Актуальность данной работы обусловлена тем, что Китай – самая большая развивающаяся страна в мире, и его потребление энергии намного больше, чем в других странах. Энергосбережение и повышение энергоэффективности экономики – это укрепление энергетической и национальной безопасности страны. Повышение энергоэффективности и энергосбережение способствуют снижению потребления природных ресурсов и сокращению вредных выбросов в окружающую среду. Объект исследования – потребление энергетических ресурсов в Китае. Предмет исследования – организационно-экономические отношения в процессе повышения энергоэффективности экономики Китая. Цель диссертационного исследования состоит в анализе современного состояния в сфере энергосбережения в мире и Китае и выработке предложений по повышению уровня энергоэффективности национальной экономики Китая. Научная новизна диссертационного исследования заключается в том, что выявлены особенности изменения структуры потребления энергетических ресурсов в стране в результате реализации энергетической политики Китая; предложено строительство фотоэлектрической солнечной электростанции в провинции Китая и проведена эколого-экономическая оценка инвестиционного проекта с применением показателя LCOE. / The relevance of this work is due to the fact that China is the largest developing country in the world, and its energy consumption is much higher than in other countries. Energy saving and increasing the energy efficiency of the economy is the strengthening of the country's energy and national security. Improving energy efficiency and saving energy helps to reduce the consumption of natural resources and reduce harmful emissions into the environment. The object of research is the consumption of energy resources in China. The subject of the research is organizational and economic relations in the process of increasing the energy efficiency of the Chinese economy. The purpose of the dissertation research is to analyze the current state of energy conservation in the world and China and to develop proposals to improve the energy efficiency of the national economy of China. The scientific novelty of the dissertation research is that the features of the change in the structure of consumption of energy resources in the country as a result of the implementation of China's energy policy are revealed; proposed the construction of a photovoltaic solar power plant in the province of China and carried out an environmental and economic assessment of the investment project using the LCOE indicator.

This degree project studies the integration of carbon capture system into biomass fired combined heat and power (bio-CHP) plants. The key disturbances from bio-CHP plants include flue gas flow rate, carbon dioxide (CO2) concentration and available heat for the reboiler because the use of versatile biomass and the dynamic operation of CHP plants results in large fluctuations in the properties of flue gas and the heat input for CO2 capture. To clearly understand the impacts of these disturbances on the performance of CO2 capture, a dynamic CO2 capture model is developed in Aspen Plus Dynamics by using monoethanolamine (MEA) based chemical absorption. Proportional-Integral (PI) feedback controllers are then implemented to further study and compare the performance of the CO2 capture process under different control strategies, the performance with general control settings and fine-tuned controllers are obtained and compared, including both the control performance and system performance. The control performance includes the maximum deviation and settling time, which could reflect only the performance of the controllers.  The system performance includes Captured CO2, reboiler duty and Energy penalty per unit CO2 captured, which could reflect CO2 capture system performance. An equilibrium stage steady state model is first developed for the key components in the CO2 capture plant in Aspen Plus, consisting of the absorber, the stripper, and lean-rich heat exchanger. By sizing the components and employing the pressure driven mode, the steady state model is enabled to be a dynamic model. The disturbances about flue gas and reboiler heat are taken from a real bio-CHP plant in Sweden. Considering the higher flue gas flowrate, the model has been scaled up to meet the requirement of this bio-CHP plant. The addition of controllers are done for the flexible operation of the CO2 capture system and the controlled variables considered in this study are the percentage of CO2 absorbed in the absorber column, reboiler temperature and rich solvent flow in the stripper column. The results show the effects of fluctuations in the key influencing factors on the control performance and the system performance . The fine-tuned controller implemented system showcases better performance when the quantity of CO2 captured is compared with that of the system in the absence of controllers, where a 1.1% increase in the amount of captured CO2 is observed when the flue gas flow rate is increased by 30%. The system also maintains a 1.8% higher capture rate when controllers are implemented. This showcases better system performance when controllers are implemented in the system. To further analyse the effects of control strategies two different control strategies are compared where controllers with general settings are compared to the controllers which are fine-tuning achieved by implementing tuning parameters which were obtained through Internal Model control (IMC) based on the system requirements. The fine tuning of the controllers results in improved system performance where the amount of captured CO2 increases by 1.4% when the reboiler duty is increased by 30% and a 1.7% decrease in the energy penalty per unit CO2 captured. Additionally, the results show that the settling time and maximum deviation are different for the two controllers where the controller which underwent fine tuning maintained the steady set point whereas the controller with general controller tuning showcases deviation before it attained stability. Therefore, the fine-tuned controller is more efficient to enable the flexible operation of CO2 capture when facing disturbance. It is studied that the tuning parameters implemented in the controllers affect the transient operation of the plant and improved the dynamic performance of the capture system. The tuned controllers offered more stability to the capture system while attaining their respective set points in a shorter time frame. It is also found that there exists a big difference between the system’s performance without controllers and that with finely tuned controllers. The difference in captured CO2 amount is approximately 26 ton/h when flue gas flow rate increases by 30%. The percentage difference is 1.1%, 7.7% and  5.9% for Captured CO2, reboiler duty and Energy penalty per unit CO2 captured respectively. In conclusion the control of the transient operation of the CO2 capture system needs the control system implemented and requires fine tuning parameters to achieve the desirable performance.

