Author Contributions
Conceptualization, G.M. and R.C.; methodology, G.M.; software, B.F.V.-P., G.M.; validation, G.M., R.C., and C.M.M.; formal analysis, G.M.; investigation, G.M.; resources, G.M.; data curation, G.M., B.F.V.-P. and C.M.M.; writing—original draft preparation, G.M.; writing—review and editing, G.M. and R.C.; visualization, G.M. and C.M.M.; supervision, G.M., R.C.; project administration, R.C., G.M.; funding acquisition, C.M.M., G.M, R.C. All authors have read and agreed to the published version of the manuscript.
Figure 1.
(
a) Location of the combined cycle power plant [
65]. (
b) Biomass energy potential in India (in MWe) [
66].
Figure 1.
(
a) Location of the combined cycle power plant [
65]. (
b) Biomass energy potential in India (in MWe) [
66].
Figure 2.
Demand curve of the steam consumer company.
Figure 2.
Demand curve of the steam consumer company.
Figure 3.
The main flowsheet of the model for the CCPP plant.
Figure 3.
The main flowsheet of the model for the CCPP plant.
Figure 4.
The flowsheet of steam turbine model.
Figure 4.
The flowsheet of steam turbine model.
Figure 5.
Input data: efficiency curve of the generator (a); Output data: efficiency curve of the high body in function of the volumetric flow (b).
Figure 5.
Input data: efficiency curve of the generator (a); Output data: efficiency curve of the high body in function of the volumetric flow (b).
Figure 6.
TQ diagram of the boiler.
Figure 6.
TQ diagram of the boiler.
Figure 7.
Analysis of the effect of gas turbine selection in Combined Cycle (a) Net power; (b) Cycle efficiency; (c) Heat rate. GE 7FA.05 (TG1), Siemens SGT6-8000H (TG2), GE7FA.04 (TG3), GEM9001E (TG4).
Figure 7.
Analysis of the effect of gas turbine selection in Combined Cycle (a) Net power; (b) Cycle efficiency; (c) Heat rate. GE 7FA.05 (TG1), Siemens SGT6-8000H (TG2), GE7FA.04 (TG3), GEM9001E (TG4).
Figure 8.
Turbine gas degradation curve.
Figure 8.
Turbine gas degradation curve.
Figure 9.
Analysis of fuel in CCPP performance: (a) Net Power; (b) Cycle efficiency; (c) Heat rate.
Figure 9.
Analysis of fuel in CCPP performance: (a) Net Power; (b) Cycle efficiency; (c) Heat rate.
Figure 10.
Exhaust CO2 percentage for the different fuels considered.
Figure 10.
Exhaust CO2 percentage for the different fuels considered.
Figure 11.
Effect of ambient temperature on combined cycle performance. Correction factors as function of ambient temperature for (a) power and (b) heat rate, with (red line) and without (black line) steam export.
Figure 11.
Effect of ambient temperature on combined cycle performance. Correction factors as function of ambient temperature for (a) power and (b) heat rate, with (red line) and without (black line) steam export.
Figure 12.
Effect of relative humidity on combined cycle performance at different ambient temperatures. Power and Heat Rate correction factors without steam export (a,b); and with steam export (c,d).
Figure 12.
Effect of relative humidity on combined cycle performance at different ambient temperatures. Power and Heat Rate correction factors without steam export (a,b); and with steam export (c,d).
Figure 13.
Effect of ambient pressure on combined cycle performance. Correction factors with (red line) and without (black line) steam export for (a) power; (b) heat rate.
Figure 13.
Effect of ambient pressure on combined cycle performance. Correction factors with (red line) and without (black line) steam export for (a) power; (b) heat rate.
Figure 14.
Effect of Fuel Low Heat value on combined cycle performance. Correction factors with (red) and without (black) steam export: (a) power; (b) heat rate.
Figure 14.
