| Gasifier is the core equipment of entrained flow gasification technology.The multiphase flow and reaction characteristics of the gasifier not only have an important impact on the performance of gasifier,but also are important index to judge whether the gasifier operates safely and stably.However,due to the characteristics of high temperature and high pressure,it is difficult to monitor the reaction flow processes of the gasifier directly and effectively.In this work,the reaction flow characteristics in the gasifier,online monitoring of the gasification temperature and real time-fast calculation of SE gasifier have been studied,and a fast prediction model for the state of SE coal water slurry(abbreviated as SE-CWS)gasifier is established state rapid prediction model was established.The main contents of this paper are as follows:1.The multiphase turbulent reaction flow process in SE-CWS gasifier was simulated by using a comprehensive gasification model considering the gas phase space reaction flow process and the particle deposition and reaction process on the wall of the gasifier.The results show that about 75%of the particles are deposited on the slag surface,and the gasification reaction continues at the slag interface.The molten slag interface reaction time is more than 10s,and about 11%of the carbon is converted.When proportion of coal slurry in the outer channel is 6%,the deposition proportion of particles in inner and outer channels on the wall is roughly same,and the proportion of carbon converted on the refractory lining of the particles injected from inner and outer channels is 11.5%and 4.5%respectively.With the increase of the proportion of CWS of outer channel,residence time of non-deposited particles decreases slightly,while the conversion ratio of deposited particles injected from the outer channel gradually increases to about 20%,and wall reaction time also extends.At the same time,the effects of oxygen coal ratio,coal slurry concentration,atomization particle size of burner,raw material properties on SE water coal gasifier were investigated,and their effects on gasifier performance and temperature distribution in the gasifier were obtained.2.The operation data of industrial SE coal water slurry entrained flow gasifier were collected and analyzed.Temperature prediction models of high temperature syngas based on heat balance calculation of the quench chamber and GABP neural network were established,and the monitoring research on the operating temperature of the gasifier was carried out.The results show that heat balance model based on quench process of high temperature syngas can quickly calculate outlet temperature of gasifier,but the reliability was low due to the effect of the temperature measuring instrument error in the gasifier device;Taking quench system parameters and reaction system parameters as input parameters of GABP neural network model,prediction accuracy is 5.3k and 10.1k respectively.GABP model based on quench system can obtain higher calculation accuracy.3.According to simulation results,the operation state database of the gasifier was established,and GABP neural network model was used to quickly predict the temperature field,velocity field and gas distribution of the gasifier under a certain working condition.Prediction results are basically consistent with the simulation results,average prediction error of temperature is 19.8K,and calculation time is about 1s.The law of temperature distribution in the gasifier under different process parameters and coal property parameters was obtained,and concluded that when the outlet temperature is equal,the distribution of the near-wall surface under different coal property is basically same.The real-time monitoring method was proposed to realize rapid and accurate prediction of the gasifier state without coal property parameters,which is combined with outlet temperature prediction based on quench process and rapid calculation of two-dimensional reaction flow process in the gasifier. |
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