal variations. There is a significant heating effect near the ZSL after sunrise, followed by strong divergence (convergence) in the upper (lower) layer and significant increases in water vapor flux convergence and ascending motions. The vorticity is strongest at midnight. Diagnosis by the complete‐form vertical vorticity tendency equation reveals that the thermal effect, dominated by vertically non‐uniform distribution of atmospheric diabatic heating, is the most crucial factor affecting the diurnal variation of ZSL’s intensity. The configuration of solar radiation and sensible heat in the near‐ground layer and latent heat in the middle and upper layers jointly dominate the vertically non‐uniform heating. The horizontally non‐uniform heating only contributes little to the local change of vorticity at 500 hPa. Ascending motion and vorticity advection have only weak effects.

Evolution and Structure of a Dry Microburst Line Observed by Multiple Remote Sensors in a Plateau Airport

The civilian airplane is a common transportation mode for the local people in the Qinghai-Tibet Plateau (QTP). Due to the profound dynamic and thermal effects, the QTP can trigger strong windstorms during the warm season, during which downbursts can cause severe low-level wind shear and threaten aviation safety. However, the study of downbursts over QTP has not been given much attention. This study analyzes and interprets a typical traveling dry microburst line that happened at the Xining Caojiapu International Airport (ZLXN) on 14 May 2020, intending to show a better understanding of the dry downbursts over QTP and explore the synergetic usage of different remote sensing technologies for downburst detection and warning in plateau airports. Specifically, the characteristics of synoptic conditions, the convective system formation process, and the structure and evolution of downbursts and relevant low-level winds are comprehensively investigated. The results show that, under the control of an upstream shallow trough, features of the local atmosphere state, including a dry-adiabatic stratification, a shallow temperature inversion, increases in solar radiation heating, and strong vertical shears of horizontal winds, can be favorable atmospheric prerequisites for the formation and development of dry storms and downbursts. Low-reflectivity storm cells of the Mesoscale Convective System (MCS) organize to form narrow bow echoes, and downbursts show features of radial wind convergences and rapid descending reflectivity cores with hanging virga as observed by a Doppler weather radar. Moreover, details of gales, gust fronts, convergences, turbulences, wind collisions, and outflow interactions triggered by the downburst line are also detected and interpreted by a scanning Doppler wind lidar from different perspectives. In addition, the findings in this work have been compared with the results observed in Denver, U.S., and some simulation studies. Finally, a few conceptual models of low-level wind evolutions influenced by the dry downburst line are given.

Concomitant Thermochromic and Phase‐Change Effect in a Switchable Spin Crossover Material for Efficient Passive Control of Day and Night Temperature Fluctuations (Adv. Sci. 24/2022)

Spin Crossover In article number 2202253, Ana Espinosa, Jose Sánchez Costa, and co-workers present a proof-of-concept by demonstrating that the spin crossover (SCO) can be induced by the solar radiation heat and that temperature fluctuations, both heating and cooling, are reduced. This behavior is understood by two concomitant effects that accompany the SCO, the phase change in the process and the light reflection variation, derived from the change of color.

The Effects of Moisture Content on the Temperature of Some Selected Soil Samples in the Presence of Internal Heat

The effect of moisture content on the temperature of some selected soil samples in the presence of internal heat was studied. The governing equation was modeled using Bosenneque’s approximation base on some necessary assumptions by which the transfer occurred. These equations were non-dimensionalized by employing some standard dimensionless parameters and later reduced to ordinary differential equations using perturbation method. This was then solved analytically. The various effects of the physical parameters that materialized were examined on the unsaturated and saturated forms of some selected soil samples. With the aid of Matlab software, the numerical results were graphed for visual examination. It was observed that the presence of moisture content in these soils helped in boosting their temperatures as the solar radiation and internal heat increase.

The role of atmospheric dynamics and large-scale topography in driving heatwaves.

