Diesel generators are crucial power sources in various settings, from providing backup power during outages in homes and businesses to ensuring continuous operation in industrial and construction sites. Central to the efficient functioning of a diesel generator is the day tank. But what exactly is a day tank, and why is it such an important component? In this article, we’ll explore the ins and outs of day tanks for diesel generators, covering their function, types, installation, and maintenance.
The Fundamental Function of a Day Tank
Fuel Storage for Immediate Use
At its core, a day tank serves as a secondary fuel storage unit for a diesel generator. Its primary purpose is to store a sufficient amount of diesel fuel to meet the generator’s immediate operational needs. The name “day tank” implies that it typically holds enough fuel to power the generator for a day, although the actual capacity can vary depending on the generator’s size and power consumption. For example, in a small – scale office building with a backup diesel generator, the day tank might be sized to provide power for 8 – 12 hours, covering a typical workday in case of a power outage. This ensures that the generator can operate without interruption, even if the main fuel supply system has issues or is temporarily unavailable.
Fuel Conditioning & Settling
Day tanks also play a role in fuel conditioning. Diesel fuel can contain contaminants such as water, dirt, and sediment. When fuel is stored in a day tank, it has a chance to settle. Heavier contaminants like sediment and water tend to sink to the bottom of the tank. This separation process helps to ensure that cleaner fuel is supplied to the generator. Some day tanks are equipped with features to facilitate this, such as a sloped bottom design that directs sediment towards a drain valve. By removing these contaminants, the day tank helps to protect the generator’s fuel system components, like fuel injectors and pumps, from damage, which in turn improves the generator’s performance and longevity.
Types of Day Tanks
Plastic Day Tanks
Plastic day tanks are a popular choice due to their lightweight nature and corrosion – resistance. They are often made from high – density polyethylene (HDPE), which can withstand the corrosive properties of diesel fuel. Plastic day tanks are relatively inexpensive compared to some other types, making them an attractive option for smaller applications, such as residential backup generators. They are also easy to install and can be molded into various shapes and sizes to fit different spaces. However, plastic day tanks may not be as durable as metal tanks in high – impact or extreme – temperature environments.
Metal Day Tanks
Metal day tanks, typically made of steel or aluminum, offer greater durability. Steel tanks are known for their strength and can withstand harsh conditions, making them suitable for industrial and commercial applications where the day tank may be exposed to rough handling or extreme weather. Aluminum tanks, on the other hand, are lighter than steel and also resist corrosion well. Metal day tanks can be painted or coated to further enhance their resistance to rust and other forms of corrosion. They are often used in larger – scale power generation setups, such as those found in data centers or manufacturing plants.
Bunded Day Tanks
Bunded day tanks are designed with an added safety feature. They consist of an inner tank, which stores the diesel fuel, and an outer containment structure, or “bund.” In the event of a leak in the inner tank, the bund is designed to catch the spilled fuel, preventing it from contaminating the surrounding environment. This makes bunded day tanks a crucial choice in areas where environmental protection is a priority, such as near water sources or in environmentally sensitive locations. Bunded day tanks are commonly used in industries that are subject to strict environmental regulations, like the oil and gas industry or in facilities located in urban areas.
Design & Installation Considerations
Tank Capacity Determination
Determining the appropriate capacity of a day tank is essential. It depends on several factors, including the generator’s fuel consumption rate, the expected duration of operation, and any regulatory requirements. To calculate the capacity, you need to know the generator’s fuel consumption in liters per hour (L/h) or gallons per hour (G/h). Multiply this consumption rate by the number of hours you want the generator to run on the day tank’s fuel. For example, if a generator consumes 5 L/h and you want it to run for 10 hours, the day tank should have a minimum capacity of 50 liters. However, it’s often advisable to add a safety margin to account for any unexpected changes in fuel consumption or extended operation times.
Location & Mounting
The location of the day tank is another critical aspect. It should be placed in a well – ventilated area, away from sources of ignition, such as open flames or electrical equipment that could produce sparks. In outdoor installations, the day tank should be protected from direct sunlight and extreme weather conditions. Mounting the day tank securely is also important. It can be mounted on a flat, stable surface, or in some cases, it may be suspended from a structure. The tank should be installed at a height that allows for gravity – fed fuel transfer to the generator, if possible. This simplifies the fuel delivery system and reduces the need for additional pumps.
Fuel Lines & Connections
Proper installation of fuel lines and connections is crucial for the safe and efficient operation of the day tank – generator system. The fuel lines should be made of materials that are compatible with diesel fuel, such as stainless – steel or high – quality rubber. The lines should be sized appropriately to ensure a steady flow of fuel to the generator. All connections should be leak – tight. Flexible hoses may be used in some applications to allow for movement and vibration isolation, but they should be regularly inspected for signs of wear or damage. Valves should be installed at key points in the fuel line system to control the flow of fuel, such as at the inlet and outlet of the day tank and near the generator.
Maintenance of Day Tanks
Regular Inspections
Regular inspections of the day tank are essential to ensure its proper functioning. Visually inspect the tank for any signs of damage, such as dents, cracks, or corrosion. Check the fuel lines and connections for leaks. Look for any signs of fuel staining or puddles around the tank or along the fuel lines. Also, inspect the tank’s vents to ensure they are clear and not blocked. Blocked vents can cause pressure build – up inside the tank, which can be dangerous. In addition, check the sediment and water drain valves. If there is a significant amount of sediment or water at the bottom of the tank, it should be drained off.
Fuel Quality Checks
Monitoring the quality of the fuel in the day tank is important. Diesel fuel can degrade over time, especially if it’s stored for long periods. Check for signs of fuel contamination, such as discoloration, the presence of particles, or a foul smell. If the fuel quality is suspect, it may need to be tested or replaced. Using fuel additives can help to preserve the quality of the fuel and prevent the formation of deposits in the tank and fuel system. Additives can also improve the fuel’s lubricity and combustion properties.
Cleaning & Servicing
Periodically, the day tank should be cleaned to remove any accumulated sediment, dirt, or contaminants. This can be done by draining the tank completely and using a suitable cleaning solution. After cleaning, the tank should be thoroughly rinsed and allowed to dry before refilling with fuel. The fuel filters in the day tank system should also be replaced regularly. Clogged filters can restrict the flow of fuel to the generator, leading to reduced performance or even engine shutdown. Servicing the tank’s valves, vents, and other components to ensure they are in good working order is also part of regular maintenance.
Conclusion
A day tank is an integral part of a diesel generator setup. It not only stores fuel for immediate use but also plays a role in fuel conditioning and safety. With different types available, including plastic, metal, and bunded day tanks, users can choose the one that best suits their needs. Proper design, installation, and maintenance are crucial to ensure the day tank functions effectively. By understanding the importance of day tanks and taking the necessary steps to manage them, operators of diesel generators can ensure reliable power supply, protect the environment, and extend the lifespan of their generator equipment.
