Refrigeration Load Ratio Control to Prevent Compressor Flooding

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Solution Overview

Problem

Traditional cooling systems face the challenge of preventing liquid refrigerant flooding back into the compressor, which can damage the compressor and is typically addressed by installing additional hardware such as heat exchangers or accumulators.

Innovation Solution

A flood prevention system that controls the ratios between refrigeration loads and uses temperature sensors to detect refrigerant temperatures, triggering alarms and deactivating loads likely to flood, thereby adjusting the refrigerant load ratios to prevent flooding without additional hardware.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional hardware such as heat exchangers or accumulators is installed to prevent refrigerant flooding, then compressor protection is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecompressor protectionVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses temperature sensors to continuously monitor refrigerant temperature and provides feedback to the controller. The controller compares the measured temperature with the saturation temperature and adjusts the expansion valve opening or compressor operation accordingly, creating a closed-loop feedback system that prevents flooding without additional hardware

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses its existing components (temperature sensors, controller, expansion valve, and refrigerant circulation system) to detect and prevent flooding conditions. The controller utilizes data already being collected by the temperature sensors and processes already being performed by the expansion valve, making the existing system serve the additional function of flood prevention

Inventive Principle:
Principle #25Self-service

2Reliability

If traditional hardware solutions are added to prevent flooding, then compressor reliability is improved, but manufacturing cost and installation complexity increase

Engineering Contradiction:
Improvecompressor reliabilityVSAvoidinstallation simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The temperature sensors and controller are designed to perform multiple functions: they monitor both the cooling performance and detect potential flooding conditions. The same sensor data used for temperature control is also used for flood prevention, making the system multi-functional and eliminating the need for separate dedicated flood prevention hardware

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

3Reliability

If the system deactivates loads to prevent flooding, then compressor protection is improved, but cooling performance and productivity decrease

Engineering Contradiction:
Improvecompressor protectionVSAvoidcooling performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically adjusts the expansion valve opening based on real-time temperature feedback rather than statically deactivating loads. This dynamic adjustment allows the system to maintain optimal refrigerant flow and cooling performance while preventing flooding conditions, avoiding the need to shut down cooling loads

Inventive Principle:
Principle #15Dynamics

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

Effectively prevents compressor flooding by managing refrigerant load ratios and deactivating cooler loads, reducing the risk of liquid refrigerant returning to the compressor without the need for extra hardware, thus protecting the compressor and maintaining system efficiency.

Implementation Method 1

The first temperature sensor is configured to detect a first temperature of the refrigerant from the first load, the second load, and the third load. The second temperature sensor is configured to detect a second temperature of the refrigerant from the first load, the second load, the third load, and the compressor.

Methodology Applied
Scientific EffectTemperature detection:

Implementation Method 2

The first compressor is configured to compress the refrigerant from the fourth load.

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

The first load is configured to use a refrigerant to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant to remove heat from a second space proximate to the second load.

Methodology Applied
Scientific EffectHeat removal: Heat Exchanger

Data Source

PatentEP3431901B1Cooling system flood prevention tool
Publication Date: 2023.01.04 HEATCRAFT REFRIGERATION PRODUCTS LLC
  • EP3431901B1 patent drawingFigure 1
  • EP3431901B1 patent drawingFigure 2
  • EP3431901B1 patent drawingFigure 3

AI summary

A flood prevention system includes a first load (205), a second load (210), a third load (215), a fourth load (220), a first compressor (225), a first temperature sensor (240), a second temperature sensor (245), and a controller (250). The first (205), second (210), third (215), and fourth (220) loads are configured to use a refrigerant to remove heat from a first, second, third, and fourth space, respectively, proximate to the first (205), second (210), third (215), and fourth (220) load, respectively. The first compressor (225) is configured to compress the refrigerant from the fourth load (220). The first temperature sensor (240) is configured to detect a first temperature of the refrigerant from the first load (205), the second load (210), and the third load (215). The second temperature sensor (245) is configured to detect a second temperature of the refrigerant from the first load (205), the second load (210), the third load (215), and the compressor. The controller (250) is configured to trigger an alarm in response to certain conditions.