Tianjin Key Laboratory of Process Measurement and Control

Tianjin, China

Tianjin Key Laboratory of Process Measurement and Control

Tianjin, China
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Yuan C.,Tianjin University | Yuan C.,Tianjin Key Laboratory of Process Measurement and Control | Xu Y.,Tianjin University | Xu Y.,Tianjin Key Laboratory of Process Measurement and Control | And 7 more authors.
Applied Thermal Engineering | Year: 2017

In the present stage, wet gas measurement is playing an increasingly significant role in the oil and gas industry. Phase fraction is an important parameter for the determination of pressure drop and heat transfer coefficient in wet gas flow. In this paper, experimental investigations of the wet gas phase fraction based on convective heat transfer (CHT) is conducted. In order to describe the “over reading” of CHT coefficient due to the existence of the liquid phase, it is innovative to define ω as the ratio of the CHT coefficients of wet gas and gas alone. An easy-to-use correlation is proposed by using the gas flow rate and the temperature measured before and after the electrical heating belt. The experiment was carried out in the wet gas flow loop in Tianjin University. System pressure ranges from 0.6 MPa to 1.2 MPa, and gas mass fraction (GMF) is from 23.8% to 100%. Final results show that the relative deviation of all data points are less than ±15%. There is no doubt that this correlation provides new data on the phase fraction in wet gas annular flow and benefits other researchers in wet gas measurement. © 2016 Elsevier Ltd


Hu C.,Tianjin Key Laboratory of Process Measurement and Control | Hu C.,Tianjin University | Yang N.,Tianjin Key Laboratory of Process Measurement and Control | Yang N.,Tianjin University | And 2 more authors.
International Journal of Advanced Robotic Systems | Year: 2017

This article investigates a tube model predictive control scheme ensuring robustness and constraints fulfillment for hypersonic vehicles with bounded external disturbances. The polytopic linear parameter varying model is established using tensor-product modeling method, and tube-model predictive control controller is designed to satisfy all vertices of the polytopic linear parameter varying model. Firstly, the nominal model predictive control law is constructed for the nominal system without disturbances. Secondly, tube invariant set strategy is introduced for the unknown bounded disturbances, and the local robust feedback control law is presented to restrain disturbances. The proposed tube-model predictive control method not only steers the nominal state to track a reference trajectory but also keeps the real states within a tube centered with the nominal trajectory. Simulation results show the effectiveness of the proposed method for the hypersonic vehicle with bounded disturbances. © 2017, © The Author(s) 2017.


Xue T.,Tianjin University | Xue T.,Tianjin Key Laboratory of Process Measurement and Control | Ruan W.-P.,Tianjin University | Ruan W.-P.,Tianjin Key Laboratory of Process Measurement and Control | And 2 more authors.
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2017

In order to reconstruct the flow regime of dense bubbly flow and to measure flow parameters, a 3D visual measurement system based on laser scanning was constructed. Laser sheet combined with a rotating polygonal prism was employed for optical scanning of the flow field. The slice images of field were recorded by a high-speed camera and the 3D structure was reconstructed by a series of image preprocessing methods. Considering the multiple exposure in slices during the scanning process, an optimization algorithm based on template convolution of second-order differential and mean was proposed, which can effectively extract feature points of multiple exposure from slices and simultaneously remove redundant and noise information. The experiment results demonstrated that the 3D structure of dense bubbly flow with overlapped projection of bubbles can be perfectly reconstructed by the proposed laser scanning method. The optimization algorithm based on second-order differential can effectively reduce the distortion of reconstructed structure. The volume void fraction of reconstructed field is less than 6% in relative error compared to the actual value. The non-intrusive measurement based on laser scanning can realize 3D reconstruction of the dense bubbly flow with high accuracy, thus proving remarkable advantages in comparison with traditional methods. © 2017, Science Press. All right reserved.


Fan W.,Civil Aviation University of China | Fan W.,Tianjin Key Laboratory of Process Measurement and Control | Lei J.,Civil Aviation University of China | Dong Y.,Civil Aviation University of China | Xue Q.,Civil Aviation University of China
Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument | Year: 2017

Carbon fiber reinforced polymer (CFRP) is widely applied in aerospace field, the implementation of structural health monitoring is significant to improve the detection level of damage tolerance during the process of airworthiness certification and reduce test cost. Aiming at the CFRP laminate structure used in airplane, the self-sensing and the sensitive electrical characteristics of CFRP structural damage are utilized. A non-destructive impedance test method based on four-probe is proposed to realize fast structural health monitoring with non-invasion, non-radiation and low cost. The anisotropic CFRP laminate models are built with COMSOL finite element software, and comparative analyses of the effect of different types of structural damages detection are conducted by extracting the effective voltage difference and voltage sensitivity parameter. Therefore, the optimal incentive measurement model for CFRP laminate structure damage detection can be obtained. Comprehensive experimental results show that the excitation of double electrodes has a better overall performance. © 2017, Science Press. All right reserved.


Guo S.,Tianjin University | Guo S.,Tianjin Key Laboratory of Process Measurement and Control | Sun L.,Tianjin University | Sun L.,Tianjin Key Laboratory of Process Measurement and Control | And 6 more authors.
Flow Measurement and Instrumentation | Year: 2013

Viscosity effect is one important factor that affects the performance of turbine flowmeter. The fluid dynamics mechanism of the viscosity effect on turbine flowmeter performance is still not fully understood. In this study, the curves of meter factor and linearity error of the turbine flowmeter changing with fluid viscosity variations were obtained from multi-viscosity experiments (the viscosity range covered is 1.0×10-6m2/s-112×10-6m2/s). The results indicate that the average meter factor of turbine flowmeter decreases with viscosity increases, while the linearity error increases. Furthermore, Computational Fluid Dynamics (CFD) simulation was carried out to analyze three-dimensional internal flow fields of turbine flowmeter. It was demonstrated that viscosity changes lead to changes of the wake flow behind the upstream flow conditioner blade and the flow velocity profile before fluid entering turbine rotor blade, which affect the distribution of pressure on the rotor blades, so impact the turbine flowmeter performance. © 2013 .


