In the world of diesel generators, the day tank is an often – overlooked yet crucial component. A diesel generator’s day tank is like a convenient pantry for the engine, providing a readily – available and clean fuel supply. It plays a pivotal role in ensuring the smooth operation of the generator, whether it’s powering a construction site, a hospital’s backup power system, or a remote telecommunications tower. In this article, we’ll explore what a day tank is, its functions, types, sizing, installation, maintenance, and how it compares to other fuel – storage options.
Definition & Basic Concept
A day tank is a small – to – medium – sized fuel storage tank that is installed in close proximity to a diesel generator. Its primary purpose is to supply fuel to the generator for a short – to – medium – term period, typically for a day’s worth of operation, hence the name. While large – scale fuel storage tanks might hold thousands of liters of diesel, a day tank’s capacity is much more modest, usually ranging from a few hundred to a couple of thousand liters, depending on the generator’s size and fuel consumption rate.
Functions of a Day Tank
Providing a Stable Fuel Supply
One of the day tank’s main functions is to offer a consistent and stable fuel source to the diesel generator. Unlike drawing fuel directly from a large, distant storage tank, a day tank is located nearby. This proximity reduces the risk of fuel delivery issues such as long – distance piping problems, siphoning difficulties, or pressure drops. For example, in a construction site where the terrain is uneven and long – distance fuel lines could be damaged or kinked, a day tank placed close to the generator ensures that fuel is always available at the right pressure.
Filtering & Settling Fuel
Day tanks often come with built – in filtration and settling mechanisms. Diesel fuel can contain impurities such as dirt, rust particles, and water. As the fuel enters the day tank, it has a chance to settle. Heavier contaminants sink to the bottom of the tank. Additionally, most day tanks are equipped with filters. These filters act as a sieve, catching smaller particles before the fuel is sent to the generator. This clean fuel is essential for the proper functioning of the generator’s fuel injectors and engine. Dirty fuel can clog injectors, leading to inefficient combustion, reduced power output, and increased fuel consumption.
Reducing Vapor Lock Risks
Vapor lock is a common problem in diesel fuel systems, especially in hot environments or when the generator is under high load. When fuel vaporizes in the fuel lines, it can create a blockage, preventing liquid fuel from reaching the engine. A day tank helps mitigate this issue. Since it is close to the generator, the fuel doesn’t have to travel long distances through hot fuel lines. The shorter the fuel path, the less likely it is for fuel to vaporize and cause a vapor lock.
Types of Day Tanks
Plastic Day Tanks
Plastic day tanks are lightweight and corrosion – resistant. Made from high – density polyethylene (HDPE) or other durable plastics, they are less likely to rust or corrode over time, even when exposed to harsh environmental conditions. Plastic tanks are also relatively inexpensive compared to some other types. They are often used in smaller – scale applications, such as residential backup generators or small – business setups. However, they may not be suitable for high – temperature environments as plastic can soften or deform at elevated temperatures.
Steel Day Tanks
Steel day tanks are robust and can withstand higher pressures. They are typically made from carbon steel or stainless steel. Carbon – steel tanks are more common and cost – effective. However, they need to be properly coated or painted to prevent rusting. Stainless – steel tanks, on the other hand, are highly resistant to corrosion but are more expensive. Steel day tanks are often used in industrial settings, where the generator is subject to heavy use and the tank needs to be durable enough to handle potential impacts or vibrations.
Composite Day Tanks
Composite day tanks combine the best features of plastic and steel. They are made from a combination of materials, such as fiberglass – reinforced plastic (FRP). These tanks are lightweight like plastic but have the strength and durability of steel. They are also highly resistant to corrosion. Composite tanks are a popular choice for applications where both strength and corrosion resistance are required, such as in marine environments or in areas with high humidity.
Sizing a Day Tank
Factors Affecting Size
Determining the appropriate size of a day tank depends on several factors. The fuel consumption rate of the diesel generator is a key factor. Generators have different fuel – consumption rates based on their power output and load. For example, a 10 – kW generator running at full load may consume 2 – 3 liters
of diesel per hour, while a 100 – kW generator could consume 20 – 30 liters per hour. The expected runtime of the generator also matters. If the generator is likely to run for 8 hours a day, the day – tank size needs to be sufficient to supply fuel for that duration. Additionally, any reserve fuel requirements should be considered. In case of unexpected power outages that last longer than a typical day, having some extra fuel in the day tank can be beneficial.
