Former studies done by other authors investigated the first- and second-layered air gaps beneath the clothing garments. None of the previous studies reported multidisciplinary clothing design testing ...approach linking both the objective measuring methods and subjective responses, while testing the thermal properties linked to a microclimatic volume formed between the layers of garments forming the ensemble. Neither was determined the limiting value of the microclimatic volume for outerwear garments, after which the thermal insulation will start to decrease due to convection. By taking the advantage of the precise three-dimensional (3D) body scanning technology and reverse engineering 3D CAD tool, the volume of the microclimatic air layers formed under outerwear garments was determined to study the impact of the ensemble’s microclimatic volume on the overall insulation value, measured by means of the thermal manikin. The jacket with the smaller microclimatic volume provided 5.2–13.5% less insulation than wider jackets, while the ensembles with tighter jackets showed 0.74–1.9% less insulation in static and 0.9–2.7% more insulation in dynamic conditions, thus proving that the limiting value of the microclimatic volume is greater than previously reported for three-layered ensembles. The effective thermal insulation value was reduced in average by 20.98–25.34% between standing and moving manikins. The thermal manikins are designed for steady-state measurements and do not work well under transient conditions, so three human subjects were employed as evaluators of the clothing thermal quality. In cooler climatic conditions, the measured physiological parameters and subjects’ grades pointed to discomfort while wearing ensembles with tighter jackets.
Some of the researches expressed connection between the numbers and size of the microclimatic air layers on thermal insulation of clothing. The insulation of the ensembles is much affected by the air ...enclosed between the clothing layers. In loose fitting clothing, they are less subjected to compression and thus add more to the overall thermal insulation. The heat and the moisture are released from the body into the microclimatic layers, subsequently changing properties of the entrapped air. The volume of the microclimatic air layers was investigated by the use of non-contact 3D CAD method. The temperature and humidity changes of microclimatic layers were also observed. This paper represents layer by layer quantification of the clothing ensemble volume with jackets as covering garment and the impact of the microclimatic volume on the clothing insulation. The three-level laboratory testing was performed with human subjects dressed in selected ensembles.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
The global energy crisis, forced by fossil fuel shortages and supply chain disruption, stimulates EU policymakers to find alternative energy replacement. Modifying the present polyisoprene footwear ...production plant into a hybrid system by combining different energy sources raises energy efficiency. The proposed hybrid system incorporates classical and solar-based technology, resulting in energy optimization by utilizing waste heat recovery. By installing an economizer for feeding water preheating using flue gas recovery, it results in the volume of the flue gases lowering from vFGP=1.7969 m3FG/kgP to vFGECOP=1.597 m3FG/kgP, or by 11.13%, while the flue gases’ temperature is lowered from 204 °C (477.15 K) to 50.99 °C (324.14 K). Further improvement in combining feed water and air preheating results in natural gas savings of 12.05%, while the flue gases’ exhaust temperature is decreased to 30.44 °C (303.59 K). The third option, using condensate heat recovery and feeding water preheating using flue gases, showed natural gas savings as much as 17.41% and exhaust flue gases cooling to 112.49 °C (385.64 K). The combination of condensate heat recovery, combustion air and feed water preheating results in the volume of the flue gases being lowered by 20.42% and natural gas savings by 20.24%, while the flue gases’ temperature is reduced to 45.11 °C (318.26 K). The proposed solar application in polyisoprene production predicts the hybrid system showing fuel savings ranging from 77.96% to 87.08% in comparison to the basic process. The greatest fuel savings of 87.08% is shown in a solarized polyisoprene footwear production plant with combustion air and feed water preheating combined with the condensate return system. Integrating the solar heat into the regular industrial process of polyisoprene production showed great potential and showed environmental sustainability through energy optimization in polyisoprene production.
The evaluation of energy efficiency improvements in polyisoprene footwear production is shown. By installing air preheater, combustion air natural gas consumption is reduced by 7%. Simultaneously, ...the boiler outlet flue gases’ temperature is decreased from 204 °C to 66.93 °C, providing a sound basis for both economical savings and energy efficiency improvements, as well as ecological benefits to the environment. The application of condensate heat recovery resulted in flue gases’ volume decreasing by 11.85% and a thermal pollution decrease of 91.34%. Combining air preheating by exhaust flue gases and condensate heat recovery resulted in a decrease in the flue gases’ volume by 17.97%, and in the temperature lowering to 66.93 °C. The energy consumption for a combined system on location φ=45°49′) with a collector field of 12.936 × 103 m2 was investigated. The hybrid system was calculated for four variants: (1) solarized process without flue gases’ heat recovery, (2) solarized processes with heat contend in flue gases using an air preheater, (3) solarized processes with condensate heat recovery, and (4) solarized processes with heat contend in flue gases using air preheater and condensate heat recovery. The highest fuel savings were shown in solarized processes with heat contend in flue gases using air preheater and condensate heat recovery, resulting in savings of up to 78.92%, while the flue gases’ volume decreased from 5390.95 m3FG/h to 932.12 m3FG/h.
