Heat Pump Heat Source Selection Based on Heat Exchange Performance

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Solution Overview

Problem

Existing heat pump systems face inefficiencies when switching between air and underground heat sources, as the selection of heat sources is based solely on temperature conditions, leading to suboptimal energy usage and increased costs due to the need for larger underground heat exchangers and varying operational efficiencies throughout the year.

Innovation Solution

A heat pump device with a refrigerant circuit and a heat exchange medium circuit that allows for simultaneous or single operation of air and underground heat exchangers, using a controller to select the most efficient heat source based on current heat exchange performance and operating conditions, rather than just temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If heat is collected simultaneously from outside air and underground, then the necessary size of the underground heat exchanger can be reduced to suppress system cost, but system efficiency may be lower when heat is collected from both sources compared to collecting from one source

Engineering Contradiction:
Improvesystem costVSAvoidsystem efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The system dynamically switches between single-source and dual-source heat collection modes based on real-time operating conditions. The controller adjusts the operation mode (simultaneous operation vs. single operation) to optimize the balance between system cost and efficiency, allowing the underground heat exchanger size to be reduced while maintaining high efficiency when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (heat collection mode) based on environmental conditions such as outside air temperature and underground temperature. By comparing temperature differences and heat exchange amounts, the system selects the optimal heat collection strategy to resolve the contradiction between cost reduction and efficiency maintenance.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the underground heat-source heat exchanger is designed to have the same processing capacity as the air heat-source heat exchanger, then heat can be collected from either source based on temperature conditions, but the construction cost increases significantly due to the large size of the underground heat exchanger required

Engineering Contradiction:
Improveheat source selection flexibilityVSAvoidconstruction cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Instead of designing the underground heat exchanger with full processing capacity equal to the air heat-source heat exchanger, the system uses partial capacity (smaller size) and compensates by switching to dual-source heat collection or single air-source operation when needed. This partial action approach reduces construction cost while maintaining adaptability through operational flexibility.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system achieves versatility in heat source selection not through oversized equipment but through multi-functional operational modes. The smaller underground heat exchanger can still provide heat collection capability, and the system supplements this with air source heat collection or dual-source operation to meet heating demands, thereby achieving adaptability without excessive construction cost.

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

3Ease of operation

If heat collection is based solely on temperature conditions, then the control logic is simple, but the system efficiency is suboptimal as it does not consider heat exchange performance variations

Engineering Contradiction:
Improvecontrol logic simplicityVSAvoidsystem efficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The system incorporates feedback control by continuously monitoring temperature conditions (outside air temperature, underground temperature) and heat exchange amounts, then adjusting the heat collection mode accordingly. This feedback mechanism allows the system to maintain relatively simple control logic while achieving optimal efficiency by responding to real-time performance variations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system autonomously determines the optimal heat collection strategy by comparing temperature differences and heat exchange amounts between air source and underground source. The controller automatically selects between simultaneous operation, single air-source operation, or single underground-source operation based on real-time conditions, eliminating the need for complex external control while maximizing efficiency.

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 approach enables high system efficiency throughout the year by selecting the appropriate heat source, reducing energy consumption and system costs by considering heat exchange performance in addition to temperature conditions.

Implementation Method 1

a first heat-source heat exchanger configured to use outside air serving as a first heat source as a heat source... a second heat-source heat exchanger... configured to exchange heat with another heat source other than the outside air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2910869B1Heat pump device
Publication Date: 2021.03.24 MITSUBISHI ELECTRIC CORP
  • EP2910869B1 patent drawingFigure 1
  • EP2910869B1 patent drawingFigure 2~3
  • EP2910869B1 patent drawingFigure 4~5

AI summary

Provided is a heat pump device (40) configured to collect heat both from outside air and another heat source. A controller (30) calculates heat exchange amounts with use of heat exchange performance of each of an air heat-source heat exchanger (5a) and an underground heat-source heat exchanger (5b) in addition to an outside air temperature and an underground temperature. Then, in switching between a simultaneous operation of causing refrigerant to flow through both of the air heat-source heat exchanger (5a) and the underground heat-source heat exchanger (5b) and a single operation of selecting the air heat-source heat exchanger (5a) or the underground heat-source heat exchanger (5b) to cause refrigerant to flow therethrough, the controller (30) selects a heat source having a larger calculated heat exchange amount. In this manner, an appropriate heat source suitable for operation conditions can be selected.