A BEV has the following requirements: eight years of operation average 24,000 km per year, averaged out over 365 days per year. Assume an average battery output of 204 Wh/km and a rated cell voltage of 3.6 V, a capacity of 3.4 Ah, and lifetime index of L = 1. i) Determine the BOL kWh storage. ii) How many cells do you need and what is the BOL range? iii) What is the BOL storage and how many cells are required for a larger pack in order to increase the BOL range to 425 km? iv) How many parallel strings are required if the pack has 96 cells in series? v) What is the battery pack mass, assuming a battery with pack density Wh/kg? vi) If the peak power is 325 kW, what is the P/E ratio of the battery for the lar- ger pack? (Ans. 39.16 k Wh, 3,200, 192 km, 86.7 kWh, 7,083, 74, 578 kg, 3.5|

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w