We have to understand why the large differential exists.  It appears to be at 
least 2 to 1 in error.  This measurement has dogged me from the beginning.

Dave



-----Original Message-----
From: Alan J Fletcher <[email protected]>
To: vortex-l <[email protected]>
Sent: Thu, Nov 10, 2011 8:13 pm
Subject: Re: [Vo]:Oct 6 Heat Exchanger Manifold Thermocouple Placement.


At 04:57 PM 11/10/2011, David Roberson wrote:

The error in thermocouple reading is far larger than suggested.  The best place 
to get an accuracy check is when Mats Lewan measured the water output flow from 
the heat exchanger at 18:57 during the October 6 test. He carefully measured 
the water out of the exchanger and calculated the flow rate as .91 
grams/second.  He then assumed it was all vapor which condensed within the 
exchanger and this is the results.
6.1 C x 4.18 joules/C-grams x 178 grams/second = 4538.644 watts According to 
thermocouple data.

My simulated  error is :

Primary Input  (HOT): 100 C water at 15 liters/hour.
Secondary Output (COLD) : 30C water at 600 liters/hour (40x ratio)
Ambient : 30 C
Thermocouple  : 31.96 C
Secondary Outlet :  30.78 C (raised slightly from 30C by conduction through the 
manifold).
Difference : 1.19 C (or 3.8 %)

But I calculated the PERCENTAGE error against the OUTPUT water temperature, not 
against the Delta-T of (say) 6C

The error in Delta-T is  1.19/6 =  20 % 

I guess it moves it back into the problematic zone !!!!





Reply via email to