Hot water at 60°C is cooled to 36°C through the tube side of a one-shell pass and two-tube passes heat exchanger. The coolant is also a water stream, for which the inlet and outlet temperatures are 7°C and 31°C, respectively. The overall heat transfer coefficient and the heat transfer area are 950 W/m2·K and 15 m2, respectively. Calculate the mass flow rates of hot and cold water streams in steady operation.

A steam condenser operates at 61 cm of Hg vacuum. The steam enters the condenser with a moisture content of 87%. Cooling water is supplied to the condenser at a temperature of 20 C with a terminal difference of 5 C. The water velocity of water inside the tube is to be limited to 2.5 m/s when using 2.5 cm outside diameter tubes whose thickness is 1.75 mm. The overall heat transfer coefficient of the tubes could be approximated by the equation U = 1213.4(v1/2), W/(m2-C) where v is the water velocity in m/sec.  Determine:  1. The required mass flow of cooling water, kg/s  2. The required capacity of the circulating pump, liter per second  3. The Logarithmic Mean Temperature Difference, C  4. The required Number of tubes  5. The required length of tubes, (m), and number of passes

A thin-walled double-pipe counter-flow heat exchanger is to be used to cool oil (Cpo= 2200 J/kg.K) from 150°C to 40°C at a rate of 2 kg/s by water (Cpw= 4180 J/kg.K) that enters at 22°C at a rate of 1.5Kg/s. If the diameter of the tube is 2.5 cm, and its length is 6 m, determine * The rate of heat transfer in the heat exchanger * The outlet temperature of the cold fluid * The Log Mean Temperature Difference (LMTD) * The overall heat transfer coefficient

The oil (cp = 1 795 W-s/kg-K) from an oil-cooled electric transformer is cooled from 79.4 oC to 29.4 oC at the rate of 1 360.5 kg/h. This is done in an oil-water het exchanger that receives 2 948 kg/h of water at 15.6 Celsius. For the exchanger, U = 295 W/m2-K. Find the exit water temperature and heating area required (a) for counter flow and (b) for parallel flow.

A long, thin-walled double-pipe heat exchanger with tube and shell diameters of 0.01 m and 0.025 m, respectively, is used to condense refrigerant-134a with water at 20°C. The refrigerant flows through the tube, with a convection heat transfer coefficient of hi= 4100 W/m² °C. Water flows through the shell at a rate of 0.3 kg/s. The thermal resistance of the inner tube is negligible since the tube material is highly conductive and its thickness is negligible. Both the water and refrigerant-134a flows are fully developed. Properties of the water and refrigerant-134a are constant. Water properties: p = 998 kg/m³, v=u/p-1.004x 10-6 m²/s, k = 0.598 W/m. °C, Pr = 7.01 Cold water D Do