The combustor is a can type which allows freedom of design and is also easy to maintain.
For high efficiency, the compressor has four axial stages and one radial stage. Gas generator turbines (GGT) and power turbines (PT) both use axial turbines. The SMGT uses two types: the F-type to maintain rated performance and the V-type for partial load performance. The V-type has the first stage nozzle of a PT and has variable axial stage nozzles of a compressor.
Its modular construction makes it easy to transport and maintain.
Research and development of the SMGT is being carried out based on the design and production technologies used for industrial gas turbines.
6. Essential R&D Topics
6.1 R&D topics
This R&D consists of a variety of research which can be roughly classified into the following three categories:
1) Developing technologies to reduce environmental impact (low NOx combustor)
2) Developing technologies to reduce fuel consumption (improving thermal efficiency)
3) Developing technologies to install the SMGT in ships
6.2 Technology to reduce environmental impact (low NOx combustor)
To reduce NOx, water or steam can be injected into the combustor (wet method), but because this requires a considerable amount of fresh water it is unsuitable for ships. The dry-type low-NOx combustor (DLN) is more suitable.
To achieve low NOx emissions, a can-type combustor like that used in industrial gas tubines is used because is allows a great deal of design freedom in terms of dimensions and shape, and it is easy to maintain.
With the single-can type, however, the turbine inlet temperature distribution varies significantly, making it unsuitable for high-temperature applications. For this reason the SMGT uses a four-can type which has much less variation in temperature distribution.