Effect of Fuel Low Heat value on combined cycle performance. Correction factors with (red) and without (black) steam export: (a) power; (b) heat rate.
Figure 15.
Corrective factors of net power (a) and heat rate (b) for different power of gas turbine with (red line) and without (black line) steam export.
Figure 15.
Corrective factors of net power (a) and heat rate (b) for different power of gas turbine with (red line) and without (black line) steam export.
Figure 16.
Operating expenses (OPEX) percentage of the CCP plant.
Figure 16.
Operating expenses (OPEX) percentage of the CCP plant.
Figure 17.
NPV for the obtained different options.
Figure 17.
NPV for the obtained different options.
Figure 18.
NPV in function of operating hours for year.
Figure 18.
NPV in function of operating hours for year.
Table 1.
Main features of the CCPP plant.
Table 1.
Main features of the CCPP plant.
Location | Province of Gurgaon (India) 30 km from New Delhi. |
Rated Power | 600 MW |
Combined cycle integration (GT/HR/ST) | 2 × 2 × 1 with refrigeration tower |
CHP/Steam demand | 102 bars, 445 °C. |
Fuel | Gas natural/Biomass Syngas |
Conditions considered in the study | New Delhi local ambient conditions |
Table 2.
Fractional energy losses for Heat Recovery Steam Generator for different design conditions and loads: winter design, summer design, annual average and maximum extreme.
Table 2.
Fractional energy losses for Heat Recovery Steam Generator for different design conditions and loads: winter design, summer design, annual average and maximum extreme.
Fraction of Energy Loss of Each Equipment | SPHT2 | SPHT3 | SPHT8 | SPHT5 | SPHT4 | EVAP3 | SPHT6 | ECON3 | SPHT1 | SPHT9 | ECON7 | EVAP2 | ECON5 | ECON6 | EVAP1 | ECON1 |
---|
Summer design 100% | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.03 |
Summer design 75% | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.001 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Summer design 50% | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.001 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Annual average 100% | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.01 | 0.001 | 0.08 | 0.001 | 0.001 | 0.08 | 0.001 | 0.001 | 0.001 | 0.03 | 0.04 |
Annual average 75% | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.01 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Annual average 50% | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.001 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Winter design 100% | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.01 | 0.001 | 0.08 | 0.001 | 0.001 | 0.08 | 0.001 | 0.001 | 0.001 | 0.03 | 0.04 |
Winter design 75% | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.01 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Winter design 50% | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.001 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Winter minimum 100% | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.01 | 0.001 | 0.08 | 0.001 | 0.01 | 0.08 | 0.001 | 0.001 | 0.001 | 0.03 | 0.04 |
Winter minimum 75% | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.01 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Winter minimum 50% | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.01 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Maximum extreme 100% | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.04 | 0.001 | 0.001 | 0.001 | 0.03 |
Maximum extreme 75% | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.001 | 0.08 | 0.08 | 0.08 | 0.08 | 0.08 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Maximum extreme 50% | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.001 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.001 | 0.001 | 0.001 | 0.001 | 0.12 |
Table 3.
Natural gas composition.
Table 3.
Natural gas composition.
| Units | Natural Gas |
---|
Methane | % mol | 84.777% |
Ethane | % mol | 6.338% |
Propane | % mol | 0.248% |
Nitrogen | % mol | 8.637% |
LHV | kJ/kg | 43,034.16 |
HCV | kJ/kg | 47,701.28 |
ratio H/C | - | 3.861 |
Table 4.
Composition of the syngases considered.
Table 4.
