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Equipment, heat losses

Improvement Considerations The first consideration is to evaluate mass and energy balances to identify problem areas. This will identify air leaks and excessive equipment heat losses and will enable determination of overall energy efficiency. [Pg.1428]

There are two ways of presenting steam balance data, schematically or tabulady. For both presentation types, a balance is made at each pressure level. In a schematic balance, such as that shown in Figure 9, horizontal lines are drawn for each pressure. The steam-using equipment is shown between the lines, and individual flows are shown vertically. Table 3 contains the same data as shown in Figure 9. In both cases the steam balance has been simplified to show only mass flows. A separate balance should be developed that identifies energy flows, including heat losses and power extraction from the turbines. [Pg.226]

Rotating equipment, except brick-hned vessels, operated above ambient temperatures is usually insulated to reduce heat losses. Exceptions are direct-heat units of bare metal construction operating at high temperatures, on which heat losses from the shell are neces-saiy to prevent overheating of the metal. Insulation is particularly necessary on cocurrent direct-heat units. It is not unusual for product cooling or condensation on the shell to occur in the last 10 to 50 percent of the cylinder length if it is not well insulated. [Pg.1200]

Maintenance or cleaning of equipment Residues Loss of containment (breaking lines) Stripping insulation Burning-off paint, flame heating components Reaction or vaporization of cleaning products... [Pg.105]

Loss of heat input to closed process equipment handling low vapor pressme materials (e.g., fractionation of alcohols and aromatic solvents), while cooling continues such as by a condenser or through heat loss to the atmosphere. [Pg.149]

Air Temperamre Design temperature for equipment and outdoor transformers shall be 98°F. Design Temperature for the Installation of Service Equipment - Maximum Temperamre 100°F - Minimum Temperamre 60°F Design Temperamre for Calculation of the Heat Loss - Normal Daily Average 79°F. The maximum mean relative humidity is 97%. Mean relative humidity -82%... [Pg.313]

In condensers where heat loss is desired, insulation often is omitted from piping carrying hot fluids to take advantage of the heat loss to the atmosphere. In any heat exchange equipment the heat released or lost by one fluid must be accounted for in an equivalent gain by a second fluid, provided that heat losses are negligible or otherwise considered. [Pg.74]

The proposals made for calculating transfer coefficients from physical data of the system and the liquid and vapour rates are all related to conditions existing in a simpler unit in the form of a wetted-wall column. In the wetted-wall column, discussed in Chapter 12, vapour rising from the boiler passes up the column which is lagged to prevent heat loss. The liquid flows down the walls, and it thus provides the simplest form of equipment giving countercurrent flow. The mass transfer in the unit may be expressed by means of the j-factor of Chilton and Colburn which is discussed in Volume 1, Chapter 10. Thus ... [Pg.647]

Inert material of the sampling device (bags, tubes, valves), no losses by diffusion Preflushing Prediction equipment Volume of the sample Sampling time.pump speed Storage time(<24h) Inert tube material (PTFE. stainless steel, glass) Preflushing Predilution equipment Heated probe jf Dust filters required... [Pg.53]

Fuel cell pressurization is typical of many optimization issues, in that there are many interrelated factors that can complicate the question of whether to pressurize the fuel cell. Pressurization improves process performance at the cost of providing the pressurization. Fundamentally, the question of pressurization is a trade-off between the improved performance (and/or reduced cell area) and the reduced piping volume, insulation, and heat loss compared to the increased parasitic load and capital cost of the compressor and pressure-rated equipment. However, other factors can further complicate the issue. To address this issue in more detail, pressurization for an MCFC system will be examined. [Pg.230]

A conservative estimate of the resulting surface temperature is obtained by assuming no convective heat losses from the target structures. Equation 5-23 is used to calculate the surface temperature of the equipment due to an incident radiative heat flux from the fire and accounting for only radiation losses from the target. [Pg.92]

Exit air usually is maintained far from saturated with moisture and at a high temperature in order to prevent recondensation of moisture in parallel current operation, with a consequent lowering of thermal efficiency. With steam heating of air the overall efficiency is about 40%. Direct fired dryers may have efficiencies of 80-85% with inlet temperatures of 500-550°C and outlet of 65-70°C. Steam consumption of spray dryers may be 1.2-1.81bsteam/lb evaporated, but the small unit of Table 9.19(b) is naturally less efficient. A 10% heat loss through the walls of the dryer often is taken for design purposes. Pressure drop in a dryer is 15-50 in. of water, depending on duct sizes and the kind of separation equipment used. [Pg.276]

The aforementioned refrigerated baths are often equipped with circulation pumps so that the chilled fluid can be passed through the jacket of a nearby electrochemical cell. The tubing connecting the circulator to the cell should be insulated to minimize heat loss. With such a circulator, experiments have been conducted at temperatures as low as -20°C [29,30], and there appears to be no reason that lower temperatures can not be achieved. [Pg.502]

Table 2.7 Typical heat losses from industrial vessels and laboratory equipment. Table 2.7 Typical heat losses from industrial vessels and laboratory equipment.
Here c represents the heat capacity of the equipment that is to be identified in the experiments, together with the heat losses. The stirrer power is calculated according to Equation 2.24. The heat exchange term is... [Pg.234]

Water is decomposed into hydrogen and oxygen as the net result of the Cu-CI thermochemical cycle. The cycle involves five steps, as listed in Table 1 1) HCl(g) production using equipment such as a fluidised bed 2) oxygen production 3) copper (Cu) production 4) drying 5) hydrogen production. Recent studies by Chukwu, et al. (2008) and Orhan, et al. (2008) have analysed the overall thermal efficiency of the five-step Cu-CI cycle. The efficiency of the cycle versus temperature was analysed for three cases x = 0.2, 0.3 and 0.4, where x refers to the fraction of heat loss to heat input to the cycle. The calculated efficiencies varied from 42 to 55% at 550°C. [Pg.231]

The first three methods of optimization are achieved by closed-loop process control and can be superimposed upon the overall boiler control system shown in Figure 2.1. The tie-in points for these optimization strategies are also shown in that figure. The benefits of the last two methods (efficiency and accountability) are not obtained in the form of closed-loop control signals, but they do contribute to better maintenance and better understanding of heat losses and equipment potentials. [Pg.144]


See other pages where Equipment, heat losses is mentioned: [Pg.100]    [Pg.100]    [Pg.357]    [Pg.389]    [Pg.502]    [Pg.528]    [Pg.292]    [Pg.7]    [Pg.1190]    [Pg.1690]    [Pg.133]    [Pg.142]    [Pg.274]    [Pg.696]    [Pg.257]    [Pg.664]    [Pg.71]    [Pg.138]    [Pg.218]    [Pg.374]    [Pg.528]    [Pg.259]    [Pg.502]    [Pg.18]    [Pg.61]    [Pg.47]   
See also in sourсe #XX -- [ Pg.188 ]




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