Economic Optimization of Stationary Nonevacuated CPC Solar Collectors

1987 ◽  
Vol 109 (1) ◽  
pp. 40-45 ◽  
Author(s):  
M. J. Carvalho ◽  
M. Collares-Pereira ◽  
J. M. Gordon
Keyword(s):  
Low Temperature ◽  
Flat Plate ◽  
Operating Temperature ◽  
Solar Collectors ◽  
Economic Optimization ◽  
Promising Alternative ◽  
Energy Delivery ◽  
Low Concentrations ◽  
East West ◽  
Concentration Ratios

Stationary, nonevacuated CPC solar collectors are a promising alternative to corresponding flat plate collectors in that they offer superior yearly energy delivery at comparable cost for low-temperature thermal applications. For realistic cost scenarios, we determine optimal concentrator configurations and concentration ratios, and calculate their sensitivity to variations in relative component costs, climate, orientation and collector operating temperature. For CPC’s that are to have the flexibility of either east-west or north-south orientation, optimized collectors are shown to have low concentrations of around 1.2, achieved by truncation from acceptance half angles of about 45 deg.

Nonimaging Solar Energy Concentrators (CPC’s) With Fully Illuminated Flat Receivers: A Viable Alternative to Flat-Plate Collectors

1986 ◽  
Vol 108 (3) ◽  
pp. 252-256 ◽  
Author(s):  
J. M. Gordon
Keyword(s):  
Solar Energy ◽  
Flat Plate ◽  
Closed Form ◽  
Ray Tracing ◽  
Production Costs ◽  
Viable Alternative ◽  
Solar Collectors ◽  
Low Concentration ◽  
Geometric Characteristics ◽  
Energy Delivery

Low-concentration, stationary, nonimaging concentrators (CPC’s) with flat receivers illuminated on both sides are considered as viable alternatives to flat-plate solar collectors. Closed-form, analytic formulae are derived for the geometric characteristics of two concentrator types of greatest interest (i.e., stationary collectors for year-round energy delivery), which enable calculations of collectible energy without computer ray-tracing stimulations. The relative merits of these concentrators in terms of energy collection and production costs are assessed with respect to each other as well as to flat-plate collectors.

scholarly journals Single and Hybrid Nanofluids to Enhance Performance of Flat Plate Solar Collectors: Application and Obstacles

2020 ◽  
Vol 65 (1) ◽  
pp. 86-102
Author(s):  
Qudama Al-Yasiri ◽  
Márta Szabó ◽  
Müslüm Arıcı
Keyword(s):  
Flat Plate ◽  
Performance Enhancement ◽  
Research Area ◽  
Concentration Limit ◽  
Solar Collectors ◽  
Thermal Systems ◽  
Solar Systems ◽  
Low Concentrations ◽  
Medium Level ◽  
Influential Parameters

Solar energy represents the best alternative for traditional energy sources used in many thermal energy systems. Among solar thermal systems, Flat Plate Solar Collectors (FPSCs) are the most utilized type implemented in low and medium-level thermal domestic applications. Recently, the usage of nanofluids (NFs) to enhance FPSCs is one of the newest technologies that has drawn the attention of researchers to improve the overall thermal efficiency of solar systems. This paper briefly reviews the recent studies carried on thermal performance enhancement of FPSCs by implementing NFs (single and hybrid NFs) considering the main influential parameters such as particle concentration, particle size, and collector area. Finally, the main obstacles reported by the researchers such as the instability, viscosity, concentration limit, corrosion effect and others are identified, which is believed to be useful for interested newcomers in this research area. Based on the studies investigated in this paper, NFs, even under low concentrations, can remarkably improve the energetic and exergetic efficiency of FPSCs.

Experimental Performance Analysis of External Compound Parabolic Concentrators With Low Concentration Ratios for Medium Temperature Applications

2014 ◽  
Author(s):  
Donghao Xu ◽  
Ming Qu
Keyword(s):  
Experimental Data ◽  
Flat Plate ◽  
Operating Temperature ◽  
Industrial Process ◽  
Solar Collectors ◽  
Medium Temperature ◽  
Actual Performance ◽  
Low Concentration ◽  
Solar Tracking ◽  
Operating Temperatures

