FORM 2
THE PATENT ACT  1970
(39 OF 1970)
AND
THE PATENTS RULES  2003

COMPLETE SPECIFICATION
(See Section 10; rule 13)

Low Pressure Module and Diffuser for efficient use in Air cooled
condenser applications

TRIVENI TURBINE LTD
an indian company 
of 12A  Peenya Industrial Area 
Banglore-560058.

The following specification particularly describes the present invention and the manner in which it is to be performed.
Note: This Patent application is modification of an invention described or disclosed in the complete specification 1410/CHE/2010 filed there for.

FIELD OF THE INVENTION:
The present invention relates to the field of low pressure module and diffuser. Particularly  the present invention relates to adaptation of low pressure module and diffuser being used along with water cooled condenser to be used in Air cooled condenser applications.

BACKGROUND OF THE INVENTION:
The primary reason for power plants to shift from usage of water cooled condenser to air cooled condenser is scarcity of water. Moreover  Government is giving subsidy to power plants which uses air cooled condensers to promote the usage of air cooled condenser and thereby conserve water.

Figure 1 illustrates a meridional view of low pressure module and diffuser used in association with water cooled condenser.

Referring to Fig. 1  there is provided a low pressure module along with diffuser comprising a rotor 210  a plurality of first stage twisted and tapered moving blades 220  a plurality of second stage twisted and tapered moving blades 230  a plurality of third stage twisted and tapered moving blades 240  a plurality of first stage nozzles 250  a plurality of second stage nozzles 260  a plurality of third stage nozzles 270 and a diffuser 280. The exit annulus area of low pressure module is 2.0 m2 and the exit annulus area of the diffuser is 3.15 m2.

Table 1 illustrates geometry defining parameters of first stage twisted and tapered moving blades 220.
Table 1
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 79.48 mm 81.21 mm 85.51 mm
Inlet Angle 51.95 deg 47.71 deg 43.97 deg
Exit Angle -68.47 deg -69.03 deg -69.38 deg
Leading edge radius 2.49 mm 2.39 mm 2.29 mm
Stagger Angle -12 deg -29.47 deg -43.12 deg
Trailing edge radius 0.99 mm 0.72 mm 0.5 mm
Unguided turning 12.46 deg 11.84 deg 10.92 deg
Angle of Attack -12 deg -29.47 deg -43.12 deg
Area 0.0015909 m2 0.00104976 m2 0.000671587 m2
Axial chord(width) 77.75 mm 70.70 mm 62.41 mm
Camber 120.43 deg 116.74 deg 113.36 deg
Maximum Thickness 19.99 mm 17.88 mm 11.31 mm
Pitch/Chord 0.609 0.70 0.75
Radius at CG 470 mm 545.85 mm 611.95 mm
Solidity 1.64 1.43 1.34
Throat/Pitch 0.368 0.369 0.365
Tmax/Chord 0.251 0.22 0.132

Table 2 illustrates geometry defining parameters of second stage twisted and tapered moving blades 230.
Table 2
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 103.86 mm 103.95 mm 109.54 mm
Inlet Angle 38.69 deg 16.29 deg -18 deg
Exit Angle -65.02 deg -65.56 deg -67.67 deg
Leading edge radius 4 mm 3.74 mm 3.5 mm
Stagger Angle -15 deg -42.03 deg -53.51 deg
Trailing edge radius 1.59 mm 1.31 mm 1.08 mm
Unguided turning 13.63 deg 12.99 deg 9.98 deg
Angle of Attack -15 deg -42.03 deg -53.51 deg
Area 0.00206122 m2 0.000949095 m2 0.000909225 m2
Axial chord(width) 100.327 mm 77.21 mm 65.12 mm
Camber 103.719 deg 81.85 deg 49.66 deg
Maximum Thickness 26.99 mm 13.16 mm 12.66 mm
Pitch/Chord 0.51 0.66 0.75
Radius at CG 470 mm 602.142 mm 709.167 mm
Solidity 1.93 1.51 1.35
Throat/Pitch 0.414 0.421 0.374
Tmax/Chord 0.259 0.126 0.115

