Potentialen för nyttiggörandet av spillvärme hos två metallindustrier utvärderas. Det ena företaget härdar stål med vatten och det andra gjuter aluminiumtackor i vattenbad och sprayar även vatten som bildar fuktig luft. Vattnet, ej det sprayade, kyls sedan i kyltorn för att kunna återanvändas i processerna. Sankey-diagram för båda företagen presenteras för att tydligt presentera energiflödena i processerna. Värmeåtervinningsförslag presenteras med gasolkostnadsbesparings exempel. Investeringskostnader och återbetalningstider har ej utvärderats. Teoridelen och metoden är användbar för den som vill utvärdera potentialen för värmeåtervinning hos industrier som använder vatten i olika typer av kylprocesser. I teorin presenteras elproduktions metoder för låga temperaturer, dock ansågs inget av företagen vara lämpliga för elproduktion. Värmeåtervinningsförslagen som presenteras innefattar golvvärme, luftvärmare, fjärrvärmeintegrering och värmelager.

<p>The report comprises two separate parts:</p><ul><li>part 1:  Temperature needs for district heating in the paint shop for axles in building 210</li><li>part 2:  Energy and low temperature waste heat solutions in heating and cooling systems for   building 64 with surroundings</li></ul><p>The paint shop for axles in part 1 has air quality requirements in places for coating of axles. Toachieve desired air properties there are different process ventilation systems, which consist ofventilation coils for heating and cooling, plus air humidifier. The ventilations coils for heating usedistrict heating. Today the ventilation coils use water of 100°C to achieve necessary air demands inthe coating boxes. This part of the report investigates whether the existing system would achievethe air requirements with a water temperature of 75°C instead of 100°C in the ventilation coilsduring the coldest parts of the year. The conclusion is that it is not possible; the existing system isadjusted for a water temperature of 100°C to achieve the air requirements. To use a watertemperature of 75°C, more or major ventilation coils are needed.</p><p>The focus of the report is at part 2. In this part, possibilities for low temperature waste heatsolutions are investigated. Those partly aim at specific local solutions for building 64 withsurroundings and on the other part of general waste heat solutions for new buildings andreconstructions in the future. To make these parts possible, the systems for heating and cooling inbuilding 64 have been identified. During this identification, potential savings that are not of wasteheat character have also been observed.</p><p>The most profitable saving concerns the control of temperature for the inner hardening vat. It isthe hardening vat for gas carburizing oven SV16838 that has been studied in this report. Today thetemperature of the hardening vat is controlled very ineffective. The conclusion is that a betteradjustment of the controller would save 180 000 SEK/year with a pay off time around two months.Worth mentioning (SV16838 included), is that there are at least five similar gas carburizing ovens atthe Scania area in Södertälje.</p><p>A pinch analysis has also been done for building 64, with it’s primarily conclusion that the groundheating is violating the pinch rules during long periods of the year. To remedy the ground heatingwill only need a different control and will lead to a saving between 20 000 – 75 000 SEK/year. Tomore accurate determine the saving, an investigation of the ground heating during winter time isneeded. Another conclusion concerning the pinch analysis is that the method for a real scenariorather shows the potential of the system than gives you an optimal solution possible to implement.More actions are to use the exhaustions of the endo gas generators and that the washing andrinsing systems if possible not should be heated with electricity. The exhaustions from the endo gasgenerators have a very high temperature, more then 300°C. If these, instead of hot water boilers,could warm the closely located water for the LPG (liquefied petroleum gas) evaporation, 125 000SEK/year can be saved. Today the hot water boilers are heated with electricity. If the washing andrinsing systems existing electricity heating instead can be heated with secondary heat (˜ districtheating), a save of 500 000 SEK/year is possible.</p><p>For waste heat solutions there are a few different approaches. Close to building 64, the largestpotential to use waste heat is in building 62 and 75, where air heaters are assessed with the largestpotential. In difference to other investigated buildings, building 210 has the possibility to use wasteheat even during the summer. This building is located 1 km from building 64. To use waste water inbuilding 210, a complex net of waste heating will be required where several buildings with asurplus of waste heat can be connected. A net like this has calculated pipe costs of 5, 2 million SEK.The saving for the use of waste heat only in building 210 will be around 1,4 million SEK/year. Thissave corresponds to the air handling systems that occur in part 1.</p>

