Thermal Engineering and Gas Dynamics (ME-601) - Important Questions

Explain boiler draught, its purpose and types of draught systems including advantages and disadvantages of artificial draught

Describe the construction and working of Benson boiler with its advantages and disadvantages.

Describe the Lamont high-pressure boiler with neat sketch showing flue gas and water paths.

Define boiler / steam generator and explain the different classifications of boilers.

Describe the Velox boiler with neat diagram and its significance in high-pressure steam generation.

Numerical problem on natural chimney draught to determine air supplied per kg of fuel from chimney height, draught, gas and air temperatures

Define and explain heat balance sheet and equivalent evaporation.

Describe the working of Loeffler boiler with a neat sketch.

What are super critical boilers? Give their advantages.

Explain boiler mountings and accessories.

What is Steam Turbine? Explain boiler efficiency and equivalent evaporation in detail.

Describe the Rankine cycle and explain its working with the help of P-V and T-S diagrams.

Explain the binary vapour cycle in detail and its applications in power generation.

Draw the vapor Carnot cycle and explain its practical difficulties and limitations for power plant application.

Explain the effect of superheat / condition of steam on the efficiency of the Rankine cycle.

Explain the working principle of a Feed Water Heater (FWH) in steam power plants. Differentiate between open-type and closed-type feed water heaters.

A steam engine admits steam at a pressure of 5.6 bar and 0.9 dry. The cut off occurs at one-half stroke and pressure at release is 2.6 bar. The back pressure is 1 bar. Find the modified Rankine efficiency of the engine, assuming the pressure drop at release to take place at a constant volume. Neglect clearance volume.

For a Rankine cycle with given steam inlet pressure, exhaust pressure and mass flow rate, determine pump work, turbine work / power, cycle efficiency, condenser heat rejection, and dryness fraction at end of expansion.

Calculate overall thermal efficiency of a steam turbine plant with superheated inlet steam, given exhaust pressure, condensate conditions, specific steam consumption and generator efficiency.

A steam power station uses the following cycle: Steam at boiler outlet - $150\, \text{bar}$, $550^{\circ}\text{C}$ Reheat at $40\, \text{bar}$ to $550^{\circ}\text{C}$ Condenser at $0.1\, \text{bar}$. Using the Mollier chart and assuming ideal processes, find the

Explain with diagram the effect of boiler pressure and condenser pressure on the efficiency of the Rankine cycle.

Express the overall efficiency of a steam plant as the product of boiler, turbine, generator and cycle efficiencies. https://www.rgpvonline.com

Derive the expression for thermal efficiency of the Rankine cycle.

Derive the expression for the speed of sound in an ideal gas.

Calculate Mach number, velocity and stagnation pressure for compressible duct flow given mass flow rate, diameter, stagnation temperature and static pressure.

Explain the significance / importance of Mach number for the study of compressible fluid / gas dynamics flow with examples.

Explain the concept of one-dimensional isentropic flow of ideal gases through a variable area duct.

What is a diffuser? Explain its function and how it affects velocity and pressure in compressible flow.

Find the velocity of a bullet fired in standard air given the Mach angle is $30^{\circ}$.

Explain the following.

Define stagnation state and explain stagnation properties.

Calculate the velocity of sound in superheated steam given pressure, temperature and specific volume.

What is Mach number?

Describe the different Mach number values / regimes for which a body is said to be supersonic and hypersonic.

Calculate the minimum work (and heat rejected to intercooler) per kg for a two-stage compressor with perfect intercooling given suction $p,T$, delivery pressure and polytropic index.

What are rotary compressors and how are air compressors / rotary compressors classified into types?

Explain the effect of clearance (volume) on volumetric efficiency and performance of a reciprocating compressor with diagram.

Classify air compressors and explain the working of a single-stage reciprocating air compressor.

Numerically determine power / indicated power, delivered air mass and delivery temperature for a single-stage reciprocating compressor without clearance.

Numerically determine volumetric efficiency, mean effective pressure, delivery temperature and power required for a single-stage reciprocating compressor with clearance following polytropic compression.

How do rotary compressors differ from reciprocating compressors, and explain the working of a centrifugal compressor?

Derive the expression for work input to a reciprocating air compressor neglecting clearance.

A single stage reciprocating air compressor takes in $8 m^{3}/min$ of air at 1 bar and $30^{\circ}C$ and delivers it at 6 bar. The clearance is 5% of the stroke, the expansion and compression are polytrophic with the value of n = 1.3. Calculate Temperature of delivered air

Calculate the volumetric efficiency of a reciprocating air compressor (numerical).

Derive the condition for minimum work done in a multistage compressor.

Define the following terms related to compressor.

Discuss back pressure in a steam condenser and its effect on power plant performance.

Derive the conditions for maximum discharge in nozzles.

Dry saturated steam at 6.5 bar with negligible velocity expands isentropically in a convergent divergent nozzle to 1.4 bar and dryness fraction of 0.95. Determine the final velocity of steam from the nozzle if 13% heat is lost in friction, find the % reduction in final velocity.

Write short notes on any two of: Cooling Towers, Ash handling of thermal power plant, Need for multistage compression, Open and closed type feed water heaters

Explain the principles of operation of different types of jet condensers, including low-level counter-flow type with sketch.

Explain supersaturated flow of steam through a nozzle and its effect on discharge and heat drop.

Explain the various sources of air leakage into a steam condenser and their effects on condensing plant performance.

Calculate the vacuum efficiency of a steam surface condenser from barometer reading, condenser vacuum, and hot-well temperature.

Calculate final steam velocity in a convergent-divergent nozzle with frictional heat loss and percentage reduction in velocity.

Discuss the different types of condensers used in steam power plants.

Explain the effect of friction on flow through nozzles and define nozzle efficiency.

Define nozzle efficiency and critical pressure ratio.

Write short notes on any three of the following.

A vessel of volume $0.04\, \text{m}^3$ contains a mixture of saturated water and saturated steam at a temperature of $250^{\circ}\text{C}$ The mass of the liquid present is $9\, \text{kg}$. Find the pressure, the mass, the specific volume, the enthalpy, the entropy, and the internal energy.

Derive the conditions for maximum output of a using a reheater and regenerator in a gas turbine.

What is the fundamental difference between the operation of impulse and reaction steam turbines?

Explain the need of compounding in steam turbines.