DCS System Research Articles

Research on Intelligent Water Treatment Strategy based on DCS Control System

Abstract In a capacity renovation project, the new DCS system as the equipment control system, and the existing AB 1756 series PLC system, there are two control systems bi-directional signal monitoring problems. This paper compares two methods of monitoring bi-directional data transmission, and analyzes and verifies the advantages and disadvantages of the two methods. From the perspective of reliability and safety of implementation, a protocol special communication card was added in the PLC controller card slot of desalination plant, and added a protocol-specific communication card to the PLC system card slot of the secondary reverse osmosis and EDI units. The actual project verification shows that this method can ensure reliability and safety performance while realizing functions.

Implementation of Siemens S7-1200 PID Control on Festo Labvolt 3531 Plant Level Controller with Topkapi SCADA Using Modbus Communication Protocol

Plant Festo LabVolt 3531 is a DCS, SCADA and process control system trainer based on the Allen Bradley Controllogix 5572 PLC and Factorytalk View SCADA. This research aims to provide another controller solution that can be used on the Festo Labvolt 3531 plant besides the Allen Bradley Controllogix 5572 PLC and FactoryTalk View SCADA. So that students have alternatives and variations of other technologies in learning. In this research, the Siemens S7-1200 PLC was used as a replacement for the Allen Bradley Controllogix 5572 PLC and Topkapi SCADA as a replacement for FactoryTalk View SCADA. As validation of the test, PID control was used to regulate the water level in both tubes at the Festo Labvolt 3531 plant. The test results for several specified height levels showed that the Siemens S7-1200 PLC with PID control integrated into Topkapi SCADA using the mobus communication protocol was successfully implemented , where the resulting control response has an average steady-state error of less than 2% and the delay between the interface and the device on the plant is 0s.

Exploring the Application of PLC Technology in Mechanical Electrical Control Devices

China's industrial sector has made great progress after years of development, and the field of science and technology has promoted the rapid growth of the industrial economy through technological upgrading. In the face of the new situation of social development, the previous manual mode of operation can no longer meet the development of the times, so it is necessary to make innovations in machinery manufacturing. Taking industrial production as an example, PLC technology is a new type of technology that can greatly improve the efficiency of industrial production and enhance the productivity of enterprises, thus solving the problems of production relations and productivity. It can be seen that in the future development stage PLC technology can get better development, especially in the field of electrical control using PLC technology, can improve the safety of electrical control devices, but also in the automation level, the level of efficiency has a good role in promoting. This article will focus on the application status of PLC technology, and a detailed description of mechanical electrical control. The impact of this technology on mechanical electrical control will be analyzed, focusing on existing control systems, such as FCS systems and DCS systems, which are the more common types of control systems today. Finally, the specific application areas of the technology in the mechanical electrical control system are analyzed, such as the basic control system of the DCS system and the integrated control system. During the application of the above content will be affected by a variety of variable factors, around which the analysis can be carried out to improve the automation level of mechanical electrical control devices.

Research on safety early warning of abnormal A-annular pressure of “three-high” gas wells based on data mining

A major safety accident will be triggered when the A-annular pressure value of high pressure, high productivity and high sulfur gas well exceeded the maximum allowable value. The A-annular pressure value of high pressure high productivity and high sulfur gas well once exceeded the allowable value will trigger a major safety accident. Therefore, this paper proposed a data mining based the gas well early warning strategy by analyzing the annular pressure mechanism and the change in the pattern of instantaneous gas volume, well temperature, and annular pressure in various conditions. To summarize, the law of gas well abnormal A-annular pressure is aimed at constructing a gas well safety warning rule for gas well stable production stage and shutdown period where the initial parameters setting in the early warning rule and adjustment optimization mechanism is also determined. Lastly, with the use of historical abnormal samples, the gas well early warning strategy bought up in this paper was verified. The example shown that compared with the traditional DCS system warning strategy, the gas well safety early warning strategy can identify the abnormal A-annular pressure phenomenon 82 h in advance thus achieving production safety management.

