RU2434297C1 - Autonomous signal-start system of firefighting - Google Patents

Abstract

FIELD: fire safety.

SUBSTANCE: system comprises a heat starter, a source of current with a pyrotechnical activator, a time relay, an actuating device and a signal device made in the form of a transmitter of a signal to a remote receiver. The transmitter comprises a driving oscillator, an n-tap line of delay, phase inverters, a summator, a power amplifier and a transmitting antenna. The receiver comprises a receiving antenna, a high-frequency amplifier, a mixer, a sawtooth generator, a heterodyne, an intermediate frequency amplifier, a detector of a phase-shift keyed signal, a phase doubler, spectrum analysers, a comparison unit, a threshold unit, delay lines, a key, a phase detector and a registration unit.

EFFECT: increased reliability of remote alarm on fire at remote, hard-to-access and rarely visited facilities by application of a radio channel and complex signals with phase manipulation.

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Description

The proposed system relates to fire fighting equipment, and more specifically to automatic fire alarm systems and controlling fire fighting equipment, and can be used for fire protection of various objects and simultaneous transmission of alarms to a remote station.

Autonomous signal-starting fire extinguishing systems are known (ed. Certificate of the USSR No. 1261676, 1277159, RF patents No. 2022250, 2024064, 2115451, 2138856, 2170951, 2165781, 2175779, 2254614, 2256228, 2275688, 2344859, 2355037; No. 3786461, 4661320; UK patent No. 2323398; EP patents No. 0360126, 0657728 and others)

Of the known systems closest to the proposed is the "Autonomous signal-starting fire extinguishing system" (RF patent No. 2355037, G08B 17/00, 2007), which is selected as a prototype.

The specified system comprises a structurally integrated thermal starter enclosed in a single housing and a current source connected to it with a pyrotechnic activator. A time relay is connected to the current source, which at the output is connected to the signal device via a normally closed contact and is additionally connected to the actuator via a normally open contact. The current source is a shell with a solid state block placed in it with the possibility of contact with a pyrotechnic activator from a solid-salt, non-separate electrochemical composition based on a lithium alloy and iron disulfide.

An object of the invention is to increase the reliability of remote signaling of a fire at remote, inaccessible and rarely visited objects by using a radio channel and complex signals with phase shift keying.

The problem is solved in that an autonomous signal-starting fire extinguishing system, containing, in accordance with the closest analogue, a heat starter connected in series, a current source with a pyrotechnic activator and a time relay, which is connected to the signal device through a normally closed contact and is additionally connected to the actuator through a normally open contact, while the thermal starter and current source with the pyrotechnic activator are structurally combined and enclosed in a building c, the thermal starter is made in the form of a spring-loaded rod installed with the possibility of translational movement and interaction with the pyrotechnic activator of the current source, and one of the end sections of the spring-loaded rod is arranged to protrude from the housing and is equipped with a latch made of material with a thermomechanical shape memory, the current source includes a shell placed in it with the possibility of contact with a pyrotechnic activator solid-state block of solid-salt non-detachable electroche of a lithium alloy and iron disulfide based composition, the signal device is made in the form of a signal transmitter to a remote receiver, differs from the closest analogue in that the signal transmitter is made in the form of serially connected master oscillator, n-tap delay line, phase inverters included in m- taps of the n-tap delay line, an adder, the (n + 1) -th input of which is connected to the output of the master oscillator, power amplifier and transmitting antenna, and the receiver is made in the form of series-connected reception an antenna, a high-frequency amplifier, a mixer, the second input of which is connected through a local oscillator to the output of a sawtooth voltage generator, an intermediate frequency amplifier, a phase doubler, a second spectrum analyzer, a comparison unit, the second input of which is connected to the output of an intermediate frequency amplifier, a threshold, through a first spectrum analyzer unit, the second input of which through the first delay line is connected to its output, a key, the second input of which is connected to the output of the intermediate frequency amplifier, phase detector, second whose first input, through the second delay line, is connected to the output of the key, and the registration unit, the control input of the sawtooth generator is connected to the output of the threshold unit.

