Integrated heating and cooling system and method for transportation refrigeration unit

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Solution Overview

Problem

Current refrigeration systems for transportation vehicles face challenges in efficiently managing the temperature of power electronics packages (PEPs), particularly in extreme environments, where both heating and cooling are necessary to ensure reliable operation, and existing cooling methods like forced air convection can lead to condensate accumulation and damage.

Innovation Solution

A temperature control system using a controller and pump to circulate a heat transfer fluid in two closed-loop circuits, with a heat source coupled to one of the flow circuits, allowing for heating or cooling of PEPs through a fluid heating apparatus, heat absorption heat exchanger, and radiator, utilizing a working fluid such as a refrigerant or organic compounds like water-propylene glycol mixtures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If forced air convection is used to cool the PEP, then cooling efficiency is improved, but condensate accumulation increases which can damage the PEP system

Engineering Contradiction:
ImprovePEP cooling efficiencyVSAvoidcondensate accumulation
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a heat transfer fluid as an intermediary substance to transfer heat from the PEP to the condenser, replacing direct air convection. This fluid-mediated heat transfer eliminates the condensate accumulation problem while maintaining effective cooling, as the fluid can be managed to prevent condensation issues.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a hydraulic system using a heat transfer fluid circulated through closed-loop circuits to transfer thermal energy. This hydraulic approach replaces pneumatic air convection with liquid-based heat transfer, which provides more controlled and reliable thermal management without condensate damage.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Device complexity

If a single cooling system is used for the PEP, then system simplicity is maintained, but the ability to heat in cold environments is lost

Engineering Contradiction:
Improvetemperature control system simplicityVSAvoidheating and cooling capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal temperature control system that performs both heating and cooling functions through a single integrated architecture. The dual closed-loop circuit system with reversible heat transfer can operate in heating mode by reversing the heat flow direction, providing year-round temperature management without requiring separate heating and cooling systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements a dynamic system where the heat transfer direction and fluid circulation can be adjusted based on environmental conditions. The system transitions between heating and cooling modes by controlling the heat source and pump operations, adapting to seasonal and operational requirements while maintaining a single system structure.

Inventive Principle:
Principle #15Dynamics

3Power

If extended fin surfaces are added to the PEP, then cooling capacity is improved, but the risk of condensate accumulation increases

Engineering Contradiction:
Improvecooling capacityVSAvoidcondensate accumulation risk
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The patent replaces direct air contact with extended fins with an intermediary heat transfer fluid system. The fluid absorbs heat through controlled contact surfaces and transports it away, providing equivalent or superior cooling capacity without the condensate accumulation that plagues exposed fin surfaces in air convection systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 system effectively regulates the temperature of PEPs, preventing overheating and ensuring reliable operation by efficiently managing heat dissipation and addition, thus enhancing the efficiency and reliability of transportation refrigeration systems.

Implementation Method 1

a pump configured to circulate a heat transfer fluid in two closed-loop circuits

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

a heat absorption heat exchanger operably coupled to a compressor discharge port; wherein the first flow circuit is fluidly coupled to the heat absorption heat exchanger

Methodology Applied
Scientific EffectHeat Exchange: Heat Exchanger

Implementation Method 3

a radiator, wherein the radiator is adjacent to a fan

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

a radiator, wherein the radiator is adjacent to a fan

Methodology Applied
Scientific EffectThermal Radiation: Thermal Radiation

Implementation Method 5

the radiator is adjacent to a fan

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Data Source

PatentEP3943321A1Integrated heating and cooling system and method for transportation refrigeration unit
Publication Date: 2022.01.26 CARRIER CORP
  • EP3943321A1 patent drawingFigure 1
  • EP3943321A1 patent drawingFigure 2
  • EP3943321A1 patent drawingFigure 3

AI summary

A system and method for operating a transportation refrigeration system including: a transportation refrigeration system 20 having a compressor 50 having a suction port 53 and a discharge port 51 configured to circulate a first working fluid through a flow circuit; a heat absorption heat exchanger 60 operably coupled to the compressor discharge port 51; and a temperature control system 200 including a fluid heating apparatus 210 operably coupled to a pump 220 configured to circulate a second working fluid by a first flow circuit 201a and at least a second flow circuit 201b, wherein the first flow circuit 201a is fluidly coupled to the heat absorption heat exchanger 60, and the second flow circuit 201b is fluidly coupled to a heat transfer apparatus and a radiator 250, and wherein the radiator 250 is adjacent to a fan 260.