Reheat factors

The reheat factor, RF, is a function of the pressure ratio across the machine, the stage efficiency, and the number of stages. The... 

The caveat on reheat factor applied to equation (14.22) applies equally to equation (15.17), and the degree of approximation involved with equations (15.17) and (15.18) will increase as each of the stage pressure ratio and the stage efficiency falls. Nevertheless, this characterization has been found to be useful and accurate enough in practical simulation studies even when the turbine has been operating a long way from design conditions. 

At temperatures above or near the eutectic temperature of the polymer phase, CSEi values are typically in the range of 0.1-2 pFcm-2 [5], However, for stiff CPEs or below this temperature, CSEI can be as low as 0.001 pFcm 2 (Fig. 16). When a CPE is cooled from 100 °C to 50 °C, the CSE1 falls by a factor of 2-3, and on reheating to 100 °C it returns to its previous value. This is an indication of void formation at the Li/CPE interface. As a result, the apparent energy of activation for ionic conduction in the SEI cannot be calculated from Arrhenius plots of 1// sei but rather from Arrhenius plots of 7SE)... 

Feedback on cracking in hot conditions in deposit metals with an austenitic base can also be drawn from the PHENDC experiment. It generally confirms what is known about the influence of elements such as boron in the basic metal (which was the example in the case of the first PHENDC reheaters, removed for other reasons after about approximately 50 000 hours of operation). The same effect applies for welds in a removed metal in which the tendency of ferritic insufficiency has been discovered and defined as a contributing deterioration factor. However, it should be pointed out that cases of cracking under heat conditions are relatively rare and are even more rarely suspected in the development of an in-service defect. 

The efficiency of the Rankine cycle can be improved by returning the steam to the boiler after partial steam expansion in a process referred to as reheat. Reheat cycles add significant complexity to the turbine, the boiler, and the controls but, at large scale, the increased complexity and cost can be justified by the increase in efficiency of a few percent. Other significant factors affecting overall... 

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