Power Cycle Components/Processes and Compressible Flow Analysis Webinar

854 views

Published on

Engineering webinar material dealing with power cycle components/processes (compression, combustion and expansion) and compressible flow (nozzle, diffuser and thrust) when air, argon, helium and nitrogen are considered as the working fluid.

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
854
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Power Cycle Components/Processes and Compressible Flow Analysis Webinar

  1. 1. Engineering Software P.O. Box 2134 Kensington, MD 20891 Phone: (301) 919-9670 E-Mail: info@engineering-4e.com http://www.engineering-4e.com Copyright © 1996
  2. 2. Power Cycle Comp. and Com. Flow Analysis Webinar Objectives In this webinar, the engineering students and professionals get familiar with the ideal power cycle components/processes and compressible flow components and their T - s and h - T diagrams, operation and major performance trends when air, argon, helium and nitrogen are considered as the working fluid. Performance Objectives: Introduce basic energy conversion engineering assumptions and equations Know basic elements of compression, combustion and expansion processes and compressible flow (nozzle, diffuser and thrust) and their T - s and h - T diagrams Be familiar with compression, combustion, expansion and compressible flow (nozzle, diffuser and thrust) operation Understand general compression, combustion, expansion and compressible flow (nozzle, diffuser and thrust) performance trends
  3. 3. This webinar consists of the following two major sections: • Power Cycle Components/Processes (compression, combustion and expansion) • Compressible Flow (nozzle, diffuser and thrust) In this webinar, first overall engineering assumptions and basic equations are provided. Furthermore, for each major section, basic engineering equations, section material and conclusions are provided. Power Cycle Comp. and Compressible Flow Analysis Webinar
  4. 4. The energy conversion analysis presented in this webinar considers ideal (isentropic) operation and air, argon, helium and nitrogen are considered as the working fluid. Furthermore, the following assumptions are valid: Power Cycle Components/Processes Single species consideration Basic equations hold (continuity, momentum and energy equations) Specific heat is constant Compressible Flow Single species consideration Basic equations hold (continuity, momentum and energy equations) Specific heat is constant Thermodynamic and Transport Properties Single species consideration Ideal gas approach is used (pv=RT) Specific heat is not constant Coefficients describing thermodynamic and transport properties were obtained from the NASA Glenn Research Center at Lewis Field in Cleveland, OH -- such coefficients conform with the standard reference temperature of 298.15 K (77 F) and the JANAF Tables Engineering Assumptions
