A fire alarm method and system suitable for public places

Abstract

The present invention provides a fire alarm method and system suitable for use in public places. The method comprises the following steps: obtaining ambient temperature data, target object surface temperature data, carbon monoxide concentration data, and smoke concentration data for the public place; and determining whether a fire has occurred based on the ambient temperature data, target object surface temperature data, carbon monoxide concentration data, and smoke concentration data. By simultaneously collecting multiple on-site environmental information and fusing them to determine whether a fire has occurred, the present invention addresses the issue of a single sensor with a single detection method. Furthermore, the present invention divides the various on-site environmental information into three scenarios based on the relationships between them, employing different judgment criteria in different scenarios to better suit public places.

Description

Technical Field

[0001] The present invention relates to a fire alarm method, in particular to a fire alarm method and system suitable for public places. Background Art

[0002] Smoke alarms are a common sensor used in a wide range of industries, including homes, the chemical industry, urban public spaces, and public transportation, to detect fires at their installation sites. Currently, smoke alarms detect smoke concentrations at the installation site. Once smoke concentrations exceed a set threshold, they trigger an audible and visual alarm. Some systems also transmit alarm information to a control center via a communication unit.

[0003] Because of the single detection method, smoke alarms may have false alarms, that is, the smoke alarm itself emits sound and light alarm signals even though there is no fire at the scene. Currently, the reasons for false alarms of smoke alarms in public places are generally as follows:

[0004] 1. Smoke from cigarettes. Generally, smoke alarms will not respond to cigarette smoke unless the smoke is very dense. For example, if many smokers are smoking in the same room, the alarm may sound. If the smoke alarm is too old, it may sound even if the smoke concentration is very low.

[0005] 2. Dust accumulation: After a period of use, the smoke alarm will become more sensitive due to dust accumulation, which may lead to false alarms or alarms even when there is less smoke.

[0006] 3. The influence of steam or moisture: Steam or moisture will condense on the smoke alarm sensor and circuit board. If too much water vapor is concentrated, it is easy to cause a false alarm.

[0007] 4. False alarms caused by volatile substances such as sunscreen spray; for example, there have been many cases on high-speed trains where smoke alarms were triggered by passengers spraying sunscreen spray or perfume in the toilet, causing the high-speed train to stop abnormally.

[0008] In order to solve the above problems, people have been seeking an ideal technical solution. Summary of the Invention

[0009] The purpose of the present invention is to address the deficiencies of the prior art and thus provide a fire alarm method and system suitable for public places.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is: a fire alarm method applicable to public places, comprising the following steps:

[0011] Obtain ambient temperature data of public places, target object surface temperature data, carbon monoxide concentration data, and smoke concentration data;

[0012] Determine whether a fire has occurred based on the ambient temperature data, target object surface temperature data, carbon monoxide concentration data, smoke concentration data, and comparison priority:

[0013] When the ambient temperature data is greater than or equal to the second alarm threshold or the target object surface temperature data is greater than or equal to the fourth alarm threshold, it is determined that a fire has occurred;

[0014] When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, and the smoke concentration data is greater than or equal to the fifth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold, the target object surface temperature data is greater than or equal to the third alarm threshold, or the carbon monoxide concentration is greater than or equal to the sixth alarm threshold, it is determined that a fire has occurred;

[0015] When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is less than the fifth alarm threshold, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold or the target object surface temperature data is greater than or equal to the third alarm threshold, it is determined that a fire has occurred;

[0016] The second alarm threshold is greater than the first alarm threshold, and the fourth alarm threshold is greater than the third alarm threshold.

[0017] Based on the above, the comparison priority order is: the ambient temperature data is greater than the target object surface temperature data, which is greater than the smoke concentration data, which is greater than the carbon monoxide concentration data;

[0018] When executing the comparison priority order, first determine whether the ambient temperature data is greater than or equal to the second alarm threshold. If it is less than, further determine whether the target object surface temperature data is greater than or equal to the fourth alarm threshold. If it is still less than, determine whether the smoke concentration data is greater than or equal to the fifth alarm threshold; if the smoke concentration data is less than the fifth alarm threshold, then determine whether the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold.

[0019] Based on the above, when the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold and the smoke concentration data is greater than or equal to the fifth alarm threshold, first determine whether the ambient temperature data is greater than or equal to the first alarm threshold. If it is less than, further determine whether the target object surface temperature data is greater than or equal to the third alarm threshold. If it is still less than, then determine whether the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold.

