Valve actuators in China have met the conditions for localization
6957 Views
2017-03-09
Song Yinli, Secretary General of the China Valve Association, stated that currently, domestic valve actuators can basically meet the requirements for safe and reliable operation of thermal power units, and have the conditions and capabilities for localization.
The actuator is the main control device of the valve, which is divided into electric actuator, pneumatic actuator, gas-liquid linkage actuator, and electro-hydraulic linkage actuator according to its structure; It can be divided into two types by function: switch type and adjustment type. At present, the executing agencies of ultra (ultra) critical thermal power units in operation in China are mainly imported. A single million kilowatt ultra supercritical thermal power unit needs to be equipped with over 600 electric actuators, over 200 pneumatic actuators, over 20 gas-liquid linkage actuators, and a small amount of electro-hydraulic actuators.
At present, the localization rate of the actuator of the million kilowatt ultra (ultra) critical thermal power unit is only about 15% based on its value, while the value of imported actuators accounts for about 85%. Especially, the localization rate of regulatory actuators is less than 10%. The electric actuators on the boiler side (including desulfurization and denitrification), air dampers, and other supporting devices are mostly imported products; A small number of non critical valves on the steam turbine side and the chemical water section are equipped with domestic electric actuators; Most pneumatic actuators use imported products; All key valves with pressure exceeding 16MPa and temperature exceeding 540 ℃ are imported products.
The main reasons why users use imported valve actuators are as follows: firstly, most imported products are intelligent actuators with simple structures, fast action and signal transmission speed, which can achieve long-distance transmission, debugging and troubleshooting are relatively simple and fast, and can achieve bidirectional transmission, PID adjustment, automatic calibration, calibration, and diagnosis. The amplifier and actuator are integrated into an integrated module, with good control performance and relatively excellent control accuracy, But the supply cycle is long and the price is expensive; 2、 The localization rate of ultra (ultra) critical valves is very low, and most key valves use imported products, while almost all imported valves are directly matched with imported actuators.
With the promotion and implementation of the localization of key valves in supercritical (ultra supercritical) thermal power units, the proportion of valve localization has increased. In addition, the pneumatic actuator is generally self-made and directly matched by the valve factory, and the proportion of actuator using domestic production will gradually increase.
The main gap between domestic and foreign electric actuators lies in: 1. There is still a slight gap in the reliability of switch type actuators compared to foreign products, with a relatively high failure rate, which makes users uneasy; 2. The lack of high torque and high speed electric actuators cannot meet the user's requirements for use; 3. The adjustable actuator mainly has a certain gap in control accuracy and reliability compared to foreign countries.
There is not much difference in the main body of pneumatic actuators, mainly in the supporting components such as positioners, solenoid valves, transmitters, locking valves, and diaphragm lifespan used for control; There are few domestic manufacturers of gas-liquid actuators, and some companies have better products. However, some companies have differences in quality stability and reliability compared to foreign countries; At present, there are almost no domestic manufacturers specializing in the production of electro-hydraulic linkage actuators. However, this product is only used in situations where fast switching is required, and its usage is minimal.
In recent years, the manufacturing industry of domestic executing agencies has significantly improved its capabilities in research and development, processing and manufacturing, as well as testing and testing. The level of quality control has significantly improved, and the products of backbone enterprises have reached or approached advanced foreign levels. Some products have gradually been applied to ultra (ultra) critical thermal power units and large petrochemical plants.
In terms of electric actuators, some of the electric actuators produced by enterprises such as Changzhou Power Station Auxiliary Equipment Factory Co., Ltd., Yangzhou Power Equipment Repair Factory, Yangzhou Hengchun Electronics Co., Ltd., Tefulong Group Co., Ltd., Tianjin Ekete Measurement and Control Technology Co., Ltd., and Shenzhen Southern General Electric Co., Ltd. have been used in ultra (ultra) critical thermal power units.
In terms of pneumatic actuators, there are almost no well-known brand enterprises specializing in the production of valve pneumatic actuators in China. Generally, pneumatic actuators are self-made by valve manufacturers. Shanghai Electric Power Repair and Manufacturing Co., Ltd., Shanghai Walde Power Station Valve Co., Ltd., Shanghai Automation Instrument No. 7 Factory, and other enterprises have used self-made actuators for some pneumatic valves supporting ultra (ultra) critical thermal power units.
The application results indicate that the domestically produced valve actuator can basically meet the requirements for safe and reliable operation of thermal power units, and has the conditions and capabilities for localization. At the same time, domestic valve actuators have also been widely used in fields such as nuclear power, metallurgy, water treatment, and petroleum and petrochemical.