  5. 5. Basic Conservation Equations Continuity Equation m = ρvA [kg/s] Momentum Equation F = (vm + pA)out - in [N] Energy Equation Q - W = ((h + v2/2 + gh)m)out - in [kW] Basic Engineering Equations
  6. 6. Ideal Gas State Equation pv = RT [kJ/kg] Perfect Gas cp = constant [kJ/kg*K] Kappa χ = cp/cv [/] Basic Engineering Equations
  7. 7. Basic Engineering Equations Physical Properties Gas Constant [kJ/kg*K] 0.2867 0.2801 2.0785 0.2969 Specific Heat [kJ/kg*K] 1.004 0.519 5.200 1.038 χ [/] 1.4 1.67 1.66 1.4 Working Fluid Air Argon Helium Nitrogen
  8. 8. Isentropic Compression T2/T1 = (p2/p1)(χ-1)/χ [/] T2/T1 = (V1/V2)(χ-1) [/] p2/p1 = (V1/V2)χ [/] wc = cp(T2 - T1) [kJ/kg] Wc = cp(T2 - T1)m [kW] Power Cycle Components/Processes Engineering Equations
  9. 9. Power Cycle Components/Processes Engineering Equations Combustion is ideal, complete with no heat loss and fuel reacts with air and oxygen enriched air as the oxidant at different stoichiometry values (stoichiometry => 1) and oxidant inlet temperature values. Also, Flame Temperature [K] hreactants = hproducts [kJ/kg]
  10. 10. Isentropic Expansion T1/T2 = (p1/p2)(χ-1)/χ [/] T1/T2 = (V2/V1)(χ-1) [/] p1/p2 = (V2/V1)χ [/] we = cp(T1 - T2) [kJ/kg] We = cp(T1 - T2)m [kW] Power Cycle Components/Processes Engineering Equations
  11. 11. Compression Schematic Layout Working Fluid In Working Fluid Out Compressor 1 2 Compression
  12. 12. Compression T - s Diagram 2 1 Temperature--T[K] Entropy -- s [kJ/kg*K] Compression
  13. 13. Compression Specific Power Input 0 1 2 3 4 5 10 15 CompressionSpecificPowerInput[MJ/kg] Air Argon Helium Nitrogen Compressor Inlet Temperature: 298 [K] Compression Compression Ratio (P2/P1) [/]
  14. 14. Compression Power Input 0 100 200 300 400 500 50 100 150 Working Fluid Mass Flow Rate [kg/s] CompressionPowerInput[MW] Air Argon Helium Nitrogen Compression Ratio (P2/P1) = 15 [/] Compression Compressor Inlet Temperature: 298 [K]
  15. 15. Combustion Schematic Layout Fuel Oxidant Combustion Products Combustion
  16. 16. Specific Enthalpy vs Temperature -20,000 -10,000 0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 80,000 90,000 500 800 1,100 1,400 1,700 2,000 2,300 2,600 2,900 3,200 3,500 3,800 4,100 4,400 4,700 5,000 O2 N2 C(S) S(S) H2 CO2 SO2 H2O H2O(L) CH4 Combustion SpecificEnthalpy[kJ/kg] Temperature [K]
  17. 17. Combustion h - T Diagram SpecificEnthalpy--h[kJ/kg] Temperature -- T [K] Reactants Products TflameTreference Combustion
  18. 18. Combustion Oxidant Composition Fuel Composition C [kg/kg] 1.000 0.000 0.000 0.780 0.860 - H [kg/kg] 0.000 1.000 0.000 0.050 0.140 - S [kg/kg] 0.000 0.000 1.000 0.030 0.000 - N [kg/kg] 0.000 0.000 0.000 0.040 0.000 - O [kg/kg] 0.000 0.000 0.000 0.080 0.000 - H2O [kg/kg] 0.000 0.000 0.000 0.020 0.000 - CH4 [kg/kg] - - - - - 1.000 Fuel Carbon Hydrogen Sulfur Coal Oil Gas N [kmol/kmol] 0.790 O [kmol/kmol] 0.210 N [kg/kg] 0.767 O [kg/kg] 0.233 Oxidant Air
