The adjustment of the TZ subsystem, in addition to the adjustment of technical means, includes checking the correctness of the TZ algorithms and realizing the connections of the TZ subsystem elements among themselves (starting from the measuring channels to the TZ actuators, including power supply and the centralized testing system) and other subsystems of the industrial control system (information presentation, archiving) .
– familiarization with the project technical documentation and its analysis;
– familiarization with the complex of technical means;
– verification of technical means;
– acceptance from installation;
– setup, testing and testing of kits and schemes;
– drawing up the necessary technical documentation;
AVR – automatic inclusion of a reserve;
ADP – analog-discrete converter;
AP – automatic switch;
ASR – automatic control systems;
ACS TP – automated process control system;
BBF – blocking and locking;
BVZ-block input protection;
БЗ – protection unit;
BI – the block of impulses;
BIR – spark ignition unit;
BKP – power control unit;
BO – block testing;
BPN – voltage conversion unit;
BRU – unified reproduction unit;
BS – alarm unit;
VIP – secondary power source;
GSI – light pulse generator;
ZB – protective blocking;
ZZU – ignition protection device;
IVS – information and computing system;
IR – measuring channel;
IM – the executive mechanism;
IPK – pulse safety valve;
IC – measuring system;
PS – actuator;
КДЗ – control of protection;
KTS – a complex of technical means;
MPT – microprocessor technology;
MPU – microprocessor device;
OS – axial displacement;
LDPE – high pressure heater;
PP – primary converter;
PRG – transmitting converter;
ASD – start-up devices;
PTK – software and hardware complex;
PU – control panel;
ASD – registration of emergency situations;
CA – automation equipment;
SVT – computer facilities;
SI – measuring instruments;
SOI – means of displaying information;
SEC – special acceptance commission;
SU TP – process control system;
TB – technological blocking;
TDM – traction mechanisms;
TZ – technological protection;
TOW – technological control object;
TPN – turbo feed pump;
TC – technological alarm;
LPF – low pass filter;
SR – plug connector;
EHR – solenoid valve.
Symbols of circuit elements:
Logical element "OR";
Logical element "AND";
Single pulse shaper;
Logical element "MEMORY".
The TZ subsystem is one of the subsystems of the automated process control system that ensures the safety of personnel and the safe operation of heat and power equipment by means of an emergency automatic transfer of the protected equipment to a safe state in the event of an emergency or pre-emergency situation.
Technological protections work in the standby mode: the operation of the TZ occurs at the moment of occurrence of the corresponding emergency situation,
At the time of the request for the operation of the TZ should be ready to perform their functions reliably and their staff must be confident in this readiness.
The subsystem TZ is designed to solve the following tasks:
– control of the appearance of signs of emergency and pre-emergency situations: the deviation of the analog signals from the specified values (response settings), the appearance of a given state of discrete signals or their specified combination;
– control of the presence of conditions of operation of the TZ: the expiration of a given time delay, the presence of technological signs and / or operational permission to act (input protection);
– formation of a team to execute an appropriate program of action (a specific set of commands to actuators of the TZ)
– ensuring the possibility of non-operational withdrawal of each protection "on signal" (repair output protection);
– generation of information on the status and operation of the TZ, indicating the protection that worked first and, if necessary, transfer this information to other subsystems of the industrial control system: signaling, archiving, control
– receiving information from other subsystems of the automated process control system.
A typical TK algorithm that implements the specified functions is shown in Figure 1.
l is a logical element "OR"; & – logical element "AND"; T is a logical element "MEMORY"; – logical element "TIME EXPOSURE"; S – logical element "PULSE"; ⊸ – logical element "NOT"; D – sensor; – light panel on the control panel; a is a comparison circuit for sensor signals; b – signal processing logic; c – automatic input device
Figure 1 – Block diagram of TK
Technical means of implementing the TOR include discrete signal sensors, specialized devices for monitoring mechanical quantities, torch brightness and
– the possibility of continuous control of the reliability of all or a certain class of input information with alarm and registration of malfunction of individual sensors or communication channels;
– ability to control the execution of commands in fact and in time;
– self-diagnostics of technical equipment with alarm and registration of failures at the level of a typical replacement element;
– the possibility of authorized control of the state of any sensor or algorithm;
– simplification of the procedure for making operational and non-operational changes in case of authorized access to such changes with simultaneous automatic registration of the fact of access and changes made;
– the possibility of fixing the time of occurrence of all recorded events;
– possibility of automatic preparation of reporting documentation;
– simplification of the procedure for testing protection;
– higher maintainability of technical equipment;
– a significant decrease in the overall dimensions of the technical equipment that implements the TZ subsystem, while expanding the functions performed;
– possibility of full redundancy of technical means with minimal complication of the system.
– the possibility of generating false signals inside the controller and the need to take special measures to eliminate the negative consequences of this;
– possible speed limits and the need to select the appropriate hardware and systems;
– opportunity "hang" programs and the need to restart the controller while maintaining current information and commands.
