Matematički modeli izgaranja, konvekcije i prijenosa topline u eksperimentalnom toplinkom uređaju i verifikacija

The presented paper deals with the analysis of turbulent burning and with transport of energy and momentum. The article specificity lies in the fact that these processes are analysed in the horizontal furnace in which the screw reactor is placed. This reactor processes organic raw materials continually and thermally. Volume input of the raw materials is about 60 kg per hour. Solution of this issue comes from the measured energy responses of this device and from the principles of mathematic 3-D modelling. The main aim is to introduce a methodology of the combined modelling of the turbulence, burning and radiation for the monitored case and to verify it on the basis of experimentally obtained data.Rad se bavi analizom turbulentnog izgaranja te prijenosom energije i količinom gibanja. Rad je specifičan po činjenici da se ti procesi analiziraju u horizontalnoj visokoj peći u koju je postavljen vijčani reaktor. Taj reaktor prerađuje organske sirovine kontinuirano i termalno. Količina unosa sirovina je oko 60 kg na sat. Rješenje ovog pitanja nalazi se u izmjerenim količinama energije tog uređaja i u principima matematičkog 3-D modeliranja. Osnovni je cilj predstaviti metodologiju kombiniranog modeliranja turbulencije, izgaranja i radijacije u istraživanom slučaju i verificirati ga na osnovi eksperimentalno dobivenih podataka.Web of Science21111211

Mathematical models of combustion, convection and heat transfer in experimental thermic device and verification

Rad se bavi analizom turbulentnog izgaranja te prijenosom energije i količinom gibanja. Rad je specifičan po činjenici da se ti procesi analiziraju u horizontalnoj visokoj peći u koju je postavljen vijčani reaktor. Taj reaktor prerađuje organske sirovine kontinuirano i termalno. Količina unosa sirovina je oko 60 kg na sat. Rješenje ovog pitanja nalazi se u izmjerenim količinama energije tog uređaja i u principima matematičkog 3-D modeliranja. Osnovni je cilj predstaviti metodologiju kombiniranog modeliranja turbulencije, izgaranja i radijacije u istraživanom slučaju i verificirati ga na osnovi eksperimentalno dobivenih podataka.The presented paper deals with the analysis of turbulent burning and with transport of energy and momentum. The article specificity lies in the fact that these processes are analysed in the horizontal furnace in which the screw reactor is placed. This reactor processes organic raw materials continually and thermally. Volume input of the raw materials is about 60 kg per hour. Solution of this issue comes from the measured energy responses of this device and from the principles of mathematic 3-D modelling. The main aim is to introduce a methodology of the combined modelling of the turbulence, burning and radiation for the monitored case and to verify it on the basis of experimentally obtained data

Návrh a výpočet ohřívání základního modulu pyrolýzní pece jednotky Pyromatic

The article is focused on definition of optimum parameters of the pyrolitic unit basic module heating with respect to specified operating conditions. Suitable available fuel gases are propane and natural gas. The total capacity of torches is 200 kW. All energetic values has been calculated and reconciled for the both gases with respect to significant factors influencing the heating process course. In the conclusion the established values are summarized and evaluated.Příspěvek je zaměřen na určení optimálních parametrů ohřívání základního modulu pyrolýzní jednotky vzhledem k požadovaným podmínkám provozu. Jako vhodné topné plyny jsou k dispozici propan a zemní plyn. Celkový výkon hořáků činí 200 kW. Veškeré energetické veličiny jsou vypočteny a srovnány pro oba plyny, a to z podstatných hledisek ovlivňujících průběh spalovacího procesu. V závěru příspěvku je shrnutí a vyhodnocení zjištěných hodnot

