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Contribution to the construction of cost and energy efficient family houses
Čech, Josef ; Mohelníková, Jitka (referee) ; Gašparik,, Jozef (referee) ; MBA, Pavel Slováček, (referee) ; Hrazdil, Václav (advisor)
Dissertation focuses on the verification of construction family houses made of concrete shell block with internal thermal insulation system. The construction technology is transferred to the Czech Republic from France. The work focuses on building envelope. The suitability of implementation is assessed on the basis of verification selected thermal technical requirements placed on building envelope. Requirements are specified by legislation in force in the ČR. The verification was performed by using software simulations and measurements on realized buildings. Critical areas of construction technology were identified on the basis software simulations and measurements on site. It was suggested solution, in which critical areas comply the thermal technical requirements. The building envelope was checked also using the thermography imaging on site. Continuous measurement of interior temperature was used to evaluate thermal comfort in the room. In the completed buildings was tested airtightness of the building envelope, which revealed other critical areas of the building envelope. Critical areas are necessary to solve with sufficient care. The economic cost of implementing each variants of exterior walls made of concrete shell block with internal thermal insulation were compared with the economic costs of implementing external walls made of burnt clay hollow blocks and made of burnt clay hollow blocks with external thermal insulation system ETICS. Subsequently, the economic return was calculated for individual variants of external walls made of concrete shell blocks with internal thermal insulation. From the environmental viewpoint was made comparison of production greenhouse gas CO2 and SO2 (cause acid rains) during the life cycle of the individual variations of exterior walls made of concrete shell blocks with system of internal thermal insulation, exterior walls made of burnt clay hollow blocks and burnt clay hollow blocks with external thermal insulation syst
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Heat transfer in the tubular exchangers
Horvát, Petr ; Krištof, Ondřej (referee) ; Svěrák, Tomáš (advisor)
Shell and tube heat exchangers and their use in cooling processes are the major topic of this thesis. The theoretical part of the thesis starts with the mechanisms of heat transfer and then deals with shell and tube heat exchangers. Their position, design specifications and equations for calculations are given. In the experimental part, the heat transfer on semi-operating shell and tube heat exchangers with baffles and glass or silicon carbide heat exchange surface is examined by cooling the humid air by 50% propylene glycol in tubes. For four or five coolant flows and three airflows, input and output flow temperatures including relative air humidity were measured. Differences in exchanged heat between the exchangers were negligible due to the low local air heat transfer coefficient, although silicon carbide has two orders of magnitude better thermal conductivity than glass. Much higher efficiency was performed by the carbide heat exchanger because the difference between air outlet temperature and liquid inlet temperature was one and half times higher for the glass heat exchanger. That was reflected in a decrease in mean temperature difference, which resulted in a 16 % higher experimental heat transfer coefficient compared with the glass surface. The theoretical model using the j factor, the correction factors for the baffles, and the correction for air humidity condensation have proven to be appropriate. For the glass surface, for the highest air flow rates the model gives an appropriate heat-transfer coefficient; at lower flow rates it gives slightly higher values. For the silicon carbide surface, it gives a lower heat-transfer coefficient because the model failed to consider a lower mean temperature difference. The results also evaluate the heat loss through the shell and the heat exchanged in addition by air humidity condensation.
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Heat transfer in the tubular exchangers
Horvát, Petr ; Krištof, Ondřej (referee) ; Svěrák, Tomáš (advisor)
Shell and tube heat exchangers and their use in cooling processes are the major topic of this thesis. The theoretical part of the thesis starts with the mechanisms of heat transfer and then deals with shell and tube heat exchangers. Their position, design specifications and equations for calculations are given. In the experimental part, the heat transfer on semi-operating shell and tube heat exchangers with baffles and glass or silicon carbide heat exchange surface is examined by cooling the humid air by 50% propylene glycol in tubes. For four or five coolant flows and three airflows, input and output flow temperatures including relative air humidity were measured. Differences in exchanged heat between the exchangers were negligible due to the low local air heat transfer coefficient, although silicon carbide has two orders of magnitude better thermal conductivity than glass. Much higher efficiency was performed by the carbide heat exchanger because the difference between air outlet temperature and liquid inlet temperature was one and half times higher for the glass heat exchanger. That was reflected in a decrease in mean temperature difference, which resulted in a 16 % higher experimental heat transfer coefficient compared with the glass surface. The theoretical model using the j factor, the correction factors for the baffles, and the correction for air humidity condensation have proven to be appropriate. For the glass surface, for the highest air flow rates the model gives an appropriate heat-transfer coefficient; at lower flow rates it gives slightly higher values. For the silicon carbide surface, it gives a lower heat-transfer coefficient because the model failed to consider a lower mean temperature difference. The results also evaluate the heat loss through the shell and the heat exchanged in addition by air humidity condensation.
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Contribution to the construction of cost and energy efficient family houses
Čech, Josef ; Mohelníková, Jitka (referee) ; Gašparik,, Jozef (referee) ; MBA, Pavel Slováček, (referee) ; Hrazdil, Václav (advisor)
Dissertation focuses on the verification of construction family houses made of concrete shell block with internal thermal insulation system. The construction technology is transferred to the Czech Republic from France. The work focuses on building envelope. The suitability of implementation is assessed on the basis of verification selected thermal technical requirements placed on building envelope. Requirements are specified by legislation in force in the ČR. The verification was performed by using software simulations and measurements on realized buildings. Critical areas of construction technology were identified on the basis software simulations and measurements on site. It was suggested solution, in which critical areas comply the thermal technical requirements. The building envelope was checked also using the thermography imaging on site. Continuous measurement of interior temperature was used to evaluate thermal comfort in the room. In the completed buildings was tested airtightness of the building envelope, which revealed other critical areas of the building envelope. Critical areas are necessary to solve with sufficient care. The economic cost of implementing each variants of exterior walls made of concrete shell block with internal thermal insulation were compared with the economic costs of implementing external walls made of burnt clay hollow blocks and made of burnt clay hollow blocks with external thermal insulation system ETICS. Subsequently, the economic return was calculated for individual variants of external walls made of concrete shell blocks with internal thermal insulation. From the environmental viewpoint was made comparison of production greenhouse gas CO2 and SO2 (cause acid rains) during the life cycle of the individual variations of exterior walls made of concrete shell blocks with system of internal thermal insulation, exterior walls made of burnt clay hollow blocks and burnt clay hollow blocks with external thermal insulation syst
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