A power generation and flow sensing apparatus for a fluid pipe

Abstract

A power generation and flow sensing apparatus for a fluid pipe, the apparatus comprising, a flow rotor configured to rotate in response to fluid flow within the pipe, a rotation rate detector configured to detect the rotation rate of the flow rotor and output a signal indicative thereof, a generator module comprising a rotator element and a stator element, wherein relative movement between the rotator element and stator element against electromagnetic resistance generates an output electrical current and a switching module configured to switch the apparatus between an active mode where the flow rotor is coupled to the generator module and a passive mode where the flow rotor is not coupled to the generator module.

Description

[0001] A POWER GENERATION AND FLOW SENSING APPARATUS FOR A FLUID PIPE

[0002] Technical Field of the Invention

[0003] The present invention relates to monitoring of fluid pipes. In particular, the invention relates to monitoring of the properties of fluid with a fluid pipe using a sensing fibre. The present invention further relates to an apparatus and a method for monitoring fluid flow and / or pressure in a fluid pipe as well as a network comprising one or more pipes monitored using the apparatus or the method of the present invention.

[0004] Background to the Invention

[0005] Many modem services rely upon a network of pipes to carry or distribute fluids. Examples include fresh water, wastewater and sewage, and fuels such as oil or gas. It is common to monitor the operation of the network and the condition of pipes. In this manner, blockages, leaks or other issues can be identified and scheduled for repair.

[0006] Fibre sensing is a technique that uses the changes in the optical properties of an optical fibre, or sensing fibre, to make measurements of the fibre’s environment, such as pressure, temperature, strain, and vibrations (acoustics). As optical fibres can be made relatively cheaply, they can be run over long distances and then used to make measurements at different points along their length. This makes them very useful for data collection activities where power or access is limited, such as along buried pipes or in remote areas. This can assist in the monitoring of pipe networks such as fresh water, wastewater and sewage, and fuels such as oil or gas. It is common to monitor the operation of the network and the condition of pipes. In this manner, blockages, leaks or other issues can be identified and scheduled for repair.

[0007] In order to make measurements, light pulses are coupled into a sensing fibre. The external environment and conditions of the sensing fibre affect backscattered light pulses generated as the light pulses travel through the sensing fibre. These backscattered pulses can then be detected and used to make a measurement of a property of interest at different points along the sensing fibre. There are a number of different techniques that can be employed such as distributed acoustic sensing (DAS) (or distributed vibration sensing (DVS)), distributed strain sensing (DSS) and distributed temperature sensing (DTS). This technique is also further described in WO2019 / 166809A1.

[0008] A current limitation of widespread monitoring systems is the cost of deployment of highly distributed sensors, so at present these are very dispersed and infrequently located, meaning the full realisation of the benefits cannot be achieved.

[0009] Another limitation is that backhaul of data on a real time basis is problematic, finite battery capacity means that sensor data is often only transmitted once per day (typically via radio, where power consumption is high), or if land lines are used this can be at very high operations (circuit rental) cost.

[0010] It is therefore an object of embodiments of the present invention to at least partially address the above issues.

[0011] Summary of the Invention

[0012] According to an aspect of the present invention, there is provided a power generation and flow sensing apparatus for a fluid pipe, the apparatus comprising: a) A flow rotor configured to rotate in response to fluid flow within the pipe; b) A rotation rate detector configured to detect the rotation rate of the flow rotor and output a signal indicative thereof; c) A generator module comprising a rotator element and a stator element, wherein relative movement between the rotator element and stator element against electromagnetic resistance generates an output electrical current; and d) A switching module configured to switch the apparatus between an active mode where the flow rotor is coupled to the generator module and a passive mode where the flow rotor is not coupled to the generator module.

[0013] Providing a power generation and flow sensing apparatus for a fluid pipe with these features allows a single flow rotor to function as both an output electrical current when coupled to the generator module and as a fluid flow velocity sensor element when decoupled from the generator module. Utilising the flow rotor as a fluid flow velocity sensor element when decoupled from the generator module may allow the flow rotor to rotate at a rate to give a more accurate representation of rotation rate due to the fluid flow velocity to the rotation rate detector.

[0014] The flow rotor may be a multipurpose rotor, provided as a part of a flow sensing apparatus to function as both a flow velocity sensor element associated with the fluid flow within the fluid pipe and having a secondary, power generation function.

[0015] The flow rotor may be mounted for rotation relative to at least one flow velocity sensor element, such as a sensing fibre which may function as the rotation rate detector and / or a tube within which the at least one flow velocity sensor element is mounted relative to the fluid pipe.

[0016] The apparatus may be switchable. A flow rotor coupled to a generator module to produce electrical current may increase the load on the flow rotor which in turn may decrease the accuracy of the rotor if used at the same time as part of a flow sensor apparatus, because the increased load on the rotor may adversely affect the relationship between the fluid flow velocity and the rotational speed of the rotor.

[0017] The flow rotor may be provided in a passive, sensing mode (decoupled from the generator) and be switched to an active, power generation mode by coupling to the generator for periods of time to generate power as required. The switching may preferably be automatic. The switching may be achieved by means of a clutch mechanism or by the disabling of electrical power generation.

[0018] When in the active mode, the rotation rate detector may be deactivated or alternatively may continue to operate, but with the signal identified as being during the active mode. Any fluid flow processing unit may be configured to process the detector output signal to extract a component of the detector output signal derived from the signal indicative of rotation rate of the flow rotor from the detector output signal when the apparatus is in the passive mode.

[0019] The generator module may only operate when the apparatus is in the active mode.

[0020] A controller may be provided (in situ or remote) to control the switching according to power required. The controller may switch the apparatus between the active mode and the passive mode according to usage. The controller may switch the apparatus between the active mode and the passive mode according to a duty cycle. The duty cycle may prioritize the active mode over the passive mode. This may mean that the apparatus provides fluid flow information for as long as possible in the active mode to generate electrical current before switching to the active mode and remains in the passive mode for the shortest time possible to measure flow. This can beneficially ensure that the generated electrical power matches or exceeds any power requirements of the present apparatus. Furthermore, intermittent flow sensing may suffice for many monitoring purposes.

[0021] For example, the controller may switch to the passive mode for less than 50% of operating time, less than 40% of operating time, or less than 30% of operating time or less than 20% of operating time or less than 10% of operating time or less than 5% of operating time or less than 2% of operating time.

[0022] The duty cycle may be varied by the controller as required, for example, if there is above normal power usage.

[0023] The generator module may provide the output electrical current directly to component(s) of the apparatus requiring power and / or to a storage device such as a battery. Providing excess electrical current to a storage device may allow the controller to reduce the active mode as the apparatus may be supplied with electrical power from the storage device. Additionally or alternatively, the storage device may be connected to one or more other sensors or devices for the purpose of providing power to said other sensors or devices.

[0024] The controller may be provided in an all-in-one configuration with the apparatus allowing for simpler installation of the apparatus relative to a fluid pipe.

[0025] The controller need not be located at the location of the apparatus and may be remotely located. A central controller may control more than one apparatus. A communication pathway may be provided between the apparatus and a controller which is remotely located.

