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#BoilerManual #OptimizingCombustion #Section9 #Page16

COMBUSTION GUIDES

It is necessary to provide the operating personnel with a device to allow manual or automatic proportioning of the amount of air to the amount of fuel.

The level of excess air is one index that is commonly used to determine the performance of the unit and to guide its everyday operation. Excess air is the amount of air supplied over and above that required for theoretically perfect combustion. It is always necessary to supply some excess air to assure complete combustion of the fuel. Any excess air not actually required constitutes a substantial loss in the form of decreased boiler efficiency and thus, a higher fuel bill. On the other hand, operating boiler efficiency and thus, a higher fuel bull. On the other hand, operating with a deficiency of air flow for the fuel being burned can also result in

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Alt = Labeled Fig. 5 Effect of sintering time. The graph is laid out exactly like Fig. 4 except for how the y axis is incremented (0 to 50, in 10s), and has 3 curves like Fig. 4 but the coal type labels aren't here--each curve is marked in respective order: 168 hours, 15 hours, and 4 hours, and the curves all have steeper curves upward, and are marked with small circles at the points where they cross vertical lines from the x axis. The 168 hours curve terminates slightly beyond where the 1500 F and the 40 mark of psi intersect; the 15 hours curve terminates exactly at the intersection of 1600 F and the 50 mark of psi; the 4 hour curve originates just to the left side of the 1500 F mark just above 0 mark of psi, and terminates just beyond where 1700 F intersects with the 30 mark of psi.

#BoilerManual #OptimizingCombustion #Section9 #Page16

COMBUSTION GUIDES

It is necessary to provide the operating personnel with a device to allow manual or automatic proportioning of the amount of air to the amount of fuel.

The level of excess air is one index that is commonly used to determine the performance of the unit and to guide its everyday operation. Excess air is the amount of air supplied over and above that required for theoretically perfect combustion. It is always necessary to supply some excess air to assure complete combustion of the fuel. Any excess air not actually required constitutes a substantial loss in the form of decreased boiler efficiency and thus, a higher fuel bill. On the other hand, operating boiler efficiency and thus, a higher fuel bull. On the other hand, operating with a deficiency of air flow for the fuel being burned can also result in

------------------------------------------------- 16 ------------------------------------------------------
Alt = Labeled Fig. 5 Effect of sintering time. The graph is laid out exactly like Fig. 4 except for how the y axis is incremented (0 to 50, in 10s), and has 3 curves like Fig. 4 but the coal type labels aren't here--each curve is marked in respective order: 168 hours, 15 hours, and 4 hours, and the curves all have steeper curves upward, and are marked with small circles at the points where they cross vertical lines from the x axis. The 168 hours curve terminates slightly beyond where the 1500 F and the 40 mark of psi intersect; the 15 hours curve terminates exactly at the intersection of 1600 F and the 50 mark of psi; the 4 hour curve originates just to the left side of the 1500 F mark just above 0 mark of psi, and terminates just beyond where 1700 F intersects with the 30 mark of psi.

#BoilerManual #Ramping #Section8 #Page16

based on flue gas temperature during most of the ramp, then on actual main steam temperature after the gas temperature probes retract.

A typical plot of firing rte is shown in Figure 7. The system is allowed to stabilize from points A to B. At point B, after steady state conditions are reached, the turbine load is manually increased causing thte 201 valve to begin opening. At point C, the turbine is automated and the MW demand station increased, initiating the ramp.

Notice that from point C to the end of the ramp at point E, there are three curves for firing rate.

During a continuous ramp, the system never reaches steady state. This means there is a continuous demand for steam flow and firing rate is being increased at this time. Because the steam flow changes faster than firing rate can change, a drop would develop in steam temperature if corrective measures were not taken. To account for this drop, the firing rate for a continuous ramp must be increased above that required to sustain a steady state condition, as shown by the actual firing rate curve.

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Alt = Labeled Fig.7 Firing rate during ramp. Similar to the previous charts with the same lines for valves 201 and 200 marked. Above those lines is a line similar to the 6A and 6B in Fig. 6, marked Boiler master and Megawatts respectively, at the far left of the chart, but at point C of the x axis, the line diverges into 3 branches, converging again at point E. The top one is a solid line with an arrow pointing rightward, marked Actual firing rate. The middle line is made of short dashes, with an arrow pointing rightward, marked Interrupted ramp. The bottom line is made of long dashes with an arrow pointing leftward, marked Deramp, and it has a vertical dashed line dropping down from its middle to the x axis at a point preceding point D, marked X.

