Performance assessment of direct injection compressed natural gas vehicle at different injection pressures using speed-sweep test method

The method of testing the gas supply systems of HBA for tightness and strength of connections is described. A schematic diagram of CNG accumulation is presented. Diagrams of test stands for compressed natural gas equipment are presented. A schematic diagram of checking the tightness of a singlefuel compressed natural gas supply system is presented. The technological process of checking the tightness of gas cylinder equipment in production conditions is presented. The technological process of inspection of a highpressure cylinder is given. The scheme of certification tests of a cylindrical CNG gas cylinder is shown. The scheme of certification and control of production of CNG cylinders is given. The diagram for testing and tightness of a twostage compressed natural gas reducer is given. Keywords rules and test methods; leakproofness; certification; singlefuel and dualfuel system; compressed natural gas; test modes; certification tests of the cylinder and gas equipment components; destruction of the cylinder

Get full-text (via PubEx)

Friction Reduction in Compressed Natural Gas Direct Injection Engine using Piston Rings with Diffusion Chromium Coating

Journal of Applied Sciences ◽

10.3923/jas.2010.462.470 ◽

2010 ◽

Vol 10 (6) ◽

pp. 462-470 ◽

Cited By ~ 5

Author(s):

S. Abdullah ◽

E. Adril ◽

A. Muchtar ◽

A.K. Ariffin

Keyword(s):

Natural Gas ◽

Direct Injection ◽

Chromium Coating ◽

Friction Reduction ◽

Piston Rings ◽

Compressed Natural Gas ◽

Direct Injection Engine

Get full-text (via PubEx)

A quasi-one-dimensional model for an outwardly opening poppet-type direct gas injector for internal combustion engines

International Journal of Engine Research ◽

10.1177/1468087419871117 ◽

2019 ◽

Vol 21 (8) ◽

pp. 1493-1519

Author(s):

Abhishek Y Deshmukh ◽

Carsten Giefer ◽

Dominik Goeb ◽

Maziar Khosravi ◽

David van Bebber ◽

...

Keyword(s):

Natural Gas ◽

Internal Combustion Engines ◽

Flow Model ◽

Direct Injection ◽

Source Model ◽

Gas Jet ◽

Nozzle Flow ◽

Combustion Engines ◽

Compressed Natural Gas ◽

One Dimensional

Direct injection of compressed natural gas in internal combustion engines is a promising technology to achieve high indicated thermal efficiency and, at the same time, reduce harmful exhaust gas emissions using relatively low-cost fuel. However, the design and analysis of direct injection–compressed natural gas systems are challenging due to small injector geometries and high-speed gas flows including shocks and discontinuities. The injector design typically involves either a multi-hole configuration with inwardly opening needle or an outwardly opening poppet-type valve with small geometries, which make accessing the near-nozzle-flow field difficult in experiments. Therefore, predictive simulations can be helpful in the design and development processes. Simulations of the gas injection process are, however, computationally very expensive, as gas passages of the order of micrometers combined with a high Mach number compressible gas flow result in very small simulation time steps of the order of nanoseconds, increasing the overall computational wall time. With substantial differences between in-nozzle and in-cylinder length and velocity scales, simultaneous simulation of both regions becomes computationally expensive. Therefore, in this work, a quasi-one-dimensional nozzle-flow model for an outwardly opening poppet-type injector is developed. The model is validated by comparison with high-fidelity large-eddy simulation results for different nozzle pressure ratios. The quasi-one-dimensional nozzle-flow model is dynamically coupled to a three-dimensional flow solver through source terms in the governing equations, named as dynamically coupled source model. The dynamically coupled source model is then applied to a temporal gas jet evolution case and a cold flow engine case. The results show that the dynamically coupled source model can reasonably predict the gas jet behavior in both cases. All simulations using the new model led to reductions of computational wall time by a factor of 5 or higher.

Get full-text (via PubEx)