AU785120B2 - Balloon launching system - Google Patents

Description

P/00/0i 128/5/91 Regulabon 3.2(2)

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: S S

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Invention Title: BALLOON LAUNCHING SYSTEM The following statement is a full description of this invention, including the best method of performing it known to :-us BALLOON LAUNCHING SYSTEM FIELD OF THE INVENTION The present invention relates generally to equipment for filling balloons. In particular, the invention concerns apparatus, systems and methods for filling a balloon with a fluid medium. The invention is especially useful for remotely launching meteorological balloons, and it will therefore be convenient to describe the invention with reference to that example application. It should be understood however that the invention is capable of much wider application and use.

BACKGROUND OF THE INVENTION In the past, and to some extent still in the present, balloons were manhandled and inflated by hand. This involves a person physically holding the gas inlet of the balloon over a filling nozzle attached to a gas bottle. Inflating a balloon in this way is very dangerous as the filling agent gas) is normally hydrogen. When hydrogen is ignited by a spark, or any other means, it will result S* 15 in an explosion and usually a very intense fire.

lo.l Various attempts have been made over the years to make the handling and inflation of hydrogen-filled meteorological balloons safe for personnel. One such attempt by the Australian Bureau of Meteorology involves a remotely controlled balloon launching system. This system includes a balloon launch table 20 in the field and a very basic launch control unit in a site office, located at a safe oeo distance from the launch table, typically about 40 meters or more away. A typical arrangement is shown in Figures 1 and 2 of the accompanying drawings.

The launch table includes a filling nozzle (not shown in Figures 1 and 2) which is movable, under the action of a pneumatic cylinder, between a filling position and a release position. Operation of the pneumatic cylinder is controlled via solenoid valves by push buttons located on the launch control unit.

In use, a rubber bung is inserted into the inlet of the balloon and the filling nozzle is inserted through the bung. The nozzle and balloon are then installed on the launch table and, once the area is clear, hydrogen from a gas cylinder or other source is allowed to flow into and inflate the balloon. The flow of hydrogen gas is controlled via a solenoid valve by push buttons on the launch control unit.

2 Once the balloon has been inflated to a desired extent, by opening the hydrogen solenoid valve for a predetermined period of time, the pneumatic cylinder is operated so as to extract the filling nozzle from the balloon. This allows the balloon to be released, carrying with it a radar target/reflector to facilitate radar tracking of the balloon and an appropriate weather monitoring and transmitting device (usually referred to as a radiosonde).

One problem often faced in launching balloons is the effect of wind at the launch site. Meteorological balloons are made of a very soft latex material so that the balloon can stretch, with expansion of the hydrogen gas inside the balloon, as it gains altitude. Typically, an inflated balloon may have a diameter of about 1 meter just prior to launch, but may expand to a diameter of about 30 meters at an altitude of about 60,000 meters. This means that as the balloon leaves the launch table it is extremely malleable and very much effected by wind. To ameliorate this problem the launch table is usually surrounded by an open topped S 15 enclosure so as to shield the table from wind. As the balloon leaves the top of the enclosure, however, wind speeds in excess of about 5 knots often cause the balloon to shear, where the top of the balloon projecting from the enclosure is pushed sidewards whilst the lower portion still within the enclosure remains stationery (horizontally). This usually leads to rupture of the balloon, and 20 consequent loss of the balloon itself and the hydrogen gas it contains.

If the hydrogen released upon rupture of the balloon happens to be ignited by a spark, perhaps caused by a faulty contact or connection within the electrical control equipment located in the launching closure, an explosion will occur. This explosion and subsequent fire will destroy the launch enclosure, the launch table and any local control equipment.

Static electricity is also a problem and such static can lead to sparks which may ignite the hydrogen gas escaping from a ruptured balloon. Even in the absence of a balloon rupture, any hydrogen leaks within the enclosure could lead to an explosion or fire. To minimise static electricity in and around the launch enclosure, a water spray system is often employed. This system is not however fully effective.

The above system has to some extent improved the safety of personnel involved in launching meteorological balloons because the personnel are located remotely from the launch table during the hydrogen filling and launch operations.

However, the system uses conventional electrical control equipment which still poses a significant risk when used in hazardous environments such as those existing in the presence of hydrogen.

The system is also prone to error because the exact volume of hydrogen which is allowed to enter the balloon is uncertain. Sometimes the balloon is under-inflated and other times the balloon is over-inflated. This means that the altitude to which the balloon will rise when it is released is uncertain, because this altitude depends on the level of inflation. There are also significant losses in the system which lead to wastage of hydrogen gas. Launching balloons using this system, whilst safer than filling a balloon by hand, is significantly more expensive.

