Apparatus and method for compressing boil-off gas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing devices for compressing boil-off gas from cryogenically stored gases are energy-intensive, waste the cold contained in the exhaust gas, and require high-strength, ductile materials that are expensive and limited in availability, especially at temperatures below -196 °C.
Innovation Solution
A device and method that utilize a compressor with integrated heat exchanger to internally recycle the cold of the exhaust gas for cooling and compression, eliminating the need for external preheating and expensive materials, using countercurrent heat exchange and diffusion-welded heat exchangers for efficient heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If external preheating systems are used to increase gas temperature before compression, then the compressor can operate with standard materials, but energy consumption increases and the cold content of the exhaust gas is wasted
Solution Approach 1:
The patent combines the preheating function with the compression process itself by using the compressed gas as a heat source. The heat exchanger integrates the preheating of incoming gas with the cooling of compressed gas, merging two separate functions (preheating and cooling) into a single integrated system that eliminates external energy input.
Solution Approach 2:
The system uses its own compressed gas to provide the heat needed for preheating incoming gas. The compressed gas, which is hot after compression, serves as the heating medium in the heat exchanger, making the system self-sufficient and eliminating the need for external energy sources.
2Temperature
If external preheating systems are used to increase gas temperature before compression, then the compressor can operate with standard materials, but the cold content of the exhaust gas is wasted
Solution Approach 1:
The patent converts the cold content of the incoming exhaust gas, which would normally be wasted, into a useful cooling resource. This cold gas is used to cool the compressed gas in the heat exchanger, transforming a waste resource into a beneficial cooling source that reduces the thermal load on the compression system.
Solution Approach 2:
Instead of discarding the cold content of the incoming gas, the system recovers and utilizes it for cooling the compressed gas. The heat exchanger captures the cooling potential of the cold incoming gas and applies it to reduce the temperature of the compressed gas, thereby recovering energy that would otherwise be lost.
3Use of energy by moving object
If the compressor operates directly with cold exhaust gas at very low temperatures, then energy efficiency is improved, but expensive low-temperature-resistant materials are required
Solution Approach 1:
The patent changes the temperature parameter of the gas entering the compressor by preheating it using the heat exchanger. This parameter change allows the compressor to operate with standard materials rather than expensive low-temperature-resistant materials, while still maintaining overall system energy efficiency through the integrated cooling of compressed gas.
4Use of energy by moving object
If the compressor operates directly with cold exhaust gas at very low temperatures, then energy efficiency is improved, but the choice of suitable materials is limited
Solution Approach 1:
By preheating the incoming gas through the integrated heat exchanger system, the patent changes the operating temperature parameter of the compressor. This allows the use of a broader range of standard materials with better mechanical properties and manufacturing availability, thereby improving material selection flexibility while maintaining energy efficiency through the simultaneous cooling of compressed gas.
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
Increases energy efficiency by up to 20% and reduces material costs by avoiding the use of expensive low-temperature-resistant materials, while maintaining operational readiness and flexibility.
Implementation Method 1
a heat exchanger for performing a heat exchange between the exhaust vapor gas and an exhaust vapor gas compressed in the first compressor stage
Implementation Method 2
a compressor with at least one compressor stage, preferably at least two compressor stages
Data Source
Figure 1a~1b
Figure 2~3a
Figure 3b~4a
AI summary
Device (100) for compressing exhaust evaporation gas (1) of a cryogenically stored gas (LG), the device (100) comprising a container (10) for cryogenically stored gas (LG) with an outlet (11) for discharging an exhaust evaporation gas (1) of the cryogenically stored gas (LG) that can be provided in the container (10), a compressor (20) with at least one compressor stage (21), and a heat exchanger (30) for carrying out a heat exchange between the exhaust evaporation gas (1) and an exhaust evaporation gas (3) compressed in the first compressor stage (21), wherein the heat exchanger (30) has a first inlet (31) for receiving the exhaust evaporation gas (1), a first outlet (32) for discharging a heated exhaust evaporation gas (2) to the first compressor stage (21), a second inlet (33) for receiving the exhaust evaporation gas compressed in the first compressor stage (21) (3), and a second outlet (34) for discharging a cooled and compressed exhaust gas (4) to a downstream process,in particular to a second compressor stage (22) of the compressor (20), which is designed to further compress the exhaust evaporation gas (4) compressed in the first compressor stage (21) and cooled in the heat exchanger (30) in order to provide a further compressed exhaust evaporation gas (5).