Energy management system for a power cycle system, power cycle system, and aircraft

Abstract

The application discloses an energy management system of a power cycle system, wherein the power cycle system is a combined power cycle system of a gas turbine and a fuel cell, and the energy management system comprises a fuel pump, a fuel distributor, a cold end heat exchanger, a cooling cycle loop and a hot end heat exchanger; and a control system is used for controlling the fuel pump, the fuel distributor and a circulating pump in the cooling cycle loop, wherein a fuel flow is obtained based on a required power of the power cycle system, a rotating speed of the fuel pump and an opening degree of the fuel distributor, a hot end heat exchanger heat is calculated through heat balance based on the fuel flow, and a cooling effect of the cooling cycle loop is realized based on the hot end heat exchanger heat and the rotating speed of the circulating pump. The application can simultaneously meet the energy saving and emission reduction and weight control requirements of an aircraft, and also solves the problem that the system power density is limited by the heat dissipation capacity.

Description

Technical Field

[0001] This invention belongs to the field of aviation new energy power technology, and particularly relates to the energy management system, power cycle system and aircraft of the power cycle system. Background Technology

[0002] As the world's energy structure evolves towards a low-carbon direction, the aviation sector faces the challenge of energy transition. Hydrogen, as a zero-carbon clean energy source with high energy density, is an important means for the aviation industry to achieve "carbon peaking and carbon neutrality." Currently, hydrogen fuel cell engines and hydrogen fuel cell propulsion systems are the two most promising directions for hydrogen-powered aviation. The former has a structure basically the same as existing aircraft engines, but its thermal efficiency has a theoretical limit of about 40%. The latter allows hydrogen to directly generate electricity and discharge water through electrochemical reactions in the battery, achieving a power generation efficiency of about 60%. However, its power density is low, making it difficult to apply in the aviation field.

[0003] A hybrid power system is a novel hybrid system that combines a fuel cell as the main component with a turbine engine. This configuration combines the advantages of both fuel cell and diesel engines, significantly reducing the adverse effects of the disadvantages of a single power source in any aspect. The hybrid system can achieve a thermal efficiency of up to 70%, making it the most efficient high-power power generation system currently available.

[0004] However, in the field of new energy power for aviation (such as aircraft), hybrid power systems have not been specifically applied to the field of new energy power for aviation. At the same time, the heat dissipation problem of electrical equipment such as generators and motors in new energy power systems for aviation still restricts the improvement of system power density. Summary of the Invention

[0005] This invention proposes an energy management system, a power cycle system, and an aircraft for a power cycle system, in order to solve the technical problems of low power generation efficiency and poor heat dissipation of electrical equipment in the prior art.

[0006] To achieve the above objectives, the present invention provides an energy management system for a power cycle system, wherein the power cycle system is a combination of a gas turbine and a fuel cell, wherein the power cycle system includes a combustion chamber, a fuel cell, a high-pressure compressor connected to the combustion chamber, a low-pressure compressor connected to the high-pressure compressor, and a fuel delivery passage connected to the combustion chamber and the fuel cell respectively, the fuel delivery passage being used to connect to a liquid hydrogen source; the energy management system includes:

[0007] fuel pump;

[0008] A fuel distributor is connected to the fuel delivery passage, and the fuel distributor is used to deliver hydrogen in the fuel delivery passage to the fuel cell and the combustion chamber respectively according to a preset ratio;

[0009] A cold-end heat exchanger is disposed on the fuel delivery passage. The cold-end heat exchanger is used to exchange heat with the fuel delivery passage so that the liquid hydrogen in the fuel delivery passage sublimates into hydrogen gas.

[0010] A cooling circulation loop is used to exchange heat with the first heat exchanger of the power circulation system, the first heat exchanger being located between the high-pressure compressor and the low-pressure compressor;

[0011] A hot-end heat exchanger is disposed on the cooling circulation loop, and the hot-end heat exchanger is used to exchange heat with the cooling circulation loop.

[0012] A control system is used to control the fuel pump, the fuel distributor, and the circulating pump in the cooling circulation loop. The fuel flow rate is obtained based on the power demand of the power circulation system, the speed of the fuel pump, and the opening of the fuel distributor. The heat of the hot-end heat exchanger is calculated based on the fuel flow rate through heat balance calculation. The coolant temperature in the cooling circulation loop is adjusted based on the heat of the hot-end heat exchanger and the speed of the circulating pump.

