Siemens Energy SGT-400 Industrial Gas Turbine

Overview

The Siemens Energy SGT-400 is a twin-shaft industrial gas turbine for power generation and mechanical drive in the 10 to 15 MW class, suitable for all climates and for both onshore and offshore installations. According to the Siemens Energy SGT-400 technical data poster, power generation ratings are 10.5, 12.9 and 14.3 MW with gross efficiencies of up to 35.6 %, and mechanical drive ratings are 10.8, 13.8 and 14.9 MW with efficiencies of up to 37.1 %. Siemens Energy reports that more than 450 units have been sold with over 11.7 million operating hours, and that the fleet leader has accumulated more than 165 000 hours, making the SGT-400 one of the most widely used gas turbines in its power class for oil and gas and industrial users.

Seven Star LLC supplies Siemens Energy SGT-400 related equipment, spare parts, instrumentation and auxiliary components to operators in the Sultanate of Oman and the GCC, with engineering support in Muscat. For new-unit enquiries we help customers assemble the technical basis of their request, and for installed fleets we focus on sourcing genuine replacement items, monitoring hardware and consumables for platforms, gas plants and power stations across Oman.

Operating Principle of the Siemens Energy SGT-400

As general engineering background, a gas turbine compresses ambient air, burns fuel in the compressed air and expands the hot gas through turbine stages to produce shaft power. In a twin-shaft machine such as the Siemens Energy SGT-400, the gas generator, consisting of the compressor and the compressor turbine that drives it, runs on its own shaft, while a separate free power turbine converts the remaining gas energy into output power. Because the power turbine is mechanically independent, its speed can vary across a wide range, which suits variable-speed compressor and pump drives and also supports power generation through a gearbox.

Siemens Energy describes the Siemens Energy SGT-400 gas generator as a two-bearing rotor with an 11-stage axial-flow transonic compressor and a two-stage overhung compressor turbine, followed by a two-stage overhung free power turbine. Variable guide vanes optimise compressor performance, and the turbine can operate efficiently across a wide load and speed range from about 10 to 15 MW. Pressure ratios range from 16.1:1 to 18.5:1 depending on the rating.

Engineering Design of the Siemens Energy SGT-400

Combustion takes place in a can-annular, single-stage Dry Low Emissions system that burns a wide variety of fuels at any load while meeting strict emission limits, and it supports true dual-fuel operation with automatic changeover between gas and liquid fuel at any load. Siemens Energy states a Wobbe index range from approximately 17.5 to 50 MJ/m³, covering wellhead gas, weak wellhead gas, coke oven gas, biogas and landfill gas as well as distillate liquid fuels, and a hydrogen capability of up to 30 vol% with DLE burners or up to 65 vol% with diffusion burners and unabated NOx. Heavy-duty casings split horizontally and vertically enable on-site maintenance, and high-chrome blades are available for corrosive environments.

The Siemens Energy SGT-400 packages for power generation and mechanical drive are compact, factory-tested modules with a high power-to-weight ratio, carrying the turbine, gearbox where required, the driven unit and shop-tested fluid modules on a common underbase. These modules include lube oil, gas fuel, auto drains and an optional liquid fuel module, all fully wired into the control system. For maintenance, the manufacturer quotes 32 000-hour hot gas path service intervals and 64 000 hours before the first major overhaul, with multiple borescope ports, axially removable first-stage rotor blades and externally accessible burner modules.

Key Features of the Siemens Energy SGT-400

The main characteristics of the Siemens Energy SGT-400 published by the manufacturer are:

• Twin-shaft design serving both power generation and mechanical drive in the 10 to 15 MW range.
• Power generation ratings of 10.5, 12.9 and 14.3 MW and mechanical drive ratings of 10.8, 13.8 and 14.9 MW.
• Gross efficiency up to 35.6 % in power generation and up to 37.1 % in mechanical drive.
• 11-stage transonic axial compressor with variable guide vanes and two-stage free power turbine.
• Can-annular DLE combustion with true dual-fuel capability and changeover at any load.
• Wide fuel flexibility, including high-inert gases and hydrogen blends within stated limits.
• Extended maintenance intervals of 32 000 hours for hot gas path and 64 000 hours to first major overhaul.
• Compact factory-tested packages suited to onshore plants, offshore platforms and FPSO vessels.

Industrial Applications

Siemens Energy positions the Siemens Energy SGT-400 for power generation on offshore platforms and FPSO vessels, as a driver for water injection pumps, crude oil processing and pipeline pumps, and as a compressor driver for gas injection, pipeline boosting and natural gas processing, as well as for simple cycle, combined cycle and combined heat and power plants. These duties correspond closely to the needs of Omani oil and gas operators, where gas turbines drive gas compression and injection at inland fields, generate island power at remote production stations and supply cogeneration steam at industrial sites in Sohar and Duqm.

Seven Star LLC supports Siemens Energy SGT-400 users with instrumentation and machinery protection equipment, for example the Bently Nevada 3500/42M Proximitor seismic monitor, and can also assist operators of larger or smaller Siemens Energy turbines such as the SGT-800 industrial gas turbine and the SGT-300 industrial gas turbine. Send us part numbers or nameplate data and our team will confirm availability.

Technical Specifications

The table reproduces the ISO performance data from the manufacturer technical data poster (natural gas fuel, standard design):

How to Order

Contact Seven Star LLC with the unit serial number, package type and the part numbers or descriptions you need for your Siemens Energy SGT-400, or with the outline requirements of a new project. Our team in Muscat will review the request, confirm what can be supplied and prepare a formal quotation for delivery in Oman and the GCC. The manufacturer technical data poster can be downloaded from this page.