Analysis of Fault Reasons for High Water Temperature of Diesel Engine
Abstract
High water temperature can cause a variety of problems for diesel engines, such as power loss, incomplete combustion, and even cylinder head gasket damage. In this article, the main fault reasons for high water temperature of diesel engine are analyzed, and the corresponding countermeasures are proposed to ensure the safe and stable operation of the diesel engine. Contents include: 1, engine over-loaded; 2, engine design defects; 3, cooling system performance degradation; 4, cooling system dirt and blockage; 5, anti-freeze cannot meet the requirements; 6, air filter blockage; 7, thermostat failure; 8, specific fault diagnosis.
Key words: diesel engine; high water temperature; fault diagnosis and repair
1 Introduction
The diesel engine is widely used in the ship, automobile, generator and other fields. Most of the engine components will be damaged or destroyed by high water temperature, resulting in the inability to normally operate. Therefore, the cooling system must operate normally, monitor the water temperature in time, and have a large enough cooling capacity to ensure that the diesel engine operates safely, stably and economically.
2 Reasons for High Water Temperature of Diesel Engine
2.1 Engine over-loading
In general, the maximum permissible load of a diesel engine should not exceed 80% of the rated value. When the diesel engine is running at a high load, the cooling water temperature rises rapidly, and the cooling system cannot dissipate the heat generated in time, resulting in high water temperature. In order to solve this kind of problem, the operator should strictly adhere to the operating regulations and reduce the engine load when the temperature is high.
2.2 Design Defects of Engine
When the design diesel engine has problems or its performance fails to meet the standards, the cooling system may not be able to reach the optimum effectiveness. Furthermore, the design of the engine layout can lead to a poor radiation effect, resulting in accumulation of heat in the engine housing. To solve this problem, an improved engine design should be adopted.
2.3 Degradation of Cooling System Performance
The normal performance of the cooling system is affected by many factors such as sediment, rust and scale deposition. Once the water tank is blocked, the heat exchange area is reduced, the water temperature rises, and the cooling effect decreases. In order to prevent this kind of fault, it is necessary to check the cooling system regularly and maintain it in time.
2.4 Cooling System Pollution and Blockage
In order to reduce the water temperature, attention should be paid to keep the cooling system clean of dirt, rust and small particles. Otherwise, due to the blockage of the cooling channels, the water temperature will go up quickly. Therefore, it is necessary to develop the correct cleaning procedures, pay attention to the water quality and add the coolant in time.
2.5 Anti-freeze Cannot Meet the Requirements
In hot areas, when the antifreeze environment temperature is lower than the engine cooling water temperature, it is difficult for the diesel engine to dissipate heat rapidly, making its heat exchange capacity insufficient and the water temperature rising. Therefore, it is necessary to choose the antifreeze with lower boiling point than the normal cooling water temperature according to the local ambient temperature, and replace the antifreeze with new one periodically.
2.6 Air Filter Blockage
When the air filter is blocked, the supply of fresh air is not sufficient, resulting in lack of intake air and an increase of the exhaust temperature. This is because the combustion chamber absorbs the intake air in order to meet the need of air supply. As a result, the cooling systems cooling and heat dissipation capacity is reduced and the water temperature rises. Therefore, it is necessary to check the air filter regularly to ensure that the air filter is clean.
2.7 Thermostat Failure
The thermostat is an important part of the engine cooling system, which plays a significant role in controlling the water temperature by regulating the cooling water circulation. When the thermostat is damaged, it will lead to an increase of the water temperature and an insufficient heat dissipation capacity of the radiator. Therefore, it is necessary to check and maintain the thermostat in time.
2.8 Specific Fault Diagnosis
Below are several fault diagnosis methods for high water temperature of diesel engine:
(1) Check for a short-circuit in the wiring. A short-circuit in the wiring can cause a wrong signal to be sent to the engine and cause the coolant to be over-heated.
(2) Check for a leaking cylinder head gasket. If the cylinder head gasket is leaking, if not addressed, it can cause the engine to overheat.
(3) Check air filter element. A clogged air filter can cause the engine to over-consume diesel, leading to an increase of exhaust gas temperature and an overheat of the coolant.
3 Conclusion
High water temperature of diesel engine is a common fault. The main reasons are as follows: engine over-loading, engine design defects, cooling system performance degradation, cooling system dirt and blockage, anti-freeze cannot meet the requirements, air filter blockage, thermostat failure, and specific fault diagnosis. Once the fault occurs, appropriate measures should be taken in time, to maintain the normal operation of the diesel engine.
