Isobaric Air Separation Using Liquid Pump Cold Energy Recovery

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Solution Overview

Problem

Current air separation apparatuses face challenges in reducing energy consumption and improving efficiency, as they rely on thermodynamic principles that do not provide a clear theoretical foundation for optimizing the refrigeration cycle, leading to suboptimal energy usage and inefficiencies in producing oxygen and nitrogen.

Innovation Solution

The introduction of a new refrigeration theory based on cold dynamics, which proposes the concept of cold energy transfer and the second law of cold dynamics, enabling isobaric separation of air to produce oxygen and nitrogen, eliminating the need for air expansion and using liquid nitrogen and oxygen pumps to increase pressure and recover cold energy, thus simplifying the process and reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If traditional thermodynamic refrigeration cycle is used for air separation, then oxygen and nitrogen can be produced through rectification, but energy consumption is high and the process is complex

Engineering Contradiction:

Improveenergy consumptionVSAvoidprocess complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent replaces the traditional thermodynamic refrigeration cycle with a cold dynamics-based system that uses liquid nitrogen pumps and oxygen pumps to achieve pressure increase and cold energy recovery, eliminating the need for complex expansion turbines and heat exchanger networks

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental operating parameters from pressure-based expansion (traditional) to constant pressure separation with liquid pumping, achieving isobaric separation that simplifies the process while reducing energy consumption by over 30%

Inventive Principle:

Principle #35Parameter changes

2Temperature

If air expansion is used for refrigeration in traditional air separation, then cooling effect is achieved, but energy efficiency is reduced due to irreversible expansion losses

Engineering Contradiction:

Improvecooling effectVSAvoidexpansion energy loss

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

Instead of using expansion to achieve cooling (traditional approach), the patent inverts the logic by using liquid pumping at constant pressure and recovering cold energy from the pumped liquids, eliminating irreversible expansion losses while maintaining the required cooling effect

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent recovers cold energy from the liquid nitrogen and liquid oxygen streams that would otherwise be wasted, using pumps to maintain pressure and redirect these cold streams to pre-cool incoming air, thereby recovering energy that would be lost in traditional expansion processes

Inventive Principle:

Principle #34Discarding and recovering

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 results in a significant reduction of energy consumption by over 30% compared to traditional methods, with a more efficient refrigeration cycle and flexible operation, while also reducing equipment and material needs, and promoting energy conservation and environmental protection.

Implementation Method 1

the refrigerating media absorbs heat from the air to be processed and releases heat to the cold source

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

The circulation process of the refrigerating media... after expansion and temperature reduction via expander, it flows via cold regenerator

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 3

liquid refrigerant from refrigerant tank flows via hydraulic pump, cold regenerator, or/and nitrogen liquefier, subcooler, or/and auxiliary cold exchanger, to form the refrigerating media superheated vapor

Methodology Applied

Scientific EffectPhase change: Phase Change

Implementation Method 4

after expansion and temperature reduction via expander, it flows via cold regenerator

Methodology Applied

Scientific EffectAdiabatic expansion: Adiabatic Cooling

Implementation Method 5

liquid refrigerant from refrigerant tank flows via hydraulic pump

Methodology Applied

Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentUS10060672B2Air separation apparatus to produce oxygen and nitrogen through isobaric separation

Publication Date: 2018.08.28 NANJING RECLAIMER ENVIRONMENTAL TEKNIK

AI summary

This invention is about an air separation apparatus to produce oxygen and nitrogen through isobaric separation, which is based on the Rankine cycle system of similar thermal energy power circulation apparatus at cryogenic side, a liquid pump is used to input work and the cold is made up to the air separation apparatus with refrigerating media, so as to realize the isobaric separation of air to produce nitrogen and oxygen. The air separation apparatus of this invention can save energy by over 30% as compared with the traditional advanced apparatus with the identical refrigerating capacity, and it can also realize centralize gas supply via the air separation apparatus, therefore it constitutes a breakthrough to the traditional air separation technology and refrigeration theory, with substantial economic, social and environmental protection benefits.