Technical guide for energy conservation, heating, flexibility retrofits of coal-fired power steam turbines
1Key Takeaways
This guideline mainly specifies the following contents: Terms and definitions related to energy saving, heat supply, and flexibility transformation of steam turbines of coal power units. General and specific requirements for energy saving, heating and flexibility transformation of steam turbines of coal power units.
2Expert Interpretation
An in-depth interpretation of the T/CEEMA 001-2022 standard, covering core contents such as turbine flow modification, parameter increase technology, and low-pressure cylinder zero output, provides a heat consumption index comparison table and implementation suggestions for energy-saving modification of 300MW+ units, and helps the clean transformation of coal-fired power.
In-depth interpretation of technical standards
This standard is aimed at the steam turbine system of coal-fired power units of 300MW and above, and systematically standardizes the three major technical paths of energy-saving transformation, heating optimization and flexibility improvement. Through 20 key technical indicators and 15 typical transformation plans, it provides standardized technical support for the clean transformation of coal-fired power.
Key technologies for energy-saving transformation
| Transformation type | Technical measures | Heat consumption reduction (kJ/kWh) | Investment payback period (years) |
|---|---|---|---|
| Flow transformation | High-efficiency blade profile + steam seal optimization | 150-300 | 3-5 |
| Temperature increase transformation | 566℃→600℃ | 130 | 6-8 |
| Cross-generation upgrade | 16.7MPa→28MPa | 550 | 8-10 |
【Application Case】
A 600MW subcritical unit adopted the Harbin Electric flow transformation solution, replaced the high-efficiency last-stage blades and optimized the steam seal clearance. The actual power supply coal consumption was reduced by 8.2g/kWh, saving 15,000 tons of standard coal annually.
Comparison of heating transformation plans
| Transformation method | Applicable pressure (MPa) | Steam supply stability | Efficiency impact |
|---|---|---|---|
| Rotating baffle | 1.0-1.6 | Stable above 40% load | Reduce cylinder efficiency by 2-3% |
| Seat cylinder valve | 1.8-4.0 | Adjustable at full load | Additional pressure loss 0.5MPa |
| Low pressure cylinder zero output | 0.2-0.5 | Back pressure mode operation | Requires 20t/h cooling steam |
Key points for flexibility transformation implementation
- Final stage blade strengthening: Adopt Stellite alloy anti-corrosion coating, dynamic stress needs to be ≤250MPa
- Shaft seal system transformation: Auxiliary steam pressure is maintained at 0.8-1.2MPa at low load
- Control system optimization: AGC response time is shortened to within 30 seconds
【Technology Evolution】
From the early dual rotor switching to the modern class=instrument>low-pressure cylinder zero output technology, the transformation cycle is shortened from 15 days to 72 hours, and the flexible operation time ratio is increased to 85%.
Standard implementation recommendations
- New units should give priority to 600℃/620℃ high parameter design
- Units with more than 15 years of service are recommended to implement cross-generation upgrades
- Heating units should be equipped with online monitoring systems to evaluate blade status in real time
- Deep peak-shaving units need to conduct full-condition stress analysis