Coastal thermal power plants rely heavily on seawater for condenser cooling and circulating water systems. While abundant and cost-effective, seawater carries a wide range of marine organisms, including algae, barnacles, mussels, and microbial spores. These organisms easily attach to the inner walls of cooling pipelines, heat exchangers, and condenser surfaces, forming persistent marine bio-fouling layers. Bio-fouling poses severe operational threats to power plants: it reduces heat transfer efficiency, increases pipeline flow resistance, elevates energy consumption, and even triggers pipeline corrosion and equipment failure, leading to unplanned downtime and soaring maintenance costs. As traditional anti-fouling methods face obvious limitations, seawater electro-chlorination has become a reliable, eco-friendly, and cost-efficient solution for long-term marine bio-fouling control in coastal power plants.
1. The Hazards of Marine Bio-Fouling to Coastal Thermal Power Plant Operations
Marine bio-fouling is an inevitable challenge for all seawater-cooled thermal power plants. The entire cooling water system, from intake pipelines to precision condenser equipment, provides a stable attachment and growth environment for marine microorganisms and macro-organisms. Once bio-fouling accumulates, a series of negative chain reactions will occur in plant operation.
First, the biological attachment layer forms a thermal barrier on heat exchange surfaces, significantly reducing the cooling efficiency of condensers. To maintain rated power generation capacity, power plants have to increase circulating water flow and unit operating load, resulting in a continuous rise in power consumption and a decline in overall power generation efficiency. Second, bio-fouling blocks local pipeline sections, increases water flow pressure loss, and exacerbates pipeline aging. Meanwhile, the metabolites and dead organisms of fouling creatures will accelerate electrochemical corrosion of metal equipment, shortening the service life of cooling system facilities.
In addition, traditional manual cleaning and regular chemical dosing require frequent system shutdowns, disrupting continuous power generation schedules and bringing huge economic losses. Improper chemical dosing will also cause residual chemical pollution to adjacent marine environments, failing to meet modern environmental protection and sustainable operation standards of power enterprises.
2. Working Principle of Seawater Electro-Chlorination Anti-Fouling Technology
Seawater electro-chlorination is an on-site, on-demand water treatment technology that fully utilizes natural chloride ions in seawater to achieve efficient bio-fouling inhibition without additional large amounts of chemical agents. The core of the technology lies in the electrolytic reaction of natural seawater through professional electrolytic cell equipment.
When pretreated seawater flows through the titanium-coated electrolytic cell with stable direct current, chloride ions (Cl⁻) in seawater undergo oxidation reaction at the anode to generate chlorine, which further reacts with water molecules to produce hypochlorous acid (HClO) and hypochlorite ions (ClO⁻). These active chlorine substances have strong oxidizing properties and can efficiently destroy the cell structures of marine microbial spores, algae larvae, and shellfish fertilized eggs in seawater.
Different from traditional high-concentration intermittent chemical disinfection, electro-chlorination realizes continuous low-concentration active chlorine dosing in the circulating water system. The trace active chlorine evenly spreads throughout the entire cooling pipeline and heat exchange system, inhibiting the attachment and reproduction of marine organisms in real time. After completing the anti-fouling function, active chlorine will naturally decompose in seawater without harmful residual accumulation, realizing zero secondary pollution to the marine ecological environment.
3. Core Advantages of Electro-Chlorination Over Traditional Anti-Fouling Methods
Compared with traditional manual cleaning, chemical agent dosing, and ultraviolet sterilization anti-fouling technologies, seawater electro-chlorination has obvious comprehensive advantages in operational stability, economic benefits, and environmental compliance, making it the mainstream anti-fouling solution for modern coastal thermal power plants.
Stable and Continuous Anti-Fouling Effect. Traditional chemical dosing adopts intermittent high-concentration treatment, which will cause periodic rebound of marine organism populations, resulting in unstable anti-fouling effects. Electro-chlorination supports 24-hour continuous online operation, maintaining stable trace active chlorine concentration in the cooling system all year round, fundamentally preventing the formation and accumulation of bio-fouling, and keeping heat exchange equipment and pipelines clean for a long time.
Low Operational and Maintenance Costs. The technology only relies on seawater and electricity for operation, eliminating the procurement, transportation, storage, and manual dosing costs of hazardous chemical agents such as liquid chlorine and sodium hypochlorite. The electrolytic cell equipment has a long service life and low failure rate, with simple daily maintenance. Practical application data of multiple power plants shows that electro-chlorination can reduce the overall anti-fouling operational cost by nearly 40% compared with traditional chemical treatment.
High Environmental and Operational Safety. It completely avoids safety risks such as chemical leakage, explosion, and corrosion caused by manual chemical handling. The decomposed active chlorine produces no toxic and harmful residues, which meets strict marine environmental protection discharge standards and helps power plants achieve green and low-carbon operation. In addition, the fully automated operation mode reduces manual intervention, effectively lowering human operation errors and safety accidents.
4. Practical Application Value for Coastal Thermal Power Plants
For coastal thermal power plants pursuing long-term stable operation and refined energy conservation and emission reduction, seawater electro-chlorination is not only a bio-fouling control technology but also an important support for optimizing plant operational efficiency and improving economic benefits.
Long-term stable anti-fouling effect ensures the efficient operation of condenser and cooling water systems, maintaining the optimal heat transfer efficiency of units and reducing auxiliary power consumption. It minimizes equipment corrosion and pipeline aging caused by bio-fouling, extending the service life of circulating water system equipment and reducing equipment replacement and maintenance costs. Meanwhile, it avoids frequent shutdown cleaning caused by bio-fouling blockage, guarantees continuous and stable power generation output, and effectively improves the economic operation level of power plants.
In the context of increasingly strict global marine environmental protection regulations, this green anti-fouling technology also helps power plants comply with environmental discharge standards, reduce ecological impact on coastal waters, and enhance the green brand image of enterprises.
Conclusion
Marine bio-fouling is a key factor restricting the efficient and stable operation of coastal thermal power plants. Traditional anti-fouling methods can no longer meet the dual requirements of modern power plants for operational efficiency, economic cost, and environmental protection. Seawater electro-chlorination technology, with its principles of on-site preparation, continuous anti-fouling, low energy consumption, and zero pollution, perfectly solves various pain points of marine bio-fouling control. It has become the most reliable and cost-effective green solution for seawater cooling system anti-fouling in coastal thermal power plants, and will continue to be widely promoted in the global thermal power industry.