Abstract: Since the 60ies and 70ies also power industry started to use computers for special calculations e.g. thermodynamic calculations of the main components of power plant cycles like steam generators, turbines, heat exchangers, etc. The interest to assess complete cycles was low because usually power plants were not delivered by one single company but the components were designed and manufactured by different companies. So each company used its own simulation program and developed it separately. Sometimes therefore funny mistakes occurred, when the components did not fit properly.
Increasing computer capacity and velocity led to increasing computing applications reducing also engineering labour. Today several commercial programs are available on the market. But they still have different foci due to their different origin and task. E.g. on the combustion and flue gas side CFD-programs like FLUENT, CFX, etc. are used, for the water steam cycle EBSILON, KRAWAL, APROS, etc., for flue gas cleaning, etc. ASPEN, FACTSAGE, etc.
At the Institute of Heat and Fuel Technologies a CFD-program FLOREAN and a cycle calculation program ENBIPRO was developed and is still further developed. The latter one is an object orientated program, which enables the user to design a thermodynamic cycle, i.e. to get information on the geometry of a component, etc., what is quite new because usually the design of the components is the input. But ENBIPRO is also capable of stationary part load calculations for a given geometry and in addition also dynamic simulations including control systems can be performed. Finally, with given geometry it can also be used for validation of measurements especially also for acceptance tests.
In the presentation a lot of examples of furnace calculations including pollutant’s emissions and slagging and fouling as well as a variety of cycle calculations, e.g. Coal Fired Rankine Cycle Power Plant, Gas Fired Combined Cycle Power Plant and in addition the following cycles will be shown: Calciumoxide – Calciumcarbonate Cycle (CaO – CaCO3) for CO2 separation from flue gases without losses in efficiency, Solar Thermal Power Plant, SOFC Solide Oxide Fuel Cell System, an Alstom Gas Turbine (GT-26), ORC Organic Rankine Cycles for the Use of Geothermal Energy, RDF (Refuse Derived Fuel) Power Plants and Compressed Air Energy Storage Combined Cycle Power Plants with Heat Storage.
In combination with CAD the so-called “Virtual Power Plant” i.e. a power plant only existing in the computer as a full model, with full virtual functionality and including virtual accessibility becomes gradually reality.

Brief Biography of the Speaker:
Prof. Dr. techn. R. Leithner (born in 1945 in Scharding, Austria) is head of the IWBT (Institute of Heat and Fuel Technologies) of Technical University Braunschweig, Germany. He has graduated as Dipl.-Ing. (Mechanical Engineering) from the Technical University in Vienna in 1970 with a diploma thesis about measurement and simulation of a heat exchanger.
From 1971 till 1983 he was working in different positions with Energie- und Verfahrenstechnik GmbH (now Alstom Power Boiler GmbH), Stuttgart, one of the leading steam generator manufacturers in Germany. During his work at EVT he wrote a doctoral thesis on the mass flow from an equally heated tube at constant pressure and was graduated as Dr. techn. from the Technical University in Vienna in 1976. His last position in this company was head of the "main department for steam generator design, development and commissioning" including stress analyses and control systems; also procuration was granted him.
In 1983 he was appointed professor and director of the IWBT - TU BS. During all these positions he was always involved in power plant simulations and design.