Electric Motor Pump Liquid Rocket Engine Cooling

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Solution Overview

Problem

Liquid rocket engines with turbines and gas generators require additional propellant for operation, increasing launch weight and experiencing energy loss due to gas discharge, and existing electric motor-driven engines lack effective cooling solutions.

Innovation Solution

A liquid rocket engine design using a pump driven by an electric motor instead of a gas generator and turbine, incorporating a cooling system that circulates propellant to cool the electric motor, reducing propellant usage and preventing overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a gas generator and turbine are used to drive the pump, then the pump can be driven at high power, but additional propellant is required and energy loss occurs due to gas discharge

Engineering Contradiction:

Improvepump driving powerVSAvoidenergy loss

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The patent replaces the gas generator and turbine mechanical system with an electric motor system. The electric motor receives electrical energy from a power supply unit and directly drives the pump, eliminating the need for combustion-based power generation and the associated energy losses from gas discharge. This substitution of mechanical/thermal energy conversion with direct electrical energy conversion resolves the energy loss problem while maintaining pump driving power.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Power

If a gas generator and turbine are used to drive the pump, then the pump can be driven at high power, but the launch weight increases due to additional propellant requirements

Engineering Contradiction:

Improvepump driving powerVSAvoidlaunch weight

Core Design Contradiction:

PowerVSWeight of moving object

Solution Approach 1:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of energy

If an electric motor is used to drive the pump, then propellant usage is reduced, but the electric motor overheats

Engineering Contradiction:

Improvepropellant usageVSAvoidelectric motor temperature

Core Design Contradiction:

Loss of energyVSTemperature

Solution Approach 1:

The patent introduces a cooling system as an intermediary between the electric motor and the propellant supply system. The cooling system includes a heat exchanger that uses a portion of the propellant (or a separate coolant) to absorb heat from the electric motor through thermal conduction and convection. This intermediary cooling mechanism allows the electric motor to operate at reduced temperature while maintaining the benefit of lower propellant consumption.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Temperature

If a cooling system is added to cool the electric motor, then overheating is prevented, but the device complexity increases

Engineering Contradiction:

Improveelectric motor temperatureVSAvoidsystem complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent designs the cooling system to serve multiple functions: it cools the electric motor, manages thermal energy, and integrates with the existing propellant supply infrastructure. The heat exchanger can be positioned to utilize existing propellant lines, and the cooled propellant or exhaust gas can be redirected to the combustion chamber, thereby cooling the motor while maintaining or enhancing overall system efficiency without proportionally increasing complexity.

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 design reduces propellant load, minimizes energy loss, and efficiently cools the electric motor, enhancing the engine's operational efficiency and stability by eliminating the need for a gas generator and turbine.

Implementation Method 1

a cooling line branched from a side of the main oxidant line to guide a part of the oxidant to the electric motor, or branched from a side of the main fuel line to guide a part of the fuel to the electric motor

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

at least one of the oxidant and the fuel is transferred to the cooling line to cool the electric motor

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentEP3318744B1Liquid rocket engine using pump driven by electric motor

Publication Date: 2021.02.17 KOREA AEROSPACE RES INST

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AI summary

The present invention relates to a liquid rocket engine using a pump driven by an electric motor, and more particularly, to a liquid rocket engine using a pump driven by an electric motor instead of using a gas generator and a turbine so that a system may be simplified, and an overheated electric motor may be efficiently cooled by circulating a propellant (an oxidant or a fuel).