[TRNSYS-users] Creating the data file for the Air Source Heat Pump (Type 119)

David BRADLEY d.bradley at tess-inc.com
Tue Dec 17 08:55:19 PST 2019


Audun,

   It is sometimes possible to make a plot of the normalized data in the 
*.dat files that are provided and then to normalize and overlay the data 
points that you have from the manufacturer. Patterns in the data files 
and in the manufacturer data may become evident and you can fill in the 
remainder of the points in the data file and also intelligently 
extrapolate beyond the data that is given in those *.dat files.

   My larger concern is that it looks to me as though the heat pump you 
are working with is a variable capacity (perhaps a variable speed 
compressor) machine while Type119 is a single capacity device that is 
either on or off and whose performance (cooling capacity, heating 
capacity, and COP) are a function primarily of the ambient temperatures 
but /not/ of part load. I have written a variable speed compressor heat 
pump model but like Type119 it still requires a performance map data file.

kind regards,

  David



On 12/16/2019 01:55, Audun Bull Kristiansen via TRNSYS-users wrote:
> I use the Air Source Heat Pump (ASHP) unit Type 119c in a simulation 
> of a container building in TRNSYS 18, since this seems to be the only 
> ASHP type available. I need to add the two external .dat- files that 
> contains the heating and cooling performance data, respectively. I 
> read in “09-Tutorials” page 163-164 that:
> “/The ASHP component model requires a data file that includes the 
> performance map for the piece of equipment. This performance map is 
> unique to the exact piece of equipment that is being modeled and you 
> will need to produce this file from the manufacturer’s performance 
> data for the specific equipment being modeled/.”
>
> The component does not extrapolate beyond the data range provided, so 
> we need to include data for outdoor temperatures between -5 °C and 40 
> °C (Shanghai climate).The indoor temperature is expected to be between 
> -5 °C and 50 °C (due to that the heat pump is turned off when no one 
> is at home).
>
> I read “10.2.3.4 Resizing the PTHP Units” that says that the 
> recommended method is to find a manufacturer of PTHP units online and 
> to search through the available product literature to find a PTHP that 
> has a capacity as close as possible without being less than the peak 
> total cooling or heating load required by the zone that will be 
> conditioned by the PTHP. Do someone know any such online source that 
> contain adequate information where I can search for a similar product?
>
> Or do you recommend me to go for the second approach, to renormalize 
> the example files ASHP_Cooling.dat and ASHP_Heating.dat that comes 
> with TRNSYS to a different rated capacity? But my highest “return air 
> dry bulb temperature” and “Outdoor dry bulb temperature” are far 
> higher than in these example files, so then I need to extrapolate the 
> data. And how do I locate the performance point in ASHP_Cooling.dat 
> that corresponds to the rated point, as described in 10.2.3.4?
>
> I have also tried to model with ideal heater and cooler and divide the 
> electric energy use for heating and cooling by their respective 
> seasonal COP, but that is not accurate enough since I need to take 
> into account the variation in COP over the year.
>
> The heat pump that we have installed and want to model is GREE 
> KFR-35W/FNhD02-A1 outdoor unit (corresponding to indoor unit model 
> KFR-35GW/(35592)FNhAa-A1) which has the following performance data:
>
>   * Cooling power (rated/min./max.): 3500/200/4200 W
>   * Heating power (rated/min./max.): 4900/500/5600 W +1000 W
>     (Additional electrical heating)
>   * Cooling input power (rated/min./max.): 840/90/1300 W
>   * Heating input power (rated/min./max.): 1450/120/1700 W
>   * Additional electrical heating input power: 1000 W
>   * Cooling seasonal COP: 5.33
>   * Heating seasonal COP: 3.53
>   * Yearly COP: 4.53
>
>
> I tried to contact the manufacturer to get input data for the files 
> and sent them the instructions from “4 Mathematical Reference” page 
> 174-175 “Data Files” and the two  example files ASHP_Cooling.dat and 
> ASHP_Heating.dat that comes with TRNSYS 18. The data they sent me, 
> however, was not for constant air flow rates. For instance, for 
> heating mode they sent me similar information as in the table below 
> for various temperatures. The problem is that these data does not keep 
> a set of fixed temperatures and air flow rates, like in the example files.
>
> indoor air temperature 	outdoor air temperature 	Total capacity (kJ/h) 
> 	Power consumption(kJ/h) 	Air Flow Rate(l/s) 	Return air dry bulb(℃)
> 30℃ 	28℃/RH50% 	762 	127 	163 	44.5
> 24℃/RH55% 	706 	128 	163 	43.3
> 20℃/RH59% 	785 	169 	163 	44.9
> 15℃/RH65% 	992 	284 	161 	49.2
> 11℃/RH75% 	1078 	362 	160 	51.2
> 7℃/RH85% 	1085 	418 	160 	51.3
> 2℃/RH85% 	1063 	485 	159 	51
>
>
> Audun
>
>
>
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-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com

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