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

I am using TRNSYS 18 and I am currently following the manual tutorial, specifically Tutorial 9, Section 9.2: “Creating a Simple TRNSYS Project.”

I have followed the instructions carefully step by step, but at the end of the tutorial I am getting results that are different from the results shown in the manual. I have repeated the tutorial twice now, and I am still getting the same incorrect/different results.

I have attached screenshots of the results I am getting, along with my project/input files, so that you can see what I have done.

Could someone please help me check what I might be doing wrong? I would really appreciate any guidance, especially on whether my component connections, parameters, or output setup are incorrect.

Thank you very much

I found a TESS data file for Yazaki Single Effect absorption chiller name Yazaki20-50ton(OneStage)S3.dat.

C:\TRNSYS18\Tess Models\SampleCatalogData\AbsorptionChiller\Single-Effect\Yazaki Model\Yazaki20-50ton(OneStage)S3.dat

I believe it is the hot water fired WFC-SC version 20, 30 and 50 tons.

The file includes 9 Hot water inlet temperatures + fraction of nominal capacity at these 9 HW inlet temperatures.

However I am wondering how to use the file since TYPE107 asks for a more detailed file including:

- Number of CW steps in data file

- Number of CHW setpoints in data file

Best regards,

To ensure comparability, I have configured both models as similarly as possible:

Type 557:

• Number of Boreholes in Series: 1
• Number of Radial Regions: 1

Type 548:

• Number of Fluid Inlets: 1
• Number of Radial Regions: 1
• Inlet to Radial Region: 0

All other parameters as well as the system connections are identical in both cases.

However, I am observing a discrepancy:

• In Type 557, the thermal energy balance closes correctly.
• In Type 548, the thermal balance does not match.

Has anyone experienced similar inconsistencies between these two Types, or could there be something subtle in the configuration of Type 548 that I might be overlooking?

Any insights would be greatly appreciated.

I am using Type786 and I set Control Mode = 0 (Parameter #1) to operate the heat pump as an ON/OFF unit. However, when I run the simulation, I receive the following error message:

"14 INPUTS are required and 16 INPUTS were specified."

I understand the reason: when Control Mode = 0, Input #15 (heating mode supply air temperature setpoint) and Input #16 (cooling mode supply air temperature setpoint) are not needed. These two inputs are only relevant when Control Mode = 1 (variable speed operation). 

My question is: is there a way to disable or deactivate Input #15 and Input #16 when Control Mode = 0, without having to modify the source code or the ProForma file? I am looking for a standard, user-level solution.

What do you recommend?

1. Use only the cooling rating flow rate (1160 CFM) for both modes (single step each)?

2. Copy the single heating flow rate 4 times to match the 4 cooling steps?

Thanks.

I would like to model a heating circuit in a building, with a single-speed pump (type 114) and a valve that is connected to a PID-controller. The valve should modulate the flow rate in the circuit, based on the control signal from the PID-controller. What is the easiest way to model this? I have not found a valve type appropriate for this purpose. Is it best to use a valve+single-speed pump, or is it easier to use a variable-speed pump instead? If I use the single-speed pump, will the flow rate be affected by a valve, or will it always keep the same, constant flow rate?

Best regards,

Johan

Mariem