Turbomachinery study for better world.pptx

Agriculture has been the backbone of Ethiopian economy and it will continue to remain for a long time and Wheat are the new targets in agriculture where still, not many researchers and manufacturers participate. This field faces some problems such as how to productivity and how to reduce the cost.Generally in Ethiopia, two types of agricultural equipment are used, manual method (conventional method) and mechanized type. Mechanization involves the use of a hybrid device between the power source and the work. This hybrid device usually transfers motion, such as rotary to linear,or provides mechanical advantages such of velocity.Agricultural machine in farming or otheragriculture.Mechanized agriculture is productivity .In modern times, powered machinery has replaced many farm jobs formerly carried out by manual labour or by working animals such as oxen and horses. The entire history of. agriculture contains many examples of the. use of tools,such as the hoe and the plough.Buttheongoingintegration of machines labour intensive.The biggest profit of automation is that it saves the labour.However,accuracy,and precision. The agricultural science is a science dealing with food and fiber production and processing. They include the technologies of soil cultivation, crop cultivation and harvesting, animal production, and the processing of plant and animal products for human consumption and use.Now a day, Ethiopia is the poor country in the world because of many reasons; such as the way of crop cultivation is traditional, or unable to use agricultural technology is one of the most predominant reason, one of the factor that affect to unable use new technology is lack of appropriate machine specially suppliers never Ethiopia farmers’ economy. In Ethiopia, farmers use traditional techniques for plowing land still now a day due to lack of properly fitting machine with them economy or economical capacity and lack of skill to operates machine as result there is insufficient way to plow the land which is time taker, tedious, consumption of human labor and ox labor. Our main objectives are designandsimulationofagriculturalploughmachine:whichismainlyconcernedonthat problem we state it made from local material, and it never required skill to operate that will help to reduce the time, reduces of the ox and human labor, increase the productivity, maximize the profit, and reduce the cost; since this machine has three share which plough three time the currently farmer use plough therefore it enables to plough large area of land with in short period of time with in effective way. By using a general In conclusion, the concept development process for a small comprehensive approach aimed at designing an efficient, user solution tailored to the needs of small scale tilling machine involves a friendly, and cost scale farmers or gardeners. Key effective stages include Problem Identification: Defining the need for a tilling machine that is compact, easy to loug

1. MEKELLE UNIVERSITY ETHIOPIAN INSTITUTE OF TECHNOLOGY-MEKELLE SCHOOL OF MECHANICAL AND INDUSTRIAL ENGINEERING DEPARTMENT OF MECHANICAL ENGINEERING Turbomachinery(ME ng3124) Group assignment

2. Group Members Name ID Section Dargie Zegeye EiTM /ur158013/11 2 Girmay Tadese EiTM /ur177192/12 2 Reda Haftu Transfer 654/10 2

3. Introduction 1.1 Definition A   reaction turbine  is a type of steam turbine that works on the principle that the rotor spins, as the name suggests, from a reaction force rather than an impact or impulse force. In reaction turbine, a part of the head (H) acting on the turbine is converted into kinetic energy and the rest remains as pressure head. The water first enters a set of movable blades (guide vanes) and passes over a set of fixed runner blades. There exists a difference of pressure between these two sets of blades which is called ‘reaction pressure’ and is responsible for the motion of the runner blades . Degree of reaction: it is defined as the ratio of the static pressure drop to the total pressure drop in the stage .

4. By the application of Bernoulli’s equation to the inlet and outlet section of the runner blade , = - ------------------(1) Where p1,p2 = pressure at inlet and outlet , = absolute of velocity at Inlet and outlet section = work done by the turbine runner Thus, if the pressure is constant at the inlet and outlet sections than such a turbine behaves purely as in impulse turbine. If on the other hand v1= v2 , then  

5. ) and this represents purely reaction turbine. Intermediate type of turbine described by the degree of reaction .  

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7. TYPES OF REACTION TURBINE Mainly two types of reaction turbine : Outward radial flow reaction turbine Inward flow reaction turbine. Outward radial flow reaction turbine The above figure shows outwards radial flow reaction turbine in which water from casing enters the stationary guide wheel. The guide wheel consists of guide vanes with direct water to enter the runner which is around the stationary guide wheel. The water flows through the vanes of the runner in the outward radial direction and is discharged at the outer diameter of the runner. u 1 < V 2 as D1<D 2

8. cntd Inward flow reaction turbine: The figure below shows inwards radial flow reaction turbine in which water from casing enters the ‘Guide Vanes Section’ through the guide vanes water flows to the runner in the inward radial direction and discharge at the inner diameter of the runner. The inner diameter of runner is outlet and diameter of runner is inlet .

