FIRE SYSTEM

Abstract

A system includes a fire panel 12 having a loop driver. A combined detection and suppression loop 18 is connected to the loop driver. A plurality of fire detection devices 14 and a plurality of fire suppression devices 19 are coupled to the detection and suppression loop 18. The fire suppression devices 19 includes multiple sprinkler devices 19, each of the sprinkler devices 10 including a sprinkler bulb 100 and a circuit 120. The circuit 120 of the sprinkler device 10 is detectable via the fire panel 12 using the detection and suppression loop 18 in order to provide information from the sprinkler device 19 to the fire panel 12.

Claims

1. A combined fire suppression and detection system comprising: a fire panel having a loop driver; a combined detection and suppression loop connected to the loop driver of the fire panel; a plurality of fire detection devices that are coupled to the detection and suppression loop; and a plurality of fire suppression devices that are coupled to the detection and suppression loop; wherein the fire suppression devices comprise multiple sprinkler devices, each of the sprinkler devices comprising a sprinkler bulb and a circuit; and wherein the circuit of the sprinkler device is detectable via the fire panel using the detection and suppression loop in order to provide information from the sprinkler device to the fire panel.

2. A combined fire suppression and detection system as claimed in claim 1, wherein the information provided from the sprinkler device is information for identification of the sprinkler and/or the sprinkler type, information related to operating parameters such as pressure in a bulb of the sprinkler, information relating to the location of the sprinkler device, and/or information giving an indication that the sprinkler has (or has not) been activated.

3. A combined fire suppression and detection system as claimed in claim 1, wherein the circuit comprises a radio-frequency identification, RFID, tag.

4. A combined fire suppression and detection system as claimed in claim 1, wherein the circuit of the sprinkler device is a circuit device comprising electronic components for communication with the fire panel.

5. A combined fire suppression and detection system as claimed in claim 4, wherein the circuit device comprises a wireless module for receiving power, and the wireless module comprises an antenna.

6. A combined fire suppression and detection system as claimed in claim 5, wherein the wireless module is configured to receive signals, and the circuit device is controllable via signals received by the wireless module.

7. A combined fire suppression and detection system as claimed in claim 5, wherein the wireless module is for communicating with a base station of the sprinkler device.

8. A combined fire suppression and detection system as claimed in claim 5, wherein the wireless module comprises an inductor and a capacitor, and wherein the capacitor is capable of changing its capacitance in response to changes in ambient pressure.

9. A combined fire suppression and detection system as claimed in claim 1, wherein some or all of the fire detection devices and/or the fire suppression devices comprise a secondary communication system for communication in a degraded mode of operation that occurs in the event of a failure of the communications with the fire panel via the combined detection and suppression loop and loop driver, the secondary communication system comprising a transceiver arrangement at each of said some or all fire detection devices and/or fire suppression devices for providing a wireless network between said some or all fire detection devices and/or fire suppression devices and/or the fire panel.

10. A combined fire suppression and detection system as claimed in claim 9, wherein the wireless network comprises a wireless mesh network.

11. A marine vessel or a building comprising a fire detection and suppression system as claimed in claim 1.

12. A kit of parts for assembly into the fire detection and suppression system as claimed in claim 1, the kit of parts comprising at least: a fire panel having a loop driver; cabling and/or connectors for forming a combined detection and suppression loop for connection to the loop driver of the fire panel; a plurality of fire detection devices for coupling to the detection and suppression loop; and a plurality of fire suppression devices for coupling to the detection and suppression loop; wherein the fire suppression devices comprise multiple sprinkler devices, each of the sprinkler devices comprising a sprinkler bulb and a circuit; and wherein the circuit of the sprinkler device is detectable via the fire panel using the detection and suppression loop in order to provide information from the sprinkler device to the fire panel.