This study represents the evaluation of energy efficiency improvement using combination of natural gas, solar energy and flue gases heat recovery in polyester production. The analyzed energy sources ...are used for dry saturated steam generation. The energy consumption for combined system on location (φ = 45°49′) with collector field of 23.23 × 10
3
m
2
, was investigated. The hybrid system was calculated for four variants: (1) solarized process without flue gases heat recovery, (2) solarized processes with heat contend in flue gases using economizer, (3) solarized processes with heat contend in flue gases using an air preheater and (4) solarized processes with heat contend in flue gases using economizer and air preheater. The best method among presented sources is solution using economizer and the air preheater with natural gas, solar energy and flue gases heat recovery. The natural gas consumption is reduced for 67.82% which indicates that this solution is the optimal one. At the same time the volume of exhaust flue gases is diminished from 4947.1 to 1430.4
/h while simultaneously decreasing outlet temperature of 172.85°. Together with considerable energy savings, this hybrid system is sustainable and environmentally acceptable.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The purpose of this paper is to analyse the impact of design solutions on the thermal insulation of the garments and the ensembles. Previous studies investigated the microclimatic air gaps and ...volumes, however only under the first - and the second - layered clothing. Since none of the previous studies covered three - layered ensembles, in this study ensembles were accompanied by jackets of different fit and length to investigate the ensembles’ thermal insulation. Variants of bomber jacket differ in the amount of the ease allowance, while variants of the parka differ in length. The thermal insulation of the ensembles increased for 21.6 to 59.7 % when one of the jacket variants was added as the outerwear garment. A threshold volume, after which the thermal insulation will start to decrease due to convection, wasn’t determined for the outerwear third - layered garments nor was the impact of the length of the garment on the thermal insulation clearly stated. This study involved laboratory testing of garments and ensembles by 3D body scanning and thermal manikin measurements. To evaluate the volume of the microclimatic air volume the accurate 3D body scanning was used and the impact of the microclimatic volume on the ensemble’s insulation was tested. The thermal insulation for the selected outerwear garments and afterwards ensembles was measured by resting thermal manikin. Analysis of the results obtained from tests, showed that the garments’ fit and length can be used to model the overall thermal insulation of the ensembles. The ensembles insulation enlargement was measured for microclimatic volumes up to 33.57 dm
3
(measured with ensembles accompanied with bomber jacket). The study proved that the limiting microclimatic volume is greater for three - layered clothing, than previously reported. The overall ensembles’ insulation increased simultaneously with the length enlargement (measured with ensembles accompanied with parka jacket). Findings will be of help in the future research on garments and ensembles thermal properties modelled through the design process and the construction.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The possibility of energy savings by means of minimizing fuel consumption in polyamide-6, i.e. nylon-6, production is investigated. Reducing energy consumption for processes with condensate and ...exhaust gases heat recovery in energy management studies presents a growth of process efficiency and contemporary decreasing of thermal pollution. The condensate heat recovery option results in fuel savings of 8.2%. At the same time, the thermal pollution is diminished by 89.3%. Using an economizer and condensate heat recovery for feed water preheating, the anthracite consumption is reduced by 16.91%, and the flue gases are cooled 132.8°. If an air preheater is applied for combustion air preheating together with condensate heat recovery, the fuel savings becomes 15.3%. Now, the flue gases temperature is reduced 170°. In the system, including boiler feed tank, economizer and air preheater, the total fuel savings reached 19.4%, while the flue gases exhaust temperature diminished 195°.