No abstract

Fifth-generation district heating and cooling (5th DHC) systems offer promising approaches to decarbonizing space heating, cooling and domestic hot water supply. By using these systems, clustered buildings combined with industrial waste heat can achieve a net-zero energy balance on a variety of time scales. Thanks to the low exergy approach, these systems are highly efficient. As part of the Smart Anergy Quarter Baden (SANBA) project, the thermal energy grid simulation tool TEGSim has been further developed and used to design an ultra-low-temperature district heating (ULTDH) network with hydraulic and thermal components fitted to the specific regional characteristics of the investigated case. Borehole thermal energy storage (BTES) used as seasonal storage ensures long-term feasibility. The annual discrepancy of input of thermal energy provided by space cooling and output of energy demanded by space heating and domestic hot water is supplied by an external low-grade industrial waste heat source. This paper presents the functionality of the simulation and shows how to interpret the findings concerning the design of all components and their interplay, energy consumption and efficiencies.

Deep geothermal resources for heat supply and waste heat potentials were assessed and measured for a high-temperature dairy plant. For the industrial waste heat, a borehole heat exchanger (BHE) seasonal storage was configured and simulated after an extensive investigation of shallow geothermal resources. We developed a concept for the subsequent use of the residual and waste heat from the plant in a low-temperature heating and cooling (LTHC) grid for the neighbouring former military camp “Martinek-Kaserne” with a future use as mixed-use urban quarter were investigated in two projects. The modelling of the deep geothermal resources showed that of the three potential reservoirs one is most feasible for geothermal heat supply with temperatures between 129 and 146 °C, which could be used with a high-temperature heat pump for process heat. The waste heat in all sub-processes of the dairy plant were measured over 18 months to identify the most suitable waste heat streams with regard to temperature and continuity. The results showed that 25 % of the waste heat from a sub-process of the plant (fresh products logistics) is sufficient to provide heat for the adjacent LTHC grid with a total energy demand of 3428 MWh per year. The simulation of the BHE field resulted in 96 BHE with 180 m depth for a dis-/charging capacity of 643.7 MWh and 20 decentral heat pumps in the buildings. The BHE field operates quite balanced with only 12.8 MWh of difference in the annual balance. The results of the feasibility study for deep and shallow geothermal resources, and the assessment of the industrial waste heat show that the whole cascade of high-temperature heat for industry to low-temperature heat for the LTHC grid could be realized at the investigated site.

No abstract

An einer automatischen KleinfeueZusammenfassung: rungsanlage für Pellets, die mit einem Vorschubrost und einer neuartigen Primärluftführung von oben auf das Brennstoffbett für landwirtschaftliche Reststoffe adaptiert wurde, sind mit einem "Low Pressure Impactor" die Feinstaubemissionen gemessen worden. Zum Einsatz kamen die Brennstoffe Weizenstroh-Pellets, Miscanthus-Pellets und als Vergleich Holz-Pellets. Die Partikelverteilung ergab bei Weizenstroh-Pellets Maxima bei einer Partikelgröße von 0,34 und 0,17 µm und bei Miscanthus-Pellets bei 0,17 µm. Eine Untersuchung der Partikeln mit dem REM/EDX zeigte eine überwiegende Partikelzusammensetzung aus Kaliumchlorid (KCl). Fine Particulate Emissions from Small Scale Combustion Units with Agricultural ResiduesWith a Low Pressure Impactor fine particulate Abstract: emissions were measured from an automatic domestic small-scale pellet furnace with a modified grate and a novel primary air supply from above to the fuel bed. As fuel were used wheat straw pellets, miscanthus pellets and as comparison wood pellets. Distribution of particles showed high concentrations at particle diameters of 0,34 and 0,17 µm for wheat straw and 0,17 µm for miscanthus. Analysis of the particles with REM/EDX showed a composition of mostly potassium chloride (KCl).