Supersonic Ejectors for Hydrocarbon Emissions Capture

Author(s):  
Yuri Biba ◽  
H. Allan Kidd ◽  
Stephen Peifer ◽  
Christopher Scott ◽  
Brian Sloof ◽  
...  

Supersonic ejectors can be applied to capture low-pressure leakage gas from the gas seal vents of a centrifugal compressor. This captured gas can be re-injected into the fuel gas line of the gas turbine driver or the captured gas can be used as a fuel for gas fired utility heaters. By capturing the gas that is normally emitted to the atmosphere the operator can reduce operating cost and enjoy a reduction in hydrocarbon foot print. Because the supersonic ejector does not have moving parts, the system operating and maintenance costs are lower than functionally comparable traditional systems. In this study, a prototype of a supersonic ejector system was developed and tested at a pipeline compressor station. The obtained test data were used for developing and tuning a mean-line aerodynamic analysis tool, which predicts the ejector’s operating map. A family of three ejectors was designed to cover a range of operating conditions associated with gas turbine driven pipeline compressors. These ejectors were built, installed on a specially designed panel, described as the ejector system, and tested on inert gas at the original equipment manufacturer’s (OEM’s) facility. A comparison of predicted and as-tested supersonic ejector performance maps is discussed and conclusions are made about the system operating range.

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Philip L. Andrew ◽  
Harika S. Kahveci

Avoiding aerodynamic separation and excessive shock losses in gas turbine turbomachinery components can reduce fuel usage and thus reduce operating cost. In order to achieve this, blading designs should be made robust to a wide range of operating conditions. Consequently, a design tool is needed—one that can be executed quickly for each of many operating conditions and on each of several design sections, which will accurately capture loss, turning, and loading. This paper presents the validation of a boundary layer code, MISES, versus experimental data from a 2D linear cascade approximating the performance of a moderately loaded mid-pitch section from a modern aircraft high-pressure turbine. The validation versus measured loading, turning, and total pressure loss is presented for a range of exit Mach numbers from ≈0.5 to 1.2 and across a range of incidence from −10 deg to +14.5 deg relative to design incidence.


Author(s):  
Raju Murugan ◽  
Dhanalakshmi Sellan ◽  
Pankaj S. Kolhe

Abstract The spatial distribution of spray plays a key role in liquid fuel combustion, which dictates the local mixture fraction and the flame temperature distribution in gas turbine engines. The swirling flow creates further decomposition of the spray droplets in liquid fuel gas turbine engine, which increases the surface area of the droplets. Turbulent mixing due to the swirling flow is essential for preheating of unburned products and flame holding in the combustor. A lab-scale swirl stabilized liquid fuel combustor was designed and fabricated with the geometric swirl number (SN) of 1. Combustor flow geometry involves internal spray from flow blurring twin-fluid atomizer, surrounded by swirling airflow which is confined with co-flow air to provide full optical access. At constant spray operating conditions, the swirl Reynolds number (Re) is increased whereas co-flow velocity was maintained constant at 0.4 m/s. An experimental study was carried out to understand the effect of Reynolds number on the aerodynamic structure of airflow, the spatial distribution of spray structure and kerosene flame structures using Particle Image Velocimetry (PIV) and direct imaging. The experimental results show that the flow structure and spray spreads radially with the increase in swirl Reynolds number and the corresponding core spray height decreases, which were evident from flame images.


Author(s):  
Yunpeng Cao ◽  
Lie Chen ◽  
Jianwei Du ◽  
Fang Yu ◽  
Qingcai Yang ◽  
...  

When a gas turbine operates in a marine environment, gradual performance degradation occurs due to salt fog in the compressor and turbine. Regular water washing of a gas turbine can effectively restore the performance loss caused by compressor salt fog fouling on the flow passage. However, inappropriate washing will increase maintenance costs, cause unnecessary down time and premature erosion of leaf surfaces. In this paper, a coefficient matching method for a three shaft marine gas turbine salt fog fouling degradation factor model is proposed, which can establish a model of salt fog fouling degradation factor according to a change in operating time and exhaust temperature in the washing cycle. The influences of load, environment temperature, inlet pressure loss and salt fog fouling rate on the performance degradation of the gas turbine are simulated and analyzed; then, the degradation regularity of the performance parameters of the gas turbine under different operating conditions and fouling degrees is obtained. Finally, a method of operating cost estimation for marine gas turbines is proposed that can estimate the cost of transient change and cumulative change in the cleaning cycle caused by the salt fog fouling, which can help the operator to determine the cleaning strategy and reduce the operation cost of the gas turbine.


Author(s):  
Michel L. Verbist ◽  
Wilfried P. J. Visser ◽  
Jos P. van Buijtenen ◽  
Rob Duivis

Gas-path-analysis (GPA) based diagnostic techniques enable health estimation of individual gas turbine components without the need for engine disassembly. Currently, the Gas turbine Simulation Program (GSP) gas path analysis tool is used at KLM Engine Services to assess component conditions of the CF6-50, CF6-80 and CFM56-7B engine families during post-overhaul performance acceptance tests. The engine condition can be much more closely followed if on-wing (i.e., in-flight) performance data are analyzed also. By reducing unnecessary maintenance due to incorrect diagnosis, maintenance costs can be reduced, safety improved and engine availability increased. Gas path analysis of on-wing performance data is different in comparison to gas path analysis with test cell data. Generally fewer performance parameters are recorded on-wing and the available data are more affected by measurement uncertainty including sensor noise, sensor bias and varying operating conditions. Consequently, this reduces the potential and validity of the diagnostic results. In collaboration with KLM Engine Services, the feasibility of gas path analysis with on-wing performance data is assessed. In this paper the results of the feasibility study are presented, together with some applications and case studies of preliminary GPA results with on-wing data.


