CN114725436A - Control method of fuel cell air system - Google Patents

Control method of fuel cell air system Download PDF

Info

Publication number
CN114725436A
CN114725436A CN202210560766.XA CN202210560766A CN114725436A CN 114725436 A CN114725436 A CN 114725436A CN 202210560766 A CN202210560766 A CN 202210560766A CN 114725436 A CN114725436 A CN 114725436A
Authority
CN
China
Prior art keywords
fuel cell
point
air system
target
control method
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202210560766.XA
Other languages
Chinese (zh)
Other versions
CN114725436B (en
Inventor
李飞强
赵兴旺
李文文
盛有冬
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Sinohytec Co Ltd
Original Assignee
Beijing Sinohytec Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beijing Sinohytec Co Ltd filed Critical Beijing Sinohytec Co Ltd
Priority to CN202210560766.XA priority Critical patent/CN114725436B/en
Publication of CN114725436A publication Critical patent/CN114725436A/en
Application granted granted Critical
Publication of CN114725436B publication Critical patent/CN114725436B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00Fuel cells; Manufacture thereof
    • H01M8/04Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04082Arrangements for control of reactant parameters, e.g. pressure or concentration
    • H01M8/04089Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F17/00Digital computing or data processing equipment or methods, specially adapted for specific functions
    • G06F17/10Complex mathematical operations
    • G06F17/15Correlation function computation including computation of convolution operations
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00Fuel cells; Manufacture thereof
    • H01M8/04Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298Processes for controlling fuel cells or fuel cell systems
    • H01M8/04992Processes for controlling fuel cells or fuel cell systems characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00Fuel cells; Manufacture thereof
    • H01M8/06Combination of fuel cells with means for production of reactants or for treatment of residues
    • H01M8/0662Treatment of gaseous reactants or gaseous residues, e.g. cleaning
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30Hydrogen technology
    • Y02E60/50Fuel cells

Abstract

The invention provides a control method of a fuel cell air system, which is different from the traditional control method for constructing a variable load path based on a steady-state point, but takes the optimal economy as a control target in the dynamic variable load process, and solves the optimal economy dynamic variable load path by solving an objective function or a method based on rules, thereby realizing the optimal economy control of the fuel cell air system.