The structural diagram of an autonomous fire alarm system is shown in figure 1. A graph of the voltage at the output contacts of the current source is shown in figure 2. Structurally combined in a single housing, a current source with a pyrotechnic activator and a thermal actuator of electrical action are depicted in figure 3. Structurally combined in a single housing, a current source with a pyrotechnic activator and thermal shock actuator are depicted in figure 4. The structural diagram of the transmitter is presented in figure 5. The block diagram of the receiver is presented in Fig.6. Timing diagrams explaining the principle of operation of the transmitter and receiver are shown in Fig.7.

The autonomous fire alarm system includes a heat starter 1 connected in series, a current source 2 with a pyrotechnic activator 3 and a time relay 4, which is connected to the signal device 5 through a normally closed contact and is additionally connected to the actuator 6 through a normally open contact.

The thermal starter 1 and the current source 2 with the pyrotechnic activator 3 are structurally combined and enclosed in a single housing 7 made of an insulating material. As an insulating (non-conductive) and non-magnetic material in the manufacture of system elements, plastic materials, materials based on glass or organ fiber can be used. The thermal starter 1 is made in the form of a cylindrical rod 8 installed in the housing 7. The rod 8 is equipped with a translational displacement drive, which is a compression spring 9 mounted coaxially on the rod 8 in its middle part. The end portion 10 of the spring-loaded stem 8 is arranged to protrude from the housing 7 and has a figured groove for interaction with a heat-sensitive latch 11, made in the form of a bracket with a diameter of about 20 mm from a material with thermomechanical shape memory, for example titanium nickelide.

The thermal starter 1 has the ability to interact with the pyrotechnic activator 3 of the current source 2 in two different ways, differing in their structural embodiments.

The thermal actuator 1 of the electrical action, shown in figure 3, is equipped with a solenoid 12 with a central axial channel 13, the terminals 14 of which are electrically connected to the pyrotechnic activator 3. In this case, the pyrotechnic activator 3 is made in the form of an incandescent bridge 15, electrically connected to the terminals 14, and a weighed portion of the initiating substance 16. In addition, the second end portion 17 of the spring-loaded rod 8 is magnetized (in the drawings, the corresponding poles of the permanent magnet are indicated by the letters S and N) and installed with awn movement within the central axial duct 13 of the solenoid 12.

The thermal actuator 1 of the shock action, shown in figure 4, is characterized in that the second end portion 17 of its spring-loaded rod 8, facing the pyrotechnic activator 3, is equipped with a conical striker 18. In this case, the pyrotechnic activator 3 is made in the form of an igniter and a weight of initiating substance 16 and capsule 19.

The current source 2 is a constant-readiness power device based on a reserve chemical type thermal current source, which is a structure in an airtight shell 20 with a solid state block 21 of a solid-salt, non-detachable electrochemical composition based on a lithium alloy and iron disulfide. In this case, the solid-state checker 21 is in direct contact with the weighed portion of the initiating substance 16 of the pyrotechnic activator 3, which is also mainly located in a sealed shell 20. The current source 2 has electrical leads 22, which are normally connected to the input contacts of the time relay 4.

The time relay 4 is an electronic on-off time switch, which is electrically connected through a normally closed output contact to a signal device 5 and simultaneously electrically connected to an actuator 6 through a normally open output contact.

The actuator 6 is mainly a fire extinguishing aerosol generator with an electric trigger, for example, a squib, which is actually connected to the normally open contact of the time relay 4.

The signal device 5 is mainly a transmitter of a radio signal to a remote receiver.

The transmitter contains serially connected master oscillator 23, an n-tap delay line 24.i (i = 1, 2, ..., n), phase inverters 25.j (j = 1, 2, ..., m) included in m taps n- the delay branch line 24.i, the adder 26, the (n + 1) -th input of which is connected to the output of the master oscillator 23, a power amplifier 27 and a transmitting antenna 28.

The receiver includes a receiving antenna 29 connected in series, a high-frequency amplifier 30, a mixer 31, the second input of which is connected through the local oscillator 33 to the output of a sawtooth generator 32, an intermediate frequency amplifier 34, a phase doubler 37, a second spectrum analyzer 38, a comparison unit 39, a second input which through the first spectrum analyzer 36 is connected to the output of the intermediate frequency amplifier 34, a threshold block 40, the second input of which through the first delay line 41 is connected to its output, a key 42, the second input of which is connected with the output of the intermediate frequency amplifier 34, a phase detector 43, the second input of which through the second delay line 44 is connected to the output of the key 42, and the registration unit 45. Spectrum analyzers 36 and 38, a phase doubler 37, a comparison unit 39, a threshold block 40, and a first delay line 41 form a phase shift signal detector (selector) 35.

