Linear optimization of district heating systems. Description of an upgraded district heating module for eTransport
MetadataShow full item record
eTransport is a linear optimization tool for evaluating energy supply alternatives for building areas. This report describes an improved, more realistic district heating (DH) module that has been developed for eTransport. The new module includes several improvements as compared to the previous module: • Varying mass flow that depends on the heat load, as opposed to constant mass flow. • Pressure included as a variable, with certain limits for minimum pressure and minimum pressure drop at the loads. • Calculation of pumping power is included in the module, and pumping power due to pressure losses in pipes and at loads is included in the objective function • A more realistic calculation of heat losses included, and the heat losses are included in the heat load • The module allows supply flow to both directions in a pipe; a property which is relevant when more heat sources are present in a DH grid. This feature is however yet to be tested properly. The report presents the main equations required for mathematical description of a district heating system are presented, followed by the approach taken for linear representation of these equations, required for eTransport. The report includes a brief evaluation of the module using a simple test network, and discusses the simplifications and limitations of the present module, giving suggestions for further improvements.