Problems with the operation of the turbine condensate pump

The level of vacuum determines the level of inlet pressure; a high vacuum can cause gases to accumulate in the pump, leading to phenomena such as gas locking. Our unit also faced the same problem as you, but we resolved it right away – it’s a trick! Hehe, no similar problems have occurred since then, and we have to reduce the flow by closing the outlet valve.

The vacuum level in the condenser has a significant impact on the operation of the condensate pump; therefore, a balance pipe must be connected at the inlet of the pump to communicate with the inside of the vessel, so as to ensure that the pressure at the pump inlet is equal to that inside the vessel.

There are requirements for the installation of the condensate pump; it should generally be 1.5 meters below the bottom of the condenser hot well. This is because the condensate water in the condenser is in a saturated state, and we must ensure that the net positive suction head at the pump inlet is greater than the required net positive suction head. By using the return valve on the outlet pipe to control the liquid level, cavitation in the pump will not occur. The balance pipe at the pump inlet is used to remove gas accumulated inside the pump, preventing gas locking when the pump is started. It is also used at runtime to expel air that has leaked in through the seals. Some pumps are equipped with return pipes and use cavitation control to save energy, but this can cause some damage to the pump impeller. With a low liquid level, high vacuum, and low pressure at the pump inlet, if the outlet pressure remains unchanged, the volume of liquid pumped should decrease.

I think there should be an impact, but it’s not very significant. This is because the condensate accumulates in the hot well due to its own gravity, and then is pumped out using a condensate pump, with the speed of the pump remaining constant. When there is an adequate amount of water, the volumetric flow rate discharged outward remains constant. The balance tube is used to reduce non-condensable gases in the condensate water. Of course, if it’s inside the atmosphere, it’s even easier.

It does not directly affect flow rate, but head does, thereby indirectly affecting the flow rate