Dear Alastair,

Thank you for your patient reply. Now I can understand the relationship between the coefficients and the parameters. And, I tried to understood the Fortran code although my poor knowledge about it.

But it sees that the pump’s power drawn result is not right according to the setting as the following, Which is much lower than the equation curve I have attached the simple project(.tpf and.txt file) and the fitting equation(.xls) data file.

For example, I has fitted a pump power curve equation as followings

p = 56877 + 49714(m/m _rated) + 1094.3(m/m _rated) ^2 (R² = 0.9959), So the setting is :

power coefficient-1 = a0=56877 (Parameter 6 for TYPE 743)

power coefficient-2 = a1=49714 (Parameter 7 for TYPE 743)

power coefficient-3 = a2=1094.3(Parameter 8 for TYPE 743)

May you tell me the reason? Thank you very much for your time!

with best regards

yours sincerely

Weiwei

Chongqing University

From: xiaoweiweiwu@hotmail.com
To: trnsys-users@lists.onebuilding.org
Subject: Type743’s power coefficients parameter setting
Date: Mon, 16 Nov 2015 13:49:52 +0800

Dear all,

In the type743’s document, there is an equation743.1 about P, which is power drawn the pump, as following:

P=a0+a1(m/mrated)+ a2(m/mrated)2+ a3(m/mrated)3+………..

In the type743’s parameter setting, parameter number 5 is set to“number of power coefficients”,if I input “3”then the parameter number6、7 、8 is as following：

power coefficient-1

power coefficient-2

power coefficient-3

And the explanation about the coefficient is “The value of the polynomial multiplier for the relationship between normalized pump power and normalized pump flow rate”.

My question is:

1)whether a1、a2 a3 is correspond to power coefficient-1、power coefficient-2 and power coefficient-3 respectively? if yes, how to set the value a0? or i just need fitting an equation that a0 is zero?

2)If not ,what is the right relationship between them?

In addition, I referred to an example named “pumps with flow rate known” in Tess models of TRNSYS software, the type743’s parameter 5 is set to 3, and the parameter6 and 7 (power coefficient-1、power coefficient-2) are both 0, while parameter 8 is set to 1. The similar situation setting could be found in other types such as TYPE510’s power coefficient.

Thank you very much help me out of this issue.

With best regards

Yours sinscerely

Weiwei

Chongqing university

Thank you very much help me out of this issue.

temperature(c) fluid flow rate(kg/hr) 26 0 26 272500 26 1428.062986 26 411.2671769 26 412 26 95.42000473 26 95.42000473 26 95.42000473 26 162.8229907 26 291.3515393 26 515.3536052 26 816.3867389 26 1188.812221 26 1629.100815 26 2132.495628 26 2694.385669 26 3310.339016 26 3976.002224 26 4687.142171 26 5439.612918 26 6229.375654 26 7052.546089 26 7905.373301 26 8784.250604 26 9685.638667 26 10606.2077 26 11542.76175 26 12492.15509 26 13451.33061 26 14417.46804 26 15388.0293 26 16360.38064 26 17331.98101 26 18300.54096 26 19264.10823 26 20220.7465 26 21168.47184 26 22105.3515 26 23029.67749 26 23940.14874 26 24835.50433 26 25714.30133 26 26575.14388 26 27417.22139 26 28239.626 26 29041.5795 26 29822.41425 26 30581.25659 26 31317.54747 26 32031.15858 26 32721.80414 26 33388.95537 26 34032.41532 26 34652.05705 26 35247.8131 26 35819.68878 26 36367.7572 26 36892.15362 26 37393.07305 26 37870.76135 26 38325.5109 26 38757.65937 26 39167.58578 26 39561.53769 26 39941.79438 26 40304.67486 26 40650.60506 26 40979.98526 26 41293.40659 26 41591.22674 26 41873.41682 26 42140.71464 26 42393.55355 26 42631.93313 26 42856.63174 26 43068.11454 26 43266.40333 26 43452.30007 26 43626.28331 26 43788.37814 26 43939.39285 26 44079.80836 26 44210.09202 26 44330.72309 26 44442.17133 26 44544.89603 26 44639.34676 26 44725.9603 26 44805.16391 26 44877.82507 26 44943.94822 26 45003.90333 26 45058.12832 26 45106.97303 26 45151.2349 26 45191.37694 26 45227.84799 26 45261.09101 26 45291.06615 26 45318.03697 26 45342.69877 26 45365.39087 26 45386.44659 26 45405.74225 26 45423.45658 26 45440.20213 26 45456.23818 26 45471.82045 26 45487.20557 26 45502.62727 26 45518.30012 26 45534.42234 26 45551.17725 26 45568.73184 26 45587.23648 26 45607.28491 26 45629.12944 26 45652.55191 26 45677.65694 26 45704.52247 26 45733.19649

Re: [TRNSYS-users] Type743’s power coefficients parameter setting

Dear Alastair,

Thank you for your patient reply. Now I can understand the relationship between the coefficients and the parameters. And, I tried to understood the Fortran code although my poor knowledge about it.

But it sees that the pump’s power drawn result is not right according to the setting as the following, Which is much lower than the equation curve I have attached the simple project(.tpf and.txt file) and the fitting equation(.xls) data file.

For example, I has fitted a pump power curve equation as followings

p = 56877 + 49714(m/m rated) + 1094.3(m/m rated) ^2 (R² = 0.9959), So the setting is :

May you tell me the reason? Thank you very much for your time!

In the type743’s document, there is an equation743.1 about P, which is power drawn the pump, as following:

P=a0+a1(m/mrated)+ a2(m/mrated)2+ a3(m/mrated)3+………..

In the type743’s parameter setting, parameter number 5 is set to“number of power coefficients”,if I input “3”then the parameter number6、7 、8 is as following：

power coefficient-1

power coefficient-2

power coefficient-3

And the explanation about the coefficient is “The value of the polynomial multiplier for the relationship between normalized pump power and normalized pump flow rate”.

My question is:

1)whether a1、a2 a3 is correspond to power coefficient-1、power coefficient-2 and power coefficient-3 respectively? if yes, how to set the value a0? or i just need fitting an equation that a0 is zero?

2)If not ,what is the right relationship between them?

Thank you very much help me out of this issue.

p = 56877 + 49714(m/m _rated) + 1094.3(m/m _rated) ^2 (R² = 0.9959), So the setting is :