SU769240A1 - Device for control of apparatus for low-temperature separation of gas - Google Patents

Description

severe constraints complicate the system.

The purpose of the invention is to simplify the automatic system, to maintain the production of condensate at the level of current consumption at the minimum gas extraction.

This goal is achieved by introducing a level regulator installed on the condensate collector and an ontimizer, the first and second inputs of which are associated respectively with the identifier and the level regulator, and the optimizer output is connected to the second inputs of the gas flow regulators.

The drawing shows a schematic diagram of the device for the automatic control of the installation of the NTS.

The device includes installations NTS 1, which are connected from the inlet side by pipelines 2 to wells 3, and output lines 4 to gas collection manifold 5, condensate collector 6 connected to each installation NTS 1 and condensate collector 7.

A gas flow regulator 8 is installed on each NTS 1 installation, the first input of which is connected to a gas flow sensor 9 installed on the output line 4 of the NTS 1 installation, and the output is connected to an actuator 10 installed on the input line 11 of the NTS 1 installation.

The device also contains a level controller 12, mounted on collection 7, and an optimizer 13, the first and second inputs of which are associated respectively with identifier 14 and controller 12, and the output of optimizer 13 is connected to the second inputs of regulators 8. To the input of identifier 14 are connected Sensors 9 and condensate flow sensor 15 mounted on a condensate collector 6.

The device works as follows.

Gas from wells 3 through pipelines 2 enters the inlet lines 11 and then through the cleaning mechanisms 10 to the HTS 1 installations, where hydrocarbon condensate is separated from the gas by cooling. The latter enters the co-condensate collector 6 and then through the condensate consumption sensor 15 into the collector 7. The purified gas from the NTS 1 installations and the output line 4 is fed to the gas collector 5.

The consumer (naiimer, condensate processing plant) selects the condensate from the collection 7 in accordance with its need. The value characterizing the correspondence between the supply and removal of condensate is the level of condensate in collector 7. If the level of condensate is constant, then the supply of condensate from the side of the HTS installations is equal to the removal of condensate by the consumer. Otherwise the level

will either decrease or increase. Compensation of the level deviation from the set point in the proposed system is carried out by changing the flow of condensate, achieved by changing the performance of the HTS installation. For this purpose, the system contains a level regulator 12 and a gas flow regulator 8. The deviation of the condensate level from

setpoint controller 12 changes the regulating effect, which through the optimizer 13 enters as a task to the second input of each controller 8. Controllers 8, comparing the current gas flow rates

through installations NTS 1, measured by sensors 9, with predetermined values, affect their actuators 10 until the current gas flow rates become equal to the specified value. Changing the performance of the NTS 1 installations leads to a change in the condensate flow rate entering the collector 7. As a result, the level deviation decreases, and if it is not zero, the controller 12 continues to change the task to the gas consumption controllers 8 (through the optimizer 13). The process of changing the setpoint to the gas flow controllers 8 is assumed until the current production of the HW installations is such that the level in the condensate collector is equal to the target and, therefore, the condensate production will correspond to its consumption.

If the output signal of the level 12 regulator was iodized to the second inputs of the gas flow regulators 8, the optimizer mine 13, the performance of all the NTS installations would be the same (in view of

that the second inputs of the gas flow controllers would be given the odioac signal of the task). In this case, the current gas withdrawal would be distributed between the NTS installations in a random way. However, such a distribution

not optimal, because the characteristics of the NTS setups, which are a dependence of the condensate yield on the plant capacity, differ from each other. This is due, mainly, to the inevitable difference in the characteristics of a group of gas wells connected to the NTS installations.

The calculations showed that the dependence of the condensate output (flow rate) on the performance of the NTS plant is approximated with sufficient accuracy by the equation:

y, (Xi) X (a, i + a, + a ,, - Xl (1)

wherei is the installation number of the NTS (i

1-n);

Xi-plant performance NTS (kg / s);

Claims (2)

g / g - condensate consumption (kg / s); , a2g, ysg are the coefficients of the approximation CP and. Expression (1) is a mathematical model of the NTS installation. The coefficients of the mathematical model (1) change (drift) over time. Therefore, they need to be continuously refined. For this purpose, an identifier 14 is used. The optimizer 13 solves the problem of determining the optimal performance of the NTS installations. The specified total condensate consumption proportional to the output signal of the level controller 12 and the coefficients of the NTS mathematical model set by identifier 14 are used as the initial information. The optimization task is formed in the area of permissible productivities of the NTS X installations. Xi X it is necessary to find such values X, - at which the total output of nsata is equal to the given:, -) ,; + a. + / g /: 1 + IZG-) PP, and the total performance of the NTS installations is minimal. “Min2 gV expressions (2) - (4) accept designations; X ;, Xi is the minimum and maximum allowable performance of the NTS installations (kg / s); ./0 - specified total condensate consumption (kg / s). The coefficients of the mathematical model of the NTS installations are determined by the identifier 14 by the measured values of the gas flow (sensors 9) and condensate (sensor 15) during normal operation. Signals proportional to the calculated coefficients of the mathematical model of the NTS installations are fed to the first input of the optimizer 13. From the controller 12 to the second input of the optimizer 13, a signal is given that characterizes the required condensate consumption g / o. The allowable performance of the NTS installations Xi and Xi are set in the optimizer 13 hand 5 10 15 20 25 30 35 40 45 50. Their values are taken from the technological regulations of the NTS installations. The optimizer 13 solves the problem (2) - (4). The resulting decisions of the optimal performance of the NTS installations are fed to the second master input of the respective gas flow controllers 8. The latter support the optimal performance of the NTS installations. Task (2) - (4), due to the nonlinearity of constraint (3), belongs to the class of linear programming problems. Therefore, one of the known methods of nonlinear programming is used to solve it. The economic effect of using this device is to reduce the cost by approximately 20% and to increase the total condensate recovery (condensate recovery) by approximately 5%. Apparatus of the Invention A device for controlling a low-temperature gas separation unit, comprising gas flow sensors connected to the first inputs of the respective gas flow controllers associated with actuating mechanisms on the installation input lines, an identifier connected to the gas flow sensors and condensate entering the collection, characterized in that, in order to maintain the production of condisate at the level of the current condensate consumption with minimum gas extraction due to an increase in the accuracy of regulation, They introduced a level regulator installed on the co-condensation collector and the optimizer, the first and second inputs of which are associated respectively with the identifier and the level regulator, and the output of the optimizer is connected to the second inputs of the gas flow regulators. Sources of information taken into account in the examination 1. Taraneiko B. F. Automatic control of low-temperature gas separation units. M., VNIIEGazprom, 1973, p. 32-35. 2. USSR author's certificate for application no. 2581092/03, cl. E 21 B 43/00, 1978 (prototype).