The diploma thesis solves a project of air-conditioning with heat recovery in the gym and adjacent dressing rooms. Furthermore, experimental measurement of temperature and relative humidity is carried out in one year in an air-conditioning device with a heat recovery heat exchanger.

This thesis deals with a heat recovery steam generator for gas turbine. According to the given parameters of the flue and steam, thermal balance boiler was design and configuration of the heating surfaces. Furthermore, the parameters calculated in the thermal balance of the individual heat transfer surfaces designed and drawn in the drawing.

The main goal of my thesis is to carry out thermic calculations for adjusted conditions of electric and heat energy consumption. The power of the generator is 330 MW. In the proposal, you can find combustion trubines type GE 9171E. Steam-gas power plant is designed to combust metallurgical gases. Effort of the thesis focuses also on giving a new informations about trends in combinated production of electric and heat energy.

The South African electricity mix is highly dependent on subcritical coal-fired power stations. The average thermal efficiency of these power plants is low. Traditional methods to increase the thermal efficiency of the cycle have been widely studied and implemented. However, utilising the waste heat at the condenser, which accounts for the biggest heat loss in the cycle, presents a large potential to increase the thermal efficiency of the cycle. Several methods can be implemented for the recovery and utilisation of low-grade waste heat. This theoretical study focuses on replacing the traditional condenser in a fossil fuel power station with a boiling condenser (BC), which operates in a similar manner to the core of a boiling water reactor at a nuclear power plant (Sharifpur, 2007). The system was theoretically tested at the Komati Power Station, South Africa's oldest power station. The power station presented an average low-grade waste heat source. The BC cycle was theoretically tested with several working fluids and numerous different configurations. Several of the theoretical configurations indicated increased thermal efficiency of the cycle. The BC cycle configurations were also tested in two theoretical scenarios. Thirty configurations and 103 working fluids were tested in these configurations. The configuration that indicated the highest increase in thermal efficiency was the BC cycle with regeneration (three regenerative heat exchangers) from the BC turbine. A 2.4% increase in thermal efficiency was obtained for the mentioned theoretical implementation of this configuration. The working fluid tested in this configuration was ethanol. This configuration also indicated a 7.6 MW generating capacity. The increased thermal efficiency of the power station presents benefits not only in increasing the available capacity on South Africa's strained grid, but also environmental benefits. The mentioned reduction of 7.6 MW in heat released into the atmosphere also indicated a direct environmental benefit. The increase in thermal efficiency could also reduce CO2 emissions released annually in tons per MW by 5.74%. The high-level economic analysis conducted, based on the theoretically implemented BC cycle with the highest increase in thermal efficiency, resulted in a possible saving of R46 million per annum. This translated to a saving of R19.2 million per annum for each percentage increase in thermal efficiency brought about by the BC cycle. The theoretical implementation of the BC, with regeneration (three regenerative heat exchangers) from the BC turbine and ethanol as a working fluid, not only indicated an increase in thermal efficiency, but also significant economic and environmental benefits. / Dissertation (MEng)--University of Pretoria, 2016. / Mechanical and Aeronautical Engineering / MEng / Unrestricted

During combustion of biomass, particulate matter is emitted, which has severe health impacts on humans. The company ITK Envifront has developed a scrubber technology that cleans the flue gas while also recovering the flue gas energy, increasing the efficiency of the combustion plant. In this thesis, a simulation model was built in MATLAB according to the Finite Element Method. Validation of the model against 3 different facilities showed reasonable accuracy with a tendency to overestimate the scrubber heat recovery and a mean prediction deviation of approximately 7 %. The model was then used to make suggestions for process optimization. An increase of funnel height, and number of spray nozzles could increase the scrubbers heat recovery with up to 7 % and 8 %, respectively. Addition of moisture to the flue gas through evaporation of water droplets had the potential to increase scrubber efficiency with 10 %, and usage of the highest setting of the adjustable nozzle bank showed the potential to increase the efficiency with up to 5 % compared to the mid-setting. Furthermore, the process parameters of a scrubber with optimized running conditions, was compared to a scrubber with the current running conditions, through running of the developed model. The optimized running conditions showed an increase in scrubber efficiency with up to 14 %, resulting in an increase in scrubber heat recovery of approx. 90 kW at a boiler load of 3 MW. As a final conclusion, the developed model shows great potential to be used to as a toolbox to further investigate and optimize the scrubber design and operation. As a future work, it would be interesting to further model its performance regarding particle removal.

The report investigates the feasibility of accessing waste heat at kiln 7 in the Cementa AB cement plant in Slite, Gotland. The background is provided, with a description of the cement manufacturing process. Most of the report concerns itself with the heat transfer capabilities of the plant, therefore a short description of the heat flow within the most essential equipment is provided. The investigation follows a set of steps to derive the conclusion. The first step investigates previous studies to obtain the three most feasible heat sources. The second step investigates the available heat of the selected sources. In the third step, accessing the source is discussed and investigated for both convection and radiation heat transfer methods. It also includes the sizing of the required heat exchangers. Using the new sources, the connection possibilities to existing infrastructure and its benefits are investigated in step four. The connections were made to the existing infrastructure used at kiln 8 for electrical generation and district heating supply. The selections of the most feasible solutions are provided based on heat recovery, payback period and practicality. The final step in the study provides for the final design, which consists of three possible connections or all of them combined. In the conclusion, the final design would provide for a reduction in oil burned, fuel consumption and CO2 emissions and an increase in electricity generated by the existing system. It is recommended that only one of the three connections be installed. / <p>The thesis was conducted at Cementa AB in Slite, Gotland. The supervisor at the plant was Fred Grönwall.</p>

