HPMA in power plants
BACKGROUND
Cooling and boiler water systems in power plants often face problems such as scale formation, corrosion and suspended solids deposition, which can seriously affect the operational efficiency and life of the equipment.The application of HPMA in these systems can effectively solve these problems.
Specific applications
- Scale inhibition
- Function: Prevent hardness ions such as calcium and magnesium in water from forming scale inside pipes, heat exchangers and boilers.
- Principle:
- Complexation: The carboxyl group (-COOH) in the HPMA molecule can form stable complexes with calcium, magnesium and other divalent metal ions in the water, and these complexes remain dissolved in the water and will not be deposited on the surface of the equipment.
- Crystal lattice distortion: Hydrolyzed Polymaleic Anhydride molecules can be adsorbed on the active point of crystal growth, interfering with the normal growth of crystals, leading to changes in crystal morphology and the formation of irregular crystals, which are not easy to be deposited on the surface of the equipment.
- Effect: Significantly improve the heat transfer efficiency, reduce energy loss, and extend the service life of the equipment.
- Dispersing effect
- Function: disperses the suspended matter and tiny particles in the water, preventing them from being deposited on the surface of the equipment.
- Principle:
- Electrostatic repulsion: HPMA molecules are negatively charged, which can be adsorbed on the surface of suspended particles, making the particles carry the same charge, generating electrostatic repulsion, preventing particles from gathering with each other and keeping them suspended.
- Spatial resistance effect: HPMA molecules are long, can form a protective layer on the surface of the particles, increase the physical distance between the particles, to prevent the particles from aggregating with each other, to maintain the suspension state.
- Effect: Reduce pipeline clogging, improve the smoothness of water flow, reduce maintenance costs.
- Corrosion inhibition
- Effect: Forms a protective film on the metal surface, slowing down the corrosion rate of the metal.
- Principle:
- Adsorption: The carboxyl group in HPMA molecule can be chemically adsorbed with the active point on the metal surface, forming a dense protective film, isolating the corrosion medium and slowing down the corrosion rate of the metal.
- Complexation: HPMA molecules can form stable complexes with metal ions to reduce the dissolution of metal ions, thus slowing down the corrosion process.
- Effect: Extend the service life of the equipment, reduce the maintenance and replacement costs caused by corrosion.
- pH Adjustment
- Effect: Adjust the pH value of water and maintain it in a suitable range to prevent acidic or alkaline corrosion.
- Principle:
- Buffering effect: The carboxyl group in the HPMA molecule can react with hydrogen ions (H+) or hydroxide ions (OH-) in the water to regulate the pH value of the water. In acidic environment, HPMA can combine with H+ to reduce acidity; in alkaline environment, HPMA can combine with OH- to reduce alkalinity.
- Neutralisation: By adding appropriate amount of HPMA, it can neutralise the acidic or alkaline substances in the water and keep the pH value of the water within a suitable range.
- Effect: Keep the system water quality stable and reduce the risk of corrosion.
Successful Cases
- Cooling water system of a coal-fired power plant:
- Problem: Serious scale and corrosion problems existed in the cooling water system, leading to a decrease in heat transfer efficiency and an increase in maintenance costs.
- Solution: Adding appropriate amount of HPMA to the cooling water effectively solves the scale and corrosion problems through scale inhibition, dispersion and corrosion inhibition.
- Effect: Heat transfer efficiency is significantly improved, maintenance costs are reduced, and the service life of the equipment is extended.
- Boiler water system of a nuclear power plant:
- Problem: Serious scale and corrosion problems exist in the boiler water system, affecting the operating efficiency and safety of the boiler.
- Solution: Adding an appropriate amount of HPMA to the boiler water effectively solves the scale and corrosion problems through scale inhibition, dispersion and corrosion inhibition.
- Effect: Boiler operation efficiency is improved, maintenance cost is reduced and safety is guaranteed.
