GB2358475A

GB2358475A - Monitoring or control of a water supply at remote sites

Info

Publication number: GB2358475A
Application number: GB0018009A
Authority: GB
Inventors: Gregory Francis Lloyd
Original assignee: SOUTH STAFFORDSHIRE GROUP PLC
Current assignee: SOUTH STAFFORDSHIRE GROUP PLC
Priority date: 1999-07-23
Filing date: 2000-07-21
Publication date: 2001-07-25
Also published as: WO2001007783A1; AU6007300A; GB0018009D0; GB9917402D0

Abstract

A battery is charged up by rotation of a turbine in a bypass line bridging a restriction in a mains water supply. The turbine causes one magnet to rotate with respect to another, powering up a charge circuit for the battery. The restriction may be a valve for controlling the flow of water. The system may also be used for pressure and flow monitoring and data logging. The arrangement may also be used for powering a remote monitoring unit.

Description

2358475 CONTROL OR MONITOR OF EQUIPMENT AT REMOTE SITES The invention

relates to the control or monitor of equipment at remote sites. Such sites can be water supply installations, e.g. valve schemes and pressure and flow monitoring schemes and be off the beaten track. From time to time things go wrong at the site and there is a need to alert operatives at the centre of the malfunction. Where it is not clear what the malfunction is, money may be wasted in sending the wrong technician, e.g. a mechanical engineer instead of an electrical one to the remote site.

It is known to install telemetry equipment to enable one to sense the condition of the sites either for routine checking or to sound an alarm. Mains supply electricity is not available (or cannot be installed at reasonable cost) and wind power generators and solar panels are not suitable. This is especially the case where the apparatus is to be installed below ground level. It is known to locate a turbine in a mains water supply, the turbine being driven by the flow of water. A system of this type may be associated with a domestic water supply or for irrigation of fields. In some cases the rotation of the turbine is used to provide information for the determination of water use charges. Such a system is not suitable for use at a remote location. It is an object of this invention to provide means for providing power which is convenient to install with no disruption to the mains supply, substantially maintenance free and reliable in use.

According to the invention in one aspect there is provided apparatus for use in controlling or monitoring equipment at a site having mains water supply, the apparatus comprising:

2 an electrical control or monitor device; a DC battery to supply power to the electric device; charging means for charging the DC battery, the charging means comprising a restriction in the mains water supply pipe; a bypass through which mains water flows, the inlet of the bypass line being upstream of the restriction and the outlet side being downstream of the restriction, means being present in the bypass line, arranged to be rotated by the flow of water thereover to drive a dynamo or generator.

The charge up means driven by the turbine means is preferably constructed to avoid the need for a drive shaft having seals. In one preferred embodiment the turbine means includes one magnet located with another, the first magnet being part of the turbine, the second having a drive shaft arranged so that rotation of the second magnet caused by rotation of the first magnet drives a dynamo or generator.

It is a feature of the invention that the electricity is generated using means which does not intrude into the mains water pipe. For this reason the turbine means is located in a bypass line. Preferably, the water turbine device is connected to the water main by a small bore (10 mm typical) bypass, which does not intrude into the water main pipe. The water turbine device is driven by a differential pressure across a valve (or other restriction) in the main water pipe. The water turbine device is not arranged to be flow dependent on the main water pipe (the valve or restriction could be completely closed therefore preventing flow but generating a pressure difference). The pressure difference 3 will need to be of sufficient size to be capable of generating sufficient electrical energy to meet the system requirements.

The apparatus is arranged to operate using surplus energy provided by the water mains pressure, this is to say that the flow rate through the turbine is sufficiently low as to ensure that over-pressurisation of the water main and associated supply area does not occur. To this end the system should preferably be designed, i.e. the dimensions of the bypass selected, to operate on flows of no greater than about 0.5 I/s.

The turbine device should be of low volume, capable of withstanding pressures up to 200m head (20 bar), provide a low friction rotary drive and be suitable for contact with potable water. The generator should be capable of meeting the electrical power requirements and possibly be waterproof due to its working environment. The apparatus should need low maintenance, have an efficiency of at least 30% and have a life expectancy of at least two years continuous operation.

The water powered battery charger and a small dynarno/generator driven by the water turbine generator are connected to one or more batteries which are charged from the generator via a charging circuit. The apparatus is arranged to provide a DC voltage, e.g. l2v or 24v at a minimum current rating of approximately I amp. Such a power source can continuously power a variety of telemetry monitoring and control equipment. (A 24v DC version should be capable of powering a 24v DC valve actuator for the main water supply, assuming that the actuator operates for say the equivalent of 2 hours continuous operation per day). This is a particularly advantageous embodiment of the 4 invention in that it is the water pressure difference caused as a result of the presence of the valve which is the prime source of the electrical power for actuation of the valve.

The apparatus is adapted to provide electrical power for a variety of equipment such as UHF radio equipment used for pressure monitoring transmission, pressure management control systems and data loggers.

In order that the invention may be well understood it will now be described by way of example only, with reference to the accompanying diagrammatic drawings, in which:

Figure 1 is a block diagram showing the layout of one battery charging circuit; Figure 2 is a block diagram showing one installation incorporating the circuit of Figure 1 and connected to a valve actuator and a cellular data communicator; Figures 3A and 3B are respectively an elevation and plan view of a turbine device used in the circuit of Figure 1; Figure 4 is a partial sectional view of a magnetically coupled water turbine and electricity generator; and Figure 5A is a partial vertical sectional view of an integral water turbine driven permanent magnetic electricity generator and Figure 5B is a transverse section thereof.

