The Design, Selection, and Application of Oil-Injected Screw Compressors for Fuel Gas Service

1995 ◽  
Vol 117 (1) ◽  
pp. 81-87
Author(s):  
S. Tsutsumi ◽  
J. Boone

Fuel gas compressors installed in cogeneration systems must be highly reliable and efficient machines, like the other main components, such as gas turbines, gas engines, etc. In the range of gas flow rate and pressure conditions generally required for such systems, the oil-injected screw compressor is often the most suitable compressor type for these requirements. Advantages of oil injected screw compressors are: improved compression efficiency; low discharge gas temperature; high reliability; simple mechanical construction; which all result from injection of lubricant into the compressor. Injected lubricant is discharged together with compressed gas on the high-pressure side but the oil is separated by a fine oil separation system down to a level that causes no problems for the downstream combustion equipment. The oil-injected screw compressor is equipped with an integral stepless capacity control by means of a slide valve, which makes part-load operation possible with reduced power consumption and improves overall system efficiency. As cogeneration systems, which are energy efficient and environmentally sound, are now increasing in number, so oil-injected screw compressors are expected to be used more widely.

1995 ◽  
Vol 117 (1) ◽  
pp. 74-80 ◽  
Author(s):  
K. D. Lelgemann

Fuel gas compressors installed in cogeneration systems must be highly reliable and efficient machines. The screw compressor can usually be designed to meet most of the gas flow rates and pressure conditions generally required for such installations. To an ever-increasing degree, alternative sources are being found for the fuel gas supply, such as coke-oven gas, blast-furnace gas, flare gas, landfill gas, and synthesis gas from coal gasification or from pyrolysis. A feature of the oil-free screw compressor when such gases are being considered is the isolation of the gas compression space from the bearing and gear lubrication system by using positive shaft seals. This ensures that the process gas cannot be contaminated by the lubricating oil, and that there is no risk of loss of lubricant viscosity by gas solution in the oil. This feature enables the compressed gas to contain relatively high levels of particulate contamination without danger of “sludge” formation, and also permits the injection of water or liquid solvents into the compression space, to reduce the temperature rise due to the heat of compression, or to “wash” any particulate matter through the compressor.


2019 ◽  
Vol 38 (2019) ◽  
pp. 837-848
Author(s):  
Du Kaiping ◽  
Gao Xiangzhou ◽  
Sun Haibo

AbstractThe raceway plays an important role in the mass and heat transportation inside a melter gasifier. Considering that pure oxygen at room temperature instead of hot air is injected into the melter gasifier, a two-dimensional mathematical model at steady state is developed in the current work to describe the effect of the additional gas injection on the characteristics around the raceway in melter gasifier. The results show that a high-speed jet with a highest temperature above 3500 K could be found in front of tuyere. Furthermore, a small scale of gas flow circulation occurs in front of tuyere that results in a more serious thermal damage to tuyere. In order to decrease the gas temperature in the raceway to prevent the blowing-down caused by tuyere damage, the additional gas, including N2, natural gas (NG) and coke oven gas (COG) should be injected through the tuyere. Compared with N2, additional fuel gas injection gives full play to the high temperature reduction advantage of hydrogen. In addition, considering the insufficient hearth heat after injecting NG and the effective utilization of secondary resource, an appropriate amount of COG is recommended to be injected for optimizing blast system.


Author(s):  
Hiroshi Sato ◽  
Toshiji Amano ◽  
Yoshihiro Iiyama ◽  
Masaaki Mori ◽  
Tsuneaki Nakamura

This paper describes the development of an ultra-low emission single-can combustor applicable to 200 kW to 3 MW size natural gas-driven gas turbines for cogeneration systems. The combustor, called a three-staged combustor, was designed by applying the theory of lean premixed staged combustion. The combustor comprises two sets of premixing injector tubes located around the combustor liner downstream of the premixing nozzle equipped with a pilot diffusion nozzle in the center. The combustor controls engine output solely by varying the fuel gas flow without the need for complex variable geometry, such as inlet guide vanes, for combustion airflow control. Reliability, response to load variation and retrofit capability have been greatly improved along with wide low-emission operating range. As the result of the atmospheric rig tests, the three-staged combustor has demonstrated superior performance of 3.5 ppm NOx (O2 = 15%) and 7 ppm CO (O2 = 15%) at full load. Assuming the relationship between NOx emission and pressure and taking into account sequential CO oxidation occurring in the scroll, the performance of the combustor at engine operation is expected to be less than 9 ppm NOx (O2 = 15%) and 50 ppm CO (O2 = 15%) emissions between 25% and 100% engine load. During the development, temperature distribution in the atmospheric combustion was measured in detail to gain comprehensive understanding of the low emissions combustion phenomena. The results of the measurement were compared with the theory of lean premixed staged combustion. Employing the concept of effective mixing ratio, the theory of lean premixed staged combustion has proved to be a powerful method to design a lean premixed staged combustor.


