US-12618360-B2 - Liquid hydrogen pumping system

US12618360B2US 12618360 B2US12618360 B2US 12618360B2US-12618360-B2

Abstract

The present disclosure relates to hydrogen pumping systems for pumping hydrogen from a fuel tank (where the hydrogen is stored as liquid hydrogen LH2) to a power generation device at which the hydrogen is used as fuel. The pumping systems include features providing system redundancy, effective heat exchange for warming the hydrogen, gas turbine air bleed cooling, component cooling and removal of hydrogen gas.

Inventors

Subrata Sarkar
Andrew John MASSON
Sandip Balasaheb GAIKWAD

Assignees

EATON INTELLIGENT POWER LIMITED

Dates

Publication Date: 20260505
Application Date: 20240924
Priority Date: 20230927

Claims (14)

1 . A fuel system for supplying hydrogen to a gas turbine engine, the fuel system comprising: a tank for containing the hydrogen in a liquid form; a fuel line that extends from the tank to the gas turbine engine; a boost pump for pumping the hydrogen through the fuel line in a direction from the tank toward the gas turbine engine; a heat exchanger positioned along the fuel line between a fuel pump and the gas turbine engine for heating the hydrogen pumped through the heat exchanger by the fuel pump; a valve positioned between the heat exchanger and the gas turbine engine for controlling a flow of the hydrogen to an injector of a combustor of the gas turbine engine; the fuel pump outside of the tank, the fuel pump including a fuel pump inlet that receives the hydrogen from the boost pump and a fuel pump outlet that pumps the hydrogen toward the heat exchanger; and a vacuum line positioned adjacent to the fuel pump inlet for drawing the hydrogen-away from the fuel pump inlet prior to initiating a start-up of the fuel pumps, wherein the vacuum line includes a vacuum pump having a vacuum pump outlet that directs the hydrogen to a fuel cell, directs the hydrogen, back to the tank, and directs the hydrogen to the fuel line at a location between the heat exchanger and the valve and, wherein a plurality of valves direct the hydrogen from the vacuum pump outlet to at least one of the fuel cell, the tank, and the fuel line.
2 . The fuel system of claim 1 , wherein the boost pump is positioned in the tank.
3 . The fuel system of claim 1 , wherein the fuel pump is powered by at least one electric motor.
4 . The fuel system of claim 3 , wherein the electric motor is cooled by the hydrogen from the fuel line.
5 . The fuel system of claim 1 , wherein the fuel pump is powered by at least two electric motors coupled to the fuel pump by a planetary gear set.
6 . The fuel system of claim 5 , wherein the at least two electric motors include first and second electric motors respectively controlled by first and second motor controllers that are separate from one another.
7 . The fuel system of claim 1 , wherein the vacuum line draws the hydrogen from a housing of the fuel pump.
8 . The fuel system of claim 1 , wherein the fuel pump is powered by an electric motor, wherein the electric motor is cooled by the hydrogen from the fuel line, wherein the electric motor is contained in a housing defining a cooling passage through which the hydrogen flows, and wherein the vacuum line draws the hydrogen from the cooling passage.
9 . The fuel system of claim 1 , wherein the heat exchanger is configured to transfer heat from a bleed air sourced from a compressor of the gas turbine engine to the hydrogen in the fuel line.
10 . The fuel system of claim 9 , wherein the bleed air is cooled in the heat exchanger to provide a cooled bleed air is used to turbine cooling at the gas turbine engine, or engine oil cooling at the gas turbine engine or combustion chamber cooling at the gas turbine engine, or is conveyed to an air conditioning system for conditioning air directed into a cabin of an aircraft on which the gas turbine engine is mounted.
11 . The fuel system of claim 1 , wherein the valve is a flow modulating valve with shut-off functionality.
12 . The fuel system of claim 11 , wherein a hydrogen mass flow is sensed in the fuel line by a fuel mass flow sensor between the heat exchanger and the valve and/or wherein a temperature is sensed in the fuel line by a fuel temperature sensor between the heat exchanger and the valve and/or wherein a pressure is sensed in the fuel line by a fuel pressure sensor between the heat exchanger and the valve, and wherein the fuel system further comprises an engine control unit that interfaces with the valve, the fuel temperature sensor, the fuel mass flow sensor, the fuel pressure sensor, a command source, sensors from the gas turbine engine, and a motor controller for controlling an electric motor that drives the fuel pump.
13 . A fuel system for supplying hydrogen to a gas turbine engine, the fuel system comprising: a tank for containing the hydrogen in a liquid form; a fuel line that extends from the tank to the gas turbine engine; a boost pump for pumping the hydrogen through the fuel line in a direction from the tank toward the gas turbine engine; a heat exchanger positioned along the fuel line between a fuel pump and the gas turbine engine for heating the hydrogen pumped through the heat exchanger by the fuel pump; a valve positioned between the heat exchanger and the gas turbine engine for controlling a flow of the hydrogen to an injector of a combustor of the gas turbine engine, the fuel pump outside of the tank, the fuel pump including a fuel pump inlet that receives the hydrogen from the boost pump and a fuel pump outlet that pumps the hydrogen toward the heat exchanger; and a vacuum line positioned adjacent to the fuel pump inlet for drawing the hydrogen away from the fuel pump inlet prior to initiating a start-up of the fuel pump, wherein the fuel pump is powered by an electric motor, wherein the electric motor is cooled by the hydrogen from the fuel line, wherein the electric motor is contained in a housing defining a cooling passage through which the hydrogen flows, and wherein the vacuum line draws the hydrogen from the cooling passage and, wherein the hydrogen that flows through the cooling passage is tapped from the fuel pump outlet and is controlled by an orifice valve.
