K. Lubikowski

ENERGY SCAVENGING IN A VEHICLE'S EXHAUST SYSTEM

Present- day development of power transmission systems, especially the ones based on combustion engines, is trying to cope with the issue of improving the energy efficiency of energy processing systems. One of the directions is to use the techniques of thermal energy recovery from an engine’s exhaust system. Vast part of the energy produced while burning the air- fuel mixture is lost in the cooling and exhaust systems. Research in this area was conducted by numerous teams, both abroad and in Poland, while focusing on use of Peltirea cells. The results of their research demonstrated small efficiency of these cells. In this paper, the authors have focused on modifications of the exhaust system in order to improve heat exchange between the exhaust system’s elements and TEG. The research was conducted while using the ECOTEC 1.8 litre engine from Opel, the X18XE model. The engine was installed in a testbed, in the mechatronic lab at the Faculty of Automotive and Construction Machinery Engineering (SIMR) of Warsaw University of Technology. Spartan HE923 radiators were installed on the cold end of the module. The paper presents the results of the research related to interworking of TEG’s with the exhaust system’s heat-generating elements of various shapes. The paper reviews the energy efficiency of TEG depending on diverse parameters of gas flow. A parallel system has been assumed (controlled stream and pressure of the flowing exhaust gases without any interference as regards the speed of the of combustion engine). The factor-related experiment accounts for the influence that the pressure and temperature difference, depending on the volume and discharge of exhaust fumes, have on the efficiency of TEG for the same temperature. The results of the experiment are presented in the last section of the article.

Analysis of Possibility of Use Peltier Modules in Task of Energy Scavenging

Actually in motor industry, specialty in car market is tender to maximum utilization of energy included in fuel air mixture, which most of part of burning process is lost. In todays times Peltier module are generally available, which is mainly used in coolers for keeping of low temperature. They make use of Peltier phenomenon, relying on power module from electric net for manufactured low temperature on cold side that module. Module producers usually available voltages characteristics thats working modules.In realize research use that same modules but for recuperate electrical energy from temperature. Research target was in temperature equivalent on cold side and warm side check value of manufactured voltage from these modules. Utilized of Seebeck phenomenon depends on heat of warm side with simultaneously cool module cold side which manufacture electricity.In effect realize research findings series of results for which equivalent characteristics describing those module capacities. The first influence from realize research is fact that characteristics isnt identical with characteristics for that same modules manufactured low temperature.

Modelling of Thermoelectric Processes in FEM Environment Based on Experimental Studies

Finite Element Method (FEM) is an effective and productive tool which is able to deal with sophisticated engineering requirements and successfully calculates expected output values often based on advanced boundary conditions and solution settings. The paper refers to modelling of thermoelectric generators in FEM environment (ANSYS software) which are based on popular Peltier modules that are frequently used in energy cogeneration branch of industry. The modelling process consists of geometry design, sensitivity study which focus on solver settings, discretization level and their impact into results (optimization of solution process total time). Last step engages parameter of Seebeck coefficient. Its modification allows adjusting the FE analysis to experimental data. The verified thermoelectric module will be able to reflect real capabilities of the commercially available thermoelectric devices. The main purpose of the process development is creation of Peltier modules (accessible in industry) FE models database. The devices from the database could easily be used in sophisticated FE analysis which consists of various physics systems (coupled) where simplified approach or indirect method will be limited or impossible to use.