13. A method for providing and/or using a combined fire detection and suppression system as claimed in claim 1, the method comprising: providing a fire panel having a loop driver; providing a combined detection and suppression loop for connection to the loop driver of the fire panel; providing a plurality of fire detection devices for installation coupled to the detection and suppression loop; and providing a plurality of fire suppression devices for installation coupled to the detection and suppression loop; wherein the fire suppression devices comprise multiple sprinkler devices, each of the sprinkler devices comprising a sprinkler bulb and a circuit; and wherein the circuit of the sprinkler device is detectable via the fire panel using the detection and suppression loop in order to provide information from the sprinkler device to the fire panel.

14. A method as claimed in claim 13 comprising testing of the system in order to ensure that the fire detection and/or fire suppression devices are correctly installed and/or are working correctly by using the fire panel to obtain information from the circuits of the sprinkler devices in order to check that the sprinkler devices are correctly installed, that installed sprinkler devices are of the correct type and/or to identify sprinkler devices that have been tampered with or otherwise damaged.

15. A method as claimed in claim 13, comprising using the information provided from the sprinkler device to the fire panel to determine the location of a missing sprinkler device or a sprinkler device having a certain status.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Certain embodiments will now be described by way of example only and with reference to the accompanying drawings in which:

[0055] FIG. 1 is a diagram of a fire detection system comprising fire detection devices on a loop;

[0056] FIG. 2 shows a proposed combined fire detection and suppression system also including sprinkler devices on the same loop as the fire detection devices; and

[0057] FIG. 3 shows a similar system to FIG. 2 with an optional wireless network capability.

DETAILED DESCRIPTION

[0058] As seen in FIG. 1 a typical fire system includes a fire panel 12 in communication with multiple remote units 14, 15, 16 in the form of manual call points 14, alert devices 15 such as bells or lights, and smoke and/or fire alarms 16. The manual call points 14 (also known as trigger points) are a form of indicating device. The alert devices 15 are fire detection devices used for alerting users to the existence of an alarm condition. The smoke and/or fire alarms 16 can function as combined indicating and fire detection devices, having a detection capability along with an alarm, such as an audible alarm. The remote units 14, 15, 16 are joined to the fire panel 12 via a master-slave communication system 18, which can be a wired system for data communications as well as providing power to the remote units.

[0059] Various types of remote units 14, 15, 16 may be used in the system, as is known in the art, such as devices functioning with one or more capabilities found in manual call points; smoke detectors; heat detectors; other protected location sensors used for fire or heat detection, such as room thermostats; sensors for supervised doors; sensors for supervised fire extinguishers; water flow sensors; sirens; bells; lights; transmitter devices and so on. The system may include input-output modules for handling information from some types of indicating devices that may lie outside of the fire system, such as thermostats or water flow sensors. Additionally or alternatively input-output modules may be provided for activating automatic door opening and/or closure systems, or door locking systems. The remote units may also include fire suppression systems that can be triggered by the system.

[0060] In FIG. 2 the system is enhanced by the addition of sprinkler devices 19 19, which are “smart” sprinkler devices 19. Each sprinkler device 19 comprises a sprinkler bulb 100 having a sealed frangible housing 110 and a circuit device 120 disposed within the housing 110. The circuit device 120 is therefore sealed inside the housing 110. The housing 110 also contains a liquid as well as a gas bubble of a type known for heat activated sprinklers.

[0061] In use, the bulb 100 is located in a sprinkler device 19 and is positioned to hold a seal, plug or the like in place to prevent fire suppression fluid from leaving the sprinkler device 19. The sprinkler bulb 100 is arranged so that it prevents deployment of fire suppressant fluid unless it breaks. In the event of a fire near the sprinkler device 19, the liquid in the housing 110 will be heated and therefore pressure within the housing 110 will increase. Once the liquid reaches a predetermined temperature (e.g. indicative of being near a fire), the resulting pressure from the heated liquid and gas bubble will break the frangible housing 110 and the seal of the sprinkler device 19 will no longer be held in place. Fire suppression fluid will then be discharged from the sprinkler device 19. The housing 110 with its liquid and gas bubble can be configured so that the housing 110 will break under predetermined conditions e.g. when the liquid reaches a predetermined temperature, and hence when the housing 110 is exposed to a predetermined pressure thereby. The housing 110 may be formed of any suitable material, and may be formed of quartzoid.

