Fault detection device and method for sampling pipe network of air-breathing smoke detector
By using volute pipe and pressure difference detection technology in the suction smoke detector, the sampling pipeline faults are identified, and the problems of high power consumption of high-temperature heating elements and susceptible to contamination in the existing technology are solved, achieving more efficient and reliable fault detection.
Patent Information
- Application Number
- CN202411701294.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-26
- Publication Date
- 2025-03-04
AI Technical Summary
When detecting blockage or rupture of the sampling pipeline network, existing aspirated smoke detectors need to install high-temperature heating elements inside the pipeline, resulting in high power consumption and inability to be used in high-temperature explosion-proof occasions. At the same time, the sensor is easily affected by airflow contamination.
The volute-type intake pipe and exhaust pipe are used to identify whether the sampling network pipe has a fault through the pressure difference between the intake pipe and exhaust pipe. The pressure sensor and signal analysis module are used to combine the fan pressure/flow characteristic database to convert the pressure difference into the pipeline flow, and monitor the flow changes and identify the fault.
There is no need to install additional sensors inside the pipeline, which reduces the impact on gas pollution and has lower power consumption. It is suitable for explosion-proof occasions in T4 and above temperature groups, and has higher detection accuracy.
Smart Images
Figure CN119555451A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fire safety technology, and in particular to a device and method for detecting faults in the sampling pipeline network of an aspirating smoke detector. Background Technology
[0002] Aspirating smoke detectors utilize laser technology and an active aspiration method to detect fires at extremely early stages. They can accurately detect fire hazards in the very early stages of a fire, when smoke is not yet visible to the human eye, providing an effective means for the early detection and prediction of fires.
[0003] Aspirating smoke detectors extract air samples from the protected area through a sampling network and sampling orifices. Blockages or ruptures in the sampling network severely affect the detector's ability to extract air samples from the protected area, significantly impacting its alarm performance. When the sampling network becomes blocked or ruptured, the flow rate changes significantly. Therefore, aspirating smoke detectors typically identify blockages, ruptures, or other faults in the sampling network by detecting the flow rate.
[0004] Currently, aspirating smoke detectors mainly use thermal flow detection technology, which measures flow based on the relationship between the heat dissipation of the heating element and the flow rate. This method requires a certain current to maintain the thermal balance of the heating element, resulting in high power consumption. Furthermore, the heating element itself has a high temperature, making it unsuitable for explosion-proof applications in temperature groups of T4 and above. In addition, the heating element needs to be installed inside the pipe, and prolonged operation can easily lead to airflow contamination, causing the sensor to become "poisoned" and affecting detection accuracy. Therefore, it is necessary to improve the existing detection methods. Summary of the Invention
[0005] To address the aforementioned technical problems, this invention discloses a fault detection device and method for aspirating smoke detector sampling network, comprising: a sampling network pipe, an air inlet pipe, a fan, an exhaust pipe, and a fault detection unit. The sampling network pipe is used to collect air from the protected area through sampling holes. The air inlet pipe connects the sampling network pipe and the fan. The fan generates negative pressure to draw in gas, and the exhaust pipe discharges the gas drawn in by the fan. The fault detection unit is used to identify whether the sampling network pipe has ruptured or become blocked.
[0006] Furthermore, the air intake pipe has a volute structure, with a small round hole at one end for connecting to the sampling network pipe, and a large round hole at the other end for connecting to the air inlet of the fan. The cross-section gradually increases from the small round hole to the large round hole, forming a volute-shaped curved surface. A short section of the first tunnel is set at the transition section between the small round hole and the large round hole. A small-diameter first pressure detection port is set between the small round hole and the first tunnel. The first pressure detection port is connected to the fault detection unit through a first rubber hose. The exhaust pipe has a square hole at one end for connecting to the exhaust port of the fan, and a round hole at the other end for connecting to the exhaust pipe or directly discharging into the air. The cross-section gradually increases from the square hole to the round hole. The cross-section of the hole gradually decreases, and a short section of the second venturi tube is set in the intermediate transition section. A small-diameter second pressure detection port is set between the second venturi tube and the circular hole. The second pressure detection port is connected to the fault detection unit through a second rubber hose. The fault detection unit is equipped with a pressure sensor and a signal analysis module. The pressure sensor is connected to the pressure detection ports of the intake pipe and the exhaust pipe respectively. The signal analysis module collects the pressure difference between the intake pipe and the exhaust pipe, converts the pressure difference into pipe flow rate through the built-in fan pressure / flow characteristic database, and then identifies whether the sampling network pipe has ruptured or blocked by monitoring the change in flow rate.