9. Comparison between O utward Flow turbines and Inward flow turbines Outward Flow Turbine Inward Flow Turbine Water enters at the inner periphery and discharges at the outer periphery Flow outward Flow rate increases Turbine runner V1<V2, because of imparted to water as it flow 2g through the turbine runner is Positive. Very difficult to control the speed Good for low medium heads Water enters at the outer periphery and discharges at the inner periphery Flow inward Flow rate does not increases Turbine runner V1>V2, because of imparted to water as it flow 2g through the turbine runner is Negative. Easy to control the speed Good for medium and high heads and best suitable for large output units. Outward Flow Turbine Inward Flow Turbine

10. Working principles of steam turbine(reaction) Reaction steam turbine has the following stages when It operates The nozzles; when the water that inters from penstock inters the nozzles fond on the rotor ,they release it in high force. Then they will experience a reaction force that revolve around the rotor at a maximum speed . The running blades : The water from the nozzle rotates the running blades and then the operation starts. Draft tube: the water comes to the draft tube after rotating the running blades. Finally the operation continues cyclically.

11. Application Areas Power Generation: Reaction turbines are commonly used in power plants to convert steam energy into mechanical energy, driving generators to produce electricity . Petroleum Refining : Steam turbines are employed in refineries for processes like fluid catalytic cracking and hydrocracking , where they help drive various pumps and compressors . Chemical Processing: Reaction turbines play a role in chemical plants by driving compressors, fans, and pumps, assisting in processes such as steam-methane reforming for hydrogen production. Sugar Industry: Steam turbines are used in sugar mills to generate power from the steam produced during sugar cane processing . Paper and Pulp Industry: Reaction turbines drive equipment such as fans, pumps, and blowers in paper and pulp mills . Textile Industry: They are utilized in textile mills for powering machinery involved in processes like spinning and weaving . District Heating: Steam turbines contribute to district heating systems, where they generate electricity and provide thermal energy for heating purposes.

12. Desalination Plants: In some desalination processes, steam turbines are employed to drive pumps and other equipment . Ship Propulsion: Some naval and commercial ships use steam turbines for propulsion, converting steam energy into rotational motion for the ship's propellers. Waste-to-Energy Plants: Reaction steam turbines can be part of waste-to-energy facilities, converting steam produced from burning waste into electricity. Textile Industry: They are utilized in textile mills for powering machinery involved in processes like spinning and weaving. District Heating: Steam turbines contribute to district heating systems, where they generate electricity and provide thermal energy for heating purposes.

13. Main Components of Reaction Steam Turbine Spiral Casing The spiral casing is responsible for distributing water from a pipeline uniformly around the guide ring. Its cross-sectional area gradually reduces from the entrance to the tip, forming a spiral or scroll casing. This design helps in the efficient flow of water. Guide Mechanism The guide vanes, fixed between two rings in a wheel-like form, are located within the spiral casing. These vanes are designed to allow water to enter the turbine without causing shocks or eddies. They can be adjusted to control the quantity of water flowing into the turbine through a regulating shaft operated by a generator. Turbine Runner Depending on the turbine type, the turbine runner contains blades fixed to a shaft or ring. These blades are carefully designed to facilitate smooth water entry and exit without causing shocks. Depending on the operating conditions, the runner may be made of cast iron or steel alloys. Draft Tube After passing through the turbine runner, the water flows down through the draft tube. The draft tube increases the water head by an amount equal to the height of the runner outlet above the tailrace, thereby enhancing the turbine's efficiency.

14. Blade Design: Optimal blade shape to efficiently extract energy from steam. Consideration of axial and radial flow aspects for effective energy transfer. Steam Path: Designing the path that steam follows through the turbine to maximize energy extraction. Ensuring proper expansion of steam to achieve desired efficiency. Material Selection: Choosing materials that can withstand high temperatures and pressures. Balancing material strength and weight for rotor and blades. Efficiency: Focusing on maximizing overall efficiency by minimizing losses due to friction, heat, and turbulence. Employing advanced materials and coatings to reduce friction and wear.