[0013] To achieve the above objectives, the present invention provides a power circulation system, comprising:

[0014] Combustion chamber;

[0015] A fuel cell is connected to the combustion chamber;

[0016] A high-pressure compressor is connected to the combustion chamber;

[0017] A low-pressure compressor is connected to the high-pressure compressor;

[0018] A fuel delivery passage is connected to both the combustion chamber and the fuel cell, and the fuel delivery passage is also connected to a liquid hydrogen source.

[0019] The energy management system of the power cycle system controls the fuel pump, fuel distributor, and circulation pump in the cooling cycle loop through the control system to regulate the temperature of the coolant in the cooling cycle loop.

[0020] Preferably, it further includes a turbine mechanism and a generator connected to the turbine mechanism, wherein the combustion chamber is used for the combustion of air and hydrogen to output high-temperature gas to drive the turbine mechanism, so that the turbine mechanism drives the generator.

[0021] Preferably, the system further includes a power management unit connected to the generator and a motor connected to the power management unit, wherein the power management unit is used to convert the energy output by the generator into electrical energy to power the motor.

[0022] Preferably, the system further includes a second heat exchanger for heat exchange with the power management unit and a third heat exchanger for heat exchange with the motor, wherein the first heat exchanger, the second heat exchanger, and the third heat exchanger are all used for heat exchange with the hot-end heat exchanger.

[0023] Preferably, it further includes an air intake passage connected to the low-pressure compressor, the air intake passage being used to connect to an air source.

[0024] Preferably, the fuel delivery passage is connected to the anode inlet of the fuel cell, and the anode outlet of the fuel cell is connected to the combustion chamber.

[0025] Preferably, the high-pressure compressor is connected to the bypass inlet of the fuel cell via an air delivery passage, and the bypass outlet of the fuel cell is connected to the combustion chamber.

[0026] The present invention also provides an aircraft including the aforementioned power cycle system.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects:

[0028] This invention provides an energy management system for a power cycle system, comprising: a fuel pump; a fuel distributor for delivering hydrogen from the fuel delivery path to the fuel cell and the combustion chamber in a preset ratio; a cold-end heat exchanger for exchanging heat with the fuel delivery path to sublimate liquid hydrogen into hydrogen gas; a cooling circulation loop for exchanging heat with a first heat exchanger of the power cycle system; a hot-end heat exchanger for exchanging heat with the cooling circulation loop; and a control system for controlling the fuel pump, the fuel distributor, and the circulation pump in the cooling circulation loop. The fuel flow rate is obtained based on the power demand of the power cycle system, the speed of the fuel pump, and the opening degree of the fuel distributor. The heat of the hot-end heat exchanger is calculated based on the fuel flow rate through heat balance calculation. The cooling effect of the cooling circulation loop is achieved based on the heat of the hot-end heat exchanger and the speed of the circulation pump. This invention introduces an energy management system that couples the power matching and heat matching processes. By using liquid hydrogen heat sinks to lower the temperature of the hot-end heat exchangers, the first heat exchanger can intercool the compressor, increasing the operating pressure ratio limit and boosting the turbine's output power. Simultaneously, the second and third heat exchangers dissipate heat from the electrical equipment, creating a low-temperature environment that improves its operating efficiency and power density, solving the problem of power density being limited by heat dissipation capacity. This allows for further weight reduction in the aircraft's power cycle system, enabling its application in the aviation field. On the other hand, the liquid hydrogen absorbs heat and is converted into hydrogen gas, which can be directly fed into the fuel cell without additional preheating.

[0029] The present invention also provides a power cycle system, which is a power cycle system combining a gas turbine and a fuel cell. This power cycle system solves the disadvantages of using a gas turbine or fuel cell as a power system alone, and can simultaneously meet the energy saving, emission reduction and weight control requirements of aircraft.

[0030] The present invention also provides an aircraft including the aforementioned power cycle system, which possesses all the advantages of the energy management system of the aforementioned power cycle system and the power cycle system itself, and can solve the technical problems of low power generation efficiency and poor heat dissipation of electrical equipment in existing aircraft. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0032] Figure 1 This is a schematic diagram of the power circulation system according to an embodiment of the present invention. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0035] Example 1

[0036] like Figure 1 As shown, this embodiment provides an energy management system for a power cycle system. The power cycle system is a power cycle system combining a gas turbine and a fuel cell. The power cycle system includes a combustion chamber, a fuel cell, a high-pressure compressor connected to the combustion chamber, a low-pressure compressor connected to the high-pressure compressor, and a fuel delivery passage connected to the combustion chamber and the fuel cell respectively. The fuel delivery passage is used to connect to a liquid hydrogen source.

