This master's thesis deals with the design of stoker-fired boiler for combustion of biomass. The main points of work are stoichiometry calculation of combustion, determining the dew point of flue gas, calculation of losses, which ones serves for determination of boiler efficiency, dimension design and detail calculation of thermosetting surfaces. In the last chapter is numbered total balance and real thermal efficiency of boiler.

The aim of the work is to design a brown coal combustion boiler of 235 t/h output. The work is divided into several parts. First, stechiometric calculations and calculations enthalpy of air and flue gas are performed. It is calculated heat balance of the boiler, the boiler losses and the thermal efficiency of the boiler is determined. After designing the combustion chamber thermal calculation is made. Then, individual heating surfaces are proposed and at the end of the calculations are controlling the overall energy balance of the boiler. For calculation was design documentation added.

The aim of the work is the design of a grate boiler of 200 t . h-1 output, which will burn brown coal or wood chips. The work is divided into several parts. First, stoichiometric calculation and the calculations enthalpy of flue gases and air are performed. After calculating the heat balance and loss of the boiler was counted boiler efficiency. The design of individual heating surfaces is proposed and at the end are controlled the overall heat balance of the boiler. The calculation is supplemented by drawings.

This thesis solves a design of a grate boiler burning wood chips or brown coal with a heat output of 160 MW. Stoichiometry flue gas is calculated according to the specified composition of each fuel. The dimensions of the individual heating surfaces are primarily calculated for burning wood chips and subsequently checked for the combustion of brown coal. Design of the boiler is completed by checking the overall heat output. Boiler design is accompanied by drawing documentation.

The aim of the master’s thesis is thermal calculation and dimensional design of boiler of 235 t/h which burns brown coal. The work is divided into several parts. In the first part, stoichiometric calculation and the calculations enthalpy of flue gases and air are performed. After calculating the heat balance and loss of the boiler, the boiler efficiency is counted. In the next part, thermal calculation of combustion chamber is calculated. Subsequently, design of the individual heating surfaces is proposed. Finally, the overall heat balance of the boiler is inspected. The calculation is supplemented by drawing of the boiler.

This thesis is focused on design of black coal combustion boiler of 160t/h output. It consists of several parts. First, stechiometric calculations and enthalpy of air and gas are made, then heat balance of boiler and the boiler losses are calculated, and also thermal efficiency is determined. In next step, the combustion chamber is designed and its thermal calculation is made. Then, each of heating surfaces are designed, and in the last step overall energy balance of the boiler is checked. The scheme of pressure system and design documentation added.

New emission legislation regarding air pollution control, as instructed by the Department of Environmental Affairs (DEA) to Eskom Generation Power Stations, implies a particulate emission limit of 100 mg/Nm3 for all existing power stations by 2015 and 50 mg/Nm3 for all new and existing power stations by the year 2020. Some of Eskom’s power stations which are equipped with Electrostatic Precipitators (ESP’s) were not designed for this stringent legislation. It is also experienced that ESP’s and coal quality in Eskom have deteriorated over time, resulting in the performance of the ESP’s not meeting the legislative requirements. Eskom is in the process of introducing various ESP enhancement projects to improve performance and aligning the operating philosophy to comply with the more stringent particulate emission legislation. An ESP efficiency test was conducted at Lethabo Power Station to determine the current state of the plant and performance. The results of the test were compared with the original design base specifications to determine the relevant deficiencies which contribute to high emissions and poor ESP performance. It was aimed to develop an ESP simulation model and validate the outputs with the test data. This study endeavours to demonstrate the greater impact on ESP performance when the ESP is operated outside the design specification. It is further aimed to demonstrate that a solution to the problem of high emissions is not only contributed by the variables within the ESP itself. This study is a coal to stack evaluation considering the ESP variables and the upstream conditions of the ESP that form part of the entire process. The intention of this study is to demonstrate the importance of operating an ESP at the designed parameters and highlight the significance of proper maintenance. It was learned that before any ESP enhancement technology can be implemented, the ESP and upstream conditions must be in accordance with design specifications. The implementation of an ESP enhancement technology will have no merit or justification on a unit that is being operated outside of its design specifications. The results obtained from the ESP simulation model correlated well with the ESP efficiency test data. The expectation of the model to assist operators and engineers to operate ESP’s according to the designer’s specifications was conceded. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

New emission legislation regarding air pollution control, as instructed by the Department of Environmental Affairs (DEA) to Eskom Generation Power Stations, implies a particulate emission limit of 100 mg/Nm3 for all existing power stations by 2015 and 50 mg/Nm3 for all new and existing power stations by the year 2020. Some of Eskom’s power stations which are equipped with Electrostatic Precipitators (ESP’s) were not designed for this stringent legislation. It is also experienced that ESP’s and coal quality in Eskom have deteriorated over time, resulting in the performance of the ESP’s not meeting the legislative requirements. Eskom is in the process of introducing various ESP enhancement projects to improve performance and aligning the operating philosophy to comply with the more stringent particulate emission legislation. An ESP efficiency test was conducted at Lethabo Power Station to determine the current state of the plant and performance. The results of the test were compared with the original design base specifications to determine the relevant deficiencies which contribute to high emissions and poor ESP performance. It was aimed to develop an ESP simulation model and validate the outputs with the test data. This study endeavours to demonstrate the greater impact on ESP performance when the ESP is operated outside the design specification. It is further aimed to demonstrate that a solution to the problem of high emissions is not only contributed by the variables within the ESP itself. This study is a coal to stack evaluation considering the ESP variables and the upstream conditions of the ESP that form part of the entire process. The intention of this study is to demonstrate the importance of operating an ESP at the designed parameters and highlight the significance of proper maintenance. It was learned that before any ESP enhancement technology can be implemented, the ESP and upstream conditions must be in accordance with design specifications. The implementation of an ESP enhancement technology will have no merit or justification on a unit that is being operated outside of its design specifications. The results obtained from the ESP simulation model correlated well with the ESP efficiency test data. The expectation of the model to assist operators and engineers to operate ESP’s according to the designer’s specifications was conceded. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

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This diploma thesis deals with the constructional and calculation design of boiler for blast furnace and coke gas mixture combustion, including sizing of the heating surfaces. The opening section is dedicated to a brief characterization of burned fuels. The following chapter shows the parameters and composition of the resulting fuel mixture. The main part of this thesis involves; determining the stoichiometric amount air required for combustion and the resulting flue gas, determining the boiler efficiency and steam production rate, calculations regarding the combustion chamber and the detailed design of the individual heat exchangers. At the end of the thesis the heat balance of the entire boiler is verified. Drawing documentation of boiler is also part of this diploma thesis.