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Passive solar gains to buildings in North European Climates can be significant and an investigation is made into the effect of orientation upon solar gains based upon known weather data. The conservatory is a particularly useful collector because of its inclusion to existing houses and its desirability to the householder for reasons other than solar collection. A conservatory was adapted and monitored. A computer model was written. The behaviour of the conservatory was examined for various criteria. The possibility of inclusion of a conservatory into houses in the existing housing stock was examined. The effect of occupancy on heating demand and solar delivery was reviewed and the likely overall energy saving was examined. A new house system was developed including the use of a first floor concrete slab and a gas warm air heating unit. A concrete floor slab was cast to examine its storage potential. A preliminary design for the heating system of the new houses was undertaken.

The main aim of this project is to develop an ESES lab on a full scale system. The solar combisystem used is available most of the time and is only used twice a year to carry out some technical courses. At the moment, there are no other laboratories about combisystems. The experiments were designed in a way to use the system to the most in order to help the students apply the theoretical knowledge in the solar thermal course as well as make them more familiar with solar systems components. The method adopted to reach this aim is to carry out several test sequences on the system, in order to help formulating at the end some educating experiments. A few tests were carried out at the beginning of the project just for the sake of understanding the system and figuring out if any additional measuring equipment is required. The level of these tests sequences was varying from a simple energy draw off or collector loop controller respond tests to more complicated tests, such as the use of the ‘collector’ heater to simulate the solar collector effect on the system. The tests results were compared and verified with the theoretical data wherever relevant. The results of the experiment about the use of the ‘collector’ heater instead of the collector were positively acceptable. Finally, the Lab guide was developed based on the results of these experiments and also the experience gotten while conducting them. The lab work covers the theories related to solar systems in general and combisystems in particular.

This thesis reports an investigation into the design of converters for induction heating systems based upon resonant switch mode power converter techniques. The proposed three phase unity power factor induction heating system consists of two stages of power conversions. The important requirements for each stage of the power conversion of a typical induction heating system working from a three-phase supply are identified. A wide range of power converters which fulfil these requirements are compared and evaluated. From the evaluation, the most applicable converter topologies are selected. Each selected converter class is investigated in great detail to outline their advantages and disadvantages. The first stage consists of a push-pull buck converter connected to a unity power factor rectifier stage. This stage converts the three phase AC mains supply to a required DC value. The second stage, which converters the DC into AC is a single ended resonant inverter system. Analysis of the converters has been made and the design procedure has been formulated. The design procedure allows a strenuous design of each resonant converter for particular converter applications. The final converter design has been simulated using the circuit simulation software packages Design Architect and Accusim to verify the results of analysis. The most important design and construction achievements can be summarised as follows: I A novel push-pull buck quasi-resonant converter with a three-phase rectifier stage has been built and tested. At its maximum operating frequency of 40kHz, the prototype converter delivers an output power of 500W. The converter draws nearly sinusoidal currents from the three-phase mains supply and has an input power factor approaching unity. A secondary stage resonant converter provides AC for the induction heater coil. This AC current flowing in the induction coil creates an alternating electromagnetic field for the workpiece. An induction heating coil has been designed and built by using electrical equivalent coil design method. A novel control strategy was developed to provide output power control. Both converter and inverter stage of the system are operated in the zero-current switching condition. The use of this technique allows higher switching frequencies and provides low switching losses. The full design details are presented along with simulation and practical results. The simulation and practical performance results presented show good correlation with theoretical predictions.

