The need for snow-free surfaces at squares, bus stops, platforms, car parks and sports facilities increases and at the same time energy price rise and the environment is becoming a hotter issue. The construction of the ground heating systems often lack thermal insulation under the heating pipes, which means that the heat from the pipes not only warm up the soil surface but also heats the surrounding soil. The insulation also has more features, by insulating the risk of frost damage is minimized. The goal of this report is to demonstrate the large heat loss and energy costs in the absence of insulation under the heating system.
The report begins with a scientific way to study and treating the soil heating system uses, and the theory involved. Furthermore it also deals with different routing principles of heat pipes depending on the facility.
All calculations are made with so called finite element method (FEM), in COMSOL Multiphysics 3,5a, where models are created with different conditions. These models are then compared to the models but with insulation. The difference is noted and further analysis is done on the results.
The conditions, on which the calculations are based on, are 100mm insulation. The surface is estimated to be 8000 square meters which corresponds to the size of a football field and the time the heating systems is assumed to be started is 3240 and 1296 hours depending on the model calculated.-
The models are divided into a stationary model, a dry dynamic model, a partially dry dynamic model and then a wet dynamic model. The differences between these are partly the time they are running, but also the certain conditions and properties of the materials and how the control of heat flow in the pipes is made.
The findings in the report show that it is economically viable to isolate sports facilities based on today's energy prices, and the investment cost insulation entails. The results also show the relatively large differences in energy consumption in each case depending on whether the construction has or lacks insulation. Despite the large investment costs estimated payback period for the investment based on a 8000 m
2 surface with an operating time of 3240 and 1296 hours/year to be in 25 years, while the heat pipes is expected to last for about 50 years.
2013. , 71 p.