Water Filtration Applications in Thermal Power Plant Steam–Water Systems

During the operation of a power plant, the cooling water system and the condensate system have entirely different requirements for water quality stability and reliability, yet both directly impact equipment lifespan, system efficiency, and the risk of shutdown. We provide a comprehensive solution featuring graded filtration and tailored equipment selection based on the operational characteristics of different water systems in power plants, ensuring long-term stable system performance and 

reducing overall maintenance costs.

1. Working Process and Key Filtering Nodes of Thermal Power Plants

The core logic involves generating steam for power production using fuel and recycling water resources, with filtration being key to water quality assurance. The process begins by burning coal or natural gas to heat the boiler, where water turns into high-temperature, high-pressure steam. This steam drives turbines to generate electricity, and the spent steam enters a condenser to be cooled by cooling water into condensate. The cooling tower's water undergoes preliminary filtration to remove large particles like sand before entering the condenser, preventing blockages in heat exchange tubes. The resulting condensate contains fine impurities such as metal particles, which are intercepted by precision filtration and further treated with mixed beds to remove ions. Once water quality meets standards, the purified condensate is recycled back to the boiler for reuse.

2. Cooling Water Filtration Solution

The sources of cooling water include rivers, seawater, lakes, and open or closed recirculating cooling systems. These water sources typically or potentially exhibit characteristics such as high suspended solids content (including sediment, algae, and rust), presence of organic matter and microorganisms, large water volume, and the need for continuous operation. The primary purpose of cooling water filtration is to protect heat exchangers and condensers, preventing issues like scaling, clogging, and corrosion in the system while reducing pressure differential and minimizing unplanned shutdowns;

Common filtration processes can be divided into two stages in order from coarse to fine, the first stage is pre-filtration (coarse filtration), primarily using equipment such as grates, drum screens, Basket Strainers, and automatic backwashing filters, which can remove large particle impurities at the micrometer level and above. The second stage is the core process of fine filtration, which employs Bag Filters, High-Flow Cartridges, and Pleated Filter Cartridges. The filtration precision typically ranges from 5–50 μm, with common grades being 50 μm, 25 μm, and 10 μm;

A common recommendation for filtration solutions in the industry is the combination of an automatic backwashing filter and a high-flow filter element. This approach not only offers advantages such as high flow capacity, compact footprint, and low filter element replacement frequency, but also features filter elements with high throughput, extended service life, and excellent pressure resistance. It significantly reduces the rate of system pressure differential rise and minimizes maintenance frequency, making it particularly suitable for the continuous 24/7 operation requirements of power plants.

3. Condensate Water Filtration Solution 

Condensate originates from turbine exhaust condensate and is high-purity recycled water with very low impurity content. However, contamination can significantly impact the boiler system, thus requiring extremely high filtration standards. The core objective of condensate water filtration is to protect the boiler feedwater system, preventing iron oxides, corrosive particles, and mixed-bed resin powder from entering the boiler, while ensuring consistently low turbidity and controlled metal ion levels.

Common configurations include two options: First, a condensate polishing system, which treats water using a combination of resin and precision filter cartridges, suitable for high-parameter units; second, precision filter cartridge filtration, employing String Wound Filter Cartridges combined with High-Precision Pleated Filter Cartridges, achieving filtration accuracy of 1, 3, or 5 microns. String Wound filter cartridges can serve as pretreatment, protecting the downstream pleated filter cartridges and extending their service life. All filter cartridges must have low precipitation, no fiber shedding, and be temperature and pressure resistant to ensure long-term stable condensate compliance. This solution is widely used in turbine condensate polishing and upstream protection of boiler feedwater systems.

4. List of Filter Application Selection for Power Plants

In summary, although the sources and water quality characteristics of cooling water, condensate water, and boiler feedwater in the steam water system of thermal power plants are different, their filtration goals always revolve around equipment protection and stable system operation. By reasonably setting filtering nodes in different water systems and selecting matching filtering accuracy and filtering forms according to the characteristics of the operating conditions, the risks of equipment scaling, corrosion, and unplanned shutdown can be effectively reduced, providing reliable guarantees for the long-term safe, stable, and efficient operation of the generator set.