Liquid hydrogen fuel energy power system, airplane and method

Abstract

The invention discloses a liquid hydrogen fuel energy power system and an airplane, and belongs to the technical field of liquid hydrogen airplane power device system integration. The system comprises a liquid hydrogen tank, a liquid hydrogen pipeline, a gas hydrogen pipeline, a heat conduction liquid circulation pipeline, an air pipeline, a hydrogen turbine engine power device, a fuel cell, a heating device, a primary heat exchanger, a secondary heat exchanger, a starter and an airborne power supply and distribution network. The system absorbs waste heat of a fuel cell and exhaust waste heat of an engine exhaust nozzle, liquid-gas-hydrogen conversion is achieved, and the problem of vaporization of liquid hydrogen fuel on a machine is effectively solved. Pressurized air is provided for the fuel cell through air entraining of an engine air compressor, waste heat of the fuel cell is absorbed through a first-stage heat exchanger, and the air side supply and heat dissipation functions of the fuel cell are achieved. According to the two-stage heat exchange device, fuel vaporization heating with different hydrogen fuel flow supply requirements is achieved according to the starting and stable operation processes, the system starting method solves the system starting heat source problem, and combined starting of the main power device and the auxiliary power device is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid hydrogen aircraft power plant system integration, and in particular relates to a liquid hydrogen fuel energy power system, an aircraft and a method. Background Art

[0002] As the environmental protection requirements of the civil aviation transportation industry continue to increase, the market has an urgent need for disruptive civil aircraft products that can reduce pollutant emissions. The main technical routes for new energy civil aircraft products that can reduce pollution emissions include: sustainable fuel SAF and hydrogen energy routes. Among them, hydrogen fuel, as an ideal clean energy to replace existing aircraft fuel (jet kerosene), has an energy density ratio three times higher than that of existing fuels. Hydrogen energy is expected to increase the payload and range of aircraft. In order to solve environmental problems, since the combustion product of hydrogen is only water, it can achieve true net zero carbon emissions and reduce environmental impact by 50% to 90% in flight. Combined with its high energy density, hydrogen energy has become an important energy source for reducing emissions in future new energy aircraft.

[0003] The volume energy density of cryogenic liquid hydrogen storage is about 3 times that of 35MPa high-pressure gas hydrogen storage and 1.8 times that of 70MPa high-pressure gas hydrogen storage. Therefore, for future long-range branch and trunk aircraft, liquid hydrogen storage will be a more feasible form of onboard fuel storage. At the same time, the high heat sink property of liquid hydrogen can improve the energy utilization efficiency of the power system and reduce fuel consumption. The application form of hydrogen fuel on hydrogen-powered aircraft is mainly to provide energy for hydrogen turbine engine power or hydrogen fuel cell power. The hydrogen turbine engine is a power device that directly burns hydrogen fuel and converts the internal energy of the fuel into mechanical energy. The fuel cell is an energy conversion device that directly converts the chemical energy of the fuel into electrical energy using chemical reactions. Based on the current state of technology, fuel cells are subject to specific power and thermal limitations, and it is difficult to expand to higher power application scenarios in the short term. Therefore, for branch and trunk long-range aircraft, hydrogen turbine engines as the main power and fuel cells as auxiliary power will be a feasible power system architecture in the future.

[0004] With the technological breakthrough of liquid hydrogen storage and hydrogen power system, hydrogen-powered branch and trunk long-range aircraft will be successfully developed. For the existing liquid hydrogen fuel energy power system solutions, most of them involve the independent working mode of the system, fail to fully utilize the cooling capacity of liquid hydrogen to participate in thermal management, the overall energy utilization efficiency of the system is low, the functional components of the system are not reasonably utilized, the system is relatively complex, and the heat source required for engine starting and power system starting when using liquid hydrogen as fuel are not considered. Summary of the invention

[0005] In view of this, the present invention discloses a liquid hydrogen fuel energy power system, an aircraft and a method.

[0006] The present invention adopts the following technical solution:

[0007] A liquid hydrogen fuel energy power system, the system comprising: a liquid hydrogen tank, a liquid hydrogen pipeline, a primary heat exchanger, a gas-hydrogen pipeline, a heat transfer liquid circulation pipeline, an air pipeline, a hydrogen turbine engine power unit, a fuel cell, a heating device, a starter, and an onboard power supply and distribution network;

[0008] The hydrogen turbine engine power unit comprises a compressor, a combustion chamber, a turbine and a tail nozzle; the compressor, the combustion chamber, the turbine and the tail nozzle are arranged in sequence;

[0009] The outlet of the liquid hydrogen tank is connected to the liquid hydrogen inlet of the primary heat exchanger through a liquid hydrogen pipeline, and a liquid hydrogen pump is provided on the liquid hydrogen pipeline;

[0010] The first branch of the gas-hydrogen outlet of the primary heat exchanger is connected to the fuel inlet of the fuel cell through a gas-hydrogen pipeline, and a temperature sensor and a regulating valve are provided at the fuel inlet of the fuel cell;

[0011] The second branch of the gas-hydrogen outlet of the primary heat exchanger is connected to the fuel inlet of the combustion chamber through a gas-hydrogen pipeline; a temperature sensor and a regulating valve are provided at the fuel inlet of the combustion chamber;

[0012] The heating device is provided on the thermal fluid circulation pipeline, and the thermal fluid circulation pipeline flows through the fuel cell and the primary heat exchanger;

[0013] The air pipeline includes: a pipeline of the engine main flow channel air flow path, a pipeline connecting the bleed air port of the compressor and the air input port of the fuel cell;

[0014] The onboard power supply and distribution network is connected to the fuel cell and the starter respectively, and the starter is connected to the turbine engine.

