ABSTRACT: An important characteristic of a steam power plant is its ability to maintain reliability and safety of the plant against frequent start-ups and load changes give rise to temperature distribution in steamturbinecasing, which results in non-uniform strain and stress distribution. The rapid increase of temperature and rotational speed during starts-ups, especially, makes conditions more severe and causes main components damage and reduction of life span for steamturbine. Thus accurate knowledge of thermal analysis and stresses distribution are required for the integrity and lifetime assessment for the turbinecasing. In this work a steady-state thermal analysis of steamturbinecasing was established by finite element method (ANSYS Mechanical). A steady-state thermal analysis calculated the effects of steady thermal loads on a system or component. Engineer/analysts often perform a steady-state analysis before performing a transient thermal analysis, which helps establish initial conditions. A steady-state analysis was last step of a transient thermal analysis. In steady-state thermal analysis we determined temperatures distribution of inner part is calculated by conduction, Heat transfer of a casing surface is affected by convection, thermal gradients, heat flow rates, various stress distributions and heat fluxes in an object that are caused by thermal loads that do not vary over time. A steady-state thermal analysis was linear with constant material properties or nonlinear with material properties that depend on temperature. The thermal properties of most material do vary with temperature, so the analysis usually is nonlinear. Including radiation effects also makes the analysis nonlinear.
In this this paper, they explained the brief concept about the low cycle fatigue in the steamturbinecasing due to cyclic loading. Since the turbine casings are huge and complex it is very important to understand the concept of low cycle fatigue and the life estimation. Their Analysis includes the calculation of lifetime for the casing and compares the results with FEM. From the analysis made, they found that the life time (number of cycles), generated by FEM was more compared with technically calculated one. From this one can say that turbine casings and bolts are safe for number of cycles calculated.
As per analysis of existing fixture, it was found that the high vibrations are induced because of the less number of truss members or stiffeners. To reduce vibration, modifications in existing fixture have been carried out. To modify existing fixture design mainly three major changes have been carried out. Numbers of truss members have been increased in existing model to eliminate vibration. By addition of horizontal support members rested on angle plate, vibration has been reduced due to unrestricted motion during drilling operation. The material for support member have been changed from mild steel to cast iron or alloy steel. Vibration was created due to unrestricted vibratory motion during drilling operation in old design, which is eliminated by the addition of horizontal support members which are rested in new designed angle plate. For job tilting purpose, the control points have been relocated at an angle of 30°, 28° and 33° in the direction of front view, right hand side view and top view respectively. The modified fixture design has been made versatile to fix different customers steamturbinecasing. After modified different components of fixture design, whole assembly has been remodeled and same as shown in Fig.4.
A suitable design procedure was chosen from the available methods to design different parts of bleed. CATIA is used extensively for making parts with diff types of operations. Then all the parts are assembled for making a complete turbine in CATIA Assembly section and analysed in ANSYS academia
The modern axial-flow turbine developed from a long line of inventions stretching back in time to the aeolipile of Heron (aka Hero) of Alexandria around 120 B.C. Although we would regard it as a toy it did demonstrate the important principle that rotary motion could be obtained by the expansion of steam through nozzles. Over the centuries many developments of rotary devices took place with wind and water driven mills, water driven turbines, and the early steamturbine of the Swedish engineer Carl de Laval in 1883.
The type of fuel used to heat to heat water in order to get vapor defines the thermal power plant in Iraq, such as coal, oil. Furthermore, creating the steam requisite to run a thermal plant can be achieved by using solar and Nuclear power. Rotary engine (turbine) power station fundamental operations of an easy to evaporate rotary engine turbine are illustrated as follows, Figure-1 Note that the saturated water enters the feeding pump and press it to enter the steam generator (boiler) to be heated again and get to the degree of vapor at elevated temperature and pressure and then enter the turbine. External work rotates the turbine where the mechanical energy is converted to electrical energy. The wet steam leaves the turbine and passes through the condenser where the pressure is lower than atmospheric pressure to help steam condense as it becomes saturated water through the cold water of the river. This station operates on a partially closed loop and is known as the Rankine Cycle .
Naturally, a gas turbine can operate at full power in summer, whereby its waste heat system produces the maximum possible amount of steam for expansion in the steamturbine, while the remaining heat, as happens in a usual combi ned process, is released into the environment (operation directed towards the production of electric power). In w inter it is possible to acquire more heat w ith additional firing in the waste heat system and operate the turbine at partial load in order to produce only as much electric power as needed in the net at that time (operation directed towards the produc tion of heat). A high degree of fuel conversion rate, however, cannot be achieved in this operation.
