Heat Pump Hot Water Circulation Bypass for Defrost Continuity

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Solution Overview

Problem

Conventional hot water supply and heating systems with heat pumps face issues such as interruption of heating and hot water supply during defrosting operations, increased installation complexity, and higher manufacturing costs due to separate water-refrigerant heat exchangers for heating and hot water supply.

Innovation Solution

A method for controlling a hot water circulation system with a heat pump that includes an outdoor unit, an indoor unit with a water-refrigerant heat exchanger, a water collection tank, and a water pump, which allows for simultaneous or selective adjustment of operation conditions based on sensed refrigerant and water temperatures, and includes a bypass mechanism to redirect refrigerant during defrosting, enabling continuous hot water supply and heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate water-refrigerant heat exchangers are used for heating and hot water supply, then heating and hot water supply can be performed independently, but installation complexity increases and manufacturing cost increases

Engineering Contradiction:
Improveindependent operation capabilityVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the heating function and hot water supply function into a single water-refrigerant heat exchanger. The heat exchanger receives refrigerant from the compressor and performs heat exchange with water that flows through it, allowing the same component to serve both heating purposes and hot water generation purposes, thereby reducing installation complexity and manufacturing cost while maintaining independent operation capability through control system management

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If defrosting operation is performed on the outdoor heat exchanger, then frost is removed and heat exchange efficiency is restored, but hot water supply and heating must stop completely

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidcontinuous supply capability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments the system into two independent thermal pathways: the refrigerant cycle for heating (outdoor heat exchanger) and the hot water supply cycle (indoor water-refrigerant heat exchanger). When defrosting is needed for the outdoor heat exchanger, only the heating function is temporarily affected while the hot water supply function continues uninterrupted through the indoor heat exchanger using refrigerant from the compressor discharge line

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary high-temperature refrigerant line that branches from the compressor discharge line to supply refrigerant directly to the indoor water-refrigerant heat exchanger. This intermediary pathway allows hot water supply to continue during outdoor defrosting operations by bypassing the outdoor heat exchanger that requires defrosting

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If separate heat exchangers are used for heating and hot water supply, then each function can be optimized independently, but manufacturing cost increases

Engineering Contradiction:
Improvefunction-specific optimizationVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent designs a universal water-refrigerant heat exchanger that performs multiple functions: it serves as the primary heat exchange component for both heating and hot water supply operations. The heat exchanger is configured to receive refrigerant from the compressor and exchange heat with water flowing through its channels, allowing a single manufactured component to replace what would traditionally require two separate heat exchangers, thereby reducing manufacturing cost while maintaining functional optimization through control system management

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 solution allows for continuous hot water supply and floor heating during defrosting operations, reduces installation complexity, and lowers manufacturing costs by using a single water-refrigerant heat exchanger, maintaining system functionality without separate defrosting cycles.

Implementation Method 1

an indoor unit including a water-refrigerant heat-exchanger which performs heat exchange between a refrigerant discharged from the compressor and water

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a water pump which pumps water discharged from the water collection tank

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 3

a hot water circulation unit which receives heat from the water pumped from the water pump to perform hot water supply or heating

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP2159494B1Method for controlling a hot water circulation system associated with a heat pump.
Publication Date: 2018.09.19 LG ELECTRONICS INC
  • EP2159494B1 patent drawingFigure 1
  • EP2159494B1 patent drawingFigure 2
  • EP2159494B1 patent drawingFigure 3

AI summary

Disclosed is a hot water circulation system associated with a heat pump and a method for controlling the same. The present invention allows the system to be defrosted while hot water supply or a heating operation is performed, making it possible to improve a phenomenon that heating efficiency is deteriorated.