The seeing to improve accuracy and ease of operation, in a historically tantalizing gas determination application.
In Canada the implementation of Enhanced production Audit schedule (Epap) will increase the need for more literal, flow determination data.
Technical Challenge
Energy producers are constantly seeing at ways to improve their accepted natural gas determination points within their operations. One indispensable area that requires consistent and dependable determination is fuel gas meters typically placed at compressor sites. On larger compressors or sites with manifold compressors where daily midpoint consumption exceeds 0.5 em/day Ercb Directive 17 stipulates that a permanent determination device must be installed for all fuel gas consumption.
A Case study: 2 large energy producers with part of their operations in Northwestern Alberta and Northeastern B.C. Were faced with seeing and standardizing on a clarification that would meet the challenges posed by measuring fuel gas accurately and consistently in a dependable and economic container that would also meet Directive 17 compliance. The significance is being underscored with the full scale implementation of Epap (Enhanced production Audit Program) in 2011 commerce wide.
Traditional means of measuring fuel gas fell short of their goals in meeting this standard. Orifice plates lacked the turndown range required to quantum both the nominal fuel gas consumption and the start gas when a compressor is activated. The associates favorite a device that could deal with both measurements seamlessly. Additionally, the lower flow ranges typically found on a fuel gas line posed a problem due to an orifice plate's high pressure drop and accuracy was compromised as a result.
While a accepted pressure and temperature coefficient can be applied to faultless the flow determination rate, this introduced a by hand process by which the operators/supervisors had to bond to for completion of their calculations. In addition, Pd meters were susceptible to damage due to over ranging when a compressor was started resulting in high-priced maintenance and downtime. A clarification was needed.
The Flowstar Solution
Both associates found their clarification in a gas determination ideas consisting of a high accuracy, robust gas turbine in concert with an electronic flow computer (Efm).
The gas turbine provides exquisite accuracy profiles (+/- 2%) in a 316 stainless steel constructed body and internal components that utilize ceramic, self lubricating, low drag bearings. A 40:1 turndown ratio ensures that both the nominal fuel gas and the compressor start gas are accurately measured. As fuel gas lines are typically smaller in compose (1") the low flows seen are in fact measured by a 1" turbine. Flexibility is built into the turbines as the rotor pitch can be changed to as low as 45 degrees to capture even lower flows at similar pressures. The accepted pitch is 15 degrees.
The Hawk 9500 Efm delivers exceptional operational execution with a rated accuracy of +/- 0.05% full scale on pressure and +/- 0.5% C on temperature. The Hawk 9500 performs fully compensated flow rate calculations to Aga7 (rotary turbines) and Aga8-92 (gas compressibility) standards. It is also Api lesson 21 audit trail compliant. With its Class I Div I Is rating and Is lithium ion battery pack, area classifications are not an issue and offer the end user ease of installation and smaller footprint. A communication board can be activated to maintain Rs 485 Modbus communications to a Scada host or Plc.
Results
Both energy associates have implemented the Flowstar gas determination clarification on a whole of compressors with exquisite results to date. With this arrangement it minimized operator involvement and interruptions and also in case,granted them with a 1 stop assistance point for any time to come technical adjustments or troubleshooting. When producing a trending graph of historical data on one single 1" line it produced a flow rate of 0.5 em/day at 110 psi. The peak volume on compressor start up, however, reached as high as 14 em/day, representing a turndown ratio of 28:1, well within the range.
In unavoidable cases, as with the other energy producers, a mechanical pipe run with the gas turbine was in case,granted without the Hawk9500 at unavoidable locations as an existing Rtu was already on site. The introduction of a pre-amplifier in fact supported this type of integration. Their operators have commented in fact on the full, reliability of the gas turbine and the relatively small footprint of the meter run piping package. Process conditions are favourable on the fuel gas line as the meter is typically installed downstream of a fuel gas scrubber. The operators also like the convenience of noting instantaneous data on the Hawk 9500 display (current flow rate, pressure and temperature and up to 40 old days of historical production) and the ability to download stored data onto the Sd card (over 1 year with 1 itsybitsy logging). This data is in fact transformed into production reports that are in case,granted to the companies' production accountants electronically.
Epap will help guide the producers to quantum gas more accurately and there are only a few options available to ensure accuracy with ease of use out in the field.
seeing for Improved Accuracy in Gas Flow Measurements?