J. Karl

Conversion of Syngas From Biomass in Solid Oxide Fuel Cells

Conversion of biomass in syngas by means of indirect gasification offers the option to improve the economic situation of any fuel cell system due to lower costs for feedstock and higher power revenues in many European countries. The coupling of an indirect gasification of biomass and residues with highly efficient solid oxide fuel cell (SOFC) systems is therefore a promising technology for reaching economic feasibility of small decentralized combined heat and power production (CHP).The predicted efficiency of common high temperature fuel cell systems with integrated gasification of solid feedstock is usually significantly lower than the efficiency of fuel cells operated with hydrogen or methane. Additional system components like the gasifier as well as the gas cleaning reduce this efficiency. Hence common fuel cell systems with integrated gasification of biomass will hardly reach electrical efficiencies above 30

Experimental investigation of heat transfer phenomena during direct contact condensation in the presence of non condensable gas by means of the linear raman spectroscopy

Condensation in the presence of non condensable gases is one of the dominating processes which determine the thermohydraulic behaviour in the primary system of a pressurized water reactor during a postulated loss of coolant accident. On this account experiments have been performed at the LAOKOON test facility at the Technische Universitat Munchen to study the effect of non condensable gases on direct contact condensation at stratified steam/water flow. The paper presents the experimental setup and the measurement techniques for the heat transfer determination, especially the linear Raman spectroscopy. This laser measurement technique allows the simultaneous investigation of concentration profiles in the vapour phase and water temperatures in the liquid phase. Furthermore the fog density in the vapour phase can be estimated, if homogenous condensation occurs in the boundary layer. The results of experiments with different system parameters are presented and the possibilities and difficulties of the linear Raman spectroscopy will both be discussed.

Measuring Water Temperatures by Means of Linear Raman Spectroscopy

In many cases it is necessary to measure local water temperatures with high local resolution. The usage of common thermocouples limits the local resolution, affects the temperature field and may cause incorrect readings.

CO2-Neutral Generation of Heat and Power in Smart Homes by Organic Rankine Cycle Powered Combined Heat and Power Micro Plants

CO2 is the main determining factor for global climate change. For this reason, the emissions of this gas have to be reduced as much and as quickly as possible. This paper discusses the possibility to realize a CO2-neutral heat and power supply for single and multi-family homes. There have been a lot of studies in the past, as well as several unsuccessful-attempts to commercialize such a system. However, this paper presents a new and simple 1 kWel setup for a smart combined heat and power (CHP) plant offers solutions for the deficiencies of previously published and demonstrated systems. A commercial pellets firing system is linked with an organic Rankine cycle (ORC), which is built with mass-produced parts. In addition, inexpensive and proven-in-use hot-water storage tanks are used as an energy buffer and for storage, resulting in reduced investment costs. Furthermore, we demonstrate that it is necessary to embed such a system into a smart home environment in order to achieve an efficient and profitable setup.