TY - JOUR A1 - Steininger, Peter A1 - Gaderer, Matthias A1 - Dawoud, Belal A1 - Gaderer, Matthias T1 - Experimental and numerical study on the solar gain and heat loss of typical existing and refurbished German buildings JF - iCRBE Procedia N2 - This communication introduces an experimental setup for investigating the effect of solar radiation on the reduction of transmission heat losses and the steady state thermal conductance of uninsulated and insulated multi-layer wall samples. The setup consists of two adjacent climatic chambers, which share a common wall, in which the multi-layer wall samples are mounted. A solar simulator is applied within the outdoor air climatic chamber, whose radiation spectrum and radiation intensity are approximately equivalent to those of the sun. The first tests have been carried out on a wall sample with a typical structure of existing buildings from the year 1930 in Germany. In addition, a high-performance insulating plaster layer has been applied on a basic test sample (with existing building structure) to replicate and assess the refurbished scenario. Furthermore, a numerical investigation on the transient heat transfer process is carried out by using the simulation software COMSOL Multiphysics®. The experimental results of both uninsulated and insulated wall samples are validated against 1D and 3D models. As seen, the uninsulated wall, whose thermal conductance was experimentally determined to be equal to 1.79 W/(m²K), absorbs a heat flux of 208 W/m² through its external wall surface over a period of 8 hours. A fraction of 9.8 % of the absorbed heat arrives as a gain on the internal wall and reduces the transmission heat losses by 11.7 % over a period of 55 hours. On the other hand, the thermal conductivity of the insulation layer of the refurbished wall sample with micro hollow glass spheres was estimated by a parameter estimation procedure using the 3D model and the obtained experimental data. Using the estimated thermal conductivity, a thermal conductance of 0.42 W/(m²K) has been obtained for the refurbished wall sample. Y1 - 2020 UR - https://www.scilit.net/article/e45ed49630736c2ed82cd848e55bb69c?action=show-references U6 - https://doi.org/10.32438/icrbe.202035 VL - 1 IS - 1 SP - 75 EP - 93 PB - Weentech ER - TY - GEN A1 - Schwanzer, Peter A1 - Dietrich, Markus A1 - Haft, Gerhard A1 - Gaderer, Matthias A1 - Rabl, Hans-Peter T1 - Oxidation Kinetics Determination of GDI Engine Soot by a Radio-Frequency Sensor T2 - 23rd Conference on Combustion Generated Nanoparticles 2019, June 17-20, Zürich, Switzerland Y1 - 2019 UR - https://www.nanoparticles.ch/archive/2019_Schwanzer_PO.pdf ER - TY - GEN A1 - Schwanzer, Peter A1 - Mieslinger, Johann A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Haft, Gerhard A1 - Walter, Stefanie A1 - Hagen, Gunter A1 - Moos, Ralf A1 - Gaderer, Matthias T1 - Monitoring of a Particulate Filter for Gasoline Direct Injection Engines with a Radio-Frequency-Sensor T2 - 11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany N2 - In order to comply with future emission regulations, the use of particulate filters in vehicles with direct injection gasoline engines is essential. The current amount of soot and ash in the filter is calculated by a soot load model in the electronic control unit in combination with a differential pressure sensor determining the pressure drop over the particulate filter. Active regeneration is initiated if the calculated amount of soot or the measured differential pressure is too high. This is associated with additional fuel consumption. An on-board diagnosis for the particulate filter is currently not part of the Euro 6d emission standard. For future exhaust emission standards, on-board diagnosis or active monitoring of the particulate filter is conceivable. One of the benefits of monitoring is the fact that unnecessary active regenerations can be avoided. As a result, there is no additional fuel consumption due to misinterpretations of the amount of soot in the filter. For active monitoring of the particulate filter, a radiofrequency (RF-) sensor, that detects the soot loading of the filter with electromagnetic waves directly, can be used. Such a system has the advantage that by utilizing the filter as a sensor more precise information about the current state of the filter, e.g. a possible damage, can be provided. Worst-case considerations of filter damages, tested at an engine test bench show the advantages which are entailed by a system like that. By means of partial regeneration of the particulate filter it is demonstrated how the remaining amount of soot in the filter can be detected in a better way in comparison to the