CN112530121A - Cable type linear temperature-sensing fire detector capable of alarming fire in short circuit - Google Patents
Cable type linear temperature-sensing fire detector capable of alarming fire in short circuit Download PDFInfo
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Abstract
The invention provides a cable type linear temperature-sensing fire detector capable of alarming fire in short circuit, which greatly saves the time cost of manual maintenance on the site of the detector by a main monitoring input unit A and a standby monitoring input unit B which are respectively arranged at two ends of a temperature-sensing cable which at least comprises two detection conductors and one of which is a detection line body with a series characteristic temperature coefficient, and simultaneously, when a short circuit fault occurs at any point of the temperature-sensing cable, two ends of the temperature-sensing cable are adopted to simultaneously detect and detect fire, the whole-line fire detection of the temperature-sensing cable in an original area protected by the detector can be still ensured, and the reliability of fire alarm of the detector is greatly improved.
Description
Technical Field
The invention belongs to the technical field of fire fighting, and relates to a cable type linear temperature-sensing fire detector, in particular to a cable type linear temperature-sensing fire detector capable of alarming fire in a short circuit.
Background
The cable type linear temperature-sensing fire detector is generally composed of a linear sensing element, a signal processing device (also called a resistance signal detection device) connected to one end of the sensing element, and a relay part connected to the other end of the sensing element. The sensing element on the cable type linear temperature-sensing fire detector is generally called as a temperature-sensing cable or a detection cable, and is divided into two types, namely a recoverable type and an unrecoverable type.
Chinese patent document CN200520119066.9 (patent name is discrete thermistor series analog quantity line type temperature sensing fire detection cable) discloses a discrete thermistor series analog quantity line type temperature sensing fire detection cable, as shown in fig. 1, the detection cable is composed of a detection line body 2, a signal transmission line 3 and a connection terminal resistor Rz therebetween, wherein the detection line body 2 is formed by connecting a plurality of thermistors 11 in series, the signal transmission line 3 is a conductor which is equal to the detection line body in length and is arranged in parallel, and an insulating layer 4 is arranged between the detection line body 2 and the signal transmission line 3. When a certain section of the detection cable is heated, the resistance value of the thermistor in the detection cable is reduced (when the thermistor is of an NTC type or a CTR type) or increased (when the thermistor is of a PTC type) along with the increase of the temperature, so that the resistance signal detection device detects the reduction or increase of the resistance between the terminals A, C, and the detector reports a fire alarm according to the change of the total resistance or other parameters caused by the change of the total resistance or the change rate.
FIG. 2 is an equivalent circuit shown in FIG. 1, in which the thermistor 11 is equivalent to a resistor R2, and its operation principle is that the signal processing device detects the signal R when it is normalMeasuringIs RIs normalWhich is equal to the resistance R of the temperature sensing cableCable with a protective layerThe value in series with the terminating resistor Rz. When the temperature sensing cable is short-circuited, as shown in fig. 3, B in fig. 3 is a short-circuit point, and the signal processing device detects a signal RMeasuringIs RShort cable(i.e. only the resistance of the temperature-sensing cable section between the short-circuit point B and the signal processing device) because of RShort cable<RIs normalAt this time, the signal processing device determines that the failure has occurred. When any part of the temperature sensing cable is heated, the signal processing device detects a signal RMeasuringIs RFire alarm(i.e. the resistance R of the temperature sensing cable after being heatedCable heaterValue in series with the terminating resistance) when RFire alarm<When the fire alarm value is set (when the detection line body is NTC type or CTR type), the signal processing device outputs a fire alarm signal; when R isFire alarm>Fire alarmWhen the alarm value is given (when the detection line body is PTC type), the signal processing device outputs the fire alarm signal.
The disadvantage is that the length of the temperature sensing cable is mostly 200 meters, the installation position of the signal processing device and the relay component (terminal resistor Rz) is far away, the debugging and the maintenance are inconvenient, and the situation that the relay component can not be found is often occurred if the temperature sensing cable is in a use place with a complex environment. Meanwhile, in the use process of the temperature sensing cable, when a short circuit occurs between the detection conductors at any position of the temperature sensing cable, although the signal processing device can report the fault, if the fault cannot be maintained urgently, the detector cannot detect the temperature sensing cable in the protection area in time along the fire, and the operation safety of the production equipment is influenced.
Disclosure of Invention
In order to solve the above problems, an object of the present invention is to provide a cable type line-type temperature-sensitive fire detector capable of detecting a fire in the entire area to be protected even when any point of a temperature-sensitive cable is short-circuited.
