Supersonic LNG Chiller Using Recycled Cold Gas Instead of Cold Boxes
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Solution Overview
Problem
Traditional LNG producing systems are costly and large due to the use of cold boxes with nitrogen or mixed refrigerants, which are inefficient and expensive for cooling natural gas.
Innovation Solution
A system utilizing a supersonic chiller and heat exchanger configuration to cool and liquefy natural gas, eliminating the need for a traditional cold box by recycling chilled gaseous natural gas to provide the necessary cooling, thereby reducing system size and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a traditional cold box with nitrogen or mixed refrigerants is used to cool natural gas, then the natural gas can be liquefied, but the system size and cost increase significantly
Solution Approach 1:
The patent extracts and eliminates the traditional cold box component from the LNG system by using a supersonic chiller instead. The supersonic chiller uses expansion nozzles to directly cool the natural gas stream through isentropic expansion, removing the need for separate refrigerant circulation systems and cold box infrastructure.
Solution Approach 2:
The patent replaces the mechanical refrigerant circulation system (compressors, heat exchangers, expansion valves) with a supersonic expansion-based cooling system. The supersonic chiller uses high-velocity gas flow through expansion nozzles to achieve cooling through kinetic energy conversion and isentropic expansion, eliminating complex mechanical refrigeration equipment.
2Temperature
If a traditional cold box with nitrogen or mixed refrigerants is used to cool natural gas, then the natural gas can be liquefied, but the system cost increases
Solution Approach 1:
The patent extracts and eliminates the traditional cold box component from the LNG system by using a supersonic chiller instead. The supersonic chiller uses expansion nozzles to directly cool the natural gas stream through isentropic expansion, removing the need for separate refrigerant circulation systems and cold box infrastructure.
Solution Approach 2:
The patent replaces the mechanical refrigerant circulation system (compressors, heat exchangers, expansion valves) with a supersonic expansion-based cooling system. The supersonic chiller uses high-velocity gas flow through expansion nozzles to achieve cooling through kinetic energy conversion and isentropic expansion, eliminating complex mechanical refrigeration equipment.
3Temperature
If nitrogen or mixed refrigerants are used in the cold box, then cooling capacity is achieved, but system complexity increases
Solution Approach 1:
The patent extracts and eliminates the traditional cold box component from the LNG system by using a supersonic chiller instead. The supersonic chiller uses expansion nozzles to directly cool the natural gas stream through isentropic expansion, removing the need for separate refrigerant circulation systems and cold box infrastructure.
Solution Approach 2:
The patent replaces the mechanical refrigerant circulation system (compressors, heat exchangers, expansion valves) with a supersonic expansion-based cooling system. The supersonic chiller uses high-velocity gas flow through expansion nozzles to achieve cooling through kinetic energy conversion and isentropic expansion, eliminating complex mechanical refrigeration equipment.
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 effectively produces liquefied natural gas with a smaller, more efficient design, reducing costs and improving operational efficiency by utilizing the recycled cold energy from the chilled gaseous natural gas stream.
Implementation Method 1
a supersonic chiller configured to chill the cooled natural gas stream to a production temperature to produce the LNG and output a chilled gaseous natural gas stream
Implementation Method 2
The compressed fluid is passed in succession through three counterflow heat exchangers to be further cooled and then expanded in a nearly isentropic expansion nozzle
Implementation Method 3
the compressed natural gas stream is cooled together with the feed natural gas stream by heat exchanging with the chilled gaseous natural gas stream
Data Source
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AI summary
A system, and a method for producing liquefied natural gas are provided. The system includes a heat exchanger, a first supersonic chiller, and a compression unit. The heat exchanger is for cooling a feed natural gas stream to obtain a cooled natural gas stream. The first supersonic chiller is for chilling the cooled natural gas stream to produce liquefied natural gas and output at least a portion of chilled gaseous natural gas to the heat exchanger to be heated to obtain a heated natural gas stream. The compression unit is for compressing the heated natural gas stream from the heat exchanger and providing a compressed natural gas stream to the heat exchanger to be cooled together with the feed natural gas stream by heat exchanging with the at least a portion of the chilled gaseous natural gas.