[0026] The rotation rate detector may comprise at least one sensing fibre provided within the fluid pipe; a light emitter for introducing light pulses with particular characteristics into the at least one sensing fibre; a light detector module configured to detect backscattering of the light pulses from the at least one sensing fibre in multiple different sensing modes and output a detector output signal in response thereto; and a fluid flow processing unit configured to process the detector output signal to extract a component of the detector output signal derived from the signal indicative of rotation rate of the flow rotor from the detector output signal so as to monitor flow velocity.

[0027] The sensing fibre may be provided at least partially inside the pipe. This enables the sensing fibre to conveniently travel between sensing locations and a base module without needing to separately lay or otherwise install the sensing fibre.

[0028] In one form, the at least one flow rotor may be located in the fluid flow for rotation according to the fluid flow.

[0029] In another form, the at least one flow rotor may be associated with the fluid flow for rotation according to the fluid flow. In this form, the flow rotor may be located in a bypass configuration relative to the fluid flow within the fluid pipe in which a portion of the fluid flow is diverted outside the fluid pipe, through a housing within which the fluid rotor is located, causing rotation of the fluid rotor, before the fluid re-enters the fluid pipe.

[0030] In some embodiments, more than one flow rotor may be provided in a fluid pipe. In some such embodiments, a single sensing fibre may be provided for each flow rotor. In other embodiments, a single sensing fibre element may be provided for multiple flow rotors.

[0031] A flow rotor of any type configured to rotate according to fluid flow in the fluid pipe may be used.

[0032] The flow rotor may be mounted for rotation about an axis which is parallel to the direction of fluid flow in the fluid pipe or transverse to the direction of fluid flow in the fluid pipe. If the flow rotor may be mounted for rotation about an axis which is transverse to the direction of fluid flow the rotation axis may be substantially horizontal or substantially vertical.

[0033] A transverse (vertical or horizontal) rotation axis may be preferred as this may allow a larger surface area of rotor, especially where the flow rotor is installed through an access opening in a pipe. Such access openings are often located on an upper side of a pipe favouring a vertical transverse axis. In concert with lower flow velocities, for instance in water pipes, this may be advantageous as the diameter of a rotor / blade assembly may be limited to the diameter of an access opening in the pipe (where such may be in the range 100mm to 200mm), but the length or the rotor / blade assembly may be up to the internal diameter of the fluid pipe itself.

[0034] The flow rotor (regardless of the flow rotor type used) may have any number of rotor elements or blades.

[0035] The flow rotor may be formed from any suitable material including but not limited to metals such as stainless steel or polymers. Use of such commonly available materials can ensure the cost of the flow rotor is minimised. The rotor material or rotor blade thickness can be selected so that the flow rotor has a relatively low mass. This can assist start of rotation in a low flow velocity environment. The rotor blade length may be selected to be relatively long. This can assist start of rotation in a low flow velocity environment.

[0036] The flow rotor may be a Savonius type rotor. A Savonius type rotor may be mounted for rotation about an axis which is transverse (horizontal) to the direction of fluid flow in the fluid pipe but preferably is mounted for rotation about an axis which is transverse (vertical) to the direction of fluid flow in the fluid pipe. A Savonius type rotor may be a ‘push’ rotor in which the rotational velocity of the flow rotor is directly linked to fluid flow velocity.

[0037] A Savonius type rotor may not need in-field calibration since rotational velocity of such a rotor may match fluid flow velocity (in situations in which the rotor was not under any load).

[0038] A Savonius type rotor may offer benefits since a push rotor may operate at a lower start-up velocity compared with a lift rotor. Such a rotor may be used for instance in water pipes where flow velocities may be quite low (often in the range 0.2-lm / s).

[0039] The flow rotor may be a propeller or Darrieus type rotor. A Darrieus type rotor may be mounted for rotation about an axis which is which is parallel to the direction of fluid flow in the fluid pipe or mounted for rotation about an axis which is transverse (vertical) to the direction of fluid flow in the fluid pipe. A Darrieus type rotor may preferably be a ‘lift’ rotor in which the rotational velocity may be a multiple of the fluid flow velocity, based on a combination of blade dimensions / parameters and fluid density.

[0040] A Darrieus type rotor may potentially require calibration or temperature compensation (even where the flow rotor was not under any load) - temperature compensation may be achieved by monitoring using DTS from a remote analyser.

[0041] In another form, the rotor may be or comprise an Archimedes screw rotor or an articulated Archimedes screw rotor with at least two Archimedes screw portions articulated relative to one another.

[0042] The rotation rate detector may comprise a static component, wherein interaction between the flow rotor and the static component generates a signal indicative of the rotation rate of the flow rotor in the form of one or more characteristic acoustic events.

[0043] The one or more characteristic acoustic events may be detected by the sensing fibre.

[0044] The interaction between the flow rotor and the static component may occur at a particular rotor orientation. The interaction between the flow rotor and the static component may generate the one or more characteristic acoustic events only when the flow rotor is rotating. For example, the interaction may only occur once the flow rotor is rotating at a substantially steady state in the fluid flow and not for example, at startup.

[0045] The static component may be or may project from a mount upon which the flow rotor is provided. In suitable embodiments, the static component may be a tube through which the at least one sensing fibre and / or sensing cable may enter or exit the fluid pipe.

[0046] The interaction between the flow rotor and the static component may be direct or may be indirect.

[0047] The detector output signal may comprise multiple channels, each channel corresponding to a particular location along the sensing fibre. Each channel may be defined by reference to the round-trip time for backscattered pulses from the particular location. Neighbouring channels may be defined by the minimum resolvable time interval between backscattered pulses from neighbouring sensing fibre locations. Accordingly, each flow velocity sensor element location can correspond to a particular channel within the detector output signal. In such embodiments, the fluid flow processing unit may be configured to extract the component of the detector output signal derived from said characteristic acoustic events by reference to a particular channel within the detector output signal. The referenced channel may correspond to the location of a particular flow velocity sensor element along the length of the sensing fibre. Accordingly, if the location of each flow velocity sensor element along the length of the sensing fibre is known the component of the detector output signal derived from said characteristic acoustic events can be extracted by reference to the corresponding channel within the detector output signal. In embodiments with multiple flow velocity sensor elements, there may be multiple referenced channels. In such cases, each channel may correspond to the location of a flow velocity sensor element.

[0048] The fluid flow processing unit may be configured to identify the signal indicative of the rotation rate of the flow rotor within the extracted component of the detector output signal. As the signal indicative of the rotation rate of the flow rotor may be the characteristic acoustic events, this may be achieved by filtering the extracted component to an acoustic frequency range corresponding to the characteristic acoustic events.

[0049] The fluid flow processing unit may be configured to calculate a fluid flow velocity from the identified the characteristic acoustic events. This may be achieved by determining the repetition rate of the characteristic acoustic events. This may further involve applying a conversion factor or series of conversion factors to the determined repetition rate to thereby calculate the fluid flow velocity. Accordingly, suitable analysis of the sensing fibre can enable calculation of a flow velocity in the fluid pipe at the sensor location, without requiring a local power source for the flow velocity sensor element.