Real-Time Effective Monitoring and Control in Oil and Gas Industry Using SCADA Technology as a Management Tool

Pipeline leakage detection, if not addressed swiftly/promptly, could result to loss of lives and properties. Researches have shown that the best means of curbing or drastically minimizing these losses is through real time monitoring using DCS and CAO-SCADA Technology as the management tool. This tool was adopted in this work and then applied to a particular oil and gas terminal in Nigeria. Research questions were generated and data obtained as well as the research instrument used were validated. A total of one hundred and thirty-five respondents were used for the study. From the formulated testing based on z-test, three hypotheses were investigated termed as HO1, HO2 and HO3. HO1 test hypothesis of pipeline failure as a result of leakages along it and if the leakage detection is because there is no DSC, CAO-SCADA management tool along the pipeline. The result obtained showed that z-calculated is less than the critical value of 1.96 with a significant level of 0.05. From the results obtained, the hypothesis HO1 is accepted, thus failure of this pipeline is because the DSO, CAO-SCADA is not present in the system. HO2 testing determined if there exists any difference significantly between the DSC and CAO-SCADA system. From the result, the z-calculated which is 0.0065 is less than the critical value which is 1. This implies that the null hypothesis (HO2) is accepted. Meaning that there is no significant difference between CAO-SCADA and the DCO for the effective management and monitoring and safety operations in the pipeline. The last hypothesis is to test if there exists significant difference between DCS and CAO-SCADA system for effective industrial system control of leakages in pipeline. Out of the 135(100%) respondents, 106(78.52%) agreed with the recommendations made by the researchers while 12.59% partially agreed. 4(5.18%) have a clear understanding and 5(0.0370%) are indifferent about the recommendations made.

Optimization of preventive maintenance of nuclear safety-class DCS based on reliability modeling

Nuclear safety-class DCS is used for nuclear reactor protection function, which is one of the key facilities to ensure nuclear power plant safety, the maintenance for DCS to keep system in a high reliability is significant. In this paper, Nuclear safety-class DCS system developed by the Nuclear Power Institute of China is investigated, the model of reliability estimation considering nuclear power plant emergency trip control process is carried out using Markov transfer process. According to the System-Subgroup-Module hierarchical iteration calculation, the evolution curve of failure probability is established, and the preventive maintenance optimization strategy is constructed combining reliability numerical calculation and periodic overhaul interval of nuclear power plant, which could provide a quantitative basis for the maintenance decision of DCS system.

An industrial control loop decoupler for process control applications

The paper describes a simple and efficient control loop decoupler for TITO (two inputs, two outputs) control systems. The inverted decoupling approach is used, and the feedforward filters are just static gains. The feedforward gains are determined in two ways, from a static analysis and from optimization. By investigating several cases found in literature, it is found that the two sets of feedforward gains are very close. The control loop decoupler is implemented in an industrial DCS system and simulation experiments as well as laboratory tests show that a significant reduction of the coupling is accomplished. Automatic tuning of the feedforward gains is derived and implemented in the system as well.

INDUSTRIAL CONTROL SYSTEM APPLIED AND PROBLEMS: A REVIEW AND EXPERIENCES

This paper aims to explain examples of industrial control system applications that are applied in the industrial world today and the problems that arise in the Industrial Control System (ICS). The methodology used in this paper is to review several journals, books, and work experiences (experiment). SCADA in the highest position, the DCS at level 2, then the PLC at the very bottom. And there are two problems encountered, namely in terms of hardware and software. In case of hardware problem SCADA, DCS and PLC hit by lightning, exposed to droplets of water seepage, electrical fuse problem, the temperature of the hot room, high humidity, mainboard problem (due to lifetime), power supply (due to lifetime and bad electric power supply). In terms of the software, its software is corrupt, so it should be in the re-install. In general, a CD contains software for one PC (personal computer) because there is one CD software there is activation code where when you enter the activation code must be connected to the internet network that is detected automatically. The effect that causes the most loss was a broken fuse. So, dividing the same load each digital output or part is good architecture. The SCADA system had to be more concerned for cybersecurity compares with the DCS system due to its connection with the network. That was for maintaining availability and reliability.

A security and authentication layer for SCADA/DCS applications

Mid 2010, a sophisticated malicious computer worm called Stuxnet targeted major ICS systems around the world causing severe damages to Siemens automation products. Stuxnet proved its ability to infect air-gapped-segregated critical computers control system. After this attack, the whole ICS industry security was thrust into spotlight. Automation suppliers have already started to re-think their business approach to cyber security. The OPC foundation have made also significant changes and improvements on its new design OPC-UA to increase security of automation applications but, what is still missing and seems to be not resolved any time soon is having security in depth for industrial automation applications. In this paper, we propose a simple but strong security control solution to be implemented as a logic level security on SCADA and DCS systems. The method presented in this work enforces message integrity to build trusts between DCS system components, but it should not be viewed as the main nor the only protection layer implemented on an industrial automation system. The proposed solution can be viewed as a low-level security procedure to avoid malicious attacks such as Stuxnet.

