Voltage power plants

PAFC systems are commercially available from the ONSI Corporation as 200-kW stationary power sources operating on natural gas. The stack cross sec tion is 1 m- (10.8 ft"). It is about 2.5 m (8.2 ft) tall and rated for a 40,000-h life. It is cooled with water/steam in a closed loop with secondary heat exchangers. The photograph of a unit is shown in Fig. 27-66. These systems are intended for on-site power and heat generation for hospitals, hotels, and small businesses. Another apphcation, however, is as dispersed 5- to 10-MW power plants in metropolitan areas. Such units would be located at elec tric utihty distribution centers, bypassing the high-voltage transmission system. The market entiy price of the system is 3000/kW. As production volumes increase, the price is projec ted to dechne to 1000 to 1500/kW. 

For example, referring to Example 22.9 and Table 22.6, the safe touch voltage, E, In the power plant area is estimated at 267 V. For this voltage, the leakage current, /, through the two feet when in parallel which is a more severe case. 

After the final designs are complete it is recommended that the actual touch (actual) and step voltage (actual) are rechecked for both power plant and switchyard areas separately, to ensure that they are within the tolerable limits as determined above. After the ground stations have been finally installed the actual step and touch voltages must be measured to verify the designs. 

Suppose 10,000 V, j (e.g., from an electrical power plant generator) is input to a transformer where the number of secondary turns is 75 times more than the number of primary turns. Then the voltage from the secondary will be 75 X 10,000 = 750,000... 

This very high voltage level is actually produced by the secondary of the transformers at a modern commercial electrical power plant the 750,000 is connected to the high voltage transmission lines (thick wire cables) that are used to transport the elec-... 

The steam power plant should become another site for an exciting project enabling a 2-fold reduction in the degree of flue gas cleaning while cutting the electric power consumption by a factor of 2 to 3. The new process that applies pulsed voltage to the precipitation filters has been successfully introduced at several other plants in Ukraine. 

Connection to the utility grid provides many advantages to on-site power producers such as reliability improvement and increase of load factor, as well as giving the electric utilities a chance to improve the supply capability. When a fuel cell power plant is used for electric utility applications, the inverter is the interface equipment between the fuel cell and the electrical network. The inverter acts as the voltage and frequency adjuster to the final load. The interface conditions require the following characteristics for the inverter ... 

IFC has been marketing the PC25, a 200 kW atmospheric PAFC unit, since 1992. Details of this commercial cycle are proprietary and not available for publication. In order to discuss an example PAFC cycle, a pressurized (8 atm) 12 MW system will be presented (50). This cycle is very similar to the 11 MW IFC PAFC cycle that went into operation in 1991 in the Tokyo Electric Power Company system at the Goi Thermal Station, except that two performance enhancements have been incorporated. Limited data are available regarding the Goi power plant. However, it is understood that the average cell voltage is 750 mV and the fuel utilization is 80% (51). The enhanced 12 MW cycle presented here utilizes values of 760 mV and 86%. This enhanced cycle (Figure 9-8) is discussed below with selected gas compositions presented in Table 9-6. 

ETFE is used in electrical applications for heat-resistant insulations and jackets of low voltage power wiring for mass transport systems, for wiring in chemical plants,... 

Combining the essences of previous researchers work, a new alkaline fuel cell that could operate at 200°C was successfully designed in the 1940s [8, 9], The fuel cell provided a current density of 1 A/cm2 at a cell voltage of 0.8 V, a significant jump in progress. Based on this prototype, Bacon in 1952 successfully developed a 5 kW AFC power plant, which resulted in the construction of alkaline fuel cell power plants by Pratt Whitney, who designed and developed the fuel cell system as part of the power supply system for the Apollo aircraft. 

Fig. 9b. A Wheatstone bridge circuit as used in power plants for C02. It operates by balancing the output voltage of two circuits, one in a reference gas concentration, and the other in the gas to be measured.

---