SU1474779A1 - Method of protecting process equipment - Google Patents

Abstract

The invention relates to electrical engineering and can be used to protect process equipment in devices for automatic control of a process variable. The purpose of the invention is to increase reliability. The goal is achieved by additionally controlling the finding of the value of the analog signal of the monitored parameter in the range of possible values using analogue relay converters 4 and 5, as well as logical blocks OR 6 and NOT 7. The discrete control signal in the logical block AND 9 is formed that the value of the analog signal reached the warning setpoint using an analog-to-relay converter 3, the limit setpoint - using an analog-to-relay converter 2. 1 Il.

Description

The body 3 is also connected to the input of the logical unit NOT .11, the output of which is connected to the first input of the logic unit 12, the second input of which is connected to the output of the analog-relay converter 2, and the output to the second input of the logical block OR 8, the output of which is connected to the signal board 13,

Thus, converters 4 and 5 serve to monitor the presence of an analog signal proportional to the value of the process parameter in the range of possible values, t, e, to monitor the health of the sensor.

If the sensor is healthy and the signal has reached the warning setpoint X, i.e.

The outputs of the analog-to-relay converter 50 are satisfied () A (xMurt x:

HALCHKS) 1, at the output of the logic unit

The searcher 3 and the logical block NOT 7 are also connected to the corresponding first and second inputs of the logic block AND 14 s whose output is connected to the signal board 15.

The device works as follows.

The analog signal X in converter 2 is compared to the limit

And 14 a signal appears, as a result of which the board 15 is triggered, notifying the operator about the violation of the technological mode (signal Zt),

If, with further development of the alarm, the analog signal reaches the limit setpoint X, t, e, the condition

Thus, converters 4 and 5 serve to monitor the presence of an analog signal proportional to the value of the technological parameter in the range of possible values, t, e, to monitor the health of the sensor.

If the sensor is healthy and the signal has reached the warning setpoint X, i.e.

And 14 a signal appears, as a result of which the board 15 is triggered, notifying the operator about the violation of the technological mode (signal Zt),

If, with further development of the alarm, the analog signal reaches the limit setpoint X, t, e, the condition

() l () l (hm x hmoks),

then all signals equal to one appear at the input of the logical block AND 9, it is triggered and the command is transmitted to the executive unit 10 Diagnostics and signaling circuits: Zf - violation of the technological mode (reaching the technological switch 4 or 5), After inversion in the logical block NOT 7, this signal, which is equal to zero, goes to one of the inputs of the logical block AND 9; Consequently, the conditions for forming a discrete control command are not fulfilled, a false movement of the actuator 10 does not occur,

10 Parameter Board 10 informs the personnel about the malfunction of the Z7,

If the transducer 2 malfunctions due to a malfunction, then the false displacement of the executive

warning setpoint when confirming the health of the sensor 1); Z, - sensor 1 malfunction or

false triggering (faulty- 15 ° Regana 10 also does not occur, because at the output of good conversion) converters 4 or 5;

Z} - about false triggering (malfunction) of converter 2. The circuit presented in the drawing without any structural changes also ensures the implementation of the proposed method with respect to protection acting upon decreasing the parameter. In this case, the numerical values of the limit X and the warning X settings will be different, than for the protection acting upon an increase in a parameter, and the conditions for forming a discrete control command Y are written as

the callout 3 signal is zero (the process parameter has not reached the warning setpoint), and the 2Q conditions of the discrete control command are not executed, Table 13 informs the staff about the fault

(Z,).

The proposed method, compared to 25 with the known one, prevents damage from false outages of the equipment and timely detection of sensor failures.

thirty

Claims (1)

Invention Formula () A () A (XMUII X Max If the process control method of technological equipment, at which the monitored parameter is measured, is converted into an analog signal, the cue parameter reached the warning 35 is compared with the set warning X and the limit X settings (output and limit set signals of the converters 3 and 2 are equal and when the value reaches ) and is in the range parameterological limit possible values of HMIC X HM disassembly, form a discrete package (the sensor is healthy and the output is a predominant command, the signals are 4 and 5, the signals are equal to increase the reliability, additionally control the finding of the value of the analog signal of the monitored parameter in the range of possible values, and form a discrete control command, provided that the value of the analog signal ly), then signals equal to one are sent to each of the three inputs of logic block 9, all the conditions for the formation of a command are fulfilled, which is fed to the executive body ten, If sensor 1 is faulty (X Hmini reached a warning and limit X X / chax), then at one of the inputs of the logical block OR 6 a sig-setting appears and is in the range equal to one (from the output of the prevailing values. Compiler R.Aponina Editor G.GerberTechred L.OliynykKorrektor L.Patai  - WH .. "...". - -, ----.--. - -. ---. - -.-...--- - .- - -. - .- .- -----. - - - .. Order 1905/53 Circulation 605 Subscription VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 raeovatel 4 or 5), After inversion in the logical block NOT 7, this signal, equal to zero, goes to one of the inputs of the logical block AND 9; Consequently, the conditions for forming the discrete control command are not executed, the false movement of the executive 3 signal is zero did not reach the warning setpoint), and the formation conditions of the discrete control command are not fulfilled, the scoreboard 13 informs the staff about the malfunction (Z,). The proposed method, in comparison with the known method, prevents damage from false outages of equipment and timely detection of sensor failures. thirty Invention Formula has reached the warning and limit settings and is in the range of possible values.