Waste heat recovery in industry and evaluation of savings: A case study of heat pipes technology

Poraba energije v industriji predstavlja velik delež celotne porabe energije v Evropski uniji, pri čemer večino energije porabijo energetsko intenzivne industrijske panoge. V zaključni nalogi smo se posvetili izrabi odvečne toplote v omenjenih panogah. Pregledali smo literaturo in opredelili procese, kjer je potencial za izkoriščanje odvečne toplote največji. Opisali smo obstoječe tehnologije izrabe odvečne toplote in predstavili inovativne prenosnike toplote na podlagi tehnologije toplotnih cevi (HPHE), ki so bili razviti v sklopu projekta ETEKINA. Poskusno sta bila dva HPHE postavljena v jeklarni SIJ Metal Ravne za izrabo odvečne toplote dimnih plinov Allino peči v namen predgrevanja zgorevalnega zraka in ogrevanja poslovnih prostorov. Izdelali smo preprosto orodje za izračun energijskih in stroškovnih prihrankov in ugotovili, da sistem obnovi 48,7 % odvečne toplote dimnih plinov, je učinkovit pri zmanjševanju emisij ter zmanjša stroške goriva, emisijskih kuponov in ogrevanja.Energy consumption in industry accounts for a large share of total energy consumption in the European Union, with the majority of energy consumed by energy-intensive industries. In the final thesis, we focused on the use of waste heat in these industries. We reviewed the literature and identified the processes where the potential for waste heat recovery is greatest. We described the existing technologies for the use of waste heat and presented innovative heat pipe heat exchangers (HPHE), which were developed as part of the ETEKINA project. Two HPHEs were experimentally installed in the SIJ Metal Ravne steel plant for the use of waste heat from the flue gases of the Allino furnace for the purpose of preheating the combustion air and heating the business premises. We developed a simple tool for calculating energy and cost savings and found that the system recovers 48.7 % of flue gas waste heat, is effective in reducing emissions and reduces the cost of fuel, EU Allowances and heating