Heatwaves are weather events characterized by extreme near‐surface temperature anomalies that persist for several days, and therefore lead to catastrophic impacts on natural ecosystems, agriculture, human health, and economies. Different physical processes can contribute to the temperature anomaly associated with heatwaves. Previous studies have shown that increased solar radiation and adiabatic heating associated with blocking systems and local land–atmosphere coupling are important drivers of summer heatwaves. Less is known about the fundamental role of atmospheric large‐scale dynamics and topography in generating heatwaves. Here, we perform idealized model simulations where all physical parameterisations are substituted by a simple zonally symmetric temperature relaxation scheme. This allows us to characterize the dynamical processes involved in the life cycle of heatwaves occurring at different latitudes. We find that blocking plays an active role in the life cycle of high‐ and midlatitude heatwaves, while blocking is less relevant for low‐latitude heatwaves. Rossby‐wave packets are the dominant drivers for midlatitude heatwaves, with horizontal advection being the main mechanism leading to heat extremes. Heatwaves exhibit a higher persistence and frequency near the pole and Equator compared with the midlatitudes, but a higher intensity in the midlatitudes compared with higher and lower latitudes. Topography located along the midlatitude jet has the largest impact on the heatwave distribution around the planet, resulting in increased heatwave frequency upstream for moderate topographic forcing and a circumglobal increase for topographic elevations above 6 km. Identifying the most relevant processes driving heatwaves can potentially benefit the prediction and representation of extreme events in operational weather and climate forecast systems.

Permafrost cooled in winter by thermal bridging through snow-covered shrub branches

Considerable expansion of shrubs across the Arctic tundra has been observed in recent decades. These shrubs are thought to have a warming effect on permafrost by increasing snowpack thermal insulation, thereby limiting winter cooling and accelerating thaw. Here, we use ground temperature observations and heat transfer simulations to show that low shrubs can actually cool the ground in winter by providing a thermal bridge through the snowpack. Observations from unmanipulated herb tundra and shrub tundra sites on Bylot Island in the Canadian high Arctic reveal a 1.21 °C cooling effect between November and February. This is despite a snowpack that is twice as insulating in shrubs. The thermal bridging effect is reversed in spring when shrub branches absorb solar radiation and transfer heat to the ground. The overall thermal effect is likely to depend on snow and shrub characteristics and terrain aspect. The inclusion of these thermal bridging processes into climate models may have an important impact on projected greenhouse gas emissions by permafrost.

Method for determining the optimal value of the specific heat capacity and temperature regime of a short-term heat accumulator of passive solar heating systems with a flat reflector of radiation

The article presents the results of the analysis and generalization of the experience of operating residential facilities with solar heating systems, even a slight accumulation of the daytime excess heat of solar radiation is determined, which can significantly increase the replacement coefficient of the heat load for heating the systems under consideration. An unjustified increase in the capacity of the heat accumulator has been determined that does not give a noticeable increase in the replacement coefficient for the heat load of the system. Studied and developed new and improved existing insolation passive solar heating systems. The article shows the results of the analysis and operation of residential buildings with solar systems, it is determined that a slight accumulation of daily excess heat of solar radiation can significantly increase the replacement coefficient for the heat load on the heating of the systems under consideration.

Komparasi Output Termoelektrik Generator ( Kuat Arus Dan Tegangan ) Pada Jalas Aspal Dan Beton Dengan 3 Variasi Bentuk Plat Tembaga

Solar radiation heat energy is energy that propagates throughout the earth's surface and is absorbed stored in various objects on the earth's surface. A thermoelectric generator is an electrical generator device that converts heat (temperature difference) directly into electrical energy, using a phenomenon called the Seebeck effect. In this research, this research was carried out by utilizing the absorption of solar radiation heat on a concrete road with a type of cast concrete class III with K 250 and asphalt type AC-WC as a thermoelectric generator. This research uses 3 thermoelectric generator modules type 1848 which will be arranged in series, the cooling system is filled with water using 2 asphalt and concrete variables, each of which has three variations of L, I and Z-shaped heat conductor plates. The test results show that asphalt has energy larger than concrete. L plate is the best plate on both asphalt and concrete roads. This research allows it to be developed to become a reference source of the latest alternative energy.
 Keywords: Heat Energy, Thermoelectric generator, Plate variation

System modelling and optimization of a low temperature local hybrid energy system based on solar energy for a residential district

