Power Plant Engineering In Ee — Part 1 MCQs with Explanations

Rankine efficiency is a measure of how well a steam power plant converts heat into electricity. The efficiency is affected by the temperature of the steam and the temperature of the cooling water that condenses the steam back into water. In winter , the cooling water (often from a river or lake) is colder . A colder cooling water temperature leads to a lower condenser pressure . A lower condenser pressure increases the net work output of the cycle. This ultimately increases the Rankine efficiency . In summer , the cooling water is warmer , so the efficiency is lower. Therefore, the Rankine efficiency is better in winter than in summer .

The Curtis turbine is a type of impulse turbine that uses velocity compounding to extract energy from high-velocity steam efficiently. In an impulse turbine , the steam undergoes a complete pressure drop in the nozzles, converting pressure energy into kinetic energy before it strikes the turbine blades. Velocity compounding involves expanding steam through a single set of nozzles to produce high-velocity jets, which then pass through multiple rows of moving blades separated by fixed blades. The fixed blades redirect the steam flow onto the next row of moving blades without changing its pressure, helping to gradually reduce its velocity and extract more work. This configuration is specifically known as the Curtis stage and is used to limit the high speed of turbine rotors, making the design more practical and efficient. Option A is incorrect because a Curtis turbine is not a reaction turbine. Option B is incorrect because “pressure velocity compounded” is not an accurate classification; Curtis turbines use velocity compounding only. Option C is incorrect because it describes pressure compounding, not velocity compounding. Option D is correct because it correctly identifies the Curtis turbine as a velocity compounded impulse steam turbine .

An economiser is used to heat feed water . Feed water: This is the water supplied to the boiler to generate steam. The economiser increases the temperature of the feed water by utilizing the heat from the flue gases exiting the boiler. Purpose: By heating the feed water, the economiser improves the overall efficiency of the boiler by recovering waste heat, thus reducing fuel consumption. Not used for: Heating air or flue gases, although it works with the heat from flue gases to perform its function.

Modern steam turbines can be classified as impulse-reaction turbines. These turbines combine elements of both impulse and reaction turbine designs to optimize their performance. Impulse turbines work on the principle of the high-velocity impact of steam or gas jets on the blades. They are primarily used for high-pressure and low-flow applications. Reaction turbines, on the other hand, work on the principle of the gradual expansion of steam or gas as it flows over the blades. They are more suitable for high-flow and low-pressure applications. Impulse-reaction turbines, as the name suggests, incorporate features of both these principles. They efficiently utilize the energy of both the high-velocity impact and the gradual expansion of steam, making them versatile and suitable for a wide range of operating conditions. So, the correct answer is Option C: impulse-reaction turbines .

The draught produced by a chimney depends on various factors such as its height, cross-sectional area, and the temperature difference between the gases inside the chimney and the outside air. For the same height, a steel chimney typically has a larger cross-sectional area compared to a brick chimney due to the thinner walls of steel chimneys. According to Bernoulli's principle, the pressure difference between the inside and outside of the chimney is inversely proportional to the cross-sectional area. Hence, a larger cross-sectional area results in less pressure difference and therefore less draught. Therefore, the draught produced by a steel chimney is less compared to that produced by a brick chimney for the same height.

The correct answer is E: Vindhyachal . Let's break down why: * Thermal power stations generate electricity by burning fuel, usually coal, to produce steam. This steam then drives turbines connected to generators. * The size of a thermal power station is typically measured by its installed capacity (how much power it can produce at its maximum). * Vindhyachal Thermal Power Station , located in Madhya Pradesh, India, has the largest installed capacity among all thermal power plants in India. Therefore, it is the largest. * The other options are also thermal power stations, but they have smaller capacities than Vindhyachal. * Kota is in Rajasthan. * Sarni is in Madhya Pradesh. * Chandrapur is in Maharashtra. * Neyveli is in Tamil Nadu, but it's primarily known for its lignite-based power generation (a type of coal). So, remember that when we talk about the "largest" thermal power station in India, we mean the one with the highest electricity generating capacity, which is Vindhyachal.

all of the above is the correct answer to “The artificial draught normally is designed to produce”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

due to the fact that pressure at the grate due to cold column is higher than the pressure at the chimney base due to hot column is the correct answer to “In a boiler installation the natural draught is produced”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

when steam is extracted from several places in different stages of steam turbine is the correct answer to “In a regenerative feed heating cycle, the greatest economy is affected”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

steam and cooling water mix is the correct answer to “In jet type condensers”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

the pressure in the turbine rotor is approximately same as in condenser is the correct answer to “In De Laval steam turbine”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

increases if the chimney gas temperature increases is the correct answer to “The draught produced by chimney of given height at given outside temperature”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

central is the correct answer to “In ______ system fuel from a central pulverizing unit is delivered to a bunker and then to the various burners”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

reducing the rotor speed is the correct answer to “Compounding of steam turbine is done for”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

change of enthaply between inlet and outlet is the correct answer to “In Rankine cycle the work output from the turbine is given by”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

initial pressures and temperature only is the correct answer to “Reheat factor in steam turbines depends on”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

there is enthalpy drop both in fixed and moving blades is the correct answer to “Incase of reaction steam turbine”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

transport and dry the coal is the correct answer to “Primary air is that air which is used to”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

condensing type is the correct answer to “Steam turbines commonly used in steam power station are”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

Tarapore is the correct answer to “India's first nuclear power plant was installed at”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

30° is the correct answer to “Belt conveyer can be used to transport coal at inclinations upto”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

more than diesel power station is the correct answer to “A steam power station requires space”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

all of the above is the correct answer to “Artificial draught is produced by”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

cooling water passes through the tubes and steam surrounds them is the correct answer to “In a shell and tube surface condenser”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

4 to 10% is the correct answer to “Economisers improve boiler efficiency by”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

secondary air is the correct answer to “The amount of air which is supplied for complete combustion is called”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

cumulative actual enthalpy drop for the stages to total is isentropic enthalpy heat drop is the correct answer to “Reheat factor is the ratio of”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

all above is the correct answer to “Mercury is a choice with steam in binary vapour cycle because it has”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

draining steam from the turbine is the correct answer to “In regenerative cycle feed water is heated by”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

1 kW/m2 is the correct answer to “The energy radiated by sun on a bright sunny day is approximately”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

20% is the correct answer to “The average ash content in Indian co als is about”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

all above is the correct answer to “The main source of production of biogas is”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

Remove dissolved gases in the water is the correct answer to “Deaerative heating is done to”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

is always greater than simple Rankine thermal efficiency is the correct answer to “Regenerative cycle thermal efficiency”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

increases with number of feed heaters increasing is the correct answer to “The maximum percentage gain in Regenerative feed heating cycle thermal efficiency”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

pressure compounded impulse steam turbine is the correct answer to “Rateau steam turbine is”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

removes air alongwith vapour and also the condensed water from condenser is the correct answer to “Edward's air pump”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

50% is the correct answer to “For Parson's reaction steam turbine, degree of reaction is”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

Boiler efficiency x turbine efficiency x generator efficiency is the correct answer to “The overall efficiency of thermal power plant is equal to”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.

Higher is the correct answer to “The thermal efficiency of the engine with condenser as compared to without condenser, for a given pressure and temperature of steam, is”. This question is standard in competitive examination syllabi for Power Plant Engineering In Ee.