As a result of their unique heat recovery properties,Humidified Gas Turbine (HGT) cycles have the potential todeliver resource-effective energy to society. The EvaporativeGas Turbine (EvGT) Consortium in Sweden has been studying thesetypes of cycles for nearly a decade, but now stands at acrossroads, with commercial demonstration remaining. Thisthesis binds together several key elements for the developmentof humidified gas turbines: water recovery and air and waterquality in the cycle, cycle selection for near-term, mid-sizedpower generation, and identifying a feasible niche market fordemonstration and market penetration. Moreover, possiblesocio-technical hinders for humidified gas turbine developmentare examined. Through modelling saltcontaminant flows in the cycle andverifying the results in the pilot plant, it was found thathumidification tower operation need not endanger the hot gaspath. Moreover, sufficient condensate can be condensed to meetfeed water demands. Air filters were found to be essential tolower the base level of contaminant in the cycle. This protectsboth the air and water stream components. By capturing airparticles of a similar size to the air filters, the humidifieractually lowers air stream salt levels. Measures to minimisedroplet entrainment were successful (50 mg droplets/kg air) andmodels predict a 1% blow down from the water circuit issufficient. The condensate is very clean, with less than 1 mg/lalkali salts and easily deionised. Based on a core engine parameter analysis for three HGTcycle configurations and a subsequent economic study, asteam-cooled steam injected cycle complemented with part-flowhumidification is recommended for the mid-size power market.This cycle was found to be particularly efficient at highpressures and turbine inlet temperatures, conditions eased bysteam cooling and even intercooling. The recommended HGT cyclegives specific investment costs 30- 35% lower than the combinedcycles and cost of electricity levels were 10-18% lower.Full-flow intercooled EvGT cycles give high performances, butseem to be penalised by the recuperator costs, while stillbeing cheaper than the CC. District heating is suggested as asuitable niche market to commercially demonstrate the HGTcycle. Here, the advantages of HGT are especially pronounceddue their very high total efficiencies. Feasibility prices forelectricity were up to 35% lower than competing combinedcycles. HGT cycles were also found to effectively include wasteheat sources. <b>Keywords:</b>gas turbines, evaporative gas turbines,humidification, power generation, combined heat and powergeneration.

<p>As a result of their unique heat recovery properties,Humidified Gas Turbine (HGT) cycles have the potential todeliver resource-effective energy to society. The EvaporativeGas Turbine (EvGT) Consortium in Sweden has been studying thesetypes of cycles for nearly a decade, but now stands at acrossroads, with commercial demonstration remaining. Thisthesis binds together several key elements for the developmentof humidified gas turbines: water recovery and air and waterquality in the cycle, cycle selection for near-term, mid-sizedpower generation, and identifying a feasible niche market fordemonstration and market penetration. Moreover, possiblesocio-technical hinders for humidified gas turbine developmentare examined.</p><p>Through modelling saltcontaminant flows in the cycle andverifying the results in the pilot plant, it was found thathumidification tower operation need not endanger the hot gaspath. Moreover, sufficient condensate can be condensed to meetfeed water demands. Air filters were found to be essential tolower the base level of contaminant in the cycle. This protectsboth the air and water stream components. By capturing airparticles of a similar size to the air filters, the humidifieractually lowers air stream salt levels. Measures to minimisedroplet entrainment were successful (50 mg droplets/kg air) andmodels predict a 1% blow down from the water circuit issufficient. The condensate is very clean, with less than 1 mg/lalkali salts and easily deionised.</p><p>Based on a core engine parameter analysis for three HGTcycle configurations and a subsequent economic study, asteam-cooled steam injected cycle complemented with part-flowhumidification is recommended for the mid-size power market.This cycle was found to be particularly efficient at highpressures and turbine inlet temperatures, conditions eased bysteam cooling and even intercooling. The recommended HGT cyclegives specific investment costs 30- 35% lower than the combinedcycles and cost of electricity levels were 10-18% lower.Full-flow intercooled EvGT cycles give high performances, butseem to be penalised by the recuperator costs, while stillbeing cheaper than the CC. District heating is suggested as asuitable niche market to commercially demonstrate the HGTcycle. Here, the advantages of HGT are especially pronounceddue their very high total efficiencies. Feasibility prices forelectricity were up to 35% lower than competing combinedcycles. HGT cycles were also found to effectively include wasteheat sources.</p><p><b>Keywords:</b>gas turbines, evaporative gas turbines,humidification, power generation, combined heat and powergeneration.</p>

