Test: Introduction to Power Plant & Steam Cycle - 1 - Mechanical Engineering MCQ

In a Rankine cycle, regeneration results in higher efficiency because 

Consider an actual regenerative Rankine cycle with one open feed water heater. For each kg steam entering the turbine, If m kg steam with a specific enthalpy of h1 is bled from the turbine, and the specific enthalpy of liquid water entering the heater is h2, then h3 specific enthalpy of saturated liquid leaving the heater Is equal to 

In a steam power plant operating on the Rankine cycle, steam enters the turbine at 4 MPa, 350°C and exits at a pressure of 15 kPa. Then it enters the condenser and exits as saturated water. Next, a pump feeds back the water to the boiler. The adiabatic efficiency of the turbine is 90%. The thermodynamic states of water and steam are given in the table

h is specific enthalpy, s is specific entropy and v the specific volume; subscripts f and g denote saturated liquid state and saturated vapour state

The net work output (kJ kg^-1) of the cycle is

In a steam power plant operating on the Rankine cycle, steam enters the turbine at 4 MPa, 350°C and exits at a pressure of 15 kPa. Then it enters the condenser and exits as saturated water. Next, a pump feeds back the water to the boiler. The adiabatic efficiency of the turbine is 90%. The thermodynamic states of water and steam are given in the table.

h is specific enthalpy, s is specific entropy and v the specific volume; subscripts f and g denote saturated liquid state and saturated vapour state.

Heat supplied (kJ kg^-1) to the cycle is 

For a given set of operating pressure limits of a Rankine cycle, the highest, efficiency occurs for 

A thermal power plant operates on a regenerative cycle with a single openfeed water heater, as shown in the figure. For the state points shown, thespecific enthalpies are: h1 = 2800 kJ/kg and h2 = 200 kJ/kg. The bleed to thefeed water heater is 20% of the boiler steam generation rate. The specificenthalpy at state 3 is

For two cycles coupled in series, the topping cycle has an efficiency of 30%and the bottoming cycle has an efficiency of 20%. The overall combinedcycle efficiency is

Consider the following processes:

1. Constant pressure heat addition

.2. Adiabatic compression.

3. Adiabatic expansion

.4. Constant pressure heat rejection.

The correct sequence of these processes in Rankine cycle is:: 

In a Rankine cycle, with the maximum steam temperature being fixed from metallurgical considerations, as the boiler pressure increases

In which one of the following working substances, does the relation  hold good if the process takes place with zero heat transfer?

Consider the following for a steam turbine power plant:

1. Reduction in blade erosion.

2. Increase in turbine speed.

3. Increase in specific output.

4. Increase in cycle efficiency.

Which of the above occur/occurs due to reheating of steam? 

Blade erosion in steam turbines takes place

Consider the following statements The reheat cycle helps to reduce

1. Fuel consumption

2. Steam flow

3. The condenser size

Which of these statements are correct? 

Consider the following statements regarding effects of heating of steam ina steam turbine:

1. It increases the specific output of the turbine

2. It decreases the cycle efficiency

3. It increases blade erosion.

4. It improves the quality of exit steam?

Which of these statements are correct? 

Employing superheated steam in turbines leads to 

Which one of the following is correct?In ideal regenerative cycle the temperature of steam entering the turbine is same as that of

In a steam power plant, the ratio of the isentropic heat drop in the primemover to the amount of heat supplied per unit mass of steam is known as