Rechargeable thermal battery systems for use in transporting or storing perishable items
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Solution Overview
Problem
Existing transportation vehicles and trailers for cooling perishable items are limited in their ability to maintain cooling for extended periods, especially when the vehicle is inoperable, and require expensive large industrial chillers for simultaneous thermal battery charging.
Innovation Solution
An apparatus featuring a cargo area heat exchanger, a thermal battery system with phase change material (PCM) embedded heat exchangers, and a closed-loop circuit for heat transfer, allowing for efficient cooling and charging of thermal batteries without the need for large industrial chillers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If conventional refrigeration units are used to cool perishable items, then cooling can be maintained while the vehicle is operational, but the vehicle cannot maintain cooling for extended periods when inoperable
Solution Approach 1:
The thermal battery system is pre-charged before the vehicle departs, storing thermal energy in advance. This preliminary charging action allows the system to provide cooling for extended periods (24-48 hours) without requiring the refrigeration unit to remain operational, thereby resolving the contradiction between cooling duration and reliability when the vehicle is inoperable.
2Productivity
If large industrial chillers are used to charge thermal batteries simultaneously, then multiple thermal batteries can be charged at once, but the equipment cost and operational cost increase significantly
Solution Approach 1:
The system divides the charging process into multiple smaller thermal battery units that can be charged independently or in parallel. Instead of requiring one large industrial chiller, multiple smaller thermal batteries are charged separately using the same chiller sequentially, or using distributed charging sources, thereby reducing the capital cost and operational cost while maintaining high charging throughput.
3Temperature
If conventional refrigeration systems are used, then cooling can be maintained during vehicle operation, but the system complexity and power requirements increase
Solution Approach 1:
The invention extracts the thermal energy storage function from the conventional refrigeration system by introducing a separate thermal battery system. The refrigeration unit only needs to charge the thermal battery during vehicle operation, while the thermal battery independently maintains cargo temperature when the vehicle is stopped, thereby simplifying the overall system architecture and reducing power requirements during critical cooling periods.
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 solution enables longer and more efficient cooling of perishable items, even when the vehicle is inoperable, and allows for simultaneous charging of multiple thermal batteries using a smaller, more cost-effective setup.
Implementation Method 1
a phase change material (PCM) with first and second heat exchangers embedded in the PCM
Implementation Method 2
a phase change material (PCM) with first and second heat exchangers embedded in the PCM
Implementation Method 3
a closed-loop circuit for heat transfer
Implementation Method 4
an onboard pump arranged in fluid communication with the fluid conduits and configured to create a fluid flow through the first plurality of fluid conduits
Data Source
AI summary
An apparatus includes a cargo area with a heat exchanger; a thermal battery system having a phase change material (PCM) with first and second heat exchangers embedded in the PCM; fluid conduits defining fluid passageways interconnecting the cargo area heat exchanger and the first PCM-embedded heat exchanger; and a pump creating a fluid flow through the fluid conduits between the cargo area heat exchanger and the first PCM-embedded heat exchanger. The apparatus also includes external ports configured for connecting to an external charging source for charging the PCM; and fluid conduits defining fluid passageways interconnecting the external ports and the second PCM-embedded heat exchanger. The first PCM-embedded heat exchanger, pump, and cargo area heat exchanger form part of a first closed-loop circuit for transferring heat between the cargo area and the thermal battery system. The second PCM-embedded heat exchanger and external ports do not part of the first closed-loop circuit.