Autonomous alarm trigger fire extinguishing system operates as follows.

The system is effective when used primarily on remote, inaccessible and rarely visited objects. The main elements of the system are delivered to the object in assembled form and in the cocked position are installed stationary in the place of the most likely fire. After installing the fire extinguishing system, all fuses are removed, including from the rod 8 (not shown in the drawing), and it is put into standby mode.

When a fire occurs and the temperature rises in the area of the heat-sensitive latch 11 to the activation threshold (72 ° C), a martensitic transformation occurs in its material, accompanied by the restoration of the predefined shape of the staple, the latter unclenches, restoring its shape, and releases the end portion 10 of the rod 8. Stock 8 under the influence of the spring 9 of the drive (its translational motion), begins to move down. Together with the rod 8, its second end section 17 also moves. Further, a pyrotechnic activator 3 with a thermal actuator 1 of electric action or a pyrotechnic activator 3 with a thermal actuator 1 of shock action can be implemented.

In the first case, the spring-loaded rod 8 interacts with the pyrotechnic activator 3 by means of a magnetized second end portion 17, which moves inside the central axial channel 13 of the solenoid 12 and generates a current pulse transmitted through the electrical leads 14 to the glow bridge 15 of the pyrotechnic activator 3. The required electric pulse is 0.5-1.0 A, and the duration is 1-10 ms.

In the second case, the spring-loaded rod 8 interacts with the pyrotechnic activator 3 by means of a conical hammer 18, which strikes the capsule 19.

In both cases, ignition of a portion of the initiating substance 16 occurs, which in a short time melts the solid-salt electrochemical composition of the solid-state checker and puts the current source 2 into the state of generating a current of a given value. As the graph (figure 2) shows, a short activation time (t ₀ ≤1 s) allows the use of a current source 2 in tools and devices with a short time to bring into working condition. During the time period t ₁ , the signaling device 5 is turned on and functioning. The duration of the time period t _{1 is} provided by the time relay 4, is set during the installation of the fire extinguishing system and depends on the schedule and emergency plan for the guarded object. During the specified period of time, the normally closed electrical contact of the output of the time relay 4 with the signal device 5 is necessarily maintained, which ensures the transmission of the radio signal to the remote receiver.

For this, the master pulse 23 generates a radio pulse (Fig.7, a)

u _c (t) = U _c Cos (w _c t + φ _c ), 0≤t≤τ _e ,

where U _c , w _c , φ _c , τ _e is the amplitude, carrier frequency, initial phase, and duration of the radio pulse.

The generated radio pulse from the output of the master oscillator 23 is fed to the input of the multi-tap delay line 24.i (i = 1, 2, ..., n) and to the (n + 1) -th input of the adder 26. In the multi-tap delay line 24.i the delay time between the nearest adjacent taps is equal to the duration of the radio pulse τ _e (τ _zi = τ _e , i = 1, 2, ..., n). In some taps of the delay line, phase inverters 25.j are included (j = 1, 2, ..., m), which provide 180 ° phase rotation at their outputs (in accordance with the identification code M (t) (Fig. 7, b) of the fire safety (Fig. 7, c, d). At the output of the adder 26, a complex signal with phase shift keying (PSK) is formed in the form of an algebraic sum of radio pulses from all taps of the delay line 24.i (i = 1, 2, ..., n) and the output of the master oscillator 23 (Fig.7, d)

u ₁ (t) = U _s · Cos [w _s t + φ _k (t) + φ _s ], 0≤t≤T _c ,

where φ _K (t) = {0, π} is the manipulated component of the phase that displays the law of phase manipulation in accordance with the modulating code M (t), and φ _K (t) = const for Kτ _e <t <(K + 1) τ _e and can change abruptly at t = Kτ _e , i.e. at the boundaries between elementary premises (radio pulses) (K = 1, 2, ..., n);

τ _e , n is the duration and number of elementary packages (radio pulses) of which a signal of duration T _s (T _s = τ _e · n) is composed.

