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07/04/2023 1
EXPERIMENAL INVESTIGATION ON HEAT RECOVERY FROM DIESEL ENGINE EXHAUST
SEMINAR BY
AMAL SAJIKUMAR
M Tech R# 123
07/04/2023 2
INTRODUCTION
Waste heat is generated by fuel combustion or
chemical reaction in an IC engine.
Exhaust gas from an IC engine carries away about
30% of the heat of combustion.
Nearly two-third of input energy of a diesel engine is
wasted through exhaust gas and cooling water.
A process is launched for conserving this energy is
waste heat recovery techniques.
07/04/2023 3
Contd…
A shell and finned tube heat exchanger integrated with
an IC engine setup to extract heat from the exhaust gas.
A Thermal Energy Storage (TES) tank used to store the
excess energy available.
A combined sensible and latent heat storage system is
designed.
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Thermal Energy Storage(TES) systems
The energy recovered from exhaust gases can be
stored here.
In sensible heat storage (SHS), thermal energy is
stored by raising the temperature of a solid or liquid.
The amount of heat stored depends on the specific
heat of the medium.
07/04/2023 5
CONTD…
Latent heat storage (LHS) is based on the heat
absorption or release
when a storage material undergoes a phase change
from solid to liquid or liquid to gas or vice versa.
Combination of sensible and latent heat storage is
always a better alternative.
07/04/2023 6
Phase Change Materials (PCM)
PCM are Latent Heat Storage materials.
PCM absorbs and release heat at a nearly constant
temperature.
They store 5-14 times more heat per unit volume than
sensible storage materials.
PCM are economical and easily available. Parraffin is
commonly used PCM material.
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Experimental investigation
Major criterion in the design of waste heat recovery
system is the proper selection of heat exchanger.
Objective is to extract heat from the exhaust gas and
to store it in the storage tank.
A separate heat exchanger with HTF is circulated to
extract heat.
Heat is then deliver it to the storage medium present in
the TES tank.
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Schematic diagram for experimental setup
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Selection of heat exchanger and storage tank configuration
Finned shell and tube heat exchanger is selected to extract heat.
Circular tubes are used in the heat exchangers.
Heat transfer fluid (HTF) used to extract heat from exhaust gas is castor oil.
Heat transfer coefficient for gases will be very low.
07/04/2023 10
CONTD…
Gas side needs to have larger area for better heat transfer.
It cannot be achieved by embedding the heat exchanger coil inside the storage tank.
So a separate HE with finned tubes are provided.
Exhaust gas is passed through shell side.
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Heat recovery system is a heat exchanger.
Shell side fluid –Exhaust gas.
Tube side fluid-Castor oil(HTF).
Four number of longitudinal copper fins are attached to
each tube at regular intervals.
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cross sectional view of the heat exchanger.
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The TES tank is a stainless steel cylindrical vessel.
It contain castor oil as the sensible storage medium
and paraffin as the latent storage medium.
The storage tank contain 15 kg paraffin filled in 48
capsules and 55kg of castor oil as the HTF.
The cylindrical capsules are kept in a mild steel stand,
having four wire meshed decks as shown below:
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Layout of thermal storage tank
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PCM container (paraffin)
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The temperature at various locations are recorded using
Cr/Al thermocouples.
Twelve thermocouples are placed in four different
horizontal planes.
Three thermocouples are placed uniformly in each plane
and also at inlet and outlet of HRHE and TES tank.
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Thermocouple location in storage tank
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PERFORMANCE OF HEAT RECOVERY HEAT EXCHANGER
Temperature variation at 25% load
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Temperature variation at 50% load
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Temp: variation at 100% load
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Heat extraction rate from exhaust
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Temperature distribution in TES system
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Charging rate and charging efficiency
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Percentage energy saved
25% 50% 75% 100%0
2
4
6
8
10
12
14
16
LOAD (%)
EN
ERGY
SAV
ED (%
)
07/04/2023 27
CONCLUTION
The effectiveness of the HRHE approaches
nearly 99% at the end of charging process at
all load conditions.
Nearly 10–15% of total heat (that would
otherwise be gone as waste) is recovered with
this system.
07/04/2023 28
CONTD…
The maximum heat extracted using the heat
exchanger at full load condition is around 3.6
kW.
Both the charging rate and charging efficiency
are very high at higher load and they decrease
with respect to load.
07/04/2023 29
Reference
Zalba Belen, Jose Marin M, Cabeza Luisa F, Mehling Harald. Review on thermal energy storage with phase change: materials, heat transfer analysis and applications. Appl Therm Eng 2008;23:251–83.
Sharma Atul, Tyagi VV, Chen CR, Buddhi D. Review on thermal energy storage with phase change material and applications. Renew Sustain Energy Rev 2009;13:318–45.
Talbi M, Agnew B. Energy recovery from diesel engine exhaust gases for performance enhancement and air conditioning. Appl Therm Eng 2009;22:693–702.
07/04/2023 30
THANK YOU…