I have been working on the source code of E+ for several months. Basically, I would like to add a heat pump water heater module for the variable refrigerant flow system, which is a bit(somehow) similar to a de-superheat water heater. I have checked the manuals and I think currently there is no module or component in EnergyPlus that can do this. That is the reason why I started working on the source code.
I did put bunches of codes into the source code (mainly in the PlantWaterThermalTank.f90, HVACVariableRefrigerantFlow.f90 and DXCoil.f90). Just as expected, the compiled .exe file could not run and it now ends with segmentation fault. Since I had no experience in Fortran before, I think it is probably caused by insufficient understanding of the structure of the original source code. I am now trying to to figure out where I should possibly embed the module in the source codes correctly because I think maybe I was doing it in the wrong way. For example, the new lines could not actually be used even though the compilation seems successful.
The questions are：
Where I shall I embed my codes? Is there a structure or " program tree" so that I could find the right places for the codes?
I would appreciate if you guys here could offer help.