Capillary Pumped Loop Thermal Control with Phase Change Storage

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Solution Overview

Problem

Existing thermal regulation devices for spacecraft and satellites require active control and electrical energy to manage temperature fluctuations, which is inefficient and costly, especially when external conditions change the temperature of hot or cold sources.

Innovation Solution

Incorporating a thermal capacity with phase change materials into a two-phase fluid loop with capillary pumping, allowing the loop to accumulate and store thermal energy, which can be used to control or stop the operation passively by absorbing or releasing latent heat based on temperature conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If active control systems with heaters are used to regulate temperature, then temperature regulation capability is improved, but device complexity and energy consumption increase

Engineering Contradiction:
Improvetemperature regulation capabilityVSAvoidcontrol system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The thermal regulation device uses itself to regulate temperature through passive thermal conduction and phase change mechanisms. The high thermal conductivity material directly conducts heat from the hot source, and the phase change material automatically absorbs or releases heat based on temperature conditions, eliminating the need for external control systems, sensors, or power sources.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces active mechanical/electrical control systems with passive thermal mechanisms. Instead of using heaters and electronic controls, the invention uses inherent thermal conduction through high conductivity materials and phase change thermodynamics to achieve temperature regulation, substituting complex active systems with simple passive physical processes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Temperature

If active control systems with heaters are used to regulate temperature, then temperature regulation capability is improved, but energy consumption increases

Engineering Contradiction:
Improvetemperature regulation capabilityVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The thermal regulation device uses itself to regulate temperature through passive thermal conduction and phase change mechanisms. The high thermal conductivity material directly conducts heat from the hot source, and the phase change material automatically absorbs or releases heat based on temperature conditions, eliminating the need for external control systems, sensors, or power sources.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces active mechanical/electrical control systems with passive thermal mechanisms. Instead of using heaters and electronic controls, the invention uses inherent thermal conduction through high conductivity materials and phase change thermodynamics to achieve temperature regulation, substituting complex active systems with simple passive physical processes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the loop operates continuously to transfer heat, then heat transfer performance is improved, but ability to respond to temperature changes worsens

Engineering Contradiction:
Improveheat transfer performanceVSAvoidresponse to temperature changes
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent changes the thermal parameters of the system by introducing materials with extreme thermal conductivity values. The high thermal conductivity material (≥10 W/m·K) enables rapid heat transfer when needed, while the phase change material provides variable thermal resistance based on temperature, allowing the system to adapt its heat transfer characteristics dynamically without active control.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The thermal regulation device introduces dynamic adaptability through phase change materials that automatically adjust their thermal properties based on temperature conditions. When the phase change material transitions between phases, it dynamically modifies the heat transfer rate, allowing the system to respond to changing temperature conditions while maintaining overall heat transfer performance.

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

Enables passive thermal regulation by modifying the loop's performance to maintain or stop heat transfer, reducing energy consumption and complexity, and effectively managing temperature fluctuations without active control systems.

Implementation Method 1

the liquid two-phase fluid present in or in the vicinity of the evaporator accumulates heat, while the loop evacuates most of the thermal power that it receives towards the condenser

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

the gas thus created is evacuated to the condenser, in a heat exchange relationship with the cold source, and in which the gas condenses and returns to the liquid state

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

a two-phase fluid with capillary pumping... liquid two-phase fluid intended for being vaporized in the evaporator... gas thus created is evacuated to the condenser... gas condenses and returns to the liquid state

Methodology Applied
Scientific EffectPhase Change: Phase Change

Implementation Method 4

the pumping of the fluid is ensured by capillarity (capillary loop), thanks to the microporous mass connected to the reserve of fluid in the liquid state and ensuring the pumping of this liquid fluid by capillarity in the evaporator

Methodology Applied
Scientific EffectCapillary Action: Capillary Action

Implementation Method 5

at least one thermal capacity, which, in nominal operation of the thermal regulation device, accumulates heat, while the loop evacuates most of the thermal power that it receives

Methodology Applied
Scientific EffectLatent Heat: Latent Heat

Data Source

PatentEP2032440B1Capillary pumped diphasic fluid loop passive thermal control device with heat capacity
Publication Date: 2012.02.15 ASTRIUM SAS
  • EP2032440B1 patent drawingFigure 1
  • EP2032440B1 patent drawingFigure 2a~2b

AI summary

The thermal control device comprises at least one capillary pumped diphasic fluid loop (1), comprising, in a known manner, an evaporator (2) extracting the heat from a source known as hot (A) and connected via a steam pipe (4) to a condenser (3) wherein the condensation of the fluid steam releases a thermal energy transmitted to a source known as cold (B), the condenser (3) being connected via a pipe of liquid (7) to the evaporator (2), and the device moreover comprises at least one heat capacity (17) in relation to permanent heat exchange with the fluid in liquid phase of said diphasic fluid loop (1). Use in particular with space vehicles such as satellites.