differential pressure sensor by using the RF-sensor. Y1 - 2020 UR - https://eref.uni-bayreuth.de/54655/ N1 - Projekttitel: Load Sensor for GPF; Projekt-ID: AZ-1288-17 ER - TY - JOUR A1 - Schwanzer, Peter A1 - Rabl, Hans-Peter A1 - Loders, S. A1 - Seifert, P. A1 - Himmelstoss, S. A1 - Gaderer, Matthias T1 - Difference in the Tailpipe Particle Number by Consideration of Sub-23-nm Particles for Different Injection Settings of a GDI Engine JF - Emission control science and technology N2 - The purpose of this study was to investigate the characteristic of nanoparticles under consideration of sub-23-nm particles from a 1.8-l direct injection (DI) gasoline engine under stoichiometric air/fuel conditions in the exhaust gas system. For future CO2 challenges, the usage of DI-instead of port fuel injection (PFI)-gasoline engines is unavoidable. Therefore, a state of the art particle management program-particle number (PN) system, the Horiba SPCS (2100) with an integrated CPC (condensation particle counter), was recalibrated from a 50% cutoff (D-50%) at 23 nm down to a cutoff at 10 nm and the PCRF (particle concentration reduction factor) for sizes smaller than 23 nm was checked. Two different modal points, out of a representative Real Driving Emission (RDE) cycle, were investigated with both calibrations, D-50%=10 nm and D-50%=23 nm. For these different load points, the fuel pressure (FUP) and the start of injection (SOI) were varied, to represent the difference in the structure and the ratio conc((10 nm))/conc((23 nm)) of the nanoparticle emissions. The particle characterization includes the particle number (PN), the particle size distribution (PSD), and the particle mass (PM). The particle number was measured with Horiba SPCS (2100). The particle size distribution was analyzed with a Grimm differential mobility analyzer (DMA) in combination with a Faraday cup electrometer (FCE). Micro Soot and Pegasor were used to determine the PM, and an optical characterization was done with a 120-kV Phillips CM12 transmission electron microscope (TEM). The position of all particle measurement systems was downstream the three-way catalyst (TWC). The results of this investigation showed that a higher injection pressure decreases the PN (without consideration of sub-23-nm particles) in general. The ratio conc((10 nm))/conc((23 nm)) was therefore higher, because smaller particles, especially ash particles, were less reduced from the FUP. This means higher FUP tends to a higher ratio. For the SOI, the main reasons of the ratio differences were explained by an encroachment between the injection jet and the piston, the valve and the wall. KW - DoE KW - GDI KW - Particle number Y1 - 2019 U6 - https://doi.org/10.1007/s40825-019-0114-1 VL - 5 IS - 1 SP - 7 EP - 22 PB - Springer Nature ER - TY - JOUR A1 - Mikhaeil, Makram A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - Experimental Investigation of the Adsorption and Desorption Kinetics on an Open-Structured Asymmetric Plate Heat Exchanger; Matching Between Small-Scale and Full-Scale Results JF - Frontiers in Energy Research N2 - This paper introduces the results of an experimental study on the adsorption and desorption kinetics of a commercially available, open-structured asymmetric plate heat exchanger adapted to act as an adsorber/desorber for the application in adsorption heat transformation processes. In addition, a volumetric large temperature jump (V-LTJ) kinetic setup was applied to measure the adsorption and desorption kinetics of a small-scale adsorbent sample prepared dedicatedly to be representative for the adsorbent domain inside the investigated adsorber plate heat exchanger (APHE). All kinetic results of the small-scale adsorbent sample and the APHE were fitted into exponential forms with a single characteristic time constant (τ) with a coefficient of determination (R2) better than 0.9531. A very good matching between the small-scale and full-scale adsorption kinetic measurements was obtained, with an average relative deviation of 12.3% in the obtained τ-values. In addition, the kinetic data of the small-scale adsorbent sample were utilized for estimating the expected specific instantaneous and moving average powers of the evaporator/condenser heat exchanger. The average relative deviation (ARD) between the moving average specific evaporator powers obtained from the small-scale and the full-scale measurements amounts between 5.4 and 15.1%. Y1 - 2022 U6 - https://doi.org/10.3389/fenrg.2022.818486 N1 - Corresponding author: Belal Dawoud VL - 10 SP - 1 EP - 15 PB - Frontiers ER - TY - JOUR A1 - Steininger, Peter A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - Assessment