The evaluation of the performance characteristics of the device has a many type, depending on the monitored parameters. In the field of continuous measurements there is a quantum of measurement systems that allow long-term tracking and feedback. Part of the submitted contribution concerns the creation of a cogeneration unit model to monitor the flue gas pathways in relation to the production of pollutants in a non-destructive method. In the case of non-destructive monitoring and interventions in the objects, the use of the virtual laboratories. Such laboratories represent a computer-generated virtual environment in which a model of a particular device is created and a simulation of specific aspects of the matter. The priority given in this paper focuses on the correctness of the operation of the existing system in the case of integration of an external device into the existing flue path and the subsequent analysis of the influence of the further course of the flue gas particles.