Means of math technology, used to implement the subsystem of TZ, must be mass-produced, adapted to solve specific problems of TK.
To increase the survivability of the system, specialized TZ devices are performed with two (less often three) controllers with their 100% redundancy. In this case, the signal of each sensor is entered equally into all controllers.
When processing input signals for the TZ function, microprocessor devices should solve the following tasks:
– receiving signals from sensors that control technological parameters and the state of mechanisms of HF;
– logical and dynamic processing of received analog and discrete signals according to p.
– diagnostics of the reliability of each input signal;
– analysis of the operation of reserved channels, the selection for each monitored parameter of a reliable signal that can be used not only in the TZ subsystem, but also in any other subsystems.
– control signal reliability of each sensor;
– monitoring the health of communication lines with sensors;
– logical and dynamic processing of discrete and analog signals (damping, linearization, scaling based on standard calibration characteristics of sensors and
– formation of a reliable signal for each monitored parameter with the possibility of restructuring the processing algorithm when detecting failures of one of several sensors of the same parameter;
– alarm detection of failures.
– formation for analog values of the settings set in the unit of measurement of the parameter;
– comparison of the signals received from the sensors with the pick-up setting;
– countdown of shutdown time;
– formation of a command to perform the corresponding algorithm of action;
– the formation of long and impulse output commands to actuators;
– automatic mode input and output of protections triggered when a parameter is lowered or mechanisms are turned off;
– ensuring the possibility of authorized non-operational withdrawal of each protection "on signal" (repair protection output) upon a command from the operator’s workplace of the central automated control system;
– formation of information for other subsystems of automated process control systems;
– receiving, if necessary, logical information from other subsystems of the automated process control systems via a digital highway.
a) when triggered TZ initiative:
– the name of the protection that triggered the first and all triggered protections;
– name of the program being executed;
b) upon the appearance of information by initiative:
– the name of the protections for which the time delay has started (for protections having a time delay of at least 15 s);
– Discrepancy of signals of discrete or analog sensors of one parameter (with a time delay of up to 1.5 s) with
only two identical sensors of this parameter;
– sensor or communication channel failure (for discrete signal sensors, if this requirement is provided for by the project);
– damage to microprocessor hardware and the fact of their partial or complete shutdown;
– automatic mode input or output TZ;
– the beginning and end of the testing of TZ (if there is an automatic testing program);
– change the state of the repair output;
c) by authorized request:
– the state of protection requiring mode input (entered – output);
– state of repair output protection – a list of protections derived "on signal";
– the results of testing the TZ (if there is an automatic testing program);
– the value of the settings (settings, timeouts).
a) when triggered TZ initiative:
– name of all triggered protections with indication of the response time;
– name of the program being executed;
b) upon the appearance of information by initiative:
– Discrepancy of signals from discrete or analog sensors of one parameter (with a time delay up to 1.5 s) with only two identical sensors of this parameter;
– malfunction of the communication channel with the sensor or the DUT, if diagnostic algorithms are provided;
– failure of any diagnosed element of technical means;
– full or partial shutdown of microprocessor-based hardware that implements TZ;
– the beginning and end of the testing of TZ (if there is an automatic testing program);
– change the state of the repair output;
c) by the authorized request (for each of the TZ channels reserving each other, if there is no software synchronization) – the status of each TZ (entered – output, triggered, disabled by the repair output):
– the results of testing the TZ (if there is an automatic testing program);
– time delay implemented for this protection;
– the pick-up setting implemented for this protection in physical units of measure;
– algorithms of all TZ;
– type of damage to microprocessor hardware with indication of the failed module.
– the operation of each protection;
– automatic input and output of TZ;
– changing the state of the repair output of each TZ;
– transfer of all or individual protections to the testing mode, the beginning and end of testing, the results of testing (if there is an automatic testing program);
– microprocessor hardware malfunction;
– partial or complete shutdown of the TZ device;
– malfunction of the communication channel with the sensor or actuator, if algorithms for their diagnostics are provided.
– automatic continuous self-diagnosis with an accuracy to the replacement element;
– constant diagnostics of the health of control channels with analog and discrete sensors, including communication lines, if provided for by the project;
– control of the reliability of input signals;
– the possibility of periodic testing of the device as a measuring instrument;
– automatic elimination of the maximum possible number of detected failures by restructuring the system at the site of failure, by connecting backup elements, by imposing a ban on generating erroneous commands (reconfiguring the system) or by partially or completely disabling the TOR device with the ability to form a command to stop the equipment (the decision to disable equipment in case of failures of the MPU TZ is adopted when developing a specific subsystem of TZ and ST);
– generating a signal about the occurrence of damage or failure with the decoding of this message with the accuracy of the replacement element;
– protection against unauthorized access to the MPU TZ.
a) with the sanction of the chief engineer of the TPP:
– change of TZ algorithms;
– change of settings of operation and protection time delay;
– changing the state of the repair output device;
b) with the sanction of the shift supervisor: – carrying out functional testing of TZ and ZB on the existing and stopped equipment.
