A fuel cell energy management system

Abstract

The application relates to a fuel cell energy management system, comprising a fuel cell stack, a hydrogen system, an air system and a cooling system, wherein the fuel cell stack is connected with the hydrogen system, the air system and the cooling system respectively; the hydrogen system comprises a hydrogen storage bottle, an electromagnetic valve, a first turbine and a first sensor which are sequentially connected through a hydrogen pipeline; the first sensor is connected with the fuel cell stack, and the first turbine is connected with the air system; the air system comprises an air filter, a second turbine, an intercooler and a second sensor which are sequentially connected through an air pipeline; the second sensor is connected with the fuel cell stack, and the second turbine is coaxially connected with the first turbine. The application utilizes the high-pressure potential energy of hydrogen to compress air, thereby effectively saving energy and improving system efficiency; the waste heat generated by the stack operation can be supplied to the hydrogen storage bottle, thereby guaranteeing the hydrogen supply flow and effectively reducing the power consumption of the radiator.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, and particularly relates to a fuel cell energy management system. Background Technology

[0002] Hydrogen fuel cells are power generation devices that use hydrogen as fuel and convert the chemical energy in the fuel into electrical energy through an electrochemical reaction. They have advantages such as high energy conversion efficiency, zero emissions, and no noise. The safe, efficient, and low-cost storage and transportation of hydrogen is a crucial link in the hydrogen energy industry chain. Among various hydrogen storage technologies, liquid hydrogen storage has a high capacity but high energy consumption and is not yet mature; high-pressure gaseous hydrogen storage has a high mass hydrogen storage density and fast charging and discharging rates, but its volumetric hydrogen storage density is relatively low; solid-state hydrogen storage has high volumetric hydrogen storage density and high hydrogen purity, but its mass hydrogen storage capacity is relatively low, and the hydrogen absorption and desorption process requires heat exchange with the external environment.

[0003] Solid-state high-pressure composite hydrogen storage refers to a hydrogen storage device filled with hydrogen storage materials at high platform pressure. This hydrogen storage method has the advantages of high volume density of solid hydrogen storage and the characteristics of fast hydrogen charging and discharging rate of high-pressure hydrogen storage. It can also make full use of the empty space caused by the limited stacking density of solid hydrogen storage powder through high pressure. Compared with high-pressure gaseous hydrogen storage, solid hydrogen storage has a stronger continuous hydrogen release capacity because it is close to constant pressure hydrogen release.

[0004] In a fuel cell system, the high-pressure hydrogen in the hydrogen cylinder of the hydrogen supply system needs to be reduced to about 2 bar through a multi-stage pressure reducing device before entering the stack. In this process, a large amount of pressure potential energy is lost. The air path and cooling path require additional energy to ensure the inlet pressure of the air (air compressor) and the flow of the coolant (water pump), resulting in energy waste and hindering the comprehensive utilization of energy. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problems of existing fuel cell systems, such as energy waste and difficulty in meeting practical needs, and to provide a fuel cell energy management system. This application utilizes a heat exchanger to supply waste heat from the fuel cell stack to solid-state hydrogen storage, which can improve system efficiency, effectively save energy, and reduce costs.

[0006] To achieve the above objectives, this invention provides a fuel cell energy management system, including a fuel cell stack, a hydrogen system, an air system, and a cooling system, wherein the fuel cell stack is connected to the hydrogen system, the air system, and the cooling system, respectively.

[0007] The hydrogen system includes a hydrogen storage tank, a solenoid valve, a first turbine, and a first sensor connected in sequence via hydrogen pipelines; the first sensor is connected to the fuel cell stack, and the first turbine is connected to the air system.

[0008] The air system includes an air filter, a second turbine, an intercooler, and a second sensor connected in sequence via air ducts. The second sensor is connected to the fuel cell stack, and the second turbine is coaxially connected to the first turbine.

[0009] In a preferred embodiment, the first sensor includes a first temperature sensor and a first pressure sensor connected together. The first temperature sensor is connected to the first turbine, and the first pressure sensor is connected to the fuel cell stack. This allows for effective monitoring of the pressure and temperature of the hydrogen entering the stack.

[0010] In a preferred embodiment, a pressure reducing valve is provided between the first turbine and the first temperature sensor. This pressure reducing valve allows for further pressure reduction of the hydrogen gas.

