Feasible Operating Parameters Of HRSG In Recovering Sinter Waste Heat By Vertical Tank

The new technology of Recovering Sinter Waste Heat by Vertical Tank is a system,which mainly composed by vertical tank,HRSG(heat recovery steam generator)and steam turbine generator.The HRSG between the vertical tank and the turbine,the operating parameter of that affects waste heat recovery efficiency and economy of the whole system.However,the temperature of the heat carrier entering the HRSG in this system is 100?130? higher than that in the traditional mode,the flow rate of heat carrier is also different,therefore the structure and the operational parameters of HRSG need to adjust.According to these,on the basis of former research of our team,the thermal performance of different structural HREG was calculated and analyzed,then the feasible structure of HRSG was selected.According to the effect of various operating parameters on the amount of steam carrying exergy,and the relationship between various operating parameters total heat transfer area of HRSG,the thermal economics model is established,and the calculation program for solving the model was compiled.We analyzed the effect of the various parameters on the capacity of HRSG,produce steam carrying exergy,total heat transfer area of boiler.Then the appropriate value of the operation parameters was determined.Based on the above research,the following conclusions are obtained.(1)Dual pressure system of waste heat boiler for tank recovery system is the most appropriate structure.Along the heat carrier flowing direction,ordinal arranges high pressure super-heater,high pressure evaporator,low pressure super-heater,high pressure economizer,low pressure evaporator and low pressure economizer is more reasonable,which different from traditional arrangement.(2)The operating parameters of HRSG affect the exergy carried by steam from the boiler.The exergy grows exponentially with high pressure steam's pressure,high pressure steam's temperature and low pressure steam's temperature increasing;it reduces exponentially with low pressure steam's pressure increasing;and it declines linearly with HRSG's pinch point and approach temperature point increasing.(3)The operating parameters of HRSG affect the boiler's transfer area.The transfer area grows exponentially with high pressure steam's pressure,high pressure steam's temperature and low pressure steam's temperature increasing;it reduces exponentially with low pressure steam's pressure,HRSG's pinch point and approach temperature point increasing.(4)The heat carrier's temperature and flow rate entering the HRSG determines the optimal internal parameters of the boiler.The higher the temperature of heat carrier,the higher the optimal high pressure steam's temperature,but there is a little influence on other optimal operation parameters.The temperature of inlet heat carrier rise,the total exergy carried by steam and the heat exchange area of HRSG increasing.(5)For a domestic 360 m2 sintering machine,mode 1 is the most appropriate condition of heat carrier condition;The corresponding optimum high pressure steam's pressure is 6.0 MPa,high presser steam's temperature is 460?,low pressure steam's pressure is 0.5 MPa,low pressure steam's temperature is 246?,high pinch point is 22.5O?,high pressure approach temperature point is 22.5?,low presser pinch point is 25?,low pressure approach temperature point is 15 ?;At this point,the estimation generated power of system is 20.17 MW,The output of tons ore is about 32.8 kWh/t.