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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Vyhodnocování a modelování zanášivého procesu ve výměníku tepla / Evaluating and modeling of fouling process in heat exchanger

Čirka, Martin January 2016 (has links)
This diploma thesis discusses fouling processes and mechanisms of industrial heat exchangers, with focus on shell side fouling of heat transfer area by flue gases, and eventually taking fouling into account, or more precisely its modeling and predicting by calculation. Thermal-hydraulic design of heat exchanger is focused mainly on shell side, as flue gases are dominant process medium in terms of fouling and heat transfer. Based on available operational data of evaluated industrial heat exchanger, specific process has been developed to determine by calculation, or more precisely predict change of fouling factor throughout operational period of heat exchanger. Usage and various options of this specific calculation technique are being discussed in conclusion, whether there is a potential to use this technique regarding more complex operational inputs or prediction of fouling process for different operational regime of heat exchanger.
152

Sorpční tepelné čerpadlo / Sorption heat pump

Veselý, Josef January 2016 (has links)
This thesis deals with the issue of sorption heat pumps. The theoretical part is devoted to a detailed description of the function of adsorption and absorption heat pumps. For a better understanding of the adsorption cycle is computed theoretical thermal cycle and the heating factor of zeolite adsorption heat pump are computed. The practical part is focused on the design absorption heat pump that works in conjunction with a natural gas boiler. The pump is designed for cooling flue gas condensing boiler and the possible use of thermal energy from other low-temperature source. The thesis contains a thermal calculations, engineering design and structural design of the heat pump.
153

Návrh dvoutlakého horizontálního kotle na odpadní teplo / Proposal of horizontal dual-pressure heat recovery steam generator

Slíva, Karel January 2016 (has links)
The focus of this thesis is a proposal of a horizontal dual-pressure heat recovery steam generator. The introductory part includes thermal calculation, as well as a design of the layout and a design of the heat transfer surfaces and the layout of the boiler. Individual chapters are broken down according to the outline of the proposal for the arrangement of the heating surfaces, according to the parameters of the flue gas and steam. The master thesis contains a scheme of a real heat transfer temperature diagram and it also includes the calculation of connecting and downcomer pipes and drums. The final part describes the calculation of the boiler draft loss. The main idea of the thesis is accompanied by the technical documentation of the drawing of the boiler.
154

Biologisk reducering av nitrat och nitrit i vatten / Biologic reduce of nitrate and nitrite in water

Sohlberg, Thomas January 2007 (has links)
<p>During the summer 2007 was a scrubber tested at Gruvön papper mill in Grums. The scrubber reduced NO<sub>x</sub> with 90 % in flue gas. NO<sub>x</sub> was transferred from the flue gas to a scrubber liquid as nitrate and nitrite. The scrubber liquid needs to be purified from nitrate and nitrite.</p><p> </p><p>One possible solution is to clean the scrubber liquid in Gruvön biologic cleaning construction.</p><p>Microorganisms in the biologic cleaning construction need to assimilate nitrogen. There are environments free from oxygen in the cleaning construction. Microorganisms can reduce nitrate in environments free from oxygen.   </p><p> </p><p>At the implementation was a labmodel built of the two first steps from Gruvön papper mill. Wastewater was collected from Gruvön papper mill. The wastewater was dosed with salts of nitrate and nitrite and pumped into the labmodel.</p><p>The results showed that nitrate and nitrite can be reduced in content with help of the biological cleaning construction.</p>
155

Biologisk reducering av nitrat och nitrit i vatten / Biologic reduce of nitrate and nitrite in water

Sohlberg, Thomas January 2007 (has links)
During the summer 2007 was a scrubber tested at Gruvön papper mill in Grums. The scrubber reduced NOx with 90 % in flue gas. NOx was transferred from the flue gas to a scrubber liquid as nitrate and nitrite. The scrubber liquid needs to be purified from nitrate and nitrite.   One possible solution is to clean the scrubber liquid in Gruvön biologic cleaning construction. Microorganisms in the biologic cleaning construction need to assimilate nitrogen. There are environments free from oxygen in the cleaning construction. Microorganisms can reduce nitrate in environments free from oxygen.      At the implementation was a labmodel built of the two first steps from Gruvön papper mill. Wastewater was collected from Gruvön papper mill. The wastewater was dosed with salts of nitrate and nitrite and pumped into the labmodel. The results showed that nitrate and nitrite can be reduced in content with help of the biological cleaning construction.
156

