Air Conditioning Recharge Control Using Pressure Difference Feedback

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Solution Overview

Problem

Current air conditioning system recharging processes are time-consuming and lack accuracy, requiring multiple transfers and relying on weight measurements of refrigerant containers, which are limited in precision and speed.

Innovation Solution

A method and apparatus utilizing pressure sensors to determine the initial and supplemental amounts of refrigerant needed, with a controller managing the flow of refrigerant based on pressure differences between the container and the air conditioning system, allowing for precise and efficient recharging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If weight measurement of refrigerant containers is used to estimate refrigerant transfer amount, then the process is simple to implement, but the recharging process becomes time-consuming and requires multiple transfers

Engineering Contradiction:
Improvesimplicity of implementationVSAvoidrecharging speed
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent replaces the mechanical weighing system with a pressure-based measurement system. Pressure sensors monitor refrigerant pressure in real-time during transfer, allowing the system to determine transfer completion based on pressure stabilization rather than weight measurement. This substitution enables continuous monitoring and faster decision-making about when to stop transfers.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system implements real-time feedback through pressure sensors that continuously monitor refrigerant pressure during the transfer process. The controller receives pressure data and adjusts the transfer process accordingly, stopping when the desired pressure level is reached. This feedback mechanism eliminates the need for multiple trial transfers required by weight-based methods.

Inventive Principle:
Principle #23Feedback

2Ease of manufacture

If weight measurement of refrigerant containers is used to estimate refrigerant transfer amount, then the process is simple to implement, but the recharging accuracy is limited

Engineering Contradiction:
Improvesimplicity of implementationVSAvoidrecharging accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical weighing system with a pressure-based measurement system. Pressure sensors monitor refrigerant pressure in real-time during transfer, allowing the system to determine transfer completion based on pressure stabilization rather than weight measurement. This substitution enables continuous monitoring and faster decision-making about when to stop transfers.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system implements real-time feedback through pressure sensors that continuously monitor refrigerant pressure during the transfer process. The controller receives pressure data and adjusts the transfer process accordingly, stopping when the desired pressure level is reached. This feedback mechanism eliminates the need for multiple trial transfers required by weight-based methods.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If the same amount of refrigerant is added with each transfer, then the process is straightforward, but fine-tuning of the amount added is not available when close to the desired amount

Engineering Contradiction:
Improveoperational simplicityVSAvoidfine-tuning capability
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements dynamic control of the refrigerant transfer process. The system transitions from fixed-amount transfers to variable-amount transfers based on real-time pressure feedback. When the system approaches the target pressure level, the controller automatically reduces the transfer rate or stops the transfer, enabling precise fine-tuning of the refrigerant amount added.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements real-time feedback through pressure sensors that continuously monitor refrigerant pressure during the transfer process. The controller receives pressure data and adjusts the transfer process accordingly, stopping when the desired pressure level is reached. This feedback mechanism eliminates the need for multiple trial transfers required by weight-based methods.

Inventive Principle:
Principle #23Feedback

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 approach significantly reduces the time and improves the accuracy of refrigerant recharging, enabling the system to reach the desired level with fewer iterations and accounting for system-specific conditions, enhancing overall efficiency and precision.

Implementation Method 1

measuring a first refrigerant pressure within the exterior container and a second refrigerant pressure within the air conditioning system

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 2

controlling the connection mechanism and, thereby, how much refrigerant flows between the container and the air conditioning system

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Data Source

PatentEP2420766B1System and method for accurately recharging an air conditioning system
Publication Date: 2018.11.07 BOSCH AUTOMOTIVE SERVICE SOLUTIONS INC
  • EP2420766B1 patent drawingFigure 1
  • EP2420766B1 patent drawingFigure 2
  • EP2420766B1 patent drawingFigure 3

AI summary

A method of adding refrigerant to an air conditioning system. The method includes measuring a first pressure inside of the air conditioning system and a second pressure inside of a container that holds refrigerant being added to the air conditioning system. The method also includes comparing the difference between the two measured pressures to empirical data in order to determine how long to pulse additional refrigerant into the air conditioning system. In addition, an apparatus configured to add refrigerant to an air conditioning system.