Operation optimisation of district heating production - District heating systems containing combined heat and power plants

With the rising demand of green power many district heating companies are using or consider building combined heat and power plants to increase their competitiveness. This however also creates the need for a way to optimize the production of said power plants. This report will investigate possible solutions for a program that can determine how to best utilize the different boilers available at heat and power plants. A study of existing methods to analyse district heating systems was conducted in order to evaluate and compare their suitability for optimization of medium sized district heating production systems containing both heat and power production. A case study of Mölndal Energi is included as an example of how a tool for this kind of analyses can be done. Modelling of the different plants is covered in detail as well as the construction of the optimization software and its interface. Data from Mölndal Energi were used along plant specifications from the contractor to create models for the plants and the heat demand. The resulting program gives a production prognosis for 24 hours and a production distribution over the plants for each hour. It does however not take into account minimum capacity of the plants or start up costs. The models used in the program are of limited precision and they will need to be fine tuned once data from actual operations of the plant is available. Overall however the program is working as intended and solves the optimization problem