1. Engineered Design & Thermodynamic Principles

The HRSG (Heat Recovery Steam Generator), as a critical component in combined cycle power plants (CCPP) and industrial waste heat recovery systems, converts exhaust gas thermal energy into high-grade steam through multi-pressure cascading systems. Key design parameters include:

• Gas Side:

  Inlet temperature(842-1202°F), velocity (65-115 ft/s), pressure drop (<0.36 psi)

• Steam Side:

  HP section (1160-2175      psi/932-1049°F), IP section (290-580 psi/572-752°F), LP section (58-145      psi/saturated)

• Efficiency Metrics:

  LMTD-based heat      transfer optimization with 85-92% typical thermal recovery rate

2. Technical Specifications of Critical Components

2.1 Material Selection for Heating Surfaces

• High-Temperature Zones (Evaporator/Superheater):

  T91/P92 ferritic steels (9-12% Cr content), creep resistance      up to 1148°F

• Mid-Low Temperature Zones (Economizer):

  SA213-T22 alloy steel with PTFE anti-corrosion coating

• Special Applications:

  Inconel 625      (ASME SB444) for high-sulfur fuel environments

2.2 Structural Design Compliance

• Modular Casing:

  ASME Section I      compliant design, shell thickness ≥0.47 in (Q345R steel)

• Tube Bank Arrangement:      

  In-line/staggered layouts selected based on particulate loading (staggered      preferred for ash mitigation)

• Expansion Joints:

  EJMA standard      metallic bellows with ≥2 in axial compensation

3. Operational Control & Failure Mode Analysis

3.1 Load-Following Control Strategies

• Sliding Pressure Operation:

  Linear      steam pressure adjustment across 30-100% load range

• Feedwater Regulation:

  Three-element      

  PID control (steam flow/drum level/feedwater flow)

3.2 Failure Response Protocols