Nozzles are designed to increase the steam velocity.
it is not based on bunoullies theorem it is based on mach number.when sonic speed of steam converted to supersonic steam by nozzle vacuum is created.
A steam ejector is a pump-like device, with no moving parts or pistons, that utilizes high-pressure steam to compress vapours or gases. This creates a vacuum in any vessel or chamber connected to the suction inlet of the ejector The adjacent diagram depicts a typical modern ejector. It consists of a motive fluid inlet nozzle and a converging-diverging outlet nozzle. In this case of a steam ejector, the motive fluid is high-pressure steam. The Venturi effect, a particular case of Bernoulli's principle, applies to the operation of this device. The high-pressure steam is converted into a high-velocity jet at the throat of the convergent-divergent nozzle which creates a low pressure at that point. The low pressure draws the suction fluid (a vapour or gas in this case) into the convergent-divergent nozzle where it mixes with the high-pressure steam. In essence, the pressure energy of the inlet steam is converted to kinetic energy in the form of velocity head at the throat of the convergent-divergent nozzle. As the mixed fluid then expands in the divergent diffuser, the kinetic energy is converted back to pressure energy at the diffuser outlet in accordance with Bernoulli's principle. The compression ratio of the steam jet ejector, P2/P1, is defined as ratio of the ejector's outlet pressure, P2, to the inlet pressure of the suction vapour or gas, P1. The entrainment ratio of the steam jet ejector, Ws/Wv, is defined as the amount of motive steam, Ws (in kg/hr), required to entrain and compress a given amount, Wv (in kg/hr), of suction vapour or gas. The compression ratio and the entrainment ratio are key parameters in designing a steam jet ejector. In practice, for suction pressure below 100 mbar absolute, more than one ejector will be used, usually with condensors between the ejector stages. Condensing of motive steam greatly improves ejector set efficiency. Both barometric and shell-and-tube surface condensers are used for this purpose. BY M.D.V.PRASAD mdvprasad007@gmail.com
with decrease in fuel consumption the amount of steam produced is also reduced.Hence when lower quantity of steam passes through the turbine the torque generated is less and since generator and turbine are coupled on a single shaft the generator torque also decrease which reduces load.
How to calculate the ratio of the inlet-to-exit area of the nozzle
Steam turbine nozzle clearance is the total energy content available in steam. This is through a valve.
1) convergent nozzle 2)divergent nozzle
Nozzles are designed to increase the steam velocity.
yes
If the flow is subsonic the pressure will increase, if however it is supersonic the pressure will decrease.
A convergent-divergent nozzle is generally used in steam turbines. This is because it drives generators in producing electricity with the use of turbine rotors with curved axes.
A NOZZLE IS A DUCT WHICH CONVERT HEAT ENERGY INTO KINETIC ENERGY.IT INCREASES VELOCITY OF FLUID PASSING THROUGH IT ,AT THE EXPENCE OF PRESSURE. STEAM EXPANDS IN NOZZLE FOLLOW RANKINE CYCLE.FLOW THROUGH NOZZLE IS ISENTROPIC. mritunjay04@gmail.com
It sends hot gases from the combustion chamber to the 1st stage turbine blades at the correct angle and speed
When dry and saturated steam is caused to expand in a nozzle,the actual measured steam flow is found to be greater than the theoretical calculated flow.This is due to the time lag in the condensation of steam & the steam remains in dry state instead of wet. Such a steam is called supersaturated steam. This time lag is cause due to the the face that, the converging part of the nozzle is to short and the steam velocity is too high that the molecules of steam have insufficient time to form droplets.
it is not based on bunoullies theorem it is based on mach number.when sonic speed of steam converted to supersonic steam by nozzle vacuum is created.
The Steam Turbine is the one which steam worked pressured Hot and exited then the shaft of the turbine starts to and fro motion due which energy is injected through nozzle in the receiver.
In a single stage steam turbine the steam is run through a nozzle to give it maximum velocity, thus the blades move at very high speeds, impractical for some applications, and only some of the energy is used, about 85-90%. In multi-stage or compound turbines the steam goes through a nozzle to increase its velocity, then after going through a set of blades, it is run through another nozzle to bring the steam back up to the correct velocity. After multiple stages there is no longer enough pressure left to up the velocity of the steam. This method increases the efficiency of the turbine and also decreases wear on the components caused by the high speed of a single stage.