Table 3 illustrates geometry defining parameters of third stage twisted and tapered moving blades 240.
Table 3
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 147.67 mm 111.33 mm 114.87 mm
Inlet Angle 37.59 deg -3.83 deg -66.03 deg
Exit Angle -53.68 deg -59.99 deg -71.79 deg
Leading edge radius 4.99 mm 4.20 mm 3 mm
Stagger Angle -10 deg -47.48 deg -68.65 deg
Trailing edge radius 2.0 mm 1.72 mm 1.3 mm
Unguided turning 8.96 deg 3.83 deg 0.433 deg
Angle of Attack -10 deg -47.48 deg -68.65 deg
Area 0.00296334 m2 0.000832312 m2 0.000471757 m2
Axial chord(width) 145.428 mm 75.23 mm 41.80 mm
Camber 91.28 deg 56.15 deg 5.75 deg
Maximum Thickness 26.15 mm 10.31 mm 6.09 mm
Pitch/Chord 0.37 0.78 0.95
Radius at CG 470 mm 731.46 mm 921.38 mm
Solidity 2.65 1.3 1.069
Throat/Pitch 0.52 0.45 0.28
Tmax/Chord 0.177 0.092 0.0530
Table 4 illustrates geometry defining parameters of first stage nozzles 250.
Table 4
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 84.59 mm 99.40 mm 112.55 mm
Inlet Angle 0 deg 0 deg 0 deg
Exit Angle 75.8471 deg 74.212 deg 72.8757 deg
Leading edge radius 5.5 mm 5.5 mm 5.5 mm
Stagger Angle 56 deg 55.0173 deg 54.1438 deg
Trailing edge radius 0.5 mm 0.5 mm 0.5 mm
Unguided turning 7.4 deg 7.4 deg 7.4 deg
Angle of Attack 56 deg 55.0173 deg 54.1438 deg
Area 0.000735219 m2 0.00093005 m2 0.00111991 m2
Axial chord(width) 47.3036 mm 56.9893 mm 65.926 mm
Camber 75.8471 deg 74.212 deg 72.8757 deg
Maximum Thickness 14.5009 mm 15.546 mm 16.4955 mm
Pitch/Chord 0.712421 0.700063 0.691776
Radius at CG 470 mm 541.201 mm 604.366 mm
Solidity 1.44 1.465 1.477
Throat/Pitch 0.22 0.25 0.28
Tmax/Chord 0.171 0.156 0.146

Table 5 illustrates geometry defining parameters of second stage nozzles 260.
Table 5
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 93.55 mm 111.309 mm 126.374 mm
Inlet Angle -23.1662 deg -9.209 deg 1.301 deg
Exit Angle 68.31 deg 69.43 deg 70.44 deg
Leading edge radius 4.5 mm 4.5 mm 4.5 mm
Stagger Angle 42.57 deg 47.09 deg 50.97 deg
Trailing edge radius 0.6 mm 0.6 mm 0.6 mm
Unguided turning 11.95 deg 12.60 deg 14.01 deg
Angle of Attack 42.57 deg 47.09 deg 50.97 deg
Area 0.000852316 m2 0.00104695 m2 0.00113846 m2
Axial chord(width) 68.89 mm 75.77 mm 79.56 mm
Camber -91.47 deg -78.64 deg -69.14 deg
Maximum Thickness 14.15 mm 15.12 mm 15.02 mm
Pitch/Chord 0.6861 0.7161 0.7336
Radius at CG 470 mm 561.646 mm 639.293 mm
Solidity 1.478 1.417 1.383
Throat/Pitch 0.38 0.37 0.37
Tmax/Chord 0.151 0.135 0.118

Table 6 illustrates geometry defining parameters of third stage nozzles 270.
Table 6
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 99.33 mm 121.116mm 138.567 mm
Inlet Angle 22.18 deg 7.90 deg 3.35 deg
Exit Angle 62.56 deg 67.15 deg 70.92 deg
Leading edge radius 4 mm 4 mm 4 mm
Stagger Angle 39.94 deg 48.07 deg 50.87 deg
Trailing edge radius 0.7 mm 0.7 mm 0.7 mm
Unguided turning 8.34 deg 13.02deg 19 deg
Angle of Attack 39.94 deg 48.07 deg 50.87 deg
Area 0.000909982 m2 0.00104043 m2 0.00137742 m2
Axial chord(width) 76.16 mm 80.92 mm 87.43 mm
Camber - 84.74 deg -75.06 deg - 67.56 deg
Maximum Thickness 14 mm 14.17 mm 16.46 mm
Pitch/Chord 0.646 0.759 0.816
Radius at CG 470 mm 642.41 mm 827 mm
Solidity 1.564 1.334 1.240
Throat/Pitch 0.44 0.41 0.41
Tmax/Chord 0.141 0.117 0.118

