The Application Research And Improvement Design On Double Cylinder Single Acting CNG Compressor

Compressed natural gas (CNG), as an ideal alternative fuel used for car, is provided with the characteristics, such as low cost, high combustion efficiency, minimum exhaust pollution, lower engine noise and prolonging engine life. This clean energy as the alternative fuel utilized by car will be widely used. This compressor researched and developed by a company, works on the principle of single-stage and two-cylinder compression, and its compression action takes part at both directions of hydraulic cylinder travel. Therefore, it is of the advantages of simple construction and low cost, lower power losses. Its input pressure is 7-20MPa, and output one is 25MPa, with widely market application prospect. Outstanding problem, however, is come across in the prototype testing, that is, the reversing valve works unstable and sometimes it is jammed, which causes reliability problem of the machine.The necessary conditions for the reversing valve regular work in the CNG compressor is investigated, flow force of the spool valve is calculated in this thesis. Aimed at the specific questions in operation of the compressor, improvement approaches are given, that is the spring ball stop and the relative subsidiary structure is added. Meanwhile, all the numerical values of the improvements mechanism are calculated, in order to guarantee the applicability of plan.