Patent Application
20210228927
The present invention relates to a fire locator device, a fire fighting system and a method for operating the fire fighting system. The present invention applies particularly, without being limited, to the field of residential fire fighting.
A residential sprinkler according to the definition provided in UL 1626 is a sprinkler intended to be installed in residential occupancies and that opens automatically by operation of a heat-responsive releasing mechanism that maintains the discharge orifice closed. Upon operating at a specified temperature, a discharge of water is distributed in a specific pattern and quantity over a designated area. Standards for the installation of sprinklers are defined, for instance, in NFPA 13 R (Residential), NFPA 13 D (Domestic), and EN16925 (Domestic and Residential).
Residential sprinklers are thus actuated by heat and usually discharge fire fighting agent, in particular water, to regions of the protected room far away from the source of the fire, which leads to severe damage caused by water. Currently listed residential sprinklers may cover areas of 20×20 ft (6.1×6.1 m), which means that an even bigger area will be wetted after a sprinkler activation.
A long desire existed therefore to fight fire at specific locations, which correspond to the actual location of the fire or hazard instead of flooding the entire space of protection, for instance the residential room. Expressed differently, the desire existed to fight the fire without collateral damage occurring due to excess discharge to regions, which are not affected by, for instance, the fire. At the same time, the reliability of the system and therefore the safety of operation must not be compromised.
It has therefore been an object of the present invention to provide a fire locator device, a fire fighting system and a corresponding method for operating a fire fighting system, which reduces the risk of collateral damage while maintaining high operational safety and reliability. Further, it has been an object of the present invention to reduce the amount of discharged fire fighting fluid to a minimum.
According to a first aspect, a fire locator device is provided, comprising a) at least one housing configured to be mounted at a certain height within or in proximity of an area of operation, in particular at a wall or a ceiling of a room of a building, b) at least one sensor component, wherein each sensor component of the at least one sensor components comprises a plurality of sensor elements in a matrix arrangement sensitive at least to radiation, c) a self-test component for validating the operability of the at least one sensor component, and d) a controller configured to validate the operability of the at least one sensor component using the self-test component and to receive sensor signals from the plurality of sensor components for determining a location of a fire within the area of operation.
Since the fire locator device comprises a controller, which can both validate the operability of the sensor components and determine a location of a fire within the area of operation, for instance the room, the operational safety and reliability can be maintained, while a fire fighting system can selectively provide, for instance, fire fighting agent to the location of the fire identified by the fire locator device. In other words, it is nearly not possible that a failure of a sensor component of the fire locator device will not be detected for more than the time between two self-tests, which is preferentially adjustable and can be, for instance, 24 hours. This safety-mechanism would avoid that a potential fire is not being detected by the corresponding sensor component, since the self-test component is provided to validate the operability of each of the sensor components, respectively. The self-test component can be configured to validate the operability of all of the sensor components or a plurality of self-test components can be provided for each of the sensor components. Also combinations are feasible.
The radiation to which the sensor elements are sensitive preferably include ultraviolet radiation or thermal radiation, in particular infrared radiation. Where the following embodiments and preferred examples are exemplarily described with reference to infrared radiation, the same benefits and advantages can be achieved when sensors sensitive to other of the preferred ranges of wavelengths of radiation, such as ultraviolet radiation or thermal radiation in general, are employed.
The sensor elements of the sensor components can also be referred to as individual pixels. Further, the sensor elements of one or more sensor components can be referred to as being in an array-like arrangement. Expressed differently, an array of sensor elements can extend over one sensor component or over a plurality of individual sensor components.
In a preferred embodiment, the controller comprises a data storage for storing activity and historic events. Thus, in case of a fire, the cause of events can be reliably reconstructed. For instance, such data can be helpful for fire investigation to identify and track back the source of the fire.
The area of operation is preferably a room of a building, or a part of a room of a building, while in other embodiments also different areas of operation can be protected by the fire locator device. For instance, the fire locator device can also be employed in protecting an area of operation located outside a building, such as a public space or only partly covered structure. It is important that the fire locator device is mounted at a certain height and position, in order to monitor the predefined area of operation in such a way that sources of radiation can be localized within that space, i.e. radiation such as infrared radiation of the fire can be localized within this area of operation.
The fire locator device being mounted within or in proximity of the area of operation is understood as a location of the fire locator device, from which it is possible to observe the area of operation. Expressed differently, the proximity is limited by the capability of the sensor components to effectively monitor the area of operation. In the preferred example of a room, the fire locator device will generally be placed at a certain height of one of the walls which circumscribe the room.
In a preferred embodiment, the self-test component emits infrared radiation and in particular comprises at least one thermal radiation source such as a heating element, the thermal radiation source being arranged in proximity to at least one of the sensor elements, wherein the controller is configured to validate the operability of at least one of the sensor elements of the sensor components by evaluating a sensor signal response to a heating of the at least one heating element.
