How A Common Diesel Injector Works and Testing Process

What Is The Objective Of A Fuel Injection Mechanism?

The configuration of a diesel motor’s injection mechanism has a significant impact on its efficiency. In reality, enhanced fuel injection system technologies were largely responsible for the most significant breakthroughs in diesel motors. While the framework’s primary function is to distribute fuel to a diesel motor’s cylinders, how well that fuel is supplied determines motor efficiency, combustion, as well as noise qualities. The diesel fuel injection system, apart from its spark-ignited predecessor, provides fuel at exceptionally high injection pressures. This means that system component architecture, as well as materials, should be chosen to endure larger stresses & operate for longer periods in need to meet the motor’s endurance goals. The system’s efficiency also necessitates increased production quality and strict specifications. Diesel injection technologies are distinguished by much more complex management needs, in addition to pricey components and production expenses. Every one of these elements adds up to a solution that might account for up to 30% of the motor’s overall cost. You should test a diesel injector, for which Diesel Injector Testing is used.  The primary function of a fuel injection device is to supply fuel to a motor’s cylinders. For the motor to utilize the most of this fuel, it must:

• Fuel must be supplied at the precise moment, i.e. injection timing, and the appropriate quantity of fuel should be provided to fulfil performance requirements, i.e. injection metering.
• Nevertheless, delivering a correctly calibrated quantity of fuel at the right time isn’t sufficient to accomplish effective ignition. Other factors that must be considered to guarantee optimum fuel injection device efficiency include:
• A fundamental architectural goal for diesel fuel injection devices is to ensure that the fuel atomizes into very minute fuel molecules. All of the fuel has an opportunity to evaporate and engage in the combustion procedure because of the small droplets. Any residual liquid droplets ignite inefficiently or escape the motor.
• Whereas the modern fuel injection processes can create fuel atomization qualities that are far superior to what is required to guarantee the full fuel evaporation for the majority of the injection procedure, a few injection system creations may well have poor atomization throughout brief but essential durations of the injection stage. One such key phase is the completion of the injection procedure.
• Combining in large quantities—While full evaporation of the fuel, as well as atomization of the fuel, are vital, guaranteeing that the vaporized fuel has enough oxygen throughout the combustion phase is also vital for excellent combustion effectiveness as well as maximum motor efficiency.
• The oxygen comes from the confined air in the cylinder, which must be compressed into the fuel jet in adequate quantities to thoroughly blend with the accessible fuel throughout the injection procedure and guarantee effective combustion.
• Air utilization—Efficient air utilisation in the combustion chamber is strongly linked to mass blending and it can be achieved by combining fuel penetration into the thick air squeezed in the cylinder with splitting the entire injected fuel into a series of jets. A decent number of jets ought to be accessible to entrain as much accessible air as feasible while preventing jet overlapping and the creation of oxygen-deficient fuel-rich regions.

Terms and Definitions

• The parts and functionality of diesel fuel injection devices are described using a variety of specific ideas and phrases. Hereunder are a few of the more prevalent ones:
• The section of the nozzle body/needle combination that interacts with the motor’s combustion chamber is referred to as the nozzle. P-Type, M-Type, and S-Type nozzles relate to standardised nozzle parameters as defined by ISO regulations.
• The portion on which the nozzle is placed is referred to as the nozzle holder or injector body. This item was primarily used in traditional injection techniques for nozzle installation and nozzle needle spring preloading. It comprises the primary functioning pieces in standard rail systems: the servo-hydraulic circuit as well as the hydraulic actuator (electromagnetic or piezoelectric).
• A nozzle holder plus nozzle arrangement are frequently referred to as the injector.
• The supply process has begun. Fuel injection is linked with the development of significant pressure in various fuel systems. The commencement of supply in such devices occurs when the high-pressure pump begins to supply fuel to the injector. The time it would take for a pressure wave to pass between the pump as well as the injector, and also the length of the line connecting the high-pressure pump as well as the injector and the speed of sound inside the fuel, impact the gap between commencement of supply and SOI. Injection latency is the time between the beginning of supply and the commencement of SOI.

Testing Procedures for Common Rail Fuel Injectors

Normal test methods were extended with extra measuring points, and a linear coefficient of determination was introduced as a new troubleshooting characteristic for rail fuel injectors. The operative test is run at a larger range of nozzle opening frequencies, allowing for a more accurate assessment of the fuel dosing mechanism (actuation). The gathered data was employed in the computation stage, which was then uploaded to the widely utilized spreadsheet programme. This avoids the requirement to change the program on the test bench. The recommended method ought to be especially beneficial in tough scenarios when a clear evaluation of the mechanical status of the fuel injector is tough.