  19. 19. Combustion Stoichiometric Combustion Combustion Products Composition on Weight and Mole Basis CO2 [kg/kg] 0.295 0.000 0.000 0.249 0.202 0.151 H2O [kg/kg] 0.000 0.255 0.000 0.041 0.080 0.124 SO2 [kg/kg] 0.000 0.000 0.378 0.005 0.000 0.000 N2 [kg/kg] 0.705 0.745 0.622 0.705 0.718 0.725 O2 [kg/kg] 0.000 0.000 0.000 0.000 0.000 0.000 CO2 [kmol/kmol] 0.210 0.000 0.000 0.170 0.132 0.095 Fuel Carbon Hydrogen Sulfur Coal Oil Gas SO2 [kmol/kmol] 0.000 0.000 0.210 0.002 0.000 0.000 N2 [kmol/kmol] 0.790 0.653 0.790 0.759 0.739 0.715 Combustion Products Flame Temperature, Stoichiometric Oxidant to Fuel Ratio and HHV Flame Temperature [K] 2,460 2,525 1,972 2,484 2,484 2,327 Stoichiometric Oxidant to Fuel Ratio [/] 11.444 34.333 4.292 10.487 14.649 17.167 HHV [Btu/lbm] 14,094 60,997 3,982 14,162 20,660 21,563 Fuel Carbon Hydrogen Sulfur Coal Oil Gas H2O [kmol/kmol] 0.000 0.347 0.000 0.068 0.129 0.190 O2 [kmol/kmol] 0.000 0.000 0.000 0.000 0.000 0.000
  20. 20. Combustion Products -- Weight Basis 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 CO2 H2O SO2 N2 O2 CombustionProducts[kg/kg] Carbon Hydrogen Sulfur Coal Oil Gas Combustion Fuel and Oxidant Inlet Temperature: 298 [K]
  21. 21. Combustion Products -- Mole Basis 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 CO2 H2O SO2 N2 O2 CombustionProducts[kmol/kmol] Carbon Hydrogen Sulfur Coal Oil Gas Combustion Fuel and Oxidant Inlet Temperature: 298 [K]
  22. 22. Combustion Products Flame Temperature 1,900 2,000 2,100 2,200 2,300 2,400 2,500 2,600 Carbon Hydrogen Sulfur Coal Oil Gas Flame Temperature [K] Combustion Fuel and Oxidant Inlet Temperature: 298 [K] FlameTemperature[K]
  23. 23. Combustion Stoichiometric Oxidant to Fuel Ratio 0 5 10 15 20 25 30 35 40 Carbon Hydrogen Sulfur Coal Oil Gas Stoichiometric Oxidant to Fuel Ratio [/] Combustion Fuel and Oxidant Inlet Temperature: 298 [K] StoichiometricOxidanttoFuelRatio[/]
  24. 24. Higher Heating Value (HHV) 0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 Carbon Hydrogen Sulfur Coal Oil Gas HHV [Btu/lbm] Combustion Fuel and Oxidant Inlet Temperature: 298 [K] HHV[Btu/lbm]
  25. 25. Combustion Stoichiometric Combustion Flame Temperature Hydrogen [K] 2,525 2,583 2,640 2,689 2,757 2,818 2,879 2,942 Sulfur [K] 1,972 2,045 2,118 2,191 2,267 2,343 2,421 2,501 Coal [K] 2,484 2,551 2,618 2,686 2,756 2,827 2,899 2,972 Oil [K] 2,484 2,551 2,616 2,683 2,751 2,820 2,891 2,963 Preheat Temperature [K] 298 400 500 600 700 800 900 1,000 Combustion Products Stoichiometric Oxidant to Fuel Ratio and HHV Stoichiometric Oxidant to Fuel Ratio [/] 11.444 34.333 4.292 10.487 14.649 17.167 HHV [Btu/lbm] 14,094 60,997 3,982 14,162 20,660 21,563 Fuel Carbon Hydrogen Sulfur Coal Oil Gas Gas [K] 2,327 2,391 2,455 2,520 2,586 2,653 2,721 2,791 Carbon [K] 2,460 2,531 2,602 2,674 2,747 2,822 2,898 2,976
  26. 26. Combustion Products Flame Temperature 0 1,000 2,000 3,000 298 400 500 600 700 800 900 1,000 FlameTemperature[K] Carbon Hydrogen Sulfur Coal Oil Gas Combustion Fuel Inlet Temperature: 298 [K] Oxidant Preheat Temperature for Stoichiometric Combustion Conditions
