How to Optimize District Heating Systems (Low-Temperature and Traditional Generations)

What is it about?

This paper presents a method for designing low-energy District Heating (DH) systems (based on low-temperature operation), with a focus on pipe dimensioning methods, substation types, and network layouts. The study aims to improve the efficiency of the DH system by reducing heat loss from the network. The traditional maximum pressure gradient (target pressure loss) method for dimensioning DH networks was discussed, and an alternative method was proposed to avoid over-dimensioning of pipe segments by use of optimization. The new method considered the pressure losses in all routes of the piping network, not just the critical route. Overall, the paper provides insights into optimizing low-energy DH systems for reduced heat loss and improved consumer satisfaction. Besides, the optimal pipe dimensions were evaluated using commercial software Termis (7T) with the input of various heat demand scenarios. Two types of network layouts (branched and looped) were compared to ensure consumer satisfaction and prevent excessive drops in supply temperature during the summer months.

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Photo by Alex Perz on Unsplash

Photo by Alex Perz on Unsplash

Why is it important?

The novelty of this paper can be listed as: - The paper introduces a novel method for designing low-temperature District Heating (DH) systems, which considers different pipe dimensioning methods, substation types, and network layouts. - The developed optimization method is shown to be highly useful in pipe dimensioning and superior to traditional dimensioning methods, leading to an appreciable reduction in heat loss from the DH network. - The study evaluates the effects of network type on pipe dimensions for substations with buffer tanks, heat exchangers, and booster pumps, providing insights into optimizing the DH system. - The paper compares two network layouts in terms of consumer satisfaction, supply temperatures, and heat loss within the DH network, aiming to prevent excessive drops in supply temperature during the summer months. - The alternative method proposed in the paper for dimensioning DH networks, which considers pressure losses in all routes of the piping network, is a novel approach to avoid over-dimensioning of pipe segments.