Check Operation of Auto Speed Limiter

The auto speed limiters with service life of more than 15 years should be checked every year. The results should meet the requirements.

The auto speed limiter for car check operation is divided into up and down check:

The components of this calibrator are as follows: the host, the positive and reverse turn of the hand, the sensor, the magnetic steel. The starting machine first enters the main interface, as follows. The main interface will display all the functions provided by the instrument, and the user can select the corresponding functions by pressing the corresponding digital key. Press the number key “1” in the main interface to enter the settings interface, the parameters need to be set are number, perimeter. The number “number” is a number of 8 bits, which is used to distinguish the speed limiter measured.

Determination of “Circumference”: The average value of the sum of the outer circumference of the speed limiter disk and the inner circumference of the speed limiter disk groove can be used as the circumference of the speed limiter disk.

The initial speed of “speed” is rated speed of speed limiter. This speeds up from rated speed to speed limit action speed.

The time taken is relatively long. At the same time, when the wheel speed is close to the rated speed of the speed limiter, when the rubber wheel of the tester moves to the outer edge of the wheel, there will be an acceleration and the speed limiter will move ahead, so that the test data will be distorted. If the initial speed of the tester is set to the lower limit of the speed limiter, and the initial speed of the tester is reset to the lower value of the first speed after the first speed is measured, the testing time can be shortened, the testing efficiency can be improved, and the working intensity of the test can also be reduced. When measuring, we must correctly grasp the balance of the test instrument runner, touch the unilateral side of the speed limiter disc wheel to make it rotate at a uniform speed.

In practice, special attention should be paid to the positive and negative sides of magnetic steel. If facing the Hall sensor head, the tester shows the change of the action speed of the electric switch. On the contrary, facing the Hall sensor head, the action speed of the electric switch of the tester is zero.

“Mode” is used to select the measurement method, there are two kinds of measurement options: linear speed (m/s) and rotational speed “rpm”.

Press the “Measure” button at the main interface to enter the measurement state. The interface shows the middle interface of the measurement as shown in Figure (B). In the middle of the measurement, the velocity is measured by the speed sensor, and when the speed limiter moves mechanically, the measurement is completed and enters the measurement stop interface.

Press the “Measure” button in the measurement stop interface to save the current measurement results into the secondary measurement display interface, press the “Print” button to print the current measurement data, press the “Exit” button to automatically save the data out of the measurement process and return to the boot main interface.

Firstly, the main reason of serious pollution to the oil system of the speed governing system is that there is a big gap in the front axle seal of the system, which causes the water vapor to enter the bearing box and causes the oil quality to change. A large amount of oil dirt will accumulate around the sliding valve components during long-term operation, which increases the resistance of the normal operation of the sliding valve and leads to the speed governing system. Slow operation and load swing. The oil system and its components should be thoroughly cleaned in time. The oil cooler can be steamed with 5% trio phosphate at high temperature. At the same time, daily oil quality analysis and oil filtration should be done well, the tank should be discharged regularly, and the gap between the front seal should be adjusted reasonably.

Secondly, the oil leakage of the equipment components will reduce the oil pressure of the speed governing system, increase the system retardation rate, cause the internal components of the governing system to run abnormally, and also reduce the safety of the turbine operation. If there is oil leakage on the steam pipeline, the steam turbine may be burned down. It is one of the important reasons for oil leakage in the oil system that the internal components of the speed governing system are worn seriously and the clearance between the components is enlarged because of its long use. It is also possible that the oil circuit is short-circuited due to the wear of the inner wall of the piston cylinder of the oil engine and the check valve of the speed governing system is not closed tightly. When oil leakage occurs inside the speed governing system, attention should be paid to the change trend of the oil pressure of the system, steam turbine can be shut down and repaired according to the need; when oil leakage occurs outside, timely leak plugging and fire prevention preparations should be made to avoid safety failures.

Leave a Reply