Determination of the Cooling Medium Composition in an Indirect Cooling System

Author(s):  
Alexander Herzog ◽  
Carolina Pelka ◽  
Rudolf Weiss ◽  
Frank Skorupa
Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 90
Author(s):  
Andrzej Bryś ◽  
Joanna Bryś ◽  
Marko Obranović ◽  
Dubravka Škevin ◽  
Szymon Głowacki ◽  
...  

The olive oil industry represents an important productive sector in the Mediterranean basin countries. Olive stone is an essential by-product generated in the olive oil extraction industries and it represents roughly 10% by weight of the olive fruit. The seeds of pickled olives are also a significant waste product. In the present study, we have investigated the possibility of the use of differential scanning calorimetry for the thermal characterization of seeds from green and black pickled olives from Croatia. The differential scanning calorimeter (DSC) with a normal pressure cell equipped with a cooling system was used to determine the thermal properties of seeds from olives. The following analyses were also performed: the determination of calorific values in a pressure bomb calorimeter, the determination of initial water content, the determination of changes of water content during drying at the temperatures of 30 °C, 50 °C and 80 °C, the determination of a percentage content of seeds mass to the mass of the whole olives, and the determination of ash content. Seeds from olives are characterized by very good parameters as a biomass. The analyzed olive seeds were characterized by low water content, low ash content, and a relatively high caloric value.


Author(s):  
A. B. Sulin ◽  
D. V. Evdulov ◽  
A. M. Ibragimova ◽  
A. I. Semilyak

Objective. The objective of the study is to develop a design model of the electronic equipment cooling system based on the combined use of high-current thermoelectric semiconductor batteries of layered design and an evaporative-condensing thermal thermosyphon, as well as to study the thermophysical processes occurring during its operation.Methods. A mathematical model of the electronic equipment cooling system based on the combined use of high-current layered thermoelectric batteries and an evaporative-condensing thermal thermosyphon is presented. The design model includes a description of heat exchange processes in a layered thermoelectric element at various supply currents, determination of the amount of heat transferred through the cross-section of the channel of a thermal thermosyphon per unit of time, and the temperature values at each channel point.Result. A 2D dynamic heat conduction problem is solved for a complex system with rectangular geometry of fragments and heat sources. The temperature distribution of a thermoelement along its longitudinal axis at different values of the supply current and the change in the heat flow along its length in a thermal evaporation-condensation thermosyphon are studied.Conclusion. The results of the research have shown the effectiveness of combined use of high-current layered thermoelectric batteries and a thermal thermosyphon in electronic equipment with dense element packaging. It is shown that to increase the efficiency of electronic equipment and reduce the heat losses that occur in the heat line when the heat-generating element of radio-electronic equipment and thermoelectric semiconductor batteries are separated by a sufficiently large distance (over 0.6 m), it is advisable to use an evaporative-condensing thermal thermosyphon as a heat line.


Author(s):  
Kenichi Kurisaka ◽  
Ryodai Nakai ◽  
Tai Asayama ◽  
Shigeru Takaya

The present paper describes a new method for determining the target value of structural reliability in the framework of the System Based Code (SBC) by considering the safety point of view. In the new method, the reliability target is derived from the proposal to a quantitative safety goal that was published by the nuclear safety commission (NSC) of Japan and the quantitative safety design requirements on the core damage frequency (CDF) and the containment failure frequency (CFF) that were determined in the Fast Reactor Cycle Technology Development (FaCT) project by Japan Atomic Energy Agency (JAEA), by utilizing analysis models of a probabilistic safety assessment (PSA). The present method was applied to determination of the reliability target of the structures and components which constitute the reactor cooling system in the Japanese sodium-cooled fast reactor (JSFR). The risk from the reactor is expressed with sum of combination of various elements in the PSA analysis model. Those elements include not only static failure of the structures and components. However, the present study focuses on the sequences including the static failure, and the probability of dynamic failures and human errors in those sequences is conservatively assumed as a unity. It was confirmed that the present method combined with the PSA analysis model for internal initiating events is applicable to determination of the reliability target associated with a random failure of the structures and components, and that the method related to seismic initiating events can derive the target value of the occurrence frequency at which any of the important structures and components fails due to an earthquake.


1999 ◽  
Vol 65 (8) ◽  
pp. 3727-3729 ◽  
Author(s):  
Florian M. Freimoser ◽  
Claude A. Jakob ◽  
Markus Aebi ◽  
Urs Tuor

ABSTRACT The entomopathogenic fungus Neozygites parvispora(Entomophthorales: Zygomycetes) grows in vitro as irregularly rod-shaped hyphal bodies in a complex medium. In order to simplify the medium composition and determine growth-promoting compounds for the cultivation of this fungus, we were looking for a rapid and quantitative method to estimate the number of living cells in small volumes of liquid culture. A colorimetric method for the determination of cell densities using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] proved to be more accurate and timesaving than conventional hemocytometer counting.