Author(s):  
Ole Gro̸ne ◽  
Kjeld Aabo ◽  
Peter Skjoldager

Two-stroke low speed diesels dominate the main propulsion engine market, being selected for nearly 80% of all ocean-going vessels. The main reason is the simplicity of the direct-coupled installation, the high reliability and the high thermal efficiencies. Four-stroke medium speed engines take the last 20%, except on the LNG carrier propulsion field where steam turbines, while being threatened, still prevail. The occasional exception to the above is a few gas turbines in passenger (cruise) vessels. Recently, two-stroke low speed diesels have been developed for electronically controlled fuel injection systems, and such engines are now gaining momentum in the industry. The electronically (rather than cam) controlled fuel injection systems bring with it many operational benefits, which will be outlined in the paper. One such feature is the ability to inject very small fuel amounts safely through the same injectors as those able for full power operation. This paves the way for a more simple and safe version of large low speed dual fuel gas engines for propulsion of LNG carriers, representing significant fuel and gas saving possibilities, reducing CO2 emissions, and also opening new frontiers for low emission high-efficiency ship propulsion systems in other vessel types, including the largest types, as well as land based power generation. The paper will outline the technology, especially with a view of emission control and its economical and environmental potential.


Author(s):  
Yizhou Yan

Fuel gas for many Combined Cycle Power Plants is supplied directly by the gas provider’s regulator station in locations where the gas pipeline pressure is sufficient without further compression. Other locations require one or more onsite compressors to boost the fuel gas pressure. A rising concern is the fuel gas system transient response immediately after a significant reduction in the plant fuel gas consumption. Transient analysis models have been developed for typical fuel gas systems of combined cycle plants to ensure that the system is configured to respond appropriately to unplanned disturbances in fuel gas flow such as when a gas turbine trip occurs. Pressure control (regulator) and booster compressor control loop tuning parameters based on quantitative transient model results could be applied to set up targets for use in specifying and commissioning the fuel gas system. Case studies are presented for typical large combined cycle plants with two gas turbines taking fuel from a common plant header. This is done for designs without or with fuel gas booster compressors.


Author(s):  
Tatsuo Fujii ◽  
Takakazu Uenaka ◽  
Hitoshi Masuo

The first Kawasaki-ABB GT13E2 gas turbine began operating at Kawasaki Gas Turbine Research Center (KGRC) in Sodegaura city, Japan in January 1994. This facility is a simple-cycle power station and is operated in DSS (Daily Start and Stop) operation mode as a peaking unit, and its output electricity is delivered to Tokyo Electric Power Company (TEPCO). The GT13E2 gas turbine at KGRC was manufactured jointly by Kawasaki Heavy Industries (KHI) and Asea Brown Boveri (ABB). KHI and ABB have a joint test program with this facility to research for high reliability, high performance and low emission for the GT13E2 and future gas turbines. The performance of the KGRC GT13E2 has been monitored continuously. It was found from these monitored data that the thermal efficiency has been maintained at a high level and could be recovered by compressor washing when the compressor was fouled. Several factors which influence NOx emissions were studied on the gas turbine, and it was found that atmospheric humidity has a major influence on NOx emissions. Also other factor such as the position of the variable inlet guide vanes (VIGV) and fuel gas flow through each burner of the combustor were adjusted to reduce NOx emission. As a result, NOx emission from the KGRC GT13E2 has been maintained at a very low level. Reliability, availability and maintainability (RAM) has been evaluated by Operational Reliability Analysis Program (ORAP®) of Strategic Power Systems, Inc. (SPS) in order to identify and improve RAM performance of the GT13E2 at KGRC. These analyses made it clear what kind of outage had an impact on the reliability, availability and starting reliability of the KGRC GT13E2 and appropriate actions have increased the starting reliability. This paper describes operating experiences of the KGRC GT13E2 including performance, emissions and RAM performance.