In a preferred embodiment, the at least one thermal radiation source is located outside a field of view of the at least one sensor component and configured to temporarily heat the at least one sensor component, in particular a housing of the at least one sensor component, such that, in case the sensor component is operable, the sensor signal response of the at least one sensor element to the temporal heating of the thermal radiation source is detectable.
In a different preferred embodiment, the thermal radiation source is located within the field of view of the at least one sensor component. By activating the thermal radiation source, i.e. infrared radiation is emitted by the thermal radiation source, to which the sensor component is sensitive. Thus, by activating the thermal radiation source of the self-test component, a sensor signal corresponding to the signal, which also triggers the sensor component in case of a fire is generated. Thus, it can be determined whether the respective sensor component is operational or not. More specifically, not even only a qualitative but also a quantitative determination of the sensor signal response can be evaluated by comparing an actual sensor signal response to an expected sensor signal response.
In a preferred embodiment, at least one of the thermal radiation sources comprises a resistive heating element. A resistive heating element is a simple and reliable example of a thermal radiation source, which can be heated by providing the resistive heating element with electrical current, for instance. By evaluating the power consumption of the resistive heating element, it is at the same time possible to validate the operability of the thermal radiation source. Thus, a two-layer security means, in which not only the operability of the sensor components but also of the self-test component itself can be validated, is provided.
In a preferred embodiment, the controller is further configured to determine the operability of the at least one sensor component and the intact connection between controller and sensor component by constantly observing a feasibility of the dataflow. In this embodiment, errors in the sensor component as a whole or the link between the sensor component and the controller can be determined in addition to erroneous individual sensor elements.
In a preferred embodiment, the controller is configured to determine the operability of a sensor element of the plurality of sensor elements, in particular of each of the sensor elements, by evaluating a sensor signal response to a direct or indirect effect of radiation from the corresponding thermal radiation source.
In a preferred embodiment, the controller is configured to effectuate a self-test of the sensor components using the self-test component on a recurrent, in particular periodic and most preferably daily, basis.
The probability for an erroneous sensor component to be timely detected can thus be increased. Of course it is also possible to have different and/or varying recurrence intervals.
In a preferred embodiment, the controller is configured to sequentially compare sensor signals from the plurality of sensor elements with a threshold value for determining a location of a fire within the area of operation, wherein the threshold value preferably includes an individual threshold value for each of the sensor elements, respectively.
Each sensor element will output a sensor signal, which is indicative of a magnitude of the incoming radiation, in particular the incoming infrared light. Thus, in case a fire is present at a location, which is “seen” by the respective sensor element, the signal must surpass the defined threshold value. Yet, the threshold has to be chosen sufficiently high, in order to decrease the probability of false alarms. Additionally, a double interlock setup with a fire detection device, in particular a smoke detector, will minimize the probability of false alarms in a preferred embodiment. That means an alarm will preferentially occur only if a sensor threshold is exceeded and the externally or internally connected fire detection device goes off.
Preferentially, each sensor element monitors a specific portion of the area of operation. Thus, there exists a correspondence between a physical portion of the area of operation and the respective sensor element. Based on this correspondence, individual thresholds for each sensor elements can be defined adequately.
In a preferred embodiment, the controller is configured to adjust the sensor signal of at least one sensor element, preferably by providing a threshold value for the signal value of the corresponding sensor element which exceeds the signal value due to hot objects in the area of operation in case a no-hazardous fire is present.
In a preferred embodiment, an individual threshold per sensor element will be used to set an appropriately high threshold to avoid false alarms due to fixed heat sources as e.g. stove, kettle, fireplace or radiators.
In a preferred embodiment, the controller is configured to additionally mask, i.e. deactivate or ignore/block the sensor signal of at least one sensor element. In a preferred embodiment, masking of sensor elements will alternatively or additionally to using individual thresholds be used to avoid false alarms due to fixed heat sources as e.g. stove, kettle, fireplace or radiators.
In a preferred embodiment, the controller is configured to determine malfunctions leading to a stop in operation, such as deadlocks, in the operability of the controller itself using a watchdog timer.
The watchdog timer is a well-known instrument to monitor operability of electronic components. In addition to the monitoring by the self-test component, the fire locator device according to this embodiment incorporates an additional layer of security, which increases overall safety of the operation of the fire locator device according to the invention.
In a preferred embodiment, the fire locator device further comprises at least one temperature sensor, preferably a thermistor, for determining a temperature signal representative of a temperature of the area of operation. For example, the temperature sensor can be located within, outside or in proximity of the housing. In other examples, the temperature sensor is provided together with the fire detection device, e.g. the smoke detector, or at a separate location independent from the location of the fire locator device and the fire detection device.
