Understanding Stage Matching of a High-Efficiency Multi-Stage Centrifugal Gas Compressor

2000 ◽  
Author(s):  
Michael J. Cave ◽  
Tim David
Keyword(s):  
Test Data ◽  
Closed Loop ◽  
High Efficiency ◽  
Analysis Software ◽  
Multi Stage ◽  
Software Program ◽  
Stage Matching ◽  
D Model

Abstract A series of closed loop development tests were conducted on a new high-efficiency, multi-stage gas compressor. Using the test data and a 1-D compressor analysis software program, stage characteristics were modeled for each of the six stages. Overall stage results from the 1-D model were compared to development test data to validate the model. Once the model was validated, it was used to understand stage-to-stage matching at design and off-design conditions.

PROCUREMENT STRATEGY AS A TOOL FOR MANAGING A FUEL AND ENERGY COMPLEX ENTERPRISE

2020 ◽  
Vol 1 (10) ◽  
pp. 13-25
Author(s):  
A. P. SOKOLOV ◽  
◽  
L. P. VASILIEVA ◽  
I. V. BRATKO ◽  
◽  
...  
Keyword(s):  
Strategic Planning ◽  
National Economy ◽  
High Efficiency ◽  
Management Tool ◽  
Market Environment ◽  
External Market ◽  
Energy Complex ◽  
Multi Stage ◽  
Procurement Strategy ◽  
Number Of Branches

The authors consider the issues of forming a procurement strategy for enterprises of the fuel and energy complex (FEC) as a management tool. The study begins with a review of the categories of strategy, purchasing, and risk. Based on the generalization and interpretation of the obtained knowledge, the author's model of procurement strategy for enterprises of the fuel and energy complex is proposed, which differs from the existing ones in that it simultaneously acts as a means of connecting the enterprise with the external market environment. The strategy has a complex multi-stage character with many elements. Through detailed strategic planning can be achieved high efficiency of the procurement activities of enterprises of fuel and energy. The proposed algorithm can form the basis of an unlimited number of branches of the national economy.

Multi-Stage System Identification of a Gas Turbine

2017 ◽  
Author(s):  
Amit Pandey ◽  
Maurício de Oliveira ◽  
Chad M. Holcomb
Keyword(s):  
Gas Turbine ◽  
Closed Loop ◽  
Open Loop ◽  
Loop System ◽  
Closed Loop Control ◽  
Input Output ◽  
Open Loop System ◽  
Loop Control ◽  
Multi Stage ◽  
Identification Techniques

Several techniques have recently been proposed to identify open-loop system models from input-output data obtained while the plant is operating under closed-loop control. So called multi-stage identification techniques are particularly useful in industrial applications where obtaining input-output information in the absence of closed-loop control is often difficult. These open-loop system models can then be employed in the design of more sophisticated closed-loop controllers. This paper introduces a methodology to identify linear open-loop models of gas turbine engines using a multi-stage identification procedure. The procedure utilizes closed-loop data to identify a closed-loop sensitivity function in the first stage and extracts the open-loop plant model in the second stage. The closed-loop data can be obtained by any sufficiently informative experiment from a plant in operation or simulation. We present simulation results here. This is the logical process to follow since using experimentation is often prohibitively expensive and unpractical. Both identification stages use standard open-loop identification techniques. We then propose a series of techniques to validate the accuracy of the identified models against first principles simulations in both the time and frequency domains. Finally, the potential to use these models for control design is discussed.

scholarly journals Load characteristics of three-plunger pumps for spray seawater fire-fighting

2020 ◽  
pp. 142-146
Author(s):  
В.А. Наумов ◽  
Н.Л. Великанов ◽  
А.В. Тришина
Keyword(s):  
Satisfactory Agreement ◽  
Test Data ◽  
High Efficiency ◽  
Measurement Data ◽  
Fire Fighting ◽  
Test Results ◽  
Hydraulic Characteristics ◽  
Fire Extinguishing ◽  
Load Characteristics ◽  
Low Pressures

Цель статьи – получить эмпирические зависимости для характеристик трехплунжерных противопожарных насосов (ТПН), необходимые для автоматизации расчетов систем тушения пожаров на судах с применением распыленной морской воды. Задачи исследования: проверка непротиворечивости данных испытаний; определение расчетных зависимостей производительности ТПН, к.п.д., затраченной мощности от давления. Проведенный анализ результатов испытаний ТПН подтвердил возможность использования предложенных зависимостей в инженерных расчетах. Данные измерений удовлетворительно согласуются с результатами расчетов, за исключением к.п.д. Отклонение экспериментальных точек от эмпирических зависимостей, скорее всего, связано с занижением значений затраченной мощности на испытаниях при небольших давлениях. Предложено для оценки к.п.д. использовать ранее полученную типовую зависимость. Построены графики для характеристик насоса NP25/41-170S. Пример расчета рабочей точки насосной установки с использованием приближенной гидравлической характеристики водяной пожарной системы судна показал высокую эффективность предложенных методик. The purpose of the article is to obtain empirical dependences for the characteristics of three-plunger fire-fighting pumps (TFP), which are necessary for automating calculations of fire extinguishing systems on ships using sprayed seawater. Research objectives: checking the consistency of test data; determining the calculated dependences of the TFP performance, efficiency, power expended on pressure. The analysis of the TFP test results confirmed the possibility of using the proposed dependencies in engineering calculations. The measurement data are in satisfactory agreement with the results of calculations, with the exception of efficiency. The deviation of experimental points from the empirical dependences is most likely due to an underestimation of the power consumed during tests at low pressures. It is proposed to use the previously obtained typical dependence to estimate the efficiency. Graphs are plotted for the characteristics of the NP25/41-170S pump. An example of calculating the working point of a pumping unit using the approximate hydraulic characteristics of the ship's water fire system showed the high efficiency of the proposed methods.

