Matters needing attention during the start-up of a coupler

Before the coupling is started, the auxiliary cavity in the lower part is filled with working fluid, so that the oil filling rate of the working chamber is reduced, the starting torque is reduced, and the start-up is smooth and soft. Conversely, if the auxiliary cavity is located above, when the hydraulic coupling starts, the 100% oil in the working chamber makes the starting torque and starting impact increase, which is not conducive to the smooth start of the machine.

It has a no-load starting motor, stable stepless speed etc., for power plant feedwater pump speed regulation, can simplify the boiler feedwater control system, reduce the number of high pressure valve, because through the speed change water and pressure to meet the unit start stop and load change, good regulation characteristics, the valve pressure drop is small, line loss that is not easy to damage, so that the water supply system to reduce the fault, when the water pump jam and seizure occurs, the pump and motor can play a protective role. Therefore, in the modern power station, the water supply pump of the unit boiler is generally adopted by the speed regulating feed water pump with the hydraulic coupling.

The main components are the pump wheel, the turbine, the rotating shell, the input shaft, the output shaft and the spoon tube. Usually, the rotation of the shell and the pump wheel are connected to the flange in the flange. Pump wheel and turbine wheel blades are called work, two, two are respectively connected with the input and output shaft, there is a gap between them, so the pump and turbine has the same radial size, cavity shape, together to form the oil chamber, the oil from the pump into the wheel, and follow the power machine rotates together, the role of oil under the centrifugal force, was thrown to the outside of the pump wheels, turbine blades forming high speed oil flow into the opposite direction, gradually slow down and flows back to the inside of the turbine inside the pump wheel, constitute an oil cycle. The absolute flow of a working liquid in a working cavity is a three-dimensional motion.

When working overload, large circulating motion of working fluid can be quickly discharged into the auxiliary cavity below by means of dynamic pressure and gravity, so that motor and working machine can be protected from overload in time. If the auxiliary cavity is above, the direction of liquid flow is opposite to that of the auxiliary cavity when overloaded. It is necessary to rely on static pressure and overcome gravity to push liquid into the auxiliary cavity above, so its discharge speed is slow, and it is not as sensitive as the fluid coupling under the auxiliary cavity.