In case of steam, the nozzle in which the kinetic energy of the steam increases at the expense of its pressure energy is called as steam nozzle. Pdf steam ejector is an important component in engineering applications, which require high vacuum, such as steam. Steam nozzle steam nozzle objective type questions and answers. Pressure and temperature of the water steam is 80 bar respectively 500 c at input to the nozzle.
It utilises the kinetic energy of a steam jet for increasing the pressure and velocity of. Htff 1522 condensation in a laval nozzle by moses and stein, dykas et al. The steamjet pump is basically comprised of an expanding motive steam nozzle producing high supersonic velocities, a combining chamber for bringing the suction fluid into contiguous or mating contact with the highvelocity motive steam, and a diffuser for. Allow to steam jewelry for approximately 2 seconds. In the step of admission of steam turbines reation there are several nozzles that distribute the steam to the blades. Both theory and experiment demonstrate that the conditions imposed upon the supersonic flow immediately downstream of the nozzles e. Nozzle is a duct by flowing through which the velocity of a fluid increases at the expense of pressure drop. Explanation of nozzles a white paper from assmann polyethylene tanks come with a variety of nozzles. A convergentdivergent nozzle is required to discharge he steam at a rate of 2 kgsec. Detail idea about convergent and convergentdivergent nozzle. Know everything you want to know about steam nozzlesturbine excluded. When compared to stable flow, the available enthalpy drop for supersaturated flow of steam through a nozzle remains same increases decreases is unpredictable the expansion of steam through a nozzle is so rapid that steam may not get time to condense and may remain in a state of homogeneous vapour. The following table contains 15 criteria for steam trap selection based on the operation of the plant and the speci. Vtunptelnmeict project progress report the project on.
Essentially a pumping device with no moving parts, the steamjet ejector consists of the steam chest, which is the connection through which a highpressure motive supply is introduced into the steam nozzle. The mass flow rate of water steam must be 0,3 kgs1. Steam quality ranges from 0 to 100% and is defined as the ratio of the amount of saturated steam vapor to the total steam amount which may consist of both saturated steam vapor and liquid. Consequently, when a steam system valve opens quickly, a rapid steam load demand occurs, and the boiler will depressurize. Steam then leaves the turbine and is utilized in other parts of the plantthat usetheheatofthesteamforotherprocesses. The frictional resistance between throat and exit is 63 kjkg. First increase dryness fraction upto certain limit and then decrees it. The adiabatic flow process of gas or steam in a nozzle is not only widely used in steam turbines or other power equipment, but also applied to ejectors, impellertype compressors, burners and other thermal devices in air conditioning, ventilation and gas engineering. Applying the principle of conversion of momentum to the mixing of the steam jet. Region of high turbulence between control stage and second stage. The focus here will be on boilers sized in between these two extremes, which is also where there is the greatest diversity of design.
Impulse and reaction principles, compounding, velocity diagrams for simple and multistage turbines, speed regulationsgovernors and nozzle governors. Pressure graph of 3 o inclination angle convergentdivergent nozzle. Density can be calculated by measuring one variable. Venting of lowpressure steam large industrial plants often vent significant quantities of lowpressure steam to the atmosphere, wasting energy, water, and watertreatment chemicals. Flow nozzles are used in thermal power plants for hightemperature and high pressure steam and water flow services, for example, main steam, hot and cold reheat steam. The main use of steam nozzle in steam turbines is to produce a.
Steam accumulators and steam boiler response to load. In this paper we will describe steam flow in nozzle and the nozzle calculation, especially the relationship between the flow. The nozzle is so shaped that it will perform this conversion of. Steam nozzles ppt steam nozzles a nozzle is a duct of. My theory is that it may be appropriate to feed the nozzle from the front of the pressure vessel, and the resultant gas steam can be addressed in a conventional manner at the nozzle. Download the book into available format new update. In the divergent parts, the friction loss may be taken as 0. Steam nozzle article about steam nozzle by the free. In the impulse steam turbine, the overall transformation of heat into mechanical work is accomplished in two distinct steps. Theory of operation the enertech nozzlecheck valve is constructed with only a few components. Menon, in transmission pipeline calculations and simulations manual, 2015. In the current paper numerical treatment of wet steam flow through the nozzle of an ejector is presented.
