-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
1/20
FROST FREE HEAT EXCHANGER FORCRYOGENIC AUTOMOTIVE PROPULSION
PRESENTED BY
M.SATHISHKUMAR
II M.ETHERMAL
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
2/20
The California Air Resources Board enacted
the Low Emission Vehicle(LEV).
Zero Emission Vehicle (ZEV).
Pollution can cause aching lungs,wheezing,
coughing and head aches.
Serious health problems.
Children is at particular risk.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
3/20
Currently, battery powered electric vehicle is
the only commercially available technology that
meet ZEV standards.
Slow recharge and high initial cost.
The energy storage medium may well be liquid
nitrogen. Frost free heat exchanger performance.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
4/20
The cryogenic automobile is a ZEV.
Operates on the thermo dynamic potential
between the ambient atmosphere and a
reservoir of liquid nitrogen.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
5/20
The liquid nitrogen is drawn from a tank,pumped up to system pressure.
Vaporized and superheated in a heat exchange
system. High pressure and ambient temperature gas-
systems motive work.
The spent low pressure gas is exhausted back toatmosphere.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
6/20
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
7/20
As nitrogen gas is the only emission ,thecryogenic automobile meets Californias ZEV
guide lines.
Frost free liquid nitrogen heat exchange system.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
8/20
Operate in a variety of conditions and is
structurally robust-not being hampered by the
build up of frost.
Dealing with frost formation fall into twocategories:
1) PASSIVE CONTROL.
2) ACTIVE CONTROL.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
9/20
Either preventing frost formation, or over sizing
the heat exchanger such that frost build up is
unimportant.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
10/20
Mechanical simplicity.
Reliability.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
11/20
In general ,less flexible in dealing with off-
design operation.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
12/20
Active control of frost formation entails allowing
frost to accrete and then removing it
mechanically.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
13/20
More operationally robust.
Performance of an actively controlled heat
exchanger is much less dependent on the
ambient or operational conditions since thesesystems can be responsive to different loading
conditions.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
14/20
Power consumption.
Poor long term reliability.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
15/20
The operating environment can be a demanding
one.
Weather conditions.
Driving conditions. Rigorous safety.
Comfort.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
16/20
To prevent frost build upon sub ambient heat
exchangers, the exterior surfaces must be kept
above the freezing point of water.
The principle is the same as for multi fluid heat
exchange systems, where heat Is transferred
from source to sink via a number of media
operating in series.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
17/20
The choice of passes
was based on twopractical condition.
Passive heat
exchangers are moretightly coupled to
environmental and
operating conditions.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
18/20
Achieve a very compact unit.
A heat exchanger has been developed which uses
rotating brushes for active frost control.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
19/20
The cryogenic automobile is a potential contender in
the ZEV market , provided certain key technologiesare demonstrated.One of these technologies is the
development of an all weather heat exchange
system.A heat exchanger that works well in a variety
of operating conditions, is structurally robust, and isnot hampered by the build up of frost is a necessary
technology for the cryogenic
automobile.Experiments are yet to be conducted to
determine the actual performance.Until road test
experiments are conducted, the actual thermalperformance will not be known with enough
accuracy to support an overall recommendation for
the final heat exchange system design.
-
7/27/2019 FREE FROST HEAT EXCAHANGER Presentation Slide.ppt
20/20