The Closed Circulating Pure Water Cooling System For The Power Generators

About GWT   News   Products   ● CPCP ● CPCG ● WTS ● ACCESSORIES   Forum                                                     1. Introduction ﹛﹛Because the high thermal efficiency of the water cooling technology, nowadays large generators for high power generation often utilize pure water for stator and sometimes in rotor cooling. As the water enters a high electrical and magnetic environment, and is in contact with copper in the Generator coils, a very low oxygen content and conductivity are essential to the safe and reliable operation of generator. ﹛﹛The purpose of water cooling system is to remove the heat from the stator and rotor coils by water coolant, and then transfer the heat from the closed water system to the cooling media in a water-to-air or water-to-water heat exchanger. Then the cooled water returns to the inlet of high-pressure circulate pump to begin another cooling circulation. ﹛﹛The dielectric properties and corrosion behavior of the water depends on the purity level of water, hence some kind of purifying equipment should be provided. In order to meet the requirement of large generator operating in high voltage, the cooling water must has a very high resistivity and alkalescence. Hence, a water treatment circuit with mixed bed ion exchanger cartridge, fine filter, and make-up reservoirs are adopted. A few percent (5~10%) of the main water flow pass through the water treatment circuit, it captures any charged particles and ions that may contaminate the system to maintain the resistivity of the water above 1M/cm, and carries out the alkalescent treatment to keep the pH of coolant between 7.2~8.6. The buffing reservoir provides a pressurization cushion of nitrogenous gas to avoid the direct contact between the coolant and the oxygen of the atmosphere. ﹛﹛The PLC based control equipment comprises a programmable control, protective and a monitoring system. Although the water-cooling system is usually remotely controlled from a central control room, it can also be operated locally via PLC. The graphic language software provides a high quality user friendly operation. The programmable control system enables well defined transfer functions, easily adjustable parameters, and tolerates partial or modified system operation. The WinCC based control system utilizes the latest technologies to provide an environment as regards security, efficiency and ergonomics. 2. Specification Number Name Specification 1 heat dissipating capacity 100-1500kW 2 Rating coolant flow 20-180T/h 3 Rating deionizing water flow 10-200 l/min 4 Resistivity of coolant >1MW*cm 5 Resistivity of deionizing water >2MW*cm 6 Water temperature in generator inlet 30~40oC 7 Water temperature in generator outlet 40~50oC 8 Content of Cu <10ppb 9 Rating water pressure 4~6 bar 10 PH 7.2~8.6 3. List of water-cooling projects Wuhan Steel Mill electrical power plant the water quality improvement project of large capacity generator with internal water cooling system Hubei Ezhou electrical power plant the water quality improvement project of large capacity generator with internal water cooling system