Measuring Technologies for CFB Solid Circulation Rate: A Review and Future Perspectives

Solid circulation rate (Gs) represents the mass flux of circulating particles in circulating fluidized bed (CFB) systems and is a significant parameter for the design and operation of CFB reactors. Many measuring technologies for Gs have been proposed, though few of them can be applied in industrial units. This paper presents a comprehensive study on measuring technologies, and the results indicate that though the accumulation method is most widely applied, it is constrained by the disturbance of normal particle circulation. Some publications have proposed mathematic models based on pressure drop or other parameters to establish Gs measurement models; these necessitate the accurate modeling of complicated gas-solid flows in industrial devices. Methods based on certain measurement devices to specify parameters like velocity require device endurance in the industrial operation environment and stable local gas-solid flow. The Gs measuring technologies are strongly influenced by local gas-solid flow states, and the packed bed flow in standpipes make the bottom of standpipes an ideal place to realize Gs measurement.

Incrementally accumulated holographic SDP characteristic fusion method in ship propulsion shafting bearing fault diagnosis

To improve the accuracy of fault diagnosis of ship propulsion shaft bearing in a harsh working environment, a visual diagnosis method based on incrementally accumulated holographic symmetrical dot pattern (SDP) characteristic fusion method is proposed in this research. The current study simultaneously extracts the time- and frequency-domain characteristic parameters of vibration signal based on the incremental accumulation method to avoid inconspicuous difference and small discrimination generated by a single parameter. Subsequently, the extracted characteristic signals are transformed into a 2D image based on the SDP method to enhance the differences between signals. Eventually, bearing fault is diagnosed based on the similarity recognition method. Simulation and engineering experiments were conducted to verify the effectiveness of the proposed method. Results demonstrate that the proposed method can effectively diagnose the ship propulsion shaft bearing fault diagnosis.

Advances in the True Eddy Accumulation Method: New theory, implementation, and field results

The true eddy accumulation method (TEA) provides direct measurements of ecosystem-level fluxes for a wide range of atmospheric constituents. TEA utilizes conditional sampling to overcome the requirement for a fast sensor response usually demanded by the state-of-the-art eddy covariance method (EC). However, the assumptions and conditions required for the TEA method are often not met. Here we explore the limitations caused by the assumption of zero mean vertical wind velocity during the averaging interval and by the fixed accumulation interval. We extend the theory of TEA method to non-zero vertical wind velocity by employing information about the scalar transport. We further derive a new method with adaptive time varying accumulation intervals. The new method, termed short-time eddy accumulation (STEA), was successfully implemented and deployed to measure CO2 fluxes over an agricultural field in Braunschweig, Germany. The measured fluxes matched very well against a conventional EC system (slope of 1.05, R2 of 0.87). We provide a detailed description of the setup and operation of the STEA system in the flow-through mode, devise an empirical correction for the effect of buffer volumes, and describe the important considerations for the successful operation of the STEA method. The new theory developments reduce the bias and uncertainty in the measured fluxes and create new ways to design eddy accumulation systems with finer control over sampling and accumulation. The results encourage the application of TEA and STEA for measuring fluxes of more challenging atmospheric constituents such as reactive species as well as other constituents where no fast gas analyzers are available.

Using the Quarterly Compound Fractional Grey Model to Predict the Air Quality in 22 Cities of China

The rapid development of industrialization leads to more and more serious air pollution, which affects human health and sustainable development of society. Predicting air quality is an important link in preventing air pollution and improving the atmospheric environment. In this paper, 22 cities of China with poor air quality in recent years are selected as the research objects. A quarterly compound accumulation grey model is used to predict the concentrations of PM2.5, PM10, SO2, and NO2 in the 22 cities. Two parameters are introduced into the model to optimize the accumulation method of the grey model. Also, seasonal factors are introduced to better simulate air quality. The forecasting results show that air quality in these cities, although varies widely on a quarterly basis, tends to decline overall. The concentrations of PM2.5 and PM10 in most cities will still exceed the standard in the next few years, especially in the first and fourth quarters of each year. The prediction results can provide reference for relevant departments.

Research and Application of a Novel Nonlinear Grey Bernoulli Simpson Model for Short-Term Coke Production Forecasting

Aims: As a basic energy source, coal occupies a leading position in the production and consumption of energy. If a reasonable coal energy production policy is to be formulated, effective forecasting is essential. Due to the lack of data, effective prediction with small samples has become the key to research. Study Design: A nonlinear grey Bernoulli Simpson model based on new information priority accumulation method is developed in this work to forecast the coke production in the Anhui China. The introduction of non-linear parameters makes the new model constructed with universality Place and Duration of Study: School of Science, Southwest University of Science and Technology, Mianyang, between April 2021 and June 2021. Methodology: This paper has established the nonlinear grey Bernoulli Simpson model with new information priority accumulation. Based on the grid search optimization, the data is divided by the leave-out method to construct a nonlinear problem to solve the nonlinear parameters of the model. Finally, the new model established was applied to the forecast of coke production in Anhui Province, China. Results: The MAPE and RMSPE of the nonlinear grey Bernoulli Simpson model based on new information priority accumulation method are 1.86% and 2.58%, which are lower than other comparative models. Conclusion: The application research of coke production shows that the new model proposed in this paper has the advantage of high prediction accuracy, which indicates that this method has great potential in the short-term prediction of energy production.

