Hydrogen Refueling Cooling Control via Compressor Thresholds

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Solution Overview

Problem

Existing hydrogen refuelling systems face challenges in maintaining sufficient cooling power, particularly when thermal inertia is insufficient, and demand for cooling changes rapidly, leading to inefficiencies and potential overheating in hydrogen tanks.

Innovation Solution

The system employs an electronic controller to manage the refrigeration system by switching the compressor on and off based on predefined temperature thresholds, using a variable speed compressor, and regulating refrigerant flow through an expansion vessel and bypass conduit to maintain optimal cooling power and superheat levels, ensuring efficient cooling of hydrogen tanks during refuelling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If thermal inertia is increased to provide sufficient cooling power, then cooling capability is improved, but device complexity and response time are worsened

Engineering Contradiction:
Improvecooling powerVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The system dynamically adjusts compressor operation based on real-time temperature feedback from the heat exchanger. The controller monitors temperature and activates the compressor only when thresholds are exceeded, transforming the static thermal inertia system into a dynamic responsive system that provides cooling power on-demand without requiring excessive thermal mass

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The heat exchanger serves dual purposes: it cools the hydrogen gas during refuelling and simultaneously acts as a temperature sensor for the control system. The system uses the heat exchanger's own temperature feedback to trigger compressor activation, creating a self-regulating mechanism that eliminates the need for separate sensing systems

Inventive Principle:
Principle #25Self-service

2Power

If compressor operates continuously to maintain cooling power, then cooling capability is improved, but energy consumption is worsened

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

Solution Approach 1:

The compressor operates periodically rather than continuously, activated only when the heat exchanger temperature exceeds predefined thresholds. This periodic operation maintains sufficient cooling power during standby and refuelling operations while dramatically reducing overall energy consumption by keeping the compressor off during periods when cooling demand is low or zero

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system implements temperature feedback control where the heat exchanger temperature is continuously monitored and used to regulate compressor operation. When temperature drops below the threshold, the compressor shuts off; when temperature rises above the threshold, the compressor activates. This feedback mechanism ensures cooling power is provided only when needed, optimizing the balance between cooling capability and energy consumption

Inventive Principle:
Principle #23Feedback

3Speed

If cooling is provided on-demand with small thermal inertia, then response time is improved, but cooling power sufficiency is worsened

Engineering Contradiction:
Improveresponse timeVSAvoidcooling power
Core Design Contradiction:
SpeedVSPower

Solution Approach 1:

The system performs preliminary cooling action by activating the compressor before the heat exchanger temperature reaches critical levels. The control thresholds are set to trigger compressor operation in advance, allowing the system to proactively maintain temperature within the desired range rather than reacting only after overheating occurs

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system changes operational parameters dynamically by adjusting compressor activation thresholds based on operating conditions. During standby mode, thresholds are set to maintain adequate cooling headroom; during active refuelling, the system can adjust parameters to provide maximum cooling power. This parameter adaptation allows the system to maintain sufficient cooling power across varying demand conditions while preserving fast response capability

Inventive Principle:
Principle #35Parameter changes

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 ensures efficient and adaptive cooling, maintaining the required temperature range for hydrogen tanks, even during rapid changes in cooling demand, thereby preventing overheating and optimizing energy use.

Implementation Method 1

a heat exchanger located in the transfer circuit and comprising a heat exchange section between the gas flowing in the transfer circuit and the evaporator section

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

an expansion valve and an evaporator section

Methodology Applied
Scientific EffectEvaporation cooling: Evaporation

Implementation Method 3

a compressor

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

a condenser section

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

a condenser section, an expansion valve and an evaporator section, the refrigeration system comprising a cold source in heat exchange with the condenser section

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3604891B1Device and process for refuelling containers with pressurized gas
Publication Date: 2022.10.12 LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE
  • EP3604891B1 patent drawingFigure 1~4
  • EP3604891B1 patent drawingFigure 5~9

AI summary

A device and process 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) and 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) configured to switch the refrigeration system in first standby mode when the device is not refuelling a container wherein the compressor is switched off when the temperature of the heat exchanger (7) is equal or below a predefined first standby temperature threshold and for started and operated for producing cooling power and cooling the heat exchanger (7) when the sensed temperature of the heat exchanger (7) is above a second standby threshold temperature.