All specified operations are performed from the workplace of the operator CASU TP or from the service panel. Transactions are archived, and the changes are printed in a special protocol.
If the power supply is lost for more than 0.5 s, the device that does not have a job to maintain performance under these conditions should turn off with a disconnect signal. At the same time, it should be possible to issue a command to stop the equipment, if such a requirement is included in a specific technical task.
Re-starting the device must be authorized. When the supply voltage appears after a break of any duration, no program reload should be required and false controller output commands should not be generated.
Operative change of user programs (change of values of settings, time delays, repair output position) in all controllers of the emergency control devices of each other reserving each other should be carried out by one command.
The kit includes UKTZ blocks:
– generation of commands for logical processing of discrete signals from a single sensor – "one of two", two sensors – "two of two", three sensors – "two out of three" (BR);
– adjustable time delay (BV);
– locking and fixing (BBF);
– signal multiplication (BRU);
– implementation of pulse commands (BI);
– input and output protection (BVZ).
A brief description of various modifications of functional blocks is given in Appendix A.
The devices are assembled in the cabinets of technological protection and power. The design is made on the basis of cabinets with a swingable double-sided frame with a cassette-block arrangement of equipment.
In each of the cabinets, there are up to 48 functional blocks, which are placed in the cassettes in the upper part of the cabinet. In the middle of the cabinet, a testing unit and a status display panel of the output relays are installed, in the lower part there is a cassette with power sources and a power control unit. Output relays are mounted in unified cells in the amount of up to 44 pcs. and located on the back of the cabinet.
Inter-unit mounting is carried out on the cassette connectors by soldering.
For external connections, a terminal block is used. "screw soldering", the number of which in each cabinet can be up to 850 pcs.
Discrete information from sensors, instruments, limit switches and
The power supply of protection circuits, in which the UKTZ equipment is applied, is performed:
– for 500 and 800 MW power units in accordance with  and ;
– for 250 and 300 MW power units (as well as smaller power units, where the turbine control pumps are not on its shaft) in accordance with  and ;
– for the remaining power units and thermal power plants with cross connections taking into account  and .
According to , the working power supply to the UKTZ cabinets should be supplied via the ATS device from two sources:
– the main section – the RUSN 380/220 V section of the especially responsible load of another block, and this section should not participate in the reservation of this block;
– backup – section RUSN 380/220 V especially responsible load of its unit.
Thus, in the event of an accident on this unit, accompanied by a voltage loss of the voltage source, the TZ devices remain at the operating voltage.
The voltage after the AVR device is supplied to the working power sources built into the UKTZ cabinets. Voltage from the PTS-16 converter connected to the tires of the battery pack is supplied to the backup power sources. The backup power source takes the load in the absence of voltage at the worker (unstressed AVR).
The power supply of sensors, normalizing transducers and protection devices is carried out according to  from the same sources: the RUSN 380/220 V tires of especially responsible load of their own and other block and PTS-16 converters tires using the AVR device.
For the turbine and boiler rooms, the power supply of the circuits and the TZ sensors is performed separately.
Interuser sensors and devices of protection devices are powered from different devices AVR.
Sensors and devices belonging to the same channel of protection of one equipment, are powered from one AVR device.
In the absence of a converter, the RUSN 380/220 V bus is used as a backup source for the especially responsible load of this unit, not participating in the backup voltage supply of the working source.
At the same time, protection is additionally performed, stopping the unit when its own voltage is lost on it. Protection is performed at a voltage of 220 V block battery and acts on the actuators, the drive and control circuit which is also performed on the battery voltage: shut-off valves on the fuel supply line to the boiler, turbine stop valves and turbine drive of feed pumps, check valves on the turbine selection lines , generator switch.
Indicator of the disappearance of their own needs on the unit is the simultaneous disappearance of an alternating voltage of 380/220 V on the AVR protection device and the fit of the turbine valves (any high-pressure cylinder valve and any high-pressure cylinder valve is closed), resulting from the shutdown of all turbine control pumps.
In those cases where the control pump is located on the turbine shaft, the protection action is not accompanied by the seating of the stop valves.
The UKTZ device has a protection testing system that checks the operability of the equipment and protection circuits from entering the BZ unit to the windings of the output relays. Testing can be performed both on the stopped and on the working equipment, and when a non-testable channel (protection) is triggered at the moment, a signal is issued prohibiting testing, and the protection device implements the necessary control program (algorithm). Testing is carried out by pressing the buttons installed in the functional blocks. The operability of the protection circuits is determined by the state of the signal equipment.
Relay equipment in the circuits of the TOR performs logical operations with a discrete change in the input value.
By appointment, the relays are divided into:
– intermediate – to expand the functions of another relay;
– Pointer – for visual signaling the operation of another relay;
– time relay – for operation with an adjustable time delay.
