scholarly journals Heat Loss Testing of Schott's 2008 PTR70 Parabolic Trough Receiver

2009 ◽  
Author(s):  
Frank Burkholder ◽  
Chuck Kutscher
Keyword(s):  
Heat Loss ◽  
Parabolic Trough

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

Heat Loss Measurement and Analyses of Solar Parabolic Trough Receiver

2013 ◽  
Vol 291-294 ◽  
pp. 127-131
Author(s):  
Jian Feng Lu ◽  
Jing Ding ◽  
Jian Ping Yang ◽  
Kang Wang
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Loss ◽  
Boundary Region ◽  
Heat Losses ◽  
Experimental Measurements ◽  
Wind Condition ◽  
Parabolic Trough ◽  
Loss Measurement ◽  
Glass Envelope

The heat loss of vacuum receiver plays critical important role in solar parabolic trough system. In this paper, experimental measurements and calculation models were conducted to investigate the heat loss of solar parabolic trough receiver with receiver length of 10.2 m and diameter of 0.120 m. In general, the heat loss of receiver decreased with the receiver wall temperature, while it can approach minimum under special wind condition. The heat loss of receiver mainly included the heat loss of glass and boundary region, and the heat losses of receiver, glass region and boundary region with tube temperatures of 176.2oC were respectively 987.1 W, 762.2 W and 224.9 W. Outside the glass envelope, the convection and radiation both play an important role in the heat loss of receiver, while the heat transfer is mainly dependent upon the radiation inside the glass envelope. In addition, the heat losses of convection outside the glass and radiation inside the glass from calculation very well agreed with the experimental data.

scholarly journals Wind Engineering Analysis of Parabolic Trough Collectors to Optimise Wind Loads and Heat Loss

2015 ◽  
Vol 69 ◽  
pp. 168-177 ◽  
Author(s):  
J. Paetzold ◽  
S. Cochard ◽  
D.F. Fletcher ◽  
A. Vassallo
Keyword(s):  
Heat Loss ◽  
Wind Engineering ◽  
Wind Loads ◽  
Engineering Analysis ◽  
Parabolic Trough

Parabolic trough solar receivers characterization using specific test bench for transmittance, absorptance and heat loss simultaneous measurement

Solar Energy ◽  
2016 ◽  
Vol 136 ◽  
pp. 268-277 ◽  
Author(s):  
J.L. Navarro-Hermoso ◽  
G. Espinosa-Rueda ◽  
C. Heras ◽  
I. Salinas ◽  
N. Martinez ◽  
...  
Keyword(s):  
Heat Loss ◽  
Simultaneous Measurement ◽  
Test Bench ◽  
Parabolic Trough ◽  
Specific Test

scholarly journals One-Dimensional Modeling of Triple-Pass Concentric Tube Heat Exchanger in the Parabolic Trough Solar Air Collector

2021 ◽  
Author(s):  
Nguyen Minh Phu ◽  
Ngo Thien Tu
Keyword(s):  
Temperature Distribution ◽  
Heat Loss ◽  
Solar Collector ◽  
Tube Length ◽  
Parabolic Trough ◽  
Tube Heat Exchanger ◽  
Dimensional Modeling ◽  
Effective Efficiency ◽  
Large Heat ◽  
Parabolic Trough Solar Collector

The parabolic trough solar collector has a very high absorber tube temperature due to the concentration of solar radiation. The high temperature leads to large heat loss to the environment which reduces efficiency of the parabolic trough collector. The heat loss reduction can be obtained by adopting a multi-pass fluid flow arrangement. In this chapter, airflow travels in three passes of the receiver to absorb heat from the glass covers and absorber tube to decrease surface temperatures. 1D mathematical model is developed to evaluate effective efficiency and the temperature distribution of surfaces and fluid. The mathematical modeling is based on air temperature gradients and solved by a numerical integration. Diameter ratios of outer glass to inner glass (r23) and inner glass to absorber tube (r12), Reynolds number (Re), and tube length (L) are varied to examine the efficiency and the temperature distribution. Results showed that the highest efficiency is archived at r23 = 1.55 and r12 in the range of 1.45 to 1.5. The efficiency increases with Re and decreases with L due to dominant heat transfer in terms of thermohydraulic behavior of a concentrating solar collector. With the optimum ratios, absorber tube temperature can reduce 15 K compared with another case.

