scholarly journals Analysis of Control System of Fuel Combustion in Boilers with Oxygen Sensor

2019 ◽  
Vol 63 (4) ◽  
pp. 241-248 ◽  
Author(s):  
Artur Zaporozhets
Keyword(s):  
Control System ◽  
Oxygen Sensor ◽  
Experimental Studies ◽  
Combustion Products ◽  
Fuel Combustion ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Fuel Quality ◽  
Combustion Control ◽  
Boiler Operation

The method of fuel quality control is considered, which is based on the using of the oxygen sensor (without sensors of incomplete fuel combustion products). An algorithm for the electric drive of a fan is proposed, which is based on a step changing in the rotation speed. The choice of broadband oxygen sensor as a basis for the development of a fuel combustion control system is determined. In the course of experimental studies, the possibility of reconstructing the boiler by replacing a burner with an installed control system was demonstrated. The commissioning works were carried out with the installed system, the optimum operating conditions of the boiler were determined (with the formation of CO in the flue gases at a minimum level <50 ppm). The technical characteristics of the boiler operation under different loads (from 10 % to 100 %) are considered. Ecological and economic analysis of the developed fuel combustion control system was carried out.

Active Combustion Control System for Reduction of NOx and Pulsation Levels in Gas Turbines

2006 ◽  
Author(s):  
Stanka Kokanovic´ ◽  
Gianfranco Guidati ◽  
Stephan Torchalla ◽  
Bruno Schuermans
Keyword(s):  
Control System ◽  
Gas Turbines ◽  
Equivalence Ratio ◽  
Safety Margin ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Combustion Control ◽  
Actual Measurement ◽  
Reduction Of Nox ◽  
Active Combustion Control

This paper presents two different active combustion control systems (ACCS) for the reduction of NOx levels, and suppression of thermo-acoustic instabilities within stationary gas turbines. Dependent on the actual measurement the ACCSs steer the fuel split between different burner groups or within the burner itself in order to find an optimum operation point. In a first step, an active control system has been developed for the ALSTOM GT13E2 gas turbine where the fuel ratio between two burner groups has to be handled to optimise NOx and pulsation levels. Since perturbations in combustion operating conditions have a direct effect on combustion pulsation behaviour, it is possible to control combustor equivalence ratio by using combustion pulsation measurements as an input for the control system. By doing that, lower operating NOx emissions are achieved as operating safety margin to lean blow out (LBO) may be reduced by more than 50% due to a more accurate and controlled handling of combustor equivalence ratio. Although combustion instabilities due to lean blow out are of minor concern within the GT26, the success of this combustion control approach has led to the development of a more advanced method where both, NOx levels and pulsation amplitudes are feedback-controlled simultaneously in order to track the optimum operating point. By using two premixed stages in the burners fuel supply, the equivalence ratio within the combustor is adapted. Engine and single burner test results confirmed control model dynamics predictions. This paper illustrates the applied closed-loop controls concepts and the successful controller verification on single burner and on engine level.

scholarly journals HARDWARE AND SOFTWARE OF AUTOMATIC CONTROL SYSTEM OF FUEL COMBUSTION PROCESS IN LOW AND MEDIUM POWER BOILERS. PART 1. METHOD AND HARDWARE

2021 ◽  
pp. 37-45
Author(s):  
Arthur Zaporozhets ◽  
Yurii Kuts
Keyword(s):  
Carbon Monoxide ◽  
Control System ◽  
Nitrogen Oxides ◽  
Oxygen Sensor ◽  
High Efficiency ◽  
Combustion Process ◽  
Fuel Mixture ◽  
Fuel Combustion ◽  
Combustion Control ◽  
Variable Frequency Drive