Composition of the syngases considered.
| | Syngas 1 [67] | Syngas 2 [68] | Syngas 3 [69] | Syngas 4 [70] |
---|
CH4 | % | 1.00% | 0.37% | 0.00% | 7.10% |
N2 | % | 6.55% | 0.00% | 12.47% | 0.00% |
H2 | % | 35.79% | 49.66% | 22.09% | 39.40% |
CO | % | 34.84% | 48.68% | 60.52% | 33.42% |
CO2 | % | 21.82% | 1.29% | 3.88% | 19.59% |
Ar | % | 0.00% | 0.00% | 1.04% | 0.00% |
O2 | % | 0.00% | 0.00% | 0.00% | 0.49% |
H2O | % | 0.00% | 0.00% | 0.00% | 0.00% |
LHV | kJ/kg (25 °C) | 8756 | 17,102 | 9771 | 12,306 |
Table 5.
Steam Turbine Net Power (MW) for different gas turbines model at full load operation. GE 7FA.05 (TG1), Siemens SGT6-8000H (TG2), GE7FA.04 (TG3), GEM9001E (TG4).
Table 5.
Steam Turbine Net Power (MW) for different gas turbines model at full load operation. GE 7FA.05 (TG1), Siemens SGT6-8000H (TG2), GE7FA.04 (TG3), GEM9001E (TG4).
| Net Power ST (MW) | TG1 | TG2 | TG3 | TG4 |
---|
100% Charge TG |
---|
Ambient Temperature (°C) | 11.5 °C | 212.12 | 244.43 | 170.07 | 113.27 |
15.7 °C | 211.74 | 242.47 | 170.76 | 113.28 |
26.5 °C | 205.96 | 236.78 | 168.06 | 113.40 |
38.4 °C | 202.04 | 222.48 | 159.36 | 108.24 |
Table 6.
Net Power of the Cycle for the different gas turbines at full load operation. GE 7FA.05 (TG1), Siemens SGT6-8000H (TG2), GE7FA.04 (TG3), GEM9001E (TG4).
Table 6.
Net Power of the Cycle for the different gas turbines at full load operation. GE 7FA.05 (TG1), Siemens SGT6-8000H (TG2), GE7FA.04 (TG3), GEM9001E (TG4).
| Cycle Net Power (MW) | TG1 | TG2 | TG3 | TG4 |
---|
100% Charge TG |
---|
Ambient Temperature (°C) | 11.5 °C | 675.990 | 731.808 | 539.939 | 354.854 |
15.7 °C | 667.889 | 721.735 | 540.418 | 349.233 |
26.5 °C | 637.402 | 690.083 | 520.028 | 335.964 |
38.4 °C | 601.325 | 642.004 | 479.576 | 315.271 |
Table 7.
Cycle efficiency for different gas turbines at full load operation. GE 7FA.05 (TG1), Siemens SGT6-8000H (TG2), GE7FA.04 (TG3), GEM9001E (TG4).
Table 7.
Cycle efficiency for different gas turbines at full load operation. GE 7FA.05 (TG1), Siemens SGT6-8000H (TG2), GE7FA.04 (TG3), GEM9001E (TG4).
| Cycle Efficiency (%) | TG1 | TG2 | TG3 | TG4 |
---|
100% Charge TG |
---|
Ambient Temperature(°C) | 11.5 °C | 57.43 | 58.74 | 50.90 | 51.52 |
15.7 °C | 56.71 | 59.26 | 50.94 | 51.57 |
26.5 °C | 53.59 | 56.44 | 49.01 | 51.70 |
38.4 °C | 49.24 | 52.41 | 45.20 | 51.15 |
Table 8.
Combined Cycle net power fuelled with different syngases.
Table 8.
Combined Cycle net power fuelled with different syngases.
| Cycle Net Power (MW) | Natural Gas | Syngas 1 | Syngas 2 | Syngas 3 | Syngas 4 |
---|
Ambient Temperature (°C) | 11.5 | 553.776 | 615.143 | 570.883 | 576.336 | 592.542 |
15.7 | 543.646 | 603.873 | 560.440 | 565.782 | 581.728 |
26.5 | 519.660 | 577.200 | 535.701 | 540.718 | 556.025 |
38.4 | 485.899 | 539.691 | 500.842 | 505.528 | 519.953 |
Table 9.