The cable type linear temperature-sensing fire detector capable of alarming fire in short circuit comprises a temperature-sensing cable and a signal processing device connected with two ends of the temperature-sensing cable; the signal processing device mainly comprises a microprocessor, a main monitoring input unit A, an output unit and a standby monitoring input unit B, wherein one end of the temperature sensing cable is connected with the main monitoring input unit A of the signal processing device, the other end of the temperature sensing cable is connected with the standby monitoring input unit B of the signal processing device, the temperature sensing cable at least comprises two detection conductors, and one of the two detection conductors is a series characteristic temperature coefficient detection line body; wherein:
the main monitoring input unit A: the temperature sensing cable detection circuit mainly comprises a detection circuit for detecting the temperature sensing cable, and a signal detected by the detection circuit is input to the microprocessor;
the standby monitoring input unit B: the microprocessor judges that the temperature sensing cable is short-circuited, wherein the control circuit switches the terminal resistance circuit into the detection circuit and inputs a signal detected by the detection circuit into the microprocessor;
the output unit: the microprocessor is used for controlling the microprocessor to output a fire alarm or fault signal;
the microprocessor: the detection signal processing judgment of the main monitoring input unit A and the detection signal processing judgment of the standby monitoring input unit B and the control circuit control of the standby monitoring input unit B are used for controlling the output of the output unit.
The standby monitoring input unit B further comprises a temperature sensing cable short-circuit monitoring circuit, wherein the temperature sensing cable short-circuit monitoring circuit monitors the current or the voltage at two ends of the terminal resistor in the terminal resistor circuit, and the microprocessor processes and judges the current or the voltage according to the monitoring voltage or the current and controls the control circuit.
The temperature sensing cable is mainly composed of at least two detection conductors and an insulating material layer arranged between the two detection conductors, and the two detection conductors are twisted or sequentially put together.
The series characteristic temperature coefficient detection line body is a continuous NCT or CTR or PCT characteristic detection line body or a detection line body formed by connecting at least 2 independent NCT or CTR or PCT characteristic thermistors in series.
The continuous NCT or CTR characteristic detection wire body or the independent NCT or CTR characteristic thermistor is made of a conductive high polymer material with negative temperature coefficient characteristic in polyacetylene, polyaniline and polyphthalazine; the continuous PCT characteristic detection line body or the independent PCT characteristic thermistor is made of one of a platinum wire, a copper wire and a nickel wire with positive temperature coefficient characteristics.
The invention also provides another cable type linear temperature-sensing fire detector for alarming fire in short circuit, which comprises a main signal processing device, a secondary signal processing device and the temperature-sensing cable connected between the main signal processing device and the secondary signal processing device; the main signal processing device mainly comprises a microprocessor, a main monitoring input unit A and an output unit, and the auxiliary signal processing device mainly comprises a microprocessor, a standby monitoring input unit B and an output unit; one end of the temperature sensing cable is connected with a main monitoring input unit A of the main signal processing device, the other end of the temperature sensing cable is connected with a standby monitoring input unit B of the auxiliary signal processing device, the temperature sensing cable at least comprises two detection conductors, and one of the two detection conductors is a series characteristic temperature coefficient detection line body; wherein:
a main monitoring input unit a of the main signal processing apparatus: the temperature sensing cable detection circuit mainly comprises a detection circuit for detecting the temperature sensing cable, and a signal detected by the detection circuit is input to a microprocessor of the temperature sensing cable detection circuit;
an output unit of the main signal processing apparatus: the microprocessor is used for controlling the main signal processing device to output a fire alarm or fault signal;
the microprocessor of the main signal processing device: the main monitoring input unit A is used for detecting signal processing judgment and controlling an output unit thereof;
the standby monitoring input unit B of the secondary signal processing device: the microprocessor judges that the temperature sensing cable is short-circuited, wherein the control circuit switches the terminal resistance circuit into the detection circuit and inputs signals detected by the detection circuit into the microprocessor;
an output unit of the secondary signal processing apparatus: the microprocessor of the signal processing device is mainly used for controlling the signal processing device to output a fire alarm or fault signal;
the microprocessor of the signal processing device: the control circuit is used for processing and judging the detection signal of the standby monitoring input unit B, processing and judging the monitoring signal of the temperature sensing cable short circuit monitoring circuit and controlling the control circuit, and controls the output unit to output.
The monitoring signal of the temperature sensing cable short circuit monitoring circuit is the current or the voltage at two ends of the terminal resistor in the terminal resistor circuit.
The temperature sensing cable also comprises a control wire core which sends an electric signal to the auxiliary signal processing device when the main signal processing device detects the short circuit of the temperature sensing cable.
The temperature sensing cable is mainly composed of at least two detection conductors and an insulating material layer arranged between the two detection conductors, and the two detection conductors are twisted or sequentially put together.
The series characteristic temperature coefficient detection line body is a continuous NCT or CTR or PCT characteristic detection line body or a detection line body formed by connecting at least 2 independent NCT or CTR or PCT characteristic thermistors in series.
