Institute of Computer Science and Technology
Faculty of Intelligent Systems and Programming
Department of Computer engineering
Specialty Computers, complexes, systems and networks
Development and research of a distributed monitoring system for a thermal power plant
Scientific adviser: Candidate of Technical Sciences, Associate Professor Zavadska Tatyana Vladimirovna
According to its sensitivity, a hydroelectric power plant (HPP) is located in second place after thermal power plants. In their work, they use the energy of water, which is converted into a developing current, and attracted to natural resources. Simple control of stations does not require a large number of personnel. The efficiency reaches up to 85%.
Electricity calculated at hydroelectric power plants is considered the cheapest, the price is about 5-6 times less than at thermal power plants. Hydroelectric power plants are highly maneuverable and can be put into operation within 3-5 minutes, while it takes several hours to power a power plant (TPP). This quality is especially important when peaks are blocked in the daily power supply schedule [2].
The main sources of origin are:
A pumped-storage power plant (PSPP) is considered quite a promising area. Their work is based on the principle of operation associated with a cyclic change in absolute water between the upper and lower basins. In the daytime, with a sharp increase in energy consumption, it is dumped down and rotates the turbines, producing energy. These stations do not grow at all from the high frequency of river flow, and reservoirs require significantly less flooded area [1].
In the first place in the calculation of electricity at nuclear power plants (NPPs). In Russia, their share in the energy sector is slightly above 10%. In the US, this figure is 20%, in Germany - more than 30%, in France - above 75%. The reduction of programs in the field of nuclear energy occurred in an emergency at the Chernobyl nuclear power plant.
The main advantages of nuclear power plants are as follows:
When considering how a nuclear power plant works, one must first focus on detecting the consequences in the event of an accident. In addition, serious problems arise with radioactive waste during its disposal. Reservoirs used for technical purposes of nuclear power plants are subject to thermal pollution [1, 3].
For the operation of diesel power plants (DPP), various types of liquid fuel can be used. Foundation withThe system is a diesel generator, which includes a diesel engine, an electric generator, lubrication and cooling systems, and a control panel. These installations are used as an alternative in remote areas where they are the main sources of electricity. As a rule, bringing stationary power lines to such places is not economically profitable. In addition, diesel power plants serve as emergency or backup power sources when consumers should not be disconnected from the power supply.
Diesel power plants can be stationary (4-5 thousand kW) and mobile (12-1000 kW). Due to their small size, they can be placed in small buildings and premises. These stations are constantly ready for launch, and the launch process itself does not take much time. Most of the functions of the units are automated, and the rest are easily transferred to automatic mode. The main disadvantage of diesel stations is imported fuel and all activities related to its delivery and storage [1].
Power plants that convert the thermal energy of fuel combustion into electrical energy are called thermal power plants (TPPs). Consider their advantages and disadvantages [3].
Benefits:
Disadvantages:
For reliable and efficient operation of equipment at modern thermal power plants, it is required to control and maintain several hundred technological parameters at set values, to perform thousands of operations to control two-position bodies, mechanisms and devices. Automatic control and management systems allow you to free the operator from the above tasks and give him the opportunity to focus on the most important parameters and control operations. Such automatic systems include subsystems for remote and discrete automatic control of mechanisms and fittings, automatic regulation and protection, thermal control and signaling, calculation of TEC.
The principle of organizing process control at TPPs is shown in Figure 1 [8].
Figure 1 - The structure of the organization of process control at TPP (animation: 11 frames; 804 kilobytes)
In figure 1, the following notation is used:
Remote control devices are designed to transfer the operator's actions to shut-off and regulatory bodies remote from the control station, devices for starting and shutting down mechanisms.
Automatic control systems (ACS) of HPPs are designed to combine local control systems into a single system. Centralized storage of information and a single control panel for the entire power plant. Group control of electric power generated by turbines and its regulation [6, 7].
Its functions include:
The ACS-TP includes the following subsystems:
The structure of the system consists of:
Features of the implementation of such a system:
The benefits of using it include:
Along with the automation of the technical process (TP), at a nuclear power plant (NPP), the control of system parameters is necessarily implemented. First of all, the control of the parameters used by the automatic control systems (ACS) in the control of the TP is carried out. These parameters include indications of sensors of position, speed, force, temperature control, level, pressure, limit switches and other signals transmitted from the equipment of the control object to the ACS. In addition, the ACS controls the transfer of information within the system itself, control of communication lines and other parameters [9].
It should also be noted that traditionally ACS for nuclear power plants are designed taking into account the following basic principles regulated by the document:
Another requirement when creating an ACS for nuclear power plants is to minimize the influence of personnel on the operation of the ACS.
When designing, manufacturing and implementing ACS, the following features of the operator's interaction with the system are usually taken into account:
A feature of modern ACS for nuclear power plants is their diversity in terms of the technical solutions used in them. First of all, this is typical for nuclear power plants that have been operating for a long time, the control systems of which have been repeatedly upgraded during their operation.
This is due to the following reasons:
The specifics of ACS design for nuclear power plants is that part of the ACS equipment is operated in the central (reactor) hall of the station or other rooms where there is a radiation load or contact with radioactive media, where special solutions are used to decontaminate equipment surfaces, and therefore, there are high humidity and temperature [10]. Sensors, motors and actuators work mainly in adverse conditions. At the same time, they try to move the ACS technical means to “clean” rooms, and where this is not possible, they use products that are resistant to the above external influences, or place them in protective shells. Nuclear power plants and ACS equipment are also designed taking into account the requirements for seismic resistance.
