Talking about the future development of electric valves
Electric valves have been increasingly used in various industries due to their numerous advantages over traditional valves. In this post, we’ll be discussing the current status of intelligent research on electric valves, including the status of electric actuators and the intelligent features of electric valves.
Current Status of Intelligent Research on Electric Valves
Electric valves are made up of two parts: a valve and an electric actuator. Currently, these two parts are produced by different manufacturers, leading to a lack of technical communication among various manufacturers. This has resulted in problems with the “set” of electric valves and a lack of corresponding basis. Furthermore, the structure of the valve is relatively simple compared to the structure of the electric actuator, which is more complicated. As a result, more attention is being paid to electric actuators to improve their intelligent level. Ignoring the intelligence level of the valve itself makes the development of the intelligence level of the two unbalanced, and the intelligence level after the “set” is not high.
On the other hand, electric actuators have achieved rapid development in recent years. Some domestic and foreign manufacturers have introduced intelligent electric actuators that hinder the fieldbus communication protocol. These intelligent valve electric actuators adopt a microprocessor system, and all control functions can be realized through programming. At present, the international and domestic advanced intelligent valve electric actuator products mainly include:
IQ Series Intelligent Electric Actuators
The British ROTORK company launched an intelligent electric actuator (IQ series) in the 1990s. Compared with ordinary actuators, it has the following characteristics: (1) Convenient parameter remote setting function. Before putting it into use, as long as the special setting tool provided by the manufacturer is used, the parameters can be remotely set by aiming at the actuator. It not only simplifies the setting work procedures, but also improves the safe operation of the equipment, especially for those places where explosion-proof is required; (2) Rich online display functions. Adopting liquid crystal display technology, using built-in liquid crystal display panel, not only can accurately display valve opening and closing status and normal valve opening, etc., but also can display important information when parameter settings or actuator failure;
ONTRAC MOE700/MME800 Series Intelligent Electric Actuators
This series of intelligent electric actuators was introduced and launched by the H& Company of Germany (now part of ABB Group) at Chongqing Chuanyi No. 10 Factory. MOE700 series are digital adjustment type-s2 control mode, MME800 is continuous adjustment type-s4 control mode. They adopt mechanical self-locking turbine and worm structure, three-phase motor variable frequency drive and intelligent monitoring, digital detection technology, and their operating speed is Torque can be set online or offline in a wide range, with a high degree of standardization. It has the characteristics of powerful function, simple use and low maintenance. It is equipped with different deceleration devices and can output angular displacement (torque up to 40,000Nm) and linear displacement (thrust up to 80KN) to drive various valve bodies or baffles.
IKZL Intelligent Electric Actuator
The IKZL intelligent electric actuator is developed by the 11th Factory of Automation Instrumentation, a subsidiary of Shanghai Automation Instrumentation Co., Ltd. It uses a modern high-efficiency single-chip MCU and peripheral chips to form a control unit, receives a unified standard DC signal, and after arithmetic processing, it finally drives the AC motor to output the corresponding linear displacement. The mechanism can be conveniently matched with the regulating valve to form an automatic regulating valve, with various action transformation functions required by the regulating valve itself, and is suitable for industrial sectors such as electric power, metallurgy, petroleum, chemical industry, and light industry.
Intelligent Features of Electric Valves
The demand of the market and the needs of the development of electric valves themselves make the intelligent process of electric valves necessary. The trend of mechatronics and the rapid development of microelectronics and computer technology provide technical guarantee for the intelligent development of electric valves. The intelligent valve referred to today mainly includes the following features:
Digital Communication of Electric Valves
The intelligent valve electric actuator is connected to the upper computer by means of power carrier. The addressable digital signal sent by the upper computer is received by the electric actuator through the power line. The electric actuator controller performs corresponding actions on the electric actuator according to the received signal. Control, make the electric valve work more flexible.
Computerization of Valve Control Process
Generally, the actuator drives the valve in accordance with the control signal from the microprocessor of the control system to adjust the valve opening to adjust the flow and pressure. If in the electric actuator, increase the servo amplifier with intelligent control, increase the set value control function. The use of an intelligent controller can change the situation that the mechanical torque control switch action value adjustment needs to be disassembled to adjust the torque value through the adjustment spring.
Intelligent Fault Diagnosis and Processing of Electric Valves
Intelligent electric valve should have perfect fault self-diagnosis function. By loading additional sensors on the valve electric actuator, it can play a role in the fault diagnosis of the electric valve. When necessary, you can also set up various detection functions in the circuit, such as intelligent electric valve can identify the negative torque, when the control command is found to be inconsistent with the execution, the contactor can be immediately controlled to reverse the phase sequence to achieve the phase sequence Synchronization; the intelligent electric valve can also detect three-phase current, and stop the valve motor immediately after detecting a phase failure.
Integration of the Overall Structure
In the process of intelligent electric valve, the integrated design of valve and electric actuator is inseparable. Through the integrated structure, the entire control loop of the valve is installed in a field instrument, which greatly simplifies the design, installation, operation, and maintenance of the control system, and reduces the effects of signal leakage and interference in the transmission. The influence of the system improves the reliability.
To conclude, the problem of valve leakage cannot be ignored as it seriously threatens safe production and even makes production impossible. The solution to valve leakage has been from the valve. Optimize the design of valve structure, select materials for manufacturing valves reasonably according to different process conditions, improve the quality control level in the valve production process, and optimize valve selection according to various process conditions in the chemical production process. Although these methods have effectively eliminated the valve leakage problem, changing the control method of the valve position and directly controlling the valve position can compensate for the valve leakage problem.