Chilled water distributaion system

[mfk87]

a chilled water distribution system, chilled water pump delivered the water in the chiller with flow 15.2 m3/hr. pressure drop in chiller and load is 34m. system is closed, chilled water distribution pump developed head is 24m and 3m NPSHR . how i calculate the operating pressure of the system ? also the relationship between operating pressure and design pressure

 

[bimr]

A sketch would be helpful. The pump head must be greater than the system head. Is there a mistake in your numbers?

 

[LittleInch]

Well with a required pressure drop of 34m@15.2m3/hr, but a pump TDH of 24m, you will not be able to pump at 15.2 m3/hr.

Operating pressure of the system could be anything from less than atmospheric to 10 barg or more. This depends wholly on how your closed loop is pressurized.

Operating pressure max ( basically d/s of the pump) must be less than design pressure of the lowest rated component.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[mfk87]

i understand it should be less than shutoff head of pump and also less than design pressure of the lowest rated component. it will greater than pressure drop in the system.

 

[itdepends]

The maximum pressure (assuming the pump is installed at the low point) = the dead head pressure of the pump (more than the developed 24m- you need to check the pump curve) plus the maximum height that the pipe work achieves on the pump discharge.

e.g. if the pump dead heads at 30m and the discharge pipe work goes vertically 25m before returning to the pump suction, the max pressure that would be observed if a valve was closed on the pump discharge would be 55m.

Ignore frictional/dynamic losses for the purpose of design pressure checks.

The only relationship between operating and design pressure is that operating pressure<=design pressure.

As a chem eng/metallurgist the first part of any answer I give starts with "It Depends"