Managing Issues in Generator Component Reliability

 
During the operation of generator sets, components often face issues such as wear, deformation, fatigue fracture, and corrosion. These phenomena not only affect the performance and efficiency of the generator set but can also lead to equipment failure and downtime, thus impacting the stability of power supply. Therefore, understanding and analyzing the mechanisms behind these issues is crucial for enhancing the reliability and extending the lifespan of generators. This article will discuss in detail the principles, classifications, and preventive measures of common issues like wear, deformation, fatigue fracture, and corrosion in generator components.
 

Wear Mechanisms Explained

Wear refers to the phenomenon where surface material is gradually lost due to the contact and relative movement of surfaces. Based on the mechanisms and characteristics of surface damage, wear can be classified into four types.
 

1. Abrasive Wear

 
Abrasive wear occurs when surface material is lost due to friction between the surface and abrasive particles. This is the most common and detrimental type of mechanical wear, accounting for over 50% of all wear cases. In field operations, harsh conditions can cause parts to come into direct contact with sand, rocks, and ash, leading to abrasive wear. Preventive measures include preventing or reducing the entry of abrasive particles between friction surfaces and enhancing the wear resistance of parts.
 

2. Adhesive Wear

Adhesive wear occurs when frictional heat causes the surface metal to melt due to the rapid temperature rise. Subsequent cooling leads to the welding of surfaces. The welded spots are torn apart during further movement, transferring material from one surface to another.
 

3. Surface Fatigue Wear

Surface fatigue wear happens when rolling or sliding-rolling friction causes cyclic contact stress, leading to the formation of micro-cracks on the material surface. As cracks propagate, high pressure from lubricating oil within the cracks causes spot-like material loss, such as bearing surface wear and gear surface wear.
 

4. Corrosive Wear

Corrosive wear is a type of mechanical-chemical wear where the metal undergoes chemical or electrochemical reactions with surrounding media during friction, resulting in surface material loss. This phenomenon is more likely to occur in high-temperature or humid environments, especially under specific media conditions like acids, alkalis, and salts.
 

Deformation in Generator Components

Deformation refers to the change in size or shape of engine parts under force during use. Deformation can significantly affect the performance and lifespan of the engine assembly. Understanding the mechanisms and influencing factors of deformation is crucial for preventing deformation and repairing deformed parts. Deformation can be categorized into elastic and plastic deformation:

Elastic Deformation: Temporary deformation that can completely recover upon removal of external force, usually small in magnitude.
Plastic Deformation: Permanent deformation that remains even after the external force is removed.
 

Fatigue Fracture in Generator Components

Fatigue fracture refers to the breaking of parts after repeated stress or energy load cycles. Approximately 60%-80% of part fractures during use are fatigue fractures. They occur at stress levels below the material's tensile strength or yield limit, displaying brittle fracture characteristics without significant plastic deformation, regardless of whether the material is brittle or plastic.
 

Corrosion in Generator Components

Corrosion is the failure of metal parts due to interaction with the surrounding environment, primarily including chemical corrosion, cavitation, and electrochemical corrosion.
 

1. Chemical Corrosion

Chemical corrosion involves the direct chemical reaction between metal parts and the medium, leading to failure. Corrosion products form directly at the corrosion site, creating a surface film whose properties determine the corrosion rate.
 

2. Cavitation

Cavitation (or pitting) occurs when parts in contact with liquid experience high-frequency impacts, causing surface failure. This manifests as pits and pinholes in localized areas, which can cluster into honeycomb-like cavities.
 

3. Electrochemical Corrosion

Electrochemical corrosion involves the electrochemical reaction between the metal surface and the surrounding medium, generating electrical currents that cause corrosion.

Wear, deformation, fatigue fracture, and corrosion are inevitable in generator components during use. These issues are influenced by material properties, working environments, loads, friction, and chemical media. By thoroughly studying these mechanisms and implementing preventive and maintenance measures, the reliability and lifespan of generators can be significantly improved. Advancements in materials and technologies are expected to further reduce these failures, ensuring stable generator operation and a reliable power supply.