  27. 27. Combustion Oxidant Composition Fuel Composition C [kg/kg] 0.000 H [kg/kg] 0.000 S [kg/kg] 0.000 N [kg/kg] 0.000 O [kg/kg] 0.000 H2O [kg/kg] 0.000 CH4 [kg/kg] 1.000 Fuel Gas N [kmol/kmol] 0.790 O [kmol/kmol] 0.210 N [kg/kg] 0.767 O [kg/kg] 0.233 Oxidant Air
  28. 28. Combustion Combustion Products Composition on Weight and Mole Basis CO2 [kg/kg] 0.151 0.078 0.052 0.040 0.032 0.026 H2O [kg/kg] 0.124 0.064 0.043 0.032 0.026 0.022 N2 [kg/kg] 0.725 0.745 0.753 0.756 0.758 0.760 O2 [kg/kg] 0.000 0.113 0.152 0.172 0.184 0.192 CO2 [kmol/kmol] 0.095 0.050 0.034 0.026 0.020 0.018 Stoichiometry [/] 1 2 3 4 5 6 N2 [kmol/kmol] 0.715 0.750 0.763 0.770 0.774 0.776 Combustion Products Flame Temperature and Oxidant to Fuel Ratio Flame Temperature [K] 2,327 1,480 1,137 951 832 750 Oxidant to Fuel Ratio [/] 17.167 34.333 51.500 68.667 85.833 103.000 H2O [kmol/kmol] 0.190 0.100 0.068 0.051 0.041 0.034 O2 [kmol/kmol] 0.000 0.100 0.135 0.153 0.165 0.172 Stoichiometry [/] 1 2 3 4 5 6
  29. 29. Combustion Products -- Weight Basis 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 CO2 H2O N2 O2 CombustionProducts[kg/kg] 1 2 3 4 5 6 Fuel and Oxidant Inlet Temperature: 298 [K] Combustion Stoichiometry [/]
  30. 30. Combustion Products -- Mole Basis 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 CO2 H2O N2 O2 CombustionProducts[kmol/kmol] 1 2 3 4 5 6 Fuel and Oxidant Inlet Temperature: 298 [K] Combustion Stoichiometry [/]
  31. 31. Combustion Products Flame Temperature 600 900 1,200 1,500 1,800 2,100 2,400 1 2 3 4 5 6 Flame Temperature [K] Combustion Stoichiometry [/] Fuel and Oxidant Inlet Temperature: 298 [K] FlameTemperature[K]
  32. 32. Combustion Oxidant to Fuel Ratio 0 30 60 90 120 1 2 3 4 5 6 Oxidant to Fuel Ratio [/] Combustion Stoichiometry [/] Fuel and Oxidant Inlet Temperature: 298 [K] OxidanttoFuelRatio[/]
  33. 33. Combustion Oxidant Composition Fuel Composition C [kg/kg] 0.000 H [kg/kg] 0.000 S [kg/kg] 0.000 N [kg/kg] 0.000 O [kg/kg] 0.000 H2O [kg/kg] 0.000 CH4 [kg/kg] 1.000 Fuel Gas N [kmol/kmol] 0.790 0.580 0.370 O [kmol/kmol] 0.210 0.420 0.630 N [kg/kg] 0.767 0.550 0.340 O [kg/kg] 0.233 0.450 0.660 Oxidant [kmol/kmol] O2 - 0.21 O2 - 0.42 O2 - 0.63
  34. 34. Combustion CO2 [kg/kg] 0.151 0.280 0.390 H2O [kg/kg] 0.124 0.229 0.319 N2 [kg/kg] 0.725 0.492 0.291 O2 [kg/kg] 0.000 0.000 0.000 CO2 [kmol/kmol] 0.095 0.174 0.240 Oxidant [kmol/kmol] O2 - 0.21 O2 - 0.42 O2 - 0.63 N2 [kmol/kmol] 0.715 0.479 0.281 Combustion Products Flame Temperature and Stoichiometric Oxidant to Fuel Ratio Flame Temperature [K] 2,327 3,505 4,300 Stoichiometric Oxidant to Fuel Ratio [/] 17.167 8.833 6.056 H2O [kmol/kmol] 0.190 0.347 0.479 O2 [kmol/kmol] 0.000 0.000 0.000 Stoichiometric Combustion Combustion Products Composition on Weight and Mole Basis Oxidant [kmol/kmol] O2 - 0.21 O2 - 0.42 O2 - 0.63
  35. 35. Combustion Products -- Weight Basis 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 CO2 H2O N2 O2 CombustionProducts[kg/kg] O2 - 0.21 O2 - 0.42 O2 - 0.63 Combustion Stoichiometric Combustion Fuel and Oxidant Inlet Temperature: 298 [K]
