Power plants FG WILSON
The choice of fuel to ensure the reliability of the regular mode
Fuel types for diesel engines can vary from volatiles and kerosene to heavy fuel oil. Most diesel engines are designed for a wide range of fuel types within the specified limits. The following information will help you choose the necessary type of fuel, which provides the best characteristics and reliability of the generator unit.
Types of fuel
Fuel quality can be a decisive factor in ensuring engine life and performance. A wide range of fuels is offered for diesel engines. Their quality depends on the purification technology and the natural properties of the crude oil from which the fuel was made. For example, a fuel can be obtained with a boiling point of 148°C to 371°C (300°C to 700°F) and have many combinations of other parameters.
Additional impurities that are in low-grade fuel can cause smoky exhaust and a stronger smell. This may be undesirable when using the generator in hospitals, shopping malls and residential areas. Therefore, when choosing the type of fuel, it is necessary to take into account the location, application and environmental conditions.
A generator set owner may use low-grade fuel if high-grade fuel is not always available at a particular location or for economy despite higher engine maintenance costs. In this case, it is necessary to frequently check the condition of the lubricant to determine the formation of sludge and the increase of sediment in the engine oil.
In addition to the various types of fuel used in diesel engines, jet fuel is sometimes used, especially where it is more readily available than general purpose fuel. Jet fuel has lower calorific value (B.T.U.) and lubricity quality. As a result, the fuel systems of some diesel engines must be modified to work with this type of fuel. Please consult F.G.Wilson before using jet fuel.
The reliability of diesel engines can vary depending on the type of fuel and depends on many factors, including fuel characteristics and engine operating conditions.
Fuels commonly referred to as “high-grade” rarely cause problems due to the formation of harmful deposits and corrosion. On the other hand, although cleaning improves fuel quality, the B.T.U. and calorific value of the fuel decrease. As a result, higher-grade fuels provide slightly less power than the same amount low-grade fuel These advantages of low-grade fuel are usually small compared to the start-up costs and more frequent overhauls, so the potential problems and additional costs must be assessed before using low-grade fuel.
Fuel types with a high carbon content cause corrosion, wear and sludge build-up in the engine. Low-volatility or high-flammability fuel types can leave a harmful residue in the engine and can make it difficult to start or operate in adverse conditions. The use of low-grade fuel may require expensive cleaning lubricants and more frequent replacement.
Recommendations for the choice of fuel
Consider the properties of the fuel according to the following table.
| Boiling point | Cetane number (min.) | Sulfur content (max.) | |
| Winter | 290°С (550°F) | 45 | 0.5% |
| Summer | 315°С (600°F) | 40 | 0.5% |
Fresh fuel support
The properties of many types of fuel deteriorate during long-term storage (several months). For generators operating in standby mode, it is desirable to store just enough fuel to support continuous operation of the generator set for several days or even eight hours, so that normal engine testing takes place with a full tank for one and a half years.
Another solution is to add fuel inhibitors or to obtain higher returns by using fuels intended for other purposes. The resin inhibitor added to diesel fuel keeps the engine in good condition for up to two years.
If the furnace of the heating system uses an oil sleeper, it is possible to burn diesel fuel in this furnace by connecting the engine and the furnace to the same fuel tank. In this case, a large consumption of diesel fuel is required for the emergency use of the generator set, and its supply is continuously replenished, as the fuel is burned in the furnace. That is why there is no problem with fuel storage.
Autonomous reliability
In some areas where there is a cheap source of gas, natural gas spark-ignition engines are used for continuous operation in generator sets. However, it is not recommended to use them for work in regular mode. The system of management and supply of natural gas significantly complicates the installation and gain in value from its use. More significantly, the reliability of power supply in emergency mode decreases. In addition to the fact that a natural gas engine is less reliable than a diesel engine, frequent storms or any randomness can cause the power supply and therefore the gas supply to fail. Therefore, a situation may arise where natural gas engines will not be able to be used when needed.
In contrast to these engines, a diesel engine with a nearby fuel tank is an autonomous system that does not depend on external influences. It is more reliable and provides greater on-duty protection than utility-dependent systems.