scholarly journals Pressure Control of Insulation Space for Liquefied Natural Gas Carrier with Nonlinear Feedback Technique

2018 ◽  
Vol 6 (4) ◽  
pp. 133
Author(s):  
Jinghua Cao ◽  
Xianku Zhang ◽  
Xiang Zou
Keyword(s):  
Natural Gas ◽  
Control Strategy ◽  
Control Strategies ◽  
Nonlinear Function ◽  
Pressure Control ◽  
Feedback Signal ◽  
Control Input ◽  
Nonlinear Feedback ◽  
Pressure Control System ◽  
Liquid Natural Gas

This paper introduces a novel control strategy into the insulation space for liquid natural gas carriers. The control strategy proposed can improve the effects of control for differential pressure and reduce the energy consumption of nitrogen. The method combines a nonlinear feedback technique with a closed-loop gain shaping algorithm (CGSA). It is designed for the pressure control system which is vital for liquid natural gas carriers (LNGCs) in marine transportation. The control error is modulated using nonlinear function. The deviation signal is replaced with a nonlinear feedback signal. Comparison experiments are conducted under different conditions to prove the effectiveness of this strategy. This paper compares three control strategies: a control strategy with nonlinear feedback based on CGSA, a control strategy without nonlinear feedback based on CGSA, and a two-degree-of-freedom (DOF) control strategy. The simulation results show that this control strategy with nonlinear feedback performs better than the other two. The average reduction of control input is about 38.8%. The effect of pressure control is satisfactory.

scholarly journals Fuzzy Coordination Control Strategy and Thermohydraulic Dynamics Modeling of a Natural Gas Heating System for in Situ Soil Thermal Remediation

Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 971 ◽  
Author(s):  
Zhai ◽  
Yang ◽  
Li ◽  
Jiang ◽  
Ye ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Natural Gas ◽  
Control Strategy ◽  
Control Strategies ◽  
Heating System ◽  
Coordination Control ◽  
Gas Heating ◽  
Thermal Remediation ◽  
Reduce Energy Consumption

Soil contamination remains a global problem. Among the different kinds of remediation technologies, in situ soil thermal remediation has attracted great attention in the environmental field, representing a potential remedial alternative for contaminated soils. Soils need to be heated to a high temperature in thermal remediation, which requires a large amount of energy. For the natural gas heating system in thermal remediation, a fuzzy coordination control strategy and thermohydraulic dynamics model have been proposed in this paper. In order to demonstrate the superiority of the strategy, the other three traditional control strategies are introduced. Analysis of the temperature rise and energy consumption of soils under different control strategies were conducted. The results showed that the energy consumption of fuzzy coordination control strategy is reduced by 33.9% compared to that of the traditional control strategy I, constant natural gas flow and excess air ratio. Further, compared to the traditional control strategy II, constant excess air ratio and desired outlet temperature of wells, the strategy proposed can reduce energy consumption by 48.7%. The results illustrate the superiority of the fuzzy coordination control strategy, and the strategy can greatly reduce energy consumption, thereby reducing the cost of in situ soil thermal remediation.

Research on Integrated Control System of the Gas Pressure in Coke Oven

2013 ◽  
Vol 397-400 ◽  
pp. 1214-1219
Author(s):  
Xia Bai ◽  
Da Lu Guan ◽  
Chen Rui
Keyword(s):  
Control System ◽  
Control Strategies ◽  
Integrated Control ◽  
Control Object ◽  
Coke Oven ◽  
Pressure Control ◽  
Expert Control ◽  
Control Scheme ◽  
Hardware Reliability ◽  
Pressure Control System

This paper combines hardware reliability and software mobility with modern intelligent control through the analysis of the control object using intelligent decoupling control scheme to control the pressure control system of the large gas collector in coke oven. By using expert control strategies based on the DCS, the paper develops the system design which is versatile and effective.

scholarly journals Design of Ship Course-Keeping Autopilot using a Sine Function-Based Nonlinear Feedback Technique