This master thesis has been conducted at Forsmark nuclear power plant. In nuclear power plants, safety is one of the most important tasks. After the Fukushima-accident, Forsmarks Kraftgrupp AB investigated the possibility to have additional emergency cooling systems. This thesis aims to investigate the use of cooling towers as mobile emergency cooling system for decay heat removal for the nuclear reactors at Forsmark NPP. The advantages and disadvantages of different cooling tower types were looked at. To achieve mobility, some restraints were considered such as dimensions and weight. In the design of cooling towers, experimental values are used. As these crucial data are missing, a backfitting from actual designs was done to derivate the missing data. The results of this thesis show that wet cooling towers are in this case more effective than dry cooling towers. The wet cooling towers cover in the best scenario up to 38MW which is 10 times higher than what can be achieved with the dry cooling tower. That covers the maximal decay heat released in the reactor F3 12 hours after a shutdown.

The report comprises two separate parts: part 1:  Temperature needs for district heating in the paint shop for axles in building 210 part 2:  Energy and low temperature waste heat solutions in heating and cooling systems for   building 64 with surroundings The paint shop for axles in part 1 has air quality requirements in places for coating of axles. Toachieve desired air properties there are different process ventilation systems, which consist ofventilation coils for heating and cooling, plus air humidifier. The ventilations coils for heating usedistrict heating. Today the ventilation coils use water of 100°C to achieve necessary air demands inthe coating boxes. This part of the report investigates whether the existing system would achievethe air requirements with a water temperature of 75°C instead of 100°C in the ventilation coilsduring the coldest parts of the year. The conclusion is that it is not possible; the existing system isadjusted for a water temperature of 100°C to achieve the air requirements. To use a watertemperature of 75°C, more or major ventilation coils are needed. The focus of the report is at part 2. In this part, possibilities for low temperature waste heatsolutions are investigated. Those partly aim at specific local solutions for building 64 withsurroundings and on the other part of general waste heat solutions for new buildings andreconstructions in the future. To make these parts possible, the systems for heating and cooling inbuilding 64 have been identified. During this identification, potential savings that are not of wasteheat character have also been observed. The most profitable saving concerns the control of temperature for the inner hardening vat. It isthe hardening vat for gas carburizing oven SV16838 that has been studied in this report. Today thetemperature of the hardening vat is controlled very ineffective. The conclusion is that a betteradjustment of the controller would save 180 000 SEK/year with a pay off time around two months.Worth mentioning (SV16838 included), is that there are at least five similar gas carburizing ovens atthe Scania area in Södertälje. A pinch analysis has also been done for building 64, with it’s primarily conclusion that the groundheating is violating the pinch rules during long periods of the year. To remedy the ground heatingwill only need a different control and will lead to a saving between 20 000 – 75 000 SEK/year. Tomore accurate determine the saving, an investigation of the ground heating during winter time isneeded. Another conclusion concerning the pinch analysis is that the method for a real scenariorather shows the potential of the system than gives you an optimal solution possible to implement.More actions are to use the exhaustions of the endo gas generators and that the washing andrinsing systems if possible not should be heated with electricity. The exhaustions from the endo gasgenerators have a very high temperature, more then 300°C. If these, instead of hot water boilers,could warm the closely located water for the LPG (liquefied petroleum gas) evaporation, 125 000SEK/year can be saved. Today the hot water boilers are heated with electricity. If the washing andrinsing systems existing electricity heating instead can be heated with secondary heat (˜ districtheating), a save of 500 000 SEK/year is possible. For waste heat solutions there are a few different approaches. Close to building 64, the largestpotential to use waste heat is in building 62 and 75, where air heaters are assessed with the largestpotential. In difference to other investigated buildings, building 210 has the possibility to use wasteheat even during the summer. This building is located 1 km from building 64. To use waste water inbuilding 210, a complex net of waste heating will be required where several buildings with asurplus of waste heat can be connected. A net like this has calculated pipe costs of 5, 2 million SEK.The saving for the use of waste heat only in building 210 will be around 1,4 million SEK/year. Thissave corresponds to the air handling systems that occur in part 1.