[0050] The sensing apparatus may further comprise a base module comprising the light emitter and the light detector. The base module may comprise a coupling assembly configured to remotely couple light pulses into the sensing fibre and backscattered light pulses out of the sensing fibre. The sensing apparatus may comprise an analyser to analyse the detector output signal. In some embodiments, the analyser may be provided within the base module. In other embodiments, the analyser may be located remotely from the base module. The analyser may interrogate a specific location of the sensing apparatus. The fluid flow processing unit may be integrated into the analyser or may be provided separately to the analyser.

[0051] The at least one sensing fibre may be provided as a part of a sensing cable extending with or within the fluid pipe.

[0052] The sensing arrangement may comprise a tube through which the at least one sensing fibre and / or sensing cable may enter or exit the fluid pipe. Such a tube may be mounted relative to a fluid pipe or pipe fitting, as described below.

[0053] The tube be mounted relative to the fluid pipe and / or pipe fitting via an isolation valve. The isolation valve may be configured to selectively fluidly isolate the tube and / or at least one sensing fibre and / or sensing cable from the fluid pipe. The isolation valve may comprise any type of suitable valve such as a ball valve, gate valve, plug valve, butterfly valve or the like. Thus, the isolation valve can allow easy connection and disconnection of the tube and / or at least one sensing fibre and / or sensing cable from the fluid pipe as needed, such as for maintenance or if it is no longer required.

[0054] The isolation valve may be provided on a section of the tube configured to, and / or intended to, remain outside the fluid pipe. The isolation valve may be provided outside the fluid pipe. This ensures that the isolation valve remains easily accessible.

[0055] The tube may comprise an opening at one end in fluid communication with the fluid pipe. The tube may extend into the fluid pipe to be monitored. The opening may be provided inside the fluid pipe to be monitored. The isolation valve may be provided between the opening and the sensing element. Thus, the tube is conveniently in communication with the fluid inside the fluid pipe.

[0056] The tube may be configured to connect to an access valve provided on the pipe to be monitored. The access valve may be configured to position the tube within the fluid pipe. The access valve may be configured to selectively fluidly isolate the tube from the fluid flow within the pipe. The access valve may comprise any suitable valve, for example as described in relation to the isolation valve.

[0057] The fluid pipe may comprise an access tube extending from the inside of the pipe to the access valve. In such embodiments, the tube may, or may not, comprise an isolation valve.

[0058] In an embodiment, the tube may extend into the fluid pipe transversely. The tube may extend to position the opening at the in-pipe end adjacent to but spaced from the pipe invert, which is the fluid pipe wall opposite to the entry end of the tube. This may assist with locating or positioning the at least one sensing fibre and / or sensing cable substantially parallel to the pipe invert. The at least one sensing fibre and / or sensing cable may abut the pipe invert.

[0059] The tube may function as a mount for the at least one flow velocity sensor element. A separate mount for the at least one flow velocity sensor element may however be provided.

[0060] The sensing apparatus may be provided relative to a pipe fitting provided on the fluid pipe, through which a sensing cable may enter or exit the fluid pipe. The pipe fitting may be configured to support the sensing fibre and or the tube. The pipe fitting may be configured to be fitted to the pipe. Thus, the pipe fitting provides convenient attachment of the sensing fibre to the fluid pipe.

[0061] The pipe fitting may provide an entry / exit point on the fluid pipe for the sensing fibre. The pipe fitting may provide an entry / exit point on the fluid pipe for the tube of the sensor. The pipe fitting may provide entry / exit points on the fluid pipe for the sensing fibre and the tubes of two sensors, each sensor associated with one of the two sensing locations. Thus, the pipe fitting enables simple and efficient connection to the inside of the pipe. The entry / exit points may be standard access openings on the fluid pipe or may be dedicated openings formed for mounting the sensing fibre and / or the tube of the sensor.

[0062] The pipe fitting may comprise a semi-rigid tubular arrangement configured to be inserted into the fluid pipe. The tubular arrangement may be configured to resist a fluid flow within the pipe. The sensing fibre may be provided inside the tubular arrangement. The tubular arrangement may be configured to control placement of the sensing fibre within the fluid pipe. Thus, the sensing fibre position in the pipe is better controlled.

[0063] In other embodiments, the pipe to be monitored may provide entry / exit points and / or tubular arrangements as described above. The pipe fitting may be configured to mount the sensing fibre and one or more sensing locations (e.g. two sensing locations) to an outside of the pipe to be monitored. Thus, the pipe fitting can be simply and easily mountable to the pipe.

[0064] In another embodiment, the rotation rate detector may comprise a non-contact detector arrangement which may include light reflection by means of an LED or laser source, or by means of an ultrasonic sonar system, with the light or sonar signal powered by electrical current generated by the generator module. In other embodiments, the rotation rate detector may comprise a semiconductor or similar magnetic field detector such as a Hall Effect sensor, or the like.

[0065] In some embodiments, the rotation rate detector may comprise a voltage meter for detecting voltage generated by rotor rotation on the unloaded generator module in the passive mode. Such a voltage developed would be directly proportional to rotational velocity of the rotor. In particular embodiments, the voltage meter may be a high impedance / high resistance voltage meter. In such cases, if the impedance / resistance is sufficiently high (e.g. > l Okohm) to prevent significant current flow in the generator, then there would be substantially no slowing of rotation rate due to power generation. Accordingly, the generated voltage would be directly related to the free rotation rate of the rotor and hence the fluid flow rate.

[0066] An acoustic event generator may be provided, associated with the at least one sensing fibre. The acoustic event generator may be a vibration unit, vibrator, sounder or the like.

[0067] The acoustic event generator may be configured to output characteristic acoustic events at a rate indicative of the fluid flow rate determined by a non-contact detector. These characteristic acoustic events can then be detected, extracted and / or processed using the sensing fibre in a corresponding manner to direct interactions. In other embodiments, an acoustic event generator may be configured to output acoustic signals whereby the acoustic frequency of the acoustic signals is indicative of non-contact detector output signals. Typically, such acoustic signals may be in a range of between 100Hz to 1kHz. Where a voltage meter is provided, the acoustic signals may be generated in response to a voltage controller oscillator connected to the voltage meter. This can thereby directly scale the voltage meter output to an acoustic frequency output.

[0068] In other embodiments, the acoustic event generator may be configured to output acoustic signals indicative of non-contact detector output signals. Such acoustic signals can be detected and extracted using the sensing fibre as described above. Subsequently, the acoustic signals may be decoded to recreate the non-contact detector output signals. This can thereby facilitate the non-contact detector output signals being transmitted over the sensing fibre for processing at a remote location.

[0069] With the provision of a generator module to produce output electrical current, this allows one or more secondary sensors which utilise electrical current to operate. Any type of secondary sensor may be provided. The secondary sensor may have any suitable configuration to sense a property to be measured. For example, a fluid flow speed, fluid flow direction, fluid temperature and / or fluid pressure sensor could be provided. The secondary sensor may be associated with an acoustic event generator to associate with the at least one sensing fibre. The fluid flow processing unit may be configured to process the detector output signal to extract a component of the detector output signal derived from any one or more secondary sensor from the detector output signal so as to monitor a desired property of the fluid in the fluid pipe.