In the TZ schemes, electromagnetic relays are mainly used, which consist of an inductive coil and a ferromagnetic armature connected to a contact system. Technical characteristics of relay equipment:
– operating voltage or operating current of the power winding;
– return coefficient is the ratio of the values of the release parameter and the trigger parameter;
– active resistance of the relay coil or power consumption when triggered;
– contact switching capacity is the limit value of the power switched by the contacts, at which the contacts reliably perform a certain number of switching;
– insulation resistance of the coil and relay contacts – the ability of the insulation to withstand long-term or short-term effects that occur during operation.
For the time relay, additional parameters are entered:
– response time – the time from the moment when the signal to the relay winding is applied to the first contact by the closing contact of the stationary contact;
– the release time is the time from the moment when the voltage is switched off from the winding to the first contact by the disconnecting contact of the fixed contact.
The relay triggering parameter is different from the operating value specified in the technical specification. The ratio of the operating parameter to the trigger parameter is called the safety factor and must be in the range of 1.1 – 1.4.
The sensitivity of the relay is characterized by the minimum power consumed by the relay coil during operation (Рср), and is estimated by the values of current or voltage of operation
where R obm is the resistance of the relay coil; I cf and U cf – current and voltage of operation.
The current (voltage) of operation – the minimum value of the parameter at which the reverse switching occurs, is called the release current (voltage). The ratio of the release parameter to the response parameter is called the return coefficient. For relays used in TZ circuits, the return coefficient is more than 0.5, since with a decrease in the return coefficient, the probability increases "sticking" anchors
The range of intermediate, indicator and relay relays offered by industry allows you to perform all the necessary logical operations in the TOR schemes. The main limitations arise from the switching capacity of contacts, depending on the type of current and the nature of the load. Conditions of work of contacts on a direct current with an inductive load are most difficult. In this case, electromagnetic energy is spent on sparking in the gap of the opening contact, which leads to the erosion of its surfaces. To eliminate sparking when opening DC circuits, spark-suppressing circuits are used, which are formed by shunting the contacts with either a chain of series-connected capacitor and resistor, or a diode.
As a shunt diode, D226 is usually used, the capacitor capacitance is taken to be 0.5 – 20 µF with voltage 400 – 500 V. The resistance of the resistor is determined by the formula
where U is the supply voltage.
Ignition-protective devices are designed to ignite the burners of the boilers and to protect the equipment of the boilers in case of extinction (malfunction) of the burners. Widespread currently received ignition-signaling device ZSU-PI production "Energotech" and "Power engineering" (Kazan), flame control sensors for burners FDCHS-1MK manufactured by "Eliza" (Sarov), burner flame control sensors SG-01/4 manufactured by "Fairway" (St. Petersburg).
Fuel – natural gas or propane-butane mixture.
The limits of ignition at a gas pressure of 0.015-0.3 MPa (0.15-3.0 kgf / cm 2) and any air pressure in the range of 0-5-700 mm
Limits of steady burning with a gas pressure of 0.003-0.3 MPa (0.03-3.0 kgf / cm 2) and any air pressure in the range of 0-700 mm
Air temperature K.
The length of the visible part of the torch at a gas pressure P g is 0.1 MPa (1 kgf / cm 2) of at least 1300 mm.
The time delay of the igniter flame detector is 1 s.
The length of the immersion part of the igniter is equal to the length of the installation pipe. Installation of ZSU-PI with deepening of a cut of a zapalnik in an adjusting pipe to 500 mm is allowed. The maximum length of the immersion part is 6500 mm, the minimum length is not limited.
The diameter of the immersion part of the igniter is 60 mm.
The overall dimensions of the igniter ZSU-PI are shown in Figure 2.
1 – high-voltage cable; 2 – candle cover; 3 – trunk; 4 – contour of the installation pipe
Figure 2 – Dimensions of the igniter ZSU-PI
The functional diagram of the igniter ZSU-PI is shown in Figure 3.
The air is supplied to the igniter through the nozzle (see Figure 3), and the gas through the nipple to the nozzles. In the ejector, the gas is mixed with air and through the flame arresting device enters the detonator and the pilot body. After the housing and the detonator are filled with an air / gas mixture, high voltage is applied to the spark plug. The mixture in the detonator is ignited, produced "shot" into the recirculation zone behind the nozzle block cut and the mixture ignites there, forming the primary combustion zone. From this zone, the main flow of the gas-air mixture prepared in an ejector nozzle is ignited. The pilot flame control is carried out by an ionization flame sensor, the signal from which is fed to the flame control circuit located on the PU.
1 – ejector; 2 – spark plug; 3 – the main combustion zone; 4 – primary combustion zone; 5 – nozzle; 6 – output ionization sensor; 7 – flame retardant mesh; 8 – air pipe
Figure 3 – Functional diagram of the igniter ZSU-PI
The control panel (control panel) is designed to work with a ZSU-PI ignition device and a USKP-G flame sensor. The circuit diagram is shown in Figure 4.