Research on the State Detection Method of Automatic Instrument Equipment Based on Construction Engineering

Nowadays, people’s demand for industrial products is increasing while the demand for quality is also higher, so each enterprise is changing the traditional manual operation equipment into automatic equipment so that the production capacity and product quality can meet the current social demand. And the development of computer technology has provided us with such convenience. Automatic instrument based on computer technology and equipment status detection can ensure the safety and normal operation of the equipment to the maximum extent. First of all, the device can determine whether there is a problem through self-diagnosis, and then the detection system needs to use PLC system or DCS system to complete the comprehensive analysis of the data. Then, the automatic point inspection system will track the equipment in real time and analyze the processing method. This paper studies the application of the state detection method of automated instrumentation equipment in construction engineering, so as to provide reference help for the implementation of construction projects.

Selected Tools Increasing Human Reliability in the Antropotechnical System

Abstract Distributed control systems (DCS) consist of process stations, operator stations, engineering stations and other elements, which all enable the exchange of data between industrial systems. Process stations are industrial controllers. They manage process control. Operator stations are used for visualisation and operator interactions. Engineering stations are designed for configuration, programming and executing control and visualisation software. Elements of the DCS system are connected by an industrial network. DCS must be properly designed, commissioned, used and operated. There is a human factor in each of these phases of the system’s existence. The article discusses software tools that increase human reliability in such a system, made in the visualisation package, i.e. the graphic environment used to visualize the process at the operator’s station.

Research on Improvement of FQNPP Reactor Protection System Hardware Logic Design

Fuqing Nuclear Power Plant Reactor Protection System has designed emergency control panel ECP, which is used to deal with the risk of loss of digital automatic protection functions due to common software failure. ECP is designed and implemented by analogy technology, which can bypass the computerized DCS system and use buttons, indicator lights, relays and other devices to achieve system-level protection functions. In practical engineering applications, it is found that the current ECP can not meet the requirements of post-accident control in some specific circumstances. Through the analysis of system design and accident management procedures, two design improvements are listed, compared and analysed, and the optimal improvement is given in this paper.

Design and Analysis of Multiband Antenna for Wireless Communication

In this manuscript a compact multiband antenna with dimension 16 × 18 × 0.787 mm3 is presented for multiple wireless applications including Digital Cellular System (1.71–1.88 GHz), Personal Communication System (1.85–1.99Gz), Bluetooth Wireless System (2.402–2.480 GHz), WiMAX (3.30–3.80 GHz), WLAN (5.150–5.825 GHz) and X-Band Downlink System (7.25–7.75 GHz). Radiating patch consist of a glass shape and a rectangular ground plane. Two resonating bands (DCS, PCS and Bluetooth Wireless System) is obtained by inserting stubs whereas remaining bands (WiMAX, WLAN and X-Band Downlink System) is obtained by etching slots on the radiating patch. There is a close agreement between simulated and measured results which is obtained by fabricating prototype.

Non-Mechanism Model for Superheater Pollution Diagnosis of Waste Incinerator Based on BP Neural Network

Dust accumulation of boiler heating surface is one of the common problems in power plants, which will affect the unit’s economic and safe operation in serious cases. In this paper, the factors that affect the ash deposition in the superheater of the garbage incinerator are analyzed, and a non-mechanism model for diagnosing the ash deposition pollution in the superheater of the garbage incinerator is established by using 3-layer BP neural network. Parameters such as garbage disposal amount, furnace temperature, primary air flow amount and secondary air flow amount are selected as input vectors, parameters such as secondary superheater inlet smoke temperature and primary superheater inlet temperature are taken as output values, and real-time data of units collected by a power plant DCS system are used as sample sets to train the network after normalization processing. The trained BP network has good effect in superheater pollution diagnosis.

Prediction of outlet air temperature of direct air condenser based on BP neural network

At present, the dynamic parameter monitoring technology of the direct air cooling system is relatively weak. According to the study of outlet air flow temperature characteristics, this paper proposes a direct air condensing unit outlet air flow temperature prediction model based on BP neural network for studying dynamic parameters of direct air cooling units. The historical data of each factor is collected from the on-site DCS system. After the data is preprocessed, the BP neural network is used to establish the air temperature prediction model of the air condenser. Finally, the model is validated by the data that does not participate in the training. The model can predict the outlet air temperature of the air condenser under different working conditions, providing a basis for the next step of developing dynamic parameter monitoring technology, and also provide a reference for the cleaning cycle of the air condenser.

