Air Separation Turbine Staging for High-Pressure Oxygen Control
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Solution Overview
Problem
High-atmospheric-pressure methods for air separation struggle with process control, particularly when producing predominantly or exclusively internally compressed gaseous oxygen at pressures ranging from 16 to 50 bar, leading to inefficiencies and reduced competitiveness in gas plants.
Innovation Solution
The method involves using a Lachmann turbine with a significantly lower air inlet temperature, reducing the amount of air to be liquefied and lowering heat input in the main heat exchanger, and employing a two-turbine unit system with Claude and Lachmann turbines to optimize air compression and decompression processes, resulting in increased efficiency and reduced power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If high-atmospheric-pressure methods are used to produce pressurized gaseous oxygen at 16-50 bar, then the pressure of the oxygen product is improved, but the process control becomes difficult and efficiency decreases
Solution Approach 1:
The patent divides the air compression and processing into multiple stages with two separate turbines (Claude turbine for high-pressure column and Lachmann turbine for low-pressure column). This segmentation allows independent optimization of each stage, improving process control while achieving the required high oxygen pressure through coordinated operation of multiple components rather than a single complex system
Solution Approach 2:
The patent utilizes parameter changes by operating the Claude turbine at higher temperatures and the Lachmann turbine at lower temperatures, and by adjusting the pressure ranges of each column (high-pressure column at 4-7 bar, low-pressure column at 1-2 bar). These parameter variations enable better process control at each stage while collectively achieving the target oxygen pressure of 16-50 bar
2Device complexity
If conventional turbine units are used in high-atmospheric-pressure methods, then the system structure is simple, but the power consumption is high and efficiency is reduced
Solution Approach 1:
The patent employs two separate turbine units (Claude turbine and Lachmann turbine) operating at different pressure levels and temperature ranges. This segmentation allows each turbine to operate in its optimal efficiency range, reducing overall power consumption compared to a single turbine system while maintaining manageable structural complexity through modular design
Solution Approach 2:
The patent changes operational parameters by running the Claude turbine at higher temperatures and pressures (feeding into high-pressure column at 4-7 bar) and the Lachmann turbine at lower temperatures and pressures (feeding into low-pressure column at 1-2 bar). This parameter differentiation optimizes energy efficiency of each turbine while achieving the required oxygen compression
3Ease of operation
If the air inlet temperature to the turbine is high, then the system operation is easier, but the amount of air to be liquefied increases and heat input requirements increase
Solution Approach 1:
The patent segments the air processing into two temperature zones: warm air processing in the Claude turbine section and cold air processing in the Lachmann turbine section. This allows the system to handle different air quantities at different temperatures independently, reducing the total amount of air requiring liquefaction while maintaining operational ease through specialized handling in each section
Solution Approach 2:
The patent implements parameter changes by operating the Claude turbine with air at higher temperatures (easier operation) and the Lachmann turbine with air at lower temperatures (reducing liquefaction requirements). This temperature parameter differentiation across two turbine stages resolves the contradiction between operational ease and reduced air quantity for liquefaction
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 approach enhances the efficiency and competitiveness of high-atmospheric-pressure methods by reducing the quantity of air to be liquefied, lowering heat input, and optimizing power usage, thereby improving the production of pressurized oxygen-rich gaseous air products.
Implementation Method 1
a second partial quantity of the feed air quantity compressed to the pressure in the third pressure range is supplied to a second turbine unit (6), in particular a Lachmann turbine, at the pressure in the third pressure range and at a temperature in a second temperature range, decompressed to a pressure in the second pressure range using the second turbine unit (6)
Implementation Method 2
a first partial quantity of the feed air quantity compressed to the pressure in the third pressure range is supplied to a first turbine unit (5), in particular a Claude turbine, at the pressure in the third pressure range or at a pressure in a fourth pressure range above the third pressure range and at a temperature in a first temperature range, decompressed to a pressure in the first pressure range using the first turbine unit (5)
Implementation Method 3
oxygen-rich liquid (I), in particular liquid oxygen, being removed from the rectification column system (10), being brought to a pressure in a sixth pressure range of from 16 to 50 bar or 25 to 50 bar, in particular 40 to 50 bar, for example approximately 43 bar, in a liquid state under heating to a temperature in a third temperature range, being supplied to the main heat exchanger (3), evaporated therein at the temperature in the third temperature range
Data Source
AI summary
The invention relates to a high-atmospheric-pressure method for producing a pressurized oxygen-rich, gaseous air product. A first partial quantity of the feed air quantity is supplied at a temperature in a first temperature range to a first turbine unit (5), decompressed using same, and fed into a high-pressure column (111). A second partial quantity of the feed air quantity is supplied at a temperature in a second temperature range to a second turbine unit (6), decompressed using same, and fed into a low-pressure column (12). The pressurized, oxygen-rich air product is provided as an internal compression product at 16 to 50 bar, wherein evaporation is effected proceeding from a temperature in a third temperature range. The third temperature range lies above the first and second temperature range, the second temperature range is selected such that a two-phase mixture with a liquid proportion of 5 to 15% forms at the outlet of the second turbine unit (6), the temperature in the first temperature range and the temperature in the second differ from each other by not more than 10 K, and a portion of less than 5% of all air products removed from the air separation plant (100) is removed from the air separation plant in an unevaporated and liquid state. The first turbine unit is braked by a cold compressor (4), the second by a generator (G) or a warm booster. The invention also relates to an air separation plant (100).