This signal, after amplification in the power amplifier 27, enters the transmitting antenna 28, is radiated by it, is picked up by the receiving antenna 29 installed at the monitoring station, and through the high-frequency amplifier 30 it is supplied to the first input of the mixer 31, to the second input of which the local oscillator voltage 33 ramp

u _g (t) = U _g Cos (w _g t + πγt ² + φ _g ), 0≤t≤T _p ,

- скорость изменения частоты гетеродина 33;Where

- the rate of change of the frequency of the local oscillator 33;

T _p - the period of perestroika.

It should be noted that the search for complex QPSK signals in a given frequency range Df is carried out using a sawtooth voltage generator 32, which linearly changes the frequency of the local oscillator 33. At the output of the mixer 31, combination voltage voltages are generated. The intermediate frequency amplifier 34 provides an intermediate frequency voltage

u _up (t) = U _up · Cos [w _up t + φ _K (t) -πγt ² ₊ φ _up ], 0 <= t = <T _s ,

;Where

;

w _up = w _with -w _g - intermediate (difference) frequency;

φ _up = φ _s -φ _g ,

which is a complex signal with combined phase shift keying and linear frequency modulation (FMN - LFM).

The voltage U _up (t) from the output of the intermediate frequency amplifier 34 is supplied to the input of the detector (selector) 35 QPSK signal, consisting of a phase doubler 37, spectrum analyzers 36 and 38, a comparison unit 39, a threshold block 40, and a first delay line 41.

A voltage is generated at the output of the phase doubler 37

u ₂ (t) = U ₂ · Cos [2w _up t-2πγt ² + 2φ _up ], 0≤t≤T _s ,

Where

in which phase manipulation is already absent.

, тогда как ширина спектра входного ФМн-сигнала определяется длительностью τ_э его элементарных посылок

, т.е. ширина спектра второй гармоники сигнала в n раз меньше ширины спектра входного сигнала

.The spectrum width Δf _{2 of the} second harmonic of the signal is determined by the duration T of _the signal

, while the width of the spectrum of the input QPSK signal is determined by the duration τ _{e of} its elementary premises

, i.e. the width of the spectrum of the second harmonic of the signal is n times smaller than the width of the spectrum of the input signal

.

Therefore, when the phase of the QPSK signal is doubled, its spectral width “folds” n times. This circumstance makes it possible to detect and select the QPSK signal even when its power at the receiver input is less than the power of noise and interference.

The width of the spectrum Δf _{from the} input QPSK signal is measured by the spectrum analyzer 36, and the spectrum width Δf _{2 of the} second harmonic of the signal is measured using the spectrum analyzer 38. Voltages U _I and U _II proportional to Δf _c and Δf _2, respectively, from the outputs of the spectrum analyzers 36 and 38 are fed to two inputs of the comparison unit 39. Since U _I >> U _II , a positive voltage is generated at the output of the comparison unit 39, which exceeds the threshold level U _then in the threshold block 40. The threshold level U _then is selected so that it does not exceed random interference. When U exceeds the threshold voltage in the threshold _then block 40 is formed by a constant voltage which is supplied to the control input of switch 42, opening it to the input of the delay line 41 and to the control input 32 of the ramp generator voltage, turning it off. The key 42 in the initial state is always closed.

Upon termination of the frequency tuning of the local oscillator 32 by the intermediate frequency amplifier 34, the following voltage is released (Fig. 7, e)

U _up1 (t) = U _pr · Cos [w _up t + φ _к (t) + φ _up ], 0≤t≤T _s ,

At the output of the phase doubler 37 in this case, the harmonic voltage is allocated (Fig.7, g)

u ₃ (t) = U ₂ · Cos (2w _up t + 2φ _up ), 0≤t≤T _s .

The voltage U _up1 (t) from the output of the intermediate frequency amplifier 34 is supplied through the public switch 42 to the two inputs of the phase detector 43 directly and through the delay line 44, the delay time τ _{s of} which is chosen to be equal to the duration τ _{e of} elementary packets (τ _s = τ _e ). In this case, the reference voltage necessary for the synchronous detection of the received PSK signal for each subsequent transmission is the previous transmission. The output of the phase detector 43 is formed of a low-frequency voltage (Fig.7, and)

u _n (t) = U _n · Cos · φ _k , 0≤t≤T _c ,

;Where

;

proportional to the modulating code M (t) (Fig.7, b), with the exception of the first elementary premise.