Efficient Human Motion Planning Using Recursive Dynamics and Optimal Control Techniques

1999 ◽  
Author(s):  
Janzen Lo ◽  
Dimitris Metaxas
Keyword(s):  
Optimal Control ◽  
Motion Planning ◽  
Closed Loop ◽  
High Efficiency ◽  
Human Motion ◽  
Lagrangian Formulation ◽  
Planning Problem ◽  
Tree Structures ◽  
Recursive Dynamics ◽  
Minimum Torque

Abstract We present an efficient optimal control based approach to simulate dynamically correct human movements. We model virtual humans as a kinematic chain consisting of serial, closed-loop, and tree-structures. To overcome the complexity limitations of the classical Lagrangian formulation and to include knowledge from biomechanical studies, we have developed a minimum-torque motion planning method. This new method is based on the use of optimal control theory within a recursive dynamics framework. Our dynamic motion planning methodology achieves high efficiency regardless of the figure topology. As opposed to a Lagrangian formulation, it obviates the need for the reformulation of the dynamic equations for different structured articulated figures. We use a quasi-Newton method based nonlinear programming technique to solve our minimum torque-based human motion planning problem. This method achieves superlinear convergence. We use the screw theoretical method to compute analytically the necessary gradient of the motion and force. This provides a better conditioned optimization computation and allows the robust and efficient implementation of our method. Cubic spline functions have been used to make the search space for an optimal solution finite. We demonstrate the efficacy of our proposed method based on a variety of human motion tasks involving open and closed loop kinematic chains. Our models are built using parameters chosen from an anthropomorphic database. The results demonstrate that our approach generates natural looking and physically correct human motions.

Lab-Scale, Closed-Loop Experimental Characterization, Model Refinement, and Validation of a Hydrokinetic Energy-Harvesting Ocean Kite

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Ayaz Siddiqui ◽  
Kartik Naik ◽  
Mitchell Cobb ◽  
Kenneth Granlund ◽  
Chris Vermillion
Keyword(s):  
Closed Loop ◽  
High Efficiency ◽  
Complex Dynamics ◽  
Water Channel ◽  
Full Scale ◽  
Ocean Current ◽  
Model Refinement ◽  
Dynamics And Control ◽  
And Control ◽  
Channel Environment

Abstract This paper presents a study wherein we experimentally characterize the dynamics and control system of a lab-scale ocean kite, and then refine, validate, and extrapolate this model for use in a full-scale system. Ocean kite systems, which harvest tidal and ocean current resources through high-efficiency cross-current motion, enable energy extraction with an order of magnitude less material (and cost) than stationary systems with the same rated power output. However, an ocean kite represents a nascent technology that is characterized by relatively complex dynamics and requires sophisticated control algorithms. In order to characterize the dynamics and control of ocean kite systems rapidly, at a relatively low cost, the authors have developed a lab-scale, closed-loop prototyping environment for characterizing tethered systems, whereby 3D printed systems are tethered and flown in a water channel environment. While this system has been shown to be capable of yielding similar dynamic characteristics to some full-scale systems, there are also fundamental limitations to the geometric scales and flow speeds within the water channel environment, making many other real-world scenarios impossible to replicate from the standpoint of dynamic similarity. To address these scenarios, we show how the lab-scale framework is used to refine and validate a scalable dynamic model of a tethered system, which can then be extrapolated to full-scale operation. In this work, we present an extensive case study of this model refinement, validation, and extrapolation on an ocean kite system intended for operation in the Gulf Stream or similar current environments.

High Capacity and High Efficiency Multi-Stage Air Intake System

2002 ◽  
Author(s):  
Alan Hashem ◽  
Dani Fadda ◽  
Kenneth J. Fewel
Keyword(s):  
Gas Turbine ◽  
Marine Environment ◽  
High Efficiency ◽  
High Capacity ◽  
Future Market ◽  
Air Treatment ◽  
Intake System ◽  
Multi Stage ◽  
Air Intake ◽  
Gas Turbine Combustion

An advanced three stage filtration/separation air intake system (Compact II) is introduced in this paper. The system was developed to meet the current and expected future market demands for gas turbine combustion air treatment in a marine environment. Developing and testing of the Compact II are subjects of this paper.

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