[0011] In a preferred embodiment, a bottle neck pressure sensor for detecting the outlet pressure of the hydrogen storage bottle is provided between the hydrogen storage bottle and the solenoid valve.

[0012] In a preferred embodiment, the hydrogen storage cylinder is a solid-state high-pressure composite hydrogen storage cylinder. This allows for the supply of more high-pressure hydrogen, and thus more high-pressure potential energy can be converted.

[0013] In a preferred embodiment, an air flow sensor is provided between the air filter and the second turbine. After being filtered by the air filter, outside air is then pressurized by the second turbocharger and cooled by the intercooler before entering the fuel cell stack.

[0014] In a preferred embodiment, the second sensor includes a second temperature sensor and a second pressure sensor connected together. The second temperature sensor is connected to the intercooler, and the second pressure sensor is connected to the fuel cell stack. This allows for effective monitoring of the pressure and temperature of the air entering the stack.

[0015] In a preferred embodiment, the cooling system includes a first water pump, a first three-way solenoid valve, a heat exchanger, a radiator, and a second water pump connected in sequence; the first water pump is connected to the hydrogen storage tank, and the second water pump is connected to the fuel cell stack.

[0016] In a preferred embodiment, a third temperature sensor is provided between the first water pump and the hydrogen storage tank; and a fourth sensor is provided between the second water pump and the fuel cell stack.

[0017] In a preferred embodiment, the fourth sensor includes a fourth temperature sensor and a fourth pressure sensor connected together. The fourth temperature sensor is connected to the second water pump, and the fourth pressure sensor is connected to the fuel cell stack.

[0018] In a preferred embodiment, the cooling system further includes a first PTC heater, a second three-way solenoid valve, and a second PTC heater; the first PTC heater is connected to the first three-way solenoid valve, the hydrogen storage tank, and the heat exchanger; the second three-way solenoid valve is connected to the heat exchanger, the second PTC heater, and the fuel cell stack; and the second PTC heater is connected to the radiator and the second water pump.

[0019] In a preferred embodiment, a fifth sensor is provided between the hydrogen storage tank and the heat exchanger. The fifth sensor includes a fifth temperature sensor and a fifth pressure sensor connected together. The fifth temperature sensor is connected to the hydrogen storage tank. The fifth pressure sensor is connected to the first PTC heater and the heat exchanger, respectively.

[0020] In a preferred embodiment, a sixth temperature sensor is provided between the second three-way solenoid valve and the fuel cell stack.

[0021] In this embodiment, the cooling system includes a first loop and a second loop. The first loop is mainly used to heat the hydrogen storage tank to ensure cold start and hydrogen supply flow at low temperatures. The coolant in the first loop is pressurized by a first water pump and then enters the first PTC heater or heat exchanger through a first three-way solenoid valve, and then enters the fuel cell stack through the coolant pipeline. The second loop is mainly used to cool the fuel cell stack to ensure normal temperature. The coolant in the second loop passes through a second three-way solenoid valve, then sequentially through the heat exchanger and radiator, or sequentially through the second PTC heater, and then is pressurized by a second water pump before entering the fuel cell stack.

[0022] This application utilizes a turbine drive mechanism formed by coaxially connecting a first turbine and a second turbine. This effectively utilizes the high-pressure potential energy of hydrogen in the storage tank. The high-pressure hydrogen drives the first turbine to rotate, converting the pressure potential energy of the hydrogen into mechanical energy. The rotation of the first turbine then drives the coaxially rotating second turbine, which compresses air, converting the mechanical energy of the second turbine's rotation into the pressure potential energy of the air. This effectively utilizes the high-pressure potential energy of hydrogen to compress air, thereby saving energy and improving system efficiency. By incorporating a heat exchanger, the waste heat generated during the operation of the fuel cell stack can be supplied to the hydrogen storage tank, ensuring a consistent hydrogen supply while effectively reducing the power consumption of the radiator. This application improves system efficiency, effectively saves energy, and reduces costs. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a fuel cell energy management system according to an embodiment of the present invention.

