LNG Cooling Component for Onboard Pressure Control
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Solution Overview
Problem
Existing systems for delivering liquefied natural gas (LNG) struggle to maintain controlled boiling pressure and temperature, particularly in onboard vehicle fuel tanks, leading to inefficient heat management and reduced LNG holding time before venting.
Innovation Solution
A system comprising a source tank, pump, cooling component, and temperature sensing valve that uses liquid nitrogen to control the temperature and saturation pressure of LNG, ensuring it is delivered at a predetermined pressure and temperature range, with features like a liquefaction engine and pressure control valves to manage heat and pressure effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If LNG is delivered through pumping and handling processes, then the LNG can be transported to the vehicle tank, but heat is absorbed during these processes causing temperature increase and saturation pressure rise
Solution Approach 1:
The system performs preliminary cooling of LNG in the source tank before pumping and delivery operations begin. By pre-cooling the LNG to a lower temperature, the system compensates for the heat absorption that will occur during subsequent pumping and handling processes, ensuring the LNG remains at the desired temperature range throughout delivery.
Solution Approach 2:
The patent introduces an intermediary cooling system that acts as a mediator between the LNG and the external environment. This cooling system, positioned in the delivery path after the pump, continuously removes heat absorbed during pumping and handling, preventing temperature increase and saturation pressure rise while maintaining efficient delivery operations.
2Stress or pressure
If the saturation pressure of LNG is kept sufficiently high to drive natural gas to the engine, then adequate pressure is available for fuel delivery, but the LNG holding time in the vehicle tank is reduced and venting becomes necessary sooner
Solution Approach 1:
The system dynamically changes the temperature parameter of LNG during storage and delivery. By maintaining LNG at a lower temperature than conventional systems, the saturation pressure is reduced while still providing adequate pressure for fuel delivery to the engine. This temperature parameter change extends the LNG holding time in the vehicle tank by reducing the rate of vaporization, delaying the need for venting operations.
3Stress or pressure
If cooling is applied after the dispensing pump in the delivery path, then lower LNG saturation pressures are achieved, but the system complexity increases with additional cooling components
Solution Approach 1:
The cooling system is designed to perform multiple functions within a single integrated unit. It not only cools the LNG to reduce saturation pressure but also compensates for heat absorption during pumping, maintains temperature during delivery, and extends holding time in the vehicle tank. This multi-functionality reduces the need for separate cooling components and control systems, thereby limiting the increase in overall system complexity.
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 effectively maintains LNG at a low saturation pressure, increasing the time before gas venting is necessary while ensuring reliable delivery to the vehicle tank, enhancing the operational efficiency of LNG fueled vehicles.
Implementation Method 1
the cooling component is configured to surround a cooling line with a cooling cryogenic fluid... the cooling component includes a cooling tank with a top portion and a bottom portion in which the top portion of the cooling component surrounds a gas portion of the cooling cryogenic fluid and the bottom portion of the cooling component surrounds a liquid portion of the cooling cryogenic fluid
Implementation Method 2
In the course of delivering LNG, the liquefied natural gas absorbs heat, such as during pumping and other normal handling
Implementation Method 3
The temperature sensing valve controller is configured to measure a temperature of the fuel in the controlled inlet line and to control the flow of fuel through the cold fuel control valve and warm fuel control valve to maintain the temperature of the fuel in the controlled inlet line within a predetermined temperature range
Implementation Method 4
The pressure control valve releases cooling cryogenic fluid when a pressure of the cooling cryogenic fluid in the cooling component exceeds a predetermined set temperature
Data Source
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AI summary
Described herein are systems and methods for cryogenic fluid delivery to achieve the lowest reasonable saturation pressure while dispensing a cryogenic fluid such as liquefied natural gas to a holding tank on a use device. The systems and methods utilize a liquid nitrogen component and a liquefaction engine, very cold liquefied natural gas and a liquefaction engine, or a combination of both very cold liquefied natural gas and a liquid nitrogen component to deliver LNG to a holding tank on a use device.