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Estimating the Power Losses in Induction Motor using Temperature Monitoring
(2025-01-01)
Suesut, Taweepol
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Nunak, Teerawat
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Nunak, Navaphattra
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Chaishome, Jedsada
The paper proposes the estimation of power losses in electrical machines using a measurement technique based on the temperature of the electrical machine and the heat transfer equation. To demonstrate this concept, the heat diffusivity of the induction motor can be illustrated through thermal images. This research addresses the impact of supply voltage unbalance on power loss in induction motors. The system comprises A contact temperature measuring circuit utilizing the IC LM 35DZ as a temperature sensor and signal converter, paired with a computer equipped with a National Instruments PCI 6014 data acquisition card. The experiment was conducted by adjusting the phase unbalance to 10%, 20%, and 50% to observe temperature changes. This allows for a direct temperature in the induction motor. The primary advantage of this method is that the machines do not need to stop or be removed from their operational process to measure their losses during preliminary maintenance.
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Optimal Design and Installation of Solar Rooftop for Thai government building
(2025-01-01)
Chaishome, Jedsada
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Nunak, Navaphattra
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Suesut, Taweepol
This research presents an approach for installing grid-connected solar cells on the rooftops of a prototype building in Thailand to offset electricity consumption, aligning with TOU electricity pricing. It includes design methods, energy-saving calculations, and illustrates the savings from solar cell installation over a one-year period, without accounting for solar cell deterioration or system loss charges. The study compares the concept of installing solar cells on the rooftop based on the building's electricity usage characteristics, distinguishing between installing solar cells across the entire rooftop area and according to the building's electricity usage behavior during daytime and working days, ensuring minimal electricity remains while still being sufficient for use. Furthermore, it calculates the comparison before and after installation to provide information for rooftop installation on the prototype building. The research results indicate that installing solar cells across the entire rooftop area can save electricity costs up to 550,000 THB per year.
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Inspection of Heat Seal Packing Bag Integrity Using Thermal Images With YOLO Algorithm
(2025-01-01)
Chaishome, Jedsada
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Khannakum, Wirat
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Nunak, Navaphattra
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Suesut, Taweepol
This paper presents an inspection of heat seal packing bag integrity using thermal imaging with a deep learning technique. The performance was evaluated by comparing the object detection rates obtained from the YOLOv4-Tiny Algorithm and the Convolutional Neural Network (CNN) technique. Two sets of completely sealed and failure-sealed packaging bags were prepared for the training (100 bags) and testing (100 bags) of the models. Some sample bags containing tomato sauce inserted between the seals represent a failure-sealed condition. The integrity of the heat seal packaging bag was analyzed by examining the differences in color shade patterns of the thermal images. As a result, the YOLOv4-Tiny model achieved a detection accuracy of 98.80%, significantly outperforming the CNN technique, which detected only 78.40%, while using the same dataset; additionally, the time required for detection and training was faster.
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Effects of heat transfer surface temperature on liquid egg yolk fouling
(2024-01-01)
Sritham, Eakasit
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Nunak, Navaphattra
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Suthanupaphwut, Worapanya
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Somlitsopak, Badin
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Chaishome, Jedsada
This study was aimed at investigating the effects of different surface temperatures (60-80°C) on the formation of egg yolk deposits on heat transfer surface. Experimental data from the fouling period were fitted with zero- and first-order reaction models and the reaction kinetics of fouling was obtained using the Arrhenius equation. Egg yolk fouling curves exhibited an asymptotic pattern showing only fouling and post-fouling periods. The fouling resistance at transition point increased with the increasing surface temperature. The zero-order reaction model was well describing the reaction rate of egg yolk fouling. The obtained activation energy of 85.47 kJ/mol was less than that for thermal denaturation of egg yolk proteins. The fouling process of egg yolk was mainly controlled by the deposition reaction.
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Development of Mathematical Model to Predict Soymilk Fouling Deposit Mass on Heat Transfer Surfaces Using Dimensional Analysis
(2023-04-01)
Sritham, Eakasit
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Nunak, Navaphattra
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Ongwongsakul, Ekarin
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Chaishome, Jedsada
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Schleining, Gerhard
The formation of fouling deposits on heat exchanger surfaces is one of the major concerns in thermal processes. The fouling behavior of food materials is complex, and its mechanism remains, in general, unclear. This study was aimed at developing a predictive model for soymilk fouling deposit formed on heated surfaces using dimensional analysis. Relevant variables affecting fouling deposit mass could be grouped into six dimensionless terms using Buckingham’s pi-theorem. Experimental data were obtained from a lab-scale plate heat exchanger. A simple model developed using the experimental data under the process conditions with the product inlet temperature, the product outlet temperature, and plate surface temperature in the ranges of 50–55 °C, 65–70 °C, and 70–85 °C, respectively, exhibited a good performance in the prediction of soymilk fouled mass. The correlation coefficient between the predicted and experimental values of fouled mass was 0.97 with an average relative error of 9.03%. Within the ranges of product inlet temperature and plate surfaces temperature studied, this model offers an opportunity to estimate soymilk fouling mass with acceptable accuracy.
