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Exhaust Temperature Stabilitation Systems for Turbocharged Engines
Böhm, Michael ; Charvát, Pavel (referee) ; Vondrák, Adam (referee) ; Štětina, Josef (advisor)
This paper describes the possibilities of reducing temperature pulsations in the exhaust manifold of an internal combustion engine. For this purpose, the concept of a heat reservoir with a phase change material that can store the heat generated in the exhaust manifold is chosen. At a temperature lower than the phase change temperature of this material, the heat storage is then able to transfer the heat back to the exhaust gas, thereby reducing the temperature pulsations. The actual design consists of an advanced heat storage design consisting of an assembly of smaller tubes that increase the heat output of the storage while causing minimal pressure drop in the exhaust manifold. This concept is validated and compared with a series engine without a stack through simulations in both 1D and 3D computing environments. The designed and constructed prototype stack is subjected to experimental testing to confirm its performance. The effects of the electrically assisted turbocharger on the exhaust gas temperature are also analyzed. Finally, all the results are summarized showing the overall potential of this system and a possible way forward in the development of these stacks with phase change materials is outlined.
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Optimization of turbocharger operation to reduce thermal instability in the exhaust
Kraicinger, Vít ; Ušiak, Michal (referee) ; Böhm, Michael (advisor)
This diploma thesis deals with the reduction of instability of exhaust gas temperatures with the help of optimized turbocharger operation, for the operation of the catalyst in the optimal temperature range. The introduction describes the individual effects on exhaust gas temperatures and the effect of this temperature on emissions. Furthermore, the work describes the turbocharger's function and individual parts, especially the types of regulations used. The 1.5 TSI EA211-EVO drive unit from Volkswagen is selected for the simulations and the optimization itself. Furthermore, the work contains the creation of two models with different turbocharger control (WG, VNT), and their subsequent optimization to approximate the real speed characteristics and adjustment for the possibility of simulations of transient phenomena. At the end of the work, the mentioned optimization of turbocharger operation on the emission WLTP cycle and the subsequent comparison of the reduction of exhaust temperature instability is performed.
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Optimization of turbocharger operation to reduce thermal instability in the exhaust
Kraicinger, Vít ; Ušiak, Michal (referee) ; Böhm, Michael (advisor)
This diploma thesis deals with the reduction of instability of exhaust gas temperatures with the help of optimized turbocharger operation, for the operation of the catalyst in the optimal temperature range. The introduction describes the individual effects on exhaust gas temperatures and the effect of this temperature on emissions. Furthermore, the work describes the turbocharger's function and individual parts, especially the types of regulations used. The 1.5 TSI EA211-EVO drive unit from Volkswagen is selected for the simulations and the optimization itself. Furthermore, the work contains the creation of two models with different turbocharger control (WG, VNT), and their subsequent optimization to approximate the real speed characteristics and adjustment for the possibility of simulations of transient phenomena. At the end of the work, the mentioned optimization of turbocharger operation on the emission WLTP cycle and the subsequent comparison of the reduction of exhaust temperature instability is performed.
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