Design and development of a supercharger for a single cylinder diesel engine | |
| Author | Kritwit Jaiklangburana |
| Call Number | AIT Thesis no.AE-04-01 |
| Subject(s) | Superchargers Cylinders Diesel motor--Cylinders |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AE-04-01 |
| Abstract | A single cylinder diesel engine is a major source of power for agricultural work in small to medium households for many years. The trend of demand for higher size of engine has increased year by year. Therefore, the higher power output with the same size of engine block will be needed in the near future. The objective of this research was to increase the power output of the existing engine by using supercharger, a kinds of air compressor, to force more air into the engine cylinder in order to increase the amount of combustible fuel or combustion efficiency. The methodology started with preliminary study of the theoretical ideal diesel cycle. The benefit gain or lost at different levels of boost pressure and air-fuel ratio were calculated. Then the artificially compressed air supply system was build up to serve as the variable boost pressure supercharger. By connecting the air reservoir to intake manifold and industrial air compressor with pressure control valve, the expected performance from supercharged engine was evaluated. After the evaluation of expected performance had been done the information obtained were used in the design of the supercharger unit according to the optimal boost pressure and fuel injection setting. Additionally, in order to benchmark performance this new design supercharger, the commercial roots type supercharger was tested. The results obtained from preliminary study of the ideal diesel cycle showed that the air fuel equivalent ratio of 1.8 is the optimal level for all boost pressure level but higher boost pressure can increase more power but at decreasing rate. The same trend was also found in expected performance test using artificially compressed air supply system. More boost pressure can increase more power but the engine had its own cooling capacity limits, so the maximum boost pressure is limited to 0.2 kg/cm2 with fuel injection setting at 12.5% more. Once the optimal boost pressure and air-fuel ratio was determined, a commercial roots type supercharger with the size closest to the research engine was selected and the performance gain was evaluated. It showed the similar trend but the benefit is quit lower than that in expected performance test due to very high fluctuation in air flow rate of single cylinder diesel engine during intake valve closing and opening. This behavior lead to very high difference of boost pressure between starting of induction stroke (intake valve opening) and just before ending of induction stroke (the engine piston was at bottom dead center). Because of this very high peak boost pressure, the charged air temperature was also raised. While in the expected performance test the artificial compressed air supply system can supply the cooled compressed air. This very high peak boost pressure with the same flow rate made the power needed to pump the air into cylinder was also higher than that calculated in expected performance test. However the selected commercial supercharger still can be found beneficial especially in low speed range both in terms of .power and fuel economy. |
| Year | 2004 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AE-04-01 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Salokhe, V.M.; |
| Examination Committee(s) | Afzulpurkar, Nitin V. ;Jayasuriya, H.P. W.; |
| Scholarship Donor(s) | The Siamkubota Industry Co., Ltd., Thailand; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2004 |