Cryogenic Cooling Layout for Stable Cold Platform Temperature

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing cryogenic cooling systems experience temperature fluctuations due to dew recondensation during the regeneration cycles of single-shot refrigerators, leading to undesirable heating and instability in the cold platform temperature.

Innovation Solution

A low hydraulic impedance path is created between the condensation surfaces of two single-shot refrigerators, allowing evaporated dew to preferentially condense on the other cooled surface instead of the cold platform, thereby reducing temperature fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If single-shot refrigerators are operated in regeneration mode, then the refrigerators can be reset for subsequent cooling cycles, but dew evaporates from the cold surface and recondenses elsewhere causing temperature fluctuations

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidcold platform temperature stability
Core Design Contradiction:
Duration of action of stationary objectVSStability of the object's composition

Solution Approach 1:

The harmful recondensation process is extracted and redirected from the cold platform to a dedicated condensation surface. The enclosure captures evaporated dew and guides it to condense on the cold surface of the other SSR, separating the harmful effect from the cold platform while maintaining continuous operation capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The enclosure acts as an intermediary system between the evaporating dew and the cold platform. It provides a controlled path that intercepts the evaporated coolant and redirects it to condense on the alternative cold surface, preventing direct recondensation on the cold platform and thus stabilizing its temperature

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of substance

If dew is allowed to recondense on the cold platform, then the coolant is recovered, but the latent heat of condensation causes undesirable heating and temperature fluctuations

Engineering Contradiction:
Improvecoolant recoveryVSAvoidcold platform temperature stability
Core Design Contradiction:
Loss of substanceVSTemperature

Solution Approach 1:

The harmful latent heat of condensation is converted into a beneficial cooling effect by redirecting the condensation process to the cold surface of the other SSR. The condensation that would normally heat the cold platform is now used to maintain the cold surface of the regenerating refrigerator, turning a harmful thermal effect into a useful cooling mechanism

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The enclosure serves as an intermediary that captures the evaporated dew and guides it to condense on the alternative cold surface. This intermediary system ensures that coolant recovery occurs while the thermal effects are directed away from the cold platform, maintaining both substance recovery and temperature stability

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 significantly reduces temperature fluctuations during the cooling-regeneration change-over period, maintaining a more stable cold platform temperature and improving the operational reliability of cryogenic cooling systems.

Implementation Method 1

the said surfaces being selectively cooled when in use by the respective first and second single-shot refrigerators such that coolant gas condenses on the surfaces as liquid coolant

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 2

the evaporated dew from a warmed condensation surface will preferentially flow to the other cooled condensation surface thereby condensing on the cold condensation surface

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

evaporated dew from a warmed condensation surface will preferentially flow to the other cooled condensation surface thereby condensing on the cold condensation surface

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

the enclosure is adapted to provide a path for gaseous coolant between the first and second condensation surfaces, the path having a lower hydraulic impedance than that between each of the condensation surfaces and the cold platform

Methodology Applied
Scientific EffectHydraulic impedance:

Data Source

PatentEP1785680B1Cooling apparatus
Publication Date: 2015.05.27 OXFORD INSTR NANOTECHNOLOGY TOOLS LTD
  • EP1785680B1 patent drawingFigure 1
  • EP1785680B1 patent drawingFigure 2
  • EP1785680B1 patent drawingFigure 3

AI summary

Cryogenic apparatus is provided having first and second single-shot refrigerators (1,2) and an enclosure (31) for containing a coolant gas. First and second condensation surfaces (13,14) are provided within the enclosure, the said surfaces being selectively cooled when in use by the respective first and second single-shot refrigerators such that coolant gas condenses on the surfaces as liquid coolant. A cold platform (10) receives the liquid coolant from the condensation surfaces. The enclosure is adapted to provide a path (20) for gaseous coolant between the first and second condensation surfaces, the path having a lower hydraulic impedance than that (11,12) between each of the condensation surfaces and the cold platform.