A computational tool for analysing the response of complex heat exchanger networks to disturbances

The heat exchanger networks (HEN) in industrial heat recovery systems often consist of large and complex subsystems. Calculating the response of such HENs to disturbances, such as varying inlet conditions or changing heat transfer capacities, may be challenging due to the presence of, e.g. stream splits and recycle loops. Extensive modelling and/or trial and error calculations may be necessary. This applies also for the analysis of different retrofit proposals. Retrofit opportunities in industrial heat recovery systems are often constrained by operability considerations, i.e. retrofit actions are supposed to have as little impact as possible on the production process to maintain the quality of the core product. Consequently, there is a clear demand for a tool to effectively screen design proposals at an early stage in the design process. In this work, a computational analysis tool is proposed to meet this demand. The proposed analysis tool allows fast evaluation of the network response when operating conditions change and/or operational settings are manipulated, and it is applicable for a wide range of HEN structures. The practical use of the analysis tool is demonstrated in a case study on the HENs of a large state-of-the-art Kraft pulp mill.