Turbine Generator Gas Analyzer OPERATING INSTRUCTIONS FOR MODEL 2750 Turbine Generator Gas Analyzer P/N M76700 4/09/2012 DANGER Toxic gases and or flammable liquids may be present in this monitoring system. Personal protective equipment may be required when servicing this instrument. Hazardous voltages exist on certain components internally which may persist for a time even after the power is turned off and disconnected. Only authorized personnel should conduct maintenance and/or servicing.
Model 2750 Copyright © 2012 Teledyne Analytical Instruments All Rights Reserved. No part of this manual may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any other language or computer language in whole or in part, in any form or by any means, whether it be electronic, mechanical, magnetic, optical, manual, or otherwise, without the prior written consent of Teledyne Analytical Instruments, 16830 Chestnut Street, City of Industry, CA 91749-1580.
Turbine Generator Gas Analyzer Specific Model Information The instrument for which this manual was supplied may incorporate one or more options not supplied in the standard instrument. Commonly available options are listed below, with check boxes. Any that are incorporated in the instrument for which this manual is supplied are indicated by a check mark in the box.
Model 2750 Safety Messages Your safety and the safety of others is very important. We have provided many important safety messages in this manual. Please read these messages carefully. A safety message alerts you to potential hazards that could hurt you or others. Each safety message is associated with a safety alert symbol. These symbols are found in the manual and inside the instrument.
Turbine Generator Gas Analyzer IF YOU USE THE ANALYZER IN A MANNER OTHER THAN THAT FOR WHICH IT WAS INTENDED, UNPREDICTABLE BEHAVIOR COULD RESULT POSSIBLY ACCOMPANIED WITH HAZARDOUS CONSEQUENCES. This manual provides information designed to guide you through the installation, calibration and operation of your new analyzer. Please read this manual and keep it available. Occasionally, some instruments are customized for a particular application or features and/or options added per customer requests.
Model 2750 Table of Contents Safety Messages .......................................................................... iv Table of Contents ......................................................................... vi List of Figures ............................................................................. viii List of Tables ................................................................................ ix Introduction .................................................................................
Turbine Generator Gas Analyzer Maintenance................................................................................. 35 5.1 Routine Maintenance 35 5.1.1 Instrument Cleaning 35 5.1.2 Periodic Calibration 35 5.1.3 Leak Checking 35 5.2 Troubleshooting 36 Appendix ...................................................................................... 39 A.1 Specifications 39 A.
Model 2750 List of Figures Figure 1-1: Front View of the Model 2750 ..................................... 12 Figure 1-2: Gas Connections......................................................... 13 Figure 1-3: Electrical Connections ................................................. 13 Figure 1-4: Interface Panel ............................................................ 14 Figure 3-1: Electronics Block Diagram .......................................... 17 Figure 3-1: Electrical Connections ..............
Turbine Generator Gas Analyzer List of Tables Table 2-1: Thermal Conductivity for Selected Gases .................... 15 Table 4-1: Troubleshooting............................................................
Model 2750 DANGER COMBUSTIBLE GAS USAGE WARNING This is a general purpose instrument designed for use in a non-hazardous area. It is the customer's responsibility to ensure safety especially when combustible gases are being analyzed. The potential for gas leaks always exist. The operator of this equipment should fully understand the principles of operation for this instrument.
Turbine Generator Gas Analyzer Introduction Introduction 1.1 Overview The Model 2750 Turbine Generator Gas analyzer is a portable microcontroller based three-channel analyzer designed to measure the concentration of a single gas component in a binary mixture of gases. A special thermal conductivity cell responds to the difference in thermal conductivity between the components of a gas mixture and produces a signal output which is linearized over the specific range of interest.
Introduction Model 2750 The thermal conductivity sensor senses the thermal conductivity (T/C) or heat transfer rate of the sampled gas mixture and produces an electrical signal proportional to its heat conductivity. The T/C of the two gases in the mixture are significantly different. Because of this difference, the T/C of the gas mixture will be proportional to the percentage of each gas in the mixture.
Turbine Generator Gas Analyzer Introduction 1.4 Connections Gas connections are made on the top cover of the enclosure using the 1/8 tube inlet and 3/16” barb sample return fittings supplied. Power is supplied from a 9V DC adapter powered from a universal 90 – 264 VAC 47-63 Hz power source. The adapter plugs into a port on the side of the main panel. Figure 1-2 shows the gas connections and Figure 1-3 shows the electrical connections. A 0-1 VDC (0.
Introduction Model 2750 1.5 Operator Interface The front panel contains the operator interface and is readily accessible after opening the enclosure. It is simple, consisting of an OFF/ON switch and two rotary switches—one for selecting between analysis or calibration modes and the other for selecting the particular analysis range to be employed during measurement. On the same panel are trim pots used in calibrating the unit. A large 3.