[0037] The energy management system includes:

[0038] fuel pump;

[0039] A fuel distributor is connected to the fuel delivery passage, and the fuel distributor is used to deliver hydrogen in the fuel delivery passage to the fuel cell and the combustion chamber respectively according to a preset ratio;

[0040] A cold-end heat exchanger is disposed on the fuel delivery passage. The cold-end heat exchanger is used to exchange heat with the fuel delivery passage so that the liquid hydrogen in the fuel delivery passage sublimates into hydrogen gas.

[0041] A cooling circulation loop is used to exchange heat with the first heat exchanger of the power circulation system, the first heat exchanger being located between the high-pressure compressor and the low-pressure compressor;

[0042] A hot-end heat exchanger is disposed on the cooling circulation loop, and the hot-end heat exchanger is used to exchange heat with the cooling circulation loop.

[0043] A control system is used to control the fuel pump, the fuel distributor, and the circulating pump in the cooling circulation loop. The fuel flow rate is obtained based on the power demand of the power circulation system, the speed of the fuel pump, and the opening of the fuel distributor. The heat of the hot-end heat exchanger is calculated based on the fuel flow rate through heat balance calculation. The coolant temperature in the cooling circulation loop is adjusted based on the heat of the hot-end heat exchanger and the speed of the circulating pump.

[0044] Specifically, the energy management system determines the system's required power P based on the system's power demand. req Calculate the fuel flow rate and adjust the fuel flow rate by controlling the speed of the fuel pump through the control system. The control system adjusts the opening of the fuel distributor to regulate the proportion φ of hydrogen entering the SOFC anode and combustion chamber, so that the power output of the power system meets the power demand requirements and achieves a balance between power supply and demand.

[0045]

[0046] In the formula P req Indicates the power required by the power system. The total fuel flow rate is represented by φ, the hydrogen distribution ratio is represented by LHV, and the lower calorific value of hydrogen is represented by U. f η represents the fuel utilization rate of SOFC. SOFC η represents the power generation efficiency of SOFC. GT This indicates the power generation efficiency of the gas turbine.

[0047] Specifically, the energy management system calculates the heat sink of the cold-end heat exchanger based on the fuel flow rate, calculates the flow rate of the coolant in the cooling circuit based on the current temperature and target temperature of the hot-end heat exchanger, and adjusts the coolant flow rate by controlling the speed of the cooling circulation pump, so that the intercooler can achieve the designed intercooling effect, and maintains the operating temperature of the motor and power management unit within the design range, thereby achieving a heat balance between the hot-end heat and the liquid hydrogen heat sink.

[0048]

[0049] In the formula Q v T represents the heat absorbed by the vaporization of a unit mass of liquid hydrogen, where C1 represents the specific heat capacity of hydrogen. SOFC T0 indicates the SOFC operating temperature, and T0 indicates the standard temperature. C1 represents the coolant flow rate, C2 represents the coolant specific heat capacity, T1 represents the coolant temperature entering the hot-end heat exchanger, and T2 represents the coolant temperature flowing through the hot-end heat exchanger.

[0050] In this embodiment, on the one hand, an energy management system is introduced to couple the power matching process and the heat matching process. Liquid hydrogen heat sinks are used to reduce the temperature of the hot-end heat exchanger, so that the first heat exchanger can intercool the compressor, improve the working pressure ratio limit, and increase the turbine output power capability. At the same time, the second and third heat exchangers dissipate heat from the electrical equipment, creating a low-temperature environment, improving its working efficiency and power density, solving the problem that the power density is limited by the heat dissipation capacity, and further reducing the weight of the aircraft's power cycle system, realizing its application in the aviation field. On the other hand, after absorbing heat, the liquid hydrogen will be converted into hydrogen gas, which can be directly fed into the fuel cell without the need for additional preheating.

[0051] Example 2

[0052] like Figure 1 As shown, this embodiment provides a power cycle system, including:

[0053] Combustion chamber;

[0054] A fuel cell is connected to the combustion chamber;

[0055] A high-pressure compressor is connected to the combustion chamber;

[0056] A low-pressure compressor is connected to the high-pressure compressor;

[0057] A fuel delivery passage is connected to both the combustion chamber and the fuel cell, and the fuel delivery passage is also connected to a liquid hydrogen source; and,

[0058] The energy management system provided in the above embodiment controls the fuel pump, fuel distributor, and circulating pump in the cooling circulation loop through the control system to regulate the temperature of the coolant in the cooling circulation loop.