In Ukraine today there are more than 6000 boiler plants with a heating capacity of up to 1 Gcal/h with an efficiency of about 70 %, requiring replacement or modernization, 40 % of boilers are operated with an efficiency of less than 82 %, about 11000 boilers with a capacity of 100 kW to 1 MW have been in operation for over 20 years. Although the part of these boilers in the municipal heat power system of Ukraine does not exceed 14 %, the projected savings in natural fuel in these boilers is more than 130 million cubic meters per year. Thus, increasing the efficiency of the fuel combustion process in small and medium power boilers is an urgent task at the present time. The article presents the results of creating a method and hardware that implements it, to increase the speed and reliability of monitoring the process of fuel combustion in boiler units based on measuring the concentration of residual oxygen in exhaust gases. The developed method is implemented by stepwise correction of the ratio of the air-fuel mixture entering to the furnace of the boiler for combustion, according to feedback signals from a broadband oxygen sensor manufactured by Bosch, located in the outgoing channel. The air-fuel ratio control with automatic adjustment of the blower fan speed depending on the amount of fossil fuel supplied for combustion ensures low-toxic combustion of fuel with low emissions of nitrogen oxides and carbon monoxide, and high efficiency. Additional use of a variable frequency drive in the combustion control system allows to reduce energy consumption by 30-40 %, eliminate starting currents and motor overloads, reduce mechanical wear of equipment, increase the service life of contact switching equipment. In general, the developed fuel combustion control system allows to optimize the fuel combustion mode, taking into account the actual conditions, operating modes of the boiler unit and fuel characteristics; to reduce specific fuel consumption by at least 10%; to reduce the level of emissions of nitrogen oxides up to 40 % and carbon monoxide up to 50 %; to increase the efficiency by at least 5 %; qualitatively to simplify the work of the boiler maintenance personnel.

An Improved Thermoeconomic Diagnosis Procedure for the Detection of Different Malfunctions of Complex Energy Systems

2003 ◽  
Author(s):  
Vittorio Verda
Keyword(s):  
Complex System ◽  
Neural Networks ◽  
Control System ◽  
Energy Systems ◽  
Operating Conditions ◽  
Fuel Quality ◽  
System Efficiency ◽  
Complex Energy ◽  
Ambient Conditions ◽  
Economic Implications

Diagnosis of energy systems mainly consists of detecting and locating anomalies that cause reduction in the system efficiency or can cause major failures. This is an important task due to its economic implications. The attention is here focused on the anomalies that affect the system efficiency. The problem of their location is not easy to solve, due to some ‘disturbs’ that make propagate the effects of an anomaly throughout the system. These effects are caused by the dependence of the components’ behavior on their operating conditions. Moreover they can be amplified by the intervention of the control system and the variations in ambient conditions, fuel quality and plant load. A technique for highly complex system has been proposed in [1]. This procedure, based on the hypothesis of small malfunctions, consists of the progressive elimination of the disturbs, so that the anomalies could be more clearly highlighted. In this paper, a procedure particularly suitable for the application to operating plants is adopted to overcome the hypothesis of small malfunction. It consists of a combination of two techniques: 1) the use of neural networks for the elimination of the malfunctions [2] induced by the dependence of efficiency of components on the operating conditions and 2) the successive application of the analysis to several operating conditions selected within the plant case history.

scholarly journals Applications of artificial neural network and Box-Behnken Design for modelling malachite green dye degradation from textile effluents using TiO2 photocatalyst

2021 ◽  
Vol 27 (1) ◽  
pp. 200553-0
Author(s):  
Chandrika K.C ◽  
T. Niranjana Prabhu ◽  
R. R. Siva Kiran ◽  
R. Hari Krishna
Keyword(s):  
Malachite Green ◽  
Dye Degradation ◽  
Anatase Phase ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Interactive Effects ◽  
Optimum Operating ◽  
Box Behnken Design ◽  
Degradation Reactions ◽  
Artificial Neural

Most of the photocatalytic studies for pollutant degradation are based on optimizing a single parameter that results in a non-linear relationship between the overall parameters and the photo-degradation reactions. To address this critical problem, herein, we report the use of Response Surface Methodology based on the Box-Behnken Design (BBD) for modeling the photocatalysis degradation of Malachite Green (MG) dye using nano TiO2 as photocatalyst. The catalyst characterizations are carried out using XRD, SEM, and TEM, indicating that the TiO2 prepared by sol-gel synthesis possesses Anatase phase with particles in the nano regime and porous surface morphology. The optimum operating conditions for degradation of MG was identified by the interactive effects of variable factors such as initial dye concentration 10-30 ppm (x1), catalyst dosage 1-3 mg (x2), contact time 20-60 min (x3) using the Box-Behnken method. Furthermore, the degradation reactions are also evaluated by Artificial Neural Networks (ANN). Their predicted results have been validated by the experimental studies and found to be acceptable. Their optimal results to achieve 90% degradation efficiency at TiO2 nanoparticle dosage (3 mg), reaction time (60 min), and initial dye concentration (20 ppm) have been validated by the experimental studies and found to be acceptable.