The diffuser 280 resembles a hollow trumpet shape. The distance of outer edge of the inlet of the diffuser from rotor axis is 926.43 mm and is generally indicated with a reference numeral Y1. The distance of inner edge of the inlet of the diffuser from rotor axis is 470 mm and is generally indicated with a reference numeral Y2. The distance outer edge and inner edge of the exhaust of the diffuser from rotor axis is 1200 mm and is generally indicated with a reference numeral Y3. The exhaust passage width of the diffuser is 420.53 mm and is generally indicated with a reference numeral X1. The thickness of the diffuser is of 11.72 mm and is indicated by a reference numeral X2. The axial length of the diffuser is 660 mm and is indicated by reference numeral X3.

Figure 2(a) illustrates a stream line flow path in low pressure module and diffuser at design point when used in association with water cooled condenser.

The design point of low pressure module in case of water cooled condenser applications is as follows:
Speed (N) in RPM 5000
Inlet Pressure (Pin) in KPa 173
Enthalpy at Inlet (hin) in J/Kg 2661500
Dryness fraction 0.98
Mass flow at Inlet (min) in Kg/Sec 31.60
Outlet Pressure (Pout) in KPa 9.82

It is evident from the figure 2(a) that the flow follows a smooth stream line flow path in low pressure module and diffuser.

Figure 2(b) illustrates a stream line flow path in low pressure module and diffuser at maximum flow point when used in association with Air cooled condenser.

Figure 2(c) illustrates a stream line flow path in low pressure module and diffuser at minimum flow point when used in association with Air cooled condenser.

In case of Air cooled condenser applications  low pressure module operates at extreme ends of the design mass flow. Two operating points: 1) At 180% of the design mass flow and 2) At 28% of the design flow are considered and simulations are run.

At Maximum Flow (i.e.  180% of design mass flow)  the operating parameters are as follows:
Speed (N) in RPM 5000
Inlet Pressure (Pin) in KPa 311.40
Enthalpy at Inlet (hin) in J/Kg 2661500
Dryness fraction 0.97
Mass flow at Inlet (min) in Kg/Sec 56.27
Outlet Pressure (Pout) in KPa 18

It is evident from the figure 2(b) that the flow follows a smooth stream line flow path in low pressure module and diffuser.

At Minimum Flow (i.e.  28% of design mass flow)  the operating parameters are as follows:
Speed (N) in RPM 5000
Inlet Pressure (Pin) in KPa 47
Enthalpy at Inlet (hin) in J/Kg 2661500
Dryness fraction 0.97
Mass flow at Inlet (min) in Kg/Sec 8.80
Outlet Pressure (Pout) in KPa 25

It is evident from the figure 2(c) that the flow suffers recirculation in third stage of low pressure module and diffuser.

The results of the simulation run on low pressure module along with diffuser at operating parameters at design point  Maximum flow and Minimum flow is tabulated in Table 7.
Table 7
Mass flow Efficiency
(Total to Total) Efficiency
(Total to Static) Pressure Ratio
(Total to Total) Pressure Ratio
(Total to Static) Power

(KW)
Design Point 31.6 Kg/sec 0.9219 0.8987 15.75 17.11 11092.4

Max Flow 56.27 Kg/sec 0.9279 0.9028 15.52 16.83 20136.2

Min Flow 8.80 Kg/sec 0.0744 0.0734 2.32 2.34 81.3

It is evident from Table 7 that the efficiency of the low pressure module along with diffuser is very less at Minimum flow point.

Therefore  there is a felt need for development of a low pressure module and diffuser to suit the requirements of Air cooled condenser.

OBJECTS OF THE INVENTION:
An object of the present invention is to provide an efficient low pressure module and diffuser suitable to be used in Air cooled condenser applications.