The phase detector 43 and the delay line 44 form an autocorrelation FMN demodulator that is free from the “reverse work” phenomenon inherent in the well-known FMN signal demodulator (A. A. Pistolkors, V. I. Siforov, G. A. Travin, D. .F. Kostasa).

The low-frequency voltage u _n (t) is detected by the recording unit 45.

The carrier frequency w _s and the modulating code M (t) are identification signs of the fire safety facility where the fire occurred. Based on these signs, a control point decides on the place of the fire and measures to eliminate it.

The delay time τ _{1 of} the delay line 41 is selected so that it is possible to fix and analyze the low-frequency voltage u _n (t).

A fifteen-second pulse (t ₁ ≤15 s) is sufficient for reliable alarm transmission. During the period of time t ₂ , the actuator 6 fire extinguishing aerosol generator is connected and started. The specified connection is provided by time relay 4, by the command of which, at the end of time period t ₁ , the normally open output contact of time relay 4 is closed with an electric trigger, for example, a squib extinguishing aerosol generator. After triggering the squib of the fire extinguishing aerosol generator, the latter operates autonomously and does not need power supply from current source 2. For a reliable start of the fire extinguishing aerosol generator of the actuator 6, a five-second pulse is sufficient (t ₂ = 2-5 s).

After the time τ _{1, the} voltage from the output of the threshold block 40 through the delay line 41 is supplied to the reset input of the threshold block 40 and resets its contents to zero. In this case, the key 42 is closed, and the sawtooth voltage generator 32 is turned on, i.e. they are transferred to their original state.

When the next QPSK signal is detected at a different carrier frequency and with a different modulating code, the receiver operates in a similar way.

Thus, the proposed system, in comparison with the prototype and other technical solutions of a similar purpose, provides increased reliability of remote signaling about the occurrence of a fire at remote, inaccessible and rarely visited objects by using a radio channel and complex signals with phase shift keying.

These signals have high noise immunity, energy and structural secrecy.

The energy secrecy of complex QPSK signals is due to their high compressibility in time and spectrum with optimal processing, which reduces the instantaneous radiated power. As a result, a complex QPSK signal at the receiving point may be masked by noise and interference. Moreover, the energy of a complex QPSK signal is by no means small; it is simply distributed over the time-frequency domain so that at each point of this region the signal power is less than the power of noise and interference.

The structural secrecy of complex QPSK signals is due to the wide variety of their shapes and significant ranges of parameter changes, which makes it difficult to optimize or at least quasi-optimal processing of QPSK signals of an a priori unknown structure in order to increase the sensitivity of the receiver.

Claims (1)

An autonomous signal-starting fire extinguishing system containing a heat starter connected in series, a current source with a pyrotechnic activator and a time relay, which is connected to the signal device through a normally closed contact and is additionally connected to the actuator through a normally open contact, while the heat starter and current source with pyrotechnic activator structurally combined and enclosed in a housing, the thermal starter is made in the form of a spring-loaded rod installed o with the possibility of translational movement and interaction with the pyrotechnic activator of the current source, moreover, one of the end sections of the spring-loaded rod is arranged to protrude from the housing and is equipped with a latch made of material with a thermomechanical shape memory, the current source includes a shell with contact with it a pyrotechnic activator with a solid-state checker from a solid-salt, non-detachable electrochemical composition based on a lithium alloy and iron disulfide, a signal The n device is made in the form of a signal transmitter to a remote receiver, characterized in that the signal transmitter is made in the form of serially connected master oscillator, n-tap delay line, phase inverters included in m-taps of the n-tap delay line, adder, (n + 1 ) -th input of which is connected to the output of the master oscillator, power amplifier and transmitting antenna, and the receiver is made in the form of a series-connected receiving antenna, high-frequency amplifier, mixer, the second input of which is connected through the local oscillator with the output of a sawtooth voltage generator, an intermediate frequency amplifier, a phase doubler, a second spectrum analyzer, a comparison unit, the second input of which is connected through the first spectrum analyzer to the output of an intermediate frequency amplifier, a threshold block, the second input of which is connected through its first delay line to its output, a key , the second input of which is connected to the output of the intermediate frequency amplifier, a phase detector, the second input of which is connected through the second delay line to the output of the key, and the registration unit, The ramp voltage generator input is connected to the output of the threshold unit.

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