Design and simulation of district heating networks: A review of modeling approaches and tools

District heating (DH) systems have been identified as an important component in efforts to mitigate greenhouse gas emissions and achieve climate targets in the near future. Software tools for analyzing these systems use different modeling approaches, making it challenging for practitioners to choose the most suitable tool based on specific use case requirements. This paper systematically reviews available DH network modeling and simulation tools, comparing their modeling approaches, application scope, and functional capabilities. An online survey was conducted among DH tool developers and experts to assess the technical evaluation criteria for these tools. First, the basic concepts and principles of DH networks modeling are discussed. Moreover, it provides an overview of DH network mathematical models, and discusses various numerical methods used for simulation and analysis, while highlighting potential areas for further research and tools development. The aim of this paper is to support academic and industrial users in selecting appropriate modeling approaches, tools, and libraries.