[0020] Based on the above, when the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is less than the fifth alarm threshold, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold, first determine whether the ambient temperature data is greater than or equal to the first alarm threshold. If it is less than, further determine whether the target object surface temperature data is greater than or equal to the third alarm threshold.

[0021] A second aspect of the present invention provides a fire alarm system suitable for use in public places, comprising:

[0022] An information collection unit, comprising an ambient temperature sensor, a non-contact temperature sensor, a smoke alarm, and a carbon monoxide sensor, wherein the ambient temperature sensor is used to collect ambient temperature data, the non-contact temperature sensor is used to collect target object surface temperature data, the smoke alarm is used to collect smoke concentration data, and the carbon monoxide sensor is used to collect carbon monoxide concentration data;

[0023] The fire judgment unit is used to judge whether a fire has occurred based on the ambient temperature data, the target object surface temperature data, the carbon monoxide concentration data, the smoke concentration data and the comparison priority:

[0024] When the ambient temperature data is greater than or equal to the second alarm threshold or the target object surface temperature data is greater than or equal to the fourth alarm threshold, it is determined that a fire has occurred;

[0025] When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, and the smoke concentration data is greater than or equal to the fifth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold, the target object surface temperature data is greater than or equal to the third alarm threshold, or the carbon monoxide concentration is greater than or equal to the sixth alarm threshold, it is determined that a fire has occurred;

[0026] When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is less than the fifth alarm threshold, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold or the target object surface temperature data is greater than or equal to the third alarm threshold, it is determined that a fire has occurred;

[0027] Wherein, the second alarm threshold is greater than the first alarm threshold, and the fourth alarm threshold is greater than the third alarm threshold;

[0028] The alarm unit is used to issue an audible and visual alarm after a fire is detected.

[0029] The present invention has outstanding substantive features and significant progress compared to the prior art. Specifically,

[0030] This paper analyzes the reasons why smoke alarms in public places produce false alarms and designs a combined sensor suitable for public places. By simultaneously collecting multiple on-site environmental information and fusing the information to determine whether a fire has occurred, the problem of a single sensor with a single detection method is solved.

[0031] The present invention adopts a reverse order judgment method of fire development stages, first judging whether it is the fire development stage, and then judging whether it is the initial stage of the fire, thereby realizing alarm and rescue according to the severity of the crisis.

[0032] The present invention is divided into three scenarios according to the relationship between multiple on-site environmental information: the ambient temperature data is greater than or equal to the second alarm threshold or the target object surface temperature data is greater than or equal to the fourth alarm threshold; the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold and the smoke concentration data exceeds the limit; the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is within the limit and the carbon monoxide concentration data exceeds the limit; different judgment criteria are adopted in different scenarios, corresponding to different fire stages in public places, so that alarms of different speeds can be issued at different fire stages. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the fire alarm process in Example 1 of the present invention.

[0034] Figure 2 This is a flow chart of an embodiment of the second embodiment of the present invention.

[0035] Figure 3 Schematic diagram of the fire alarm system in Example 3 of the present invention.

[0036] Figure 4 This is a schematic diagram of the flow of the fire judgment unit selecting the multiplexing circuit in embodiment 4 of the present invention. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0038] Example 1

[0039] like Figure 1 As shown, the present invention provides a fire alarm method applicable to public places, comprising the following steps:

[0040] Obtain ambient temperature data of public places, target object surface temperature data, carbon monoxide concentration data, and smoke concentration data;

[0041] Determine whether a fire has occurred based on the ambient temperature data, target object surface temperature data, carbon monoxide concentration data, smoke concentration data, and comparison priority:

[0042] When the ambient temperature data is greater than or equal to the second alarm threshold or the target object surface temperature data is greater than or equal to the fourth alarm threshold, it is determined that a fire has occurred;

[0043] When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, and the smoke concentration data exceeds the limit, if the ambient temperature data is greater than or equal to the first alarm threshold, the target object surface temperature data is greater than or equal to the third alarm threshold, or the carbon monoxide concentration exceeds the limit, it is determined that a fire has occurred;

[0044] When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is within the limit, and the carbon monoxide concentration data is exceeded, if the ambient temperature data is greater than or equal to the first alarm threshold or the target object surface temperature data is greater than or equal to the third alarm threshold, it is determined that a fire has occurred;

[0045] The second alarm threshold is greater than the first alarm threshold, and the fourth alarm threshold is greater than the third alarm threshold.

