Jérémy
The
heating rate is independent of the time step.
If
you are heating at 10,800 kJ/hr and you are running the system for 0.05 hr (3
minutes) then the aux heater will provide 540kJ per time step. You could also
write the 10,800 kJ/hr as 3 kW or kJ/sec.
You
are mixing up energy (kJ) and power (kJ/hr).
A
good way to understand this is by looking at the starting and final temperature
and the mass of the water.
If
you want 60C, start the tank at 40C and observe how long it takes to get the
temperature up to 60C at 10,800kJ/hr. Qdot*t=mcdT, 10,800*t =
m*4.186*(60-40) input the mass of the water, and then solve for time, t.
Hope
that helps,
Fred
|
Fred Betz PhD.,
LEED AP |
|
AEI |
AFFILIATED ENGINEERS, INC. |
From: Maurel Jeremy
[mailto:Jeremy.Maurel@aldes.com]
Sent: Friday, May 07, 2010 4:23 AM
To: trnsys-users@cae.wisc.edu
Subject: [TRNSYS-users] storage tank and time step
hello
trnsys user's
I
wonder about type 60 (storage tank) and trnsys step time. The tank has a 10800
kJ/hour auxiliary heating and the trnsys time step is 0.05.
The problem is that when the heating is activated it delivers a power of 10800
kj/hour in 0.05 hour that is impossible. Do you know if this problem is
solvable ?
Regards