If the steam floe rate is 1 kgs and the initial velocity of steam is negligible, find the minimum area of the nozzle. The maximum gas flow through a nozzle is determined by critical pressure. The nozzlecheck valve has one of the lowest vmin of any check valve design in the industry, thereby eliminating mid. The expansion process is then stated to be critical thermally equilibrium metastable. Venting of lowpressure steam us department of energy. Steam turbine design options, how to specify or upgrade 31 figure 4.
Pdf study on steam pressure characteristics in various types of. Steam nozzles a nozzle is a duct of smoothly varying cross sectional area, in which a steadily flowing fluid can be accelerated to a high velocity by a drop in pressure of the fluid along the duct. Fuel exits the fuel pump, into a fuel solenoid valve 25 which controls fuel flow to the fuel nozzle 26. Dual lance 20, or steam lance on the hhb303, and exits the nozzle 21. A 100% steam quality translates to zero amount of saturated steam liquid and, in this condition, the steam is termed to be dry. The principle of a steam nozzle may also be applied to a steam injector. Unit 4 flow through nozzles velocity and heat drop, mass discharge through a nozzle, critical pressure ratio and its significance, effect of friction, nozzle efficiency, supersaturated flow, design pressure ratio. Vanita thakkar bit 52 supersaturated flow when steam flows expands through a nozzle, it would be normally expected that the discharge of steam through the nozzle would be slightly less than the theoretical value. Steam expands in a set of nozzle from 10 bar, 300 0c to 1 bar. Density is a function of both temperature and pressure. The steam nozzle, the heart of the ejector, converts motive pressure to velocity energy that is used to collect vapors in the suction head. A passage of uniformly varying crosssection in which the kinetic energy of fluid increases at the expense of its pressure energy is called as nozzle. Consider a convergentdivergent nozzle in which steam enters at 0. But, experiments on flow of wet steam show that discharge is slightly greater than that calculated by the formulae.
And then the later part of the nozzle, in which the steam derives more in volume than in velocity. The steam possessesa very high velocity at the end of the expansion. The flow of steam through nozzles may be takenas adiabatic expansion. During the first part of the nozzle, the steam increases its velocity. Steam jet ejector cooling powered by low grade waste or solar heat by. Unit iii unit iii steam nozzles and turbines flow of steam through nozzles, shapes of nozzles, effect of friction, critical pressure ratio,supersaturated flow. The nozzle is said to begin where the chamber diameter begins to decrease by the way, we assume the nozzle is axisymmetric, i. The following is a general guideline to help select the proper nozzles for the job. Theory of simple carburettor 49 petrol injection 51 5 fuel supply in ci engine. The steam which contains some water particles in superposition.
In noncondensing turbines or backpressure turbines, steam exhausts at a pressure greater than atmospheric. Using the tweezers, hold jewelry approximately one inch beneath the steam nozzle. A flow nozzle which is held between flanges of pipe carrying the fluid whose flow rate is being measured. Steam nozzle 215 steam nozzle analysis 217 supersaturated flow 220 normal shock 224. The nozzle is supplied a steam with a pressure at 7 bar and temp 180 0 c. Please contact factory or customer service for availability and material breakdowns.
Nozzles are used in steam and gas turbines, jet engines, rockets, in flow measurement, in injectors for pumping water, in ejectors for removing air from condensers etc. Recovery of the latent heat content of lowpressure steam reduces the boiler load, resulting in energy and fuel cost savings. Often the nozzles are misapplied and can cause problems shortly after installation. Pdf numerical study on condensation process of steam flow in.
How to calculate the steam flow through each nozzle. In order of increasing capacity, three boiler types are the firetube, watertube and waterwall boilers. In the model, the classical homogeneous nucleation theory. Loss in the nozzle is 15% in divergent portion only. When the dry steam is further heated at constant pressure, the temperature increases the above saturation temperature. Calculate base dimensions of the nozzle and state of water steam at the exit. Requirements are detailed in the asme documents previously listed. Maintenance and overhaul of steam turbines wgp42 05. To stop steaming, simply pull back on the steam button which will release the continuous steam setting. Nozzle nozzle is duct of smoothly varying crosssectional area in which a steadily flowing fluid can be made to accelerate by a pressure drop along the duct. The addition of divergent part of the nozzle after the throat does not affect the discharge of steam passing through the nozzle, but it only accelerates the steam leaving the nozzle. Pdf steam jet refrigeration sjr is one of the most widely applied technologies in the industry. The convergent parts of the nozzle are sharp and frictionless. When insufficient steam is available, depressurization occurs in seconds.