of the Annual Transmission Heat Loss Reduction of a Refurbished Existing Building with an Advanced Solar Selective Thermal Insulation System JF - Sustainability N2 - A numerical parameter sensitivity analysis of the design parameters of the recently published solar selective thermal insulation system (SATIS) has been carried out to enhance its thermal and optical properties. It turned out that the insulation properties of SATIS can be effectively improved by reducing the length of the glass closure element. Increasing the area share of the light conducting elements (LCEs) and decreasing their length-to-diameter (L/D) ratio were identified as key parameters in order to increase the solar gain. Two SATIS variants were compared with the same wall insulation without SATIS in a yearly energetic performance assessment. The SATIS variant with 10 mm length of the closure element, 44.2% area share of LCE, as well as front and rear diameters of 12 mm/9 mm shows an 11.8% lower transmission heat loss over the heating period than the wall insulation without SATIS. A new methodology was developed to enable the implementation of the computed solar gains of SATIS in 1D simulation tools. The result is a radiant heat flow map for integration as a heat source in 1D simulation models. A comparison between the 1D and 3D models of the inside wall heat fluxes showed an integral yearly agreement of 98%. KW - effective thermal conductivity KW - parameter sensitivity analysis KW - radiant heat flow map KW - solar selective thermal insulation system (SATIS) KW - total solar energy transmittance KW - yearly energetic performance assessment Y1 - 2021 U6 - https://doi.org/10.3390/su13137336 N1 - Corresponding author: Belal Dawoud VL - 13 IS - 13 SP - 1 EP - 19 PB - MDPI CY - Basel ER - TY - JOUR A1 - Gamisch, Bernd A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - On the Development of Thermochemical Hydrogen Storage: An Experimental Study of the Kinetics of the Redox Reactions under Different Operating Conditions JF - Applied Sciences N2 - This work aims at investigating the reduction/oxidation (redox) reaction kinetics on iron oxide pellets under different operating conditions of thermochemical hydrogen storage. In order to reduce the iron oxide pellets (90% Fe2O3, 10% stabilizing cement), hydrogen (H2) is applied in different concentrations with nitrogen (N2), as a carrier gas, at temperatures between between 700 ∘C and 900 ∘C, thus simulating the charging phase. The discharge phase is triggered by the flow of a mixture out of steam (H2O) and N2 at different concentrations in the same temperature range, resulting in the oxidizing of the previously reduced pellets. All investigations were carried out in a thermo-gravimetric analyzer (TGA) with a flow rate of 250mL/min. To describe the obtained kinetic results, a simplified analytical model, based on the linear driving force model, was developed. The investigated iron oxide pellets showed a stable redox performance of 23.8% weight reduction/gain, which corresponds to a volumetric storage density of 2.8kWh/(L bulk), also after the 29 performed redox cycles. Recalling that there is no H2 stored during the storage phase but iron, the introduced hydrogen storage technology is deemed very promising for applications in urban areas as day-night or seasonal storage for green hydrogen. KW - hydrogen storage KW - iron/iron oxide KW - reaction kinetics KW - redox reactions Y1 - 2021 U6 - https://doi.org/10.3390/app11041623 N1 - Corresponding author: Belal Dawoud VL - 11 IS - 4 SP - 1 EP - 15 PB - MDPI CY - Basel ER - TY - INPR A1 - Gärtner, Sebastian A1 - Marx-Schubach, Thomas A1 - Gaderer, Matthias A1 - Schmitz, Gerhard A1 - Sterner, Michael T1 - Introduction of an Innovative Energy Concept for low Emission Glass Melting based on Carbon Capture and Usage N2 - Due to the very high fossil energy demand, the glass industry is looking for innovative approaches for the reduction of CO2 emissions and the integration of renewable energy sources. In this paper, we present a novel power-to-gas concept, which has no impact on established melting processes and discuss it for this purpose. A special focus is set on the required CO2 capture from typical flue gases in the glass industry, as this process has not been investigated in detail yet. We used a process simulation approach to investigate post-combustion CO2 capture by absorption processes, followed by a techno-economic evaluation. Our investigations found the designed CO2 capture plant to be approx. 