Energy optimal sizing of parallelepiped-shaped technical objects

2021 ◽  
Vol 2 ◽  
pp. 36-40
Author(s):  
Alexandr Galkin ◽  
Vladimir Pankov
Keyword(s):  
Surface Area ◽  
Optimization Criterion ◽  
Heat Losses ◽  
Energy Requirements ◽  
Technical Object ◽  
Optimal Sizing ◽  
Storage Cells ◽  
Industrial Needs

Parallelepiped-shaped technical objects, such as tanks, storage cells, etc., are commonly used for industrial needs. Many of them require energy intensive heating. Achieving the lowest energy requirements is possible by optimizing heat losses by choosing optimal sizing of those objects. This specific case of unconditional optimization has been investigated and described in this paper. Equations for calculating optimal sizing have been suggested. The smallest surface area has been chosen as an optimization criterion while a volume of an experimental parallelepiped-shaped technical object varied. The results show that the cube shape can be taken as optimal.

scholarly journals EFFECTS OF SOCIAL FACTORS ON A DESIRED LEVEL OF THERMAL PROTECTION OF OUTER WALLS OF RESIDENTIAL BUILDINGS

Vestnik MGSU ◽  
2017 ◽  
pp. 741-746
Author(s):  
Aleksey Ivanovich Ananev ◽  
Andrey Georgievich Rymarov ◽  
Elena Valer'evna Voitovich ◽  
Aleksey Petrovich Latushkin
Keyword(s):  
Energy Saving ◽  
Surface Area ◽  
Heat Generation ◽  
Social Factors ◽  
Heat Recovery ◽  
Thermal Protection ◽  
Residential Buildings ◽  
Heat Losses ◽  
Residential Density ◽  
Comparison Data

The requirements to a desired level of thermal protection of outer walls of buildings have been analysed. The relation between such requirements and social factors of a country was shown. Comparison data regarding heat releasing surface area of outer walls and windows and heat losses per person have been received for variable residential density of apartments. The authors have shown international practices and the needs for transition to construction of buildings with a higher level of thermal protection of outer walls. Since cold generation is 3-5 times as expensive as heat generation for many buildings, the transition was made from ventilation of the naturally driven type to controlled and mechanical one providing heat recovery of exhaust air. It was suggested that problem of energy-saving in the sector of construction and housing and communal services could be solved providing a desired life of outer walls and costs of current and major repairs required for projected lifetime of a building.

scholarly journals Possibilities for using solar energy to fulfil the energy needs of buildings in the city centre

2018 ◽  
Vol 45 ◽  
pp. 00013
Author(s):  
Adam Bujarkiewicz ◽  
Jacek Sztubecki
Keyword(s):  
Solar Energy ◽  
Surface Area ◽  
Energy Requirements ◽  
City Centre ◽  
Historical Buildings ◽  
Architectural Elements ◽  
European Cities ◽  
Downtown Development ◽  
Energy Needs ◽  
The City

Historical buildings in the centre of European cities are characterized by compact built-up areas with diversified heights of buildings, most often with multi-sloped roofs. Architectural elements, dormers, chimneys and bay windows, cause limitations in the availability of surface area for solar installations. The paper presents the results of an analysis for possibilities in meeting energy requirements with the use of solar energy for old-town buildings in the centre of Bydgoszcz. Based on the calculations made, it was determined that the dense downtown development has a very large roof surface, however, the vicinity of buildings, roof slope angles, and obstacles cause significant restrictions on the location of such installations. The article analyzes selected fragments of the Downtown district. The height of buildings, their shape and the surface of their roofs and all the obstacles that occur there were taken into account. The conclusions concern an assessment of the possibility of using the potential of solar energy in this type of building. The efficiency of solar installations and the losses associated with energy conversion and transmission to customers is also included.

Patterns of shortening and thickening of the human diaphragm

1997 ◽  
Vol 83 (4) ◽  
pp. 1123-1132 ◽  
Author(s):  
J. L. Wait ◽  
R. L. Johnson
Keyword(s):  
Surface Area ◽  
Fiber Length ◽  
Human Subjects ◽  
Wall Stress ◽  
Total Surface Area ◽  
Energy Requirements ◽  
One Dimension ◽  
Unexpected Finding ◽  
Similar Relationship ◽  
Rectangular Strip

