Atmospheric Test Rig Research Articles

The ash chemistry in fluidised bed gasification of biomass fuels. Part II: Ash behaviour prediction versus bench scale agglomeration tests

This paper is part II in a series of two. Ash behaviour modelling of the gasification of four biomass fuels is compared with pilot-scale experiments carried out in a pressurised fluidised bed gasifier at the Royal Institute of Technology (KTH) and an atmospheric test rig of Termiska Processer AB (TPS). Experiments were provocative with respect to agglomeration of the bed material. Thus, in the experiments, the agglomeration was allowed to happen without any corrective changes in the operation. Small-scale experiments showed clear defluidisation in five cases. Some degree of bed disturbance or agglomeration occurred in seven out of 13 cases. In nine of these cases, agglomerates were also found in the samples analysed with SEM/EDX analyses. In six out of 13 cases, the thermodynamic multi-phase multi-component equilibrium calculations were in agreement with SEM/EDX analysis, i.e. predicted formation of agglomerates. In two cases, no or small amounts of agglomerates were predicted, nor were these found with SEM/EDX analysis. In two cases out of 13, the modelling predicted some degree of agglomeration while no agglomerates could be detected with SEM/EDX analysis. However, in these cases, agglomerates were found in the pilot-scale experiments. Thus it is shown that the thermodynamic multi-phase multi-component equilibrium calculations are a useful prediction tool for the formation of agglomerates in (pressurised) fluidised bed gasification of biomass fuels thereby enhancing the understanding of the chemistry involved.

Adaptive predictive control of combustor NO x emissions

The design and implementation for the active control of oxides of nitrogen (NO x ) emissions from gas turbine combustors is considered in this paper. Predictive control techniques with both fixed and adaptive parameters are employed. An on-line parameter estimation algorithm provides good modelling of the nonlinear characteristics of the combustor NO x process. To obtain a comparison with other control techniques, an optimal PID controller is detailed. The actuator that controls the gas flow to the combustor is an electromagnetic shaker. Gain-scheduling control is applied to provide accurate position tracking of the shaker whose characteristics vary between different operating points. These control strategies are implemented using the SIMULINK/dSPACE controller development environment. Their performance is evaluated on an atmospheric test rig fitted with a commercial combustor.

Design and implementation of an adaptive predictive controller for combustor NOx emissions

Abstract This paper is concerned with the design and implementation of an adaptive predictive controller for oxides of nitrogen (NOx) emissions from gas turbine combustors. Predictive control techniques with both fixed and adaptive parameters are introduced. An online parameter estimation algorithm is used to model the nonlinear characteristics of the combustor NOx process. The predictive control strategies are implemented using the MATLAB/dSPACE, controller development environment. Their performance is evaluated on an atmospheric test rig fitted with a commercial combustor and also compared with a PID controller. ©

Adaptive Predictive Control of Combustor NOx Emissions

The design and implementation of an adaptive predictive controller for oxides of nitrogen (NOx) emissions from gas turbine combustors is considered in this paper. Predictive control techniques with both fixed and adaptive parameters are introduced. An on-line parameter estimation algorithm is used to model the nonlinear characteristics of die combustor NOx process. The predictive control strategies are implemented using the MATLAB/dSPACE controller development environment. Their performance is evaluated on an atmospheric test rig fitted with a commercial combustor and also compared with a PID controller.

Heat Transfer Processes in Diesel Engines

The heat transfer processes taking place in the combustion chamber of direct-injection diesel engines are reviewed based on experiments performed in an atmospheric test rig, where a diesel engine spray was impinging vertically and at an angle onto a heated plate with and without a cross-stream of air simulating swirl, and in a single-cylinder engine incorporating a variable swirl mechanism. The convective heat transfer associated with the impinging spray on the wall of the piston-bowl and the radiative heat transfer associated with the high temperature soot particles formed during combustion were estimated for two swirl ratios, based on the measured temperature of the gas and the piston wall by means of two-colour pyrometry and fast-response thermocouples, respectively.