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Od 1970-ih godina najpopularniji potplati cipela jesu EVA potplati, napravljeni od etilen vinil acetata, kopolimera koji se sastoji od etilena i vinil acetata. Duromeri i elastomeri (gume), među koje ...ubrajamo i EVA polimere, čine oko 30% ukupne proizvodnje u tonama svih proizvedenih sintetskih polimera, pri čemu gume sintetskog podrijetla premašuju količinom proizvodnju guma prirodnog podrijetla. Imajući tu činjenicu na umu, energetske uštede u tvornicama proizvodnje gume iznimno su važne, a ovaj rad analizira potencijale energetskih ušteda u proizvodnji potplata za cipele napravljenih od etilen vinil acetata (EVA). EVA potplati za cipele jesu lagani, jednostavni za modeliranje, vodootporni i vlagootporni, jako elastični, amortiziraju udarce, dobri su toplinski izolatori, iznimno su otporni itd. Energetske uštede povratom topline procesnoga kondenzata prezentirane su u procesu proizvodnje potplata za cipele. Povrat topline kondenzata rezultira smanjenom potrošnjom pojne vode, znatnim uštedama goriva potrebnog za proizvodnju pare i rezultiraju smanjenom potrošnjom kemikalija potrebnih u
proizvodnom procesu. Povrat vreloga procesnoga kondenzata u kotao rezultira smanjenjem potrošnje nafte 14,9 %. Također se smanjuje toplinsko zagađenje 95,3 %, dok se volumen ispušnih plinova smanjuje od 17,11 m3FG/kgNEC do 14,57 m3FG/kgNEC ili 14,8 %. Ovakav sustav omogućuje
istodobnu uštedu nafte i smanjenje toplinskog zagađenja. Usporedbom procesa s povratom topline dimnih plinova u odnosu prema procesu bez povratka topline dimnih plinova, pokazuje uštede od 18,76 %, uz smanjenje temperature dimnih plinova sa 221° C na 137,39° C, pri čemu se
volumen dimnih plinova smanjuje na 13,90 m3FG/kgP.
Since 1970’s, the most popular shoe soles are (EVA) soles, made from Ethylene Vinyl Acetate, copolymer consisting of ethylene and vinyl acetate. The thermosets and elastomers (rubbers), among them ...accounting EVA, encompasses around 30% of the tonnage of all synthetic polymers produced, with the synthetic rubbers exceeding the tonnage of natural rubber. With that in mind, the energy savings in rubber processing plants are of great importance and the paper analyses the potential of energy savings in shoe soles production process made of Ethylene Vinyl Acetate (EVA). The shoe soles made from EVA are lightweight, easy to mould, water and moisture resistant, highly elastic, shock absorbent, great thermal insulators, highly durable, etc. The energy savings using the process return condensate in shoe sole production process are presented. Using the return condensate results in lower make up water consumption, substantial fuel savings needed to produce steam and lower chemical consumption. Returning hot process condensate to the boiler results in oil savings of 14,9%. Also, the thermal pollution is reduced by 95,3%, while the volume of the flue gases is lowered from 17,11 m3FG/kgNEC to 14,57 m3FG/kgNEC or by 14,8%. Such a system enables both the oil savings and reduces the thermal pollution. The comparison of process with and without flue gases heat recovery shows fuel savings of 18,76%, while the temperature reduces from 221°C to 137,39°C and while the volume of the flue gases is lowered to 13,90 m3FG/ kgP.
Kontinuirani razvoj novih pojmova, materijala, mjernih instrumenata i mjernih metoda zahtjeva i uvođenje unificiranih specifikacija i definiranje normi, kako bi se uspostavio jasan sustav kontrole ...kvalitete, što proizvodnih postupaka, što testnih metoda. U području mjerenja toplinskih karakteristika okoliša, odjevnih predmeta i odjevnih sustava te termofiziologije ljudskog tijela, najznačajnije norme izdaju međunarodne organizacije ASTM International i ISO, a priručnike ASHRAE. Tim se normama definiraju izolacijske karakteristike različitih materijala, odjevnih predmeta i sustava, otpornost prolasku vodene pare i topline, mjerni uređaji i protokol ispitivanja, uvjeti pri testiranjima, indeks toplinske ugodnosti, odnosno toplinskog stresa, okoliši i interpretacija rezultata ispitivanja. Norme s područja ergonomije toplinskih okoliša definiraju parametre i mjerne metode, koji utječu na ljudsku termoregulaciju u nekom specifičnom okolišu, a druge norme opisuju kako se na temelju tih parametara može predvidjeti stupanj toplinske zaštite, odnosno toplinska ugodnost ili neugodnost te zdravstveni rizik kojemu ljudski subjekt može biti izložen u određenom okolišu.
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