scholarly journals Features of Automatic Control of Technological Parameters of Water Level in the Drum Steam Boilers

Author(s):  
Isamiddin Siddikov ◽  
Dilnoza Umurzakova

The three-pulse system of automatic control of the water level in the boiler drum received maximum distribution in the energy sector, as well as its modifications, which have the following disadvantages : the presence of static control errors at the end of the transition process in the development of internal disturbances and disturbances of superheated steam flow; large level deviations with sharp and significant changes in the load, which often leads to unloading or shutdown of the boiler or power unit. To eliminate these drawbacks, invariant systems for automatic regulation of the power supply of the drum boiler were previously developed. In work the system of automatic control of technological parameters of water level in a drum of steam boilers is considered. The description of control systems and a detailed description of the electrical power systems of the control system are given. Various methods of tuning the PI controller of a typical three-pulse automatic power control system are considered. The application of the method of structural-parametric optimization and the theory of invariance makes it possible by changing the structure of the system and optimizing the dynamic adjustment of the automatic power control system to significantly improve the quality of maintaining the water level in the boiler drum. Invariant automatic control systems eliminate static control errors under all influences and can significantly improve the quality of maintaining the level under variable conditions. The methods are proposed to significantly improve the quality of water level control in the boiler drum, eliminating the shortcomings of the typical automatic control system. The results of the work can be used in the design of power control systems of steam drum boilers. The results obtained can be used in the development of adaptive control systems for other thermal power facilities.

Author(s):  
G. T. Kulakov ◽  
K. I. Artsiomenka

The article concerns the problem of structure-and-parametric optimization of a cascade automatic control system (CACS) by an example of a boiler power controller and a fuel controller. This CACS, which is a part of automatic control systems for power units, consists of two loops, viz. of an inner loop (which purpose is stabilization of the system) and an outer loop (designed for the adjustment) and, also, of two controller, viz. an outer controller (which is a basic one) provided for stabilization of the output value of the object (in our case, of the actual power unit capacity) and of an inner controller (which is an auxiliary one) provided to regulate fuel consumption. The internal controller builds up the control action with the aid of the boiler load controller of the power unit. As compared to single-loop automatic control systems, the cascade  system provides better quality of transient control due to the higher performance of the internal loop of the system. This advantage is especially noticeable when compensating for disturbances that come through the channel of regulating impact. The article presents two methods of setting, viz. the fuel controller and the boiler power controller. The application of these methods can improve the quality of power control and reduce fuel consumption in transient modes in comparison with the setting of these controllers of a typical power unit automatic power control system. The results of computer simulation of transient processes in CACS for input step surge and internal perturbation confirm the advantages of the methods are presented in this article.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1257
Author(s):  
Alexey Dorokhov ◽  
Alexander Aksenov ◽  
Alexey Sibirev ◽  
Nikolay Sazonov ◽  
Maxim Mosyakov ◽  
...  

The roller and sieve machines most commonly used in Russia for the post-harvest processing of root and tuber crops and onions have a number of disadvantages, the main one being a decrease in the quality of sorting due to the contamination of working bodies, which increases the quantity of losses during sorting and storage. To obtain high-quality competitive production, it is necessary to combine a number of technological operations during the sorting process, such as dividing the material into classes and fractions by quality and size, as well as identifying and removing damaged products. In order to improve the quality of sorting of root tubers and onions by size, it is necessary to ensure the development of an automatic control system for operating and technological parameters, the use of which will eliminate manual sorting on bulkhead tables in post-harvest processing. To fulfill these conditions, the developed automatic control system must have the ability to identify the material on the sorting surface, taking into account external damage and ensuring the automatic removal of impurities. In this study, the highest sorting accuracy of tubers (of more than 91%) was achieved with a forward speed of 1.2 m/s for the conveyor of the sorting table, with damage to 2.2% of the tubers, which meets the agrotechnical requirements for post-harvest processing. This feature distinguishes the developed device from similar ones.


2021 ◽  
Vol 22 (1) ◽  
pp. 287-297
Author(s):  
Dilnoza Umurzakova

The purpose of this article is to develop high-quality combined automatic control systems (ACS) for the water level in the drum of steam boilers of thermal power plants (TPPs), which can significantly improve the quality of regulation and increase the efficiency of TPPs in a wide range of load changes. To improve the quality of water level control in the drum of steam generators of nuclear power plants with a pressurized water-cooled power reactor (PWPR), it is proposed to use a combined automatic control system based on a control loop with a correcting PI-controller tuned to a symmetrical optimum, with smoothing the reference signal and device compensation of the most dangerous internal and external measurable disturbances. A technique has been developed for assessing the impact of changes in the quality characteristics of transients of combined self-propelled guns by the water level in the drum of steam boilers and steam generators on the safety, reliability, durability, and efficiency of thermal power equipment of thermal power plants. Comparison was made of direct indicators of the quality of three ACS (typical and three-pulse, digital system with an observer state, and the proposed combined ACS). The simulation results of transients of the proposed and typical three-pulse self-propelled guns confirmed the advantages of the first. ABSTRAK: Artikel ini bertujuan bagi membina sistem kombinasi automatik (ACS) berkualiti tinggi bagi aras air dalam drum dandang stim tenaga terma logi kuasa (TPP). Ini dapat meningkatkan mutu peraturan dan meningkatkan kecekapan TPP secara signifikan dengan pelbagai perubahan beban. Bagi meningkatkan kualiti kawalan aras air dalam drum penjana wap loji kuasa tenaga nuklear dengan reaktor berpendingin air bertekanan (PWPR). Gabungan sistem kawalan automatik berdasarkan gelung kawalan dengan pembetulan PI telah dicadangkan dan diselaraskan simetri secara optimum, dengan melancarkan isyarat rujukan dan pembetulan peranti dari gangguan yang boleh diukur dari dalam dan luar. Satu teknik telah dibina bagi menilai kesan perubahan ciri kualiti transien gabungan berjentera pada aras air di tong dandang stim dan drum penjana wap pada keselamatan, kebolehpercayaan, ketahanan dan kecekapan peralatan tenaga terma loji janakuasa. Perbandingan dibuat pada kualiti tiga ACS (sistem digital khas dan tiga signal dengan keadaan pemerhati dan gabungan ACS yang dicadangkan). Hasil sistem simulasi transien yang dicadangkan dan tiga signal biasa berjentera mengesahkan kelebihan pada yang pertama.