Description

Control method of fuel cell air system
Technical Field
The invention relates to the field of fuel cells, in particular to a control method of a fuel cell air system.
Background
The air exhaust of the fuel cell system is high-pressure gas, and in order to improve the efficiency of the fuel cell system, an air compressor-expander integrated gas compression and energy recovery scheme is usually adopted, but because the existing air compressor-expander is coaxially designed, when the current is low, the air pressure is low, and the recovery efficiency is poor. During the operation of the fuel cell system, the fuel cell system usually includes a steady-state operation point and a dynamic load variation process, and usually, the dynamic load variation process is generally realized by continuously jumping between discrete steady-state operation points, but the efficiency optimization problem of the dynamic load variation process is not fully considered in this control manner.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a control method of a fuel cell air system, which can realize the economic optimization control of a dynamic variable load process.
The fuel cell air system comprises a flow meter, an air compressor, a fuel cell stack, a pressure regulating valve and an expander; the flow meter and the air compressor are arranged on an air inlet pipe of the fuel cell stack, and the pressure regulating valve and the expander are arranged on an air tail pipe of the fuel cell stack; the expansion machine and the air compressor are coaxially arranged, and the recovered energy is utilized to assist the air compressor to work.
The control method provided by the invention comprises the following steps:
s1: receiving target power, and determining the operating parameters of the air system corresponding to the target power as target points;
s2: judging the number of steady-state points between the target power and the current power; if there are more than two steady-state points, executing step S31, if there is only one steady-state point, executing step S41, if there is no steady-state point, executing step S51;
s31: solving and determining an intermediate point with optimal economy through an objective function optimization algorithm or a rule-based method;
s32: the operation parameters of the air system are changed to the middle point and then changed to the target point;
s41: the operation parameters of the air system are changed to a steady-state point closest to the target power and then changed to a target point;
s51: and directly changing the operating parameters of the air system to target points.
Specifically, the steady-state point referred to in step S2 is a plurality of discrete points calibrated in advance by the fuel cell system, for example, a steady-state point is calibrated every 10kW from 10kW to 100kW, and when the steady-state point is reached, the operating parameters of the fuel cell system are kept constant, such as current density or power, air pressure and flow, hydrogen pressure, water temperatures at the outlet and inlet of the stack, water content in the membrane, and the like, and the voltage can be kept stable for a long time.
The objective function optimization algorithm is to construct an objective function by taking energy consumed by an air compressor and an expander as a target and taking controllability of hydrothermal management inside a fuel cell stack as a boundary condition, and solve an optimal solution of the objective function. Specifically, the objective function is:
Figure 826901DEST_PATH_IMAGE002
wherein J is the energy consumed in the time of Δ t = t1-t0, P (t) is the power consumption P of the air compressorACMPPower consumption P of expansion machineTurboAt time t0, the air compressor is at the initial operating point, and at time t1, the air compressor is at the target point. PACMPAnd PTurboCan be determined according to conventional theoretical formulas or empirical formulas, and the invention is not particularly limited in this regard.
The rule-based method specifically means that an intermediate point with optimal economy is determined on an air compressor MAP by a preset geometric method. Preferably, the geometric method is: and drawing a tangent line of the target parameter equal efficiency line and a perpendicular line from the current parameter to the target parameter equal efficiency line, and taking an intersection point of the tangent line and the perpendicular line as a middle point.
Alternatively, the step S41 solves and determines the most economical intermediate point by an objective function optimization algorithm or a rule-based method; then, step S42 is executed: and (4) the operation parameters of the air system are changed to the middle point and then changed to the target point.
Also alternatively, the step S51 solves and determines the most economical intermediate point by an objective function optimization algorithm or a rule-based method; then, step S52 is executed: and (4) the operation parameters of the air system are changed to the middle point and then changed to the target point. It will be appreciated that the alternative enables further optimisation of the efficiency of the dynamic load change process whilst also adding to some extent the complexity of the system control method.
According to the control method provided by the invention, the fuel cell air system takes the optimal economy as a control target in the dynamic variable load process, and the dynamic variable load path with the optimal economy is obtained by solving an objective function or a rule-based method, so that the economic optimization control of the fuel cell air system is realized.
Drawings
The foregoing and other objects, features and advantages of the disclosure will be apparent from the following more particular descriptions of exemplary embodiments of the disclosure as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the exemplary embodiments of the disclosure.
Fig. 1 shows the basic constitution of a fuel cell air system;
FIG. 2 is a flowchart showing a control method in the embodiment;
fig. 3 shows a dynamic load change path diagram corresponding to the control method in the embodiment.
Description of reference numerals: 1-a flow meter; 2, an air compressor; 3-a dispensing valve; 4-fuel cell stack, 5-pressure regulating valve; 6-expander.
Detailed Description
Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
The term "include" and variations thereof as used herein is meant to be inclusive in an open-ended manner, i.e., "including but not limited to". Unless specifically stated otherwise, the term "or" means "and/or". The term "based on" means "based at least in part on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first," "second," and the like may refer to different or the same object. Other explicit and implicit definitions are also possible below.
Fig. 1 shows the basic configuration of a fuel cell air system. As shown in fig. 1, the fuel cell air system includes a flow meter 1, an air compressor 2, a distribution valve 3, a fuel cell stack 4, a pressure regulating valve 5, and an expander 6.
The flow meter 1, the air compressor 2 and the distribution valve 3 are arranged on an air inlet pipeline of the fuel cell stack 4 and are used for providing air required by electrochemical reaction for the fuel cell stack 4; the pressure regulating valve 5 and the expander 6 are arranged on an air exhaust pipeline of the fuel cell stack 4, and the expander 6 recovers energy by utilizing high-pressure air exhaust exhausted by the fuel cell stack 4 and is coaxially arranged with the air compressor 2.
In addition to the above components, the fuel cell air system generally further includes components such as an intercooler, a humidifier, a gas-liquid separator, and a temperature sensor, a pressure sensor, and the like, and those skilled in the art can configure the components according to actual needs, which is not described in detail herein.
Fig. 2 shows a specific embodiment of the control method of the present invention. As shown in fig. 2, the control method in this embodiment includes the following steps:
s1: receiving target power, and determining the operating parameters of the air system corresponding to the target power as target points;
s2: judging the number of steady-state points between the target power and the current power; if there are more than two steady-state points, executing step S31, if there is only one steady-state point, executing step S41, if there is no steady-state point, executing step S51;
s31: the method for solving and determining the intermediate point with the optimal economy through a rule-based method specifically comprises the following steps: drawing a tangent line of the equal efficiency line where the target point is located and a perpendicular line from the current parameter to the equal efficiency line where the target point is located, and taking an intersection point of the tangent line and the perpendicular line as a middle point;
s32: the operation parameters of the air system are changed to the middle point and then changed to the target point;
s41: the operation parameters of the air system are changed to a steady-state point closest to the target power and then changed to a target point;
s51: and directly changing the operating parameters of the air system to target points.
Fig. 3 illustrates a specific application scenario as an example. Fig. 3 shows a MAP of the air compressor, where n1, n2, n3 represent equal rotational speed lines, and k1, k2, k3 represent equal efficiency lines. In a specific application scenario, there are 2 steady-state points B between the target power and the current power1、B2A-B is usually performed, as per the control method in the prior art1-B2-a load change path of C. According to the control method provided in the above embodiment, since there are two stable points, step S31 is performed, the intermediate point D is determined by the intersection of the tangent and the perpendicular, and then the load is changed from the current point a to the intermediate point D and then to the target point C in step S32.
Having described embodiments of the present disclosure, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein were chosen in order to best explain the principles of the embodiments, the practical application, or technical improvements to the techniques in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (7)

