Introduction

This document provides a detailed overview of Taishan Group's Waste Heat Recovery Boilers (WHRB) designed for municipal solid waste incineration plants. It covers product models, engineering project examples, and comprehensive thermal calculation results focused on efficient steam generation from waste heat.

Main Products

• SLC300-23.5-4.0/400
• SLC400-32-4.0/400
• SLC500-42-4.0/400
• SLC600-54-4.0/450
• SLC800-68-5.3/485
• SLC550-54.5-4.0/450

Engineering Project Examples and Key Parameters

Four representative projects illustrate the application and performance of Taishan WHRBs:

• Chongqing Kaixian 2×300t/d Boiler: 300 tons/day waste capacity, 23.5 t/h steam evaporation, 4.0 MPa steam pressure, 400 °C steam temperature, 130 °C feedwater temperature, 80% efficiency, Kangheng grate. Thermal calculations show ~81% efficiency with detailed heat loss analysis.
• Jinxiang 2×400t/d Boiler: 400 tons/day capacity, 32 t/h steam evaporation, 4.0 MPa/400 °C steam, 130 °C feedwater, 80.01% efficiency, Guangda grate. Includes detailed flue gas composition and heat transfer data; spray water desuperheating used for steam temperature control.
• Haiyang 500t/d Boiler: 500 tons/day, 42 t/h steam evaporation, 4.0 MPa/400 °C steam, 130 °C feedwater, 80.2% efficiency, Kangheng grate. Thermal balance and spray water desuperheating maintain stable steam temperature and low heat losses.
• Taian 2×600t/d Boiler: 600 tons/day, 54 t/h steam evaporation, 4.0 MPa/450 °C steam, 150 °C feedwater, 80% efficiency, Ebara grate. Thermal calculations show ~80.4% efficiency with detailed heat transfer data; spray water desuperheating applied; feedwater pressure 5.05 MPa, drum pressure 4.8 MPa.

Thermal Calculation and Heat Transfer Analysis

Each project includes comprehensive thermal balance calculations covering:

• Boiler rated capacity and load rate
• Steam output temperature and pressure
• Feedwater temperature and pressure
• Fuel composition and lower heating value
• Theoretical air and combustion gas volumes
• Heat losses: flue gas, incomplete combustion, mechanical, ash, radiation
• Boiler efficiency and heat absorption by furnace walls, superheaters, economizers, evaporative convection bundles
• Heat transfer coefficients for radiation and convection on flue gas and water/steam sides
• Spray water desuperheating parameters for steam temperature control

Heat transfer components analyzed include furnace walls, multiple superheater stages, evaporative convection bundles, economizers, and convection wall tubes. Parameters such as gas and steam temperatures, enthalpy, flow rates, velocities, and heat transfer coefficients are tabulated to verify thermal balance with minimal relative errors.

Key Technical Specifications and Parameters

• Steam pressures typically at 4.0 MPa; drum pressures slightly higher (4.6–5.5 MPa)
• Steam temperatures range from 400 °C to 450 °C depending on model
• Feedwater temperatures between 130 °C and 150 °C
• Boiler efficiencies around 80% to 82%
• Flue gas discharge temperatures maintained near 190 °C
• Fuel lower heating values approximately 6280–6700 kJ/kg
• Use of spray water desuperheating for precise steam temperature control
• Boiler grates supplied by reputable manufacturers (Kangheng, Guangda, Ebara)

Recommendations and Best Practices

• Continuous monitoring of flue gas composition and temperature to optimize combustion and heat recovery
• Ensure proper operation and maintenance of spray water desuperheaters for steam temperature control
• Regular inspection and upkeep of boiler grates to maintain efficient fuel combustion
• Use detailed thermal balance calculations to identify and minimize heat losses
• Apply accurate heat transfer coefficients and flow parameters for design and operational optimization

Heat Transfer Parameters and Calculations

Detailed heat transfer coefficients and parameters are provided for various boiler components, including radiation and convection coefficients on flue gas and working fluid sides. Key parameters include pollution/utilization coefficients, heat transfer coefficients (radiation and convection), overall heat transfer coefficients, average temperatures and pressures, heat transfer quantities, and relative error percentages. These are tabulated for different pipe specifications and operating conditions, illustrating variations in heat transfer performance and efficiency.

Summary of Heat Transfer Component Calculations

Calculations for evaporative convection tube bundles, wall tubes, and economizer tubes include tube specifications, convective heat transfer areas, flue gas inlet/outlet temperatures, enthalpy values, and flow rates/velocities of flue gas and working fluid. This provides a comprehensive overview of thermal performance and heat absorption efficiency across boiler sections.

Waste Heat Boiler Design Proposals

• 550T Waste Heat Boiler: 550 tons/day capacity, 54.5 t/h rated evaporation, 450 °C steam output, 130 °C feedwater, 7116 kJ/kg design heat value, 190 °C flue gas discharge, 80.2% efficiency, 4.0 MPa steam pressure.
• 800T Waste Heat Boiler: 800 tons/day capacity, 68 t/h rated evaporation, 485 °C steam output, 150 °C feedwater, 6700 kJ/kg design heat value, 190 °C flue gas discharge, 83% efficiency, 5.3 MPa steam pressure.

Thermal Calculation Summary for 800T/D Boiler

Includes tube specifications for various boiler sections, heat transfer areas for radiation channels, evaporators, superheaters, and economizers, flue gas and working fluid temperatures, average velocities, main steam flow rate (68 t/h), and primary/secondary desuperheating water flow rates (0.95 t/h and 1 t/h). This data is critical for evaluating boiler performance and optimizing heat exchange efficiency.

Key Observations and Recommendations

• Heat transfer coefficients vary significantly with pipe specifications and operating conditions, affecting overall boiler efficiency.
• Maintaining optimal flue gas and working fluid temperatures is essential for maximizing heat absorption and minimizing thermal losses.
• Pollution/utilization coefficients impact heat transfer effectiveness and should be monitored to ensure system cleanliness and performance.
• Design parameters such as feedwater temperature, steam output temperature, and pressure are tailored to waste disposal capacity and fuel characteristics.
• Regular thermal balance checks and error analysis are recommended to validate calculation accuracy and operational stability.

Summary

Taishan Group's waste heat recovery boilers are engineered for efficient steam generation from municipal solid waste incineration. The document provides detailed technical data, thermal calculations, and operational parameters for multiple boiler models and projects. Emphasis is placed on maintaining high boiler efficiency (~80%), controlling steam parameters, and minimizing heat losses through precise thermal management and component design.