Combined Heat and Power Unit (CHP)
Gas turbine (Aurelia)
Introduction
A gas turbine is a combustion engine at the heart of a power plant that can convert natural gas or other liquid fuels to mechanical energy. This energy then drives a generator that produces the electrical energy that is used for several purposes. Combined heat and power (CHP)—sometimes called cogeneration—is an integrated set of technologies for the simultaneous, on-site production of electricity and heat.
The CHP Unit used for the ROBINSON project's case is the Aurelia® A400.
Aurelia® A400
Technical Description
The innovative gas turbine Aurelia® A400 - a combined heat and power (CHP) unit - can be fueled by a mixture of biomethane, hydrogen and syngas. This CHP unit will supply dispatchable energy to the electricity grid coupled with exhaust heat recovery. The gas turbine has a maximum electrical power output, electrical efficiency and thermal efficiency are equal to 400 kW, 40% and up to 50%, respectively. It requires 28.2 m2 (3m x 9.4m) of land and 93.1 m3 of volume (3.3m in height). The fuels of the CHP unit are syngas (generated from the gasification of locally available waste wood), hydrogen and biomethane (from the AD-BES). A gas mixer is exploited to blend these (renewable) fuels, while the CHP gas turbine can process different fuel compositions and shares of (renewable) energy sources. The gas turbine has an initial cost of 400,000 euros, resulting in a specific investment cost (CAPEX) of 1000 euros per kWel. A prominent step of the ROBINSON project is to validate this product operation under site-specific conditions (i.e. Eigerøy). The installation of the Aurelia turbine is proposed for both commercial and small industrial use.
Aurelia® A400 gas turbine
|
Parameter |
Value |
Unit |
|
Capacity |
400 |
[kWe] |
|
Electric efficiency |
40.2 |
[%] |
|
Thermal efficiency |
Up to 50 |
[%] |
|
Operation hours |
8322 |
[hours/year] |
|
Lifetime |
20 |
[years] |
Technical specifications of the gas turbine (Aurelia, 2022)
Technology requirements and operating conditions
The turbine is a twin-spool, intercooled and recuperated gas turbine, with both spools including a compressor, turbine, and generator. The compressor and the turbine are both of radial type. Generators are permanent magnet generators; they can operate at variable speeds, and they are directly linked to the spool without a gearbox. Due to its modular design, the combustion chamber can be properly adjusted to meet the requirements of different fuels. The turbine is designed to use all standard liquid and gaseous fuels and give options for non-standard fuels and mixtures.
The fuel supply pressure range is 7 to 8 bar (abs) and the temperature range is -10 to +80°C. Table 2 contains further operational boundary conditions. During the installation of the gas turbine, fuel composition will be within those stated in Table 3.
|
Item |
Value |
|
Mass flow rate of Air |
2.16 kg/s |
|
Air pressure after LP compressor |
273 kPa (abs) |
|
Exhaust gas temperature at full power |
185 °C |
|
Exhaust energy at full power |
2.2 kg/s |
|
Heat recovery from intercooler |
278 kW |
|
Heat recovery from exhaust gas |
240 kW |
|
Operating temperature |
-20 …. +40 oC |
|
Operating atmosphere |
0 – 95% RH non condensing, non corrosive |
Operational Boundary conditions
|
Fuel specification |
Natural gas |
Biogas 1/ Flare gas 1 |
Biogas 2/ Flare gas 2 |
Syngas 1 |
Syngas 2 |
|
CH4 [vol%] |
98 |
75 |
30 |
65 |
5 |
|
H2 [vol%] |
0 |
2 |
0 |
28 |
30 |
|
CO2 [vol%] |
0 |
10 |
0 |
2 |
12 |
|
N2 [vol%] |
2 |
13 |
70 |
5 |
53 |
|
Molar mass [g/mol] |
16.3 |
20.1 |
34.2 |
13.3 |
21.5 |
|
Density at 1.013 bar & 273 K [kg/m3] |
0.7 |
0.9 |
1.5 |
0.6 |
1.0 |
|
LHV [MJ/kg] |
48 |
30 |
8 |
44 |
5 |
|
Fuel qm,min [g/s] |
4 |
7 |
25 |
5 |
40 |
|
Fuel qm,max [g/s] |
23 |
37 |
125 |
25 |
256 |
|
Max thermal power [kW] |
23 |
37 |
125 |
25 |
256 |
|
Supply pressure |
7-8 bars (abs) |
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|
Supply temperature |
-10…+80 °C |
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Aurelia® A400 working fuel compositions