The inclusion of the electric circuit PU is carried out by the switch B1. If switch B2 is set to "On", and the OT switch to the position "Gas", then relay P1 is triggered and through the contacts
If it is necessary to turn off the ignitor, switch B2 "ON-3SU" set to "ZSU". The relay P1 is de-energized and the voltage of 220 V is removed from the EMC.
If the switch OT "Gas-Avt" set to "Auth", when there is a pilot flame through the open transistor T1 of the relay P1 is turned on, but if the pilot flame disappears, the relay P1 will be de-energized and the EMC will close.
The circuit, assembled on D2, T2, VZ, is intended for generating a signal when working with a USKP-G type flame detector.
A block diagram of the control of the igniter using the PU is shown in Figure 5.
Figure 4 – Schematic diagram of the control panel
Figure 5 – Block diagram of the control of the igniter ZSU-PI using PU
With the help of PU produced:
– opening of an EHR and its closing in manual or automatic mode;
– high voltage supply to the BIR;
– receiving signals from the igniter flame sensor and the burner flame sensor;
– the formation of signals about the presence of the pilot flame and the flame of the burner in other schemes.
When designing systems using ZSU-PI, one or another solutions are possible, which allow to fully or partially use the opportunities inherent in PU. Due to the use of other burner flame control sensors rather than USKP-G, the burner flame indication channel is often not used in PU, therefore this channel can be used to indicate the flame of the second igniter. The control circuit of the igniter may also differ from the scheme incorporated in the PU.
The spark ignition unit is designed to form a spark discharge between the candle and the mass in the ZSU-PI devices.
Main technical characteristic
Limits of the working spark gap under normal conditions
Duration of one ignition on
The circuit diagram of the BIR is shown in Figure 6.
Figure 6 – The BIR circuit diagram
The basic electrical circuit of the electronic board of the BIR unit is shown in Figure 7. The principle of the BID operation is as follows. With a positive half-period on contact XI, the high-voltage capacitor C1 (see Figure 6) is charged through the chain Rl, R 2, V D2, X3 (see Figure 7), and the starting capacitor C1 is charged simultaneously through the chain Rl, R 2, R 3, UDS (see figure 7).
Figure 7 – Schematic circuit diagram of the electronic board of the BIR
When the negative half-period on the contact X 1 opens the transistor T1 and the starting capacitor through the open transistor and the resistor R 4 is discharged to the control electrode of the V D5 thyristor, through the open thyristor the high-voltage capacitor is discharged to the primary winding of the transformer Tp 1, as a result of which high voltage is excited in the secondary winding , sufficient for the breakdown of the spark gap of a spark-plug, connected through a high-voltage cable to the BIR.
The solenoid valve consists of a check valve and an electromagnetic actuator.
The de-energized position is closed.
When voltage is applied, the core retracts into the electromagnet and opens the passage of gas through the discharge opening. 220V valve supply voltage
The device is designed for the selective control of the flame of gas-oil-fired boilers. The device FDCHS-1MK block type and consists of a terminal module with light and arrow indication on each channel of selective control and two, four or six installation sensors, depending on the modification. Figure 8 shows the FDCHS-1MK device with a four-channel terminal module.
– control of the burner on the background of the remaining burners;
– alarm in case of breakaway and extinguishing the torch torch.
Figure 8 – Sensor FDCHS-1MK
Operating conditions of operation of blocks
Air temperature of the terminal module
Temperature of the installation module (sensor)
Upper limit of relative air humidity at 35 ° С
The intensity of the external magnetic field
Not more than 400 A / m
Power supply of the device from a single-phase AC network
Power supply frequency
The power consumed by the device from the network to one channel
The characteristic of the switched signal
Parameters of the communication line between the sensor and the terminal module
installation module (sensor)
Execution – four-core cable.
Terminal Module Design – Instrument Standard "Cherry".
Physical principles of the FDES-1MK
The study of various physical methods used to register the combustion process on burners of heat and power equipment revealed the following basic principles for solving the problem of selective control:
– spatial-optical registration of the combustion process;
– spectral recording of the combustion zone;
– measurement of the dynamic characteristics of the combustion process.
The FDCHS-1MK device implements an algorithm using all three principles of selective control, which made it possible to obtain high selectivity.
The device is designed to monitor the presence of the flame of pilot burners of boilers operating on liquid or gaseous fuels.
The number of controlled oil-gas burners
The length of the communication line between the sensors and the secondary device
Not less than 10,000 h
Average service life
At least 10 years
The principle of operation of SG-01/4 is the conversion of the ultraviolet flame component for gas and high-frequency pulsations of the visible area for fuel oil into electrical signals. The principle of operation is explained in Figure 9.