[0062] The sprinkler bulb 100 of the sprinkler devices 19 comprises a circuit device 120 sealed within the housing 110, such as a passive circuit device 120. The circuit device 120 provides information to the fire panel 12, e.g. via the master-slave loop 18. The circuit device 120 in this example comprises a wireless module such as an LC circuit, comprising a capacitor and an inductor. The sprinkler device 19 also comprises a base station 200 arranged to wirelessly supply power to the circuit device 120 and monitor changes in a resonant frequency of the wireless module. The circuit device also comprises a heating element and a pair of Zener diodes arranged as a voltage dependent switch for controlling operation of the heating element.

[0063] The resonant frequency of the wireless module is determined by properties of the inductor and capacitor. The circuit device 120 therefore is responsive to signals over a certain bandwidth from an antenna of the base station 200.

[0064] The circuit device 120 is disposed within the housing 110. It is necessary for proper operation of the sprinkler bulb 100 that the housing 110 is sealed to prevent any and all leaks (e.g. to prevent ingress of any fluid into the housing 110, and/or prevent egress of any fluid out of the housing 110) otherwise the housing 110 may not break in the event of an emergency, as described above. The circuit device 120 is therefore sealed within the housing 110 and cannot simply be provided with external connections e.g. for power and/or communication.

[0065] The example base station 200 comprises a resonance tracking unit for detecting and tracking changes in a resonant frequency of the wireless module of the circuit device 120. It also comprises an antenna for emitting to, and receiving signal from, the wireless module. A power supply is provided to power to the base station 200, and also to power the passive circuit device 120 via interaction of the antenna and wireless module. A communication and integration module is provided to communicate with and integrate into a system architecture comprising e.g. the fire panel 12 and other sprinkler devices 19. A device controller is provided to control operation of the base station 200 and circuit device 120. The device controller may control operation of the sprinkler device 19 autonomously, or may control operation of the sprinkler device 19 under the control of a remote system controller arranged to control e.g. a plurality of sprinkler devices 19 and other devices on the loop 18.

[0066] As set out above, the circuit device 120 provides information to the fire panel 12 as well as optionally to other devices, e.g. outside of the system. The information may comprise an identification of the sprinkler device 19 to the fire panel 12, such as one or more of a unique ID, an indication of sprinkler type, an indication of a serial number of product identifier, or any other code or information provided by the manufacturer. In addition or alternatively the information may comprise an indication of the state of the sprinkler and/or a bulb of the sprinkler, for example pressure information as discussed in more detail below. It is also possible for the presence/absence of the circuit 120 to be used to provide information, i.e. to indicate the presence/absence of the sprinkler device 19 and/or of the sprinkler bulb 100.

[0067] If the housing 110 of the bulb 100 is damaged, for example by a crack, pressure increases in the liquid inside the housing 110 may be able to normalise with ambient pressure outside the housing 110. For example, liquid may leak out of the housing 110 and/or gas may leak into the housing 110. In that case, pressure within the housing may not reach the level needed to cause the housing 110 to break, and therefore the sprinkler device 19 may not be able to discharge fire suppressing fluid in the event of a fire. Thus, damage to or cracks in the housing 110 can jeopardize operational safety of the sprinkler device 19. Even micro-cracks—which may not be visible to an unaided human eye—can prevent proper functioning of the sprinkler blub 100.

[0068] Therefore, known methods of detecting cracks in sprinkler bulbs installed in sprinkler devices 19 in the field—which methods typically involve inspection of the bulbs by eye—may not be sufficient to ensure that a sprinkler device 19 is in working order, and hence may not ensure operational safety of a fire suppression system. Further, such methods are time intensive. Methods which do not involve inspecting bulbs by eye are also known, but are unsuitable for use outside laboratory or factory conditions and with bulbs installed on site, and are typically unsuitable for testing bulbs en mass. Given that sprinkler devices 19 are safety-critical, improvements in regard to testing are desirable.