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The steel manufacturing industry is one of the largest emitters of CO2, accounting for upwards of 8.8% of all anthropogenic CO2 emissions. The governments are charging taxes on CO2 emissions, which incentivize the industry to further reduce CO2 emissions. At present, much of the CO2, produced in the steel manufacturing process occurs as a result of coke oven and blast furnace gas by-products. As such, two major strategies have been proposed to reduce steel-manufacturing-related CO2 emissions: producing more electricity via optimized combined cycle power plants (CCPP), and converting off-gas by-products into methanol (CBMeOH). The present research consists of an economic and environmental analysis of the status quo, CCPP, and CBMeOH systems for five locations: Ontario, the USA, Finland, Mexico, and China. The economic analysis considered factors such as carbon tax, electricity price, methanol price, electricity carbon intensity, power purchasing parity, and income tax. In the CCPP process, desulphurization is conducted using ProMax with MDEA as the solvent, while the CBMeOH process uses a membrane to separate the bulk H2S, with organic sulfurs such as thiophene being removed via CO2+steam reforming and middle-temperature removal. The results of the economic analysis revealed the CBMeOH plant to be the most profitable in Ontario, the USA, China, and Mexico, while the CCPP system was shown to be the most profitable in Finland. The environmental analysis was conducted using the TRACI, CML-IA, ReCiPe2016, and IMPACT2002+ tools in SimaPro V9, with the results showing the CBMeOH system to be the most environmentally option in Ontario, Finland, and China, and the CCPP system as the most environmentally friendly option in the USA and Mexico. / Dissertation / Doctor of Philosophy (PhD)

An approach to hybrid cooling technique is proposed using air jets which impinge on a triangular grooved surface with dry grooves and grooves containing water. One major application is for condensers of thermoelectric power plants. The heat and mass transfer analogy were successfully used to evaluate the simultaneous heat and mass transfer. Results showed that hybrid jet impingement produced high heat flux levels at low jet velocities and flow rates. Experimental results were used to characterize the resulting heat transfer under different conditions such as flow open area percentage, array orifices diameter and array to surface stand-off distance. The results have shown that jet impingement is capable of delivering high transfer rates with lower cooling cost rates compared to current industry conventional techniques. Water is efficiently used in hybrid jet impingement because evaporative energy is absorbed directly from the surface instead of cooling air to near wet-bulb temperature. / Master of Science / Array jet impingement cooling experiments were conducted on a triangular grooved surface with the surface at a constant temperature. Results showed that jet impingement can provide high transfer rates with lower rates of cooling cost in comparison to contemporary conventional techniques in the industry. Experiments on the triangular grooved surfaces were performed at dry and wet surface conditions. Under the dry conditions, the objective is to characterize the resulting heat transfer under varying operational conditions such as jet speed, array orifice diameter, array to surface stand-off distance, and flow open area percentage. Results from the triangular surface when dry showed less improvement in heat transfer than the rectangular grooved surface. A hybrid cooling technique approach was proposed and developed by using air jets impinging on a triangular grooved surface with the grooves containing water. The approach is being suggested and experimentally tested for its viability as an alternative to thermoelectric power plant cooling towers. Convection heat and mass transfer coefficients were experimentally measured for different wet coverage of the surface. Results showed that the hybrid jet impingement produced high heat flux levels at low jet velocities and flow rates. The highest heat transfer was consistently found with a 50% coverage of the surface. Hybrid jet impingement showed an improvement up to 500% in heat transfer as compared to jet impingement on a dry grooved surface.