scholarly journals Assessment of Performance Enhancement Potential of a High-Temperature Parabolic Trough Collector System Combining the Optimized IR-Reflectors

2020 ◽  
Vol 10 (11) ◽  
pp. 3744 ◽  
Author(s):  
Qiliang Wang ◽  
Hongxing Yang ◽  
Gang Pei ◽  
Honglun Yang ◽  
Jingyu Cao ◽  
...  
Keyword(s):  
Heat Loss ◽  
Solar Irradiance ◽  
Superior Performance ◽  
Cutoff Wavelength ◽  
The Novel ◽  
Parabolic Trough ◽  
Optimal Cutoff ◽  
Parabolic Trough Collector ◽  
Photothermal Conversion ◽  
Overall Performance

Heat collecting elements (HCEs) are the core components in the parabolic trough collector (PTC) system because photothermal conversion of the whole system occurs in the HCEs. However, considerable heat loss from the HCEs at high operating temperature exerts seriously negative impact on the photothermal conversion efficiency of the PTC system and subsequent application systems. To effectively reduce the heat loss and thus enhance the overall performance of the PTC system, in our previous work, we proposed three kinds of novel HCEs by partially depositing different IR-reflector coatings on the inner and outer surfaces of the glass envelope. The infrared (IR)-reflector of actual transparent conductive oxide (TCO) film, IR-reflector with a fixed cutoff wavelength of 2.5 μm, and the IR-reflector with optimal cutoff wavelength showed extremely effective roles in the reduction of heat loss in HCEs. In this paper, the comprehensive energy and exergy performances of these three novel HCEs in a real 72 m small-scale PTC system are further investigated by the mathematical models established. Additionally, the comparisons among overall performances of the proposed HCEs under different direct solar irradiances are also carried out. The results show that the simulated data yields good consistence with the experimental results, and that all three of the novel HCEs achieve superior overall performance compared with the conventional HCEs. The PTC system installing the novel HCEs with the IR-reflector coating which possesses the optimal cutoff wavelength has the best energetic and exergetic efficiencies, which are significantly improved by 25.2% and 28.1% compared with the conventional HCEs at the solar irradiance of 800 W/m2 and inlet temperature of 580 °C. Moreover, the proposed novel HCEs have a much superior performance at lower solar irradiance. The performance-enhanced PTC system will play a significantly positive role in the performance improvement of the heating and cooling of buildings in the future.

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 A Transient Thermography Method to Separate Heat Loss Mechanisms in Parabolic Trough Receivers

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Marc Röger ◽  
Peter Potzel ◽  
Johannes Pernpeintner ◽  
Simon Caron
Keyword(s):  
Heat Loss ◽  
Temperature Measurements ◽  
Thermal Excitation ◽  
Transient Method ◽  
Parabolic Trough ◽  
Selective Coating ◽  
Transient Thermography ◽  
Energy Balances ◽  
Glass Envelope ◽  
Loss Mechanisms

This paper describes a transient thermography method to measure the heat loss of parabolic trough receivers and separate their heat loss mechanisms. This method is complementary to existing stationary techniques, which use either energy balances or glass envelope temperature measurements to derive overall heat losses. It is shown that the receiver heat loss can be calculated by applying a thermal excitation on the absorber tube and measuring both absorber tube and glass envelope temperature signals. Additionally, the emittance of the absorber selective coating and the vacuum quality of the annulus can be derived. The benefits and the limits of the transient method are presented and compared to the established stationary method based on glass envelope temperature measurements. Simulation studies and first validation experiments are described. A simulation based uncertainty analysis indicates that an uncertainty level of approximately 5% could be achieved on heat loss measurements for the transient method introduced in this paper, whereas for a conventional stationary field measurement technique, the uncertainty is estimated to 17–19%.

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