05-05-2012, 03:35 PM
Design and Analysis of a Turbocharger System for a Diesel Engine and Its Impact on Engine Power
Proposal.pdf (Size: 139.26 KB / Downloads: 85)
Introduction/Background
In any thermodynamic process there are always losses. These losses translate to lower efficiencies
and lower power, among other things. Never is this more apparent than in a car engine. Ever stood
next to the tail pipe of a car and felt the hot gases coming out? That's lost power. A turbocharger
puts that power back into the engine!
A turbocharger uses exhaust gas from the outlet of the engine to power a turbine. The turbine spins
on a shaft, which is connected to a compressor. The compressor compresses incoming ambient air
and is routed to the engine air intake. The increased density of the air allows for more efficient
and powerful combustion. Under compression, however, the air temperature increases, which
creates premature detonation in a diesel engine. Cooling the air after it is compressed not only
increases the efficiency of the combustion, it delays detonation and causes it to happen at a lower
temperature.
The compressed air is cooled by a heat exchanger, or intercooler (IC) in the turbocharger system,
which is perhaps more important than the design and selection of the turbocharger. There are
several types of ICs, but the focus of this project will be the water-air IC. Water is cooled by a
radiator and the cool water takes heat away from the compressed air before it enters the engine air
intake.
Problem Description/Methodology
The purpose of this project is to design an IC system to boost the power of a diesel engine
(suburban) in order to increase towing capacity on steep grades (Colorado Rockies). The IC will
be a water-air system, which will include a radiator, reservoir, water pump, and water-air heat
exchanger (IC). The development of the IC and system will be accomplished with a baseline
analysis of a system using heat transfer and thermodynamic principles. Once a refined idea of
the size of the heat exchanger, pump, and reservoir is determined, they can be installed into the
Suburban. Trial runs with the new turbocharger system will be made. Boost pressure, exhaust gas
temperature, and increased towing capacity will be measured/calculated and compared against the
analytical design. Due to cost it would be ideal to perform this iteration only once, however, upon
seeing the performance of the turbocharger, the option would be to repeat the analysis using the
data collected and reiterate the turbocharger system until the desired power is reached.
To perform the analysis on the system, Microsoft Excel, MathCAD, MATLab or similar program
will be used for the computations. Data will be collected and analyzed using Microsoft Excel.
There are several technical papers on turbochargers in the Society of Automotive Engineers (SAE)
journal as well as the Japanese Society of Automotive Engineers (JSAE). These publications will
serve as the technical basis for the project. In addition the book, “Maximum Boost” by Corky Bell
will be used as the major source for operation and installation of the system.