2015 ◽  
Vol 69 (2) ◽  
pp. 246-256 ◽  
Author(s):  
Xian-ku Zhang ◽  
Guo-qing Zhang
Keyword(s):  
Control Strategies ◽  
Feedback Signal ◽  
Sine Function ◽  
Nonlinear Feedback ◽  
Control Effect ◽  
Control Error ◽  
Closed Loop Systems ◽  
Automatic Navigation ◽  
Feedback Scheme ◽  
Control Scheme

Course keeping for ships is the core of automatic navigation in sea transportation. Much work has concentrated on developing novel control strategies for closed loop systems. We have turned our attention the other way to improve the control performance of marine autopilots in this work by “modulating” the control error using a sine function while the construction of the controller is not changed. The nonlinear feedback signal thus obtained is sent to the controller to replace the control error itself, which used to be the deviation between the output response and the reference input of the system. Such a control scheme is called “nonlinear feedback control” hereafter. Theoretical analysis by using a describing function and robust control theory shows that the same control quality is guaranteed with minor control actions for the nonlinear feedback scheme. Simulation experiments were carried out for the ship Yulong of Dalian Maritime University. It is shown that the method postulated in this paper has advantages of safety and energy saving in navigation; the maximum initial rudder angle is reduced by 31·2% with satisfactory control effect.

Control Strategy of Energy Saving Based on Intelligence-Fusion in Water Supply Engineering

2013 ◽  
Vol 401-403 ◽  
pp. 1822-1825
Author(s):  
De Qi Ren
Keyword(s):  
Water Supply ◽  
Energy Saving ◽  
Control Strategy ◽  
Comparative Research ◽  
Control Algorithm ◽  
Control Method ◽  
Pressure Control ◽  
Pressure Control System ◽  
And Control ◽  
Better Than

Aimed at the puzzle that it is heavy in energy consumption and not better in water quality to water supply engineering resulted in inappropriate control strategy, the paper explored the energy saving strategy and control mechanism of water supply system. In the paper, it discussed the cybernetics characteristic of water supply process, proposed the intelligence-fusion based control strategy and the energy saving executing strategy, and analyzed the control model of water supply purifying process and the control algorithm of constant pressure control system. The comparative research of simulation demonstrated that the proposed strategy would be better than conventional PID control method. The simulation results show that the strategy combined intelligence-fusion based control with speed control by inverter has better application prospect.

scholarly journals Improving Vehicle Ride and Handling Using LQG CNF Fusion Control Strategy for an Active Antiroll Bar System

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
N. Zulkarnain ◽  
H. Zamzuri ◽  
Y. M. Sam ◽  
S. A. Mazlan ◽  
S. M. H. F. Zainal
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Control Strategies ◽  
Linear Feedback ◽  
Nonlinear Feedback ◽  
Handling Performance ◽  
Car Model ◽  
Initial Stage ◽  
System Output ◽  
Ride And Handling

This paper analyses a comparison of performance for an active antiroll bar (ARB) system using two types of control strategy. First of all, the LQG control strategy is investigated and then a novel LQG CNF fusion control method is developed to improve the performances on vehicle ride and handling for an active antiroll bar system. However, the ARB system has to balance the trade-off between ride and handling performance, where the CNF consists of a linear feedback law and a nonlinear feedback law. Typically, the linear feedback is designed to yield a quick response at the initial stage, while the nonlinear feedback law is used to smooth out overshoots in the system output when it approaches the target reference. The half car model is combined with a linear single track model with roll dynamics which are used for the analysis and simulation of ride and handling. The performances of the control strategies are compared and the simulation results show the LQG CNF fusion improves the performances in vehicle ride and handling.

