Universal input refrigerating machine

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional low power refrigerating machines for cooling electronic or electromechanical devices have low operating efficiency and are designed for specific electric power supplies, making them inefficient and complex to adapt to varying mains power voltages and frequencies.

Innovation Solution

A refrigerating machine with an AC/DC converter and DC/AC converter system that can operate across single-phase, three-phase, or DC electrical networks, using a synchronous electric motor powered by a variable voltage and frequency, allowing universal compatibility and efficient modulation of cooling power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional refrigerating machines use fixed-speed compressors with ON/OFF control, then the device complexity is reduced, but the operating efficiency deteriorates

Engineering Contradiction:
Improvecompressor control systemVSAvoidoperating efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent applies dynamics by transitioning from fixed-speed ON/OFF control to variable-speed control of the compressor. The electric motor driving the compressor can continuously adjust its speed according to the actual cooling demand, eliminating the energy waste associated with frequent start-stop cycles and maintaining optimal operating efficiency across varying load conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by allowing the compressor speed to vary continuously rather than remaining fixed. The control system adjusts the operating parameters (speed, torque) of the electric motor based on temperature feedback and cooling requirements, enabling efficient operation across a wide range of operating conditions without the energy penalties of binary ON/OFF control.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If refrigerating machines are designed for specific mains power supplies, then the device complexity is reduced, but the adaptability deteriorates

Engineering Contradiction:
Improvepower supply apparatusVSAvoidmains power supply compatibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies universality by designing the power supply apparatus to accept multiple types of mains power supplies (single-phase, three-phase, different voltages and frequencies) through a single unified interface. The system incorporates intelligent detection capabilities that automatically identify the input power characteristics and adjust the drive parameters accordingly, eliminating the need for separate designs for different geographical regions.

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

Solution Approach 2:

The patent uses an intermediary approach by introducing a sophisticated control system between the power supply apparatus and the electric motor. This intermediary control layer detects the mains power characteristics and translates them into appropriate motor drive parameters, acting as a buffer that decouples the motor design from specific power supply requirements and enables universal compatibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If refrigerating machines use variable-speed electric motors with advanced power conversion, then the operating efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improveoperating efficiencyVSAvoidoperating apparatus
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies merging by integrating multiple functions into the operating apparatus: power detection, parameter calculation, pulse generation, and motor control are combined into a single unified control system. The control unit consolidates the detection of power characteristics, calculation of optimal drive parameters, and generation of control pulses, reducing the need for separate complex subsystems while maintaining high operating efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements self-service by enabling the control system to automatically detect the mains power supply characteristics and self-adjust the motor drive parameters without external intervention. The system autonomously calculates the appropriate frequency and voltage based on detected power parameters, eliminating the need for manual configuration or complex external control infrastructure.

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

The solution enables a refrigerating machine with improved performance and simplified design, capable of operating across a wide range of power supplies and cooling powers, enhancing efficiency and reducing complexity and cost.

Implementation Method 1

an AC/DC converter (16) configured so that it may be connected, by means of a first input connector (17), to a single-phase or three-phase or DC electrical network (18)

Methodology Applied
Scientific EffectAC/DC conversion:

Implementation Method 2

a DC/AC converter device (20) connected to the first output connector (19) so as to powered by the latter at the output voltage Vu and having a second output connector (21) connected directly to the electric motor (13)

Methodology Applied
Scientific EffectDC/AC conversion:

Implementation Method 3

an electric motor (13) connected to the compressor (12) in order to operate it

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP3474437B1Universal input refrigerating machine
Publication Date: 2020.12.02 CAREL IND SPA
  • EP3474437B1 patent drawingFigure 1

AI summary

The low power refrigerating machine (10) for cooling a power cabinet or an electronic or electromechanical device which comprises: - a cooling circuit (11) comprising a compressor (12) and a variable-flowrate valve (15); - an electric motor (13) connected to the compressor (12); - an operating apparatus (14) connected to the electric motor (13) in order to power it. The operating apparatus (14) comprises: - an AC/DC (16) converter device (16) configured so that it can be connected to a single-phase or three-phase or direct current electrical network (18); - a DC/AC converter device (20) connected to the AC/DC converter device (16) and connected directly to the electric motor (13) in order to power it. The DC/AC converter device (20) is configured to power the electric motor (13) with a power supply voltage (Va) and at a power supply frequency which are variable upon command and independent of the power supply provided by the electrical network (18).