Thermal Energy Storage Control for Transient Heat Load Management

Solution Overview

Problem

Conventional thermal energy management systems face instability and inefficiency due to rapid load changes and oversized components, which lead to increased size, weight, and energy consumption, especially when operating under intermittent fast transient heat loads.

Innovation Solution

A method and system that modulate valves to control the temperature and pressure of a primary fluid flowing through a thermal energy storage system, allowing heat transfer between the primary fluid and the thermal energy storage based on system capacity, enabling efficient heat management by transferring heat from or to the thermal energy storage when the primary thermal load exceeds or is less than the system capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the heat rejecting component is sized for maximum design heat load at maximum design ambient temperature, then the system can handle peak loads, but the system size, weight, and energy consumption increase

Engineering Contradiction:

Improvesystem stability under peak loadVSAvoidcondenser and fan size

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The thermal energy storage system performs preliminary cooling during low-load periods, storing cold energy in advance. This pre-cooled energy is then utilized during peak load periods, allowing the heat rejecting components to be sized for average rather than peak load, thereby reducing system size and weight while maintaining reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically switches between different operational modes (cooling mode, heating mode, and thermal energy storage mode) based on real-time thermal load conditions. This dynamic operation allows the system to adapt to varying loads, enabling smaller heat rejecting components that operate efficiently at average load rather than being oversized for peak conditions.

Inventive Principle:

Principle #15Dynamics

2Speed

If the compressor accelerates and decelerates quickly to keep pace with real-time load demands, then the system responds to load changes, but the system becomes unstable and fails to maintain constant temperature refrigerant

Engineering Contradiction:

Improvecompressor response speedVSAvoidsystem stability and temperature constancy

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

The thermal energy storage system performs preliminary cooling during low-load periods, storing cold energy in advance. This pre-cooled energy is then utilized during peak load periods, allowing the heat rejecting components to be sized for average rather than peak load, thereby reducing system size and weight while maintaining reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically switches between different operational modes (cooling mode, heating mode, and thermal energy storage mode) based on real-time thermal load conditions. This dynamic operation allows the system to adapt to varying loads, enabling smaller heat rejecting components that operate efficiently at average load rather than being oversized for peak conditions.

Inventive Principle:

Principle #15Dynamics

3Quantity of substance

If conventional PCM based thermal energy storage is used to meet heat load requirements, then the thermal energy storage capacity is sufficient, but the system becomes quite large and heavy

Engineering Contradiction:

Improvethermal energy storage capacityVSAvoidthermal energy storage system weight

Core Design Contradiction:

Quantity of substanceVSWeight of stationary object

Solution Approach 1:

The thermal energy storage system serves multiple functions: it provides thermal energy storage capacity, enables dynamic load management, and allows the heat rejecting components to be downsized. This multi-functionality achieves sufficient thermal energy storage capacity while reducing overall system weight compared to conventional PCM-based systems.

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

This approach enhances the stability and response characteristics of the thermal energy management system, reduces the burden on the compressor, and decreases the size and weight requirements by optimizing the thermal energy storage and refrigerant volume, while maintaining efficient heat transfer and system stability.

Implementation Method 1

transferring heat from the primary thermal load to a primary fluid via an evaporator

Methodology Applied

Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

compressing the primary fluid in a compressor downstream of the evaporator

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 3

transferring an amount of heat from the primary fluid to an ambient environment via a condenser

Methodology Applied

Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 4

transferring heat from the TES to the primary fluid or from the primary fluid to the TES

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS11761712B2Method of controlling thermal energy storage in a thermal energy management system

Publication Date: 2023.09.19 ROLLS ROYCE CORP

AI summary

Methods are provided for controlling thermal energy storage in a thermal energy management system that may operate in response to a variable or high transient heat load. Thermal energy management systems are also provided for controlling thermal energy storage that may operate in response to a variable or high transient heat load.