Secondary-Loop Heat Pump Layout for Low-Leakage Hot Water Heating

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Solution Overview

Problem

Heat pump devices for multi-air-conditioning systems face issues such as high energy consumption due to long circulation passages for heat media, poor constructability, noise, refrigerant leakage risks, and inefficient hot water generation, particularly with secondary-loop refrigeration cycles.

Innovation Solution

A heat pump device employing a secondary-loop refrigeration cycle with a heat medium relay unit that connects the outdoor unit to indoor units via reduced piping, utilizing a binary cycle configuration to efficiently distribute cooling and heating energy while minimizing refrigerant circulation to indoor spaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the refrigerant is made to circulate to each indoor unit, then heat transfer efficiency is improved, but refrigerant leakage risk increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidrefrigerant leakage risk
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a heat medium (water or antifreeze solution) as an intermediary substance that carries thermal energy between the outdoor heat source unit and indoor heat exchange units. This heat medium circulates through insulated pipes instead of using refrigerant, thereby eliminating refrigerant leakage risks while maintaining effective heat transfer through the heat exchange units at each indoor location

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the circulation passage for heat medium is long, then heat can be transported to multiple indoor units, but energy consumption increases

Engineering Contradiction:
Improveability to serve multiple indoor unitsVSAvoidenergy consumption
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The system divides the heat distribution network into multiple independent circulation loops, each serving specific indoor units. The heat source unit contains multiple heat exchange units that can independently exchange heat with heat medium circulating in respective loops. This segmentation allows heat to be distributed to multiple indoor units while minimizing the total circulation path length and reducing energy consumption for heat medium circulation

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If four pipes are used to connect outdoor unit and indoor units for cooling and heating operations, then operational flexibility is improved, but constructability deteriorates

Engineering Contradiction:
Improveoperational flexibilityVSAvoidconstructability
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent designs the heat exchange units at indoor locations to be multi-functional, capable of performing both cooling and heating operations using the same physical infrastructure. The heat medium circulation system and heat exchange units can switch between cooling and heating modes without requiring separate pipe systems, thereby achieving operational flexibility with reduced piping complexity and improved constructability

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

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 configuration reduces energy consumption, enhances safety by minimizing refrigerant leakage, improves constructability, and achieves high-efficiency heating of a second heat medium while ensuring reliability and efficiency in both cooling and heating operations.

Implementation Method 1

a heat medium, such as water or antifreeze, is heated or cooled by a heat exchanger disposed within the outdoor unit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

The refrigerant transfers heat or receives heat so that an air-conditioned space is cooled or heated by cooled air or heated air

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP2650620B1Heat pump device
Publication Date: 2018.02.07 MITSUBISHI ELECTRIC CORP
  • EP2650620B1 patent drawingFigure 1
  • EP2650620B1 patent drawingFigure 2
  • EP2650620B1 patent drawingFigure 3

AI summary

Provided is a heat pump device that heats a second heat medium to a high temperature with high efficiency by using a secondary-loop refrigeration cycle while achieving a cooling operation and a heating operation simultaneously in a state where reliability and efficiency are ensured. In a heat pump device 100, a heat medium relay unit 3 and a water heating unit 300 are each provided with two connection ports (i.e., connection ports 51 a and 51 b, connection ports 305a and 305b) that are connectable to refrigerant pipes 311, a refrigerant circuit A and a refrigerant circuit C are connected to each other via a heat exchanger 304 included in the water heating unit 300, and a second heat medium is heated in a heat exchanger 302.