Energy efficiency and renewable energy become more attractive in smart grid. In order to efficiently reduce global energy usage in building energy systems and to improve local environmental sustainability, it is essential to optimize the operation and the performance of combined heat and power (CHP) systems. In addition, intermittent renewable energy and imprecisely predicted customer loads have introduced great challenges in energy-efficient buildings' optimal operation. In the deterministic optimal operation, we study the modeling of components in energy-efficient building systems, including the power grid interface, CHP and boiler units, energy storage devices, and building appliances. The mixed energy resources are applied to collaboratively supply both electric and thermal loads. The results show that CHP can effectively improve overall energy efficiency by coordinating electric and thermal power supplies. Through the coordinated operation of all power sources, the daily operation cost of building energy system for generating energy can be significantly reduced. In order to address the risk from energy consumption forecast errors and renewable energy production volatility, we utilize the approach of stochastic programming and robust optimizations to operate energy-efficient building systems under uncertainty. The multi-stage stochastic programming model is introduced so that the reliable operation of building energy systems would be probabilistically guaranteed with stochastic decisions. The simulation results show that the stochastic operation of building energy systems is a promising strategy to account for the impact of the uncertainty on power dispatch decisions of energy-efficient building systems. In order to provide absolute guarantee for the reliable operation of building energy systems, a robust energy supply to electric and thermal loads is studied by exploring the effectiveness of energy storage on energy supply against the uncertainty. The robustness can be adjusted to control the conservativeness of the proposed robust operation model. For the purpose of achieving adaptability in the robust optimal operation and attaining robustness in the stochastic optimal operation of building energy systems, we also develop an innovative robust stochastic optimization (RSO) model. The proposed RSO model not only overcomes the conservativeness in the robust operation model, but also circumvents the curse of dimensionality in the stochastic operation model.

The main objective of this study is to develop a methodology which can be used to assess the economic potential for combined heat and power (CHP) systems to be employed in an effort to offset a portion or all of the conventionally supplied power and thermal energy at industrial manufacturing facilities. A methodology is developed which determines the economic considerations of proposed industrial CHP projects once the system configuration is specified. This methodology is then applied to a number of different industrial facilities in a parametric analysis in order to demonstrate how it can be used to assess the potential for success for CHP at industrial sites for a wide range of manufacturing processes. Many of the methodology inputs, such as facility operational hours, facility thermal load, etc. are then varied in order to determine how they affect the economic considerations of the corresponding project. Conclusions are subsequently made as to how each of these parameters can be indicative of project success before employing the methodology. This study focuses on industrial sites in the Southeast U.S., which historically have relatively low utility usage rates. The Southeast U.S. also lacks adequate policy applicable to CHP systems, such as net metering and interconnection standards rules, when compared to the rest of the country. It is for this reason that the methodology developed in this research assumes that a base load CHP system is the most economically viable CHP option and the current status of policy applicable to CHP at industrial facilities located in the Southeast U.S. is also investigated. The results of the parametric analysis are modified to determine if improved economics can be attained if the associated facilities engage in net metering programs. As a result, suggested net metering rates that can positively affect the economic considerations of industrial CHP projects in the Southeast U.S. are realized. Finally, a simple tool based on the methodology presented in this research was developed and can be used to calculate the project economics of an industrial facility CHP system.

The amount of available biomass feedstock and associated cost components were analyzed to determine the potential increase in energy capacity of two existing combined heat and power plants in Mississippi. The amount of corn stover and forest logging residue within a 10-mile radius can satisfy the existing requirements of CHP plants in Scott (1 MW) and Washington counties (5 MW). Transporting feedstock within a smaller source area had lower transportation costs, but higher total unit cost than the two other source buffer scenarios. However, capital costs associated with higher plant capacities were significantly higher and plant expansion may not be economically advantageous. Increasing the CHP capacity from 1 MW to 2 MW in Scott county and 5 MW to 10 MW in Washington county might be a sustainable approach by drawing feedstock from a smaller area and at lower utilization rates, while keeping transportation costs low.

No description available.

