Power plant, auxiliaries costs

Multiple-step variable-speed fan control, type d. is best applied with steam-turbine drives. In aplant with ac auxiliary motor drives, slip-ring motors with damper integration must be used between steps, making the installation expensive. Although dc motor drives would be less costly, few power plants other than marine propulsion plants have direct current available. And since marine units normally operate at full load 90 percent or more of the time, part-load operating economics are unimportant. If steam-turbine drive will be used for the fans, plot the power-input curve LMD, using data from the fan manufacturer. 

As of the mid-1990s, many older conventional steam plants have been converted to combined cycle. The old boiler is removed and replaced by a combustion turbine and heat recovery steam generator. Although the cycle efficiency is not as high as completely new plants, substantial capital cost is avoided by the modification and reuse of existing steam turbine and auxiliary equipment. In many combined cycle power plants, steam is injected into the combustors of the combustion turbine to lower peak flame temperatures and consequendy lower NO. ... 

A detailed cost analysis for a polymer electrolyte membrane fuel cell power plant of 5 kW was provided in 2006 by Kamarudin et al. According to their data, the total cost of such a plant will be about 1200 of which 500 is for the actual fuel-cell stack and 700 for the auxiliary equipment (pumps, heat exchangers, etc.). The cost of the fuel-cell stack is derived from the components as 55 /kW for the membranes, 52 /kW for the platinum, 128 /kW for the electrodes, and 148 /kW for the bipolar plates. 

As to the cost of the power plant, the final goal would be 50/kW, or about 5000 for one electric car. The cost of the power plant depends not only on the cost of the fuel cell stack as such, but also on the cost of ah auxiliary units and systems, including hydrogen storage and supply. The authors do not rule out the possibility that the goal could be achieved when changing over to mass production of such power plants (many millions of units). 

The assessment of operational costs was based on utilities experience of nuclear power plant operation. A goal of EFR design is to avoid there being significant differences in operation and maintenance (O M) costs compared with PWRs, this intention being supported by a comparison of the number and complexity of the nuclear related systems and auxiliary plant. It is an established fact that radiation doses to operators are substantially lower in a fast reactor station than a PWR this has favourable consequences for O M costs. 

Of all the system characteristics of DMFC with regard to commercialization as a mobile device energy source, energy efficiency, energy density, power density, and cost have to be competitive with rechargeable batteries. These requirements are somewhat different from other types of fuel cells for residential or vehicle application, which can utilize auxiliary compartments more freely. These compartments include a balance of plant (BOP), such as a compressor or pump, for fuel and oxidant supply, humidifier, heat exchanger, and so on. These comparnnents have to be miniaturized effectively or eliminated. This means that the materials in the stack should themselves have the functions of BOP. 

Unique operating characteristics of fuel cell power plants are as follows. Beneficial operating characteristics of fuel cells saves cost and other benefits include load following, power factor correction, quick response to generating unit outages, control of distribution line voltage and quality control can control real and reactive power independently control of power factor, line voltage and frequency can minimize transmission losses, reduce requirement for reserve capacity and auxiliary electric equipment fuel cells have an excellent part load heat rate and can respond to transmission loads. 

Very large, modem WT boilers with sophisticated heat-recovery auxiliaries may attain efficiencies approaching 88 to 90%. However, the overall efficiency of a fossil fuel utility power generation plant system falls to only 32 to 38% when the efficiency of electricity generation and condenser cooling is included. Nevertheless, it only requires 10% more in fuel costs to operate a boiler at 1,250 psig than... 

If low-cost natural gas is available, a gas turbine can be used to generate power. In this case, the waste heat in the exhaust gas is used to produce steam in a heat recovery boiler (HR boiler). This approach also is used with some gas turbine plants (as in some high-speed navy vessels). Where an HR boiler is employed, if steam demand exceeds power demand, the boiler is fitted with auxiliary burners. 

A cost reduction (up to a factor of 1.5 against the first-of-kind plant) may be achieved in the case of a serial production of the ELENA-NTEP plants. The reactor operates at nominal power in an unattended mode that does not require the involvement of operating personnel in the process control. The start-up, shutdown, routine inspection and if required, repair, are performed by personnel from the control centre on a shift basis. The site security may require auxiliary personnel residing in the plant deployment area. 

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