[Equest-users] Steam loop pumping energy

[Steven Savich]

All,

 

John's solution below works.  Setting the pump kW to zero causes the program
to ignore the input, but if you input a vanishingly small pump kW input it
will be used by the program.  Of note, if you also input actual head and
flow along with the 0.00001 pump kW, eQuest gives you an error message -
"PUMP design input is unreasonable Check Values".  So it's necessary to
specify ONLY the PUMP-KW if you're doing this workaround.

 

Two things - 

check the PS-C report to be sure that it's working.  Pump Elec use should be
zero.

Heating energy use will increase since there is no pump energy loss into the
heating loop working fluid.

 

Thanks for all the responses and suggestions!

 

Steven

 

Steven Savich

Systems West Engineers

411 High Street

Eugene, OR  97401-2427

(541) 342-7210

(541) 342-7220 (fax)

 

 

Try setting the pump kW itself to 0, or at least 0.0001 if 0 doesn't work.

 

John R. Aulbach, PE, CEM

Project Manager

Nexant, Inc.

701 West Kimberly Ave., Suite 245

Placentia, CA 92870-6342 USA

Phone: 714-524-4402

Fax: 714-524-4407

email: jaulbach at nexant.com

 

  _____  

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Steven
Savich
Sent: Tuesday, October 14, 2008 9:27 AM
To: 'David S Eldridge'
Cc: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Steam loop pumping energy

 

David,

 

Tried that.  The program ignores the 0 pump power input and calculates the
required power, even with actual flow and head input.  PS-C report still
shows pump energy consumption by the heating water loop pump.

 

FYI I'm using eQuest ver 3-61e.  Do later or earlier versions allow this 0
kW workaround?

 

Steven

 

Steven Savich

Systems West Engineers

411 High Street

Eugene, OR  97401-2427

(541) 342-7210

(541) 342-7220 (fax)

  _____  

From: David S Eldridge [mailto:DSE at grummanbutkus.com] 
Sent: Tuesday, October 14, 2008 9:09 AM
To: 'Steven Savich'
Subject: RE: [Equest-users] Steam loop pumping energy

 

You can use the actual flow and head so the program doesn't crash, but enter
a pump power of 0 kW.  "Magic" pump motors.

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Steven
Savich
Sent: Tuesday, October 14, 2008 10:52 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Steam loop pumping energy

 

All,

 

I'm modeling a university campus building with heat provided by central
plant steam boilers, providing 15# steam.  I've done this by eliminating
boilers in the model and attaching a steam meter to the hot water loop.

 

My problem is with pumping energy.  Equest requires that a pump be attached
to the hot water loop, but the actual installation has gravity return
condensate.  How do I zero out the pumping energy?  I have set pump head =
0, but this gives me pages of error reports.  Any other methods?

 

Thanks,

Steven

 

Steven Savich

Systems West Engineers

411 High Street

Eugene, OR  97401-2427

(541) 342-7210

(541) 342-7220 (fax)

 

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