This document provides the rationale for the design and manufacture of the test rig forming Work Package 2 Task 2. This document is one of two for the circular duct experiments and provided the details of the test rig, what parameters it has been designed for to support the test program.
The rig will provide an experimental facility to investigate the flame out of CCGT/CCGE systems and the consequences of unburnt fuel passing through the turbine (in the CCGT case) and into the exhaust system. In such circumstances the maximum hydrogen concentration in the downstream mixture is not expected to exceed 10-12% v/v hydrogen (when fuelled with pure hydrogen), and be at temperatures of the order of 400–600°C, depending on the exhaust composition and the degree of compression achieved in the compressor. For CCGE applications the hydrogen concentration may be higher by up toa factor of two. If re-ignition in the exhaust system is then assumed to occur, the project seeks to assess the potential consequences, particularly with reference to the flame acceleration and the detonation propensity of the air/fuel mixtures. This rig provides a reduced scale model of an actual turbine exhaust system such that the appropriate scaling criteria can be identified to enable predictions to be made of the hazards at full scale.
The rig can also contain a simulated heat exchanger so that its effect on initiating detonations can be examined as a precursor to the definitive heat exchanger tests proposed for the WP2.3 test rig using an actual heat exchanger but scaled down to a representative size
The rig will provide an experimental facility to investigate the flame out of CCGT/CCGE systems and the consequences of unburnt fuel passing through the turbine (in the CCGT case) and into the exhaust system. In such circumstances the maximum hydrogen concentration in the downstream mixture is not expected to exceed 10-12% v/v hydrogen (when fuelled with pure hydrogen), and be at temperatures of the order of 400–600°C, depending on the exhaust composition and the degree of compression achieved in the compressor. For CCGE applications the hydrogen concentration may be higher by up toa factor of two. If re-ignition in the exhaust system is then assumed to occur, the project seeks to assess the potential consequences, particularly with reference to the flame acceleration and the detonation propensity of the air/fuel mixtures. This rig provides a reduced scale model of an actual turbine exhaust system such that the appropriate scaling criteria can be identified to enable predictions to be made of the hazards at full scale.
The rig can also contain a simulated heat exchanger so that its effect on initiating detonations can be examined as a precursor to the definitive heat exchanger tests proposed for the WP2.3 test rig using an actual heat exchanger but scaled down to a representative size