There therefore remains a need for a balloon launching system which is 15 safe for personnel and which more accurately inflates the balloons to the required level without wasting valuable hydrogen gas. There also remains a need for an improved launch enclosure. The present invention seeks to address at least some of these needs.

Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material formed part of the prior art base or the common general knowledge in the relevant art in Australia on or before the o priority date of the claims herein.

SUMMARY OF THE INVENTION 25 In accordance with the present invention there is provided a system for filling a balloon with a fluid medium and launching the balloon, the system including a filling nozzle for admitting the medium to the balloon, measurement means for measuring flow of the medium to the filling nozzle; flow control means for controlling the flow of the medium to the filling nozzle; and processing means, responsive to the measurement means, for establishing according to a predetermined criteria when a predetermined amount of the medium has been admitted to the balloon and, upon reaching the predetermined amount, causing the flow control means to terminate the flow of the medium and the filling nozzle to disengage with the balloon, thereby launching the balloon.

Preferably, the predetermined criteria relates to any one or a combination of: pressure, flow rate and temperature of the medium. The criteria may be used as a basis for calculating a volume of the medium.

In a typical application of the invention, the fluid medium is a gas and the balloon is a meteorological balloon.

In one embodiment the processing means includes a programmable logic controller (PLC). The PLC is connected to field instrumentation and control equipment located in the region of the balloon being filled, preferably via "intrinsically safe" inputs and outputs.

In one embodiment, the system includes an operator interface connected to the processing means for providing a visual representation of the balloon launching system and for providing operational data, such as hydrogen gas and 15 air pressures, flows and temperatures. The operator interface may include a personal computer (PC) running supervisory control and data acquisition So (SCADA) software. Preferably, the PLC and PC are adapted to be located •o remotely from the region of the balloon as it is being filled.

In one embodiment, the measurement means includes a flow transmitter and/or a pressure transmitter. Measurement signals may be connected to the S.remote PLC/PC system. In a preferred embodiment, the measurement means further include a temperature transmitter. In this embodiment the processing means the PLC) may take into account the temperature of the gas when calculating the amount of gas admitted to the balloon. This makes it possible to 25 accurately measure the volume of gas within the balloon.

Preferably, the system further includes an enclosure for protecting the balloon from prevailing wind during filling and launching. The enclosure includes a main outlet hatch which, when closed, holds an inflated balloon within the enclosure and, when opened, releases the balloon to the atmosphere.

Preferably, an upper portion of the closure is formed such that, prior to opening of a door of the outlet hatch, the balloon rests against the door. The outlet hatch is preferably angled relative to the vertical plane so as to facilitate launching of the balloon from the outlet hatch.

In one embodiment the enclosure includes a rotatable base to allow at least a portion of the enclosure to rotate so that the outlet hatch can face in a desired direction. In use, the outlet hatch is directed down wind. Preferably, the rotatable base is driven by an electric motor but it may alternatively be rotated by hand or other means.

In a particularly preferred embodiment, the enclosure includes a vent hatch, opposite the outlet hatch, to allow air to enter the enclosure and to aid launching of the balloon within the enclosure. When the vent hatch is opened, air entering through the vent hatch serves to push the balloon from the outlet hatch.

This greatly reduces sheer forces acting on the balloon and reduces the likelihood of the balloon rupturing as it leaves the enclosure.

In one embodiment the vent hatch is mechanically operated to open when the outlet hatch is about half open. The vent hatch may be independently operated but, preferably, is mechanically linked to the outlet hatch so that opening 15 of the outlet hatch also causes the vent hatch to open.

Preferably, the main outlet opening faces in a substantially horizontal direction.

BRIEF DESCRIPTION OF THE DRAWINGS To assist the further understanding of the invention, reference is now made to the accompanying drawings which illustrate preferred embodiments of the present invention. It is to be appreciated that these embodiments are given by way of illustration only and the invention is not to be limited by this illustration.

In the drawings: -Figure 1 is a system diagram for a prior art remotely controlled balloon 25 launching system.

o. Figure 2 is a site layout map for the prior art system shown in Figure 1.

Figure 3 is a flow diagram of a balloon launching system in accordance with a preferred embodiment of the present invention.

Figure 4 is a block diagram of the control system employed in the balloon launching system of Figure 3.

Figure 5 is a side elevation of a balloon launch enclosure in accordance with another aspect of the invention.

6 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Figures 3 and 4 show an exemplary embodiment of a balloon launching system in accordance with the present invention. The system includes several separate but interrelated systems. Each of these systems is controlled from an operator interface 10 which provides a visual representation of the whole system, as well as monitoring and control functions. The separate systems include: a launch table of the general type described above, located within a launch enclosure 12 in the field and including a movable filling nozzle 14, movable between a filling position and a release position, under the action of a pneumatic cylinder 16.

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:00000 000** 00.00 000* 0 ::00* a compressed air system 18 to provide driving force for the pneumatic cylinder 16.

an ambient air system 20 providing a flow of ambient air to the launch table in order to stabilise the temperature of a transmitting device (not shown) which, in use, is tethered to the balloon.

a water spray control system 22 to minimise electrostatic charges.

hydrogen monitoring and flow control systems 24 including solenoid operated valves to control the flow of hydrogen gas to the filling nozzle 14.

processing system including a Programmable Logic Controller (PLC) 30 to monitor and control all functions of the system.

operator interface 10 including a Personal Computer (PC) running Supervisory Control and Data Acquisition (SCADA) software to provide a visual representation of the system and enable an operator to monitor and control S-operation of the system.

S 15 Similar to the prior art system described above, the balloon launching system of the present invention is remotely monitored and controlled from a site office which is located a safe distance from the launch enclosure 12. The operator interface PC/SCADA system 10), the processing system PLC 30) and a Remote Input/Output (RIO) system 32 are located in the site office.

20 The source of hydrogen 26 may be bottled gas or it may be a hydrogen generator. In either case, the hydrogen source is also located a safe distance from the launch enclosure 16.

Hardware and Software Components Based on the latest PLC technology with desk top PC based graphics control, the inventor has designed the remote balloon launching system utilizing the latest 'Intrinsically Safe' I/O system, coupled with a powerful PLC, thus giving an excellent combination of field control. The balloon launching system has the added benefit of control from anywhere in the world via Internet connection. The design and construction has undergone a full hazard and operability (HAZOP) study, and gives an extremely safe operational environment for hydrogen handling/storage. The balloon launching system has a designed maintenance cycle of a minimum of 5 years, with all instrumentation fault diagnostics, ranging and calibrations performed by the same 'internet' connected PC, using HART protocol.

The SCADA system employed in the present invention is a commercially available, computer based software system called Citect. This software is produced by Ci Technologies of Australia. It is configured in the present balloon launching system to include the following features: Current alarm indication and historical summary; Launcher system interactive mimic displays; Data logging and trend displays; Report generation (optional); Sequence control and monitoring; Reconfiguration and modifications to system (password protected).

It is preferable to run the PC system in a Microsoft Windows environment for the ability to remotely administer the machine.

S 15 It is also desirable to have access to a printer 34 from the PC 10 that is running Citect. The printer can be used to provide a hard copy of a mimic screen, a data trend or an optional daily launch report.

The SCADA system is configured to operate as a stand alone I/O (Input/Output) Server. This machine has full operation and control functions with 20 access rights being restricted via individual password protection.

The facility to remotely access this machine for future unmanned systems is possible via a number of different methodologies.

o The PLC 30 is an Allen Bradley SLC5/05 and incorporates the following equipment: o Power supply for processing unit and input/output rack; Programming software to enable program generation, editing, monitoring, upload and download from a PC; All necessary software and software development for the complete system requirements; o A modbus interface card for accessing the real-time status of I/O from the RIO system; and SProgram documentation including: Complete listing of mnemonic labels and comments for all I/O (including internal registers); Input/Output allocation tables (including mnemonics as above); and Ladder logic diagrams.

The PLC is located in a main control cabinet to be installed in the site office. Communications to the SCADA is via the CPU communications port 36 (port 0) using RS232 DF1 protocol or Ethernet. Communications to a programming PC 38 is via the CPU communications port 40 (port 1) using the DH485 protocol. A 1747-PIC is provided to allow conversion from the DH485 protocol to the standard RS232 used by a PC serial port.

The PLC also contains a Prosoft Modbus communications interface module 42. This module has two ports, however only one is required at this stage *0 .0 o and is connected via RS485/422 protocol to the RIO system 32.

15 The remote input/output (RIO) system 32 includes an MTL 8000 series process I/O system. This system is produced by Measurement Technology S.Limited of Bedfordshire, England. It provides "intrinsically safe" inputs and outputs for hazardous area field wiring, thereby making ignition of combustible gases impossible by restricting the energy available in areas where the risk is S 20 high. In the present invention the RIO is configured to incorporates the following S" features: Modbus BIM (Bus Interface Module) interfaces to PLC via modbus RS485/422 Non-intrinsically safe rack and I/O modules Intrinsically safe rack and I/O modules Power supplies PC software for configuring BIM module.