  36. 36. Combustion Products -- Mole Basis 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 CO2 H2O N2 O2 CombustionProducts[kmol/kmol] O2 - 0.21 O2 - 0.42 O2 - 0.63 Combustion Stoichiometric Combustion Fuel and Oxidant Inlet Temperature: 298 [K]
  37. 37. Combustion Products Flame Temperature 0 1,000 2,000 3,000 4,000 5,000 O2 - 0.21 O2 - 0.42 O2 - 0.63 Flame Temperature [K] Combustion Stoichiometric Combustion Fuel and Oxidant Inlet Temperature: 298 [K] FlameTemperature[K]
  38. 38. Combustion Stoichiometric Oxidant to Fuel Ratio 0 5 10 15 20 O2 - 0.21 O2 - 0.42 O2 - 0.63 Stoichiometric Oxidant to Fuel Ratio [/] Combustion Stoichiometric Combustion Fuel and Oxidant Inlet Temperature: 298 [K] StoichiometricOxidanttoFuelRatio[/]
  39. 39. Expansion Schematic Layout Working Fluid In Working Fluid Out Turbine 1 2 Expansion
  40. 40. Expansion T - s Diagram 1 2 Temperature--T[K] Entropy -- s [kJ/kg*K] Expansion
  41. 41. Expansion Specific Power Output 0 2 4 6 5 10 15 ExpansionSpecificPowerOutput[MJ/kg] Air Argon Helium Nitrogen Turbine Inlet Temperature: 1,500 [K] Expansion Expansion Ratio (P1/P2) [/]
  42. 42. Expansion Power Output 0 200 400 600 800 50 100 150 Working Fluid Mass Flow Rate [kg/s] ExpansionPowerOutput[MW] Air Argon Helium Nitrogen Expansion Expansion Ratio (P1/P2) = 15 [/] Turbine Inlet Temperature: 1,500 [K]
  43. 43. Power Cycle Components/Processes Conclusions The compression specific power input increases with an increase in the compression ratio values. As the working fluid mass flow rate increases for the fixed compression ratio and compression inlet temperature values, the compression power input requirements increase too. The compression specific power input and power input increase for the working fluid having higher specific heat values. Hydrogen as the fuel has the highest flame temperature, requires the most mass amount of oxidant in order to have complete combustion per unit mass amount of fuel and has the largest fuel higher heating value. When hydrogen reacts with oxidant, there is no CO2 present in the combustion products. The flame temperature increases as the oxidant, air, preheat temperature increases for a fixed stoichiometry value. The flame temperature decreases as the stoichiometry values increase. For stoichiometric combustion conditions, the amount of oxidant decreases as the oxygen enriched air level in the oxidant increases. Also, the flame temperature for such combustion conditions increases. The expansion specific power output increases with an increase in the expansion ratio values. As the working fluid mass flow rate increases for the fixed expansion ratio and expansion inlet temperature values, the expansion power output values increase too. The expansion specific power output and power output increase for the working fluid having higher specific heat values.
