Cryogenic Liquid Level Sensing with Vacuum-Isolated Temperature Sensor

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Solution Overview

Problem

Existing technologies face challenges in accurately detecting the liquid level of cryogenic liquids, leading to instability and reliability issues in fuel cell systems due to sensor deformation and heat transfer, which affects hydrogen storage and discharge.

Innovation Solution

A cryogenic liquid storage apparatus with a vacuum-sealed temperature sensor system that detects liquid levels through a housing member, minimizing direct exposure to cryogenic liquids and heat transfer, using a vacuum thermal insulation layer and elastic support for the sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the temperature sensor is directly exposed to the cryogenic liquid for accurate liquid level detection, then the measurement precision is improved, but the temperature sensor deforms and damages due to extreme cold exposure

Engineering Contradiction:

Improveliquid level detection accuracyVSAvoidtemperature sensor durability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent introduces a housing member as an intermediary structure that allows the temperature sensor to detect liquid level through its inner surface without direct exposure to cryogenic liquid. The sensor is positioned in a vacuum space and contacts the housing member's inner surface, which acts as a thermal interface, enabling indirect measurement while protecting the sensor from extreme temperatures and deformation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the temperature sensor is protected from direct cryogenic liquid exposure, then the temperature sensor durability is improved, but the liquid level detection accuracy deteriorates due to heat transfer barriers

Engineering Contradiction:

Improvetemperature sensor durabilityVSAvoidliquid level detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces direct thermal contact with indirect thermal sensing through the housing member structure. The temperature sensor detects temperature changes in the housing member's inner surface, which reflects the liquid level position, substituting direct sensor-liquid contact with a mechanical/structural intermediary that preserves measurement capability while ensuring sensor protection.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Duration of action of stationary object

If the storage container is well-insulated to minimize heat transfer to cryogenic liquid, then the hydrogen storage duration is extended, but the device complexity increases due to vacuum insulation layers

Engineering Contradiction:

Improvehydrogen storage durationVSAvoidinsulation structure complexity

Core Design Contradiction:

Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The patent merges the insulation function with the sensor housing structure. The housing member that protects the temperature sensor also serves as part of the thermal insulation system, with the vacuum space between the housing member and storage container providing thermal insulation. This integration reduces overall system complexity while extending hydrogen storage duration.

Inventive Principle:

Principle #5Merging (Combining)

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

Stable and accurate detection of cryogenic liquid levels, reducing hydrogen discharge and extending storage duration by preventing sensor damage and heat transfer, thus enhancing system reliability and efficiency.

Implementation Method 1

a vacuum thermal insulation layer defined between the inner container and the outer container

Methodology Applied

Scientific EffectVacuum insulation: Vacuum

Implementation Method 2

vacuum thermal insulation layer defined between the inner container and the outer container

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

a temperature sensor provided in the vacuum space so as to be in contact with an inner surface of the housing member and configured to sense a signal to detect a liquid level of the cryogenic liquid

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS12553578B2Cryogenic liquid storage apparatus and liquid level measurement device

Publication Date: 2026.02.17 HYUNDAI MOTOR CO LTD

AI summary

Disclosed is a cryogenic liquid storage apparatus including a storage container configured to accommodate a cryogenic liquid, a housing member provided in the storage container and configured to define a vacuum space spatially separated from an internal space of the storage container, and a temperature sensor provided in the vacuum space so as to be in contact with an inner surface of the housing member and sense a signal to detect a liquid level of the cryogenic liquid.