This study explored the feasibility of integrating pellet production to the combined heat and power plant Bristaverket, owned by the energy company Stockholm Exergi, with the aim of achieving a more energy and resource efficient process. The study was divided into three parts: development of a technical process, evaluation of techno-economic performance, and examination of organizational learning opportunities. A limitation of the study was to only consider the process at Bristaverket. The technical process was developed following a general modeling design process, utilizing MATLAB as software. Economic performance was assessed through investment and sensitivity analysis. Organizational learning opportunities were identified through interviews and thematic analysis using the 4I-framework. The proposed technical process involved transferring heat from Bristaverket to a 4 MW water-heated belt dryer. The annual pellet production amounted to 50.4 kilotons with 85% plant operation, and the specific energy consumption was 717 kWh/tpellet. The pellets achieved the classification I3 for industrial use and the specific production cost was 2,218 SEK/tpellet. The investment analysis was executed for three scenarios: a future scenario, a 2020 scenario and a 2023 scenario. The future scenario yielded a net present value (NPV) of 270 MSEK, an investment return rate (IRR) of 74%, and a payback time (PBT) of 1.4 years. For the 2020 scenario and 2023 scenario, the NPV was -1 MSEK and 88 MSEK, the IRR was 8% and 32%, and the PBT was 9.5 years and 3.3 years respectively. The investment was sensitive to changes in operational costs, foremost changes in pellet and wood chip prices. The study's techno-economic findings could contribute to organizational learning at Stockholm Exergi during meetings, through questions, at the final presentation, and through conversations between colleagues. Suggestions for enhancing organizational learning included establishing routines for knowledge sharing and discussions during and after thesis projects. / Denna studie utforskade möjligheten att integrera pelletsproduktion vid kraftvärmeverket Bristaverket, som ägs av energiföretaget Stockholm Exergi, med syfte att uppnå en mer energi- och resurseffektiv process. Studien delades in i tre delar: utveckling av en teknisk process, utvärdering av teknoekonomiskt resultat och undersökning av möjligheter till organisatoriskt lärande. En avgränsning som gjordes i studien var att bara undersöka processen i Bristaverket. Den tekniska processen utvecklades genom att följa en allmän modelleringsdesignprocess med MATLAB som programvara. Det ekonomiska resultatet utvärderades genom investerings- och känslighetsanalys. Möjligheter till organisatoriskt lärande identifierades genom intervjuer och tematisk analys med hjälp av 4Iramverket. Den föreslagna tekniska processen innebar överföring av värme från Bristaverket till en 4 MW vattenuppvärmd bandtork. Den årliga pelletsproduktionen uppgick till 50,4 kiloton med 85% drifttid och den specifika energiförbrukning var 717 kWh/tpellet. Pelletsen klassificerades som I3 för industriellt bruk och den specifika produktionskostnaden var 2 218 SEK/tpellet. Investeringsanalysen gjordes för tre scenarios: ett framtidsscenario, ett 2020-scenario och ett 2023-scenario. Framtidsscenariot gav ett nettonuvärde på 270 MSEK, en internränta på 74 % och en återbetalningstid på 1,4 år. För 2020- och 2023-scenariot var nettonuvärdet -1 respektive 88 MSEK, internräntan 8 respektive 32 % och återbetalningstiden 9,5 respektive 3,3 år. Investeringen var känslig mot förändringar i driftkostnader, framför allt i form av pellets- och flispriser. Studiens teknoekonomiska resultat skulle kunna bidra till organisatoriskt lärande på Stockholm Exergi genom möten, frågor, vid slutpresentationen och genom samtal mellan kollegor. Förslag för att förbättra möjligheterna till organisatoriskt lärande inkluderade att etablera rutiner för kunskapsdelning och diskussioner under och efter examensprojekt.

