RU215283U1 - DEVICE FOR DETECTING FIRE-OVERHEATING SITES - Google Patents

Abstract

The utility model relates to devices and methods for detecting places of fire-overheating at control objects, which can be objects of aviation, railway transport, logistics mine workings (centers, warehouses), as well as objects with a large number of compartments, access to which is difficult or impossible and others. The technical result of the utility model is to increase the accuracy of assessing the degree of danger when a fire alarm is triggered. A device for detecting places of fire-overheating of a conductor consists of a conductor, a generator of periodic pulses, a receiver, a decision device, and an indication and visualization device. The generator of periodic pulses and the receiver are connected to the conductor. The output of the receiver is connected to the input of the solver. The output of the receiver is connected to the decision device, the first input of the block for calculating the pulse delay, the information input of the memory element, the reduced input of the subtractor and the synchronizer. The output of the periodic pulse generator is connected to the second input of the pulse delay calculation unit. The output of the pulse delay block is connected to the block for calculating the place of overheating. The output of the block for calculating the place of overheating is connected to the first input of the display and visualization device. The output of the deciding device is connected to the second input of the display and visualization device. The synchronizer output is connected to the control input of the memory element. The output of the memory element is connected to the subtracted input of the subtractor. The subtractor output is connected to the module driver. The output of the module shaper is connected to the third input of the display and visualization device. The decision device is made with memory elements of threshold values. 2 ill.

Description

The utility model relates to devices and methods for detecting places of fire-overheating at control objects, which can be objects of aviation, railway transport, logistics mine workings (centers, warehouses), as well as objects with a large number of compartments, access to which is difficult or impossible, etc. [C04B17/06, C04B17/02, C04B29/00, C04B29/145].

The prior art is known SYSTEM AND EQUIPMENT FIRE ALARM AND HEAT DETECTION [US 4814766, publ. 03/21/1989], which uses a thermoplastic film tape made of plastic, while the plastic can be made of, for example, polyvinyl chloride, polyethylene, polypropylene, hydrochloride, rubber, polyvinylidene chloride, polyester or nylon, the plastic has a significant drop in tensile strength at a given temperature, the conductive wire is laid along the entire length of the tape, the tape and wire are made with the possibility of breaking when a predetermined temperature is reached, the circuit integrity monitoring device is connected to the current conductor to detect a break, and the alarm mechanism connected to it generates an alarm signal when a break in the current conductor is detected, the system is characterized by , the solution uses plastic film shrinkage, and the operating temperature is a variable, while the shrink point is fixed for different plastic films.

Also known from the prior art FIRE ALARM SYSTEM FOR UNDERGROUND CABLE AND METHOD OF ITS WORK [CN 114360190, publ. 04/15/2022]. The invention discloses a fire alarm system for an underground cable and a method for operating the fire alarm system. The system contains a controller, a signal processing unit and one or more thermally sensitive optical fibers of different lengths, while the outer surface of one or more thermally sensitive optical fibers is in contact with the outer surface of the detected cable, one or more temperature sensitive optical fibers are connected to the processing unit signals, a signal processing unit is connected to the controller and is used to convert optical signals into electrical signals and input electrical signals to the controller, the cable to be detected is in contact with one or more temperature-sensitive optical fibers of different lengths. According to the invention, an accurate measurement of the actual temperature of the cable in real time is implemented, thereby reducing the possibility of measurement error.

Also known from the prior art FIRE ALARM SYSTEM [US 2022246022, publ. 08/04/2022], which includes: a sensor, which is periodically supplied with a communication signal used for detection; an input circuit block providing a constant current flow for the impedance measurement connected to the sensor so that it is superimposed on the communication signal used for detection; a signal processor for measuring an impedance during a communication signal outage period; a store that stores an impedance threshold value, wherein the threshold value is used to determine the wear of a cable connected to the sensor; and a controller for diagnosing when the measured impedance exceeds a threshold value.