[0015] Furthermore, the system includes a secondary heat exchanger, the gas-hydrogen outlet of the primary heat exchanger also includes a third branch, the third branch is connected to the gas-hydrogen inlet of the secondary heat exchanger through a gas-hydrogen pipeline, the gas-hydrogen outlet of the secondary heat exchanger is connected to the fuel inlet of the combustion chamber through a gas-hydrogen pipeline, and a temperature sensor and a regulating valve are provided at the fuel inlet position of the combustion chamber; the secondary heat exchanger is arranged at the tail nozzle position.

[0016] Further, the gas-hydrogen pipeline comprises: a first gas-hydrogen pipeline, a second gas-hydrogen pipeline and a third gas-hydrogen pipeline;

[0017] The first gas-hydrogen pipeline includes: connecting the primary heat exchanger, the inlet of the first three-way valve, the first outlet of the first three-way valve, the first regulating valve, and the fuel inlet of the fuel cell in sequence; a temperature sensor is provided between the first regulating valve and the fuel inlet of the fuel cell;

[0018] The second gas-hydrogen pipeline includes: a pipeline sequentially connected to the primary heat exchanger, the inlet of the first three-way valve, the second outlet of the first three-way valve, the inlet of the second three-way valve, the first outlet of the second three-way valve, the second regulating valve and the fuel inlet of the combustion chamber;

[0019] The third gas-hydrogen pipeline includes: a second outlet of the second three-way valve, a secondary heat exchanger, a one-way valve, the second regulating valve and a fuel inlet of the combustion chamber connected in sequence; a temperature sensor is provided between the second regulating valve and the fuel inlet of the combustion chamber.

[0020] Further, the heat transfer liquid circulation pipeline includes a first circulation pipeline and a second circulation pipeline;

[0021] The first circulation pipeline includes: a thermal fluid output port of the fuel cell, a thermal fluid circulation pump, an inlet of the third three-way valve, a first outlet of the third three-way valve, a heating device and a thermal fluid input port of the fuel cell connected in sequence;

[0022] The second circulation pipeline includes: connecting the fuel cell thermal fluid output port, the thermal fluid circulation pump, the inlet of the third three-way valve, the second outlet of the third three-way valve, the primary heat exchanger and the thermal fluid input port in sequence.

[0023] Furthermore, a stop valve is provided at the outlet of the liquid hydrogen tank.

[0024] Furthermore, the onboard power supply and distribution network is connected to the onboard equipment.

[0025] Furthermore, the starter is connected to the hydrogen turbine engine power unit via a transmission mechanism.

[0026] Furthermore, a propulsion device is provided at one end of the transmission shaft.

[0027] An aircraft is provided with the above-mentioned liquid hydrogen fuel energy power system, the hydrogen storage tank is arranged at the rear half of the fuselage, and the fuel cell is arranged at the tail end of the fuselage.

[0028] The combined starting method of the above-mentioned liquid hydrogen fuel energy power system comprises:

[0029] S1 turns on the fuel cell self-heating device and the heat transfer fluid circulation pump, opens the inlet of the third three-way valve and the first outlet of the third three-way valve, and continues to heat the heat transfer fluid until the temperature inside the fuel cell reaches the operating temperature;

[0030] S2 closes the first outlet of the third three-way valve, opens the second outlet of the third three-way valve, and the thermal fluid circulation pump delivers the thermal fluid into the primary heat exchanger;

[0031] S3 turns on the starter, which drives the hydrogen turbine engine to start operating initially through the transmission mechanism;

[0032] S4 starts the liquid hydrogen pump, and the liquid hydrogen exchanges heat with the heat transfer liquid in the primary heat exchanger and vaporizes. The inlet of the first three-way valve and the second outlet of the first three-way valve, the inlet of the second three-way valve and the first outlet of the second three-way valve are opened, and the fuel inlet temperature of the combustion chamber is monitored at the same time;

[0033] S5 changes the flow of heat transfer fluid by adjusting the opening of the third three-way valve, and then adjusts the heat exchange of the first-stage heat exchanger to adjust the fuel inlet temperature of the combustion chamber; when the gas hydrogen temperature reaches the combustion requirement, ignition is carried out, the hydrogen turbine engine continues to operate, gradually enters the ground slow-speed state, and completes the start;

[0034] The compressor of the S6 engine is running, and part of the high-pressure air is drawn from the compressor as the air source for the fuel cell, while the gas and hydrogen temperature at the inlet of the first three-way valve is monitored;

[0035] S7 When the temperature of the gaseous hydrogen at the inlet of the first three-way valve reaches the hydrogen supply temperature required by the fuel cell, the first outlet of the first three-way valve is opened, the gaseous hydrogen enters the fuel cell to undergo a chemical reaction, and the fuel cell is started.

