Flooded A/C Heat Exchanger With Receiver for Integrated Refrigeration

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Solution Overview

Problem

Integrated air conditioning and refrigeration systems in commercial settings, such as grocery stores, are less efficient than separate systems, particularly on hot days, due to shared refrigerant and components, resulting in an 8% efficiency loss.

Innovation Solution

The system floods the air conditioning low side heat exchanger to allow both liquid and vapor refrigerant to exit, with an additional receiver storing the refrigerant and directing vapor to a compressor, and using residual liquid in the refrigeration system when the liquid level exceeds a threshold, improving efficiency by subcooling refrigerant and controlling pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the air conditioning low side heat exchanger is flooded to allow both liquid and vapor refrigerant to exit, then system efficiency is improved, but device complexity increases due to additional receivers and control mechanisms

Engineering Contradiction:
Improvesystem efficiencyVSAvoiddevice complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The system divides refrigerant handling into separate pathways: one for liquid refrigerant (stored in first receiver, used in refrigeration system) and one for vapor refrigerant (directed to compressor). This segmentation allows optimized handling of each phase, improving overall system efficiency while managing complexity through structured organization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An additional receiver is introduced as an intermediary component between the flooded heat exchanger and the rest of the system. This receiver acts as a buffer and separation point, enabling the system to handle mixed liquid-vapor refrigerant efficiently without requiring complete system redesign.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If an additional receiver is added to store refrigerant from the flooded heat exchanger, then refrigerant management is improved, but device complexity increases

Engineering Contradiction:
Improverefrigerant managementVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The refrigerant storage function is segmented into multiple receivers: the first receiver handles liquid refrigerant from the flooded heat exchanger, while the second receiver handles refrigerant from the high side heat exchanger. This segmentation improves refrigerant management by ensuring proper phase separation and availability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The additional receiver serves multiple functions: storing liquid refrigerant, separating phases, preventing overflow to the refrigeration system, and providing a buffer for vapor refrigerant. This multi-functionality justifies the added component by consolidating several critical functions into one element.

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

3Loss of energy

If liquid refrigerant is used in the refrigeration system when receiver level exceeds threshold, then efficiency is improved, but control complexity increases

Engineering Contradiction:
ImproveefficiencyVSAvoidcontrol complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The system incorporates level sensing in the receiver that provides feedback on liquid refrigerant levels. When the level exceeds a threshold, the control system automatically diverts liquid refrigerant to the refrigeration system, preventing overflow and optimizing efficiency. This feedback mechanism automates control decisions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The flooded heat exchanger and receiver system is designed to automatically regulate refrigerant flow and phase separation without requiring active control. The system self-adjusts by allowing gravity and pressure differentials to direct liquid and vapor refrigerant to appropriate destinations, reducing control complexity.

Inventive Principle:
Principle #25Self-service

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 enhances the efficiency of integrated systems to match or exceed that of separate systems on hot days, improving overall performance and reducing the system footprint.

Implementation Method 1

a high side heat exchanger, configured to remove heat from a refrigerant

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

an air conditioning low side heat exchanger, configured to use the refrigerant from the high side heat exchanger to cool a space proximate the air conditioning low side heat exchanger

Methodology Applied
Scientific EffectHeat absorption: Heat Exchanger

Implementation Method 3

the air conditioning low side heat exchanger is flooded such that the air conditioning low side heat exchanger does not evaporate all the liquid refrigerant entering the air conditioning low side heat exchanger

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3739277B1Integrated cooling system with flooded air conditioning heat exchanger
Publication Date: 2023.03.08 HEATCRAFT REFRIGERATION PRODUCTS LLC
  • EP3739277B1 patent drawingFigure 1
  • EP3739277B1 patent drawingFigure 2A
  • EP3739277B1 patent drawingFigure 2B

AI summary

The disclosure relates to an integrated system (200B) that floods an air conditioning low side heat exchanger (120) such that the air conditioning low side heat exchanger (120) does not evaporate all the liquid refrigerant entering the air conditioning low side heat exchanger (120). As a result, both liquid and vapor refrigerant leave the air conditioning low side heat exchanger (120). The system (200B) includes a receiver (125) that stores the refrigerant leaving the air conditioning low side heat exchanger (120). In some examples, to prevent the liquid refrigerant in the receiver (125) from overflowing, the liquid refrigerant in the receiver is used in a refrigeration system when the level of liquid refrigerant in the receiver exceeds a threshold (e.g., as detected by a sensor in the receiver).