Cryogenic Fuel Delivery Component Precooling via Vapor-Liquid Staging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Machines fueled by cryogenically-stored fuels face issues with vaporization of liquid fuels during the initial introduction into warm fuel delivery components, leading to undesirable two-phase flow effects and increased reservoir pressure due to phase change expansion.
Innovation Solution
A two-stage cooling system that initially uses vapor from the reservoir to precool fuel delivery components, followed by liquid precooling to the operating temperature, reducing vaporization and stabilizing fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If liquid cryogenic fuel is introduced into warm fuel delivery components at the beginning of a fueling cycle, then the fuel delivery components are cooled to operating temperature, but liquid fuel vaporization occurs leading to two-phase flow and increased reservoir pressure
Solution Approach 1:
The system performs preliminary cooling of the fuel delivery components using vapor before introducing liquid fuel. This preliminary action reduces the temperature difference between the components and the liquid fuel, preventing excessive vaporization when the liquid fuel is introduced. The vapor cooling occurs first, followed by liquid fuel delivery, ensuring components are pre-cooled to near operating temperature.
Solution Approach 2:
The system utilizes the phase transition of the cryogenic fuel from vapor to liquid in a controlled sequence. First, vapor is used to cool the components (vapor phase), then liquid fuel is introduced after the components have been pre-cooled. This controlled phase transition approach prevents uncontrolled vaporization that would occur if liquid fuel were introduced directly into warm components.
2Temperature
If liquid fuel is used to precool fuel delivery components, then cooling effectiveness is improved, but liquid evaporation during precooling increases
Solution Approach 1:
The system performs preliminary cooling with vapor before introducing liquid fuel for final cooling. This preliminary vapor cooling action removes the majority of the thermal energy from the components, so that when liquid fuel is subsequently introduced, there is minimal temperature differential to drive evaporation. The liquid fuel then completes the cooling process with minimal loss.
Solution Approach 2:
The system changes the physical parameter (phase) of the cooling medium from vapor to liquid in a controlled sequence. By using vapor first (higher temperature, lower density) and then liquid (lower temperature, higher density), the system optimizes the cooling process to minimize evaporation losses while achieving the required cooling effectiveness.
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 two-stage cooling system effectively minimizes liquid fuel vaporization and prevents pressure buildup in the reservoir, ensuring efficient and stable fuel delivery by maintaining components at or below the boiling point of the cryogenic fuel.
Implementation Method 1
some or all of the fuel delivery components are partially cooled with the vapor from the reservoir
Implementation Method 2
the fuel delivery components are further cooled with the liquid from the reservoir to the operating temperature
Implementation Method 3
When the cold liquid fuel is initially introduced into the warm fuel delivery components at the beginning of a fueling cycle, heat may be introduced into the fuel due to cooling of the fuel delivery components by contact with the fuel. As a result, some of the liquid fuel may be vaporized
Data Source
AI summary
A method for precooling fuel delivery components of a machine having an engine fueled by a cryogenically-stored fuel is described. The fuel delivery components may be configured to operate at an operating temperature at or below a boiling point of the cryogenically-stored fuel. The method may comprise, in a vapor precooling mode, cooling the fuel delivery components to a temperature approaching the operating temperature with a vapor of the fuel taken from a reservoir cryogenically storing the fuel. The method may further comprise, in a liquid precooling mode, further cooling the fuel delivery components to the operating temperature with a liquid of the fuel taken from the reservoir.