Využití absorpčních systémů v teplárenství / Utilization of absorption systems in the heating systems

Vidlák, David January 2018 (has links)
Main goal of this work is familiarization with basic features of absorption heat pumps and it’s growing importance on the market. In the first part of the work there is a research for clarifying facts associated with such pumps. In the introduction there are descriptions of basic information from the field of heating industry and its connections to our systems. Next there is a brief analysis of price changes in electricity and heat in the last five years. Main part of the analytical section is a description of the used absorption system. Second part of the work is focused on the calculation of the absorption system itself. First there is calculated internal and external part of the device according to the parameters from GE Power s.r.o. After this step there are parametric studies based on changes of key parameters of the default device for a demonstration of the behavior of a heating pump. In the end of the work there is a integration of the unit into the heating cycle for variations including flue gas condenser and using a cooling water from the turbine condenser.
157

Provozní účinnosti zdrojů tepla / Operational efficiency of boilers

Doležal, Lukáš January 2019 (has links)
The topic of this diploma thesis is the operational efficiency of heat sources. The work had several goals. The first was to determine the efficiency of the wood boiler according to available calculation methods and to compare the methods among them. The second was to determine the difference in the performance of the flue gas analyzer and the real calculation. Further, to determine the efficiency of a boiler firing different wood species - spruce and hornbeam based on their properties and elemental composition. Experimental measurement of various operating states of effectiveness took place in an older two-generation family house, which was also the subject of the project part. Due to lack of project documentation, it was necessary to focus and plot the object. Afterwards, the building was thermally inspected and the design of the heating system and the reconstruction of the whole heating system was carried out. The project was developed in two variants for two different heat sources - a heat pump and a solid fuel boiler for heating and water preparation. The thesis deals with the technical report, the conceptual solution of the related professions, the evaluation of the heat source variants and the project documentation.
158

Verifikace modelu pro predikci vlastností spalovacího procesu / Verification of the model for predicting the properties of the combustion process

Horsák, Jan January 2014 (has links)
This work thoroughly analyzes a previously created computational model for predicting characteristic properties of the combustion process in an experimental combustion chamber. Any found shortcomings of the original model are removed and the model is further improved prior to its application on 11 real cases of combustion tests performed at various conditions and with various fuels. Data provided by the model are confronted with the data obtained during the combustion tests and the model accuracy is evaluated, based on local heat flux along the length of the combustion chamber. Finally, the overall usefulness of the model is determined by the means of evaluating the acquired accuracy values, and further possibilities of model improvement and use are presented.
159

Dvoutlaký horizontální kotel na odpadní teplo (HRSG) / Heat Recovery Steam Generator with Two Pressure Levels

Maršík, Jaroslav January 2015 (has links)
The Master’s thesis dealing with design of heat recovery steam generator with two pressure levels is split into nine sections. The first section describes the design and the layout of HRSG. The second part deals with heat calculation. The third section deals with design of flue-gas duct. The fourth part describes designs of individual heating surfaces, including steam superheaters, vaporizers and economizer. Next section shows the real temperature diagram and choice of the materials. The seventh section describes the calculation of outer pipelines and the eighth part deals with the drums design. The last section deals with the calculation of draft loss of steam generator.
160

Návrh dvoutlakého horizontálního kotle na odpadní teplo / Proposal two-pressures horizontal waste heat boiler

Med, Lukáš January 2016 (has links)
This master's thesis deals with thermal calculation and design of proportions of calorific components of a heat recovery steam generator (HRSG), which is placed behind a combustion turbine, for given parameters of exhaust gases and requested parameters of steam. In the first chapters is described the design, layout of HRSG and the thermal calculation. The next parts deal with the design of flue-gas duct and each individual heating surface. Next section shows computations of dimensions of drums, flooding pipes, transferring pipes and all other outer pipes. The chosen materials are described in one of the last chapters and the last chapter deals with calculation of draft loss of steam generator.

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