Fire extinguishing system with self-checking function and application method

Abstract

A fire fighting system with a self-checking function belongs to the technical field of fire fighting, and comprises a temperature sensor, a smoke sensor, a short message module, an electromagnetic valve, a temperature detection circuit, a smoke detection circuit, a control circuit and a checking mechanism, the temperature sensor, the smoke sensor, the short message module, the electromagnetic valve, the temperature detection circuit, the smoke detection circuit, the control circuit and the verification mechanism are installed together. The verification mechanism comprises an electric heating plate and a shell. The application method of the fire extinguishing system with the self-checking function comprises three steps. According to the invention, under the combined action of the temperature sensor, the temperature detection circuit, the smoke sensor, the smoke detection circuit and the like, whether a fire occurs in a field cannot be detected in a temperature and smoke sensing mode, and the performance of the temperature and smoke sensor can be detected and calibrated in a heating mode at regular intervals. When a problem occurs, related personnel can be prompted to carry out maintenance through short messages at the first time, and the fire detection and fire extinguishing effects are effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of fire fighting devices, in particular to a fire fighting system with a self-checking function and an application method thereof. Background Art

[0002] With the development of technology, systems with automatic detection and fire extinguishing functions have been widely used, which can extinguish fires as quickly as possible and greatly reduce the chance of accidents expanding after a fire occurs. The general structure of existing automatic fire extinguishing devices includes smoke sensors, temperature sensors and corresponding control circuits, and fire extinguishing pipes connected in series with water pipes through solenoid valves, etc. When working, smoke sensors and temperature sensors (two sensors can achieve better fire detection effects) detect that smoke or temperature rises due to fire at the scene, and the control circuit will control the solenoid valve to open the electric valve core, and then pressurized water will be sprayed out through the front side of the fire extinguishing pipe to extinguish the fire at the relevant location.

[0003] Although the existing automatic fire extinguishing devices meet the needs of detection and fire extinguishing to a certain extent, they are limited by the structure and still have the following technical disadvantages. Specifically, due to their own quality and after working for a long time, there is a probability that the smoke and temperature sensors will have low detection sensitivity or even be damaged. In this way, when a fire occurs, since the sensors cannot detect the fire information, they cannot control the solenoid valves to be powered on. Furthermore, since the fire information cannot be effectively detected and the fire cannot be extinguished, there is a probability that the fire accident will be expanded. In summary, it is particularly necessary to provide a fire protection system and application method that can calibrate the performance of smoke and temperature sensors at intervals to ensure the fire extinguishing effect. Summary of the invention

[0004] In order to overcome the drawbacks of existing automatic fire extinguishing devices due to structural limitations as described in the background, the present invention provides a fire protection system and application method with self-checking function, which cannot detect whether a fire occurs on site by temperature and smoke sensing under the joint action of relevant mechanisms, and can check and calibrate the performance of temperature and smoke sensors at regular intervals. When a problem occurs, it can prompt relevant personnel to perform maintenance at the first time, thereby effectively ensuring the fire detection and fire extinguishing effects.

[0005] The technical solution adopted by the present invention to solve its technical problem is: A fire protection system with a self-checking function comprises a temperature sensor, a smoke sensor, a text message module, a solenoid valve, a temperature detection circuit, a smoke detection circuit, a control circuit, and a verification mechanism; the verification mechanism comprises an electric heating plate and a shell, and there are at least two electric heating plates, one of which is fixedly mounted on the side end of the temperature sensor, and a mounting bin is mounted on the lower end of the shell, and the other electric heating plate is mounted in the mounting bin; a support plate is mounted on the upper side of the shell, grease is filled inside the shell, and the support plate of the shell is mounted on the lower end of the detection surface of the smoke sensor; the temperature sensor, smoke sensor, text message module, temperature detection circuit, smoke detection circuit, and control circuit are mounted In the component box; the signal output ends of the temperature sensor and the smoke sensor are electrically connected to the signal input ends of the temperature detection circuit and the smoke detection circuit, respectively; the trigger output end of the temperature detection circuit is electrically connected to the control signal end of the smoke detection circuit, the control power output end of the smoke detection circuit is electrically connected to the power input end of the solenoid valve, the power output end of the control circuit is electrically connected to the power input end of the two electric heating plates and the SMS module; the alarm signal output ends of the temperature detection circuit and the smoke detection circuit are electrically connected to the two signal input ends of the SMS module; the control output end of the control circuit is electrically connected to the two control input ends of the smoke detection circuit.

