Heat Pump Mode Switching for Shared Hot Water and HVAC

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Solution Overview

Problem

In heat pump systems where both hot-water supply and air cooling/heating operations are connected to a shared heat source unit, users often overlook the necessity of switching the four-way switching valve, leading to operational mistakes due to the complexity of thermoregulation mode switching, which can result in undesired operation outcomes.

Innovation Solution

A heat pump system with a heat source unit connected to both a first usage unit for hot-water supply and a second usage unit for air cooling/heating, featuring a heat-source-side switching mechanism that allows for switching between radiating and evaporating operations, enabling the system to automatically switch to a suitable thermoregulation mode based on user commands without requiring manual operation of the four-way switching valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a four-way switching valve is used to switch between hot-water supply and air cooling/heating operations in a heat pump system, then the system can perform multiple thermoregulation modes, but the operational complexity increases and users may make mistakes when switching modes

Engineering Contradiction:
Improvethermoregulation mode switching capabilityVSAvoiduser operation simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The heat pump system automatically determines and switches between thermoregulation modes (hot-water supply, air cooling, air warming) based on user commands and environmental conditions without requiring manual operation of the four-way switching valve. The controller autonomously manages the switching logic, eliminating the need for users to understand or manually operate the complex valve switching mechanism while still providing multiple operational modes.

Inventive Principle:
Principle #25Self-service

2Device complexity

If manual operation of the four-way switching valve is required for mode switching, then the system structure remains simple, but operational mistakes occur and desired operations may not be performed correctly

Engineering Contradiction:
Improvesystem structure simplicityVSAvoidoperational accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

A controller acts as an intermediary between the user and the four-way switching valve. The user provides simple commands (hot-water supply, air cooling, or air warming), and the controller automatically translates these into the appropriate valve switching operations and compressor control parameters. This intermediary layer maintains the simple user interface while ensuring accurate and reliable mode switching without operational mistakes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The manual mechanical operation of the four-way switching valve is replaced with automated electronic control. The controller uses solenoid valves or electronic expansion valves under electronic control to switch refrigerant flow paths, replacing the need for manual mechanical valve operation. This substitution maintains structural simplicity while dramatically improving operational reliability.

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

3Reliability

If automatic mode switching is implemented based on user commands and outside air temperature, then operational reliability improves, but control system complexity increases

Engineering Contradiction:
Improvemode switching accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The controller continuously monitors outside air temperature and user commands to automatically determine the appropriate thermoregulation mode. The system uses feedback from temperature sensors and user input to dynamically adjust the four-way switching valve position and compressor operation parameters. This feedback-based control ensures reliable mode switching while using simple temperature thresholds and logic to minimize control system complexity.

Inventive Principle:
Principle #23Feedback

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

Ensures proper thermoregulation mode switching, preventing operational mistakes and ensuring that the desired operations are performed correctly, even in complex scenarios like summer air cooling or winter air warming, by automating the switching process based on user commands and outside air temperature.

Implementation Method 1

a compressor for compressing a refrigerant

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

a heat-source-side heat exchanger... capable of switching between a radiating operation state in which the heat-source-side heat exchanger is made to function as a radiator of refrigerant and an evaporating operation state in which the heat-source-side heat exchanger is made to function as an evaporator of refrigerant

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a first usage-side heat exchanger that functions as a radiator of refrigerant... capable of performing a hot-water supply operation for heating an aqueous medium by the heat radiation of the refrigerant in the first usage-side heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 4

a second usage-side heat exchanger that functions as an evaporator of refrigerant... capable of performing an air-cooling operation of cooling an air medium by the evaporation of the refrigerant in the second usage-side heat exchanger, as well as performing an air-warming operation of heating the air medium by the heat radiation of the refrigerant in the second usage-side heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2402685B1Heat pump system
Publication Date: 2018.08.22 DAIKIN INDUSTRIES LTD
  • EP2402685B1 patent drawingFigure 1
  • EP2402685B1 patent drawingFigure 2
  • EP2402685B1 patent drawingFigure 3

AI summary

A heat pump system (1) has a configuration in which a first usage unit (4a) for performing a hot-water supply operation of heating an aqueous medium and a second usage unit (10a) for performing air-cooling and air-warming operations of cooling or heating an air medium are both connected to a shared heat source unit (2) in such a manner that they are incapable of individually selecting and operating a hot-water supply operation, an air-cooling operation, or an air-warming operation, and the heat pump system is capable of switching operation to a thermoregulation mode different from the switched state of a heat-source-side switching mechanism (23) as a thermoregulation mode commanded by a first usage-side controller (77a).