[0007] A method for detecting faults in the sampling network of an inhalation-type smoke detector, wherein the fault detection unit identifies whether a fault has occurred in the sampling network by using the pressure difference between the intake and exhaust pipes, and the identification method includes the following steps: Step S1: After installing the sampling network pipe and sampling holes according to the fire protection specifications, use the detector network calculation software to obtain the theoretical flow value of the current network and write this value into the fault detection unit as the network flow reference value. Step S2: Turn on the fan, operate the fault detection unit to enter the initial calibration state, collect the pressure difference between the intake and exhaust pipes, convert the pressure difference into a flow rate value through the fan characteristic curve, and compare it with the reference value in step S1. If the error meets the requirements, the current flow rate value is used as the reference flow rate value of the sampling network; otherwise, return to step S1 to adjust the calculation software parameters and recalculate.
[0008] Step S3: During normal operation of the detector, the fault detection unit collects the pressure difference between the intake pipe and the exhaust pipe at fixed time intervals. After filtering, the pressure difference is converted into a flow rate value and compared with the reference flow rate in step S2. When the detected flow rate is greater than the set threshold of the reference flow rate, the fault detection unit reports a sampling network tube rupture fault. When it is less than the set threshold of the reference flow rate, the sampling network tube blockage fault is reported.
[0009] Step S4: Fault Confirmation and Troubleshooting. When the fault detection unit reports a rupture or blockage in the sampling network pipe, the fault confirmation procedure is initiated. First, check the fan's operating status to ensure it is working properly and rule out abnormal flow caused by fan failure. Check if the connections between the intake and exhaust pipes are loose or damaged. Inspect the pressure detection ports and rubber hoses to ensure they are free from blockages, damage, or leaks. If all the above checks are satisfactory, further investigate the sampling network pipe section by section. The specific location of the fault can be determined by observing flow changes after closing some sampling holes.
[0010] Step S5: Fault Repair and Verification. Based on the fault location determined in Step S4, take corresponding repair measures. If the sampling network pipe is broken, repair or replace the damaged part; if it is blocked, clean it. After the repair is completed, restart the fan and fault detection unit, enter the initial calibration state, and collect the pressure difference between the intake and exhaust pipes again, convert it into a flow rate value, and compare it with the reference flow rate value. When the error meets the requirements, the fault repair is confirmed to be successful; otherwise, continue to investigate and repair the problem until the fault is completely eliminated.
[0011] The advantages of this invention compared with the prior art are: (1) This invention does not require the installation of additional sensors inside the pipe, is less susceptible to external gas pollution, and has higher reliability; (2) This invention has no high-temperature heating element, has lower power consumption, and can be directly applied to explosion-proof occasions of temperature group T4 and above, with wider applicability. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the structure of the present invention.
[0013] Figure 2 This is a cross-sectional view of the structure of the present invention.
[0014] Figure 3 This is a flowchart illustrating the detection method of the present invention.
[0015] Figure descriptions: 1-Sampling network tube; 2-Sampling hole; 3-Inlet pipe; 4-Fan; 5-Exhaust pipe; 6-Fault detection unit; 7-First Venturi tube; 8-First pressure detection port; 9-Second Venturi tube; 10-Second pressure detection port; 11-First rubber hose; 12-Second rubber hose; 13-Pressure sensor; 14-Signal analysis module. Detailed Implementation
[0016] Example: Figure 1 , Figure 2As shown, this embodiment provides a fault detection device for aspirating smoke detector sampling network, including: sampling network pipe 1, air inlet pipe 3, fan 4, exhaust pipe 5, and fault detection unit 6. The sampling network pipe 1 is used to collect air from the protected area through sampling holes 2. The air inlet pipe 3 is used to connect the sampling network pipe 1 and the fan 4. The fan 4 generates negative pressure to draw in gas, and the exhaust pipe 5 discharges the gas drawn in by the fan 4. The fault detection unit 6 is used to identify whether the sampling network pipe 1 has a rupture or blockage fault.