[0006] Furthermore, one end of the solenoid valve is connected to a water pipe, the other end of the solenoid valve is connected to one end of a fire-extinguishing water pipe, and a fire-extinguishing spray head is installed at the other end of the fire-extinguishing water pipe; the solenoid valve is a normally closed valve core solenoid valve.

[0007] Furthermore, the temperature detection circuit includes electrically connected resistors, transistors, and diodes, one end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is connected to the base of the first transistor, the collector of the first transistor is connected to one end of the third resistor and the cathode of the diode, the other end of the third resistor is connected to the base of the second transistor, and the other end of the first resistor is connected to the emitter of the first transistor.

[0008] Furthermore, the smoke detection circuit includes an electrically connected diode and resistor, a thyristor, a relay, and a transistor, one end of the first resistor is connected to the cathode of the diode, the anode of the diode is connected to one end of the second resistor, the other end of the first resistor is connected to the control electrode of the thyristor, the cathode of the thyristor is connected to the positive power input end of the relay, the other end of the second resistor is connected to the base of the transistor, and the negative power input end of the relay is connected to the emitter of the transistor.

[0009] Furthermore, the control circuit includes an electrically connected time-controlled switch and a relay, the positive power supply output terminal of the time-controlled switch is connected to the positive power supply input terminal of the first relay, the positive power supply input terminal of the second relay and the control power supply input terminal, and the negative power supply output terminal of the time-controlled switch is connected to the negative power supply input terminals of the two relays.

[0010] An application method of a fire protection system with a self-checking function comprises the following steps: S1: a temperature sensor and a smoke sensor respectively detect whether the temperature rises due to a fire and whether smoke is generated at the scene. When the fire causes the temperature to rise and smoke to be generated at the scene, the temperature sensor and the smoke sensor respectively output signals to the signal input ends of the temperature detection circuit and the smoke detection circuit; S2: the temperature detection circuit and the smoke detection circuit output signals to the power input end of the electromagnetic valve, the valve core of the electromagnetic valve is energized to open, and the water with pressure in the fire extinguishing water pipe is sprayed from the fire extinguishing spray head to extinguish the fire at the fire point; S3: the control circuit controls two electric heating plates to be energized to work at set intervals, and the two electric heating plates are energized to heat the temperature sensor and the grease in the shell respectively. When the temperature sensor is normal and the temperature detected by the temperature detection circuit is too high, and the smoke sensor is normal and the smoke detection circuit detects smoke, the short message module can respectively send two short messages to the mobile phone of the remote manager. After receiving the short messages at the corresponding time, the manager can understand whether the performance of the temperature sensor and the smoke sensor is normal.

[0011] Furthermore, in step S3, when the control circuit controls the temperature sensor and the smoke sensor to be heated and reaches the time set by the control circuit, if the SMS module does not send a SMS or only sends one SMS, it means that all the temperature sensors and the smoke sensors fail, or one of the temperature sensors and the smoke sensors fails.

[0012] Furthermore, in step S3, the control circuit controls the temperature sensor and the smoke sensor to be powered on and heated, and controls the power supply output from the smoke detection circuit to the solenoid valve to be open.

[0013] Compared with the prior art, the present invention has the following beneficial effects: under the joint action of the temperature sensor and temperature detection circuit, the smoke sensor and the smoke detection circuit, the present invention cannot detect whether a fire occurs on site by temperature and smoke sensing (when a fire occurs, the solenoid valve can be energized and the valve core can be opened to extinguish the fire in time), and the performance of the temperature and smoke sensors can be inspected and calibrated by heating at regular intervals. When a problem occurs, the relevant personnel can be prompted to perform maintenance by SMS in the first time, effectively ensuring the fire detection and fire extinguishing effects. In summary, the present invention has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the present invention.

