scholarly journals Parabolic trough receiver heat loss and optical efficiency round robin 2015/2016

2017 ◽  
Author(s):  
Johannes Pernpeintner ◽  
Björn Schiricke ◽  
Fabienne Sallaberry ◽  
Alberto García de Jalón ◽  
Rafael López-Martín ◽  
...  
Keyword(s):  
Heat Loss ◽  
Round Robin ◽  
Parabolic Trough ◽  
Optical Efficiency

scholarly journals Generation of a Parabolic Trough Collector Efficiency Curve From Separate Measurements of Outdoor Optical Efficiency and Indoor Receiver Heat Loss

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Charles Kutscher ◽  
Frank Burkholder ◽  
J. Kathleen Stynes
Keyword(s):  
Ambient Temperature ◽  
Heat Loss ◽  
Thermal Efficiency ◽  
Operating Temperature ◽  
Efficiency Curve ◽  
Parabolic Trough ◽  
Optical Efficiency ◽  
Parabolic Trough Collector ◽  
Collector Efficiency ◽  
The Difference

The thermal efficiency of a parabolic trough collector is a function of both the fraction of direct normal radiation absorbed by the receiver (the optical efficiency) and the heat lost to the environment when the receiver is at operating temperature. The thermal efficiency can be determined by testing the collector under actual operating conditions or by separately measuring these two components. This paper describes how outdoor measurement of the optical efficiency is combined with laboratory measurements of receiver heat loss to obtain the thermal efficiency curve. This paper describes this approach and also makes the case that there are advantages to plotting collector efficiency versus the difference between the operating temperature and the ambient temperature at which the receiver heat loss was measured divided by radiation to a fractional power (on the order of 1/3 but obtained via data regression)—as opposed to the difference between operating and ambient temperatures divided by the radiation. The results are shown to be robust over wide ranges of ambient temperature, sky temperature, and wind speed.

Comparison of Two Linear Collectors in Solar Thermal Plants: Parabolic Trough vs Fresnel

2011 ◽  
Author(s):  
A. Giostri ◽  
M. Binotti ◽  
P. Silva ◽  
E. Macchi ◽  
G. Manzolini
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Solar Thermal ◽  
Heat Transfer Fluid ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Research Activity ◽  
Optical Efficiency ◽  
Synthetic Oil ◽  
Yearly Average

Parabolic trough can be considered the state of the art for solar thermal power plants thanks to the almost 30 years experience gained in SEGS and, recently, Nevada Solar One plants in US and Andasol plants in Spain. One of the major issues that limits the wide diffusion of this technology is the high investment cost of the solar field and, particularly, of the solar collector. For this reason, since several years research activity has been trying to develop new solutions with the aim of cost reduction. This work compares commercial Fresnel technology with conventional parabolic trough plant based on synthetic oil as heat transfer fluid at nominal conditions and evaluates yearly average performances. In both technologies, no thermal storage system is considered. In addition, for Fresnel, a Direct Steam Generation (DSG) case is investigated. Performances are calculated by a commercial code, Thermoflex®, with dedicated component to evaluate solar plant. Results will show that, at nominal conditions, Fresnel technology have an optical efficiency of 67% which is lower than 75% of parabolic trough. Calculated net electric efficiency is about 19.25%, while parabolic trough technology achieves 23.6%. In off-design conditions, the gap between Fresnel and parabolic trough increases because the former is significantly affected by high radiation incident angles. The calculated sun-to-electric annual average efficiency for Fresnel plant is 10.2%, consequence of the average optical efficiency of 38.8%, while parabolic trough achieve an overall efficiency of 16%, with an optical one of 52.7%. An additional case with Fresnel collector and synthetic oil outlines differences among investigated cases. Finally, because part of performance difference between PT and Fresnel is simple due to different definitions, additional indexes are introduced in order to make a consistent comparison.

Study on Optical Efficiency Characteristics of Receivers in a Solar Parabolic Trough Concentrator

2016 ◽  
Vol 36 (1) ◽  
pp. 0122002
Author(s):  
冯志康 Feng Zhikang ◽  
李明 Li Ming ◽  
王云峰 Wang Yunfeng ◽  
陈飞 Chen Fei ◽  
冀孟恩 Ji Meng′en ◽  
...  
Keyword(s):  
Parabolic Trough ◽  
Optical Efficiency

scholarly journals Effect of the Orientation Schemes of the Energy Collection Element on the Optical Performance of a Parabolic Trough Concentrating Collector

