Sizing Energy Equipment

For many pieces of equipment, such as heat exchangers and distillation columns, stand-alone programs are available that calculate material and energy balances around that piece of equipment, size the equipment, and calculate or rate its performance. 

A great variety of factors are in use, depending on the time available and the accuracy expected. Normally the input information required is the base cost. Determination of this cost usually requires a knowledge of equipment sizes, probably using mass and energy balances for the proposed process. 

With turbulent flow, shear stress also results from the behavior of transient random eddies, including large-scale eddies which decay to small eddies or fluctuations. The scale of the large eddies depends on equipment size. On the other hand, the scale of small eddies, which dissipate energy primarily through viscous shear, is almost independent of agitator and tank size. 

The impact of incorrect equipment sizing practices is magnified in an energy-efficient home that has dramatically reduced heating and cooling loads. 

Many pubhcahons refer to the use of micro reactors for process intensificahon, with all the imphcahons related to this definition - safety, cost reduchon, high productivity rate, environmental friendliness, energy efficiency and so on [5, 25, 104]. A particular feature of interest is the reduction of the equipment size (see also Section 1.4.3.5 for a systematic top-down description of this topic). 

TES-based systems are usually economically justifiable when the annualized capital and operating costs are less than those for primary generating equipment supplying the same service loads and periods. TES is often installed to reduce initial costs of other plant components and operating costs. Lower initial equipment costs are usually obtained when large durations occur between periods of energy demand. Secondary capital costs may also be lower for TES-based systems. For example, the electrical service equipment size can sometimes be reduced when energy demand is lowered. 

The benefits of TES include [2] (i) reduced energy costs, (ii) reduced energy consumption, (iii) improved indoor air quality, (iv) increased flexibility of operation, (v) reduced initial and maintenance costs, (vi) reduced equipment size, (vii) more efficient and effective utilization of equipment, (viii) conservation of fossil fuels, and (viii) reduced pollutant emissions. 

Equipment Sizing Before equipment costs can be obtained, it is necessary to determine equipment size from material and energy balances. For preliminary estimates, rules of thumb may be used but for definitive and detailed estimates, detailed equipment calculations must be made. 

Process intensification consists of the development of novel apparatuses and techniques that, compared to those commonly used today, are expected to bring dramatic improvements in manufacturing and processing, substantially decreasing the ratio of equipment size to production capacity, energy consumption, or waste production and ultimately resulting in cheaper and more sustainable technologies (35). 

As previously reported, membrane contactors present interesting advantages with respect to traditional units. Moreover, they well respond to the main targets of the process intensification, such as to develop systems of production with lower equipment-size/production-capacity ratio, lower energy consumption, lower waste production, higher efficiency. In order to better identify the potentialities of membrane contactors in this logic, they have been recently compared to traditional devices for the sparkling-water production in terms of new defined indexes [24]. In particular, the comparison has been made at parity of plant capacity and quality of final product. The metrics used for the comparison between membranes and traditional units are ... 

Associated, respectively, with increasing the reactor and separation equipment size, and with the amount of energy required by daily operations. 

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