Q.1
How many fluids remain at a constant temperature during the process of boiling and condensation?
  • a) 1
  • b) 2
  • c) 3
  • d) 4
Q.2
Identify the correct expression for effectiveness
  • a) 4 – exponential (- NTU)
  • b) 3 – exponential (- NTU)
  • c) 2 – exponential (- NTU)
  • d) 1 – exponential (- NTU)
Q.3
In a gas turbine recuperator, the capacity ratio becomes
  • a) 2
  • b) 1
  • c) 4
  • d) 3
Q.4
In a gas turbine recuperator, the expression for effectiveness for the parallel flow configuration reduces to
  • a) 1 – exponential (- NTU)/3
  • b) 1 – exponential (- NTU)/4
  • c) 1 – exponential (- 2 NTU)/2
  • d) 1 – exponential (- NTU)/6
Q.5
What is the maximum efficiency for parallel flow heat exchanger?
  • a) 5%
  • b) 10%
  • c) 20%
  • d) 50%
Q.6
A two pass surface condenser is required to handle the exhaust from a turbine developingMW with specific steam consumption of 5 kg/k W h. The quality of exhaust steam is 0.the condenser vacuum iscm of mercury while the bar meter readscm of mercury. The condenser tubes aremm inside diameter, 4 mm thick and water flows through tubes with a speed of 3 m/s and inlet temperaturedegree Celsius. All the steam is condensed, the condensate is saturated water and temperature of cooling water at exit is 5 degree Celsius less than the condensate temperature. Assuming that overall coefficient of heat transfer is 4 k W/m2 degree, determine the mass of cooling water circulated
Questionheat-transfer-questions-answers6.jpg
  • a) 746.13 kg/s
  • b) 646.13 kg/s
  • c) 546.13 kg/s
  • d) 446.13 kg/s
Q.7
The curve of effectiveness versus NTU parameters indicates the relationship between
  • a) i and ii
  • b) i, ii and iii
  • c) ii only
  • d) iii only
Q.8
Hot water having specific heatJ/kg K flows through a heat exchanger at the rate of 4 kg/min with an inlet temperature ofdegree Celsius. A cold fluid having a specific heatJ/kg K flows in at a rate of 8 kg/min and with inlet temperaturedegree Celsius. Make calculations for maximum possible effectiveness if the fluid flow conforms to parallel flow arrangement
  • a) 0.533
  • b) 0.633
  • c) 0.733
  • d) 1
Q.9
Consider the above problem, make calculations for maximum possible effectiveness if the fluid flow conforms to counter flow arrangement
  • a) 1.23
  • b) 0.5
  • c) 1
  • d) 0.465
Q.10
A counter flow heat exchanger is used to colkg/hr of oil (c p = 2.5 k J/kg K) fromdegree Celsius todegree Celsius by the use of water entering atdegree Celsius. If the overall heat transfer coefficient is expected to be 1.5 k W/m2 K, find out the water flow rate. Presume that the exit temperature of the water is not to exceeddegree Celsius
  • a) 1680.2 kg/hr
  • b) 1580.2 kg/hr
  • c) 1480.2 kg/hr
  • d) 1380.2 kg/hr
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