Session: 17-02 Techno-Economic Analysis of Energy Systems

Paper Number: 120898

120898 - Development of an Efficient Compressor and Turbine for a 2MW-Class Emergency Gas Turbine 

The emergency gas turbine generators offered by IHI Power Systems are designed to supply large volumes of electric power instantaneously in the event of power outages. They are installed in data centers, public amenities, waterworks systems, and other facilities, where they play key roles in ensuring the safety and security of people and society.

To meet the growing needs for power generators in recent years, we have developed a power generation device with an output of 2000kW that is even smaller than conventional products.

In this paper, we will describe the entire power generation equipment, such as the newly designed gas turbine and Enclosures.

 

When an emergency gas turbine generator receives a starting signal, Electricity is supplied from the battery to the starter motor. This instantly starts the gas turbine, which begins to operate independently and generate power. The power generated by the gas turbine is transmitted through the reduction gear to the coaxially coupled generator and converted into electric power. Since emergency generators are sometimes installed on the rooftop or basements of buildings in the city center, the engines must be lightweight and compact.

Our original designed NGT series gas turbine has strengths in durability and ease of maintenance. The configuration is simple, consisting of a two-stage centrifugal compressor, a single-can combustor, and a three-stage axial flow turbine, all of which are single-shaft.

Our main engine lineup is the NGT2 series in the 1000 kW class and the NGT3 series in the 2000kW class. This time, we developed component technologies for gas turbine that can output 2000kW based on the NGT2B engine, which has a rated output of 1600kW.

As a result, the power generation device package can be more than 25% smaller than our conventional products. Additionally, fuel consumption was reduced by more than 10%. 

 

One method to increase the power of a gas turbine engine is to larger the engine size. Specifically, we use the similarity law to scale up the existing engine. The advantage of this method is that it is a relatively simple design work and that the output can be increased while maintaining conventional reliability and performance. However, larger engines are heavier and require more installation space. As the amount of exhaust gas also increases, the size and production cost of the exhaust silencer also increases.

Another method is to change the heat cycle. This allows you to increase the output while maintaining the size of the engine, but that must redesign the main parts such as impellers and turbine blades. This poses a developmental technical risk.

   For the development of component technologies for gas turbine, we chose the latter method. First, we performed cycle calculations using the pressure ratio and intake air flow rate as parameters to determine a cycle that maintains turbine inlet temperature (TIT), exhaust temperature, and exhaust flow rate at appropriated levels. By increasing the air flow rate and pressure ratio of a compressor and maintaining TIT and exhaust temperatures close to those of conventional engines, we can maintain high temperature component durability and reliability.

From the specifications obtained by cycle calculation, we have developed an impeller that operates at high pressure with a large intake flow rate and a turbine that demonstrates performance in a high expansion ratio.

In the design work, through-flow calculations, Q3D, CFD, and FEM were used to meet aerodynamic performance and strength.

In the paper, we will also describe the actual engine test results.

Presenting Author: Takao Kohama IHI Power Systems Co., Ltd.

Presenting Author Biography: I joined my current company in 2007, and since then, I have been involved in the overall design of gas turbine power generation equipment.
Among them, my specialty design field is the aerodynamic design of axial turbines.

Authors:

Takao Kohama IHI Power Systems Co., Ltd.
Shuichi Anzawa IHI Power Systems Co., Ltd.
Yutaro Seki IHI Power Systems Co., Ltd.