Description

The present disclosure relates to a system and method for detecting at least one fire in a predefined region with the features of claim 1 and 16.

In particular, in industrial or chemical plants, such as e.g. recycling plants or battery recycling plants, open fire poses a considerable operational risk due to the endangerment of persons and the plants themselves. Given the combustible materials handled, in some cases a slight deviation from the operation conditions of the plant might cause open fires that flare up in a predefined region such as the plant area or an area around a specific recycling plant.

Therefore, efficient systems and methods for detecting fires in such predefined regions are required.

This issue is addressed by a system with the features of claim 1 .

At least one sensor device monitors the temperature in at least one predefined spatial region in a plant, each of the at least one sensor devices transmitting the monitored temperature data to a control device. The plant can be in a closed building or under the sky.

The control device is configured to detect at least one fire by detecting a temperature exceeding at least one predetermined temperature threshold and the control device is further being configured to emit a fire signal in dependence of the detection of at least one temperature exceeding the at least one predetermined temperature.

Therefore, the detection and eventually the extinguishing of the fire can be automated for the predefined spatial region.

In one embodiment, the fire signal activates a control system, in particular a programmable logic controller, which activates then at least one fire extinguishing device for the at least one predefined spatial region in which the increased temperature was determined and the at least one fire extinguishing device is configured to apply fire extinguishing fluid over an extinguishing area within the at least predefined spatial region. Therefore, it is possible to detect at least a fire in a predetermined spatial region and automatically initiate the extinguishing of the fire.

It is also possible that the fire signal activates an audible alarm, a haptic signal, a visual signal and I or an alarm call to an external unit.

In a further embodiment, the at least one predefined spatial region represents a space, in particular a building comprising a chemical plant, in particular in a building comprising a chemical plant, in particular with a chemical reactor and I or separation device, in particular with an extraction or distillation device, with a battery recycling processing device, in a manufacturing plant, in a waste deposit facility, in a power station, in an oil refinery, in a galvanic plant, in a hangar or in a storage facility. In those kind of facilities, fire hazards occur within predefinable regions.

The at least one predefined spatial region can be within an angular sector of the at least one sensor device in the horizontal plane, in particular with an angle between 1 ° and 120°, in particular between 30° and 100° and I or the one predefined spatial region (1 , 2) is within an angular sector of the at least one sensor device in the vertical plane, in particular with an angle between 20 and 90°. Alternatively, or in addition, the one predefined spatial region can be within an angular sector of the at least one sensor device in the vertical plane, in particular with an angle between 20 and 90°. If several sensor devices are coupled, large angles, like e.g. 360° can be covered. With those viewing angles, a potential temperature increase - and hence the detection of a fire - can effectively be made.

An extinguishing area of the at least one extinguishing device is covering all or at least a part of the at least one predefined spatial region.

In one embodiment, the at least one sensor device comprises a thermal camera and I or a thermal sensor for detecting the infrared data. The at least one sensor device, in particular a thermal camera can generate an image comprising at least one sector representing a part of the predefined spatial region. The sector could be a part of a screen of a thermal imager. That sector would be a 2D representation of a spatial region monitored by the thermal camera.

The control device can - in one embodiment - be integrated with the sensor device. This means that the threshold can be monitored e.g. with a computing device within a thermal imager.

Given the use of several sensor devices, each predefined spatial region and I or sector can be assigned a specific temperature threshold. Further, one sensor device can have several temperature thresholds. This can take into account e.g. the machinery operating in that predefined spatial region and I or the spatial distribution of the machinery within that spatial region.

The temperature threshold can be time dependent, in particular, different temperature thresholds are assigned for off-hours and working hours of devices in the respective predefined spatial regions.

In one embodiment, the temperature threshold is determined through a deviation from a stored temperature pattern, i.e. a prestored temperature is a field in the at least one predefined spatial region and I or the at least one sector and I or the temperature threshold is set as a predetermined value. From the temperature pattern, a single threshold value can be generated by calculating the average temperature over a certain part or taking the maximum temperature as threshold value. Different embodiments can use e.g. at least one fire extinguishing device with a water cannon, a foam dispenser and / or a gas dispenser. All these fluids can be used to extinguish the fire.

