H41221 Answer Guide

| State | Pressure (kPa) | Temperature (°C) | Specific Enthalpy (kJ/kg) | Specific Entropy (kJ/kg·K) | |-------|----------------|------------------|---------------------------|----------------------------| | 1 (Boiler exit) | 10,000 | 600 | h₁ = 3625.3 | s₁ = 6.9029 | | 2 (Extraction 1) | 800 | (Superheated) | h₂ = 2950.6 | s₂ = 6.9029 | | 3 (Extraction 2) | 200 | (Superheated) | h₃ = 2625.4 | s₃ = 6.9029 | | 4 (Condenser exit) | 10 | Sat. liquid | h₄ = 191.81 | — | | 5 (Pump 1 exit) | 200 | Subcooled | h₅ ≈ 192.8 (≈ v₄*(P₅-P₄)) | — | | 6 (FWH 2 exit) | 200 | Sat. liquid | h₆ = 504.7 | — | | 7 (Pump 2 exit) | 800 | Subcooled | h₇ ≈ 506.5 | — | | 8 (FWH 1 exit) | 800 | Sat. liquid | h₈ = 721.1 | — | | 9 (Pump 3 exit) | 10,000 | Subcooled | h₉ ≈ 727.9 | — |

“A steam power plant operates on an ideal regenerative Rankine cycle with two open feedwater heaters. Steam enters the turbine at 10 MPa and 600°C and exhausts to the condenser at 10 kPa. Steam is extracted from the turbine at 0.8 MPa and 0.2 MPa. Determine the thermal efficiency of the cycle.” H41221 Answer

However, do not simply copy that number. Read the full breakdown below to ensure it matches your specific variables. | State | Pressure (kPa) | Temperature (°C)

Need further clarification? Leave a comment or consult your course instructor with the specific variables from your problem set. And remember: understanding the “why” behind the H41221 answer matters more than the numeric value alone. liquid | h₈ = 721