[0025] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, top, bottom, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0028] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0029] It should be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0030] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0031] Currently, in fuel cell systems, high-pressure hydrogen in the hydrogen cylinder of the hydrogen supply system needs to be reduced to about 2 bar through a multi-stage pressure reduction device before entering the fuel cell stack. This process results in a significant loss of pressure potential energy. Furthermore, the air and cooling circuits require additional energy to maintain the inlet pressure of the air (air compressor) and the flow of coolant (water pump), leading to energy waste and hindering comprehensive energy utilization. Therefore, it is necessary to provide a hydrogen fuel cell controller and forklift power system to solve these problems.

[0032] Specifically, such as Figure 1 As shown in the figure, an embodiment of the present invention proposes a fuel cell energy management system, including a fuel cell stack 10, a hydrogen system 20, an air system 30 and a cooling system 40, wherein the fuel cell stack 10 is connected to the hydrogen system 20, the air system 30 and the cooling system 40 respectively.

[0033] The hydrogen system 20 includes a hydrogen storage tank 22, a solenoid valve 23, a first turbine 24 and a first sensor 25 connected in sequence through a hydrogen pipeline 21; the first sensor 25 is connected to the fuel cell stack 10 and the first turbine 24 is connected to the air system 30.

[0034] The air system 30 includes an air filter 32, a second turbine 33, an intercooler 34, and a second sensor 35 connected in sequence through an air duct 31. The second sensor 35 is connected to the fuel cell stack 10, and the second turbine 33 is coaxially connected to the first turbine 24.

[0035] In a preferred embodiment, the first sensor 25 includes a first temperature sensor 251 and a first pressure sensor 252 connected together. The first temperature sensor 251 is connected to the first turbine 24, and the first pressure sensor 252 is connected to the fuel cell stack 10. This allows for effective monitoring of the pressure and temperature of the hydrogen entering the stack.

[0036] In a preferred embodiment, a pressure reducing valve 26 is provided between the first turbine 24 and the first temperature sensor 251. The pressure reducing valve 26 can further reduce the pressure of the hydrogen gas.

[0037] In a preferred embodiment, a bottle mouth pressure sensor 27 for detecting the outlet pressure of the hydrogen storage bottle 22 is provided between the hydrogen storage bottle 22 and the solenoid valve 23.

[0038] In a preferred embodiment, the hydrogen storage cylinder 22 is a solid-state high-pressure composite hydrogen storage cylinder. This allows for the supply of more high-pressure hydrogen, and thus more high-pressure potential energy can be converted.

[0039] In a preferred embodiment, an air flow sensor 36 is provided between the air filter 32 and the second turbine 33. After being filtered by the air filter 32, the outside air is pressurized by the second turbine 33 and cooled by the intercooler 34 before entering the fuel cell stack 10.

[0040] In a preferred embodiment, the second sensor 35 includes a second temperature sensor 351 and a second pressure sensor 352 connected together. The second temperature sensor 351 is connected to the intercooler 34, and the second pressure sensor 352 is connected to the fuel cell stack 10. This allows for effective monitoring of the pressure and temperature of the air entering the stack.

[0041] In a preferred embodiment, the cooling system 40 includes a first water pump 41, a first three-way solenoid valve 42, a heat exchanger 43, a radiator 44, and a second water pump 45 connected in sequence; the first water pump 41 is connected to the hydrogen storage tank 22, and the second water pump 45 is connected to the fuel cell stack 10.

[0042] In a preferred embodiment, a third temperature sensor 221 is provided between the first water pump 41 and the hydrogen storage tank 22; and a fourth sensor 46 is provided between the second water pump 45 and the fuel cell stack 10.

[0043] In a preferred embodiment, the fourth sensor 46 includes a fourth temperature sensor 461 and a fourth pressure sensor 462 connected together. The fourth temperature sensor 461 is connected to the second water pump 45, and the fourth pressure sensor 462 is connected to the fuel cell stack 10.

[0044] In a preferred embodiment, the cooling system 40 further includes a first PTC heater 47, a second three-way solenoid valve 48, and a second PTC heater 49; the first PTC heater 47 is connected to the first three-way solenoid valve 42, the hydrogen storage tank 22, and the heat exchanger 43 respectively; the second three-way solenoid valve 48 is connected to the heat exchanger 43, the second PTC heater 49, and the fuel cell stack 10 respectively; the second PTC heater 49 is connected to the radiator 44 and the second water pump 45 respectively.

