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HEVs idle their engine during the stops to meet the cooling and heating needs. But, idling decreases fuel economy and increases engine wear and emissions. The report explores alternative strategies for air conditioning the HEV during the stop times. Simulation analyses are used to identify fundamental differences and new technology tradeoffs encoun...
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... the additional battery size in the heating mode (which can cover 90% of all stop times in heating season) is only ~10 kJ and thus the 'extra battery' for cooling (~ 60 kJ) can also be used in winters to provide heating. The results for cooling and heating season have been summarized in form of annual fuel consumption for different modes in Figure 17. ...
Citations
... If the temperature drops (on cold days) or rises (on hot days) engine has to be powered on, to provide energy to the cabin HVAC system. It increases fuel consumption and increases CO 2 emission [3]. ...
Thermal energy storage (TES) in automotive applications is currently growing in importance. TES can visibly reduce primary energy consumptions, decrease CO2 emission, and improve thermal comfort in electric as well as hybrid vehicles. However, to meet the new ambitious target (15% reduction of CO2 emissions in the new cars until 2025) it is required to use plug-in electric vehicles. For this reason, this paper focuses on the optimization of key coil designing parameters. For the reference geometry, both experimental and CFD results have been presented. The optimization of coil geometrical parameters has been carried out based on numerical modelling. The prototype of TES is proposed as a honeycomb battery of individual modules. The results show that increasing the diameter and pitch of the coil decreases the melting and solidification time by 13.2% and 11.8% respectively for chosen geometry. CFD calculation has also been made for TES with a hexagonal geometry. The best results were obtained for the TES with a cylindrical shell. However, the results for the TES with hexagonal shell were, very similar (the difference was less than 1% of the share of the liquid phase). It is seen that presented coil optimization is also a good fit for TES with hexagonal shell geometry.
... where COP is the coefficient of performance of the cooling system [30]. Eventually, the total power requested to each cell is increased by P cool , leading to the following equation: ...
The battery pack accounts for a large share of an Electric Vehicle cost. In this context, making sure that the battery pack life matches the lifetime of the vehicle is critical. The present work proposes a battery aging management framework which is capable of controlling the battery capacity degradation while guaranteeing acceptable vehicle performance in terms of driving range, recharge time, and drivability. The strategy acts on the maximum battery current, and on the depth of discharge. The formalization of the battery management issue leads to a multi-objective, multi-input optimization problem for which we propose an online solution. The algorithm, given the current battery residual capacity and a prediction of the driver's behavior, iteratively selects the best control variables over a suitable control discretization step. We show that the best aging strategy depends on the driving style. The strategy is thus made adaptive by including a self-learnt, Markov-chain-based driving style model in the optimization routine. Extensive simulations demonstrate the advantages of the proposed strategy against a trivial strategy and an offline benchmark policy over a life of 200,000 km.
... The COP depends on the ambient temperature since it becomes less efficient to remove heat as the external temperature increases. A reasonable COP function is taken from [15]. The electric power from the cooling system is then summed to the power requested by the driving cycle. ...
... The infiltration rate for a typical vehicle is approximately 0.005 m 3 s À1 (10 CFM (cubic foot per minute)) [20]. The airconditioning system of a vehicle is normally designed to have certain amount of external air circulation for ventilation. ...
The following article presents experimental comparison research on a hexagonal shelland-tube latent thermal
energy storage (TES). Such shape of a shell was deliberately chosen instead of a cylindrical one due to its high
modularity and with intent for future applications in automobiles (EV and PHEV) air conditioning systems
(HVAC). Two geometries of helical coils, acting as tubes, were studied in this article. One was a simple helical
coil with a small pitch. The other one was a helical coil with a larger pitch but enhanced with six longitudinal fins
for each corner of the hexagon. Fins were added to study the effects of higher heat transfer area as well as effects
of better thermal penetration of the Phase Change Material (PCM). Geometries of coils were matched with intent
to occupy the same volume in the storage tank for a better comparison of the results. Results were also compared
with previous studies carried out by authors for a copper pipe placed in a cylindrical shell. PCM chosen for this
study was RT18HC due to its high value of latent heat and the melting temperature close to 18◦C. Melting
temperature value is crucial for applications in vehicle thermal control systems.
This paper presents cooling load calculation for SmarT EV.2 electric vehicle using CLTD/SCL/CLF method. SmarT EV.2 is National Electric Vehicle using electric motor as power and composite materials as the body developed by Sebelas Maret University. Steady state cooling load includes as major contributors, conduction, radiation, metabolic, ventilation, and air conditioning load. The result indicates that peak cooling load can be occured when vehicle runs to west direction, which total amount 2080.53 watts.