[0036] Beneficial effects of the present invention:

[0037] (1) Liquid-to-gas hydrogen conversion is achieved by absorbing waste heat from the fuel cell and the engine tail nozzle exhaust, effectively solving the problem of liquid hydrogen fuel vaporization on board. At the same time, it saves fuel cell heat dissipation energy, increases the temperature and enthalpy of the engine supply fuel, reduces fuel consumption, and improves the comprehensive energy utilization efficiency of the system.

[0038] (2) In addition to providing the initial ambient temperature for fuel cell startup, the fuel cell heating device will also serve as the initial heat source to achieve liquid-gas hydrogen conversion and provide heat source function. The engine compressor bleed air is used to provide pressurized air for the fuel cell, and the primary heat exchanger is used to absorb the fuel cell waste heat to achieve the fuel cell air side supply and heat dissipation functions. There is no need to equip a separate air intake booster device and heat dissipation device, which realizes the functional reuse of components within the system and reduces system equipment.

[0039] (3) A two-stage heat exchange device is used to achieve fuel vaporization heating for different hydrogen fuel flow supply requirements during the startup process and stable operation process, with large adjustable margin and flexible adjustment. Under the condition of low flow hydrogen fuel supply during the startup process, liquid hydrogen fuel does not need to pass through the secondary heat exchanger, which reduces the fuel flow path, reduces pressure loss along the process, and improves the fuel supply quality.

[0040] (4) A system starting method is proposed to solve the system starting heat source problem and realize the joint starting of the main power unit and the auxiliary power unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 It is a schematic diagram of the structure of the liquid hydrogen fuel energy power system of the present invention;

[0043] Figure 2 It is a schematic diagram of a liquid hydrogen fuel energy power system aircraft of the present invention.

[0044] Illustration Description: Figure 1 The line marked with "1" represents the liquid hydrogen pipeline, the line marked with "2" represents the gas hydrogen pipeline, and the line marked with "3" represents the heat transfer fluid circulation pipeline. DETAILED DESCRIPTION

[0045] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0046] It should be clear that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Embodiment 1:

[0048] like Figure 1 As shown, Figure 1 Herein, “three-way valve 1” is the first three-way valve in this embodiment, “three-way valve 2” is the second three-way valve in this embodiment, and “three-way valve 3” is the third three-way valve in this embodiment; Figure 1 The “regulating valve 1” is the first regulating valve in this embodiment, and the “regulating valve 2” is the second regulating valve in this embodiment.

[0049] A liquid hydrogen fuel energy power system, the system comprising: a liquid hydrogen tank, a primary heat exchanger, a liquid hydrogen pipeline, a gas hydrogen pipeline, a heat transfer liquid circulation pipeline, an air pipeline, a hydrogen turbine engine power unit, a fuel cell, a heating device, a starter, and an airborne power supply and distribution network; the hydrogen turbine power unit outputs shaft power for driving a propulsion device or a power generation device to generate electrical energy.

[0050] The hydrogen turbine engine power unit comprises a compressor, a combustion chamber, a turbine and a tail nozzle; the compressor, the combustion chamber, the turbine and the tail nozzle are arranged in sequence;

[0051] The outlet of the liquid hydrogen tank is connected to the liquid hydrogen inlet of the primary heat exchanger through a liquid hydrogen pipeline, and a liquid hydrogen pump is provided on the liquid hydrogen pipeline;

[0052] The first branch of the gas-hydrogen outlet of the primary heat exchanger is connected to the fuel inlet of the fuel cell through a gas-hydrogen pipeline, and a temperature sensor and a regulating valve are provided at the fuel inlet of the fuel cell;

[0053] The second branch of the gas-hydrogen outlet of the primary heat exchanger is connected to the fuel inlet of the combustion chamber through a gas-hydrogen pipeline; a temperature sensor and a regulating valve are provided at the fuel inlet of the combustion chamber;

[0054] The heating device is provided on the thermal fluid circulation pipeline, and the thermal fluid circulation pipeline flows through the fuel cell and the primary heat exchanger;

[0055] The air pipeline includes: a pipeline of the engine main flow channel air flow path, a pipeline connecting the bleed air port of the compressor and the air input port of the fuel cell;

[0056] The onboard power supply and distribution network is connected to the fuel cell and the starter respectively, and the starter is connected to the turbine engine.

[0057] Furthermore, the system includes a secondary heat exchanger, the gas-hydrogen outlet of the primary heat exchanger also includes a third branch, the third branch is connected to the gas-hydrogen inlet of the secondary heat exchanger through a gas-hydrogen pipeline, the gas-hydrogen outlet of the secondary heat exchanger is connected to the fuel inlet of the combustion chamber through the gas-hydrogen pipeline, and a temperature sensor and a regulating valve are provided at the fuel inlet position of the combustion chamber; the secondary heat exchanger is arranged at the tail nozzle position.

