Fuel injection valves

Simple fuel injection valves are operated from single camshaft. 

Piping for snuffing steam injection into a heater firebox is required to help put out a fire if a tube mpture occurs. The snuffing steam isolation valve needs to be located at an accessible spot remote from the heater. Also, a remote fuel shutoff valve should be located adjacent to the snuffing steam valve so that both valves can be accessed quickly in case of fire. 

Premature ignition can be reduced or eliminated by redesigning the fuel delivery system, which can be categorized into three types central-, port-, and direct injection. Central and port fuel injections form the fuel-air mixture during the intake stroke. In the case of central injection (or a carburetor), the injection is at the inlet of the air intake manifold. In the case of port injection, fuel is injected at the inlet port. Direct injection is technologically sophisticated and involves forming the fuel-air mixture inside the combustion cylinder after the air intake valve has closed [27-36]. 

With the introduction of fuel injected vehicles during the mid-1980s, it was found that some carburetor/fuel injector detergents actually contributed to the formation of deposits on intake valves, especially when used at high concentrations. For this reason, it became necessary to determine whether fuel detergents contributed to IVD problems or helped to prevent IVD deposits. 

The vast majority of propane fuel systems used on light-duty vehicles to date have been of the mechanical-control type that meter propane in proportion to the amount of air used by the engine (air-valve and venturi-type mixers ). While these systems work well, their capabilities have been overshadowed by gasoline fuel injection systems and often lag behind gasoline systems in terms of acceleration, driveability, and cold-start performance. Chrysler Canada and one European equipment manufacturer offer liquid propane injection systems that are direct analogs to gasoline port fuel injection systems. These systems should have inherent performance advantages compared to the vaporized propane fuel systems. 

Fuel-handling systems (diaphragms for fuel pumps, see Figure 5.5, fuel hose or fuel hose liner, inject or nozzle seals, needle valves, filter casing gaskets, fuel shutoff valves, carburetor parts)... 

Electrorheological (ER) fluids are materials whose rheological properties (viscosity, yield stress, shear modulus, etc.) can be readily controlled using an external electric field. For example, in some cases, they can switch from a liquid-like material to a solid-like material within a millisecond with the aid of an electric field, by means of the so-called ER effect.1617 The unique feature of the ER effect is that ER fluids can reversibly and continuously change from a liquid state to a solid state. ER fluid research is focused mainly on the automotive and robotics industry as electrical and mechanical interfaces for applications such as clutches, brakes, damping devices, fuel injection, and hydraulic valves. However, more recently, there is growing... 

To meet the requirements of fuel consumption and emissions, modern fuel-injection systems require precise metering of the intake air mass. There are two main approaches direct and indirect measurement. In the indirect method the density of the air upstream of the intake valves is determined by measuring pressure and temperature, volumetric flow is determined from engine speed and displacement, including the volumetric efficiency of the engine. With direct measurement the disadvantages of the indirect method (adulteration due to exhaust gas recirculation and changes in the volumetric efficiency) can be avoided. 

The electronic fuel injection (EFI) system meters the hydrogen to each cylinder. This system uses individual electronic fuel injectors (solenoid valves) for each cylinder and are plumbed to a common fuel rail located down the center of the intake manifold. Whereas the CVI system uses constant injection timing and variable fuel rail pressure, the EFI system uses variable injection timing and constant fuel rail pressure. 

Water content varies from 0.5 to 1%. Water is introduced into residual fuels by poor storage. The standards allow water up to a maximum of 1% in residual fuels. However, the majority of fuel deliveries have water contents below 0.5%. The problems with high water levels in fuel can be complex and include sludging of fuel tanks, filter blockage, corrosion of fuel injection equipment, exhaust valve corrosion, etc. 

Modifications of the fuel injectors of an advanced combustor were made to permit spatial control of individual fuel-injection sites. Miniature fuel delivery valves were developed and flow bench was tested to characterize the valve flow characteristics. Optical sensors and a translating gas sampling rake are being integrated in an experimental rig to evaluate the level of pattern factor control at the combustor exit. The CFD simulations were run, and the results will be validated with data that will be acquired from the forthcoming APFC experiments. The numerical solutions will then be used to develop control algorithms that will be used for future closed-loop APFC experiments. 

Lovett s team at Pratt Whitney (Chapter 17) applied a fuel-control system in an actual aircraft engine combustor to actively control pattern factor. For this purpose, available fuel injectors were properly equipped with miniature valves to make possible spatial control of individual fuel injection sites. Optical temperature sensor probes and a traversing gas-sampling rake were integrated into a test rig to quantify the spatial exit temperature distribution in the combustor. Preliminary results have shown good ability to control pattern factor this way. 

To allow for dual-fuel operation, some modifications on the engine itself and its subsystems have been carried out. For example the injection valves for the external mixture formation, the hydrogen supply rail and the ignition system. A concept... 

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