Cryogenic Hydrogen Tank With Immersed Cryopump for Low-Pressure Delivery
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Solution Overview
Problem
Existing mobile cryostorage systems for hydrogen in motor vehicles face inefficiencies due to high operating pressures in the inner tank, which reduce storage capacity and pressure build-up time, and require high power consumption for pressure increase, especially in active systems with blowers and compressors.
Innovation Solution
Incorporating a cryopump fully surrounded by cryogenic fluid within the inner tank, which operates at very low temperatures to extract and deliver hydrogen at pressures greater than the inner tank pressure, minimizing operating pressure and energy consumption while allowing flexible mass flow and pressure adaptation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the operating pressure in the inner tank is increased to enable hydrogen extraction, then the hydrogen can be delivered to the consumer, but the usable storage capacity decreases due to reduced liquid density at low temperatures
Solution Approach 1:
The patent replaces the conventional thermal heating system with a mechanical cryopump system. The cryopump uses mechanical compression to increase hydrogen pressure and temperature simultaneously, eliminating the need to heat the entire tank content to achieve extraction pressure.
Solution Approach 2:
The invention changes the state parameters of the hydrogen by using the cryopump to directly compress and warm the liquid hydrogen at the point of extraction. This localized parameter change allows pressure increase without affecting the overall temperature and density of the stored hydrogen in the inner tank.
2Duration of action of moving object
If a high-power blower is used to increase inner tank pressure independently, then pressure build-up time is reduced, but power consumption increases to kW range
Solution Approach 1:
The patent extracts the pressure increase function from the bulk storage system and relocates it to a localized cryopump at the extraction point. This eliminates the need for high-power blowers that would heat and pressurize the entire tank, instead using only the minimal energy required to pump the specific amount of hydrogen being extracted.
Solution Approach 2:
The cryopump utilizes the cold energy already present in the liquid hydrogen to operate, with the hydrogen itself serving as the cooling medium for the pump. This self-service approach eliminates the need for external high-power heating and compression systems.
3Reliability
If the inner tank pressure is maintained above consumer supply pressure for reliable extraction, then hydrogen delivery is ensured, but tank weight increases due to higher design pressure requirements
Solution Approach 1:
The patent replaces the passive pressure-maintenance approach with an active mechanical pumping system. The cryopump dynamically generates the necessary pressure differential at the point of extraction, allowing the tank itself to be designed for lower static pressure while ensuring reliable delivery through active pumping.
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 configuration reduces energy consumption, extends pressure build-up times, allows for lighter tank designs, and enhances filling rates by maintaining lower inner tank pressures, enabling efficient and reliable hydrogen extraction and delivery.
Implementation Method 1
at least one cryopump arranged in the inner tank of the cryocontainer, the cryopump being fully surrounded by cryogenic fluid during normal operation and/or a cryopump drive of the cryopump being operable to operate at very low temperatures
Implementation Method 2
via a heat exchanger, which warms (i.e., increases the temperature) the hydrogen to be delivered to a consumer
Data Source
AI summary
A cryostorage system that includes a cryocontainer operable to store liquid hydrogen and/or gaseous hydrogen, the cryocontainer having an inner tank and an outer container, and at least one cryopump, operable to operate at low temperatures, arranged in the inner tank to be fully surrounded, during normal operation, by cryogenic fluid, the cryopump delivering liquid hydrogen and/or gaseous hydrogen in one or more stages to a consumer at a pressure greater than a pressure in the inner tank.