[0070] The output of any secondary sensor may be monitored outside of the fluid pipe.

[0071] The output of any secondary sensor may be converted into a sensor output such as a suitable pulsed frequency. Such a pulsed frequency may be preferentially in the range 250Hz to 2kHz.

[0072] A secondary sensor may be a low power electronic based differential pressure monitor to derive flow velocity from dynamic pressure at an upstream pitot port and a standing fluid pressure at the downstream pitot pressure port in a bypass configuration. An electronics assembly may take flow readings from the sensor and transmit a representative acoustic signal into the pipe and / or sensor cable and / or sensing fibre via a vibrator or similar.

[0073] A secondary sensor may be a fibre strain based differential pressure monitor which may derive flow velocity from a dynamic pressure at an upstream pitot port and a standing fluid pressure at a downstream pitot pressure port in a bypass configuration. A length of fibre suitable to exceed one gauge length from a DSS analyser parameters (for instance in the range 20m to 50m) could be used to separate the upstream and downstream fibre sensors such that strain reading could be correctly determined by an analyser. The length of fibre may be prepared in a coiled format.

[0074] A bypass configuration may be provided with an upstream conduit extending into the fluid flow and a downstream conduit extending into the fluid flow. The upstream conduit extending into the fluid flow preferably has a fluid entry oriented toward the fluid flow. The downstream conduit extending into the fluid flow preferably has a fluid exit oriented in the direction of the fluid flow, or alternatively may take the form of a traditional static pressure tube. An upper end of the upstream conduit and the downstream conduit may be within the fluid pipe, but preferably extend outside the fluid pipe. A housing or chamber may be provided to fluidly connect the upper ends of the upstream conduit and the downstream conduit. One or more sensors may be provided in the housing or chamber. In one form, an upstream sensor and a downstream sensor are provided.

[0075] Any one or more sensors may be powered up and down as required. This may allow a reduction in overall power consumption but still provide quasi real-time sensor readings. However, the provision of a flow rotor or similar to generate electrical current based on fluid flow, may allow any secondary sensing apparatus to operate at all times, providing true real-time sensor readings.

[0076] The fluid pipe in which the sensing arrangement is provided may be a single unbranched length of pipe. In such embodiments, the sensing fibre may run along the pipe from one end to the other. In other such embodiments the sensing cable may run in a loop from one end of the pipe to be monitored to the other end and back again. The fluid pipe in which the sensing arrangement is provided may comprise a branched network of pipes or part of a branched network of pipes. In such embodiments the sensing cable may run in a loop from an entry point to the far end of each branch in turn.

[0077] The branched network may be any suitable branched network of fluid pipes. In one example, the branched network is a district metered area of a water supply network.

[0078] In some embodiments, a sensing arrangement may be adapted to monitor multiple pipes under test. In such embodiments, each pipe to be monitored may be a single unbranched length of pipe or each pipe to be monitored may be branched network of pipes or part of a branched network of pipes. In further such embodiments, some pipes to be monitored may be single unbranched lengths of pipe and other pipes to be monitored may be branched networks of pipes or parts of branched networks of pipes.

[0079] In an aspect of the present invention there is provided a method for power generation and flow sensing in a fluid pipe utilising a flow rotor configured to rotate in response to fluid flow within the pipe, a rotation rate detector configured to detect the rotation rate of the flow rotor and output a signal indicative thereof and a generator module comprising a rotator element and a stator element, wherein relative movement between the rotator element and stator element against electromagnetic resistance generates an output electrical current; the method comprising the steps of:

[0080] Operating the apparatus in a passive mode where the flow rotor is not coupled to the generator module; and

[0081] Switching the apparatus to active mode where the flow rotor is coupled to the generator module according to a duty cycle.

[0082] The method may further comprise the steps of: providing a sensing fibre within the fluid pipe to be monitored; introducing light pulses generated by a light emitter into the sensing fibre; and when in the passive mode, detecting backscattered light pulse from the sensing fibre with a light detector configured to output a detector output signal corresponding to the detected backscattered light; and extracting a component of the detector output signal derived from said signal indicative of the rotation rate of the flow rotor so as to monitor flow velocity in the fluid pipe.

[0083] The detector output signal may comprise multiple channels, each channel corresponding to a particular location along the sensing fibre. Each channel may be defined by reference to the round-trip time for backscattered pulses from the particular location. Neighbouring channels may be defined by the minimum resolvable time interval between backscattered pulses from neighbouring sensing fibre locations. Accordingly, each flow rotor location can correspond to a particular channel within the detector output signal. In such embodiments, the component of the detector output signal derived from said signal indicative of the rotation rate of the flow rotor can be extracted by reference to a particular channel within the detector output signal. The referenced channel may correspond to the location of a particular flow rotor along the length of the sensing fibre. In embodiments with multiple flow rotors, there may be multiple referenced channels. In such cases, each channel may correspond to the location of a flow rotor.

[0084] The method may comprise the step of identifying the signal indicative of the rotation rate of the flow rotor within the extracted component of the detector output signal. As mentioned above, the signal may comprise characteristic acoustic events. This may be achieved by filtering the extracted component to an acoustic frequency range corresponding to the characteristic acoustic events.

[0085] The method may comprise the step of calculating a fluid flow velocity from the identified the signal and / or characteristic acoustic events. This may be achieved by determining the repetition rate of the characteristic acoustic events. This may further involve applying a conversion factor or series of conversion factors to the determined repetition rate to thereby calculate the fluid flow velocity. Accordingly, suitable analysis of the sensing fibre can enable calculation of a fluid flow velocity in the fluid pipe at the flow rotor location, without requiring a local power source for the flow rotor. However, when the apparatus is in the active mode, electrical current may be produced for sensing or for other purposes

[0086] In another aspect of the present invention, there is provided a fluid distribution system comprising one or more fluid pipes and at least one power generation and flow sensing apparatus according to the present invention provided at one or more points within the fluid distribution system; and a system controller wherein each power generation and flow sensing apparatus is connected to the system controller.

[0087] In this manner, the system controller can monitor fluid flow at multiple points within a fluid distribution system.

[0088] The skilled person will appreciate that except where mutually exclusive, a feature described in relation to any one of the aspects, methods, examples or embodiments described herein may be applied to any other method, aspect, example, embodiment or feature. Further, the description of any aspect, method, example or feature may form part of or the entirety of an embodiment of the invention as defined by the claims. Any of the examples described herein may be an example which embodies the invention defined by the claims and thus an embodiment of the invention.

[0089] Detailed Description of the Invention

[0090] In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0091] Figure 1A is a schematic side elevation view of a pipe with a rotor therein according to an embodiment.

[0092] Figure IB is a top view of the configuration illustrated in Figure 1A.

[0093] Figure 2A is a schematic side elevation view of a pipe with a rotor therein according to an embodiment.

[0094] Figure 2B is a top view of the configuration illustrated in Figure 2A.

[0095] Figure 3A is a schematic side elevation view of a pipe with a rotor therein according to an embodiment.

[0096] Figure 3B is a top view of the configuration illustrated in Figure 3A. Figure 4A is a schematic side elevation view of a pipe with a rotor therein according to an embodiment.

