The computer simulation program BOILER was developed by a graduate student at the faculty of Educational Science and Technology at the University of Twente. During the development there was cooperation with staff members of the Stichting voor de Leerplanontwikkeling (Foundation for the development of curriculums) Enschede of the project Alternatieve Energie (alternative energy) in elementary vocational education. The computer program is available for Apple Macintosh and MS.DOS computers.

Educational aim

The computer simulation program BOILER enables students to become familiar with the characteristics of a solar boiler and to gain insight into the influences of different interventions in the model around the installation. The model simulates the working of a solar boiler installation consisting of a collector, a storage vessel, a heat exchanger with a pump which runs through the collector and storage vessel and a possibility for tapping. Intervention is possible in the model. For example, students can change the intensity of the sun-rays or the heat capacity of the collector. The students has two screen pages at their disposal. One page with a visualized representation of the underlying mathematical model of the solar boiler installation and a page graphically representing the temperature of the heated water.


The user has to imagine that he or she is in a marketplace in the middle of Africa. The intensity of the sun (Fz) which is normally 1 (standard value) is in this case equal to 3.6. The outside temperature (T0) is in this case 350C. The intention of this case is that the student imagines himself in a situation in which (much) more energy of the sun is available but now it has to be considered how this energy can be used optimally. The second case works with a collector with a very high heat capacity (Ccol = 3.5; the default value was 1) and a very low reflection (Fv = 0.1; the default value was 1). This means that the collector converts solar heat into the heat of the water very effectively. The point in these cases is that the student learns to work with the differences which can appear in the quality of the collectors. The third case deals with the situation in which the drain leaks (fs = 0.05 m3/hour). It is also very cold in this case (the outside temperature T0 = 1 0C). The repair of the drain is impossible in this case so the student has to manage somehow to heat the water in the boiler.