PLC CONTROL: The PLC 30 provides equipment and sequence control and monitoring functions as described below: Equipment Monitoring: The PLC continuously monitors the status of all equipment which provides inputs to the system. The status of these inputs is monitored regardless of the launcher control mode or whether the item is in operation. This monitoring process provides information to allow the following: SCADA display of the current status of equipment (eg normal/fault, running/stopped, open/closed); SCADA logging of all status changes (if required); SCADA totalisation and logging of hours of operation (if required); and Fault discrepancy logic as described below.

•Drive Control: 15 Where provided for, the PLC can start an item of equipment by energising the 'Stop' output and pulsing the 'Start' output until a 'Running' signal is received back from the field. To stop the item of equipment the 'Stop' output is deenergised.

Valve Control: Each automatic valve is provided with one output for control which is l:ll•: energised to 'Open' the valve for a normally closed valve or energised to 'Close' S for a normally open valve.

Fault Discrepancy Logic: Software based Fault Discrepancy Logic is provided which utilises the equipment status inputs. The PLC polls the appropriate 'Running' input and 'Run' output status and if, after a predetermined period, the two states do not agree the 'Failed' fault discrepancy alarm is initiated.

On detection of a fault discrepancy alarm, the PLC responds as follows: the equipment 'Run' output is de-energised; 9 an alarm will be initiated; and appropriate sequences are halted or aborted.

11 It is not possible to re-select equipment or reinitiate a sequence involving failed equipment until the fault discrepancy logic has been reset in the SCADA.

Analogue Inputs: All analogue inputs are provided with the facility to initiate two low and two high level alarms. Each of the alarm set points are independently adjustable over the full range of the process variable.

Analogue signals proportional to the analogue input signals received by the PLC are communicated to the SCADA for display and/or logging as required.

Alarms: Alarm logic is performed in the PLC with alarm set points being determined from the PLC program or SCADA inputs as appropriate. SCADA established alarm set points are adjustable only by authorised personnel and the SCADA system incorporates a password protection system to prevent oO.o 15 unauthorised adjustment of alarm parameters.

Alarms are displayed in an alarm window built in as part of all display S.:i screens, are added on occurrence to the current alarm list and are logged within the SCADA (an event/alarm printer can also be added to trace all activity on the i system to a hardcopy printout). Each alarm displays the appropriate description o0020 together with the time date of occurrence.

Three alarm priorities are provided to distinguish between plant shutdown alarms, critical and non-critical alarms.

An alarm is acknowledged at the SCADA. Acknowledged alarms clear if field conditions revert to normal. Unacknowledged alarms, where field conditions revert to normal, do not clear until they have been acknowledged.

When an alarm is acknowledged or cleared, the event is logged within the SCADA (and on the event/alarm printer if included) with the time of acknowledgment or clearance being recorded.

The current alarm list (either full page or window display) shows acknowledged and unacknowledged alarms in different colours.

SCADA CONTROL: Each item of equipment which can be operated automatically by the PLC, will be displayed on the SCADA launcher mimic. Each item of equipment will have the following possible SCADA states: 9 AUTO under auto sequence control by the PLC; OFF isolated from SCADA and PLC control; and MANUAL allows Start/Stop/Open/Close from SCADA by operator but will not be available to auto sequence.

Each of the SCADA states are mutually exclusive and are selected by the operator from the SCADA screen.

FIELD CONTROL: Each item of equipment which can be operated automatically by the PLC, can also be operated manually from the field.

•Valves: oI** 15 Field operation of a valve is possible at all times. The field operation will override the PLC operation.

COMPRESSED AIR SYSTEM Automatic Operation: Under normal operating circumstances the air compressor (M002) will run S 20 in automatic control. The operator will select the device to Auto control from the SCADA mimic screen. When placed in Auto mode the power will be switched to the compressor. The air system pressure will then be monitored by the PLC and if it drops below the low level alarm point the compressor will be started. Once running the compressor will continue to run until the air system pressure goes above the high level alarm point.

A high air system pressure switch is hard wired into the compressor run signal so that the compressor will cut out if the high pressure switch level is reached before the software generated high level alarm.

Manual Operation: If selected to manual control the air compressor can be started and stopped from the SCADA mimic screen. Once started in manual mode the air 13 compressor will continue to run until either the air system high pressure switch or the software generated high level alarm is reached.

The compressor can be operated in manual from the push buttons on the electrical control cabinet. Once power is established to the compressor the start button will run the compressor until the air system high pressure switch level is reached. The compressor can be stopped by use of the power off button.