[ES] La mejora de la eficiencia de las centrales térmicas mediante el aumento de la temperatura y la presión de trabajo permite reducir el consumo de combustibles fósiles y las emisiones de CO2 , pero requiere el desarrollo de nuevos materiales capaces de soportar estas condiciones más extremas. En el presente trabajo se han estudiado nuevos aceros que podrían ser utilizados para la fabricación de componentes en centrales térmicas de alta eficiencia y baja emisión de CO2 . Se han clasificado en dos grupos, Grupo I: Aceros con 14 % Cr diseñados para aplicaciones hasta 650 ºC y Grupo II: Aceros con 2,25% Cr diseñados para aplicaciones hasta 600 ºC. Las distintas aleaciones fueron obtenidas por colada y laminadas a 900 ºC. Posteriormente se sometieron a un tratamiento térmico de solubilización y revenido para la obtención de una microestructura de martensita revenida reforzada con partículas de segunda fase, finas y homogéneamente distribuidas. La caracterización mecánica se realizó entre 540 y 650 ºC mediante ensayos de compresión con cambios en la velocidad de deformación y ensayos de fluencia. Para la identificación de las fases presentes y el análisis de los cambios microestructurales que se producen durante el tiempo de permanencia a alta temperatura, las aleaciones fueron estudiadas tanto antes como después de los ensayos mecánicos, mediante difracción de rayos X, dureza Vickers, microscopía óptica y electrónica de barrido y transmisión (SEM y TEM) y difracción de electrones retrodispersados (EBSD). Se detectó un cambio de comportamiento entre las regiones de alta y baja tensión y una pérdida de resistencia asociada a la degradación microestructural sufrida durante el tiempo de permanencia a elevada temperatura. A pesar de esto, algunas aleaciones alcanzan tensiones de rotura cercanas a los 100 MPa a 100.000 horas, debido a la gran interacción existente entre las dislocaciones y las partículas de refuerzo. / Benavente Martínez, E. (2014). Estudio de la microestructura y las propiedades mecánicas de nuevos aceros diseñados para aplicaciones en centrales térmicas de alta eficiencia y baja emisión de CO2 [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39349

Dedicated sensors are widely used throughout many industries to monitor everyday operations, maintain safety, and report performance characteristics. In order to adopt a more sustainable solution, much research is being applied to self-powered sensing, implementing solutions which harvest wasted ambient energy sources to power these dedicated sensors. The adoption of not only wireless sensor nodes, but also self-powered capabilities in the nuclear energy process is critical as it can address issues in the overall safety and longevity of nuclear power. The removal of wires for data and power transmission can greatly reduce the cost of both installation and upkeep of power plants, while self-powered capabilities can further reduce effort and money spent in replacing batteries, and importantly may enable sensors to work even in losses to power across the plant, increasing plant safety. This thesis outlines three harvesting opportunities in the nuclear energy process from: thermal, vibration, and radiation sources in the main structure of the power plant, and from thermal and radiation energy from spent fuel in dry cask storage. Thermal energy harvesters for the primary and secondary coolant loops are outlined, and experimental analysis done on their longevity in high-radiation environments is discussed. A vibrational energy harvester for large rotating plant machine vibration is designed, prototyped, and tested, and a model is produced to describe its motion and energy output. Finally, an introduction to the design of a gamma radiation and thermal energy harvester for spent nuclear fuel canisters is discussed, and further research steps are suggested. / Master of Science / In this work multiple energy harvesters are investigated aimed at collecting wasted ambient energy to locally power sensor nodes in nuclear power plants, and in spent nuclear fuel canisters. Locally self-powered, wireless sensors can increase safety and reliability throughout the nuclear process. To address this a thermal energy harvester is tested in a radiation rich environment, and its performance before and after irradiation is analyzed. A vibrational energy harvester designed for use on large rotating machinery is discussed, manufactured, and tested, and a mathematical model describing it is produced. Finally, an introduction to harvesting radiation and heat given off from spent nuclear fuel in dry cask canister storage is investigated. Power capabilities for each design are considered, and the impact of such energy harvesting for wireless sensor nodes on the longevity, safety, and reliability of nuclear power plants is discussed.