| A vertical dual-pressure waste heat power generation system of ferroalloy submerged arc furnace is studied. Firstly, the waste heat resource assessment and exergy of 4×25500kVA Ferroalloy submerged arc furnace are analysised , and the residual heat value of flue gas is 65528.MJ/h. Secondly, taking the temperature difference at warm end of the superheater as 40℃, the pinch point temperature of the evaporator is 30℃，the approach point temperature difference of the economizer as 5℃, the steam generated is 1.55 MPa, 360.0℃, 40.2 t/h; 0.3MPa, 180℃, 7.5t/h of vertical dual-pressure system，and the steam generated is 1.15MPa, 360℃, 42.1t/h of single pressure system. The dual-pressure system has a lower exhaust gas temperature of 21.5℃, a higher vapor Consumption Rate of 0.16 (kW·h/kg), a higher generator output power of 774.1 KW, and a high overall system efficiency of 1.6% than the single pressure system. According to the actual operation experience of the project,, the heat transfer characteristics, the steam-water, cycle mode, air-leakage rate, system resistance,cleaning efficiency,occupied area of the dual-pressure vertical boiler is better than the single pressure horizontal boiler. According to the operation performance of the 4×25500kVA ferroalloy furnace, the economic benefit analysis of the dual pressure system is carried out, and the annual average after-tax profit is 11.42 million yuan. The internal rate of return of the whole investment is 20.8%, and the total investment payback period is 3.7 years. In the end, the final prospect is based on the annual output of iron alloys of about 13 million tons, and the annual heat generation capacity of waste heat power generation is 10 billion KWh, so this technology has wide application prospects. |
