Hi everybody,
While learning about power plant operation today, when the pump for the condensate extraction was to be started, we noticed that a recirculation valve was open to 20%.
So,
we came to know that 20% recirculation of water in pump is done to avoid pump churning.
Edit: The pumps are of centrifugal type and maybe the phenomenon is sometimes simply referred to rise in temperature.
While learning about power plant operation today, when the pump for the condensate extraction was to be started, we noticed that a recirculation valve was open to 20%.
So,
we came to know that 20% recirculation of water in pump is done to avoid pump churning.
Am I correct?..Any ideas?The Question:
But what exactly is this pump churning? When does it happen?
From what I Know, this seems to happen when discharge of pump is closed and perhaps the suction is closed(?). So for a high power pump (rated in MW) the small quantity of water entrapped in pump casing gets heated up. This rise in temperature can cause undesirable deformation in pump hence not desirable.
Edit: The pumps are of centrifugal type and maybe the phenomenon is sometimes simply referred to rise in temperature.