Hydrogen Refueling Cooling Circuit with Dynamic Refrigerant Segmentation

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Solution Overview

Problem

Current hydrogen refuelling stations face challenges in maintaining consistent cooling due to insufficient thermal inertia in refrigeration systems, especially during rapid changes in cooling demand, and struggle to maintain optimal refrigerant temperatures and superheat levels, leading to inefficient cooling and potential overheating in hydrogen tanks.

Innovation Solution

The implementation of a refrigerant cooling loop circuit with a bypass conduit and a bypass regulating valve, controlled by an electronic controller, which adjusts refrigerant flow based on real-time cooling power demands, gas flow rate, temperature, and pressure changes, ensuring efficient cooling power distribution and maintaining predetermined temperature ranges and superheat levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a refrigeration system with thermal inertia is used to provide cooling, then cooling stability is improved, but device complexity and response time to demand changes worsen

Engineering Contradiction:
Improvecooling stabilityVSAvoidsystem complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The refrigeration system is segmented into two independent circuits: a first refrigeration circuit with thermal inertia for baseline cooling stability, and a second refrigeration circuit with rapid response capability for demand fluctuations. This segmentation allows each circuit to specialize in one function, resolving the contradiction between stability and responsiveness without excessive complexity in a single system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between the first and second refrigeration circuits based on real-time cooling demand. The electronic controller activates the high-power second circuit when demand exceeds the first circuit's capacity, and deactivates it when demand is low, enabling adaptive response to changing conditions while maintaining overall system efficiency.

Inventive Principle:
Principle #15Dynamics

2Power

If cooling power is increased to meet high demand, then cooling capacity is improved, but energy consumption increases

Engineering Contradiction:
Improvecooling powerVSAvoidenergy consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts cooling power by switching between the first refrigeration circuit operating alone at low power, and the second refrigeration circuit joining to provide high power when needed. The electronic controller monitors cooling demand and activates the high-power second circuit only when necessary, thereby achieving high cooling capacity on demand while minimizing energy consumption during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the refrigeration circuits based on demand: the first circuit operates continuously at optimized low-power settings, while the second circuit remains standby and activates only when cooling demand exceeds a threshold, changing the system from a static high-power configuration to a dynamic hybrid configuration that optimizes energy efficiency.

Inventive Principle:
Principle #35Parameter changes

3Power

If refrigerant flow is increased to provide more cooling, then cooling capacity is improved, but refrigerant temperature control and superheat maintenance become difficult

Engineering Contradiction:
Improvecooling capacityVSAvoidtemperature control precision
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The refrigerant flow control is segmented between two circuits with different flow characteristics. The first circuit provides stable, controlled refrigerant flow for precise temperature management. The second circuit provides additional refrigerant flow capacity when needed but is independently controlled, allowing the system to maintain precise temperature control in the first circuit while adding cooling capacity through the second circuit without compromising overall temperature precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electronic controller acts as an intermediary that coordinates refrigerant flow between the two circuits and the evaporator. It monitors temperature and superheat levels and adjusts the expansion valves of both circuits to maintain optimal refrigerant flow distribution, ensuring that increased total cooling capacity does not compromise temperature control precision or superheat maintenance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution enables precise control of cooling power, maintaining stable hydrogen tank temperatures between -33°C and -40°C, even during rapid demand changes, ensuring efficient and consistent refuelling operations while minimizing energy consumption and preventing overheating.

Implementation Method 1

A known cooling or refrigeration system feeds a hydrogen cooling heat exchanger with a refrigerant of a refrigerant cooling loop circuit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

an evaporator section. The refrigerant flowing in the cooling loop circuit is preferably carbon dioxide

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

the cooling energy has to be provided when there is a demand

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Implementation Method 4

a compressor, a condenser section, an expansion valve and an evaporator section

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 5

an expansion valve and an evaporator section

Methodology Applied
Scientific EffectPressure reduction cooling: Joule-Thomson Effect

Data Source

PatentEP3604892B1Device and process for refuelling containers with pressurized gas
Publication Date: 2023.06.07 LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE
  • EP3604892B1 patent drawingFigure 1~4
  • EP3604892B1 patent drawingFigure 5~9

AI summary

A device for refuelling containers with pressurized gas, comprising a pressurized gas source (2), a transfer circuit (4) intended to be removably connected to a container (3), the device (1) comprising a refrigeration system for cooling the gas flowing from the gas source (2) prior to its entering into the container (3), the refrigeration system comprising a refrigerant cooling loop circuit (20) comprising, arranged in series, a compressor (8), a condenser section (9), an expansion valve (10) and an evaporator section (11), the refrigeration system comprising a cold source (12) in heat exchange with the condenser section (9) and a heat exchanger (7) located in the transfer circuit (4) and comprising a heat exchange section between the gas flowing in the transfer circuit (4) and the evaporator section (11), the device comprising an electronic controller (21) connected to the expansion valve (10) and configured for controlling cooling power produced by the refrigeration system via the control of the opening of the expansion valve (10), characterized in that the electronic controller (21) is configured to generate or receive a signal indicative of the cooling power needed at heat exchanger (7) for cooling the flow of gas in the transfer circuit through the heat exchanger (7) and, in response, for controlling the cooling power produced by the refrigeration accordingly.