The Involvement of the Coolers of the Compressor for Energy Headquarters with the Accumulation of Electrical Energy - EC CAES

Diplomová práce se zabývá koncepcí návrhů zapojení chladičů kompresoru v energetické centrále s akumulací energie v tlakovém vzduchu. První část se zabývá výběrem vhodného kompresoru pro daný účel, popisem jeho způsobu práce a vysvětlením principu akumulace energie v tlakovém vzduchu v energetické centrále. Druhá část se zabývá samostatným návrhem daného kompresoru a vhodnou koncepcí zapojení jeho chladičů pro splnění požadovaných účelů. Na konci této části je provedeno zhodnocení všech uvedených koncepcí s hodnocením jejich kladů a záporů.The diploma thesis deals with the design of conceptions of the compressor´s coolers involvement in compressed air energy storage in the energy headquarters. The first part describes the selection of compressor for its purpose and his description of working process and with the description of the compressed air energy storage in the energy headquarters. The second part deals with the design of the centrifugal compressor and with suitable conceptions of the coolers involvement for the compressor and the fulfillment of required purposes. At the end is evaluation of the conceptions and stated their pros and cons.361 - Katedra energetikyvýborn

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

The Occurrence of Problems with the Shock Compression and Shock Expansion - Study

Import 02/11/2016Bakalářská práce se zabývá výskytem rázové komprese a rázové expanze. V první části jsou popsány stroje, jichž se daná problematika týká a rozebrána podstata samotného problému. Druhá část práce se zabývá vlivem rázové komprese a expanze na energetické charakteristiky simulovaného šroubového kompresoru. Tato část práce také zahrnuje návrh měřicí trati, na které by mohly být uvedené problémy simulovány a měřeny veličiny nutné pro popis jejich vlivu na provoz strojů. V poslední části jsou předloženy vlastní návrhy regulace provozu a možné konstrukční úpravy strojů.The bachelor thesis deals with the occurence of under compression and over compression. The first part describes the machines concerned by the issues discused and concerns the essence of the problem itself. The second part describes the influence of under and over compression at energy characteristics on simulated rotary screw compressor. This part of thesis also includes design of measuring track where could be the problems simulated and measured values required to describe their impact on the operation of the machines. The last part submits own suggestions for regulation in operation and construction designs.361 - Katedra energetikyvýborn

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

Verification of the analytical design model of a subcritical air ejector and assessment of the behavior of the manufactured machine under different operating conditions

Ejectors are dynamic energy machines that can be designed using analytical methodologies that have been in use for decades. These calculation methods consist of coefficients and equations, which are now untraceable and have not been updated since they were first proposed. Modern literature is devoid of ejector design; therefore, to conduct research on ejectors, it is first necessary to verify the validity of existing computational methods. In this study, we conducted computational fluid dynamics (CFD)-assisted experiments to simulate a subcritical air-to-air ejector with the possibility of controlling the distance of the nozzle mouth from the mixing chamber inlet. It was found that the optimum distance of the nozzle mouth from the mixing chamber inlet (i.e. 7.9 mm) corresponds to the design condition when the ejection coefficient is 1.673 and the secondary medium quantities reach the maximum value of 31.19 kg/h. A change in the position of the nozzle outside the optimum point leads to a deviation in the ejection coefficient and flow rate. The experimental results were compared with those from CFD analysis and the deviation between them did not exceed 2%. Two turbulent flow models, namely k-omega BSL and k-epsilon standard, were used for the comparison.Web of Science4438039802

Pollutants production, energy recovery and environmental impact of sewage sludge co-incineration with biomass pellets

