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h i g h l i g h t sA steady-state analysis method for gas networks was developed. This method is used for gas networks with distributed injection of alternative gas. A gas network with injection of upgraded biogas and hydrogen was simulated. Results show the impact on pressure and gas quality in the network. a b s t r a c tA steady state analysis method was developed for gas networks with distributed injection of alternative gas. A low pressure gas network was used to validate the method. Case studies were carried out with centralized and decentralized injection of hydrogen and upgraded biogas. Results show the impact of utilizing a diversity of gas supply sources on pressure distribution and gas quality in the network. It is shown that appropriate management of using a diversity of gas supply sources can support network management while reducing carbon emissions.

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The development of accurate dynamic models of thermal energy storage (TES) units is important for their effective operation within cooling systems. This paper presents a one‐dimensional discretised dynamic model of an ice‐based TES tank. Simplicity and portability are key attributes of the presented model as they enable its implementation in any programing language which would, in turn, facilitate the simulation and analysis of complex cooling systems. The model considers three main components: energy balance, definition of the specific heat curve, and calculation of the overall heat transfer coefficient. An advantage of the model is that it can be adapted to other types of TES units employing phase change materials. The modelling approach assumes equal flow and temperature distribution in the tank and considers two internal tubes only to represent the whole tank—significantly reducing the number of equations required and thus the computation time. Thermophysical properties of water during the phase change and of the heat transfer fluid are captured. The ice‐based TES tank model has been implemented in MATLAB/Simulink. A good agreement between simulation results and experimental data available in the literature has been achieved—providing confidence in the validity of the mathematical model.