Air Receiver Pressure Low Indicator: Regardless of the mode of operation of the air compressor, if the Air System Pressure Low Alarm is current, then the PLC will set the Air Receiver Pressure Low output on to enable the indicator on the front of the electrical control cabinet.

Emergency Shutdown System (ESD): Operation of the plant ESD system will not effect the operation of the air compressor. The compressor will continue to operate normally in all control •15 modes.

AMBIENT AIR SYSTEM Automatic Operation: Under normal operating circumstances the ambient air fan (FN001) will run i in automatic control. The operator will select the device to Auto control from the 20 SCADA mimic screen. When placed in Auto mode the fan will be available for the °oioo° automatic launch sequence. In the launch sequence the fan will be started at step 1 (See Launch Sequence Description below) and will continue to run until the final o step (step 11) of the sequence. If the sequence faults whilst the fan is running the fan will continue to operate on the fault step. The period the fan runs for prior to balloon filling is operator adjustable from the SCADA.

Manual Operation: If selected to manual control the ambient air fan can be started and stopped from the SCADA mimic screen. Once started in manual mode the fan will continue to run until either control is switched from manual or it is stopped from the SCADA screen. Activating the stop button on the electrical control cabinet will always stop the fan.

14 The fan can be operated in manual from the push buttons on the electrical control cabinet.

Ambient Air Flow Low: An ambient air flow low alarm is generated by the PLC once the fan has been operating for a proof time. The occurrence of this alarm will halt the automatic launch sequence.

Ambient Air Supply Temperature: The temperature is screen monitored logged, for future comparisons.

Emergency Shutdown System (ESD): Operation of the plant ESD system will not effect the operation of the ambient air fan. The fan will continue to operate normally in all control modes.

Hydrogen Supply In the event that a hydrogen generator is employed, rather than bottled "i gas, the balloon launching equipment may also control operation of the hydrogen 15 generator as follows: Automatic Operation: Under normal operating circumstances the hydrogen generator (HG001) will run in automatic control. The operator will select the device to Auto control 2 from the SCADA mimic screen. When placed in Auto mode the generator will be 20 powered up and will run under it's own local control system.

Manual Operation: :If selected to manual control the power to the hydrogen generator can be turned on or off from the SCADA mimic screen.

The hydrogen generator can be operated in manual from the push buttons on the electrical control cabinet.

Interlock Alarms: Three digital switched from the hydrogen generator are wired into the RIO.

The status of these interlocks are retransmitted by the RIO as outputs and will disable the generator.

Emergency Shutdown System (ESD): Operation of the plant ESD system will isolate the hydrogen generator. It will not be possible to run the generator again until the ESD has been reset.

Hydrogen Flow Control A smart pressure transmitter PIT senses hydrogen pressure at the source point of input. Downstream from the pressure transmitter PIT is a flow transmitter FIT which accurately senses the flow of hydrogen. An isolation valve XV1 has been positioned after the flow transmitter to give complete shut off of the gas supply. These three items are installed close to the source of hydrogen supply.

Downstream of this isolation valve XV1 is a flow regulator FCV which is used to limit the flow of gas. A stainless steel tube runs from the flow regulator FCV to a second isolation valve XV2 at the launch table. This isolation valve XV2, as with the first isolation valve XV1, is controlled by the PLC system and gives feedback to the screen-based graphics control of position indication. The benefits of this o•O.

S. 15 system are that: There is great accuracy in the metering of hydrogen to the balloon; Accuracy of the repeatability, as best as can be provided with current technology; Less or no air is introduced into the balloon. With prior art systems, about 2 kg of air was introduced into the balloon as a result of air being present in the pipe(s) between the hydrogen supply and the launch table in the field. This air in the balloon reduces the lift available, and hence the height to which the balloon will reach. The system of the present invention eliminates the presence of air in the gas supply pipes by means of the isolation valves XV1 and XV2. This eliminates or minimises the presence of air in the balloon, thus leading the greater lift and correspondingly greater altitude being achieved by an equivalent balloon.

Cheaper to operate because less hydrogen is used for a given balloon to be launched to a given altitude.

9 Due to the selection of instrumentation, leak detection is possible by closing isolation valves XV1 and XV2 and monitoring the pressure at the 16 pressure transmitter PIT any leaks will be apparent as a gradual drop in pressure).

Automatic Operation: Under normal operating circumstances the hydrogen isolation valves XV1 XV2 will run in automatic control. The operator will select the device to Auto control from the SCADA mimic screen. When placed in Auto mode the isolation valves will be automatically open during the automatic launch sequence on two different occasions. The first occasion is the priming of the line with hydrogen and the other is the filling operation. These occur at step 4 and step 7 respectively.