The flame signal is sensed by sensor 1. Then the signal is transmitted to the input of amplifier 2 and then to the input of detector 3. From the detector output, the signal goes to the input of integrator 4, which controls the comparator 5. Relay 7 is connected to the output of the comparator, the state of which is determined by the presence (absence) flame. The channels of the device include control devices 8, which, when a fault occurs in the sensor circuits, generate a signal acting on the relay 9, which signals a fault. Pin 6 of relay 7 is used to signal the presence (absence) of a torch. Power to the detector is supplied from the power source 10.
Figure 9 – Functional diagram of the SG-01/4 sensor
Protective functions during the extinction of the torch in the furnaces of boilers burning fuel oil and natural gas are implemented by the most common complete system. "Torch 2"that generates a signal in the protection circuit to turn off the boiler in the absence of pulsation of the flame.
In the instrument set "Torch 2" include:
– alarm device (secondary device) – 1 pc .;
– photo sensor – 2 pcs. (according to additional instructions in the application – any number).
The main technical characteristics of the kit:
– power sources – AC mains with frequency of 50 ± 1 Hz and voltage;
– PD supply voltage – 11.5 ± 0.5 V;
– the number of connected PDs with a communication line length up to 150 m – 2 pcs .;
– inertia – the time after which the output relay of the device triggers after a jump-like change of the test input signal with a frequency of 3.3 Hz from the value corresponding to the double setpoint to zero, must lie within 1 – 2.5 s.
The photo sensor is a two-channel photoelectric converter whose sensitive elements are photoresistors: the first channel is SF-2-6 (3 pieces) connected in parallel, the second channel is FSA or FSD, or FSK (1 piece before 1977) or FR1 (1 piece since 1978). The photo sensor can work on the first channel, complete with a signaling device"Torch-1" (currently unavailable), on the second channel – with a signaling device "Torch 2".
The main technical characteristics of the photoresistor FR1-3:
– dark resistance – 47 ± 23 kΩ;
– the multiplicity of resistance changes with illumination of 200-300 lx from radiation source A according to GOST 7721-76 with a color temperature of 573K and climatic conditions according to GOST 18167-72 – not less than 2.5;
– spectral sensitivity – in the range of wavelengths (1.0 – 3.2) × 10 -6 m;
– permissible power dissipation – 0,006 W;
– maximum spectral sensitivity – at a wavelength of 1.5 × 10 -6 m.
The structural and basic electrical circuits of the detector are shown in Figures 10, 10a. The detector consists of an input node 1, a barrier filter 2, AC amplifiers 3 and 4, a detector 5 with a switch indicator 6, a smoothing filter 7, a reference voltage source 8, a regenerative comparator 9, a pulse shaper 10, a thyristor switch 11, an output electromagnetic relay 12 , power supply unit 13 and test verification unit of operation 14.
The input functional unit 1 is a bridge circuit, made on resistors 1 R -1, 1 R -2, 1- R 16, 1- R 17, 1- R 29 and PD photoresistor. At the same time, the variable component of the voltage at point A, reflecting the change in the resistance of the photodiode FD, due to the pulsations of the torch radiation flux flowing through it "1- R 2- C 1" enters the input of the barrier filter 2.
The barrier filter is designed to suppress industrial frequency interference coming through the instrument’s communication lines with PD. After the filter, the signal on the presence of a controlled flame is amplified by amplifiers 3 and 4, straightened by detectors 5, smoothed by filter 7 and fed to a threshold device of the regenerative comparator 9, where it is compared with the value of the reference voltage.
The threshold device of the comparator 9, when the input signal exceeds the value of the reference voltage, forms a ban on the operation of the comparator pulse generator, and when the signal does not have a torch, the pulse generator is excited, putting into operation the driver of control pulses 10 of the thyristor switch 11, which opens, causing the output electromagnetic relay 12 alarm.
Upon the subsequent return of the regenerative comparator to the initial state (in the presence of a torch), the control pulses of the thyristor switch disappear, which closes automatically when the supply voltage drops to zero, causing the output relay of the indicator to shut off.
Amplifiers 3 and 4 are covered by non-linear positive feedback through coupling capacitor 1-С11 and zener diode 1-Д1. This connection, the switching element of which is a Zener diode 1-D1, enters into operation at fault (3-6 kΩ or less) or breakage (100-130 kΩ or more); The conditions necessary for this are formed by the bridge circuit of the input node 1 in the FD sensitive elements or in the circuits of their interfacing with the signaling device and excites the amplifiers 3 and 4, which then go into the regeneration mode of the pulses, preventing false alarm. Simulation of short circuits and breaks in the FD circuits is used in the relevant test modes for the operation of the detector.
The normal state of the output relay of the indicator in the presence of a controlled torch is de-energized, which prevents the false operation of the indicator when the supply voltage disappears; in the absence of the torch relay is triggered. The operating mode of the detector operation is provided with the button pressed. "Job" and pressed all the other buttons of the test check switch.
To prevent possible cases of false alarms of alarms or their failures with significant fluctuations in the supply voltage "Torch 2" should be organized from the voltage regulator C-0.16, loading it with an additional load of about 50 VA (for output to the working section of the characteristic).