The closest in technical essence is the FIRE ALARM SYSTEM [US 2022230530, publ. 07/21/2022], in which the pulsed voltage is applied to the signaling device several times in a row, and the pulsed voltage has such a short duration that the signaling device does not produce a noticeable alarm signal, the power consumption is measured for each of the pulsed voltages, any of the average value of the set of power consumption , the maximum value of the power demand set, or the minimum value of the power demand set is calculated as a statistic value, when the difference between the statistic value and the predetermined reference value is greater than the predetermined threshold, it is determined that a failure has occurred and a fire alarm is triggered.

The main technical problem of the analogs and the prototype is the low accuracy of the assessment of the degree of danger when the alarm is triggered, due to the limited functionality of the solutions, namely, the claimed solutions do not allow simultaneously obtaining data on the presence of the fact of overheating of the conductor or the occurrence of a fire at the control object, information on the place of occurrence overheating and the rate of increase (change) of key parameters (for example, temperature) when overheating occurs. Thus, in the solutions of analogs and the prototype, it is impossible to accurately determine the degree of danger, namely the exact location and intensity of the ongoing processes, which prevents the use of adequate measures to eliminate the causes of the alarm, and as a result, if a fire occurs, it can lead to an increase in the time for its elimination.

The purpose of the utility model is to eliminate the shortcomings of the prototype.

The technical result is to increase the accuracy of assessing the degree of danger when a fire alarm is triggered.

The specified technical result is achieved due to the fact that a device for detecting places of fire-overheating, consisting of a conductor, a periodic pulse generator, a receiver, a decisive device and an indication and visualization device, while the periodic pulse generator and the receiver are connected to the conductor, the receiver output is connected to the input of the decision device, the output of which is connected to the display and visualization device, characterized in that the output of the receiver is connected to the decision device, made with threshold memory elements, the first input of the pulse delay calculation unit, the information input of the memory element, the reduced input of the subtractor and the synchronizer, the output the generator is connected to the second input of the pulse delay calculation unit, the output of which is connected to the overheating point calculation unit, the output of which is connected to the first input of the indicating and visualization device, the output of the decisive device is connected to the second input of the indicating and visualization device , the output of the synchronizer is connected to the control input of the memory element, the output of which is connected to the subtracted input of the subtractor, the output of which is connected to the driver of the module, the output of which is connected to the third input of the display and visualization device.

Brief description of the drawings

In FIG. 1 shows a diagram of a device for detecting places of fire-overheating.

In FIG. 2 shows a variant of the scheme of the device for detecting places of fire-overheating.

The drawings indicate:

1 - conductor, 2 - generator, 3 - receiver, 4 - decision device, 5 - pulse delay calculation unit, 6 - overheating point calculation unit, 7 - memory element, 8 - synchronizer, 9 - subtractor, 10 - module shaper, 11 - display and visualization device, 12 - polling device.

A device for detecting places of fire-overheating of the conductor (figure 1) consists of a generator 2 of periodic pulses and a receiver 3 connected to the conductor 1. In this case, the conductor 1 is laid along the most significant (fire hazardous) places of the control objects. The output of the receiver 3 is connected to the decision device 4, made with threshold memory elements, the first input of the pulse delay calculation block 5, the first (information) input of the memory element 7, the first (reduced) input of the subtractor 9 and the synchronizer 8. The output of the generator 2 is connected to the second the input of the block for calculating the delay of the pulse 5, the output of which is connected to the block for calculating the place of overheating 6, the output of which is connected to the first input of the display and visualization device 11. The output of the decisive device 4 is connected to the second input of the display and visualization device 11. The output of the synchronizer 8 is connected to the second ( control) input of the memory element 7, the output of which is connected to the second (subtracted) input of the subtractor 9, the output of which is connected to the shaper of the module 10, the output of which is connected to the third input of the display and visualization device 11.

In the second embodiment of the claimed device (Fig. 2), several conductors 1 are used connected to the polling device 12, which is connected to the generator 2 and the receiver 3.

The device for detecting places of fire-overheating of the conductor operates as follows.

