This research focuses on the raw-material management such as fuel of a case study company being a freight forwarder in Chonburi province. The objective is to determine the economic order quantity (EOQ) and the reorder point (ROP) that minimize the total cost of handling. Five forecasting techniques are investigated to predict the future demand and it was found that the time series decomposition was the most suitable method with the least error. At the result of demand forecasting the economic order quantity is 16308.89 liters per time the total cost of handling the fuel tank is 17287.43 baht and there are ordering around 19 times per year. In addition the sensitivity study on demand factors affecting the cost of fuel tank management are also considered in this paper. It was found that 21% of the increased fuel demand brings the total handling cost is 1728.74 baht or increasing 10%. Therefore ordering economically can reduce the total cost of 1295.97 baht or 6.85%. If the company brings the studied results to improve the ordering process it will be able to forecast the order quantity more appropriately and effectively.

According to the research entitled “the innovative engine prototype powered by diesel and LPG as fuel for agricultural” in 2019 the problems found while using the engine were as follows: the accumulated heat in the auxiliary combustion chamber reached 300 C in case of gasoline engine use and a lot of black smoke in the exhaust was found at the speed higher than 1800 rpm in case of a diesel engine use. In order to extend the research and solve two foresaid problems the objectives of this study were 1) to develop an auxiliary combustion chamber for cooling 2) to develop a scalable gas-air mixing device and 3) to compare diesel and LPG consumption rates by modifying a small diesel engine Yanmar version TF120DI to install LPG fuel systems and ignition system. In addition a gas-air mixing device was modified while an auxiliary combustion chamber was developed to reduce the compression ratio to the same level as the gasoline engine for replacing the position of the original diesel fuel injector. This method could support LPG fueling only whose function was characterized by the function of a gasoline engine. The auxiliary combustion chamber could be removed and then installed a diesel injector to return using diesel fuel. From an experiment to compare the modified engine operating as a gasoline engine it was found that the temperature of the auxiliary combustion chamber and the temperature of the engine cylinder head of Honda GX160 were measured at the maximum speed of 182 C and 186 C respectively. It was found that carbon monoxide content was 0.41 % and 1315 ppm hydrocarbons. When used as a diesel engine it was found that the black smoke was exhausted at 1.5 % which was similar to the diesel engine before the modification. From the experiment of using the power engine for pumping water with an Irrigation propeller pump with the diameter of 8 inch at a constant engine speed of 1000 rpm it was found that the average diesel usage was 0.65 kg/hr or about 0.77 L/hr with the cost of 21.00 Baht/hr and if using LPG as fuel the average LPG consumption was 0.57 kg/hr with the cost of 13.71 Baht/hr which could save up to 34.71 % of costs.

Young coconut shells are a byproduct after processing coconut juice which can be used to produce a solid-fuel. This fuel from the coconut shell is an alternative source instead of using firewood or charcoal made of timber in the natural forest. The solid-fuel from young coconut shells was prepared by using a wet glue powder as a binder then was compressed by using a briquette machine. The black coconut briquette was stable after exposure to the sun. The average of the briquette combustion rate was at 11.24 g /min. There is no eruption smut smoke and odor by using the young coconut shell briquette yo start a fire. To sum up a young coconut shell has a high potential as an alternative biomass material for producing a briquette especially for commercial. This solution can increase the reduction of haze weather in the sight of solid waste incineration and also global warming.

The study of the efficiency of fuel consumption by adjusting the fuel injection pressure is basically one optimization method to maximize the engine combustion. In this current study the Honda wave 110 cc. engine has been used to test in particular the fuel injection by adjusting the pressure of injector. To control the pressure of injection was made by automatic valve injectors with three different pneumatic pressure which were 2 2.5 and 3 bars respectively and the similar running distance of 5km. The results showed that at 2 bars the obtained fuel saving was 1020.68 km/L and the speed at 25.23 km/h which corresponded to the highest CO2 emissions during the engine combustion.

Objectives of this study are (i) to investigate characteristics of a fuel injector and to establish the characteristic correlation for correcting the fuel injection rate calculated from the control signal of a fuel injector and (ii) to design and fabricate the fuel consumption monitoring system by measuring the control signal of fuel injector in conjunction with considering the obtained characteristic correlation to enhance accuracy of the measured fuel consumption rate. The characteristics of a fuel injector (maximum fuel injection rate of 270 cm3/min) e.g. engine speeds percentages of injector’s duty cycle and pressure differences between fuel rail and intake manifold were experimentally investigated on a test set in the laboratory. The study found that when the engine speed increased the fuel injection rate increased. When the percentages of infector’s duty cycle increased the increasing ratio was less than the one-to-one increasing ratio as a case of the ideal. Moreover when the pressure difference increased the fuel injection rate increased. After that the fuel consumption monitoring system was designed and fabricated based on the Arduino Mega 2560 microcontroller. Trip distance was measured by a GPS module. The real-time fuel consumption rate could be shown on a LCD display. All recorded data were stored onto a SD card for further data analysis. Finally the on-road-test validation was conducted by on the 2011 Mitsubishi Triton installed with the 4-cylinder gasoline engine with total displacement of 2351 cm3. It was found from that the average discrepancy of the measured fuel volume was ± 1.88% compared to the actual fuel volume obtained by measuring a decreasing volume of consumed fuel.