Heat Pump Heating Systems With Dual-Temperature Water Routing

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Solution Overview

Problem

Existing heating systems with heat pumps struggle to achieve energy-efficient operation when handling consumers with different temperature levels, such as low-temperature heating circuits and hot water tanks, due to inefficient heat recovery and unregulated compressor operation, particularly in new buildings with lower heating requirements.

Innovation Solution

A method involving a heat pump system with hydraulic controls using 3-way valves and mixers to manage water flow and temperature distribution between a low-temperature heating circuit and a hot water storage tank, allowing for efficient operation by redirecting water flows and adjusting temperatures to maintain constant energy output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the heat pump heats water to high temperature for hot water storage tank, then the hot water demand is satisfied, but the energy efficiency decreases due to higher compression work proportion

Engineering Contradiction:
Improvehot water temperatureVSAvoidenergy efficiency of heat pump
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The heating system is segmented into two independent circuits: a hot water circuit with storage tank and a heating circuit with radiators. The heat pump can serve each circuit independently or simultaneously, allowing optimization of operating temperatures for each function separately.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the operating temperature parameter dynamically based on demand. When only hot water is needed, the heat pump operates at higher temperatures (60-70°C). When heating is needed, it operates at lower temperatures (30-50°C), optimizing the compression work proportion and energy efficiency.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the heat pump operates with internal control system (frequency-controlled compressors or adjustable throttles), then the operation efficiency improves, but the device complexity and cost increase

Engineering Contradiction:
Improveoperation efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The system uses self-regulating thermal dynamics where the heat pump operates without complex electronic controls. The natural thermal interaction between the hot water tank and heating circuit, combined with simple hydraulic balancing, allows the system to self-adjust and maintain efficient operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

A single heat pump unit serves multiple functions (hot water heating and space heating) without requiring different control systems for each function. The same heat pump compressor and heating elements are used for both purposes, reducing overall system complexity.

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

3Temperature

If the heating circuit water is cooled down in a mixer after passing through the hot water heating system, then the heating circuit operates at lower temperatures, but the system complexity increases

Engineering Contradiction:
Improveheating circuit temperatureVSAvoidmixing system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The system merges the hot water heating circuit and the heating circuit into a unified thermal system. The heating circuit water flow is used to cool the hot water tank, and the cooled water returns to the heat pump, creating an integrated thermal management system without requiring separate cooling mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The heating circuit water acts as an intermediary medium, transferring heat from the hot water tank to the heat pump evaporator. This intermediary approach allows temperature reduction without requiring active cooling devices or complex mixing systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enhances energy efficiency by optimizing heat recovery and allowing the use of unregulated, robust heat pumps, while ensuring optimal temperature supply to consumers, even in varying demand scenarios.

Implementation Method 1

a heat pump (1) having an evaporator (2) and a condenser (3)... the heat released in the heat pump's condenser is made up of heat extracted from the environment, which is recovered in the evaporator

Methodology Applied
Scientific EffectHeat pump heat transfer: Heat Exchanger

Implementation Method 2

the compression work of the compressor in the heat pump... as the release temperature on the secondary power side, i.e. at the condenser, increases, the efficiency of heat recovery from the environment decreases

Methodology Applied
Scientific EffectCompression work: Compression

Data Source

PatentEP3980695B1Method for operating a heating system with a heat pump and heating system
Publication Date: 2025.08.06 WOLF PETER
  • EP3980695B1 patent drawingFigure 1
  • EP3980695B1 patent drawingFigure 2
  • EP3980695B1 patent drawingFigure 3

AI summary

In a method for operating a heating system with a heat pump, which has an evaporator and a condenser, and with a low-temperature heating circuit, which has a feed and a return, and with a hot water tank, the invention proposes that, if the low-temperature heating circuit only is in operation, the heat pump provides a greater volume of water at lower temperature than in the event of simultaneous water demand by the hot water tank. When hot water is demanded for the hot water tank, all of the hot water generated by the heat pump is conveyed to the hot water tank and the somewhat cooled water flowing out of the hot water tank is supplied to the feed of the low-temperature heating circuit. Some of the water in the return of the low-temperature heating circuit is conveyed back to the heat pump and some is conveyed to the feed of the low-temperature heating circuit.