[0058] Further, the gas-hydrogen pipeline comprises: a first gas-hydrogen pipeline, a second gas-hydrogen pipeline and a third gas-hydrogen pipeline;

[0059] The first gas-hydrogen pipeline includes: connecting the primary heat exchanger, the inlet of the first three-way valve, the first outlet of the first three-way valve, the first regulating valve, and the fuel inlet of the fuel cell in sequence; a temperature sensor is provided between the first regulating valve and the fuel inlet of the fuel cell;

[0060] The second gas-hydrogen pipeline includes: a pipeline sequentially connected to the primary heat exchanger, the inlet of the first three-way valve, the second outlet of the first three-way valve, the inlet of the second three-way valve, the first outlet of the second three-way valve, the second regulating valve and the fuel inlet of the combustion chamber;

[0061] The third gas-hydrogen pipeline includes: a second outlet of the second three-way valve, a secondary heat exchanger, a one-way valve, the second regulating valve and a fuel inlet of the combustion chamber connected in sequence; a temperature sensor is provided between the second regulating valve and the fuel inlet of the combustion chamber.

[0062] Further, the heat transfer liquid circulation pipeline includes a first circulation pipeline and a second circulation pipeline;

[0063] The first circulation pipeline includes: a thermal fluid output port of the fuel cell, a thermal fluid circulation pump, an inlet of the third three-way valve, a first outlet of the third three-way valve, a heating device and a thermal fluid input port of the fuel cell connected in sequence;

[0064] The second circulation pipeline includes: connecting the fuel cell thermal fluid output port, the thermal fluid circulation pump, the inlet of the third three-way valve, the second outlet of the third three-way valve, the primary heat exchanger and the thermal fluid input port in sequence.

[0065] Furthermore, a stop valve is provided at the outlet of the liquid hydrogen tank.

[0066] Furthermore, the onboard power supply and distribution network is connected to the onboard equipment.

[0067] Furthermore, the starter is connected to the hydrogen turbine engine power unit via a transmission mechanism.

[0068] Furthermore, a propulsion device is provided at one end of the transmission shaft.

[0069] An aircraft is provided with the above-mentioned liquid hydrogen fuel energy power system, the hydrogen storage tank is arranged at the rear half of the fuselage, and the fuel cell is arranged at the tail end of the fuselage. Figure 2 shown.

[0070] The combined starting method of the above-mentioned liquid hydrogen fuel energy power system comprises:

[0071] S1 turns on the fuel cell self-heating device and the heat transfer fluid circulation pump, opens the inlet of the third three-way valve and the first outlet of the third three-way valve, and continues to heat the heat transfer fluid until the temperature inside the fuel cell reaches the operating temperature;

[0072] S2 closes the first outlet of the third three-way valve, opens the second outlet of the third three-way valve, and the thermal fluid circulation pump delivers the thermal fluid into the primary heat exchanger;

[0073] S3 turns on the starter, which drives the hydrogen turbine engine to start operating initially through the transmission mechanism;

[0074] S4 starts the liquid hydrogen pump, and the liquid hydrogen exchanges heat with the heat transfer liquid in the primary heat exchanger and vaporizes. The inlet of the first three-way valve and the second outlet of the first three-way valve, the inlet of the second three-way valve and the first outlet of the second three-way valve are opened, and the fuel inlet temperature of the combustion chamber is monitored at the same time;

[0075] S5 changes the flow of heat transfer fluid by adjusting the opening of the third three-way valve, and then adjusts the heat exchange of the first-stage heat exchanger to adjust the fuel inlet temperature of the combustion chamber; when the gas hydrogen temperature reaches the combustion requirement, ignition is carried out, the hydrogen turbine engine continues to operate, gradually enters the ground slow-speed state, and completes the start;

[0076] The compressor of the S6 engine is running, and part of the high-pressure air is drawn from the compressor as the air source for the fuel cell, while the gas and hydrogen temperature at the inlet of the first three-way valve is monitored;

[0077] S7 When the temperature of the gaseous hydrogen at the inlet of the first three-way valve reaches the hydrogen supply temperature required by the fuel cell, the first outlet of the first three-way valve is opened, the gaseous hydrogen enters the fuel cell to undergo a chemical reaction, and the fuel cell is started.

[0078] Example 2

[0079] A liquid hydrogen energy power system for the whole aircraft, using liquid hydrogen as fuel, hydrogen turbine engine as main propulsion power, fuel cell as auxiliary power, suitable for branch and trunk long-range aircraft. In this system, the comprehensive utilization of energy, functional reuse of system components, flexible adjustment of fuel supply, system starting heat source and starting method are considered, so as to realize the efficient utilization of liquid hydrogen fuel from low-temperature hydrogen storage device to hydrogen power, so as to improve the energy utilization efficiency of the system, reduce system equipment, reduce system complexity, and improve the adjustable margin of fuel supply.

[0080] A liquid hydrogen fuel energy power system includes a hydrogen turbine engine power unit, a fuel cell auxiliary power unit (mainly including a fuel cell), a hydrogen storage device (mainly including a liquid hydrogen tank), a two-stage heat exchange device (mainly including a primary heat exchanger and a secondary heat exchanger), an energy storage battery, a starter, and an onboard power supply and distribution network.

[0081] The hydrogen turbine engine power unit includes a compressor, a combustion chamber, a turbine and a tail nozzle. The hydrogen turbine power unit outputs shaft power to drive a propulsion device or a power generation device to generate electrical energy.

