B.TECH - Semester 7 refrigeration and air conditioning Question Paper 2019 (jun)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- The following data relate to a steam ejector refrigeration system: Condition of the motive steam $=7$ bar, dry saturated, Temperature of water in the flash chamber $=4.5^{\circ} \mathrm{C}$, Temperature at which the make-up water is supplied $=18^{\c...
- Discuss briefly the following systems of lubrication: (i) Splash lubrication system and (ii) Pressure lubrication system.
- Atmospheric air at a pressure of 760 mm Hg has temperature of $32^{\circ} \mathrm{C}$ and a percentage saturation as determined from a psychrometric chart of $52 \%$. Calculate: (i) The partial pressure of the vapour and the dry air, (ii) The specifi...
- An air-conditioned auditorium is to be maintained at $27^{\circ} \mathrm{C}$ DBT and $60 \% \mathrm{RH}$. The ambient condition is $40^{\circ} \mathrm{C}$ DBT and $30^{\circ} \mathrm{C}$ WBT. The total sensible heat load $10^{5} \mathrm{~kJ} / \mathr...
- Give the comparison between vapour absorption and vapour compression systems.
- Derive an expression for specific humidity and show that it is function of vapour pressure and barometric pressure of air.
- Sketch 'comfort chart' and show on it the 'comfort zone'.
- State the factors which should be taken into consideration while selecting a system of air-conditioning. ( $\mathbf{1 0} \boldsymbol{\times} \mathbf{4} \boldsymbol{=} \mathbf{4 0}$ Marks) PART - B Module - I
- An ammonia vapour compression refrigerator has a single stage, single acting reciprocating compressor which has a bore of 127 mm , a stroke of 152 mm and a speed of 240 rpm . The pressure in the evaporator is 1.588 bar and that in the condenser is 13...
- A single compressor system using R-12 as refrigerant has three evaporators of capacities 18 tonnes, 27 tonnes and 9 tonnes of refrigeration. The temperatures in the three evaporators are to be maintained at $-5^{\circ} \mathrm{C}, 0^{\circ} \mathrm{C...
- Define the figure of merit related to thermoelectric refrigeration system and explain its effect on C.O.P of the system.
- Describe briefly the methods used for the liquefaction of hydrogen and helium.
- What is the function of flash intercooler provided in a compound vapour compression refrigeration system?
- Write a short noted on 'Pressure Enthalphy (p-h) chart'.
- Name three refrigerants that are commonly used in commercial refrigerators. Discuss their relative merits and demerits.
- Derive an expression for finding out the mass of motive steam required per kg of water vapour produced. P.T.O.