Upstream Metering Pump for NGL Sample Phase Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for analyzing Natural Gas Liquids (NGL) suffer from inaccuracies due to the retention or generation of entrained gas in the liquid product during cryogenic separation, making accurate and reproducible analysis challenging, especially in the Ethane Recovery phase, where the fluid remains in a 'dense' phase with significant volume differences between liquid and vapor states.
Innovation Solution
A system featuring a sample take-off probe, a sample conditioning unit, and an in-line metering pump that pressurizes the extracted multi-phase fluid to achieve complete condensation into a single fully liquid phase, combined with a coalescing filter and a speed loop for reinjection, ensuring accurate and repeatable measurements and minimizing lag time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional cryogenic separation processing is used, then NGL extraction from pipeline is achieved, but entrained gas is retained or generated in the liquid product causing analysis inaccuracy
Solution Approach 1:
The metering pump is positioned upstream of the sample conditioning equipment to preliminarily pressurize and condense the multi-phase fluid sample before it enters the conditioning unit. This preliminary action ensures complete liquid phase formation before vaporization and analysis, preventing entrained gas from forming during the process.
Solution Approach 2:
The system changes the pressure parameter by using a metering pump to increase pressure on the extracted fluid sample, causing condensation from dense phase to fully liquid phase. This parameter change maximizes phase transition completion and eliminates gas entrainment that would otherwise occur during conventional cryogenic separation.
2Measurement precision
If pressure is increased to maximize liquid phase transition, then measurement accuracy improves, but equipment complexity increases
Solution Approach 1:
The metering pump serves multiple functions: it pressurizes the sample, condenses the fluid to maximum liquid phase, and provides sufficient residual pressure to overcome takeoff vacuum for unfiltered bypass flow. This multi-functionality achieves measurement accuracy without proportionally increasing system complexity.
Solution Approach 2:
The system uses the pipeline's own takeoff vacuum to promote unfiltered bypass flow, and the metering pump generates residual pressure to overcome this vacuum. The system essentially uses its own components to solve the pressure balance issue without requiring additional complex equipment.
3Loss of information
If sample conditioning equipment is used to vaporize and analyze NGL, then component analysis is performed, but lag time between takeoff and analysis increases
Solution Approach 1:
The metering pump performs preliminary pressurization and condensation of the sample before it enters the conditioning equipment. This preliminary action reduces the time required for phase change completion during conditioning, thereby reducing overall sample lag time while maintaining complete component analysis capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enhances measurement accuracy and repeatability by ensuring a single phase liquid state, reducing lag time, and allowing for the reinjection of unfiltered samples, thereby improving NGL process control and avoiding system inaccuracies that could lead to inappropriate product distribution.
Implementation Method 1
a metering pump disposed in-line between the sample take-off probe and the sample conditioning unit to increase pressure on and condense the extracted fluid sample to maximize transition of the multi-phase fluid sample into a single fully liquid phase
Implementation Method 2
a sample conditioning unit for vaporizing the extracted fluid sample and maintaining the vaporized sample in select temperature and pressure ranges to prevent dew point dropout
Data Source
Figure 1
AI summary
A post-probe upstream metering pump for insuring phase change completion of a multi-phase fluid such as Natural Gas Liquid (NGL) in a sample conditioning system having a pipeline sample take-off probe for fluid extraction, a sample conditioning unit for conditioning the extracted fluid to a select range of temperature and pressure for analysis of the fluid sample by an associated analyzer without dew point dropout or phase separation, and a metering pump disposed in-line between the sample take-off probe and the sample conditioning unit to pressurize the fluid sample to condense into a substantially fully liquid phase and to reduce lag time between extraction and fluid sample conditioning.