Hybrid heating system using geothermal heat

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Solution Overview

Problem

Existing geothermal heating systems with heat pumps struggle to achieve high coefficients of heating performance and are inefficient in terms of energy consumption on an annual level, limiting their energy-saving potential.

Innovation Solution

A hybrid heating system incorporating a geothermal circuit, a multi-layer cross-flow heat exchanger for intake and exhaust air devices, and a layered heat pump configuration that allows flexible operation and efficient heat transfer, enabling the use of geothermal and exhaust air heat sources to preheat intake air directly, thereby reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a conventional heat pump system with geothermal heating is used, then heating can be provided, but the coefficient of heating performance is low and annual energy consumption is high

Engineering Contradiction:
Improveenergy consumptionVSAvoidsystem complexity
Core Design Contradiction:
Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The patent combines multiple heat sources (geothermal circuit, exhaust air heat recovery) and heat sinks (intake air heating, building heating) into a single integrated hybrid heating system. The geothermal circuit and exhaust air device are both connected to the heat pump's collector circuit, allowing the system to merge multiple thermal streams and operate more efficiently by selecting optimal heat sources based on conditions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The heat pump system is designed to serve multiple functions: heating the building, heating intake air, and recovering heat from exhaust air. The intake air device can be connected to either the heat emitter circuit or heat collector circuit, allowing it to function as either a heat sink or heat source depending on operational conditions, providing universal applicability.

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

2Power

If the heat pump power output is increased to improve heating capacity, then heating performance improves, but energy efficiency decreases

Engineering Contradiction:
Improveheating capacityVSAvoidenergy efficiency
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The exhaust air device pre-heats the intake air before it enters the building, and the geothermal circuit provides pre-heating to the heat pump's collector circuit. This preliminary heating action reduces the heating load that the main heat pump must handle, allowing the system to achieve adequate heating capacity with lower power output while maintaining high energy efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The intake air device acts as an intermediary thermal exchange medium between the external environment and the building interior. By heating the intake air separately through the heat exchanger connected to the collector circuit, the system reduces the energy burden on the main heat emitter circuit, improving overall energy efficiency while maintaining heating capacity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Use of energy by moving object

If a single-layer heat exchanger is used for intake and exhaust air, then device complexity is low, but heat transfer efficiency is insufficient

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidheat exchanger structure
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent transitions from a single-layer heat exchanger to a multi-layer cross-flow heat exchanger structure. This dimensional change from one layer to multiple layers significantly increases the heat transfer surface area and improves thermal exchange efficiency between intake and exhaust air streams, while the cross-flow configuration optimizes the temperature gradient across layers.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

The system achieves significant energy efficiency by reducing the power output of the heat pump, allowing for efficient heating and cooling with reduced primary energy use, and can operate effectively even at low temperatures, enhancing overall energy efficiency and flexibility.

Implementation Method 1

a geothermal circuit (50) as a primary heat source... the geothermal circuit is connected to the collector circuit of the heat pump

Methodology Applied
Scientific EffectGeothermal heating: Heat Exchanger

Implementation Method 2

the intake air device and/or the exhaust air device, as opposite heat exchangers, is a multi-layer cross-flow heat exchanger with a high coefficient of performance

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a heat pump, including a heat collector circuit and a heat emitter circuit which emits heat at a higher temperature

Methodology Applied
Scientific EffectHeat pump heating: Heat Exchanger

Implementation Method 4

an exhaust air device with heat recovery... the exhaust flow of the exhaust air device (20) can be heated directly by a supply flow of the geothermal circuit or the intake air device

Methodology Applied
Scientific EffectHeat recovery: Heat Exchanger

Data Source

PatentEP3809050B1Hybrid heating system using geothermal heat
Publication Date: 2024.06.26 HOGFORSGST OY
  • EP3809050B1 patent drawingFigure 1
  • EP3809050B1 patent drawingFigure 2
  • EP3809050B1 patent drawingFigure 3

AI summary

The object of the invention is a hybrid heating system, which includes ∘ a geothermal circuit (50, 52, 54) as a primary heat source ∘ a heat pump (30), including a heat collector circuit (302) and a heat emitter circuit (304) which emits heat at a high temperature ∘ an intake air device (10) which is connectable in heating/cooling operation to a selected side of the heat pump to operate in a selectable manner for the heating or the cooling of the intake air and which is connected directly to the collector circuit (302) and indirectly to the heat emitter circuit (304) via a heat exchanger, ∘ an exhaust air device (20) with heat recovery, and • the geothermal circuit (50, 52, 54) is connected to the collector circuit of the heat pump (302), • the exhaust air circuit (20) is connected to the collector circuit of the heat pump (302), and • the intake air device (10) is connected in a selectable manner to the heat emitter circuit (304) or to the heat collector circuit (302) of the heat pump ∘ the intake air device (10) and/or the exhaust air device (20) is a heat exchanger with a high coefficient of performance, for example a multi-layer cross-flow heat exchanger, so that a return flow of fluid of the heat exchanger can be utilized in the intake flow of the opposite heat exchanger or in the geothermal circuit during at least a part of the year, ∘ the supply flow of the intake air device (10) is adapted in a selected mode to be pre-heatable directly by the geothermal circuit (50, 52, 54) and/or by the exhaust air device (20), and ∘ the heat pump (30) is layered and comprises two or more units that are adapted to operate in series together or in small groups.