Continuous Steam Blowpipe

Steam blows are used prior to initial turbine powering for steam power plants to clear debris and surface scale that could potentially damage turbine blades during plant operation. Normally, stable pressure method is applied for super critical units and common header units. The method can maintain boiler running stable, but has some deficiency, such as short duration, 12 hours cooling intervals, large steam consumption and simple clean force ratio calculation method. The paper discusses how to lengthen the steam blowing duration, namely continuous steam blowing as far as this pipeline blowing is completed, simultaneously enhances the blowing effect.During the steam blow, the nature of the flow is adiabatic, compressible with friction and choked. The paper provides the model of design calculation and field calculation. Steam analysis is the use of steam table, computer programs are used to determine the most efficient conditions for cleaning steam system piping. Typically, the boiler pressures during steam blow provide a dynamic pressure throughout the piping, which is at least 20% higher than would be experienced for all plant operating conditions (CFR=1.2). By using of actual steam flow and volume, the calculation method of clean force ratio is more precise.The method has some improvements than present stable pressure method. The low-pressure continuous steam blowing method does not use any type of blowing or throttling valve to control the flow of steam. Steam flow for each cleaning circuit will be controlled by strategically placed orifice plates. Effectiveness and duration of blowing processes depends upon the ability to "thermal cycle" the system piping from maximum...