| Abstrakt: |
Advanced combustion concepts such as Reactivity Controlled Compression Ignition (RCCI) demonstrate very high thermal efficiencies combined with ultra low NOxemissions. As RCCI is sensitive for operating conditions, closed-loop control is a crucial enabler for stable and robust combustion. The feedback design is complex due to the coupling between inputs, such as intake manifold temperature, blend ratio (BR), and air-to-fuel ratio (λ), and, on the other hand, combustion parameters. Contrary to earlier, parallel SISO approaches, a multivariable feedback control strategy is applied, which uses a new combination of control parameters. Following the linearisation of a validated multi-zone RCCI combustion model, a MIMO feedback control strategy is designed. This cycle-to-cycle control strategy uses diesel injection timing, diesel fuel quantity, and natural gas (NG) fuel quantity information to track the desired engine load, ignition delay, and a new control parameter: BR. The designed controller is validated with simulation cases for disturbance rejection and simultaneous multivariable reference tracking. Simulation results demonstrate robust performance, effective decoupling action, and fast settling time (within 3 engine cycles) of the designed controller. |