  44. 44. Sonic Velocity vs = (χ RT)1/2 [m/s] Mach Number M = v/vs [/] Compressible Flow Engineering Equations
  45. 45. Isentropic Flow Tt/T = (1 + M2(χ - 1)/2) [/] pt/p = (1 + M2(χ - 1)/2)χ/(χ-1) [/] ht = (h + v2/2) [kJ/kg] Tt = (T + v2/(2cp)) [K] Thrust = vm + (p - pa)A [N] Compressible Flow Engineering Equations
  46. 46. Nozzle Schematic Layout Working Fluid In Working Fluid Out Nozzle 1 2 Nozzle
  47. 47. Nozzle T - s Diagram 1 2 Temperature--T[K] Entropy -- s [kJ/kg*K] Nozzle
  48. 48. Nozzle Performance 1.00 1.10 1.20 1.30 1.40 1.50 0.39 0.67 1.00 Mach Number [/] Tstagnation/Tstatic[/] Air Argon Helium Nitrogen Nozzle Nozzle Inlet Stagnation Conditions -- Temperature: 1,500 [K] and Pressure: 10 [atm]
  49. 49. Nozzle Performance 1.00 1.30 1.60 1.90 2.20 2.50 0.39 0.67 1.00 Mach Number [/] Pstagnation/Pstatic[/] Air Argon Helium Nitrogen Nozzle Nozzle Inlet Stagnation Conditions -- Temperature: 1,500 [K] and Pressure: 10 [atm]
  50. 50. Diffuser Schematic Layout Working Fluid In Working Fluid Out Diffuser 1 2 Diffuser
  51. 51. Diffuser T - s Diagram 2 1 Temperature--T[K] Entropy -- s [kJ/kg*K] Diffuser
  52. 52. Diffuser Performance 1.00 1.10 1.20 1.30 1.40 1.50 0.29 0.58 0.95 Mach Number [/] Tstagnation/Tstatic[/] Air Argon Helium Nitrogen Diffuser Diffuser Inlet Static Conditions -- Temperature: 298 [K] and Pressure: 1 [atm]
  53. 53. Diffuser Performance 1.00 1.30 1.60 1.90 2.20 2.50 0.29 0.58 0.95 Mach Number [/] Pstagnation/Pstatic[/] Air Argon Helium Nitrogen Diffuser Diffuser Inlet Static Conditions -- Temperature: 298 [K] and Pressure: 1 [atm]
  54. 54. Thrust Schematic Layout Working Fluid Out Nozzle 21 Working Fluid at Still Thrust
  55. 55. Thrust T - s Diagram 1 2 Temperature--T[K] Entropy -- s [kJ/kg*K] Thrust
  56. 56. Thrust 500 1,000 1,500 2,000 2,500 3,000 900 1,200 1,500 Nozzle Inlet Stagnation Temperature [K] Thrust[N] Air Argon Helium Nitrogen Working Fluid Mass Flow Rate: 1 [kg/s] Thrust Nozzle Outlet Static Conditions -- Mach Number: 0.85 [/] Nozzle Inlet Stagnation Pressure: 10 [atm] and Ambient Conditions Pressure: 1 [atm]
  57. 57. Nozzle -- Thrust Performance 1.14 1.17 1.20 1.23 1.26 900 1,200 1,500 Nozzle Inlet Stagnation Temperature [K] Tstagnation/Tstatic[/] Air Argon Helium Nitrogen Thrust Nozzle Outlet Static Conditions -- Mach Number: 0.85 [/] Nozzle Inlet Stagnation Pressure: 10 [atm] and Ambient Conditions Pressure: 1 [atm]
  58. 58. Nozzle -- Thrust Performance 1.58 1.62 1.66 1.70 1.74 900 1,200 1,500 Nozzle Inlet Stagnation Temperature [K] Pstagnation/Pstatic[/] Air Argon Helium Nitrogen Thrust Nozzle Outlet Static Conditions -- Mach Number: 0.85 [/] Nozzle Inlet Stagnation Pressure: 10 [atm] and Ambient Conditions Pressure: 1 [atm]
  59. 59. Compressible Flow Conclusions Nozzle stagnation over static temperature and pressure ratio values increase with an increase in the Mach Number. Diffuser stagnation over static temperature and pressure ratio values increase with an increase in the Mach Number. Thrust increases with an increase in the inlet stagnation temperature. The nozzle, diffuser and thrust performance increases for the working fluid having higher specific heat values.

×