In this embodiment, the temperature sensor can advantageously be employed to guarantee a double interlock system in case the self-test component determines at least one of the sensor elements and/or sensor components inoperable. In case the temperature sensor indicates an increased temperature, for instance exceeding a predefined threshold, while at the same time, for instance, none of the sensor elements indicates the presence of a fire, the fire locator device can nevertheless realise the unusual situation and, for instance, trigger a fire alarm or the like. In this embodiment, it can be expected that the fire is present at the location of the area of operation corresponding to the inoperable sensor element or sensor component.
The threshold is preferentially selected to correspond to approximately 30K above the temperature expected in the area of operation. In one example, the threshold can be set to a value between 40° C. and 80° C., more preferably to between 55° C. and 75° C. and most preferably to a value between 65° C. and 70° C., such as 68° C. The threshold can also be set with respect to an average temperature measured in the area of operation in the past. For instance, the threshold can be set relative to an average temperature of the last hour, day, week, and the like. In particular, the average can correspond to a moving average, more preferably a weighted moving average. In other examples, the threshold can be predefined and substantially fixed for a particular area of operation.
Further preferentially, the fire fighting is triggered only in case the fire detection device, e.g. the smoke detector, indicates the presence of a fire, such that the double interlock system is ensured. In particular, the fire fighting is preferentially triggered with respect to the zone of the area of operation corresponding to the inoperable sensor element or sensor component. Thus, according to this embodiment, the fire locator device incorporates an additional layer of security, wherein a fire can also be detected and reacted to in case at least one of the other components is inoperable.
In a preferred embodiment, the number of sensor components is three and wherein the array of sensor elements of each sensor components comprises at least 4×4 pixels, in particular at least 8×8 pixels.
It is a finding of the inventors of the present invention that three sensor components comprising, in particular 8×8 pixels, with preferably at least a 60×60 degree field of view is a favourable trade-off between the number of sensor elements and the capability of reliably monitoring an area of operation formed by a standard room, wherein the resolution of the sensor elements is high enough to allow for an accurate positioning of the location of the fire. In other embodiments also sensor components comprising a field of view of at least 180 degrees are contemplated. In such embodiments, provision of a single sensor component can be sufficient to cover an entire area of operation, e.g. a room of a building.
In a preferred embodiment, the sensor components are positioned and oriented in the housing to completely cover a floor of the area of operation extending over 4.27 m×4.27 m, in particular over 5.3 m×4.3 m, when the fire locator device is mounted in a height of between 1.94 m and 2.74 m, in particular between 2.3 m and 2.5 m, wherein the height of the fire locator device is determined as the central position of the plurality of sensor components.
In a preferred embodiment, the controller is configured to determine the location of the fire by mapping at least one of the plurality of sensor elements to at least one zone of the area of operation, preferably to up to two zones out of at least five zones.
The mapping of the sensor elements to zones allows that a corresponding zone, which corresponds to the activated sensor element, is determined as the location of the fire. The correspondence of one sensor element to more than one zone is particularly useful for borders or edges of zones, i.e. regions where two zones border each other.
In a preferred embodiment, the controller is configured to activate a respective one of a plurality of stationary fire fighting devices associated with one of the zones of the area of operation for each of the zones determined as the location of the fire.
In a preferred embodiment, the fire locator device further comprising a power supply, the power supply comprising a mains power supply and optionally a fallback power supply, the fallback power supply preferably comprising a battery. Thus, operational safety can be maintained even in periods in which no mains power is available. The fallback power supply applies in particular for higher risk applications.
In a preferred embodiment, the sensor components are fixedly arranged at defined positions and orientations within the housing, wherein the positions and orientations are defined such that the field of view of the sensor elements of the sensor components is optimized to the geometry of the area of operation.
In a preferred embodiment, all of the sensor components are arranged in a substantially horizontal plane, wherein one of the sensor components is arranged closer to a front of the housing than the other sensor components.
In a preferred embodiment, the orientations of all sensor components are unique.
In a preferred embodiment, a field of view of each sensor component is rectangular, preferentially quadratic.
Preferentially, the field of view of each sensor component spans an opening angle of at least 45 degrees and in particular at least 60 degrees in a vertical and horizontal direction. Thus, the opening angle allows to cover the entire area of operation with a limited number of sensor components. However, the field of view of each sensor component is not limited to a certain minimum opening angle. Alternatively, a larger number of sensor components having smaller opening angles can be employed. A larger number of sensor components reduces the impact of a failure of an individual sensor component, such as the extension of a blind spot resulting therefrom.
In a preferred embodiment, the controller is configured to receive an input signal from an external fire detection device, in particular from a smoke detector.
