<I have the following situation. I have an input data file with the QCOOL from a server room which was served by a split unit. Now I am trying to find the electrical consumption of the split unit, both indoor and outdoor.
I was hoping to modulate the indoor fan flow until the delivered cooling to the room equals my QCOOL. I set parameter10 "Total air flow rate" (the air flow over the indoor unit coil) to -1, so that I can pass it the flow as described. I have an itterative controller that watches the total cooling rate of the type, compares it to my QCOOL data, and tries to set the input4 "Return air flow rate" (the flow rate over the inside unit coil) so that the cooling powers match. Various flow rates seem to have no effect. Any ideas?>
That model uses the user-provided flow rate and then "looks up" the performance of the heat pump in the external data file given the temperatures, flow rate, etc. Did you modify the external data file to provide performance at the off-rated flow conditions such that you can back out the capacity at the current flow rate? If you're using the default files, the flow rates are set pretty close to the nominal flow rate - and the model does not extrapolate beyond the data points - so you're not going to see a difference in capacity as you slow the air flow down or speed it up past the current minimum and maximum values in the data file.
Jeff
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Jeff Thornton
President - TESS LLC
22 N. Carroll Street, Madison WI USA 53703
Office: (608) 274-2577 Fax: (608) 278-1475
www.tess-inc.com
E-Mail: thornton@tess-inc.com
On 11/19/2012 2:31 am, Jean Marais wrote:
Dear Group,
Regards,
Jean.