Author(s):  
Gabriele Lucherini ◽  
Vittorio Michelassi ◽  
Stefano Minotti

Abstract A gas turbine is usually installed inside a package to reduce the acoustics emissions and protect against adverse environmental conditions. An enclosure ventilation system is keeps temperatures under acceptable limits and dilutes any potentially explosive accumulation of gas due to unexpected leakages. The functional and structural integrity as well as certification needs of the instrumentation and auxiliary systems in the package require that temperatures do not exceed a given threshold. Moreover, accidental fuel gas leakages inside the package must be studied in detail for safety purposes as required by ISO21789. CFD is routinely used in BHGE (Baker Hughes, a GE Company) to assist in the design and verification of the complete enclosure and ventilation system. This may require multiple CFD runs of very complex domains and flow fields in several operating conditions, with a large computational effort. Modeling assumptions and simulation set-up in terms of turbulence and thermal models, and the steady or unsteady nature of the simulations must be carefully assessed. In order to find a good compromise between accuracy and computational effort the present work focuses on the analysis of three different approaches, RANS, URANS and Hybrid-LES. The different computational approaches are first applied to an isothermal scaled-down model for validation purposes where it was possible to determine the impact of the large-scale flow unsteadiness and compare with measurements. Then, the analysis proceeds to a full-scale real aero-derivative gas turbine package. in which the aero and thermal field were investigated by a set of URANS and Hybrid-LES that includes the heat released by the engine. The different approaches are compared by analyzing flow and temperature fields. Finally, an accidental gas leak and the subsequent gas diffusion and/or accumulation inside the package are studied and compared. The outcome of this work highlights how the most suitable approach to be followed for industrial purposes depends on the goal of the CFD study and on the specific scenario, such as NPI Program or RQS Project.


1995 ◽  
Vol 117 (1) ◽  
pp. 88-93
Author(s):  
D. Hough

This paper describes the design and application of reciprocating compressors for fuel gas service. In fuel gas services and particularly power generation it is important to minimize all parasitic losses. Efficiency over a range of operating conditions requires sophisticated control systems and the paper describes the merits of each system and their effect on operating cost. Some of the important operational considerations are described together with major design features. The use of staging and the advantages of a modular approach to compressor design are also covered, which demonstrates the suitability of the reciprocating compressor for fuel gas service particularly when variation of inlet conditions cannot be avoided.


Author(s):  
Philip L. Andrew ◽  
Harika S. Kahveci

Avoiding aerodynamic separation and excessive shock losses in gas turbine turbomachinery components can reduce fuel usage, and thus reduce operating cost. In order to achieve this, blading designs should be made robust to a wide range of operating conditions. Consequently, a design tool is needed which can be executed quickly for each of many operating conditions, and on each of several design sections which will accurately capture loss, turning and loading. This paper presents the validation of a boundary layer code, MISES, versus experimental data from a 2-D linear cascade approximating the performance of a moderately-loaded, mid-pitch section from a modern aircraft high-pressure turbine [1–2]. The validation versus measured loading, turning, and total pressure loss is presented for a range of exit Mach numbers from ≈ 0.5 to 1.2, and across a range of incidence from −10° to +14.5° relative to design incidence.


2010 ◽  
Vol 156-157 ◽  
pp. 1545-1554 ◽  
Author(s):  
Napassavong Rojanarowan ◽  
Angsumalin Senjuntichai

The objective of this study is to develop an efficient washing system to remove cutting oil from machining part surface. The proposed washing system consists of two processes: the dipping process and the modified automatic ultrasonic washing process. The automatic ultrasonic washing process is redesigned and developed to reduce operating cost and increase productivity from the previously developed machine. For this proposed system, experiments have been performed to determine the washing conditions that yield satisfactory proportion of defectives due to oil contamination. Under the suggested operating conditions, the proportion of defectives due to oil contamination is reduced from 12.8% to 1.78%, which leads to $16,800 defective cost reduction. The proposed washing system yields 42.9% increase in washing productivity. Furthermore, it as has more standard procedure than the current washing process.


Complex chemical reactions and downstream processing can be performed in reactive distillation column to overcome with equilibrium limitations and to make it an economical process. An existing reactive distillation unit is costly to modify due its complex configuration and existing limitations of structure, space area, etc. Modifying an existing plant is a tedious task and more complex than a new process. Thus, to modify the existing operating conditions and input design variables it is necessary to verify by applying the same in real plant condition. This is done using revamping based on rigorous simulation and optimization in Aspen Plus process simulator. The main form of energy generator used in a distillation column is reboiler which directly affects the utilities such as cooling water, electricity and steam. Therefore, optimizing this reboiler duty to reduce energy losses is done using optimization model analysis tool of Aspen Plus. This reduction of energy demands diminishes the operating cost as per the reduction in utility cost. Now this reduction in operating cost is evaluated corresponding to the optimized reflux ratio and number of plates as obtained using sensitivity analysis tool of Aspen Plus.


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