This study describes the production of pollutants, energy recovery and environmental impact of the co-incineration of sewage sludge and biomass pellets. The main objective of this study is to describe the use of energy generated by co-incineration and to assess the environmental impact of emitted pollutants. Co-incineration takes place in five different blended. The combustion takes place in a fluidised bed reactor with an average combustion temperature of 915–939 ◦C. The combustion process is mapped by Fourier transform infrared spectroscopy, Continuous Mercury Monitoring Systems, thermocouples, pressures, and flows sensors. The results show that the concentrations of harmful substances, namely SO2 and NOX, reach values of 12.39–1730.33 mg•m–3 N for SO2 and 93.30–1156 mg•m–3 N for NOX. This means that the emission limits are exceeded 40 times for SO2 and 8 times for NOX in the worst case. Regarding heat recovery, the resulting value of potential energy recovery from the flue gas is 5.35–7.69 MJ•kg–1 , and as the sewage sludge content in the fuel increases, the heat recovery value decreases. The resulting values of pollutant concentrations are also analyzed using a life cycle assessment approach using the GaBi software. The results show that sewage sludge incineration has the greatest impact on climate change, terrestrial ecotoxicity, and human toxicity. Again, as the sewage sludge content in the fuel decreases, the hazardousness of the discharged flue gas decreases. This study presents a relatively promising option to use sewage sludge as a secondary fuel in large combustion sources under certain conditions.Web of Science32art. no. 10340

Softwood and solid recovered fuel gasification residual chars as sorbents for flue gas mercury capture

The scope of this paper is focused on gasification char (GC) utilisation as a direct sorbent for mercury capture from coal combustion flue gas. GC, being a waste material from thermochemical conversion, can represent an economically feasible variation of active coal-based sorbent. The aim of this study is to determine the absorption capacities of GC produced from softwood pellets (SWP) and solid recovered fuel (SRF). The influence of particle size and hot steam activation was examined. The carbon content in produced GC was between 73.7 and 93.4% wt., and SBET parameter up to 737.2 m2middotg-1. The Hg removal efficiency eta Hg was determined by a continuous mercury monitoring system. Promising removal efficiency results were obtained in the case of 0.5-2 mm particle size, hot-steam activated with 76.5 and 62.3% for SWP and SRF GC material, respectively. The results clearly suggest a promising, unconventional approach to waste utilisation in energetics, avoiding its inconvenient disposal. Thus, GC utilisation in the proper way may help to improve the sustainability of the circular economy on both small and big scales and, consequently, have a positive impact on various environmental aspects, such as air pollution control or extraction of resources minimalization.Web of Science29art. no. 10297

Comparative study by life cycle assessment of an air ejector and orifice plate for experimental measuring stand manufactured by conventional manufacturing and additive manufacturing

An integral part of the rapid development of modern technologies is additive manufacturing (AM) or threedimensional (3D) printing, which produces specific products that can replace the classic subtractive methods of machining or conventional manufacturing (CM). This study assessed the manufacturing processes of these two methods during the production of an air ejector and a centric orifice plate using the life cycle assessment (LCA) with the cradle-to-grave method, supported by experimental measurements. In general, the study serves as a tool for the companies for the development of circular economy. This study is specifically focused on and conducted for the industrial sector in the Czech Republic. This study presents a comprehensive assessment of the energy and material flows during the processes of mining, production of semi-finished products, processing of byproducts, and subsequent recycling. Moreover, it includes an assessment of the production of emissions and their effect and impact on the environment and, subsequently, the social aspect. It was found that from a primary energy demand (PED) perspective, AM single build is 30% more demanding in the case without recycling and 27.5% more demanding with the inclusion of the end-of-life phase. Moreover, the impact of AM is greater in four out of six impact categories for the ReCiPe 2016v 1.1 methodology. In addition, for the CML 2001 - Aug. 2016 methodology, AM is greater in four out of five categories. Finally, AM is greater in four out of four impact categories for the EF 3.0 methodology. The study highlights the hypothesis based on the production time for the full build, where from a PED perspective, AM with the end-of-life phase is only 2.76% and 3.89% more demanding with and without the offsetting of time deviation, respectively. The results of this study discuss the potential development and reduction of the burden on the environment during the life cycle of AM, especially during the cooling AM and the production of metallic powder. Although previous studies compared AM and CM were conducted, common and simple rotating components were virtually absent. This study aims to address this problem and arouse interest in the development of the issues presented.Web of Science32art. no. e0043