The Imara project - the local departure control system for airports

The paper deals with the issue of Local Departure Control System (further only DCS) and its application in the airport environment. The authors submit their own DCS system solution supported by the Slovak Research and Development Agency under the contract no. VEGA-15-0527. The aim of the project was to design and then implement a solution that would meet the highest criteria of reliability, safety, and usability of the proposed solution in the field of its deployment. The primary target groups are local carriers, airlines, and airports operating in Slovakia with a special focus on regional low-cost companies and charter companies. Within the implementation of the project, algorithms of provided functions and activities of individual software modules were designed. Subsequently, the DCS hardware elements were optimally dimensioned, programmed, tested and tuned for the correct application code for the DCS system modules, as well as for CKI, Gate and PNL terminals.

Safety Analysis and Fault Automatic Recognition Technology of Regenerative Adsorption Dryer

In oil and gas processing station, the regenerative adsorption dryer absorbs the compressed air moisture to ensure the dew point of the gas. Once the dryer fails, it will cause the water dew point to rise, which will affect the operation parameters of the device in winter when the automatic control valves freeze. Control valves freezing can lead to serious consequences such as release, gas-Migration, and unqualified product quality and so on, which are difficult to deal with. The pressure of dryer and regenerative pressure are characterized by a certain periodic change when dryer is working. This paper introduces the automatic identification technology of the dryer fault. Logic analysis through DCS system can identify faults by analyzing the time curve of regenerative pressure, catching abnormal changes of the curve during the failure of dryer. The automatic identification technology of the dryer fault will be achieved in a short time and send out alarm signal to ensure the safe operation of the oil and gas treatment station. It is highly valuable for wide extension and application.

The algorithm of steam soot blowers operation based on the monitoring of fouling factors of heating surfaces of a coal-fired boiler under operating conditions

The article deals with the problem of optimizing the operation of soot blowers in a pulverized coal-fired boiler based on the instantaneous degree of cleanliness of heating surfaces, determined in real time. The elaborated methodology of calculations and the algorithm that determines the optimal configuration of the blowers operation has been implemented and tested on a boiler with a capacity of 380 t/h. The indicator defining the degree of cleanliness of a given heating surface is calculated using available measurements of process parameters based on the epsilon-NTU method. The calculations are carried out in the DCS system for each surface individually (air and water heaters, evaporator, superheaters). During the standard operation of the boiler, the adopted methodology was verified, having analysed the usefulness of the tool to assess the boiler cleanliness under operating condition.

Network fault diagnosis and rectification Suggestions for 300MW unit under I/A Series system

With the progress of science and technology, DCS has been widely used in the field of power plant automation. It integrates modern computer technology, modern control technology, modern communication technology and CRT technology to realize the monitoring and control of power production process. DCS network adopts 10Mbps Ethernet, which is the data transmission channel of DCS system. Its stability is related to the safe operation of the whole power plant. Therefore, more and more power generation enterprises begin to attach importance to network security management of DCS. In this paper, the author puts forward his own views on the network failure phenomenon of Foxboro I/A Series system, and gives the solution, hoping to have some reference significance for the safety management work of other similar DCS network of the unit.

Realization of BP neural network modeling based on NOXof CFB boiler in DCS

In the CFB boiler installed with SNCR denitrification system, the mass concentration of NOX is difficult to be predicted by the conventional mathematical model, and the step response mathematical model, obtained by using the step disturbance test of ammonia injection,is inaccurate. this paper presents two kinds of BP neural network model, according to the relationship between the generated mass concentration of NOX and the load, the ratio of air to coal without using the SNCR system, as well as the relationship between the tested mass concentration of NOX and the load, the ratio of air to coal and the amount of ammonia using the SNCR system. then itrealized the on-line prediction of the mass concentration of NOX and the remaining mass concentration of NOXafter reductionreaction in DCS system. the practical results show that the average error per hour between generation and the prediction of the amount of NOX mass concentration is within 10 mg/Nm3,the reducing reaction of measured and predicted hourly average error is within 2 mg/Nm3, all in error range, which provides a more accurate model for solvingthe problem on NOX automatic control of SNCR system.