Selection of variables for on-line monitoring, diagnosis, and control of anaerobic digestion processes

2009 ◽  
Vol 60 (3) ◽  
pp. 615-622 ◽  
Author(s):  
F. Molina ◽  
M. Castellano ◽  
C. García ◽  
E. Roca ◽  
J. M. Lema

This work aims to systematize the study of indicators for two types of wastewaters: carbohydrate-based and protein-based synthetic wastewaters. Characterization of steady states and dynamic response analysis against disturbances were carried out using both a factorial discriminant analysis (FDA) and a phenomenological analysis, respectively. This research seeks reconciling both sets of indicators in order to optimize resources and provide a minimal cost in instrumentation for its implementation at industrial scale. According to the results of this research, the best indicators for the two types of wastewaters, considering both process steady states and organic load perturbations are: Biogas flow rate or Methane flow rate, and Hydrogen concentration in the biogas; Volatile fatty acids and Partial alkalinity in the liquid phase.

Author(s):  
J. M. Ko¨hler ◽  
P. A. Groß

The stability of fluid segments is limited by deformation stress and by coalescence events. Both factors are typical for the passage of fluid segments through micro fluidic networks. Therefore, the coalescence behaviour of micro fluid segments in simple net work structures in dependence of flow rate ratios was investigated and characterized by the composition of obtained segment populations. Series of segments of different size and distance were generated either in a double T- or in a triple T-arrangement. PTFE elements were used for the micro fluid network. Nearly pulsation-free fluid actuation was realized by syringe pumps. The flow conditions in the input streams of carrier liquid and injected solutions remained constant during the experiments. Segment sequences become divers by different injection, stacking and coalescence events. The resulting segment sequences were characterized by on-line micro photometry. The populations of obtained micro fluid segments during each experiment were characterized by the distribution of segment size and segment distance or segment periode, respectively. Simulations support the assumption, that the character of segment populations is mainly determined by the flow rate ratios and by the coalescence sensitivity beside the topology of the fluidic network.


1994 ◽  
Vol 30 (4) ◽  
pp. 265-274 ◽  
Author(s):  
H. Brouwer ◽  
A. Klapwijk ◽  
K. J. Keesman

In this paper. development of a cODlIol system for the activated sludge plant of Quest International Naarden BV is presented. The control system is based on on-line measurements of the actual respiration rate in the carrousel. From model sim ulations we conclude that overloading can be prevented by manipulating the wastewater flow rate. Energy can be saved. A day/night control of the aerators will result in energy cost savings between 11 and 21 %.


2006 ◽  
Vol 53 (1) ◽  
pp. 169-177 ◽  
Author(s):  
F. Ciappelloni ◽  
D. Mazouni ◽  
J. Harmand ◽  
L. Lardon

This paper presents a new software developed in MATLAB for analyzing on-line data of an aerobic SBR, detecting faults and, in this case, proposing the most probable causes of fault. Process diagnosis is achieved using a statistical method divided in two main phases: off-line model building and on-line data diagnosis. The off-line model identifies the correct working conditions of the system (standard operative conditions). It includes the characterization of the deviation of the system from these standard conditions in the case of changing in the biomass properties or carbon and nitrogen load characteristics. The on-line diagnosis aims at collecting and analyzing all the available data available through industrial sensors, and at classifying the behavior of each treatment cycle. The diagnosis performance of the proposed method is tested using a data set of an aerobic SBR pilot plant.


1994 ◽  
Vol 33 (01) ◽  
pp. 60-63 ◽  
Author(s):  
E. J. Manders ◽  
D. P. Lindstrom ◽  
B. M. Dawant

Abstract:On-line intelligent monitoring, diagnosis, and control of dynamic systems such as patients in intensive care units necessitates the context-dependent acquisition, processing, analysis, and interpretation of large amounts of possibly noisy and incomplete data. The dynamic nature of the process also requires a continuous evaluation and adaptation of the monitoring strategy to respond to changes both in the monitored patient and in the monitoring equipment. Moreover, real-time constraints may imply data losses, the importance of which has to be minimized. This paper presents a computer architecture designed to accomplish these tasks. Its main components are a model and a data abstraction module. The model provides the system with a monitoring context related to the patient status. The data abstraction module relies on that information to adapt the monitoring strategy and provide the model with the necessary information. This paper focuses on the data abstraction module and its interaction with the model.


2003 ◽  
Vol 3 (1-2) ◽  
pp. 351-357
Author(s):  
S. Le Bonté ◽  
M.-N. Pons ◽  
O. Potier ◽  
S. Chanel ◽  
M. Baklouti

An adaptive principal component analysis applied to sets of data provided by global analytical methods (UV-visible spectra, buffer capacity curves, respirometric tests) is proposed as a generic procedure for on-line and fast characterization of wastewater. The data-mining procedure is able to deal with a large amount of information, takes into account the normal variations of wastewater composition related to human activity, and enables a rapid detection of abnormal situations such as the presence of toxic substances by comparison of the actual wastewater state with a continuously updated reference. The procedure has been validated on municipal wastewater.


Author(s):  
Zhenhua Li ◽  
Weihui Jiang ◽  
Li Qiu ◽  
Zhenxing Li ◽  
Yanchun Xu

Background: Winding deformation is one of the most common faults in power transformers, which seriously threatens the safe operation of transformers. In order to discover the hidden trouble of transformer in time, it is of great significance to actively carry out the research of transformer winding deformation detection technology. Methods: In this paper, several methods of winding deformation detection with on-line detection prospects are summarized. The principles and characteristics of each method are analyzed, and the advantages and disadvantages of each method as well as the future research directions are expounded. Finally, aiming at the existing problems, the development direction of detection method for winding deformation in the future is prospected. Results: The on-line frequency response analysis method is still immature, and the vibration detection method is still in the theoretical research stage. Conclusion: The ΔV − I1 locus method provides a new direction for on-line detection of transformer winding deformation faults, which has certain application prospects and practical engineering value.


Author(s):  
Elizabeth S. Radcliffe

The Introduction offers, first, a brief historical background to Hume’s theory of the passions, which is further elaborated in the APPENDIX. Foremost among the theses of the early modern rationalists—like Reynolds, Senault, Descartes, Cudworth, and Clarke—to which Hume is responding are: that many passions left unregulated lead to the pursuit of unsuitable objects, that reason can overcome the pernicious influence of the passions and control our actions, and that the passions are states that represent good and evil. Second, the Introduction presents a sketch of Hume’s characterization of reason and passion and his account of their relationship. Third, it explains the method of interpretation used in this book and previews its chapters. The approach is coherentist: to present an intelligible and consistent picture of Hume’s theory of passion and action, accounting for as many of the relevant texts as possible.


Robotica ◽  
2020 ◽  
pp. 1-18
Author(s):  
M. Garcia ◽  
P. Castillo ◽  
E. Campos ◽  
R. Lozano

SUMMARY A novel underwater vehicle configuration with an operating principle as the Sepiida animal is presented and developed in this paper. The mathematical equations describing the movements of the vehicle are obtained using the Newton–Euler approach. An analysis of the dynamic model is done for control purposes. A prototype and its embedded system are developed for validating analytically and experimentally the proposed mathematical representation. A real-time characterization of one mass is done to relate the pitch angle with the radio of displacement of the mass. In addition, first validation of the closed-loop system is done using a linear controller.


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