Process Analysis for Achieving Highly Enhanced Total Efficiency on Multi-Stage Fuel Supplied SOFC System

2015 ◽  
Vol 68 (1) ◽  
pp. 3107-3113
Author(s):  
Y. Tachikawa ◽  
Y. Matsuzaki ◽  
T. Hatae ◽  
S. Taniguchi ◽  
K. Sasaki
Keyword(s):  
Process Analysis ◽  
Total Efficiency ◽  
Multi Stage

scholarly journals Process Analysis and Prediction of a Multi-stage Landslide Dam Failure

2021 ◽  
Vol 861 (6) ◽  
pp. 062011
Author(s):  
Shuang-Shuang Wu ◽  
Xin-Li Hu ◽  
Peng Xia ◽  
Chang Liu ◽  
Jianchuan Wu
Keyword(s):  
Process Analysis ◽  
Landslide Dam ◽  
Dam Failure ◽  
Multi Stage

Automatically Designed Deep Gaussian Process for Turbomachinery Application

2021 ◽  
Author(s):  
Yuan Jin ◽  
Jin Chai ◽  
Olivier Jung
Keyword(s):  
Gaussian Processes ◽  
Structural Data ◽  
High Dimensional ◽  
Total Efficiency ◽  
Frame Design ◽  
Low Pressure Turbine ◽  
Doubly Stochastic ◽  
Stochastic Variational Inference ◽  
Analytical Functions ◽  
Multi Stage

Abstract Thanks to their flexibility and robustness to overfitting, Gaussian Processes (GPs) are widely used as black-box function approximators. Deep Gaussian Processes (DGPs) are multilayer generations of GPs. The deep architecture alleviates the kernel dependance of GPs, while complicates model inference. The so-called doubly stochastic variational approach, which does not force the independence between layers, shows its effectiveness in large dataset classification and regression in the literature. Meanwhile, similar to deep neural network, DGPs also require application-specific architecture. In addition, the doubly stochastic process introduces extra hyperparameters, which further increases the difficulty in model definition and training. In this study, we apply doubly stochastic variational inference DGP as surrogate model on high-dimensional structural data regression drawn from turbomachinery area. A discrete optimizer, which is based on classification discriminating good solutions from bad ones, is utilized to realize automatic DGP model design and tuning. Empirical experiments are performed firstly on analytical functions to demonstrate the capability of DPGs in high-dimensional and non-stationary data handling. Two industrial turbomachinery problems with respectively 80 and 180 input dimensions are addressed. The first application consists in a turbine frame design problem. In the second application, DGP is used to describe the correlation between 3D blade profiles of a multi-stage low pressure turbine and the corresponding turbine total-total efficiency. Through these two applications, we show the applicability of the proposed automatically designed DGPs in turbomachinery area by highlighting their outperformance with respect to classic GPs.

Transient Numerical Investigation of Rotor Clocking in 1.5 Stage of an Axial Test Turbine With a Blade-to-Vane Ratio of 1.5

2010 ◽  
Author(s):  
K. Kusterer ◽  
N. Moritz ◽  
D. Bohn ◽  
T. Sugimoto ◽  
R. Tanaka
Keyword(s):  
Transient Flow ◽  
Leading Edge ◽  
Total Efficiency ◽  
Unsteady Forces ◽  
Axial Compressors ◽  
Scientific Investigations ◽  
Flow And Heat Transfer ◽  
Multi Stage ◽  
Stators And Rotors ◽  
Momentum Region

