نتایج جستجو برای: surge valve
تعداد نتایج: 120608 فیلتر نتایج به سال:
surge and rotating stall phenomena are two dynamic instabilities that occur in both axial and centrifugal compressors. surge is the stream instability phenomenon in compressor that imposes severe damages to the compressors. nowadays, suppressing surge phenomenon is one of the most important issues in oil and gas industries, especially when flow reduction or gas reflux is considered. this resear...
surge is one of the two destructive factors in compressors. surge is the stream instability phenomenon in compressor that imposes severe damages to the compressors. nowadays, suppressingsurge phenomenon is one of the most important issues in oil and gas industries, especially when flow reduction or gas reflux is considered. according to moore-greitzer compressor model, this paper designs an act...
In a hydroelectric power plant or in a pumping station in order to avoid sudden large increase of pressure due to instantaneous valve closure sometimes a surge tank is installed. The height of surge tank is designed by the highest possible water level during the operation. The theoretical treatment of oscillation in a surge tank is difficult because of the non-linearity of friction term in the ...
Previous work on stabilization of compressor surge is extended to include control of the angular velocity of the compressor. First a low-order centrifugal compressor model is presented where the states are mass flow, pressure rise, and rotational speed of the spool. Energy transfer considerations are used to develop a compressor characteristic. In order to stabilize equilibria to the left of th...
In this paper we propose anti surge controllers for a close coupled valve in a compression system. The valve modifies the characteristic of the compressor, and allows for stable operation beyond the original surge line. The design tool used is backstepping and global uniform asymptotic stability is proven. Damping terms are included in the controllers, and in the presence of both mass flow and ...
This thesis contains new results in the eld of modeling and control of rotating stall and surge in compressors. A close coupled valve is included in the Moore-Greitzer compression system model and controllers for both surge and rotating stall is derived using backstepping. Disturbances, constant and time varying, are then taken into account, and nonlinear controllers are derived. Stability resu...
Water hammer is one of the unsteady flows in urban water distribution networks, which has been of great importance due to the damage caused to the pipeline and has always been of interest to researchers. In this study, the phenomenon of water hammer due to the sudden closure of the valve in the downstream end has been investigated in a laboratory and using a numerical model. In the laboratory s...
Stable operation of axial and centrifugal compressors is limited towards low mass 1ows due to the occurrence of surge. The stable operating region can be enlarged by active control. In this study, we use a control valve which is fully closed in the desired operating point and only opens to stabilize the system around this point. As a result, only nonnegative control values are allowed, which co...
An experimental study was performed to identify the surge inception dynamics and to demonstrate an active surge control on a 600 HP class Allison 250-C30 gas turbine engine. Throttling orifices inserted between the compressor and the combustor were used to move the steady state operating line toward the surge line. The compressor was then adjustably throttled into surge using water injection do...
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