The continuous NCT or CTR characteristic detection wire body or the independent NCT or CTR characteristic thermistor is made of a conductive high polymer material with negative temperature coefficient characteristic in polyacetylene, polyaniline and polyphthalazine; the continuous PCT characteristic detection line body or the independent PCT characteristic thermistor is made of one of a platinum wire, a copper wire and a nickel wire with positive temperature coefficient characteristics.
In order to connect the cable type linear temperature-sensing fire detector end to form a series of detection modes, the cable type linear temperature-sensing fire detector further comprises an adjacent temperature-sensing cable connected with the main signal processing device, the main signal processing device further comprises a standby monitoring input unit B, wherein one end of the adjacent temperature-sensing cable is connected with the standby monitoring input unit B of the main signal processing device;
wherein:
a standby monitoring input unit B of the main signal processing device: the main signal processing device is mainly composed of a terminal resistance circuit, a detection circuit, a control circuit and a short circuit monitoring circuit of adjacent temperature sensing cables, wherein when the microprocessor of the main signal processing device judges that the adjacent temperature sensing cables are short-circuited, the control circuit switches the terminal resistance circuit into the detection circuit and inputs signals detected by the detection circuit into the microprocessor;
the microprocessor of the main signal processing device: the device is also used for processing and judging the detection signal of the standby monitoring input unit B of the main signal processing device and the monitoring signal of the adjacent temperature sensing cable short circuit monitoring circuit, controlling the control circuit of the adjacent temperature sensing cable short circuit monitoring circuit, and controlling the output unit of the main signal processing device to correspondingly output the detection signal.
The cable type linear temperature-sensing fire detector also comprises an adjacent temperature-sensing cable connected with the secondary signal processing device, and the secondary signal processing device also comprises a main monitoring input unit A, wherein one end of the adjacent temperature-sensing cable is connected with the main monitoring input unit A of the secondary signal processing device;
wherein:
the main monitoring input unit A of the secondary signal processing device: mainly comprises a detection circuit for detecting adjacent temperature-sensing cables, and inputs signals detected by the detection circuit into a microprocessor thereof;
the microprocessor of the signal processing device: the device is also used for processing and judging the detection signal of the main monitoring input unit A of the secondary signal processing device, and controlling the output unit to output correspondingly.
The cable type linear temperature-sensing fire detector capable of alarming fire in short circuit provided by the invention has the advantages that the main monitoring input unit A and the standby monitoring input unit B which are respectively arranged at the two ends of the temperature-sensing cable which at least comprises two detection conductors and one of which is a detection line body with the temperature coefficient of the series characteristic are respectively arranged, so that the manual maintenance time cost of the detector field is greatly saved no matter the main monitoring input unit A and the standby monitoring input unit B are arranged in the same signal processing device on the field or in two different signal processing devices on the field, and meanwhile, once the short circuit fault occurs at any point of the temperature-sensing cable, the fire is simultaneously detected by adopting the two ends of the temperature-sensing cable, the whole-line fire detection of the temperature-sensing cable in the original area protected by the detector can be still ensured, and the fire alarm reliability.
Drawings
Fig. 1 is a schematic structural diagram of a conventional detection cable.
FIG. 2 is an equivalent circuit schematic of the probe cable shown in FIG. 1.
Fig. 3 is a schematic diagram of an equivalent circuit of the detection cable shown in fig. 1 when the detection cable is short-circuited.
Fig. 4 is a schematic structural view of a cable-type linear temperature-sensitive fire detector for alarming a fire in a short circuit according to an embodiment.
Fig. 5 is a schematic structural view of a first cable-type linear temperature-sensitive fire detector for alarming fire in case of short circuit according to the second embodiment.
Fig. 6 is a schematic structural view of a second cable-type linear temperature-sensitive fire detector for alarming fire in case of short circuit according to the second embodiment.
FIG. 7 is a schematic view showing a series of end-to-end connections of the improved cable-type line-type heat fire detector shown in FIG. 5.
Detailed Description
The cable type linear temperature-sensing fire detector for alarming fire in case of short circuit according to the present invention will be described in detail with reference to the accompanying drawings and embodiments.
