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 ◽  
...  

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.

Author(s):  
Bin Liu ◽  
Long Quan ◽  
Lei Ge

Applying the independent metering circuit on the excavator is an effective way to reduce energy consumption and improve the performance of the actuators, e.g. the boom in the negative load circuit. This paper aims to improve the energy efficiency and the stationarity of the boom system based on the independent metering circuit using the strategy of flow and pressure accordance, pump and valve coordinate in dynamic and static. After studying the mechanic structure of the boom, principles of the system and elements characteristics, the four control strategies are designed to settle the problems in the traditional throttling system using mechanically connected orifices valves such as the load-sensing system and new coordinate challenges brought with the multivariable. Finally, experiments based on load sensing and independent metering circuit are implemented on a physical prototype. The experimental results show that the energy consumption of the boom system falls by 15% compared to the load-sensing system; the pressure pulsations of the pump when the boom starts to move reduce from 6.9 MPa to 1.7 MPa. Therefore, the independent metering circuit and the control strategy are good configuration for the boom actuator.


Author(s):  
Kai Wang ◽  
Xinping Yan ◽  
Yupeng Yuan

Nowadays, with the higher voice of ship energy saving and emission reduction, the research on energy efficiency management is particularly necessary. Energy efficiency management and control of ships is an effective way to improve the ship energy efficiency. In this paper, according to the new clean propulsion system configurations of 5000 tons of bulk carrier, the energy efficiency management control strategy of the clean propulsion system is designed based on the model of advanced brushless doubly-fed shaft generator, propulsion system using LNG/diesel dual fuel engine and energy consumption of the main engine for reducing energy consumption. The simulation model of the entire propulsion system and the designed control strategy were designed. The influence of the engine speed on the ship energy efficiency was analyzed, and the feasibility of the energy efficiency management control strategies was verified by simulation using Matlab/Simulink. The results show that the designed strategies can ensure the power requirement of the whole ship under different conditions and improve the ship energy efficiency and reduce CO2 emissions.


2018 ◽  
Vol 6 (4) ◽  
pp. 133
Author(s):  
Jinghua Cao ◽  
Xianku Zhang ◽  
Xiang Zou

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.


2000 ◽  
Vol 123 (4) ◽  
pp. 722-727 ◽  
Author(s):  
A. Ferrara, ◽  
L. Magnani, and ◽  
R. Scattolini

Vibration suppression of a large space structure is achieved by switching between different actuators in order to optimize control performance and to reduce energy consumption. The theoretical properties of the proposed control strategy are reported together with some experimental results.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5257
Author(s):  
Iain Walker ◽  
Brennan Less ◽  
David Lorenzetti ◽  
Michael D. Sohn

This study examined the use of zoned ventilation systems using a coupled CONTAM/EnergyPlus model for new California dwellings. Several smart control strategies were developed with a target of halving ventilation-related energy use, largely through reducing dwelling ventilation rates based on zone occupancy. The controls were evaluated based on the annual energy consumption relative to continuously operating non-zoned, code-compliant mechanical ventilation systems. The systems were also evaluated from an indoor air quality perspective using the equivalency approach, where the annual personal concentration of a contaminant for a control strategy is compared to the personal concentration that would have occurred using a continuously operating, non-zoned system. Individual occupant personal concentrations were calculated for the following contaminants of concern: moisture, CO2, particles, and a generic contaminant. Zonal controls that saved energy by reducing outside airflow achieved typical reductions in ventilation-related energy of 10% to 30%, compared to the 7% savings from the unzoned control. However, this was at the expense of increased personal concentrations for some contaminants in most cases. In addition, care is required in the design and evaluation of zonal controls, because control strategies may reduce exposure to some contaminants, while increasing exposure to others.


Author(s):  
Wim Zeiler ◽  
Gert Boxem ◽  
Rinus van Houten ◽  
Joep van der Velden ◽  
Willem Wortel ◽  
...  

In Europe comfort in buildings needs 40% of the total energy. With effects of Global warming becoming more and more apparent there is a need to reduce this energy demand by comfort within the built environment. In comfort control strategy there is an exciting development based on inclusive design: the user’s preferences and their behaviour have become central in the building services control strategy. Synergy between end-user and building is the ultimate in the intelligent comfort control concept. This new comfort control technology is based on the use of agent technology and can further reduce energy consumption of buildings while at the same time improve individual comfort. The TU/e (Technische Universiteit Eindhoven) together with Kropman and ECN (Energy research Centre Netherlands) work together in the research for user based preference indoor climate control technology. Central in this approach is the user focus of the whole building design process which makes it possible to reduce energy consumption by tuning demand and supply of the energy needed to fulfill the comfort demand of the occupants building.


2008 ◽  
Vol 6 (1) ◽  
pp. 139-153 ◽  
Author(s):  
Dejan Brkic

Natural gas can be directly used for heating of flats by gas distribution system. Indirectly, heating power plant can disburse natural gas and deliver hot water or steam for heating of flats. Decision of optimal way for gas heating usage is done based on spatial disposal of building, number and size of buildings in settlement, etc. Optimal solution, between gas distribution and district heating system (local or district heating by natural gas), can be done according to methodology (model approach) shown in this paper. According to variety of Serbian settlements (in density, size and layout of buildings) model which has ability to represent their different characteristics is formed. This model could be simple and useful tool for initial decision about energy supply system.


2013 ◽  
Vol 860-863 ◽  
pp. 1754-1760
Author(s):  
Lei Yu ◽  
Qing Yang ◽  
You Tong Zhang

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.


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