Natural Gas Pressure Reduction Paths for Valve Freeze Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The rapid pressure changes in the natural gas supply to the electronic pressure regulating valve in high-pressure direct injection engines cause excessive temperature drops, leading to potential faults and damage.

Innovation Solution

A method and apparatus that dynamically adjust the pressure reduction pipeline by determining the current engine operating condition, selecting the appropriate pressure reduction pipeline with stabilizing tanks, and connecting it to the electronic pressure regulating valve to stabilize the pressure and prevent excessive temperature drops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the pressure of natural gas is reduced from 580 bar to 280 bar through the electronic pressure regulating valve, then the injection pressure is adjusted to meet engine load requirements, but the temperature drops excessively causing fault in the electronic pressure regulating valve

Engineering Contradiction:
Improveinjection pressure adjustment rangeVSAvoidelectronic pressure regulating valve operation
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The single-stage pressure reduction is divided into multiple stages by introducing intermediate pressure reducing valves and stabilizing tanks. The natural gas pressure is reduced in steps (e.g., 580 bar → 350 bar → 280 bar) rather than directly, with each stage having its own stabilizing tank to buffer the gas and control temperature drop, thereby protecting the electronic pressure regulating valve from excessive temperature changes while maintaining the ability to achieve various injection pressures.

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If multiple pressure reduction pipelines are introduced to stabilize pressure, then the pressure stability improves, but the system complexity increases

Engineering Contradiction:
Improvepressure stabilityVSAvoidpressure reduction pipeline structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The system uses switching valves to dynamically select which pressure reduction pipeline is active based on current engine operating conditions and required injection pressure. This allows the system to adapt between different pressure reduction paths (e.g., direct connection for high pressure, or through intermediate valves for lower pressures) without permanently installing all possible pipelines, thus reducing overall system complexity while maintaining pressure stability when needed.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If stabilizing tanks are added to each pressure reduction pipeline, then the pressure fluctuation is reduced, but the system volume increases

Engineering Contradiction:
Improvepressure fluctuationVSAvoidsystem volume
Core Design Contradiction:
Stability of the object's compositionVSVolume of stationary object

Solution Approach 1:

Multiple stabilizing tanks are merged into a single shared stabilizing tank that serves all pressure reduction pipelines. The stabilizing tank is positioned to receive gas from different pressure reduction paths and provide stabilization for the entire system. This eliminates the need for separate stabilizing tanks for each pipeline, significantly reducing system volume while still providing effective pressure fluctuation damping for all pipelines.

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

Ensures stable pressure delivery to the electronic pressure regulating valve, preventing damage and ensuring smooth engine operation while allowing for timely pipeline switching in case of faults.

Implementation Method 1

stabilizing pressure values of the stabilizing tanks on different pressure reduction pipelines are different

Methodology Applied
Scientific EffectPressure stabilization:

Implementation Method 2

The pressure reduction process is achieved by 'vaporizing the liquefied natural gas'

Methodology Applied
Scientific EffectVaporization: Evaporation

Implementation Method 3

If the pressure of natural gas changes too much, such as from 580 bar to 280 bar, it will cause a very large temperature drop at the electronic pressure regulating valve

Methodology Applied
Scientific EffectJoule-Thomson effect: Joule-Thomson Effect

Data Source

PatentEP4700221A1Pressure regulation method, apparatus, vehicle, medium, and program product
Publication Date: 2026.02.25 WEICHAI POWER CO LTD
  • EP4700221A1 patent drawingFigure 1
  • EP4700221A1 patent drawingFigure 2
  • EP4700221A1 patent drawingFigure 3

AI summary

The present application relates to the technical field of engine control, and specifically to a pressure regulation method, an apparatus, a vehicle, a medium, and a program product. The method includes: determining current operating condition of an engine during vehicle's driving process; determining a required injection pressure value for the engine based on the current operating condition; determining a target pressure reduction pipeline from multiple pressure reduction pipelines based on the injection pressure value; and connecting the target pressure reduction pipeline with the electronic pressure regulating valve by adjusting a connecting valve. By using the above method, the natural gas can be stabilized within a certain pressure range after passing through the target pressure reduction pipeline, thereby avoiding the problem of excessive temperature drop caused by excessive pressure change of the natural gas behind the electronic pressure regulating valve, which may lead to damage to the electronic pressure regulating valve.