[0097] Figure 4B is a top view of the configuration illustrated in Figure 4A.

[0098] Figure 5 is a schematic side elevation view of a pipe with a magnetic sensor arrangement and an active mechanism to deliver acoustic energy to a cable or fibre according to an embodiment.

[0099] Figure 5A is a schematic side elevation view of the active mechanism illustrated in Figure 5 as ‘A’ in a first embodiment.

[0100] Figure 5B is a schematic side elevation view of the active mechanism illustrated in Figure 5 as ‘A’ in a second embodiment.

[0101] Figure 6 is a schematic side elevation view of a pipe with a magnetic sensor arrangement and an active mechanism to deliver acoustic energy to the fluid pipe according to an embodiment.

[0102] Figure 6A is a schematic side elevation view of the active mechanism illustrated in Figure 6 as ‘B’ in a first embodiment.

[0103] Figure 6B is a schematic side elevation view of the active mechanism illustrated in Figure 6 as ‘B’ in a second embodiment.

[0104] Figure 7 is a schematic side elevation view of a pipe with a sensor arrangement and an active mechanism to deliver acoustic energy to a cable or fibre according to an embodiment.

[0105] Figure 7A is a schematic side elevation view of the active mechanism illustrated in Figure 7 as ‘C’ in a first embodiment.

[0106] Figure 7B is a schematic side elevation view of the active mechanism illustrated in Figure 7 as ‘C’ in a second embodiment.

[0107] Figure 8 is a schematic side elevation view of a pipe with a sensor arrangement and an active mechanism to deliver acoustic energy to the fluid pipe according to an embodiment. Figure 8A is a schematic side elevation view of the active mechanism illustrated in Figure 8 as ‘D’ in a first embodiment.

[0108] Figure 8B is a schematic side elevation view of the active mechanism illustrated in Figure 8 as ‘D’ in a second embodiment.

[0109] Figure 9 is a schematic side elevation view of a pipe with a sensor arrangement in a bypass configuration and with an active mechanism to deliver acoustic energy to a cable or fibre.

[0110] Figure 10 is a detailed view of the sensor and active mechanism as shown in Figure

[0111] 9.

[0112] Figure 11 is a schematic side elevation view of a pipe with a sensor arrangement in a bypass configuration and with an active mechanism to deliver acoustic energy to a cable or fibre.

[0113] Figure 12 is a detailed view of the sensor and active mechanism as shown in Figure

[0114] 11.

[0115] Figure 13 is a schematic side elevation view of a pipe with a sensor arrangement in a first bypass configuration.

[0116] Figure 13A is an end view from an upstream end of the configuration shown in Figure 13.

[0117] Figure 13B is an end view from an upstream end of the configuration shown in Figure 13.

[0118] Figure 14 is a schematic side elevation view of a pipe with a sensor arrangement in a second bypass configuration.

[0119] Figure 14A is an end view from an upstream end of the configuration shown in Figure 14.

[0120] Figure 14B is an end view from an upstream end of the configuration shown in Figure 14.

[0121] Figure 15 is a schematic side elevation view of a pipe with a sensor arrangement in a further bypass configuration. Figure 15A is a detailed view of the sensor as shown in Figure 15 with loop of fibre to increase gauge length.

[0122] Figure 16 is a schematic side view of a fluid pipe with continuous fibre length according to an embodiment.

[0123] Figure 17 is a schematic block diagram of a sensing apparatus for monitoring the condition of a fluid pipe as used in the present invention.

[0124] Figure 18 a schematic block diagram of a processing arrangement, according to the prior art, for the sensing apparatus of figure 17.

[0125] Figure 19 is a schematic side elevation view of a pipe with a sensor arrangement in a further bypass configuration.

[0126] Figure 20 is a detailed view of the sensor arrangement as shown in Figure 19.

[0127] Figure 21 is a schematic block diagram of the control architecture of for switching the flow rotor between active and passive modes.

[0128] Figure 22 is a schematic side elevation view of a pipe with a sensor arrangement showing a trace of the characteristic acoustic signals.

[0129] Figure 23 is a schematic diagram of a switching module arrangement according to an embodiment.

[0130] Many examples of sensing arrangements are illustrated in the accompanying Figures.

[0131] Figures 1A to 4B show variations of rotor configurations which may be used in different embodiments. The rotors shown in these Figures are mounted within a fluid pipe 2, relative to a pipe access port 1 which in the illustrated embodiments, includes a flange.

[0132] Figures 1A to 2B show a side view and a top view of a Savonius type rotor 3. A Savonius type rotor may be mounted for rotation about an axis 4a which is transverse (horizontal) to the direction of fluid flow 6 in the fluid pipe 6 as shown in Figure 1A and IB, or mounted for rotation about an axis 4b which is transverse (vertical) to the direction of fluid flow 6 in the fluid pipe 2as shown in Figures 2 A and 2B. A Savonius type rotor is considered to be a ‘push’ rotor in which the rotational velocity of the rotor in the direction 5 is directly linked to fluid flow velocity.

[0133] A Savonius type rotor 3 may offer benefits since a push rotor may operate at a lower start-up velocity compared with a lift rotor. Such a push rotor may be used for instance in water pipes where flow velocities may be quite low (often in the range 0.2- Im / s).

[0134] The rotor may be a propeller or Darrieus type rotor such as the examples illustrated in Figures 3 A to 4B. A Darrieus type rotor may be mounted for rotation about an axis 7 which is parallel to the direction of fluid flow 6 in the fluid pipe 2 or mounted for rotation about an axis 9 which is transverse to the direction of fluid flow 6 in the fluid pipe 2. A Darrieus type rotor is considered to be a ‘lift’ rotor in which the rotational velocity in the direction 8 in Figure 3a and 3B and 10 in Figures 4A and 4B, is a multiple of the fluid flow velocity, based on a combination of blade dimensions / parameters and fluid density.

[0135] The rotor configuration of Figure 3A and 3B is a propeller type rotor and the rotor configuration of Figure 4A and 4B is a H-rotor or H-Darrieus rotor, with a number of vertically oriented blades 11 mounted on arms radiating from the axis 9.

[0136] Overall, a vertical axis may be preferred as this may allow a larger surface area of rotor. In concert with lower flow velocities, for instance in water pipes, this may be advantageous as the diameter of a rotor / blade assembly may be limited to the diameter of an opening in the pipe to allow access (where such may be in the range 100mm to 200mm), but the length or the rotor / blade assembly may be up to the internal diameter of the fluid pipe itself.

[0137] A number of alternative configurations of sensing apparatus mounted relative to a fluid pipe access port are illustrated in Figures 5 to 8B.

[0138] The embodiments illustrated in Figures 5 to 8B each involve a sensor element in the form of a rotor 3, and each also have a sounder or vibrator 32 to deliver acoustic energy to the sensor element 15 or the tube 14 through which the sensor element 15 extends or into the fluid pipe 2 itself which is then detected by the sensor element 15. As shown in Figure 5, the rotor 3 with blades 11 may be provided with one or more magnetic or ferrite elements 17. The rotor 3 is vertically mounted relative to the tube 14 through which the sensor element 15 extends into or out of the fluid pipe 2. A detector is provided relative to the rotor 3.

