Viktor Plaček

Transfer Issues of Control Optimizing Combustion from Small-scale to Medium-scale Biomass-fired Boilers

Abstract The quick development of biomass fired boilers increased the attention being paid to the ecological and economical aspects of their operation. A very important role in the process of adapting to harder regulations has been the control technology replacing older simple solutions. Lately, we have been offered a very interesting opportunity to make use of our experience with small-scale boiler control which has been gradually equipped with instruments for more sophisticated experiments and to transfer verified control algorithms to a district heating boiler of medium-scale size. The following text describes what has been achieved in experiments with the small-scale boiler and how this can be transferred to bigger scale one. An algorithm to optimize the combustion process from the efficiency point of view, as well as harmful emission reduction is described in detail.

Continuous Control Issues Concerning Operation Improvement of Small-Scale Biomass Boilers

Abstract To meet the increasing environmental and efficiency requirements, the possibilities to improve the performance of a 25 kWth wood pellet boiler by utilizing PLC and feedback control are investigated. The process is first stabilized by improving the grate sweeping sequence, which originally disturbs the process. Prior to continuous combustion control development, the process is analyzed and identified. After sequential control improvements the combustion behaves well but tends to drift. A PID controller was designed to enable drifting compensation. It is shown that improved grate sweeping sequence and continuous feedback control provide a major improvement for system performance cost effectively.

Neural Network Evaluation of Combustion Process for Continuous Control of Small Scale Biomass Fired Boilers

Abstract Boilers based on combustion of biomass become widely used as a heating source nowadays. The modern ones are typically controlled automatically. The control algorithm of those boilers is crucial in reaching optimal operational conditions by means of maximal efficiency and minimal environmental impact. On the other hand, the acquisition costs of these advanced devices should be maintained at reasonable level. This paper deals with implementation of modern proper control algorithm and obtaining the necessary input values that cannot be easily measured operationally by a direct measurement.

Optimal Combustion Conditions for a Small-scale Biomass Boiler

This paper reports on an attempt to achieve maximum efficiency and lowest possible emissions for a small-scale biomass boiler. This aim can be attained only by changing the control algorithm of the boiler, and in this way not raising the acquisition costs for the boiler. This paper describes the experimental facility, the problems that arose while establishing the facility, and how we have dealt with them. The focus is on discontinuities arising after periodic grate sweeping, and on finding the parameters of the PID control loops. Alongside these methods, which need a lambda probe signal for proper functionality, we inroduce another method, which is able to intercept the optimal combustion working point without the need to use a lambda sensor.

SMALL AND MEDIUM SCALE BIOMASS COMBUSTION CONTROL POSSIBILITIES

Biomass combustion is one of the most versatile and spread heat source for residential usage in the world. Nowadays a lot of new combustion devices in developed countries are controlled automatically. The control algorithm used in these devices is crucial in attaining optimal service economy with minimal environmental impact. This contribution deals with two ways how to implement proper control algorithms to small and medium scale boilers. The first method is by applying modern methods of controller development and the second by adapting tested algorithms from full-scale boilers. The used algorithms are implemented and tested on experimental devices based on common market products.