Alignment of the heat recovery potential with the local area heat demand for selected industrial entities in the city of Gliwice

Abstract

Waste heat plays a significant role in obtaining the 4th and 5th generation of District Heating (DH) System in cities. This article presents the possibilities of integrating selected waste heat emitters into DH, with the objective of meeting the demand for heat for the selected residential area (approx. 4000 inhabitants) in the city of Gliwice (180 000 inhabitants). The total heating demand of the studied area was estimated at 19 800 GJ including both space heating and domestic hot water. The maximum thermal power was estimated at approx. 2.45 MW. The demand was calculated on the basis of registered metering values for individual buildings which were processed and summarized due to the lack of collective meters for the district. A detailed data classification, correction and completion procedure was elaborated to deal with non-uniform and low-quality data registration. Two industrial objects with waste heat generation were examined to be integrated with the local DH network. The waste heat generation potential equals 9.0 MW for plant #1 and 0.9 MW for plant #2. Apart from the constant generation declared by the industrial entities, realistic profiles including possible shaft-work and maintenance periods were created. It has been shown that the total heat demand for selected residential areas can be covered by integrating waste heat into the current DH network. Depending on the waste heat generation profile, the local area heat demand can be covered entirely or to a large degree (coverage factor ranges from 72 to 100%). The waste heat utilization factor ranges from 6.3 to 8.3%. To manage the remaining waste heat potential, it is required to build additional district heating pipelines and nodes connecting to the existing network to receive an additional 7.45 MW thermal power. The potential of waste heat recovery is significant at the scale of a medium sized city: integrating two large industrial emitters allows up to 13% decarbonization of heats production in the local district heating plant.