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.

Nowadays the fuel energy is consumed more than it was used in the past and most of energy used comes from petroleum which is not reuseable. Morever the crude oil which is raw material to be refmed is likely to take place in nature; it usually takes a long time. Therefore this natural resource must be used efficiently to maximize its benefits. Contructing Econo Power Car will be one ofmany methods to decrease the energy consumption. The Econo Power Car was designed to be water drop in order to reduce the wind resistance. The body was designed to cover all parts in order to decrease the circulation of air and the lightweight aluminium alloys were the materials to use. Besides the engine was improved to increase the complete combustion by adding 2 more spark plugs and an inlet valve rocker arm slide was installed to reduce the energy consumption ofthe engine while it was turn off. The test to fmd out the economy rate was done by collecting data based on the theory from the Automotive Engineering. The crucial factors affecting the economical fuel consumption was frictions which were friction of the road and friction of the air. Therefore the design to be water drop-shaped with closed cover was done to reduce friction and the wheels were adjusted everytime before competition. The results revealed that it archieves the goal. From the 7th Honda Econo Power it could save energy at the rate 543.018 km per litre at the speed 25 km per hours.

The objective of this research is to study the development of eco cars using power-cutting mechanism technique of Transmission System. Two eco cars had been studied. The first car was conducted with the aim of developing transmission system and clutch system by changing from gear drive transmission system and chain drive mechanical clutch to belt and pulley transmission system by new designing the belt and pulley transmission system to have propeller shaft as the device to transmit power from the right to the left side with bearings to help reduce friction. Pulley system and clutch lever were installed in which the newly built clutch can be controlled by driver. The new model of transmission system is weight 0.7 kg which is lighter than the previous weight of 0.8 kg. Based on the first testing by participating in the 22nd Honda Eco Mileage Challenge at Chang International Circuit it was found that the system with belt tension at 1 kN resulted in good performance of transmission system and clutch system with fuel efficiency value at 626.157 km/L. After that the belt tension was adjusted and set up at 1.1 kN for 3 tests at Solar Track Thailand and it was found that the maximum fuel efficiency value was 1061.18 km/L at the speed of 34 km/hr. The second car was improved in transmission system suspension system steering system and also engine. The first trial was experimented on the 22nd racing event at the Chang International Circuit where this fuel efficient prototype car could run at 18 km. The result showed that it could have good mileage which was 275 km/L. After improvement the car was tested again for three times at the Solar Track Thailand circuit where it ran at 16 kilometers. The result revealed that the best saving was equivalent to 613 km/L at the speed of 30.6 km/hr.

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.

Thesis is the development of radio-controlled lawn mower which can move and cut the grass in the desired environment and dangerous to human. The objective is to develop a radio-controlled lawn mower. The results showed that the rate of fuel consumption of controlled lawn mower in to cutting grass. The height of the grass at 6 8 and 10 cm. It has the average fuel consumption is 113 117 and 123 ml. The average time in the mowing is 6.6 8.01 and 9.69 minutes