[0045] In a preferred embodiment, a fifth sensor 222 is provided between the hydrogen storage tank 22 and the heat exchanger 43. The fifth sensor 222 includes a fifth temperature sensor 2221 and a fifth pressure sensor 2222 connected together. The fifth temperature sensor 2221 is connected to the hydrogen storage tank 22. The fifth pressure sensor 2222 is connected to the first PTC heater 47 and the heat exchanger 43 respectively.

[0046] In a preferred embodiment, a sixth temperature sensor 481 is provided between the second three-way solenoid valve 48 and the fuel cell stack 10.

[0047] In this embodiment, the cooling system includes a first loop and a second loop. The first loop is mainly used to heat the hydrogen storage tank to ensure cold start and hydrogen supply flow at low temperatures. The coolant in the first loop is pressurized by a first water pump and then enters the first PTC heater or heat exchanger through a first three-way solenoid valve, and then enters the fuel cell stack through the coolant pipeline. The second loop is mainly used to cool the fuel cell stack to ensure normal temperature. The coolant in the second loop passes through a second three-way solenoid valve, then sequentially through the heat exchanger and radiator, or sequentially through the second PTC heater, and then is pressurized by a second water pump before entering the fuel cell stack.

[0048] During a cold start of the fuel cell, the hydrogen pressure in the storage tank is first monitored by a pressure sensor at the tank opening. If the pressure is low, the first water pump of the cooling system is activated, and the first three-way solenoid valve is connected to the first PTC heater, which heats the hydrogen storage tank. Once the hydrogen pressure is normal, the solenoid valve of the hydrogen system is opened, and hydrogen flows through the first turbine and is depressurized by a pressure reducing valve before entering the fuel cell stack. The first turbine drives the second turbine to rotate, pressurizing the air and sending it into the fuel cell stack. Simultaneously, the second water pump of the cooling system is activated, and the second three-way solenoid valve is connected to the second PTC heater, allowing the stack temperature to reach normal operating temperature as quickly as possible. The temperature of the coolant is monitored by a fourth and a sixth temperature sensor. Once the coolant reaches normal operating temperature, the first and second three-way solenoid valves are connected to the heat exchanger, shutting off the first and second PTC heaters. Waste heat from the fuel cell stack is then used to heat the high-pressure solid-state composite hydrogen storage device.

[0049] The energy utilization principle of a turbine is as follows:

[0050] Energy losses during an ideal gas throttling and decompression process:

[0051] e L =h1-h2+T0(s2-s1)

[0052] In the formula, h and s are the enthalpy and entropy of hydrogen, respectively, and T0 is the resting temperature, i.e., the ambient temperature. Since the throttling process can be considered an adiabatic process, and the changes in kinetic and potential energy are negligible, h1 = h2. Hydrogen entropy change. Taking a hydrogen storage tank with a pressure of P1 = 35 MPa and a pressure after depressurization of P2 = 0.2 MPa as an example, the calculated value is Δs = 43 J / mol·K, and the usable energy loss is e. L =12814 J / mol.

[0053] Hydrogen inlet flow rate of fuel cell stack:

[0054]

[0055] Given a current I = 430 A, a number of cells n = 330, and a Faraday constant F = 96485 C / mol, Q can be calculated. H2 =1.47 g / s, taking the excess coefficient as 1.8, then Q H2 = 1.323 mol / s.

[0056] Power loss:

[0057] P 损 =Q H2 ·e L =16953J / s =16.95KW

[0058] Referring to the relationship between the power, pressure ratio, and flow rate of relevant air compressors, the energy lost from high-pressure hydrogen can fully meet the requirements for reactor inlet pressure and flow rate.

[0059] Waste heat utilization of the heat exchanger needs to consider the relationship between the heat transferred by the fuel cell coolant through the heat exchanger and the heat required for normal hydrogen supply from the alloy. The hydrogen storage material used in high-pressure solid-state composite hydrogen storage systems is generally a Ti-Cr-Mn-Fe based high-platform hydrogen storage alloy. Taking the hydrogen release enthalpy change of the alloy as ΔH = 20 kJ / mol·H2, and the hydrogen supply flow rate as given above, Q... H2 =1.323mol / s, so the heat required for the alloy to supply hydrogen is 26.46kJ / s.

