Control system and control method for impressed current cathodic protection

Abstract

The invention discloses a control system and a control method for impressed current cathodic protection. The control method for impressed current cathodic protection comprises the steps that the potential of an inner container is detected; and current output is controlled according to the detected potential of the inner container so that the potential of the inner container can keep within the preset range. According to the control method for impressed current cathodic protection, the applicable water quality range of the inner container is wide, and the protection effect is good.

Description

technical field [0001] The invention relates to the technical field of anti-corrosion protection, in particular to a control system and control method for forced current cathodic protection. Background technique [0002] There are two types of metal cathodic protection against corrosion: 1. Sacrificial anode cathodic protection; 2. External forced current cathodic protection. In the second scheme, the applied current cathodic protection method involves the electrical control method. The general technique is to directly output direct current in the inner tank and the medium to apply a certain negative current to the protected metal, so that the electrode potential of the protected metal is polarized through the cathode. Reach the set potential protection range to slow down the corrosion and protect the metal. [0003] The above technologies are widely used in ships, reservoir gates, underground pipelines and other places; the application of domestic hot water machine tanks i...

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Problems solved by technology

[0004] Although the technical basic principles and theories are exactly the same, there are great differences in technical details due to different application conditions in specific use; most water heater storage tank products on the market still use sacrificial anode cathodic protection, the most common is the use of magnesium The alloy is used as a sacrificial anode, and this method has the following problems: 1. Consumption of metal; 2. The scope of protection is limited; 3. The power supply provided by the potential difference between the potential of the active metal itself and the protected metal is not adjustable; 4. Pollution of water quality; 5. Regular maintenance is required and the maintenance cost is high; 6. The maintenance cycle is uncertain due to regional water quality differences; 7. Difficult maintenance, etc.

Due to the characteristics of the above products, the forced current cathodic protection needs to be refined, intelligent, and adaptable, and the technical solution is feasible; the ordinary forced current cathodic protection technology uses a simple DC power supply to provide a certain current to the inner liner of the water tank for forced current cathodic protection (Electronic anode); the cathode potential value of the inner tank of the water heater storage tank is different under different water temperature and water quality conditions, and the potential response of the metal in the inner tank is different in different media. When the constant current cathodic protection scheme is adopted, if the current value is too small , the cathodic protection cannot achieve complete protection under the condition of high conductivity water quality; if the current value is too large, over-protection will occur when the water quality conductivity is small; therefore, the ordinary simple control current cathodic protection method is applicable to a small range of water quality ;The protective effect is poor under poor water quality conditions (such as PH value less than 5)

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