(EECR-11)Realized measures for energy-efficient process gas use in metallurgical plants

摘要

During the production of high-quality steel products combustible process gases accrue as a by-product inmetallurgical plants. The calorific value of these process gases varies between 3 and 20 MJ/m3STP. The energycontent of process gases can be used profitably, e.g. for partial substitution of natural gas in firing plants like powerplant, cowper, coke oven or hot rolling mill. Thus the company’s energy costs are reduced and the environmentpollution is decreased, since the process gases are not flared unused. Besides these advantages the use of theprocess gases is also connected with challenges. Amount and composition of the process gases are dependent onproduction and process conditions. Thus adjustments at the firing plants are necessary. Adaptation of productionprocesses as well as connecting or switching off firing plants changes the volume flow of the process gases. Thiscauses pressure fluctuations in the gas network. Additionally, changes in the process gas composition lead tofluctuations in the calorific value. As the firing plants are connected through a large gas network, pressurefluctuations or changes in the gas composition usually have negative effects on the combustion process within theattached plants. Thus the use of process gases is considerably sophisticated. AMB, AMEH and BFI havedeveloped measures for the energy-efficient use of process gases. The measures have been realised at theparticipating metallurgical plants. E. g. the pressure and gas flow distribution in process gas networks have beenimproved and a gas management system with process gas production, consumption and prognosis functions hasbeen developed. The obtained results and operational experiences of the control of pressure fluctuations in gasnetworks and of the energetically useful utilization of process gases in metallurgical plants are presented.