[0046] There is no necessary relationship between the second alarm threshold and the third alarm threshold, but under normal circumstances, the second alarm threshold will not be higher than the third alarm threshold.

[0047] As we all know, when a fire occurs at the installation site, the surface temperature of objects will be high. Even burning paper will reach 200°C. The surrounding temperature will also rise. The combustion will also produce gases such as carbon monoxide, accompanied by particulate matter such as smoke. Therefore, this environmental information can be collected to make fire judgments.

[0048] Smoke alarms and carbon monoxide sensors are susceptible to false alarms due to smoke, steam or moisture produced by cigarettes, as well as volatile substances such as sunscreen sprays in the environment. Temperature sensors, on the other hand, utilize the various physical properties of substances and convert temperature directly into electrical quantity according to the temperature change law. They are very stable and will not experience the above situation.

[0049] Therefore, when it is detected that the ambient temperature at the installation site or the surface temperature of an object exceeds the upper limit of their respective alarm thresholds, it can be directly determined that a large-scale fire has occurred at the scene; and when it is detected that the ambient temperature at the installation site or the surface temperature of an object does not exceed the upper limit of their respective alarm thresholds, and the smoke alarm or carbon monoxide sensor exceeds its alarm threshold, it is necessary to integrate other environmental information for auxiliary judgment, thereby avoiding false alarms caused by a single smoke alarm or a single carbon monoxide sensor due to environmental interference.

[0050] Specifically, the comparison priority order of the ambient temperature data, the target object surface temperature data, the carbon monoxide concentration data and the smoke concentration data is: the ambient temperature data is greater than the target object surface temperature data, which is greater than the smoke concentration data, which is greater than the carbon monoxide concentration data.

[0051] During the execution process, first determine whether the ambient temperature data is greater than or equal to the second alarm threshold. If it is less than, then further determine whether the target object surface temperature data is greater than or equal to the fourth alarm threshold. If it is still less than, then determine whether the smoke concentration data is greater than or equal to the fifth alarm threshold; if the smoke concentration data is less than the fifth alarm threshold, then determine whether the carbon monoxide concentration data exceeds the limit.

[0052] It is understandable that as dust accumulates, the sensitivity of the smoke alarm may increase after a period of use. In this way, it is possible that the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, and the smoke concentration data is greater than or equal to the fifth alarm threshold. At this time, it is also necessary to use the ambient temperature data, the target object surface temperature data and / or the carbon monoxide concentration data to assist in determining whether the smoke alarm is a false alarm.

[0053] Specifically, the system first determines whether the ambient temperature data is greater than or equal to the first alarm threshold. If so, it further determines whether the target object surface temperature data is greater than or equal to the third alarm threshold. If still less than this, it then determines whether the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold. If the ambient temperature data is less than the first alarm threshold, the target object surface temperature data is less than the third alarm threshold, and the carbon monoxide concentration data is less than the sixth alarm threshold, then, since only the smoke concentration data exceeds the limit, it is determined that no fire has occurred and the smoke alarm has falsely alarmed, possibly due to smoking or spraying sunscreen.

[0054] Similarly, after a period of use, the sensitivity of the carbon monoxide sensor will increase. In this way, it is possible that the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is less than the fifth alarm threshold, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold. At this time, it is also necessary to use the ambient temperature data and / or the target object surface temperature data to assist in determining whether the carbon monoxide sensor is falsely alarming.

[0055] Specifically, the system first determines whether the ambient temperature data is greater than or equal to the first alarm threshold. If so, it then determines whether the target object surface temperature data is greater than or equal to the third alarm threshold. If both the ambient temperature data and the target object surface temperature data are less than the first alarm threshold and the third alarm threshold, since only the carbon monoxide concentration data exceeds the limit, it is determined that no fire has occurred and the carbon monoxide sensor has a false alarm.

[0056] Example 2

[0057] This embodiment provides a specific example: in the installation location of a smoke alarm, the ambient temperature generally rarely reaches 50°C, and the surface temperature of an object rarely reaches 100°C. Therefore, two alarm thresholds TA1 (assuming 55°C) and TA2 (assuming 80°C) can be set for the ambient temperature; two alarm thresholds TB1 (assuming 120°C) and TB2 (assuming 150°C) can also be set for the surface temperature of the target object; the alarm threshold for smoke concentration is TC (assuming 5% obs / m3); and the alarm threshold for carbon monoxide is TD (assuming 50 ppm).