Reduction of man –power is due to the implementation of automated machine. Almost all the machines, used nowadays in various fields like Industrial production, packing etc. are electric power dependent. Even house holding machines like fridges, washing machines, dishwasher, microwave ovens etc., depends on electricity. Mostly all the electrical and electronical equipments are current dependent.Inorder to meet both hands to get rid of this electricity demand,power generation should be incremented/increased.There are many resources used in building power plants for power generation. Among those all, hydropower generation (HPG) has its own role. It uses turbines mainly. In this paper, we present a novel approach of generating electricity with the help of two forms of turbines, water and steam. In order to run the steamturbine, filtered water is boiled, for that, wastes are burned. Non bio-degradable wastes are mostly burned here.Hazardous gases liberated during this burning process pollutes air. In order to avoid such risks, Air Purification process is undertaken. Not only the electricity demand, but also pollution control is a major and serious issue too. As water is more equally important than food for most species, water pollution should be controlled in serious. And it is a global issue too. Burning of screened wastes to produce heat energy for boiling the water, may produce harmful gases. This gas leakage is measured by a sensor, so that, the surrounding air may not polluted more. Hence if the solution for both the problem is found in a single setup, the consequence will be even more effective. The objective of this paper is to controlling the water pollution combined with power generation.
Severally, there have often been suggestions from literatures of the combination of two or more thermal cycles within a single power plant with the intention of increasing efficiency over that of single cycles. In a study on the performance of combined gas turbine-steam cycle for power generation, it was noted that thermal processes can be combined in this way whether they operate with the same or with differing working media. The study concluded that a combination of cycles with different working media as in combined cycle is more inter- esting because their advantage can complement one another . Korobitsyn  in his analysis of cogeneration, combined and integrated cycles observed that improved efficiency can be achieved by modifications to the original simple cycle to recover heat from the turbine exhaust for generation of steam in a steamturbine bot- toming cycle as found in combined cycle.
A steamturbine may be defined as a form of heat engine in which the energy of the steam is transformed into kinetic energy by expansion through nozzles, and the kinetic energy of resulting jet is in turn converted into force doing work on rings of blades mounted on a rotating disc. The majority of steam turbines have, therefore two important elements:
of there may be done by adding heat so that the temperature of the working fluid is increased after compression. To get a higher temperature of the working fluid a combustion chamber is required where combustion of air and fuel takes place giving temperature rise to the working fluid. The turbine escapes energy from the exhaust gas. Like the compressor, turbine can be centrifugal or axial. In each type the fast moving exhaust gas is sued to spin the turbine, since the turbine is attached to the same shaft as the compressor at the front of the engine, and the compressor will turn together, The turbine may extract just enough energy to turn the compressor. The rest of the exhaust gas is left to exit the rear of the engine to provide thrust as in a pure jet engine. Or extra turbine stages may be used to turn other shafts to power other machinery such as the rotor of a helicopter, the propellers of a ship or electrical generators in power stations. The present paper deals with the first type is centrifugal stresses that act on the blade due to high angular speeds and second is thermal stresses that arise due to temperature gradient within the blade material. The analysis of turbine blade mainly consists of the following two parts: Structural and thermal analysis. The analysis is carried out under steady state conditionsusing Ansys software. The study has been conducted with two different materials epoxy-resign and inconel 680 superalloys. Turbine rotors used in power plants are subjected to high temperature especially during start up cycle. The rotor of steamturbine is subjected to temperature variations in short periods of time due to the start and stop cycles of the turbine. This causes sudden changes in the temperature with transient thermal stresses being induced into the turbine rotor. The transient effect is due to the changes in the material properties like Density, Specific heat and Young’s Modulus. The estimate
Thermal power plants use boilers to generate steam for steam turbines. A significant part of the world energy consumption is found to be used for operating boilers to facilitate the heating process or power generation. The design of the boiler, internal combustion engine, or gas turbine has a major effect on the operation. NOx formation tends to increase with an increase in boiler capacity, because larger boilers tend to have more intense combustion with higher combustion temperatures and longer residence time for flue gases. The same appears to be true in case of engines and turbines.
A nuclear reactor produces and controls the release of energy from splitting the atoms of elements such as uranium and plutonium. In a nuclear power reactor, the energy released from continuous fission of the atoms in the fuel as heat is used to make steam. The steam is used to drive the turbines which produce electricity (as in most fossil fuel plants).