It is also possible that the at least one fire extinguishing device is movable under control of the control system to adjust for temperature data detected by at least one sensor device. If the control system detects a fire within a certain part of the predetermined spatial region, one or more fire extinguishing devices can be moved into positions that allow the best position for attacking the fire.

In one embodiment, the control system, the at least one sensor device and the at least one fire extinguishing device are configured to exchange data wirelessly. For added security, the transmitted data could be encrypted.

The issue is also addressed by a method with the features of claim 16.

Here, at least one sensor device monitors the temperature in the at least one predefined spatial region, the at least one sensor device transmits the monitored temperature data to a control system.

In a second step, the control device detects at least one fire after a temperature increase in the at least one predefined spatial region beyond a predefined threshold temperature is registered.

In a third step, the control device detects at least one fire by detecting a temperature exceeding at least one predetermined temperature threshold and the control device then emits a fire signal.

In one embodiment, the at least one fire is treated with water for a period of time, in particular 120 seconds, and subsequently, the temperature of the respective region is measured again and evaluated relative to the respective temperature threshold for that part. If then the measured temperature still exceeds the temperature threshold, the fire extinguishing is modified, in particular, the extinguishing of the fire is continued with a water - foam mixture for a period of time. With this approach, the fire extinguishing is adaptive and can take into account the result of the previous attempts to extinguish the fire. The duration of the period of time and I or the mixtures can be adjusted to the actually determined temperatures and I or for different parts of the predetermined spatial region.

This can be repeated until a stop condition is reached, in particular, a temperature below the temperature threshold.

At one point, the control system and I or the control device may send an automatic alarm to an external entity, in particular a fire department, if a certain predefined condition is met, in particular a certain value of a temperature is exceeded or a certain number of predefined spatial regions in which the temperature threshold is exceeded in a predetermined time. This is a safeguard in case the system cannot automatically cope with the fire or the fires.

It is also possible that the control device and I or the control system initiates an automatic stop of machinery in the at least one predefined spatial region or in a spatial region materially connected to the at least one predefined spatial region.

Embodiments will now be described by way of example only, with reference to the schematic Figures, in which:

Figure 1 schematically shows a plant and a fire in a predefined spatial region and an embodiment of a system for detecting and extinguishing that fire,

Figure 1a schematically shows a view of an image taken by a sensor device,

Figure 2 schematically shows a plant and two fires in two predefined spatial regions and a further embodiment of a system for detecting and extinguishing those fires, Figure 3 shows a flowchart for an embodiment of a method for detecting and extinguishing a fire.

In Fig. 1 a plant 100 comprising machinery e.g. for the recycling of batteries is shown. In alternative embodiments, the plant 100 can comprise a chemical plant, separation devices (e.g. an extraction device or a distillation device), a manufacturing plant, a waste deposit facility, a power station, an oil refinery, a galvanic plant, a hangar or a storage facility.

Within such a plant 100, potentially hazardous parts (e.g. lithium containing batteries) are generally known beforehand so that a sensor device 21 is monitoring a predefined spatial region 1 within that plant 100. Here, the predefined spatial region 1 is represented by a rectangle in a horizontal plane. In alternative embodiments, the predefined spatial regions 1 , 2 could be represented by a different shape, e.g. circular, elliptical or polygonal. The predefined spatial region generally will have a 3D shape.

Here, the sensor device 21 comprises a thermal sensor (e.g. a thermal camera or a thermal imager) which is sensitive to infrared radiation that e.g. can be visualized in the form of a heat map. This infrared sensing concept does work independently of the lighting conditions in the plant 100. The sensor device 21 does determine a measured temperature field. The maximum temperature in that field (or a sector 24 of the field) can e.g. be set as the measured temperature value T. In any case, the sensor device 21 can determine a temperature field or a temperature value.

In the given example, the predefined spatial region 1 lies within the view field of the sensor device 21 , the view field having a horizontal angular sector of approximately a = 60°. In other embodiments, that angular sector can be larger or smaller, depending on the properties of the sensor device 21 .