[0139] In the embodiment shown in Figure 5A, the rotor movement detector uses a non-contact relay 30 such as a reed relay or similar activated by magnet 17 on the rotor.

[0140] In the embodiment shown in Figure 9B, the rotor movement detector uses a semiconductor or similar magnetic field detector 31 (such as a Hall Effect sensor, or the like) activated by magnet 17.

[0141] In both embodiments, a relay 29 is provided associated with the respective detector, to work with sounder or vibrator 28, to apply an acoustic signal to the sensing fibre 15 or a sounder or vibrator 32 to apply an acoustic signal to the pipe 2 or fluid within the pipe 2. The acoustic signal may then be analysed by an analyser to interrogate the specific location of the sensor apparatus and to ascertain the characteristic acoustic profile of the acoustic signal 26. The acoustic signal may be a periodic signal with a repetition rate indicative of the fluid flow rate detected. If so, an algorithm may then relate the periodicity of the acoustic signal 25 and derive and / or remotely monitor the fluid flow velocity in the fluid pipe 2 at the sensor location. In these embodiments, the detector 30, 31, relay 29 and / or sounder 28 will require power to function and the power can be provided by a battery or similar or by provision of a power generator in association with the rotor 3.

[0142] In alternative arrangements, the sounder or vibrator 28, 32 is configured to directly output acoustic signals indicative of the relay 30 or magnetic field detector 31 output. Such acoustic signals can be detected and extracted using the sensing fibre as described above. Subsequently, the acoustic signals may be decoded to recreate the hall effect sensor 31 output. This can thereby facilitate the relay 30 or magnetic field detector 31 output being transmitted over the sensing fibre for processing at a remote location.

[0143] The configuration illustrated in Figures 6 to 6B is similar to the configuration illustrated in Figures 5 to 5B except that the rotor mount 27 is a standalone fitting and does not have a sensor element extending therethrough. In this configuration, the sensor element would be provided elsewhere in the fluid pipe, again, preferably extending along a sidewall of the fluid pipe.

[0144] In this configuration, a non-contact relay 30 such as a reed relay or similar activated by magnet 17 on the rotor in Figure 10A or a semiconductor or similar magnetic field detector 31 (such as a Hall Effect sensor, or the like) activated by magnet 17 in Figure 10B may again be used. A relay 29 is again provided but in the embodiments in Figures 10A and 10B, the sounder or vibrator 32 delivers acoustic energy into the fluid pipe, or a knocker (such as a solenoid or similar) to tap a wall of pipe, either of which may be located internally or externally to the pipe. This creates a signal in the pipe which can be detected by the sensing fibre preferably extending along a sidewall of the fluid pipe which may be analysed as previously described.

[0145] The embodiments illustrated in Figures 7 to 7B and 8 to 8B are similar to those illustrated and described in Figures 5 to 5B and 6 to 6B, except that in Figures 7 A and 8 A, the rotor movement detector is a light transceiver 33. The light transceiver 33 outputs light of a suitable frequency and detects reflections of the output light. The output light may be generated by an FED or laser and may typically have a frequency in the infra red range. In Figures 11B and 12B, the rotor movement detector is a sonar transceiver 34. The sonar transceiver 34 outputs sound of a suitable frequency and detects reflections of the output sound. The output sound may have a frequency in the ultrasonic range, for instance 20kHz - 40kHz. The output sound may be generated by a piezo-electric source.

[0146] A number of alternative configurations of sensing apparatus mounted relative to a fluid pipe bypass configuration are illustrated in Figures 9 to 18.

[0147] As illustrated in Figure 9, a fluid pipe is provided with an access port in the form of a flange and a flange top plate is provided with a tube 14 mounted thereto, within which extends a sensing cable / fibre 15 to extend into the pipe and along the pipe invert as shown. The fluid flow direction in the fluid pipe is denoted as 6.

[0148] A bypass arrangement is shown including an upstream dynamic pressure pitot tube 39 and a downstream static pressure tube 40. A pressure sensor 35 is arranged outside the fluid pipe, relative to the pipe access fitting, and between the upstream dynamic pressure pitot tube 39 and a downstream static pressure tube 40.

[0149] As shown in more detail in Figure 10, the pressure sensor 35 contains two pressure sensor units 36, 37 each fed respectively from the upstream pitot tube 39 and the static pressure port 40. A sensor relay 38 is provided to take pressure data from sensors 36 & 37, process to data and provide to a sounder or vibrator 28, to apply an acoustic signal to the sensor element 15 as shown in Figure 10.

[0150] The difference between the configuration in Figures 11 and 12 as compared to Figures 13 and 14 is that the sensor relay 38 is provided to take pressure data from sensors 36 & 37, process to data and provide to a sounder or vibrator 32, to apply an acoustic signal to the fluid pipe as shown in Figure 16.

[0151] The upstream facing orifice 41 of the upstream dynamic pressure pitot tube 39 may be of similar nominal cross-sectional area to the exit orifice 42 of the downstream static pressure tube 40 as shown in Figures 13 to 13B

[0152] In an alternative embodiment, the upstream facing orifice 43 of the upstream dynamic pressure pitot tube 39 may be of substantially larger nominal cross-sectional area to the exit orifice 42 of the downstream static pressure tube 40 as shown in Figures 14 to 14B.

[0153] Figures 15 and 15A show an alternative embodiment of a pressure sensor arrangement of pressure sensor 68, which may be internal or preferentially external to the fluid pipe 2, in which fibre strain-based pressure detectors 69 are implemented on the upstream pitot 39 and downstream static ports 40 within the fluid pipe.

[0154] In this form, one of the fibre strain-based pressure sensors 69 for remote analyser based detection is connected to an in-bound sensing fibre 70 from sensing cable 15 (into fitting 73) and the other of the fibre strain-based pressure sensors 69 is connected to on-bound connection 72 back into pipe 2 from a second fitting, spliced into the appropriate fibre within the sensing cable 15 (into fitting 74 via spliced interconnect fibre 58). A loop of fibre 71 is provided between the sensors 69 with a suitable length with respect to the gauge length of the analyser to allow differentiation and correct determination of strain from the two fibre strain sensors 69. The sensing cable is elongate, entering the fluid pipe through fittings 74, and exiting the fluid pipe through fittings 73, before exiting 59 a final time in connection with to a base module 110.

[0155] Figure 17 is a schematic illustration of a sensing apparatus 100. The sensing monitoring apparatus 100 comprises a base module 110 connected to one end of a sensing fibre 15 provided within a pipe 2. The sensing fibre 15 can be of a pre-set length or may be provided to a length corresponding to that of the pipe 2 to be monitored. If the pipe 2 comprises a branched network, the length of the sensing fibre 15 can be selected to correspond the length of fibre required to loop around all branches of the network to be monitored.

[0156] The base module 110 comprises a light emitter 111 (such as a laser) and a light detector 112 to detect backscattered light and output a detector output signal in response to the detected backscattered light. The base module further comprises a local optical coupling assembly 113 configured to couple the emitter 111 and the detector 112 to the sensing fibre 15.

