Analysis of Flue Gas Emission Data from Fluidized Bed Combustion Using Self-Organizing Maps

Efficient combustion of fuels with lower emissions levels has become a demanding task in modern power plants, and new tools are needed to diagnose their energy production. The goals of the study were to find dependencies between process variables and the concentrations of gaseous emission components and to create multivariate nonlinear models describing their formation in the process. First, a generic process model was created by using a self-organizing map, which was clustered with the k-means algorithm to create subsets representing the different states of the process. Characteristically, these process states may include high- and low- load situations and transition states where the load is increased or decreased. Then emission models were constructed for both the entire process and for the process state of high boiler load. The main conclusion is that the methodology used is able to reveal such phenomena that occur within the process states and that could otherwise be difficult to observe

Self-Organizing Maps for Analysis of Expandable Polystyrene Batch Process

Self-organizing maps (SOM) have been successfully applied in many fields of research. In this paper, we demonstrate the use of SOM-based method for the analysis of Expandable PolyStyrene (EPS) batch process. To this end, a data set of EPS-batch process was used for training a SOM. Reference vectors of the SOM were then classified by K-means algorithm into six clusters, which represent product types of the process. This SOM could also be used for estimating the optimal amounts of the stabilisation agent. The results of a validation data set showed a good agreement between the actual and estimated amounts of the stabilisation agent. Based on this model a Web application was made for test use at the plant. The results indicate that the SOM method can also be efficiently applied to the analysis of the batch process

Modelling of Water Quality: An Application to a Water Treatment Process

The modelling of water treatment processes is challenging because of its complexity, nonlinearity, and numerous contributory variables, but it is of particular importance since water of low quality causes health-related and economic problems which have a considerable impact on people’s daily lives. Linear and nonlinear modelling methods are used here to model residual aluminium and turbidity in treated water, using both laboratory and process data as input variables. The approach includes variable selection to find the most important factors affecting the quality parameters. Correlations of ∼0.7–0.9 between the modelled and real values for the target parameters were ultimately achieved. This data analysis procedure seems to provide an efficient means of modelling the water treatment process and defining its most essential variables

Responses of the atmospheric concentration of radon-222 to the vertical mixing and spatial transportation

Radon-222 (Rn-222) has traditionally been used as an atmospheric tracer for studying air masses and planetary boundary-layer evolution. However, there are various factors that influence its atmospheric concentration. Therefore, we investigated the variability of the atmospheric radon concentration in response to the vertical air mixing and spatial transport in a boreal forest environment in northern Europe. Long-term Rn-222 data collected at the SMEAR II station in southern Finland during 2000-2006 were analysed along with meteorological data, mixing layer height retrievals and air-mass back trajectory information. The daily mean atmospheric radon concentration followed a log-normal distribution within the range <0.1-11 Bq m(-3), with the geometric mean of 2.5 Bq m(-3) and a geometric standard deviation of 1.7 Bq m(3). In spring, summer, autumn and winter, the daily mean concentrations were 1.7, 2.7, 2.8 and 2.7 Bq m(-3), respectively. The low, spring radon concentration was especially attributed to the joint effect of enhanced vertical mixing due to the increasing solar irradiance and inhibited local emissions due to snow thawing. The lowest atmospheric radon concentration was observed with northwesterly winds and high radon concentrations with southeasterly winds, which were associated with the marine and continental origins of air masses, respectively. The atmospheric radon concentration was in general inversely proportional to the mixing layer height. However, the ambient temperature and small-scale turbulent mixing were observed to disturb this relationship. The evolution of turbulence within the mixing layer was expected to be a key explanation for the delay in the response of the atmospheric radon concentration to the changes in the mixing layer thickness. Radon is a valuable naturally-occurring tracer for studying boundary layer mixing processes and transport patterns, especially when the mixing layer is fully developed. However, complementing information, provided by understanding the variability of the atmospheric radon concentration, is of high necessity to be taken into consideration for realistically interpreting the evolution of air masses or planetary boundary layer.Peer reviewe

Accurate measurements of CO2 mole fraction in the atmospheric surface layer by an affordable instrumentation

We aimed to assess the feasibility of an affordable instrumentation, based on a non-dispersive infrared analyser, to obtain atmospheric CO2 mole fraction data for background CO2 measurements from a flux tower site in southern Finland. The measurement period was November 2006 to December 2011. We describe the instrumentation, calibration, measurements and data processing and a comparison between two analysers, inter-comparisons with a flask sampling system and with reference gas cylinders and a comparison with an independent inversion model. The obtained accuracy was better than 0.5 ppm. The inter-comparisons showed discrepancies ranging from -0.3 ppm to 0.06 ppm between the measured and reference data. The comparison between the analyzers showed a 0.1 +/- 0.4 ppm difference. The trend and phase of the measured and simulated data agreed generally well and the bias of the simulation was 0.2 +/- 3.3 ppm. The study highlighted the importance of quantifying all sources of measurement uncertainty

Life-cycle covering traceability and information management for electronic product using RFID