With a proper calibration the thermal sensor 21 can detect relatively small temperature differences within the predefined spatial region 1 . If a thermal camera is used as sensor device 21 , a so-called ..emission value" can be set. Human skin for example has an emission value of 0,96. The emission value is then converted into a value in the Celsius scale. The thermal camera captures all actual rays of heat that are transmitted from physical objects (strictly speaking all objects with aggregate phases solid or liquid) and converts them into an actual temperature. Temperature thresholds can be set for different parts of the predefined spatial region 1 , 2 and I or their representations on a screen in the thermal camera (e.g. a sector 24). This allows a flexible assignment of thresholds to different parts in a plant to be monitored.

In Fig. 1A, an image 23 e.g. from a screen of a thermal camera 21 is shown. Within that image 23, the sector 24 indicates a part of that image 23 in the middle of the image 23.

As the thermal profile of the predefined spatial region 1 under nominal operating conditions is known, a deviation from that condition can serve as a temperature threshold TT. In this case, the nominal temperature pattern is used as a basis for defining the temperature threshold TT. It is also possible that the temperature threshold T _T is predetermined and stored in a control device 30 and / or a control system 40. The control device 30 can e.g. be integrated with the thermal sensor 21 . The control system 40 (see e.g. Fig. 3) can be a supervisory control system.

The temperature threshold TT can also depend on time. For example, it is possible to have different patterns during working hours of the plant 100 during which the measured temperatures T will be generally higher and off-working hours, during which the measured temperatures T will be generally lower. Hence, a small absolute temperature value would more likely trigger the temperature threshold TT during off- working hours, than during working hours.

If within the geometrical view field of the sensor device 21 e.g. a temperature deviates by 100°C from the nominal temperature, this would, in this example, be considered as a temperature threshold TT.

The sensor device 21 is connected or integrated with the control device 30 which receives the temperature data, e.g. as images. The control device 30 is equipped with software, which can detect thermal deviations from the nominal temperatures and hence detects temperature data representing a transgression of the predefined temperature threshold TT.

The nominal temperature within the predefined spatial region 1 does not have to be homogenous, as different parts of the plant 100 will nominally have different temperatures. As the nominal temperature pattern can be stored in the control device 30, the deviation, and hence an exceeding of the temperature threshold TT, can be detected.

This excess beyond the temperature threshold TT would indicate a fire 11 within the predefined region 1 .

Once, the control device 30 detects a temperature exceeding the temperature threshold TT, it can activate a fire extinguishing device 41 , 42; here comprising two water cannons which can douse the predefined spatial region 1 . Alternatively, or in addition, a fire signal S such as a siren or an automated call to an external fire station can be activated by the control device 30 if the threshold condition is met. Some or all of those functions can be taken over by the control system 40.

The fire extinguishing device 41 , 42 can spray an extinguishing fluid, e.g. water or a water I foam mixture, onto the fire. In alternative embodiments, the extinguishing device 41 , 42 can use gas, e.g. carbon dioxide, to extinguish the fire 11 .

In the embodiment shown, the two extinguishing devices 41 , 42 each have an extinguishing area 51 , 52 covering a part of the predefined spatial region 1 ; the location of the detected fire 11 being covered by both extinguishing areas 51 , 52. The extinguishing areas 51 , 52 are only covering a part of the predefined spatial region 1 , i.e. the part in which the fire 11 is detected. The control device 30 or a supervisory control system 40 can decide, which of the existing extinguishing devices 41 , 42 should be activated. In the embodiment shown, a third extinguishing device 43 is not activated by the control device 30, as the other two extinguishing devices 41 , 42 are deemed to be better placed. The fire extinguishing devices 41 , 42 can be spatially adjusted to the thermal data obtained by the control device 30. If the measured thermal data indicates that the fire 11 is moving or spreading, the fire extinguishing devices 41 , 42 can e.g.be directed towards the parts of the region which requires the extinguishing fluid or the third fire extinguishing device 43 can be activated.

In Fig. 2, a variation of the embodiment described in Fig. 1 is shown, so that reference to the respective description can be made.

Other than in the first embodiment, here two fires 11 , 12 are detected by sensor devices 21 , 22, both being wirelessly connected to a control system 40 which here is positioned outside of the plant 100.

The angular range of the first sensor device 21 is a1 = 90°, the angular range of the second sensor device 22 is a2 = 90°.

The first fire 11 in the first predefined spatial region 1 is attacked by the first extinguishing device 41 (under control of the control system 40) which is spatially fixed relative to the first predefined spatial region 1 , as in the first embodiment.

