Development Of The Multi-Channel Gas Flow Computer

With a large number of the national natural gas pipeline construction, the need for com-mercial flow computer increases significantly. A muti-functional, low-cost and configurable gas flow computer has been developed in this paper after analysis and summarization of existing flow computers.The main contents of this paper are:1. Implementation of high-precision compressibility factor algorithm SGERG-88and AGA8-92DC. Tests were performed and the results show that the proposed algorithm satisfies the computation requirement.2. Proposal of Vector Floating-Point Coprocessor (VFP) available microprocessor S3C6410X and Embedded Linux based, bus connected, multiple plug-in flow computer.3. Developed the principle of the flow computer prototype, including hardware design of CPU card, base board and flow card, software design as well as prototyping testing.4.Design and implement of Modbus/TCP and Modbus based protocol.The main contributions or innovation points of this paper are described as follows:1. The accuracy of calculating the compressibility factor can reach0.1%, owing to the adoption of the high-precision algorithms AGA8-92DC and SGERG-88from National Standard "GB/T17747-2011Natural Gas Compressibility Factor Calculation"2. The VFP11embedded in S3C6410X is used to process the double precision floating number computation, so that the flow computer is capable of real-time processing of mul-ti-channel sampling data.3. The low-power consumption microprocessor MSP430F5438by Texas Instrument is ap-plied on the flow card, which makes it capable of receiving independently all the signals of a measure point. These signals are used for calculating the volume flow or heat Thus parallel computation of multichannel can be achieved, resulting in the enhancement of system real-time performance and reduction of computation burden for S3C6410X. Since each flow card will manage all data through one flow channel, the communication protocol and configuration soft-ware for host computers can be simplified. Furthermore, the design makes it easier to fault de-tect, isolate and change the flow cards, as well as realize hardware redundancy.4. It is an irresistible trend that the quantity of heat, instead of volume of gas, will be used for commercial gas measurement. The proposed flow computer is capable of measuring the quantity of heat based on signals such as throughput volume, concentration and enthalpy of known ingredients.