Water is heated by hot air in a heat exchanger. The flow rate of the water is 12 kg/s and that of the air is 2 kg/s. The water enters at 40?C and the air enters at 460?C. The overall heat transfer coefficient of the heat exchanger is 275 W/(m2 K) based on a surface area of 14 m2. Determine the effectiveness of the heat exchanger if it is(a) Parallel-flow type or a(b) Cross-flow type (both fluids unmixed). Then calculate the heat transfer rate for the two types of heat exchangers described and the outlet temperatures of the hot and cold fluids for the conditions given.GIVENWater heated by air in a heat exchangerWater flow rate (mw) = 12 kg/sAir flow rate (ma) = 2 kg/sInlet temperaturesWater (Tw,in) = 40?CAir (Ta,in) = 460?COverall heat transfer coefficient (U) = 275 W/(m2 K)Transfer area (A) = 14 m2ASSUMPTIONSSteadystate

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Water Tw h = 40°C Tan-460°C Ar Alr Ta in = 460°C Ta out Water Tw In -40°C Tw, out 1. Parallel Flow 2. Cross-flow