Aus der Einleitung: "Durch die Verwendung von Kraft-Wärme-Kopplung (KWK) kann sowohl die erzeugte elektrische als auch die anfallende thermische Energie genutzt und somit der Nutzungsgrad der eingesetzten Primärenergie deutlich gesteigert werden. Dieses Konzept wird sowohl in Blockheizkraftwerken (BHKW) wie auch in Range Extendern (RE) verwendet (Ferrari et al. 2012). Die bisher geringe Reichweite von Elektrofahrzeugen wird durch die zusätzlich vom RE bereitgestellte elektrische Energie erweitert. ..."

Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2008.

Selecting a suitable power source, during the design process, for a stand-alone soya business unit is challenging and complex. Especially with the aim of optimizing electrical and thermal energy, as well as minimizing the life cycle cost. During the design and development of a soya business unit it was realized that a design tool is needed to assist with the decision making process when selecting a power source. Waste heat can be recovered from either or both the exhaust gas and cooling system of the power source and can be utilized in the soya process. Research of available literature revealed no design tool to assist with the decision making process of the stand-alone business unit and consequently lead to this study. This dissertation presents different possible power sources that could be utilized in supplying energy to the business unit, as well as design tools available. Advantages and disadvantages of the different power sources are discussed. The shortfalls of a number of the available design tools are also discussed. A diesel generator set was selected as the preferred power source for the business unit. Criteria for this selection included the price per kWhe generated, the ease of maintenance, the availability of the diesel generators in rural areas and the availability of diesel as a fuel. The diesel engine was characterized through experimental work for a more in depth understanding of the energy profile of the engine at part load conditions. These results were used as guidelines in the development of the design tool. The design tool was developed with the aim of being user friendly and versatile. The time intervals of the required load of the business unit are flexible. Different types of power sources and fuels can be used within the design tool. User defined heat exchangers are utilized to calculate the possible heat recovery from the power source. The design tool matches the available energy of different power sources at part load conditions with the required load profile of the soya business unit. It then eliminates power sources that would not be able to deliver the minimum required energy. The running cost is calculated for each of the remaining power sources and the power source with the minimum annualized cost, which includes capital cost, maintenance cost and fuel cost, is suggested. The design tool was verified against a base load condition of the soya business unit and the suggested power source showed a saving of 31,4% in electrical energy, an increased overall efficiency of 24,9% and a saving in annualized cost of 27,3%. The design tool can be used to optimize specific components and design options within a combined heat and power system. Sensitivity analysis can be performed with the design tool to determine various influences on the designed system. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2008.

Selecting a suitable power source, during the design process, for a stand-alone soya business unit is challenging and complex. Especially with the aim of optimizing electrical and thermal energy, as well as minimizing the life cycle cost. During the design and development of a soya business unit it was realized that a design tool is needed to assist with the decision making process when selecting a power source. Waste heat can be recovered from either or both the exhaust gas and cooling system of the power source and can be utilized in the soya process. Research of available literature revealed no design tool to assist with the decision making process of the stand-alone business unit and consequently lead to this study. This dissertation presents different possible power sources that could be utilized in supplying energy to the business unit, as well as design tools available. Advantages and disadvantages of the different power sources are discussed. The shortfalls of a number of the available design tools are also discussed. A diesel generator set was selected as the preferred power source for the business unit. Criteria for this selection included the price per kWhe generated, the ease of maintenance, the availability of the diesel generators in rural areas and the availability of diesel as a fuel. The diesel engine was characterized through experimental work for a more in depth understanding of the energy profile of the engine at part load conditions. These results were used as guidelines in the development of the design tool. The design tool was developed with the aim of being user friendly and versatile. The time intervals of the required load of the business unit are flexible. Different types of power sources and fuels can be used within the design tool. User defined heat exchangers are utilized to calculate the possible heat recovery from the power source. The design tool matches the available energy of different power sources at part load conditions with the required load profile of the soya business unit. It then eliminates power sources that would not be able to deliver the minimum required energy. The running cost is calculated for each of the remaining power sources and the power source with the minimum annualized cost, which includes capital cost, maintenance cost and fuel cost, is suggested. The design tool was verified against a base load condition of the soya business unit and the suggested power source showed a saving of 31,4% in electrical energy, an increased overall efficiency of 24,9% and a saving in annualized cost of 27,3%. The design tool can be used to optimize specific components and design options within a combined heat and power system. Sensitivity analysis can be performed with the design tool to determine various influences on the designed system. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2008.