Generator Preheating for Electric Vehicle Engine Cold Start

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Solution Overview

Problem

Electric vehicles with internal combustion engines for range extension face challenges with cold start emissions, as the internal combustion engine is frequently started and stopped, leading to inefficient and pollutant-rich cold starts due to the varying state of charge of the energy storage device.

Innovation Solution

A method involving preheating the internal combustion engine by compressing air in the combustion chamber using the generator, accelerating the engine to a predetermined starting speed, and maintaining the engine at a favorable starting temperature to reduce cold start emissions, with the generator powering the engine only when the temperature and speed thresholds are met.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the internal combustion engine is started frequently to maintain state of charge in the energy storage device, then the energy supply reliability is improved, but cold start emissions increase significantly

Engineering Contradiction:
Improveenergy supply reliabilityVSAvoidcold start emissions
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system performs preliminary heating of the internal combustion engine before actual operation begins. The heating element activates first to raise the engine temperature, and only after the temperature threshold is reached does the engine start operating. This preliminary thermal preparation eliminates cold start emissions while maintaining the ability to frequently start the engine for energy supply.

Inventive Principle:
Principle #10Preliminary action

2Object-generated harmful factors

If the internal combustion engine is preheated before operation, then cold start emissions are reduced, but the starting process time increases

Engineering Contradiction:
Improvecold start emissionsVSAvoidstarting process time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The heating element operates in periodic cycles rather than continuously. It activates to heat the engine, then stops when the temperature threshold is reached, allowing the engine to start immediately. This periodic heating approach minimizes the time addition to the starting process while still achieving emission reduction through thermal preparation.

Inventive Principle:
Principle #19Periodic action

3Productivity

If the generator is used to drive the internal combustion engine, then the energy generation efficiency is improved, but the system complexity increases

Engineering Contradiction:
Improveenergy generation efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The generator is designed with dual functionality: it serves as both a power generation device (converting mechanical energy to electrical energy) and as a motor to start the internal combustion engine (converting electrical energy to mechanical energy). This multi-functionality improves energy generation efficiency by using the generator for engine starting while reducing system complexity by eliminating the need for a separate starting motor.

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 approach significantly reduces cold start emissions and improves the starting process by ensuring the engine is warmed up before operation, enhancing the overall efficiency and reducing pollutant emissions.

Implementation Method 1

the generator (3) is supplied with electrical power from the energy storage device (4), the electrical power being converted into mechanical power

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

A method involving preheating the internal combustion engine by compressing air in the combustion chamber using the generator

Methodology Applied
Scientific EffectCompression heating: Adiabatic Heating

Implementation Method 3

An internal combustion engine is preferably understood to mean a device in which chemically bound energy is converted into mechanical power, preferably through an exothermic reaction

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2605930B1Method for starting internal power generation in an electric vehicle
Publication Date: 2016.03.16 AVL LIST GMBH
  • EP2605930B1 patent drawingFigure 1
  • EP2605930B1 patent drawingFigure 2~3b

AI summary

The invention relates to a method for starting an internal combustion engine, in particular a reciprocating piston engine or a rotary engine in an electric vehicle for internal power generation, the method comprising at least the following steps: driving of the internal combustion engine by means of the generator; compression of a working medium, in particular air, in the combustion chamber; measuring of a preheating temperature, in particular in the combustion chamber walls; and starting of the torque transmission from the internal combustion engine to the generator when the preheating temperature has reached or exceeded a predeterminable threshold value (starting temperature).