1. Fault definition of Marine diesel engine.

Marine diesel engine is a kind of complicated thermal machinery.
Complicated working conditions and poor working conditions.
Therefore, it is inevitable that a fault occurs in use.
The accident that the ship diesel engine loses the regulation function becomes the ship diesel engine failure.

The category of fault of Marine diesel engine includes two aspects:

The failure caused by the failure of the ship's diesel engine caused immediate loss of function.
Such as Marine diesel engine burning, holding tank, etc.
 

The reduction of the performance of the ship caused the performance of the diesel engine to decrease.
If Marine diesel engine smoke, oil consumption increase, etc.
 

2. Classification of Marine diesel engine failure.

Marine diesel engines can be classified in different ways.
 

The fault of the essential fault is the essential failure due to the intrinsic factor or defect of the Marine diesel engine and its parts.
For example, Marine diesel engine cylinder nest erosion, connecting rod fracture.
 

The failure of a fault to be used or caused by an external factor is called a misuse failure.
If the oil slick is not enough to cause burning, etc.
 

A derived fault caused by a fault of a subordinate fault.
Also known as related failures.
Such as the body crack caused by the fracture of the connecting rod bolt.
 

2.1 according to the damage fault severity and classification of ship diesel engine fault according to the severity and the damage, can be divided into the cause of failure, severe failure, general fault and mild four classes.
 

In the case of fatal failure, the failure of an important part is called a fatal failure.
Also known as hazard failure.
Such as connecting rod bolt, broken body, etc.
 

The main performance index of the diesel engine is over the limit, and the failure of the main parts damage or disassembly is called a serious fault.
Such as high fuel consumption, piston ring rupture, etc.
 

In general, the diesel engine needs to be shut down for maintenance, and it is necessary to replace the non-essential parts. The faults which can be excluded by the random tools are generally referred to as minor faults.
If three leaks (leakage, leakage, oil leakage), cover plate damage, etc.
 

In the case of a minor fault, the ship's diesel engine will not be shut down, and no replacement parts will be needed. The fault that can be eliminated in a short time by the random tool is called a minor fault.
If the ship diesel engine seal leakage, cover plate screw loose, etc.
 

2.2 the fast and slow classification of Marine diesel engine according to the time of failure can be divided into two types: sudden failure and gradual failure.
 

The sudden onset of a sudden failure in a short time can not be predicted by early diagnosis.
Such as connecting rod bolt, valve spring break, etc.
 

There is a gradual process of gradual failure, which can be predicted by early diagnosis.
Such as cylinder liner wear, valve leakage, etc.

2.3 according to the location of the faults, the diesel engine can be divided into two types: the whole machine fault and the parts failure.
 

The fault of the whole machine is also called comprehensive fault.
It affects the whole machine performance, the reason is comprehensive.
Such as starting, low power, flying car, unstable speed, abnormal pressure, etc.
 

The fault of a part refers to the failure of a part.
If the gear breaks, the pump pump is too small.
 

The fault of Marine diesel engine according to its cause and phenomenon can be divided into three categories: wear fault, fault and weak fault.
 

The failure caused by the excessive wear of the friction pair is called the wear failure.
This fault is a predictable failure in normal wear under normal conditions.
If the piston ring is excessively worn, causing serious air leakage and insufficient power, this kind of failure usually has no serious consequences.
 

The fault of the misused fault in the actual use condition is more than the fault caused by the original design ability.
If overload use of Marine diesel engine caused black smoke, shafting fracture and so on.
 

(3) under the condition of weak fault in actual use, the load does not exceed the design ability, design error cause some weak links, resulting in failure of parts of incapacity as weak fault.
Most of these failures occur on newly developed models.
Generally, the parts are broken, shafting and bracket breakage.