[0016] Figure 2 It is a schematic diagram of the planar structure when viewed from above of the present invention.

[0017] Figure 3 It is a schematic diagram of the planar structure between the temperature sensor and the electric heating plate of the present invention.

[0018] Figure 4 It is a schematic diagram of the planar structure between the smoke sensor, the electric heating plate and the housing of the present invention.

[0019] Figure 5 It is a circuit diagram of the present invention. DETAILED DESCRIPTION

[0020] Figure 1 , 2 As shown in , 3, 4, and 5, a fire protection system with a self-checking function includes a temperature sensor WT, a smoke sensor U2, a power module U1, a text message module U4, and a solenoid valve DC1. It also has a temperature detection circuit 1, a smoke detection circuit 2, a control circuit 3, and a verification mechanism 4; the verification mechanism includes electric heating plates RT1 and RT2, and a shell 51. There are two electric heating plates, one of which is fixedly installed on the side end of the temperature sensor WT and the side end of one of the electric heating plates RT1 is close to the side end of the heating surface of the temperature sensor RT1. An isolation plate is sealed and welded at the lower end of the shell 51, and the lower end of the shell isolation plate is used as an installation compartment 52, and the other electric The heating plate RT2 is fixedly installed at the upper end of the installation chamber 52, and the heating surface of the other electric heating plate RT2 is close to the outside of the lower end of the installation chamber 52; a support plate 53 is welded in the middle of both sides of the upper end of the shell, and grease 54 (such as cooking oil) is filled inside the shell 51. The two support plates 53 at the upper end of the shell are welded to the two side ends below the detection surface of the smoke sensor U2; the temperature sensor WT, smoke sensor U2, power module U1, SMS module U4, temperature detection circuit 1, smoke detection circuit 2, and control circuit 3 are installed on the circuit board in the component box 6, and the heating surface of the temperature sensor WT and the detection surface of the smoke sensor U2 are located at the lower outer end of the component box 6.

[0021] Figure 1 , 2As shown in , 3, 4, and 5, one end of the solenoid valve DC1 is connected to the tap water pipe via threads, and the other end of the solenoid valve DC1 is connected to one end of the fire extinguishing water pipe via threads. The other end of the fire extinguishing water pipe (not shown in the figure) is threadedly installed with a fire extinguishing spray head (not shown in the figure, the fire extinguishing spray head is located in the fire prone area); the solenoid valve DC1 is a normally closed valve core solenoid valve. The temperature detection circuit includes resistors R1, R2, R3 and transistors Q1 and Q2, and a diode VD2 connected via circuit board wiring. One end of the first resistor R1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is connected to the base of the first transistor Q1. The collector of the first transistor Q1 is connected to one end of the third resistor R3 and the cathode of the diode VD2. The other end of the third resistor R3 is connected to the base of the second transistor Q2, and the other end of the first resistor R1 is connected to the emitter of the first transistor Q1. The smoke detection circuit includes a diode VD1 and resistors R4 and R5, a thyristor VS, a relay J1, and a transistor Q3 connected via circuit board wiring. One end of the first resistor R4 is connected to the cathode of the diode VD1, the anode of the diode VD1 is connected to one end of the second resistor R5, the other end of the first resistor R4 is connected to the control electrode of the thyristor VS, the cathode of the thyristor VS is connected to the positive power input end of the relay J1, the other end of the second resistor R5 is connected to the base of the transistor Q3, and the negative power input end of the relay J1 is connected to the emitter of the transistor Q3. The control circuit includes a time-controlled switch U3 and relays J2 and J3 connected via circuit board wiring. The positive power output end 3 of the time-controlled switch U3 is connected to the positive power input end of the first relay J2, the positive power input end of the second relay J3, and the control power input end, and the negative power output end 4 of the time-controlled switch U3 is connected to the negative power input ends of the two relays J2 and J3.