The input signal from an external fire detection device can thus be used to form a double interlock security system. The double interlock system requires two events to occur before water or other fire fighting agent is released from the system. Thus, only in case the fire detection device, in particular the smoke detector, detects a fire and additionally, for instance, a fire is located by the fire locator according to the invention, fire fighting agent, such as water, is permitted to be released.
In a preferred embodiment, the controller is configured to receive an input signal from one or more internal and/or external temperature sensors, in particular from thermistors. The input signal from the temperature sensor, which is indicative of a temperature of the area of operation, can thus form a double interlock system together with the input signal from the external fire detection device in case at least one of the sensor components and/or the sensor elements is determined to be inoperable. In case an increased temperature is detected, for instance a temperature exceeding a predefined or definable threshold, and the fire detection device indicates the presence of a fire, the fire is determined to exist in a location corresponding to the inoperable sensor elements/sensor components and appropriate action can be taken. Thus, integrity of the system can be guaranteed even in a period until the inoperable components return to be operable, e.g. have been repaired or replaced.
In a preferred embodiment, at least one, preferably all, of the sensor components comprises an infrared sensing array forming the sensor elements.
In a preferred embodiment, the controller comprises a logging component, in particular including a memory, configured to store logging data regarding the fire locator device.
In a preferred embodiment, the controller comprises a network or communication interface, preferably a Wireless Local Area Network or Zigbee interface, to exchange information or store logging data with a centralized server, e.g. a fire alarm central or in a cloud.
In a preferred embodiment at least one of the sensor components comprises a thermopile array having an array of thermophile elements as sensor elements.
A thermopile array is a particularly beneficial selection for the sensor component due to its high reliability and affordable cost. Since the thermopile elements of the thermopile array generate a voltage proportional to the incurring radiation, in particular incurring infrared radiation, a very simple processing of the signal output of the thermopile elements is possible. Thus, overall complexity of the system is kept reasonable.
In a preferred embodiment the thermopile array comprises an array of 8×8 thermopile elements, wherein the number of the plurality of zones is less than the number of thermopile elements, wherein the number of the plurality of zones is in particular four to twenty-five, particularly preferred five including a centrally overlapping zone.
Of course, also higher or lower numbers of thermopile elements and/or zones are contemplated.
Even further, it is contemplated to provide two or more fire locator devices in one single room, wherein the two or more fire locator devices can operate cooperatively on the same area of operation or individually.
In a preferred embodiment the fire locator device comprises at least three thermopile arrays arranged adjacently to each other, each preferentially comprising an array of 8×8 thermopile elements. Thus, a larger angle of view, e.g. to monitor a larger room, can be achieved.
According to a second aspect, a fire fighting system for fighting a fire in an area of operation, in particular in a room of a building, is disclosed. The fire fighting system comprises the fire locator device according to the first aspect or a preferred embodiment thereof, and a plurality of stationary fire fighting devices, each associated with and configured to distribute fire fighting agent within a respective zone of the area of operation, wherein the controller of the fire locator device is configured to a) locate the zone of the area of operation having the fire by identifying those sensor elements of at least one of the sensor components, which sense radiation exceeding a predetermined threshold level, and to b) activate the at least one fire fighting device associated with the located zone.
The fire fighting system according to the invention thus employs the fire locator device according to the present invention to locate a fire in an area of operation, associate the location of the fire with a corresponding zone of the area of operation and then specifically activate the fire fighting device associated with the identified zone. As a result, only the located zone or zones of the plurality of zones of the area of operation is supplied with fire fighting agent, and thus potential damages are limited to the activated zone or zones.
It should be emphasized that the fire fighting system according to the second aspect can advantageously be combined with the preferred embodiments described above with respect to the fire locator device.
In a preferred embodiment, the system further comprises an external fire detection device, in particular a smoke detector, wherein the controller of the fire locator device is configured to activate the at least one fire fighting device associated with the located zone only in case the fire detection device detects a fire.
In a preferred embodiment the system further comprises at least one fire detection device, in particular at least one fire detection device selected from the list consisting of smoke detector, in particular optical beam smoke detector or aspiration smoke detector; flame detector, in particular infrared (IR) flame detector, ultraviolet (UV) flame detector or combined IR/UV flame detector; heat detector; gas detector; or multi-sensor-detector. The controller is configured to control the plurality of fire fighting devices to only provide fire fighting agent to the fire fighting area in case the fire detection device determines the fire.
The fire detection device can thus determine the presence or non-presence of a fire. The fire detection device not necessarily allows for any spatial resolution, i.e. does not need to be able to provide the location of the fire, while it is enough for the fire detection device to detect whether the fire is present or not. Thus, in this embodiment, the detection by the fire detection device presents a requirement for the controller, while the controllable fire fighting devices are only controlled to provide fire fighting agent in case the fire detection device detects the presence of the fire in the room.
