TRNSYS Information

General Information on Running a Simulation


Introduction
The following paragraphs are intended to give you an idea about how you run a RENEWisc simulation and what kind of output you can expect to get from it. When yo download the program, you will also have some step by step tutorials that lead you through setting up your simulations. Please bear in mind that RENEWisc is not intended to be able to model every single building configuration - such tasks are left to complex simulation programs such as TRNSYS, the one on which RENEWisc is built. Instead, RENEWisc is meant to to give you an idea of the energy and economic impact renewable energy technologies can have on building projects.
Launching a Simulation
To launch a RENEWisc simulation, select “Calculate” from the TRNSYS menu at the top of the screen or press the F8 key. After a moment, an online display of system variables will pop up and your simulation will begin to run. At the end of the simulation, a message will pop up saying that calculations have completed, do you wish to exit the online plotter. If you click yes, RENEWisc will revert back to it’s input screen. If you click no, the online plotter will stay visible until you select “Exit Online Plotter” from the “Calculations” menu at the top left of the screen. Information on viewing and interpreting results is included in the Seeing and Interpreting Results section of this document.
Setting up a Simulation
RENEWisc simulations are set up entirely from a set of input screens. In each screen, you will notice that there are certain types of input fields. In numerical value fields, you will type the value of a certain parameter, say the area of a solar thermal collector, or the heating capacity of a furnace. RENEWisc will try to detect if a parameter that you have typed is out of range and warn you accordingly. In a pull down field, you are asked to select an option from a list, for example the manufacturer and model of a wind turbine. Third, you are able to click on active buttons and set sliders that determine schedules. The final type of input field is a radio button in which you are also asked to select an option. Groups of radio buttons are used to configure the basis renewable energy system whose performance you plan to simulate.
If you click on a button to launch a slider and you get an error message that refers to an “OCX File,” there is a file missing from your computer. Please see the “Troubleshooting RENEWisc” section below for help on resolving the problem.
Getting Detailed Help
Most of the parameter groups (a set of inputs enclosed in a box) are set up with an associated help file. To get help on a given parameter, click on the question mark icon at the t of that group and your internet browser (Internet Explorer or Netscape) will launch, displaying additional information about all the parameters in the group.
Seeing and Interpreting Results
There are a few different ways that you can see results from a RENEWisc simulation. Once a simulation has completed, you can click “No” when asked whether you want to exit the online plotter. With the online plot still displayed, hold down the shift key and move the mouse back and forth and the names of the displayed variables (at the top of the plot) will be replaced by their values. If the plot is too complex, you can “switch off” variables from the display by clicking on their names. If a variable is “off” (not displayed” you can turn it on again by re-clicking the name. You can also change the background color of the plot between black and white using the “Plot Options” menu. You will notice that only one week of data is displayed at a time but you can use the forward and back arrows at the bottom left and right of the plot to scroll around through your entire simulation.
The second way of looking at results is that certain variables are integrated and reported monthly and over the entire simulation length. These results are deposited in text files in the \Renewisc\Results folder. The following files are created each time RENEWisc runs:
RENEWiscAnnualResults.txt: A file containing an annual summary of all systems in the current RENEWisc setup being simulated. If an entire year was not simulated, this file contains results for the simulation duration that was run.
RENEWiscMonthlyResults.txt: A file containing a monthly summary of all systems in the current RENEWisc setup being simulated.
PVHourly.txt: A file containing an entry for each hour of the simulation and for each variable plotted on the photovoltaic system (PV) plot.
SDHWHourly.txt: A file containing an entry for each hour of the simulation and for each variable plotted on the solar domestic hot water system (SDHW) plot.
FuelCellHourly.txt: A file containing an entry for each hour of the simulation and for each variable plotted on the fuel cell plot.
WECSHourly.txt: A file containing an entry for each hour of the simulation and for each variable plotted on the wind energy conversion system (WECS) plot.
BuildingHourly.txt: A file containing an entry for each hour of the simulation and for each variable plotted on the building plot.
AverageZoneTemps.txt: A file containing an average day of indoor zone temperature for each month of the year. This file is useful in seeing the average impact of changing something about the building set points.
Troubleshooting RENEWisc
If ever you run a simulation and RENEWisc encounters a problem, it will display the message that “an error was found in the deck, please check the listing file for more information.” RENEWisc is built on a generic energy simulation program called TRNSYS; the deck is the TRNSYS input file and the listing file is generated every time TRNSYS (RENEWisc) is run. There is an immense amount of complex information in the listing file but the actual errors that caused the simulation to stop are reported in a file called RENEWiscErrors.txt (also in the \renewisc\Results directory). You can open this file and look at the error that caused the simulation to stop. Chances are that the error will be cryptic and difficult for you to fix so the best option at this point is to call (or email us) and let us try and resolve the error.
If you try to click on the button to bring up the sliders that set various RENEWisc schedules (for lighting, equipment, water draws etc.) you may get an error that says something to the effect that the “comdlg.ocx file” is missing. COMDLG is an operating system file and the reason that it is not installed along with RENEWisc is that it may already be part of your operating system. If the RENEWisc installation overwrites your existing file, it can cause major problems with your operating system and we don’t want to do that! Instead, the OCX files that you need are located in the \RENEWisc\Troubleshooting\ directory.