英文叫anode rod 请看ZT
The anode rod is usually an aluminum or magnesium rod placed in a gas water heater tank and is used to protect against corrosion of the tank. It is sometimes called a sacrificial anode since it dissolves slowly and sacrifices itself to protect the metal tank. As the anode reacts with substances in the water, it undergoes an electrochemical reaction and draws corrosion to itself rather than the glass lined steel tank.