Question

Question1 You must solve the following problem: An automobile heater is required to provide 30m/min air at 30°C to the passengers when the outside temperature is -10°C. If a coolant is available at 85°C, determine the mass flow of coolant needed to heat the air if the coolant cannot leave the heater at a temperature lower than 45°C. (a) Would you need transport equations or equilibrium thermodynamics assumptions to solve this problem? Briefly give your reasons that justify your election (b) Solve the problem 120 marksl

Answer 1

ven con sideina density *f oi1 : . mass flow Yate of a m in m c Temperature of inside aiv- Tia: 300 Temperatue f dutside cir: T-1 Initial tempera tute。…elant.Ķegs* Minimum allbe tempevtu of Coolant. Toc: 4s (a) we just need the energy blance to sotve this problem a ssum p hons. A ssumphons are ' C'I All +he heat 1»st b colant is gainedbyait Lii There is no hecd loss to h) Ta Solve *his pyob)em we heed to asSVme ar Cs、lant. Let the coslant be wate, heat lost by water : heek gained vy air abinet ids . Atmosphere

If water is used as Coolant, I- must be Svpplird at the