Heating and/or air conditioning system with internal heat exchangers

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Solution Overview

Problem

Existing heating and air conditioning systems with refrigerant circuits face challenges in regulating internal heat exchange, leading to risks of excessive overheating or undercooling, and require additional valves and direct intervention in the refrigerant circuit, which limits flexibility and increases costs.

Innovation Solution

The system incorporates a secondary circuit with two internal heat exchangers thermally coupled using a pump and valves, allowing indirect regulation of internal heat exchange without direct intervention in the refrigerant circuit, using water or water-glycol as the heat medium to manage temperature and pressure differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If an internal heat exchanger is used to improve efficiency in the refrigerant circuit, then heat exchange between hot and cold refrigerant sections is achieved, but excessive superheating of refrigerant upstream of the compressor and excessive subcooling upstream of the expansion device may occur

Engineering Contradiction:
Improveefficiency of refrigerant circuitVSAvoidrisk of excessive superheating or subcooling
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent introduces a heat transfer medium as an intermediary substance that facilitates heat exchange between the hot high-pressure refrigerant section and the cold low-pressure refrigerant section. Instead of direct refrigerant-to-refrigerant heat exchange, the heat transfer medium acts as a mediator, absorbing heat from the condenser outlet and transferring it to the evaporator outlet, thereby controlling the heat exchange process and preventing excessive superheating or subcooling

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a controllable pump to regulate the flow rate of the heat transfer medium through the internal heat exchanger. By dynamically adjusting the flow rate parameter, the system can control the amount of heat exchanged between refrigerant sections, preventing excessive superheating or subcooling while maintaining optimal efficiency under varying operating conditions

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the internal heat exchanger is controlled using additional valves and direct intervention in the refrigerant circuit, then heat exchange regulation is achieved, but device complexity and cost increase

Engineering Contradiction:
Improvecontrol of internal heat exchangeVSAvoidnumber of additional valves and circuit modifications
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts the control mechanism from the refrigerant circuit by using a separate secondary circuit with a heat transfer medium. The pump controlling the heat transfer medium flow is located outside the refrigerant circuit, allowing heat exchange regulation without adding valves or complex control elements to the refrigerant circuit itself

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The heat transfer medium circuit serves multiple functions: it acts as a working fluid circulation system, a heat transfer pathway, and a control mechanism all in one. The pump controlling the heat transfer medium flow rate provides universal control over the internal heat exchange process without requiring separate control valves in the refrigerant circuit

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 solution enables continuous regulation of internal heat exchange, reducing the risk of overheating or undercooling and eliminating the need for additional valves, thereby enhancing system efficiency and flexibility while minimizing costs.

Implementation Method 1

a first internal heat exchanger (13) in the high-pressure section of the refrigerant circuit between the condenser/gas cooler (5) and the expansion element (7), which is designed for heat exchange between the refrigerant of the refrigerant circuit and a heat medium of a secondary circuit intended for heat transfer

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

The pump (17) is controllable in its pumping capacity... heat exchange between the refrigerant of the refrigerant circuit and the heat medium of the secondary circuit

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3756916B1Heating and/or air conditioning system with internal heat exchangers
Publication Date: 2023.09.27 KONVEKTA
  • EP3756916B1 patent drawingFigure 1
  • EP3756916B1 patent drawingFigure 2
  • EP3756916B1 patent drawingFigure 3

AI summary

The invention relates to a heating and/or air conditioning system (1) with a refrigerant circuit (11) and with at least one secondary circuit (15) comprising a pump (17) for a heat medium, wherein in the high-pressure area of ​​the refrigerant circuit (11) between the condenser/gas cooler (5) and the expansion element (7) a first internal heat exchanger (13) is provided for heat exchange between the refrigerant of the refrigerant circuit (11) and the heat medium of the secondary circuit (15), and in the low-pressure area of ​​the refrigerant circuit (11) between the evaporator (9) and compressor (3) a second internal heat exchanger (19) is provided for heat exchange between the refrigerant of the refrigerant circuit (11) and the heat medium of the secondary circuit (15), and the first internal heat exchanger (13) and the second internal heat exchanger (19) are thermally coupled by means of at least the heat medium of the secondary circuit (15).Furthermore, the invention relates to a vehicle with a heating and/or air conditioning system and a method for controlling such a heating and/or air conditioning system (1).