[0059] It should be noted that the power cycle system provided in this embodiment has all the advantages of the energy management system provided in Embodiment 1 above.

[0060] Specifically, the power cycle system also includes a turbine mechanism and a generator connected to the turbine mechanism. The combustion chamber is used for the combustion of air and hydrogen, outputting high-temperature gas to drive the turbine mechanism, thereby enabling the turbine mechanism to drive the generator. The turbine mechanism includes a high-pressure turbine, a low-pressure turbine, and a free turbine. The low-pressure turbine is mechanically connected to the low-pressure compressor via the low-pressure turbine, the high-pressure turbine is mechanically connected to the high-pressure compressor via the high-pressure turbine shaft, and the free turbine is connected to the generator to output electrical power. Simultaneously, the exhaust gas from the free turbine is discharged through a tailpipe.

[0061] Specifically, the power cycle system also includes a power management unit connected to the generator and an electric motor connected to the power management unit. The power management unit converts the energy output by the generator into electrical energy to power the electric motor. The power management unit is connected via cables to the output terminals of the solid oxide fuel cell system and the gas turbine power generation system to supply power to the electric motor.

[0062] Specifically, the power circulation system also includes a second heat exchanger for heat exchange with the power management unit and a third heat exchanger for heat exchange with the motor. The first, second, and third heat exchangers are all used for heat exchange with the hot-end heat exchanger, which can provide equipment cooling capacity.

[0063] Specifically, the fuel delivery passage is connected to the anode inlet of the fuel cell, and the anode outlet of the fuel cell is connected to the combustion chamber.

[0064] In this embodiment, the fuel enters the fuel distributor after heat exchange in the energy management system. The fuel distributor is connected to the SOFC anode inlet and the combustion chamber inlet via hydrogen flow pipes. The fuel distributor inputs hydrogen into the SOFC anode inlet and the combustion chamber inlet according to a set ratio. After passing through the energy management system, the liquid hydrogen absorbs heat from the hot end of the cooling circuit, creating a low-temperature environment for the electric propulsion system. On the other hand, after absorbing heat, the liquid hydrogen is converted into hydrogen gas, which can directly enter the anode of the solid oxide fuel cell without additional preheating.

[0065] Specifically, the power cycle system also includes an intake passage connected to the low-pressure compressor, the intake passage being used to connect to an air source.

[0066] Specifically, the high-pressure compressor is connected to the bypass inlet of the fuel cell through an air delivery passage, the bypass outlet of the fuel cell is connected to the combustion chamber, and the fuel cell cathode, anode, and bypass exhaust gas passage are directly connected to the combustion chamber.

[0067] In this embodiment, the fuel cell is a solid oxide fuel cell.

[0068] The power cycle system in this embodiment is a power cycle system combining a gas turbine and a fuel cell. This power cycle system solves the disadvantages of using a single gas turbine or fuel cell as a power system, and can simultaneously meet the energy-saving, emission-reduction and weight control requirements of the aircraft.

[0069] Example 3

[0070] This embodiment also provides an aircraft, including the power cycle system provided in Embodiment 2. The aircraft can be a civil aircraft, airship, etc. It has all the advantages of the power cycle system provided in Embodiment 2 and can solve the technical problems of low power generation efficiency and poor heat dissipation of electrical equipment in existing aircraft.

