WO1990015278A1

WO1990015278A1 - Apparatus comprising a valve

Info

Publication number: WO1990015278A1
Application number: PCT/NO1990/000101
Authority: WO
Inventors: Erland Helmer Larsen
Original assignee: Erland Helmer Larsen
Priority date: 1989-06-08
Filing date: 1990-06-06
Publication date: 1990-12-13
Also published as: NO892348L; NO892348D0; AU5746790A

Abstract

A valve (11) for the control of a fluid medium (10) is connected to an external control system by an electric or optical fibre cable (2) and is supplied with means of activation (4, 5, 6). The means of activation (4, 5, 6) comprise an electronic control unit (4), preferably a microprocessor (4), an amplifier (5), and an electromechanical valve actuator (6). An energy converter (9) is placed in contact with the medium (10) so that it can produce energy from the medium (10). The energy converter (9) supplies the means of activation (4, 5, 6) with energy. The micropocessor (4) is also connected to a number of sensor (7a-d) which are located to acquire relevant ambient data. The energy converter is preferably designed as an electric generator (9), comprising a mainstream-powered turbine and/or a turbine powered by part of the stream, alternatively a motor powered by the displacement principle with a rotating and/or oscillating electromagnet.

Description

Apparatus Comprising a Valve

This invention relates to a valve, or similar, which uses the energy in the medium it controls to activate the valve, as described in the introductory part of Claim 1. The control of the valve is done by means of digital signals transmitted by cable. The invention can be used in all pipe systems where fluids and gases are to be controlled.

Known present day technology has given valves with a range of different types of control, for example: manual, mechanical, pneumatic, hydraulic, electric or electronic. A common feature of all these different forms of control is that the valves must be supplied with energy from external sources to activate them. This means that the controlling energy must be led from a central position to each valve through pipes or cables. In many cases, this will involve considerable distances, which means the expense of labour and high material costs. If status information is required (such as pressure, temperature, flow-rate volume, position) from every valve in the system, additional pipes/cables are necessary. Malfunctions and damage can easily occur in such pipe/cable systems resulting in leakages and fractured cables. Malfunctions are also possible in connecting terminals, switches and such like.

The main objective of the invention is to reduce the number of pipe/cable systems required for the control of valves. A second objective is to enable many independent systems to be controlled by a single control unit. A further objective of the invention is to integrate the control of switches and starters for electric motors into a control system for valves. Another objective of the invention is to provide signal transmission which is completely noise resistant.

The main objective of the invention is realized by a valve in accordance with the characterizing part of Claim 1. Other advantageous features are described in the subsidiary claims.

The principle of the invention is a valve with an in-built generator powered by the flow of a medium/pressure of a medium. The valve also comprises a battery, an electromagnet for activation and sensors for pressure, temperature, volume etc. Communication with the control unit and the control of the electromagnet, the charge circuit and sensors, is provided by means of a programmable electronic unit (microprocessor). Where valves are to be controlled by optical fibre, an optical converter is also included.

The invention will be described in more detail in the following, with reference to the accompanying drawings, in which:

Figure 1 shows a block diagram of one design in accordance with the present invention, Figure 2 shows a block diagram with a number of connected units in a design in accordance with the present invention. Figure 1 shows a valve unit, generally indicated by 1. The valve unit 1 comprises an optical converter 3 connected to a optical fibre cable 2. The optical converter 3 is connected to an electronic unit, or microprocessor 4. This is in turn connected to an amplifier 5 for an electromagnet 6. The microprocessor 4 is also connected to a series of sensors 7 through an analog/digital converter 8. The sensors can, for example, be a pressure sensor 7a, a flow sensor 7b, a temperature sensor 7c, and a sensor 7d for various purposes. A generator 9 is mechanically connected to the medium 10 that the valve 11 controls. The generator 9 is powered by a turbine that can be alternatively built as a flow-powered turbine where energy can be extracted from the main flow of the medium when there is a low fall in pressure, or from part of the flow using all the available fall in pressure. A displacement motor could be used as an alternative to the turbine principle. The generator 9 can be built with a rotating and oscillating magnet. The generator 9 provides power to a battery 13 through a charge controller 12. The battery 13 also supplies the microprocessor 4 and the amplifier 5 with power. The valve unit 1 also has a particular address. This is not shown in the figure, but can be implemented with mechanical switches or the like. The valve 11 can be of any type, the figure indicates a valve 11 with an electronic actuator 6, an inflow side 10 and an outflow side 14. If reference is also made to Figure 2, the functioning of one or more valve units in accordance with the invention will be explained. A central control unit 15 controls a number of valve units, or the like, la-lf, by means of a optical fibre cable 2 connected in a series circuit. All communication units in the system are preferably able to provide two-way communication. The central unit 15 consists of a microprocessor 16, that has software stored in a memory 17. The microprocessor 16 is connected to an optical fibre converter 18 which again is linked by a transmission cable 2. Each valve unit 1 in the system has its own identity. The optical fibre cable that links the central unit 15 to valve unit la, is led by means of a T-junction further to valve unit lb, and then on to valve unit lc etc. When the last valve is reached, the connection is routed back to the central unit 15 so that a circuit is formed. A control signal is transmitted in the circuit with the address of the valve unit 1 that is to be operated. Local control units 19 can be connected to circuit 2 where necessary; on board vessels, these could be deck cranes, anchor winches, cargo hatches etc.

