Distributed Cargo Sensors for Refrigerated Container Temperature Control
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Solution Overview
Problem
Current refrigeration systems in cargo containers are inaccurate in maintaining desired cargo temperatures, especially for temperature-sensitive goods, as they rely on air temperature sensing, which can vary significantly from actual cargo temperatures, and fail to detect localized hot or cold spots, leading to potential spoilage.
Innovation Solution
The implementation of multiple cargo temperature sensors, such as thermal cameras or laser sensors, to accurately determine cargo temperatures and a controller that adjusts the refrigeration unit's operation based on these readings, ensuring consistent cargo temperature and addressing localized variations by controlling airflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If air temperature sensing is used to control refrigeration, then the control system is simple, but the temperature measurement precision is poor
Solution Approach 1:
The patent divides the temperature monitoring function into multiple distributed cargo temperature sensors placed throughout the container, rather than relying on a single air temperature sensor. This segmentation allows direct measurement of cargo temperature at multiple locations, improving measurement precision while the modular sensor design keeps individual components simple
Solution Approach 2:
The patent replaces the indirect mechanical air temperature sensing system with direct cargo temperature sensing using thermal cameras or laser sensors that measure cargo temperature directly through non-contact methods, eliminating the need for physical contact with cargo and improving measurement accuracy
2Reliability
If air temperature is used to determine refrigeration settings, then the control method is simple, but the reliability of temperature control is poor
Solution Approach 1:
The patent implements a feedback control system where multiple cargo temperature sensors continuously monitor cargo temperature at different locations, and the controller adjusts refrigeration unit settings based on this direct cargo temperature feedback, ensuring reliable temperature control. The system also provides alerts when temperature deviations occur
Solution Approach 2:
The patent transitions from one-dimensional air temperature measurement to three-dimensional cargo temperature monitoring by placing sensors throughout the container volume, enabling detection of localized hot or cold spots and providing comprehensive temperature control reliability
3Difficulty of detecting and measuring
If single air temperature sensing is used, then the device complexity is low, but the ability to detect localized temperature variations is poor
Solution Approach 1:
The patent segments the temperature monitoring function by placing multiple cargo temperature sensors at different locations within the container, enabling detection of localized hot or cold spots that a single sensor would miss. This distributed segmentation provides comprehensive spatial coverage
Solution Approach 2:
The patent employs thermal cameras that detect infrared radiation and convert it into visual thermal images showing temperature distributions through color variations, making localized hot or cold spots visually detectable and easy to identify
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 solution allows for precise temperature control and detection of hot or cold spots within the container, minimizing cargo spoilage and ensuring that the cargo is maintained at the desired temperature, even in varying conditions.
Implementation Method 1
The plurality of cargo temperature sensors may be noncontact sensors, such as thermal cameras, laser temperature sensors, or the like
Implementation Method 2
one or more evaporator fans of the refrigeration unit blow a flow of air across the evaporator coil cooling the air
Implementation Method 3
A volume of refrigerant circulates throughout the refrigeration unit, and one or more evaporator fans of the refrigeration unit blow a flow of air across the evaporator coil
Data Source
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AI summary
A method of monitoring and controlling temperature of a cargo in a refrigerated transportation cargo container includes measuring a temperature of a plurality of portions of the cargo located in the cargo container via a plurality of temperature sensors directed at the portions of the cargo. One or more of the measured cargo temperatures are compared to a preselected threshold. Operation of a refrigeration unit disposed at the cargo container in operable communication with the plurality of temperature sensors is changed based on a result of the comparison. A transportation cargo container refrigeration system includes a plurality of cargo temperature sensors configured to determine a temperature of at least portions of a cargo. A refrigeration unit and controller are connected to the refrigeration unit and the cargo temperature sensors to control operation of the refrigeration unit based on data received from the cargo temperature sensors.