Pipe Flow Expert User Guide
Low pressure loss gas systems
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- Điều hướng trang này:
- High pressure loss gas systems
- Using Fluid Zones with gas systems
| Low pressure loss gas systems:
Where the pressure loss is less than 10% of the highest absolute pressure in the system, if the pressure drop is calculated using the entering fluid density then good reliability of the results can be expected. High pressure loss gas systems: Where the pressure loss is more than 10% but less than 40% of the highest absolute pressure in the system, if the pressure drop is calculated using the average fluid density then good reliability of the results can be expected. Where a system has a total pressure loss which exceeds 40% of the highest absolute pressure in the system, then if you are using the Non-Compressible Flow Calculation Engine (which is not recommended for gas systems) it will be necessary to model the system using a number of different fluid zones with the fluid density data defined for different pressure conditions). Up to 20 fluid zones can be used in a Pipe Flow Expert model. Note: We include the above information for completeness, however we would recommend using the Compressible Flow Calculation Engine to solve gas system, which will automatically account for density changes with pressure losses (even for losses higher than 40% of the highest absolute pressure) and these systems can then be modeled with a single fluid zone (provided that there are no significant temperature changes). Using Fluid Zones with gas systems: Where a gas system has been split into a number of separate fluid zones, the fluid density and the fluid viscosity for each fluid zone should be set independently. The density of each fluid zone in the gas system must reflect the average density of the compressed fluid condition in that fluid zone, in order for the Darcy-Weisbach equation to give a reasonably accurate result. When a gas system is solved with the Non-Compressible Calculation Engine (and the Darcy- Weisbach equation), if the fluid density is not within 5% of the average fluid density for a particular zone, a warning will be issued in the results log. Suggestions to Update Fluid Zone Data to have a particular density based on the average pressure within the fluid zone will be issued in the results log. tải về 4.95 Mb. Chia sẻ với bạn bè của bạn:
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