[0069] Using the combined fire detection and suppression system described herein, the housing 110 of the bulb 100 may be tested for cracks using the circuit device 120. The device controller, which may be a part of the fire panel 12, is configured to control operation of the circuit device 120 in order to carry out such a test. Thus, pressure testing to identify damaged bulbs 100 can be done centrally from the fire panel 12, and this may conveniently occur during other tests of the detection devices 16 and so on. In the example arrangement, during a test the device controller (e.g., at the fire panel 12) instructs the antenna of the base station 200 to emit a signal which is received by the wireless module of the circuit device 120. The signal has an amplitude greater than a predetermined threshold and large enough to active the voltage switch provided by the two Zener diodes. The heating element is therefore activated and the liquid within the housing 110 is heated so that pressure inside the sprinkler bulb 100 increases. The resulting pressure increase in the liquid causes the capacitor of the circuit device to deform and hence changes its capacitance.

[0070] An example of a standard capacitor for use as the capacitor of the wireless module of the circuit device 120 will now be described. The capacitor comprises a plurality of conductive sheets (i.e. electrodes) separated by a predetermined distance using a dielectric material. An active area of the capacitor is defined by an overlap of the conductive sheets. If the capacitor is subjected to a change in pressure it will deform and the predetermined distance between the conductive sheets will change, thereby changing the capacitance of the capacitor. The greater the change in the predetermined distance, the greater the change in the capacitance. This relationship can be determined theoretically and/or empirically, and therefore the pressure within the housing 110 of the sprinkler bulb is known as a function of capacitance.

[0071] The resonant frequency of the LC circuit is a two-variable function of the inductance of the inductor and of the capacitance of the capacitor. However, the inductance of the inductor is substantially insensitive to changes in ambient pressure. As the pressure in the sprinkler bulb 100 increases and the capacitance of the capacitor changes, the resonant frequency of the LC circuit will change correspondingly. The greater the change in pressure, the greater the change in the capacitance and resulting change in the resonant frequency of the wireless module.

[0072] Therefore, by being arranged to monitor the resonant frequency of the wireless module, the base station 200 is thereby able to monitor the pressure of the liquid within the housing 110. The base station 200 measures the resonant frequency using the resonance tracking unit and the device controller correlates the resonant frequency with a pressure inside the sprinkler bulb 100. The device controller therefore determines pressure in the sprinkler bulb 100 via the wireless module.

[0073] The sprinkler device 19 may therefore measure pressure and/or monitor pressure changes within the housing of the sprinkler bulb 100 where the circuit device 120 is located. The sprinkler device 19 is then also able to test integrity of the sprinkler bulb 100 using the method set out above, and related information can be communicated back to the fire panel 12.

[0074] Thus, autonomous, reliable and remote testing of sprinkler bulbs 100 may be accomplished, and may be performed en mass. Bulbs 100 may be checked regularly by a central system, e.g. at the fire panel 12, and faulty bulbs 100 may be flagged for replacement. As set out elsewhere herein the fire panel 12 may also receive other information from the circuit device 120, such as the type of sprinkler and/or its location, amongst other options. The combined fire detection and suppression system therefore gives various advantages by incorporation of smart sprinklers 19 into a detection loop 18.

[0075] As shown in FIG. 3, a secondary communication system 20 can also be used for the combined fire detection and suppression system, and in this example the secondary communication system 20 is in the form of a Bluetooth mesh network. The secondary communication system 20 is overlaid on the primary communication network, as provided by the master-slave system via loop 18. This gives advantages including the ability to still operate and communicate in a degraded mode in the event of failure of the master-slave communications.

[0076] The secondary communication system 20 may also enable communications with an external device 22, such as via a smartphone 22 as shown in FIG. 3, or via some other kind of computer device. This allows for a user to access the secondary communication system 20 upon demand, as well as during the degraded mode. For example, via the smartphone 22 an authorised user may perform maintenance, inspection and/or installation operations, as well as monitoring alarm events and/or controlling the system. This may hence allow for the same testing and maintenance operations that are available via the fire panel 12 to be performed at any location where a device is present with a suitable transceiver, e.g. as may be incorporated within a smart sprinkler device 19.