The second fire 12 in the second predefined spatial region 2 is attacked by the second fire extinguishing device 42 (under control of the control system 40) but it is movable relative to the second predefined spatial region 2. The second fire extinguishing device 42, at the beginning of the extinguishing process (shown in Fig. 2), is not in the vicinity of the second fire 12. Due to the data obtained through the second sensor device 22, the control system 40 knows where the temperature threshold TT is exceeded most and it can direct the second fire extinguishing device 42 along e.g. a rail (see arrow in Fig. 2) towards a position best suited for attacking the second fire 12.

The control system 40 can also trigger an alarm A to an external site, e.g. the fire department, if the fires 11 , 12 cannot be contained within a certain time frame. The number of sensor devices 21 , 22 and I or fire extinguishing devices 41 , 42, 43 can be higher in other embodiments.

Fig. 3 shows a flowchart for one embodiment of a method for detecting and extinguishing fire in a predefined spatial region 1 , 2.

In a first step, the at least one sensor device 21 , 22 is monitoring 201 the temperature in the at least one predefined spatial region 1 , 2. The monitoring 201 comprises that each of the at least one sensor devices 21 , 22 are transmitting the measured temperature data T to the control device 30 (see Fig. 1 or 2).

In a second step, the control device 30 is detecting 202 at least one fire 11 , 12 after a temperature increase in the at least one predefined spatial region 1 , 2 is determined beyond the predefined temperature threshold TT. AS mentioned above in connection with the embodiments shown in Fig. 1 and 2, the temperature threshold TT can be determined by a deviation from a predetermined and stored temperature pattern (field) within the predefined spatial region 1 , 2. The temperature threshold Ty can also be a fixed predetermined temperature value.

In the third step, the control device 30 detects 203 at least one fire 11 , 12 by detecting a temperature T exceeding at least one predetermined temperature threshold TT and the control device 30 then emits a fire signal S. It also can activate at least one fire extinguishing device 41 , 42, 43 for the at least one predefined spatial region 1 , 2 in which the increased temperature was determined.

Then, in a fourth step, the at least one fire extinguishing device 41 , 42, 43 applies 204 fire extinguishing fluid over an extinguishing area 51 , 52 within the at least predefined spatial region 1 , 2. Since the control device 30 has identified the location of at least one fire 11 , 12, the extinguishing fluid can be applied in targeted way.

The embodiment shown in Fig. 3 shows some further optional steps. In a fifth step, the at least one fire 11 , 12 is treated 205 with water as an extinguishing fluid for a period of time, in particular 120 seconds. Depending on the effect of this treatment, the further steps are determined. In alternative embodiments, other extinguishing fluids can be used.

If the measured temperature T in the predetermined spatial region 1 , 2 is below the temperature threshold TT (step 206), the procedure can stop (step 207). This step 206 can comprise the condition that the measured temperature has to remain below the temperature threshold TT for a predetermined time.

If the measured temperature T in the predetermined spatial region 1 , 2 is above the temperature threshold TT, the same extinguishing step as e.g. in step 204 is repeated in step 208 or it is modified to reflect the persistent fire 11 , 12.

One possible modification is the use of a water - foam mixture (instead of using water only) for a period of time. For example, as a starting step, only water is used. If that does not have the desired effect, 1 % foam can be added and the extinguishing is repeated for a period of time (e.g. 5 min). Then, the control device 30 determines if the temperature in the predefined spatial region 1 , 2 is below the temperature threshold TT (i.e. a repetition of step 206). If not, the percentage of the foaming agent in the water can be increased in steps (e.g. 3%) and then the extinguishing is continued, until the measured temperature is below the temperature threshold value TT (e.g. for a predetermined time).

List of reference numbers

1 first spatial predefined region

2 second spatial predefined region

11 first fire

12 second fire

21 first sensor device

22 second sensor device

23 image of sensor device

24 sector within image

30 control device

40 control system

41 first fire extinguishing device

42 second fire extinguishing device

43 third fire extinguishing device

51 first extinguishing area

52 second extinguishing area

100 plant, e.g. a battery recycling plant a angle of sector of predefined spatial region in horizontal plane

A alarm to external site

S fire signal

T measured temperature (field)

TT temperature threshold (value)