Diesel Engines
Essay by stracn • April 8, 2019 • Term Paper • 705 Words (3 Pages) • 636 Views
In recent decades, diesel engines have evolved by leaps and bounds and have transformed into much more efficient and reliable beasts than they once were. As time passes pieces of technology get worn out and thus, get tweaked until they are inevitably replaced completely. While some pieces of technology remain a focal point, such as glow plugs, it is inevitable that items, such as conventional diesel pumps, get replaced with more modern and efficient pieces of technology. Specifically, these conventional diesel pumps would later be almost entirely replaced by common rail diesel systems that aid these engines operate much more effectively. These evolutions aid in differentiating these engines from anything else created in the industry; Heck, these evolutions even aid in differentiating these motors from each other based on modern technology compared to what was in these vehicles thirty to forty years ago.
In modern diesel engines, conventional diesel pumps have been mostly replaced by CRD, or common rail diesel systems, due to several key factors. For example, conventional diesel pumps have multiple lines that connect the injectors to the pump and for each injector there is one line designated to connect it to the high pressure pump. In comparison, a common rail diesel system has one common line that connects the high pressure system to the common rail. From this line, which due to the high pressure pump is held under intense pressure, there are several short lines to each injector. Furthermore, unlike the conventional diesel pumps, which are mechanically operated by fuel pressure, in common rail diesel systems each injector is operated by a solenoid valve. While these two may differ in this aspect, both are responsible for ensuring that the injectors spray fuel into combustion chamber in order to ensure combustion within the engines. Moreover, as diesel engines have evolved from one system to the next things such as multiple pre-injections have become a much more feasible task. For those who do not know, pre-injection refers to a miniscule amount of fuel being injected prior to the primary injection within the cylinder head. This is primarily due to the fact that these modern common rail diesel systems controls the injections electronically rather than mechanically. When you combine the fact that the air has already been preheated, the short pre-injections allow for a uniform increase in combustion pressure; This aids in lowering noise from the engine, increasing fuel efficiency, and reducing emissions.
Incidentally, the high pressure pump carries over the same speed as the camshaft and half the speed of the crankshaft; In other words for every revolution per minute the crankshaft produces, the high pressure pump only produces one half of a revolution. This pump is powered by the timing belt and provides the common rails with the high pressure that it needs to properly function. At set intervals
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