What is the difference between velocity compounding and pressure compounding?

Difference between velocity compounding and pressure compounding are: Pressure of the steam remains constant in every fixed blade and moving blades except in the first nozzle in velocity compounding whereas in pressure compounding turbine pressure of steam increase in every nozzle.

Which is more efficient impulse turbine or reaction turbine?

The efficiency of the reaction turbine is higher due to blade suction effects. This combined construction has the advantage that both the number of stages is less than a fully reaction turbine, and the efficiency is higher than a fully impulse turbine.

What are the advantage of velocity compounding?

Advantages and disadvantages of velocity compounding Fewer number of stages and length of turbine is short. Due to fewer stages, the space required and initial cost is less. Low-pressure operation, so the leakage of steam is less.

What are the advantages and disadvantages of velocity compounded impulse turbine?

As number of moving blades rows in wheel increases, highest stage efficiency and the optimum value of blade speed to steam speed percentage decreases. Due to comparatively large heat fall a velocity compounded impulse turbine requires a reasonably small number of stages. Because of less stage its cost is fewer.

What is stage efficiency of a turbine?

Explanation: Gross or Stage Efficiency: It is the ratio of work done on the blades per kg of steam to the total energy supplied or heat drop per stage per kg of steam. It is also defined as the product of Blade efficiency and Nozzle efficiency.

What is meant by pressure compounding in a turbine?

Pressure compounding is the method in which pressure in a steam turbine is made to drop in a number of stages rather than in a single nozzle. This method of compounding is used in Rateau and Zoelly turbines.

Which turbine has more efficiency?

Large Francis turbines are individually designed for each site to operate with the given water flow and water head at the highest possible efficiency, typically over 90\% (to 99\%). In contrast to the Pelton turbine, the Francis turbine operates at its best completely filled with water at all times.

What is the advantage of pressure and velocity compound?

All rotors are mounted on the same shaft. Pressure velocity compounding gives the advantage of producing a shortened rotor compared to pure velocity compounding. In this design steam velocity at exit to the nozzles is kept reasonable and thus the blade speed (hence rotor rpm) reduced.

What is pressure velocity compounding?

Impulse stages may be either pressure-compounded, velocity-compounded, or pressure-velocity compounded. Pressure-velocity compounding is a combination of the above two types of compounding. It then passes over the 3-4 rings of moving blades (with fixed blades between them), where nearly all of its velocity is absorbed.

What is the isentropic efficiency of a turbine?

Hence, the definition of isentropic efficiency of turbine is the ratio of the actual work output of the turbine to the work output of the turbine if the turbine undergoes an isentropic process between the same inlet and exit pressures.

How do you find the efficiency of a turbine?

How to Calculate Turbine Efficiency

1. Define the steam turbine calculation.
2. Calculate the actual power used by the generator to produce the 1.2 megawatt-hours of electricity: 1.2 megawatt-hours divided by 0.82 (82 percent) generator efficiency = 1.4634 megawatt-hours of power.

What is velocity compound turbine?

The above figure shows the velocity and pressure curve while working fluid passing through the blades of velocity compounded turbine. Here the kinetic energy (velocity) is extracted from working in multiple stages. This is known as velocity compounding. Figure show the arrangement of a velocity compound turbine.

What is Pressure compounding in wind turbine?

In curves of velocity and pressure shows that the absorption of pressure energy in multiple steps. This type of compounding of turbine known as pressure compounding. The inlet steam velocity for each set of the blade is essentially equal, and velocity is very less when compared to velocity compounding.

Which method of pressure-velocity compounding is used in Curtis turbine?

The method of pressure-velocity compounding is used in the Curtis turbine. Compounding of steam turbines is the method in which energy from the steam is extracted in a number of stages rather than a single stage in a turbine. In all turbines the rotating blade velocity is proportional to the steam velocity passing over the blade.

What are the advantages of a steam turbine?

Less steam consumption when compared to velocity compounding. Ratio of blade velocity to steam velocity is constant. Steam pressure inside the turbine is literally equal to the atmospheric pressure so there will be no problem of steam leakage.