Staggered Air Multiplier Layout for Transformer Cooling Airflow

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Solution Overview

Problem

Existing transformer cooling systems, particularly for high-power transformers, face inefficiencies in airflow generation, leading to high power consumption, noise, and complex maintenance due to the use of conventional fans and natural convection, which are inadequate for effective heat dissipation.

Innovation Solution

An airflow generator comprising a ducted fan and multiple air multipliers of varying sizes positioned along an axis, with support means and optional actuators for adjustable positioning, to enhance airflow distribution and efficiency, reducing power consumption and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional bladed fans are used for transformer cooling, then forced convection cooling is achieved, but the system produces high noise, has complex structure, and is heavy

Engineering Contradiction:
Improvecooling capabilityVSAvoidstructure complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The cooling system is segmented into multiple air multipliers distributed along the first axis, each handling a portion of the cooling load. This distributes the complexity across multiple simpler units rather than one complex fan system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces conventional bladed fans with air multipliers that use fluid dynamic principles (Coanda effect) to amplify airflow. This substitutes a complex mechanical fan system with a more elegant fluid-based solution that has fewer moving parts and lower complexity

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

2Productivity

If larger fans are used to increase airflow rate, then cooling efficiency improves, but power consumption increases

Engineering Contradiction:
Improveairflow rateVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The air multipliers act as intermediaries that take the airflow from a relatively small ducted fan and amplify it to a much larger volume. The fan provides the initial driving force, and the air multipliers multiply this effect, achieving high airflow rates without requiring a proportionally large and power-hungry fan

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the airflow parameters through the air multipliers, which modify the flow characteristics and amplify the volume. This allows achieving high productivity with lower power input by optimizing the airflow parameters through the multiplier devices

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If air multipliers are positioned closer together in the same plane, then airflow coverage is improved, but flow restrictions increase

Engineering Contradiction:
Improveairflow coverage areaVSAvoidflow restriction loss
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

Instead of positioning all air multipliers in the same plane, the patent distributes them along the first axis (longitudinal dimension). This spatial reconfiguration allows airflow from multiple multipliers to combine effectively without creating restrictions, as each multiplier operates in a slightly different position along the axis

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Productivity

If a single large fan is used to cool the transformer, then cooling coverage is sufficient, but noise emission increases

Engineering Contradiction:
Improvecooling coverageVSAvoidnoise emission
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The single large fan is replaced by multiple smaller air multipliers distributed along the first axis. Each multiplier operates at lower individual noise levels, and their distributed arrangement prevents the concentrated noise emission of a single large fan, achieving sufficient cooling coverage with reduced overall noise

Inventive Principle:
Principle #1Segmentation

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 airflow generator achieves a more even airflow distribution, lowers power consumption, and reduces noise, enabling a compact and efficient cooling system for transformers.

Implementation Method 1

US 2017/057621 shows a nesting of Coanda-effect air multipliers that increase the airflow within the multiplier. US 2019/277317 shows angled and staggered Coanda-effect air multipliers.

Methodology Applied
Scientific EffectCoanda effect: Coanda Effect

Implementation Method 2

This disclosure concerns cooling systems using forced convection. Forced convection is typically achieved using one or more large fans blowing air through or onto the radiator(s).

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP4415006B1An airflow generator
Publication Date: 2025.09.10 HITACHI ENERGY LTD
  • EP4415006B1 patent drawingFigure 1a~2b
  • EP4415006B1 patent drawingFigure 3~4
  • EP4415006B1 patent drawingFigure 5~6

AI summary

An airflow generator (1) comprising a ducted fan (2) and a plurality of air multipliers (7a, 7b, 7c) for discharging air along a first axis (A), each air multiplier (7a, 7b, 7c) comprising an inlet (8) and an outlet (9), said ducted fan (2) being fluidly connected to the inlets (8) of the air multipliers (7a, 7b, 7c), wherein the air multipliers (7a, 7b, 7c) are differently sized to provide airflows of different cross-sectional size, and are positioned such that smaller ones (7b, 7c) of the air multipliers (7a, 7b, 7c) provide airflows reinforcing a respective sub-portion of the airflows provided by larger air multipliers (7a, 7b), and wherein the air multipliers (7a, 7b, 7c) are distributed along the first axis (A).