1. A control method of a fuel cell air system is characterized in that the fuel cell air system comprises a flow meter, an air compressor, a fuel cell stack, a pressure regulating valve and an expander; the flow meter and the air compressor are arranged on an air inlet pipe of the fuel cell stack, and the pressure regulating valve and the expander are arranged on an air tail pipe of the fuel cell stack; the expansion machine and the air compressor are coaxially arranged, and the recovered energy is utilized to assist the air compressor to work;
the control method comprises the following steps:
s1: receiving target power, and determining the operating parameters of the air system corresponding to the target power as target points;
s2: judging the number of steady-state points between the target power and the current power; if there are more than two steady-state points, executing step S31, if there is only one steady-state point, executing step S41, if there is no steady-state point, executing step S51;
s31: solving and determining an intermediate point with optimal economy through an objective function optimization algorithm or a rule-based method;
s32: the operation parameters of the air system are changed to the middle point and then changed to the target point;
s41: the operation parameters of the air system are changed to a steady-state point closest to the target power and then changed to a target point;
s51: and directly changing the operating parameters of the air system to target points.
2. The control method of the fuel cell air system according to claim 1, wherein the objective function optimization algorithm is to construct an objective function by taking energy consumed by the air compressor and the expander as an objective and taking controllability of hydrothermal management inside the fuel cell stack as a boundary condition, and solve an optimal solution of the objective function.
3. The fuel cell air system control method according to claim 2, wherein the objective function is:
Figure DEST_PATH_IMAGE002
wherein J is the energy consumed in the time of Δ t = t1-t0, P (t) is the power consumption P of the air compressorACMPPower consumption P of expansion machineTurboWherein the air compressor is located at the initial operation point at time t0, and the air compressor is located at the target point at time t 1.
4. The fuel cell air system control method according to claim 1, wherein the rule-based method is to determine an economically optimal intermediate point on an air compressor MAP by a predetermined geometric method.
5. The fuel cell air system control method according to claim 4, characterized in that the geometric method is: and drawing a tangent line of the equal efficiency line where the target point is located and a perpendicular line from the current parameter to the equal efficiency line where the target point is located, and taking the intersection point of the tangent line and the perpendicular line as a middle point.
6. The fuel cell air system control method according to claim 1, wherein the step S41 is to determine an economically optimal intermediate point by solving an objective function optimization algorithm or a rule-based method; then, step S42 is executed: and (4) the operation parameters of the air system are changed to the middle point and then changed to the target point.
7. The fuel cell air system control method according to claim 1, wherein the step S51 is to determine an economically optimal intermediate point by solving an objective function optimization algorithm or a rule-based method; then, step S52 is executed: and (4) the operation parameters of the air system are changed to the middle point and then changed to the target point.
CN202210560766.XA 2022-05-23 2022-05-23 Control method of fuel cell air system Active CN114725436B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210560766.XA CN114725436B (en) 2022-05-23 2022-05-23 Control method of fuel cell air system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210560766.XA CN114725436B (en) 2022-05-23 2022-05-23 Control method of fuel cell air system

