Preliminary Assessment of Waste Heat Steam Turbine Projects in Cement, Steel & Non-Ferrous Metallurgy
Waste heat power generation projects in cement, steel and non-ferrous metallurgy plants often involve multiple heat sources with different operating conditions. Before defining steam turbine parameters, engineers need to identify available heat sources, evaluate their recovery potential and determine how they can be integrated into a steam system.
1. Identify Waste Heat Sources in Different Industries
Each industry has different production processes and waste heat characteristics. Within the cement, steel and non-ferrous metallurgy industries, the typical recoverable waste-heat sources are as follows:
Industry | Recoverable Waste Heat Sources | Description |
Cement Plants | 1. Preheater Exhaust Gas 2. Clinker Cooler Exhaust Air 3. Kiln Bypass Gas (where applicable) | These sources carry recoverable thermal energy, with varied temperature, flow rate and dust concentration. Kiln stability and existing heat recovery systems will influence available heat. |
Steel Plants | 1. Coke Dry Quenching (CDQ) Systems 2. Sinter Cooler Exhaust Air 3. Sintering Machine Exhaust Gas 4. Basic Oxygen Furnace (BOF) Off-Gas 5. Electric Arc Furnace (EAF) Off-Gas 6. Reheating Furnace Flue Gas (where applicable) | These heat sources differ in temperature levels and operating patterns. Their availability and compatibility need assessment prior to designing a combined steam system. |
Non-Ferrous Metallurgy Plants | 1. Copper Smelting Furnace Off-Gas 2. Lead Smelting Furnace Off-Gas 3. Zinc Smelting Furnace Off-Gas 4. Sintering Machine Off-Gas 5. Anode Baking Furnace Flue Gas 6. Aluminum Melting Furnace Exhaust Gas 7. Calcination Furnace Exhaust Gas | Copper, lead and zinc smelting produces high-temperature furnace exhaust gas. Gas composition, dust content and corrosive substances vary by process, affecting heat recovery performance and boiler requirements. |
2. Evaluate Key Flue Gas Parameters
For each independent heat source, collect the following operating data. These parameters influence heat transfer performance, equipment design and long-term operation, so project feasibility should be based on practically recoverable heat rather than theoretical heat content alone.
Parameter | Impact on Heat Recovery |
Flue Gas Temperature | Indicates the available thermal energy |
Gas Flow Rate | Helps estimate recoverable heat |
Dust Concentration | Affects fouling and cleaning requirements |
Gas Composition | Helps identify corrosion risks |
Acid Dew Point | Helps prevent acid condensation |
3. Analyze Production Fluctuations
Cement kilns, steel production lines and smelting furnaces may experience different load changes and shutdown schedules. The assessment should cover:
- Normal, minimum and peak operating conditions
- Changes in waste heat temperature and flow rate
- Planned maintenance and shutdown periods
- Annual operating hours
When multiple sources are involved, their fluctuations may not occur simultaneously. This affects the continuity of heat supply and steam generation. Evaluating different operating scenarios helps determine whether the system can provide a stable steam supply throughout the year.
4. Assess Boiler Integration and Steam Conditions
The boiler arrangement should consider heat source locations, gas conditions, plant layout and operating requirements.
Depending on the project, separate waste heat boilers may be required, with recovered steam collected through a common header where technically suitable. Before integration, engineers should confirm:
- Steam pressure from each boiler
- Steam temperature
- Steam flow rate
- Compatibility of different steam sources
These parameters establish the overall steam balance and provide the operating basis for subsequent power generation assessment.
5. Evaluate the Steam Turbine Generator Set
Once the available steam conditions are established, engineers can assess the suitable turbine-generator arrangement. Key considerations include:
- Total steam flow and its operating range
- Turbine inlet pressure and temperature
- Process steam demand and plant electricity consumption
- Auxiliary power consumption
- Expected annual operating hours
Depending on project conditions, back-pressure, condensing or extraction-condensing configurations may be considered. Both gross power output and net electrical output should be evaluated to estimate actual power generation potential.
Preliminary Project Evaluation by YTS
YTS provides 1–60 MW industrial steam turbine and generator sets, including back-pressure, condensing, extraction-condensing and extraction-back-pressure configurations for industrial power generation and waste heat recovery projects.
For a preliminary assessment, share the operating data of each waste heat source, including gas temperature, flow rate, dust content and annual operating hours, together with any available boiler or steam parameters.
Our engineering team can review the available steam conditions and provide initial technical recommendations for the turbine-generator arrangement.
Planning a waste heat power generation project? Share your waste heat source data with YTS for a preliminary technical assessment.