The image shows the CAD model of the annealing zone in a galvanization simulator. The zone is electrically heated with a AC current of 5597A at 2.09V. This whole zone is surrounded by insulating material. The power input is 11.7kW. Electrical energy is converted into heat energy. The sample rods are inserted into the heating pipe for annealing.
We calculated various heat losses/power losses in the system which are as follows:
- The heat loss into the sample rods, measured in the cooling water is 2 kW
- The heat loss into the top and the bottom flanges, measured in the cooling water is 3,4 kW
- The outside area of the Zone insulation is 78°C in average, the area has 0,65 m². Estimated heat loss should be about 0,7 kW (according to housing heating tables for 1-plate heaters)
- Heat losses in sum: 0,7 kW + 2 kW + 3,4 kW = 6,1 kW
The consumed electric power to heat the Zone is 11.7 kW
In principle, the input energy (electricity) should be equal to the out energy (heat).
I wanted to find other heat sinks or power losses (e.g. electric losses). What are the various heat losses in the system?
What am I missing here?