Optimisation of supply temperature and mass flow rate for a district heating network

Heat losses and pump electrical energy consumption are inevitable during the operation of a district heating (DH) network. Therefore, the appropriate design and operating strategy of a DH network is required in order to reduce the heat losses and pump energy consumption. This study is aimed at optimising the supply water temperature and mass flow rate in a DH network, according to the heating load variations. For this purpose, two different design cases of a DH pipe network were considered. An optimisation model was developed using FICO TM Xpress optimisation tool. Hydraulic and thermal calculations of the model were validated with the commercial software PSS SINCAL. The DH networks were optimised with respect to the annual energy (heat losses and pump energy consumption), and associated costs. The optimum supply temperature and mass (volume) flow rate were obtained for each case. Consequently, optimum heat losses and pump power were calculated.