Initially, at the factory, the device is calibrated, which is implemented in two stages.

At the first stage, the decision device 4 is calibrated under normal conditions (at an ambient temperature of +15-25°C, with a given length of the conductor 1), for which the generator 2 is turned on, which generates periodic pulses, which, when passing through the conductor 1, are reflected from all places of inhomogeneities of a particular conductor 1 (associated with its manufacturing features, material, possible manufacturing defects, etc.), including the inhomogeneity at its end. Pulse delay calculation unit 5 fixes constant values of signal propagation delays along conductor 1, overheating area calculation unit 6 calculates the distance from generator 2 to the end of conductor 1 (and all detected inhomogeneity sites), the amplitude values of the received (reflected) signals are constant values, at the outputs subtractor 9 and module shaper 10, values close to zero are obtained. In this case, as the first threshold value of the deciding device 4, the average value of the amplitude of the received signals reflected from the places of inhomogeneities of the conductor 1, associated with the specifics of its manufacture, is fixed, while the amplitudes of the signals from the inhomogeneity at the end of the conductor 1 are not taken into account.

At the second stage, the decisive device 4 is calibrated under the conditions of heating the conductor 1 to its maximum operating temperature, which is necessary for a particular object. Why the conductor 1 is heated in several places (for example, in two or three) to the maximum operating temperature, after which the level of the peak values of the amplitudes of the received signals during heating is fixed in each place.

In this case, as the second threshold value for the heating section of the decisive device 4, the average value of the amplitudes of the received signals obtained for each heating point of the conductor 1 is fixed, increased by 10%; as the third threshold value for the heating section of the deciding device 4, the average value of the amplitudes of the received signals increased by 15% is taken (the values of 10 and 15% are indicated as an implementation example, the values \u200b\u200bcan be changed depending on the permissible operating temperatures of the conductor 1 at a particular object (section object)).

Thus, after the completion of the calibration procedure, the fixed first and second and third threshold values of the amplitudes of the received signals are used as the threshold values of the resolver 1. For this purpose, an array of threshold values is formed in the memory element of the resolver 4 in accordance with a specific object and taking into account the features the used conductor 1, while the decision device operates in accordance with the following algorithm: when receiving amplitude values of the received signals below any of the second threshold values from the array of threshold values, the output signal is sent to the display and visualization device 11 about the normal state of the object; when receiving the values of the amplitudes of the received signals between the second and third thresholds at the output, a signal is sent to the display and visualization device 11 about overheating of the conductor 1 in the corresponding section; when receiving the values of the amplitudes of the received signals, the amplitudes of which are higher than the third threshold value at the output, a signal is sent to the display and visualization device 11 about a fire at the facility in the corresponding area.

In the second embodiment (with interrogator 12), the above procedure is implemented for each conductor 1.

After the completion of the calibration process, the complete device is delivered to the place of its use according to its functional purpose.

At the facility where it is necessary to monitor the state of fire safety, conductor 1 (or conductors 1) is laid along the most significant (fire hazardous) areas. Further, after the conductor 1 is installed, a self-control test is carried out, in which the coincidence of the operating modes of the device is checked with factory calibration data under normal conditions.