[0022] Figure 1 , 2As shown in Figures 3, 4, and 5, the power input terminals 1 and 2 of the power module U1 are connected to the two poles of the AC 220V power supply through wires, and the power output terminals 3 and 4 of the power module U1 are connected to one end of the power input of the temperature sensor WT, the power input terminals 1 and 2 of the smoke sensor U2, the emitter of the transistor Q2 and the emitter of the transistor Q1 at the power input of the temperature detection circuit, the control power input terminal and the negative power input terminal of the relay J1 at the power input of the smoke detection circuit, and the power input terminals 1 and 2 of the time-controlled switch U3 at the power input of the control circuit. The other end of the temperature sensor WT, the 3rd foot of the smoke sensor U2, one end of the resistor R1 at the signal input of the temperature detection circuit, and the positive pole of the diode VD1 at the signal input of the smoke detection circuit are connected through wires. The collector of the transistor Q2 at the trigger output end of the temperature detection circuit and the other end of the resistor R4 at the control signal end of the smoke detection circuit are connected via wires. The normally open contact end and the negative power input end of the control power output end of the smoke detection circuit and the power input ends of the solenoid valve DC1 are connected via wires. The normally open contact end and the negative power input end of the control circuit power output end relay J3 and the power input ends of the two electric heating plates RT and RT1 are connected via wires. The positive pole of the diode VD2 of the temperature detection circuit, the collector of the transistor Q3 of the smoke detection circuit and the two signal input ends 3 and 4 of the SMS module U4 are connected via wires. The control power input end of the relay J2 of the control circuit and the control power input end of the relay J1 are connected via wires, and the normally closed contact end of the relay J2 and the anode of the thyristor VS are connected via wires. The power input ends 1 and 2 of the SMS module U4 and the power output ends 3 and 4 of the time-controlled switch U3 are connected via wires.

[0023] Figure 1 , 2As shown in Figures 3, 4, and 5, after the AC 220V power supply enters the power input terminal of the power module U1, the 3rd and 4th pins of the power module U1 output a stable DC 12V power supply that enters the power input terminal of the temperature sensor WT, the smoke sensor U2, the temperature detection circuit, the smoke detection circuit, and the control circuit. When there is no fire at the scene and the temperature at the scene is low (for example, the temperature is lower than 50°C), the temperature detected by the heated surface of the temperature sensor WT is relatively low and its resistance value is relatively high. The voltage division between the temperature sensor WT and the resistor R1 is large. The 12V power supply is divided by the temperature sensor WT and the resistor R1. The resistor R2 reduces the voltage and limits the current to enter the base of the transistor Q1, which is lower than 0.7V. The transistor Q1 will not be turned on, the solenoid valve DC1 will not be energized and the valve core will be closed, and the relevant area will not be extinguished. When a fire occurs and the temperature at the scene is high (for example, the temperature is higher than 50℃), the temperature detected by the heated surface of the temperature sensor WT is relatively high and its resistance value is relatively low. The voltage between the temperature sensor WT and the resistor R1 is small. The 12V power supply is divided by the temperature sensor WT and the resistor R1. The resistor R2 reduces the voltage and limits the current to enter the base of the transistor Q1, which is higher than 0.7V. The transistor Q1 will conduct the collector and output a low level to enter the base of the transistor Q2 (resistor R3 reduces the voltage and limits the current). The transistor Q2 conducts the collector and outputs a high level. The resistor R4 reduces the voltage and limits the current to trigger the thyristor VS to conduct. The relay J1 is energized to attract its control power input end and the normally open contact end to close. The solenoid valve DC1 is energized to open the valve core. In this way, the fire extinguishing water pipe outputs pressurized water and sprays it out through the fire extinguishing spray head to extinguish the fire scene. When there is no fire and no smoke at the scene, the 3rd pin of the smoke sensor U2 does not output a high level, the solenoid valve DC1 will not be energized to close the valve core, and the relevant area will not be extinguished. When a fire occurs and smoke and temperature are generated at the scene, the 3rd pin of the smoke sensor U2 outputs a high level through a diode VD1 that is unilaterally conducted, the resistor R4 reduces the voltage and limits the current to trigger the thyristor VS to conduct, the relay J1 is energized to attract its control power input terminal and the normally open contact terminal to close, and the solenoid valve DC1 is energized to open the valve core, so that the fire extinguishing water pipe outputs pressurized water that is sprayed out through the fire extinguishing spray head to extinguish the fire at the scene. Through the above, the present invention can extinguish the fire in time when a fire occurs at the scene and smoke is generated or the temperature rises.

