26-07-2012, 12:05 PM
Rotor Engine- A Waste Energy Recovery Device from I. C. Engine Exhaust
A waste energy recovery device from an IC engine.docx (Size: 1.91 MB / Downloads: 124)
INTRODUCTION
The basic purpose of the project is to make use of energy of exhaust gases that are produce from the combustion of fuel in the engine. In an internal combustion engine fuel in the presence of air burns from which various gases produce. These gases are thrown out in the atmosphere from the engine through an exhaust pipe with a certain velocity. With the help of a proper arrangement at the exhaust pipe we can make use of these exhaust gases which can be used in many ways.
The basic principle of the engine is identical to any and all engines that extract energy from chemical fuel.
The basic 4 steps for any internal combustion engine are:
1. Intake of air (and possibly fuel).
2. Compression of the air (and possibly fuel).
3. Combustion, where fuel is injected (if it was not drawn in with the intake air) and burned to convert the stored energy.
4. Expansion and exhaust, where the converted energy is put to use.
Introduction to the waste heat recovery system
Waste heat is heat, which is generated in a process by way of fuel combustion or chemical reaction, and then “dumped” into the environment even though it could still be reused for some useful and economic purpose. The essential quality of heat is not the amount but rather its “value”. The strategy of how to recover this heat depends in part on the temperature of the waste heat gases and the economics involved.
Large quantity of hot flue gases is generated from Boilers, Kilns, Ovens and Furnaces.
If some of this waste heat could be recovered, a considerable amount of primary fuel could be saved. The energy lost in waste gases cannot be fully recovered. However, much of the heat could be recovered and loss minimized by adopting following measures as outlined in this chapter.
Classification and Application
In considering the potential for heat recovery, it is useful to note all the possibilities, and grade the waste heat in terms of potential value as shown in the following Table 1.1:
Low Temperature Heat Recovery
The following Table 1.4 lists some heat sources in the low temperature range. In this range it is usually not practical to extract work from the source, though air production may not be completely excluded if there is a need for low-pressure air. Low temperature waste heat may be useful in a supplementary way for preheating purposes.
Economic Evaluation of Waste Heat Recovery System
It is necessary to evaluate the selected waste heat recovery system on the basis of financial analysis such as investment, depreciation, payback period, rate of return etc. In addition the advice of experienced consultants and suppliers must be obtained for rational decision. Next section gives a brief description of common heat recovery devices available commercially and its typical industrial applications.