Turbine Generator Gas Analyzer Theory of Operation Theory of Operation The heart of the Model 2750 Turbine Generator Gas Analyzer is the compact thermal conductivity cell. It senses differences in thermal conductivity of the gas mixture and generates an output signal based on the thermal characteristics of the gas. Since the sensor measures the absolute T/C using an internal thermal reference, a reference gas is not required. 2.
Theory of Operation Model 2750 As seen in table 2-1, CO2 has over 10% change in its thermal conductivity over the stated temperature range. This would result in unacceptable accuracy if the temperature of the gas were not controlled during analysis. Simply compensating for the temperature change is not sufficient unless the temperature fluctuation is extremely small.
Turbine Generator Gas Analyzer Theory of Operation 2.2 Electronics The Model 2750 uses a sophisticated miniature solid-state thermal conductivity sensor. This cell uses internal temperature compensation circuitry. It has both a reference and a measurement leg. The reference leg is driven by a constant current source and is used to heat the sensor’s substrate and to thermally compensate for ambient fluctuations. The sensor membrane then operates at a constant temperature around 70°C.
Theory of Operation Model 2750 width modulated (PWM) signal that is proportional to the gas concentration on that specific range. The PWM signal is passed through a low pass filter and is used to drive the display and the 0-1 VDC output signal (0.8 – 1VDC for the H2/Air range). The calibration switch is a rotary switch and allows either the percent of range signal or the output from the zero offset gain amplifiers to be sent to the display.
Turbine Generator Gas Analyzer Installation Installation The Model 2750 is a portable unit and can easily be setup close to the analysis site. To ensure accuracy, however, the analyzer should be setup in such a manner as to avoid: Direct sunlight Drafts of air Shock and vibration Temperatures below 30° F or above 110° F For best results, the analyzer should be placed as close as possible to the sample point to minimize the effects of sample line lag time on the analysis.
Installation Model 2750 shielded cable (nominally No. 22 wire size) between the analyzer output connector and the recording equipment. See Figure 3-1. Note: The signal output connector must be removed before closing the analyzer cover. Figure 3-1: Electrical Connections 3.2 Gas Connections Inlet gas connections are made at the gas control valve mounted on the upper panel. Connect the sample or calibration gas to the gas control valve using the 1/8” tube connector on the gas control valve.
Turbine Generator Gas Analyzer Installation there are no kinks or obstructions in the return line to avoid over pressurizing and possibly damaging the analyzer. Figure 3-2: Gas Connections 3.2.1 Vent Line Gases exiting the instrument should be vented to an area remote from the analyzer. This line must not be blocked! The following precautions must be observed in vent line installation: 1. Use 3/16” ID tubing to eliminate any backpressure or restricted flow. 2.
Installation Model 2750 Note: Always use two stage regulators on incoming gas lines from high-pressure sources. Sample pressure should be set between 0.5—30 psi, typically 5 psig at the analyzer. CAUTION: HIGH FLOW RATES CAN DAMAGE THE SENSOR. 3.3 Calibration The Model 2750 has been calibrated at the factory but will require periodic recalibration (zero and span).
Turbine Generator Gas Analyzer Installation 3.3.1 Zero Calibration Procedure 1. Connect the zero gas (100% CO2) to the sample valve. Make sure that the pressure regulator is set at approximately 5 psig. CAUTION: ALWAYS HAVE THE SAMPLE FLOW VALVE CLOSED WHEN TURNING ON THE SAMPLE (OR CALIBRATION GAS) STREAM. FLOW RATES GREATER THAN 2.5 SCFH CAN DAMAGE THE SENSOR. 2. If not already connected, connect the vent line. 3. Plug the DC adapter into the unit. See Figure 3-2.
Installation Model 2750 Figure 3-4: Interface Panel Showing Calibration Switch Position 7. Use the air/CO2 zero trim pot to adjust the display to zero. See Figure 3-4 above. 8. Move the calibration switch to the H2/CO2 position and verify that the range selector switch is on H2/CO2. Use the H2/CO2 zero trim pot to adjust the display to zero.
Turbine Generator Gas Analyzer Installation 9. After successfully zeroing with CO2 on the two ranges (air/CO2 and H2/CO2) close the sample valve and disconnect the CO2 source. Replace with 100% air source. Make sure that the pressure regulator is set at approximately 5 psig. CAUTION: ALWAYS HAVE THE SAMPLE FLOW VALVE CLOSED WHEN TURNING ON THE SAMPLE (OR CALIBRATION) GAS SOURCE. FLOW RATES GREATER THAN 2.5 SCFH CAN DAMAGE THE SENSOR. 10. Allow the air to flow through the analyzer.
Installation Model 2750 Please note that the 80-100% H2 in Air range is actually a 0-20% H2 in Air range with the 2750 doing the simple calculation to report the reading as hydrogen purity. Thus the zero adjustment uses 100% air. The zero calibration is now complete, continue with a span calibration. 3.3.2 Span Calibration Procedure Note: A zero calibration must be performed before a span calibration. CAUTION: ADJUST THE SPAN POT SLOWLY AS THE READING APPROACHES 100%.
