Liquid Hydrogen Pressurization to 80–100 MPa Using Pump-Thermal Staging
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Solution Overview
Problem
Traditional mechanical methods for pressurizing liquid hydrogen using high-pressure liquid hydrogen pumps suffer from significant performance degradation and high energy consumption, while thermal compression methods face issues like hydrogen discharge and slow pressurization speeds.
Innovation Solution
A liquid hydrogen pressurization and refueling system that synergistically combines power and heat, using an efficient liquid hydrogen pump for low-pressure pressurization and thermal compression without power consumption for high-pressure pressurization, achieving staged pressurization to 80-100 MPa.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-pressure liquid hydrogen pumps are used for pressurization, then pressurization efficiency is improved, but performance deteriorates significantly under high-pressure conditions (90 MPa) due to increased leakage and friction losses
Solution Approach 1:
The pressurization process is divided into two stages: a first pressurization stage using a liquid hydrogen pump to reach intermediate pressure (below 50 MPa), and a second pressurization stage using thermal compression to reach final high pressure (80-100 MPa). This segmentation allows each method to operate in its optimal pressure range, avoiding the energy losses associated with using high-pressure pumps throughout the entire pressurization range.
Solution Approach 2:
The patent replaces the purely mechanical pressurization method (high-pressure liquid hydrogen pump) with a thermal compression method for the second stage. Thermal compression uses heat input to increase pressure without mechanical work, substituting mechanical energy conversion with thermal energy conversion to achieve high-pressure pressurization with minimal energy loss.
2Use of energy by moving object
If thermal compression is used for pressurization, then energy consumption is reduced, but hydrogen discharge increases (over 30% discharged) and pressurization speed decreases
Solution Approach 1:
The pressurization process is divided into two stages: a first pressurization stage using a liquid hydrogen pump to reach intermediate pressure (below 50 MPa), and a second pressurization stage using thermal compression to reach final high pressure (80-100 MPa). This segmentation allows the system to benefit from both methods: the pump provides rapid initial pressurization while thermal compression provides energy-efficient final pressurization.
Solution Approach 2:
The liquid hydrogen pump performs preliminary pressurization to reach an intermediate pressure state before thermal compression is applied. This preliminary action prepares the system for the subsequent thermal compression stage, enabling the thermal process to start from a more favorable initial state that reduces hydrogen discharge and improves overall efficiency.
3Use of energy by stationary object
If thermal compression is used for pressurization, then power consumption is reduced, but continuous and rapid filling becomes challenging
Solution Approach 1:
The pressurization process is divided into two stages: a first pressurization stage using a liquid hydrogen pump to reach intermediate pressure (below 50 MPa), and a second pressurization stage using thermal compression to reach final high pressure (80-100 MPa). This segmentation allows the system to benefit from both methods: the pump provides rapid initial pressurization while thermal compression provides energy-efficient final pressurization.
Solution Approach 2:
The liquid hydrogen pump performs preliminary pressurization to reach an intermediate pressure state before thermal compression is applied. This preliminary action prepares the system for the subsequent thermal compression stage, enabling the thermal process to start from a more favorable initial state that reduces hydrogen discharge and improves overall efficiency.
4Ease of operation
If a 90 MPa high-pressure liquid hydrogen pump is used, then direct high-pressure fill is achieved, but equipment cost and complexity increase
Solution Approach 1:
The pressurization process is divided into two stages: a first pressurization stage using a liquid hydrogen pump to reach intermediate pressure (below 50 MPa), and a second pressurization stage using thermal compression to reach final high pressure (80-100 MPa). This segmentation allows each method to operate in its optimal pressure range, avoiding the energy losses associated with using high-pressure pumps throughout the entire pressurization range.
Solution Approach 2:
The patent replaces the purely mechanical pressurization method (high-pressure liquid hydrogen pump) with a thermal compression method for the second stage. Thermal compression uses heat input to increase pressure without mechanical work, substituting mechanical energy conversion with thermal energy conversion to achieve high-pressure pressurization with minimal energy loss.
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 low-energy-consumption filling of liquid hydrogen refueling stations by utilizing a common and efficient 50 MPa liquid hydrogen pump, reducing equipment costs and exergy loss, and enabling continuous and rapid pressurization and filling operations.
Implementation Method 1
a reciprocating liquid hydrogen pump pressurizes liquid hydrogen from a liquid hydrogen storage tank
Implementation Method 2
in-tank heat exchangers are installed inside the cryogenic and high-pressure vessels... equal-capacity thermal compression pressurization to 80-100 MPa is performed on the cryogenic and high-pressure vessels
Data Source
AI summary
The present invention discloses a liquid hydrogen pressurization and refueling system synergistically driven by power and heat, at its core is a cascaded cryogenic and high-pressure vessel group, which achieves staged pressurization of liquid hydrogen to 80-100 MPa by combining reciprocating liquid hydrogen pump pressurization and equal-capacity thermal compression using cryogenic and high-pressure vessels, the filling of a vehicle-mounted storage tank occurs through these cascaded vessels; the pressurization and filling processes are closely integrated, with hydrogen flow in the filling process serving as a heat-transfer medium. Efficient in-tank thermal compression of the cryogenic and high-pressure vessels is achieved without additional driving force. Based on the combination of efficient low-pressure compression using the liquid hydrogen pump and high-pressure thermal compression without power consumption, the present invention fully utilized liquid hydrogen cooling capacity to replace the high pump power consumption typically required in the traditional pressurization process; and a cascaded storage tank is combined to reduce the exergy loss in the filling process, resulting in low-energy-consumption continuous filling of the liquid hydrogen refueling station.