#BoilerManual #Ramping #Section8 #Page16

based on flue gas temperature during most of the ramp, then on actual main steam temperature after the gas temperature probes retract.

A typical plot of firing rte is shown in Figure 7. The system is allowed to stabilize from points A to B. At point B, after steady state conditions are reached, the turbine load is manually increased causing thte 201 valve to begin opening. At point C, the turbine is automated and the MW demand station increased, initiating the ramp.

Notice that from point C to the end of the ramp at point E, there are three curves for firing rate.

During a continuous ramp, the system never reaches steady state. This means there is a continuous demand for steam flow and firing rate is being increased at this time. Because the steam flow changes faster than firing rate can change, a drop would develop in steam temperature if corrective measures were not taken. To account for this drop, the firing rate for a continuous ramp must be increased above that required to sustain a steady state condition, as shown by the actual firing rate curve.

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Alt = Labeled Fig.7 Firing rate during ramp. Similar to the previous charts with the same lines for valves 201 and 200 marked. Above those lines is a line similar to the 6A and 6B in Fig. 6, marked Boiler master and Megawatts respectively, at the far left of the chart, but at point C of the x axis, the line diverges into 3 branches, converging again at point E. The top one is a solid line with an arrow pointing rightward, marked Actual firing rate. The middle line is made of short dashes, with an arrow pointing rightward, marked Interrupted ramp. The bottom line is made of long dashes with an arrow pointing leftward, marked Deramp, and it has a vertical dashed line dropping down from its middle to the x axis at a point preceding point D, marked X.

#BoilerManual #BypassSystem #Section7 #Page16

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Alt = Labeled Fig. 4E Startup -- Turbine rolling. As before, this image is sideways with the bottom long the right edge and the top along the left edge and resembles the others in this series with the difference being that valve status has changed, focus is on the turbine, best described in the main text.

#BoilerManual #BypassSystem #Section7 #Page16

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Alt = Labeled Fig. 4E Startup -- Turbine rolling. As before, this image is sideways with the bottom long the right edge and the top along the left edge and resembles the others in this series with the difference being that valve status has changed, focus is on the turbine, best described in the main text.

#BoilerManual #CycloneOperation #Section6 #Page16

CYCLONE FIRING PERMISSIVES

The common firing permissives as well as the individual cyclone firing permissives must be satisfied in order to start a cyclone. The common firing permissives are the same as the boiler firing permissives. The individual cyclone firing permissives are as follows:

* Lighter and cyclone trips reset.
* Cyclone enabled.
* Feeder speed and velocity control damper set to light off.
* Feeder switch in remote.
* Feeder outlet valve closed.
* Feeder inlet valve open.
* Coal detected at feeder inlet (secoal).
* Feeder off.
* Feeder temperature normal.
* Feeder pressurized.
* Cyclone jacket cooling water on.
* Lighter successfully lit.

If all these permissives are satisfied, the red Cyclone Ready indicating light on the cyclone control panel will be lit.

LIGHTER

The lighter permissives again integrate the common (boiler firing) as well as the individual lighter permissives. The individual lighter permissives include:

* Lighter oil valve closed.
* Lighter retracted.
* Cyclone successfully lit or shutdown.

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#BoilerManual #CycloneOperation #Section6 #Page16

CYCLONE FIRING PERMISSIVES

The common firing permissives as well as the individual cyclone firing permissives must be satisfied in order to start a cyclone. The common firing permissives are the same as the boiler firing permissives. The individual cyclone firing permissives are as follows:

* Lighter and cyclone trips reset.
* Cyclone enabled.
* Feeder speed and velocity control damper set to light off.
* Feeder switch in remote.
* Feeder outlet valve closed.
* Feeder inlet valve open.
* Coal detected at feeder inlet (secoal).
* Feeder off.
* Feeder temperature normal.
* Feeder pressurized.
* Cyclone jacket cooling water on.
* Lighter successfully lit.

If all these permissives are satisfied, the red Cyclone Ready indicating light on the cyclone control panel will be lit.

LIGHTER

The lighter permissives again integrate the common (boiler firing) as well as the individual lighter permissives. The individual lighter permissives include:

* Lighter oil valve closed.
* Lighter retracted.
* Cyclone successfully lit or shutdown.