In a preferred embodiment, the controller is configured to determine the operability of the sensor elements of the sensor components using the self-test component, and, in case at least one sensor element is determined to be inoperable, to activate the at least one fire fighting device associated with the zone corresponding to the inoperable sensor element in case a temperature signal indicative of a temperature from a temperature sensor, such as from a thermistor, exceeds a predefined threshold.
Advantageously, also in this situation, in which at least one sensor element is determined to be inoperable, the desired double interlock system can be maintained by relying on the signal of the temperature sensor and the fire detection device. Expressed differently, a reliable activation can be ensured even in case one or more of the sensor elements are inoperable. In this case, i.e. in case at least one sensor element is inoperable, the temperature signal can be considered a verification for the fire detection device, in particular the smoke detector, indicating presence of a fire. The location and zone of the fire is deemed to be the location corresponding to the inoperable sensor element. It should be noted that the same principle can be maintained by using any arbitrary combination of at least two independent fire detection devices.
Preferentially, the fire detection device and the sensor components both positively verify the presence of a fire, before a fire signal is triggered and the activation of a fire fighting device is triggered. In case at least one sensor component is inoperable, the temperature signal can replace the sensor components for verification of the fire detection signal by the fire detection device. In one example, in case it is possible to determine which of the sensor elements is inoperable, the activation of the zone corresponding to the inoperable sensor elements is initiated. Alternatively, or in case no location of the inoperative sensor element can be determined, all available zones associated exclusively with the inoperable sensor component can be activated.
Preferentially, by considering zones associated exclusively with the inoperable sensor component and not with any of the further sensor components. To this end, preferentially a redundancy is created by having overlapping coverage of zones by the different sensor components, such that it is particularly preferentially sufficient to activate at most two zones at the same time. Thus, a sufficient flow rate of fire fighting agent to the concurrently activated zones can be ensured.
Further, in case the fire detection device is inoperable, the temperature sensor can replace the fire detection device and act as a double interlock device for verifying the presence of a fire detected by at least one of the operable sensor components. In this configuration, a high reliability of the entire system is ensured, without requiring additional components for redundancy and the like. However, at the same time, in case at least one of the components of the system fails, it is preferred for a signal to be triggered, which indicates the requirement of maintenance as soon as possible.
In a preferred embodiment the controller is configured to associate each of the sensor elements of the sensor components to at least one of the zones so that at least two zones overlap. Since at least two zones overlap, a risk of insufficient coverage, particularly at the edges between two zones, can be reduced. Further, inaccuracies related to the definition of the zones have less impact.
In a preferred embodiment at least two adjacent zones out of the plurality of zones partially overlap at their edges, respectively.
Preferentially, in case adjacent zones overlap at their edges, a fire being determined in the overlapping portion of the adjacent zones can result in both of the adjacent zones being designated as the fire fighting area. It can thus be avoided that a fire being present at or near by an edge be insufficiently extinguished by activating both of the adjacent zones.
Further, even in case one of the stationary fire fighting devices does not have a completely uniform discharge pattern of fire fighting agent, e.g. a fluid flow is less near the edge of the zone covered by the respective fire fighting devices, as a sufficient fluid flow of fire fighting agent even for fires occurring at or near an edge of the respective zones can be guaranteed.
In a preferred embodiment at least one zone of the plurality of zones entirely overlaps one or more of the other zones of the plurality of zones. The zone entirely overlapping one or more of the other zones can be regarded a redundant zone, which is advantageous to activate in case the fire is detected far away from the centers of those zones, which are overlapped by the overlapping zone. It is thus not necessary to provide fighting agent to areas far away from the detected fire by adding the overlapping zone to the fire fighting area. Accordingly, a risk of damage due to excess fire fighting agent can be reduced.
In a preferred embodiment the floor of the zone is distributed among four adjacent zones of the plurality of zones. A fifth zone of the plurality of zones is located in a central area of the room, overlapping a portion of each of the first to fourth zone of the plurality of zones. In a further preferred embodiment, also at least part of the wall surface is additionally distributed among the zones.
In a preferred embodiment a surface area of each of the plurality of zones is approximately equal. Thus, assuming that a fluid flow through each of the stationary fire fighting devices covering the fire fighting area is approximately equal, also the fluid flow to each portion of the respective zones is approximately equal. Thus, a homogeneous fluid supply to each portion of the area of operation can be assured.
Preferentially, the surface area comprises a floor and a wall surface area. In some embodiments, the floor area can be given a higher weight, i.e. the calculation of the total area to be provided with fire fighting agent of each zone can be biased towards the floor area. Thus, for example, a need for more fluid flow to the floor surface as compared to the wall surface per surface area can be implemented.
In a preferred embodiment the grid of sensor elements of at least one of the sensor components defines a pixel matrix. The controller is configured to determine a transformation between the pixel matrix and the plurality of zones.