[0058] When using, such as Figure 2 As shown, the ambient temperature data of public places, the surface temperature data of target objects, the carbon monoxide concentration data and the smoke concentration data are obtained. Under normal circumstances, the ambient temperature will not exceed 50°C. During the development and fierce stages of the fire, the combustion temperature rises and the radiant heat is the strongest. Therefore, if the ambient temperature is too high, there must be an abnormality on site. Therefore, in this embodiment, it is first determined whether the ambient temperature data of the installation site is greater than or equal to TA2. If the ambient temperature data is greater than or equal to TA2, it is determined that a fire has occurred on site, and an on-site alarm and data upload are triggered. In this scenario, only the on-site ambient temperature data needs to be measured to quickly determine the occurrence of a fire, quickly alarm, and achieve the purpose of timely fire extinguishing.

[0059] Under normal circumstances, the surface temperature of an object will not exceed 100°C. However, in the early stages of a fire, with localized open flames or smoldering, the surface temperature of any object will rise; even burning paper can exceed 200°C. Therefore, when the ambient temperature is less than TA2, the system further determines whether the surface temperature of the target object at the installation site is greater than or equal to TB2. If so, a fire is detected, triggering an on-site alarm and data upload. In this scenario, simply measuring the ambient temperature and the target object's surface temperature allows for rapid fire detection, alarm activation, and timely extinguishing.

[0060] Because the burning material may be outside the detection range of the non-contact temperature sensor or obscured, the temperature cannot be detected, so further analysis is required using other data. Fires can be classified into two types: open flame and smoldering. Both types produce smoke (except for clean energy sources such as natural gas). However, carbon monoxide is only produced during smoldering, and once complete combustion occurs, the carbon monoxide concentration may be undetectable.

[0061] Therefore, when the surface temperature of the target object is less than TB2, it is also necessary to determine whether the smoke concentration on site exceeds the limit. If the smoke concentration exceeds the limit, the on-site detection parameters are determined to be exceeded in the following priority order, where the priority order is: whether the ambient temperature is greater than or equal to TA1 > whether the object surface temperature is greater than or equal to TB1 > whether the carbon monoxide concentration exceeds TD; when the ambient temperature is greater than or equal to TA1, or when the ambient temperature is less than TA1 and the object surface temperature is greater than or equal to TB1, or when the ambient temperature is less than TA1, the object surface temperature is less than TB1, and the carbon monoxide concentration exceeds TD, it can be determined that a fire has occurred on site, triggering an on-site alarm and data upload; when the ambient temperature is less than TA1, the object surface temperature is less than TB1, and the carbon monoxide concentration is less than TD, it is determined that no fire has occurred.

[0062] If the smoke concentration is within the limit, the on-site carbon monoxide concentration is further determined to be beyond the limit. If the carbon monoxide concentration exceeds TD, the on-site detection parameters are determined to be beyond the limit in the following priority order, where the priority order is: whether the ambient temperature is greater than or equal to TA1 > whether the object surface temperature is greater than or equal to TB1; when the ambient temperature is greater than or equal to TA1, or when the ambient temperature is less than TA1 and the object surface temperature is greater than or equal to TB1, it can be determined that a fire has occurred on-site, triggering an on-site alarm and data upload; when the ambient temperature is less than TA1 and the object surface temperature is less than TB1, it is determined that no fire has occurred.

[0063] For the latter two scenarios, since at least three types of environmental information are needed to determine the occurrence of a fire, the speed is slower than the first two scenarios. However, since the latter two scenarios are in the early stages of a fire, they will not affect fire rescue.