Example one
As shown in fig. 4, the cable type linear temperature-sensing fire detector for alarming fire in short circuit according to this embodiment includes a signal processing device 20 and a temperature-sensing cable 30, wherein the signal processing device 20 mainly includes a microprocessor 21, a main monitoring input unit a22, an output unit 23, and a standby monitoring input unit B24, the temperature-sensing cable 30 at least includes two detection conductors, one of which is a series characteristic temperature coefficient detection line, one end of the temperature-sensing cable 30 is connected to the main monitoring input unit a22 of the signal processing device 20, and the other end is connected to the standby monitoring input unit B24 of the signal processing device 20; the main monitoring input unit A22 mainly comprises a detection circuit for detecting the temperature sensing cable 30, and inputs the signal detected by the detection circuit to the microprocessor 21, and the standby monitoring input unit B24 mainly comprises a terminal resistor Rz circuit, a detection circuit, a control circuit for switching the detection circuit and the detection circuit, and a temperature sensing cable short circuit monitoring circuit; when the microprocessor 21 judges that the temperature sensing cable 30 is short-circuited, the control circuit switches the connection between the standby monitoring input unit B24 and the temperature sensing cable from a terminal resistor Rz circuit to a detection circuit access state, and inputs a signal detected by the detection circuit into the microprocessor 21; the output unit 23 is used for controlling the microprocessor 21 to output a fire alarm or fault signal; the microprocessor 21 is used for processing and judging the detection signal of the main monitoring input unit a22, processing and judging the detection signal of the standby monitoring input unit B24, processing and judging the monitoring signal of the temperature sensing cable short-circuit monitoring circuit, controlling the control circuit of the temperature sensing cable short-circuit monitoring circuit, and controlling the output of the output unit 23, wherein the temperature sensing cable short-circuit monitoring circuit in the standby monitoring input unit B24 monitors the current I or the voltage V at two ends of the terminal resistor Rz to judge whether the temperature sensing cable has a short-circuit fault or not (if the temperature sensing cable short-circuit is judged only by processing the detection signal of the main monitoring input unit a22, then the temperature sensing cable short-circuit monitoring circuit in the standby monitoring input unit B24 can be cancelled, and certainly, the two temperature sensing cable short-circuit monitoring judgments can exist for the more reliable.
1) When the detector works normally, the connection between the standby monitoring input unit B24 of the signal processing device 20 and the temperature sensing cable is in a terminal resistance Rz circuit connection state, the main monitoring input unit A22 constantly detects the resistance value of the detection loop formed by the temperature sensing cable 30 and the standby monitoring input unit B24, the microprocessor 21 judges and compares according to the detection signal input by the main monitoring input unit A22, and when the detection resistance value is equal to the normal value RIs normalThe microprocessor 21 determines that the state is normal.
2) When a short circuit occurs at any position of the temperature sensing cable 30, the main monitoring input unit a22 of the signal processing device 20 detects that the resistance value of the detection loop is smaller than RIs normalIf the fault is detected, the microprocessor 21 determines that the fault is a short-circuit fault, and the output unit 23 outputs a fault signal; meanwhile, the connection between the standby monitoring input unit B24 and the temperature sensing cable is switched to a detection circuit access state by a terminal resistor Rz circuit, and the detection circuit is used for detecting the resistance value of the temperature sensing cable section which is connected with and between the short circuit point and the standby monitoring input unit B24; the main monitoring input unit A22 continuously detects the resistance value of the temperature sensing cable section connected between the short circuit point and the main monitoring input unit A22; therefore, the signal processing device 20 always performs the all-line detection and fire alarm on the temperature sensing cable 30 having the short-circuit point through the main monitoring input unit a22 and the backup monitoring input unit B24, and the microprocessor 21 performs the fire judgment based on the detection signals input by the main monitoring input unit a22 and the backup monitoring input unit B24.
Meanwhile, a) if the series characteristic temperature coefficient detection line body in the temperature sensing cable is an NTC type or CTR type detection line body:
when a fire occurs in the area protected by the temperature-sensing cable section between the short circuit point and the standby monitoring input unit B24, the resistance of the temperature-sensing cable section is reduced when heated, and when the standby monitoring input unit B24 detects that the resistance is lower than the short circuit resistance, the fire alarm is triggeredThreshold value RFire alarm BIf so, the microprocessor 21 judges a fire alarm, and the output unit 23 outputs a fire alarm signal; when a fire breaks out in the area protected by the temperature-sensing cable section between the short-circuit point and the main monitoring input unit A22, the resistance of the temperature-sensing cable section is reduced when heated, and when the main monitoring input unit A22 detects that the resistance is lower than the short-circuit fire alarm threshold RFire alarm AIf the fire is detected, the microprocessor 21 determines that the fire is detected, and the output unit 23 outputs a fire signal.
b) If the series characteristic temperature coefficient detection line body in the temperature sensing cable is a PTC type detection line body:
when a fire disaster occurs in the area protected by the temperature sensing cable section between the short circuit point and the standby monitoring input unit B24, the resistance value of the temperature sensing cable section rises due to heating, and when the standby monitoring input unit B24 detects that the resistance value is larger than the fire alarm threshold value R during short circuitFire alarm BIf so, the microprocessor 21 judges a fire alarm, and the output unit 23 outputs a fire alarm signal; when a fire breaks out in the area protected by the temperature-sensing cable section between the short-circuit point and the main monitoring input unit A22, the resistance of the temperature-sensing cable section rises due to heating, and when the main monitoring input unit A22 detects that the resistance is larger than the fire alarm threshold R during short-circuitFire alarm AIf the fire is detected, the microprocessor 21 determines that the fire is detected, and the output unit 23 outputs a fire signal.
