Negative effects of high temperatures on cattle milk production is a specific problem. Dairy-cows, who produce much more heat than cows that are not milked, are more susceptible to high temperatures of the surrounding environment than other cattle. Changes in temperatures and atmospheric pressure were monitored throughout a year and then its influence on the milk production of cattle has been evaluated. It has been discovered that low temperatures do not have any significant influence on dairy-cows. However, at high temperatures dairy-cows suffer from heat stress and it leads to lower volumes of the daily milk production. The Holstein breed showed a higher sensitivity to temperature fluctuations than the Czech spotted breed; however, the Holstein breed milk production is better balanced in a long run (a year period).

The aim of this study was to detect surface temperature changes in the České Budějovice during last 30 years. The aim was also to asses the influence of vegetation on the surface temperature. The study is based on the thermal data acquired by the Landsat TM 4 and 5 and the study site was in the České Budějovice and surroundings.

The main aim of the diploma thesis is to determine if BMI (Body Mass Index) in humans is related to the indoor room temperature. Lower room temperature can lead to the activation of brown adipose tissue (BAT), thereby increasing energy expenditure. Because the thermal comfort is individual to some extent, the task is to determine whether there is a correlation between BMI and the frequency of perceived thermal discomfort. The research was attended by 202 respondents in the age range of 3 to 27. All were measured and weighed, and then the temperature habits were recorded through questionnaire. A group of students underwent more detailed data collection. For the evaluation of the data was used PCA (Principal Component Analysis) and regression analysis, for determining the influence of the room temperature, data were weighed by the coefficient of the thermal insulation during the night. The results showed that BMI, respectively the percentile BMI class of respondents in-creases with increasing average bedroom night temperature. Results are less clear for the age categories with no dependency between BMI and room temperature in the youngest age category, significant correlation in adolescent females and adult men, but not signifi-cant correlation in adolescent males and adult females. Evaluation of 87 responses from adolescent and adult respondents to the question regard-ing the frequency of subjective cold feeling showed that the more they felt the coldness in their dwellings, the lower was percentile BMI class and BMI in different age groups. Based on these results we can state that the room temperature during sleep is another sig-nificant factor influencing BMI and lowering the temperature in the homes could lead to the reduction of population obesity.

Práce je zaměřena na sestavení numerického modelu akumulace tepelné energie s fázovou přeměnou. Následně je tento model použit při tvarové optimalizaci, jejíž cílem je maximalizace uloženého tepla v tepelném výměníku. Kvůli komplexitě objektové funkce byl zvolen genetický algoritmus pro řešní úloh tvarové optimalizace. Práce obsahuje analýzu dvou problému týkající se tvarové optimalizace s následnou diskuzí nad obdrženými výsledky. Celý problém byl implementován v softwaru Matlab.

Fouling of tube bundles in boilers on the flue gas side affects not only the service life, but also the boiler heat output and increases maintenance and operating costs. Therefore, it is necessary to minimize or completely eliminate this process. This thesis focuses on comparison of the service life and the heat output of the tube bundles with and without deposit in the coal fired boiler. Simulations of flue gas flow in area of tube bundles with and without deposit are performed using ANSYS Fluent software, which shows that the surface of tube bundles with deposit is much less heated than the surface without deposit. The thermal loads of tubes obtained by the CFD analysis are applied to the model, which is created in the program ANSYS Mechanical, where the calculation of the temperature field in the cross section of the pipe is realized. The effect of fouling on creep life and heat output is then evaluated based on simulation results. The results show that fouling increases creep life, but significantly reduces heat output of heavily fouled tubes. Hence the flue gas flows at a higher temperature to the rest of the tube bundle, and the service life of those tubes will therefore probably decrease.

This thesis deals with the design grate boilers with natural circulation for the combustion of contaminated biomass. The boiler output is output 45 t/h. Produced superheated steam with the output parameters of 440 °C 4,2 at MPa feed water temperature 115 °C. The stoichiometric calculations and the thermal calculation are based on the specified fuel composition. Thanks to this, the basic dimensional design of the boiler and its efficiency are determined. Calculation of this work focuses mainly on thermal calculations and dimensional design of individual heat transfer surfaces. Basic drawing of the boiler is available in the attachment of the thesis.

The master’s thesis deals with the design of a boiler for RDF combustion, based on the required power output and superheated steam parameters. The first part of the thesis focuses on combustion calculations. Boiler efficiency is also calculated in this chapter, using the heat balance efficiency method. The main part of the thesis consists of dimensional design and heat transfer calculations. The precision of the calculations is checked at the end of the thesis along with the chlorine corrosion, which is considered because of the higher amount of chlorine in the fuel. The thesis comes with a basic schematic of the designed boiler.

The master thesis deals with the replacement of heat exchanger surfaces during simulations in the ANSYS Fluent. The aim of this work is to find a simplified model of the heat exchanger usable for flow simulations in large process and energy units, where it is not possible to model the entire heat exchanger in detail. The calculation procedures are applied to „tube bank” heat exchanger. The master thesis is divided into three parts. First part deals with pressure losses. The "porous zone" approach is used as a replacement for the heat exchanger surface. In the second part, the heat transfer by convection and conduction through the heat exchanger is replaced by the "Heat Exchanger" module. The third part examines the influence of material properties, heat source and fixed temperatures on incident radiation. All calculations resulting from the methods are performed using a script that prepares the output data in format suitable for insertion into ANSYS Fluent. A simplification, which faithfully replaces a fully modeled heat exchanger, has been found in all three parts of the thesis.

The aim of the thesis is a design of a grate steam boiler with capacity of 35 t/h and output steam parameters with temperature 430 °C and pressure 4,1 MPa. The first part of the thesis deals with stoichiometric calculations and boiler efficiency. The theses mainly focuses on the heat transfer calculation and the geometric design of individual heat transfer surfaces. The specifics of fuel are taken into consideration. The drawing of the basic boiler scheme is a part of the thesis.

This thesis deals with a design of a steam boiler combusting natural gas. It consists of stoichiometric calculation, determination of boiler efficiency, thermal calculations and determining geometric parameters of the boiler and its heat transfer surfaces. The results are verified by the heat balance of the boiler.