Liner Holes Research Articles

Penanganan Lonjakan Vibrasi pada Rotor Elektrik Turbin di PLTU Gresik

This analysis will discuss how to handle vibrations in the Turbine Rotor. The measuring instrument used is Vibration Analysis test with Prov. 2140 type which measured amplitude, time and frequency domain of vibration signal. The results obtained in this study, firstly, the measurement vibration of rotor at PT PJB Gresik found the highest amplitude of vibration was 59,6 μm at 3000 rpm. In this condition, the rotor is in very good condition as per standard vibration in ISO 7919-2 stated 80 μm at 3000 rpm. However in the next measurement, there is an dramatically increase of amplitude in each vibration measurement. The top amplitude of vibration reached at 115 μm at 3000 rpm and shown a symtom of damage on the rotor as a result of vibration. In solving the problem this time we use the method Root couse analysis (RCA). The results of this research found that there was a short turn to turn on the rotor windings and the closed slot liner holes that caused electric vibrations and needed to be repaired to eliminate vibration disturbances. After repairing the vibration, it decreased which initially 115 μm to 33.5 μm at 3000 Rpm, it is still on the range of the permitted safe zone of ISO standard 7919−2.

Development of a laser-based measuring system for the inner geometrical dimension of cylinder liner

The accuracy inner geometrical dimension of cylinder liner has a positive effect on increasing engine efficiency, reducing oil consumption and prolonging engine life. In order to realize the on-line measurement of the cylinder liner hole diameter and roundness in the intelligent production line, a laser-based measuring system is proposed. First, two methods for calculating the inner diameter are described according to the mathematic model established by us, and the effect of input parameters on calculating results are analyzed by use of the full-factorial design. Next, the means for compensating measurement errors caused by the distance between the center axis of the workpiece and the center axis of the rotary actuator is proposed and analyzed. Then, the repeatability and reproducibility (R&R) test for the laser-based measuring system is carried out by the guidelines of measurement systems analysis (MSA), and the test results show that the R&R of the laser-based measuring system is acceptable. Finally, the tests of the laser-based measuring versus the manual measuring and the laser-based measuring versus the contact measuring are carried out, and the maximum difference for each test is 10 μm and 7 μm, respectively.

Effect of Combustor Casing Deformation on the Air Flow at Annulus

This paper describes an experimental analysis of the flow inside a real part of a can combustor used in Babylon/Iraq gas turbine power station. The combustor which has been studied contains deformation in the outer air casing due to the high temperature within the liner. Flow quality through annulus is crucial as it feeds air to the primary, secondary and dilution holes. One of the most important criterions of combustion chamber design is to have uniformity of pressure in the annulus region as early as possible which ensures flow split through various liner holes and minimum combustor length .This can be achieved by sufficient as well as efficient diffusion of air from compressor. Used pitot static tube to measure the velocity profile at ten stations in the outer annuls. The performance of the system was also assessed in terms of total pressure loss and static pressure recovery between the first and last measurement stations. It was observed that the deformation effected on the flow uniformity and penetration of air through the holes, thus effected on the performance of the combustor.

3D RANS Simulation of Turbulent Flow and Combustion in a 5 MW Reverse-Flow Type Gas Turbine Combustor

This study is concerned with 3D RANS simulation of turbulent flow and combustion in a 5 MW commercial gas turbine combustor. The combustor under consideration is a reverse flow, dry low NOx type, in which methane and air are partially mixed inside swirl vanes. We evaluated different turbulent combustion models to provide insights into mixing, temperature distribution, and emission in the combustor. Validation is performed for the models in STAR-CCM+ against the measurement data for a simple swirl flame (http://public.ca.sandia.gov/TNF/swirlflames.html). The standard k-ε model with enhanced wall treatment is employed to model turbulent swirl flow, whereas eddy break-up (EBU), presumed probability density function laminar flamelet model, and partially premixed coherent flame model (PCFM) are tried for reacting flow in the combustor. Independent simulations are carried out for the main and pilot nozzles to avoid flashback and to provide realistic inflow boundary conditions for the combustor. Geometrical details such as air swirlers, vane passages, and liner holes are all taken into account. Tested combustion models show similar downstream distributions of the mean flow and temperature, while EBU and PCFM show a lifted flame with stronger effects of swirl due to limited increase in axial momentum by expansion.

An integrated approach for optimal design of micro gas turbine combustors

The present work presents an approach for the optimized design of small gas turbine combustors, that integrates a 0-D code, CFD analyses and an advanced game theory multi-objective optimization algorithm. The output of the 0-D code is a baseline design of the combustor, given the required fuel characteristics, the basic geometry (tubular or annular) and the combustion concept (i.e. lean premixed primary zone or diffusive processes). For the optimization of the baseline design a simplified parametric CAD/mesher model is then defined and submitted to a CFD code. Free parameters of the optimization process are position and size of the liner hole arrays, their total area and the shape of the exit duct, while different objectives are the minimization of NOx emissions, pressure losses and combustor exit Pattern Factor. A 3D simulation of the optimized geometry completes the design procedure. As a first demonstrative example, the integrated design process was applied to a tubular combustion chamber with a lean premixed primary zone for a recuperative methane-fuelled small gas turbine of the 100 kW class.