Utilizing solar energy for heat supply can reduce CO2 emissions and mitigate global climate change. In the Nordic region (e.g., Iceland and Finland), a tremendous seasonal mismatch exists between the availability of solar radiation and building heating demand. This paper proposes a local hybrid energy system based on solar energy for a residential district. It applies a borehole thermal energy storage to store solar energy in non-heating seasons, and uses stored energy for part of total heating demand in a residential neighbourhood in heating seasons. Photovoltaic panels are used to generate electricity for heat pump operation. To find out cost-optimal and eco-friendly solutions, the local energy system was first modelled and simulated in TRNSYS. Then, genetic algorithms were applied to optimize the system performance and costs. In optimal solutions, 38%-58% of total heating demand could be covered by on-site heat energy with the levelized cost of energy of 110–184 €/MWh. On this basis, importing additional electricity from grid to increase the utilization rate of air-to-water heat pumps can further increase the on-site heat energy fraction to 41%-88% with the levelized cost of energy of 108–201 €/MWh. Compared with the situation of fully district heating input, the proposed system can annually reduce CO2 emissions by 102–217 tons with the rate of 31–66%. Although the initial cost of the studied system is higher than that of district heating, the local hybrid energy system is worth further developing considering decentralizing heat energy production and reducing CO2 emissions.

Experimental characterization of the temperature gradient inside a membrane distillation module

One of the solutions to the current fresh water challenge is desalination using low-grade heat (solar radiation or waste heat), such as Air-gap Membrane Distillation (AGMD). Based on evaporation, induced by a temperature gradient across a hydrophobic membrane, this process has an improved energy efficiency thanks to the inclusion of the air-gap by limiting the heat losses, while hindering the mass transfer at the same time. Understanding of the temperature distribution in the module is crucial for working towards improved efficiency and freshwater output.This work describes a setup and optical measurement method dedicated to analysis of energy and mass transfer resistances through temperature gradient measurement in the bulk and observation of boundary layer at the membrane. In particular data acquisition, processing and interpretation framework is presented, and compared to existing literature. Initial results indicate that the method is successful, although a number of improvements are proposed to address the identified shortcomings.

Solar Radiant Heat Reflected on the Termination Shock Might Create Excess Microwave Radiation in the Horn Antenna (Thermal Telescope)

In this contribution, we model the Solar radiant heat as waves obeying the Stefan-Boltzmann law. The Solar radiant heat is reflected on the termination shock (TS) back towards to the Solar System. The geometry of the TS is known from the recent data of Voyager 1 and Voyager 2. This reflected radiant heat might create the observed excess microwave background (MB) in heated thermal telescopes (e.g., the Holmdel horn antenna). This model can be easily experimentally falsified in the spirit of Karl Popper by measuring the microwave background monopole, the microwave background dipole, and the small heat fluctuations coming from the sound waves in the TS shock and not uniform distribution of particles in the TS. This proposed experiment can be realized by the existing technology in the Solar System between the Sun and the termination shock.

A predictive control strategy for electrochromic glazing to balance the visual and thermal environmental requirements: Approach and energy-saving potential assessment

Electrochromic (EC) glazing provides a promising solution to actively adjusting the sunlight and radiant heat through windows in response to building visual and thermal environmental requirements, and control strategies play a critical role in the application of EC technology in buildings. However, there is a conflict between the visual and thermal environmental requirements for EC regulation during a cooling season. To solve this problem, this paper developed a predictive control strategy for EC glazing. It was achieved based on two theoretical models which could predict the energy performance of EC glazing at different tint states, including the solar radiation heat transmitted through the glazing and lighting energy consumption. The optimum glazing state was determined based on real-time minimized energy consumption. Study results showed that the predictive control strategy outperformed the rule-based control strategy, with percentage energy saving of an office room in Beijing, China from 8.04% to 12.78% over an entire cooling season. In addition, the paper evaluated the energy-saving of using EC glazing under the predictive control strategy in 28 Chinese cities. The results indicated that EC glazing was highly applicable in most of cities with energy saving from 2.35 kWh/m2 to 5.04 kWh/m2 over an entire cooling season.