Example two
As shown in fig. 5, the cable type linear temperature-sensing fire detector for alarming fire in short circuit according to the present embodiment includes a main signal processing device 20, a sub signal processing device 40, and a temperature-sensing cable 30 connected therebetween; the main signal processing device 20 mainly comprises a microprocessor 21, a main monitoring input unit A22 and an output unit 23, the auxiliary signal processing device 40 mainly comprises a microprocessor 41, an output unit 43 and a standby monitoring input unit B44, the temperature sensing cable 30 at least comprises two detection conductors, one of the two detection conductors is a series characteristic temperature coefficient detection line body, one end of the temperature sensing cable 30 is connected with the main monitoring input unit A22 of the main signal processing device 20, and the other end of the temperature sensing cable is connected with the standby monitoring input unit B44 of the auxiliary signal processing device 40.
The main monitor input unit a22 of the main signal processing device 20 is mainly composed of a detection circuit for detecting the temperature sensing cable 30, and inputs a signal detected by the detection circuit to the microprocessor 21; the output unit 23 of the main signal processing device is used for controlling and outputting a fire alarm or fault signal by the microprocessor 21 of the main signal processing device; the microprocessor 21 of the main signal processing apparatus is used for the main monitor input unit a22 to detect the signal processing decision and the control of the output unit 23.
The standby monitoring input unit B44 of the secondary signal processing device 40 mainly comprises a terminal resistor Rz circuit, a detection circuit, a control circuit for switching between the terminal resistor Rz circuit and the detection circuit, and a temperature sensing cable short circuit monitoring circuit, when the microprocessor 41 judges that the temperature sensing cable is short-circuited, the control circuit switches the connection between the standby monitoring input unit B44 and the temperature sensing cable from the terminal resistor Rz circuit to the detection circuit access state, and inputs the signal detected by the detection circuit to the microprocessor 41; the output unit 43 of the secondary signal processing device is mainly controlled by the microprocessor 41 of the secondary signal processing device to output a fire alarm or fault signal; the microprocessor 41 of the sub-signal processing device 40 is used for the detection signal processing judgment of the backup monitoring input unit B44, the temperature-sensitive cable short-circuit monitoring signal processing judgment and the control circuit control, and controls the output unit 43 to output.
1) When the detector works normally, the connection between the backup monitoring input unit B44 of the secondary signal processing device 40 and the temperature sensing cable is in a terminal resistance Rz circuit access state, and the main monitoring input unit a22 of the main signal processing device 20 constantly detects the resistance value of a detection loop formed by the temperature sensing cable 30 and the backup monitoring input unit B44 of the signal processing device 40; when the detected resistance value is equal to the normal value RIs normalThen, the microprocessor 21 judges that the temperature sensing cable 30 is in a normal state; meanwhile, the temperature sensing circuit short-circuit monitoring circuit in the standby monitoring input unit B44 of the auxiliary signal processing device 40 monitors the voltage V at two ends of the terminal resistor RzIs normalThe microprocessor 41 determines that the temperature sensitive cable 30 is also normal. Thus, the detector is in a normal state.
2) When a short circuit occurs at any position of the temperature sensing cable 30, the main monitoring input unit a22 of the main signal processing device 20 detects that the resistance value of the detection loop is smaller than RIs normalWhen the microprocessor 21 determines that the short circuit is generatedA fault is generated, and a fault signal is output by the output unit 23; meanwhile, when the temperature-sensing circuit short-circuit monitoring circuit in the standby monitoring input unit B44 of the secondary signal processing device 40 cannot monitor the current or the voltage at both ends of the terminal resistor Rz, the connection between the standby monitoring input unit B44 and the temperature-sensing cable is switched to the detection circuit access state; in this way, the main monitor input unit a22 of the main signal processing device 20 detects the resistance value of the temperature-sensitive cable segment connected to and between the short-circuit point and the main monitor input unit a22, and the auxiliary monitor input unit B44 of the auxiliary signal processing device 40 detects the resistance value of the temperature-sensitive cable segment connected to and between the short-circuit point and the auxiliary monitor input unit B44. Therefore, the main monitor input means a22 of the main signal processing device 1 and the backup monitor input means B44 of the sub signal processing device 40 always perform the all-line monitor fire alarm on the temperature sensitive cable 30 having the short circuit point.
