The valve industry plays an important role in the development of the national economy as an important part of the preparation of the manufacturing industry. Since China's domestic valve manufacturing industry still has a certain gap compared with the international advanced level, many key valves with high parameters, high temperature and high pressure and high grade have always relied on imports.

 

In order to promote the localization of valves, after the State Council issued a number of "Opinions on Accelerating the Revitalization of Equipment Manufacturing Industry", the relevant state departments have made a series of major arrangements in accordance with the requirements of the localization of major equipment made by the state, and the National Development and Reform Commission took the lead. The China Machinery Industry Federation and the China General Machinery Industry Association have deployed and formulated the localization of valves for major equipment in related fields, and have coordinated with relevant departments for many times. Today, valve localization has reached a consensus in the domestic valve industry.

 

Song Yinli, secretary general of the China Valve Association, said that the domestic valve actuators can basically meet the requirements of the safe and reliable operation of the thermal power unit, and have the conditions and capabilities for localization.

 

The actuator is the most important control device of the valve. It is divided into electric actuator, pneumatic actuator, gas-liquid linkage actuator and electro-hydraulic linkage actuator according to the structure. It can be divided into switch type and regulation type according to function. At present, the implementation agencies in the super (super) thermal power units operating in China are mainly imported. A single million kilowatt super (super) critical thermal power unit needs more than 600 electric actuators, more than 200 pneumatic actuators, more than 20 gas-liquid linkage actuators and a small number of electro-hydraulic actuators.

 

At present, the localization rate of the implementation of the million kilowatt ultra-supercritical thermal power unit is only about 15% according to the value, and the value of the import actuator is about 85%, especially the localization rate of the regulated actuator is less than 10%. Among them, the electric actuators on the boiler side (including desulfurization and denitration) and dampers are mostly imported products; a small number of non-critical valves on the turbine side and the water part are equipped with domestic electric actuators; most of the pneumatic actuators use imported products; The key valves of 16 MPa and temperature exceeding 540 °C are all imported products.

 

The main reasons for users to adopt imported valve actuators are as follows: 1. Imported products are mostly intelligent actuators. The structure is simple, the action and signal transmission speed are fast, and the long-distance transmission can be realized. The debugging and troubleshooting are relatively simple and fast, and the two-way transmission can be realized. , PID adjustment, automatic calibration, calibration and diagnosis, the amplifier and the actuator are integrated into one integrated module, the control performance is good, the control precision is relatively good, but the delivery period is long and expensive; Second, the super (super) critical valve localization rate Very low, most of the key valves use imported products, and imported valves are almost all directly supporting import actuators.

 

With the promotion and implementation of the localization of key valves for supercritical thermal power units, the proportion of localized valves has increased. In addition, pneumatic actuators generally adopt the direct matching method of valve manufacturers, and the proportion of domestically produced actuators will be gradually improved.