400 times smaller than absorption based CO2 separation processes for conventional power plants. Due to the many options for waste heat utilization, the waste heat required for CO2 desorption can be generated in a particularly efficient and cost-effective way. The resulting CO2 avoidance costs range between 41-42 €/t CO2, depending on waste heat utilization for desorption, and thus offer a cost effective way of CO2 removal from glass industry melting processes. These costs are well below the values of 50-65 €/t CO2 described so far for comparable industrial applications. In addition, we describe optimization options, like solvent and process improvements, to enable further cost reductions. These results motivate further research and development on the overall process presented in this work. KW - glass KW - Oxyfuel KW - Methanation KW - Power-to-Gas KW - CO2 capture KW - Economic Analysis Y1 - 2022 U6 - https://doi.org/10.31224/2642 ER - TY - CHAP A1 - Altmann, Robert A1 - Gebhard, Jürgen A1 - Troeger, Adrian A1 - Winkler, Markus A1 - Töpfer, Georg A1 - Remmele, Edgar A1 - Gaderer, Matthias A1 - Rabl, Hans-Peter ED - Berns, Karsten ED - Dressler, Klaus ED - Kalmar, Ralf ED - Stephan, Nicole ED - Teutsch, Roman ED - Thul, Martin T1 - Engine performance and emission analysis of a NRMM CI engine with common rail injection system operated with diesel fuel and rapeseed oil fuel T2 - Proceedings of the 6th Commercial Vehicle Technology Symposium 2020/2021 N2 - The use of alternative fuels in high-power non-road mobile machinery (NRMM) combustion engines is a possible way to substitute fossil fuel. By using pure vegetable oil fuels, like rapeseed oil fuel (DIN 51605), the greenhouse gases can be reduced effectively. Due to the differences in physical and chemical properties, a modification of the engine control unit calibration is necessary to adapt the working process on the fuel. Without modifications, the engine power output with rapeseed oil fuel is lower than with diesel fuel because of the smaller energy content. By adapting the engine settings, like the injection fuel mass, the power loss can be compensated but it accompanies with a higher fuel consumption. The engine emissions at part load conditions show, that there are benefits in particle emissions by using rapeseed oil at similar NOx emissions. Therefore, a design of experiment setup was initiated on a selected engine operation point to determine the effects of further parameters, like rail pressure, manifold pressure and injection pattern, on the process and to see the potential of an optimized calibration. KW - CI engine KW - common rail injection KW - Diesel Engine KW - DoE KW - rapeseed oil Y1 - 2021 SN - 978-3-658-29716-9 U6 - https://doi.org/10.1007/978-3-658-29717-6_16 SP - 231 EP - 242 PB - Springer Vieweg CY - Wiesbaden ER - TY - JOUR A1 - Steininger, Peter A1 - Gaderer, Matthias A1 - Steffens, Oliver A1 - Dawoud, Belal T1 - Experimental and Numerical Study on the Heat Transfer Characteristics of a Newly-Developed Solar Active Thermal Insulation System JF - Buildings N2 - A newly-developed solar active thermal insulation system (SATIS) is introduced with the main objective to accomplish a highly-dependent total solar transmittance on the irradiation angle. SATIS is also designed to obtain the maximum transmittance at a prescribed design irradiation angle and to reduce it remarkably at higher irradiation angles. A purely mineral thermal insulation plaster with micro hollow glass spheres is applied to manufacture the investigated SATIS prototype. Light-conducting elements (LCEs) have been introduced into SATIS and suitable closing elements have been applied. The SATIS prototype has been investigated both experimentally and numerically. It turned out that the contributions of conduction, radiation and convection to the effective thermal conductivity of SATIS, without the closing elements (49 mWmK), amount to 86.2%, 13.2% and 0.6%, respectively. The angle-dependent short-wave radiation exchange within the LCE has been investigated via ray tracing. At the incidence angle of 19% (design angle), 27% of the radiation within the LCE is absorbed by the absorber plate, resulting in measured and computed total solar energy transmittances of 11.2%/11.7%, respectively. For a typical summer irradiation angle of 60%, 98% of the incident radiation is absorbed by the surfaces at the entrance of the LCE. The corresponding total solar energy transmittance amounts to 2.9%. KW - angle-dependent total solar energy transmittance KW - effective thermal conductivity KW - experimental investigation KW - numerical simulation KW - ray tracing KW - solar active thermal insulation system (SATIS) Y1 - 2021 U6 - https://doi.org/10.3390/buildings11030123 N1 - Corresponding author: Belal Dawoud VL - 11 IS - 3 SP - 1 EP - 22 PB - MDPI ER -