Study of the Optical Impact of Receiver Position Error on Parabolic Trough Collectors

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Guangdong Zhu
Keyword(s):  
Measurement Data ◽  
Position Error ◽  
Geometrical Parameters ◽  
Parabolic Trough ◽  
Error Sources ◽  
Actual Measurement ◽  
Effective Coefficients ◽  
Slope Error ◽  
Computationally Intensive ◽  
Optical Impact

A newly developed analytical optical approach—first-principle OPTical intercept calculation (FirstOPTIC)—is employed to study the optical impact of receiver position error on parabolic trough collectors. The FirstOPTIC method treats optical error sources the way they are typically characterized in laboratory measurements using a geometrical or optical interpretation. By analyzing a large number of cases with varying system parameters, such as overall system optical error and the collector's geometrical parameters, a practical correlation between actual measurement data and its corresponding error-convolution approximation for receiver position error is established from parametric study; the correlation enables a direct comparison of receiver position error to the sun shape and other optical error sources (such as mirror specularity and slope error) with respect to the collector optical performance. The effective coefficients that define the correlation of actual measurement data and its error-convolution approximation for receiver position error are also summarized for several existing trough collectors; these make it convenient to characterize the relative impact of receiver position error compared with other optical error sources, which was not straightforward in the past. It is shown that FirstOPTIC is a suitable tool for in-depth optical analysis and fast collector design optimization, which otherwise require computationally intensive ray-tracing simulations.

The Impact of Receiver Position Error on Parabolic Trough Collector Optical Performance

2012 ◽  
Author(s):  
Guangdong Zhu
Keyword(s):  
Position Error ◽  
Geometrical Parameters ◽  
First Principle ◽  
Optical Performance ◽  
Optical Analysis ◽  
Parabolic Trough ◽  
Actual Measurement ◽  
Position Errors ◽  
Effective Coefficients ◽  
The Impact

A newly developed analytical optical approach — First-principle OPTical Intercept Calculation (FirstOPTIC) — is employed to study the optical impact of receiver position error on parabolic trough collectors. The FirstOPTIC program performs first-principle treatment system optical error sources. By analyzing a large number of cases with varying system parameters such as the overall system optical error and the collector geometrical parameters, the paper quantitatively examines the difference between the first-principle treatment and probability approximation to receiver position error. In addition, a practical correlation between actual measurement data and its probability approximation for receiver position errors is established from parametric study; the correlation can be used to evaluate the relative importance of receiver position error to the collector’s optical performance. The effective coefficients defining the correlation of receiver position errors are also summarized for some existing trough collectors and make it convenient to conduct error-convolution-based optical analysis, which was not straightforward before. It is also shown that FirstOPTIC is a suitable tool for in-depth optical analysis and fast collector design optimization, which otherwise requires computationally intensive ray-tracing simulations.

Research on Method of Process System with Error Tracing Based on PSO

2014 ◽  
Vol 1046 ◽  
pp. 227-231
Author(s):  
Yi Yong Yao ◽  
Xu Wang ◽  
Guang Zhou Diao
Keyword(s):  
Theoretical Model ◽  
Measurement Data ◽  
Optimal Solution ◽  
Machining Process ◽  
Error Sources ◽  
Actual Measurement ◽  
System Error ◽  
Process System ◽  
Error Tracing ◽  
The Stability

In machining process, the machining systems are usually described by the stable theoretical model. However, there are still various process errors existed. To recognize, compensate and eliminate the errors, a method of process system error tracing based on PSO is proposed to explore the errors existing in the machining process. The determined theoretical model is defined and actual measurement data samples are used to find the optimal solution, get the deviation value of each error sources. Finally, the process system error tracing of the Arc Cam is taken as an example to prove the stability and validity of proposed method.

Dynamic Measurement of Spatial Attitude at Bottom Rotating Drillstring: Simulation, Experimental, and Field Test

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Qilong Xue ◽  
Ruihe Wang ◽  
Baolin Liu ◽  
Leilei Huang
Keyword(s):  
Real Time ◽  
Measurement Errors ◽  
Time Window ◽  
Measurement Data ◽  
Movement Patterns ◽  
Dynamic Measurement ◽  
Drilling Process ◽  
Stick Slip ◽  
Actual Measurement ◽  
Gas Drilling