[0017] In this embodiment, the air intake pipe 3 has a volute structure. One end has a small circular hole with an inner diameter of 25.5 mm, used to connect to the sampling network pipe 1, and the other end has a large circular hole with an inner diameter of 62 mm, used to connect to the air inlet of the fan 4. The cross-section gradually increases from the small circular hole to the large circular hole, forming a volute curved surface shape. A short section of the first tunnel 7 is set in the transition section between the small circular hole and the large circular hole. A small-diameter first pressure detection port 8 is set between the small circular hole and the first tunnel 7. The first pressure detection port 8 is connected to the fault detection unit 6 through the first rubber hose 11. One end of the exhaust pipe 5 has a square hole, used to connect to the exhaust port of the fan 4, and the other end has a round hole, used to connect to the exhaust pipe or directly exhaust into the air. The cross-section gradually increases from the square hole to the round hole. The cross-section gradually decreases, and a short section of the second venturi tube 9 is set in the intermediate transition section. A small-diameter second pressure detection port 10 is set between the second venturi tube 9 and the circular hole. The second pressure detection port 10 is connected to the fault detection unit 6 through the second rubber hose 12. The fault detection unit 6 is equipped with a pressure sensor 13 and a signal analysis module 14. The pressure sensor 13 is connected to the pressure detection ports of the intake pipe 3 and the exhaust pipe 5 respectively. The signal analysis module 14 collects the pressure difference between the intake pipe 3 and the exhaust pipe 5, converts the pressure difference into pipe flow through the built-in fan pressure / flow characteristic database, and then identifies whether the sampling network pipe 1 has ruptured or blocked by monitoring the change in flow.
[0018] This embodiment also provides a method for detecting faults in the sampling network of an inhalation-type smoke detector. The fault detection unit 6 identifies whether a fault has occurred in the sampling network pipe 1 by using the pressure difference between the inlet pipe 3 and the exhaust pipe 5. The identification method includes the following steps: Step S1: After installing sampling pipe network 1 and sampling port 2 according to fire protection specifications, obtain the theoretical flow rate value of the current pipe network using detector pipe network calculation software, and write this value into fault detection unit 6 as the pipe network flow rate reference value. ; Step S2: Turn on the fan 4, operate the fault detection unit 6 to enter the initial calibration state, and collect the pressure difference between the intake pipe 3 and the exhaust pipe 5 within 1 minute to calculate the average value. The pressure difference is obtained from the pressure / flow characteristic curve database of fan 4. Convert to flow value and compared with the flow reference value in step S1 In comparison, when and If the difference is less than 10% of the error band, then the current flow rate value will be adjusted. As the initial reference flow rate of the sampling pipeline network Otherwise, return to step S1 to adjust the calculation software parameters and recalculate; Step S3: During normal operation of the detector, the fault detection unit 6 collects the pressure difference between the intake and exhaust pipes every 100ms. The average pressure difference is obtained by filtering every 100 times. The pressure / flow characteristic curve database of fan 4 is used to obtain the pressure Convert to traffic and will Compared with the baseline flow rate value in step S2 When making comparisons, Greater than the baseline flow rate When the flow rate is less than 150% of the baseline threshold, the fault detection unit 6 reports a sampling pipeline rupture fault. When the threshold of 50% is reached, a sampling pipeline blockage fault will be reported.
[0019] Step S4: Fault Confirmation and Troubleshooting. When the fault detection unit reports a rupture or blockage in sampling network pipe 1, the fault confirmation procedure is initiated. First, check the operating status of the fan to ensure that the fan (4) is working normally and eliminate the abnormal flow caused by the fault of the fan 4; check whether the connection between the air inlet pipe (3) and the exhaust pipe 5 is loose or damaged; check the pressure detection port and rubber hose to ensure that they are not blocked, damaged or leaking; if there are no problems in the above checks, further troubleshoot the sampling network pipe in sections; the specific location of the fault can be determined by observing the flow change by closing some sampling holes.
[0020] Step S5: Fault Repair and Verification. Based on the fault location determined in Step S4, take corresponding repair measures. If the sampling network pipe 1 is ruptured, repair or replace the damaged part; if it is blocked, clean it. After the repair is completed, restart the fan and fault detection unit, enter the initial calibration state, and collect the pressure difference between the intake pipe 3 and the exhaust pipe 5 again, convert it into a flow rate value and compare it with the reference flow rate value. When the error meets the requirements, the fault repair is confirmed to be successful; otherwise, continue to investigate and repair the problem until the fault is completely eliminated.
[0021] The above embodiments are merely illustrative of the technical concept and features of the present invention, intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A gas type smoke detector sampling pipe network fault detection device, comprising: A sampling network pipe (1), an air intake pipe (3), a fan (4), an exhaust pipe (5) and a fault detection unit (6), characterized in that: the sampling network pipe (1) is used to collect air in a protected area through a sampling hole (2); the air intake pipe (3) is used to connect the sampling network pipe (1) and the fan (4); the fan (4) generates negative pressure to absorb gas; and the exhaust pipe (5) discharges the gas absorbed by the fan (4); and the fault detection unit (6) is used to identify whether the sampling network pipe (1) is broken or blocked.