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#BoilerManual #CycloneDescription #Section5 #Page16

.....* Incorrect fuel/air ratio - flue gas analyses are used to determine the correct ratio.

.....* Coal size too large - adjusting or rebuilding the coal conditions will improve coal sizing.

.....* Unbalanced firing - coal feeders must be maintained in a condition that will result in equal coal flow to each cyclone.

FIRING LIMITATIONS

Unbalanced firing limitations are in effect at loads of 33% or below. Cyclone water flow is split into 2 paths - A and B. The designation A and B should not be confused with the cyclone numbering system at your plant, there is no relationship.

Each flow path supplies seven cyclones; 4 lower cyclones on one wall interconnect with the 3 upper cyclones of the opposite wall, refer to Figure 8.

------------------------------------------------------------------------------------

.................................Path A cyclones

.................... Lower Front Wall ..........-.......... A1, A3, A5, A7
.................... Upper Rear Wall ..........-.......... B2, B4, B6

.................................Path B cyclones

.................... Lower Rear Wall ..........-.......... B1, B3, B5, B7
.................... Upper Front Wall ..........-.......... A2, A4, A6

------------------------------------------------------------------------------------

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#BoilerManual #CycloneDescription #Section5 #Page16

.....* Incorrect fuel/air ratio - flue gas analyses are used to determine the correct ratio.

.....* Coal size too large - adjusting or rebuilding the coal conditions will improve coal sizing.

.....* Unbalanced firing - coal feeders must be maintained in a condition that will result in equal coal flow to each cyclone.

FIRING LIMITATIONS

Unbalanced firing limitations are in effect at loads of 33% or below. Cyclone water flow is split into 2 paths - A and B. The designation A and B should not be confused with the cyclone numbering system at your plant, there is no relationship.

Each flow path supplies seven cyclones; 4 lower cyclones on one wall interconnect with the 3 upper cyclones of the opposite wall, refer to Figure 8.

------------------------------------------------------------------------------------

.................................Path A cyclones

.................... Lower Front Wall ..........-.......... A1, A3, A5, A7
.................... Upper Rear Wall ..........-.......... B2, B4, B6

.................................Path B cyclones

.................... Lower Rear Wall ..........-.......... B1, B3, B5, B7
.................... Upper Front Wall ..........-.......... A2, A4, A6

------------------------------------------------------------------------------------

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#BoilerManual #Lighters #Section4 #Page16

EMERGENCY STOP

If the lighters do not light within the normal 10 to 20 seconds after they are turned on, the oil and ignition transformers must be turned off and the lighters retracted without purging the oil lines and lighters. Operation of the various valves and switches is similar to the lighter retract sequence.

The ignition transformers and solenoid valves 8A, 8B, 8C and 8D are de-energized. Control air to valves 7A, 7B and 7C is vented, causing them to shift to their closed positions.

Pressure switch 9A and 9D open to indicate no oil pressure to the lighters and no purge air pressure.

Solenoid valve 8A is de-energized and shifts valve 41 (air cylinder control valve) to the retracted position. Air from valve 41 retracts the lighters. Pressure switch 9C opens when the lighters reach their retracted position and mechanical stops on the lighters open the retracted interlock valve. Air from the interlock valves close pressure switch 9B to indicate that the lighters are retracted.

ADJUSTMENTS

For proper operation of the lighters, the following checks and adjustments must be made:

1. Remove and clean electrode.

2. Set electrode spark gap at 1/8th inch.

3. Remove and clean atomizer cap and spray plate (clean with solvent,

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#BoilerManual #Lighters #Section4 #Page16

EMERGENCY STOP

If the lighters do not light within the normal 10 to 20 seconds after they are turned on, the oil and ignition transformers must be turned off and the lighters retracted without purging the oil lines and lighters. Operation of the various valves and switches is similar to the lighter retract sequence.

The ignition transformers and solenoid valves 8A, 8B, 8C and 8D are de-energized. Control air to valves 7A, 7B and 7C is vented, causing them to shift to their closed positions.

Pressure switch 9A and 9D open to indicate no oil pressure to the lighters and no purge air pressure.

Solenoid valve 8A is de-energized and shifts valve 41 (air cylinder control valve) to the retracted position. Air from valve 41 retracts the lighters. Pressure switch 9C opens when the lighters reach their retracted position and mechanical stops on the lighters open the retracted interlock valve. Air from the interlock valves close pressure switch 9B to indicate that the lighters are retracted.