[0060] Heat generation of fuel cell stack:

[0061]

[0062] ε0 = 1.47V, current I = 430A, single-chip voltage ε cell =0.7V, number of single cells n=330, Q can be calculated. stack =109.26KW, which is far greater than the heat required for the alloy to supply hydrogen, and therefore can meet the heat requirements for the alloy to supply hydrogen.

[0063] This application utilizes a turbine drive mechanism formed by coaxially connecting a first turbine and a second turbine. This effectively utilizes the high-pressure potential energy of hydrogen in the hydrogen storage tank. The high-pressure hydrogen (≥30MPa) drives the first turbine to rotate, converting the pressure potential energy of the hydrogen into mechanical energy. The rotation of the first turbine then drives the coaxially rotating second turbine, which compresses air, converting the mechanical energy of the second turbine's rotation into the pressure potential energy of the air. This effectively utilizes the high-pressure potential energy of hydrogen to compress air, thereby saving energy and improving system efficiency. By incorporating a heat exchanger, the waste heat generated during the operation of the fuel cell stack can be supplied to the hydrogen storage tank, ensuring a consistent hydrogen supply while effectively reducing the power consumption of the radiator. This application improves system efficiency, effectively saves energy, and reduces costs.

[0064] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A fuel cell energy management system, characterized in that, It includes a fuel cell stack, a hydrogen system, an air system, and a cooling system, wherein the fuel cell stack is connected to the hydrogen system, the air system, and the cooling system, respectively. The hydrogen system includes a hydrogen storage tank, a solenoid valve, a first turbine, and a first sensor connected in sequence via hydrogen pipelines; the first sensor is connected to the fuel cell stack, and the first turbine is connected to the air system. The air system includes an air filter, a second turbine, an intercooler, and a second sensor connected in sequence via air ducts. The second sensor is connected to the fuel cell stack, and the second turbine is coaxially connected to the first turbine. The cooling system includes a first water pump, a first three-way solenoid valve, a heat exchanger, a radiator, and a second water pump connected in sequence; the first water pump is connected to the hydrogen storage tank, and the second water pump is connected to the fuel cell stack. The cooling system further includes a first PTC heater, a second three-way solenoid valve, and a second PTC heater; the first PTC heater is connected to the first three-way solenoid valve, the hydrogen storage tank, and the heat exchanger respectively; the second three-way solenoid valve is connected to the heat exchanger, the second PTC heater, and the fuel cell stack respectively; the second PTC heater is connected to the radiator and the second water pump respectively.

2. The fuel cell energy management system according to claim 1, characterized in that, The first sensor includes a first temperature sensor and a first pressure sensor connected together. The first temperature sensor is connected to the first turbine, and the first pressure sensor is connected to the fuel cell stack.

3. The fuel cell energy management system according to claim 2, characterized in that, A pressure reducing valve is provided between the first turbine and the first temperature sensor; A bottle mouth pressure sensor for detecting the outlet pressure of the hydrogen storage bottle is provided between the hydrogen storage bottle and the solenoid valve; the hydrogen storage bottle is a solid high-pressure composite hydrogen storage bottle.

4. The fuel cell energy management system according to claim 1, characterized in that, An air flow sensor is installed between the air filter and the second turbine.

5. The fuel cell energy management system according to claim 1, characterized in that, The second sensor includes a second temperature sensor and a second pressure sensor connected together. The second temperature sensor is connected to the intercooler, and the second pressure sensor is connected to the fuel cell stack.

6. The fuel cell energy management system according to claim 1, characterized in that, A third temperature sensor is installed between the first water pump and the hydrogen storage tank; a fourth sensor is installed between the second water pump and the fuel cell stack. The fourth sensor includes a fourth temperature sensor and a fourth pressure sensor connected together. The fourth temperature sensor is connected to the second water pump, and the fourth pressure sensor is connected to the fuel cell stack.

7. The fuel cell energy management system according to claim 1, characterized in that, A fifth sensor is provided between the hydrogen storage tank and the heat exchanger. The fifth sensor includes a fifth temperature sensor and a fifth pressure sensor connected together. The fifth temperature sensor is connected to the hydrogen storage tank. The fifth pressure sensor is connected to the first PTC heater and the heat exchanger, respectively.

8. The fuel cell energy management system according to claim 1, characterized in that, A sixth temperature sensor is provided between the second three-way solenoid valve and the fuel cell stack.

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