Automatic control of a hydrocracker
AssigneePhillips Petroleum Company
InventorsDavid A. Christie, James W. Hobbs
Life of this patent
Estimating the term…
Abstract
From the values for the recycle oil feed rate and the fresh oil feed rate of a hydrocracker a material balance conversion computation is carried out resulting in a material balance conversion signal. From the values for the hydrogen flow rate the temperatures and the pressures thereof and the total oil feed flow rate and the flow rate and temperature of the material leaving the hydrocracker, an enthalpy balance conversion computation is carried out resulting in an enthalpy balance conversion signal. The material balance conversion signal and the enthalpy balance conversion signals are computed into a control signal. The control signal regulates the temperature of the total charge to the hydrocracker to maintain the actual percentage conversion at a desired value.
Claims11
A method for controlling the conversion of a hydrocracker comprising
- a. passing a stream of fresh oil feed into the feed inlet portion of said hydrocracker as part of the charge thereto,
- b. passing at least one hydrogen stream into the feed inlet portion of said hydrocracker as part of the charge thereto,
- c. withdrawing reactor effluent from said hydrocracker,
- d. separating from said reactor effluent a recycle oil stream,
- e. passing said recycle oil stream into the feed inlet portion of said hydrocracker as part of the charge thereto,
- f. determining the rate of total oil flow into the hydrocracker and generating a total oil flow rate signal responsive thereto,
- g. generating hydrogen mass flow rate signals for each hydrogen stream introduced into the reactor,
- h. determining the inlet temperature of the charge to the hydrocracker at the feed inlet portion thereof and generating an inlet temperature signal responsive thereto,
- i. determining the temperature of the effluent withdrawn from the hydrocracker proximate to the outlet portion thereof and generating an outlet temperature signal responsive thereto,
- j. automatically computing from the signals generated in step (f) through (i) an enthalpy balance conversion and generating an enthalpy balance conversion signal responsive thereto,
- k. determining the flow rate of said recycle oil stream and generating a recycle oil flow rate signal,
- l. automatically computing from said total oil flow rate signal and from said recycle oil flow rate signal a material balance conversion and generating a material balance conversion signal responsive thereto,
- m. generating an inlet temperature control signal responsive to both the material balance conversion signal and the enthalpy balance conversion signal, with the further provision that the material balance conversion is calculated for a first set of parameters and the enthalpy balance conversion is calculated for a second set of parameters determined at a time subsequent to the determination of the first set of parameters,
- n. generating a control signal responsive to the inlet temperature control signal and the inlet temperature signal.
- o. regulating the temperature of the charge to the hydrocracker at the feed inlet port thereof responsive to said control signal such as to control the actual conversion rate of the hydrocracker to keep it at a desired value.
Dependencies are inferred from the claim text.