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#BoilerManual #Ramping #Section8 #Page25

Answers for ramping

1. When load is at 10% and flashtank steam is 500 psi, the ramp is begun.

2. The 205 valve controls flow from the flashtank to the turbine.

3. False.
You must get 700 F and wait until the temperature has stabilized before proceeding with the ramp.

4. The operator sets the megawatt demand station for final load and load rate of change.

5. Early in the ramp, firing rate is based on gas temperature. After the thermoprobes retract, firing rate is based on main steam temperature.

6. The ramp begins at Point C.

7. The turbine is in automatic and megawatt demand is increased to 33% of full load flow.

8. The 202 and 207 valves close to maintain 33% boiler flow as the 201 opens to increase turbine flow. Closing of the the 202 and 207 valves reduce flow to the flashtank to compensate.

9. Since steam flow changes faster than firing rate, the firing must be kept above desired steam flow.

10. The steam temperature at the primary superheater and convection pass outlets are firing rate indicators.

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#BoilerManual #Ramping #Section8 #Page25

Answers for ramping

1. When load is at 10% and flashtank steam is 500 psi, the ramp is begun.

2. The 205 valve controls flow from the flashtank to the turbine.

3. False.
You must get 700 F and wait until the temperature has stabilized before proceeding with the ramp.

4. The operator sets the megawatt demand station for final load and load rate of change.

5. Early in the ramp, firing rate is based on gas temperature. After the thermoprobes retract, firing rate is based on main steam temperature.

6. The ramp begins at Point C.

7. The turbine is in automatic and megawatt demand is increased to 33% of full load flow.

8. The 202 and 207 valves close to maintain 33% boiler flow as the 201 opens to increase turbine flow. Closing of the the 202 and 207 valves reduce flow to the flashtank to compensate.

9. Since steam flow changes faster than firing rate, the firing must be kept above desired steam flow.

10. The steam temperature at the primary superheater and convection pass outlets are firing rate indicators.

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#BoilerManual #AirAndGasFlow #Section3 #Page25

Why Control is Necessary

To hold the optimum heat rate of a turbine designed to utilize full throttle pressure over a given load range, it is essential to regulate steam temperature over t his range by an effective means of control.

The time in which a turbine may be brought to full load is established by the turbine manufacturer in accordance with a safe steam temperature-time curve. Since the temperature of the steam is directly related to the degree of expansion of the turbine elements, and consequently the

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Alt = A graph labeled Fig. 19 "Typical" calibration curve. The x axis is labeled "Primary air flow (1000 lb/hr)" and increments from 0 to 100 every 10 units.The y axis is labeled Entrance cone air flow differential (inches of water), and increments sequentially from 0 to 10. Three curves are plotted from the 0 origin curving upward, all of them stopping at the 8 mark on the y axis but on slightly different points along the x axis, from slightly below the 90 mark to not quite the 100 mark; the rightmost is marked 500 F. ; the middle curve is marked 600 F; the rightmost curve is marked 500 F.

#BoilerManual #AirAndGasFlow #Section3 #Page25

Why Control is Necessary

To hold the optimum heat rate of a turbine designed to utilize full throttle pressure over a given load range, it is essential to regulate steam temperature over t his range by an effective means of control.

The time in which a turbine may be brought to full load is established by the turbine manufacturer in accordance with a safe steam temperature-time curve. Since the temperature of the steam is directly related to the degree of expansion of the turbine elements, and consequently the

------------------------------------------------- 25 ------------------------------------------------------
Alt = A graph labeled Fig. 19 "Typical" calibration curve. The x axis is labeled "Primary air flow (1000 lb/hr)" and increments from 0 to 100 every 10 units.The y axis is labeled Entrance cone air flow differential (inches of water), and increments sequentially from 0 to 10. Three curves are plotted from the 0 origin curving upward, all of them stopping at the 8 mark on the y axis but on slightly different points along the x axis, from slightly below the 90 mark to not quite the 100 mark; the rightmost is marked 500 F. ; the middle curve is marked 600 F; the rightmost curve is marked 500 F.

#BoilerManual #FluidCirculation #Section2 #Page25

FURNACE SIDE WALL TUBES

Now that we have covered the furnace front and rear walls, let's complete the furnace enclosure. Each of the furnace side walls are of similar construction (left/right). The side walls are divided into two sections, the first and second passes. The furnace side wall headers are supplied by the cyclone discharge mix bottle as are the front and rear walls. From the inlet headers, flow travels directly up the side walls to the first pass mix bottle. There is one bottle located on each side of the unit.

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Alt = Labeled Fig. 21 Fluid flow paths. Its a complex line drawing with circled numbers at various points along the lines superimposed on a line outline of a furnace, with a title in the lower right, ORDER OF FLOW 1 THRU 13. Circled 1 begins at what would be the barbed end of an inverted fish hook, the form that the complete furnace takes, with the firebox and cyclones located where the bottom of the shank would be, where the eye of the hook would be. At that end are numbers 3 and 4, but the illustration matches what is covered in the text body for details of how it goes.

#BoilerManual #FluidCirculation #Section2 #Page25

FURNACE SIDE WALL TUBES

Now that we have covered the furnace front and rear walls, let's complete the furnace enclosure. Each of the furnace side walls are of similar construction (left/right). The side walls are divided into two sections, the first and second passes. The furnace side wall headers are supplied by the cyclone discharge mix bottle as are the front and rear walls. From the inlet headers, flow travels directly up the side walls to the first pass mix bottle. There is one bottle located on each side of the unit.

------------------------------------------------- 25 ------------------------------------------------------
Alt = Labeled Fig. 21 Fluid flow paths. Its a complex line drawing with circled numbers at various points along the lines superimposed on a line outline of a furnace, with a title in the lower right, ORDER OF FLOW 1 THRU 13. Circled 1 begins at what would be the barbed end of an inverted fish hook, the form that the complete furnace takes, with the firebox and cyclones located where the bottom of the shank would be, where the eye of the hook would be. At that end are numbers 3 and 4, but the illustration matches what is covered in the text body for details of how it goes.