Radio frequency identification (RFID) is automatic object identification technology based on radio waves, and it has been seen as a promising technology to automate identification and control of items in manufacturing. RFID has been used in a wide scale of applications from simple tracking solutions to complicated systems for managing the entire supply chain. ERFID (Elektroniikkatuotteen elinkaaren kattava jäljitettävyys ja tiedonhallinta RFID-tekniikan avulla - Life-cycle covering traceability and information management for electronic product using RFID) project was set up to improve product traceability in the electronics industry using this technology. Because the lifecycle of a product involves the whole chain of design, manufacturing, supply chain, use, and disposal of product, the two main contributions of this research and its results are 1) to test and experience the applicability of RFID technology to the improvement of different manufacturing operations, and 2) to advance the use of RFID in the product lifecycle management of electronic products. Both practical research and review of existing research results were performed in the project to achieve these goals. A number of practical tests were conducted both in laboratory and factory environments to test the practical applicability of the technology to different manufacturing and lifecycle traceability problems. The results of this research are promising and they have shown that RFID technology has an increasing potential in existing and novel applications which can improve the efficiency and effectiveness of manufacturing and lifecycle management, but also drawbacks, restrictions, and important things to be considered when using the technology were noticed. Therefore, one of the main findings of the research is that a thorough testing period is always needed before implementing the technology in a larger scale. Moreover, also other important issues to be noted when implementing the technology in a factory are discussed in this report, as well as suggestions on using RFID in lifecycle covering data management.Radiotaajuista etätunnistustekniikkaa (Radio frequency identification, RFID) voidaan käyttää kohteiden automaattiseen tunnistamiseen radioaaltojen avulla, ja sitä on pidetty lupaavana teknologiana tuotteiden ja puolivalmisteiden tunnistamiseen ja hallintaan myös kappaletavaratuotannossa. RFID-tekniikkaa on käytetty teollisuudessa monenlaisissa sovelluksissa yksinkertaisista tunnistusratkaisuista aina monimutkaisiin tuotteiden jakeluketjujen hallintajärjestelmiin. ERFID-projektin (Elektroniikkatuotteen elinkaaren kattava jäljitettävyys ja tiedonhallinta RFID-tekniikan avulla) tavoitteena oli tuotekohtaisen jäljitettävyyden parantaminen elektroniikkateollisuudessa kyseisen tekniikan avulla. Koska tuotteen elinkaari käsittää suunnittelun, tuotannon, jakelun, käytön ja käytöstä poistamisen, hankkeessa saavutettujen tulosten vaikuttavuus on kaksitahoinen: 1) saavutettiin kokemuksia RFID-tekniikan soveltuvuudesta erilaisten elektroniikan tuotantoprosessien hallinnan parantamisessa, ja 2) luotiin ideoita RFID-tekniikan käytöstä elektroniikkatuotteen elinkaaren kattavan tiedonhallinnan apuvälineenä ja selvitettiin sen soveltuvuutta siihen. Tulosten saavuttamiseksi sekä tehtiin käytännönläheistä testausta ja luotiin testiympäristöjä että käytiin läpi jo olemassa olevaa tutkimusmateriaalia. Käytännön testejä tehtiin sekä laboratorio-olosuhteissa että todellisissa tuotantoympäristöissä, jotta saatiin mahdollisimman paljon käytännön kokemuksia tekniikan soveltuvuudesta erilaisiin tunnistussovelluksiin tuotannossa ja elinkaaren aikana. Tutkimuksen tulokset ovat lupaavia ja ne osoittavat, että RFID-tekniikalla on potentiaalia toimia tuotannon tehostajana ja elinkaarisovellusten pohjana, mutta tutkimuksessa tulivat hyvin esille myös tekniikan asettamat rajoitteet ja seikat, jotka täytyy huomioida kun sitä ollaan ottamassa käyttöön. Yksi tutkimuksen tärkeimmistä tuloksista onkin se, että kunnollinen testausjakso on aina järjestettävä ennen RFID-tekniikan integroimasta tuotantoon. Raportissa käydään läpi myös muita tärkeitä seikkoja, jotka on huomioitava otettaessa tekniikkaa käyttöön teollisuudessa, sekä myös ajatuksia RFID:n käytöstä elinkaarisovellusten ydinteknologiana

Real-time measurement system for determining metal concentrations in water-intensive processes

The main purpose of this paper is to demonstrate the potential of time-domain nuclear magnetic resonance (TD-NMR) technology for monitoring the concentrations of metal ions in water-based solutions. The main focus of this work was paramagnetic ions, such as Mn2+, Cu2+, Fe3+, Fe2+, Zn2+ and Ni2+, which are often the principal metal components in mining waters. Laboratory samples of different concentrations of single metals and mixtures of them and samples of real mining water were used in the relaxation rate (R2) measurements. The measurements of single metal ions were used for the determination of the relaxivities of those ions. The concentrations of the ions in the mining water as a function of pH were also estimated by means of the X-ray fluorescence (XRF) method and ChemEQL software for calculating chemical speciation equilibria. Using these concentration values and the relaxivities of the metal ions, the total relaxation rate (R2) results were then calculated. Principally, the results of these three different determinations are in relatively good agreement. It can be concluded that TD-NMR has great potential for monitoring metal ion concentrations during water treatment