Rail Vehicle Air Conditioning Flow Control via Mass Flow Measurement

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Solution Overview

Problem

Existing air conditioning systems for rail vehicles require interpretation of measurement data to determine operating states, leading to potential errors and unreliable air flow provision, which can result in incorrect assumptions and discomfort for passengers.

Innovation Solution

A method and device that includes a filter, heat exchanger, fan, and measuring device to control air flow based on mass or volume flow measurements, ensuring reliable air conditioning by setting target flow rates and adjusting fan speed to maintain comfortable air speeds within the vehicle, while compensating for filter contamination and optimizing heat exchanger performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If measurement data interpretation is used to determine operating states, then air conditioning control is achieved, but reliability is reduced due to potential errors and incorrect assumptions

Engineering Contradiction:
Improvereliability of air flow provisionVSAvoidaccuracy of operating state determination
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical/interpretive system with a direct measurement system. Instead of interpreting measurement data to infer operating states, the system directly measures the air flow velocity using a measuring device arranged in the air flow path, providing reliable data without requiring interpretation or assumption.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a measuring device as an intermediary between the air conditioning system and the control unit. This device directly measures air flow velocity and communicates this information to the control unit, eliminating the need for complex data interpretation and providing accurate operating state information.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If filter device is used to remove particles, then air quality is improved, but air flow velocity is reduced due to filter contamination

Engineering Contradiction:
Improveair qualityVSAvoidair flow velocity
Core Design Contradiction:
Object-affected harmful factorsVSSpeed

Solution Approach 1:

The patent implements a feedback mechanism where a measuring device continuously monitors air flow velocity downstream of the filter. When the measuring device detects reduced air flow velocity due to filter contamination, it signals the control unit to increase fan speed, compensating for the filter's resistance and maintaining adequate air flow velocity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent makes the fan speed dynamic rather than static. The control unit continuously adjusts fan speed based on feedback from the measuring device, allowing the system to adapt to changing conditions such as filter contamination and maintain optimal air flow velocity throughout operation.

Inventive Principle:
Principle #15Dynamics

3Temperature

If heat exchanger device is oversized to compensate for reduced air flow, then temperature control is maintained, but device complexity and cost increase

Engineering Contradiction:
Improvetemperature controlVSAvoidheat exchanger sizing
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent makes the heat exchanger system dynamic by continuously adjusting fan speed based on measured air flow velocity. This dynamic adjustment allows a properly sized heat exchanger to maintain effective temperature control even when air flow varies, eliminating the need for oversized equipment designed to compensate for worst-case scenarios.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameters of the air conditioning system by continuously monitoring air flow velocity and adjusting fan speed accordingly. This parameter change approach allows the heat exchanger to operate at optimal conditions across varying air flow rates, eliminating the need for oversized design margins.

Inventive Principle:
Principle #35Parameter changes

4Speed

If fan speed is increased to compensate for filter contamination, then air flow velocity is maintained, but energy consumption increases

Engineering Contradiction:
Improveair flow velocityVSAvoidfan energy consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent uses feedback from the measuring device to intelligently control fan speed. The control unit increases fan speed only when the measuring device detects reduced air flow velocity due to filter contamination, and only to the extent necessary to maintain adequate air flow, rather than continuously operating at high speed.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent maintains continuous monitoring of air flow velocity and continuous adjustment of fan speed as needed. This ensures that the fan operates at the minimum necessary speed to maintain adequate air flow, avoiding unnecessary energy consumption while ensuring continuous effective air conditioning.

Inventive Principle:
Principle #20Continuity of useful action

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 solution ensures reliable and comfortable air conditioning by accurately controlling air flow and temperature, reducing the need for overdimensioned heat exchangers and maintaining passenger comfort despite filter contamination, thereby enhancing the overall air conditioning performance.

Implementation Method 1

a measuring device for determining a mass flow or volume flow of the air flow is arranged upstream of the outlet in the duct

Methodology Applied
Scientific EffectMass flow measurement:

Implementation Method 2

A fan conveys air from the inlet to the outlet through the duct

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 3

a heat exchanger device for influencing a temperature of the air present in the duct or air flowing through it

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 4

A filter device for filtering out dust and particles from the air is provided in the channel

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3156302B1Device for conditioning an interior of a railway vehicle
Publication Date: 2020.07.08 BOMBARDIER TRANSPORTATION GMBH
  • EP3156302B1 patent drawingFigure 1
  • EP3156302B1 patent drawingFigure 2

AI summary

The invention relates to a method for operating a device for air conditioning a rail vehicle. The invention provides an improved air conditioning device, particularly one that ensures a reliable supply of an air-conditioning airflow. To this end, a method is described in which the device comprises a unit for airflow. A filter device (5) is provided in the unit, which can be arranged directly at the inlet of the duct (2). Downstream of the filter device is a heat exchanger device (6) for influencing the temperature of the air present in the duct. Air is moved from the inlet to the outlet through the duct by means of a fan (7). The airflow is conveyed through the duct towards the outlet, and a measuring device (8) for measuring and determining the mass or volume flow rate is arranged upstream of the outlet in the duct.First, a target mass or volume flow rate is specified for the device. In a further step, the actual mass or volume flow rate of the airflow through the device's duct is measured and compared to the target value. Based on the difference between the target and actual mass or volume flow rates, the fan speed is then adjusted so that the actual mass or volume flow rate matches the target value and compensates for any reduction caused by filter clogging.