I have carefully searched for more instructions on how to set up the control signals for the heat pump Type 525. However, I have not found any relevant information. If you have set up the control for this type of heat pump, could you please provide me with some guidance? Alternatively, if there is already a post about this, please let me know, as I was unable to find it.

In my case, I am trying to use the PV surplus instead of an electrical battery. I am using a heat pump to charge a PCM tank. Since Type 941 has a fixed-speed compressor, it will only run when the PV surplus is much higher than its rated power.

I have tried splitting my Type 941 heat pump into two units, and I was able to improve the results by operating a smaller-capacity unit when the PV surplus is lower. This made me think that using the variable-speed compressor Type 525 could be a better solution for maximizing heat storage based on the available PV surplus, as I could better adjust the heat pump's operation according to the available surplus.

The annual data I have consist of the building's heating and cooling loads in kW, and I am using Type 682 to simulate the building. Therefore, I am not using Type 56.

If there is any other information you need in order to help me, please feel free to ask.

Thank you.

Humberto

unfortunately I couln't reply earlier. But I still want to provide a link to an article that might be helpful:

https://doi.org/10.1016/j.egypro.2017.09.371

The authors analyzed the results of TRNSYS and EnergyPlus simulating thick walls up tp 1.9 m. The walls thicker than 1 m were split into two layers. Maybe this helps.

Regards, Doris

Did you play around at all with the parameters that control the number of nodes in the collector and the number of subtimesteps that the model uses? If not I would start by increasing those values.

If that doesn't solve the problem then my guess as to the problem is that at times when there is little solar radiation the model is trying to slow the flow down to a very small rate so that it can achieve the desired outlet temperature and at those flow rates the temperature changes from node to node might be getting unrealistically large. 

In reality pumps can only turn down to perhaps 10-20% of their rated flow. What I usually do in the case of a collector that is trying to maintain an outlet temperature is to send the collector's "desired" flow rate to a pump that has a minimum turndown imposed on it. The flow rate that the collector actually gets may be higher than it wanted and  the collector may not achieve the desired temperature during low solar radiation periods but that is a more realistic situation anyway. Sometimes I use two instances of the collector model; one instance is calculating the desired flow rate and then the other instance is just getting the actual flow rate from a pump model.

~david

The primary cause of this problem is if you've installed some other software that uses a similar command prompt file, the TESS libraries can get confused and try to reference that other location. Try uninstalling the TESS libraries from the TESSLibs_Uninstall.exe in your TRNSYS directory and reinstalling them. Also make sure that you install the same version of the TESS libraries as you did for TRNSYS (64-bit or 32-bit). If you are in TRNSYS18, I recommend the 64-bit version. With a new PC it may be possible that it no longer supports the 32-bit version.

I hope this helps!

Have you checked the \UserLib\DebugDLLs and \UserLib\ReleaseDLLs folders? My guess is that you need to reinstall Type344 and direct it to install in your TRNSYS18 directory. Be sure to use the 64-bit version of the Type. Copying the dll from your TRNSYS17 directory won't work because TRNSYS17 is 32-bit. If you don't have a Type344 installer for 64-bit or compatible with TRNSYS18, reach out to your distributor and they can help you get the appropriate installer.

Type344 could not be located in either the TRNdll64.dll or in an external dll. Please relink theTRNDll64.dll including this Type or make sure that an external DLL in the \UserLib\DebugDLLs and \UserLib\ReleaseDLLs folders contain the Type.

It works properly in TRNSYS 17 without any errors.

My question is: during the simulation, I very frequently get the error shown in the attached picture. Does anyone know why this error appears?

Thank you very much