This article describes the application of technology for quenching catalytic pyrolysis gas at the Daqing commercial CPP test unit and the Shenyang commercial CPP production unit.On the basis of results for application...This article describes the application of technology for quenching catalytic pyrolysis gas at the Daqing commercial CPP test unit and the Shenyang commercial CPP production unit.On the basis of results for application of the Shenyang CPP unit this paper puts forward an improved process flow scheme for quenching the pyrolysis gas and made calculations using the process flowsheet software.Case Ⅰ of the process flow scheme,which is designed for full circulation of slurry,intends to use the pyrolysis light oil and fresh feed oil as the quenching media with the product slurry oil and fresh feedstock being discharged from the quench cooler bottom and routed directly to the reactor so that the fresh feed oil can be preheated prior to pyrolysis.Case Ⅱ of the process flow scheme intends to adopt recycle oil as the quenching medium with the product slurry and recycle oil being discharged from the quench cooler bottom to the fractionator,which then delivers the slurry from the bottom.These two cases for improving the process flow diagram can all effectively control the density and viscosity of the quenching medium to secure the smooth operation of quench cooler.展开更多
Transient heat transfer has been experimentally investigated for subcooled water jet impingement quenching of a hot rotating stainless steel cylinder. Temperatures beneath the impinged surface were measured during que...Transient heat transfer has been experimentally investigated for subcooled water jet impingement quenching of a hot rotating stainless steel cylinder. Temperatures beneath the impinged surface were measured during quenching and used to estimate surface temperature and surface heat flux by using a developed numerical inverse solution of heat conduction. Heat flux reached its maximum value just after the WF （wetting front） （visible leading edge of boiling region） started moving from stagnation towards the circumferential region. WF moved in a non-uniform manner in angular direction on the hot rotating surface. With the increase of surface velocity, heat flux decreased. Higher surface velocity moved away the produced vapor bubbles and reduced the solid-liquid contact time which made it one-dimensional heat conduction from multi-dimensional, that reduced heat flux. The generated boiling curve from the estimated heat flux showed a reasonable agreement with existing studies. The surface maximum heat flux （maximum value in each cycle） distribution trend with radial position is entirely comparable with the static surface critical heat flux in literature. An explosive to a sheet like flow patterns were observed with the decrease of surface temperature. The flow patterns were followed by the intensity of sound during quenching.展开更多
文摘This article describes the application of technology for quenching catalytic pyrolysis gas at the Daqing commercial CPP test unit and the Shenyang commercial CPP production unit.On the basis of results for application of the Shenyang CPP unit this paper puts forward an improved process flow scheme for quenching the pyrolysis gas and made calculations using the process flowsheet software.Case Ⅰ of the process flow scheme,which is designed for full circulation of slurry,intends to use the pyrolysis light oil and fresh feed oil as the quenching media with the product slurry oil and fresh feedstock being discharged from the quench cooler bottom and routed directly to the reactor so that the fresh feed oil can be preheated prior to pyrolysis.Case Ⅱ of the process flow scheme intends to adopt recycle oil as the quenching medium with the product slurry and recycle oil being discharged from the quench cooler bottom to the fractionator,which then delivers the slurry from the bottom.These two cases for improving the process flow diagram can all effectively control the density and viscosity of the quenching medium to secure the smooth operation of quench cooler.
文摘Transient heat transfer has been experimentally investigated for subcooled water jet impingement quenching of a hot rotating stainless steel cylinder. Temperatures beneath the impinged surface were measured during quenching and used to estimate surface temperature and surface heat flux by using a developed numerical inverse solution of heat conduction. Heat flux reached its maximum value just after the WF （wetting front） （visible leading edge of boiling region） started moving from stagnation towards the circumferential region. WF moved in a non-uniform manner in angular direction on the hot rotating surface. With the increase of surface velocity, heat flux decreased. Higher surface velocity moved away the produced vapor bubbles and reduced the solid-liquid contact time which made it one-dimensional heat conduction from multi-dimensional, that reduced heat flux. The generated boiling curve from the estimated heat flux showed a reasonable agreement with existing studies. The surface maximum heat flux （maximum value in each cycle） distribution trend with radial position is entirely comparable with the static surface critical heat flux in literature. An explosive to a sheet like flow patterns were observed with the decrease of surface temperature. The flow patterns were followed by the intensity of sound during quenching.
