Songkran Wiriyasart

Natural and liquefied petroleum gases are widely used in industrial heat treatment. However, the rising cost of gas, combined with increased demand, has significantly impacted production costs and the environment. The annealing process typically relies on natural or liquefied petroleum gases as the primary heat source. In this study, we aimed to investigate the use of biomass fuel as a replacement for fossil fuels and to evaluate the mechanical properties and microstructure of wire rod steel after annealing using indirect heat from a gasifier. We experimented to examine the effects of annealing temperatures of 650 °C, 700 °C (below the critical temperature Ac1), and 750 °C (above Ac1 but below the upper temperature Ac3). The batch furnace, made of stainless steel, was modified from a traditional wire annealing furnace that originally used CNG and LPG gas burners. It was adapted into a wire annealing furnace connected to a cross-draft gasifier. The furnace’s interior was designed with spiral cooling fins to minimize energy consumption and shorten annealing time. Additionally, it was modified to use biomass as a substitute fuel, reducing environmental pollution. The furnace was coated with thermal insulation, and the biomass gasifier stove was a cross-draft device with primary air feeding at 20 m³/h and secondary air supplied at a constant flow rate of 32 m³/h, 36 m³/h, or 40 m³/h. As a fuel source, we used eucalyptus. The mechanical properties of wire rod steel were measured in terms of tensile strength and torsion, following the TIS 138-2562 standard. This standard specifies that the tensile strength must be at least 260 MPa. Regarding torsion, the TIS 138-2562 requirements state that the wire must withstand at least 75 rounds of twisting without breaking. Our results showed that after annealing at 650 °C, 700 °C, or 750 °C, with a soaking time of 30 min and subsequent cooling in the furnace at natural temperature for 24 h, the tensile strength values were 494.82, 430.87, and 381.33 MPa, respectively. The torsion values were 126.92, 125.8, and 125.76 rounds, respectively. Additionally, ferrite grain size increased with annealing temperature, reaching a maximum of 750 °C. The total annealing duration for each batch was 2 h and 40 min at 650 °C, 2 h and 10 min at 700 °C, and 2 h at 750 °C.

The Industrial Internet of Things (IIoT) plays a key role in industrial applications and manufacturing processes. Numerous technologies are implementing IIoT to monitor and control manufacturing processes, maintain reliability, and increase productivity. In this study, IIoT was used to demonstrate the heat transfer performance of a double‐pipe heat exchanger at the laboratory scale to provide research guidelines. Two types of inner pipes, smooth and corrugated pipes, were used in the experiment. In the experiment, the hot‐ and cold‐water mass flow rates were 9 and 10 L/m, respectively. The cold‐ and hot‐water temperatures were set at 20°C, 22°C, and 24°C and 35°C, 40°C, and 45°C, respectively. Equipment operation control and reading and recording of the experimental data were performed using PLC and IIoT platforms. The experimental results showed that heat exchange using corrugated pipes was more efficient than smooth pipes when considering the overall heat transfer coefficient, with an effectiveness of approximately 19%. However, corrugated pipes exhibited a 30% higher pressure difference compared to smooth pipes. This reveals that IIoT has been established and can be effectively applied to laboratory thermal solutions, allowing operators to read real‐time data at any time, both inside and outside the work area.

Heat recovered by the heat exchanger helps increase the coefficient of performance (COP) of both the air conditioner and the water heater.

Household biomass gasifier stoves (HBGSs) are used in remote areas using natural firewood that is burned in the HBGS for general purposes, such as cooking and warming in winter. The heat dissipation from the walls is assumed to be heat loss. This paper evaluates the electrical performance of thermoelectric generators (TEGs) using heat recovered from the hot walls of an HBGS, considering the effect of three primary air valve angles of 0°, 9°, and 18°. The heat recovered from the HBGS that is electrically transferred through a TEG is assessed. The results showed that the wall heat loss increases with the primary air valve angle of the HBGS. The upper zone near the HBGS gas combustion zone exhibits higher wall temperatures than the middle and lower zones, with a maximum wall temperature of 140°C resulting in an output voltage of 2.55 V. However, the middle and lower zones are also considered as their capacities are consistent with the TEG temperature range. The heat loss from the HBGS is considerably larger than that from other heat sources, and the specific heating area of the heat source is a variable that should be considered to increase the number of TEGs to achieve the desired output values for practical applications. Furthermore, this research serves as a guideline for applying TEGs to recover waste heat from various applications.

Thermoelectric cooling (TEC) reverses the electrical energy to temperature caused by the Peltier effect, where a temperature difference occurs between two conductors, that is, hot and cold junctions. This article presents the enhanced heat transfer of a TEC module using a TEC1‐12710 model integrated with a wavy channel heat sink using ferrofluid as a coolant under continuous and pulsating flows, where the differences in the distance of the magnetic field are considered. Square permanent magnets measuring 30 mm × 20 mm × 4 mm (width × length × height) are used to transmit a magnetic field to the heat sink and then tested under a magnetic distance of 10–30 mm. The test is performed at a water flow rate from 0.0083 to 0.028 kg/s and supplied with a constant TEC voltage of 12 V. By applying a magnetic field to the TEC module with a magnetic distance of 20 mm and a ferrofluid concentration ratio of 0.015%, the cooling efficiency increases by approximately 18.64%. Hence, using pulsating flow may improve thermal efficiency by approximately 23%. The results show an exponential increase in the cooling efficiency when both passive and active cooling techniques are used.