15. Control System: Implementing a reliable control system to manage turbine speed and optimize power output. Ensuring safe and efficient operation under varying loads . Casing Design: Designing the casing to contain steam and guide it through the turbine efficiently. Considering expansion joints and thermal expansion effects . Rotor Dynamics: Evaluating rotor dynamics to prevent issues like vibration and resonance. Balancing the rotor for smooth operation and to minimize bearing loads . Environmental Considerations: Addressing environmental concerns, such as minimizing steam leaks and emissions Incorporating features for sustainable and eco-friendly operation.

16. Cooling Systems: Incorporating effective cooling systems to manage temperature gradients and prevent overheating. Considering both internal and external cooling methods. Maintenance Accessibility: Designing the turbine for ease of maintenance, including access to critical components. Considering modular designs to facilitate component replacement . Safety Features : Implementing safety features to handle abnormal operating conditions. Ensuring emergency shutdown systems are in place . Testing and Simulation: Utilizing advanced testing and simulation tools to optimize the design before physical construction. Iterative testing to refine the design for optimal performance.

17. Velocity Diagrams Velocity Diagram for Reaction Stage: In a reaction stage, there is an increase of relative velocity between entrance and exit, due to the pressure drop in the blade channel. The fixed and moving rings have identical blades, and the heat drop for the “ double ” stage is divided equally between the rings. Assuming the same friction losses in the identical rings, it follows that with the same exit angle Q = dj the exit and entrance triangles are identical, as shown in t he figure on the next slide. Thus = , and = . From the geometry of the figure it is evident that the differ velocity of whirl is = (2 cosƟ -u). Hence the work per lb. done on the moving ring of the “ double-stage ” is   Where Ɵ is the constant exit blade angle and  

18. cntd The constant entrance angle for each ring is and  

19. In this case, as a rule, the necessary particulars can be more easily obtained by direct calculation from equations above. It should be noted that if the exit blade angle Ɵ is increased and the blade speed and change of velocity of whirl Vw remain constant, the speed ratio is reduced, but the work done on the blades remains the same. This will be apparent from an examination of the dotted triangles , which show increased values of Ɵ but the same value of Vw as the full-line diagram. In the first case the value of is 0.5 , in the second it is 0.455. In connection with the wide-angled blades at the L.P. stages of the Parsons axial flow turbine. With the condition of identical velocity triangles for a double reaction stage, it will be evident that the axial components of the steam velocity are equal and the dynamical thrust is zero. With the usual construction, however, in which the blade heights are kept constant throughout a group or expansion, there is a progressive increase of velocity and consequently a slight thrust. Normally this is too small to be of any account, and it is neglected. There is, however, a statical thrust , which does not occur in the impulse machine. This is due to the difference of pressure between entrance and exit, at each moving ring . The cumulative effect of these small thrusts cannot be properly discussed at this stage.  

20. Euler Equation It states that the torque on the rotor equals the rate of change of moment of momentum of the fluid as it passes through the runner. Let u1 be the tangential velocity at entry and u 2 be the tangential velocity at exit. Let Vu 1 be the tangential component of the absolute velocity of the fluid at inlet and let Vu 2 be the tangential component of the absolute velocity of the fluid at exit. Let r 1 and r 2 be the radii at inlet and exit. The tangential momentum of the fluid at inlet = m Vu 1

21. cntd The tangential momentum of the fluid at exit = mVu 2 The moment of momentum at inlet = mVu 1 r 1 The moment of momentum at exit = mVu 2 r 2 Torque ,

22. Thus, the Euler Turbine equation becomes:

23. Performance Characterstics Model turbines are tested under different conditions of head, discharge, speed, power, efficiency. Results are plotted in the form of curves and are known as performance characteristic curves . Head curves Curves are drawn by conducting experiment at constant head. Head and gate openings are kept constant and speed is varied by varying load on the turbine. For each value of speed, corresponding values of power and discharge are obtained

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26. Speed Curves Testsareperformedatconstantspeed . Constant speed is attained by regulating the gate opening there by varying the discharge flowing through the turbine as the load varies. Head may or may not kept constant .

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28. Efficiency curve

29. Thank you!