[0024] Figure 1 , 2As shown in , 3, 4, and 5, after the time switch U3 is powered on, its 3 and 4 pins will output a certain amount of power to the power input terminals of relays J2, J3 and the SMS module U4 at certain intervals (for example, 1 minute of power is output every 120 hours), and relay J2 is powered on to open its control power input terminal and the normally closed contact terminal, and relay J3 is powered on to close its control power input terminal and the normally open contact terminal. Since the normally closed contact terminal of relay J2 is connected to the anode of the thyristor VS, the thyristor VS will not be powered within 1 minute, preventing the SMS module U4 from falsely alarming during the calibration and detection of the temperature sensor and the smoke sensor. After relay J3 is powered on to close its control power input terminal and the normally open contact terminal, the two electric heating plates RT and RT1 are powered on to generate heat. When the electric heating plate RT obtains the electric heating temperature sensor WT, if the performance of the temperature sensor WT is normal, the resistance value RT of the temperature sensor WT decreases after being heated by the electric heating plate RT for about 10 seconds. The 12V power supply is divided between the temperature sensor WT and the resistor R1. The resistor R2 reduces the voltage and limits the current to enter the base of the transistor Q1, which is higher than 0.7V. The transistor Q1 will conduct the collector to output a low level and enter the base of the transistor Q1. The transistor Q1 conducts the collector to output a low level and enters the 3rd pin of the SMS module U4 through a unidirectional conduction through the diode VD2. Therefore, the SMS module U4 will send out the first SMS stored internally. After the mobile phone of the relevant remote personnel receives the SMS in the corresponding time period (the time period when the remote management personnel know that the SMS module should send SMS), they can intuitively understand that the performance of the temperature sensor is normal. When the electric heating plate RT obtains the electric heating temperature sensor WT, if the performance of the temperature sensor WT is abnormal, its resistance value RT does not decrease (is larger) due to the heating effect of the electric heating plate RT, and the 12V power supply is divided between the temperature sensor WT and the resistor R1, and the resistor R2 reduces the voltage and limits the current to enter the base of the transistor Q1 less than 0.7V, and the collector of the transistor Q1 is cut off and does not output a low level to enter the base of the transistor Q1. The collector of the transistor Q1 is cut off and does not output a low level to enter the 3rd pin of the SMS module U4, and the SMS module U4 will not send the first SMS in the corresponding time period. When the mobile phone of the remote relevant personnel does not receive the SMS in the corresponding time period (the remote management personnel know the time period when the SMS module should send SMS), they can intuitively understand that the performance of the temperature sensor is abnormal.