ADJUSTMENTS

For proper operation of the lighters, the following checks and adjustments must be made:

1. Remove and clean electrode.

2. Set electrode spark gap at 1/8th inch.

3. Remove and clean atomizer cap and spray plate (clean with solvent,

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#BoilerManual #AirAndGasFlow #Section3 #Page16

A second factor which affects air flow is density. Density is measured as a unit of mass within a given volume (lb/cubic foot). A given mass (lb) of air will occupy a certain volume (cubic foot) {Now is a good time to review Boyle's Laws} at a particular static pressure and temperature. Assuming the mass and the static pressure do not change as the air is heated, its volume will expand. It will become less dense as illustrated in Table 2.

Applying this relationship to air flow, it is found that as air is heated and density decreases, there will be a corresponding drop in air flow. Again, assuming no change in pressure.

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Alt = Labeled Fig. 12 Rated steam flow (percent) and is almost but not quite identical to Fig. 10. The x axis is identically labeled in terms of precentage increments but is marked Rated flow (percent); the y axis is labeled Differential pressure (inches of water) but is incremented from 0 to 2.0. The curve is nearly identical.

#BoilerManual #AirAndGasFlow #Section3 #Page16

A second factor which affects air flow is density. Density is measured as a unit of mass within a given volume (lb/cubic foot). A given mass (lb) of air will occupy a certain volume (cubic foot) {Now is a good time to review Boyle's Laws} at a particular static pressure and temperature. Assuming the mass and the static pressure do not change as the air is heated, its volume will expand. It will become less dense as illustrated in Table 2.

Applying this relationship to air flow, it is found that as air is heated and density decreases, there will be a corresponding drop in air flow. Again, assuming no change in pressure.

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Alt = Labeled Fig. 12 Rated steam flow (percent) and is almost but not quite identical to Fig. 10. The x axis is identically labeled in terms of precentage increments but is marked Rated flow (percent); the y axis is labeled Differential pressure (inches of water) but is incremented from 0 to 2.0. The curve is nearly identical.

#BoilerManual #FluidCirculation #Section2 #Page16

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Alt = Labeled "Figure 14A Cyclone circuits". Two side view mechanical drawings of a cyclone are depicted on the left side of the image in top down order, with the Neck part facing right. A third drawing of a cyclone is a cross section view, on the right side of the image. The top left cyclone drawing points out Re-entrant throat inlet/outlet headers at the upper left; Neck outlet header at the upper right of the cyclone; in top down order below the Neck outlet header are indicated the Barrel outlet header, the Secondary air inlet, and Intermediate header. On the bottom left of the cyclone is the indication of the other Re-entrant throat inlet/outlet headers.

#BoilerManual #FluidCirculation #Section2 #Page16

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Alt = Labeled "Figure 14A Cyclone circuits". Two side view mechanical drawings of a cyclone are depicted on the left side of the image in top down order, with the Neck part facing right. A third drawing of a cyclone is a cross section view, on the right side of the image. The top left cyclone drawing points out Re-entrant throat inlet/outlet headers at the upper left; Neck outlet header at the upper right of the cyclone; in top down order below the Neck outlet header are indicated the Barrel outlet header, the Secondary air inlet, and Intermediate header. On the bottom left of the cyclone is the indication of the other Re-entrant throat inlet/outlet headers.

@Su_G #BoilerManual #UnitDescription #Section1 #Page16

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Alt = Figure 7 Studded tube construction shows a cross section of 3 tubes whose sides are separated by flat metal and then showing 3 radial studs each that then are coated by refractory (that's a term you might as well use the word "insulation" instead, although they're similar but not alike).
Figure 8 Ribbed tube construction shows a length of tube cut lengthwise to show inner ribs protruding from the inner walls in helical pattern.

@Su_G #BoilerManual #UnitDescription #Section1 #Page16

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Alt = Figure 7 Studded tube construction shows a cross section of 3 tubes whose sides are separated by flat metal and then showing 3 radial studs each that then are coated by refractory (that's a term you might as well use the word "insulation" instead, although they're similar but not alike).
Figure 8 Ribbed tube construction shows a length of tube cut lengthwise to show inner ribs protruding from the inner walls in helical pattern.

@philipdutre ik ben dit beginnen lezen https://www.pisa.ugent.be/uploads/files/Vlaams-Rapport_PISA2022.pdf#page16