Overall Cycle Thermal Performance

A range of operating parameters (e g., pressure and temperature) will need to be established early in the design, taking into consideration measurement uncertainty, minimum slider movement, minimum Brayton speed increment, operating bands, slider (or drum) sensitivity, component performance decrement over life, overall cycle thermal efficiency, and transients during normal operations and recoverable casualties. 

The ASME, Performance Test Code on Overall Plant Performance, ASME PTC 46, was designed to determine the performance of the entire heat cycle as an integrated system. This code provides explicit procedures to determination of power plant thermal performance and electrical output. 

Polyurethane. Two polyurethane foams (Stepan Bx 250A, and General Electric Polyurethane) exhibited the best overall performance. The thermal performance of these insulations was initially excellent and degraded very slowly (see Fig. 13a). Both of these insulations survived the entire test series (over 4200 thermal cycles or the equivalent of approximately 15 years of airline service), with no evidence of structural failure. 

The design of a thermal power conversion system will have two subcomponents— the heat removal method from the nuclear core, and the closed Brayton cycle machinery design. The work performed and reported here was focused on achieving a maximal overall cycle thermodynamic efficiency. 

Table 15.2 gives performance data for typical industrial type schemes using thermal power plant in a condensing steam cycle. These do not operate strictly in the simple cycle mode as varying degrees of feed heating are employed. However, overall they convey the basic cycle conditions that the industrial user would encounter and give efficiencies that can be expected. 

Entrained catalyst is removed from the product off-gas by means of cyclones. The catalyst circulates continuously from the reactor to the regenerator and vice versa by means of transfer lines. Coke deposited on the catalyst is burnt off in the regenerator however, because the amount of coke is relatively small, additional fuel must be burnt in the regenerator to satisfy the thermal requirements of the endothermic dehydrogenation reaction. However, while this approach is similar to that in the Houdry process, FED does not have a catalyst reduction step with hydrogen before proceeding to the dehydrogenation cycle lack of this step is believed to be somewhat detrimental to the overall performance of the process. 

The efficiency and overall performance of a given redox catalyst, as will he seen helow, depend on several factors. Kinetically, reaction (60) on the catalyst surface should he very fast to compete with fast thermal hack-electron-transfer reactions. Also the reaction should he c[uantitative as written. Furthermore, the catalyst should he stable and not susceptible to catalyst poisoning over extensive cycles of the reactions such as (60). 

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