Application of high-pressure boiler feed pumps.

1. Main Application Fields

Thermal Power Plants

Subcritical Units: Pressure typically ranges from 15-25 MPa.

Supercritical/Ultra-Supercritical Units: Pressure can be as high as 30-40 MPa, with feedwater temperatures reaching 250-300°C.

The most widespread and demanding application. Whether coal-fired, gas-fired, or oil-fired, any plant using a steam turbine for power generation must employ high-pressure boiler feed pumps.

Parameter Range: Pressures and temperatures are extremely high, increasing with unit capacity and parameters.

Nuclear Power Plants

In Pressurized Water Reactors, feed pumps are used to replenish water in the steam generators (which act as boilers) to maintain the normal operation of the secondary loop. Their reliability and safety requirements are extremely stringent.

Large Industrial Boiler Systems

Petrochemical Industry: Such as ethylene cracker units and refineries, which require high-pressure steam for cracking, catalysis, and heating.

Metallurgical Industry: Provides motive and heating steam for blast furnaces and steel rolling production lines.

Paper, Textile, Pharmaceutical Industries: Require a stable supply of high-pressure steam as a process heat source and for power.

Marine Propulsion

High-pressure boiler feed pumps are needed for the steam turbine propulsion systems of large vessels (e.g., aircraft carriers, large container ships).

2. Operating Environment and Technical Characteristics

High-pressure boiler feed pumps operate under extremely harsh conditions:

High Temperature: The suction water is saturated water from the deaerator, with temperatures reaching 150-180°C. The pump casing must withstand thermal expansion and thermal shock.

High Pressure: The discharge pressure is extremely high, demanding exceptional mechanical strength from the pump casing, shaft, and sealing components.

High Speed: Modern large feed pumps are typically multi-stage centrifugal pumps driven by steam turbines or variable frequency drives, with speeds reaching 5,000-8,000 RPM or even higher to reduce pump size and the number of stages.

Cavitation Resistance: The pump suction is receiving saturated water, making it highly susceptible to cavitation. Therefore, the pump's Required Net Positive Suction Head must be very low, often necessitating a booster pump to provide sufficient suction head.

3. Summary

In conclusion, a high-pressure boiler feed pump is not an ordinary pump. It is a technology-intensive product that integrates cutting-edge technologies from various fields including fluid dynamics, materials science, mechanical engineering, and automatic control. Its application is directly crucial for the safe, efficient, and stable operation of vital industries such as energy, power, and heavy industry.

Its development progresses in lockstep with power generation technology's trend towards higher parameters, larger capacity, and greater efficiency. It is a key indicator of a nation's capability in major equipment manufacturing.