A developed combined control method for induction machine drives based on PWM

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hassan Dahmardeh ◽  
Mahmood Ghanbari ◽  
Seyed Mehdi Rakhtala
Keyword(s):  
Control System ◽  
Simple Structure ◽  
Sliding Mode ◽  
Experimental Studies ◽  
Induction Machine ◽  
Operating Conditions ◽  
Torque Control ◽  
Switching Frequency ◽  
Content Type ◽  
Combined Control

Purpose The purpose of this paper is to develop a combined control (CC) technique based on the direct torque control (DTC) strategy and vector control (VC) method, to improve the overall performance of a three-phase induction machine (TPIM) drives. Design/methodology/approach The proposed control scheme includes a table-based DTC strategy in connection with a proportional-integral-sliding mode controller and pulse width modulation switching strategy. The control system has merits of DTC technique such as simple structure, less dependent on machine parameters, fast dynamic response and merits of VC technique such as high accuracy and constant switching frequency. Findings To validate the effectiveness of the proposed control system, simulation and experimental studies are carried out for a 0.75 kW TPIM in different operating conditions. The achieved results show the superiority of the proposed method in terms of fast dynamics and simple structure compared to the VC strategy and low speed and torque ripples and constant switching frequency compared to the DTC method. Originality/value Compared to the conventional CC strategies, the control law of the proposed method is based on DTC theory and modulation is established based on VC. In other words, the variable switching frequency which is one of the main disadvantages of the conventional CC strategies is rectified using the proposed CC scheme.

YSZ oxygen sensor for lean burn combustion control system

1993 ◽  
Vol 13 (1-3) ◽  
pp. 114-116 ◽  
Author(s):  
Dong Hyun Yun ◽  
Dong Il Kim ◽  
Chong Ook Park
Keyword(s):  
Control System ◽  
Oxygen Sensor ◽  
Combustion Control ◽  
Lean Burn

scholarly journals Heat Exchange and Hydrodynamic Characteristics of Unified Package of Cold Layer of RAH

2021 ◽  
pp. 51-54
Author(s):  
Tetiana Rymar
Keyword(s):  
Hydraulic Resistance ◽  
Combustion Products ◽  
Fuel Combustion ◽  
Hydrodynamic Characteristics ◽  
Convective Heating ◽  
Equivalent Diameter ◽  
Fuel Quality ◽  
Operational Parameters ◽  
Coefficient Of Hydraulic Resistance ◽  
Heating Surfaces

Heating the air in the boiler air heater with the heat of fuel combustion products performs the functions of increasing the fuel combustion temperature, increasing the temperature level of gases in convective heating surfaces, improving ignition and fuel combustion conditions, increasing boiler efficiency by utilizing waste gas heat, improving fuel quality due to its preliminary supply, etc. However, the peculiarities of the process of heating the air in the air heaters do not allow to achieve a decrease in the temperature of the exhaust gases. This is due to the unfavorable ratio of heat capacities of flue gases and air, as well as corrosion and contamination of the heating surfaces of air heaters. The research of heat transfer processes and hydraulic resistance of unified package of cold layer of RAH is depicted at this work. The graphic dependence of the change in the coefficient of hydraulic resistance and Nu number for unified packages with single line of sheets and simplified profile with corrosion resistance enamel from the Reynolds number for different values of the length of the replaced areas was constructed. The unified packing of the simplified profile has increased by 1.17 times equivalent diameter and is characterized by good operational parameters and takes into account the risk of contamination of heating surfaces due to the enamel coating.

Influence of the distribution of fuel supply in a double-circuit burner on the concentration of harmful substances in combustion products

2021 ◽  
pp. 10-13
Author(s):  
A.V. Baklanov
Keyword(s):  
Nitrogen Oxides ◽  
Combustion Chamber ◽  
Experimental Studies ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Fuel Combustion ◽  
Minimum Concentration ◽  
Fuel Supply ◽  
Low Emission ◽  
Harmful Substances

The design of a double-circuit burner of a low-emission combustion chamber of a gas turbine engine working on natural gas is considered. The distribution of the fuel supply in the double-circuit burner is investigated and its influence on the emissions of harmful substances is determined. Bench equipment, features of experimental studies of the concentration of gas mixture components in combustion products and calculations of the fuel combustion efficiency are presented. The ratio of fuel consumption along the circuits at a minimum concentration of nitrogen oxides and maximum combustion efficiency of carbon oxide in combustion products is determined. Keywords: double-circuit burner, low-emission combustion chamber, experiment, fuel, combustion efficiency, combustion products, nitrogen oxides. [email protected]

АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ

2020 ◽  
pp. 62-80
Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко
Keyword(s):  
Control System ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Spectral Characteristics ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Detection Range ◽  
Acoustic Signature ◽  
Static Conditions

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.

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