LNG Ambient Air Vaporizer Performance Evaluation via Fluid-Thermal Coupling
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Solution Overview
Problem
Current methods for evaluating the performance of liquefied natural gas (LNG) ambient air vaporizers (AAVs) face challenges such as low outlet temperature, insufficient vaporizing capacity, and resource waste due to the use of liquid nitrogen for testing, which cannot accurately assess vaporization capacity and fatigue life under varying conditions, leading to potential safety hazards and inefficiencies.
Innovation Solution
A performance evaluation method using finite element analysis (FEA) software for fluid-thermal coupling calculations, combined with site tests and model modifications, to optimize fluid-thermal coupling conditions and perform fluid-thermal-structure coupling calculations, allowing for simultaneous evaluation of vaporization performance and fatigue life of AAVs under different operational and ambient conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid nitrogen is used for performance testing of LNG AAV, then safety hazards are reduced, but calculation errors increase due to performance parameter differences between nitrogen and natural gas
Solution Approach 1:
The patent creates a computational model that copies the actual LNG vaporization process rather than using liquid nitrogen as a physical substitute. The CFD simulation replicates LNG flow, heat transfer, and phase change characteristics, eliminating the need for nitrogen substitution while maintaining measurement accuracy for natural gas-specific properties.
Solution Approach 2:
The patent replaces physical testing with liquid nitrogen with computational simulation using CFD software. This substitution eliminates the fundamental mismatch between nitrogen and natural gas properties by directly modeling LNG behavior, thereby resolving both the safety concern and the calculation accuracy issue simultaneously.
2Adaptability or versatility
If multiple separate tests are conducted under different ambient and operation conditions, then comprehensive performance data is obtained, but operational complexity and time consumption increase
Solution Approach 1:
The patent develops a universal CFD simulation model that can evaluate AAV performance across multiple ambient and operation conditions within a single computational framework. By parameterizing the simulation to accept different environmental inputs, the system achieves comprehensive performance evaluation without requiring separate physical test setups for each condition.
Solution Approach 2:
The patent performs preliminary validation by comparing simulation results with existing test data, then uses this validated model to predict performance under various conditions. This preliminary computational work eliminates the need for conducting multiple separate physical tests, as the model can rapidly evaluate different scenarios once calibrated.
3Measurement precision
If LNG is used for performance testing instead of liquid nitrogen, then measurement accuracy improves, but safety hazards increase due to low temperature and flammability
Solution Approach 1:
The patent replaces physical LNG testing with computational simulation that models LNG behavior. This substitution maintains measurement accuracy by directly calculating LNG-specific properties while eliminating all safety hazards associated with handling actual LNG during testing. The CFD simulation creates a virtual test environment where no physical hazards exist.
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
This method enables accurate evaluation of vaporization performance and fatigue life, improving operational safety and efficiency by reducing calculation errors and eliminating the need for repeated tests under various conditions, thus enhancing the operability and economic efficiency of AAVs.
Implementation Method 1
A liquefied natural gas (LNG) ambient air vaporizer (AAV) is heat exchange equipment for heating LNG in finned tubes via convection of ambient air to make it completely evaporated into gas
Implementation Method 2
A liquefied natural gas (LNG) ambient air vaporizer (AAV) is heat exchange equipment for heating LNG in finned tubes
Implementation Method 3
performing a site test on an actually-operating LNG AAV and obtaining its parameters, establishing a fluid-thermal coupling calculation method of the LNG AAV by use of finite element analysis (FEA) software
Implementation Method 4
performing fluid-thermal-structure coupling calculation, adding a submodel module for optimization and validation tests, and solving a stress value of a final stress concentration zone of the AAV
Data Source
AI summary
The present disclosure discloses a performance evaluation method of a LNG ambient air vaporizer, comprising: step 1, performing a site test on an actually-operating LNG AAV and obtaining its parameters, performing a fluid-thermal coupling calculation and simulation of the LNG AAV by use of FEA software, then performing model modification based on the test results; step 2, performing fluid-thermal-structure coupling calculation of an AAV for validation in the FEA software, adding a submodel module for optimization and validation tests; step 3, performing fluid-thermal-structure coupling calculation on the LNG AAV to be evaluated under a design operation condition and an operation condition of the AAV to be put into service in a certain region, and evaluating the LNG AAV according to the results. The present disclosure can evaluate vaporization performance and fatigue life of the AAV simultaneously and has good operability and economical efficiency.