Adaptive Fuzzy PID Applied in Steam Pressure Control System

2012 ◽  
Vol 485 ◽  
pp. 203-206
Author(s):  
Yun Jing Liu ◽  
Feng Wen Wang
Keyword(s):  
Control System ◽  
Control Strategy ◽  
Pid Control ◽  
Pressure Control ◽  
Steam Pressure ◽  
System Response ◽  
Fuzzy Pid ◽  
Fuzzy Pid Control ◽  
Adaptive Fuzzy ◽  
Pressure Control System

Boiler steam pressure control system is important because of affecting the turbine speed directly. In engineering, the steam pressure control system is mostly dominated by traditional PID control. But the traditional PID control strategy can’t obtain satisfied control effects with the changing of the fuel and give-wind flow. The use of intelligent control strategy has been studied in recent years in order to improve steam pressure control. In this paper steam pressure control system with adaptive fuzzy PID control is presented, and the simulation results based on MATLAB show that the proposed algorithm can largely improve the system response performance compared to the traditional PID control.

Researches on Electronic Control System of Diesel-CNG Dual Fuel Engine

2013 ◽  
Vol 860-863 ◽  
pp. 1754-1760
Author(s):  
Lei Yu ◽  
Qing Yang ◽  
You Tong Zhang
Keyword(s):  
Control System ◽  
Diesel Engine ◽  
Natural Gas ◽  
Control Strategy ◽  
Control Strategies ◽  
Dual Fuel ◽  
Engine Fuel ◽  
Electronic Control ◽  
Present Contribution ◽  
Electronic Control System

Natural gas has been one of the most important kinds of vehicle fuel since the discovery of abundant shale gas storage. Operating costs of diesel engine can be reduced by replacing diesel with diesel-CNG dual fuel. The present contribution is mainly about the electronic control system of diesel-CNG dual fuel engine. Hardware and software of the electronic control system were designed. Two control strategies named equivalent power control strategy and diesel-saving control strategy were put forward for different control targets. Furthermore, these two strategies were testified by experiments conducted on engine test bench. Results show that average natural gas replacement could up to 70%. Comparing with diesel engine, fuel consumption of diesel-CNG dual fuel engine can be reduced significantly and the power increases slightly also. Both power and economy performances of the engine are improved.

Development and Application on the Optimization Control System of the Gas Collector Pressure in Coke Oven

2013 ◽  
Vol 756-759 ◽  
pp. 415-419
Author(s):  
Xue Jun He ◽  
Zong Ren Gao ◽  
Jun Zhang
Keyword(s):  
Control System ◽  
Control Strategies ◽  
Engineering Application ◽  
Coke Oven ◽  
Pressure Control ◽  
Decoupling Control ◽  
Control Scheme ◽  
Advanced Control ◽  
Optimization Control ◽  
Pressure Control System

In view of the pressure control system of the large gas collector in coke oven, this paper puts forward a optimization control scheme of coke oven collector pressure intelligent decoupling control system. Using a variety of advanced control strategies based on the DCS , it develops a large coke oven collector pressure control system.The engineering application shows that the system design is versatile and effectiveness.

Research on Control Strategy of the Stand-Alone PV/Battery System

2013 ◽  
Vol 860-863 ◽  
pp. 168-171
Author(s):  
Shu Zhao Wang ◽  
Hong Bin Wu
Keyword(s):  
Control Strategy ◽  
Control Strategies ◽  
Nonlinear Function ◽  
Photovoltaic System ◽  
Power Fluctuation ◽  
Battery System ◽  
Voltage Frequency ◽  
Dc Bus ◽  
And Control ◽  
Hysteresis Control

With the battery charging or discharging, it can effectively stabilize power fluctuation of the photovoltaic generation (PV) or the load in a stand-alone power generation system. In this paper, based on the mathematical models of the PV and the battery, it connected the PV and the battery on the same DC bus and proposed energy management system with hysteresis control on the DC bus. In order to prevent the battery from switching back and forth among working state and stopping state, the outer voltage loop took the nonlinear function control strategy of the battery. With the inverter adopting voltage frequency (V/f) control strategy, it maintained the voltage and frequency on AC bus. With the PSCAD/EMTDC, it analyzed the ability of the battery stabilizing the power fluctuation of the PV or the load. And it proved the correctness and feasibility of the established models and control strategies. So those provided theoretical reference for the photovoltaic system that was employed efficiency in the remote areas.

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