Impact of Different Design Guidelines on the Total Distribution Costs of 4th Generation District Heating Networks

Best, Isabelle; Orozaliev, Janybek; Vajen, Klaus

doi:10.1016/j.egypro.2018.08.179

Cited by 20 publications

(7 citation statements)

References 3 publications

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“…According to [30], the specific pressure drop per meter pipe length should range from 70 Pa/m to 350 Pa/m. In this study, a maximum specific pressure drop Δp max of 250 Pa/m is assumed for the optimization.…”

Section: Linear District Heating Modelmentioning

confidence: 99%

A Nonlinear Optimization Method for Expansion Planning of District Heating Systems with Graph Preprocessing

Lambert

Spliethoff

2023

36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 20

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This paper presents a method to find the optimal topology, pipe sizing, and operational parameters of a district heating system under consideration of one design point. The current high costs of district heating systems set limits regarding the minimum heat demand density required for economic network expansions. Optimized routing with ideal pipe sizing and optimal operating parameters offers a potential for cost reduction. With a lower network temperature, the consideration of nonlinear transport phenomena within the district heating network becomes increasingly important. Therefore, a new nonlinear optimization method is introduced, where graph preprocessing reduces the computational effort of the subsequent nonlinear optimization. A cost penalization method, using a smooth approximation of a Heaviside function is applied to pipe investment costs to account for discrete piping diameters. To guarantee fast convergence of the optimization algorithm, the Jacobian matrixes are calculated and the problem is solved with an interior point algorithm. As a proof of concept, the district heating system for a small fictional town with 42 consumers is optimized and analyzed. The whole nonlinear optimization is performed in 19.37 sec and in most cases discrete or near discrete diameters are achieved in a nonlinear continuous optimization.

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Section: Linear District Heating Modelmentioning

confidence: 99%

A Nonlinear Optimization Method for Expansion Planning of District Heating Systems with Graph Preprocessing

Lambert

Spliethoff

2023

36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 20

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“…Different guidelines recommend different thresholds for the design velocity. The impact of different design guidelines on the DH network cost has been evaluated by Best et al [57]. They compared the guidelines of Sweden, Germany, and Austria and concluded that allowing high specific pressure drops of ≥300 Pa/m at maximum heat load leads to transportation pipe investment savings of 6-8%.…”

Section: Distribution Networkmentioning

confidence: 99%

Recent Progress in District Heating with Emphasis on Low-Temperature Systems

Khosravy¹

2022

Geothermal Energy

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District heating plays an important role in future sustainable energy system by integrating any available heat source, including waste heat and renewable heat sources such as geothermal or solar heat. The low-temperature district heating system is the latest generation of district heating. It was introduced less than ten years ago in adaption to the need for lower heat demand of energy-efficient buildings. The low-temperature district heating system provides an infrastructure for a higher share of renewable energy sources while reduces heat loss in pipes. Several small-scale projects were commissioned since the introduction of the technology, and many existing district heating systems are in the process of adaptation. The recent progress of low-temperature district heating systems has been discussed here. First, the fundamental knowledge that is required to understand the main advantages of a low-temperature district heating system was explained briefly. Then the most recent and important projects were discussed with emphasis on solar and geothermal district heating systems. The results of case studies show that the low-temperature solution has the lowest capital costs and has a unique position to be the primary source for building heating demand.

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“…The price of a single pipe system can be considered 640 EUR per meter [24]. Although this price means a high investment return time, there are additional advantages: (i) installing piping of the higher insulation class (22% reduction of the distribution heat loss [25]), (ii) a reduction of the chemical water treatment costs, and (iii) a reduction of water pumping costs. The leak elimination helps to achieve the required pressure at the DH end points.…”

Section: Significance Of Small Leakage Detection In Dh Networkmentioning

confidence: 99%

The Ability of a Soil Temperature Gradient-Based Methodology to Detect Leaks from Pipelines in Buried District Heating Channels

Perpar

Rek

2021

Energies

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We carried out several numerical experiments to analyze how different boundary conditions affect the ability to detect small pipeline leaks. Our method is based on determining the soil temperature gradient above a buried district heating channel. The equivalent thermal conductivity of a wet insulation (λeq) value of 0.5 W/(m·K) was used to mimic a small water leakage. To evaluate the heat loss through the channel cross section, the heat conduction model was used for the pipe insulation, the concrete, and the soil, while the convection model was considered within the channel. The following effects were used to simulate different operating conditions: heat convection at the soil surface, leakage only from the supply or return pipe, soil height above the channel, soil thermal conductivity, and pipe diameter. With the exception of leakage only from the return pipe and low soil thermal conductivity 0.4 W/(m·K), the results showed a doubling of the soil temperature gradient when compared with the no-leakage case. This fact undoubtedly confirms the potential of the method, which is particularly suitable for leak detection in old pipelines that have priority for renovation. A key added value of this research is that the soil temperature gradient-based leak detection technique was found useful in most foreseeable DH operating situations.

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Impact of Different Design Guidelines on the Total Distribution Costs of 4th Generation District Heating Networks

Cited by 20 publications

References 3 publications

A Nonlinear Optimization Method for Expansion Planning of District Heating Systems with Graph Preprocessing

A Nonlinear Optimization Method for Expansion Planning of District Heating Systems with Graph Preprocessing

Recent Progress in District Heating with Emphasis on Low-Temperature Systems

The Ability of a Soil Temperature Gradient-Based Methodology to Detect Leaks from Pipelines in Buried District Heating Channels

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