Types of plant

The most common use is radioisotope-powered thermoelectric generators for the electric loads on board. Power is typically about 1 kWe, subdivided between three or more units. Radioisotope-powered heat generators (2.7 g of plutonium, 1 W) are currently used to guarantee the suitable thermal conditions for the equipment on board during a mission. 

Both types of generators are usually powered by the heat produced by plutonium-238, which has an optimal thermal power to weight ratio (= 0.57 W g- ). 

The reason for the use of radioisotopes is that space missions require absolutely reliable sources of electric energy and heat, without any need for maintenance, that are capable of operating for 

The use of these devices is based on more than thirty years of operation experience on space vehicles of various types. As an example, the US Department of Energy (DoE) has up to now suppUed 44 radioisotope-powered thermoelectric generator systems, used in 24 space missions. The most recent thermoelectric generator built by the DoE, the General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG), (Fig. 26-1), produces 290 W of electric energy with less than 11 kg of plutonium dioxide. Three units are installed on the Cassini vehicle for the exploration of Saturn, 

Currently, plutonium is used in oxide form which is more robust in accident conditions than the metallic plutonium initially used. 

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Herbicide Glasses and Databases. Herbicides can be classified as selective and nonselective. Selective herbicides, like 2,4-D (2,4-dichlorophenoxyacetic acid), metolachlor [51218-45-2] and EPTC [759-94 ] are more effective against some types of plants than others, eg, broadleaved plants vs grasses. Glyphosate [1071 -83-6] is representative of the nonselective herbicides used for total vegetable control. 

Order-of-magnitude estimate (ratio estimate). Rule-of-thumb method based on cost data for previous similar types of plant probable error within 10 to 50 percent. 

Factored electrical cost as a percentage of total installed plant cost for specific types of plant... 

Type of plant Electrical (process and service) lustrumeutatiou ... 

The unit-cost method can give a quick and accurate estimation, provided it is based on accumulated data from many jobs on various types of plant. The ac tual data are analyzed to provide unit-cost information for elec trical components as follows ... 

It should be noted that these values are based on previous experience with certain types of plants, but appropriate values which apply to other processes and locations could be selected. 

Complete Plant Costs It is difficult to compare costs of domestic and overseas plants owing to the wide variation in types of plants and sizes and the rapid changes in technology. Useful data are scarce, and the following comparisons must be used with caution and then only for order-of-magnitude estimates of fixed-capital costs. 

Product Main characteristics tons/year Purity Type of plant Country Client... 

Because of cell speciaHzation, some produces are produced in cultures of those cellular types. Three main classifications of the types of plant cell and tissue cultures are ... 

Figure 1-1. Typical heat rates of various types of plants.

Type of Plant Capital Cost /kW Heat Rate Btu/kWh kJ/kWh Net Efficiency Variable Operation Maintenance ( /MWh) Fixed Operation Maintenance ( /MWh) Availability Reliability Time from Planning to Completion Months... 

The location of the plant is the principal determination of the type of plant best configured to meet its needs. Aero-derivatives are used on offshore platforms. Industrial turbines are mostly used in petrochemical applications, and the frame type units are used for large power production. 

Condition and life assessment is significant for all types of plants, and especially Combined Cycle Power Plants. The most important aspect of a plant is high availability, and reliability, in some cases even more significant than higher efficiency. 

Vk = Capacity of the known plant F = Factor, usually between 0.4 and 0.9, depending on the type of plant... 

Including a term that is a function of the integral of the error can, with the type of plant shown in Figure 4.23, eliminate steady-state errors. 

In this chapter we focus our attention on some of the point sources of air emissions within different types of plant operations, along with the methods of abatement. Although we do not make direct comparisons between prevention and control methodologies until Chapter 6, the reader should gain an appreciation for the simplicity of applying pollution prevention as opposed to incorporating engineering controls in many situations. 

List the various types of plant forms that can enter into and contaminate drinking water. 

Single losses were most costly at refineries than in any other type of plant at an average loss of 73.700,000, The second most costly accidents occurred at petrochemical plants w iih an avciagc loss of 80,800,000. Although only 1% of the losses occurred at gas processing plants, the hiahest (vcrage loss was 117,800,000. 

Consistent with previous risk studies, the average CDFs reported for BWRs is less than for PWR as shown in Figure 1. l-l. BWR and PWR results are strongly affected by the support system considerations discussed above, but some differences between the two types of plants explain why the average is less for BWRs ... 

The discussion of the last section is then useful in considering the evaporative cycles. We shall see that the effect of water injection downstream of the compressor (and possibly in the cold side of the heat exchanger) may lead towards the [CBTJiXr type of plant, with increased cold side effective specific heat and hence increased heat exchanger effectiveness. Water injection in the compressor may lead to a plant with isothermal compression. 

But for power station applications, the thermal efficiency is not the only measure of the performance of a plant. While a new type of plant may involve some reduction in running costs due to improved thermal efficiency, it may also involve additional capital costs. The cost of electricity produced is the crucial criterion within the overall economics, and this depends not only on the thermal efficiency and capital costs, but also on the price of fuel, operational and maintenance costs, and the taxes imposed. Yet another factor, which has recently become important, is the production by gas turbine plants of greenhouse gases (mainly carbon dioxide) which contribute to global warming. Many countries are now considering the imposition of a special tax on the amount of CO2 produced by a power plant, and this may adversely affect the economics. So consideration of a new plant in future will involve not only the factors listed above but also the amount of CO2 produced per unit of electricity together with the extra taxes that may have to be paid. 

Chiesa and Consonni [ 1 ] presented a detailed analysis of this type of plant. They found that the net efficiency of the plant dropped by about 5.5% below that of a basic CCGT plant... 

The incidents described could occur in many different types of plants and are therefore of widespread interest. Some of them illustrate the hazards involved in activities such as preparing equipment for maintenance and modifying plants. Others illustrate the hazards associated with widely used equipment, such as storage tanks and hoses, and with that universal component of all plants and processes people. Other incidents illustrate the need for techniques, such as hazard and operability studies, and protective devices, such as emergency isolation valves. 

Although the types of plant and equipment using flame arresters vary widely, they often have some common features. Frequently the system is... 

Many factors may lettd or contribute to a plant c.xplosion. How cvcr, plant e.xplosions most often encountered in industiy are caused either by fiiulty operational procedures or by faulty equipment. We now discuss scvcnil of tlie more common types of plant e.xplosion chemical, nuclear, e. panding vapors, and pressurized gas e.xplosions. 

The amount of biomass produced in a habitat— the productivity of the habitat—is determined by the types of plants (some species are more efficient photosynthesizers than others), the intensity and duration of solar radiation, the amount of nutrients available, and climatic factors such as temperature... 

The most difficult feature of this method is that for each type of plant or plant product as well as for each type of equipment there is a break-point where the 0.6 no longer correlates the change in capacity. For small equipment or plants in reasonable pilot or semi-works size, the slope of the cost curve increases and the cost ratio is greater than 0.6, sometimes 0.75, 0.8 or 0.9. From several cost values for respective capacities a log-log plot of capacity versus cost will indicate the proper exponent by the slope of the resultant curve. Extrapolation beyond eight or ten fold is usually not too accurate. 

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