Heat detector and heat detection system

Abstract

To provide a heat detector that is unlikely to generate a false fire alarm due to heating.SOLUTION: A heat detector according to the present invention is a thermistor-type heat detector, which detects a fire in a fixed temperature mode when a heating device is in operation and detects a fire in a differential mode when the heating device is not in operation.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to thermistor-based heat detectors and heat sensing systems. [Background technology]

[0002] Fire detectors include smoke detectors that detect smoke from a fire and heat detectors that detect heat from a fire, and heat detectors are classified into constant temperature and differential types (Patent Document 1). Constant temperature heat detectors detect the temperature of the monitored environment using a thermistor or the like, and determine that a fire has occurred when the detected temperature exceeds a predetermined temperature. Differential heat detectors also detect the temperature of the monitored environment using a thermistor or the like, and determine that a fire has occurred when the detected temperature rises above a predetermined temperature within a predetermined period of time. When the indoor temperature rises in summer, the temperature can become relatively high even without a fire occurring. However, because the rate of temperature rise is lower than when a fire occurs, differential heat detectors are less likely to issue false fire alarms even in such cases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-69160 Summary of the Invention [Problem to be solved by the invention]

[0004] In addition to temperature rises caused by fires and climatic factors, the temperature of a differential heat detector can also rise due to the warm air from a heating system. When a cold room is heated by a heating system such as an air conditioner, the warm air warms the differential heat detector, causing a high rate of temperature rise and potentially resulting in a false fire alarm. The more powerful the heating system, which can quickly heat the room, the higher the chance of a false fire alarm.

[0005] An object of the present invention is to provide a heat detector that is less likely to cause false fire alarms due to heating. [Means for solving the problem]

[0006] The heat detector in one embodiment of the present invention is a thermistor-type heat detector, which is characterized by detecting fires in a constant temperature manner when the heating device is in operation, and in a differential manner when the heating device is in an inoperative state. [Effects of the Invention]

[0007] The present invention can provide a heat detector that is less likely to cause false fire alarms due to heating. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a vertical cross-sectional view of the heat detector and the like in the first embodiment. [Figure 2] FIG. 2 is a diagram showing the internal configuration of the heat detector according to the first embodiment. [Figure 3] 3 is an operation flow diagram of the heat detector in the first embodiment. [Figure 4] 10 is a diagram of a heat detector and the like in the second embodiment. [Figure 5] FIG. 10 is a diagram showing the internal configuration of a heat detector according to a second embodiment. [Figure 6] FIG. 10 is an operation flow diagram of the heat detector according to the second embodiment. [Figure 7] FIG. 10 is a cross-sectional view of a louver of an indoor unit in a modified example of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0009] FIG. 1 shows a vertical cross-sectional view of a heat detector 1 and other components in Example 1. The heat detector 1 is attached below a ceiling panel C1 and is a thermistor-type heat detector with a thermistor 11 protruding downward. There is a step on the side of the ceiling panel C1 in FIG. 1, and a ceiling panel C2 is provided at a lower position than the ceiling panel C1. An indoor unit 2 of an air conditioner is provided above the ceiling panel C2. The indoor unit 2 has an air outlet 21 facing sideways at the step between the ceiling panels C1 and C2, and an air intake 22 facing downward on the ceiling panel C2. In Example 1, the heat detector 1 is located ahead of the airflow W sent out from the air outlet 21. The indoor unit 2 has a control unit 23 and a communication unit 24 inside.

[0010] 2 shows the internal configuration of the heat detector 1 in Example 1. The heat detector 1 has a thermistor 11, an A / D converter 12, a control unit 13, a memory 14, an alarm means 15, and a communication means 16. The control unit 13 is a CPU and operates according to software stored in the memory 14. The alarm means 15 is connected to a fire receiver (not shown) by wire and sends a detection signal when it detects a fire. The communication means 16 communicates with the indoor unit 2 wirelessly.

[0011] The thermistor 11 is connected to an A / D converter 12, which is connected to a control unit 13 along with a memory 14, an alarm means 15, and a communication means 16. The temperature measured by the thermistor 11 is converted into a digital temperature signal by the A / D converter 12 and input to the control unit 13. Fire detection is then performed by software stored in the memory 14.

[0012] 3 shows the operation flow of the heat detector 1 in Example 1. This operation flow is controlled by the control unit 13. Note that the operating state in Example 1 is the operation of the heating device, and operations other than heating, such as cooling operation, are not considered to be the operating state of Example 1 because they are not operations as a heating device.

