[TRNSYS-users] Heat Pump mass flow rates (e.g. Type 401)

leen peeters l.f.r.peeters at gmail.com
Sat Oct 20 07:42:56 PDT 2012


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 at 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
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu
> https://mailman.cae.wisc.edu/listinfo/trnsys-users
>
>
>
>
>
>
> 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 at cae.wisc.edu
> https://mailman.cae.wisc.edu/listinfo/trnsys-users
>
>
>
>
>
>
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu
> https://mailman.cae.wisc.edu/listinfo/trnsys-users
>
>
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