Research The Application Of DCS For Thermalpower Unit Chemical Water Treatment

In modern large-scale thermal power plants, with the increase of capacity of the units and steam parameters, the safety control of the operation of power plants has a direct and restraining effect on the development of our national economy. As we all know, Water and steam are the refrigerant–the"blood"which turns heat into mechanical energy in thermal power plants. For the thermal power units, especially high-power units, the poor-quality running of the water vapor system may result in tube rupture in the boiler and steam turbine corrosion and scaling, which will directly threaten the safety of the units and economic operation. Therefore, DCS centralized control of chemical water treatment which can achieve the quality of steam in thermal system of the power plants has already become the urgent need for the large and medium sized thermal power plants. It is also our purpose of researching and exploring the DCS Control System for the thermal power unit chemical water treatment.This paper is designed a chemical water treatment Control System based on Foxboro I / A Series DCS control system, Slove the Open-ended questions of the power plant DCS System during Information and integration process. The chemical water treatment DCS control system achieved precise control of steam quality, Reduced Labor-intensive operation and maintenance workload, achieved improve the requirements of safe and economic operation.Firstly, this paper analysis the features and development process of Foxboro I/A Series, proposed feasibility of Foxboro I/A Series applied in the power plant chemical water treatment and technical difficulties of achieve DCS control of power plant chemical water treatment. Proposed detailed design for the specific situation. Detailed describe the system hardware design and software design. System hardware design include network structure, I/O Configuration, power, Grounding and so on. System software design include the main control function of DCS system, DAS, SCS, MCS, Steam Quality Expert Diagnostic System.Secondly, this article also introduces the communication method between I/A Series and MIS, Implementation process in detail. Developing an OPC Data Access Model according to the analysis of the exiting OPC based data access mechanisms,and developing OPC client applications using Visual C++ 6.0.As new standard of Industrial Control field in the world, OPC technology overcomes such obstacles as data exchange among many manufacturers and standard application interface routine design, and makes great progress in recent years. The application of OPC technology ensures the reliability, standardization, and certain technique progress of system communication, and establish base for the expanding of system.DCS system of chemical water treatment was put into operation since 2004, which shows that the system runs stably. Accidents, which result from DCS system or control equipment and affect the safe operation of chemical equipment, do not occur in the process of operation. All the control parameters reach the relevant technical standards.