English

It is demonstrated how Modelica™ is used in an application to develop models that are useful when solving real problems. Modelica is a new unified modeling language being developed in an international effort to promote object-oriented and non-causal modelling, and exchange of model libraries. The application is a heat exchanger where1 the media are liquids, typically water. This type of heat exchangers can be used for district heating of houses and for production of hot tap water. The model developed illustrates very nicely the power of Modelica.

Five hundred homes had been selected in Saint John, New Brunswick to evaluate the relationship between lead in blood and lead in drinking water. From this sample one hundred were selected to examine the additional contribution of lead from food, soil, dust, and paint to the blood lead levels of residents. Fifty homes were selected where residents were known to have raised blood lead levels, and 50 further homes were selected where residents were known to have low blood lead levels.

The paper deals with simulation of the heat exchanger and model evaluation. There are presented partial differential equations of heat exchanger model, which assume liquid mediums. Presented, in the paper, model is used as an approximation for three different type heat exchangers. The purpose of these investigations was to explain weather the same model could match well to different of shape and type exchangers by adjusting some model parameters. There is shown a method of determining model parameters. Results of simulation are compared with measured data.

By the EROS Project the potentials of a retrofitting process for a typical school building in West-Germany were to be demonstrated from an energetic point of view. Combining the renewal of the space heating system with the reconstruction of the building envelope yields synergetic effects. The project aims at minimizing the future energy consumption and optimizing the economy of the retrofitting at the same time. Thus, both operating costs and emissions are reduced.

Political and economical changes that have been started in Poland since 1989 strongly influenced the building construction market. New owners or managers of institutional buildings have begun the process of retrofitting, focusing on: