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Copyright of Waste Forum is the property of Czech Environment Management Center (CEMC) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aerosols in the atmosphere affect our health and quality of life. The most commonly measured property is their mass concentration. In this work was measured the mass concentration of aerosols by optical particle sizer in the range from 0.3 μm to 10 μm. It was realized in the laboratory with an automatic heat source for pellet combustion. Aerosols were firstly measured before the combustion process, then during combustion of three types of samples: pellets from pure sawdust, pellets from 5 % of disintegrated face masks FFP2 blended with spruce sawdust and from10 % of disintegrated face masks FFP2 blended with spruce sawdust. The lowest total mass concentration was measured during the combustion of pellets from pure spruce sawdust. However, results indicate that the combustion process does not have an impact on aerosol mass concentration in the laboratory space for the particle range 0.3-10 μm when an automatic heat source for pellets is used.

The use of refrigerants requires to meet ecology and legislation requirements. The aim of the legislation is also to reduce the global warming potential (GWP). Natural refrigerants such as carbon dioxide, ammonia, and hydrocarbons such as propane, isobutene, and propylene are used mainly because of their environmental benefits compared to synthetic refrigerants. This work compares two natural refrigerants: R-744 and R-290 and two synthetic refrigerants: R-134a and R-32. All these refrigerants are used mainly in heat pumps. In this work were calculated and compared the following performance parameters: heat rejected in the condenser, cooling power, compressor power, and the coefficient of performance (COP). The most important parameter is the coefficient of performance because when it decreases, electric energy consumption increases. It requires reaching a high value of COP. Further, this work deals with the economic analyses of selected refrigerants. The last aim of this article is their ecologic analysis based on the GWP factor.

Solid fuel combustion accompanies particulate matter production. These particles negatively affect human health, so ways of capturing them are being sought. Local heat sources are a major producer, with this article focusing on the flue gas tract of this heat source. A baffle has been placed in the flue gas tract, the position of which is changing. It is observed the impact of particulate matter flowing through this baffle with a focus on the settling areas. Particles are trapped in the settling areas and do not flow further through the flue gas tract. Particulate matter flowing was investigated by the visualization method called Particle image velocimetry (PIV). Visualizing the flow allows to get a figure of the flow and a dynamic record of the state of the object. The result of the visualization is the assessment of the monitored flow, the determination of its trajectory and streamlines.

The demand for energy is growing in the world, and therefore attention has been focused on the use of possible alternative energy sources. For countries with limited access to common hydrocarbon gases, methane hydrates appear to be a potential source of energy. Under certain pressure and temperature conditions, it is also possible to produce hydrates of hydrocarbon gases under laboratory conditions. However, we are currently at a very early stage in the development of methane hydrates. The transition from scientific theory to practical extraction is currently underway. This article describes the influence of selected physical parameters on the nucleation rate of hydrocarbon gas hydrates.

The standard detection of the emission and power parameters of the combustion process can be time and money consuming due to the performance of experimental measurements with the necessary measuring instruments. Alternatives to describe the combustion process are mathematical models. Their variability is high and therefore, depending on the need for use, an analytical mathematical model was chosen. Among the computationally faster and less time-consuming models is the analytical model, which can not only describe some parameters of the combustion process (power, emissions and others) but also predict the parameters of the combustion process according to the selected input values. This work is focused on the prediction of selected emission parameters through an analytical model for 100 % straw and 100 % wood pellets.

Biomass has been still on the rise in recent years in the world. But combustion of biomass led to the increase of emissions in the atmosphere. Mainly in winter time is formed a large amount of particulate matter. They have adverse impact on our health when human breathes them. This is a reason why is important to produce low level of these emissions. However, several aspects impact on their formation. This article examines impact of type of fuel and operation of heat source on PM formation. It compares particulate matter from combustion of wood chips and sawdust at nominal and reduced output.

It is very important to separate particulate matter before their leaving into the air because of their harmful impact on human health. It exists a lot of devices, which can separate these particles. But their implementation and operation in small heat source can be considerably difficult on finances, and often have complex maintenance. Therefore, it is important to look for solutions of reduction the producing of particulate matter with easier maintenance and also less financial difficulty. This article deals with flow modelling of particulate matter by using baffles placed in the flue tract of wood stove. Influence of baffles is observed by using CFD simulations.

Micro-cogeneration is cogeneration with small performance, with maximal electric power up to 50 kWe. On the present, there are available small micro-cogeneration units with small electric performance, about 1 kWe, which are usable also in single family houses or flats. These micro-cogeneration units operate on principle of conventional combustion engine, Stirling engine, steam engine or fuel cell. Micro-cogeneration units with fuel cells are new progressive developing type of units for single family houses. Fuel cell is electrochemical device which by oxidation-reduction reaction turn directly chemical energy of fuel to electric power, secondary products are pure water and thermal energy. The aim of paper is measuring and evaluation of operation parameters of micro-cogeneration unit with fuel cell which uses natural gas as a fuel.

Copyright of Waste Forum is the property of Czech Environment Management Center (CEMC) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Presence of particulate matter (PM) in the atmosphere is a problem mainly in the winter time. PM are getting into atmosphere from combustion of solid fuels in heat sources. Their impact on people health is harmful, when we breathe them. Therefore, it is necessary for reduction these emissions in the atmosphere. This article investigates downfall velocities of particulate matter based on calculations and then it observes velocity simulation of particulate matter flowing through baffles placed in the flue tract of local heat source by using program Ansys. These baffles are usable for separation of particulate matter in the flue tract. When particles reach downfall velocity, forces which acting on them are in equilibrium and they would not get into atmosphere from the flue tract of heat source. CFD simulation in program Ansys allows us to observe velocity distribution in flue tract and compare it with calculated downfall velocity of these particles. [ABSTRACT FROM AUTHOR]