2. A gas type smoke detector sampling pipe network fault detection device according to claim 1, characterized in that: The air intake duct (3) is a volute structure, one end of which is a small circular hole for connecting to the sampling network tube (1), and the other end is a large circular hole for connecting to the air inlet of the fan (4). The cross-section from the small circular hole to the large circular hole gradually increases to form a volute curved surface shape. A small section of a first tuyere (7) is provided in the transition section between the small circular hole and the large circular hole, and a small-caliber first pressure detection port (8) is provided between the small circular hole and the first tuyere (7). The first pressure detection port (8) is connected to the fault detection unit (6) through a first rubber hose (11). One end of the exhaust duct (5) is a square hole for connecting to the exhaust port of the fan (4), and the other end is a circular hole for connecting to the exhaust pipe or directly discharging into the air. The cross-section from the square hole to the circular hole gradually decreases, and the cross-section in the middle is A short section of a second venturi tube (9) is provided at the transition section, a second pressure detection port (10) with a small diameter is provided between the second venturi tube (9) and the circular hole, and the second pressure detection port (10) is connected to a fault detection unit (6) via a second rubber hose (12); a pressure sensor (13) and a signal analysis module (14) are provided in the fault detection unit (6), the pressure sensor (13) is connected to the pressure detection ports of the intake pipe (3) and the exhaust pipe (5) respectively, the signal analysis module (14) collects the pressure difference between the intake pipe (3) and the exhaust pipe (5), converts the pressure difference into pipe flow through a built-in fan pressure / flow characteristic database, and further identifies whether the sampling network pipe (1) has a rupture or blockage fault by monitoring the change in flow.
3. A method for detecting faults in a sampling pipe network of an aspirating smoke detector, comprising a fault detection unit (6) identifying whether a fault occurs in a sampling pipe network (1) by using a pressure difference between an air intake pipe (3) and an exhaust pipe (5), characterized in that: The identification method includes the following steps: Step S1, the sampling network pipe (1) and the sampling hole (2) are installed according to the fire protection regulations, the theoretical flow value of the current network is obtained by using the detector network calculation software, and the value is written into the fault detection unit (6) as a reference value of the network flow; Step S2, turning on the fan (4), operating the fault detection unit (6) to enter the initial calibration state, collecting the pressure difference between the intake duct (3) and the exhaust duct (5), converting the pressure difference into a flow value through the fan characteristic curve, and comparing it with the reference value in step S1, when the error meets the requirement, the current flow value is used as the reference flow value of the sampling network management (1), otherwise, returning to step S1 to adjust the calculation software parameters and recalculate; Step S3, during the normal operation of the detector, the fault detection unit (6) collects the pressure difference between the air intake pipe (3) and the exhaust pipe (5) at fixed time intervals, converts the pressure difference into a flow value after filtering, and compares it with the reference flow in the sampling hole (2) in step S. When the detected flow is greater than the set threshold of the reference flow, the fault detection unit (6) reports a rupture fault to the sampling network management (1); when it is less than the set threshold of the reference flow, the fault detection unit (6) reports a blockage fault to the sampling network management (1); Step S4: Fault confirmation and troubleshooting. When the fault detection unit reports that the sampling network pipe (1) is broken or blocked, the fault confirmation procedure is started. First, the operating status of the fan is checked to ensure that the fan (4) is working normally and to eliminate the abnormal flow caused by the failure of the fan (4). Check whether the connection between the air inlet pipe (3) and the exhaust pipe (5) is loose or damaged. Check the pressure detection port and the rubber hose to ensure that they are not blocked, damaged or leaking. If the above checks are all correct, the sampling network pipe is further checked in sections. By closing some sampling holes and observing the flow changes, the specific location of the fault can be determined. Step S5: Fault repair and verification. According to the fault location determined in step S4, take corresponding repair measures; if the sampling network pipe (1) is broken, repair or replace the damaged part; if it is blocked, clean it; after the repair is completed, restart the fan and the fault detection unit, enter the initial calibration state, collect the pressure difference between the intake pipe (3) and the exhaust pipe (5) again, convert it into a flow value and compare it with the reference flow value; when the error meets the requirements, confirm that the fault repair is successful, otherwise continue to troubleshoot and repair the problem until the fault is completely eliminated.