The transformation, which could also be referred to as a mapping between pixel matrix and plurality of zones, thus ascertains a correspondence between pixels of the pixel matrix defined by the sensor elements of the sensor components and the zones of the area of operation. The transformation can be determined by the controller using input from the user and/or relying on a predefined configuration. The predefined configuration can take, for instance, geometrical details of the area of operation, e.g. the covered room, into consideration.
In a preferred embodiment the controller is configured to determine the transformation under consideration of at least one of a spatial angular resolution of the sensor elements of the array sensor, a field of view of the array sensor and a location of the array sensor in the room. Thus, also a distance, angle and other distortion, which effect the field of view of the array sensor with respect to the room are considered.
According to a third aspect, a method of operating a fire locator device according to the first aspect or a fire fighting system according to the second aspect or a preferred embodiment thereof is disclosed. The method comprises a) validating an operability of the sensor elements of the sensor components by means of the self-testing component, b) determining a fire detection signal indicative of a fire, in particular from a fire detection device, preferably from a smoke detector, c) determining a sensor signal for each sensor element of the sensor components, and, d) determining an operation mode of the fire fighting device in response to the fire detection signal, the operability of the sensor elements and the sensor signals.
Preferentially, the method includes constantly validating the connection and operability of the sensor components, the connection to fire detection device, e.g. the smoke detector, and/or the operability of the temperature sensor, e.g. the thermistor.
The method achieves the same advantages as the fire locator device or the fire fighting system described above and can be advantageously adopted to and combined with any of the preferred embodiments described with reference to the fire fighting device above.
In a preferred embodiment, the method further comprises e) determining a temperature within the area of operation, in particular from at least one temperature sensor, preferably from a thermistor, wherein the operation mode of the fire fighting device is additionally determined in response to the temperature. In this embodiment, as described before, operability of the fire locator device or system can be maintained even in case a sensor component/sensor element or the external fire detection device is inoperative or erroneous.
In a preferred embodiment, a normal operation mode is determined in case the sensor elements are determined to be operable and at least one of the following conditions are fulfilled: the fire detection signal indicates no fire, and/or no sensor signal exceeds a predefined threshold, wherein the predefined threshold is preferentially predefined individually for each sensor element, respectively.
In a preferred embodiment, the fire locator device is configured to selectively activate at least one out of a plurality of stationary fire fighting devices in a normal activation mode, each of the stationary fire fighting devices associated with and configured to distribute fire fighting agent within a respective zone of the area of operation, wherein the controller locates the zone of the area of operation having the fire by identifying at least one hot spot formed by at least one sensor signal exceeding a predetermined threshold level.
In a preferred embodiment, a normal activation mode is determined as the operating mode in which the at least one fire fighting device associated with the located zone is activated in case all sensor elements are determined to be operable, at least one sensor signal exceeds a predefined threshold, wherein the predefined threshold is preferentially predefined individually for each sensor element, respectively, and the fire detection signal indicates the presence of a fire.
In a preferred embodiment, a maintenance warning mode is determined as the operation mode in case at least one of the sensor components or sensor elements is determined to be inoperable and/or a connection error is determined, the fire detection device or the temperature sensor is determined to be inoperable and/or a connection error is determined, and/or a malfunction leading to a stop in operation, such as a dead lock in the operability of the controller, is determined using a watchdog timer.
In a preferred embodiment, a first failure valve opening mode is determined as the operation mode in case at least one sensor element is determined to be inoperable, the fire detection signal indicates the presence of a fire and the temperature signal exceeds a predefined threshold. In the first valve opening mode, the fire fighting device is preferentially configured to selectively activate the stationary fire fighting device or devices corresponding to the zone or zones associated with the inoperable sensor element or elements.
In principle, it is thus required for the fire detection signal to indicate a fire and to further have at least one of the sensor signals exceeding a predefined threshold or the temperature within the housing exceeding a predefined threshold. Thus, in all cases, a double interlock system is guaranteed.
Further, in case of the first failure valve opening mode, the temperature signal is the second triggering activation signal in addition to the fire detection signal and thus replaces the sensor signal of the inoperable sensor elements or sensor components, which thus does not exceed a predefined threshold. However, the inoperable sensor elements can be allocated to respective zones, which allows for determining the zone or zones in which a fire can be present, i.e. a selective activation restricted to zones which are expected to have a fire is possible also in the first failure valve opening mode.
In the alternative, preferentially an activation can be carried out independent from the mode of activation and the association to respective zones in the first failure valve opening mode.
In a preferred embodiment, a second failure valve opening mode is determined as the operation mode in case the fire detection signal indicates no presence of a fire, the temperature signal exceeds a predefined threshold, and at least one of the sensor signals exceeds a predefined threshold, respectively. In the second failure valve opening mode, it is assumed that the fire detection signal is incorrect, for instance due to an inoperative fire detection device or a compromised connection between the fire detection device and the fire fighting device. Activation of one or more of the stationary fire fighting devices is then performed as in the normal activation mode.
Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings in greater detail.
Mainboard 92 further comprises a power interface 95, which is configured to be connected to a power supply 78, such as a mains connection. Further, a serial interface 96, such as an USB interface, designed to communicate with, for instance, a computer, is provided. Finally, a maintenance button 98 is provided, with which a maintenance mode can be activated, for instance.
Fire locator device 7 is further adapted to indicate its status using a status indicator 72, a maintenance indicator 74 and an acoustical indicator 76, for instance. The status indicator 72 and the maintenance indicator 74 can also be arranged in the same indicator, such as a single RGB-LED. Also other implementations are of course feasible. Acoustical indicator 76 can, for instance, indicate acoustically in case a fire is located by fire locator device 7.
Fire locator device 7 is configured to communicate with a fire detection device 6, such as a smoke detector, which is provided external to fire locator device 7. Most importantly, fire locator device 7 in general is only configured to activate one or more out of fire fighting devices 3a, 3b, 3c, 3d and/or 3e in case fire detection device 6 confirms the presence of a fire, for instance detects smoke. In one example, each of fire fighting devices 3a, 3b, 3c, 3d and/or 3e comprises a relais or different interface, which is configured to communicate with controller 9. Fire detection device 6 is communicating with controller 9 by means of a connection 62, which can be provided as a wire or wirelessly.
Each of the sensor components 5a, 5b and 5c comprises an array sensor 50 having a plurality of thermopile elements as sensor elements, a heating element 52 and an interface 54. Heating element 52 is part of self-test component and is configured to heat array sensor 50 in order to evaluate the sensor signal in response to the heating. In case at least one of the sensor elements of array sensor 50 is inoperable, a deviation of the expected signal response can be detected. Thus, it can reliably be detected that each of sensor component 5a, 5b, 5c is operating normally. The triggering of the self-testing of sensor component 5a, 5b and 5c is preferentially conducted or initiated by controller 9, while it can also automatically be initiated by a dedicated circuitry provided with each of sensor components 5a, 5b and 5c.
Preferentially, heating element 52 is provided at a suitable position touching the sensors case to optimally heat up the sensor component. In other examples, the heating element 52 is provided at a suitable position in front of array sensor 50 or a transition component is provided, which is capable of moving heating element 52 to its operating position in front of or in proximity of array sensor 50 in case the self-testing is performed. In either case it is advantages that heating element 52 does not obstruct portions of the feel of view of array sensor 50, which could lead to less accurate localization results. Interface 54 is configured to provide the sensor signals originating from array sensor 50 to controller 9 and can further be configured to communicate or initiate signals relating to operation of heating element 52, i.e. to the self-testing functionality.
In case at least one of the sensor elements of array sensor 50 indicates the presence of a fire, i.e. provides a signal value exceeding a predefined threshold, and, at the same time, fire detection device 6 indicates the presence of a fire, controller 9 is configured to open at least one of valve 32 connected to at least one of fire fighting devices 3a, 3b, 3c, 3d and/or 3e. Fire fighting devices 3a to 3e are not part of fire locator device 7 but are comprised in a system 1 for fire fighting, which will also be described with respect to the further figures. Expressed differently, the fire fighting devices 3a, 3b, 3c, 3d and 3e can be provided separate and distant from fire locator device 7, while it is of sole importance that controller 9 is capable of activating the respective fire fighting device 3a to 3e, if required.
In order to determine which of fire fighting devices 3a to 3e is to be activated by controller 9, a mapping between sensor elements of array sensors 50 and zones of the area of operation, which is monitored by fire locator device 7 is determined or provided. Further, each of fire fighting devices 3a to 3e is associated with one of these zones, respectively. An example of the determination of zones and the association with respective sensor elements will be described below with reference to, for instance,
Then, in a step S235, the double interlock is performed, in other words, it is determined whether the signal is a true fire. To this end, an output of fire detection device 6 is additionally considered. Only in case fire detection device 6 additionally indicates the present of a fire, step S240 is executed, leading to an activation of at least one of the fire fighting devices 3a to 3e. Thus, the fire fighting is initiated.
It should be noted that, while an entire room 101 is illustrated in
The system 1 comprises a number of fire fighting devices 3a, b which are installed for example under the ceiling 105 of the room 101, but could alternatively also be wall-mounted. The fire fighting devices 3a, b may for example be open fire fighting nozzles of a deluge system.
The system 1 further comprises a plurality of fire detection devices 6 installed in the room 101, for example under the ceiling 105 and/or on one of the side walls 103. While a plurality of fire detection devices 6 is illustrated in
The system 1 further comprises a fire locator device 7 that is configured to locate a fire F in the room 101. The fire detector devices 6 are configured to detect the presence of a fire in the room 101. The fire fighting devices 3a, b are each positioned such that they distribute fire fighting agent within a respective coverage zone 11a, b (hereinafter also “zone”) of the room 101. The zones 11a, b may overlap.