Publications (2)

Publication Number Publication Date
CN114725436A true CN114725436A (en) 2022-07-08
CN114725436B CN114725436B (en) 2023-10-10

Family

ID=82231183

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210560766.XA Active CN114725436B (en) 2022-05-23 2022-05-23 Control method of fuel cell air system

Country Status (1)

Country Link
CN (1) CN114725436B (en)

Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6051192A (en) * 1997-04-15 2000-04-18 International Fuel Cells Corporation Control system and method for controlling a gas generating system
JP2001355588A (en) * 2000-06-12 2001-12-26 Hitachi Ltd Power recovery scroll fluid machine and fuel cell system using it
JP2002209306A (en) * 2001-01-12 2002-07-26 Nissan Motor Co Ltd Fuel cell vehicle control system, and controlling method
JP2002310081A (en) * 2001-04-12 2002-10-23 Hitachi Ltd Screw type fluid machine for fuel cell
US20020164515A1 (en) * 2001-05-04 2002-11-07 Oglesby Keith Andrew System and method for supplying air to a fuel cell for use in a vehicle
JP2003120542A (en) * 2001-10-10 2003-04-23 Nissan Motor Co Ltd Air supplying device
US20040253489A1 (en) * 2003-06-12 2004-12-16 Horgan Thomas J. Technique and apparatus to control a fuel cell system
US20050014045A1 (en) * 2003-07-17 2005-01-20 Rolf Schaller Thermal integration of pressurized fuel cell systems with expander
JP2009257119A (en) * 2008-04-14 2009-11-05 Kobe Steel Ltd Steam expander driven air compression apparatus
CN102939679A (en) * 2010-06-12 2013-02-20 戴姆勒股份公司 Fuel cell system having fuel cell arranged in housing
JP2019033046A (en) * 2017-08-09 2019-02-28 トヨタ自動車株式会社 Fuel cell system
US20190123367A1 (en) * 2017-10-20 2019-04-25 Toyota Jidosha Kabushiki Kaisha Fuel cell system and control method of fuel cell system
CN110957505A (en) * 2019-11-25 2020-04-03 中国第一汽车股份有限公司 Control method of multi-mode fuel cell system
CN113964406A (en) * 2021-10-29 2022-01-21 北京亿华通科技股份有限公司 Testing device and testing method of expander for fuel cell
CN114122454A (en) * 2021-11-25 2022-03-01 上海捷氢科技股份有限公司 Fuel cell and air supply system thereof
CN114284531A (en) * 2021-11-15 2022-04-05 电子科技大学 Multi-stack hybrid energy management method based on distributed consistency optimization algorithm
CN114388843A (en) * 2022-03-23 2022-04-22 中山大洋电机股份有限公司 Fuel cell system and control method