Laboratorní a poloprovozní výzkum pyrolýzního procesu

Pyrolysis is a suitable recycling method that leads to a creation of 3 pyrolyzed phases (gas, liquid and solid) and every phase has its possible utilisation. Pyrolysis is a complicated process and its description in the light of system analysis by means co called transport system enables its reduc-tion on a system of masses transport and a system of energy transport. A transport system consists of accumulative elements (a reservoir), transformation elements (a pyrolysis retort, a burner) and transport elements (pipes). In a system of pyrolysis, by means of transformation elements, the follow-ing actions are realised: a flow of mass and energy, transformation of input material to a pyrolyzed phase in a transformation element and storage of products in accumulative elements. Quantity and composition of pyrolyzed products are dependent on process conditions of a pyrolysis especially temperature. Pyrolysis of scrap tyres was tested in a laboratory thermic analyzer and in semi opera-tional unit of Pyromatic. Presented article presents results obtained from both devices.Pyrolýza je vhodným recyklačním procesem, při kterém z organického materiálu vznikají produkty tří fází (plyn, kapalina polokoks). Každý z těchto produktů má své využití. Systémová analýza umožňuje pomocí transportního systému popsat pyrolýzu jako transport hmoty a energie. Transportní systém je složen ze 3 druhů prvků – akumulačních (nádoby různého typu), transformačních (pyrolýzní retorta, hořák) a transportních (potrubí). V takto definovaném systému dochází k přeměně hmoty a energie vstupního materiálu v transformačních prvcích na jednotlivé pyrolýzní fáze, které jsou následně ukládány v akumulačních prvcích. Kvantita a kvalita jednotlivých pyrolýzních fází závisí na procesních podmínkách pyrolýzy, především na teplotě. Pyrolýza odpadní pryže byla testována v laboratorním termickém analyzátoru a následně v poloprovozním zařízení Pyromatic. Tento článek se v souladu se systémovou analýzou zabývá výsledky experimentálních měření na obou těchto zařízeních

Zhodnocení kvality výstupního produktu technologického celku pro pyrolýzu organických odpadních látek

The issue of ecological removal of organic polymer materials and wastes polluting the environment is very much alive and it is clear that it will take on ever greater importance. a promising and innovative technology for environmentally friendly disposal of waste organic matter is pyrolysis. This method of thermal processing of waste for its degradation as well as a source of valuable energy products using the new system Pyromatic. This paper presents its technical description and evaluation of the quality of output product from the pyrolysis of tires, plastics and coal.Problematika ekologického odstraňování polymerních materiálů a odpadů znečišťujících životní prostředí je V současnosti velmi živá a je zřejmé, že bude nabývat na stále větší důležitosti. Perspektivní a inovativní technologií pro ekologickou likvidaci odpadních organických látek je pyro-lýza. Tento způsob termického zpracování odpadů za účelem jejich degradace a zároveň zisku energeticky hodnotných produktů využívá nový systém Pyromatic. V příspěvku je předložen jeho technický popis a zhodnocení kvality výstupního produktu Z pyrolýzy pneumatik, plastů a uhlí

Energy balance sheet of a semi operational thermic system

The article is focused onthe energetical balance of a technical system for the conversion of crushed tyres by pyrolysis. Process temperatures were set in the range from 500 to 650°C. Mass input of the material was 30 kg per hour. The aim of the article is to answer the following questions as regards the individual products: Under which process conditions can the highest quality of the individual products related to energy be reached? How does the thermal efficiency of the system change in reaction to various conditions of the process? On the basis of the experimental measurements and calculations, apart from other things, it was discovered that the pyrolysis liquid reaches the highest energetic value, i.e. 42.7 MJ.kg-1, out of all the individual products of the pyrolysis process. Generated pyrolysis gas disposes of the highest lower calorific value 37.1 MJ.kg-1 and the pyrolysis coke disposes of the maximum 30.9 MJ kg-1. From the energetic balance, the thermal efficiency of the experimental unit under the stated operational modes ranging from about 52 % to 56 % has been estimated. Individual findings are elaborated on detail in the article.Web of Science35332931

