Wheel-Driven Generator Torque Control for Overheat-Limited Refrigeration

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Solution Overview

Problem

Existing transport refrigeration systems face inefficiencies in energy generation, particularly in electrically driven systems, which leads to increased fuel usage and potential overheating of electrical generation devices.

Innovation Solution

The transport refrigeration system incorporates an energy storage device, an electric generation device connected to a wheel or wheel axle, and a power management module that adjusts the torque limit of the electric generation device based on its temperature and ambient conditions to optimize energy generation and prevent overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the electric generation device operates at high torque to maximize energy generation, then power output increases, but the device overheats and reliability decreases

Engineering Contradiction:
Improvepower outputVSAvoiddevice reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The torque limit of the electric generation device is made dynamic rather than fixed. The power management module continuously adjusts the torque limit based on real-time temperature conditions, allowing the device to operate at higher torque when cool and reducing torque when temperature rises, thus preventing overheating while maximizing power generation during optimal conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A feedback control system is implemented where the power management module monitors the temperature of the electric generation device and adjusts the torque limit accordingly. The system uses temperature sensor data to continuously modify operational parameters, creating a closed-loop control that balances power output with thermal management to maintain reliability

Inventive Principle:
Principle #23Feedback

2Reliability

If the torque limit is reduced to prevent overheating, then device reliability improves, but energy generation efficiency decreases

Engineering Contradiction:
Improvedevice reliabilityVSAvoidenergy generation efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The torque limit is dynamically adjusted based on thermal conditions rather than being statically reduced. When the device temperature is within acceptable ranges, the torque limit is increased to maximize energy generation. Only when temperature thresholds are approached does the system reduce torque, minimizing energy loss while maintaining reliability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system proactively manages thermal conditions by monitoring temperature trends and adjusting torque limits before critical overheating occurs. This preliminary thermal management allows the device to operate at optimal torque levels for longer periods, reducing unnecessary energy loss while preventing reliability issues

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If ambient temperature is high, then the device operates in challenging environmental conditions, but the risk of overheating increases and requires torque reduction

Engineering Contradiction:
Improveenvironmental adaptabilityVSAvoiddevice temperature
Core Design Contradiction:
Adaptability or versatilityVSTemperature

Solution Approach 1:

The power management module uses feedback from temperature sensors to continuously monitor both ambient and device temperatures. Based on this feedback, the system dynamically adjusts the torque limit to compensate for high ambient temperatures, reducing torque when necessary to prevent overheating while maintaining operation in diverse environmental conditions

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes operational parameters (torque limit) in response to changing environmental conditions (ambient temperature). By adjusting the torque limit parameter based on ambient temperature readings, the system adapts to different environmental conditions while maintaining safe operating temperatures

Inventive Principle:
Principle #35Parameter changes

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 enhances energy efficiency by optimizing power generation and reducing fuel consumption, while also preventing overheating of electrical generation devices, thus ensuring reliable operation of the transport refrigeration system.

Implementation Method 1

an electric generation device operably connected to at least one of a wheel of the transport refrigeration system and a wheel axle of the transport refrigeration system, the electric generation device being configured to generate electrical power from at least one of the wheel and the wheel axle

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3860870B1Generator temperature control
Publication Date: 2025.01.22 CARRIER CORP
  • EP3860870B1 patent drawingFigure 1
  • EP3860870B1 patent drawingFigure 2
  • EP3860870B1 patent drawingFigure 3

AI summary

A transportation refrigeration system (100) including: a transportation refrigeration unit; an energy storage device (350) configured to provide electrical power to the transportation refrigeration unit; an electric generation device (340) operably connected to at least one of a wheel (364) or axle (365) of the transport refrigeration system, the electric generation device being configured to generate electrical power from at least one of the wheel and the wheel axle to charge the energy storage device when the electric generation device is activated; a power management module (310) in electrical communication with the energy storage device and the electric generation device, the power management module being configured to determine a current temperature of the electric generation device (340), wherein the power management module is configured to adjust a torque limit of the electric generation device in response to a current temperature of the electric generation device.