SU1236260A1 - Device for checking operation of heat equipment - Google Patents

Description

The invention relates to the field of automation of heat and power plants, more specifically to control devices for supplying fuel to the furnace, and can be used for furnaces of various heat generating units, such as boilers, steam generators, air heaters, etc.

The purpose of the invention is to increase the reliability of control of the heat unit.

Figure 1 shows the functional diagram of the device; 2 shows time diagrams explaining the operation of the device; FIG. 3 is a functional block diagram of the control unit.

The device contains sensors 1.1 - 1 .p of operating parameters, keys 2.1-2.p, amplifier 3, threshold device 4, synchronous triggers 5.1-5.P, asynchronous triggers 6.1--6. P, control unit 7, actuator 8, time setting unit 9 and distributor 10. The control unit includes AND 11 and OR 12 circuitry.

Sensors 1.1 - 1.P are connected to the information inputs of keys 2.1-2.p. The outputs of the keys are combined and connected to the input of the amplifier 3 connected to the threshold device 4. The output of the threshold device 4 is connected to the combined information inputs of synchronous triggers 5.1–5.p. The outputs of the tripleters are connected to the inputs of the control unit 7 via asynchronous triggers 6.1-6. The output of the control unit 7 is connected to the actuator 8.

The setting device 9 of time intervals is connected with the input of the distributor 10. The outputs of the distributor connection 1 with the control inputs of keys 2.1-2.P and clock inputs of synchronous triggers 5.1-5.p so that the first output is connected to the first key and the last trigger, and The i-th output is with the i-th key and (i -1) -m trigger.

The device works as follows.

The time interval adjuster В1з1 works on the sequence of pulses shown in Fig. 2a.

These pulses are fed to the input of the distributor 10, which has n outputs, where n is the number of sensors. Pulses at the outputs are different. iggel appear alternately. Fig.26 shows the pulses at the (i-1) output. Fig. 2d shows the pulses at an arbitrary i-M output of the distributor.

On fig.2d and 2d are presented signals coming from sensors 1 with numbers (i-1) and i, respectively.

During the time interval titj with

The output of the distributor with the number i --- l is fed to the control input of the key with the same number-m signal (Fig. 26), which unlocks this key.

The sensor signal with the number (i-1) goes through the corresponding public key to the input of the amplifier 3, the output of which is shown on fig.2e.

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During the time interval 1-2-ts, a pulse appears at the output of the distributor 10 with the number i, which opens the i-th key. The signal from sensor 1 with the number i is input to the amplifier 3, and the corresponding voltage appears at the amplifier output with some delay by the amount of signal delay in the amplifier At. Because of this, the signal arriving at the input of the amplifier at time t2 appears at the output at time ti t2 + At, and the time ta of disappearance of the i-ro sensor at the input of the amplifier corresponds to the time ta 1z + At pa output.

During the cycle of operation of the distributor 10, sensors 1 are connected in turn to the input of amplifier 3, then the cycle is repeated again, and so on.

At the time t4, an accident occurs (for example, the disappearance of the engine at the point monitored by the sensor with the number i-1). At the same time, the voltage at the output of the sensor drops (Figure 2d). At the moment to, the next connection of the sensor with the number i-1 to the input of the amplifier begins. Due to the delay in the output of the amplifier, the voltage drops to the threshold of the triggering of the threshold device 4 by the time ts tf, (Fig. 2e). At time t.3, the voltage of the alarm sensor is disconnected from the input of amplifier 3, however, due to the delay, the voltage at the output of the amplifier remains below the threshold until the time t ts.

The threshold device 4 produces at its output a unit sig-1al at a point in time when the voltage at its input is less than the threshold (figure 2g). At the time of SAT at the output, allocate: 1 second, the next control signal appears, which arrives at the key with the no. W at the clock input of the synchronous trigger number i-1. At the clock input of this trigger at time t (i, a transition appears from O 3 1 (FIG. 2b)), which breaks information into the trigger at its input. At this time, information at the trigger input (at the output of the threshold device, FIG. 2g) corresponds to the alarm condition of the sensor with the number i- - -1.

In a cut; one-two-Pa output of a synchronous trigger with Sumer i- appears a single emergency sn | -ial in .y.%; E; 1t to (Fig. 2h). At the same time, this signal from the output of the synchronous trigger is rewritten into an asynchronous trigger with the number Om i - 1 (Figure 2).

At time t Avar1-; nd; The state of the sensor with the number (i-1) is terminated.

In the nearest cycle of connecting the sensor with the number i-1 to the input of the amplifier 3 (interval t; v - t4, fig.26), the output of the amplifier is voltage exceeding the threshold level (fig.2e). As a result, the threshold device 4 does not work and at its output there will be a zero signal corresponding to the normal state of the sensor with the i-1 tag.

Due to the delay in amplifier 3 at time tg, when sensor 1 with number i-i is disconnected from the input of amplifier and sensor i is connected, at the output of amplifier 3 and threshold device 4 the signal still corresponds to the voltage coming from sensor i-1 At the moment tg, this signal will be detected in the synchronous trigger with the number i-1, at the output of this trigger the emergency single pulse will change to a normal zero (Fig. 2h). The zero signal at the output of the synchronous trigger does not change the state of the asynchronous trigger (Fig. 2 and), which ensures that the root cause of the accident is memorized. After eliminating the alarm, the operator returns the trigger to its original state, forcibly dropping it to zero. The signals from the outputs of asynchronous triggers 6.1-6. P are sent to the alarm signaling the root cause of the accident and to the control unit 7.

An alarm that controls the activation of the actuator 8 is generated by the control unit at the output of the OR circuit 12 if all the flame sensors signal the absence of a flame or at least one sensor of operating parameters of another type (draft, water, fuel temperature, etc.). .) signals the alarm value of the corresponding parameter.

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Claims (1)

DEVICE FOR MONITORING THE HEAT UNIT OPERATION, containing mode parameters sensors, an amplifier connected to a threshold device, a time interval adjuster and a control unit, the output of which is connected to an actuator, characterized in that, in order to increase reliability, it contains a distributor and a key for each sensor synchronous and asynchronous triggers, with each sensor connected to the information input of the corresponding key, the key outputs are combined and connected to the input of the amplifier, the output of which is connected to house of the threshold device, the output of the latter is connected to the information inputs of synchronous triggers, the outputs of the latter are connected to the inputs of the corresponding asynchronous triggers, the outputs of which are connected to the inputs of the control unit, and the time slider is connected to the input of the distributor, the outputs of which are connected to the control inputs of the keys and to the clock inputs synchronous triggers. no oo 05 no 05