How to Improve Fuel Supply Uniformity in Diesel Generator Sets

 
Uneven fuel supply in diesel generator sets poses significant threats to both fuel efficiency and mechanical integrity. This issue can lead to increased fuel consumption and potentially severe mechanical failures, undermining the stability and efficiency of the diesel generator. Multiple factors contribute to this problem in practical operation, including mechanical wear from long-term usage, discrepancies between fuel pump calibration and real-world conditions, among others. Addressing these issues through precise adjustments is crucial for optimizing engine performance and extending its operational life.
 

Analysis of Causes

 
The uneven fuel supply in diesel generator sets can be attributed to various reasons, primarily including the following aspects.
 
1. Mechanical Failures: Over time, internal components such as couplings, drive gears, and fuel injectors can wear or loosen, causing instability in fuel pump operation and resulting in uneven fuel distribution among cylinders. Vibrations or poor fastening of high-pressure fuel pipe joints can also cause fuel leaks, further compromising uniform fuel supply.
 
2. Discrepancies in Test Bench vs. Real Conditions: Fuel pump calibration typically occurs under standard temperature conditions, whereas actual engine operation involves significantly higher temperatures (up to 500-700°C in cylinders) and pressures. These differences affect the precision of fuel injection timing and quantity, contributing to uneven fuel supply during real-world operation.
 
3. Piston and Valve Wear: Prolonged engine use leads to wear on pistons and valves, causing variations in compression temperatures and pressures among cylinders. This uneven wear affects fuel spray patterns, thereby influencing fuel supply to each cylinder.
 
4. Improper Fuel Injection Timing: Accurate adjustment of fuel injection timing is critical. Incorrect timing, whether too advanced or delayed, can disrupt combustion efficiency and overall engine stability.
 
5. Other Fuel System Issues: Problems like clogged fuel filters or blocked/leaking fuel lines can lead to insufficient or uneven fuel supply to certain cylinders.
 

Adjustment Steps

 
Achieving uniform fuel supply in diesel generator sets requires meticulous adjustment of the fuel pump. The following detailed steps outline the adjustment process.
 
1. Initial Adjustment
 
Start the generator set and allow it to idle for 2-3 minutes.
Monitor the operating conditions and exhaust temperatures of each cylinder.
Identify any cylinder significantly hotter than others as an initial indicator of potential over-fueling.

2. Check Fuel Injection Timing
 
Use specialized tools to verify fuel injection timing.
Ensure precise timing adjustments tailored to each cylinder to optimize combustion efficiency.

3. Real-World Adjustment
 
Consider actual operating conditions such as exhaust temperature, pressure, and smoke color to gauge fuel supply adequacy.
Adjust fuel quantity and injection timing gradually to achieve uniform fuel supply among cylinders.
Observe and respond to anomalies such as abnormal temperatures or smoke emissions by further refining pump settings.

4. Fine-Tuning
 
Monitor engine feedback during operation, including changes in exhaust smoke color or noise levels.
Adjust fuel pump parameters to compensate for mechanical wear effects, such as piston and valve wear, based on measured data and test results.

5. Implementation Considerations
 
Account for differences between test bench conditions and actual operating environments.
Adapt fuel pump settings based on accurate assessments of cylinder temperatures and pressures.
Regularly inspect and maintain fuel pumps and related components to sustain stable fuel delivery.
 
By following these comprehensive adjustment steps, diesel generator operators can effectively mitigate uneven fuel supply issues. This approach not only enhances generator reliability and stability but also reduces fuel consumption and extends equipment lifespan. Flexibility in adjustment according to specific operational conditions ensures optimal fuel supply to each cylinder, promoting efficient and reliable generator performance over time.