[0157] The detector output signal comprises multiple channels, each channel corresponding to a particular location along the sensing fibre. Each channel may be defined by reference to the round-trip time for backscattered pulses from the particular location. Neighbouring channels may be defined by the minimum resolvable time interval between backscattered pulses from neighbouring sensing fibre locations. By analysing the detector output signal, indications can be obtained of the condition of the pipe and / or events occurring within or in the vicinity of the pipe.

[0158] The detector 112 typically comprises a photosensor configured to output signals in response to detected backscattered light. Optionally, the detector 112 can also comprise a phase module configured to extract phase information from the photosensor output and thereby generate a detector output signal including phase information. In such cases, each detector output signal channel contains phase information related to the phase of the detected backscattered light from the particular fibre location.

[0159] As illustrated in Figure 18, the apparatus 100 is connected to a flow processing unit 121, and an analyser 122, in this instance cloud based. One or more users 123 can receive processed data from analyser 122, as required or desired. The skilled person will appreciate that the flow processing unit 121 can be integrated into the analyser 122. The skilled person will also appreciate that the flow processing unit 121 and / or the analyser 122 can each be provided in the base unit 110 or in the cloud.

[0160] As discussed above and illustrated schematically in Figure 22, if the vibrator or sounder 28, 32 outputs a periodic signal 26 comprising successive characteristic acoustic events, this is detectable by the sensing fibre 15. The sensing fibre 15 shown in Figure 22, enters the fluid pipe through entry fitting 23 and exits at exit fitting 24. A base unit 100 (as described above) is provided at the end of the sensing fibre 15 after it exits the pipe 2.

[0161] The flow processing unit 121 is configured to extract the component of the detector output signal derived from said characteristic acoustic events. This can be achieved by reference to the channel corresponding to the rotor 3 location within the detector output signal.

[0162] The location of the rotor 3 (or each rotor 3 if multiple rotors 3 are provided) corresponds to a particular channel within the detector output signal. In such embodiments, the component of the detector output signal derived from said characteristic acoustic events can be extracted by reference to a particular channel within the detector output signal. The referenced channel may correspond to the location of a particular rotor along the length of the sensing fibre.

[0163] Once the component of the detector output signal derived from said characteristic acoustic events is extracted, the flow processing unit 121 can process this extract to identify the characteristic acoustic events. This may be achieved by filtering the extracted component to an acoustic frequency range corresponding to the characteristic acoustic events. Once the characteristic acoustic events are identified the flow processing unit 121 can process the identified signals to calculate a fluid flow velocity by determining the repetition rate of the characteristic acoustic events. This may further involve applying a conversion factor or series of conversion factors to the determined repetition rate to thereby convert a rotor rotation rate to an associated fluid flow velocity. Accordingly, suitable analysis of the sensing fibre can enable calculation of a flow velocity in the fluid pipe at the sensor location, without requiring a local power source for the flow velocity sensor element.

[0164] The embodiment illustrated in Figures 19 and 20 is also a bypass configuration. In this embodiment, a containment chamber 75 is provided to allow through flow under dynamic pressure from the upstream pitot 39 and downstream static ports 40 within the fluid pipe.

[0165] A rotor may be provided within the containment chamber as shown in Figure 22. The rotor may be of any type previously described or disclosed.

[0166] A chamber detector apparatus 77 may be provided in association with containment chamber 75 to detect rotor rotation (per previous methods described) and to provide either direct impulse signals to a sensing fibre 15 or tube 14 (per methods previously described), or via electronic means to derive an acoustic or knocking signal (per methods previously described).

[0167] As is described schematically in Figure 21, in use, the flow rotor 3 is coupled to a generator module 201 by a switching module 202. The generator module 201 is configured to generate electrical power from rotary motion. A typical generator module, as is known in the art, comprises a rotator element (not shown) and a stator element (not shown), wherein relative movement between the rotator element and stator element against electromagnetic resistance generates an output electrical current. The switching module 201 is configured to switch the apparatus between an active mode where the flow rotor 3 is coupled to the generator module 202 and a passive mode where the flow rotor 3 is not coupled to the generator module 202. Accordingly, in the active mode, the flow rotor 3 drives the rotor element of the generator 202 and electrical power is generated. In the passive mode, the flow rotor 3 does not drive the rotor element of the generator module 202 and no electrical power is generated. Any excess electrical current generated during the active mode can be provided to a local power storage device 204, typically a battery.

[0168] In use, the switching module 201 can be operated in response to a controller 205. This allows the operation of the switching module 201 to automated where appropriate. In particular, this allows the apparatus to operate at a desired duty cycle between active and passive modes.

[0169] In passive mode, the flow rate can be monitored using any of the detector arrangement described in Figures 5-8. If appropriate detectors such as relay 30, magnetic field detector 31 , light transceiver 32 or sonar transceiver 34 can be powered by the storage device 204. Similarly, a vibrator or sounder 28, 32 can be powered using the storage device where required.

[0170] In one implementation, the apparatus may run primarily in active mode and periodically switch to passive mode. This allows the apparatus to primarily act as a generator and then occasionally act as a flow sensor. This beneficially ensures that the apparatus has sufficient power to carry out flow sensing whenever in passive mode. It also ensures that

[0171] Operating primarily in active mode also allows any surplus generated power to be stored in the storage device. Where there is available power in the storage device 204, the controller 205 may be configured to control the supply of that power to one or more additional devices 210. In the schematic illustration, the additional devices 210 may include secondary sensors such as a pressure sensor. The skilled person will appreciate that multiple additional sensors 210 could be provided as required or desired.

[0172] A possible switching module arrangement is illustrated in Figure 23. Figure 23 shows alternator 230 for generating power. The alternator 230 may include a device to generate pulses during rotation, which could be magnetic (with Hall Effect or similar sensing), or non-contact IR / ultrasonic switch for example.

[0173] Also shown in Figure 23 is a switch 231 which switches alternator output to charge a battery 232 to store electrical charge for later use, or high impedance / resistance voltage sensor 233. The switch 231 shown is a pulse- width modulated switch between a power generation mode and flow velocity sensing mode as discussed above. The pulse width may be fixed or modified remotely.

[0174] In Figure 23, the energy generation switching profile 234 may provide a greater time period for energy generation whereas the voltage sensing profile 235 is the inverse of energy generation switching profile 234. The high impedance / resistance voltage sensor 233 will preferably provide a scaled voltage output relative to flow velocity when no power is being generated and the rotor is rotating freely in the flow velocity sensing mode as discussed above.

[0175] As mentioned above, the switching may occur as a result of a remote trigger input 236 to switch 231. When in the flow velocity sensing mode, the high impedance / resistance voltage sensor 233 may transmit data as acoustic energy 238 for remote detection by a DAS analyser via transmitter 237 or by other means 239, such as fibre data cable, fixed land lines, radio or similar.

[0176] Figure 23 also shows a transmitter 240 associated with the alternator 230, to transmit data from which rotational velocity to fluid flow velocity may be derived remotely. Again, this data may be transmitted as acoustic energy 238 for remote detection by a DAS analyser or by other means 239, such as fibre data cable, fixed land lines, radio or similar.