[0064] Example 3

[0065] This embodiment provides a fire alarm system suitable for use in public places, including:

[0066] An information collection unit, comprising an ambient temperature sensor, a non-contact temperature sensor, a smoke alarm, and a carbon monoxide sensor, wherein the ambient temperature sensor is used to collect ambient temperature data, the non-contact temperature sensor is used to collect target object surface temperature data, the smoke alarm is used to collect smoke concentration data, and the carbon monoxide sensor is used to collect carbon monoxide concentration data;

[0067] The fire judgment unit is used to judge whether a fire has occurred based on the ambient temperature data, the target object surface temperature data, the carbon monoxide concentration data, and the smoke concentration data:

[0068] When the ambient temperature data is greater than or equal to the second alarm threshold or the target object surface temperature data is greater than or equal to the fourth alarm threshold, it is determined that a fire has occurred;

[0069] When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, and the smoke concentration data is greater than or equal to the fifth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold, the target object surface temperature data is greater than or equal to the third alarm threshold, or the carbon monoxide concentration is greater than or equal to the sixth alarm threshold, it is determined that a fire has occurred;

[0070] When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is less than the fifth alarm threshold, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold or the target object surface temperature data is greater than or equal to the third alarm threshold, it is determined that a fire has occurred;

[0071] Wherein, the second alarm threshold is greater than the first alarm threshold, and the fourth alarm threshold is greater than the third alarm threshold;

[0072] The alarm unit is used to issue an audible and visual alarm after a fire is detected.

[0073] Preferably, the ambient temperature sensor adopts a digital temperature and humidity sensor, and the non-contact temperature sensor adopts a thermopile temperature sensor. When in use, the detection range of the thermopile sensor can be set by a Fresnel lens so that it focuses on detecting the surface temperature of objects in flammable areas; the smoke alarm adopts a photoelectric smoke alarm, and the carbon monoxide sensor adopts an electrochemical carbon monoxide sensor.

[0074] In specific implementation, such as Figure 3 As shown, the judgment priority order is: the ambient temperature data is greater than the target object surface temperature data, greater than the smoke concentration data, greater than the carbon monoxide concentration data;

[0075] First, determine whether the ambient temperature data is greater than or equal to the second alarm threshold TA2. If it is less than, further determine whether the target object surface temperature data is greater than or equal to the fourth alarm threshold TB2. If it is still less than, determine whether the smoke concentration data is greater than or equal to the fifth alarm threshold TC; if the smoke concentration data is less than the fifth alarm threshold, then determine whether the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold TD.

[0076] It can be understood that when the ambient temperature data is less than the second alarm threshold TA2, the target object surface temperature data is less than the fourth alarm threshold TB2 and the smoke concentration data is greater than or equal to the fifth alarm threshold TC, it is first determined whether the ambient temperature data is greater than or equal to the first alarm threshold TA1. If it is less than, it is further determined whether the target object surface temperature data is greater than or equal to the third alarm threshold TB1. If it is still less than, it is then determined whether the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold TD.

[0077] When the ambient temperature data is less than the second alarm threshold TA2, the target object surface temperature data is less than the fourth alarm threshold TB2, the smoke concentration data is less than the fifth alarm threshold TC, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold TD, first determine whether the ambient temperature data is greater than or equal to the first alarm threshold TA1. If it is less than, further determine whether the target object surface temperature data is greater than or equal to the third alarm threshold TB1.

[0078] It can be understood that the fire alarm system also includes a self-check / test module, which is used to control the operation of the information acquisition unit after the system is initialized, and determine whether the sensor is faulty based on the acquisition results; if a fault is determined to have occurred, the alarm unit is controlled to operate and an alarm is issued.

[0079] Furthermore, the fire alarm system also includes a communication unit and a heartbeat detection unit. The heartbeat detection unit performs timing according to a preset heartbeat rule. When there is no alarm, the communication unit uploads data according to a preset heartbeat frequency; when there is an alarm, the communication unit reports according to a preset alarm upload frequency; when a transition occurs from an alarm state to a non-alarm state or from a non-alarm state to an alarm state, the communication unit immediately uploads data.

[0080] Example 4

[0081] This embodiment provides another specific embodiment of the information collection unit.

[0082] The information acquisition unit includes not only an ambient temperature sensor, a non-contact temperature sensor, a smoke alarm and a carbon monoxide sensor, but also a multiplexing circuit.

[0083] The ambient temperature sensor, the non-contact temperature sensor, the smoke alarm, and the carbon monoxide sensor are each connected to the fire determination unit via a multiplexing circuit; wherein the communication status between the multiplexing circuit and the different sensors is controlled by the fire determination unit. The ambient temperature sensor is directly connected to the fire determination unit; the non-contact temperature sensor, the smoke alarm, and the carbon monoxide sensor are each connected to the fire determination unit via a multiplexing circuit; wherein the communication status between the multiplexing circuit and the different sensors is controlled by the fire determination unit.

