Dual-Mode Heat Pump Control for Occupancy-Based Space Heating

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Solution Overview

Problem

Existing heating systems in buildings, particularly those using air-source heat pumps, face inefficiencies due to unnecessary energy consumption when heating unoccupied spaces and reduced coefficient of performance (COP) during daytime due to higher ambient temperatures, leading to increased energy usage and emissions.

Innovation Solution

A dual-mode heat pump system that switches between air-source and water-source modes, utilizing the thermal mass of the building to increase COP without additional heat storage, by transferring heat from one space to another during unoccupied periods and using outside air during occupied periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the heat pump operates in air-source mode during daytime, then the COP is higher due to higher ambient temperature, but the energy consumption increases because the heat pump runs at partial load

Engineering Contradiction:
Improveenergy consumptionVSAvoidCOP
Core Design Contradiction:
Loss of energyVSUse of energy by stationary object

Solution Approach 1:

The system dynamically switches between air-source mode and water-source mode based on real-time conditions such as occupancy detection and temperature differentials. The control system adjusts the heat pump operation mode to optimize energy efficiency, transitioning from static single-mode operation to dynamic multi-mode operation that adapts to changing building conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the operational parameters of the heat pump by introducing a dual-mode system that varies the heat source (outside air vs. internal building spaces) based on environmental conditions and occupancy patterns. This parameter change allows the system to maintain higher COP by selecting the most efficient heat source under different operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the heating system supplies heat to all rooms continuously, then the indoor temperature is maintained, but unnecessary energy is consumed in unoccupied rooms

Engineering Contradiction:
Improveindoor temperature maintenanceVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system applies local quality by directing heating resources selectively to occupied spaces rather than uniformly heating all rooms. Occupancy detection enables the control system to identify which spaces require heating and adjust the water-source heat pump to serve only those areas, reducing energy waste in unoccupied rooms while maintaining comfort where needed.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The building's internal thermal mass and existing heat in occupied spaces serve themselves by acting as the heat source for unoccupied spaces. The water-source heat pump utilizes waste heat from occupied rooms to heat unoccupied rooms, creating a self-sustaining thermal balance that reduces external energy input while maintaining temperature standards.

Inventive Principle:
Principle #25Self-service

3Loss of energy

If a water-source mode is introduced to transfer heat between spaces, then the COP increases by utilizing thermal mass, but the device complexity increases

Engineering Contradiction:
ImproveCOPVSAvoidsystem configuration
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The water-source heat pump serves multiple functions: it acts as a traditional heat pump during air-source mode, operates as a heat recovery system during water-source mode, and can function in hybrid modes. This multi-functionality allows a single device to handle diverse heating scenarios, reducing the need for separate systems while maintaining high COP through intelligent mode selection based on building conditions.

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 approach enhances the overall COP of the heating system, reducing energy consumption by up to 5% compared to conventional systems, while maintaining occupant comfort by optimizing heat distribution based on occupancy and ambient temperature.

Implementation Method 1

In the air-source mode, the heat pump transfers heat from the outside to the at least two separate spaces

Methodology Applied
Scientific EffectHeat transfer: Convection

Implementation Method 2

In the water-source mode, the heat pump transfers heat from at least a first space of the at least two separate spaces to at least a second space of the at least two separate spaces

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3943820B1Method and heating system for heating at least two different spaces inside a building using a dual mode operation heat pump
Publication Date: 2024.05.01 MITSUBISHI ELECTRIC CORP
  • EP3943820B1 patent drawingFigure 1~2(d)
  • EP3943820B1 patent drawingFigure 3(a)~3(d)
  • EP3943820B1 patent drawingFigure 4(a)~4(b)

AI summary

The present invention relates to a method for heating at least two different spaces in a building using a dual-mode heat pump and a heating system comprising said heat pump.