Turbine Generator Gas Analyzer Installation Figure 3-8: Range Switch in AIR/CO2 Position 5. Adjust the air/CO2 span trim pot so that the display indicates 100% ±0.1%. See Figure 3-9 Figure 3-9: AIR/CO2 Span Trimpot 6. After successfully completing the span calibration on the air/CO2 range, close the sample valve and replace the air span gas source with the H2 span gas source. Make sure the regulator is set at approximately 5 psig. CAUTION: HYDROGEN IS A FLAMMABLE AND EXPLOSIVE GAS.
Installation Model 2750 Figure 3-10: Range Switch in H2/CO2 Position 9. Use the H2/CO2 span trim pot to adjust the display to 100% ±0.1%. See Figure 3-11 Figure 3-11: H2/CO2 Span Trimpot 10. Select The H2/Air range with the range selector switch.
Turbine Generator Gas Analyzer Installation 11. Adjust the display to read 100% ±0.1% using the H2/Air span trimpot. See Figure 3-13 Figure 3-13: H2/AIR Span Trimpot Please note that while the operating range of the analyzer is 80-100% H2 in Air, the electronics of the 2750 have been configured to allow for the use of 100% H2 span gas to calibrate this range to reduce the number of calibration gases that are required. The analyzer is now fully calibrated and ready for service.
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Turbine Generator Gas Analyzer Setup and Operation Setup and Operation 4.1 Setup Setup consists of: Calibrating the instrument Attaching the sample and vent lines Leak checking Attaching power cable Attaching output cable Turning the instrument on and allowing it to warm up Prior to using the Model 2750, it must be calibrated on all three ranges. Refer to Section 3.3 for calibration procedures. Once the instrument is calibrated, it may be transported to the analysis site.
Setup and Operation Model 2750 Figure 4-1: Power and Output Connections to the Model 2750 The thermal conductivity sensor relies on a precise heat load to produce an accurate thermally compensated output signal. The sensor must be allowed to heat up and equilibrate before using the instrument for analysis. Generally, warm up time takes about 15-20 minutes before the heater lamp begins to cycle indicating it is at the operation temperature. The instrument is now ready to be used for analysis. 4.
Turbine Generator Gas Analyzer Setup and Operation 2. Adjust the pressure regulator to 0.5-30 psig. 3. Slowly open the sample valve and adjust the flow on the flowmeter to 0.1-1 SCFH. Note: The operator must know in advance what gas mixture is present in the sample stream to be able to properly select the instrument range. All ranges will give some indication of output (even if zero) but only that range corresponding to the correct sample gas mixture will give an accurate reading. 4.
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Turbine Generator Gas Analyzer Maintenance Maintenance 5.1 Routine Maintenance The Model 2750 Turbine Generator Gas Analyzer is a rugged instrument and needs little maintenance. Routine maintenance is limited to instrument cleaning, periodic calibration and leak checking. If any part of the instrument malfunctions or fails to perform, the unit should be removed from service and returned for repair and calibration. The 2750 contains no user-serviceable parts. 5.1.
Maintenance Model 2750 If a leak detector is available, the model can be leak checked with the power off. Use helium and pressurize the lines to 1-5 psig and sniff all fittings and lines. If a leak detector is not available, admit air at 1-5 psig through the instrument lines. Liberally apply a commercial soap bubble solution to all fittings and lines. Most leaks occur at the gas inlet fitting. CAUTION: DO NOT USE THIS INSTRUMENT UNTIL IT SUCCESSFULLY PASSES A LEAK CHECK TEST. 5.
Turbine Generator Gas Analyzer analyzer) in the calibration mode. Maintenance check and recalibrate if necessary. or (b) Improper zero source. Check source. or (c) Improper range selected— select proper range for zero. No sample flow (a) Sample flow valve closed— open the valve. or (b) Pressure at regulator set too low—reset the regulator to 0.530 psig or (c) No sample gas connected— connect sample gas. or (d) Vent or sample in line is blocked. Remove constriction or blockage.
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Turbine Generator Gas Analyzer Appendix Appendix A.1 Specifications Range: 0-100% hydrogen in CO2 0-100% air in CO2 80-100% hydrogen in air Accuracy: +5% at constant temp & pres (equilibrium) +6% at constant pressure over operating temp range Sensor: Thermal conductivity cell Resolution: 0.1% Response Time: 0-90% in less than 10 seconds (0.5 SCFH flowrate) Drift Rate: <1%/day Display: 3 1/2” LCD Flowrate: 0.5-1 SCFH nominal 2.5 SCFH maximum (0.
Appendix Model 2750 A.2 Spare Parts List QTY PART NO DESCRIPTION 1 A692 9 VDC POWER Adapter 90-264 VAC 4763Hz 1 P1244 Trim Pot Tool ____________________ A minimum charge is applicable to spare parts orders. Note: Orders for replacement parts should include the part number (if available) and the model and serial number of the instrument for which the parts are intended.