Wait, J. L., and R. L. Johnson. Patterns of shortening and thickening of the human diaphragm. J. Appl. Physiol. 83(4): 1123–1132, 1997.—To study how the human diaphragm changes configuration during inspiration, we simultaneously measured diaphragm thickening using ultrasound and inspired volumes using a pneumotachograph. Diaphragm length was assessed by chest radiography. We found that thickening and shortening were greatest during a breath taken primarily with the abdomen. However, the degree of thickening was greater than expected for fiber shortening, assuming parallel muscle fibers and no shear. So, to clarify this unexpected finding, we considered geometric models of the diaphragm. How a muscle thickens as its fibers shorten is critically dependent on geometry. Thus, if a flat rectangular sheet of muscle shortens along one dimension, surface area-to-length ratio along this dimension should remain constant, and thickness would be inversely proportional to length during shortening. The simplest model of the diaphragm, however, is a cylindrical sheet of muscle in the zone of apposition capped by a dome; the ratio of surface area to radial fiber length in the dome is substantially less than the ratio of area to length of the cylindrical zone of apposition; hence, as the zone of apposition shortens while the dome radius remains constant, the ratio of total surface area to combined length (i.e., dome + zone of apposition) must decrease and thickening of the muscle correspondingly must increase more than expected for a simple rectangular strip. A similar relationship can be derived between thickening and length in a muscle sheet with a wedge-shaped insertion into a thin flat tendon. Comparison of calculations with these types of models to data from human subjects indicates that the unexpected thickening in the zone of apposition is explained by the peculiar geometry of the diaphragm. The greater thickening of the diaphragm in the zone of apposition suggests that more of the muscle mass and more sarcomeres are retained in the zone of apposition as the dome descends. Physiologically, this greater thickening may have importance by reducing wall stress in the zone of apposition and reducing the work or energy requirements per sarcomere.

The effects of ambient temperature and air movement on heat loss from the pig

1981 ◽  
Vol 32 (1) ◽  
pp. 75-84 ◽  
Author(s):  
W. H. Close ◽  
R. P. Heavens ◽  
D. Brown
Keyword(s):  
Critical Temperature ◽  
Heat Loss ◽  
Environmental Temperature ◽  
Heat Losses ◽  
Energy Requirements ◽  
Movement Rates ◽  
Air Movement ◽  
Body Weights ◽  
Lower Critical Temperature ◽  
Environmental Temperatures

ABSTRACTThe heat losses of 24 individually housed pigs (initial body weights 20·0 to 31·8 kg) were measured for periods of 7 days at environmental temperatures of 10, 20 and 30°C. Within each environmental temperature three levels of air movement, 3, 33 and 56cm/s, were applied for a 2- or 3-day period either in an increasing or decreasing order.Heat loss was dependent on the environmental temperature and level of air movement to which the animals were exposed. The decrease in total thermal insulation at the highest air movement was equivalent to reducing the air-ambient insulation to almost zero. In terms of its thermal effect a 5cm/s increase in wind-speed was equivalent to a 1°C decrease in temperature.The lower critical temperature increased with increase in air movement from 19° at 3cm/s to 25° and 30°C at 33 and 56cm/s, respectively. Between air movement rates of 33 and 56cm/s, a 1°C decrease in critical temperature resulted from a 5·3cm/s decrease in air movement.The effect of increasing air movement from 3 to 56cm/s was to increase the animal's maintenance energy requirements from 706 to 881 kJ/kg0·75 per day at 10°C, from 490 to 715 at 20°C and from 517 to 625 at 30°C.

Comparison of Heat Losses for Different Shapes and Size Volumes

2012 ◽  
Vol 622-623 ◽  
pp. 1601-1605
Author(s):  
Marketa Kozakova ◽  
Darja Kubečková
Keyword(s):  
Surface Area ◽  
Heat Loss ◽  
Heat Losses ◽  
Ground Plan ◽  
Floor Surface ◽  
Different Shapes ◽  
The Ideal

The shape of a house significantly affects the amount of heat loss. Compact building, especially without various projections, has a smaller proportion of the cooled surface of the floor surface area and its volume. The ideal shape is a sphere, but in terms of practical use in the cube or block layout is preferable. For this purpose, were created on the same ground plan standards areas and various levels of the circuit. These demonstrate the amount of heat loss, depending on the shape of the object.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

Cell morphology, volume, and surface area determinations from multilevel contouring within HVEM micrographs of serial sections and whole-cell mounts

1987 ◽  
Vol 45 ◽  
pp. 588-589
Author(s):  
M. Marko ◽  
A. Leith ◽  
D. Parsons
Keyword(s):  
Surface Area ◽  
Electron Micrographs ◽  
Cell Morphology ◽  
Individual Variation ◽  
Serial Section ◽  
Stereo Pair ◽  
Complex Structures ◽  
Serial Sections ◽  
Surface Areas ◽  
Computer Based

The use of serial sections and computer-based 3-D reconstruction techniques affords an opportunity not only to visualize the shape and distribution of the structures being studied, but also to determine their volumes and surface areas. Up until now, this has been done using serial ultrathin sections.The serial-section approach differs from the stereo logical methods of Weibel in that it is based on the Information from a set of single, complete cells (or organelles) rather than on a random 2-dimensional sampling of a population of cells. Because of this, it can more easily provide absolute values of volume and surface area, especially for highly-complex structures. It also allows study of individual variation among the cells, and study of structures which occur only infrequently.We have developed a system for 3-D reconstruction of objects from stereo-pair electron micrographs of thick specimens.

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