Cost-effective Power Generation Research Articles

Numerical method for determining the allowable medium temperature during transient operation of a thick-walled boiler element in power plant

Numerical method for determining the allowable medium temperature during transient operation of a thick-walled boiler element in power plant Secure and cost-effective power generation has become very important nowdays. Care must be taken while designing and operating modern steam power plants. There are regulations such as German boiler regulations (Technische Regeln für Dampfkessel 301) or European Standards that guide the user how to operate the steam power plants. However, those regulations are based on the quasi-steady state assumption and one dimensional temperature distribution in the entire element. This simplifications may not guarantee that the heating and cooling operations are conducted in the most efficient way. Thus, it was important to find an improved method that can allow to establish optimum parameters for heating and cooling operations. The optimum parameters should guarantee that the maximum total stresses in the construction element are in the allowable limits and the entire process is conducted in the shortest time. This paper summarizes mathematical descriptions how to optimize shut down process of power block devices. The optimization formulation is based on the assumption that the maximum total stresses in the whole construction element should be kept within allowable limits during cooling operation. Additionally, the operation should be processed in the shortest time possible.

Power Generation Efficiency with Extremely Large Z factor Thermoelectric Material

ABSTRACTA recently developed generic model of a thermoelectric power generation system suggests a promising future for cost effective and scalable power generation. The model is based on co-optimizing the thermoelectric module together with the heat sink. Using this model, efficiency at maximum output power is calculated. It is shown that this approaches the Curzon-Ahlborn limit at very large Z values which is consistent with thermodynamic systems with irreversible heat engines. However, this happens only when the thermal resistances of the thermoelectric device with hot and cold heat sinks exactly match. For asymmetrical thermal resistances, the efficiency at maximum output power is different. This is consistent with the very recent results for the thermodynamic engines. Finally, we study the impact of lowering the thermal conductivity of the thermoelectric material or increasing its power factor and how these affect the performance of the thermoelectric power generation system.

Pilbarite from the Pilbara Goldfields

This paper presents a new multi-objective optimization framework to design a photovoltaic/diesel generator (PV/DG) power generation system for an isolated community in the presence of operating reserve. Operating reserve is the safety margin to ensure the system reliability despite variability in load and PV power supply. For this aim, three objectives, namely, total net present cost (TNPC), CO2 emission and loss of power supply probability (LPSP) have been considered to have a cost-effective, clean and reliable power generation system. In order to solve the optimization problem, multi-objective version of a recently developed meta-heuristic method, crow search algorithm (CSA), has been proposed. To validate the results obtained by multi-objective CSA (MO-CSA), the sizing problem is also solved by multi-objective particle swarm optimization (MOPSO). Simulated results show that by considering operating reserve, the size (correspondingly the cost) of the system increases significantly. Moreover, in comparison with MOPSO, the Pareto front obtained by MO-CSA is well-distributed and widely spread.