Fuel Flow-Through System

FIGURE 16.5 Dependence of specific conductance on ionic strength of potassium phosphate buffer, pH 7. 

Individual fuel lines to each ceU of the stack (parallel fuel lines) might avoid some of those problems, but fuel must be ionicaUy insulated for each cell in both the fuel source tank/reservoir and the waste container. Moreover, such parallel fuel lines are impractical and difficult to integrate in the stack hardware (e.g., bipolar plates) in this case, the design of the entire stack assembly becomes much more complicated. External tubing connections to each cell are not a good design solution, and parallel fuel supply lines make the system complicated, heavier, and bulkier. 

3 Fuel Flow-Through Operation and Fuel Waste Management 

The fuel flow-through system should be activated only in the event of EEC power generation, or in regular intervals to refresh the fuel in the system and potentially perform self-system checks such as ceU voltage at the pump electric loading. 

As discussed, the fuel composition might define the fuel waste management. Eor instance, if hazardous diffusive mediators are suppUed with the fuel, then the waste 

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Quotes from two vendors were obtained on a venturi scrubber and cyclone combination, similar to that shown in Figure 1, to be used for deeming a pressurized gas stream. The information from the quotes is contained in Table I. From the information presented it is not immediately clear which equipment would be the better choice. A superficial look at the table might lead to the conclusion that Unit A is preferable Its initial cost is less and the operating costs associated with pump power will be less. After further observation, however, it is realized that there is an operating cost associated with the pressure drop of the gas flowing through system A "fuel" must be supplied somewhere in the system in order to compensate for this. Should other matters be... 

There are two viable jproaches to inducing fuel flow through an EFC. One is to integrate an extremely low power eonsumption pump. The eonsumed power for pumping must be signifieantly low with respect to the total generated power by the entire EFC system. The other is to use apassive pumping system that does not eonsume eleetric power. 

The key components in the fuel vapor control system include the fuel tank, vapor vent valves, vapor control valve, vapor tubing, the activated carbon canister, and the engine vapor management valve (VMV) [25,26], During normal vehicle operation, fuel tank vapor pressure is relieved through the use of vapor vent valves installed in the vapor dome of the fuel tank. The vent valves are designed to allow for the flow of fuel vapor from the tank, and to assure that liquid fuel does not pass through the valve. 

From a practical standpoint, coal, because of its abundance, has received the most attention as a source for synthetic fuels. As early as 1807, a coal-gas system was used to light the streets of London, and until the 1930s, when less expensive and safer natural gas started to flow through newly constructed pipelines, gas piped to homes in the Eastern United States was derived from coal. Kerosene, originally a byproduct from the coking of coal tor metallurgical applications, can be considered the first synthetic lic -uid fuel made in quantity. But once crude oil became cheap and abundant, there was little serious research on synthetic liquid fuels in the industrial world until the Energy Crisis of 1973. The main exceptions to... 

Binary liquid metal systems were used in liquid-metal magnetohydrodynamic generators and liquid-metal fuel cell systems for which boiling heat transfer characteristics were required. Mori et al. (1970) studied a binary liquid metal of mercury and the eutectic alloy of bismuth and lead flowing through a vertical, alloy steel tube of 2.54-cm (1-in) O.D., which was heated by radiation in an electric furnace. In their experiments, both axial and radial temperature distributions were measured, and the liquid temperature continued to increase when boiling occurred. A radial temperature gradient also existed even away from the thin layer next to the... 

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