Power Plant EDI Modules: Function and Application for High-Purity Water Systems

Application

Function of EDI Modules in Thermal Power Plants

In the application of EDI modules in thermal power plants water is not merely a medium but the lifeblood of the entire system, circulating and transferring heat and energy. The core water circuits, including boiler feedwater, condensate, and stator cooling water, run through the plant like arteries.

Maintaining high water purity is essential to prevent corrosion, scaling, and salt deposition. EDI modules provide a continuous, stable, and chemical-free desalination process, ensuring reliable water quality and supporting efficient, long-term plant operation while avoiding unplanned shutdowns.

Why Power Plants Depend on High-Purity Water

High-pressure boilers and steam turbines operate under extreme conditions, placing strict demands on water purity. ASME standards limit silica to no more than 0.02 mg/L. The VGB-S-010-T-00:2011-12.EN standard further requires, at 25 °C, conductivity ≤ 0.08 µS/cm, silica ≤ 0.010 mg/L, and sodium ≤ 0.005 mg/L. If these standards are not met, calcium and magnesium cause scaling, oxygen and carbon dioxide drive corrosion, and impurities recirculate to form hidden deposits. The higher the water purity, the more stable and efficient the system.

Some Functions of EDI Modules in Thermal Power Plants

From Reverse Osmosis to EDI – The Final Step Toward Ultra-Pure Water

A modern power plant generally uses the following water treatment sequence:

Raw Water → Pretreatment → Reverse Osmosis → EDI → Mixed-Bed Ion Exchange → Storage → Boiler.

In this process, EDI (Electrodeionization) provides deep deionization. It replaces traditional mixed-bed systems, requires no acid or alkali regeneration, and continuously produces ultra-pure water, making it a safer, more environmentally friendly, and low-maintenance solution.

With years of experience in industrial water treatment, we understand the stringent water quality requirements of thermal power systems. To meet boiler feedwater and condensate polishing needs, we developed a new generation of EDI modules that deliver an optimal balance of performance, durability, and safety.

Internal Structure of EDI Modules for Thermal Power Plants

Technical Advantages of SNOWATE EDI

The core components of our EDI modules use high-specification materials. High-performance ion exchange membranes and platinum-coated titanium anodes ensure long-term stability in high-purity water production. Each module features a fully filled structure, with both dilute and concentrate chambers packed with Dow ion exchange resin to improve deionization efficiency and maintain consistent product water quality. In operation, the modules achieve a 5–8 year service life and provide a warranty of over 3 years. They offer notable energy savings, strong acid and alkali resistance, and require no chemical regeneration, delivering both efficiency and environmental benefits.

In structural design, we emphasizes both safety and practicality. The power connector and water inlet are positioned on opposite sides to prevent electrical risks in case of leakage. An aviation quick-connect makes installation faster and safer, while a dedicated lifting handle improves handling and protects the equipment. The end plate is thickened, and the recessed water port reduces impact risk.

Stainless steel extended cover-type nuts save installation space and time, resulting in a more compact and stable assembly. The module also includes metric-universal adapters and a 3-meter cable for direct power connection without welding. Its clean, industrial design reflects the high-end engineering aesthetics of the new-generation EDI technology.

In thermal power generation, water quality stability directly affects unit reliability. With professional EDI technology, We helps power plants and EPC projects achieve an optimal balance between stability and energy efficiency. If you are evaluating upgrades for boiler feedwater or condensate systems, our engineering team can provide full technical support and customized solutions. Together, we can make energy cleaner and project operation more controllable.