Vapor Jet System Using Sublimable Solid Fuel

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Solution Overview

Problem

Conventional spacecraft propulsion systems are heavy, complex, and inefficient, particularly for small satellites, due to the need for gas-liquid separation and the risk of unvaporized fuel being jetted out, leading to reduced fuel efficiency and unstable satellite attitudes.

Innovation Solution

A vapor jet system using a container for a sublimable solid with a vapor discharge port, a filter to prevent solid passage, and heaters to control sublimation pressure, allowing controlled vapor jetting without unvaporized fuel, featuring a simple structure and reduced weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gas-liquid separation devices (porous metal, filter, vane) are used to extract gaseous fuel from liquid fuel tank in microgravity, then fuel extraction is improved, but system complexity and weight increase

Engineering Contradiction:
Improvefuel extraction reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses sublimation (solid to gas phase transition) instead of liquid-to-gas evaporation. The sublimable solid directly transitions to vapor without requiring gas-liquid separation devices, eliminating the need for porous metal, filters, or vanes while maintaining reliable fuel extraction in microgravity conditions

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The invention extracts the gas-liquid separation function from the system by using sublimable solid fuel that directly produces vapor. This removes the need for separate separation devices (porous metal, filters, vanes) while maintaining the essential function of extracting gaseous fuel from the storage container

Inventive Principle:
Principle #2Taking out (Extraction)

2Force

If conventional propulsion systems are used for small satellite attitude control or orbital maneuver, then thrust is provided, but mounting space and weight increase due to system complexity

Engineering Contradiction:
ImprovethrustVSAvoidspacecraft weight
Core Design Contradiction:
ForceVSWeight of moving object

Solution Approach 1:

The patent removes unnecessary components (gas accumulator, combustor, gas-liquid separation devices) from the propulsion system by using sublimable solid fuel that directly generates vapor. This extraction of essential functions to minimal components reduces both weight and mounting space while maintaining thrust capability for small satellites

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the fuel state parameter from liquid or compressed gas to sublimable solid. This parameter change enables direct vapor generation without complex support systems, significantly reducing weight and mounting space while providing sufficient thrust for small satellite applications

Inventive Principle:
Principle #35Parameter changes

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 system achieves improved continuous jetting performance, enhanced fuel efficiency, and stabilized satellite attitude by using a sublimable solid with a higher density, preventing unvaporized fuel from being jetted and allowing precise control of thrust levels.

Implementation Method 1

a container (10) for storing a sublimable solid (30), the container (10) having a vapor discharge port (10a) for discharging vapor (32) generated by sublimation of the sublimable solid (30)

Methodology Applied
Scientific EffectSublimation: Sublimation

Implementation Method 2

a heater (12) for heating the sublimable solid (30) stored in the container (10)

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

a filter (16) for preventing passage of the sublimable solid and allowing the vapor to pass through, the filter (16) being provided to the vapor flow path

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3133283B1Vapor jet system
Publication Date: 2020.01.15 JAPAN AEROSPACE EXPLORATION AGENCY
  • EP3133283B1 patent drawingFigure 1~2
  • EP3133283B1 patent drawingFigure 3~4

AI summary

A vapor jet system includes a container for storing a sublimable solid, the container having a vapor discharge port for discharging vapor generated by sublimation of the sublimable solid; a member having an opening for jetting out the vapor to the outside of the vapor jet system; a vapor flow path between the vapor discharge port and the opening; and a filter for preventing passage of the sublimable solid and allowing the vapor to pass through, the filter being provided to the vapor flow path.