Energy converter, thermal efficiency

Vehicle fuel economy is normally measured in miles per gallon. At any given instant, it depends on the energy content of a gallon of fuel (Qf), the vehicle velocity (V.,) and power required (P,-5q), the thermal efficiency with which the engine converts fuel energy into useful output work (rj,.), and the mechanical efficiency with which the driveline delivers that work to the vehicle wheels (r j). Specifically,... 

A current-carrying wire converts electric energy to thermal energy with an efficiency of nearly 100 per-... 

In comparing the fuels, it is important to take into account the utilization efficiencies at the user end. For utilization by the user, fuels are converted to various energy forms, such as thermal, mechanical, and electrical. Studies show that in almost every instance of utilization, hydrogen can be converted to the desired energy form more efficiently than other fuels [6], Table 5 presents the utilization efficiency factors, defined as the fossil fuel utilization efficiency divided by the hydrogen utilization efficiency, for ... 

The conventional generation of electrical energy from a fuel requires the use of a heat engine which converts thermal energy to mechanical energy. All heat engines operate by the Carnot cycle, and their maximum efficiency is about 40-50% (for the modern gas-fired power stations, the efficiency is about 55%). 

Figure 1.5 describes basic galvanic elements discriminated according to energy density (per mass) and temperature. All those galvanic cells that directly convert chemical into electrical energy, without thermal detours, are hence not bound by Carnot s efficiency, and offer high theoretical efficiencies. The application of solid... 

In part III of Fig. 1.11, the 160 short tons of UgOg consumed per year corresponds to a daily feed rate of 341 kg natural uranium. As this pressurized-water nuclear power plant has a thermal efficiency of 32.5 percent, the fraction of the natural uranium feed converted to energy is... 

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