A Nonlinear Steady-State Characteristic Performance Curve for Medium-Temperature Solar Energy Collectors

1991 ◽  
Vol 113 (3) ◽  
pp. 164-171 ◽  
Author(s):  
P. C. Eames ◽  
B. Norton
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Solar Energy ◽  
Environmental Conditions ◽  
Solar Collector ◽  
Performance Curve ◽  
State Characteristic ◽  
Medium Temperature ◽  
New Approach ◽  
Made In

A numerical simulation model was employed to investigate the effects of ambient temperature and insolation of the efficiency of compound parabolic concentrating solar energy collectors. The limitations of presently used collector performance characterization curves were investigated and a new approach proposed. The major advantage of the new procedure over those employed previously is that different solar collector performance characteristics can now be readily normalized to a common set of environmental conditions. Thus, an equitable comparison may be made, in the context of the application conditions, of rating characteristics for disparate collectors which were obtained initially under different conditions.

scholarly journals A New Approach to Solar Desalination Using a Humidification–Dehumidification Process for Remote Areas

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1120
Author(s):  
Mishal Alsehli
Keyword(s):  
Solar Energy ◽  
Solar Collector ◽  
Critical Issue ◽  
Feed Water ◽  
Daily Production ◽  
New Approach ◽  
Remote Areas ◽  
Solar Desalination ◽  
Two Phases ◽  
Solar Powered

Freshwater supply in remote areas has become a critical issue. This paper aims to introduce a new approach to a solar-powered humidification–dehumidification (HDH) desalination system. The design uses a solar collector, a thermal storage tank, and an HDH unit. The HDH works continuously by feeding water to absorb solar energy during the day and then relaying the desalination units with feed water at a top brine temperature (TBT) at night. The model predicts the amount of solar energy stored for the next day, and based on this, the amount of feed water that should be raised to the TBT is calculated. The system operation is carried out in two phases. During the day, the feed water absorbs the heat of solar energy, thereby increasing its temperature to TBT. This hot feed water is then kept in storage tanks. At night, the tank switches to discharging mode and starts feeding the HDH with the hot feed water. The system is designed so that the roles of the tank are rotated at sunset. To achieve the same TBT every day in response to changes in the available solar energy, the mass of the feed water is adjusted daily. The design is simulated using a dynamic model of the energy and mass balance resulting in an average daily production of 7.6 kg of fresh water per unit area of the solar collector. The daily average of the gain output and the recovery ratios are 0.3 and 0.09 respectively.

scholarly journals Realization of a Based Concrete Thermal Storage Module used with a Medium Temperature Parabolic Trough Solar Collector

2015 ◽  
Vol 10 (1) ◽  
Keyword(s):  
Solar Energy ◽  
Solar Collector ◽  
Thermal Characteristic ◽  
Operation Time ◽  
Thermal Storage ◽  
Solar Irradiation ◽  
Parabolic Trough ◽  
Night Time ◽  
Medium Temperature ◽  
Parabolic Trough Solar Collector

Thermal solar energy has been considered for years as one of the most promising candidate for the substitution of the conventional systems providing a clean and sustainable energy solution. However, the intermittent aspect of the solar irradiation received by the earth surface presented a major obstacle for the exploitation and the integration of such technology in various applications. In order to avoid this barrier a thermal storage system for solar energy became a necessity especially for the concentrated solar power technologies. This paper shows the work carried out to determine the thermal behavior of a concrete storage unit for medium temperature applications. The experimental thermal storage module using concrete was realized and tested in order to be integrated in an advanced setup to a solar cooling installation powered by a parabolic trough solar collector. The thermal characteristic of the used concrete matrix was determined. The thermal storage module was tested under the same thermal conditions provided by the solar collectors. The temperature variations of the module during the charging and the heat loss during the night time were investigated. The test results showed some interesting thermal inertia of the concrete based storage module. The integration of the proposed storage module to the solar loop of the cooling installation will lead to extend the operation time after sunset and to decrease time lasted by the solar parabolic trough collector to reach the required operational temperature in the morning.

The Design on Heating System for Experiment of Solar Energy and Geothermal-Source Heat Pump

2012 ◽  
Vol 512-515 ◽  
pp. 194-197
Author(s):  
Ying Ling Cai ◽  
Yin Long Wu ◽  
Hua Zhang ◽  
Ji Wei Li
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Solar Energy ◽  
Heat Pump ◽  
Dynamic Load ◽  
Solar Collector ◽  
Heating System ◽  
Solar Collectors ◽  
Heating Load ◽  
The Mathematical Model

Through the study on the project, we can easily find that if we do not need heat the whole day, adopting the dynamic load method to calculate the heating load is more advisable compared to adopting a steady-state one, especially when we select the equipment. After establishing the mathematical model of the project, under the premise of meeting the heating load, considered the economy, the optimal solar collector area of this project is 11.1 square meters. In addition, through simulating the project, we can learn that the best azimuth of solar collectors in Shanghai is south by east 22.5 °.