In recent years clocking of stators and rotors in multi-stage axial compressors and turbines has become an important scope of scientific investigations aiming to reduce aerodynamic losses in these turbo machines and to affect the aerodynamic and thermal load, the unsteady forces and the flow conditions of following stages. Regarding the loss reduction, the target of clocking is to find a relative circumferential position of successive rows of vanes or blades, so that the low momentum region in the wake of the upstream airfoil impinges the leading edge of the vanes or blades of the following stage. Numerical investigations of clocking in a multi-stage arrangement require the transient calculation of the instationary flow field, so that the transient interaction between stationary and rotating airfoils is part of the calculations. In the present investigation, the transient version of the conjugate fluid flow and heat transfer solver CHTflow has been used. In this theoretical study the 1st rotor, 2nd vane and 2nd rotor of an axial test turbine are investigated. The cooling of 1st rotor and 2nd vane is taken into account by slot injections on the blade surface. The influence of the blade clocking has been investigated at four different circumferential positions of the 2nd rotor with respect to the 1st rotor. Despite of this change, all other geometric parameters and the boundary conditions are unchanged for the four configurations. The transient flow structures are analyzed by visualization of the entropy distribution and the helicity at different time steps in a midspan section. Thereby, it can be seen how the wakes of the rotor 1 are chopped by the successive stator and how they impinge on rotor 2. It is shown that the flow pattern in front of rotor 2 is not equivalent for the 3 blades in the calculated segment. Thus, the wakes of rotor 1 cannot continuously impinge the leading edges of rotor 2, so that there is no significant influence of the clocking position on the time averaged total efficiency of the stages to be found, although the time dependent values of the total efficiency show different behaviors for the analyzed clocking positions. Therefore it can be concluded that for the investigated configuration the effect of clocking on the efficiency is significantly reduced in case of a blade-to-vane ratio of 1.5, so that the distinction between advantageous and disadvantageous assembly positions is not important.

Calculation Method of the Initial Strains of Cables in Pretensioning Construction of Prestressed Space Reticulated Structures

2011 ◽  
Vol 250-253 ◽  
pp. 2571-2574
Author(s):  
Yong Jun He ◽  
Xu Hong Zhou ◽  
Jia Wei Zhou
Keyword(s):  
Calculation Method ◽  
Process Analysis ◽  
Whole Process ◽  
Multi Stage ◽  
Target Values ◽  
Complicated Process ◽  
Tensile Forces ◽  
The Difference ◽  
Initial Strains

It is a complicated process to adjust the tensile forces of cables to their target forces in the practical tensioning construction of prestressed space reticulated structure. In this paper a calculation method for whole-process analysis of the multi-stage and multi-batch tensioning construction is presented to improve the tensioning efficiency. By diminishing the difference between the actual tensile forces of the cables and their target values gradually, the initial strains of the cables for tensioning in construction can be obtained. All the cables can reach to their target values one time if they are stretched to the calculated initial strains in accordance with the predetermined tensioning sequence. The analysis on a prestressed spherical reticulated mega-structure with span of 150m is carried out; the results indicate that this method is feasible in practice.

Process analysis of catalytic multi-stage hydropyrolysis of lignite

Fuel ◽  
2002 ◽  
Vol 81 (11-12) ◽  
pp. 1491-1497 ◽  
Author(s):  
Wen Li ◽  
Na Wang ◽  
Baoqing Li
Keyword(s):  
Process Analysis ◽  
Multi Stage

Upgrade of a 16-Stage Industrial Compressor: Part I — Development of an Innovative Performance Analysis Method

2006 ◽  
Author(s):  
Magdy S. Attia
Keyword(s):  
Axial Compressor ◽  
Total Efficiency ◽  
Turbine Engine ◽  
Streamline Curvature ◽  
Multi Stage ◽  
Point Increase ◽  
Innovative System ◽  
Compressor Performance ◽  
Cycle Efficiency ◽  
Compressor Efficiency

The compressor belonging to a 165 MW-class gas turbine engine designed in the 1970’s with initial operation starting in the early 1980’s, is to be upgraded. The goal of the redesign is to develop a retrofittable upgrade which will deliver a 6% increase in flow and a 2-point increase in adiabatic total-to-total efficiency. The desired increase in compressor efficiency is equivalent to a 0.7-point increase in simple cycle efficiency, approximately. To initiate the upgrade process, a thorough performance evaluation of the existing configuration was needed using the current technology. In this case, the S1S2 prediction did not match measured performance to within an acceptable band. Therefore, a new and innovative system was developed to overcome the existing limitations. This paper presents a simple, physically sound, reliable, and efficient method for predicting axial compressor performance using a combination of single-row CFD and Streamline Curvature (Throughflow) codes. The method has been developed and tested on several industrial multi-stage compressors including this 16-stage compressor with excellent results.

Planning and Search in Multi-Stage Risky Decision Making

2011 ◽  
Author(s):  
Jared Hotaling ◽  
Jerry Busemeyer ◽  
Richard Shiffrin
Keyword(s):  
Decision Making ◽  
Risky Decision Making ◽  
Risky Decision ◽  
Multi Stage
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