scholarly journals Performance test of greenhouse effect (GHE) vent dryer with the addition of paraffin as a heat storage medium

2021 ◽  
Vol 922 (1) ◽  
pp. 012045
Author(s):  
Mustaqimah ◽  
A Ahmar ◽  
D Nurba
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Ambient Temperature ◽  
Performance Test ◽  
Heat Storage ◽  
Study Data ◽  
Final Conclusion ◽  
Storage Medium ◽  
Storage Media ◽  
Air Flow Velocity

Abstract Green House Effect (GHE) vent dryer is a kind of dryer design by utilizing solar energy as a drying energy source. Adding paraffin as a heat storage medium is one solution so that the GHE vent dryer can operate when the solar energy has dimmed. The purpose of this study was to test the performance of heat storage media using paraffin as a heat storage medium. 9 kg of paraffin was prepared, put into 9 copper pipes and placed in the absorber chamber. The data measured were the temperature in the drying room (T1=room 1, T2=room 2 and T3=room 3), the temperature of the absorber room, the temperature of the outlet, ambient temperature, air velocity and solar radiation. The results showed that the average ambient temperature ranged from 30°C to 40°C. Meanwhile, the average temperature in the GHE vent dryer ranges from 69°C to 71°C. The drying air flow velocity in the environment reaches 1.3 m/s and on the ventilator 1.1 m/s. During the study, data on solar radiation was also obtained on average reaching 6.6 W.h/m2. The final conclusion of this study shows that the use of paraffin as a heat storage medium in the GHE vent dryer is able to maintain the temperature in the drying chamber for 4 to 5 hours when solar radiation is not present.

Solar Chimney Power Plant Performance for Different Seasons Under Varying Solar Irradiance and Temperature Distribution

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Ulku Ece Ayli ◽  
Ekin Özgirgin ◽  
Maısarh Tareq
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Ambient Temperature ◽  
Solar Irradiance ◽  
Power Plants ◽  
Low Cost ◽  
Renewable Energy Sources ◽  
Three Dimensional ◽  
Plant Performance ◽  
Solar Chimney

Abstract One of the most promising renewable energy sources is solar energy due to low cost and low harmful emissions, and from the 1980s, one of the most beneficial applications of solar energy is the utilization of solar chimney power plants (SCPP). Recently, with the advancement in computer technology, the use of computational fluid dynamics (CFD) methodology for studying SCPP has become an extensive, robust, and powerful technique. In light of the above, in this study, numerical simulations of an SCPP through three-dimensional axisymmetric modeling is performed. A numerical model is created using CFD software, and the results are verified with an experimental study from the literature. The amount of solar radiation and surrounding weather (ambient temperature) were analyzed, and the effects of the irradiance and air temperature on the output power of the SCPP were studied. Ambient temperature is considered as one of the most important factors that influence collector efficiency in a negative or a positive manner. Solar irradiance is considered to be the most important factor that has an impact on SCPP performance. The investigation includes the study of the relationship between solar insolation and ambient temperatures during the daytime since the difference between the minimum and maximum power values and the performance are very important considering seasonal changes. According to the results, power values are dependent on the amount of solar radiation as well as the ambient temperature, and the importance of selection of location thus climate for an SCPP is found to affect the design of the SCPP.

Study on Collector Efficiency of Flat-Plate-Type Evacuated Solar Collector to Get Hot Water Near 100°C

2010 ◽  
Author(s):  
Shigeki Hirasawa ◽  
Tsuyoshi Kawanami
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Solar Collector ◽  
Storage Tank ◽  
Heat Storage ◽  
Hot Water ◽  
Measured Temperature ◽  
Control Methods ◽  
Collector System ◽  
Collector Efficiency

We studied effects of parameters on collector efficiency of evacuated solar collector system to get hot water near 100°C. Change of temperature in the solar collector system is calculated for a daily change of solar radiation with 5 minutes cloud. Six operation-control methods are examined. Calculation results show that the effect of the control methods on average collector efficiency for one day is small as 1%. Best control method to minimize effect of the cloud on exit temperature fluctuation of the water is that the flow rate of the water is controlled proportional to the solar radiation. Two types of heat storage system are examined: a non-circulating type (supply new water and accumulate heated water in the heat storage tank) and a circulating type (circulating water from the heat storage tank). The non-circulating type is effective to use the solar energy in the daytime, and the circulating type is effective to use solar energy in the evening. Also, we measured temperature of a collector plate under actual solar radiation in a fine day.

Sand as a Heat Storage Media for a Solar Application: Simulation Results

2014 ◽  
Vol 621 ◽  
pp. 214-220 ◽  
Author(s):  
Nadjiba Mahfoudi ◽  
Abdelhafid Moummi ◽  
Mohammed El Ganaoui
Keyword(s):  
Solar Energy ◽  
Heat Storage ◽  
Thermal Inertia ◽  
Transient Behavior ◽  
Storage Unit ◽  
Storage Media ◽  
Bed Temperature ◽  
Charging Energy ◽  
Solar Application ◽  
Storage Characteristics

This paper deals with the numerical investigation of transient behavior and thermal storage capability of a sensible heat storage unit. The former has a cubic configuration with embedded charging tubes; it is used to store solar energy with sand as a storage media. The system operates in the range of low temperature. To analyze their heat storage characteristics (including the bed temperature, energy stored rate, charging energy efficiency), a finite element based 2-D mathematical model has been developed using COMSOL Multiphysics. The results show that sand has an important thermal inertia. However, it was interesting to develop these storage systems in the region where both sand and solar energy were plentiful.

scholarly journals Evaluating the Impacts of Ground and Atmospheric Conditions on the Efficiency of Solar Energy System and Its Economic Analysis

2018 ◽  
Author(s):  
Ali Saleh Aziz ◽  
Mohammad Faridun Naim Tajuddin ◽  
Sanjeevikumar Padmanaban ◽  
Lucian Mihet-Popa ◽  
Mohd Rafi Adzman ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Ambient Temperature ◽  
Economic Performance ◽  
Base Station ◽  
Base Case ◽  
Solar Pv ◽  
Pv Systems ◽  
Pv Array ◽  
Pv Modules

The There are many factors influencing the performance of photovoltaic (PV) systems. Among these factors, temperature and solar radiation are two major parameters that have a large effect on the efficiency of PV systems. The cell temperature of PV panels is related to the ambient temperature while the solar radiation incident on the surface of the PV modules depends on the slope and azimuth of these modules. Furthermore, ground reflectance (albedo) affects the irradiance incident on the PV panel surface, which in turn affects the output of a PV system. Nevertheless, the effects of these factors on the economic performance of the solar PV systems are scarcely reported. This paper presents a complete design of a stand-alone PV/battery system to supply electric power for a mobile base station in Choman, Erbil, Iraq. The effects of different factors on the total electricity produced by PV arrays and its economic performance are simultaneously investigated. HOMER software has been used as a tool for the techno-economic and environmental analysis. As indicated from the simulation results, the PV array capacity and its economic performance are highly affected by the variation of the slope and azimuth. With a base case (albedo of 20% and average annual ambient temperature of 11°C), the best feasible system which is achieved by facing PV due to south with a tilt angle of 40° or 45°, is found to have net present cost (NPC) of 70595 $ and cost of energy (COE) of 0.54 $/kWh. Moreover, the results indicate that increasing the ground reflectance from 10% to 90% results in a 7.2% decrease in the PV array capacity and about 3% decrease in the NPC and COE. On the other hand, increasing the ambient temperature from 0°C to 40°C results in a 19.7% increase in the PV array capacity and an 8.2% increase in the NPC and COE. Furthermore, according to the ambient temperature of Choman, using PV modules with high sensitivity to temperature is found to be an attractive option. Provided simulation performance analysis proves that the studied parameters must be treated well to establish an enabling environment for solar energy development in Iraq.