Optical Cascade Heat-Collection for Effective Solar Energy Gain

1987 ◽  
Vol 109 (4) ◽  
pp. 298-302 ◽  
Author(s):  
Isao Oshida ◽  
Akio Suzuki
Keyword(s):  
Solar Energy ◽  
Solar Collector ◽  
Fluid Flows ◽  
The Other ◽  
Heat Transfer Fluid ◽  
Cascade System ◽  
Medium Temperature ◽  
Fresnel Lenses ◽  
Higher Temperature ◽  
Tracking Device

Optical cascade heat collection of solar energy has proved effective for gaining thermal energy in the medium temperature region (80∼150° C). The cascade system consists of two separate absorbers (one hot and the other warm) and an optical system including CPC’s and Fresnel lenses which concentrate the direct solar radiation on one of the two absorbers. The temperature of the heat transfer fluid can be increased effectively if the fluid flows into the warm absorber first and then flows into the hot absorber. This type of solar collector, having no mechanical tracking device, can theoretically collect heat at a higher temperature than usual flat-plate collectors.

scholarly journals STUDI SIMULASI NUMERIK PENGARUH PENAMBAHAN FINS SETENGAH SILINDER DISUSUN SECARA STAGGERED TERHADAP KINERJA KOLEKTOR SURYA PEMANAS UDARA DENGAN PLAT PENYERAP V-CORRUGATED

POROS ◽  
2018 ◽  
Vol 15 (1) ◽  
pp. 35
Author(s):  
Sulaiman Ali ◽  
Djatmiko Ichsani
Keyword(s):  
Numerical Simulation ◽  
Solar Energy ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Flow Direction ◽  
Convection Heat Transfer ◽  
Working Fluid ◽  
Absorber Plate ◽  
Optimum Diameter ◽  
Flow Turbulence

Abstract: The use of solar energy by using solar collector has been extensively researched to optimize existing solar energy source, one of the methods to utilize solar energy is by using solar collector and has been widely utilized by humans in the drying process. To create a solar collector with optimum performance the thermal efficiency needs to be increased, as for increasing the thermal efficiency of solar collector one by extending the absorption field and increasing the convection heat transfer coefficient by creating a turbulent flow inside the solar collector duct, the flow turbulence can be achieved by Provides obstacle and fins disturbance to the flow direction of the working fluid under the hot absorber plate. This research was conducted with 3D Steady flow numerical simulation with turbulence viscos k-omega SST. The objective of this research is to know the optimum diameter and spacing of fins variation with 6mm, 8mm, and 10mm fins diameter, and variation of fins distance to obstacle 0,25L; 0.5L and 0.75L. The result of numerical simulation optimum fins is determined by the smallest ratio of ΔP/ΔT and this research continued to the experiment. The solar collector used in this study is a solar collector using a v-corrugated absorber plate with triangular obstacle and half cylindrical fins arranged staggered inside a solar collector duct. The results obtained from this research is, the most optimum half cylinder fins are 6 mm fins with a fins distance to obstacle 0.75L. 

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

scholarly journals Tuning Bandgaps of Mixed Halide and Oxide Perovskites CsSnX3 (X=Cl, I), and SrBO3 (B=Rh, Ti)

2021 ◽  
Vol 11 (15) ◽  
pp. 6862
Author(s):  
Hongzhe Wen ◽  
Xuan Luo
Keyword(s):  
Solar Energy ◽  
Electronic Properties ◽  
Density Functional ◽  
Photovoltaic Cell ◽  
Photovoltaic Properties ◽  
Functional Theory ◽  
New Approach ◽  
Energy Applications ◽  
Valence Bands ◽  
The Ideal

Perovskites have recently attracted interest in the field of solar energy due to their excellent photovoltaic properties. We herein present a new approach to the composition of lead free perovskites via mixing of halide and oxide perovskites that share the cubic ABX3 structure. Using first-principles calculations through Density Functional Theory, we systematically investigated the atomic and electronic structures of mixed perovskite compounds composed of four cubic ABX3 perovskites. Our result shows that the B and X atoms play important roles in their band structure. On the other hand, their valence bands contributed by O-2p, Rh-4p, and Ti-3p orbitals, and their electronic properties were determined by Rh-O and Ti-O bonds. With new understandings of the electronic properties of cubic halide or oxide perovskites, we lastly combined the cubic perovskites in various configurations to improve stability and tune the bandgap to values desirable for photovoltaic cell applications. Our investigations suggest that the mixed perovskite compound Cs2Sn2Cl3I3Sr2TiRhO6 produced a bandgap of 1.2 eV, which falls into the ideal range of 1.0 to 1.7 eV, indicating high photo-conversion efficiency and showing promise towards solar energy applications.

scholarly journals Photo-rechargeable zinc-ion batteries

2020 ◽  
Vol 13 (8) ◽  
pp. 2414-2421 ◽  
Author(s):  
Buddha Deka Boruah ◽  
Angus Mathieson ◽  
Bo Wen ◽  
Sascha Feldmann ◽  
Wesley M. Dose ◽  
...  
Keyword(s):  
Solar Cell ◽  
Solar Energy ◽  
Zinc Ion ◽  
New Approach

This paper presents a zinc-ion battery that can be recharged directly by light without the need for a solar cell, which offers a new approach to balancing the unpredictable energy surpluses and deficits associated with solar energy.

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