Selection and allocation of a warehouse linked to reloading terminal and seaport

Combined transport provides great possibilities for material reloading in terminals or warehouses. However, this cannot be done without a tailored warehouse, geographically suitable for all stakeholders, technically adequate for the handled material, providing the required service while keeping the transport costs at minimum. Allocation design and warehouse erection, connecting the warehouse with the reloading terminal - the seaport, provides an ever-increasing number of options and solutions in the form of integrated freight trains and regular container trains linking seaports with reloading terminals, which significantly saves transport costs and allows for more route and transport type combinations. The paper presents how a suitable warehouse is selected and how its allocation is decided on to cater to transport of the material through the reloading terminal and the seaport. Warehouse allocation was proposed using the Cooper iteration method. The given warehouse location will ensure the optimal cost of shipping and deliveries to individual customers.Web of Science65417316

Techno-economic analysis of fluidized bed combustion of a mixed fuel from sewage and paper mill sludge

The treatment and disposal of sewage sludge is one of the most important and critical issues of wastewater treatment plants. One option for sludge liquidation is the production of fuel in the form of pellets from mixed sewage and paper mill sludge. This study presents the results of the combustion of pelletized fuels, namely sewage and paper mill sludge, and their 2:1 and 4:1 blends in a fluidized bed combustor. The flue gas was analysed after reaching a steady state at bed temperatures of 700-800 degrees C. Commonly used flue gas cleaning is still necessary, especially for SO2; therefore, it is worth mentioning that the addition of paper mill sludge reduced the mercury concentration in the flue gas to limits acceptable in most EU countries. The analysis of ash after combustion showed that magnesium, potassium, calcium, chromium, copper, zinc, arsenic, and lead remained mostly in the ash after combustion, while all cadmium from all fuels used was transferred into the flue gas together with a substantial part of chlorine and mercury. The pellets containing both sewage and paper mill sludge can be used as an environmentally friendly alternative fuel for fluidised bed combustion. The levelized cost of this alternative fuel is at the same current price level as lignite.Web of Science1523art. no. 896

Ideal mathematical model of shock compression and shock expansion

Shock compression and expansion are phenomena which occur mainly in screw or vane compressors. They occur when there is an imbalance in the built-in and total pressure ratio. These are phenomena that have a negative impact on the operation of these machines and, in general, cause instability in operation, an increase in energy consumption and an overall worsening of the operational economy. The aim of this article is to present newly discovered information regarding making work processes of said compressors more effective, as in many cases, shock phenomena are subconsciously underestimated. The set aim was reached by creating an ideal simulation of isothermal compression of an ideal gas with the implementation of shock phenomena, which were performed on a screw compressor with the operating pressure 7 bar and a flow performance of 3 440 l min(-1). Based on the simulations performed, the hypotheses which set forth that the impact of shock phenomena ultimately leads to a sudden increase in compressor power consumption were confirmed. E.g. at 6 bar, the instantaneous power consumption increases by about 5.74% during shock compression and by about 55.95% during shock expansion. This paper deals with new insights and at the same time presents the follow-up research.Web of Science9169668

Current options in the life cycle assessment of additive manufacturing products

Additive manufacturing (AM) is a manufacturing process that allows for the creation of a physical object from a digital model. Additive manufacturing has a number of advantages over the conventional methods, inter alia the production of very complex machinery components, and a lower consumption of raw materials. Thanks to these advantages, the technology has been booming recently. The paper compares the advantages and disadvantages of additive technologies in the context of environmental impacts using Life Cycle Assessment (LCA). The paper describes the most important aspects of additive manufacturing, reviews the basic principles and phases of LCA method, including its application in AM, and outlines selected publications dealing with LCA and additive technologies. In conclusion, we recommend the most suitable methodologies to assess environmental impacts of additive technologies. To be specific, LCA is suitable to assess AM as for the material and energy flows, and in general, research in this field is considered highly promising.Web of Science9168267