Abstract: Through the relationship of CNG density changing with pressure and temperature, this paper studies the theoretical basis of increasing pressure and effective measures to improve the driving range of CNG vehicles.The calculation model of CNG gas compression factor is established, and it is calculated that 35 MPa is the best comprehensive efficiency improvement point of CNG pressure.The variation of CNG density with temperature under 20 MPa and 35 MPa pressure is compared and analyzed. The inflation efficiency can be increased by about 45% in theoretical state, and about 50%～54% in actual rapid filling condition.Compared with WLTC test, the driving range can be increased by 70%. It is verified that the filling mode and charging temperature are the key factors affecting the charging efficiency. Graded cooling and charging after pressure increase is an effective measure to further improve the driving range of CNG vehicles.

Key words: CNG vehicle; Pressure increase; Driving range; Change relationship

摘要： 通过 CNG 密度随压力和温度变化关系研究提升压力的理论依据和提高 CNG 汽车续驶 里程的有效措施，建立 CNG 气体压缩因子计算模型，计算得到 35 MPa 是 CNG 压力最佳综合 效能提升点；对比分析 20 MPa 和 35 MPa 压力下 CNG 密度随温度的变化关系，理论状态下 可提高充气效率约 45%，而实际快速充装条件下可提高约 50%～54%；并通过 WLTC 试验对 比续驶里程可增加达 70%，验证了加气方式和充气温度是影响充气效率的关键因素，压力提 升后分级降温充气是进一步提高 CNG 汽车续驶里程的有效措施。

关键词: CNG 汽车；压力提升；续驶里程；变化关系