DG boiler feedwater pump for water supply

Description :

　　Characteristics of boiler feedwater pump products

　　The hydraulic model is advanced, efficient, and has a wide range of performance. The pump runs smoothly with low noise. The shaft seal adopts soft packing seal or mechanical seal, which is safe, reliable, structurally simple, and easy to maintain. The shaft is a fully sealed structure, ensuring no contact with the medium, no corrosion, and a long service life.

　　The phenomenon of reverse operation of DG boiler feedwater pump

　　The flow rate at the inlet of the feed pump is zero. The speed of the feed pump increases while the opening of the spoon tube remains unchanged. The significant decrease in water supply flow often triggers the low water level protection action of the steam drum. The rapid rise in temperature of the bearings in the feedwater pump. On site melting plug or already melted, spray a large amount of oil outwards.

　　Reasons for Reverse Operation of DG Boiler Feed Pump

　　The reversal of the feedwater pump occurs during the process of switching the feedwater mode when the unit starts and stops (including tripping). When the outlet pressure of the running steam driven feedwater pump is higher than the outlet pressure of the feedwater pump, the outlet valve of the feedwater pump is in the open state. Due to the blockage of the outlet check valve, it is not tightly closed, resulting in the reversal of the electric feedwater pump.

　　Treatment method for reverse operation of DG boiler feedwater pump

　　When confirming the reversal of the water supply pump, the electric valve at the outlet of the electric water supply pump should be immediately closed, and the auxiliary oil pump of the electric water supply pump should be started at the same time. Adjust the feedwater flow rate during the time when the electric valve at the outlet of the feedwater pump is closed, maintain the water level in the steam drum, and ensure that the speed of the steam driven feedwater pump and the opening of the inlet control valve do not exceed the limit. The boiler can cooperate with load reduction. Adjust the opening of the spoon tube according to the specific situation. The spoon tube has a large opening, high reverse torque, and changing the direction of axial thrust can easily damage the equipment; If the opening of the spoon tube is small, the resistance to reverse rotation is small and the flying speed is high. It is prohibited to shut down the electric motor of the feedwater pump, except for protective actions. Because after clicking to stop, the electric motor rotates in reverse along with the feed water pump, and the oil pump driven by the pump wheel rotates in reverse. There is a check valve at the outlet of the working oil pump, which causes the feed water pump to cut off oil and burn tiles. Inspect the water supply pump on site, and if necessary, disassemble it for inspection. Inspect the check valve of the water supply pump and test its flexibility and reliability before putting it into standby.

　　Prevention of Reverse Rotation in DG Boiler Feed Pump Operation

　　When starting the water supply pump, check whether the recirculation valve is open, and the water supply pump should be tested under no-load with the outlet valve closed. Before stopping the feedwater pump, the outlet electric valve should be closed first. When the feedwater pump is integrated into the system, increase the speed of the electric feedwater pump to bring it close to the outlet pressure of the steam driven feedwater pump, and then open the outlet valve of the water pump. When increasing the speed of the electric pump during the start-up of the water supply pump, attention should be paid to the stable increase of the inlet pressure and speed of the water supply pump without significant fluctuations, the absence of significant fluctuations in the outlet flow rate, and the absence of sudden decreases in the water supply flow rate. When the standby outlet valve of the water supply pump is put into operation, there should be inspection personnel on standby at the local control switch of the outlet valve and the water supply pump site, paying attention to whether the rotor rotates, whether the CRT monitors the speed and outlet pressure of the electric water supply pump for changes, and whether there is a reverse signal. If the electric feedwater pump is found to be reversing, the outlet valve should be immediately closed.

AfterSalesService :

• boiler feed pump