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
- 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