The purpose of the thesis is to determine the potential of lessening the high energy cost in the hospitality industry so that the industry could stay alive after a three decades of civil war in Sri Lanka. The hospitality industry is a significant contributor to the country’s economic growth. Tourism industry has much hope of recovering in the year 2010. Improved tourism would also benefit larger part of Sri Lankan population as they are directly and indirectly employed to serve the tourism industry. Sri Lanka has a high electricity production cost as it depends heavily on the imported fossil fuel. Survival of hospitality industry would depend on the manner in which the energy cost - the second highest overhead in hotels is managed. If the industry survives, Sri Lanka would receive more foreign exchange and thereby improve country’s foreign currency reserve which could contribute to high growth rate. As electricity production is mainly depending on thermal, the volatility of world crude oil prices is directly affecting the country’s electricity prices. However, low dependence on the grid would help the hospitality industry to mitigate the energy cost. As the electricity and diesel costs -the highest and the next - are considerable portions in energy cost in hospitality industry, the study aims to discuss the possible ways of mitigating such costs. Measurements done by the presenters found that the usage of electricity for air conditioning system does constitute most of the electricity consumption for a hotel whilst most of the diesel consumption is for thermal applications. If Air Conditioning (AC) can be operated without electricity and thermal applications could be operated using abundantly available alternative energy sources then the overall energy costs of hospitality industry could be reduced thereby making higher profits. This would ensure industry survives and country gets more foreign exchange.  Study and calculations done by the presenters proved that operating of generators only for electricity production is not viable, due to high fossil fuel cost, however if its high exhaust temperature which is wasted otherwise, could be utilized for operation of absorption chillier then the dependence of grid electricity for air conditioning could be minimized. Further studies also revealed that if water cooled generator is used for such purpose instead of air cooled, and then the hot water requirement of hotel also could be fulfilled, thus mitigating the dependence of fossil fuel which is used otherwise for hot water production. Study also revealed that if thermal energy could be fed with biomass- Sri Lanka being a tropical country is blessed with abundantly available biomass - then the dependency on the fossil fuel for thermal applications could be avoided. This would not only mitigate the second highest energy cost for hotels but also create less carbon foot print, more environmental friendly and produce less noxious exhaust gases thereby creating an advertisement to attract tourists who longing to support green hotels

Thesis: M.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1980 / Includes bibliographical references. / by Joseph A. Halsch. / M.S. / M.S. Massachusetts Institute of Technology, Department of Mechanical Engineering

One of the great challenges facing society is to convert theglobal energy system to a sustainable process. Currently, 80%of the world´s energy is supplied through the combustionof fossil fuels. Not only are the fossil resources limited, theutilisation also increases the level of greenhouse gases in theatmosphere. The convertion to a sustainable energy system isproblematic since the technology needed to exploit mostnon-fossil energy sources is not yet fully developed, e.g.solar energy. Biofuel is an available renewable energy sourcewhich is already widely used in many countries. If an effectiveswitch-over from fossil fuels to biofuels is to be realised,biofuels must be viewed as a limited resource. Consequently, itis important that the handling, upgrading and utilisationprocesses involving biofuels are efficient so that itspotential can be fully exploited. This thesis considers efficient biofuel utilisation andupgrading within the sawmill industry. The goal has been toanalyse not only the technical opportunities for energy savingsin the sawmill industry, but also to analyse the costeffectiveness and environmental impact of studied measures. Theheat demand of the sawmill industry is almost completelycovered by its own by-products; primarily bark, sawdust andwood chips. The increased demand and improved economic value ofwoody biofuels on the market is thus an incentive for thesawmill industry to place more focus on energy issues. Thesawmill industry also has a more or less constant heat loadover the year, which is a beneficial factor for integrationwith district heating networks, biofuel upgrading plants andcombined heat and power plants. The conclusion of the study is that a variety of energyproducts such as heat, unrefined biofuel, pellets andelectricity can be efficiently produced in the sawmill industryand sold for profit to external customers. The payback periodsfor the proposed investments are moderate and both theemissions of volatile organic compounds and global CO2 aredecreased. Should the proposed measures be fully implemented atSwedish sawmills, about 2.8 TWh of biofuel could be savedannually, 0.5 TWh of waste heat could be sold as districtheating and 0.8 TWh of green electricity could be produced.Language: English Keywords:Sawmill industry, energy efficiency, heatrecovery, integration, biofuel, upgrading, district heating,fuel pellets, CHP, VOC, CO2

This thesis was conducted to analyze and investigate improvement methods for the testing process of steam sterilizers at Getinge AB.Getinge is a leading MedTech multinational company based in Sweden. Steam sterilizer is one of their prominent products. A series of testing must be done before handing over the product to the customer, which mainly requires water and steam as consumable resources. The intention of this project is to find improvement methods or optimization techniques for the testing process and reduce the consumption of resources which would significantly impact the production lead time and cost. Upon the careful examination of the testing process it has been noticed that a significant amount of pure water with heat content has been wasted during the testing process, which could be recirculated/ reused, and the heat could be regenerated for useful purposes. The proposed optimization suggestions through this project are a thermally stratified tank which could handle cold and hot water as the testing process needs the supply of both. Majority of the faults during testing are identified in software implementation and a few in mechanical. A dummy testing is recommended to identify the faults in the implementation of the software without the need of consumable resources. A few methods to tackle mechanical faults are discussed further in this report. When implementing these optimization suggestions, it would drastically improve the testing process by reducing the consumption of resources like water, steam, natural gas, time, and labor.