Another object of the present invention is to achieve structurally rigid and more reliable low pressure module blades for Air cooled condenser applications.

One more object of the present invention is to provide a low pressure module and diffuser which ensures in smooth streamline flow path and prevents recirculation.

Still another object of the present invention is to provide a diffuser with maximum pressure recovery.

BRIEF DESCRIPTION OF THE DRAWINGS:
The invention will now be described with reference to the accompanying drawings in which:

Figure 1 illustrates a meridional view of low pressure module and diffuser used in association with water cooled condenser;

Figure 2(a) illustrates a stream line flow path in low pressure module and diffuser at design point when used in association with water cooled condenser;

Figure 2(b) illustrates a stream line flow path in low pressure module and diffuser at maximum flow point when used in association with Air cooled condenser;

Figure 2(c) illustrates a stream line flow path in low pressure module and diffuser at minimum flow point when used in association with Air cooled condenser;

Figure 3 illustrates a pictorial view of low pressure module and diffuser before and after flow trim operation;

Figure 4(a) illustrates a stream line flow path in low pressure module and diffuser at design point when used in association with Air cooled condenser;

Figure 4(b) illustrates a stream line flow path in low pressure module and diffuser at maximum flow point when used in association with Air cooled condenser;

Figure 4(c) illustrates a stream line flow path in low pressure module and diffuser at minimum flow point when used in association with Air cooled condenser;

Figure 5 illustrates profile differences between diffusers before and after the flow trim operation; and

Figure 6 illustrates a meridional view of low pressure module along with diffuser after flow trim operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
Figure 3 illustrates a pictorial view of low pressure module and diffuser before and after flow trim operation.

Referring to Fig. 3  there is provided a low pressure module along with diffuser comprising a plurality of first stage twisted and tapered moving blades 320  a plurality of second stage twisted and tapered moving blades 330  a plurality of third stage twisted and tapered moving blades 340  a plurality of first stage nozzles 350  a plurality of second stage nozzles 360  a plurality of third stage nozzles 370 and a diffuser 380.

In accordance with the present invention  flow trim operation is performed on the low pressure module such that the exit area of 2.0 m2 is reduced to 1.6 m2. The black line represents 2.0 m2 flow path and is indicated by a reference numeral I. The blue line represents 1.6 m2 flow path and is indicated by a reference numeral II. The last stage moving blade height is reduced by keeping the exit area to 1.6 m2 and by maintaining a flare of 15 degrees. The flow trim operation on the preceding moving blades and nozzles is performed by following a stream line flow path as shown in figure 3. It is evident from the figure 3 that the flow trim operation resulted in the reduction of height of the plurality of third stage twisted and tapered moving blades 340  plurality of third stage nozzles 370 and plurality of second stage twisted and tapered moving blades 330.

All the geometry defining features of plurality of second nozzles 360  plurality of first stage twisted and tapered moving blades 320 and plurality of first stage nozzles 350 remain same as disclosed in Table 5  Table 1 and Table 4 respectively. The geometry defining features of plurality of third stage twisted and tapered moving blades 340  plurality of third stage nozzles 370 and plurality of second stage twisted and tapered moving blades 330 also remain same as disclosed in Table 3  Table 6 and Table 2 except the parameter Radius at CG which defines the height of the blade (Radius at Tip-Radius at Hub).

Table 8 illustrates the geometry defining parameters of plurality of third stage twisted and tapered moving blades 340.
Table 8
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 147.67 mm 111.33 mm 114.87 mm
Inlet Angle 37.59 deg -3.83 deg -66.03 deg
Exit Angle -53.68 deg -59.99 deg -71.79 deg
Leading edge radius 4.99 mm 4.20 mm 3 mm
Stagger Angle -10 deg -47.48 deg -68.65 deg
Trailing edge radius 2.0 mm 1.72 mm 1.3 mm
Unguided turning 8.96 deg 3.83 deg 0.433 deg
Angle of Attack -10 deg -47.48 deg -68.65 deg
Area 0.00296334 m2 0.000832312 m2 0.000471757 m2
Axial chord(width) 145.428 mm 75.23 mm 41.80 mm
Camber 91.28 deg 56.15 deg 5.75 deg
Maximum Thickness 26.15 mm 10.31 mm 6.09 mm
Pitch/Chord 0.37 0.78 0.95
Radius at CG 470 mm 731.46 mm 855 mm
Solidity 2.65 1.3 1.069
Throat/Pitch 0.52 0.45 0.28
Tmax/Chord 0.177 0.092 0.0530

The height of the third stage twisted and tapered moving blades 340 is reduced from 451.38mm to 385mm.

