Shell and tube heat exchangers are key components in organic rankine cycle (ORC) power plants commonly used for exploitation of low temperature energy sources (industrial waste heat, geothermal, solar thermal). Due to increased flexible operation, analysis of the transient behavior of the heat exchangers becomes relevant for a further process optimization. Up to date, simulation of the devices is rather focused on stationary analysis than including transient effects. Though transient simulation models do exist, there is minor focus on heat exchangers with shell-side evaporation. As a tool for detailed analysis of the dynamic characteristics of evaporation, highly influenced by the specific parameters of the organic working fluids, a modular simulation model is required. In the frame of this publication, the development of such a transient simulation model especially adapted for a flooded shell and tube heat exchanger (TEMA-E) is presented. The model allows for two dimensional simulation of heat transfer from a liquid heat carrier located in the pipes to the evaporating working fluid. A detailed overview of the model is given and first simulation results based on selected, characteristic input parameters are presented. The paper concludes with an outlook on future use of the model and possible optimization.