Hindawi Publishing Corporation Advances in Mechanical Engineering Volume 2013, Article ID 685157, 7 pages http://dx.doi.org/10.1155/2013/685157 Research Article Biomass Combustion Control and Stabilization Using Low-Cost Sensors Ján Pite8, Jana MiDáková, and Alexander Hošovský Faculty of Manufacturing Technologies with a Seat in Preˇ sov, Technical University of Koˇ sice, Bayerova 1, 080 01 Preˇ sov, Slovakia Correspondence should be addressed to Jana Miˇ z´ akov´ a; jana.mizakova@tuke.sk Received 12 August 2013; Accepted 9 December 2013 Academic Editor: Junwu Wang Copyright © 2013 J´ an Pitel’ et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te paper describes methods for biomass combustion process control and burning stabilization based on low-cost sensing of carbon monoxide emissions and oxygen concentration in the fue gas. Te designed control system was tested on medium-scale biomass- fred boilers and some results are evaluated and presented in the paper. 1. Introduction Te quality and efciency of combustion process versus air pollution is a global problem of not only economically developed countries, but also poor countries in the world. Currently, the consumption of power includes a high propor- tion of heat production in some countries. Small-scale biomass-fred boilers with a fuel in the form of woodchips, possibly sawdust or other secondary wood- working production sources, are ofen operated uncontrolled or with a very simple control mechanism, mostly mechanical controller. Te environmental contribution of such uncon- trolled or poorly controlled boilers in comparison with fossils fuels ones can be very small if any [1]. A typical issue is an improperly controlled air-to-fuel ratio during transition states (e.g., boiler lighting, burn-out phase, sudden increase of power demand, etc.) [2]. Such poor control method moves combustion process out of optimal combustion interval and causes signifcant heat loses and high emission production. Emissions usually consist of solid organic carbon, which in combination with ash is visible part of emissions [3–5]. Tese problems ofen appear also in medium-scale biomass-fred boilers. During the last decade, a substantial efort has been spent to improve the biomass boiler design. Tis resulted in an ef- ciency increase. However, development of control algorithms ensuring optimality of combustion process is quite behind in the development of the design. One way in the combustion process control algorithm development is to modify a control algorithm used on medium- or full-scale boilers and adapt it to small-scale boilers. Tis approach can be partially used, but it runs against some specifcs of small-scale boilers [6, 7]. Main diferences of small-scale boilers cover [8] (i) faster fuctuation of a combustion process due to a smaller mass of combustion chamber walls; (ii) higher sensitivity of a combustion process to external infuences; (iii) a poor and nonperiodical maintenance due to care- lessness of many users; (iv) unserviced sensors with uncertain measurements; (v) the budget for automation of a boiler necessity of keeping low, and so forth. In solving of project “Research and development of intel- ligent control systems for biomass based heat production and supply,” we dealt with possibilities of increasing of biomass combustion efciency by using low-cost carbon monoxide (CO) emissions and oxygen (O 2 ) concentration sensors instead of commonly used fue gases analyzer. Tis analyzer is quite expensive for continuous emission sensing in small- scale and also medium-scale biomass-fred boilers unlike in large-scale boilers, where the price of control system including analyzer is not so important. In order to increase combustion efciency and to decrease emission production in medium-scale biomass-fred boilers, we designed new control algorithms for fuel supply and for combustion process