[0082] The fuel cell auxiliary power unit includes a fuel cell, and the thermal management also includes a heating device, a heat transfer fluid circulation pump, a primary heat exchanger, and a heat transfer fluid. The air intake system includes a gas hydrogen intake and a high-pressure air intake. The fuel cell auxiliary power unit outputs electrical energy and transmits it to the onboard power supply and distribution network.

[0083] The hydrogen storage device is a cryogenic liquid hydrogen storage tank, equipped with a liquid hydrogen filling port, a liquid hydrogen discharge port, a sensor installation interface, a safety valve, a pressure regulating valve and other valve interfaces, etc. The shape of the storage tank can be conventional spherical, cylindrical or special-shaped.

[0084] The two-stage heat exchanger is located downstream of the hydrogen storage device and at the tail nozzle of the engine. The first-stage heat exchanger is used to realize the heat flow transfer between the heat generated by the fuel cell and the liquid hydrogen fuel, and the second-stage heat exchanger is used to realize the heat flow transfer between the exhaust waste heat of the tail nozzle and the hydrogen fuel. The first-stage heat exchanger completes the vaporization of the liquid hydrogen fuel, and the second-stage heat exchanger realizes the fuel temperature rise required when the engine is in a large flow fuel supply demand.

[0085] Example 3

[0086] like Figure 1 As shown, Figure 1 Herein, “three-way valve 1” is the first three-way valve in this embodiment, “three-way valve 2” is the second three-way valve in this embodiment, and “three-way valve 3” is the third three-way valve in this embodiment; Figure 1 The “regulating valve 1” is the first regulating valve in this embodiment, and the “regulating valve 2” is the second regulating valve in this embodiment.

[0087] A liquid hydrogen fuel energy power system, including a hydrogen turbine engine power unit, a fuel cell auxiliary power unit, a hydrogen storage device, a two-stage heat exchange device, an energy storage battery, a starter, an onboard power supply and distribution network, onboard equipment, a stop valve, a liquid hydrogen pump, a thermal fluid circulation pump, a three-way valve, a regulating valve, a liquid hydrogen pipeline, a gas hydrogen pipeline, an air pipeline, and a thermal fluid circulation pipeline. The liquid hydrogen fuel energy power system solution includes:

[0088] The liquid hydrogen pipeline is connected in sequence to the liquid hydrogen storage tank, the shut-off valve, the liquid hydrogen pump, and the primary heat exchanger. It is used to pressurize the output liquid hydrogen to the required pressure, and then transport it to the downstream after being vaporized in the primary heat exchanger for use in fuel cells and hydrogen turbine engines.

[0089] The gas-hydrogen pipeline is divided into three routes, namely the first gas-hydrogen pipeline, the second gas-hydrogen pipeline and the third gas-hydrogen pipeline. The first gas-hydrogen pipeline is sequentially connected to the primary heat exchanger, the first three-way valve inlet, the first three-way valve first outlet, the first regulating valve, and the fuel cell hydrogen input port, and is used to supply gas-hydrogen to the hydrogen intake side of the fuel cell and enter the fuel cell to participate in the chemical reaction. The second gas-hydrogen pipeline is sequentially connected to the primary heat exchanger, the first three-way valve inlet, the first three-way valve second outlet, the second three-way valve inlet, the second three-way valve first outlet, the second regulating valve, and the combustion chamber fuel inlet, and is used to transport gas-hydrogen to the hydrogen turbine engine combustion chamber for combustion. The third gas-hydrogen pipeline is sequentially connected to the second outlet of the second three-way valve, the secondary heat exchanger, the one-way valve, the second regulating valve, and the combustion chamber fuel inlet, and is used to further heat the gas-hydrogen and transport it to the hydrogen turbine engine combustion chamber for combustion. Figure 1 As shown in the figure, the line marked with "1" represents the liquid hydrogen pipeline, the line marked with "2" represents the gas hydrogen pipeline, and the line marked with "3" represents the heat transfer liquid circulation pipeline.

[0090] The two-stage heat exchange device is located downstream of the hydrogen storage device and at the tail nozzle, respectively. The two-stage heat exchange device includes a primary heat exchanger and a secondary heat exchanger. The primary heat exchanger includes two heat exchange channels, namely, a liquid hydrogen fuel channel and a heat transfer fluid channel. The heat transfer fluid takes out the waste heat generated by the fuel cell and transfers the waste heat to the liquid hydrogen fuel through the primary heat exchanger, thereby realizing liquid-gas hydrogen conversion and fuel cell heat dissipation. The secondary heat exchanger includes two heat exchange channels, namely, a gas hydrogen fuel channel and an engine tail nozzle exhaust channel. The secondary heat exchanger is used to transfer the tail nozzle exhaust waste heat to the gas hydrogen fuel, thereby further heating the gas hydrogen fuel and meeting the minimum combustion temperature requirement of the combustion chamber.

[0091] The air pipeline is divided into two paths. One path connects the compressor air inlet port and the fuel cell air input port, using the high-pressure air generated by the compressor to provide air for the fuel cell, realizing the reuse of the compressor function. The other path is the engine main channel air flow path, which completes the compressor supercharging, combustion chamber combustion, turbine work, and tail nozzle exhaust in sequence. The exhaust heat is absorbed by low-temperature gas hydrogen to recover waste heat.