[0013] First, the heat detector 1 communicates with the indoor unit 2 of the air conditioner that functions as a heating device (step S1). The communication means 16 performs wireless communication with the communication unit 24 of the indoor unit 2, and receives an operating state signal that indicates the operating state of the air conditioner.

[0014] Next, it is determined whether the air conditioner, which is a heating device, is in operation based on the operation status signal (step S2). If the operation status signal does not indicate an operation status (NO), the heat detector 1 performs differential fire detection (step S3). In differential fire detection, a fire is determined to have occurred when the temperature detected by the thermistor 11 rises above a predetermined temperature within a predetermined period of time. In the heat detector 1 of the first embodiment, the temperature for each hour is stored in the memory 14, and in step S3, a fire is determined to have occurred if the current temperature is higher by the predetermined temperature or more than the temperature from the previous predetermined period of time.

[0015] If the operation status signal indicates an activated state (YES) in step S2, the heat detector 1 performs constant temperature fire detection (step S4). In constant temperature fire detection, a fire is determined to have occurred when the detected current temperature exceeds a predetermined temperature. After step S3 or step S4 is completed, a fire alarm is issued when a fire is determined to have occurred (step S5). Then, the process returns to before step S1. A fire alarm is issued by sending a detection signal from the alarm means 15 to a fire receiver (not shown). [Example]

[0016] FIG. 4 shows a heat detector 3 and other components in Example 2. In FIG. 4(a), the heat detector 3 and ceiling panel C are shown in vertical cross section, and the indoor unit 4 is shown from the side. FIG. 4(b) is a bottom view showing the indoor unit 4 and heat detector 3 attached to the ceiling panel C as viewed from below. The heat detector 3 is attached below the ceiling panel C. The heat detector 3 is a thermistor type, with the thermistor 31 protruding downward and a camera 36 facing the indoor unit 4. The ceiling panel C also has an air conditioner indoor unit 4 attached. As shown in FIG. 4(a), the indoor unit 4 is attached so that it barely protrudes downward from the ceiling panel C. As shown in FIG. 4(b), the indoor unit 4 is approximately square when viewed from below. Air outlets 41 are provided near the four sides of the approximately square, and an air intake 42 is provided in the center of the four air outlets 41. Louvers 411 are provided at each of the four air outlets 41.

[0017] When the air conditioner blows air, as shown in Figure 4(a), the louvers 411 open downward with the portions near the sides using the center as a fulcrum. Figures 4(a) and 4(b) show the air blowing state with the louvers open downward. In this state, the hot or cold air blown out from the air outlet 41 hits the diagonally opened louvers 411 and spreads outward from the indoor unit 4, becoming air blown W. Then, as shown in Figures 4(a) and 4(b), part of the air blown W is directed toward the heat detector 3.

[0018] 5 shows the internal configuration of the heat detector 3 in Example 2. The heat detector 3 has a thermistor 31, an A / D converter 32, a control unit 33, a memory 34, a notification means 35, and a camera 36. The control unit 33 is a CPU, and operates according to software stored in the memory 34. The thermistor 31 is connected to the A / D converter 32, and the A / D converter 32 is connected to the control unit 33 together with the memory 34, the notification means 35, and the camera 36.

[0019] The temperature measured by the thermistor 31 is converted into a digital temperature signal by an A / D converter 32 and input to a control unit 33. Then, fire detection is performed by software stored in a memory 34. In addition, an image obtained by a camera 36 is also input to the control unit 33 as a digital image signal. Then, fire detection is performed by software stored in the memory 34.

[0020] Fig. 6 shows the operation flow of the heat detector 3 in Example 2. This operation flow is performed by the control unit 33. In Example 2, the heat detector 3 detects the operating state of the indoor unit 4 from images taken by the camera 36, ​​but cannot determine whether hot air is being blown out. Therefore, in Example 2, the operating state is the air blowing state in which the louver 411 is open.

[0021] First, the camera 36 acquires an image of the indoor unit 4 of the air conditioner (step S11). The air conditioner and the indoor unit 4 are heating devices. In the state of the indoor unit 4 shown in FIGS. 4(a) and 4(b), the louver 411 is lowered and the indoor unit 4 is in an operating state. The image of the indoor unit 4 output from the camera 36 shows the louver 411 lowered.