[0025] Figure 1 , 2As shown in , 3, 4, and 5, after the electric heating plate RT1 electrically heats the shell for about 50 seconds, the oil in the shell is heated and evaporated to produce oil mist. If the smoke sensor U2 works normally, the 3rd pin of the smoke sensor U2 outputs a high level, and the high level enters the base of the transistor Q3 through the resistor R5 for voltage reduction and current limiting (the collector of the transistor Q2 is reversely cut off due to the diode VD1, and the output high level will not enter the resistor R5), the transistor Q3 is turned on, the collector outputs a low level, and is unidirectionally conducted through the diode VD1 into the 4th pin of the SMS module U4, so the SMS module U4 will send out the second SMS stored inside, and the mobile phone of the remote relevant personnel will receive the SMS in the corresponding time period (the remote management personnel understand the time period when the SMS module should send SMS) and can intuitively understand that the performance of the smoke sensor is normal. After the electric heating plate RT1 is electrically heated for about 50 seconds, if the smoke sensor U2 does not work properly, even if the oil in the shell is heated and evaporated to produce oil mist, the 3rd pin of the smoke sensor U2 does not output a high level to enter the base of the transistor Q3, and the transistor Q3 is cut off. The collector does not output a low level to enter the 4th pin of the SMS module U4, and the SMS module U4 does not send out the second SMS stored inside. The mobile phone of the remote relevant personnel does not receive the SMS in the corresponding time period (the remote management personnel understand that the SMS module should send SMS time period) and can intuitively understand that the performance of the smoke sensor is abnormal. Through the above, the present invention cannot detect whether a fire occurs on the scene by temperature and smoke sensing (when a fire occurs, the valve core of the control valve is electrically opened to extinguish the fire in time), and can test and calibrate the performance of the temperature and smoke sensors by heating at regular intervals. When a problem occurs, it can prompt the relevant personnel to repair it by SMS in the first time, effectively ensuring the fire detection and fire extinguishing effect. Figure 5In the figure, the temperature sensor WT is a negative temperature coefficient thermistor of model NTC103D; the relays J1, J2, and J3 are DC12V; the transistor Q1 is 9013 (NPN); the transistors Q2 and Q3 are 9012 (PNP); the thyristor VS is a single-phase thyristor of model MCR100-1; the resistance values ​​of resistors R1, R2, R3, R4, and R5 are 20K, 47K, 10K, 10K, and 10K respectively; the diodes VD1 and VD2 are 1N4007; the solenoid valve DC1 is a normally closed valve core solenoid valve with a power of 2W; the electric heating plates RT and RT1 are stainless steel armored 20W and 30W 60℃ and 400℃ PTC constant temperature electric heating plate finished products respectively; the power module U1 is an AC 220V to DC 1 2V power module finished product; time switch U3 is a time controller finished product of model KG316T, which has two power input terminals, two power output terminals, and seven setting buttons. By operating the seven setting buttons respectively, the user can set the time for the two power output terminals to output power; smoke sensor U2 is a smoke sensor module finished product of model MQ-2, which has two power input terminals and one power output terminal. When the detection head detects a smoke signal, the power output terminal outputs power, otherwise it does not output power; SMS module U4 is a SMS alarm module of model GSM800. The SMS alarm module finished product has two power input terminals 1 and 2 feet, and signal input ports 3-8 feet. After each signal input port inputs a low-level signal, the SMS alarm module finished product will send a text message respectively. Through the above, the present invention cannot detect whether a fire occurs on the scene by temperature and smoke sensing (when a fire occurs, the valve core is promptly controlled to open and extinguish the fire), and can test and calibrate the temperature and smoke sensing performance by heating at a certain interval. When a problem occurs, it can prompt the relevant personnel to repair it by SMS in the first time, effectively ensuring the fire detection and fire extinguishing effect. In summary, the present invention has good application prospects.

[0026] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0027] In addition, it should be understood that although the present specification is described according to the implementation mode, the implementation mode does not only include an independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A fire protection system with a self-checking function, comprising a temperature sensor, a smoke sensor, a text message module, and a solenoid valve, characterized in that: It also has a temperature detection circuit, a smoke detection circuit, a control circuit, and a verification mechanism; the verification mechanism includes an electric heating plate and a shell, there are at least two electric heating plates, one of which is fixedly installed on the side end of the temperature sensor, and a mounting compartment is installed at the lower end of the shell, and the other electric heating plate is installed in the mounting compartment; a support plate is installed on the upper side of the shell, grease is filled inside the shell, and the support plate of the shell is installed at the lower end of the detection surface of the smoke sensor; the temperature sensor, smoke sensor, SMS module, temperature detection circuit, smoke detection circuit, and control circuit are installed in the component box; the temperature sensor, smoke sensor The signal output end of the device is electrically connected to the signal input end of the temperature detection circuit and the smoke detection circuit respectively, the trigger output end of the temperature detection circuit is electrically connected to the control signal end of the smoke detection circuit, the control power output end of the smoke detection circuit is electrically connected to the power input end of the solenoid valve, the power output end of the control circuit is electrically connected to the two electric heating plates and the power input end of the SMS module; the alarm signal output ends of the temperature detection circuit and the smoke detection circuit are electrically connected to the two signal input ends of the SMS module respectively; the control output end of the control circuit is electrically connected to the two control input ends of the smoke detection circuit respectively.

