Combustion, Fuels and Emissions for Industrial Gas Turbines
It is important that gas turbines used in Oil & Gas applications can burn a wide variety of fuels with the minimum impact on the environment or economics. Many types of gaseous and liquid fuels that can be used in Gas Turbines are discussed, as will be the two basic types of combustion system employed – ‘conventional’ and ‘Dry Low Emissions’ – along with the flexibility of these systems to accept different types of fuel. Some of the common contaminants found in fuels are discussed along with the impact these have on the operability and maintenance of industrial and aero-derivative gas turbines. Topics include: Types of gas turbines Types of exhaust emissions regulated Conventional combustion systems Dry Low (Pre-mixed) emissions combustion systems Fuel quality requirements ‘Pipeline’ quality Natural Gas fuels Premium liquid fuels (diesel, kerosene) Wellhead Gases as a Gas Turbine Fuel Liquified Natural Gas (LNG) Biogas fuels Refinery and process off gases Syngas Natural Gas Liquids and LPG fuels Crude Oil Operational impact of contaminants Water in fuel Storing fuels correctly
Study of biodiesel specifications for heavy-duty gas turbine application
Implementing a 20% biodiesel blend in diesel fuel (B20) has been launched since January 1th, 2016, and it was increased to 30% (B30) on January 1th, 2020, implemented in all sectors, including power generators. Gas turbines utilized as power generators designed to use natural gas or diesel fuel as fuel. Therefore, a study to use biodiesel blend as fuel in gas turbines was required. A comparative study was conducted to analyze the fuel requirements of General Electric’s (GE) Heavy Duty (HD) Gas Turbine specification compared to either of SNI 7182: 2015 and EN 14214 specifications. An assessment was conducted on samples of two biodiesel quality levels called biodiesel and distilled biodiesel to meet the GE HD Gas Turbine’s requirements. This study indicates that the biodiesel quality standards, both SNI 7182: 2015 and EN 14214, are insufficient to meet the gas turbine fuel specifications of the GE HD gas turbine. It is required a more specific quality standard dedicated to gas turbines. On the other hand, among the two samples, distilled biodiesel fulfills the fuel requirements of GE HD gas turbines and might be utilized as fuel for this type of gas turbine. According to the result of this study, a test run of 100% biodiesel (B100) as gas turbine fuel can be proposed to be implemented immediately.
Tempest Dual Fuel DLE Development and Commercial Operating Experience and Ultra Low NOx Gas Operation
Following on from the experience gained on the Typhoon generator set, ALSTOM Power’s generic dual fuel Dry Low Emissions (DLE) combustion system has been successfully developed for operation on the Tempest generator set. The first engine fitted with the full DLE dual fuel system entered service in October 2000.NOx emissions levels of less than 30vppm at 15% O2 have been demonstrated on distillate fuel. Low levels of combustion dynamics and pilot burner tip temperatures have been demonstarted on both fuels as well as gas fuel emission levels remaining less than 20vppm at 15% O2, the same as the gas only DLE version.This paper describes the development of the dual fuel DLE system on the Tempest at ALSTOM’s test facilities in Lincoln, England as well as the commercial operating experience gained to date on both the full dual fuel DLE and liquid standby DLE systems. The commercial operating experience will cover areas such as operating concept, liquid starting reliability, and site issues encountered.The lead Tempest gas only DLE units have successfully completed 22000 hours operation without any issues and will be discussed in the paper.Copyright © 2001 by ASME