Cycle heat rate for the different syngases considered.
Table 9.
Cycle heat rate for the different syngases considered.
| Cycle Heat Rate (kJ/kWh) | Natural Gas | Syngas 1 | Syngas 2 | Syngas 3 | Syngas 4 |
---|
Ambient Temperature (°C) | 11.5 | 6864.0 | 6622.7 | 6790.1 | 6774.0 | 6684.0 |
15.7 | 6856.6 | 6616.1 | 6782.8 | 6766.6 | 6676.6 |
26.5 | 6837.5 | 6599.0 | 6764.3 | 6749.3 | 6659.5 |
38.4 | 6918.7 | 6677.7 | 6845.7 | 6829.9 | 6737.7 |
Table 10.
Cycle efficiency for the different fuels considered.
Table 10.
Cycle efficiency for the different fuels considered.
| Cycle Efficiency (%) | Natural Gas | Syngas 1 | Syngas 2 | Syngas 3 | Syngas 4 |
---|
Ambient Temperature (°C) | 11.5 | 52.446 | 54.356 | 53.017 | 53.143 | 53.858 |
15.7 | 52.502 | 54.410 | 53.074 | 53.200 | 53.865 |
26.5 | 52.649 | 54.552 | 53.219 | 53.337 | 54.056 |
38.4 | 52.031 | 53.909 | 52.586 | 52.707 | 53.429 |
Table 11.
Different cases proposed with different mixture percentage of natural gas and syngas.
Table 11.
Different cases proposed with different mixture percentage of natural gas and syngas.
| Natural Gas (%) | Syngas GS2 (%) |
---|
Case 1 | 90 | 10 |
Case 2 | 80 | 20 |
Case 3 | 70 | 30 |
Table 12.
Power and heat rate values without and with steam export at full load operation (100% load).
Table 12.
Power and heat rate values without and with steam export at full load operation (100% load).
-REFERENCE VALUES AS POWER PLANT (without Steam Export) | |
Net Power (MW) | 587.68 |
Net Heat rate (KJ/KWh) | 684.13 |
-REFERENCE VALUES AS CHP (with Steam Export) | |
Net Power (MW) | 576.68 |
Net Heat rate (KJ/KWh) | 6970.5 |
Table 13.
Capital Expenditure (Capex).
Table 13.
Capital Expenditure (Capex).
Initial Investment | Weight | Absolute Value (M€) |
---|
Gas turbines (assembly and supply) | 28.7% | 104.64 |
Boilers (assembly and supply) | 14.0% | 50.94 |
Steam turbines (assembly and supply) | 11.0% | 40.01 |
Cooling tower (assembly and supply) | 1.7% | 6.07 |
Gas and fuel system | 1.9% | 6.83 |
Electrical installations | 7.3% | 26.63 |
Civil works and land conditioning | 15.9% | 57.92 |
Control systems | 4.1% | 14.82 |
External engineering required | 3.0% | 10.77 |
Temporary works facilities | 2.1% | 7.80 |
Personal expenses | 4.6% | 16.83 |
Start-up | 5.1% | 18.63 |
Initial expenses (permits, guarantees, etc.) | 0.9% | 3.11 |
Total | 100% | 365 |
Table 14.
Utilization factor for the different cases considered.
Table 14.
Utilization factor for the different cases considered.
| Utilization Factor | Operating Hours per Year |
---|
Case 1 | 0.9 | 7884 |
Case 2 | 0.7 | 6132 |
Case 3 | 0.6 | 5256 |
Case 4 | 0.5 | 4380 |
Table 15.
NPV and IRR values for the different cases considered.
Table 15.
NPV and IRR values for the different cases considered.
| NPV (MM€) | IRR (%) |
---|
Case 1 | 137.379 | 14.122 |
Case 2 | 119.455 | 13.914 |
Case 3 | 80.991 | 13.686 |
Case 4 | 47.356 | 13.516 |