07-10-2014, 12:30 PM
Review on Exhaust Gas Heat Recovery for I.C.
Engine
Review on Exhaust.pdf (Size: 319.08 KB / Downloads: 133)
Abstract -
The increasingly worldwide problem regarding rapid
economy development and a relative shortage of energy, the
internal combustion engine exhaust waste heat and
environmental pollution has been more emphasized heavily
recently. Out of the total heat supplied to the engine in the form of
fuel, approximately, 30 to 40% is converted into useful
mechanical work; the remaining heat is expelled to the
environment through exhaust gases and engine cooling systems,
resulting in to entropy rise and serious environmental pollution,
so it is required to utilized waste heat into useful work. The
recovery and utilization of waste heat not only conserves fuel
(fossil fuel) but also reduces the amount of waste heat and
greenhouse gases damped to environment. The study shows the
availability and possibility of waste heat from internal combustion
engine, also describe loss of exhaust gas energy of an internal
combustion engine. Possible methods to recover the waste heat
from internal combustion engine and performance and emissions
of the internal combustion engine. Waste heat recovery system is
the best way to recover waste heat and saving the fuel.
INTRODUCTION
Recent trend about the best ways of using the deployable
sources of energy in to useful work in order to reduce the rate
of consumption of fossil fuel as well as pollution. Out of all
the available sources, the internal combustion engines are the
major consumer of fossil fuel around the globe. Out of the
total heat supplied to the engine in the form of fuel,
approximately, 30 to 40% is converted into useful mechanical
work. The remaining heat is expelled to the environment
through exhaust gases and engine cooling systems, resulting
in to entropy rise and serious environmental pollution, so it is
required to utilized waste heat into useful work. The recovery
and utilization of waste heat not only conserves fuel, usually
fossil fuel but also reduces the amount of waste heat and
greenhouse gases damped to environment. It is imperative
that serious and concrete effort should be launched for
conserving this energy through exhaust heat recovery
techniques. Such a waste heat recovery would ultimately
reduce the overall energy requirement and also the impact on
global warming. The Internal Combustion Engine has been a
primary power source for automobiles and automotives over
the past century. Presently, high fuel costs and concerns about
foreign oil dependence have resulted in increasingly complex
engine designs to decrease fuel consumption. For example,
POSSIBILITY OF HEAT RECOVERY AND
AVAILABILITY FROM I.C. ENGINE
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. This heat depends in part
on the temperature of the waste heat gases and mass flow rate
of exhaust gas. Waste heat losses arise both from equipment
inefficiencies and from thermodynamic limitations on
equipment and processes. For example, consider internal
combustion engine approximately 30 to 40% is converted into
useful mechanical work. The remaining heat is expelled to the
environment through exhaust gases and engine cooling
systems [4]. It means approximately 60 to 70% energy losses
POSSIBLE WAY OF USING HEAT RECOVERY
SYSTEM
The increasing fuel costs and diminishing petroleum
supplies are forcing governments and industries to increase
the power efficiency of engines. A cursory look at the internal
combustion engine heat balance indicates that the input
energy is divided into roughly three equal parts: energy
converted to useful work, energy transferred to coolant and
energy lost with the exhaust gases. There are several
technologies for recovering this energy on a internal
combustion engine, where as the dominating ones are: Waste
heat can utilized for heating purpose, power generation
purpose, refrigeration purpose, etc
CONCLUSION
It has been identified that there are large potentials of
energy savings through the use of waste heat recovery
technologies. Waste heat recovery defines capturing and
reusing the waste heat from internal combustion engine for
heating, generating mechanical or electrical work and
refrigeration system. It would also help to recognize the
improvement in performance and emissions of the engine. If
these technologies were adopted by the automotive
manufacturers then it will be result in efficient engine
performance and Low emission. The waste heat recovery
from exhaust gas and conversion in to mechanical power is
possible with the help of Rankine, Stirling and Brayton
thermodynamic cycles, vapour absorption. For waste heat
recovery thermoelectric generator is use low heat, which has
low efficiency. It is helpful for the same amount of increases
in thermal efficiency and reduction in emission.