Large fan / turbine digital flow control system
The efficient use of large-scale blast furnace blower transmission, great power, in order to save energy, the general use of blast furnace heat value gas combustion steam boiler, reoccupy steam to drive a turbine driven fan, to blast furnace air, so as to realize energy. Due to the special requirements of blast furnace condition and need a series of control of the wind turbine, including air control, pressure control, turbine speed control, fan static blade angle adjusting control, coordination control, the anti surge control and anti control for speed and so on, and because of the steam turbine is high pressure superheated steam, large inertia system, coupled with the blast furnace production for many years, the importance of and a series of control and safety requirements is very important. But for a long time, turbine / fan system control optimization problem is difficult to solve, old-fashioned control system is very complex, remained unchanged for decades. It pendulum technology, mechanical technology, hydraulic servo technology, and lever, a spring, a pressure, cam, electronic, sensor and so on a lot of complex technology, the result is due to the control system too primitive, too complicated, not only greatly reduce the reliability of the system, and people there are very difficult to master a set of control technology. Therefore, not only it is difficult to achieve the wind turbine and steam turbine co optimization control, but also makes the failure increases, maintenance is very troublesome, if not handled properly, but also directly restricts the further improvement of the yield of the blast furnace, and even bring major accidents (such as wind turbine surge, blast furnace material collapse, etc.). So it has been a difficult problem to solve the optimization control of the blast furnace steam turbine and the large wind turbine.
In recent years, in order to improve the reliability of the operation of the blast furnace, to improve the yield of the blast furnace, in the new production of blast furnace, blast furnace directly by motor direct drive, but this is bound to bring raise the cost of production, and motor drive, still has a series of more expensive self-control problems, and therefore is not the best. Of some famous foreign companies such as Westinghouse, Sulzer company has begun using servo valve and servo cylinder servo system to control the inlet steam valves, but servo system structure is complex, anti-jamming, anti pollution ability is poor, maintenance requirements are very strict, reliability is not high, so the steam turbine speed control for many years to come.
Digital hydraulic technology is a known as hydraulic revolutionary technology. It the advantages of large hydraulic technology strength, stability, high reliability, and focused on the characteristic of digital technology, computer technology, fast response, flexible control, multi strategy, convenient adjustment, high reliability, both high power and high frequency response the dual advantages of high precision, so it is reliable means to implement autocontrol of metallurgy heavy equipment in the field. Its control method is:
With digital hydraulic cylinder instead of the original hydraulic servo system to control the system of rapid cut-off valve, inlet steam regulating valve, a blower vane control valve, the size of the vent valve and so on. The principle of the signals from the various sensors for the direct detection system, signal after A / D conversion sent directly to the computer (PLC), with the set value after comparing the difference after billion Bo advanced control algorithm output regulation and send digital pulse signal, direct drive digital hydraulic cylinder to complete the adjustment and control of the large flow rate valve. This system not only greatly reduces the control link, the system becomes very simple, and because of the digital cylinder strength, response speed, high positioning accuracy, fretting, but also has automatic Suo set function, and thus can receive computer micro pulse modulation signal and stable to keep the valve opening constant, not because of the sudden failure of the control signal of the coaster, with very good security. And easy digital signal transmission, without A / D and D / A conversion, strong anti-interference ability, digital cylinder oil with high ability of anti pollution, which increased the reliability of the system, the control system is much better than that of foreign servo valve system, with leading level at home and abroad. The prominent advantage of the system is the original very complex control method becomes very simple and intuitive. It not only improves the accuracy and reliability of the system, but also greatly reduce the maintenance difficulty, improve the system operation efficiency, provides a reliable guarantee for long campaign of blast furnace and high yield.
The digital hydraulic control technology for wind turbine static blade angle control, in order to improve the efficiency of the fan, to achieve the purpose of energy saving, then the digital cylinder is used to realize the automatic control valve, fan anti surge, we adjust the valve, can also play a stable pressure, volume adjustment function, on the basis of the micro turbine inlet valve used in cylinder direct digital control and fast shut-off valve, can realize all the turbine / assist Fan combined automatic (i.e., air pressure and quantity, leaked, ESD) and a number of control, to further improve the level of control, but also can achieve automatic control and machine downtime, because in the process of cutting machine, steam valve and valve can press the machine program requirements gradually open the valve, steam rises at a constant speed, realize slip starting, and rising slope Can be arbitrarily adjusted, down time can also be in accordance with the requirements of the automatic shutdown of the curve, to achieve full automatic control.
Economic and technical indicators:
A optimization implementation of turbine fan control, improve the efficiency of the fan, energy saving.
Can reduce the equipment failure rate, improve the stability of the fan operation, prolong the service life of the equipment, and can reduce the maintenance workload.
Can provide pressure and air flow stability for blast furnace, blast furnace for improving yield for material guarantee.