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Showing posts with the label steam turbine

Chain conveyor troubleshoot guide

  Problem Identification & Corrective Action Sl No. Problem Potential Cause Solution 1 Chain rises off from sprocket 1.Excess chain slack. 2.Excess wear at the bases of sprocket teeth. 3.Excess chain extension. 4.Foreign material stuck to the bases of sprocket teeth. 5.Reverse rotation of conveyor 6.Uneven chain tightening of chain 1.Adjust the amount of slack equally at both sides. 2.Carryout hard facing of the sprockets 3.Replace the elongated chain parts. 4.Remove the foreign material from the bases of the teeth. 5.Avoid reverse rotation of the conveyor when chain tightened is uneven 2 Chain separates poorly from the sprocket. 1.Sprocket misalignment. 2.Excess chain slack. 3.Excess wear at the bases of sprocket teeth. 4.Uneven chain tightening of chain 1-Adjust alignment. 2-Adjust the amount of slack.

Why does vacuum in steam condenser reduce or drop??

  1-High exhaust temperature: Vacuum drops or maintains at lower side due to high exhaust steam temperature flow into steam condenser. This high exhaust temperature is mainly due to 1-Operation of Turbine at lower loads 2-More clearance in labyrinth seals 3-Not operating exhaust hood sprays 4-More load on condenser 5-Breaking of ejector U loop 2-Low circulating cooling water flow Vacuum in condenser reduces due to inadequate cooling water flow through steam condenser. This is mainly due to; 1-Problems associated with pumps 2-Air pockets in pipe line 3-Leakages in cooling water line 4-Stuck of discharge valve of pump 3-High cooling water temperature at condenser inlet Higher cooling water temperature at condenser inlet results into reduction of vacuum due to poor heat transfer from steam to water 4-Poor heat transfer in condenser Very less or poor heat transfer in steam condenser reduces vacuum to very low level resulting into high exhaust temperature &am

Why does load hunting occur in steam Turbines??

 If Turbine does not maintain the load as per set load, then this condition is called load hunting.Following are the some potential reasons for load hunting 1-Problems associated with actuators: These are related to leakages in actuators, piston stuck up, oil holes elongation etc. Because of these issues there will interruption or fluctuation of secondary oil flow through actuators, this creates the problems of actuator miss-operation & eventually load hunting. 2-Improper calibration of actuators: This results into mismatch of actuator opening & given set point or valve demand 3-Lower control oil pressure than required: Actuators are designed for specific pressure of control oil, if the control oil pressure at actuator inlet becomes less, then there will be more chances of mal function of actuator. 4-Fluctuation of control oil pressure/flow: Fluctuation of control oil pressure or flow due to malfunction of pump or line PRV may lead to actuator misoperation & h

Calculated reasons for increase in Turbine specific steam consumption

1. Lower vacuum Turbine consumes more steam, if vacuum in condenser is maintained on lower side. Example:   Consider a 20 MW Steam Turbine having Inlet steam parameters 65 kg/cm2 & 490 Deg C & Vacuum maintained in condenser is -0.9 kg/cm2. Calculate the steam consumption of turbine at vacuum -0.9 kg/cm2 & -0.85 kg/cm2 A-Steam consumption Q at -0.9 kg/cm2 to develop 20 MW power P =Steam flow X( Enthalpy of inlet steam-Enthalpy of exhaust steam)/ 860 Enthalpy of inlet steam at inlet steam parameters =810 kcal/kg Exhaust steam enthalpy at -0.9 kg/cm2 vacuum = 619 kcal/kg Then, 20 = Q X (810-619)/860 Q1 = 90 MT B- Steam consumption Q at -0.85 kg/cm2 to develop 20 MW power Exhaust steam enthalpy at -0.85 kg/cm2 vacuum= 623 kcal/kg Then, 20 = Q X (810-623)/860 Q 2= 90.9 MT It is clear that, Turbine operating at -0.9 kg/cm2 vacuum consumes lesser steam as compared to turbine operating at vacuum-0.85 kg/cm2 2. Lower inlet main stream pressure& temp

How do you calculate the Power generation in steam Turbines??

Power in the steam Turbines produces at every stage where the steam is taken out, whether it may be bleed, extraction or exhaust steam. As the steam out from the turbine increases the power developed on that particular stage will increase. Power generation phenomenon. Power generation in steam Turbines is calculated based on difference between the heat content of inlet steam & extracted steam. Factors affecting the power generation: Power generation at particular stage increases, when there is more steam flow &vice versa Power generation at particular stage increases when there is more difference between inlet & extraction steam & Vice versa Power develop at particular stage decreases if its extraction pressure increases & vice versa Power developed at particular stage decreases if its extraction temperature increases & vice versa Power developed in steam Turbine decreases if inlet live steam pressure & temperature decrease If steam v