[0071] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An energy management system for a power cycle system, characterized in that, The power cycle system is a combination of a gas turbine and a fuel cell, comprising a combustion chamber, a fuel cell, a high-pressure compressor connected to the combustion chamber, a low-pressure compressor connected to the high-pressure compressor, and a fuel delivery passage connected to both the combustion chamber and the fuel cell, wherein the fuel delivery passage is connected to a liquid hydrogen source; the energy management system includes: fuel pump; A fuel distributor is connected to the fuel delivery passage, and the fuel distributor is used to deliver hydrogen in the fuel delivery passage to the fuel cell and the combustion chamber respectively according to a preset ratio; A cold-end heat exchanger is disposed on the fuel delivery passage. The cold-end heat exchanger is used to exchange heat with the fuel delivery passage so that the liquid hydrogen in the fuel delivery passage sublimates into hydrogen gas. A cooling circulation loop is used to exchange heat with the first heat exchanger of the power circulation system, the first heat exchanger being located between the high-pressure compressor and the low-pressure compressor; A hot-end heat exchanger is disposed on the cooling circulation loop, and the hot-end heat exchanger is used to exchange heat with the cooling circulation loop. A control system is used to control the fuel pump, the fuel distributor, and the circulating pump in the cooling circulation loop. The fuel flow rate is obtained based on the power demand of the power circulation system, the speed of the fuel pump, and the opening of the fuel distributor. The heat of the hot-end heat exchanger is calculated based on the fuel flow rate through heat balance calculation. The coolant temperature in the cooling circulation loop is adjusted based on the heat of the hot-end heat exchanger and the speed of the circulating pump. Based on the power demand of the power cycle system Calculate the fuel flow rate and adjust the fuel flow rate by controlling the speed of the fuel pump through the control system. The proportion of hydrogen entering the SOFC anode and combustion chamber is adjusted by controlling the opening of the fuel distributor through the control system. This ensures that the output power of the power cycle system meets the power demand requirement, achieving a power supply-demand balance. Its expression is: ； In the formula This indicates the power demand of the power cycle system. Indicates total fuel flow. Indicates the hydrogen distribution ratio. This indicates that hydrogen has a low calorific value. This indicates the fuel utilization rate of SOFC. This indicates the power generation efficiency of SOFC. This indicates the power generation efficiency of the gas turbine; The heat sink of the cold-end heat exchanger is calculated based on the fuel flow rate. The flow rate of the coolant in the cooling loop is calculated based on the current temperature and target temperature of the hot-end heat exchanger. The coolant flow rate is adjusted by controlling the speed of the cooling circulation pump to ensure that the intercooler achieves the designed intercooling effect, maintaining the operating temperature of the motor and power management unit within the design range, and achieving heat balance between the hot-end heat and the liquid hydrogen heat sink. The expression is as follows: ； In the formula This represents the amount of heat absorbed by the vaporization of a unit mass of liquid hydrogen. This indicates the specific heat capacity of hydrogen. Indicates the SOFC operating temperature. Indicates standard temperature. Indicates coolant flow rate. This indicates the specific heat capacity of the coolant. This indicates the temperature of the coolant entering the hot-end heat exchanger. This indicates the temperature of the coolant flowing through the hot-end heat exchanger.

2. A power cycle system, characterized in that, include: Combustion chamber; A fuel cell is connected to the combustion chamber; A high-pressure compressor is connected to the combustion chamber; A low-pressure compressor is connected to the high-pressure compressor; A fuel delivery passage is connected to both the combustion chamber and the fuel cell, and the fuel delivery passage is also connected to a liquid hydrogen source. The energy management system of the power cycle system according to claim 1 controls the fuel pump, fuel distributor, and circulation pump in the cooling cycle loop through the control system to regulate the temperature of the coolant in the cooling cycle loop.

3. The power cycle system according to claim 2, characterized in that, It also includes a turbine mechanism and a generator connected to the turbine mechanism, wherein the combustion chamber is used for the combustion of air and hydrogen to output high-temperature gas to drive the turbine mechanism, so that the turbine mechanism drives the generator.

4. The power circulation system according to claim 3, characterized in that, It also includes a power management unit connected to the generator and a motor connected to the power management unit, wherein the power management unit is used to convert the energy output by the generator into electrical energy to power the motor.

5. The power cycle system according to claim 4, characterized in that, It also includes a second heat exchanger for heat exchange with the power management unit and a third heat exchanger for heat exchange with the motor, wherein the first heat exchanger, the second heat exchanger and the third heat exchanger are all used for heat exchange with the hot end heat exchanger.

6. The power cycle system according to claim 2, characterized in that, It also includes an air intake passage connected to the low-pressure compressor, the air intake passage being used to connect to an air source.

7. The power cycle system according to claim 2, characterized in that, The fuel delivery passage is connected to the anode inlet of the fuel cell, and the anode outlet of the fuel cell is connected to the combustion chamber.

8. The power cycle system according to claim 2, characterized in that, The high-pressure compressor is connected to the bypass inlet of the fuel cell via an air delivery passage, and the bypass outlet of the fuel cell is connected to the combustion chamber.

9. An aircraft, characterized in that, Includes the power circulation system as described in any one of claims 2-8.

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