Linear programming optimization of heat distribution in a district-heatingsystem by valve adjustments and substation retrofit

The unbalanced distribution of heat in a district-heating system may be cau sed by the increase of hydraulic resistance of pipe network, decrease of he at transmittance of radiators inside buildings, and increase of heat transm ittance of building envelope. This situation yields the overheating of some buildings and underheating of other buildings. A district-heating system i s analyzed that consists of heat plant, primary pipe network, substation, s econdary pipe network, and three buildings. A steady-state, bottom-up appro ach and the sequential linear programming is used to solve this optimizatio n problem. Results show that significant improvement of thermal comfort may be reached by adjusting the valves of secondary pipe network and resizing of the substation heat exchanger. (C) 1999 Elsevier Science Ltd. All rights reserved.