Table 9 illustrates the geometry defining parameters of plurality of third stage nozzles 370.
Table 9
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 99.33 mm 121.116mm 138.567 mm
Inlet Angle 22.18 deg 7.90 deg 3.35 deg
Exit Angle 62.56 deg 67.15 deg 70.92 deg
Leading edge radius 4 mm 4 mm 4 mm
Stagger Angle 39.94 deg 48.07 deg 50.87 deg
Trailing edge radius 0.7 mm 0.7 mm 0.7 mm
Unguided turning 8.34 deg 13.02deg 19 deg
Angle of Attack 39.94 deg 48.07 deg 50.87 deg
Area 0.000909982 m2 0.00104043 m2 0.00137742 m2
Axial chord(width) 76.16 mm 80.92 mm 87.43 mm
Camber - 84.74 deg -75.06 deg - 67.56 deg
Maximum Thickness 14 mm 14.17 mm 16.46 mm
Pitch/Chord 0.646 0.759 0.816
Radius at CG 470 mm 642.41 mm 801.5 mm
Solidity 1.564 1.334 1.240
Throat/Pitch 0.44 0.41 0.41
Tmax/Chord 0.141 0.117 0.118

The height of the third stage nozzles 370 is reduced from 357 mm to 331.5 mm

Table 10 illustrates the geometry defining parameters of plurality of second stage twisted and tapered moving blades 330.
Table 10
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 103.86 mm 103.95 mm 109.54 mm
Inlet Angle 38.69 deg 16.29 deg -18 deg
Exit Angle -65.02 deg -65.56 deg -67.67 deg
Leading edge radius 4 mm 3.74 mm 3.5 mm
Stagger Angle -15 deg -42.03 deg -53.51 deg
Trailing edge radius 1.59 mm 1.31 mm 1.08 mm
Unguided turning 13.63 deg 12.99 deg 9.98 deg
Angle of Attack -15 deg -42.03 deg -53.51 deg
Area 0.00206122 m2 0.000949095 m2 0.000909225 m2
Axial chord(width) 100.327 mm 77.21 mm 65.12 mm
Camber 103.719 deg 81.85 deg 49.66 deg
Maximum Thickness 26.99 mm 13.16 mm 12.66 mm
Pitch/Chord 0.51 0.66 0.75
Radius at CG 470 mm 602.142 mm 699.2 mm
Solidity 1.93 1.51 1.35
Throat/Pitch 0.414 0.421 0.374
Tmax/Chord 0.259 0.126 0.115

The height of the second stage twisted and tapered moving blades 330 is reduced from 239.16mm to 229.2 mm.

Figure 4(a) illustrates a stream line flow path in low pressure module and diffuser at design point when used in association with Air cooled condenser.

The design point of low pressure module in case of Air cooled condenser applications is as follows:
Speed (N) in RPM 5000
Inlet Pressure (Pin) in KPa 275
Enthalpy at Inlet (hin) in J/Kg 2699
Dryness fraction 0.9902
Mass flow at Inlet (min) in Kg/Sec 50
Outlet Pressure (Pout) in KPa 18

It is evident from the figure 4(a) that the flow follows a smooth stream line flow path in low pressure module and diffuser.

Figure 4(b) illustrates a stream line flow path in low pressure module and diffuser at maximum flow point when used in association with Air cooled condenser.

Figure 4(c) illustrates a stream line flow path in low pressure module and diffuser at minimum flow point when used in association with Air cooled condenser.

In case of Air cooled condenser applications  low pressure module operates at extreme ends of the design mass flow. Two operating points: 1) At 130% of the design mass flow and 2) At 25% of the design flow are considered and simulations are run.