[0084] Specifically, the ambient temperature sensor, the non-contact temperature sensor, the smoke alarm, and the carbon monoxide sensor are all sensors that output analog signals or sensors that output digital signals. In this embodiment, sensors that output digital signals are preferred.

[0085] like Figure 4As shown, in the initial state, the fire judgment unit selects the channel connecting the ambient temperature sensor and the multiplexing circuit; the ambient temperature sensor collects ambient temperature data and sends the collected ambient temperature data to the fire judgment unit in the form of numerical values;

[0086] The fire judgment unit judges whether the installation environment temperature data is greater than or equal to TA2. If so, it determines that a fire has occurred on site, triggering an on-site alarm and data upload;

[0087] Otherwise, controlling the channel selection of the multiplexing circuit connected to the non-contact temperature sensor, reading the surface temperature data of the target object on site collected by the non-contact temperature sensor, and determining whether the surface temperature data of the target object on site is greater than or equal to TB2. If so, determining that a fire has occurred on site, triggering an on-site alarm and data uploading;

[0088] Otherwise, the channel selection of the multiplexing circuit connected to the smoke alarm is further controlled to read the on-site smoke concentration data collected by the smoke alarm, and determine whether the on-site smoke concentration data exceeds the limit. If the on-site smoke concentration data exceeds the limit, the on-site detection parameters are determined to be exceeded in the following priority order. When any one of the parameters exceeds the limit, it can be determined that a fire has occurred on the scene, triggering an on-site alarm and data upload; wherein, the priority order is: whether the ambient temperature is greater than or equal to TA1 > whether the object surface temperature is greater than or equal to TB1; if neither exceeds the limit, the channel selection of the multiplexing circuit connected to the carbon monoxide sensor is further controlled to read the on-site carbon monoxide concentration data collected by the carbon monoxide sensor, and determine whether the on-site carbon monoxide concentration data exceeds the limit. If so, it is determined that a fire has occurred on the scene, triggering an on-site alarm and data upload;

[0089] If the on-site smoke concentration data does not exceed the limit, the channel selection of the multiplexing circuit connected to the carbon monoxide sensor is further controlled to read the on-site carbon monoxide concentration data collected by the carbon monoxide sensor, and determine whether the on-site carbon monoxide concentration data exceeds the limit. If it exceeds the limit, it is determined that a fire has occurred on the scene, and an on-site alarm and data upload are triggered; if it does not exceed the limit, the on-site detection parameters are determined to be out of limit according to the following priority order. When any one of the items exceeds the limit, it can be determined that a fire has occurred on the scene, and an on-site alarm and data upload can be triggered; among which, the priority order is: whether the ambient temperature is greater than or equal to TA1> whether the object surface temperature is greater than or equal to TB1.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solutions of the present invention. They should all be included in the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A fire alarm method suitable for public places, characterized in that: The following steps are involved: Obtain ambient temperature data of public places, target object surface temperature data, carbon monoxide concentration data, and smoke concentration data; Determine whether a fire has occurred based on the ambient temperature data, target object surface temperature data, carbon monoxide concentration data, smoke concentration data, and comparison priority: The comparison priority order is: ambient temperature data is greater than target object surface temperature data, greater than smoke concentration data, greater than carbon monoxide concentration data; When executing the comparison priority order, first determine whether the ambient temperature data is greater than or equal to the second alarm threshold. If it is less than, then further determine whether the target object surface temperature data is greater than or equal to the fourth alarm threshold. If it is still less than, then determine whether the smoke concentration data is greater than or equal to the fifth alarm threshold; if the smoke concentration data is less than the fifth alarm threshold, then determine whether the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold; When the ambient temperature data is greater than or equal to the second alarm threshold or the target object surface temperature data is greater than or equal to the fourth alarm threshold, it is determined that a fire has occurred; When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, and the smoke concentration data is greater than or equal to the fifth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold, the target object surface temperature data is greater than or equal to the third alarm threshold, or the carbon monoxide concentration is greater than or equal to the sixth alarm threshold, it is determined that a fire has occurred; When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is less than the fifth alarm threshold, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold or the target object surface temperature data is greater than or equal to the third alarm threshold, it is determined that a fire has occurred; The second alarm threshold is greater than the first alarm threshold, and the fourth alarm threshold is greater than the third alarm threshold.

