How to use Cooling Tower free cooling in Apring/May and October?

How to simulate free cooling with a cooling tower using Ironbug building HVAC sytem, where the main process involves turning off the cooling tower fan in spring and fall, only running the cooling tower pump, and then integrating the cooling tower with the indoor air conditioning module? The EnergyPlus EMS (Energy Management System) module can be used, or it can be implemented using Python.

Here is the chiller water loop.


Here is two speed cooling tower, it can set free convection.But it not worked.
Is it possible building another plant loop for Cooling Tower free cooling?

Here is a detailed document.