Franz N. Fett

THEORETICAL AND EXPERIMENTAL INVESTIGATION OF HOAR-FROST GENERATION AND THAW OFF PROCESS ON A COMPACT ENERGY-ABSORBER

ABSTRACT A mathematical model is presented which describes the hoar-frost generation and the thaw off process on a compact energy-absorber. Simulation results which show the influence of a hoar-frost layer on the energy gain are discussed. The simulation results also show the dependence of the energy gain and the energy demand of the thaw off process under different operation and weather conditions. Finally suggestions are given for the optimum operation of an energy absorber.

THEORETICAL AND EXPERIMENTAL ANALYSIS OF DESIGN AND OPERATION OF MULTI-ENERGY SOURCE HEATING SYSTEMS

ABSTRACT Comparison of simulation results with experimental results for a multi-energy source heating system are presented. The heating system consists of a compact energy-absorber-heat pump system with an integrated cold water storage. A laboratory building acts as heat load. This first intermediate report shows that the simulation results agree well with experimental data. The aim of this project is to develop a mathematical model of a multienergy heating system in order to determine the optimum layout and operational mode.

MATHEMATICAL MODELING OF PERFORMANCE AND OPERATIONAL MODE OF ENERGY-ABSORBERS

ABSTRACT A mathematical model is presented which describes the operational mode and the performance characteristics of energy-absorbers. The simulation of different types of energy-absorbers shows the dependence of the daily and annual average value of specific energy gain and its composition due to different energy sources from the environment. Furthermore the annual average value of the specific energy gain as a function of the temperature difference between environmental and working fluid and as a function of the working fluid flow rate is shown for different types of energy-absorbers. The climatic input values for the calculation are generated by a weather model. Finally suggestions are given for the optimum operation of energy absorbers.