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 128 ◽  
Author(s):  
Majedul Islam ◽  
Prasad Yarlagadda ◽  
Azharul Karim
Keyword(s):  
Monte Carlo ◽  
State Of The Art ◽  
Tracking Error ◽  
Surface Group ◽  
Energy Performance ◽  
Optical Performance ◽  
Extended Version ◽  
Parabolic Trough ◽  
Tracking Errors ◽  
Optical Efficiency

While the circular shape is currently the proven optimum design of the energy collection element (ECE) of a parabolic trough collector, that is yet to be confirmed for parabolic trough concentrating collectors (PTCCs) like trough concentrating photovoltaic collectors and hybrid photovoltaic/thermal collectors. Orientation scheme of the ECE is expected to have significant effect on the optical performance including the irradiance distribution around the ECE and the optical efficiency, and therefore, on the overall energy performance of the PTCC. However, little progress addressing this issue has been reported in the literature. In this study, a thorough investigation has been conducted to determine the effect of the orientation schemes of ECE on the optical performance of a PTCC applying a state-of-the-art Monte Carlo ray tracing (MCRT) technique. The orientation schemes considered are a flat rectangular target and a hollow circular, semi-circular, triangular, inverted triangular, rectangular and rectangle on semi-circle (RSc). The effect of ECE defocus, Sun tracking error and trough rim angle on the optical performance is also investigated. The MCRT study reveals that the ECE orientation schemes with a curved surface at the trough end showed much higher optical efficiency than those with a linear surface under ideal conditions. ECEs among the linear surface group, the inverted triangular orientation exhibited the highest optical efficiency, whereas the flat and triangular ones exhibited the lowest optical efficiency, and the rectangular one was in between them. In the event of defocus and tracking errors, a significant portion of the concentrated light was observed to be intercepted by the surfaces of the rectangular and RSc ECEs that are perpendicular to the trough aperture. This is an extended version of a published work by the current authors, which will help to design an optically efficient ECE for a parabolic trough concentrating collector.

Analysis of the influence of heat loss factors on the overall performance of utility-scale parabolic trough solar collectors

Energy ◽  
2018 ◽  
Vol 162 ◽  
pp. 1077-1091 ◽  
Author(s):  
Li Xu ◽  
Feihu Sun ◽  
Linrui Ma ◽  
Xiaolei Li ◽  
Guofeng Yuan ◽  
...  
Keyword(s):  
Heat Loss ◽  
Solar Collectors ◽  
Parabolic Trough ◽  
Overall Performance ◽  
Utility Scale ◽  
Loss Factors

Comparison of Two Linear Collectors in Solar Thermal Plants: Parabolic Trough Versus Fresnel

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
A. Giostri ◽  
M. Binotti ◽  
P. Silva ◽  
E. Macchi ◽  
G. Manzolini
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
The United States ◽  
Solar Thermal ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Annual Average ◽  
Optical Efficiency ◽  
Levelized Cost Of Electricity ◽  
Synthetic Oil

Parabolic trough (PT) technology can be considered the state of the art for solar thermal power plants thanks to the almost 30 yr of experience gained in SEGS and, recently, Nevada Solar One plants in the United States and Andasol plant in Spain. One of the major issues that limits the wide diffusion of this technology is the high investment cost of the solar field and, particularly, of the solar collector. For this reason, research has focused on developing new solutions that aim to reduce costs. This paper compares, at nominal conditions, commercial Fresnel technology for direct steam generation with conventional parabolic trough technology based on synthetic oil as heat-transfer. The comparison addresses nominal conditions as well as annual average performance. In both technologies, no thermal storage system is considered. Performance is calculated by Thermoflex®, a commercial code, with a dedicated component to evaluate solar plant. Results will show that, at nominal conditions, Fresnel technology has an optical efficiency of 67%, which is lower than the 75% efficiency of the parabolic trough. Calculated net electric efficiency is about 19.25%, whereas PT technology achieves 23.6% efficiency. In off-design conditions, the performance gap between Fresnel and parabolic trough increases because the former is significantly affected by high incident angles of solar radiation. The calculated sun-to-electric annual average efficiency for a Fresnel plant is 10.2%, which is a consequence of the average optical efficiency of 38.8%; a parabolic trough achieves an overall efficiency of 16%, with an optical efficiency of 52.7%. An additional case with a Fresnel collector and synthetic-oil outlines the differences among the cases investigated. Since part of the performance difference between Fresnel and PT technologies is simply due to different definitions, we introduce additional indexes to make a consistent comparison. Finally, a simplified economic assessment shows that Fresnel collectors must reduce investment costs of at least 45% than parabolic trough to achieve the same levelized cost of electricity.

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