Diesel Generator Sets: Fuel Tank Types and Their Importance

 
Diesel generator sets are essential backup power equipment, capable of providing stable electrical energy during power outages through fuel combustion. To ensure that the generator sets start promptly and run continuously in emergencies, fuel storage and management are crucial. Based on usage requirements and environmental conditions, diesel generator fuel tanks can be categorized into three types: sub-base fuel tanks, underground fuel tanks, and aboveground fuel tanks. Each type has unique structural characteristics, applications, and safety requirements, and users should select the appropriate storage solution based on their specific situation.

Sub-Base Fuel Tanks

 
Sub-base fuel tanks are common auxiliary facilities for diesel generator sets, primarily used for medium and small fuel storage needs. Their compact design and efficient performance make them widely applicable, providing reliable fuel supply for generator operation. Below is a detailed overview of their structure and applications.

1. Structural Features

 
Sub-base fuel tanks are typically used to store less than 3,785 liters (approximately 1,000 gallons) of fuel and are designed as rectangular double-walled fuel tanks. They are installed beneath the generator set and above ground, saving space. The double-wall design enhances the fuel tank's strength and effectively prevents fuel spillage during leaks. These tanks are usually constructed from large-diameter welded steel, creating an isolation space between the inner and outer walls to detect and prevent fuel leaks.

2. Accessories and Functions

 
Sub-base fuel tanks are equipped with fuel supply and return ports, exhaust ports, emergency pressure relief valves, and high/low fuel level alarm devices. These pipes and accessories connect to the main fuel tank, ensuring safety and efficiency during fuel filling, transportation, and usage. The filling system is designed with an automatic shutoff feature that closes the inlet valve when the tank reaches 95% capacity, preventing overflow.

3. Safety Testing

 
After installation, the main fuel tank must be tested at 5 psig (approximately 34.5 kPa), while the secondary fuel tank is tested at 3 psig (approximately 20.7 kPa) to verify its seal and safety, ensuring the tank's reliability during use.

Underground Fuel Tanks

 
For situations requiring large fuel storage capacity, underground fuel tanks are an ideal choice for storing diesel for generator sets. They effectively isolate from external environmental impacts and offer longer service life and higher safety. Below are their structural, material, and safety features.

1. Structure and Materials

 
Underground fuel tanks are suitable for storing over 3,785 liters of fuel. Although initial installation costs are higher, their isolation from the environment leads to a longer lifespan. These tanks can be made from fiberglass reinforced plastic (FRP) or steel. FRP offers advantages like corrosion resistance, lightweight, and high strength, usually designed with ribbed structures to enhance compressive strength. Steel fuel tanks require cathodic protection to prevent corrosion from groundwater.

2. Piping and Connections

 
Fuel transport pipes between underground fuel tanks and diesel generator sets can be made of FRP or cathodically protected steel pipes. FRP pipes are lightweight, durable, and easy to install, with excellent corrosion resistance; cathodically protected steel pipes effectively resist corrosion while ensuring strength.

3. Safety Measures and Leak Prevention

 
The risk of leaks and spills in underground fuel tank systems is significant, potentially causing severe environmental pollution and economic loss. Therefore, these systems must be equipped with spill prevention devices and emergency response procedures. During installation, concrete floors and walls should be constructed around the fuel tank to contain spilled fuel. Once installed, the surrounding area should be filled with sand and gravel to enhance the tank's stability and safety.

Aboveground Fuel Tanks

 
Aboveground fuel tanks are another common fuel storage method, especially suitable for storing and managing large volumes of fuel. Compared to underground tanks, they are easier to install and maintain but require stricter safety measures for fire and leak prevention. Below, we detail the characteristics, installation requirements, and application scenarios of aboveground fuel tanks.

1. Structural Features and Application Scenarios

 
Aboveground fuel tanks are installed above ground and are suitable for storing large volumes of fuel. Their structure is similar to that of underground fuel tanks, typically cylindrical or rectangular, either single-wall or double-wall. Although installation is relatively straightforward, being exposed to the elements necessitates higher protective measures.

2. Fire Safety and Safety Distances

 
Due to the fire risk posed by exposed aboveground fuel tanks, they must maintain a certain distance from other facilities to minimize fire spread risks. Additionally, a containment bund should be constructed around the fuel tank, typically with a volume equal to 110% of the tank's capacity to collect any leaked fuel and prevent its dispersion.

3. Structural Protection and Maintenance

 
To protect against external damage, aboveground fuel tanks should be equipped with protective structures, such as wind and sun shields or fencing. Regular inspections and maintenance are essential to ensure structural integrity and functionality, preventing corrosion or damage due to prolonged exposure.

Selecting and Applying Fuel Tank Types

 
When choosing a fuel tank type for a diesel generator set, users must consider fuel storage volume, installation environment, and safety requirements comprehensively. Each fuel tank type has unique advantages and applicable scenarios.

1. Application Scenarios for Sub-Base Fuel Tanks

 
Sub-base fuel tanks are suitable for small or medium diesel generator sets, easy to install, space-saving, and ideal for lower fuel storage needs, such as in office buildings, data centers, or small industrial facilities.

2. Application Scenarios for Underground Fuel Tanks

 
Underground fuel tanks are ideal for long-term fuel storage and areas with high safety requirements, such as large industrial parks, military bases, and backup power systems needing long-term operation. Their isolation from external environments effectively prevents adverse effects on the tanks, leading to longer service life.

3. Application Scenarios for Aboveground Fuel Tanks

 
Aboveground fuel tanks are suitable for situations requiring large fuel storage, such as factories, mines, and transportation hubs. These fuel tanks are relatively easy to install, but strict adherence to safety standards is necessary for protection and management to reduce fire and leak risks.

Conclusion

 
The selection and management of fuel tanks for diesel generator sets directly affect the stability and safety of equipment operation. Sub-base fuel tanks are suitable for medium and small storage needs, offering compact structures and easy installation; underground fuel tanks cater to large fuel storage with high safety and longevity; aboveground fuel tanks are easy to install and maintain but require enhanced safety measures. Choosing the appropriate fuel tank type based on actual needs and strictly adhering to relevant standards and regulations during installation and maintenance can effectively ensure the continuous power supply capability and safe operation of diesel generator sets.