Power plant seawater desulfurization system and its vertical long axis semi submersible turbine pump solution

The seawater desulfurization system of power plants is a key system for flue gas desulfurization in thermal power plants. It absorbs acidic gases such as sulfur dioxide in the flue gas through the alkaline components of seawater, achieves flue gas purification, and finally discharges the treated seawater back into the ocean. It has both environmental protection and economic benefits, especially suitable for coastal power plants.
Solution for long axis pump of seawater desulfurization system in power station
1. Equipment selection and adaptation
Conventional seawater desulfurization scenario: A vertical long axis semi submersible turbine pump is selected as the core equipment for seawater transportation. The overcurrent components and key structures are made of super duplex steel material, which has excellent resistance to chloride stress corrosion cracking and high mechanical strength. It can adapt to highly corrosive seawater media and complex working conditions, ensuring long-term stable operation of the equipment and reducing maintenance costs. The pump has a wide range of head coverage and can meet the seawater transportation needs of power plants of different scales, with a flow rate of thousands of cubic meters per hour.
Special working condition scenario: If the sediment content in seawater is high, wear-resistant lining plates can be installed on the pump body, and the core components can be equipped with wear-resistant coatings to further enhance the anti abrasion ability; For high-temperature seawater media, a water-cooled bearing box can be configured to ensure the normal operation of the vertical long shaft semi submersible turbine pump equipment in high-temperature environments.
2. Stable operation guarantee
The rotor of the vertical long shaft semi submersible turbine pump adopts a withdrawable design, which can complete the maintenance of core components such as impellers and guide bearings without disassembling the pump body, greatly reducing downtime and ensuring the continuity of seawater desulfurization process.
Equipped with an external cooling and lubrication system to ensure the normal operation of the guide bearing under high temperature and high load conditions; The shaft seal adopts a mechanical seal structure, and rolling bearings are installed at the installation site of the mechanical seal to reduce the deflection of the pump shaft and avoid leakage problems caused by uneven stress on the sealing surface. At the same time, ordinary material pump shafts can be used to reduce equipment costs.
3. Energy saving optimization and upgrading
The vertical long axis semi submersible turbine pump is equipped with an intelligent variable frequency control system, which automatically adjusts the pump's water output according to the requirements of flue gas desulfurization and fluctuations in seawater flow, avoiding ineffective energy consumption and achieving an energy-saving effect of 20% -25%.
For large power plants, a vertical long axis semi submersible turbine pump multi pump parallel operation scheme can be adopted to intelligently start and stop the water pumps according to actual seawater demand, further improving energy utilization efficiency.
4. Intelligent control and system optimization
Deploy flow, pressure, and water quality sensors, build an IoT monitoring network, collect real-time data and upload it to the cloud to achieve data-driven precision scheduling, and promptly warn of equipment failures and water quality abnormalities.
Optimize the overall layout of the seawater desulfurization system, set up pump station locations and pipeline routes reasonably, and reduce pipeline resistance losses; At the same time, strengthen the seawater pretreatment process, control the sediment and impurity content in seawater, and reduce the wear and corrosion of vertical long shaft semi submersible turbine pumps.
 
Case study of vertical long shaft pump for seawater desulfurization in Huaneng Haimen Power Plant
Scenario Requirements
As a benchmark power plant for million kilowatt ultra supercritical units in China, the seawater desulfurization process of Huaneng Haimen Power Plant Phase II Units 5 and 6 (2 × 1000MW) requires extremely high reliability, corrosion resistance, and service life of supporting equipment. The strong corrosiveness of seawater poses a severe test on equipment materials and manufacturing processes, requiring equipment to be able to stably complete the key task of seawater transportation in the long term.
Plan and Implementation
Selecting a vertical long axis semi submersible turbine pump as the core equipment for seawater desulfurization process:
The overcurrent components and key structures are made of super duplex steel material, which has excellent resistance to chloride stress corrosion cracking and high mechanical strength. It can perfectly adapt to seawater media and complex working conditions, effectively reducing maintenance costs.
The equipment is manufactured strictly in accordance with the technical agreement and national standards. All acceptance items such as pump unit size accuracy, form and position tolerances, key weld inspection, assembly quality, and hydraulic performance testing have passed all at once, and all performance indicators are better than the design requirements.
Operational advantages
The commissioning of this batch of vertical long shaft semi submersible turbine pumps provides strong support for the smooth commissioning and stable operation of the second phase units of Huaneng Haimen Power Plant.