In the oil and gas drilling engineering, measurement-while-drilling (MWD) system is usually used to provide real-time monitoring of the position and orientation of the bottom hole. Particularly in the rotary steerable drilling technology and application, it is a challenge to measure the spatial attitude of the bottom drillstring accurately in real time while the drillstring is rotating. A set of “strap-down” measurement system was developed in this paper. The triaxial accelerometer and triaxial fluxgate were installed near the bit, and real-time inclination and azimuth can be measured while the drillstring is rotating. Furthermore, the mathematical model of the continuous measurement was established during drilling. The real-time signals of the accelerometer and the fluxgate sensors are processed and analyzed in a time window, and the movement patterns of the drilling bit will be observed, such as stationary, uniform rotation, and stick–slip. Different signal processing methods will be used for different movement patterns. Additionally, a scientific approach was put forward to improve the solver accuracy benefit from the use of stick–slip vibration phenomenon. We also developed the Kalman filter (KF) to improve the solver accuracy. The actual measurement data through drilling process verify that the algorithm proposed in this paper is reliable and effective and the dynamic measurement errors of inclination and azimuth are effectively reduced.

Blade Fault Recognition Based on Signal Processing and Adaptive Fluid Dynamic Modelling

1997 ◽  
Author(s):  
A. Stamatis ◽  
N. Aretakis ◽  
K. Mathioudakis
Keyword(s):  
Flow Field ◽  
Fluid Dynamic ◽  
Measurement Data ◽  
Dynamic Modelling ◽  
Physical Modelling ◽  
Diagnostic Procedures ◽  
Measured Quantity ◽  
Test Cases ◽  
Actual Measurement ◽  
Fault Recognition

An approach for identification of faults in blades of a gas turbine, based on physical modelling is presented. A measured quantity is used as an input and the deformed blading configuration is produced as an output. This is achieved without using any kind of “signature”, as is customary in diagnostic procedures for this kind of faults. A fluid dynamic model is used in a manner similar to what is known as “inverse design methods”: the solid boundaries which produce a certain flow field are calculated by prescribing this flow field. In the present case a signal, corresponding to the pressure variation on the blade-to-blade plane, is measured. The blade cascade geometry that has produced this signal is then produced by the method. In the paper the method is described and applications to test cases are presented. The test cases include theoretically produced faults as well as experimental cases, where actual measurement data are shown to produce the geometrical deformations which existed in the test engine.

scholarly journals Evaluating the Accuracy of Railway Total Simulator Compared with Actual Measurement Data

2018 ◽  
Vol 7 (5) ◽  
pp. 416-424
Author(s):  
Tsutomu Miyauchi ◽  
Kenji Imamoto ◽  
Keiko Teramura ◽  
Hirotaka Takahashi
Keyword(s):  
Measurement Data ◽  
Actual Measurement

Application of Entropy-Weight Hierarchy Analysis on Study of Height Prediction of Water Conducted Zone

2013 ◽  
Vol 742 ◽  
pp. 497-500
Author(s):  
Meng Lin Xu ◽  
De Shen Zhao
Keyword(s):  
Analytic Hierarchy Process ◽  
Measurement Data ◽  
Entropy Weight ◽  
Analytic Hierarchy ◽  
Actual Measurement ◽  
Entropy Weight Method ◽  
Hierarchy Analysis ◽  
Height Prediction ◽  
Weight Method ◽  
Hierarchy Process

Based on actual measurement data in Da Ping as the samples,according to the experience, and ends with calculate every factors weight and height prediction of the water conducted zone by Matlab using the combination entropy-weight method and analytic hierarchy process. this paper introduces a comprehensive prediction model consisting of analytic hierarchy process and combination entropy-weight method. The method,overcoming weights imbalance,gives the evaluation result better than does the single analytic hierarchy process, it is a new valid method for scientific forecast on water conducted zone.

scholarly journals Diagnostic Procedures for Jet Engines

1985 ◽  
Author(s):  
R. Lunderstädt ◽  
K. Fiedler
Keyword(s):  
Mathematical Model ◽  
Path Analysis ◽  
Working Conditions ◽  
Measurement Data ◽  
Diagnostic Procedures ◽  
Practical Significance ◽  
Jet Engines ◽  
Actual Measurement ◽  
Jet Engine ◽  
The Mathematical Model

In the paper to be presented diagnostic procedures on the basis of a gas path analysis are applied on a two-shaft jet engine. Starting from the mathematical model of the engine a filter-algorithm is used which delivers from actual measurement data the state of the engine for different working conditions. The procedure is proven for some examples and discussed in regard of its practical significance.

scholarly journals Influence of Lawns on the Summer Thermal Environment and Microclimate of Heritage Sites: A Case Study of Fuling Mausoleum, China

