Compounding: It is the method of absorbing the jet velocity in stages when the steam flows over moving blades. Degree of reaction: It is defined as the ratio of isentropic heat drop in th e moving blade to isentrpic heat drop in the entire stages of the reaction turbine.ġ6. then the ratio is called critica l pressure ratio.ġ5. Critical pressure ratio: There is only one value of ratio (P2/P1) which produces maximum discharge fro m the nozzle. Coefficient of nozzle: It is the ratio of actual enthalpy drop to isentropic enthalpy drop.ġ4. Nozzle:It is a duct of varying cross sectional area in which the velocity increases with the corresponding drop in pressure.ġ3. Degree of super heat: The difference between the temperature of saturated steam and saturated temperature is c alled degree of superheat.ġ2. The steam has obtained is called super heated stea m.ġ1. Super heated steam: When the dry steam is further heated at consta nt pressure, the temperature increases the above saturation temperature. Dry steam / dry saturated steam: When whole mass of steam is converted into steam then it is called as dry steam.ġ0.
Wet steam: The steam w hich contains some water particles in superposition.ĩ. extraction turbine - ste am is withdrawn from one or more stages, at one or more pressures, for heating, pl ant process, or feedwater heater needs.Ĩ.
Steam download dropping to 0 generator#
steam rate - The steam rate is the pounds of steam that must be supplied per kilowatt-hour of generator output at the steam turbine inlet.ħ. balance piston - Instead of piston, seal strips are also used to duplicate a piston's counter force.Ħ. Axial clearance - the fore -and-aft clearance, at the sides of the rotor and t he casing.ĥ. Radial clearance - cleara nce at the tips of the rotor and casing.Ĥ. Radial - flow turbine - st eam flows outward from the shaft to the casing.ģ. Initiall pressure (P 1) = 7bar = 7× 10 5N/m 2įrom st eam table for P1 = 7bar and T1 = 200 oC V 1 =ġ.Diaphragm - Partitions b etween pressure stages in a turbine's casing.Ģ. when the flow is in equilibrium through all and super saturated with PV 1.3=C. Velocity of s team by considering the nozzle efficiency,ģ.A convergent divergent nozzle receives steam at 7bar and 200 oc and it expands isentropically into a space of 3bar neglecting the inlet velocity calculat e the exit area required for a mass flow of 0.1Kg/sec. Find th e % reduction in the final velocity.įrom steam table for initial pressure P1 = 6.5bar, take values h 1 = De termine the final velocity of steam from th e nozzle if 13% heat is loss in friction. Dry saturated steam at 6.5 bar with negligible velocity expands isentropically in a convergent divergent nozzle to 1.4 bar and dryness fraction 0.956. find the discharge velocity.įrom steam table, For 10 bar, 250°c, h 1=2943 KJ/kg s 1=6.926 KJ/kgk
A convergent divergent adiabatic steam nozzle is supplied with steam at 10 bar and 250°c.the discharge pressure is 1.2 bar.assuming that the nozzle efficiency is 100% and initial velocity of steam is 50 m/s.
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