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Thermal performance evaluation of water-based gel packs and insulating covers: A case study on raw milk preservation for local transport
(2025-12-01)
Chaomuang, Nattawut
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Laguerre, Onrawee
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Flick, Denis
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Duret, Steven
Maintaining the quality and safety of raw milk during transportation to collection centers poses significant challenges for small-scale producers, especially in regions with limited access to advanced refrigeration systems. This study proposes a cost-effective cooling system utilizing water-based phase change material (PCM) gel packs and UV-reflective covers. The thermal performance was evaluated using a tank filled with water, both with and without PCM, under constant and variable ambient temperature conditions. Results demonstrated that the tanks with PCM achieved a temperature reduction of 10–13 °C within an hour. Comparative analysis revealed similar thermal behaviors for milk and water, enabling the extrapolation of results. A simplified heat transfer model based on energy balance was developed to predict product temperature changes under different operational conditions. Some input parameters were adjusted using experimental data, and the model was subsequently validated against separate experimental datasets, showing reasonable accuracy (RMSE < 3.0 °C). The model could be used for application under comparable conditions. Furthermore, milk quality preservation was assessed through the enumeration of Escherichia coli and total coliforms in milk stored in tanks with and without PCM, as well as through predictive microbiological modeling. Both measured and predicted results suggested a moderate reduction in E. coli growth rates (1.1–1.3 times slower) in the tank with PCM, depending on initial microbial load. Based on these findings, the proposed system offers an effective and economical solution for small milk producers, enhancing cold-chain management and reducing spoilage.
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Storage conditions, energy consumption, and food safety implications of domestic refrigerators in Bangkok
(2025-12-01)
Chaomuang, Nattawut
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Potisuwan, Cheeraphat
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Duret, Steven
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Derens-Bertheau, Evelyne
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Paviet-Salomon, Yvanne
Domestic refrigeration plays a critical role in food preservation and safety by maintaining optimal storage conditions for perishable items. This study investigated the temperature and humidity conditions, as well as the energy consumption, of domestic refrigerators in Bangkok. Data were collected through on-site investigations of 123 refrigerators using data loggers to record temperature, humidity, and electrical consumption over a five-day period. In addition, a predictive microbiological model was used to assess the potential for microbial growth under the investigated storage conditions, specifically of Listeria monocytogenes and lactic acid bacteria (LAB). Results indicated that although the overall mean temperatures of chilling compartments (5.0 ± 2.5 °C) were within the recommended range for domestic refrigeration, only about 30–40 % of individual refrigerators consistently maintained temperatures at or below 5 °C on the top and middle shelves throughout the five-day monitoring period, where fresh and ready-to-eat products are typically stored. Electrical consumption analysis revealed significant differences across refrigerator types; appliances with two doors and bottom freezers exhibited the highest annual electrical consumption, while single door refrigerators recorded the lowest. However, the specific energy consumption (SEC) did not differ significantly among refrigerator types. The microbial exposure assessment based on a test product highlighted that for over 50 % of refrigerators, L. monocytogenes load exceeds the regulation safety limits (> 10<sup>2</sup> CFU/g) within five days. These findings emphasize the need for improved temperature control, appliance design, and consumer education to ensure food safety and energy efficiency in domestic refrigeration.
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Developing Efficient Temperature Control for HERMS: A Study on P, P-Logic, PI, and PID Controllers
(2025-01-01)
Subhagandha, Thanachok
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Boksuwan, Sungwan
The Heat Exchange Recirculating Mash System (HERMS) is widely used in craft brewing to maintain precise temperature control during the mashing process, which is crucial for achieving optimal sugar extraction and mash efficiency. This study investigates the performance of four different temperature control strategies-P, P-logic, PI, and PID-in maintaining the desired mash temperature profile. The system was modeled using both First-Order Plus Delay (FOPD) and Second-Order Plus Delay (SOPD) models to optimize controller gains through Skogestad's method. Validation of the control strategies was conducted through simulations in MATLAB Simulink. The results showed that while P-logic control maintained stable temperature with 0% overshoot, PI and PID controllers achieved the same with only 30% input energy, compared to 100% used by P-logic. A real-world mashing is conducted with P-logic control. Wort quality was also assessed, with specific gravity, pH, and mash efficiency analyzed. This study highlights the trade-offs between control precision and energy consumption, providing valuable insights for improving HERMS system efficiency in both homebrewing and commercial applications.