Calculation Methods
To calculate the size of a day tank, you first need to know the generator’s fuel – consumption rate in liters per hour (L/h). Multiply this rate by the number of hours the generator is expected to run in a day. For example, if a generator has a fuel – consumption rate of 5 L/h and is expected to run for 6 hours a day, the minimum day – tank size should be 5 L/h × 6 h = 30 liters. However, it’s advisable to add a 10 – 20% reserve. So, in this case, a day tank of 33 – 36 liters would be more appropriate.
Installation of a Day Tank
Location Considerations
The location of the day tank is crucial. It should be placed as close as possible to the diesel generator to minimize fuel – line length. This reduces the risk of fuel delivery problems and vapor lock. However, it also needs to be in a well – ventilated area. Diesel fuel vapors are flammable, and a well – ventilated location helps disperse any vapors that may escape. The day tank should also be on a stable and level surface. Uneven surfaces can cause the tank to tilt, which may affect fuel flow and could potentially lead to leaks.
Plumbing & Connection Requirements
Connecting the day tank to the generator involves proper plumbing. The fuel lines should be made of appropriate materials, such as high – quality rubber or metal. They need to be sized correctly to ensure a smooth and sufficient fuel flow. A shut – off valve should be installed between the day tank and the generator. This valve allows for easy maintenance and can be closed in case of emergencies. Additionally, a vent line is necessary to prevent pressure build – up in the day tank as fuel is consumed.
Maintenance of a Day Tank
Regular Inspection
Regular inspection of the day tank is essential. Check for any signs of leaks, such as fuel stains around the tank or on the ground beneath it. Inspect the fuel lines for cracks, kinks, or loose connections. The tank’s fittings, valves, and vents should also be examined for proper functioning. Look for signs of corrosion, especially in steel tanks. If corrosion is detected, it should be addressed promptly, either by cleaning and repainting or, in severe cases, replacing the affected parts.
Fuel Quality Checks
Monitoring the quality of the fuel in the day tank is important. Check for water contamination. Water in diesel fuel can cause engine problems, such as corrosion of internal components and poor combustion. There are simple water – detection kits available that can be used to test the fuel. If water is present, it should be drained from the bottom of the tank. Also, check for sediment and debris. Over time, dirt and rust particles can accumulate in the tank. If the fuel appears dirty or has visible particles, the tank may need to be drained and cleaned.
Filter Replacement
The filters in the day tank, which are responsible for removing impurities from the fuel, need to be replaced regularly. The frequency of filter replacement depends on the quality of the fuel and the generator’s usage. In general, filters should be replaced every few months or after a certain number of operating hours. A clogged filter can restrict fuel flow, leading to engine performance issues. When replacing the filter, make sure to use the correct type and size specified by the manufacturer.
Comparison with Other Fuel – Storage Options
Large – Scale Fuel Tanks
Large – scale fuel tanks, such as underground storage tanks or large above – ground tanks, can store much more fuel than a day tank. They are suitable for applications where long – term, continuous power generation is required, such as in large industrial plants or data centers. However, they are more expensive to install and maintain. They also require more complex safety and environmental compliance measures. Day tanks, on the other hand, are more cost – effective for short – term, smaller – scale power – generation needs. They are easier to install, maintain, and monitor.
Portable Fuel Cans
Portable fuel cans are a simple and inexpensive way to store fuel for a diesel generator. They are highly portable and can be easily refilled. However, they have a limited capacity, usually only a few liters to tens of liters. They are more suitable for very small generators or for emergency backup in cases where the power outage is expected to be very short. Day tanks offer a larger and more stable fuel supply, making them a better choice for applications where the generator needs to run for several hours or more.
Conclusion
The day tank is an integral part of a diesel – generator system. It provides a stable, clean, and easily accessible fuel supply, ensuring the efficient operation of the generator. Understanding its functions, types, sizing, installation, and maintenance requirements is crucial for anyone using a diesel generator. Whether it’s for backup power in a home, a small business, or a large industrial operation, the right day – tank setup can make a significant difference in the reliability and performance of the diesel – generator system. By choosing the appropriate day – tank type, sizing it correctly, and maintaining it properly, users can optimize the operation of their diesel generators and avoid potential fuel – related issues.
