Design method for the optimization of district heating systems using mixed integer linear programming

Abstract

During winter, district heating systems may be used to heat dense built environment in large cities. After several years of use, performance of such a system would change because of either refurbishment or ageing. As a result, air temperatures in heated rooms would be different from the design (thermal comfort) temperatures. It is investigated how the system performance changes owing to ageing and refurbishment of the primary pipeline and envelope of heated buildings. To determine how to recover the design temperatures of air in heated rooms, mixed integer linear programming is used. The objective was to select an optimal scenario that would achieve the minimum difference between the corrected and design temperatures inside the investigated rooms. The scenario refers to installation of new (option) valves and water pumps that would require installing in the primary pipe network of the old district heating system examined to re-establish its optimum performance.