Convective heat transfer coefficients for Fluid 1 and Fluid 2 in a heat exchanger, as shown in the figure below, are $50 \mathrm{~W} /\left(\mathrm{m}^2 \mathrm{~K}\right)$ and $80 \mathrm{~W} /\left(\mathrm{m}^2 \mathrm{~K}\right)$, respectively. The inner tube is made of a material which has a thermal conductivity $386 \mathrm{~W} /(\mathrm{m} \mathrm{K})$ for the given range of temperatures in the heat exchanger. The length of the heat exchanging surface, the inside radius of the inner tube, and thickness of the inner tube are $1 \mathrm{~m}, 10 \mathrm{~mm}$, and 1 mm , respectively. Considering no heat exchange between the outer tube and the surrounding, the heat transfer rate for the heat exchanger is $\_\_\_\_$ W (rounded off to 1 decimal place).

A condenser is used as a heat exchanger in a large steam power plant in which steam is condensed to liquid water. The condenser is a shell and tube heat exchanger which consists of 1 shell and 20,000 tubes. Water flows through each of the tubes at a rate of 1 kg/s with an inlet temperature of 30 °C. The steam in the condenser shell condenses at the rate of 430 kg/s at a temperature of 50 °C. If the heat of vaporization is 2.326 MJ/kg and specific heat of water is 4 kJ/(kg.K), the effectiveness of the heat exchanger is _______ (rounded off to 3 decimal places).

During open-heart surgery, a patient’s blood is cooled down to 25 °C from 37 °C using a concentric tube counter-flow heat exchanger. Water enters the heat exchanger at 4 °C and leaves at 18 °C. Blood flow rate during the surgery is 5 L/minute.

Use the following fluid properties :

Effectiveness of the heat exchanger is _________ (round off to 2 decimal places).