Author(s):  
Jean-Roch Jacques ◽  
Noor Azman Mohamat Nor

Abstract Outboard-traverse flame migration in an annular profile, combustion gas pathway of a Siemens aero-derivative turbine engine can be detected with a dual immersion thermocouple. This solution is applicable for Oil & Gas operators using gas turbines fueled by natural gas. The typical flame profile within the annular combustion gas flow path is disturbed by introducing poor quality fuel into the engine. The skewed or outward bias flame profile in turn causes severe overheating of the hot section components around the outer radius of the annular combustor exit wall covering a number of hot section components. This ultimately causes accelerated components deterioration and failure to meet its target design life. Consequently, resulting in rejection of these components and increasing the life cycle cost of their asset operations. The introduction of the dual immersion thermocouple allow us to detect outward bias flame pattern using the exhaust gas temperature profile during operation and warn the operator of this condition via software alarm and trip provision. By implementing a means of detecting outward bias flame patterns, the operator will be made aware of this condition and can then take means to resolve this matter by first, allowing to optimize hot section components boundary limits and saving overhaul costs and second, avoid unplanned maintenance outages due to hot section premature failures.


Author(s):  
Robert G. Laycock ◽  
Thomas H. Fletcher

Some industrial gas turbines are currently being fired directly using heavy fuel oil, which contains a small percentage of inorganic material that can lead to fouling and corrosion of turbine components. Deposits of heavy fuel oil ash were created in the Turbine Accelerated Deposition Facility (TADF) at Brigham Young University under gas turbine-related conditions. Ash was produced by burning heavy fuel oil in a downward-fired combustor and collecting the ash from the exhaust stream. The mass mean ash particle diameter from these tests was 33 microns. This ash was then introduced into the TADF and entrained in a hot gas flow that varied from 1088 to 1206°C. The gas and particle velocity was accelerated to over 200 m/s in these tests. This particle-laden hot gas stream then impinged on a nickel base superalloy metal coupon approximately 3 cm in diameter, and an ash deposit formed on the coupon. Sulfur dioxide was introduced to the system to achieve 1.1 mol% SO2 in the exhaust stream in order to simulate SO2 levels in turbines currently burning heavy fuel oil. The ash deposits were collected, and the capture efficiency, surface roughness, and deposit composition were measured. The deposits were then washed with deionized water, dried, and underwent the same analysis. It was found that, as the gas temperature increased, there was no effect on capture efficiency and the post-wash roughness of the samples decreased. Washing aided in the removal of sulfur, magnesium, potassium, and calcium.


2020 ◽  
Vol 46 (11) ◽  
pp. 1114-1123
Author(s):  
N. P. Vagin ◽  
A. A. Ionin ◽  
A. Yu. Kozlov ◽  
I. V. Kochetov ◽  
A. P. Napartovich ◽  
...  

Author(s):  
Hafiz M Hassan ◽  
Adeel Javed ◽  
Asif H Khoja ◽  
Majid Ali ◽  
Muhammad B Sajid

A clear understanding of the flow characteristics in the older generation of industrial gas turbines operating with silo combustors is important for potential upgrades. Non-uniformities in the form of circumferential and radial variations in internal flow properties can have a significant impact on the gas turbine stage performance and durability. This paper presents a comprehensive study of the underlying internal flow features involved in the advent of non-uniformities from twin-silo combustors and their propagation through a single axial turbine stage of the Siemens v94.2 industrial gas turbine. Results indicate the formation of strong vortical structures alongside large temperature, pressure, velocity, and flow angle deviations that are mostly located in the top and bottom sections of the turbine stage caused by the excessive flow turning in the upstream tandem silo combustors. A favorable validation of the simulated exhaust gas temperature (EGT) profile is also achieved via comparison with the measured data. A drop in isentropic efficiency and power output equivalent to 2.28% points and 2.1 MW, respectively is observed at baseload compared to an ideal straight hot gas path reference case. Furthermore, the analysis of internal flow topography identifies the underperforming turbine blading due to the upstream non-uniformities. The findings not only have implications for the turbine aerothermodynamic design, but also the combustor layout from a repowering perspective.


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