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How to simulate a primary-only hot water loop with one-speed HW pump?

asked 2016-10-05 09:14:31 -0600

updated 2016-10-24 14:32:50 -0600

I would like to simulate a primary-only hot water loop, and the hot water pump is riding the pump curve which means one-speed pump. It is expected that the pump rides its curve as the flow varies, and the hot water loop flow rate could vary based on the load. In order to model the one-speed pump, I use "Pump:ConstantSpeed". Then I check "Pump Mass Flow Rate" in results. It seems the hot water loop is actually constant flow and gpm never changes.
Is there anything wrong in my setup? Or any other setup needed such as bypass?

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answered 2016-10-05 11:54:59 -0600

Use a Pump:VariableSpeed and set the curve coefficients per the table below to represent a pump riding the curve.

From page 3.221 of The PNNL Performance Rating Method Reference Manual:

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So the "Pump:ConstantSpeed" means constant plant loop flow rate?

Yan gravatar image Yan  ( 2016-10-05 12:59:22 -0600 )edit

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Asked: 2016-10-05 09:14:31 -0600

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Last updated: Oct 05 '16