Meanwhile, a) if the series characteristic temperature coefficient detection line body in the temperature sensing cable is an NTC type or CTR type detection line body:
when a fire occurs in the area protected by the temperature-sensing cable segment between the short-circuit point and the backup monitoring input unit B44 of the secondary signal processing device 40, the resistance of the temperature-sensing cable segment decreases due to heating, and when the backup monitoring input unit B44 detects that the resistance is lower than the short-circuit fire alarm threshold RFire alarm BIf the microprocessor 41 determines a fire alarm, the output unit 43 outputs a fire alarm signal; when a fire occurs in the area protected by the temperature-sensing cable section between the short-circuit point and the main monitoring input unit A22 of the main signal processing device 20, the resistance of the temperature-sensing cable section will decrease due to heating, and when the main monitoring input unit A22 of the main signal processing device 20 detects that the resistance is lower than the short-circuit fire alarm threshold RFire alarm AIn this case, the microprocessor 21 in the main signal processing device 20 determines a fire alarm, and the output unit 23 in the signal processing device 20 outputs a fire alarm signal.
b) If the series characteristic temperature coefficient detection line body in the temperature sensing cable is a PTC type detection line body:
when a fire occurs in the area protected by the temperature-sensing cable segment between the short-circuit point and the backup monitoring input unit B44 in the secondary signal processing device 40, the temperature-sensing cable segment is heatedThe resistance value is increased, and when the standby monitoring input unit B44 detects that the resistance value is larger than the short-circuit fire alarm threshold value RFire alarm BIf the microprocessor 41 determines a fire alarm, the output unit 43 outputs a fire alarm signal; when a fire occurs in the area protected by the temperature-sensing cable section between the short-circuit point and the main monitoring input unit A22 of the main signal processing device 20, the resistance of the temperature-sensing cable section increases due to heating, and when the main monitoring input unit A22 of the main signal processing device 20 detects that the resistance is greater than the short-circuit fire alarm threshold RFire alarm AIn this case, the microprocessor 21 in the main signal processing device 20 determines a fire alarm, and the output unit 23 in the main signal processing device 20 outputs a fire alarm signal.
As shown in fig. 6, in order to ensure that the connection between the backup monitor input unit B44 of the secondary signal processing apparatus 40 and the temperature sensing cable can be switched to the monitor circuit connection state more reliably when a short circuit occurs at any point of the temperature sensing cable 3, a control core 31 is additionally provided along the temperature sensing circuit 30 between the main monitor input unit a22 and the backup monitor input unit B44 of the secondary signal processing apparatus 40 in the main signal processing apparatus 20. In normal operation, the main signal processing device 20 is a main monitoring device, the microprocessor 21 sends a normal signal to the main monitoring input unit a22, the main monitoring input unit a22 sends a high level signal to the standby monitoring input unit B44 in the auxiliary signal processing device 40 through the control wire core 31, the standby monitoring input unit B44 sends the high level signal to the microprocessor 41, and the microprocessor 41 keeps the connection between the standby monitoring input unit B44 and the temperature sensing cable in a terminal resistance Rz circuit connection state. On the contrary, when a short circuit occurs between the detection conductors at any position of the temperature sensing cable 30, the microprocessor 21 in the main signal processing device 20 sends a short circuit signal to the main monitoring input unit a22 thereof, and the main monitoring input unit a22 sends a low level signal (i.e. a transition signal which changes from a high level to a low level, or vice versa) to the standby monitoring input unit B44 in the subsidiary signal processing device 40 through the control wire core 31, the connection between the standby monitoring input unit B44 in the subsidiary signal processing device 4 and the temperature sensing cable is switched to a monitoring circuit (the control wire core 31 may not be additionally provided between the main monitoring input unit a22 in the main signal processing device 20 and the standby monitoring input unit B44 in the subsidiary signal processing device 40 along the temperature sensing cable 30, and the electric signals are transmitted therebetween through a wireless signal transmission method).
Fig. 7 is a schematic view of a series of end-to-end cable-type line-type temperature-sensitive fire detectors for alarming fire in case of short circuit shown in fig. 5, which is different from fig. 5 in that: the main and auxiliary signal processing devices connected with the head and tail ends of each section of temperature sensing cable are internally provided with a main monitoring input unit and a standby monitoring input unit.
The temperature sensing cable is mainly formed by twisting or sequentially arranging at least two detection conductors and an insulating material layer arranged between the detection conductors, wherein one detection conductor is a series characteristic temperature coefficient detection line body.
The series characteristic temperature coefficient detection line body of the temperature sensing cable can be made of one of high polymer materials with polyacetylene, polyaniline and polyphthalazine as main conductive substances, and has the characteristic of negative temperature coefficient; or made of one of platinum wire, copper wire and nickel wire, and the detecting wire body has the characteristic of positive temperature coefficient.
The detection line body can be manufactured by processes of extrusion, drawing and the like, and can also be formed by connecting a discrete thermistor, a thermal resistor, a normally closed type thermal switch and the like in series.
