Multi-sensor closed-loop refrigeration control for freight containers
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Solution Overview
Problem
Refrigerated freight containers face challenges in maintaining thermal compliance with cargo loads due to faults in refrigeration systems, leading to potential cargo spoilage and waste, particularly in transporting perishable goods.
Innovation Solution
A multi-sensor closed-loop refrigeration control system is implemented, where thermal sensor nodes within the container wirelessly relay temperature measurements to a gateway, which uses thermal models to optimize refrigeration system control, ensuring compliance with cargo-specific parameters and minimizing losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional refrigeration control systems are used, then the system structure is simple, but thermal compliance cannot be maintained due to lack of real-time monitoring and closed-loop control
Solution Approach 1:
The patent implements a closed-loop control system where temperature sensors continuously monitor cargo temperature, the controller receives this feedback data, compares it against target temperature ranges, and automatically adjusts refrigeration system operation to maintain thermal compliance. This feedback mechanism transforms the open-loop traditional system into a self-regulating closed-loop system that reliably maintains thermal conditions.
Solution Approach 2:
The patent introduces a gateway device as an intermediary between the distributed temperature sensors and the central controller. The gateway aggregates temperature data from multiple sensors, performs preliminary processing, and communicates with the controller, thereby simplifying the overall system architecture while enabling comprehensive monitoring without requiring direct complex connections between all sensors and the controller.
2Measurement precision
If multiple sensors are deployed for comprehensive monitoring, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent divides the monitoring function into distributed temperature sensor nodes placed throughout the cargo container. Each sensor independently monitors its local zone, providing granular temperature data. This segmentation enables comprehensive coverage and high measurement precision while allowing the system to process information in manageable discrete units rather than as a monolithic complex system.
Solution Approach 2:
The gateway device serves multiple functions: it acts as a data aggregation point for temperature sensors, performs data validation and processing, stores historical temperature records, and communicates with both the controller and external systems. This multi-functionality consolidates what would otherwise require multiple separate components, reducing overall system complexity while maintaining comprehensive monitoring capabilities.
3Loss of substance
If real-time closed-loop control is implemented, then cargo loss is reduced, but energy consumption increases
Solution Approach 1:
The closed-loop control system operates by periodically sampling temperature data from sensors, processing this information through the gateway, and making incremental adjustments to refrigeration system operation. This periodic control approach maintains cargo temperature within acceptable ranges through small, targeted refrigeration cycles rather than continuous high-power operation, thereby reducing overall energy consumption while preventing cargo loss.
Solution Approach 2:
The system dynamically adjusts refrigeration system operation based on real-time temperature conditions and cargo characteristics. Rather than maintaining constant high-power refrigeration, the controller modulates refrigeration output dynamically in response to actual thermal conditions, loading patterns, and environmental factors. This dynamic operation minimizes energy consumption while ensuring thermal compliance is maintained throughout the shipping journey.
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 maintains thermal compliance, reduces cargo losses, optimizes energy usage, and provides real-time monitoring and alerts, enhancing the reliability and efficiency of refrigerated freight operations.
Implementation Method 1
Temperature measurements can be wirelessly relayed from the sensor nodes to a gateway associated with the freight container
Implementation Method 2
The refrigeration system can be controlled in response to processing the thermal models to optimize compliance parameters associated with the cargo loads
Data Source
AI summary
Systems and methods can control refrigeration within a refrigerated freight container. Thermal sensor nodes can be positioned within the freight container. Temperature measurements can be wirelessly relayed from the sensor nodes to a gateway associated with the freight container. The received temperature measurements can be aggregated and logged at the gateway. Thermal models of the freight container and associated cargo loads can be established in response to the logged temperature measurements and loading plan for the foreign container. The refrigeration system can be controlled in response to processing the thermal models. The refrigeration system can be controlled to optimize compliance parameters associated with the cargo loads.