1 – input node; 2 – barrier filter; 3 – microcircuit amplifier AC; 4 – transistor amplifier AC; 5 – detector; 6 – dial indicator; 7 – smoothing filter; 8 – reference voltage source; 9 – regenerative comparator; 10 – shaper control pulses; 11 – thyristor key; 12 – output electromagnetic relay; 13 – power supply; 14 – test test node
Figure 10 – Block diagram of the detector "Torch 2"
Figure 10a – Schematic diagram of the detector "Torch 2"
Hardware kit "Torch-3M" designed to control the presence of the torch in the furnaces of gas-oil and pulverized coal boilers and generate a signal to turn off the fuel supply when it goes out. The equipment works on the principle of extracting the pulsation of the brightness of the common torch in the boiler furnace during the combustion of fuel. The ripple of the brightness of the torch is converted by photosensitive elements of photo sensors into an electrical signal, which enters the alarm device and is converted into a relay signal in it.
Power supply equipment "Torch-3M" – from an alternating current source with a frequency of 50 Hz, a rated voltage of 220 V. The power consumed from an alternating current network is not more than 12 VA.
Hardware kit "Torch-3M" consists of two photo sensors and a signaling device connected by cable lines.
The photo sensor consists of a housing and a flange (Figure 11). The flange is designed for mounting a photo sensor on a radiator or sight pipe. A protective glass, an electromechanical curtain, a board with photosensitive elements and a board with a preamplifier are placed inside the case. Electromechanical shutter allows you to test the kit "Torch-3M" on a running boiler. Remote shutter control button "Counter."located on the signaling device. When voltage is applied to the solenoid, the shutter blocks the access of the light flux to the photosensitive elements. On the back of the case there is a connector for connecting external electrical circuits.
Photodiodes V D1 and V D2 are used as photosensitive elements in the photosensor (Figure 12). In view of the low sensitivity and high output impedance of photodiodes, a photovoltaic pre-amplifier of voltage transistors VT 1– VT 3 and a current amplifier VT 4 were used in the photosensor, which ensures operation on a long communication line. This board provides footprints for the photoresistances of the device. "Torch-1". To adjust the voltage on pin 4 of the A2 board to the desired value (2.5 V), use the trimming resistor R 4.
The detector represents a dustproof instrument.
1 – pipe; 2 – radiator; 3 – photo sensor
Figure 11 – Scheme of installation of the detector "Torch-3M"
Figure 12 – The principal electrical circuit of the photo sensor in the detector "Torch-3M"
On the front panel of the device (Figure 13) there is an indicator, four light-emitting diodes, a potentiometer for adjusting the output relay response delay, a potentiometer "Set point". On the rear panel of the device there are connectors for connecting sensors, a connector for supplying voltage, an output connector for connecting technological protection circuits and technological alarm.
The electrical circuit of the detector (Figure 14 cm inset) is placed on printed circuit boards A1 and A2. On the A1 board, the main channel of signal processing of photosensors is located, on the A2 board – the control channel.
The main channel has two input amplifiers on DA 1 and DA 2 microcircuits, working on a common load, which ensures the operation of the detector "Torch-3M" both with two, and with one photosensor. Elements C4-C7 and R 6- R 10 have a rejector filter for suppressing 50 Hz interference.
The overall gain of the main channel on the input signal (not less than 1000) is provided by voltage amplifiers on DA 3 and DA 5 microcircuits. Gain adjustment of the entire channel is performed by R 3 – "Set point"which can be used to set the alarm threshold required for this type of boiler "Torch-3M" (the brightness of the torch when the pilot burners are on).
Figure 13 – The front panel of the detector (without cover)
The frequency properties of the detector determines the active low-pass filter with a cutoff frequency of 9 Hz, performed on a DA 4 chip. The lower frequency transmission of the detector is determined by the transition capacitors C4, C16, C19 and is 3 Hz.
The amplified signal is converted by a rectifier on a DA 6 chip to a pulsating DC voltage proportional to the input signal, which is smoothed by the RC circuit, R 38, C22. The magnitude of the signal can be judged by the indications of the pointer device P1.
The voltage level of the direct current is compared on the comparator DA 7 with the setpoint of the output relay. The setpoint voltage may vary with a K40 potentiometer depending on the size of the output signal and interference. When the constant level of the converted input signal becomes lower than the setpoint voltage (less than 10 divisions by the dial indicator), the DA 7 comparator issues a signal to start the time delay device on the DA 8 chip, which provides the output relay response delay from 0.7 to 9.0 s. The change in the response delay of the output relay is made by the resistor R 1 on the front panel of the detector.
The output short-circuit relay is turned on by the VT 2 transistor. On the DA 9 microcircuit, there is one vibrator that blocks the operation of the VT 2 transistor during the transients in the circuit when the power is turned on. The output relay is signaled by a V D4 LED.
