Elkraftseffektivisering av SSAB i Luleå

The aim of this master thesis was to help formulate an electrical consumption plan for SSAB in Luleå. The consumption plan is based on a number of efficiency measures which was investigated for various help systems. The help systems affected in this work are engine pre-heaters, lightning, ventilation, pumps, fans, transformers and to some extent electric motors. An important delimitation for this work has been to study units that can act as leading examples for future efficiency work. The project resulted in a number of appropriate efficiency measures with great savings potential and a short payback period. For some help systems a full study has been performed while it for others only has been possible to estimate the potential savings. Engine pre-heaters are always running when the temperature is below 10°C. In this study the possibility of introducing controlling have been examined. This would reduce the operating costs by about 80 percent with a payback period of just over two years. The total operating costs can be reduced by nearly 1 million SEK per year with the proposed action. The current choice of lightning and controlling differ greatly between locals and subareas. In office buildings with older lightning systems a change of light source demonstrated the largest effect. With this measure, the energy costs are reduced with 50 - 60 percent depending on the current situation and the choice of light source. The substations reached the largest energy savings through the introduction of presence control. This measure results in large savings with a very low investment cost. The saving potential is strongly dependent on current lightning control and use and can at best reduce the costs by 83 percent. Workshops use a large amount of mercury- and metal halogen lamps. These lamps have a high installed effect and a long ignition time which means that they are rarely switched off. Because of this both the use of more effective light sources and the introduction of presence control lead to large savings. Together, these measures reduce the energy costs by about 90 percent, which for a single workshop results in nearly 60 000 SEK per year. A lot of the ventilation systems uses time control of the fans to minimize the operating costs. This measure reduces a ventilation systems operating cost by about 60 percent. Other measures that can be taken are to decrease the supply air temperature or the supply air flow if either of these is too high. However, these measures do not demonstrate any particularly large saving potential and carelessness may have negative effects. Pumps and fans are, in terms of the investigated help systems, large electricity consumers which often are in operation all year round. At constant conditions an appropriate measure is to investigate if the machines are performing optimally of if the efficiency has deteriorated over time. An increase of the efficiency from the current state to its optimum results in an average saving of about 40 percent. Efficiency increases can occur with better maintenance, renovation of replacement of the machine. If there instead is large flow variations the most profitable measure is to introduce an effective regulation method. How large of a reduction that can be achieved depends greatly on the flow variation, the greater the variation the more profitable. A transformer is used to transform current from one voltage level to another. It is important that the transformer have low losses so as much as possible of the electrical energy input can be taken out. To continuously replace old and oversized transformers with new low loss transformers is therefore an important measure. A replacement reduces the operating costs by 40 percent and the investment has a payback period of less than two years. The total operating costs are reduced by nearly 150 000 SEK per year. This work has provided an overview of the potential of an active work with efficiency measures at SSAB in Luleå. Presented are also suggestions of future work in the various areas to further immerse in the efficiency work.Validerat; 20140813 (global_studentproject_submitter