Peltier Module Lavatory Cooling Without Air Extraction
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Solution Overview
Problem
In train cars, the lack of ventilation in lavatories during tunnel passages leads to temperature increases, causing discomfort, especially for the elderly, and installing air conditioning systems risks air leaks and odor issues when air extraction vents are closed.
Innovation Solution
A Peltier module is integrated into the lavatory to produce cold air through convection, directing it towards the floor without air extraction, maintaining temperature control without altering pressure and preventing air leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an air conditioning system is installed in the lavatory to cool it during tunnel passages, then the temperature inside the lavatory is reduced, but air pressure increases causing air leaks towards the platform and potential odor nuisance
Solution Approach 1:
The invention extracts the harmful function of active air extraction from the cooling system. By using a passive cooling device that relies on natural convection rather than forced air extraction, the system eliminates the cause of air leaks and odor problems while still achieving cooling during tunnel passages when air extraction is closed
Solution Approach 2:
The invention introduces a thermal mass (phase change material or heat storage element) as an intermediary between the cooling system and the lavatory environment. This intermediary stores cooling capacity and releases it gradually through convection, enabling cooling without creating the pressure differential that causes air leaks
2Object-affected harmful factors
If the train passes under a tunnel and all openings are closed to prevent pressure waves, then passenger comfort regarding ear pressure is improved, but ventilation in the lavatory stops and temperature rises causing discomfort
Solution Approach 1:
The invention applies preliminary action by pre-cooling the lavatory air or storing thermal energy before the train enters the tunnel. The passive cooling device is activated in advance to create a thermal reservoir that maintains comfortable temperature throughout the tunnel passage when ventilation is closed
Solution Approach 2:
The cooling system serves itself by using natural convection currents generated within the lavatory to distribute cold air without requiring external ventilation. The system creates its own air circulation pattern using the temperature differential, eliminating dependence on the air extraction system that must be closed during tunnel passages
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 Peltier module effectively cools the lavatory during tunnel passages without air leaks, ensuring passenger comfort and preventing odor nuisance, while operating independently of air extraction systems.
Implementation Method 1
The Peltier module produces, by convection with the ambient air inside the lavatory, a current of cold air
Implementation Method 2
The Peltier module produces, by convection with the ambient air inside the lavatory, a current of cold air which is directed under its own weight towards the floor of the lavatory
Implementation Method 3
a current of cold air which is directed under its own weight towards the floor of the lavatory
Data Source
Figure 1
AI summary
The invention relates to a train car comprising a platform serving at least one toilet compartment (2), the toilet compartment comprising at least one air inlet (4) for drawing air from the platform into the toilet compartment and an air exhaust vent (6) for expelling air from the toilet compartment to the outside of the car. The toilet compartment (2) is equipped with a cooling system comprising a Peltier module (12).