Innovative Chemical Water Treatment (CWT) System for Kharkiv's Heating Networks (CHP-3)
This article presents an overview of the completed project for the reconstruction of a comprehensive Chemical Water Treatment (CWT) system, which is critically important for ensuring the stable and efficient operation of the heating networks in the city of Kharkiv, specifically for CHP-3 (Combined Heat and Power Plant No. 3). The company "EKVIVES", together with leading partners, implemented this project, which represents a significant engineering achievement and guarantees the supply of high-quality treated water necessary for the functioning of the city's heating system.
General Characteristics and Strategic Significance
The CWT system at CHP-3 is a complex engineering facility, designed to treat large volumes of water to protect boiler equipment, pipelines, and heat exchangers from corrosion, scaling (deposit formation), and biological fouling.
Scale: The complex includes 20 pumping stations, numerous reservoirs, and specialized filtration units.
Capacity: The system's design capacity is $500\text{ m}^3/\text{hour}$.
Contribution to Heat Supply: The system provides about 50% of the city's total consumption of treated water for the needs of the heating networks.
The implementation of this system is a key factor in extending the service life of the equipment, reducing operating costs, and increasing the energy efficiency of the Kharkiv heating network.
Technological Water Treatment Scheme
The water purification process is a multi-stage cycle that combines physical and chemical methods to achieve the required water quality parameters.
1. Intake and Primary Water Preparation
The initial stage begins with the intake of raw water from the Udy River.
Main Pumping Station: The most powerful station in the system is equipped with two double-suction pumping units. This ensures reliable and efficient intake of large volumes of river water and its supply to subsequent preparation stages.
Biocidal Treatment: To prevent the growth of microorganisms and biological fouling, which can damage membranes and equipment, a biocide is added at the start of the cycle.
2. Physical Filtration
After primary treatment, the water passes through phases of mechanical purification to remove suspended solids and large contaminants.
Mechanical Filtration: Water passes through mechanical filtration units to remove solid particles.
Ultrafiltration (UF): This is the next critical step, where water is passed through specialized membranes. The UF process effectively removes colloidal particles, viruses, and bacteria, bringing the water to the required density (reducing the Fouling Index or Silt Density Index) before feeding it into the reverse osmosis stage.
3. Deep Desalination and Quality Regulation
The most crucial stage for achieving the chemical quality required for boiler equipment is Reverse Osmosis.
Reverse Osmosis (RO): This is the final membrane filtration process. RO units ensure the retention of dissolved salts, ions, and minerals, bringing the water's hardness and total mineralization indicators to the strict standards required by the thermal power industry.
4. Water Movement and Storage
The movement of water between technological cycles and stations is ensured by a complex network of pumps and reservoirs.
Pumping Stations: The water movement within the preparation system is maintained by numerous pumping stations, predominantly equipped with end-suction and close-coupled end-suction pumps. These units provide the necessary pressure and flow rate for the water to pass through the various preparation cycles.
Reservoir Park: To ensure flexibility and reliability, intermediate reservoirs for storing treated water are integrated before each subsequent station.
Final Preparation and Supply to the Heating Network
The purified water, which meets all chemical requirements, goes through the final stages before being supplied to consumers.
Boiler Units: The treated water is directed to the boiler unit system, where heating and deaeration (removal of dissolved gases, primarily oxygen and carbon dioxide, to prevent corrosion) take place.
Consumer Network: After this, the water reaches its goal, entering the heating network of the city of Kharkiv.
Redundancy and Emergency Reserve
To guarantee uninterrupted heat supply, the project provides for a significant volume of emergency reserves of treated water.
Emergency Reservoirs: A portion of the treated water is constantly stored in emergency reserve tanks. The total volume of these reservoirs is $2,400\text{ m}^3$, which is critical for promptly responding to any emergency situations in the heating supply system.
Conclusion
The completed CWT system project for the Kharkiv heating networks (CHP-3), implemented by "EKVIVES" and its partners, is a model of a modern engineering solution in the field of communal thermal energy. It demonstrates a comprehensive approach to water treatment, combining biocidal treatment, mechanical filtration, ultrafiltration, and reverse osmosis. The efficiency, the capacity of $500\text{ m}^3/\text{hour}$, and the availability of a significant reserve water stock ensure the reliability and longevity of the entire city's heating infrastructure, which is critically important for the stable life of Kharkiv residents.
