Heavy hammer butterfly valve system new technology application guide

1, Technical Principle Heavy hammer butterfly valve consists of butterfly valve body, hydraulic bypass valve, weight, release device, manual pump (or electric pump), rack drive cylinder and electronic control. The pressure oil from the oil pump is input to the rack drive oil cylinder. After the piston on the rack drives the gear on the main shaft of the butterfly plate to rotate, the butterfly plate is opened and the on-axis weight is lifted to the high point. The pawl on the weight is locked by releasing the lock spindle on the device; the spindle lock is fixed by the electromagnet and holding device. When the accident occurred, due to the electronic control part of the action, the electromagnet power, the lock spindle lost control, under the weight of the weight of the tripping around the axis of rotation, so that the butterfly valve automatically shut down. The butterfly valve hydraulic system, the use of two-stage throttling to control the closure of the butterfly valve speed, the closing speed at the beginning to reduce the speed and duration of speed up; slow closure after the stage to control the rate of rise of water pressure. 2, Technical characteristics and main technical parameters 2.1 Technical Features Flashlight dual-purpose hydraulic system with complete machine assembly makes the whole machine compact and easy to operate. In the absence of external power supply, can use gravity storage can be shut down. When the unit over speed, bearing overheating and generator loss of magnetism can automatically shut down, thus the unit has been automatically protected. With the speed of two closed features. The electromagnet-controlled lock ingot mechanism is safe and reliable with low operating force. 2.2 The main technical parameters, indicators D741-10 heavy hammer butterfly valve, for example, the main technical data are: pressure, 1MPa; diameter, φ400, φ500, φ600, φ800, φ1000, φ1200; maximum use of water head, 100m; Water head, 145m; open time, manual about 5min, electric 1min; closing time, fast off section 5 ~ 10s; slow off section 10 ~ 50s; over speed protection range, 1.8 times the rated speed (adjustable). 3, the specific application site and effect Linhai City, Zhejiang Province Chaitan Hydropower plant using Pingyang County, Zhejiang hydropower automatic plant two D741X-10 hammer hammer valve. The type of power station is hybrid, pressure tunnel 1100m, hole diameter 2.6m, pressure pipe length 50m, diameter 1.2m, design head 45.5m, maximum head 47m, design flow 1.8m3 / s, turbine HL220-WJ-50A, power generation Machine SFW-630-6 / 990 (reactive shunt excitation), rated voltage 400V, rated capacity 630kW, rated speed 1000r / min. January 2, 1991 into large power grid to March 1993, the two aircraft together run 7780h. The hammer valve operates in good condition and is evaluated as follows: (1) The equipment is operated correctly and the safety is achieved. The two butterfly valves open 203 times and close 203 times, the correct operation rate is 100%. (2) The average time for electric opening is 55 seconds Load fast off time is set to 5s, the first fast to reduce the rate of increase in speed, the rate of increase within 40% control, slow turn-off time is set to 20s, after the slow is to reduce the rate of increase of water pressure, the rate of increase of 21% (3) When the unit overrides during the accident shutdown, when it exceeds 1.4 times the rated speed, it will be instructed by the speed measuring device to automatically release the heavy hammer to close the water inlet valve to avoid the accident expanding and increase the operational safety. 4 Conclusion First of all, improve the reliability of equipment operation, to ensure a safe shutdown. Second, the labor intensity of running workers is reduced and the maintenance workload is reduced. Two units to reduce the number of on-duty staff 4, annual savings of about 80,000 yuan. In addition, the valve in the no one (less people) on-grid or isolated power plant when the loss of plant power can automatically tripping the weight off, without the need for standby DC power supply. In some power plant designs, it is not possible to find a suitable guide vane closing time under the conditions of a given unit GD2 and hydraulic structures to ensure that both the unit rate rise and the water pressure rise do not exceed the allowable values ​​specified in the standard , This time can take heavy hammer butterfly valve closed two sections of speed, the first fast to reduce the speed increase, slow and can reduce the water pressure. This method is more reliable than setting artificial resistance than setting surge economy.