When you press the SB button
The control channel, consisting of four comparators, rectifiers, power supply stabilizers and a relay, is designed to detect faults in the communication lines of photo sensors with a signaling device. The DAI, DA 3 comparators monitor the state of the communication line with sensor 1, and the DA 2, DA 4 comparators monitor the communication line with sensor 2.
With a good communication line, the value of the DC voltage coming from photo sensors is set in the range from 1.5 to 7.0 V. At values of this voltage less than 1.5 V or more than 7.0 V, the comparators are DAI, DA 3 or DA 2 , DA 4 will give the line fault signals ("LINE FAILURE 1" or "LINE FAILURE 2"). If two communication lines fail, the output relay is simultaneously blocked and the indication does not work "Torch" missing. If one communication link fails, the device remains operational, the output relay does not lock, a failure indication of a specific communication link appears and the contact group of the corresponding control relay is switched.
Relays K1 and K2, signaling the state of the communication line, are turned on by transistors VT 1 and VT 2, the operation of which is accompanied by the glow of the LEDs V D1 and V D2. The supply voltage of the relay is +27 V non-stabilized. Relay signal about the state of the communication line is also supplied to pins 1-6 of the connector "Output" and can be used for technological signaling in the security system.
Two stabilizers with voltages of the detector circuit are made on VT 3, VT 4 transistors and V D9 and V D10 zener diodes.
Figure 14 – Schematic diagram of the device indicating the presence of a torch in the boiler furnace "Torch-3M"
The equipment controls the mechanical parameters of steam and gas turbines, turbo compressors and
With the help of the equipment, the following parameters are monitored:
– vibration speed bearing bearings;
– axial displacement of the turbine rotor;
– relative expansion of the rotor and stator of the turbine;
– turbine shaft curvature;
– the position of the locking and regulatory authorities;
– turbine rotor speed. The equipment includes:
– sensors and transducers;
– auxiliary units and mounting accessories.
The equipment is supplied in frames and cabinets.
The block diagram of the measuring channel of the equipment is shown in Figure 15.
The signal from the sensor enters the control board (if necessary through the spark barriers), where it is amplified, filtered, detected, converted into a unified signal, compared with the settings.
Discrete signals of the control board arrive at the PC-70, PC-71 boards, which process the signals of several control boards.
In addition to measuring and monitoring the parameter, the equipment provides monitoring of the health of sensors, transducers, communication lines, power sources. At malfunction of the equipment there is a signal.
Figure 15 – Block diagram of the measuring channel of the equipment
Figure 16 – Block diagram of the converter
The converter contains functional units – generator, linearizer, normalizer. The output signal of the converter is 1 – 5 mA.
The sensitive element of the sensor is a piezoelectric element that converts the forces applied to it into an electrical signal. The block diagram of the vibration velocity sensor is shown in Figure 17.
Figure 17 – Block diagram of the vibration velocity sensor
The signal from the piezoelectric element is amplified, integrated, filtered and converted into an output signal of 1-5 mA.
The block diagram of the control board is shown in Figure 18.
The output signal of the sensor or converter enters the input stage and passes through the coupling capacitor C further to the scaling amplifier, low pass filter, detector, converter "voltage-current".
The voltage from the detector output is fed to the zero-organs of the settings, where it is compared with the specified voltages. Then the signals pass through the discrete logic circuits to the output of the board.
The value of the input signal is controlled by the zero-body OK. If the input signal exceeds 2-10 V, the zero-body triggers and blocks the output signals.
Figure 18 – Block diagram of the control board
Measurement of the parameter, settings, the constant component of the input signal is carried out using the switch S 1, repeater and microammeter.
The structural scheme for measuring the rotational speed is presented in Figure 19.
Figure 19 – Structural diagram of the rotational speed measurement
The main nodes are: a multiplier of the frequency of the input pulses 60 times, a quartz oscillator of time intervals 1s, 1 min and a null organ of small revolutions.
The sensor produces one pulse per revolution of the rotor, then the frequency of the input pulses is multiplied by 60.
With a rotation frequency of less than 100, pulses are counted in 1 minute (direct counting). Switching to direct counting mode is performed by a low-speed zero-organ.
Additional pulses are generated on the display unit to update the measurement results. "Reset" and "Transfer".
The block diagram of the control panel PK-70 is shown in Figure 20.
The board has: one input, one input Δ and 14 inputs ΔΔ.
Figure 20 – Block diagram of the control panel PK-70
Inputs and Δ provide parallel connection of any number of control boards. When triggered, on any control board, zero organs, Δ, the power supply of the relay Kl, K 2 is activated. With signals on the inputs Δ Δ, the board performs logical processing. Relay K 4 triggers when there is a signal on any of the inputs. A signal on the output of two of the two appears in the presence of signals on any two adjacent inputs 1-2, 2-3,. 13-14. The board contains a voltage control unit.
The ON, OFF switch is designed to turn off the executive alarm relay during inspections, tests, replacement of the control system components.
The relay (Figure 21) is designed to control changes in the level of liquids to a certain value.