The main point of the invention is that the main monitoring input unit and the standby monitoring input unit are respectively arranged at two ends of the temperature sensing cable which at least comprises two detection conductors and one of which is a detection line body with the temperature coefficient of the series characteristic, once a short circuit occurs at a certain position of the temperature sensing cable, the connection between the standby monitoring input unit and the temperature sensing circuit is switched from a terminal resistance Rz circuit to a monitoring circuit, thereby carrying out the all-line monitoring and fire alarm on the temperature sensing cable from two ends thereof. When the temperature sensing cable is short-circuited, the temperature sensing cable short-circuit monitoring circuit can be arranged in the standby monitoring input unit and can also be arranged in the main monitoring input unit; whether the main monitoring input unit and the standby monitoring input unit which are connected with the same temperature sensing cable are arranged in the same signal processing device or two different signal processing devices or whether the short-circuit signal is transmitted wirelessly or in a wired mode; the connection between the standby monitoring input unit and the temperature sensing cable is switched to the access state of the detection circuit. The scope of the invention is described in the claims, but any modifications that include the gist of the invention are within the scope of the invention.
Claims (11)
1. A cable type linear temperature-sensing fire detector capable of alarming fire in short circuit is characterized by comprising a temperature-sensing cable (30) and a signal processing device (20) connected with two ends of the temperature-sensing cable; the signal processing device (20) mainly comprises a microprocessor (21), a main monitoring input unit A (22), an output unit (23) and a standby monitoring input unit B (24), one end of the temperature sensing cable (30) is connected with the main monitoring input unit A (22) of the signal processing device (20), the other end of the temperature sensing cable is connected with the standby monitoring input unit B (24) of the signal processing device (20), the temperature sensing cable (30) at least comprises two detection conductors, and one of the two detection conductors is a series characteristic temperature coefficient detection line body; wherein:
the main monitoring input unit A (22): mainly composed of a detection circuit for detecting the temperature sensing cable, and inputting the signal detected by the detection circuit to a microprocessor (21);
the standby monitoring input unit B (24): the temperature sensing cable short-circuit detection circuit mainly comprises a terminal resistance circuit, a detection circuit and a control circuit switched between the terminal resistance circuit and the detection circuit, wherein when the microprocessor (21) judges that the temperature sensing cable (30) is short-circuited, the control circuit switches the terminal resistance circuit into the detection circuit and inputs a signal detected by the detection circuit into the microprocessor (21);
the output unit (23): for controlling the microprocessor (21) to output a fire alarm or fault signal;
said microprocessor (21): the detection signal processing judgment for the main monitoring input unit A (22), the detection signal processing judgment for the standby monitoring input unit B (24) and the control circuit control thereof, and the control output unit (23).
2. The cable-type line-type temperature-sensitive fire detector according to claim 1, wherein the backup monitor input unit B (24) further comprises a temperature-sensitive cable short-circuit monitor circuit for monitoring the current or the voltage across the terminal resistor in the terminal resistor circuit, and the microprocessor processes the determination and controls the control circuit according to the monitored voltage or current.
3. The cable type line-type temperature-sensitive fire detector according to claim 1 or 2, wherein the temperature-sensitive cable is mainly composed of at least two detection conductors and an insulating material layer disposed therebetween, and twisted or laid down together.
4. The cable-type line-type temperature-sensitive fire detector according to claim 1 or 2, wherein the series characteristic temperature coefficient detection line is a continuous NCT or CTR or PCT characteristic detection line or a detection line formed by connecting at least 2 independent NCT or CTR or PCT characteristic thermistors in series.
5. A cable type linear temperature-sensing fire detector for alarming fire in short circuit, which is characterized in that the detector comprises a main signal processing device (20), a secondary signal processing device (40) and a temperature-sensing cable (30) connected between the main signal processing device and the secondary signal processing device; the main signal processing device (20) mainly comprises a microprocessor (21), a main monitoring input unit A (22) and an output unit (23), and the auxiliary signal processing device (40) mainly comprises a microprocessor (41), a standby monitoring input unit B (44) and an output unit (43); one end of the temperature sensing cable (30) is connected with a main monitoring input unit A (22) of the main signal processing device (20), the other end of the temperature sensing cable is connected with a standby monitoring input unit B (44) of the auxiliary signal processing device (40), the temperature sensing cable (30) at least comprises two detection conductors, and one of the two detection conductors is a series characteristic temperature coefficient detection line body; wherein:
a main monitoring input unit A (22) of the main signal processing device (20): mainly composed of a detection circuit for detecting the temperature sensing cable, and inputting the signal detected by the detection circuit to a microprocessor (21) thereof;
an output unit (23) of the main signal processing device: for controlling its output fire or fault signal by the microprocessor (21) of the main signal processing means;
-a microprocessor (21) of the main signal processing means: the main monitoring input unit A (22) is used for detecting signal processing judgment and controlling an output unit (23) thereof;
a standby monitoring input unit B (44) of the secondary signal processing device (40): the temperature-sensing cable short-circuit monitoring circuit mainly comprises a terminal resistance circuit, a detection circuit, a control circuit and a temperature-sensing cable short-circuit monitoring circuit, wherein when the microprocessor (41) judges that the temperature-sensing cable (30) is short-circuited, the control circuit switches the terminal resistance circuit into the detection circuit and inputs a signal detected by the detection circuit into the microprocessor (41);
an output unit (43) of the secondary signal processing device (40): the microprocessor (41) of the signal processing device is mainly used for controlling the signal processing device to output a fire alarm or fault signal;
-a microprocessor (41) of said secondary signal processing means (40): the detection signal processing and judgment, the temperature sensing cable short circuit monitoring signal processing and judgment and the control circuit control are used for the standby monitoring input unit B (44), and the output unit (43) is controlled to output.