[0092] The thermal fluid circulation pipeline is divided into two routes, namely the first circulation pipeline and the second circulation pipeline. The first circulation pipeline is connected in sequence to the fuel cell thermal fluid output port, the thermal fluid circulation pump, the first outlet of the third three-way valve, the heating device and the thermal fluid input port, and is used to achieve the efficient operating environment required for the cold start of the fuel cell. The fuel cell heating is to maintain the normal operating temperature of the battery to prevent the battery from degrading its performance or failing to work properly in a low temperature environment. When the fuel cell is cold started, the heating device is turned on to heat the thermal fluid until the fuel cell reaches the most suitable operating temperature, and then the heating device is turned off. The thermal fluid is used to maintain the internal temperature of the fuel cell at the most suitable operating temperature.

[0093] The second circulation pipeline is connected in sequence to the fuel cell thermal fluid output port, the thermal fluid circulation pump, the second outlet of the third three-way valve, the primary heat exchanger and the thermal fluid input port, and is used to transfer the waste heat generated by the operation of the fuel cell to the liquid hydrogen fuel, so as to realize liquid-gas-hydrogen conversion and fuel cell heat dissipation. Fuel cells use liquid cooling, which is widely used in high-power fuel cell stacks because the heat transfer coefficient of liquid flow is higher than that of air flow and it is easier to achieve efficient heat recovery.

[0094] In addition, the starter is connected to the onboard power supply and distribution network, and the starter power supply is provided by the onboard energy storage battery. The hydrogen turbine engine uses the starter to start, and the onboard high-power density energy storage battery drives the starter and is connected to the engine shaft through a transmission mechanism. The fuel cell and energy storage battery output electrical energy to the onboard power supply and distribution network for the starter and onboard equipment. At the same time, the fuel cell can charge the energy storage battery.

[0095] The secondary heat exchanger is integrated with the hydrogen turbine engine to fully utilize the engine heat source for heat exchange, and utilize the high heat sink properties of liquid hydrogen to improve engine performance. In the embodiment, a heat exchanger and tail nozzle integrated layout scheme is proposed to utilize the exhaust waste heat of the tail nozzle to improve energy utilization efficiency. In addition, other forms of integrated schemes can also be used to use liquid hydrogen cooling capacity. This engine thermodynamic cycle established by considering the use of liquid hydrogen cooling source properties for heat exchange is usually called an unconventional thermodynamic cycle, including intercooling cycle, hydrogen-cooled turbine cycle and heat recovery cycle. Among them, the intercooling cycle refers to the use of liquid hydrogen to cool the compressor inlet airflow, reduce the compressor work, and improve the cycle efficiency; the hydrogen-cooled turbine cycle refers to the use of liquid hydrogen to cool the turbine cooling gas, improve the cooling capacity of the cooling gas, thereby increasing the temperature before the turbine and improving the cycle efficiency; the heat recovery cycle refers to the use of liquid hydrogen to absorb the high-temperature exhaust waste heat of the engine, increase the fuel temperature and enthalpy value, and reduce fuel consumption.

[0096] Liquid hydrogen consumes energy during its preparation. In order to compensate for this initial energy consumption, the coldness carried by liquid hydrogen should be fully utilized during its use to conduct comprehensive energy management of the energy power system. On the one hand, the fuel cell cooling circuit is connected to the primary heat exchanger to cool the fuel cell using the coldness of liquid hydrogen. At the same time, the waste heat generated by the fuel cell is utilized to heat the low-temperature fuel. On the other hand, the exhaust from the engine tail nozzle is connected to the secondary heat exchanger to heat the low-temperature fuel using the waste heat from the exhaust. Both methods increase the fuel enthalpy, reduce fuel consumption, and improve the comprehensive energy utilization efficiency of the system.

[0097] In addition to providing the initial environment required for fuel cell startup, the fuel cell heating device will also generate heat to achieve the initial conversion of liquid and gas hydrogen required for system startup, effectively solving the system startup heat source problem without the need for a separate liquid hydrogen vaporization heating device. In addition, the engine compressor bleed air is used to provide pressurized air for the fuel cell, and the primary heat exchanger is used to absorb the fuel cell waste heat to achieve the fuel cell air side supply and heat dissipation functions, without the need for a separate air intake booster device and heat dissipation device. In this way, the system component functions can be reused, the system equipment can be reduced, and the system complexity can be reduced.

[0098] The hydrogen fuel is heat-exchanged and regulated through a two-stage heat exchanger. When the system is in the startup process or slow-running state, the fuel flow demand is small and the heating required for the low-temperature fuel is small. At this time, the gas hydrogen fuel does not need to pass through the secondary heat exchanger and directly enters the combustion chamber through the second gas hydrogen pipeline to participate in combustion, reducing the fuel flow path, reducing pressure loss along the way, and improving the fuel supply quality. When the system is in operating conditions such as takeoff, climb, and cruise, the fuel flow demand is large and the heating required for the low-temperature fuel is also large. At this time, the gas hydrogen fuel must pass through the secondary heat exchanger to further absorb heat to achieve the minimum temperature requirement for hydrogen fuel combustion under large flow. Fuel regulation is carried out through a two-stage heat exchange device to achieve fuel vaporization heating under different hydrogen fuel flow supply requirements, with large adjustable supply margin and flexible adjustment.

