Phase-Change Thermal Storage Loop for Short-Duration DEW Cooling

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Solution Overview

Problem

Directed energy weapons (DEWs) generate significant heat during operation, leading to oversized, inefficient, and heavy thermal management systems due to large thermal transients, which are inefficient and unsuitable for sustained operation.

Innovation Solution

A thermal management system with a closed loop configuration, including a first heat exchanger coupled to the DEW, a second heat exchanger connected to a secondary system, and a thermal storage device, utilizing a thermal management fluid and phase change materials to manage heat during firing and charging modes, allowing for adaptive cooling based on material state changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a thermal management system is designed to handle large thermal transients during firing mode, then the thermal load of the DEW is managed, but the system becomes significantly oversized, inefficient and heavy for normal operating modes

Engineering Contradiction:
Improvethermal load managementVSAvoidsystem weight
Core Design Contradiction:
TemperatureVSWeight of stationary object

Solution Approach 1:

The thermal management system is divided into two functional segments: a thermal storage device (reservoir) that handles transient thermal loads during firing mode, and a secondary thermal management system that handles steady-state cooling during charging mode. This segmentation allows each subsystem to be optimized for its specific operational requirement, preventing the need for an oversized system that must handle peak loads.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The thermal storage reservoir is pre-filled with thermal management fluid before operation. During firing mode, this pre-stored fluid immediately absorbs thermal transients without requiring the secondary system to be oversized. The preliminary preparation of the thermal storage device enables rapid response to thermal loads while keeping the secondary system compact.

Inventive Principle:
Principle #10Preliminary action

2Duration of action of moving object

If the thermal management system is sized for sustained operation, then continuous cooling is provided, but the system is inefficient and heavy for brief firing intervals

Engineering Contradiction:
Improvesustained operation capabilityVSAvoidsystem efficiency
Core Design Contradiction:
Duration of action of moving objectVSLoss of energy

Solution Approach 1:

The system operates in periodic cycles alternating between firing mode (brief intervals requiring high cooling power) and charging mode (long intervals with minimal cooling requirements). The thermal storage reservoir is replenished during charging mode and discharged during firing mode, enabling the system to meet peak demands without continuous high-power operation, thus improving overall efficiency.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically changes operational parameters by switching between two modes: during firing mode, the thermal storage reservoir provides high cooling capacity to handle thermal transients; during charging mode, the secondary system operates at reduced capacity to maintain fluid temperature. This parameter switching optimizes energy efficiency across different operational phases.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If a thermal storage device is added to the closed loop system, then thermal loads are managed more efficiently, but the device complexity increases

Engineering Contradiction:
Improvethermal management efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The thermal management fluid serves multiple functions: it cools the DEW during firing mode by absorbing thermal transients in the reservoir, and it is re-cooled during charging mode by the secondary system. This multi-functionality of the same fluid and system components increases thermal management efficiency without requiring separate systems for each function, thereby limiting complexity growth.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 effectively manages thermal loads, reducing the size and power requirements of the thermal management system, enabling efficient operation and protecting onboard components from thermal transients by optimizing cooling based on the DEW's operational modes.

Implementation Method 1

the material within the thermal storage device is a phase change material

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

the phase change material transforming to a first state during the charging mode and the phase change material transforming to a second state during the firing mode

Methodology Applied
Scientific EffectLatent heat: Latent Heat

Implementation Method 3

a first heat exchanger thermally coupled to the directed energy weapon and a second heat exchanger arranged in fluid communication with the first heat exchanger

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP4293312A1Thermal storage for high load short duration cooling
Publication Date: 2023.12.20 HAMILTON SUNDSTRAND CORP
  • EP4293312A1 patent drawingFigure 1
  • EP4293312A1 patent drawingFigure 2
  • EP4293312A1 patent drawingFigure 3

AI summary

A thermal management system for a directed energy weapon includes a first heat exchanger (24) thermally coupled to the directed energy weapon and a second heat exchanger (26) arranged in fluid communication with the first heat exchanger to form a closed loop. The second heat exchanger is thermally coupled to a secondary system and a thermal management fluid circulates within the closed loop. A thermal storage device (50) is arranged in fluid communication with the first heat exchanger and the second heat exchanger. The thermal storage device contains a material and a mode of operation of the directed energy weapon is dependent on a condition of the material in the thermal storage device.