A Fractional Discrete Grey Model with Particle Swarm Optimizer and Its Applications in Forecasting the Gasoline Consumption in Chongqing China

Forecasting gasoline consumption is of great significance for formulating oil production, foreign trade policies, and ensuring the balance of domestic refined oil supply. Based on grey system theory, a fractional accumulation operator is constructed to optimize the accumulation method of the traditional discrete grey model, and the Particle Swarm Optimization algorithm is used to solve the fractional nonlinear parameters. This model was used in the prediction of gasoline consumption in Chongqing, China, and compared with the existing 7 models. The results show that the fractional discrete grey model optimized by PSO has better prediction accuracy. The fractional discrete grey model optimized by PSO can be used as a quantitative method in the field of energy forecasting.

TRANSFORMING OBJECTS INTO ART WORKS BY METHOD ACCUMULATION IN ARTv

In addition to the way of expressing art from the past to the present, diversity of different methods and techniques are seen. The art world underwent a great change under the influence of modernism in the 20th century and lost its “Art object” uniqueness. As a result, painting and sculpture moved away from classical art understanding. The art formations of the period not only changed the production techniques and theories in art, but also changed the work of art and the place where it is exhibited. With the mechanization, the increase in mass production and the desire to consume different products brought the concept of object and waste-garbage phenomenon. Although it may seem like a current problem, this waste-garbage problem has always been the biggest problem of humanity since the early civilization. With the development of technology, the number of objects that qualify as garbage has been removed and it has become the material of art. In this article, the position of waste objects that have lost their function in contemporary art practices is discussed. In addition, it was aimed to analyze the artists' processes of transforming these objects into artworks by using the accumulation method, their techniques and their plastic approach to the subject. Keywords: Art, accumulation, waste, garbage, art object

Wavelet Energy Accumulation Method Applied on the Rio Papaloapan Bridge for Damage Identification

Large civil structures such as bridges must be permanently monitored to ensure integrity and avoid collapses due to damage resulting in devastating human fatalities and economic losses. In this article, a wavelet-based method called the Wavelet Energy Accumulation Method (WEAM) is developed in order to detect, locate and quantify damage in vehicular bridges. The WEAM consists of measuring the vibration signals on different points along the bridge while a vehicle crosses it, then those signals and the corresponding ones of the healthy bridge are subtracted and the Continuous Wavelet Transform (CWT) is applied on both, the healthy and the subtracted signals, to obtain the corresponding diagrams, which provide a clue about where the damage is located; then, the border effects must be eliminated. Finally, the Wavelet Energy (WE) is obtained by calculating the area under the curve along the selected range of scale for each point of the bridge deck. The energy of a healthy bridge is low and flat, whereas for a damaged bridge there is a WE accumulation at the damage location. The Rio Papaloapan Bridge (RPB) is considered for this research and the results obtained numerically and experimentally are very promissory to apply this method and avoid accidents.

Monitoring of stable isotopes (δ2H, δ18O) in precipitations of Moscow city (Russia): comparison for 2005–2014 and 1970–1979 periods

The isotopic composition of oxygen (δ18O) and hydrogen (δ2H) of atmospheric precipitation in Moscow in 2005–2014 was studied by sampling single precipitations (a total of 842 measurements after rejection of unreliable samples). A comparison is made with similar studies carried out by VSEGINGEO and IVP RAS for the IAEA-WMO GNIP network in 1969–1979, when monthly average samples were taken by the accumulation method (61 pair determinations of deuterium and oxygen-18, mainly in 1975–1979). The 2005–2015 series is reduced to a similar form for the 1969–1979 series, recalculated through the data on the volume of precipitation at the nearest meteorological station. It was found that in the last decade there has been a significant change in the equation of the local line of meteoric waters, which for the first period had the form δ2H = 6.09×δ18O – 23.0 ‰ (R2 = 0.87), and is currently described by the relation δ2H = 6.93×δ18O – 11.3 ‰ (R2 = 0.944). There is also a decrease in depletion of the average values of δ2H and δ18O, compared with the first observation period, which apparently reflects the course of climatic changes. At the same time, within each of the periods, a negative (albeit relatively small) slope of the line of approximation of chronological data is noted. Deuterium excess naturally changes seasonally, taking negative values in summer, primarily due to non-equilibrium fractionation during evaporation. In 2005–2014, the temperature dependence of the isotopic composition of precipitation changed significantly in comparison with 1969–1979, which makes it impossible to reconstruct the composition of precipitation in the past from meteorological observations.