Combustion in Automotive Engines
Gardner Compression Ignitions Engine
RME
Introduction
One of the most important energy sources are fuels being used primarily in road vehicles and power plants where high efficiencies is required. Using fuel, mainly fossil fuel, comes with the drawback of emitting greenhouse gases to a large extent carbon dioxide which contributes to global warming due to the trapped gases in the atmosphere making the planet absorb infrared radiation by the Sun and not reflecting back. Reducing fuel consumption and emissions are the main target to be fulfilled by today's manufactures to help the environment.
R/P ratio are defined based on the annual production either in barrels per year or cubic feet per year depending on fuel type, as the ratio to reserves of crude oil or natural gas again in barrels or cubic feet. These ratio currently give a steady interpretation so that there is enough for the next 40-50 years, but the problem as times goes on and the reserves do deplete, prices will increase sharply.
To prevent the use up of fossil fuel to quickly it is been suggested to look for alternative ways of energy sources. One of the solutions are Biodiesel (RME). They have lower emissions as mentioned above, carbon dioxide has to be reduced so biodiesels have lower greenhouse gases lowering global warming. The most important fact is that biodiesel is renewable based on organic materials and in theory there is an infinite amount available. Biodiesel are made of grown organic material when grown, they will absorb carbon dioxide, hence there won't be a total net production of carbon dioxide. There are two major drawbacks in using bio fuels, one is the increased energy requirement of producing bio fuels compared with other fuels and, second the mass production of crops which requires farming for only produce bio fuel taking up the space, reducing considerably other type of farming for such as food.
PROCEDURE
The engine was ignited and then it was made to run at 1500 revolutions per minute. The shaft of the engine was connected to the dynamometer, and then the brake load on the engine was 4kg, 8kg,
12kg, 16kg and 18kg but the last load could not be done because the engine cannot handle it so load
18kg has been discarded . Each time changing the load, the following readings have been taken:
a) air temperature near the inlet to damping vessel, (θa)
b) manometer level, (h)
c) time to the engine to consume 50 ml of fuel, (t)
d) engine speed, (N)
e) net brake load, (L)
f)
exhaust temperature near the exhaust valve, (Tex)
g) mole fractions of the exhaust gas species (O2, CO, CO2, NOx)
Method to obtain the individual readings:Air temperature near the inlet to damping vessel, (θa)
The temperature of air was measured from the thermometer which was located at the throat of the air box. The air box is the box which is used to damp down the pressure fluctuations and the air flow in the air box before it comes into the engine.
Manometer level, (h)
The manometer is connected to the throat of the air box, and it gives the pressure difference between the atmosphere and inside the air box. The obtained pressure difference is then used to calculate the mass flow rate of air going in the engine.
Time to the engine to consume 50 ml of fuel, (t)
The fuel was flowing from the fuel tank into the fuel flow meter, where the tube was calibrated into
50 ml gaps. The tube was filled in through a valve, then the time was noted for the drop in fuel level in one gap. This gave the time for the engine to consume 50 ml of fuel, to obtain the mass flow rate.
Engine speed, (N)
The engine speed was set to 1500 revolution per minutes which has not been changed.
Net brake load, (L)
It is the applied load on the engine which can be adjusted and shown on a big dial.
Exhaust temperature near the exhaust valve, (Tex)
On different brake load when the crank angle and pressure was recorded