Quite stringent requirements are imposed on the reliability of ACS. For example, the reliability of the refueling machine control system is characterized by the following indicators:
The assigned service life of the control system of the refueling machine is at least 30 years.
These indicators are achieved through the use of components with high reliability, redundancy and providing the user with the necessary set of spare parts.
The information management system (IMS), using the example of the Starobeshevsky thermal power plant (TPP), is designed to collect, process and issue information to managers necessary for making management decisions and monitoring their implementation. An information management system is a permanent system of interconnection of people, technical means and methodological techniques, designed to collect, classify, analyze, evaluate and disseminate relevant, timely and accurate information for use by its managers in order to improve planning, implementation and control of activities. carried out by the organization [11].
An information management system should provide information about the past, present and future; keep track of all significant events within the organization and outside it. The overall purpose of the IMS is to facilitate the effective performance of the functions of planning, control and production activities. Its most important task is to provide the right information to the right people at the right time, IMS in organizations can consist of a number of information systems, each of which serves to make decisions in a certain area.
Information and control systems, except for the availability of informationtions, ensure the implementation of the planning and control functions. Control commands, which are the result of processing the received information data and making decisions, are transferred directly to the control object. A person retains the functions of monitoring the state and behavior of systems. Let's take a closer look at its structural elements.
A power unit is an almost autonomous part of a thermal power plant, which is a technological complex for generating electricity, including various equipment, such as a steam boiler, a turbine, a turbogenerator, a step-up transformer, auxiliary thermal mechanical and electrical equipment, steam and feed water pipelines, and more. The power unit is directly controlled at the block control board.
The unit control panel (BCR) serves to control the operation of all equipment of the units and coordinate the operation. The senior operators and block operators located in the control room premises ensure the normal operation of the station blocks.
The block control panel is used to control the power unit of the TPP. Start-up of the power unit, bringing it to power, start-up of the turbine, synchronization of generators, remote control of safety systems, as well as the inclusion of auxiliary systems are carried out from the control room.
The block control panel is placed in the main building of the TPP between the turbine and boiler rooms. The shield is equipped with vertical panels and inclined consoles 2, on which control and monitoring devices are placed. These consoles and panels are arranged in an arc for a better view. To the right and left of the consoles there are panels of a non-operational circuit with protection devices for the boiler, turbine, generator.
The power plant is controlled from block control panels located between the boiler units at the control mark.
The unit control system includes control, automation, alarm and remote control devices. Communication with workplaces and the central control panel is also carried out from the control room. In addition, control and information-computing machines are located on the control room, if their installation is provided for by the project.
All elements of the control system are located on the operational panels and control panels. The block board also houses the electrical panels of the generator-transformer unit, technological protection panels, regulator panels, power panels, central alarm panels and a number of other non-operational panels. Remote control keys for gate valves and electric motors are located on the control panels, which allow starting, stopping and normal operation of the unit. The presence of a mnemonic diagram and alarm panels facilitates the work of operational personnel both in normal and emergency conditions. With the main control room, the generator is also switched on in parallel operation.
According to established practice, control of two units is located in one room of the control room. This allows you to expand the control zone without reducing the reliability of work.
It should be noted that at present there is no unified layout of panels and consoles, even for the same type of equipment. This is explained by the search for the most convenient and rational layout of the control and management elements of the unit.
The use of block control panels made it possible to concentrate all the control of the block in one place, which made the operation of the equipment more efficient, especially in emergency cases. Such a solution to the problem provided a high level of automation of modern equipment, measuring equipment and remote control. With the introduction of centralized management methods, safe working conditions are improving due to the abolition of permanent jobs near working equipment. The soundproofing of the control room, good lighting conditions and air conditioning create favorable sanitary conditions for operational personnel.
Some drawback of the centralized control system is that the operating personnel are deprived of the possibility of visual observation of the operating equipment, since the periodic inspection of the equipment by the on-duty crawlers cannot replace systematic observation. This problem can be solved by the widespread use of television installations, the television cameras of which are located in the most critical places of the block. Having one TV screen, the operator can use a special switch to receive an image of any nodes and objects of interest to him.
Initially, data collection and control was done manually. There was a large roll of paper on which the mechanism used a needle with a writing tip to draw graphs.
This mechanismwas replaced by secondary devices, data from them were read using self-written programs.
Over time, the load volume grew and new secondary devices were added. With the advent of new secondary devices, self-written programs became more and more.
It was decided to upgrade the system in 3 stages:
The data was stored on paper, which made it much more difficult to record information.
The computer has a direction for data collection (self-written programs) from secondary devices. These programs are designed for a small number of devices. As their number grows, programs begin to malfunction, show inaccurate data, and freeze.
Now the update time is 5 seconds, and is designed for approximately 200 signals. Over time, the number of signals grows, the new program will be able to update the data every 2 seconds and work with about 1000 signals.
On the local computer where the secondary devices are installed, data is written to the database (DB), graphs are displayed, programs are installed that can be used to view the history. The computer is connected via a network to an Internet server that stores the data of all power units. Based on them, the efficiency of all power units is built.