Question

8. A battery pack with a total internal resistance of 1 ohm delivers 100 amps under steady state conditions. The pack is cooled with water. a. (3 pts) Estimate the mass flow rate of water required to keep the water temperature change from inlet to exit within 5°C. b. (3 pts) The cooling flow arrangement results in an average convection coefficient of 200 W/m2K. Estimate the temperature of a cell close to the water exit, where the water temperature is 35°C. There are 150 cells in the pack, and the exposed surface area of a single cell is 0.03 m².

Answer 1

< we have given Internal Resistance of batteryha is Flauring current though battaly -1.600 omy 3) The rate gheat genercek for in battery Heat genercekiel - ICR = (rool2 (1)2 ü ? 10000. W :) 100002 4 q) mass fliew scue: Tempescitur difference: sc the spasffe heart of water=4180J/kg 2) a = rm Cp CAT) mx 4180xs 2) [m=0.478 18/5 b) Tempeseter og cell closs tee erit; aug.convective hear tsoons fer cofficent = Zoovy riak Temparaties of weiter exit= .35°C Tokhaea of cell = no, og cerey are goreceu =150 X 0.03 - usm?

-) 0 : 4 Atotal (Trece- Twater) =) 10,000 - 200 X 405 (Toeel- $5°c) =) Tree -36 - Nill => [Teen = 46.11c] The exit temperater of cell es 46110 Lee mess few relle 0.478 kg/s