Energy efficiency and ventilation in Swedish industries barriers, simulation and control strategy

University dissertation from Linköping : Linköping University Electronic Press

Abstract: The energy issue is presently in focus worldwide. This is not only due to increasing environmental concern regarding energy related emissions, but also due to the trend of increasing energy prices. Energy usage in the industrial sector in Sweden today represents about one third of the national energy use. A substantial part of that is related to support processes such as heating, ventilation and cooling systems. These systems are important as they are related both to energy cost and indoor climate management as well as to the health of the occupants.The purpose of this thesis is to reach a more comprehensive view on industrial energy efficiency and indoor environment issues related to industrial ventilation. This has been studied in three themes where the first part addresses barriers to energy efficiency in Swedish industries, the second theme discuss simulation as decision support, and the third studies the variable air volume system in industrial facilities.In the first theme three different studies were made: the first studies non-energy intensive companies in Oskarshamn in Sweden, the second studies the energy intensive foundry industry and the third study was part of an evaluation of a large energy efficiency program called Project Highland. These studies had several findings in common, such as the importance of a strategic view on the energy issue and the presence of a person with real ambition with power over investment decisions related to energy issues at the company. The studies also show that several information related barriers are important for decision makers at the studied companies. This shows that information related barriers are one reason in why energy efficient equipment is not implemented.In the second theme the use of simulation in the form of Computational Fluid Dynamics (CFD) and Building Energy Simulation (BES) are used as decision support for industrial ventilation related studies at two different industries, one foundry is investigated and one dairy. BES has mainly been used to simulate energy and power related parameters while CFD was used to give a detailed description of the indoor and product environment. Together these methods can be used to better evaluate the energy, indoor and product environment and thus enable the implementation of more efficient heating, ventilation and air-conditioning systems.In the third theme the use of Variable Air Volume (VAV) systems was evaluated, and was found to be an efficient way to reduce energy use at the studied sites. At the studied foundry the VAV system is predicted to reduce space heating and electricity use by fans by about 30%, and in the dairy case by about 60% for space heating and 20% for electricity.