Methods and systems for maintaining cargo at an ultra-low temperature over an extended period of time
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Solution Overview
Problem
Existing transport climate control systems face challenges in maintaining ultra-low temperatures between −30° C. to −80° C. for perishable cargo due to the high cost and inefficiency of standalone vapor-compression or sublimating/evaporative systems, which may not provide sufficient cooling capacity over extended periods.
Innovation Solution
A transport climate control system comprising a primary climate control system with a compressor, condenser, expander, and evaporator, combined with a secondary sublimating/evaporative climate control system using an ultra-low temperature phase changing medium like dry ice or liquid nitrogen, providing additional or backup cooling capacity to maintain ultra-low temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stand-alone vapor-compression type climate control system is used to maintain ultra-low temperature, then the cooling capacity is sufficient, but the cost and safety issues make it unfeasible
Solution Approach 1:
The climate control system is divided into two independent subsystems: a primary vapor-compression system for active cooling and a secondary phase-change system for passive ultra-low temperature maintenance. Each subsystem operates independently to address different temperature requirements, avoiding the need for a single complex system to handle all conditions.
Solution Approach 2:
The patent combines the primary vapor-compression climate control system with a secondary phase-change system using ultra-low temperature phase changing medium. The two systems work together in a hybrid architecture where the primary system handles active cooling and the secondary system provides passive ultra-low temperature maintenance, achieving cost-effective and safe ultra-low temperature control.
2Device complexity
If a stand-alone sublimating/evaporative climate control system is used, then the cost is reduced, but the cooling capacity is insufficient for extended periods
Solution Approach 1:
The phase-changing medium is pre-positioned in the cargo area and pre-cooled to ultra-low temperatures before the shipping journey begins. This preliminary preparation ensures that when the primary climate control system experiences interruptions or failures, the pre-positioned phase-change material can immediately provide the necessary cooling without delay, extending the effective cooling duration.
Solution Approach 2:
The secondary phase-change system acts as a cushion or backup mechanism that compensates for potential failures or interruptions in the primary vapor-compression system. By having this reserve cooling capacity in place beforehand, the system ensures continuous ultra-low temperature maintenance even when the primary system cannot operate, effectively extending the reliable cooling duration.
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 combination effectively and cost-effectively maintains ultra-low temperatures over extended periods, ensuring the preservation of sensitive cargo by enhancing cooling capacity and reducing operational costs.
Implementation Method 1
a stand-alone vapor-compression type climate control system
Implementation Method 2
an ultra-low temperature phase changing medium packaged inside or outside of an enclosure for a cargo
Implementation Method 3
a stand-alone sublimating/evaporative climate control system
Data Source
AI summary
A transport climate control system to cost-effectively maintain an ultra-low temperature over an extended period of time is provided. The transport climate control system includes a primary climate control system and a secondary climate control system. The primary climate control system includes a first compressor, a first condenser, a first expander, and a main evaporator that is configured to thermally communicate with a climate controlled space. The secondary climate control system includes an ultra-low temperature phase changing medium packaged inside or outside of an enclosure for a cargo. The secondary climate control system is configured to thermally communicate with the climate controlled space, the primary climate control system, and the cargo to provide additional or backup climate control capacity at the ultra-low temperature.