scholarly journals A Five-Level H-Bridge STATCOM for an Off-Grid PV Solar Farm under Two Controllers PI and PIλ-MPC Hybrid

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Onur Ozdal Mengi
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Ambient Temperature ◽  
Predictive Control ◽  
Reactive Power ◽  
Energy System ◽  
Reactive Power Compensation ◽  
Static Synchronous Compensator ◽  
Network Load ◽  
Pi Controllers

Investigations were presented in order to eliminate the reactive power on microgrid loads fed by an off-grid and mid-power photovoltaic solar energy system (PVSES) with a static synchronous compensator (STATCOM) device. The electric network is specifically characterized by P-Q loads, ambient temperature, and widely variable solar radiation levels. Two main innovations are developed. Firstly, the STATCOM apparatus is a 5-level H-bridge inverter with capacitances as load and must totally compensates the reactive power in the network load. Secondly, this compensation is controlled by a set of fractional PI (PIλ) and model predictive control (MPC) hybrid. The efficiencies of these controllers were compared with classical PI controllers. Large simulations, without and with reactive power compensation, in steady and transient states, are carried out to underline the merits of the presented works, by performing in the MATLAB-Simulink environment.

scholarly journals Detrended Multiple Cross-Correlation Coefficient applied to solar radiation, air temperature and relative humidity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea de Almeida Brito ◽  
Heráclio Alves de Araújo ◽  
Gilney Figueira Zebende
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Solar Energy ◽  
Correlation Coefficient ◽  
Air Temperature ◽  
Cross Correlation ◽  
Global Solar Radiation ◽  
Meteorological Variables ◽  
Hourly Data ◽  
Cross Correlations

AbstractDue to the importance of generating energy sustainably, with the Sun being a large solar power plant for the Earth, we study the cross-correlations between the main meteorological variables (global solar radiation, air temperature, and relative air humidity) from a global cross-correlation perspective to efficiently capture solar energy. This is done initially between pairs of these variables, with the Detrended Cross-Correlation Coefficient, ρDCCA, and subsequently with the recently developed Multiple Detrended Cross-Correlation Coefficient, $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2. We use the hourly data from three meteorological stations of the Brazilian Institute of Meteorology located in the state of Bahia (Brazil). Initially, with the original data, we set up a color map for each variable to show the time dynamics. After, ρDCCA was calculated, thus obtaining a positive value between the global solar radiation and air temperature, and a negative value between the global solar radiation and air relative humidity, for all time scales. Finally, for the first time, was applied $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2 to analyze cross-correlations between three meteorological variables at the same time. On taking the global radiation as the dependent variable, and assuming that $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}={\bf{1}}$$DMCx2=1 (which varies from 0 to 1) is the ideal value for the capture of solar energy, our analysis finds some patterns (differences) involving these meteorological stations with a high intensity of annual solar radiation.

Sunlight-Activated Phase Change Materials for Controlled Heat Storage and Triggered Release

2021 ◽  
Author(s):  
Yuran Shi ◽  
Mihael Gerkman ◽  
Qianfeng Qiu ◽  
Shuren Zhang ◽  
Grace G. D. Han
Keyword(s):  
Phase Transition ◽  
Solar Radiation ◽  
Phase Change ◽  
Latent Heat ◽  
Photon Energy ◽  
Organic Phase ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Triggered Release

We report the design of photo-responsive organic phase change materials that can absorb filtered solar radiation to store both latent heat and photon energy via simultaneous phase transition and photo-isomerization....

scholarly journals The role of L/W in the solar radiation for Saharian cities

2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Energy Levels ◽  
Direct Solar Radiation ◽  
Test Field ◽  
Natural Lighting ◽  
The Difference ◽  
The Impact ◽  
The Relationship

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.

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