ColSim: a new simultaion environment for complex system analysis and controllers

The paper describes the main features of the new simulation environment ColSim [15] and a special application for investigating ventilation strategies in buildings. ColSim was developed with the intention of simulating and testing complex control strategies in different HVAC and thermal solar systems, coupled to a building model. It is based on a modular structure and a modified Euler algorithm was chosen for the numerical integration of the nonlinear differential equations. In contrast to existing programs, time steps ranging down to one second are used in order to receive an accurate response of the dynamic systems. An energy and mass flow balance is automatically executed within every time step. Current activities focus on the development of controllers to drive pumps and fans in various applications. All control routines and models within ColSim are implemented in ANSI-C code and can be operated on LINUX/UNIX platforms as well as in embedded system controllers. Different public domain tools are integrated in ColSim e.g. for graphical input or online plotting.