6. The cable type line-type temperature-sensitive fire detector according to claim 5, wherein the monitoring signal of the temperature-sensitive cable short-circuit monitoring circuit is a current or a voltage across a terminating resistor in the terminating resistor circuit.
7. The cable type line-type temperature-sensitive fire detector according to claim 5, wherein the temperature-sensitive cable (30) further includes a control core (31) for transmitting an electrical signal to the secondary signal processing means when the primary signal processing means detects a short circuit of the temperature-sensitive cable.
8. The cable type line-type temperature-sensitive fire detector according to claim 5, 6 or 7, wherein the temperature-sensitive cable is mainly composed of at least two detection conductors with an insulating material layer interposed therebetween, and twisted or laid down.
9. The cable-type linear temperature-sensitive fire detector according to claim 5, 6 or 7, wherein the series characteristic temperature coefficient detection line is a continuous NCT or CTR or PCT characteristic detection line or a detection line formed by connecting at least 2 independent NCT or CTR or PCT characteristic thermistors in series.
10. The cable-type line-type temperature-sensitive fire detector according to claim 5, further comprising an adjacent temperature-sensitive cable connected to the main signal processing device (20), wherein the main signal processing device (20) further comprises a backup monitor input unit B (24), wherein one end of the adjacent temperature-sensitive cable is connected to the backup monitor input unit B (24) of the main signal processing device (20);
wherein:
a standby monitoring input unit B (24) of the main signal processing device (20): the main signal processing device mainly comprises a terminal resistance circuit, a detection circuit, a control circuit and a short circuit monitoring circuit of adjacent temperature sensing cables, wherein the control circuit is switched to the detection circuit by the terminal resistance circuit when a microprocessor (21) of the main signal processing device (20) judges that the adjacent temperature sensing cables (30) are short-circuited, and a signal detected by the detection circuit is input to the microprocessor (21) by the control circuit;
-a microprocessor (21) of the main signal processing device (20): the detection signal of a standby monitoring input unit B (24) of the main signal processing device, the processing judgment of the monitoring signal of the adjacent temperature sensing cable short circuit monitoring circuit and the control circuit thereof control, and the output unit (23) thereof is controlled to output correspondingly.
11. The cable type line-type temperature-sensitive fire detector of claim 5,
the auxiliary signal processing device (40) also comprises an adjacent temperature sensing cable connected with the auxiliary signal processing device (40), the auxiliary signal processing device (40) also comprises a main monitoring input unit A (42), wherein one end of the adjacent temperature sensing cable is connected with the main monitoring input unit A (42) of the auxiliary signal processing device (40);
wherein:
a main monitoring input unit A (42) of the secondary signal processing device (40): mainly comprises a detection circuit for detecting adjacent temperature-sensing cables, and inputs signals detected by the detection circuit into a microprocessor (41) thereof;
-a microprocessor (41) of said signal processing means: and the detection signal processing and judgment device is also used for the detection signal processing and judgment of a main monitoring input unit A (42) of the signal processing device, and controls an output unit (43) of the signal processing device to output correspondingly.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910873796.4A CN112530121A (en) | 2019-09-17 | 2019-09-17 | Cable type linear temperature-sensing fire detector capable of alarming fire in short circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910873796.4A CN112530121A (en) | 2019-09-17 | 2019-09-17 | Cable type linear temperature-sensing fire detector capable of alarming fire in short circuit |
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| CN112530121A true CN112530121A (en) | 2021-03-19 |
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| CN201910873796.4A Pending CN112530121A (en) | 2019-09-17 | 2019-09-17 | Cable type linear temperature-sensing fire detector capable of alarming fire in short circuit |
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| Country | Link |
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