In a basic form of the system, the volume of gas to be admitted to the balloon is determined by manually adjusting a fill timer set point. Thus, given a predetermined flow rate, as established by the flow regulator FCV, the volume of gas is directly proportional to the time period for which the isolation valves XV1 and XV2 are held open.

i 15 This basic form of the system is not highly accurate, however, due to variations in pressure of the gas source, variations in flow rate as a result of an imperfect flow regulator, and variations in temperature of the gas. A preferred S form of the system therefore measures actual flow rate and calculates the actual volume of gas being admitted to the balloon taking into account pressure and/or temperature.

Manual Operation: If selected to manual control from the SCADA the hydrogen isolation Svalves XV1 XV2 can be opened and closed manually from the SCADA screen.

The hydrogen isolation valves XV1 XV2 can also be operated in manual mode from the push buttons on the electrical control cabinet.

Supply Flow, Pressure Temperature: In the preferred form of the system, hydrogen supply pressure, temperature and flow signals are used for calculation of gas volume being admitted to the balloon, and for monitoring and generating of alarms.

Correction of flow for pressure and temperature is done using the 'ideal gas' law to change the flow to standard conditions of one atmosphere and zero degrees Celsius.

17 To do this, the measured flow is multiplied by the square root of the measured absolute pressure and divided by the square root of 273.2 divided by the measured temperature in degrees Kelvin (degrees Kelvin measured temperature 273.2 The corrected flow rate is then used to calculate the actual volume of gas being admitted to the balloon. This is done by integrating the actual flow rate (measured in cubic meters per hour, for example) over time, so as to determine the actual volume (measured in cubic meters, for example).

When a predetermined volume of gas has been admitted to the balloon, the isolation valves XV1 and XV2 are closed.

In one example system, model 3051 pressure and flow transmitters by Fisher-Rosemount may be used. These have been found to provide sufficient accuracy for use in the system of the present invention. A suitable temperature *eo• transmitter is model 644H produced by Fisher-Rosemount.

Emergency Shutdown System ESD: 15 Operation of the plant ESD system will close the hydrogen isolation valves XV1 XV2. It will not be possible to open the valves again until the ESD has been reset.

Filling Nozzle Automatic Operation: 20 Under normal operating circumstances the hydrogen filling nozzle will run in automatic control. The operator will select the device to Auto control from the SCADA mimic screen. When placed in Auto mode the filling nozzle will be moved forward during the automatic launch sequence prior to and during filling of the balloon at steps 6, 7 8. At step 9 the nozzle will be moved back to allow the balloon to launch.

Manual Operation: If selected to manual control from the SCADA the hydrogen filling nozzle can be moved forward or back manually from the SCADA screen.

The hydrogen filling nozzle can be operated in manual from the push buttons on the electrical control cabinet.

18 Emergency Shutdown System: Operation of the plant ESD system will leave the hydrogen filling nozzle in its current position.

GENERAL

All field instrumentation are Hart Smart compatible and can be calibrated and set up from remote locations. The instrumentation, due to its' accuracy, will take more than 15 years to wander from its' programmed set points and being smart, will report internal fault diagnosis to the computer system. Therefore it is envisaged the maintenance of this equipment will be somewhere between 10 and 15 years.

DESCRIPTION OF OPERATION From the screen based SCADA control system 10 the operator would select the size of balloon to be launched. He would then bring forward the filling nozzle cylinder 16. The system is then held in "safe mode" until a balloon 29 is 15 installed on the filling table and the filling nozzle 14 has been engaged. When the operator leaves the launch enclosure 12, closing the enclosure door 13 enables .the system to continue. From the SCADA system 10, the operator initiates the filling sequence and hydrogen flows to the balloon 29. On completion of the filling sequence, the system pauses and the operator can release the balloon, from either the screen or at release push buttons strategically located. The balloon 29 is released by the return of the filling nozzle cylinder 16. The system is now ready for another balloon.

Should a training cycle be required, the hydrogen can be purged to ooe.

atmosphere and a full balloon inflation cycle completed using air. On completion 25 of a training cycle, the system can return to hydrogen by purging the air and filling with hydrogen. These two systems are fully automatic and operator error has been removed.

19 LAUNCH SEQUENCE DESCRIPTION Motor Control: Step 0 Air Compressor: Outputs: Power on output pulsed.

Power off output pulsed.

Run/stop output on (Closed) output off (open).

Inputs: Running (screen indication).

General trip (screen indication).

Main circuit breaker open (screen indication).

S PT-1109 stops compressor on high, starts compressor on low.

o 15 NOTE: provide a bar scale on screen for operator high and low settings.

PT-009: Analog representation of signal (in kPa). Hart unit, Fault diagnosis, and Calibration.

SAmbient Air Fan: Step 1 20 Outputs: :o Start output pulsed.

Stop output pulsed.

Inputs Running (screen indication).

General trip (screen indication).

Main circuit breaker open (screen indication).

Hydrogen Generator Power Supply: Step 2 Outputs: Power on output pulsed.

Power off output pulsed.

Inputs: Running (screen indication).

General trip (screen indication).

Main circuit breaker open (screen indication).

Warning Beacons: Step 3 Outputs: On/Off output on (Closed) output off (open). This output is initiated when the balloon is in launch mode, the output will be timed before the launch mode and for a preset time after the launch made. Or if the ESD has been initiated.

The operator will have the option of changing the times from the screen.

Hydrogen Supply Flow: Step 4 Outputs: Low flow alarm.

High flow alarm.

Extra low flow alarm/leak detection.

t Inputs: 20 Analog in for flow Hydrogen Supply Pressure: l• Step 5 Outputs: Low low pressure alarm.

Low pressure (start compressor).

High pressure (stop compressor).

High high pressure alarm.

Inputs: Analog in for flow Sequence Start: Step 6 Outputs: None.

Inputs: None.

NOTE: This control push button is screen based. On initiation, the automatic balloon filling sequence will commence.

Balloon Launcher Water Spray Valve: Step 7 Outputs: Valve open.

Inputs: Open position limit switch. (screen open/closed indication).

Hydrogen Supply Isolation Valves: 15 Step8- Outputs: Valve A open.

Valve B open.

Inputs: 20 Open position valve A limit switch. (screen open/closed indication) SOpen position valve B limit switch. (screen open/closed indication) Hydrogen Filling Nozzle. Piston Solenoid Valve: Step 9 Outputs: Nozzle forward.

Nozzle back.

Inputs: Nozzle forward limit switch. (screen open/closed indication).

Nozzle back limit switch. (screen open/closed indication).

NOTE: This valve fails to the stay-put position. In the event of and ESD initiation the valve will stay-put, filling will be halted. On clearing the fault/ESD, the filling sequence will resume from the point of interruption.

Balloon Launcher Enclosure Door Step 10 Outputs: Warning beacons on.

Inputs: Door limit switch.

NOTE: Activation of this limit switch inhibits the opening of the hydrogen isolation valves, and prevents movement of the filling nozzle cylinder.

Ambient Air Fan Step 11 Inputs: *15 Low flow.

Outputs: Alarm.

Balloon Filling Sequence: Operator makes selections, Select balloon etc.

20 Initiate screen based push button.

Warning beacons operating.

Start ambient air fan.

Air supply sufficient? Delay minutes (operator set).

Launch enclosure water spray is initiated.

Delay minutes.

Launch enclosure water spray off.

Open hydrogen isolation valves.

Hydrogen supply pipe is purged with hydrogen.

Delay minutes (variable).

Close hydrogen supply valves.

0 Pause (operator set).

0 Filling nozzle, cylinder forward.

Confirm filling nozzle in position.

Open hydrogen supply valves.

9 Timed filling dependent on volume (operator set).

Close hydrogen supply valves.

0 Pause.

Balloon launch release push button operated (field or screen).

0 Filling nozzle cylinder back.

Confirm filling nozzle in position.

Launch enclosure water spray initiated.

Hydrogen line air purge initiated.

Delay minutes (variable).

Air purge off.

a Launch enclosure water spray off.

Warning lights off.

Ready.

:.Fgr LAUNCH ENCLOSURE 2Figure 5 shows a general arrangement of one preferred embodiment of a 20 launch enclosure 50. The enclosure is intended to house a balloon launch table S: as described above and to protect the balloon from prevailing winds during a filling and launch operation. The enclosure includes a main outlet hatch 52 shown, in solid lines in Figure 5, in a closed position and shown, in broken lines, in an open position 52'. The angle A of the hatch 52 may be varied to suit the site location of the enclosure. For example, the angle A would be less for locations where greater wind velocities are encountered.

Opposite the main hatch 52, the enclosure 50 also includes a vent hatch 54. The vent hatch 54 allows air to enter the enclosure to aid launching of the balloon within the enclosure. Compressed air may be added to aid air flow if necessary. In figure 5, the vent hatch 54 is shown in solid lines in its closed position and shown in broken lines 54' in its open position.

The enclosure 50 also includes a rotatable base 56 which allows it to rotate so that the main outlet hatch 52 is facing down wind. Once a balloon is inflated, the outlet hatch 52 is opened, thereby releasing the balloon. At approximately the half way point for the outlet hatch 52 opening, the rear vent hatch 54 will also open and allow the balloon to be pushed from the enclosure by air flow entering through the vent hatch 54.

In the embodiment shown, the main outlet hatch 52 is opened and closed by a pneumatic cylinder 58. Operation of the vent hatch 54 is controlled by a cantilever link arrangement 60 including levers 61-63 and connecting shaft 64 as shown. Lever 61 is connected to the outlet hatch 52, lever 63 in connected to the vent hatch 54 and the two levers 61, 62 are connected together by shaft 64. The shaft 64 is moved substantially horizontally (in Figure 5) by pivotal movement of lever 62 in response to actuation of the pneumatic cylinder 58. Once again, solid t lines in the drawing represent the closed position whilst broken lines represent 15 the fully open position. Preferably, the main outlet hatch 52 and vent hatch 54 i are mounted using spring tension so as to allow rapid decompression of the enclosure 50 in the event of an explosion.

The enclosure 50 can be rotated by hand or by an electric motor so as to S.direct the main outlet hatch 52 downwind.

20 The launch enclosure 50 is preferably manufactured from steel and includes a marine style access hatch 65 for loading of the balloons.

A recess 66 may be provided in an upper portion of the enclosure 50 to support a transmitter attached to the balloon.

Although preferred embodiments of the invention have been described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.

Claims (19)

1. A system for filling a balloon with a fluid medium and launching the balloon, the system including: a filling nozzle for admitting the medium to the balloon, measurement means for measuring flow of the medium to the filling nozzle; flow control means for controlling the flow of the medium to the filling nozzle; and processing means, responsive to the measurement means, for establishing according to a predetermined criteria when a predetermined amount of the medium has been admitted to the balloon and, upon reaching the predetermined amount, causing the flow control means to terminate the flow of the medium and the filling nozzle to disengage with the balloon, thereby launching the balloon. 9

2. A system as defined in claim 1 wherein the predetermined criteria relates o to any one or a combination of: pressure, flow rate and temperature of the medium.

3. A system as defined in either claim 1 or claim 2 wherein the criteria is used as a basis for calculating a volume of the medium. 9 9o.. 20

4. A system as defined in any one of the preceding claims wherein the processing means includes a programmable logic controller.

A system as defined in any one of the preceding claims wherein the processing means is connected to field instrumentation and control equipment located in the region of the filling nozzle via intrinsically safe inputs and outputs.

6. A system as defined in any one of the preceding claims wherein the measurement means includes a flow transmitter and a pressure transmitter.

7. A system as defined in claim 6 wherein the measurement means further includes a temperature transmitter and the processing means takes into account the temperature of the medium when calculating the amount of medium admitted to the balloon.

8. A system as defined in any one of the preceding claims, further including an operator interface connected to the processing means for providing a visual representation of the balloon launching system and for providing operational data.

9. A system as defined in any one of the preceding claims wherein the processing means and operator interface are adapted to be located remotely from the region of the filling nozzle.

A system as defined in claim 8 wherein the operator interface includes a personal computer running supervisory control and data acquisition software.

11. A system as defined in any one of the preceding claims, further including *...actuating means operably connected to the processing means for disengaging S 15 the filling nozzle.

12. A system as defined in claim 11 wherein the actuating means is a pneumatic cylinder. oioo

13. A system as defined in any one of the preceding claims, further including an enclosure for protecting the balloon from prevailing wind during filling and °log 20 launching, the enclosure including a main outlet hatch which, when closed, holds an inflated balloon within the enclosure and, when opened, releases the balloon the atmosphere.

14. A system as defined in claim 13 wherein an upper portion of the enclosure is formed such that, prior to opening of a door of the outlet hatch, the balloon rests against the door.

A system as defined in claim 13 or claim 14 wherein the outlet hatch is angled relative to the vertical plane.

16. A system as defined in any one of claims 13 to 15 further including a rotatable base to allow at least a portion of the enclosure to rotate so that the outlet hatch can face in a desired direction.

17. A system as defined in claim 16 wherein the rotatable base is driven by an electric motor.

18. A system as defined in any one of claims 13 to 17 further including a vent hatch, opposite the outlet hatch, to allow air to enter the enclosure.

19. A system as defined in claim 18 wherein the vent hatch is mechanically operated to open when the outlet hatch is about half open. A system substantially as hereinbefore described with reference to Figures 3 and 4 of the accompanying drawings. "DATED this 20 th day of July 2006 ENGERTROL PTY LTD WATERMARK PATENT TRADE MARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA *99U P19493AU00