2. The fire alarm method applicable to public places according to claim 1, characterized in that: When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, and the smoke concentration data is greater than or equal to the fifth alarm threshold, first determine whether the ambient temperature data is greater than or equal to the first alarm threshold. If it is less than, further determine whether the target object surface temperature data is greater than or equal to the third alarm threshold. If it is still less than, then determine whether the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold.

3. The fire alarm method applicable to public places according to claim 1, characterized in that: When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is less than the fifth alarm threshold, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold, first determine whether the ambient temperature data is greater than or equal to the first alarm threshold. If it is less than, further determine whether the target object surface temperature data is greater than or equal to the third alarm threshold.

4. A fire alarm system suitable for public places, characterized in that: include: An information collection unit, comprising an ambient temperature sensor, a non-contact temperature sensor, a smoke alarm, and a carbon monoxide sensor, wherein the ambient temperature sensor is used to collect ambient temperature data, the non-contact temperature sensor is used to collect target object surface temperature data, the smoke alarm is used to collect smoke concentration data, and the carbon monoxide sensor is used to collect carbon monoxide concentration data; The fire judgment unit is used to judge whether a fire has occurred based on the ambient temperature data, the target object surface temperature data, the carbon monoxide concentration data, the smoke concentration data and the comparison priority: The comparison priority order is: ambient temperature data is greater than target object surface temperature data, greater than smoke concentration data, greater than carbon monoxide concentration data; First, determine whether the ambient temperature data is greater than or equal to the second alarm threshold. If less than, further determine whether the target object surface temperature data is greater than or equal to the fourth alarm threshold. If still less than, determine whether the smoke concentration data is greater than or equal to the fifth alarm threshold. If the smoke concentration data is less than the fifth alarm threshold, then determine whether the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold. When the ambient temperature data is greater than or equal to the second alarm threshold or the target object surface temperature data is greater than or equal to the fourth alarm threshold, it is determined that a fire has occurred; When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, and the smoke concentration data is greater than or equal to the fifth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold, the target object surface temperature data is greater than or equal to the third alarm threshold, or the carbon monoxide concentration is greater than or equal to the sixth alarm threshold, it is determined that a fire has occurred; When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is less than the fifth alarm threshold, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold, if the ambient temperature data is greater than or equal to the first alarm threshold or the target object surface temperature data is greater than or equal to the third alarm threshold, it is determined that a fire has occurred; Wherein, the second alarm threshold is greater than the first alarm threshold, and the fourth alarm threshold is greater than the third alarm threshold; The alarm unit is used to issue an audible and visual alarm after a fire is detected.

5. The fire alarm system suitable for public places according to claim 4, characterized in that: When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, and the smoke concentration data is greater than or equal to the fifth alarm threshold, first determine whether the ambient temperature data is greater than or equal to the first alarm threshold. If it is less than, further determine whether the target object surface temperature data is greater than or equal to the third alarm threshold. If it is still less than, then determine whether the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold.

6. The fire alarm system suitable for public places according to claim 4, characterized in that: When the ambient temperature data is less than the second alarm threshold, the target object surface temperature data is less than the fourth alarm threshold, the smoke concentration data is less than the fifth alarm threshold, and the carbon monoxide concentration data is greater than or equal to the sixth alarm threshold, first determine whether the ambient temperature data is greater than or equal to the first alarm threshold. If it is less than, further determine whether the target object surface temperature data is greater than or equal to the third alarm threshold.

7. The fire alarm system suitable for public places according to claim 4, characterized in that: The information collection unit further includes a multiplexing circuit, and the ambient temperature sensor, the non-contact temperature sensor, the smoke alarm, and the carbon monoxide sensor are respectively connected to the fire judgment unit via the multiplexing circuit; wherein the connectivity between the multiplexing circuit and different sensors is controlled by the fire judgment unit.

8. The fire alarm system suitable for public places according to claim 4, characterized in that: It also includes a communication unit and a heartbeat detection unit. The heartbeat detection unit performs timing according to a preset heartbeat rule. When there is no alarm, the communication unit uploads data according to a preset heartbeat frequency; when there is an alarm, the communication unit reports according to a preset alarm upload frequency; when a transition occurs from an alarm state to a non-alarm state or from a non-alarm state to an alarm state, the communication unit immediately uploads data.

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