The translated title on the bachelor project is converting from high-pressure hot water to district heating. The project is the final assignment in the education as Bachelor of Management, Technology and Maritime Engineering at Aarhus School of Marine and Technical Engineering.
The project is concerning a future converting of the heat supply at Danfoss from high-pressure hot water to district heating.
It has been decided to establish a district heating transmission line between Sønderborg and Nordborg, so that Sønderborg Fjernvarme can supply a larger area of the island Als with district heating. One of the foundations for this transmission line is, that the company Danfoss, which is placed in the northern part of Als, is connected to this transmission line, so that Danfoss in the future will be supplied with district heating, and uses this as heating supply.
The district heating transmission line will, according the project layout, have supply-pipe temperature on 80 °C.
Danfoss is at the moment self-sufficient with heating from the internal boiler house, where there is gas boilers and a gas engine driven combined heat and power station. The boilers and the combined heat and power station are set for a supply-pipe temperature at 150 °C. Because of this supply-pipe temperature, most of the ventilation systems, and the production machinery, which uses heat in the process, are constructed to use high-pressure hot water.
With the converting to district heating, the supply-pipe temperature will be lowered to the temperature, which the district heating transmission line is delivering.
The reduction of temperature will cause some problems, because the systems cannot deliver the desired output, with the lower inlet temperature.
This will require a large rebuilding of all affected ventilation systems at the factory, together with a search for possibilities and alternative suggestions, so the affected production processes can continue to operate.
In this project the oil evaporator is used as point of reference, which is used to remove water from the used oil emulsion that is used by production machinery and machining centers, to minimize the amount of used oil, that need to be disposed of at Kommune Kemi.
The oil evaporator are using high-pressure hot water to the evaporating process, and to find a solution to be able to continue the operation, is the heat requirement analyzed to be able to set the demands to a new heat supply. In the analysis it is concluded, that the continuous heat requirement is approximately 880 kW, with peak values at 1.500 kW.
As suggested solution a hot oil boiler is used, which can fulfill the required demands to a heat supply. The hot oil boiler can supply the oil evaporator with the effects that is required according to the process.
The hot oil boiler has an effect output on 2.000 kW, and uses hot oil as heat distribution remedy. The boiler is using a gas burner to heat the oil.
It is also examined what to expenses there will be to purchasing of the hot oil boiler, and what the gas expenses will be to operate it.
At the moment the oil evaporator is using the central heating system to condense the water steam, and the effect which is transferred to the central heating system is used for heating purposes. It is also examined what the economic consequences of the use of the condensing effects are.