Xu Y.,Tianjin Key Laboratory of Process Measurement and Control | Xu Y.,Tianjin University | Yuan C.,Tianjin Key Laboratory of Process Measurement and Control | Yuan C.,Tianjin University | And 6 more authors.
Flow Measurement and Instrumentation | Year: 2013

In this paper a novel flow measurement device composed of a long throat Venturi tube and a V-cone was proposed to deal with the wet gas flow measurement without separation, and a new metering method was put forward based on the triple differential pressures. The correlations were based on the gas densiometric Froude number, gas-liquid density ratio, and the differential pressure ratios, which were then compared and validated by the laboratory and field tests. The laboratory test results showed that the uncertainty of relative errors for the gas and liquid flow rates were less than 3% and 6%, respectively. The field test results showed that the uncertainty of relative errors for the gas flow rates before correction varied from 5.53% to 11.57%. After correction the uncertainty of relative errors for gas flow rate varied from 1.37% to 3.22% and full-scale error for liquid flow rate was less than ±10%. © 2013 Elsevier Ltd.


Zhang D.,Tianjin University | Zhang D.,Tianjin Key Laboratory of Process Measurement and Control | Cheng B.,Tianjin University | Wu A.,Tianjin University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

A hybrid parallel neural network that combined a forward neural network with a recurrent neural network was proposed to predict the biomass concentration in fermentation. Each of forward neural network and recurrent neural network worked as an individual channel of the hybrid neural network and made up each other. Their accumulated error was reduced by another neural network. The maximum error of hybrid neural network was proved be less than or equal to that of the channel and finally the steps of algorithm were given. The simulation shows the proposed approach is effective in the complex environment. © 2012 Springer-Verlag.


Yang Z.,Tianjin University | Yang Z.,Tianjin Key Laboratory of Process Measurement and Control | Wang T.,Tianjin University | Duan Z.,Tianjin University | And 2 more authors.
2012 2nd International Conference on Consumer Electronics, Communications and Networks, CECNet 2012 - Proceedings | Year: 2012

Both nonlinear theories and Fourier analysis predicate theoretically that low-order nonlinear transformation has three advantages. First, it can increase the signal-to-noise ratio of a complex time series that has a large fluctuation. Second, it can insulate negative effects of outliers or bad data. Last, it can improve the distinction between the signal and white noise. The trend in the classical decomposition of trend plus seasonals plus residuals of a complex time series is equivalent to a non-periodic signal with continuous frequency spectrum, and is inevitably lost partly by the discrete Fourier transform for the discrete finite time point. Our numerical experiments with natural logarithmic transformation confirm these theoretical deductions. © 2012 IEEE.


Xu Y.,Tianjin Key Laboratory of Process Measurement and Control | Xu Y.,Tianjin University | Zhang Q.,Chengdu Verification Branch for Natural Gas Flow Meter of National Crude Oil Large Flow Measurement Station | Zhang T.,Tianjin Key Laboratory of Process Measurement and Control | And 2 more authors.
Measurement: Journal of the International Measurement Confederation | Year: 2015

The objective of this study is to develop a wet gas overreading model for nonstandard Venturi meters. This overreading model was proposed based on a new characteristic parameter, H correction factor, which took into account the effect of gas densiometric Froude number, beta ratio and throat length on overreading. Four nonstandard DN-80 Venturi meters with different beta ratio and throat length was designed for laboratory experiments that conducted in Tianjin University (TJU) low-pressure wet gas test loop and validate the model. The experimental results showed that this correlation gave a good prediction to the overreading of the four nonstandard Venturi meters with a prediction error of ±4% and an uncertainty of better than ±2.5%. It was used to predict the gas flow rates of the Venturi tube used in de Leeuw correlation. The relative bias is ±4% between this model and the de Leeuw correlation. © 2014 Elsevier Ltd. All rights reserved.


Xue T.,Tianjin University | Xue T.,Tianjin Key Laboratory of Process Measurement and Control | Cao Z.-F.,Tianjin University | Cao Z.-F.,Tianjin Key Laboratory of Process Measurement and Control | And 2 more authors.
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2012

A calibration technique for the three-dimensional measurement system of gas-liquid two phase flow based on a virtual stereo vision was researched. Firstly, a single high-speed camera and two groups of mirrors were used to construct the virtual stereo vision system and to establish a perspective transformation model for the high-speed camera and a virtual stereo vision three-dimensional measurement model. Then, the camera and the virtual stereo vision sensor in the virtual stereo vision system were calibrated. Finally, the distribution of the bubble in the water was simulated by a target standard ball and its space distance was regard as the measurement standards. Furthermore, the impacts of different calibration methods on the accuracy of three-dimensional reconstruction were compared. Experimental results indicate that the accuracy of the three-dimensional reconstruction is the best when the calibration reference is placed in a water tank and the left and right virtual cameras and sensors are calibrated, respectively. The absolute error and the relative error of the measurement distance are better than 0.13 mm and 0.49%, respectively. It suggests that the impact of the light splitting path and tube wall refraction on the calibration accuracy should be taken full account of in the calibration of the gas-liquid two-phase flow three-dimensional measurement system based on the virtual stereo vision system.

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