[0099] Fuel cells are used during flight as onboard energy output, reducing the aircraft's demand for engine power extraction and improving engine performance.

[0100] The present invention also provides a liquid hydrogen fuel energy power system joint starting method, which is as follows:

[0101] (1) Turn on the fuel cell self-heating device and the thermal fluid circulation pump, open the inlet and the first outlet of the third three-way valve, and continue to heat the thermal fluid until the temperature inside the fuel cell reaches a suitable operating temperature;

[0102] (2) Close the first outlet of the third three-way valve, open the second outlet, and the thermal fluid circulation pump pumps the thermal fluid into the primary heat exchanger;

[0103] (3) Turn on the starter, which drives the hydrogen turbine engine to start operating initially through the transmission mechanism;

[0104] (4) Turn on the liquid hydrogen pump, and the liquid hydrogen exchanges heat with the heat transfer fluid in the primary heat exchanger to vaporize. Open the inlet and second outlet of the first three-way valve, the inlet and first outlet of the second three-way valve, and monitor the fuel inlet temperature of the combustion chamber at the same time;

[0105] (5) By adjusting the opening of the third three-way valve, the flow rate of the heat transfer fluid is changed, thereby affecting the heat exchange of the first-stage heat exchanger, so as to achieve the purpose of adjusting the fuel inlet temperature of the combustion chamber. When the gas hydrogen temperature reaches the minimum combustion requirement, ignition is performed, the hydrogen turbine engine continues to operate, gradually enters the ground slow-speed state, and completes the start-up;

[0106] (6) The engine compressor is running, and part of the high-pressure air is drawn from the compressor as the fuel cell air source, while monitoring the gas and hydrogen temperature at the inlet of the first three-way valve;

[0107] (7) When the temperature of the gaseous hydrogen at the inlet of the first three-way valve reaches the hydrogen supply temperature required by the fuel cell, the first outlet of the first three-way valve is opened, the gaseous hydrogen enters the fuel cell to undergo a chemical reaction, and the fuel cell is started.

[0108] like Figure 1 As shown, Figure 1 Herein, “three-way valve 1” is the first three-way valve in this embodiment, “three-way valve 2” is the second three-way valve in this embodiment, and “three-way valve 3” is the third three-way valve in this embodiment; Figure 1 The “regulating valve 1” is the first regulating valve in this embodiment, and the “regulating valve 2” is the second regulating valve in this embodiment.

[0109] This system is an energy power system composed of a hydrogen turbine power unit using liquid hydrogen as fuel and a fuel cell auxiliary power unit; a combined starting method and starting heat source for a hydrogen turbine power unit and a fuel cell auxiliary power unit using liquid hydrogen as fuel; the fuel cell cooling circuit is connected to the primary heat exchanger, and the liquid hydrogen cooling capacity is used to cool the fuel cell, while the waste heat generated by the fuel cell is used to heat the low-temperature fuel; the engine tail nozzle exhaust is connected to the secondary heat exchanger, and the exhaust waste heat is used to heat the low-temperature fuel. Both methods increase the fuel enthalpy value, reduce fuel consumption, and improve the comprehensive energy utilization efficiency of the system; in addition to providing the initial environment required for the fuel cell to start, the fuel cell heating device generates a heat source that will also be used to achieve the initial conversion of liquid and gas hydrogen required for the system to start, providing a system starting heat source, without the need to equip a separate liquid hydrogen vaporization heating device. The engine compressor bleed air is used to provide pressurized air for the fuel cell, and the primary heat exchanger is used to absorb the fuel cell waste heat to achieve the fuel cell air side supply and heat dissipation functions, without the need to equip a separate air intake booster device and heat dissipation device. The system component functions can be reused to reduce the additional equipment in the system. For the fuel vaporization heating under different hydrogen fuel flow supply requirements during the startup process and stable operation, a one-stage or two-stage heating method can be adopted, and the fuel supply can be adjusted with a large margin and flexible adjustment.

[0110] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A liquid hydrogen fuel energy power system, characterized in that: The system includes: a liquid hydrogen tank, a liquid hydrogen pipeline, a primary heat exchanger, a gas-hydrogen pipeline, a heat transfer liquid circulation pipeline, an air pipeline, a hydrogen turbine engine power unit, a fuel cell, a heating device, a starter, and an onboard power supply and distribution network; The hydrogen turbine engine power unit comprises a compressor, a combustion chamber, a turbine and a tail nozzle; the compressor, the combustion chamber, the turbine and the tail nozzle are arranged in sequence; The outlet of the liquid hydrogen tank is connected to the liquid hydrogen inlet of the primary heat exchanger through a liquid hydrogen pipeline, and a liquid hydrogen pump is provided on the liquid hydrogen pipeline; The first branch of the gas-hydrogen outlet of the primary heat exchanger is connected to the fuel inlet of the fuel cell through a gas-hydrogen pipeline, and a temperature sensor and a regulating valve are provided at the fuel inlet of the fuel cell; The second branch of the gas-hydrogen outlet of the first-stage heat exchanger is connected to the fuel inlet of the combustion chamber through a gas-hydrogen pipeline; a temperature sensor and a regulating valve are provided at the fuel inlet of the combustion chamber; The heating device is provided on the thermal fluid circulation pipeline, and the thermal fluid circulation pipeline flows through the fuel cell and the primary heat exchanger; The air pipeline includes: a pipeline of the engine main flow channel air flow path, a pipeline connecting the bleed air port of the compressor and the air input port of the fuel cell; The onboard power supply and distribution network is connected to the fuel cell and the starter respectively, and the starter is connected to the turbine engine.