2019 ◽  
Vol 973 ◽  
pp. 9-14 ◽  
Author(s):  
Mikhail S. Chepchurov ◽  
Nikolay S. Lubimyi ◽  
Vladimir P. Voronenko ◽  
Daniel R. Adeniyi

The use of metal-polymers in the manufacture of mold-forming parts allows for the significant reduction in price and time used in manufacturing of parts. Using data on the thermal conductivity of metal-polymers in calculations of the cooling system of molds allows calculating the optimal cycle of obtaining the product. The authors propose a method of determining the coefficient of heat transfer of metal-polymers based on a die matrix, filled with aluminum. The chosen equipment or measuring tool by them, allows determining the heat transfer coefficient of the material in use. The values of the coefficient of heat transfer of the material in question, obtained in the course of the research can be use in different databases of applications used for modeling production by injection molding. The described method of determining the coefficient of heat transfer may be repeated for samples of metal-polymers.


2016 ◽  
Vol 15 (1) ◽  
pp. 20
Author(s):  
L. L. Manetti ◽  
I. Dias Jr ◽  
I. S. Kiyomura ◽  
R. C. Cavalcanti ◽  
F. B. Pagliosa

The focus of this work is the design, construction and evaluation of a thermal conductivity meter apparatus based on ASTM E- 1225 standard. The thermal conductivity is a heat-transport propriety and with the development of new materials the determination of thermophysical properties for its correct use becomes necessary. The apparatus was projected in CAD software and the material selection was done following the standard recommendations. For the meter bars were used 304 stainless steel, since its thermal conductivity is known. The heater was made with an aluminum cylinder block and a cartridge electric resistance. The cooling system was assembled using a Peltier thermoelectric plate and a fin heat sink equipped with a fan. Lastly, a steel pipe was used for building the guard cylinder. In order to evaluate the apparatus, the first specimen tested was the 304 stainless steel, the same material as the meter bars. The result of thermal conductivity showed an error of 6% relative to the value found in literature. However, in this test the temperature of isothermal guard cylinder was lower than the temperature required by the standard. Thus, the future goals will be the development of a temperature control for the guard cylinder and realization of more tests with different materials.


Author(s):  
Kazuaki Yazawa ◽  
Gary L. Solbrekken ◽  
Avram Bar-Cohen

A compact, energy efficient heat sink design methodology is presented for shrouded, parallel plate fins in laminar flow. The analytic model accounts for the sensible temperature rise of the air flowing between fins, convective heat transfer to the flowing stream, and conduction in the fins. To evaluate the efficiency of the air cooling system, consideration is also given to the determination of the fan pumping power. This paper focuses on the optimization of the heat sink-fan combination for energy efficiency, subject to volumetric constraints. The design optimum is found by matching the most efficient operating point of the fan with the corresponding optimum fin geometry. A series of parametric studies was completed to identify the sensitivity of the cooling solution to parametric variations. This numerically validated model has been used to visualize the parametric impact of dealing with “real world” manufacturing limitation in the development of thermal packaging solutions for notebook computers and other electronic products.


2020 ◽  
Vol 14 (1) ◽  
pp. 5
Author(s):  
SIPRIYADI SIPRIYADI ◽  
ARIS TRI WAHYUDI ◽  
MAGGY THENAWIDJAYA SUHARTONO ◽  
ANJA MERYANDINI

Xylanase is an important hydrolytic enzymes with many application in several industries, but to obtain enzyme derived products is not easy. Thus, the optimization of efficient xylanases production is a great interest for biotechnological application. This study aims to determine the type of substrate, medium composition, and optimum conditions of xylanase production by S. costaricanus 45I-3. Determination of substrate type was done by growing the tested bacteria on birchwood xylan, beechwood xylan, oat spelled xylan, corn cobs xylan, and tobacco xylan substrate, meanwhile the determination of medium composition and enzyme production were done by measuring xylanase activity at various substrate concentration and replacing the carbon, nitrogen, phosphate and surfactants source. The results showed that the highest enzymatic index (EI) produced from corn cob xylan substrate at 3.60 meanwhile the second highest was beechwood xylan substrate at 2.87 EI, however this substrate is purer, thus this substrate was selected and used as xylan sources for further optimization measurement. The best xylanase activity (2.29 U/mL) obtained on eighth day after inoculation on rotary incubator at 120 rpm in 28 ºC. Arabinose as the source of carbon generate the highest activity at 3.161 U/mL meanwhile the most preferred source of phosphate is Na2HPO4 (2.37 U/mL). Both source of nitrogen i.e. nitrogen ammonium sulphate (NH4)2SO4 and yeast extract were able to produce xylanase at 2.57 and 2.36 U/mL. The addition of surfactant in production medium showed addition of SDS surfactant (0.146 U/mL) and Tween 80 (0.438 U/mL) showed a negative response by decreasing the activity. The conclusion showed that the xylanase activity was increased after optimization at various C, N, and P sources, and the use of nitrogen source (NH4)2SO4), become a more economical alternative to replacing a nitrogen source yeast extract so it can lower the production costs of xylanase enzyme.


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