Effect of swirl on the flow characteristics in the outer annulus of a prototype reverse-flow gas turbine combustor

Flow characteristics in the outer annulus and its effects on the flow splits through different liner holes have been established by conducting experiments on a full annulus prototype reverse-flow gas turbine combustor for different intensities of swirl imposed on the inlet flow. Measurements have been taken with a direction-sensitive pressure probe and a standard hot wire probe. It is seen that imposition of swirl improves the uniformity of outlet flow in θ-plane. It is observed that the flow split through the turn-section cooling holes and primary holes remains nearly constant up to S=0.55, while the split through the dilution holes decreases. With increase in the swirl intensity (S=0.84) the flow split through the turn-section and dilution holes increases while flow split through the primary holes reduces. The turbulence intensity level at the outlet is not affected by the imposed inlet swirl.

Eddy currents calculation in the TEXTOR 94 modified liner/vacuum vessel system during plasma disruption

The Dynamic Ergodic Divertor—to be installed inside the vacuum vessel of the TEXTOR 94 tokamak—requires a new liner design. The new liner represents a thin toroidal shell with numerous holes. One-third of the liner shell, facing the ergodic coils, is cut out for purposes of the ergodic divertor structures. To sustain the electromagnetic loads the cut-off edges of the inconel liner shell are reinforced with massive steel structures. Edges of the liner holes are reinforced with different types of steel structures. Calculation of the induced currents in the liner and vacuum vessel and electromagnetic forces on the structures due to interaction of the induced currents with the electromagnetic field during a plasma disruption is presented. The eddy currents in the segments of the vacuum vessel separated by bellows form closed loops. Because of numerous ports in the vacuum vessel and numerous holes in the liner, there are currents flowing perpendicular to the toroidal magnetic field. This leads to bending and twisting of the structures. The calculated electromagnetic forces were used for the subsequent structural analysis.

Velocity Distribution in the Annuli of a Plane Reverse-Flow Combustor Model

This paper reports the yclodity profiles and flow distribution in the annuli of a plane reverse-flow gas turbine GOmbustor model. Based on these, flow-split through different liner holes and swirlers has been estimated. it is seen that percentage flow-split through the outer liner surface holes, compared to that through liner dome and inner liner surface holes, is not affected significantly by increase in theinlet flow velocity.

An experimental study for preliminary design of gas turbine combustor

The preliminary design and performance test were carried out for determining dimensions of gas turbine combustor. The combustor design program was developed and applied to design our combustor, and the specific dimensions for swirler, dome and liner holes were determined by the semiempirical manner. Based on the first performance test data, the swirl angle governing the combustion characteristics of primary combustor zone was determined as 40 deg.. Using the second performance test data, the swirler dimensions were readjusted by 24 mm i.d., 34 mm o.d., and swirl angle of 45 deg.. The geometry of liner holes were determined by considering the flame stability and recirculation zone size. It was found that flame can be more easily stabilized by adjusting the swirler dimensions rather than liner holes. The geometry of swirler and liner holes were readjusted by using the final performance test data with dilution holes. Also, the combustor performance and emission characteristics were evaluated by analysis of exhaust gases.

Flow in Liner Holes for Countercurrent Combustion Systems

Heavy-duty gas turbine combustion systems have a “reverse flow” combustion-cooling air network. High-temperature gradients have been observed in some combustion liners around the plain holes, or around the cylindrical inserts welded into the mixing holes. Flow visualization tests were performed in a countercurrent flow facility. Measurements of pressure and velocity distributions in and around the mixing hole jet were taken, and mass flow rates and discharge coefficients were calculated in order to characterize and compare the two geometries. The results with a plain hole (square-edged orifice) and the cylindrical insert show the presence of a sharp separation region at the trailing edge (combustion side) of the liner hole, which may cause the high-temperature gradients observed under operating conditions. The measured discharge coefficients show a dependence on the insert geometry, the flow parameter (K), and the bottom section (combustion side) countercurrent flow velocity.

Completion of a Deep, Hot, Corrosive East Texas Gas Well

Summary A 19,011-ft [5795-m] wildcat in Houston County, TX, was successfully completed in March 1984. It tested the Lower Cotton Valley sand, which produced 14.5 MMscf/D [411×103 std m3/d] at a flowing tubing pressure of 8,671 psig [59.8 MPa]. The produced gas contained 4.9% CO2 and 24 ppm H2S. A bottomhole temperature (BHT) of 400°F [204°C] and bottomhole pressure (BHP) of 17,000 psig [117.2 MPa] intensified the corrosion potential. Tubular corrosion protection was provided by a 13% Cr production liner and a combination tubing string of 13 and 22% Cr alloys. The high pressure necessitated a 6,200-psig [42.7 MPa] underbalance liner top test. This paper outlines the completion and the supporting logic. It includes a discussion of the liner cementing, hole displacement, packer selection, tubing design, perforating, wellhead selection, and flowline design.

An Improved Method for Accurate Prediction of Mass Flows Through Combustor Liner Holes

A theory is devised for predicting the coefficients of discharge for some types of combustor liner holes and for calculating the local quantity of airflow into the liner. The resulting equations are tested against reliable empirical data and they show an agreement of better than 99 percent. The new correlation is particularly amenable to the preliminary design and development of combustors and could usefully be incorporated into numerical modeling techniques. The theory is also used to devise a simple but very accurate method of correlating experimental data that has advantages over many of the methods in current use.

Experimental Research on Air Flow through Liner Holes

Experimental Research on Air Flow through Liner Holes