Valve units la-lf are controlled by messages that contain at least one address and a command. The optical converter 3 on the valve unit 1, picks up the digital signals from circuit 2, converts them and transmits them to the microprocessor 4. The address of the received command is checked here. If the command is not directed to that particular valve unit 1, there will not be any response by the microprocessor 4. If, on other hand, the command is directed to this valve unit 1, the microprocessor 4 will accept the command and execute the order. This could be to give a signal to the amplifier 5, for example. The signal to the switch magnet 6 will then be amplified; then the magnet is activated, and the valve 11 opens or closes, respectively.

The microprocessor 4 also receives signals from the various sensors 7a-d via the A/D converter 8. When single commands such as "close" or "open" come from central unit 15, the function of the sensors 7 is just to monitor the situation. The commands can also contain conditions, such as: "open, close when pressure = xxx" , "open, close when volume = xxx", "open, maintain temperature = xxx °C", "close, open when pressure = xxx", etc.

With such commands, information from the sensors 7 is also used. This can occur locally in the valve unit 1 using the logic in the microprocessor 4, but it can also be done by the microprocessor 4 sending the necessary values to the central unit 15. The central unit 15 monitors the values and when the conditions are met, it sends a new command to the valve.

Messages are generated in the central unit 15. If there is manual control this can be done by means of a joystick, wheel, push button, or similar. As this is not part of the invention it is not shown in the figure. Automatic control may take the form of communication between valve units la-f and the central unit^'s 15 microprocessor 16, using the software 17 in microprocessor 16. Messages are transmitted from the central unit 15 to valve units la-f, these contain the following: address, command, report status. The valve unit 1 with the relevant address receives the command, carries out the message, and reports the status back to the central unit 15. This status report can, for instance, contain information on pressure, temperature, volume etc. This information can be used in sequences where one wishes to place conditions on the execution of certain functions, depending on the measured values. Commands with such conditions can be exemplified by: "open, close when pressure > xxx", "open, close when volume = xxx", "open, maintain volume = xxx litres/min" , "open, maintain temperature = xxx degrees" "close, open when pressure > xxx", etc.

The values received are compared with the conditional value. If these values agree, the conditional command is automatically transmitted to the valve. In a servo system the status report can contain an answer to the central unit 15 and provide a basis for corrections in relation to certain previously-determined parameters.

Apart from the necessary control of a unit (a towline winch on board a vessel, for example), there may be cases where a local transmitter unit 19 is connected to an optical fibre cable 2 and located in an appropriate position. This is done so that it cannot influence other valves than the one in the unit it is connected to. The valve unit 1 can be programmed to transmit status messages back to the central unit 15 either continuously or at intervals. This enables the state of the valve to be continuously monitored and/or controlled. The messages can thus be used as answers in a servo system, for pressure control, volume control, temperature control etc.

The invention means that it is unnecessary to supply external energy to control the valve. This avoids a lot of the work and material costs connected with the laying of cables or pipes. It is only necessary to lay a single core optical fibre cable from the control position to the first valve, then from the first to the second etc. A single core optical fibre cable can at the same time transmit signals in the order of a thousand to valve unit 1. When the last valve is reached, the cable is routed back to the central unit 15 so that a circuit is formed. This ensures that all valves receive their signals, even if there is a fracture in the cable 2. If the system is to be expanded or extra equipment is to be added, the invention means that it is only necessary to connect this new valve/these new valves to the system between two existing valves, and then configure the software to the identification and mode of operation of the valve(s). The system also enables switches and starters for electric motors to be controlled in the same way as valves, and by means of the same control medium (optical fibre cable, for example). This simplifies the control of automatic processes, and further reduces the material and installation costs.

Claims

1. Apparatus comprising a valve (11) for the control of a fluid medium (10), where the valve is connected to an external control system by an electric or optical fibre cable (2) and where the valve is supplied with means of activation (4,5,6), characterized by further comprising an energy converter (9) which is placed in contact with the medium (10) so that it can produce energy from the medium (10), and where the energy converter (9) supplies energy to the means of activation (4,5,6).

2. Apparatus as claimed in Claim 1, characterized by the energy converter (9) comprising an electric generator (9) powered by the medium connected by a charge control unit (12) to an accumulator battery (13).

3. Apparatus as claimed in Claims 1-2, characterized by the means of activation (4,5,6) comprising an electronic control unit (4), preferably a microprocessor (4), an amplifier (5), and an electromechanical valve actuator (6) .

4. Apparatus as claimed in Claims 1-3, characterized by the microprocessor (4) which is connected to a number of sensors (7a-d) which are located for the acquisition of relevant ambient data.

5. Apparatus as claimed in Claims 1-4, characterized by each valve unit (1) being furnished with an address, and a number of valve units (1) being connected by the same signalling medium (2), and where one or more signal units (15,19) are connected to the same medium (2) and are able to give messages to at least one of the valve units (1) and receive status reports from the same unit.

6. Apparatus as claimed in Claims 1-5, characterized by relays, switches, starters for electric motors and electromechanical actuators or similar controllable equipment being connected by the same signalling medium (2), further comprising electronic control equipment for the receipt, decoding and processing of commands through the medium (2).

7. Apparatus as claimed in Claims 1-6, characterized by the electric generator (9), comprising a mainstream-powered turbine and/or a turbine powered by part of the stream.

8. Apparatus as claimed in Claims 1-6, characterized by the electric generator (9), comprising a motor powered by the displacement principle with a rotating and/or oscillating electromagnet.