The off-design performance of a combined cycle gas turbine (CCGT) plant for power generation is of great importance. In this work, a detailed mathematical model is developed for a triple-pressure reheat combined cycle power plant. Using the model, CCGT off-design operation and efficiency are studied under four gas turbine (GT) strategies. Controlling the turbine inlet temperature (TIT) gives be...

A data-driven approach for optimizing the reheat process in a variable-air-volume box is presented. Data-mining algorithms derive temporal predictive models from the reheat process data. The biobjective model formed is solved with a modified particle swarm optimization algorithm. To increase computational efficiency, two levels of non-dominated solutions are introduced while solving the optimiz...

The VAV Reheat Versus Active Chilled Beams & DOAS paper published in the May 2013 issue of the ASHRAE Journal covers an HVAC system design competition for a real office building at UC in Davis, California. The systems under evaluation are Active Chilled Beams with Dedicated Outdoor Air (ACB+DOAS), a Variable Air Volume system with Reheat (VAVR) and a hybrid of VAVR and ACB’s. Energy and cost mo...

Although failure of the seam weld on reheat steam piping has been an infrequent occurrence, such failure is still a major safety concern for fossil plant operations. EPRI has provided guidelines for a piping management program based on periodic inspection. More recently, EPRI has also sponsored research to develop inspection techniques to both improve the quality and reduce the cost of piping i...

Owing to the stringent regulations on pollutant emissions that are imposed by International Maritime Organization and increasing fuel prices, there has been significant research developing cleaner fuels novel propulsion systems. This study presents a techno-economical risk assessment method for evaluating alternative technologies as substitutes heavy oil two-stroke diesel engines in marine tran...

This paper deals with the application of multi-agent system concept for optimization of dynamic uncertain process. These problems are known to have a computationally demanding objective function, which could turn to be infeasible when large problems are considered. Therefore, fast approximations to the objective function are required. This paper employs bundle of intelligent systems algorithms ...

We study the cosmological gravitino production in gauge mediated supersymmetry breaking models, while properly taking into account the existence of the messenger mass scale. It is found that for sizable parameter range of the model the messenger sector contribution leads to more stringent upper bound on the reheat temperature obtained from the condition that the universe should not be overclose...

A Vuilleumier (VM) cycle heat pump is a closed gas cycle driven by heat energy. It has the highest performance among all known heat driven technologies. In this paper, two thermodynamic analyses, including energy and exergy analysis, are carried out to evaluate the application of a VM cycle heat pump for waste heat utilization. For a prototype VM cycle heat pump, equations for theoretical and a...