2020 ◽  
Author(s):  
Xiaoyu Wang ◽  
Peng Liu ◽  
Gongwen Xu
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Thermal Environment ◽  
Measurement Data ◽  
Ground Temperature ◽  
Rapid Urbanization ◽  
Actual Measurement ◽  
Heritage Sites ◽  
Human Thermal Comfort ◽  
The Impact

Abstract The thermal environment and microclimate of heritage sites has been severely impacted by rapid urbanization. This study collected various meteorological measurement data as a reference for computational fluid dynamics (CFD) simulation settings. Then CFD was applied to simulate the impact of lawns on the thermal environment and microclimate of Fuling Mausoleum. We found that lawns and soil can cool the air through evaporation, and thus have a specific cooling effect on the bricked ground. After lawns were planted, the bricked ground temperature decreased by 1.56–17.54°C than that before lawns were planted at 14:00, a decrease of 2.68%–24.20%. Under normal circumstances, when the wind speed or relative humidity increased, the ground temperature dropped. Greenbelt vegetation can adjust the microclimate and human thermal comfort indicators. The consistency of the difference between the actual measurement and the CFD simulation results shows that CFD simulation can thus accurately reflect the internal temperature field distribution if the selection of simulation parameters is reasonable. Theoretical calculation and analysis, experimental measurement research, and modern computer simulation analysis methods applied together constitute a complete system for studying modern physical environmental problems and can provide reliable and economic results.

scholarly journals Characterization and Corrections for Clamp-On Fluid Temperature Measurements in Turbulent Flows

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Bijan Nouri ◽  
Marc Röger ◽  
Nicole Janotte ◽  
Christoph Hilgert
Keyword(s):  
Fluid Flow ◽  
Turbulent Flows ◽  
Power Plants ◽  
Measurement Data ◽  
Temperature Measurements ◽  
Correction Function ◽  
Acceptance Testing ◽  
Fluid Temperature ◽  
Parabolic Trough ◽  
Operation Conditions

A clamp-on measurement system for flexible and accurate fluid temperature measurements for turbulent flows with Reynolds numbers higher than 30,000 is presented in this paper. This noninvasive system can be deployed without interference with the fluid flow while delivering the high accuracies necessary for performance and acceptance testing for power plants in terms of measurement accuracy and position. The system is experimentally validated in the fluid flow of a solar thermal parabolic trough collector test bench, equipped with built-in sensors as reference. Its applicability under industrial conditions is demonstrated at the 50 MWel AndaSol-3 parabolic trough solar power plant in Spain. A function based on large experimental data correcting the temperature gradient between the measured clamp-on sensor and actual fluid temperature is developed, achieving an uncertainty below ±0.7 K (2σ) for fluid temperatures up to 400 °C. In addition, the experimental results are used to validate a numerical model. Based on the results of this model, a general dimensionless correction function for a wider range of application scenarios is derived. The clamp-on system, together with the dimensionless correction function, supports numerous combinations of fluids, pipe materials, insulations, geometries, and operation conditions and should be useful in a variety of industrial applications of the power and chemical industry where temporal noninvasive fluid temperature measurement is needed with good accuracy. The comparison of the general dimensionless correction function with measurement data indicates a measurement uncertainty below 1 K (2σ).

In Vitro Physical and Biological Evaluations of a 2.4 GHz Electromagnetic Exposure Setup

2021 ◽  
Vol 36 (1) ◽  
pp. 82-88
Author(s):  
Mengxi Wang ◽  
Guohui Yang ◽  
Yu Li ◽  
Qun Wu
Keyword(s):  
Electromagnetic Radiation ◽  
Specific Absorption Rate ◽  
Measurement Data ◽  
Energy Coupling ◽  
Fdtd Simulation ◽  
Biological Experiment ◽  
Actual Measurement ◽  
Physical Test ◽  
Polarization Characteristics

In this paper, a 2.4 GHz electromagnetic radiation system for cells in vitro was designed from the perspective of optimal energy coupling of cell samples. The validity of the design was verified by FDTD simulation, physical test and biological experiment. The electromagnetic parameters of SAR (Specific Absorption Rate) and temperature rise were obtained by FDTD simulation. The validation of temperature simulation was confirmed by comparing the actual measurement data and the simulation data. The SAR relative uniformity between samples was tested by cell biological experiment, in which ROS (Reactive Oxygen Species), a typical and sensitive biological parameter reacting to electromagnetic radiation in cells, of different sample dishes induced by 2.4 GHz electromagnetic radiation with an incident power of 0.5 W was analyzed. We found that the size of cell dish affects the energy coupling intensity, the polarization characteristics of electromagnetic wave determines the distribution pattern of SAR, and the uniformity of sample energy absorption in this radiation system is good.

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