At Maximum Flow (i.e.  130% of design mass flow)  the operating parameters are as follows:
Speed (N) in RPM 5000
Inlet Pressure (Pin) in KPa 357.9
Enthalpy at Inlet (hin) in J/Kg 2746.68
Dryness fraction 1.0057
Mass flow at Inlet (min) in Kg/Sec 65
Outlet Pressure (Pout) in KPa 18

It is evident from the figure 4(b) that the flow follows a smooth stream line flow path in low pressure module and diffuser.

At Minimum Flow (i.e.  25% of design mass flow)  the operating parameters are as follows:
Speed (N) in RPM 5000
Inlet Pressure (Pin) in KPa 70.92
Enthalpy at Inlet (hin) in J/Kg 2487.02
Dryness fraction 0.9239
Mass flow at Inlet (min) in Kg/Sec 12.5
Outlet Pressure (Pout) in KPa 18

It is evident from the figure 4(c) that the recirculation is eliminated in third stage of low pressure module and the magnitude of recirculation is reduced when compared to recirculation in figure 2(c).

The results of the simulation run on low pressure module along with diffuser at operating parameters at design point  Maximum flow and Minimum flow after flow trim operation is tabulated in Table 11.
Table 11
Mass flow Efficiency
(Total to Total) Efficiency
(Total to Static) Pressure Ratio
(Total to Total) Pressure Ratio
(Total to Static) Power

(KW)
Design Point 48.11 Kg/sec 0.8885 0.8558 13.71 15.41 16587.9

Max Flow 61.5 Kg/sec 0.9146 0.8340 13.27 17.83 21065.6

Min Flow 13.4 Kg/sec 0.6455 0.6621 4.22 4.06 1806.5

It is evident from Table 11 that the efficiency of the low pressure module along with diffuser is comparatively very high when compared to efficiency in Table 7 at Minimum flow point.

Figure 5 illustrates profile differences between diffusers before and after the flow trim operation. The dashed line represents the diffuser of low pressure module having an exit area of 2.0 m2 before flow trim operation and is indicated by a reference numeral III. The solid line represents the diffuser of low pressure module having an exit area of 1.6 m2 after flow trim operation and is indicated by a reference numeral IV. The length and height of the diffuser is reduced to increase static pressure recovery in the diffuser.

Figure 6 illustrates a meridional view of low pressure module along with diffuser after flow trim operation.

The diffuser 380 resembles a hollow trumpet shape. The distance of outer edge of the inlet of the diffuser from rotor axis is 852.83 mm and is generally indicated with a reference numeral Y12. The distance of inner edge of the inlet of the diffuser from rotor axis is 470 mm and is generally indicated with a reference numeral Y22. The distance outer edge and inner edge of the exhaust of the diffuser from rotor axis is 1000 mm and is generally indicated with a reference numeral Y32. The exhaust passage width of the diffuser is 346.58 mm and is generally indicated with a reference numeral X12. The axial length of the diffuser is 475 mm and is indicated by reference numeral X32.

Although the invention has been described herein above with reference to the embodiments of the invention  the invention is not limited to the embodiments described herein above. It is to be understood that modifications and variations of the embodiments can be made without departing from the spirit and scope of the invention.

We claim:
1) Low pressure module and diffuser for efficient use in Air cooled condenser applications comprising:
a) a plurality of first stage  second stage and third stage moving blades and a plurality of first stage  second stage and third stage nozzles  wherein a flow trim operation is performed on the third stage moving blade of exit annulus area of 2.0 m2 by keeping the exit annulus area of 1.6 m2 and by following a stream line flow path such that the height of the third stage moving blade is reduced from 451.38 mm to 385mm  the height of the third stage nozzle is reduced from 357 mm to 331.5 mm and the height of the second stage moving blade is reduced from 239.16 mm to 229.2 mm; and
b) a diffuser placed adjacent to the third stage moving blades  wherein the height of the outer edge of said diffuser from rotor axis at the inlet is reduced from 926.43 mm to 852.53 mm maintaining the height of inner edge of said diffuser from rotor axis at the inlet at 470mm and achieving an inlet area of 1.6 m2 complementary to exit annulus area of said third stage moving blades  the height of the inner edge and outer edge of said diffuser at the exit is reduced from 1200 mm to 1000 mm and the axial length of said diffuser is reduced from 660 mm to 475 mm.

