Cryogenic Thermal Siphon Venting for Fast Pump Start-Up

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Solution Overview

Problem

Existing cryogenic containers face a conflict between minimizing heat input and ensuring efficient operation of fluid conveying devices, particularly pumps, due to the need for maintaining a cold pump temperature to prevent evaporation of cryogenic fluids, which leads to inefficient pump operation and prolonged start-up times.

Innovation Solution

A system with a cryogenic container and fluid conveying device featuring a thermal siphon pipeline with a vent line that can be closed to form an insulating gas cushion and opened to allow fluid flow, enabling quick cooling and efficient operation without engine or pump running, while maintaining low heat input.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the pipeline outside the inner tank is designed as a thermal siphon to minimize heat input, then the heat input into the cryogenic container is reduced, but the pump cannot operate efficiently because the cryogenic fluid evaporates in the gas phase at the pump

Engineering Contradiction:

Improveheat inputVSAvoidpump efficiency

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The pipeline is divided into two functional sections: a first section that acts as a thermal siphon to minimize heat input, and a second section that allows liquid phase flow to the pump. This segmentation enables each section to fulfill its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A vent line is introduced as an intermediary element connected to the pipeline at a highest point. The vent line with a valve controls the release of gas phase cryogenic fluid, preventing it from reaching the pump while maintaining the thermal siphon effect in the first section.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the pump is allowed to protrude into the cryogenic container to continuously wash cold cryogenic fluid around it, then the pump can operate quickly with high efficiency, but the heat input into the cryogenic container increases

Engineering Contradiction:

Improvepump start-up timeVSAvoidheat input

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The pump is extracted from the cryogenic container environment and positioned outside the inner tank. The pipeline is configured to deliver liquid phase cryogenic fluid to the pump without requiring the pump to be immersed in the cryogenic fluid, thus eliminating the heat input associated with cooling the pump while maintaining efficient operation.

Inventive Principle:

Principle #2Taking out (Extraction)

3Loss of energy

If the valve on the vent line is closed to maintain an insulating gas cushion, then heat input is minimized, but the pump cannot be cooled down quickly for rapid operation

Engineering Contradiction:

Improveheat inputVSAvoidcooling time

Core Design Contradiction:

Loss of energyVSLoss of time

Solution Approach 1:

The valve on the vent line is made dynamically controllable, allowing it to be opened during pump start-up to accelerate cooling by removing the insulating gas cushion, and closed during normal operation to maintain the thermal siphon effect and minimize heat input. This dynamic adjustment resolves the contradiction between rapid cooling and heat minimization.

Inventive Principle:

Principle #15Dynamics

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

The system achieves reduced heat input into the cryogenic container and rapid start-up of the fluid conveying device by utilizing a thermal siphon with a vent line, allowing efficient fluid delivery and quick engine start without prolonged warm-up times.

Implementation Method 1

the cryogenic fluid evaporates at that end of the pipeline, but is unable to flow back into the cryogenic container through the thermal siphon due to the buoyancy of the gas

Methodology Applied

Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

the inner tank is accommodated in the outer container and is thermally insulated from it, e.g., by having a vacuum between the inner tank and the outer container

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

the cryogenic fluid is heated at the end of the pipeline that is located outside of the inner tank

Methodology Applied

Scientific EffectHeat transfer: Heating

Data Source

PatentUS12523343B2System comprising a cryogenic container and a thermal siphon

Publication Date: 2026.01.13 CRYOSHELTER GMBH

AI summary

A system includes a vehicle, and a cryogenic container on the vehicle and having an inner tank and an outer container which is vacuum-insulated relative to the inner tank, the system including a fluid conveying device and a pipeline that is routed out of the inner tank for the removal of cryogenic fluid and is connected to the fluid conveying device. The fluid conveying device is outside of the inner tank, the pipeline is a thermal siphon with one section rising towards the fluid conveying device, which is partially arranged in an area that is insulated relative to cryogenic fluid located in the inner tank. A vent line closable by a valve in the area, on a removal level of the fluid conveying device, is connected to the pipeline or directly to the fluid conveying device and routed back into the inner tank above the connection point to the pipeline.