[0022] Next, it is determined whether the air conditioner, which is a heating device, is in an operating state (step S12). Whether the louvers 411 of the indoor unit 4 are in an operating state (lowered) or in an inoperable state (not lowered) is determined by image analysis of the image obtained by the camera 36 using software stored in the memory 34. The image analysis may be performed using software obtained by supervised learning, or may be performed using other software.

[0023] If the answer is NO, meaning the air conditioner is not in operation but in an inoperative state, differential fire detection is performed (step S13). In differential fire detection, a fire is determined to have occurred when the temperature sensed by the thermistor 31 rises above a predetermined temperature within a predetermined period of time. In the heat detector 3 of the second embodiment, the temperature for each hour is stored in the memory 34, and in step S13, a fire is determined to have occurred if the current temperature is higher by the predetermined temperature or more than the temperature from the previous predetermined period of time.

[0024] If step S12 determines that the air conditioner is operating (YES), constant temperature fire detection is performed (step S14). In constant temperature fire detection, a fire is determined to have occurred when the detected current temperature exceeds a predetermined temperature. After step S13 or step S14, a fire alarm is issued when a fire is determined to have occurred (step S15). Then, the process returns to before step S11. A fire alarm is issued by sending a detection signal from the alarm means 35 to a fire receiver (not shown).

[0025] <Modification> In Example 2, software stored in memory 34 performs image analysis of the image acquired by camera 36 using software obtained by supervised learning, etc., to determine whether the heating device is in operation. In a modified example of Example 2, a heat detector 5 (not shown) reads a barcode from an image acquired by camera 51 (not shown) to determine whether the heating device is in operation. The modified example is a heat detection system equipped with a heat detector 5 and a thermochromic barcode, and the heat detector 5 determines whether the heating device is in operation based on the image of the thermochromic barcode. This barcode is a thermochromic barcode that changes color at high temperatures and is displayed as a barcode. The thermochromic barcode does not change color at low temperatures, and the barcode is not displayed.

[0026] Fig. 7 shows a cross-sectional view of the vicinity of louver 611 in an indoor unit 6 (not shown) in a modified example. Fig. 7(a) shows horizontal louver 611 with air outlet 61 (not shown) closed, and Fig. 7(b) shows inclined louver 611 with air outlet 61 open. The left-right direction in Fig. 7(a) indicates the short direction of rectangular louver 611. The indoor unit 6 having louver 611 is a ceiling-embedded type that is fitted to a flat ceiling and is provided with louvers 611 in four locations, similar to the indoor unit 4 shown in Fig. 4.

[0027] An insulating layer 613 is laminated on the upper side of the louver 611, and a thermosensitive coloring barcode layer 612 is laminated on top of that. The thermosensitive coloring barcode layer 612 does not display a barcode at low temperatures, but changes color and the barcode appears as the temperature increases. In this modified example, the color changes to black. The insulating layer 613 is provided between the louver 611 and the thermosensitive coloring barcode layer 612 so that the temperature of the thermosensitive coloring barcode layer 612 can be easily changed by hot air.

[0028] When air is blown from the indoor unit 6, the left side of the louver 611 shown in FIG. 7(a) rotates downward in the direction of the arrow indicated by rotation D, opening the air outlet 61, as shown in FIG. 7(b). The airflow Wd blown downward in the state shown in FIG. 7(b) hits the thermosensitive color-developing barcode layer 612, changes direction, and is blown toward the camera 51. The camera 51 is located in the direction of the thick arrow (51) in FIG. 7(b). If the airflow Wd is hot air, the hot air warms the thermosensitive color-developing barcode layer 612. Then, as shown in FIG. 7(b), the thermosensitive color-developing barcode layer 612 changes color, revealing a barcode. In FIG. 7(b), the camera 51 of the heat detector 5, which is located in the direction of the thick arrow (51), captures the barcode. The heat detector 5 can determine that the air conditioner is operating in heating mode by detecting the barcode captured by the camera 51.

[0029] On the other hand, in cooling operation other than heating operation, the airflow Wd is not warm. Therefore, the thermosensitive color-developing barcode layer 612 is not heated, and the barcode does not appear. Even if the louvers 611 are open and the thermosensitive color-developing barcode layer 612 is visible to the camera 51 positioned in the direction of the thick arrow (51) in Figure 7(b), the barcode will not be captured. Therefore, the heat detector 5 can determine that the air conditioner is not operating in heating mode.