As shown in Figure 1, a differential pressure exists across a main valve or other restriction device 2 in a water main pipe 1 having a typical diameter of 150 mm. The water pressure on the upstream side of the valve or restriction 2 is higher than the pressure on the downstream side. For example the pressure upstream may be 70mhd and downstream 40mhd. According to the invention a bypass circuit 3 is present, bridging the main pipe 1 on each side of the main valve or restriction 2. The bypass circuit 3 is a small bore pipe, say 10 mm, having an isolating valve 4 on each side of the main valve 2. A water turbine-like device 5 is present in the bypass circuit 3 and is connected to a dynamo/generator 6, connected to a charging circuit 7 linked to a 12v or 24v battery supply 8. The structure of some devices 5 is shown in Figure 3, 4 and 5.

The turbine-like device 5 and associated charging components can form one unit U and be located in a box in an above or below ground installation. Preferably the unit is located underground at a site remote from a control centre.

Figure 2 shows an installation incorporating the circuit of Figure 1 and associated data measurement and transmission components. A flowmeter 10 is present downstream of the valve 2. The meter 10 passes an output signal to a flow pulse output unit 11 which passes its signal to a valve controller/logger 12. This communicates with a valve actuator 13 and is powered from a power line from the charge unit U. The 6 controller/logger 12 communicates with a cellular data transmitter 14 which is also powered by the charge unit U. As will be seen, the charge circuit can operate a number of components, yet still be self sufficient, compact and efficient in use.

Figure 3 shows one turbine device 20. This consists of a rotor 21 having radially spaced apart blades 22 arranged so that water entering a tangential inlet 23 can flow over the blades 22 and exit via a central outlet 24. At one side there is an axle 25 covered with magnetic material and which is received in a socket housing 26 of magnetic material at the end of the generator drive shaft 27. The turbine is thus magnetically coupled to the drive shaft. The water flow rotates the shaft and so cause charge up.

In operation the bypass circuit 3 is opened from time to time or continuously and the turbine-like device 5 powers up the dynarno 6 which in turn powers the charging circuit 7 to keep the battery 8 in power.

The charging means of Figure 4 comprises a drive shaft 31 extending from an electricity generator 32 and terminating in a cup shaped magnet 33A. The cup contains a second magnet 33B in the form of a bifurcated shank and surrounding a post 34 depending from the underside of a roof 35. An infill 36 forming a watertight seal is present between the two magnets 33A, 33B. The head has an inlet for water 37 at one side and an outlet 38 in the top of the roof 35 and the outside is formed with turbine blades 39.

7 The device of Figure 4 is fitted in a circuit as shown in Figures 1 and 2. The water enters the inlet 37 and exits via the outlet 38. As the water flows the turbine the integral magnet 33A setting up a force field which causes magnet 33B to rotate so rotating the drive shaft 31 to power up the DC battery.

In the embodiment of Figures 5A and 5B, one magnet 33B is integrated with the turbine (as in the Figure 4 embodiment) and the other 33A with the generator. In this case the magnet 33A is made up of laminated pole pieces 40 about the permanent magnet 33B and joined at one end to a laminated iron core 41 within a coil winding 42. Rotation of the turbine rotates the permanent magnet 33B which induces an electromotive force in the coil 42. This obviates the need for a separate generator.

Equipment (not shown) can be powered to operate valves, measure flow rates, transmit signals and the like.

The typical power requirements of a variety of equipment which may be powered from the proposed power supply are shown below:

Equipment Voltage DC Current Frequency (Amps) Data Logger 12 0.005 Continuous Programmable Logic Controller (PLC) 24 0.800 Continuous Pressure Transducer 12-24 0.020 Continuous Solenoid Valve 24 0.500 Continuous UHF Radio Telmetry Link @ 50OmW 12 1.000 Continuous Valve Actuator 24 10.0002 Hrs/Day

Claims

8 CLAIMS

1. Apparatus for use in controlling or monitoring equipment at a site having mains water supply, the apparatus comprising:

an electrical control or monitor device; a DC battery to supply power to the electric device; charging means for charging the DC battery, the charging means comprising a restriction in the mains water supply pipe; a bypass through which mains water flows, the inlet of the bypass line being upstream of the restriction and the outlet side being downstream of the restriction, means being present in the bypass line, arranged to be rotated by the flow of water thereover to drive a dynamo or generator.

2. Apparatus according to Claim 1, wherein the means present in the bypass line is arranged to be rotated at a flow rate of less than 0.5 lls.

3. Apparatus according to Claim 2, wherein the bypass line has a diameter of the order of 1Omm.

4. Apparatus according to any preceding Claim, wherein the drive means driven by the turbine means is constructed to avoid the need for a drive shaft having seals.

9 5. Apparatus according to Claim 4, wherein the turbine means comprises one magnet located with another, the first magnet being part of the turbine, the second having a drive shaft arranged so that rotation of the second magnet caused by rotation of the first magnet drives a generator.

6. Apparatus according to Claim 5, wherein rotation of the first magnet is arranged to induce an electromotive force in a surrounding coil.

7. Apparatus according to any preceding Claim, wherein the electrical control or monitor device is telemetry monitoring and control equipment.

8. Apparatus according to any preceding Claim, in the form of a selfcontained unit capable of being set in a substrate at a site which is remote from a control centre.