System 1 further comprises a controller 9 which is in signal communication with the fire fighting devices 3a, b with the fire detection devices 6 and with the fire locator device 7. The controller 9 is configured to activate the fire fighting devices 3a, b in reaction to a detection of the fire F as is detailed further herein below.
Each of the sensor components 5a, 5b, 5c of the fire locator device 7, which was described in detail with reference to
Preferably, the sensor array 15 is an infrared sensor array, in particular a thermopile array. The array sensor 50 is configured to generate for each pixel a signal representative for a temperature within the portion of the projection 13 in the room 101. The fire F will cause representative temperature signals to be generated by the array sensor 50. The controller 9 is configured to receive the representative temperature signals from the array sensor 50. Also, the controller 9 is configured to allocate specific threshold values T1, T2 to each pixel of the sensor array 15. There may be two or more different threshold values used across the array. According to the invention, it is possible to designate a threshold value that will be reached only in case of a fire, or not be reached at all, the latter being especially useful to permanently “blind” the array sensor from certain stationary hotspots that are indicative of non-hazardous fire related heat sources. More specifically, it is even possible to “blind” individual pixels of the sensor array 15 and thus keep the area, which is “excluded” to a minimum area around the stationary hot spots.
However, each threshold value may also be indicative of a temperature limit, the breach of which happens only in case of a fire in that specific portion of the room. As soon as the temperature in the pixels of the sensor array 15 exceeds the predetermined threshold levels T1, T2 indicative of a fire, the controller not only has identified the presence of a fire F in the room 101, but additionally has located the portion within the projection 13 (
Depending on whether the fire has been located in a zone that is overlapped by the zones 11a, b covered by a plurality of fire fighting devices 3a, b, the controller 9 may also activate more than one fire fighting device 3a, b, but ideally no more than two fire fighting devices 3a, b.
In many rooms, in particular residential rooms, it is to be expected that stationary heat sources such as heat source 107 are present in a portion monitored by the fire locator device 7. In order to prevent false fire alarms, and in order to prevent inaccurate location of actual fires due to the influence of stationary heat sources, the controller 9 is configured to assign specific threshold values T2 to all pixels which are within range of the stationary hot spot 109 formed by the stationary heat source 107. As is depicted in
This allows the controller 9 to distinguish between a fire F and a fire-unrelated or non-hazardous-fire heat source NF. Basically, any number of stationary heat sources may be accounted for in this way.
While the embodiments of
In
In this example, both the room and each of the respective zones 210a-210e are of quadratic shape for the ease of illustration, while of course also different examples of shapes are contemplated. The quadratic shape is particularly beneficial in combination with specific controllable nozzles as fire fighting devices, e.g. fire fighting device 3a-3e, such as a Viking Model A full cone nozzle or a similarly operating, publically available nozzle.
In the example of
Accordingly, in this example also the situation, in which more than two zones are comprised in the fire fighting area 220 is illustrated. The example of
It is of course contemplated that also in the example of
Overlapping regions 212a and 212b correspond to the region in which zone 210a overlaps zone 210b and vice versa. Accordingly, the fire fighting area 220 in case a fire F is detected in either region 212a or region 212b will be comprised of both zone 210a and 210b. Likewise, in overlapping regions 212c and 212d zones 210a and 210c will form the fire fighting area 220. A fire F in overlapping region 212e or 212f will yield a fire fighting area 220 with zones 210c and 210d, while a fire F in overlapping region 212g or 212h will result in fire fighting area 220 being formed of zones 210b and 210d.
Finally, in case a fire is present in the outer region of zone 210e, i.e. the region near the edge of zone 210e, which are indicated with 212i, 212j, 212k or 212l, the fire fighting area 220 is formed of zone 210e and one of zones 210a-210d, respectively. Thus, also in this example with overlapping regions, it can be ensured that not more than two zones will be comprised in the fire fighting area 220 at the same time.
It can be seen that the entire surface of the room 101 is imaged by at least one of the sensor components 5a, 5b, 5c, i.e. the fields of view 1420, 1430, 1440 completely fill the area of the room 101. In central areas 1450, the fields of view of different sensor components partially overlap.
Sensor elements corresponding to a region 1601 will not be mapped to any of zones 210a-210e, since they image an area outside the area of observation. Sensor elements corresponding to a region 1602 will be mapped to zone 210a, region 1603 will be mapped to zone 210c and the further sensor elements corresponding to a region 1604 will be mapped to one or more of zones 210b, 210d and 210e.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 101 687.5 | Jan 2020 | DE | national |
