In order to better match the tandem composite turbine and study the utilization of engine exhaust gas energy under various working conditions, the thermodynamic model of a gasoline homogeneous charge compression ignition(HCCI) engine and the mathematical model of its tandem composite turbine system were established. A one-dimensional simulation model of the HCCI engine was also constructed. Based on the tandem composite turbine parameters calculated by the mathematical model, an appropriate tandem composite turbine system was selected, and the one-dimensional simulation verification was carried out. Based on the matching results, the energy distribution in the tandem composite turbine system was studied. The results show that the tandem composite turbine system selected by the proposed matching method can effectively recover the exhaust gas energy and improve the performance of the whole machine. At a speed of 2200r/min and an indicated mean effective pressure(IMEP) of 1.26MPa, the power of the whole machine is increased by 3.17kW, and the efficiency of the whole machine is improved by 2.49%. The exhaust gas energy distribution results show that the power turbine is suitable for the working condition of the engine speed higher than 1600r/min and the IMEP greater than 1.07MPa. There is an optimal intake pressure at this time, so that the exhaust gas energy obtained by the power turbine has the best proportion of exhaust gas energy, leading to an optimized engine thermal efficiency.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |