Hydrogen Dispensing Using Joule-Thomson Cooling
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Solution Overview
Problem
Current hydrogen refuelling methods, particularly for high-pressure gaseous hydrogen, are complicated by temperature increases in vehicle tanks during refuelling, leading to inefficiencies and high costs due to the need for refrigeration systems or liquid nitrogen, which are expensive and require extensive maintenance and infrastructure.
Innovation Solution
An energy-efficient process involving an isenthalpic valve to cool gaseous hydrogen before dispensing, utilizing a smaller intermediate vessel to exploit the inverse thermodynamic phenomenon that causes temperature increases in the vehicle tank, thereby reducing energy costs and maintenance requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If refrigeration based heat exchanger system is used to cool gaseous hydrogen, then the temperature control is improved, but the system cost and complexity increase
Solution Approach 1:
The invention converts the harmful temperature increase that occurs during hydrogen dispensing into a beneficial cooling effect. By utilizing the thermodynamic phenomenon where hydrogen cools when expanding from high pressure in the storage vessel to lower pressure in the dispensing vessel, the system achieves temperature control without requiring external refrigeration equipment. The process naturally produces cold hydrogen (down to -40°C) during the dispensing operation itself, eliminating the need for separate cooling systems.
2Temperature
If refrigeration based heat exchanger system is used to cool gaseous hydrogen, then the temperature control is improved, but the energy consumption increases
Solution Approach 1:
The system converts the energy that would otherwise be wasted as heat during compression and dispensing into useful cooling. The thermodynamic process of hydrogen expanding from the high-pressure storage vessel through the pressure reduction valve to the dispensing vessel naturally absorbs heat, cooling the hydrogen to the required temperature without requiring additional energy input for refrigeration.
3Speed
If liquid nitrogen based cooling is used, then the response time is improved, but the infrastructure requirements and cost increase
Solution Approach 1:
The invention extracts and eliminates the need for liquid nitrogen infrastructure by using the hydrogen itself as the cooling medium. Instead of introducing an external cooling agent (liquid nitrogen) with all its associated storage, handling, and safety infrastructure, the system uses the thermodynamic properties of the hydrogen gas during its own dispensing process to achieve the required cooling, thereby removing the complex liquid nitrogen infrastructure entirely.
4Temperature
If slow refuelling process is used to allow heat dissipation, then the temperature control is improved, but the refuelling time increases
Solution Approach 1:
Instead of allowing heat to dissipate slowly during refuelling (which would maintain temperature control but reduce speed), the invention inverts the approach by pre-cooling the hydrogen before dispensing. The hydrogen is cooled to -40°C before entering the vehicle tank, which means that even during fast refuelling, the temperature remains controlled because the hydrogen starts at a lower temperature and the thermodynamic expansion during dispensing continues to provide cooling throughout the process.
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 enables fast and cost-effective hydrogen dispensing without the need for refrigeration systems or liquid nitrogen, maintaining the temperature within certified limits while reducing infrastructure and energy use, making hydrogen fuelling stations more viable alternatives to gasoline stations.
Implementation Method 1
passing in the range of from 40 to 100 wt %, based on the weight of the first quantity, of the first quantity of gaseous hydrogen from the first vessel through an isenthalpic valve to obtain a cold second quantity of gaseous hydrogen
Implementation Method 2
cooling the gaseous hydrogen using the inverse thermodynamic phenomenon that causes the hydrogen to heat in the vehicle tank prior to providing the hydrogen to the hydrogen tank of a vehicle
Data Source
AI summary
The present invention provides a process for dispensing gaseous hydrogen, comprising the steps of: a) providing a first vessel comprising a first quantity of gaseous hydrogen at a pressure in the range of from 350 to 1000 bar absolute and a temperature in the range of from −20° C. to 50° C.; b) passing in the range of from 40 to 100 wt %, based on the weight of the first quantity, of the first quantity gaseous hydrogen from the first vessel through an isenthalpic valve to obtain a cold second quantity of gaseous hydrogen having a temperature in the range of from −100 to −20° C.; and c) dispensing the cold second quantity of gaseous hydrogen to a second vessel. In a further aspect the invention provides a system for dispensing gaseous hydrogen.