Heat pump arrangement and method for operating a heat pump arrangement

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Solution Overview

Problem

Heat pumps using low-temperature heat sources result in a low coefficient of performance due to the necessity of reducing the evaporation temperature, leading to inefficient energy transfer and increased pressure ratios.

Innovation Solution

A heat pump arrangement incorporating a jet pump and a bypass line with a heat exchanger, where the working fluid is partially routed through the heat exchanger before the evaporator, allowing efficient integration of low-temperature heat sources without additional power-consuming components, and utilizing a secondary working circuit to enhance energy efficiency by recycling waste heat from the compressor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a low-temperature heat source is used, then the heat pump can access more heat sources, but the coefficient of performance decreases

Engineering Contradiction:
Improveheat source accessibilityVSAvoidcoefficient of performance
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The working fluid flow is segmented into multiple paths: a main path through the evaporator and a bypass path through the heat exchanger. This segmentation allows selective heat exchange at different temperature levels, enabling the system to efficiently utilize low-temperature heat sources while maintaining high COP by separating the heat absorption functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bypass line acts as an intermediary path that introduces working fluid from after the jet pump directly to the heat exchanger, bypassing the evaporator. This intermediary route enables heat exchange with low-temperature sources at a stage where the working fluid has different thermodynamic properties, resolving the conflict between temperature matching and efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If the evaporation temperature is reduced to match low-temperature heat sources, then heat transfer efficiency improves, but the pressure ratio increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidpressure ratio
Core Design Contradiction:
Loss of energyVSStress or pressure

Solution Approach 1:

Different parts of the working fluid experience different temperature and pressure conditions through the segmented flow paths. The bypass line introduces fluid at a specific thermodynamic state to the heat exchanger, creating local quality variations that optimize heat transfer at each stage without requiring a uniform reduction in evaporation temperature throughout the entire cycle.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes the thermodynamic parameters (temperature, pressure, enthalpy) of the working fluid by introducing it at different stages through the bypass line. This parameter change allows heat exchange with low-temperature sources while avoiding the need to reduce the main evaporator temperature, thereby maintaining lower pressure ratios.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If additional components such as pumps are added to the bypass line, then heat exchange efficiency improves, but the device complexity increases

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The system uses the working fluid itself to drive the heat exchange process in the bypass line. By introducing working fluid from after the jet pump, the system creates a self-regulating flow that requires no additional pumps or external power sources, achieving efficient heat exchange while maintaining simplicity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The working fluid serves multiple functions: it acts as the heat transfer medium in both the evaporator and the heat exchanger, and it provides the driving force for the bypass line flow. This multi-functionality eliminates the need for separate pumping systems, reducing device complexity while maintaining heat exchange efficiency.

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 configuration improves energy efficiency by maintaining a high coefficient of performance and reduces the need for additional structural components, such as pumps, while allowing the integration of low-temperature heat sources and recycling waste heat, thereby enhancing overall system efficiency and reducing costs.

Implementation Method 1

the jet pump generates a negative pressure due to which the bypass line can be operated, ie due to which the working fluid in the bypass line is sucked back into the primary working circuit

Methodology Applied
Scientific EffectNegative pressure generation: Pressure Gradient

Implementation Method 2

By means of the heat exchanger, the thermal energy of the heat source is at least partially transferred to the working fluid within the bypass line

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

a working fluid within a working circuit is compressed by means of a compressor

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

condensed by means of a condenser

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

evaporated by means of an evaporator

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3571450B1Heat pump arrangement and method for operating a heat pump arrangement
Publication Date: 2020.12.30 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP3571450B1 patent drawingFigure 1

AI summary

The invention relates to a heat pump arrangement (1) which comprises a compressor (2), a condenser (6) and an evaporator (8) that are fluidically coupled by means of a working circuit (100) for a working fluid. According to the invention, the heat pump arrangement (1) comprises a heat exchanger (41), a jet pump (42) and a bypass line (4), said bypass line (4) being designed to conduct at least part of the working fluid downstream of the jet pump (42) and upstream of the condenser (8) to the heat exchanger (41) and back to the jet pump (42). The invention further relates to a method for operating a heat pump arrangement (1) according to the invention.