2. A fire protection system with self-checking function according to claim 1, characterized in that: One end of the solenoid valve is connected to a water pipe, and the other end of the solenoid valve is connected to one end of a fire-extinguishing water pipe, and a fire-extinguishing spray head is installed at the other end of the fire-extinguishing water pipe; the solenoid valve is a normally closed valve core solenoid valve.

3. A fire protection system with self-checking function according to claim 1, characterized in that: The temperature detection circuit includes an electrically connected resistor, a transistor and a diode. One end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is connected to the base of the first transistor, the collector of the first transistor is connected to one end of the third resistor and the cathode of the diode, the other end of the third resistor is connected to the base of the second transistor, and the other end of the first resistor is connected to the emitter of the first transistor.

4. A fire protection system with self-checking function according to claim 1, characterized in that: The smoke detection circuit includes an electrically connected diode and resistor, a thyristor, a relay, and a transistor. One end of the first resistor is connected to the cathode of the diode, the anode of the diode is connected to one end of the second resistor, the other end of the first resistor is connected to the control electrode of the thyristor, the cathode of the thyristor is connected to the positive power input end of the relay, the other end of the second resistor is connected to the base of the transistor, and the negative power input end of the relay is connected to the emitter of the transistor.

5. A fire protection system with self-checking function according to claim 1, characterized in that: The control circuit includes an electrically connected time-controlled switch and a relay, wherein the positive power supply output terminal of the time-controlled switch is connected to the positive power supply input terminal of the first relay, the positive power supply input terminal of the second relay and the control power supply input terminal, and the negative power supply output terminal of the time-controlled switch is connected to the negative power supply input terminals of the two relays.

6. The application method of a fire protection system with a self-checking function according to any one of claims 1 to 5, characterized in that: The invention comprises the following steps: S1: a temperature sensor and a smoke sensor respectively detect whether the temperature rises due to the fire and whether smoke is generated at the scene. When the fire causes the temperature to rise and smoke to be generated at the scene, the temperature sensor and the smoke sensor respectively output signals to the signal input ends of the temperature detection circuit and the smoke detection circuit; S2: the temperature detection circuit and the smoke detection circuit output signals to the power input end of the electromagnetic valve, the valve core of the electromagnetic valve is powered on and opens, and the water with pressure in the fire extinguishing water pipe is sprayed from the fire extinguishing spray head to extinguish the fire at the fire point; S3: the control circuit controls the two electric heating plates to be powered on at set intervals, and the two electric heating plates are powered on to heat the temperature sensor and the grease in the shell respectively. When the temperature sensor is normal and the temperature detected by the temperature detection circuit is too high, and the smoke sensor is normal and the smoke detection circuit detects smoke, the SMS module can send two SMS messages to the remote mobile phone of the manager respectively. After receiving the SMS messages at the corresponding time, the manager can understand whether the performance of the temperature sensor and the smoke sensor is normal.

7. The application method of a fire protection system with a self-checking function according to any one of claim 6, characterized in that: In step S3, when the control circuit controls the temperature sensor and the smoke sensor to be heated and reaches the time set by the control circuit, if the SMS module does not send a SMS or only sends one SMS, it means that all the temperature sensors and the smoke sensors fail, or one of the temperature sensors and the smoke sensors fails.

8. The application method of a fire protection system with a self-checking function according to any one of claim 6, characterized in that: In step S3, the control circuit controls the temperature sensor and the smoke sensor to be powered and heated, and controls the power output from the smoke detection circuit to the solenoid valve to be open.

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