Patent Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6051192A (en) * 1997-04-15 2000-04-18 International Fuel Cells Corporation Control system and method for controlling a gas generating system
JP2001355588A (en) * 2000-06-12 2001-12-26 Hitachi Ltd Power recovery scroll fluid machine and fuel cell system using it
JP2002209306A (en) * 2001-01-12 2002-07-26 Nissan Motor Co Ltd Fuel cell vehicle control system, and controlling method
JP2002310081A (en) * 2001-04-12 2002-10-23 Hitachi Ltd Screw type fluid machine for fuel cell
US20020164515A1 (en) * 2001-05-04 2002-11-07 Oglesby Keith Andrew System and method for supplying air to a fuel cell for use in a vehicle
JP2003120542A (en) * 2001-10-10 2003-04-23 Nissan Motor Co Ltd Air supplying device
US20040253489A1 (en) * 2003-06-12 2004-12-16 Horgan Thomas J. Technique and apparatus to control a fuel cell system
US20050014045A1 (en) * 2003-07-17 2005-01-20 Rolf Schaller Thermal integration of pressurized fuel cell systems with expander
JP2009257119A (en) * 2008-04-14 2009-11-05 Kobe Steel Ltd Steam expander driven air compression apparatus
CN102939679A (en) * 2010-06-12 2013-02-20 戴姆勒股份公司 Fuel cell system having fuel cell arranged in housing
JP2019033046A (en) * 2017-08-09 2019-02-28 トヨタ自動車株式会社 Fuel cell system
US20190123367A1 (en) * 2017-10-20 2019-04-25 Toyota Jidosha Kabushiki Kaisha Fuel cell system and control method of fuel cell system
CN110957505A (en) * 2019-11-25 2020-04-03 中国第一汽车股份有限公司 Control method of multi-mode fuel cell system
CN113964406A (en) * 2021-10-29 2022-01-21 北京亿华通科技股份有限公司 Testing device and testing method of expander for fuel cell
CN114284531A (en) * 2021-11-15 2022-04-05 电子科技大学 Multi-stack hybrid energy management method based on distributed consistency optimization algorithm
CN114122454A (en) * 2021-11-25 2022-03-01 上海捷氢科技股份有限公司 Fuel cell and air supply system thereof
CN114388843A (en) * 2022-03-23 2022-04-22 中山大洋电机股份有限公司 Fuel cell system and control method

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
AHLUWALIA等: "Achieving 5,000-h and 8,000-h Low-PGM Electrode Durability on Automotive Drive Cycles", 《JOURNAL OF THE ELECTROCHEMICAL SOCIETY》, vol. 168, no. 4, pages 044518 *
ZHE WANG等: "Energy, exergy and economy (3E) investigation of a SOFC-GT-ORC waste heat recovery system for green power ships", 《THERMAL SCIENCE AND ENGINEERING PROGRESS 》, vol. 32, pages 101342 *
冯霄等: "考虑经济性的功量交换网络的最优匹配", 《清华大学学报 自然科学版》, vol. 52, no. 3, pages 298 - 302 *
应天杏: "基于功率需求预测的燃料电池汽车能量管理自适应控制策略研究", 《中国优秀硕士学位论文全文数据库 (工程科技Ⅱ辑)》, no. 1, pages 035 - 891 *
陈会翠等: "质子交换膜(PEM)燃料电池变载过程动态模型", 《清华大学学报 (自然科学版)》, vol. 54, no. 10, pages 1298 - 1303 *

Also Published As

Publication number Publication date
CN114725436B (en) 2023-10-10

Similar Documents

Publication Publication Date Title
US7824815B2 (en) Fuel cell system
US10305127B2 (en) Wet state control method for fuel cell system and wet state control device for the same
Bakalis et al. Optimization methodology of turbomachines for hybrid SOFC–GT applications
CN100527508C (en) Fuel cell system and liquid discharging method for the same
CN108091909A (en) It is a kind of based on optimal peroxide than fuel battery air flow control methods
JP4185671B2 (en) Control device for fuel cell system
KR20190072910A (en) Control method and control system of hydrogen purging
KR102316963B1 (en) Fuel cell system
US7718287B2 (en) Compact anode flow shift design for small fuel cell vehicles
EP3333952B1 (en) Fuel cell system and method of operating fuel cell system
CN114725436B (en) Control method of fuel cell air system
CN115020758A (en) Fuel cell system, and cathode energy recovery control method and device
EP1422777A1 (en) Fuel cell system detecting and controlling the H2-concentration in the exhaust gas
US11152633B2 (en) Fuel cell system and method of controlling the same
US20190372140A1 (en) Fuel cell system
CN115050996B (en) Air supply method and air supply system for fuel cell
CN101170186A (en) An adjusting system for air supply of fuel battery system
US11705565B2 (en) Fuel cell system
CN103459786A (en) Vessel's power generation system
Quan et al. A hierarchical predictive strategy-based hydrogen stoichiometry control for automotive fuel cell power system
CN113659169B (en) Fuel cell engine and cold start system and method thereof
JP6245128B2 (en) Purge interval determination device for fuel cell system
JP2007234311A (en) Fuel cell system
CN216054820U (en) Fuel cell system
Chen et al. Efficiency improvement and Thermo-economic analysis of proton exchange membrane fuel cell system with energy recovery for both air and hydrogen

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant