The Standard Combustion Control System:

Transcription

1 Bergmans Mechatronics LLC The Standard Combustion Control System: A General Purpose Design to Simplify Development and Testing of Combustion Devices Thermocouple Input Module Analog Input Module TC Inputs (48) Analog Input Panel (120 receptacles) Transducer Excitation Power Supply Control Power Output Module Control Power Output Panel (48 receptacles) Relay Banks (24 Channels) (x2) Power Supplies (24 VDC at 33A) (x3) Rackmount PC USB Output Analog Input Board (x3) USB Input March 2009 BML Document Number: Doc 2009-P Bedford Lane, Unit A, Newport Beach, CA Phone: Fax:

2 1. Introduction Nearly every practical combustion system requires some form of control and monitoring equipment for safe and effective operation. One class of system with a requirement for such equipment is test stands which are used to evaluate the performance of prototype or experimental combustion devices such as rocket motor and oxy-fuel combustion systems. The development of control and data acquisition systems for this application can require considerable expenditures of time and effort associated with the component selection, hardware design and software development. These expenditures arise from activities which include: i) the selection of proper components from a multitude of available hardware options; and, ii) the development of complex and robust, yet intuitive software. To simplify the combustion test stand development process, Bergmans Mechatronics LLC (BML) offers a Standard Combustion Control System (Standard CCS) package consisting of a set of pre-selected hardware components and test-proven software (Figure 1). The only customization necessary by BML is the modification of the Graphical User Interface (GUI) to match that of the client s combustion system test stand. The hardware components in the package are those which meet the basic requirements common to most combustion system developers. from stand Thermocouple Input Module from stand Oxy-Fuel Test Stand GUI to stand Analog Input Module Rocket Test Stand GUI Control Power Output Module Rackmount PC Standard Hardware Customized Graphical User Interface Standard Control and Data Acquisition Functions Software: Custom GUI and Standard Core Functions Figure 1. Standard Combustion Control System Package BML s Standard CCS design features: 120 analog voltage inputs channels; 48 thermocouple input channels; and, 48 digital output channels capable of driving solenoids or other actuators. The control software allows system operation in manual mode or automatic sequencing mode and provides the capability to view and record test stand instrumentation data. This document provides details on the Standard CCS hardware (Section 2) and software (Section 3). Cost and terms information is presented in Section 4, and Section 5 provides information about BML. 1

3 2. Hardware The hardware of the Standard Combustion Control System consists of the four major components illustrated in Figure 2: i) a rackmount PC; ii) a Thermocouple Input Module; iii) an Analog Input Module; and, iv) a Control Power Output Module. Details of each of these components are presented below. Note that hardware selections identified here are the most suitable at the time of the preparation of this document. Hardware selections may change if superior components are identified. Thermocouple Input Module TC Inputs (48) Analog Input Module Analog Input Panel (120 receptacles) Transducer Excitation Power Supply Control Power Output Panel (48 receptacles) Control Power Output Module Relay Banks (24 Channels) (x2) Power Supplies (24 VDC at 33A) (x3) Rackmount PC USB Output Analog Input Board (x3) USB Input Figure 2. Combustion Control System Hardware Overview 2.1 Rackmount PC The system software re sides on an industrial rackmount PC from CyberResearch Inc. (Branford, CT) with a clock speed of at least 2.2 MHz; at least 5 PCI expansion slots; and the the Microsoft Windows XP Professional operating system. The LabVIEW-based CCS software is described in Section 3. 2

4 During a hot firing on a test stand, the system operator, located in a control room a distance of at least several hundred feet from the stand, operates the rackmount PC from a remote PC via an Ethernet connection using the Remote Login capability of Windows XP. 2.2 Temperature Input Thermocouple (TC) data is input to the system via a TEMPpoint thermocouple interface, manufactured by Data Translation, Inc. (Marlboro, MA). The TEMPpoint model DT (Figure 3) is a 48 channel, USB-based interface capable of sampling TC data at 10 samples/sec per channel ( This device allows any arbitrary combination of B, E, J, K, N, R, S, and/or T TC types to be connected to the unit simultaneously. A rackmount accessory kit enables the unit to be mounted in a standard 19 rack. Figure Channel, USB-based TEMPpoint thermocouple interface from Data Translation, Inc. 2.3 Analog Input The system is designed to accept 120 analog input channels. Analog signals are acquired by the PC using a set of three PCI-6225 data acquisition boards from National Instruments Corp. (Austin, TX). Each PCI-6225 board features 40 differential input channels. Input ranges for each channel are between +/- 220 mv and +/-10 V. Input ranges for each channel can be set on a per channel basis. The three PCI-6225 boards are located in the rackmount PC. The analog input sampling rate and storage to data file is at least 200 samples/sec per channel. Transducer excitation voltage is supplied to each input channel connector to provide power, as required, to the system transducers. Since the excitation voltage is dependent on the type and number of transducers in the system, details related to the transducer excitation power supply(ies) will be determined in consultation with the client. Analog signals are input to the system via a set of 120 Amphenol PT02A-10-6S 6-pin female receptacles (Figure 4) mounted on the front panel of the Analog Input Module. This type of connector is employed due to its robust design. The recommended plug for this connector is equally rugged and features a built-in strain-relief mechanism. Figure 4. 6-Pin Bayonet-Coupled Receptacle (Amphenol PT02A-10-6S) 3

5 2.3 Digital Output In the Standard CCS design, it is assumed that all electromechanical actuators on the test stand to be controlled directly by the CCS are of a discrete type and have only two settings, either on/off or open/closed. Actuators of this type include: i) small solenoid valves which provide direct control of fluid flow; ii) pilot valves for pneumatically controlled fluid flow valves; and, iii) relays and contactors which in turn control larger components such as pumps, heaters and igniters. Based on this assumption, output power for control of the actuators is provided by two USB-ERB24 relay modules from Measurement Computing Corp (Norton, MA). Each relay bank consists of 24 mechanical relays which are each capable of switching up to 24 VDC at up to 6 A, although the CCS power budget limits the relay output to 2 A per channel. The relay modules are connected to the control PC via USB bus. Each output channel is fused for 2A and features flyback diodes to capture voltage transients which occur when switching inductive loads. Electrical power to the relay banks is provided by three VSCP-1K5-24 power supplies from V-Infinity (Tualatin, OR), each providing 24 VDC at up to 33 A using 120 VAC input power. Power output signals to the actuators are accessed through a set of 48 Amphenol PT02A-8-2P 2-pin female receptacles on the front panel of the Control Power Output Module. These receptacles are similar in design to the analog input receptacles, but are slightly smaller. The power supplies are enabled by a local key switch and computer-controlled relay. As an extra safeguard, an input for a physical emergency stop switch is provided. This switch is typically located at the operator control station and provides an independent capability to the operator to shut down the test stand. 2.4 Rackmount Case The hardware components of the Standard CCS are mounted in portable, rackmount case manufactured by Georgia Case Company (Tucker, GA). This type of foam-lined case allows all of the system hardware to be isolated from physical vibrations and shock loads. BML has developed several systems using this type of case (Figure 5) and has had good success in safely shipping these systems using standard freight-forwarding shipping companies. LTS-100 Laser Temperature Sensor Transportable Load Cell Data Acquisition System Figure 5. BML systems featuring shock-resistant foam-lined cases 4

6 3. Software The Standard CCS software consists of three main components: i) Graphical User Interface; ii) data acquisition software; and, iii) control software. Each of these components is detailed below. The system software is written using the National Instruments LabVIEW graphical programming environment and executes within a Windows XP Professional environment on the rackmount PC. 3.1 Graphical User Interface The Graphical User Interface (GUI) software enables the user to interact with the underlying data acquisition and control code. The GUI provides the following features: a graphical representation of flowpaths, instrumentation and control components on the test stand; controls for individual system actuators; displays of data channels readings; system status indicators; and, ability to setup, verify, initiate and manually terminate relay auto-sequencing. The GUI for a notional oxy-fuel system, incorporating many of the features of previous BML systems, is shown in Figure 6. The CCS GUI will be customized by BML to match the design of the client s test stand. 3.2 Data Acquisition Software The data acquisition software will perform the following functions: i) receive data from the sensors via the data acquisition hardware; ii) convert the data to engineering units, as required; iii) send the data to the GUI; and, iv) log data to data file(s) at a user-prescribed rate. 3.3 Control Software The control software is responsible for controlling the actuators on the test stand. The control software features two modes of operation: i) Manual mode; and, ii) Automatic Sequencing mode. Manual Mode In Manual mode, the activation state of individual relays or groups of relays is determined by GUI button selections generated by the user. Relay synchronization logic, previously developed by BML (Figure 7), enables user-defined relay groups to be activated/deactivated as a set, based on a user-generated selection of a single GUI button. Automatic Sequencing Mode In Automatic Sequencing mode, relays are set based on a preprogrammed schedule, or sequence, of relay settings as a function of time. Execution of the sequence is initiated by the user. The system provides the capability to select between two user-defined hot firing sequences: i) an igniter firing sequence; and, ii) a full system firing sequence. A user-defined abort of the sequence may be initiated manually; or, automatically if a system parameter is determined to be outside of a predetermined range. Multiple software interlocks inhibit inadvertent execution of the automatic hot firing sequencer, as detailed in GUI screenshots of Figure 8. An added interlock feature not shown in this figure is that the sequencer Auto Start switch will only remain enabled and in the Enable position (Figure 8b) if all relays settings match a pre-programmed state. This feature ensures that the system is in the correct initial state at the beginning of a hot firing test. 5

7 Figure 6. Graphical User Interface for notional oxy-fuel combustion test stand a) Synchronization Off Valve 1 and Valve 2 b) Synchronization On Switching either Valve are controlled independently 1or 2 will automatically switch both valves Figure 7. Relay synchronization logic in BML combustion control system 6

8 a) Upon starting the software, the Auto Start switch and Auto Start Controls are disabled. The user must press the Ack (Acknowledge) button to enable the Auto Start switch. b) After pressing Ack, the user may set the Auto Start switch to Enable. The Start Option may then be selected. Available Start options are Igniter Test and System Start. If neither option is selected, the Start button remains disabled. c) When one of the start options is selected, the Start button is enabled and turns from red to green. At this point, the preprogrammed relay schedule will execute if Start is pressed. Figure 8. Multiple software interlocks inhibit inadvertent sequencer execution Optional Control Functions In consultation with the client, optional control functions, such as BML s existing automatic ignition detection logic (Figure 9) may be integrated into the software. Other optional control capabilities include open-loop and closed-loop functions of system parameters and support for modulation of proportional actuators. Combustor Temperature Maximum Combustor Temperature 3 High Combustor Temperature. Run Abort Sequence 1 Combustor Ignition Threshold Temperature Nominal Combustor Ignition Stable Igniter Operation Combustor Ignition Failed. Run Abort Sequence 2 Maximum Time to Threshold Temperature Time Figure 9. Optional BML ignition detection logic using combustor temperature as ignition criterion 7

9 4. Deliverables, Cost and Terms 4.1 Deliverables A list of major hardware components to be delivered with the system is included in Table 1. BML may make substitutions if more suitable components become available. Table 1. Major CCS Hardware Components Function Manufacturer Model Description Quantity Temperature Input Data Translation DT TEMPpoint USB Instrument for 1 Thermocouples (48 TC channels) Data Translation EP373 Rack mount kit for TEMPpoint 1 Analog Input National Instruments PCI-6225 Analog input card (PCI bus, 40 3 Differential Inputs) National Instruments SHC68-68-EPM SHC68-68-EP Noise Rejecting, Shielded 3 Cable, 1 m National Instruments SHC68-68 Basic Shielded Cable for M Series 3 Amphenol PT02A-10-6S Analog input panel-mount receptacle (6 pin, female, bayonet coupling) 120 Digital Output Measurement Computing USB-ERB24 Relay Module (24 Channels, max 6A per channel at 24 VDC) V-Infinity VSCP-1K VDC, 33 A power supply (110 VAC Input) Amphenol PT02A-10-2S Relay output panel-mount receptacle (2 pin, female, bayonet coupling) Computer Hardware CyberResearch PC 1 Monitor 1 Keyboard 1 Mouse 1 Other Hardware Protocase Rackmount enclosures 3 Georgia Case Portable rackmount case 2 An executable version of the LabVIEW-based CCS software will be installed on the rackmount PC. A backup CD containing the software executable will be provided. A User s Manual documenting the setup and operation of the system will also be included. System delivery will occur 8 weeks after receipt of an order. 4.2 Optional Items Optional items for consideration include: additional control functions (Section 3.3); instrumentation selection and sourcing service; field cable assemblies; on-site integration with the client s combustion system; user training; test support; and, software source code. The capabilities of the Standard CCS can optionally be expanded to include the use of: i) LabVIEW Real-Time for improved determinism; ii) National Instruments PXI or Compact DAQ platforms for improved reliability; and, iii) an Object Linking and Embedding (OLE) for Process Control (OPC) interface to Allen-Bradley equipment to enable interfacing to a wide variety of standard industrial equipment. Please contact BML for additional details