2) Low pressure module and diffuser for efficient use in Air cooled condenser applications as claimed in claim 1  wherein the geometry defining parameters of said third stage moving blades are according to the following table:
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 147.67 mm 111.33 mm 114.87 mm
Inlet Angle 37.59 deg -3.83 deg -66.03 deg
Exit Angle -53.68 deg -59.99 deg -71.79 deg
Leading edge radius 4.99 mm 4.20 mm 3 mm
Stagger Angle -10 deg -47.48 deg -68.65 deg
Trailing edge radius 2.0 mm 1.72 mm 1.3 mm
Unguided turning 8.96 deg 3.83 deg 0.433 deg
Angle of Attack -10 deg -47.48 deg -68.65 deg
Area 0.00296334 m2 0.000832312 m2 0.000471757 m2
Axial chord(width) 145.428 mm 75.23 mm 41.80 mm
Camber 91.28 deg 56.15 deg 5.75 deg
Maximum Thickness 26.15 mm 10.31 mm 6.09 mm
Pitch/Chord 0.37 0.78 0.95
Radius at CG 470 mm 731.46 mm 855 mm
Solidity 2.65 1.3 1.069
Throat/Pitch 0.52 0.45 0.28
Tmax/Chord 0.177 0.092 0.0530

3) Low pressure module and diffuser for efficient use in Air cooled condenser applications as claimed in claim 1  wherein the geometry defining parameters of said third stage nozzles are according to the following table:
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 99.33 mm 121.116mm 138.567 mm
Inlet Angle 22.18 deg 7.90 deg 3.35 deg
Exit Angle 62.56 deg 67.15 deg 70.92 deg
Leading edge radius 4 mm 4 mm 4 mm
Stagger Angle 39.94 deg 48.07 deg 50.87 deg
Trailing edge radius 0.7 mm 0.7 mm 0.7 mm
Unguided turning 8.34 deg 13.02deg 19 deg
Angle of Attack 39.94 deg 48.07 deg 50.87 deg
Area 0.000909982 m2 0.00104043 m2 0.00137742 m2
Axial chord(width) 76.16 mm 80.92 mm 87.43 mm
Camber - 84.74 deg -75.06 deg - 67.56 deg
Maximum Thickness 14 mm 14.17 mm 16.46 mm
Pitch/Chord 0.646 0.759 0.816
Radius at CG 470 mm 642.41 mm 801.5 mm
Solidity 1.564 1.334 1.240
Throat/Pitch 0.44 0.41 0.41
Tmax/Chord 0.141 0.117 0.118

4) Low pressure module and diffuser for efficient use in Air cooled condenser applications as claimed in claim 1  wherein the geometry defining parameters of said second stage moving blades are according to the following table:
Parameter Hub Section(H-H) Mean Section(M-M) Tip section(T-T)
Chord 103.86 mm 103.95 mm 109.54 mm
Inlet Angle 38.69 deg 16.29 deg -18 deg
Exit Angle -65.02 deg -65.56 deg -67.67 deg
Leading edge radius 4 mm 3.74 mm 3.5 mm
Stagger Angle -15 deg -42.03 deg -53.51 deg
Trailing edge radius 1.59 mm 1.31 mm 1.08 mm
Unguided turning 13.63 deg 12.99 deg 9.98 deg
Angle of Attack -15 deg -42.03 deg -53.51 deg
Area 0.00206122 m2 0.000949095 m2 0.000909225 m2
Axial chord(width) 100.327 mm 77.21 mm 65.12 mm
Camber 103.719 deg 81.85 deg 49.66 deg
Maximum Thickness 26.99 mm 13.16 mm 12.66 mm
Pitch/Chord 0.51 0.66 0.75
Radius at CG 470 mm 602.142 mm 699.2 mm
Solidity 1.93 1.51 1.35
Throat/Pitch 0.414 0.421 0.374
Tmax/Chord 0.259 0.126 0.115

5) Low pressure module and diffuser for efficient use in Air cooled condenser applications as described herein the description and accompanying drawings.

Dated this 22nd day of May  2012 (for Triveni Turbine Ltd)


Dr.Sunil Jajit
GM-IPR