Author(s):  
G. Kalimbetov ◽  
A. Toigozhinovа ◽  
W. Wojcik

Among the promising automatic control systems, logical-dynamic control systems that change both the structure and parameters of the control device using switches formed on the basis of a certain logical algorithm have proven themselves well. The use of logical algorithms as part of MACS subsystems for complex technical objects makes it possible to increase the static and dynamic accuracy of control due to purposeful qualitative and quantitative changes in the control signal. This approach will give the control system fundamentally new properties that allow to fully take into account the nature and dynamics of the movement of the control object. When developing existing logical control algorithms, the issues of their application for multi-connected and multifunctional objects control were not considered. Common to existing logical algorithms is that when switching the structure and/or changing parameters, only the dynamics of its own subsystem is taken into account, which is unacceptable in the case of multi-connected dynamic object control, since cross-links have a significant impact on the quality of control. Thus, the problem of synthesis of logical algorithms for multi-connected objects control is an actual theoretical and applied problem. Despite the considerable amount of research conducted in this area, the application of logical algorithms for complex multidimensional objects control is not sufficiently considered, and there is no unified design concept for this type of MACS, taking into account the required quality of functioning in various operating modes. In this regard, there is a need to synthesize algorithms for logical multi-connected control that form control signals in order to coordinate the actions of all separate MACS subsystems in accordance with new external conditions and operating modes. The problem under consideration determined the purpose of this work and the research objectives.


2018 ◽  
Vol 51 (1-2) ◽  
pp. 4-15 ◽  
Author(s):  
Mariusz Pawlak

This paper presents a water-level control system in a drum boiler. The system was equipped with a fault tolerant control–type diagnostic system. The paper presents the results of tests conducted on the fault tolerant control system implemented in the water-level control system in a boiler drum. The diagnostics of the measurement circuits was carried out online. To that end, the appropriate partial models were developed and tested. This allowed for the application of analytical redundancy for the measurement circuits. The paper also identifies the influence of diagnostics and fault tolerance on the values of reliability indices and operating safety of a power unit. Fault tolerant control systems increase the safety of a power unit operation, and the studies described in the paper directly contribute to them. These kinds of systems have not been used so far in power unit automation. Site tests confirmed the validity of the acquired concept for the diagnostic system. Fault tolerant control systems have not been commonly applied in power engineering yet. Studies of the water-level control system in a steam drum using the fault tolerant control system for the measurement circuits as presented in the paper are original ideas, providing a new solution. All control systems made for the study fulfil their role in a satisfactory way, which results in a minor deviation in the water-level adjustment in the boiler drum. The tests confirmed the efficiency of the fault detection algorithm. The created models of the water level and flows proved to be successful. Under a no-fault condition of the facility, there were no errors in the diagnoses and the values of all residua were below the detection thresholds. This was achieved despite a high value of measurement noises. The residua helped detect minor faults.


2020 ◽  
Vol 55 (3) ◽  
pp. 99-107
Author(s):  
F.N. Gallyamov ◽  
◽  
A.V. Sharafutdinov ◽  
M.V. Pyatayev ◽  
◽  
...  

The paper discusses technical aspects involved in developing seeding control systems for grain seeders and sowing machines. Construction and technological parameters of seeding control systems are based on the analysis of the available machinery. As a result an operation-performing unit was constructed and tested in field trials. The RatinalRose visual simulation environment was used to design the software of the seeding control system. The environment allowed for interpreting the volume concentration of particles. A procedure for collecting and presenting data was developed. COMPAS com106 puter program was used to create a 3D design of the sensor and measure its parameters, then the sensor case was made using a 3D printer. Field trials involved comparing 2 identical drills under identical conditions. The drill equipped with the seeding control system had better indices of time saving and efficiency (by 22 %). The study results allowed us to develop the software for the seeding control system and determine the optimal design and process parameters of the seeding control sensor for a pneumatic drill in order to reduce clogging in the seed pipes and improve the quality of seed distribution.


Author(s):  
Osama Mahfooz ◽  
Mujtaba Memon ◽  
Asim Iftikhar

<span>A PLC is a digital computer used to automate electromechanical processes. This research is<span> based on automation of a water tank by using Siemens PLC. Automatic control of water tanks<span> can work continuously and can provide accurate quantity of water in less time. In such process<span> there is no need of labor so there is no human error. Without human error, the quality of product<span> is better and the cost of production would definitely decrease with no error in quantity required.<span> Water level sensing can be implemented in industrial plants, commercial use and even at home<br /><br class="Apple-interchange-newline" /></span></span></span></span></span></span>


2012 ◽  
Vol 459 ◽  
pp. 75-78
Author(s):  
Lian Jun Hu ◽  
Xiao Hui Zeng ◽  
Gui Xu Chen ◽  
Hong Song

An automatic control system for multi-axes motions based on multi-CPU embedded systems is proposed in the paper, in order to overcome insufficiencies of available multi-axes automatic dispensing control systems. It is shown from experimental results that expected control objectives for multi-axes motions are achieved.


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