Steamturbine is an excellent prime mover to convert heat energy of steam to mechanical energy. Of all heat engines and prime movers the steamturbine is nearest to the best and it is widely used in power plants and in all industries where power is needed for process.In power generation mostly steamturbine is used because of its greater thermal efficiency and higher power-to-weight ratio. Because the turbine generates rotary motion, it is particularly suited to be used to drive an electrical generator–about 80% of all electricity generation in the world is by use of steam turbines.In this project we are going to design a propeller blade assembly in Catia V5 R21 and thermal analysis is done in Ansys. In order to evaluate the effectiveness of composites and metal propeller using FEA packaged (ANSYS). Thermal analysis is performed on both Aluminum and composite propeller to find out the heat flux and thermal error.
Single valve control means that all the control valves accept a valve control signal to make the valves turn up or down at the same time, which is characterized by the throttle adjusting and full arc admission. The cylinder rotor heat expansion is uniform and the metal tempera- ture of different steamturbine parts is in a stable condi- tion, making the unit withstand greater load change rate. But because all of the adjustment valves are not in the fully opened state, the valves have a great throttle loss, reducing the thermal efficiency of the unit.
of tension in the sheet should not cause any concern and pressure acting on the blades arise mainly from the central expelling charge and vibratory response of the blades. Vibrating pressure are maintained usually is at a low level through the frequencies to ensure we reach the narrow limits, thus avoiding the resonant vibration and reduce steam bending stresses. And the total number of sheets in a certain stage of the groups is divided. The blades are connected in each group of skin rods passing through the holes of the outer and inner skin. Preserve the strength of the group to join the leather bars with copper sheets on the edges of the hole. As materials impurities and surface defects to reduce the tendency to fatigue are minimized. Regarding the environment \ pay attention to the quality of steam so that fatigue does not occur by corrosion. We are carrying out a lot of investment to achieve the best turbine design with clean steel and have the right microstructure and mechanical properties. Failures that still face are mainly related to the maintenance conditions and improper operation. Knowledge of failure because of these reasons often go a long way in preventing failures and greatly improves the economics of power generation. This paper presents the results of the analysis unit blades of the lp turbine failed 109
This paper is meant to help with failure investigation, presenting a review of the causes and effects involved when blades fail. Included are descriptions of failure mechanisms (stress; resonance; environment) and of the conditions causing the failures (design; manufacturing; operation). the first with a crack initiating at the strain raiser point and propagating at low rate, a second where and the third one consisting of unstable fracture. Stress intensity factor approach is used to identify the three crack zones and establish the mechanism of the machine failure. Blade failure is a common problem of a steamturbine and it’s failure in-service results in safety risky, repair cost and operational revenue losses. Thus, the reliability of these blade is very the important for successful operation of a steamturbine. Dynamic analysis of a steamturbine blade in computational environment is carried out in the present work. Turbines are device for power generation. These are the source for converting the energy into electrical energy. Turbine blades are main component which rotates under fluid flow, which causes the conversion of potential/kinetic energy to convert into electrical energy. The sound stability of the turbine blades is essential to achieve the target. During exposure to adverse condition it may lead to formation of cracks either by corrosion or by erosion. In the present work attempt has been made to locate the cause of failure of the blade of steamturbine.
Co-firing refers to mixing biomass with fossil fuels in conventional power plants. Coal-fired power plants can use cofiring systems to significantly reduce emissions, especially sulfur dioxide emissions. Gasification systems use high temperatures and an oxygen-starved environment to convert biomass into synthesis gas, a mixture of hydrogen and carbon monoxide. The synthesis gas, or "syngas," can then be chemically converted into other fuels or products, burned in a conventional boiler, or used instead of natural gas in a gas turbine. Gas turbines are very much like jet engines, only they turn electric generators instead of propelling a jet. Highly efficient to begin with, they can be made to operate in a combined cycle, in which their exhaust gases are used to boil water for steam, a second round of power generation, and even higher efficiency. Biomass fuels can come from many different sources. While most all of these can be used to produce fuel, their suitability for specific conversion technologies must be assessed. Typically, biomass for energy generation comes from the following sources:
Abstract. In order to evaluate the training process of steamturbine virtual maintenance for personnel training more reasonably, a quantitative evaluation method of turbine virtual maintenance based on improved analytic hierarchy process (AHP) is proposed in this paper. This paper establishes a set of evaluation index system and gives the quantitative algorithm of the corresponding index according to the characteristics of virtual maintenance of steamturbine equipment. The traditional AHP is also improved without consistency checking, which avoids the blindness of artificial adjustment of the judgment matrix and makes it easier and faster to get the weight value of the index. Under the balanced consideration of all evaluation factors, the evaluation of operators is completed, and the results of the comprehensive evaluation are more objective and credible. This method has been applied to a virtual maintenance training and assessment platform of steamturbine in thermal power plant, and the validity of the method has been verified.