XERIC project: Hybrid climate control system able to control separately temperature and humidity
Stefano Lazzari – University of Genoa (Italy)XERIC’s Deputy Coordinator
H2020 - GV - 2014 / GV - 2 - 2014 / RIA n° 653605
- EC-funded project- Start: June 1, 2015- End: May 31, 2018- 8 partners + 1 third party
What is XERIC?
Developing an energy-friendly climate-control system for electric vehicles capable of reducing of at least 50% the energy used.
By building a novel 3F – CMC contactor (gas – liquid) www.xeric.eu
GREEN VEHICLES
Partners
VITOEMH
AINGVSTICASS / UNIGEFRIGOMAR
FRAUNHOFERUDE
Bologna, November 24, 2016
XERIC at a glance
Current EVs
XERIC EVs
AC
What makes this an achievable result?
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Air-Conditioning System in an ICE car: Vapour Compression Cycle (VCC)
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XERIC in a nutshell
The XERIC system adds to the traditional VCC a liquid desiccant (LiCl acqueoussolution) cycle with two innovative membrane contactors, called 3F-CMCs. The useof semi-permable membrane allows the adoption of liquid desiccant in vehicles.
moist air
outside air
expansiontank
HE
3F-CMC2
LIQUID DESSICCANT CYCLE
3F-CMC1
Diluted dessiccant
Concentrated dessicant
Dehumidified/cooled air
Evaporatingrefrigerant
Condensingrefrigerant
3F-CMC1 dehumidifies and partially cools the process air.
3F-CMC2 re-concentrates the weak solution.
The economizer HE reduces parasitic heat transfer.
Main advantages: the heat exchange between the desiccant and the refrigerant
allows the desiccant temperature to be controlled throughout all the 3F-CMC;
high efficiency and compactness (i.e., increase in sensible and latent heat loads that can be faced).
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EV cars: heat pump system architecture in summer conditions
outs
ide
air
insi
de a
ir
fresh
/circ
ulat
edo
or
floor
defro
st
vent
evaporator
outside air
compressor lamination valve
door door door
condenser refrigerant
door
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EV cars: heat pump system architecture in winter conditions
compressor
outs
ide
air
insi
de a
ir
fresh
/circ
ulat
edo
or
floor
defro
st
vent
evaporatoroutside air
lamination valve
door door door
condenser
refrigerant
door
C
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XERIC system architecture: heat pump + desiccant cycle
outs
ide
air
insi
de a
ir
fresh
/circ
ulat
edo
or
floor
defro
st
vent
HE1
outside air
compressor lamination valve
door door door
3F-CMC2
HE2 refrigerant
door
HE
3F-CMC1
expansiontank
liquid desiccant
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Why XERIC system is so attractive to EV cars?
Since it allows:
separate air-dehumidification and air-cooling processes (no need for under-cooling);
development of tailored systems (thanks to the flexibility given by modularity);
no carryover of desiccant droplets into the process air (thanks to the semi-permeable membrane).
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Raining days:
XERIC system allows dehumidification only, with a small cooling effect.
Winter:
XERIC system works as a heat pump; the heating effect is more efficient incomparison to an electrical resistance and, as a consequence, passengers comfortcan be obtained with less energy requirement.
Summarizing
4 1
23
Enthalpy kJ/kg
Summer and intermediate seasons:
XERIC system allows energy savingsbecause the VCC cycle operates at higherevaporation temperature and lowercondensation temperature.
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Some specs
Characteristic Objective stated in GA Design value
External air flow rate(T=30°C and RH=60%), m3/h 100 100
Vapour extraction from the external air, kg/h 0.3 > 0.3
Pressure drop, Pa < 100 < 100
Extrapolated size of full-scale 3F-CMC - l/w/d, mm must fit commercial vehicles ≈310x285x185mm
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Main technological aspects / issues faced by XERIC Team
Physical and mechanical constraints
• addressing the needed heat / mass fluxes preserving a reasonable compactness;
• stresses due to pressure / temperature gradients in working conditions;
• minimum allowed thickness of the components;• needed mechanical stiffness;
• proper sealing to avoid leakages;• …..
Manufacturing issues
• pressure / temperature stresses induced on the frame during membrane welding;
• pressure stresses on the components during assembling procedures;
• pressure / temperature stresses during working conditions;
• ..…
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Physical aspects: where to focus on
' A Bv 2
A m B
ψ - ψ kgg =z + z + z m s
ΨA , ΨB mass transfer driving potentials
zA, zm, zB mass transfer resistances (air-side, membrane, liquid-side)
3F-CMC compactness is directly and strongly dependent on zA and zm
zA is to be reduced by increasing the air side heat transfer coefficient
zm is to be reduced by reducing the mass transfer resistance of the membrane
We worked in different areas which require different competences. Thistransdisciplinary approach of XERIC allows the results to be widen to a largenumber of applications.
Bologna, November 24, 2016
The core of XERIC: 3F-CMC
At design stage……supported by CFD (Fluent, COMSOL Multiphysics) and by mechanical stability simulations (Abaqus)
Bologna, November 24, 2016
The core of XERIC: 3F-CMC
At prototype stage……for preliminary tests in the lab
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PVDF membrane development
Process development, tests, measurementsCharacteristics
average pore size
pore size distribution
maximum thickness
surface tension
surface property
water vapourtransmission resistance
stability in contact with desiccant
thermal resistance
chemical resistance
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Development & preparation of electronic control system including compressor and electronic expansion valve
Control module
Power module
BLDC Electric Motor
Compressor
Equipment setup in the lab for testing purpose only
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Then, all the Simulink blocks will be connected to evaluate the performance of the XERIC system.
Modeling the several components of the XERIC system in Matlab/Simulink environment
AC evaporator Simulink evaporator block
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Next generation of air conditioning system for EV under development according to planned schedule;
New generation of membrane contactors, 3F-CMC, developed and first prototype manufactured;
Patents on 3F-CMC and new membranes already filed or in preparation; Extensive know how in:
- developing customized membranes with pre-specified characteristics;- thermodynamics analysis of advanced air conditioning systems and their
components;- high level Laboratory facilities for testing air conditioning devices and
components;- modeling and simulation of air conditioning and related systems and
processes; Networking with other EU projects in area of green energy Dissemination in progress
Summary:
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Thank you for your kind attention