Further, during the operation of the device, the generator 2 generates pulses, which, reflected from the inhomogeneities of the conductor 1, arrive at the receiver 3. Further, the amplitude values of the received signal are compared with the threshold values of the decisive device 4 received from the overheating area calculation unit 6, the evaluation results are transmitted to the device indication and visualization 11. At the same time, data on the place of possible overheating or fire are formed as follows: the pulse delay calculation unit 5 receives the value of the generation time of the next pulse from the generator 2 and the value of the time of receipt of the reflected generated pulses from the receiver 3 (from each place of conductor inhomogeneities ). Next, the pulse delay calculation unit 5 generates the value of the reflected signal delay, which is transmitted to the overheating site calculation unit 6, where, according to the signal propagation delay, the distance to the inhomogeneities of the conductor 1, where the reflection occurred, is calculated, the calculation results are transmitted to the display and visualization device 11 and in decision device 4. At the same time, the amplitude values of the received signal from the receiver 3 are fed to the subtractor 9 and the memory element 7. The memory element 7 stores the value of the received signal until the next signal arrives from the receiver 3, the moment the next signal arrives from the receiver is fixed by the synchronizer 8, which commands the operation of the memory element 7, in this case, delayed, for one clock cycle of the generator 2, the value of the amplitude of the received signal is fed to the subtractor 9. The subtractor 9 generates at the output the difference between the amplitude values of the received signal and the amplitude of the previous signal of the generator 2, module generator 10 calculates the absolute value of the obtained value, the calculation results are transmitted to the display and visualization device 11, thereby calculating the rate of change in the amplitude of the reflected signals.

In the event of a fire-overheating at one of the control objects along the route of laying conductor 1, the ambient temperature around the section of conductor 1 rises significantly, as a result of which its resistance increases and heterogeneity occurs in this section. In this case, the pulses from the generator 2 of periodic pulses 3, when passing through the conductor 1, are reflected from the inhomogeneity formed due to the thermal effect. The reflected signal obtained in this way (from the place of thermal impact) has a significantly changed amplitude value, the level of the electric field changes, which is captured by the receiver 3. In this case, at the output of the decision device 4, a signal about the presence of overheating (potential ignition) is generated, which is transmitted to display and visualization device 11. At the same time, the pulse delay calculation unit 5 generates a new delay value, this value is transmitted to the overheating site calculation unit 6, which calculates the distance from the generator 2 to the overheating site and feeds the resulting value to the display and visualization device 11. At the same time, from the output of the shaper of the module 10, the values of the increments of the amplitude values are received, which make it possible to estimate the rate of temperature rise in the conductor 1, this information is also transmitted to the display and visualization device 11.

In the second embodiment, when there are several conductors 1, the device functions in a similar way, only with a given time interval, switching between several conductors 1 is carried out. This procedure is implemented due to the presence of a polling device 12, which implements a serial poll of all connected conductors 1.

Examples of the implementation of the functional elements of the device.

The conductor 1 can be made in the form of cables or wires.

As the generator 2 can be used, the generator 2, made with the possibility of supplying a probing sinusoidal signal to the line, for example, with a frequency of 50 Hz with a delay time between probing signals of 20 ms.

The receiver 3 can be used as a synchronous detector of probing signals, which fixes the peak amplitude values of the reflected probing signals.

A multilevel comparator can be used as a decision device 4. Specific threshold values are selected based on the calibration procedure and depend on the type of conductor 1 used, its length and the parameters of generator 2.

As a block for calculating the delay of the pulse 5, a device that implements the frequency-pulse method for calculating the signal delay can be used.

As a block for calculating the place of overheating 6, an arithmetic device can be used that can implement the following arithmetic operation: the speed of propagation of electric current in conductor 1 (as a fundamental physical constant) is multiplied with the obtained value of the pulse delay divided in half, the resulting value exhaustively characterizes the place on conductor 1 , where heating or ignition occurred, namely, the distance from the generator 2 of periodic pulses and the receiver 3 to the inhomogeneity on the conductor 1.

As a memory element 7 can be used shift registers or parametric memory elements. The memory element 7 is configured to store the value of the amplitude of the reflected signal during the delay time of the next probing signal, and then transfer it to the subtractor 9 upon receipt of the corresponding control command from the synchronizer 8.

As a synchronizer 8, a matching device can be used, which is configured to generate a control command to transfer a value from the memory element 7 to the subtractor 9 when fixing the receipt of the next reflected probing pulse at the receiver 3.

Subtractor 9 can be used as an arithmetic device that implements the mathematical operation of subtraction.

An arithmetic device that implements the operation of finding the absolute value of a number can be used as a generator of module 10.

The display and visualization device 11 can be an electronic device with a display for displaying incoming information and with elements of audio and/or light indication.