[0177] The transmitters 237, 240 may transmit data in any format, not limited to pulse data (in which pulse rate may be indicative of rotation speed, with a higher pulse rate representing a higher rotation speed for example), or frequency data (in which the frequency of the signal may be indicative of rotation speed, with a higher frequency representing a higher rotation speed for example). If transmitted as frequency data, the data frequencies may be in a range of between 100Hz to 1kHz. In such embodiments, this can be achieved by connecting the output of the high impedance / resistance voltage sensor 233 to a voltage controlled oscillator. This can thereby directly scale the voltage sensor 233 output to an acoustic frequency output.

[0178] The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.

Claims

CLAIMS1. A power generation and flow sensing apparatus for a fluid pipe, the apparatus comprising: a. A flow rotor configured to rotate in response to fluid flow within the pipe; b. A rotation rate detector configured to detect the rotation rate of the flow rotor and output a signal indicative thereof; c. A generator module comprising a rotator element and a stator element, wherein relative movement between the rotator element and stator element against electromagnetic resistance generates an output electrical current; and d. A switching module configured to switch the apparatus between an active mode where the flow rotor is coupled to the generator module and a passive mode where the flow rotor is not coupled to the generator module.

2. A power generation and flow sensing apparatus as claimed in claim 1 wherein the flow rotor is located in the fluid flow for rotation according to the fluid flow.

3. A power generation and flow sensing apparatus as claimed in claim 1 wherein the flow rotor is associated with the fluid flow, located in a bypass configuration relative to the fluid flow within the fluid pipe in which a portion of the fluid flow is diverted outside the fluid pipe, through a housing within which the flow rotor is located, causing rotation of the flow rotor, before the portion of the fluid flow re-enters the fluid pipe.

4. A power generation and flow sensing apparatus as claimed in any one of the preceding claims wherein the at least one rotor is a Savonius type rotor or a Darrieus type rotor.

5. A power generation and flow sensing apparatus as claimed in any one of the preceding claims further comprising a controller provided to control the switching module according to power required, usage or according to a duty cycle.

6. A power generation and flow sensing apparatus as claimed in claim 5 wherein the controller switches to the passive mode for less than 50% of operating time,less than 40% of operating time, or less than 30% of operating time, or less than 20% of operating time, or less than 10% of operating time, or less than 5% of operating time, or less than 2% of operating time.

7. A power generation and flow sensing apparatus as claimed in any one of the preceding claims wherein the generator module provides the output electrical current directly to the apparatus requiring power and / or to a storage device.

8. A power generation and flow sensing apparatus as claimed in any one of the preceding claims wherein the rotation rate detector comprises: a. at least one sensing fibre provided within the fluid pipe; b. a light emitter for introducing light pulses with particular characteristics into the at least one sensing fibre; c. a light detector module configured to detect backscattering of the light pulses from the at least one sensing fibre in multiple different sensing modes and output a detector output signal in response thereto; d. a fluid flow processing unit configured to process the detector output signal to extract a component of the detector output signal derived from the signal indicative of rotation rate of the flow rotor from the detector output signal so as to monitor flow velocity.

9. A power generation and flow sensing apparatus as claimed in claim 8 further comprising a base module comprising the light emitter, the light detector and a coupling assembly configured to remotely couple light pulses into the sensing fibre and backscattered light pulses out of the at least one sensing fibre.

10. A power generation and flow sensing apparatus as claimed in claim 8 or claim 9 further comprising an analyser to analyse the detector output signal.

11. A power generation and flow sensing apparatus as claimed in any one of claims 8 to 10 wherein the rotation rate detector comprises a static component, wherein interaction between the flow rotor and the static component generates a signal indicative of the rotation rate of the flow rotor in the form of one or more characteristic acoustic events detected by the at least one sensing fibre.

12. A power generation and flow sensing apparatus as claimed in claim 11 wherein the static component is or projects from the flow rotor or from a mount upon which the flow rotor is provided.

13. A power generation and flow sensing apparatus as claimed in claim 11 or claim 12 wherein the interaction between the flow rotor and the static component is direct or indirect.

14. A power generation and flow sensing apparatus as claimed in claim 13 wherein indirect interaction comprises light reflection by means of an LED or laser source, an ultrasonic sonar system, a semiconductor or similar magnetic field detector powered by electrical current generated by the generator module.

15. A power generation and flow sensing apparatus as claimed in any preceding claim wherein the rotation rate detector comprises a voltage meter for detecting voltage generated by rotor rotation on the unloaded generator module in the passive mode.

16. A power generation and flow sensing apparatus as claimed in claim 14 or claim 15 further comprising an acoustic event generator associated with the at least one sensing fibre, the acoustic event generator configured to output characteristic acoustic events at a rate indicative of the fluid flow rate determined by a non-contact detector, or to output acoustic signals indicative of non-contact detector output signals.

17. A method for power generation and flow sensing in a fluid pipe utilising a flow rotor configured to rotate in response to fluid flow within the pipe, a rotation rate detector configured to detect the rotation rate of the flow rotor and output a signal indicative thereof and a generator module comprising a rotator element and a stator element, wherein relative movement between the rotator element and stator element against electromagnetic resistance generates an output electrical current; the method comprising the steps of: a. Operating the apparatus in a passive mode where the flow rotor is not coupled to the generator module; and b. Switching the apparatus to active mode where the flow rotor is coupled to the generator module according to a duty cycle.

18. The method as claimed in claim 17 further comprising the steps of: providing a sensing fibre within the fluid pipe to be monitored;introducing light pulses generated by a light emitter into the sensing fibre; and when in the passive mode, detecting backscattered light pulse from the sensing fibre with a light detector configured to output a detector output signal corresponding to the detected backscattered light; and extracting a component of the detector output signal derived from said signal indicative of the rotation rate of the flow rotor so as to monitor flow velocity in the fluid pipe.

19. The method as claimed in claim 18 wherein the detector output signal comprises multiple channels, each channel corresponding to a particular location along the sensing fibre.

20. The method as claimed in claim 19 further including the step of identifying the particular location of each flow rotor location corresponding to each channel within the detector output signal.

21. The method as claimed in any one of claims 17 to 20 further comprising the step of identifying the signal indicative of the rotation rate of the flow rotor within the extracted component of the detector output signal.

22. The method as claimed in any one of claims 17 to 21 further comprising the step of calculating a fluid flow velocity from the identified the signal and / or characteristic acoustic events. This may be achieved by determining the repetition rate of the characteristic acoustic events. This may further involve applying a conversion factor or series of conversion factors to the determined repetition rate to thereby calculate the fluid flow velocity.

23. The method as claimed in any one of claims 17 to 22 further comprising the step of deactivating the rotation rate detector in the active mode.

24. The method as claimed in any one of claims 17 to 23 further comprising the step of operating the generator module only when the apparatus is in the active mode.

25. A fluid distribution system comprising one or more fluid pipes and at least one power generation and flow sensing apparatus as claimed in any one of claims 1to 16 provided at one or more points within the fluid distribution system; and a system controller wherein each power generation and flow sensing apparatus is connected to the system controller.

Images