A Neural Network Model for Predicting NOx at the Mělník 1

This paper presents a non-conventional dynamic neural network that was designed for real time prediction of NOx at the coal powder power plant Mělnik 1, and results on real data are shown and discussed. The paper also presents the signal preprocessing techniques, the input-reconfigurable architecture, and the learning algorithm of the proposed neural network, which was designed to handle the non-stationarity of the burning process as well as individual failures of the measured variables. The advantages of our designed neural network over conventional neural networks are discussed

MEASUREMENT OF O2 IN COMBUSTION CHAMBER WITH AN ANALYSIS OF THE BURN OUT RATIO

An aim of this experimental research work was to achieve more detailed information about the combustion process in pulverized coal boilers. An O2 analyser was developed and manufactured for the measurement of O2volumetric concentration directly in the combustion chamber. The volumetric concentration of O2 in the combustion chamber is important information about the burn out ratio, quality of combustion and the space distribution of the flame. The uniformity of the flame or the even distribution of the combustion parameters could be a possible way how to move to satisfy new emission limits. Measured parameters of the combustion process could be used for the control system of the boiler. The O2 analyser was manufactured for the permanent measurement with acceptable results. The measurement of the air excess ratio in the combustion chamber shows that for the left and right side of the combustion chamber could be highly non-uniform. For correct interpretation of the air excess ratio measured in the combustion chamber is necessary to know local amount of the unburnedcarbon in the position of the measurement. Therefore a new extraction line with an isokinetic probe was installed in the boiler for an extraction of the particles from the combustion chamber. The extracted sample was analysed in the laboratory and in the position where the combustion process should be terminated was measured from 3-12% of the flammable substance in the analysed sample

Measurement of O2 in the Combustion Chamber of Apulverized Coal Boiler

Operational measurements of the O2 concentration in the combustion chamber of a pulverized coal boiler are not yet common practice. Operators are generally satisfied with measuring the O2 concentration in the second pass of the boiler, usually behind the economizer, where a flue gas sample is extracted for analysis in a classical analyzer. A disadvantage of this approach is that there is a very weak relation between the measured value and the condition in specific locations in the fireplace, e.g. the function of the individual burners and the combustion process as a whole. A new extractionline was developed for measuring the O2 concentration in the combustion chamber. A planar lambda probe is used in this approach. The extraction line is designed to get outputs that can be used directly for diagnosis or management of the combustion in the boiler

Aerosol in the steam turbine?

The small amount of admixtures in steam circuits of power stations influences their life-expectancy and energetic efficiency. It is likely that non-volatile admixtures are in the environment of the dry (superheated) steam transported in the form lf dry particles or concentrated nanometric droplets, aerosols. For the detection of these particles a new sampling line is proposed, using the aerosol technology. It will be possible to connect the sampling line to sampling ports of a steam turbine

Experimental investigation of the steam wetness in a 1000 MW steam turbine

The aim of this paper is to introduce the experimental data of the wetness distribution obtained in the year 2015 in front of and behind the last stage of the 1000MW steam turbine in the power plant Temelín. Two different optical probes developed at Czech Technical University were used. For the first time in the Czech Republic pneumatic and optical measurement of the wet steam flow field in front of the last stage of a nuclear power-station steam turbine was provided. This unique measurement opportunity provided lots of new information for the manufacturer and operator of the steam turbine and valuable experimental data for the phase transition modelling in the wet steam flow. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o

Wet steam wetness measurement in a 10 MW steam turbine

The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o

CTU Optical probes for liquid phase detection in the 1000 MW steam turbine

The aim of this paper is to introduce the measurement capacity of a new generation of CTU’s optical probes to determine the liquid phase distribution in steam turbines and other energy systems. At the same time the paper presents the first part of the results concerning output wetness achieved through the use of experimental research performed with the probes in a new low pressure (LP) part of the steam turbine 1000MW in the Temelin nuclear power plant (ETE). Two different probes were used. A small size extinction probe with a diameter of 25mm which was developed for measuring in a wider range of turbines in comparison with the previous generation with a diameter of 50mm. The second probe used was a photogrammetric probe developed to observe the coarse droplets. This probe is still under development and this measurement was focused on verifying the capabilities of the probe. The data processing technique is presented together with yielded examples of the wetness distribution along the last blade of the 1000MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o. (DSP)

Wet steam flow in 1100 MW turbine

The paper deals with the wet steam flow in a steam turbine operating in a nuclear power plant. Using a pneumatic and an optical probe, the static pressure, steam velocity, steam wetness and the fine water droplets diameter spectra were measured before and beyond the last turbine low-pressure stage. The results of the experiment serve to understand better the wet steam flow and map its liquid phase in this area. The wet steam data is also used to modify the condensation model used in computational fluid dynamics simulations. The condensation model, i.e. the nucleation rate and the growth rate of the droplets, is adjusted so that results of the numerical simulations are in a good agreement with the experimental results. A 3D computational fluid dynamics simulations was performed for the lowpressure part of the turbine considering non-equilibrium steam condensation. In the post-processing of the of the numerical calculation result, the thermodynamic wetness loss was evaluated and analysed. Loss analysis was performed for the turbine outputs of 600, 800, and 1100 MW, respectively

Experimental investigation of the steam wetness in a 1000 MW steam turbine

The aim of this paper is to introduce the experimental data of the wetness distribution obtained in the year 2015 in front of and behind the last stage of the 1000MW steam turbine in the power plant Temelín. Two different optical probes developed at Czech Technical University were used. For the first time in the Czech Republic pneumatic and optical measurement of the wet steam flow field in front of the last stage of a nuclear power-station steam turbine was provided. This unique measurement opportunity provided lots of new information for the manufacturer and operator of the steam turbine and valuable experimental data for the phase transition modelling in the wet steam flow. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o