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An investigation of oil residue on surface by infrared thermography
(2020-01-01)
Chaishome, Jedsada
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Nunak, Teerawat
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Tuppadung, Yutthapong
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Suesut, Taweepol
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Nunak, Navaphattra
This work aims to propose a visual inspection, infrared thermography technique, of oil residual mass on stainless steel surface (SS) (hydrophilic surface representative) and polytetrafluoroethylene (PTFE) surface (hydrophobic surface representative). An improved understanding of the oil fouling characteristic is a key point to develop this technique. The effect of surface roughness on the oil contact angle, oil residual mass, and the resulting average temperature of the residues on SS and PTFE surface was studied. For the infrared thermography technique, the mass of oil adhered to each interface using heating at a temperature of 800C for 10 minutes. SS AISI 304 plaques with the average surface roughness of 0.4, 0.8, and 3.2 µm and PTFE with that of 0.4 and 0.8 µm were examined. All samples were snapped top view using a thermal image camera. The average temperatures were obtained from the color spectrum of the thermal images. It could be summarized that the proposed measurement is possible to detect the accumulation of oil on the SS whereas it was not clearly different that on the PTFE surface. A greater oil residual mass on both hydrophilic and hydrophobic surfaces is a result of an increase in surface roughness and sequential wettability from the contact angle as expected. Moreover, each liquid-solid interfacial material has its specific surface characteristic. Finally, each liquid-solid interfacial material has its specific surface characteristic and the new and used oil-SS interface could be detected by infrared thermography technique.
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Ripening control of nam dok mai mango (Mangifera indica Linn.) with titanium dioxide
(2019-01-01)
Chaishome, Jedsada
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Tunsathitsak, Yossakorn
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Boonyaritthongchai, Panida
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Supapvanich, Suriyan
— This research aims to slow down the release of ethylene of ‘Nam Dok Mai’ mango during shipment transportation by using titanium dioxide as an absorbent. The result found that the mango begin to the ripening process after stored at 13°C for 12 days (ethylene and carbon dioxide around 0.06910 µL C2H4/kg.hr and 32.10 mg CO2/kg.hr, respectively). Then, the appropriate titanium dioxide was tested by trial at 3, 5 and 10 grams. The result showed that titanium dioxide decreased ethylene but each treatment were not statistically different (p <0.05). Afterward, all fruits were stored at 13°C for 14 days and at 25°C for 4 days, respectively. The physical and chemical properties of fruit were analyzed during storage time. After 14 days at 13°C, firmness, color, titratable acidity, pH, total soluble solids and ripening index of the treatments of titanium dioxide and control treatment were significant different. After 4 days at 25°C, the ripening process of fruit between titanium dioxide treatment and control treatment were not significant differences.
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Alleviation of internal browning in queen pineapple fruit by peduncle infiltration with solutions of methyl jasmonate during cold storage
(2019-01-01)
Chaishome, Jedsada
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Srimuk, Sutikarn
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Supapvanich, Suriyan
— The effect of methyl jasmonate solution (MeJA) and methyl jasmonate gel on procreation internal browning (IB) of ‘Trad-see-thong’ pineapple (‘Queen’ group) fruit was investigated. The pineapple fruit were peduncle-infiltrated parallel with 1 mM MeJA, 1 mM and 10 mM MeJA-gel, then stored at 10°C for 12 days. The results showed that internal browning symptom of pineapple fruit with treatment was visible following 4 days of storage. On day 12 of storage, control treatment (no solution), internal browning score of 4 (almost maximum score), that was significantly higher than other treatments (p < 0.05). The 1 mM MeJA solution had internal browning score of 3.8, expected that the amount of MeJA solution with peduncle-infiltration in pineapple fruit had too exorbitant (overdose). Moreover, the 1 mM and 10 mM gel-treated had internal browning score of 3.2 and 3.4, respectively. It was found that the amount of MeJA solution with peduncle-infiltration in pineapple fruit is able to alleviate better than the other. The 1 mM and 10 mM MeJA-gel had lightness in pulp tissues significantly higher than other groups worthy 44.95 and 46.74, respectively.
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Effect of alkaline treatment on decomposition temperature of fibres from empty oil palm bunch
(2019-01-01)
Chaishome, Jedsada
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Nunak, Navaphattra
—This article reports an investigation of the decomposition temperature of fibres from empty oil palm bunch to achieve improved understanding of the processing temperature limitation of this fibre as reinforcement for thermoplastic composite manufacturing. The effect of alkaline treatments on their chemical decomposition and sample weight changes were performed, using fourier transform infrared spectrometry (FTIR) and thermogravimetry (TG) techniques. The results show that the hemicellulose removal of fibres after treatment is a factor that provides an advantage on the thermal stability of the fibres. Both initial decomposition temperature (T<inf>0</inf>) and maximum decomposition temperature (T<inf>max</inf>) are minor increase. This could reduce the detrimental effect of thermal degradation on the single fibre performance and leads to shift its consolidation temperature ceiling from below 221oC (untreated fibres) to 243oC (5% NaOH treated fibres) during composite consolidation.
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Tensile properties of PLA/PBAT blends and PLA fibre-reinforced PBAT composite
(2018-08-14)
Sritham, Eakasit
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Phunsombat, Phakaimat
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Chaishome, Jedsada
The tensile properties of PLA/PBAT blends, PLA fibre reinforced PBAT composite (PLAF) at room temperature and -18°C were investigated. The concentrations of PLA in the blends were 10%, 20%, 30% and 40% (by volume). There was an improvement of elastic modulus (E) for PLA/PBAT blends when PLA was 40%. There was no significant difference of ultimate tensile strength (UTS) among the blends. For the same concentration of PLA (40%) in PLA-PBAT mixture, PLAF exhibited higher values of E and UTS than that of PLA/PBAT blends. Elongation of PLA/PBAT blends rapidly decreased upon the addition of PLA to the blends. The values of E and UTS for PLA/PBAT blends and composite, neat PLA, and PP increased with the decreasing of temperature from room temperature to -18°C. The effect of decreasing temperature was not observed on elongation. It was appeared from the results obtained for FTIR and DSC measurements that PLA and PBAT were immiscible, separating into two phases.

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