Efficient District Heating in a Decarbonisation Perspective: A Case Study in Italy

Abstract

The European and national regulations in the decarbonisation path towards 2050 promote district heating in achieving the goals of efficiency, energy sustainability, use of renewables, and reduction of fossil fuel use. Improved management and optimisation, use of RES, and waste heat/cold sources decrease the overall demand for primary energy, a condition that is further supported by building renovations and new construction of under (almost) zero energy buildings, with a foreseeable decrease in the temperature of domestic heating systems. Models for the simulation of efficient thermal networks were implemented and described in this paper, together with results from a real case study in Italy, i.e., University Campus of Parma. Activities include the creation and validation of calculation codes and specific models in the Modelica language (Dymola software), aimed at investigating stationary regimes and dynamic behaviour as well. An indirect heat exchange substation was coupled with a resistive-capacitive model, which describes the building behaviour and the thermal exchanges by the use of thermos-physical parameters. To optimise indoor comfort conditions and minimise consumption, dynamic simulations were carried out for different operating sets: modulating the supply temperature in the plant depending on external conditions (Scenario 4) decreases the supplied thermal energy (−2.34%) and heat losses (−8.91%), even if a lower temperature level results in higher electricity consumption for pumping (+12.96%), the total energy consumption is reduced by 1.41%. A simulation of the entire heating season was performed for the optimised scenario, combining benefits from turning off the supply in the case of no thermal demand (Scenario 3) and from the modulation of the supply temperature (Scenario 4), resulting in lower energy consumption (the thermal energy supplied by the power plant −3.54%, pumping +7.76%), operating costs (−2.40), and emissions (−3.02%). The energy balance ex-ante and ex-post deep renovation in a single user was then assessed, showing how lowering the network operating temperature at 55 °C decreases the supplied thermal energy (−22.38%) and heat losses (−22.11%) with a slightly higher pumping consumption (+3.28%), while maintaining good comfort conditions. These promising results are useful for evaluating the application of low-temperature operations to the existing district heating networks, especially for large interventions of building renovation, and confirm their potential contribution to the energy efficiency targets.

The Impact of Thermo-Modernization and Predictive Regulation on Heat Energy Consumption and Emission of Pollutants into the Atmosphere - The Case of Prefabricated Buildings

“…Table 12 shows the results of calculations of pollutant emissions along with the reduction of pollutant emissions after the introduction of the forecast regulation as compared to the period after deep thermal modernization. The calculations were made in accordance with Formulas (10) and (12).…”

“…The heating load is influenced by several factors, including the building's energy efficiency standard, its heating power and the location of the rooms in relation to each other or to the external walls. Another important aspect is the location of the building in relation to world directions and the density of buildings in the surroundings [11][12][13][14]. Scientific studies have shown that the operating habits and routine of residents with respect to their temperature preferences also have a significant impact on the heat demand [15][16][17].…”

Building Heat Supply System Based on Hybrid Solar Collectors

“…Currently, there are many modern technologies that will make it possible to provide humanity with nuclear energy and energy from fossil fuels for many years to come. But, despite the world community's attempt to implement a policy of decarbonization of production, the level of atmospheric pollution continues to grow, which leads to the destruction of the biosphere (Ricci et al, 2022). Waste storage, the consequences of accidents, thermal and radiation pollution are also a big problem.…”

Challenges for District Heating in Poland

“…The paper [21] offers legislative steps and highlights significant turning points on the path to a full heat transition in order to accelerate the execution of the roadmap for the decarbonization of the European heating and cooling sector. A case study in Italy concerning the efficient DH in a decarbonization perspective can be found in [22]. To reduce the harmful emissions in DH systems smart technologies can be applied.…”