Control system for shape steel intensive pressure water cooling high-pressure variable-frequency water pumps

Abstract

The invention relates to a control system for shape steel intensive pressure water cooling high-pressure variable-frequency water pumps. The control system comprises a water spraying valve state monitoring unit, a high-pressure variable-frequency water pump running number limiting unit, an automatic pump-stop pulse signal generation unit, a first high-pressure variable-frequency water pump start and stop control unit, a second high-pressure variable-frequency water pump start and stop control unit and a third high-pressure variable-frequency water pump start and stop control unit. The automatic pump-stop pulse signal generation unit sends output signals of itself to the first high-pressure variable-frequency water pump start and stop control unit. The water spraying valve state monitoring unit sends output signals of itself to the second high-pressure variable-frequency water pump start and stop control unit. The high-pressure variable-frequency water pump running number limiting unit sends output signals of itself to the third high-pressure variable-frequency water pump start and stop control unit. After the control system for the H shape steel intensive pressure water cooling high-pressure variable-frequency water pumps is adopted, the influences of severe pressure fluctuation of water passing high-pressure pipelines on the high-pressure water pumps, valves, filters and high-pressure water pipes can be eliminated, and a good energy conservation effect can be achieved.

Description

technical field [0001] The invention belongs to the technical field of electric automation control, belongs to the production process of the main charge of blast furnace ironmaking, and in particular relates to a control system and method of a high-pressure variable-frequency water pump for water-through cooling of section steel. Background technique [0002] Masteel No. 3 Iron and Steel Rolling Plant’s large H-beam finishing rolling water cooling system was put into operation in 2010. The system mainly consists of three high-pressure water pumps (560KW / set), backwash filter, water bypass valve, and stage I and the water cooling device for rolled pieces in the second section (including cooling water nozzles, water spray control valves, manual gate valves, cooling water nozzle moving frames and cooling water collection trays, etc.), rolled piece cooling water return tanks, return pools, lift pumps, high-speed It is composed of filters and suction wells, etc. The structure dia...

AI Technical Summary

Problems solved by technology

The above-mentioned cooling water control method of the water-piercing system has many defects: First, for the existing steel-piercing water-piercing cooling system, in order to prevent the steel-piercing cooling water from overflowing from the cooling water collection tray, the water-piercing cooling device passes A piece of steel, the spray control valve and the water bypass valve need to be switched quickly twice, and thus the outlet pressure of the high-pressure water pump in the system fluctuates twice violently

It is precisely because of the frequent and violent fluctuations in the outlet pressure of the high-pressure water pump that the water hammer phenomenon occurs in the water supply pipeline of the system, which leads to frequent welding and bursting of the system pipeline, damage to the inner cavity of the pipeline filter, broken impeller of the high-pressure water pump, and valve plate of the outlet valve Second, from the statistics of the water penetration of various specifications of H-beams in the large H-beam production line of Masteel, it can be seen that for most H-beams of various specifications that need to penetrate water, the water flow requirements for water penetration of the steel are usually at In the state where the water supply volume of one pump is too small and the water supply volume of two pumps is too large

Since the water supply pump of the water piercing system uses a high-pressure water pump directly powered by a 10KV power supply network, the running speed of the high-pressure water pump cannot be adjusted. In this way, the adjustment of the water volume of the section steel water piercing can only be realized by controlling the number of openings of the cooling water nozzles. In this case, when the actual amount of water sprayed by the section steel is less than or far less than the water flow that the pump can provide under the rated load state, it will inevitably cause the high-pressure water pump to appear pressure and overload during the section steel water penetration, resulting in high pressure. The cavitation of the water pump is serious, the average service life of the impeller is less than four months, and the service life of the pump body is only about one year; third, the average steel passing rhythm of the large H-beam water cooling device of Masteel is usually 4 minutes, The average time for steel to pass through the water cooling device is only 28 seconds

It can be seen that in the continuous production process, the high-pressure water pump of the water-piercing system is doing useless work most of the time (that is, the cooling water output by the high-pressure water pump is directly returned to the return pool through the water-piercing bypass valve), resulting in a large amount of useless power consumption

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