The interrogator 12 can be a device that automatically closes the outputs and inputs of the generator 2 and receiver 3 to a specific conductor 1 after a predetermined time. Such time, for example, can be a value of 100 ms (or any other value depending on the object or customer requirements).

Also, depending on the specific variant of the technical implementation of the device, blocks 2 (generator) and 3 (receiver) can be made in the form of a single functional element, namely, a transceiver. Similarly, blocks 5 (pulse delay calculation block) and 6 (overheating point calculation block) can be made as a single functional element, namely, a pulse delay and overheating point calculation block.

The claimed technical result - an increase in the accuracy of assessing the degree of danger when a fire alarm is triggered, is achieved due to the presence of a decision device 4 made with threshold memory elements and connected to the overheating location calculation unit 6, which allows you to accurately determine the presence of overheating in a particular place and evaluate it the degree of danger, namely, the occurrence of overheating of the conductor or fire at the facility. Also, the claimed technical result is achieved due to the presence of a memory element 7, a synchronizer 8, a subtractor 9 and a module shaper 10, which makes it possible to determine the dynamics of the change in the amplitude of the received signal, and as a result, to determine the level of intensity of overheating or fire, which also allows us to draw a conclusion about the degree of danger that has arisen. situations. Thus, the claimed technical solution allows you to accurately determine the degree of danger, namely the exact location and intensity of the ongoing processes, which contributes to the use of adequate measures to eliminate the causes of the alarm, and as a result, if a fire occurs, it can lead to a decrease in the time to eliminate it. Also, the claimed technical result can be achieved due to the possibility of working with several conductors by means of a polling device 12, in which case it is possible to assess the degree of danger when a fire alarm is triggered due to a larger area covered by conductors 1 of a fire hazardous object.

Also, the claimed technical solution has the following useful properties:

ease of manufacture and installation at the control object;

ease of maintenance due to the possibility of replacing the conductors 1 when they are worn and/or mechanically deformed.

The applicant in 2022 produced a prototype of the claimed technical solution, the operation of which confirmed the claimed technical result - the accuracy of assessing the degree of danger when a fire alarm was triggered was 95%.

Examples of achieving a technical result.

Example 1. During the operation of the device, the indication and visualization device 11 displayed information about the triggering of the second threshold device in the corresponding section of the object, while the increase in the amplitude values of the received signal over the observation period was insignificant and did not reach the third threshold value. In this case, it was concluded that the degree of danger was low, and technical personnel were sent to the site of the facility to repair the damage to conductor 1.

Example 2. During operation of the device, the display and visualization device 11 displayed information about the triggering of the second threshold device in the corresponding section of the object and after a few seconds about the triggering of the third threshold device, while the increase in the amplitude values of the received signal over the observation period had an avalanche-like character. In this case, it was concluded that a fire had occurred, a fire alarm was announced at the facility, followed by immediate implementation of appropriate organizational and technical measures.

The claimed device is manufactured at the enterprise and is a single product consisting of mechanically and electrically connected functional elements and is supplied as part of a set of equipment.

Claims (1)

A device for detecting places of fire-overheating of a conductor, consisting of a conductor, a generator of periodic pulses, a receiver, a decisive device and an indication and visualization device, while the generator of periodic impulses and the receiver are connected to the conductor, the output of the receiver is connected to the input of the decisive device, the output of which is connected to an indication and visualization device, characterized in that the receiver output is connected to a decision device made with threshold value memory elements, the first input of the pulse delay calculation block, the information input of the memory element, the reduced input of the subtractor and the synchronizer, the generator output is connected to the second input of the delay calculation block pulse, the output of which is connected to the block for calculating the place of overheating, the output of which is connected to the first input of the indicating and visualization device, the output of the decisive device is connected to the second input of the indicating and visualization device, the synchronizer output is connected to the control input m of a memory element, the output of which is connected to the subtracted input of the subtractor, the output of which is connected to the driver of the module, the output of which is connected to the third input of the display and visualization device.

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