Thermal Power Plant Water Pump Applications Summary

Thermal power plants are critical facilities in electricity production, and their operation relies on numerous auxiliary equipment, among which water pumps are key components.   Pumps in thermal power plants perform essential functions such as water supply, cooling, circulation, condensate recovery, and ash/slurry handling, directly impacting the unit's safety and economic efficiency.   This article summarizes the main types, application scenarios, technical characteristics, and operational maintenance considerations for pumps in thermal power plants.

Main Application Scenarios

(1) Boiler Feedwater Pump:

Delivers high-pressure deaerated water to the boiler to maintain water circulation.  High pressure (up to 20 MPa or more) and high temperature (150–200°C).  Typically uses multistage centrifugal pumps;   some ultra-supercritical units employ high-speed centrifugal pumps or plunger pumps.  Requires high reliability, usually configured with "1 operating + 1 standby" or "2 operating + 1 standby" arrangements.

Precautions:

Prevent cavitation by ensuring stable deaerator water level and pressure.  Monitor bearing temperature and vibration to avoid overheating damage.  Regularly inspect mechanical seals to prevent leaks.

(2) Circulating Water Pump

Supplies cooling water (seawater, freshwater, or recirculated cooling water) to the condenser.  High flow, low head (typically ≤30 m), often using double-suction split-case pumps, axial flow pumps, or mixed-flow pumps.  Must be corrosion-resistant (e.g., duplex stainless steel or titanium alloy for seawater applications).  Some plants use variable frequency drives (VFDs) to adjust flow seasonally.

Precautions:

Prevent seawater corrosion;   regularly inspect impellers and casings.  Avoid cavitation by ensuring sufficient submergence at the suction inlet.  Implement freeze protection in winter to prevent cooling water from freezing.

(3) Condensate Pump

Transfers condensate from the condenser to the deaerator. Handles near-saturated pure water;   designed with low NPSHr (Net Positive Suction Head required).  Typically uses vertical can-type pumps or multistage centrifugal pumps.

Precautions:Maintain stable condenser water level to prevent pump dry running. Monitor sealing water systems to avoid air ingress affecting vacuum. Regularly check bearing alignment and coupling conditions.

(4) Cooling Water Pump

Provides cooling water for bearings, motors, and other equipment. Usually single-stage centrifugal pumps with small flow rates but high stability requirements.

Precautions:Ensure cooling water cleanliness to prevent clogging.Monitor motor current to avoid overload operation.

(5) Ash/Slurry Pump

Transports flue gas desulfurization (FGD) wastewater or ash/slag mixtures.Highly wear-resistant design (e.g., ceramic-lined or high-chrome alloy impellers).Handles high-solid-content media, making them prone to wear.

Precautions:Regularly inspect impeller and casing wear, replacing vulnerable parts promptly.Prevent blockages by ensuring proper fluidity of the medium.

Conclusion

Water pumps in thermal power plants play a vital role in ensuring operational efficiency and safety.   Proper selection, operation, and maintenance are crucial to minimizing downtime and optimizing performance.   With advancements in energy-efficient designs (e.g., VFDs, optimized impellers) and smart monitoring systems, future pump systems will further enhance plant reliability and reduce energy consumption.