Heat pump device

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Solution Overview

Problem

Existing protection devices for preventing refrigerant leaks from reaching combustible densities in heat pump systems fail when disconnected from the indoor unit, potentially allowing leaked refrigerant to accumulate and pose safety risks.

Innovation Solution

A fan drive circuit with a forced operation mechanism that ensures the fan is forcibly operated even if the protection device, such as a refrigerant sensor, is disconnected from the heat pump device, thereby diffusing any leaked refrigerant and preventing accumulation at combustible densities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If protection devices (refrigerant sensor, alarm, ventilator) are connected to the indoor unit, then the protection function against refrigerant leakage is improved, but the reliability deteriorates when the connection fails or is disconnected

Engineering Contradiction:
Improveprotection function reliabilityVSAvoidconnection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The indoor unit's control circuit automatically detects the connection status of protection devices and autonomously activates the fan motor when disconnection is detected, eliminating the need for external control systems and ensuring self-protecting functionality

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control circuit is pre-configured with detection capabilities for protection device connections and pre-programmed response protocols that automatically activate the fan motor upon detecting disconnection, providing fail-safe protection before actual refrigerant leakage can cause harm

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Device complexity

If the fan is operated only when protection devices are connected and functioning, then the device complexity is reduced, but the safety deteriorates when protection devices are disconnected

Engineering Contradiction:
Improvecontrol system complexityVSAvoidrefrigerant accumulation hazard
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The control circuit independently monitors protection device connection status and autonomously controls fan motor operation based on this status, ensuring the fan operates as a fail-safe measure when protection devices are disconnected without requiring complex external control systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control circuit proactively detects disconnection of protection devices and pre-activates the fan motor to prevent refrigerant accumulation before leakage can occur or to immediately respond if leakage occurs in the disconnected state

Inventive Principle:
Principle #9Preliminary anti-action

3Object-affected harmful factors

If the fan is forcibly operated when protection device connection is undetectable, then the safety against refrigerant accumulation is improved, but the energy consumption increases

Engineering Contradiction:
Improverefrigerant accumulation preventionVSAvoidfan motor energy consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The control circuit autonomously determines fan motor operation based on protection device connection status detection, activating the fan only when disconnection is detected and deactivating it when connection is confirmed, optimizing energy usage while maintaining safety

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 solution ensures the safety of indoor residents and equipment by preventing refrigerant accumulation at combustible densities even if the protection device and heat pump are disconnected, maintaining safety during refrigerant leaks.

Implementation Method 1

the indoor fan is operated to diffuse the leaked refrigerant

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Data Source

PatentEP3447406B1Heat pump device
Publication Date: 2024.04.10 DAIKIN INDUSTRIES LTD
  • EP3447406B1 patent drawingFigure 1
  • EP3447406B1 patent drawingFigure 2
  • EP3447406B1 patent drawingFigure 3

AI summary

A fan drive circuit 1 for a heat pump device is provided. The heat pump device blows air heat exchanged by a heat exchanger using a mildly-flammable or flammable refrigerant having a specific gravity greater than that of air from a blowout port using a fan. The fan drive circuit 1 is equipped with a forced operation circuit configured to operate the fan in the event that it is undetectable that a protection device for preventing a leaked refrigerant from the heat pump device from reaching a combustible density is connected to the heat pump device.