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EXPERIMENTAL STUDY ON ENERGY CONSUMPTION OF TEMPERATURE CONTROL BY USING ON-OFF INTELLIGENT FUNCTION
(2023-05-01)
Pongswatd, Sawai
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Sopha, Watcharapon
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Asadi, Farzin
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Smerpitak, Krit
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Thepmanee, Teerawat
In order to save electrical energy for on-off temperature control, a useful concept of on-off intelligent function to execute in a programmable logic controller (PLC) is presented. An implementation of PLC-based control system based on electric heating is also described as a case study to demonstrate the performance of the proposed function. IEC 61131-3-based ladder diagrams were created by using Studio 5000 software to run in the PLC modeled CompactLogix L30ER. Compared with the traditional on-off control action, the proposed on-off intelligent function can minimize energy consumption of a heater used in the implemented temperature control by 4.57%-6.65%.
1
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Implementation of control and SCADA system: Case study of Allen Bradley PLC by using WirelessHART to temperature control and device diagnostic
(2022-04-01)
Thepmanee, Teerawat
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Pongswatd, Sawai
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Asadi, Farzin
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Ukakimaparn, Prapart
System integration for process automation promoted the technologies that were accessed to functions and data of field device, controller, and SCADA system. In addition, the data from filed devices can apply to solve device diagnostic and preventive maintenance. This paper describes the practical technique to configure and implement of control and SCADA system that focus on integration of field device, PLC controller, and SCADA system. The paper presents case study of Allen-Bradley (AB) PLC by using WirelessHART device to temperature control and device diagnostic through SCADA system. PLC's input/output (I/O) modules are installed that consists of Modbus module, digital I/O module, analog I/O module. In addition, Prosoft configuration builder and Studio 5000 software are new software to build add on Modbus instruction and ladder diagrams, respectively. The experiments perform in case study of temperature control by using Proportional–Integral–Derivative (PID) function in the AB PLC. Wonderware InTouch SCADA software is implemented to monitor the process mimic, trend, and alarm. Moreover, the technique can support the operators and engineers to make decision for process control and devices diagnostic.
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Optimization of Temperature Sensors for Drying Mangosteen Peel
(2021-01-01)
Pongsuttiyakorn, Thadchapong
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Sooraksa, Pitikhate
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Pornchalermpong, Pimpen
This paper presents the design and implementation of temperature sensors for drying mangosteen peel. To enhance the performance of temperature sensors in the drying process, Kalman innovation sequences and natural tracking indicators are employed. The natural tracking indicators can be realized by setting the maximum possible product surface temperature limit (PSTL) as the tracking points. This is very useful for preventing the loss of quality of food products. The use of temperature sensors designed using the PSTL control system is optimal in the sense that the system is adaptively adjusted for faster tracking to the set points and less energy consumption. According to experiments using mangosteen peel as the test material, the dried peel has the desired food quality. This implies that the proposed paradigm can be applied to enhance the performance of temperature sensors.
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Field-based temperature control using foundation™ fieldbus
(2015-01-01)
Petchmaneelumka, Wandee
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Pannil, Pittaya
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Julsereewong, Amphawan
In this article, a field-based temperature control using FOUNDATION™ Fieldbus (FF) is described. The proposed architecture is based on a powerful capability of FF H1 devices for building control in the field strategy. A plant model is designed and implemented for training purposes. H1 field instruments used are a 3144P temperature transmitter and an FI302 FF-to-current (FI) converter. Control block inside either the temperature transmitter or FI converter can be assigned for control decision. The NI-FBUS configurator and the developed LabVIEW-based human machine interface (HMI) are used for device configuration, control configuration, device commissioning, troubleshooting, and segment operation. Experimental results of temperature control in the range of 40-60°C verifying a workability of the proposed system are also included.

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