Due to the mounting concerns about climate changes and depletion of fossil fuels, solar energy, as one type of renewable energy, has attracted a lot of interests from academia, industries, and government in the past few decades. Currently, solar thermal technologies have been applied to the applications at the low operating temperature below 100°C by using flat-plate solar collectors and at the high operating temperature above 250°C by using solar tracking concentrators. For the medium operating temperatures between 100°C and 250°C, flat-plate solar collectors can hardly reach 100°C and solar tracking concentrators are too expensive. In this context, the use of external compound parabolic concentrators (XCPC) for applications operated at medium temperature draws quite attentions because of its higher efficiency than flat plate solar collectors and better cost effectiveness than solar tracking concentrators. However, currently only a few experimental data is available on the actual performance of XCPCs from literatures, especially for the recently new XCPCs with a low concentration ratio. In order to contribute to the knowledge, a series of experiments have been conducted on the new XCPCs recently installed at Bowen Lab, Purdue University, West Lafayette, Indiana. The experiments showed that the XCPCs raised the temperature to 170°C, which is 140°C higher than the ambient temperatures, with a thermal efficiency of 29%. Based on the data collected from the experiments, the optical and thermal efficiencies of XCPCs are determined for different solar irradiations, operating temperatures, and incident angles. A new regression model is proposed and fitted accordingly. The experimental data and analysis demonstrated the feasibility and potentials of using XCPCs for applications in medium temperature range such as solar absorption cooling and heating systems, seawater desalination, solar disinfection, post-combustion carbon capture systems and other industrial process heating.

Calculating Solar Radiation Received by Tubular Collectors

1995 ◽  
Vol 117 (4) ◽  
pp. 341-344 ◽  
Author(s):  
R. Perez ◽  
R. Seals ◽  
J. Anderson ◽  
D. Menicucci
Keyword(s):  
Low Temperature ◽  
Solar Radiation ◽  
Flat Plate ◽  
Solar Collectors ◽  
The Subject ◽  
Evacuated Tubes ◽  
The Difference ◽  
Tubular Arrays

Tubular absorbers installed inside evacuated tubes represent an increasingly common design for low-temperature solar collectors. Much work has been done on the subject of solar radiation received by flat-plate collectors; much less has been done for tubular collectors. In this paper we present an algorithm to estimate irradiance impinging on tubular arrays. Key examples are provided to illustrate the difference of energy collected between flat-plate and tubular collectors.

Investigation of High Percentage Acetone-Butanol-Ethanol (ABE) Blended With Diesel in a Constant Volume Chamber

2014 ◽  
Author(s):  
Yilu Lin ◽  
Han Wu ◽  
Karthik Nithyanandan ◽  
Timothy H. Lee ◽  
Chia-fon F. Lee ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Constant Volume ◽  
Low Temperature Combustion ◽  
Transportation Fuel ◽  
Promising Alternative ◽  
Alternative Transportation ◽  
Constant Volume Chamber ◽  
Temperature Combustion ◽  
Acetone Butanol Ethanol

Bio-butanol, a promising alternative transportation fuel, has its industrial-scale production hindered significantly by high cost component purification process from acetone-butanol-ethanol (ABE) broth. The purpose of this study is to investigate the possibility of using ABE-Diesel blends with high ABE percentages as an alternative transportation fuel. An optical-accessible constant volume chamber capable of controlling ambient temperature, pressure and oxygen concentration was used to mimic the environmental conditions inside a real diesel engine cylinder. ABE fuel with typical volumetric ratios of 30% acetone, 60% butanol and 10% ethanol were blended with ultra-low sulfur diesel at 80% vol. and were tested in this study. The ambient temperature was set to be at 1100K and 900K, which represents normal combustion conditions and low temperature combustion conditions respectively. The ambient oxygen concentrations were set to be at 21%, 16% and 11%, representing different EGR ratios. The in-cylinder pressure was recorded by using a pressure transducer and the time-resolved Mie-scattering image and natural flame luminosity was captured using a high-speed camera coupled with a copper vapor laser. The results show that the liquid penetration is reduced by the high percentage of ABE in the blends. At the same time, the soot formation is reduced significantly by increasing oxygen content in the ABE fuel. Even more interesting, a soot-free combustion was achieved by combining the low temperature combustion with the higher percentage ABE case. In terms of soot emission, high ABE ratio blends are a very promising alternative fuel to be directly used in diesel engines especially under low-temperature combustion conditions.

Thermal and mechanical performance of sealed, gas-filled, flat plate solar collectors

Solar Energy ◽  
2012 ◽  
Vol 86 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Johan Vestlund ◽  
Jan-Olof Dalenbäck ◽  
Mats Rönnelid
Keyword(s):  
Flat Plate ◽  
Mechanical Performance ◽  
Solar Collectors
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