Browsing by Author "Sany Izan Ihsan, Ph.D"

This study aims to design, fabricate, and study the performance of a thermal cell absorber attached to a flat plate absorber collector. Flat Plate Solar Collector (FPSC) is widely used in agricultural products for drying applications. An investigation into the effect of design parameters on FPSC has been carried out. Flat Plate Base-Thermal Cell Absorber (FPBTCA) has been designed and fabricated based on the design parameters experiment results which are; absorber base materials (AL), absorber base thickness (0.5 mm), the air gap distance between glass and absorber base (10 mm), the air gap distance between glass 1 and glass 2 (0.4 mm), double glass, glass thickness (2.0 mm), thermal cell thickness (1.0 mm) and material (SS). The experiment was performed using a solar simulator with solar radiation of 700 W/m2. The solar simulator is used as the artificial sun, which is exposed to solar radiation for 300 seconds and without solar radiation also for 300 seconds. The heat transfer rate of the collector (Q ̇) and efficiency of the collector shows that stainless steel 1.0 mm with aluminum base absorber has a higher value which is 412 kJ, 18.21 kW, and 47.08 %, respectively. The performance of the outlet temperature in the drying chamber of stainless steel with an aluminum absorber has a higher value of energy gain which is 116.08 J at 300 seconds. Evaluation under outdoor conditions revealed that the FPBTCA has a lower temperature discharge rate as compared to the FPSC. FPBTCA also shows the highest heat absorption (Q ̇), which is 96079.37 J on 4 March 2021, then FPSC, which is 49187.07 J. The highest efficiency for FPBTCA at 360 minutes is 30.24 %, and for FPSC is 21.81 %. The efficiency of FPBTCA is consistent while the solar radiation is decreased at 120 minutes and 180 minutes. Mathematical modelling analysis proved that the error for energy balance is below 5%. FPBTCA has been introduced to enhance the thermal performance and efficiency of solar thermal collector systems. It also has higher heat storage capabilities during solar radiation drops when the weather is cloudy.

An efficient solar collector design that effectively absorbs solar energy and converts it into heat is required during intermittent solar radiation. Existing Flat Plate Collector (FPC) and Heat-Pipe Evacuated Tube Collector (HP ETC) are designed for water heating required storage tanks, while an additional heat exchanger is required for air heating application which leads to extra spacing and cost. The installation also needs to be tilted at the correct angle and positioned to south/north facing to optimize the system performance. These could lead to design limitations. Therefore, this study aims to design, develop and investigate the thermal performance of an Evacuated Glass-Thermal Absorber Tube Collector (EGATC) for air heating applications. EGATC was designed from a conventional HP ETC, and the performance was compared through parameter and performance experimental setup. The three days performance experiments showed EGATC performed better with daily outlet temperature increased by 9.0%, 7.2%, and 4.9%, respectively, with an average of 7.0% compared with HP ETC. EGATC also had greater efficiency compared to HP ETC, with the average efficiency for EGATC being 51.3% compared with HP ETC's 41.8%. EGATC's inner absorber was designed to create a double pass flow with the ventilated chamber. The parameter experiment shows the design could increase the outlet temperature by a difference of 6.3% (for stainless-steel inner absorber compared with insulation material inner absorber). Regarding energy storage, the stainless-steel inner absorber also had an advantage compared to the insulation material inner absorber, with a 1.3% difference. On the effect of other parameters such as inner absorber surface area air contact (perforated fin), outer absorber selective coating surface, outer absorber wall thickness, double layer non-vacuum glass tube, single layer transparent outer glass tube, and single-layer thin film inner glass tube was investigated by parameter experimental setup on energy storage. It was proven that the outlet temperature, energy store, and energy buffer could be enhanced with the combination of wind speed 0.9 m/s, zero (0) perforated fin, non-coating outer absorber, and 1 mm outer absorber wall thickness. It was also reported that double-layer vacuum glass tubes promise better thermal performance enhancement compared with double-layer non-vacuum glass tubes, single-layer transparent outer glass tubes, and single-layer thin film inner glass tubes. The mathematical equation of each EGATC component was formulated based on the first law of thermodynamics. The total acceptable error of 5% shows that the model at each node was valid. The performance curves for those 0 fins (equation), 0 fin (experimental), and 3 fins (experimental) were obtained. The results showed that the efficiency (collector + storage) was affected by the number of fins. The efficiency (collector + storage) was 68.7%, 71.2%, and 71.0%, respectively. In conclusion, the application of EGATC in air heating applications proved beneficial to the application of solar drying processes, especially in equatorial climate countries such as Malaysia.

There have been several studies on heat transfer surfaces, where air and water temperatures are elevated by the heat transfer from other media. This research presented a new approach which entails a preventive maintenance technique, for improving the boiler efficiency, analysed using a specific methodology and literature data. A high boiler efficiency can be achieved, using an optimal approach of the preventive method, with an optimisation technique. Particularly in the State of Kuwait, steam boilers used to be more in numbers, and in some industries, breakdown and failures during the operation have been found. Therefore, in these cases, some additional care is required on such studies; a preventive maintenance technique is a suitable approach for the boilers used in the oil and gas industries in Kuwait. This approach has numerous advantages that make this technique helpful for any plant size. Most of the oil and gas industries in Kuwait are significant, and this approach will be cost-effective and efficient for large industries. When the plant assets value is high, the return will be high, and while using this approach, the proper maintenance helps to keep the high boiler performance, even for the old system. The results obtained showed that, the preventive maintenance is essential not only for improving the production rate of the industry, it also helps to make the boilers safe for the operators to work there. Based on the analysis conducted, it was revealed that, the preventive maintenance reduces the operating costs by preventing boiler failures. The research further recommended that, the results produced in the present thesis proved the benefits of the preventive maintenance for a high boiler efficiency in oil and gas industries in the State of Kuwait.