Cold weather is a challenge for compression ignition engines. As Diesel fuel creates wax crystals when temperature goes down enough, it comes to plug the fuel filter and the fuel injection system, leading to undesirable effects like loss of power, engine stall after start or even the engine not starting at all.
Moreover, it has been shown that FAME Biodiesel has additional negative impacts on vehicle cold flow operability.
Despite fuel additives which can support cold conditions, the whole fuel injection system has to be designed to support engine operability in variable environments, meaning also in very cold conditions, with variable fuel qualities.
The Diesel Fuel Filter is a key element of the fuel injection system, as it could become to get plugged by wax and deposit formed at cold temperatures. This can generate fuel shortage on the common rail and high pressure fuel injectors. Addressing this filter plugging effect, can be crucial for vehicle operability.
In order to understand and quantify the cold fuel flow impact on the Diesel fuel filter, a design of experiment has been set-up and achieved. Various fuels, filter geometries and filter media have been evaluated all together in order to identify the key parameters which impact the cold flow properties.
Thanks to that, some design guidelines have been defined. This should permit to adapt filter designs, in accordance with environment constraints, in order to propose the best vehicle operability, even in very cold conditions using worst cold sensitivity Biodiesels.