14 . A fuel system for supplying hydrogen to a gas turbine, the fuel system comprising: a tank for containing the hydrogen in a liquid form; a fuel line that extends from the tank to the gas turbine engine; a boost pump positioned in the tank; a fuel pump positioned outside of the tank, the fuel pump including a fuel pump inlet that receives the hydrogen from the boost pump and a fuel pump outlet that pumps the hydrogen toward the gas turbine engine; and a vacuum line adjacent the fuel pump inlet to draw the hydrogen away from the fuel pump inlet prior to initiating a start-up of the fuel pump, wherein the vacuum line includes a vacuum pump having a vacuum pump outlet that directs the hydrogen to a fuel cell, directs the hydrogen back to the tank, and directs the hydrogen to the fuel line at a location between a heat exchanger and a valve and, wherein a plurality of valves direct the hydrogen from the vacuum pump outlet to at least one of the fuel cell, the tank, and the fuel line.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Indian Provisional Patent Application No. 202311064844, filed Sep. 27, 2023, which is incorporated by reference herein in its entirety. TECHNICAL FIELD The present disclosure relates to fuel systems such as fuel systems used for aircraft. BACKGROUND The use of hydrogen can potentially reduce green-house gas emissions considerably as compared to fossil fuel-based aircraft fuel systems. Thus, there is a need for development in the area of hydrogen fuel systems for aircraft and other applications. SUMMARY The present disclosure relates to hydrogen pumping systems for pumping hydrogen from a fuel tank (where the hydrogen is stored as liquid hydrogen LH2) to a power generation device at which the hydrogen is used as fuel. The pumping systems include features providing system redundancy, effective heat exchange for warming the hydrogen, gas turbine air bleed cooling, component cooling and removal of hydrogen gas. Aspects of the present disclosure relate to hydrogen pumping systems for pumping hydrogen from a fuel tank (where the hydrogen is stored as liquid hydrogen LH2) to a power generation device at which the hydrogen is used as fuel. Example combustion-based power generation devices include gas turbine engines (e.g., gas turbine engines for providing aircraft propulsion) and internal combustion engines. Example electrochemical-based power generation devices include fuel cells (e.g., a fuel cell for power generation at an auxiliary power unit (APU) of an aircraft). In certain examples, the LH2 may be stored at low temperatures (e.g., cryogenic temperatures) in the fuel tank and can be pressurized. In certain examples, the relatively low temperature of the hydrogen can be used to provide cooling of system components. In one example, the hydrogen is pumped toward the power generation device by a hydraulic pump (e.g., a centrifugal pump) driven by an electric motor, and the hydrogen is used to provide cooling of the electric motor by routing the hydrogen through a cooling passage (e.g., a cooling sleeve/jacket) the flows along and/or through a casing/housing of the electric motor and extracts heat generated by the electric motor. In one example, the hydrogen is used to cool bleed gas from a gas turbine engine (e.g., a gas turbine engine of an aircraft). The cooled bleed gas can be used to provide cooling of a combustion chamber of the gas turbine engine, turbines of the gas turbine engine and engine oil of the gas turbine engine; and can also be used for air conditioning of the aircraft cabin or other aircraft functions. In certain examples, the bleed gas can be sourced from a compressor of the gas turbine engine at an early compression stage (e.g., for lower pressures) and/or at a later compression stage (e.g., for higher pressures). In certain examples, the bleed gas can be routed through a heat exchanger through which the hydrogen is pumped such that the hydrogen extracts heat from the bleed gas (e.g., the hydrogen is warmed by the bleed gas and the bleed gas is cooled by the hydrogen). In certain examples, the hydrogen pumping system can include a fuel pump for pumping the hydrogen toward the power generation device. The fuel pump can be located outside of the tank where the LH2 is stored, and a boost pump (or a plurality of boost pumps) can be provided in the tank for pumping LH2 to a pump inlet of the fuel pump. A vacuum line can be provided for removing hydrogen gas from the pump inlet prior to start-up of the fuel pump. In one example, the vacuum line can also draw hydrogen from a casing of the fuel pump. In one example, the fuel pump is powered by an electric motor, and the vacuum line can be configured to draw hydrogen through a cooling structure of the electric motor. In one example, the vacuum line includes a vacuum pump that directs hydrogen to a fuel cell (e.g., a fuel cell for providing power at an APU), back to tank, and/or back to the fuel line at a location downstream from the fuel pump. In one example, the hydrogen pumping system can include a heat exchanger through which hydrogen is pumped by the fuel pump to provide warming of the hydrogen prior to use (e.g., combustion) at the power generation device and to provide cooling of a fluid directed elsewhere in the system where cooling is desired. In one example, the power generation device is a gas turbine engine, and the fluid is bleed air supplied from a compressor of the gas turbine engine. In one example, prior to start-up of the fuel pump, the vacuum pump directs hydrogen (e.g., including evacuated hydrogen gas from the fuel pump inlet) back to the fuel line at a location downstream of the heat exchanger. In one example, a flow modulating and shutoff valve can be provided along the fuel line at a location between the heat exchanger and the power generation device. In one example, mass flow sensing, temperature sensing and/or pressure sensing of the hydrogen in the