2. The power system according to claim 1, characterized in that: The system includes a secondary heat exchanger, the gas-hydrogen outlet of the primary heat exchanger also includes a third branch, the third branch is connected to the gas-hydrogen inlet of the secondary heat exchanger through a gas-hydrogen pipeline, the gas-hydrogen outlet of the secondary heat exchanger is connected to the fuel inlet of the combustion chamber through the gas-hydrogen pipeline, and a temperature sensor and a regulating valve are provided at the fuel inlet position of the combustion chamber; the secondary heat exchanger is arranged at the tail nozzle position.

3. The power system according to claim 2, characterized in that: The gas-hydrogen pipeline comprises: a first gas-hydrogen pipeline, a second gas-hydrogen pipeline and a third gas-hydrogen pipeline; The first gas-hydrogen pipeline includes: connecting the primary heat exchanger, the inlet of the first three-way valve, the first outlet of the first three-way valve, the first regulating valve, and the fuel inlet of the fuel cell in sequence; a temperature sensor is provided between the first regulating valve and the fuel inlet of the fuel cell; The second gas-hydrogen pipeline includes: a pipeline sequentially connected to the primary heat exchanger, the inlet of the first three-way valve, the second outlet of the first three-way valve, the inlet of the second three-way valve, the first outlet of the second three-way valve, the second regulating valve and the fuel inlet of the combustion chamber; The third gas-hydrogen pipeline includes: a second outlet of the second three-way valve, a secondary heat exchanger, a one-way valve, the second regulating valve and a fuel inlet of the combustion chamber connected in sequence; a temperature sensor is provided between the second regulating valve and the fuel inlet of the combustion chamber.

4. The power system according to claim 1, characterized in that: The heat transfer liquid circulation pipeline comprises a first circulation pipeline and a second circulation pipeline; The first circulation pipeline includes: a thermal fluid output port of the fuel cell, a thermal fluid circulation pump, an inlet of the third three-way valve, a first outlet of the third three-way valve, a heating device and a thermal fluid input port of the fuel cell connected in sequence; The second circulation pipeline includes: connecting the fuel cell thermal fluid output port, the thermal fluid circulation pump, the inlet of the third three-way valve, the second outlet of the third three-way valve, the primary heat exchanger and the thermal fluid input port in sequence.

5. The power system according to claim 1, characterized in that: A stop valve is provided at the outlet of the liquid hydrogen tank.

6. The power system according to claim 1, characterized in that: The onboard power supply and distribution network is connected to the onboard equipment.

7. The power system according to claim 1, characterized in that: The starter is connected to the hydrogen turbine engine power device through a transmission mechanism.

8. The power system according to claim 1, characterized in that: One end of the transmission shaft is provided with a propulsion device.

9. An aircraft, the aircraft being provided with a liquid hydrogen fuel energy power system as claimed in any one of claims 1 to 8, the hydrogen storage tank being arranged at the rear half of the fuselage, and the fuel cell being arranged at the tail end of the fuselage.

10. The combined starting method of the liquid hydrogen fuel energy power system according to any one of claims 2 to 8, characterized in that: The method comprises: S1 turns on the fuel cell self-heating device and the heat transfer fluid circulation pump, opens the inlet of the third three-way valve and the first outlet of the third three-way valve, and continues to heat the heat transfer fluid until the temperature inside the fuel cell reaches the operating temperature; S2 closes the first outlet of the third three-way valve, opens the second outlet of the third three-way valve, and the thermal fluid circulation pump delivers the thermal fluid into the primary heat exchanger; S3 turns on the starter, which drives the hydrogen turbine engine to start operating initially through the transmission mechanism; S4 starts the liquid hydrogen pump, and the liquid hydrogen exchanges heat with the heat transfer liquid in the primary heat exchanger and vaporizes. The inlet of the first three-way valve and the second outlet of the first three-way valve, the inlet of the second three-way valve and the first outlet of the second three-way valve are opened, and the fuel inlet temperature of the combustion chamber is monitored at the same time; S5 changes the flow of heat transfer fluid by adjusting the opening of the third three-way valve, and then adjusts the heat exchange of the first-stage heat exchanger to adjust the fuel inlet temperature of the combustion chamber; when the gas hydrogen temperature reaches the combustion requirement, ignition is carried out, the hydrogen turbine engine continues to operate, gradually enters the ground slow-speed state, and completes the start; The compressor of the S6 engine is running, and part of the high-pressure air is drawn from the compressor as the air source for the fuel cell, while the gas and hydrogen temperature at the inlet of the first three-way valve is monitored; S7 When the temperature of the gaseous hydrogen at the inlet of the first three-way valve reaches the hydrogen supply temperature required by the fuel cell, the first outlet of the first three-way valve is opened, the gaseous hydrogen enters the fuel cell to undergo a chemical reaction, and the fuel cell is started.

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