10 4.3 Cost The total cost for the Standard Combustion Control System is $84,500, including shipping costs to any location within the United States. Not included in this price are CA sales taxes, if applicable. 4.4 Terms Payment terms are 50% ($42,250) on receipt of order, 25% ($21,125) at the completion of hardware assembly and 25% upon system delivery. Payments may be made by check, wire transfer or major credit card. The system includes a warranty against defects due to normal use for a period of 6 months. 4.5 Notice In general, a combustion control system can be employed safely and reliably. While every reasonable effort is made to ensure that the BML Standard Combustion Control System meets this objective, improper setup or use of the system, or other factors, may result in property damage; or, injury to or death of personnel. Due to these potential consequences, i) BML offers the Standard CCS only to qualified combustion system developers and users; and, ii) purchasers are required to sign a Hold Harmless agreement. THE ULTIMATE RESPONSIBILITY FOR SAFE INSTALLATION, USE AND MAINTENANCE OF THE SYSTEM WILL BE WITH THE PURCHASER AND BML SHALL NOT BE LIABLE FOR ANY DAMAGES CAUSED DIRECTLY OR INDIRECTLY BY THE SYSTEM. 9

11 5. About BML BML is focused on the development of specialized electronic and software systems. The firm was founded in 2003 by Mr. John Bergmans and is based in Newport Beach, CA. Mr. Bergmans related experience with combustion test stand projects is summarized in Table 2. The software for each of these systems was written using National Instruments LabVIEW. Firings of the AirLaunch LLC Horizontal Test Stand using BML s software are shown in Figure 10. Table 2. Related Combustion Test Stand Projects Project BML Client(s) BML On-site Support Location Date Primary BML Activities HMX Phase 1 Small Orion Propulsion, Inc. Gurley, AL Feb 04 - Mar 04 Data acq and control software development Scale Motor Testing Trained Test Conductor on use of software AirLaunch Horizontal Orion Propulsion, Inc. Mojave, CA Dec 04 - May 07 Data acq and control software development Test Stand Air Launch LLC Trained multiple Test Conductors on use of software Protoflight, Inc. Operated test stand as Test Conductor Performed test data reduction and analysis Oxy-Fuel Combustion Confidential Confidential Nov 05 - present Control software development Test Stand Expanded capabilities of existing data acq software Expanded existing data acquisition hardware and added control system hardware AirLaunch Vertical Air Launch LLC Mojave, CA Jun 06 - Apr 07 Data acq and control software development Test Stand Developed data acquisition and control system hardware, in cooperation with Orion Trained Test Conductor on use of software NASA GOx/Methane Orion Propulsion, Inc. none Jun 06 - Jul 06 Data acq and control software development Thruster 2006 Firing 2007 Firing Figure 10. Photos of AirLaunch Horizontal Test Stand firings using BML-developed data acquisition and control software Prior to establishing BML, Mr. Bergmans worked at CFD Research Corporation (Huntsville, AL), from 1995 to During this period, he was responsible for the development and testing of control systems used to actively control several solid propellant gas generators as well as a solid rocket motor device. In addition, he developed data acquisition systems for a number of experimental programs. Mr. Bergmans received his B. Eng. (Mechanical) in 1992 and M. Eng. (Mechanical) in 1995, both from Carleton University in Ottawa, Canada. 10