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Re: [TRNSYS-users] Heat Pump mass flow rates (e.g. Type 401)
Michael,
the radiant-convective split as function of the characteritics of the radiator and the inlet temperature can be found in my PhD,chapter 3.
Use a small timestep and supply heat in case you are not at the top of your deadband (what I explained you with the ctr_heat).
The calculation of how much heat you want, depends on a lot of things. So make a standard calculation to estimate the heating power of your room for design conditions (use your maximum temperature e.g. 50 DC fir that) and lower the temperatue in case you need less heat or allow fluctuations in your heat delivery.
You have to dare to play with TRNSYS, it is not difficult. Just adapt one thing at a time. test the outputs to make sure you know what you are doing.
With your storage tank, it is the same. There are multiple models for that. Check them out, test them, tune the paramters and see what it gives. Avoid losing work, and save every file under a different name. Keep a logbook.I do not know which tank you used, but e.g. type 38 has a deadband. Lower that to something like 1K if you do not like it to fluctuate too much.
leen
On Sat, Oct 20, 2012 at 3:43 PM, Michael Diekerhof
<Michael.diekerhof@web.de> wrote:
David,
Unfortunetaly I don´t have access to the TESS library. I´m sorry
but I dont understand what you were meaning with: "If you do
not, then I would imagine that you might be able to come up with
a simplified set of equations that would give you the gains to
the space that you need.
"
Do you mean that I use the GAINS to adjust the radiative and
convective part ? But how to take the room temperature into
account by also considering the outlet temperature out of my
storage ?? Isn´t there also a way to work with HEATING INPUTS ?! I
still dont have an idea how to cover my heat demand by using the
outlet temperature :(
Best,
Michael
Am 19.10.2012 20:15, schrieb David BRADLEY:
Michael,
Ideally, you need a radiator model that will deal with the water
side, take room temperature from Type56 and output the convective
and radiative gains to the space as outputs. Such a model exists
in the TESS HVAC library for Trnsys17 if you have access to it
(Type1231). If you do not, then I would imagine that you might be
able to come up with a simplified set of equations that would give
you the gains to the space that you need.
Best,
David
On 10/18/2012 09:24, Michael Diekerhof wrote:
David,
thanks a lot. I´ll have a look.
Could you please help me in another case. My plan is to connect
the HP to a storage tank and then giving a temperature from the
storage (type4) to my type56... How can I realize that my type
56 can be heated to achieve a constant room temperature of e.g.
20°C ?!
Someone told me that I must use HEATING and then INPUT... but
what if i would like to simulate a simple radiator with a simple
inlet temperature of e.g. 55°C.
Do you understand my problem? I dont know how to cover my heat
demand out of the storage.
Thanks in advance
Best,
Michael
Am 18.10.2012 16:16, schrieb David BRADLEY:
Michael,
I would recommend that you look online at manufacturer's
sites for similarly sized heat pumps. Trane and Carrier both
have significant amounts of performance data in the product
literature parts of their sites. You can probably get a good
estimate of the flow rates on both the condenser and
evaporator sizes from them.
Best,
david
On 10/18/2012 03:53, Michael Diekerhof wrote:
Dear all,
I´m working with the heat pump non-standard type 401 and try
to display an air-source heat pump.
I dont have typical values for the Input 2 (evaporator mass
flowrate) and Input 4 (condenser mass flowrate).
The only real connection I´m using is the dry bulb temp,
coming from type 15, as the evaporator inlet temperature.
For the massflowrates I would like to assume constant
values.
How can I adjust an outlet condenser temperature of e.g.
55°C. Just about the massflowrates ?!
Does anyone have experience with heat pump mass flow rates?!
I guess it´s not necessary to have expieriences with Type
401.
I´m thankful for any advices.
Best,
Michael
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Am 18.10.2012 16:16, schrieb David BRADLEY:
Michael,
I would recommend that you look online at manufacturer's
sites for similarly sized heat pumps. Trane and Carrier both
have significant amounts of performance data in the product
literature parts of their sites. You can probably get a good
estimate of the flow rates on both the condenser and
evaporator sizes from them.
Best,
david
On 10/18/2012 03:53, Michael Diekerhof wrote:
Dear all,
I´m working with the heat pump non-standard type 401 and try
to display an air-source heat pump.
I dont have typical values for the Input 2 (evaporator mass
flowrate) and Input 4 (condenser mass flowrate).
The only real connection I´m using is the dry bulb temp,
coming from type 15, as the evaporator inlet temperature.
For the massflowrates I would like to assume constant
values.
How can I adjust an outlet condenser temperature of e.g.
55°C. Just about the massflowrates ?!
Does anyone have experience with heat pump mass flow rates?!
I guess it´s not necessary to have expieriences with Type
401.
I´m thankful for any advices.
Best,
Michael
_______________________________________________
TRNSYS-users mailing list
TRNSYS-users@cae.wisc.edu
https://mailman.cae.wisc.edu/listinfo/trnsys-users
_______________________________________________
TRNSYS-users mailing list
TRNSYS-users@cae.wisc.edu
https://mailman.cae.wisc.edu/listinfo/trnsys-users