Analysis Of The Operation Effect And Modification Of A Light Hydrocarbon Recovery Unit

Currently,according to the conditions of the unit raw gas has larger diference from the time when it has been designing,the content of the C3+ has increased?the amount of the rude gas has declined and the pressure of the raw gas has rised up by years, all of above changes lead to the decline of the skid mounted unit's yield of C3 and C3,by the same time the unit has some problems of the process design and the operation of the equipment,this thesis is mainly analyzed the operation of the skid mounted unit.In order to solve a series of problems in the actual production process of the equipment and make sure that the set of devices maintained in good working condition, improve the C3 and C3+ recovery rate as well as the output of liquefied natural gas and stable light hydrocarbon,this paper have use HYSYS simulation software analysis the impact factors for the light hydrocarbon recovery unit, found that the current parameters of the device in the content of C3+ components, raw temperature, low temperature separator operating temperature and expander have a greater impact, lower raw material gas pre-cooling temperature, increasing the turbo expander expansion ratio, lower deethanizer reboiler temperatures are conducive to improve the C3 and C3+ recovery rate.To the problem of the C3 and C3+ recovery rate is not high enough,the thesis has put forward four solutions:parameter optimization?the remnant gas circulation technology? membrane separation technique?DHX technique.And has conducted a comprehensive comparison on the yield of C3 and C3+?the energy cusumption per unit of output value and the quantities of the unit modification. It's found out that the parameter optimization is the most appropriate project to improve the current C3 and C3+ recovery rate of the unit.By the same time the paper has discussed some shortcomings in the current operation system processes of the unit,such as the ice blockage in the pre-treatment system?the interconnected control of the raw gas of the pre-treatment system and the natural gas transportation doesn't work?the water cooling tower and the heat exchanger has serious scale formation?the filler of the low temperature part of the quick action emergency valve of the turbo expander booster is too short to lead ice blockage and the boiler, compressorare still have some problems in the process of operation of the system, provided further optimization measures. Such as change the pre-treatment system to upflow regeneration?the transformation of the turbo expander booster expansion process may improve the expansion side of inlet pressure, and increase the expansion ratio and cooling efficiency, an RO reverse osmosis water treatment device, so that the light hydrocarbon recovery unit to enhance quality, reduce fouling and by the transformation of the internal structure of the compressor before and after the transformation process pipe, reducing vibration effects.And the thesis has compare the before and after of the unit which has taken optimized and equipment reformatted,these also give reference to the design of light hydrocarbon recovery unit.