[0030] The heat detection system of the modified example has a heat detector 5 and an indoor unit 6. A camera 51 of the heat detector 5 photographs a thermosensitive color-developing barcode layer 612 on the indoor unit 6. By detecting the barcode, the heat detector 5 determines whether the indoor unit 6, which is a heating device, is in an operating state or an inoperating state, and switches between a constant temperature type and a differential type.

[0031] In a modified example, the thermal color-changing barcode is not displayed at all when not heated, and a barcode indicating the operating state appears when heated. However, when not heated, a barcode different from the barcode indicating the operating state may be displayed, and when heated, the black portion may increase, becoming a barcode indicating the operating state. Also, when heated, the black portion of the thermal color-changing barcode may disappear partially, becoming a barcode indicating the operating state. The thermal color-changing barcode may be a color other than black.

[0032] Furthermore, instead of a thermosensitive color-changing barcode, a normal barcode may be displayed by pasting it on the top of the louver 611, and when the louver 611 is open, the barcode indicating the operating state may be captured by the camera 51. Existing software can be used for the determination by barcode. Because the louver 611 is rectangular, it is preferable to use a one-dimensional barcode, but a two-dimensional barcode may also be used. The heat insulating layer 613 of the modified example may not be necessary.

[0033] In the above-mentioned Examples 1 and 2, when the heating device is in an inoperative state, a fire is detected using a differential system, and when the heating device is in an activated state, a fire is detected using a constant temperature system. However, after a certain time has passed since the heating device was activated, the temperature change becomes smaller, so the possibility of a false fire alarm being generated by the differential heat detector becomes smaller for the warm air after the time has passed. Therefore, after a predetermined time has passed since the heating device was activated, the heat detector may be configured to detect a fire using a differential system even when the heating device is in an activated state.

[0034] The heat detector 1 of the first embodiment uses a wireless signal from the indoor unit 2 to determine whether the heating device is in an operating state or not through communication via a communication means. The heat detector 3 of the second embodiment determines whether the heating device is in an operating state or not from an image captured by a camera 36. However, other methods may be used to determine whether the heating device is in an operating state or not. For example, a microphone may be provided in the heat detector, and whether the heating device is in an operating state or not may be determined from an audio signal from the microphone. The determination based on the audio signal is performed by recognizing the frequency of the sound when the heating device is in an operating state or special sounds such as howling. The determination based on the audio signal may also be performed using supervised learning.

[0035] The indoor units 2 and 4 in the first and second embodiments are ceiling-embedded types. However, the heat detectors in the first and second embodiments may be applied to general indoor units that are installed inside a wall.

[0036] Furthermore, the specific configuration is not limited to the embodiments, and the present invention includes design changes within the scope of the gist of the present invention. Furthermore, the above-mentioned examples and modifications can be combined by utilizing each other's technology as long as there are no particular contradictions or problems in the purpose, configuration, etc. [Explanation of symbols]

[0037] C1 ceiling panel, C2 ceiling panel, C ceiling panel, W airflow, R remote controller, D rotation, Wd airflow, 1 heat detector, 11 thermistor, 12 A / D converter, 13 control unit, 14 memory, 15 notification means, 16 communication means, 2 indoor unit, 21 air outlet, 22 air intake, 23 control unit, 24 communication unit, 3 Heat detector, 31 Thermistor, 32 A / D converter, 33 Control unit, 34 Memory, 35 Notification means, 36 Camera, 4 indoor unit, 41 air outlet, 411 louver, 42 air intake, 5 heat detectors, 51 cameras, 6 indoor unit, 61 air outlet, 611 louver, 612 heat-sensitive coloring barcode layer, 613 heat insulating layer

Claims

1. A thermistor-type heat detector, When the heating system is in operation, it detects fires using a constant temperature system. A heat detector that detects fires differentially when the heating system is inactive.

2. have means of communication, 2. The heat detector according to claim 1, wherein the communication means determines whether the heating device is in an operating state or a non-operating state.

3. Has a camera, 2. The heat detector according to claim 1, wherein it is determined whether the heating device is in an operating state or in an inoperable state from the image of the camera.

4. having a microphone, 2. The heat detector according to claim 1, wherein the audio signal from the microphone determines whether the heating device is in an operating state or not.

5. 5. The heat detector according to claim 1, wherein the heat detector detects a fire differentially even if the heating device is in an operating state after a predetermined time has elapsed since the heating device was in an operating state.

6. A device comprising the heat detector according to claim 3 and a thermosensitive color-developing barcode, A heat detection system that determines whether a heating device is in operation based on the image of the thermosensitive color-changing barcode.

Images