An emerging trend in the building services industry is the installation of passive deaerators on the flow line of domestic wet central heating systems. To date, no data and theoretical models predicting the two-phase flow characteristics in domestic wet central heating systems are available in the open literature. This gap in literature has prevented essential design improvements to passive deaerators thus impeding the efficiency enhancement of such devices. Hence, the current study is aimed at assisting designers of deaeration devices by providing fundamental data and model correlations with respect to the two-phase flow characteristics typical in a wet domestic central heating system. For this purpose an experimental research project was adopted and several studies were carried out, including; (1) a comprehensive review to understand the background of the phenomena, (2) the design and construction of an experimental test rig to conduct the necessary investigations into the phenomenon of two-phase flow in domestic wet central heating systems, (3) the development of a reliable image capture and analysis technique, (4) the completion of a number of experiments to investigate typical bubble sizes, volumetric void fractions, bubble distributions and nucleation and dissolution rates and (5) the correlation of the data gathered as part of the present study with existing bubble size, nucleation and dissolution prediction models. This research has, for the first time, provided an in depth analysis into two-phase flow characteristics in wet domestic central heating systems through the use of a high speed camera and image analysis techniques. The two-phase phenomenon finds its origins in high dissolved gas concentrations present in the water flowing through the closed loop system, thus resulting in super saturation conditions at the primary heat exchange wall conditions. Bubble sizes at the boiler flow line were found to be dependent on the bulk fluid velocity, heat flux and pressure, with a measured mean diameter in the range of 0.13 mm to 0.39 mm. The Winterton (1972a) force balance model for bubble size prediction was in reasonable agreement with the experimental results. This model was further improved through the correlation of our data with the inclusion of dimensionless groups. Bubble nucleation rates have been calculated in the range of 0.3 to 4 bubbles / cm2 s with total system bubble production rates measured in the range of 784 to 6920 bubbles per second. Bubble nucleation rates have been calculated through the consideration of the heat exchanger surface under super saturation conditions. A correlation for the model by Hepworth et al. (2003) for nonclassical heterogeneous nucleation is proposed based on the experimental data gathered during the present study. Experimental results have shown dissolution rates for the bubble size ratio in the range of 0.4 to 12 % per second with system conditions. A modification of the model developed by Epstein and Plesset (1950) for stationary bubble dissolution is proposed with the inclusion of the Sherwood number to capture the effects of turbulent diffusion. The volumetric void fraction distribution in vertical pipes was found to be quasi-homogenous across the pipe section while being strongly dependent on gravitational and turbulence effects in horizontal pipe bubbly flow. A CFD simulation predicted the volumetric void fraction distribution with reasonable accuracy.

Solar heating systems, by the nature of their design and inherent thermal mass, are sensitive to the changes in the prevailing climatic conditions. A computer program has been developed to predict and display the dynamic performance of solar water heating systems and their installation designs under transient climatic and restricted site conditions. A multi-node capacitance model describes the dynamic heat transfer and energy storage processes within the solar collector unit, storage tank and the connecting pipework. This simulation model predicts the dynamic system performance under intermittent solar radiation, system operation and energy usage conditions. Validation studies have been carried out on the computer simulation results against the performance of a purpose-built solar collector test facility and a commercial solar water heating system in actual operation in Aberdeen. A good correlation has been obtained in both cases. The accuracy of the prediction was found to be dependant upon the time interval of the available climatic data and the complexity of the thermal simulation network chosen. The experimental facilities and the computer simulation program have been developed to investigate the effect of integrating the solar collector installation as part of the roof fabric, as a possible technique to improve the system performance in exposed locations. The application of this computer program lies in the development of innovative solar collector system and installation designs to achieve optimum system performance under transient climatic and restricted urban site conditions.

The aims of the thesis are modern methods of control of heating systems. Basic principles of regulations are explained and methods of control of heating sources and exchangers are explored. Heating system of family building is projected with two types of control – equithermal regulation with thermostatic heads and individual room control (IRC). Both variants are simulated in program TRNSYS 16.1. From the results are concluded advantages and disadvantages of examined systems of control.

The diploma thesis is focused on problems connecting of fireplace with water heating systems. The thesis comprises concise description of fireplace and water heating systems. Particular the thesis is concerned with design proposal of heat water exchanger for fireplace. Last part is devoted to experimental measurement of operating parameters and summarize of getting results.

This thesis is focused on the design and implementation of heating controller system of the model house. In terms of design is the emphasis on simplicity, efficiency and scalability. Implemented heating controller system includes a central controller unit and modules that are placed around the model house and can perform several functions - temperature measurement, control actuators or remote parts of the wireless link. This thesis describes the complete development from the initial system design through assembly of all elements of hardware, firmware implementations for each module type and a control program running in the control unit. It also describes the communication between system elements. Suitably chosen solution combines wired and wireless connections, depending on how it is ideal in terms of the model house. The whole system of functional prototypes was tested and the results were summarized in the conclusion.

This thesis processes heating of the apartment house in Rožnov pod Radhoštěm, Vsetín district. Revit program was used for the design of the heating. Some calculations were made in Revit too. Then the correctness of the calculations was checked. The Revit families were made in this thesis. These families support the calculations and design automation. Then these procedures were applied to the apartment house. It is five floors building with 1012 m2 of built area. Thesis solves design of heating and technical room equipment. The technical room is placed in first floor. Heat supply is solved as central heat supply system. The ventilation is mechanical, equal pressure. Thesis is in – cooperation with the house planner and the air – conditioning system design.