Vehicle Air Conditioner Degassing Layout for Refrigerant Leak Venting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The use of refrigerants posing health risks, such as R290 (propane), in vehicle air conditioning systems is challenging due to the risk of leaks contaminating the passenger compartment, and existing systems lack effective measures to safely manage such leaks.

Innovation Solution

A fluidically separated air conditioning unit with a lockable degassing device and a refrigerant detector that connects the cooling and supply air flow channels during emergencies, utilizing the Bernoulli effect and condenser fan to vent contaminated supply air outside, and optionally throttling or shutting off the supply fan to enhance the discharge process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hazardous refrigerants like R290 are used in the refrigeration circuit, then the environmental friendliness and efficiency of the air conditioning system is improved, but the risk to human health and safety of passengers deteriorates

Engineering Contradiction:
Improvesafety of refrigerant useVSAvoidhealth risk to passengers
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The air conditioning unit is divided into two fluidically separated sections: a cooling air section and a supply air section, separated by a partition. This segmentation prevents refrigerant leakage from contaminating the passenger compartment while allowing the use of hazardous refrigerants like R290 in the refrigeration circuit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A degassing device is introduced as an intermediary component in the partition between the cooling air section and supply air section. This device can be opened to release accumulated refrigerant from the cooling air section through the common partition into the supply air section, which is then discharged outside the vehicle, preventing direct contamination of the passenger compartment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a leak in the refrigeration circuit occurs near the evaporator, then refrigerant escapes into the supply air flow channel, but the existing system lacks effective measures to manage such leaks

Engineering Contradiction:
Improveleak response capabilityVSAvoidemergency operation capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

A detector for the refrigerant is installed in the supply air section to detect refrigerant leakage in advance. When refrigerant is detected, the detector automatically triggers the degassing device to open, releasing the accumulated refrigerant before it can contaminate the passenger compartment, enabling automatic emergency response without manual intervention.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the condenser fan is made larger to increase cooling air volume flow, then the cooling performance is improved, but the Bernoulli effect at the degassing device intensifies, causing supply air to be drawn into the cooling air flow channel

Engineering Contradiction:
Improvecooling air volume flowVSAvoidfluid flow control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The Bernoulli effect, which causes supply air to be drawn into the cooling air flow channel due to the high-speed cooling air from the large condenser fan, is converted into a beneficial effect. This effect is utilized to actively draw refrigerant-laden supply air through the open degassing device and discharge it outside the vehicle, enhancing the leak response capability while maintaining the large condenser fan size for optimal cooling performance.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Effectively reduces the risk to passengers by safely discharging refrigerant-laden air from the vehicle, ensuring passenger safety in the event of a leak, while allowing the use of hazardous refrigerants in air conditioning systems.

Implementation Method 1

the Bernoulli effect occurs in the area of the degassing device, which leads to the intake of the supply air located in the supply air duct, which is charged with refrigerant in the event of a leak

Methodology Applied
Scientific EffectBernoulli effect: Bernoulli Effect

Data Source

PatentEP4087765B1Passenger transport vehicle
Publication Date: 2023.10.25 SIEMENS MOBILITY GMBH DE
  • EP4087765B1 patent drawingFigure 1
  • EP4087765B1 patent drawingFigure 2~3

AI summary

The invention relates to a passenger transport vehicle comprising an air conditioner which has a refrigerant circuit (1) operated using a refrigerant, wherein: the refrigerant circuit (1) has a condenser (3) having an associated condenser fan (4) for conveying cooling air (20) and has an evaporator (6), that belongs to an air treatment part (8) of the air conditioner, for controlling the temperature of supply air conveyed by means of a supply fan (11) into a passenger compartment of the vehicle; a flow duct (18) for the cooling air and a flow duct (19) for the supply air (21) are fluidically separated from one another inside the air conditioner by a common partition wall (17); the partition wall (17) has a closable degassing device (14; 22; 23) which can be switched between a closed state for normal operation of the air conditioner and an open state for emergency operation of the air conditioner, in which emergency operation the degassing device (14; 22; 23) directly fluidically connects the flow duct (18) for the cooling air and the flow duct (19) for the supply air to one another; and a detector (24) for the refrigerant is provided in the region of the vehicle to which supply air is provided, said detector being connected by means of signals to the degassing device (14; 22; 23) such that said detector, when it detects the refrigerant, triggers actuation of the degassing device (14; 22; 23) so that said degassing device assumes its open state.