Gas Pressure Regulator Preheating in Monovalent CNG Cold Starts

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Solution Overview

Problem

Existing cold start systems for compressed gas-operated vehicles with monovalent fuel supply face challenges in preventing icing of fuel supply components, particularly the gas pressure regulator, during cold start and warm-up phases, as the available warm fluid from the cooling circuit is limited.

Innovation Solution

A cold start system that integrates an auxiliary heating unit powered by compressed gas, which heats a circulating fluid through an auxiliary heater preheating circuit, including a gas pressure regulator heating circuit, with switchable valves to manage heat distribution and ensure the gas pressure regulator is prioritarily heated to prevent freezing, and subsequently heats the internal combustion engine and vehicle interior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the auxiliary heating unit heats the circulating fluid through the auxiliary heater preheating circuit, then the gas pressure regulator is heated to prevent freezing, but the available warm fluid from the cooling circuit is limited

Engineering Contradiction:
Improveoperational reliability of the fuel supply systemVSAvoidavailable warm fluid
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The auxiliary heating unit is activated before the internal combustion engine starts to preheat the circulating fluid and the gas pressure regulator. This preliminary heating action ensures that the fuel supply system components are warmed up before cold start conditions set in, preventing icing while the engine is being started.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The heating system is divided into separate circuits: the auxiliary heater preheating circuit for heating the circulating fluid and the gas pressure regulator heating circuit for specifically heating the gas pressure regulator. This segmentation allows targeted heating of critical components with limited warm fluid resources.

Inventive Principle:
Principle #1Segmentation

2Reliability

If switchable valves are used to manage heat distribution and prioritize heating of the gas pressure regulator, then the gas pressure regulator is effectively heated, but the device complexity increases

Engineering Contradiction:
Improveheating effectiveness of the gas pressure regulatorVSAvoidcomplexity of the cold start system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Switchable valves are incorporated into the heating circuits to dynamically redirect the flow of warm fluid based on operational requirements. During cold start, the valves prioritize directing warm fluid to the gas pressure regulator, and later redirect to the interior heating circuit, allowing adaptive heat distribution without permanent complex routing.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The switchable valves act as intermediaries that control and manage the distribution of warm fluid between different heating circuits. These valves simplify the overall system design by providing a straightforward control mechanism rather than requiring complex permanent routing or multiple heating units.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Use of energy by moving object

If the auxiliary heating unit is powered by compressed gas, then efficient use of monovalent fuel is achieved, but the device complexity increases

Engineering Contradiction:
Improvefuel efficiency of the auxiliary heating unitVSAvoidcomplexity of the fuel supply system
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The auxiliary heating unit is designed to be powered by compressed gas, the same monovalent fuel that powers the internal combustion engine. This multi-functionality allows the vehicle to use a single fuel type for both propulsion and heating operations, eliminating the need for separate fuel storage and delivery systems for different fuel types.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The fuel supply system is merged into a unified monovalent system where the compressed gas fuel supply serves both the internal combustion engine and the auxiliary heating unit. This consolidation reduces the overall complexity by eliminating redundant fuel storage tanks, pressure regulators, and delivery infrastructure that would be required for multiple fuel types.

Inventive Principle:
Principle #5Merging (Combining)

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 prevents the gas pressure regulator from freezing by prioritizing its heating, ensuring operational reliability and efficient use of monovalent fuel, while also providing heat to the internal combustion engine and vehicle interior, thus enhancing the cold start and warm-up capabilities of the vehicle.

Implementation Method 1

at least one auxiliary heating unit (20), also powered by gas, which heats a circulating fluid

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

The fluid is guided in an auxiliary heating preheating circuit in which a preheating circuit pump (21) is arranged

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 3

a pressure reducing device for reducing fuel pressure from a tank pressure to a supply pressure of a fuel injection device

Methodology Applied
Scientific EffectPressure reduction: Pressure Drop

Implementation Method 4

an internal combustion engine (10), which is operated exclusively with compressed gas

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP4031761B1Cold start system for a vehicle which is operated with compressed gas and which has a monovalent fuel supply
Publication Date: 2024.05.01 VOLKSWAGEN AG
  • EP4031761B1 patent drawingFigure 1
  • EP4031761B1 patent drawingFigure 2
  • EP4031761B1 patent drawingFigure 3

AI summary

The invention relates to a cold start system and to an associated method for a vehicle which is operated with compressed gas and which has a monovalent fuel supply. A cold start system (100) and an associated method for operating the cold start system (100) are provided, which cold start system is provided for a monovalent internal combustion engine (10) operated with a gas. The cold start system (100) comprises at least one engine-independent heater apparatus (20) which is likewise operated with the gas and which warms a circulatory fluid which is conducted in an engine-independent heater pre-warming circuit (20VL, 20RL) in which a pre-warming circuit pump (21) is arranged, wherein a feed line (20VL) of the engine-independent heater pre-warming circuit (20VL, 20RL) has at least one first branch to a heating circuit (30VL, 30RL) of at least one component (30) for warming, the return line (30RL) of which heating circuit is connected into the return line (20RL) of the engine-independent heater pre-warming circuit.