Power plant cooling water circulation system and its vertical long axis semi submersible turbine pump solution

The cooling water circulation system of power plants is a key system to ensure the stable operation of power plant equipment. It carries away the heat generated by equipment operation by conveying cooling water, avoiding equipment overheating faults and improving energy utilization efficiency. The system mainly consists of a cooling water tank, a circulating water pump, a pipeline system, a cooling tower, and heat exchange equipment (such as a condenser). The workflow is as follows: the water in the cooling water tank is pumped out by the circulating water pump, transported through pipelines to the heat exchange equipment to absorb heat, then enters the cooling tower to dissipate heat and cool down, and finally flows back to the cooling water tank to form a cycle.
Solution for vertical long shaft semi submersible turbine pump in power plant cooling water circulation system
1. Equipment selection and adaptation
Conventional freshwater cooling scenario: A vertical long shaft semi submersible turbine pump with multi-stage impeller design is selected, with a head covering 10-400 meters and a flow rate of 80-5600 m ³/h, suitable for the continuous operation of large flow in power plants; The pump body is made of duplex steel material, which is corrosion-resistant and wear-resistant, and can handle circulating water media containing small amounts of impurities.
Coastal power plant seawater cooling scenario: The seawater circulation pump adopts a vertical long axis semi submersible turbine pump structure, which belongs to the VS1 basic pump type in the API610 standard. Key components such as the pump shaft, impeller, and guide vane body are made of super duplex stainless steel material, which has excellent resistance to chloride stress corrosion cracking and can adapt to strong corrosive seawater environments; The design flow rate of a single pump can reach 2500-5000m ³/h, with a head of 28-56m. In large-scale projects, the highest flow rate can reach 36.2m ³/s, with a head of 16.5m.
2. Stable operation guarantee
Equipped with an external cooling and lubrication system to ensure the normal operation of the guide bearing under high temperature and high load conditions; The rotor of the vertical long shaft semi submersible turbine pump can adopt a pull-out design, which can complete maintenance without disassembling the pump body, greatly reducing downtime.
The core components are equipped with wear-resistant coatings, which can reduce maintenance frequency and extend service life, and are suitable for the transportation needs of high sand content or corrosive media.
3. Energy saving optimization and upgrading
Equipped with an intelligent frequency conversion control system, the water output can be automatically adjusted according to the cooling needs of the power station, seasonal changes, or load fluctuations, achieving an energy-saving effect of 25% -30%.
For seawater circulation pumps in coastal power plants, the three-dimensional flow high-efficiency energy-saving rotor technology can be adopted to significantly improve the operating efficiency of vertical long shaft semi submersible turbine pumps under high flow conditions; Adjustable blade seawater circulation pump can also be used to adjust the blade angle according to the actual operating conditions of the nuclear power unit, optimize the circulating water flow rate, and save motor power consumption.
4. Intelligent control and system optimization
Deploy water temperature, flow, and pressure sensors, build an IoT monitoring network, collect real-time data and upload it to the cloud to achieve data-driven precision scheduling.
Upgrade the management of circulating water quality, add ultrafiltration and reverse osmosis devices, control the turbidity of circulating water to<5NTU and hardness to<100mg/L, and reduce the impact of scaling on heat transfer efficiency; Simultaneously optimize the spray layout and packing structure of the cooling tower to increase the cooling temperature difference by 2-3 ℃, indirectly reducing the demand for circulating water.
Case Study of Circulating Water System in Thermal Power Plant
After a large domestic thermal power plant adopted a vertical long shaft semi submersible turbine pump to construct a circulating water system, the problems of difficult maintenance and high energy consumption of traditional pump types were solved. The efficiency of circulating water transportation was improved by 15%, and the annual operation and maintenance cost was reduced by 2 million yuan, while ensuring the stable operation of the power plant.