Cooling System Pump Activation for Low-Temperature Compressor Idling

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Solution Overview

Problem

Existing cooling systems face challenges in efficiently operating with low-GWP refrigerants, particularly in low ambient temperatures, leading to issues such as difficulty in compressor switching and increased risk of dehumidification and freezing.

Innovation Solution

A cooling system that activates a refrigerant pump instead of the compressor when outdoor temperatures are below a threshold, using low-GWP refrigerants like R513A, R515B, R1234ze, and R471A, and switches to normal operation based on temperature and cooling requests, reducing compressor usage and enhancing evaporating temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a compressor is used to circulate refrigerant in low ambient temperatures, then the cooling system can operate, but the compressor has difficulty switching on and the risk of dehumidification and freezing increases

Engineering Contradiction:
Improvecompressor switching reliabilityVSAvoiddehumidification and freezing risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A refrigerant pump is introduced as an intermediary device to circulate refrigerant liquid during low ambient temperature operation, replacing the compressor's circulation function. The pump is activated when outdoor temperature is at or below a threshold (e.g., 32°F), preventing compressor switching issues and reducing the risk of dehumidification and freezing by controlling refrigerant flow more reliably in cold conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If low-GWP refrigerants are used to meet emissions standards, then environmental compliance is improved, but the refrigerants pose problems for existing cooling systems

Engineering Contradiction:
Improveglobal warming potentialVSAvoidcompatibility with existing cooling systems
Core Design Contradiction:
Object-generated harmful factorsVSAdaptability or versatility

Solution Approach 1:

The system dynamically switches between compressor-based operation and pump-based operation based on outdoor temperature conditions. When temperature is at or below the threshold, the pump activates to circulate refrigerant; when above the threshold, the compressor operates normally. This dynamic adaptation allows the system to effectively use low-GWP refrigerants while maintaining compatibility with existing cooling system infrastructure.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the compressor is activated in low temperatures, then cooling can be provided, but the system efficiency decreases due to operational difficulties

Engineering Contradiction:
Improvecooling provisionVSAvoidcompressor energy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The mechanical compression and circulation system is partially replaced with a pump-based liquid circulation system during low temperature operation. The refrigerant pump requires less energy to circulate refrigerant liquid compared to the compressor operating in cold conditions, thereby improving system efficiency while still providing the necessary cooling function.

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

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

The system reduces the risk of dehumidification and freezing, meets industry emissions standards, and improves efficiency, thereby reducing carbon footprint and indirect emissions.

Implementation Method 1

a condenser coupled to the CRAC unit, where the condenser is configured to cool the provided refrigerant liquid

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

a refrigerant pump coupled to the CRAC unit, where the refrigerant pump refrigerant is configured to provide a refrigerant liquid to the CRAC unit

Methodology Applied
Scientific EffectPumping: Pump

Data Source

PatentEP4696950A1Cooling system comprising a compressor and a pump and asssociated method for activating a pump
Publication Date: 2026.02.18 VERTIV CORP
  • EP4696950A1 patent drawingFigure 1
  • EP4696950A1 patent drawingFigure 2
  • EP4696950A1 patent drawingFigure 3A

AI summary

A method for activating a pump operation circuit of a cooling system may include receiving outdoor temperature data from an outdoor temperature sensor and receiving a predetermined outdoor temperature threshold. The method may include determining whether the received outdoor temperature data exceeds the received predetermined outdoor temperature threshold by comparing the received outdoor temperature data to the received predetermined outdoor temperature threshold. Upon determining the received outdoor temperature does not exceed the received predetermined outdoor temperature threshold, the method may include generating one or more control signals configured to cause a compressor of a computer room air conditioning unit to be idled and generating one or more control signals configured to cause a pump to be activated.