CN115810773B - Method, device, medium, equipment and fuel cell for estimating humidity of humidifier - Google Patents
Method, device, medium, equipment and fuel cell for estimating humidity of humidifier Download PDFInfo
- Publication number
- CN115810773B CN115810773B CN202310065514.4A CN202310065514A CN115810773B CN 115810773 B CN115810773 B CN 115810773B CN 202310065514 A CN202310065514 A CN 202310065514A CN 115810773 B CN115810773 B CN 115810773B
- Authority
- CN
- China
- Prior art keywords
- water vapor
- partial pressure
- dry side
- humidifier
- dry
- 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.)
- Active
Links
Images
Classifications
-
- Y—GENERAL 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Landscapes
- Fuel Cell (AREA)
- Air Humidification (AREA)
Abstract
In the humidity estimation method, the device, the medium, the equipment and the fuel cell of the humidifier, the humidifier comprises a diaphragm, wherein the diaphragm is used for diffusing water vapor from a wet side to a dry side of the humidifier; the wet side of the humidifier comprises a wet side inlet, the dry side of the humidifier comprises a dry side outlet, the first water vapor partial pressure of the wet side inlet, the gas parameter of the dry side and the material parameter of the diaphragm are obtained, and the third water vapor partial pressure of the position of the dry side outlet is determined based on the parameters, so that the air humidity of the position is estimated under the condition that the position of the dry side outlet is detected without directly using a humidity sensor.
Description
Technical Field
The present invention relates to the field of fuel cells, and in particular, to a method, an apparatus, a medium, a device, and a fuel cell for estimating humidity of a humidifier.
Background
A fuel cell is a chemical device that directly converts chemical energy of fuel into electric energy, and is also called an electrochemical generator. The fuel cell stack uses fuel and oxygen as raw materials, and has no mechanical transmission parts, so the fuel cell stack has the advantages of high energy conversion efficiency, zero emission, long service life and the like.
The proton exchange membrane in the electric pile needs to be continuously moisturized by the water vapor to work normally, so the fuel cell also usually comprises a humidifier for adjusting the humidity of the gas entering the electric pile, and the actual moisturizing effect of the humidifier has a great influence on the performance and the service life of the fuel cell.
However, the stack gas inlet position is in a high-temperature and high-humidity humid environment, and a humidity sensor (or dew point sensor) for directly measuring the air humidity has difficulty in reliably operating there for a long period of time.
Disclosure of Invention
In order to overcome at least one of the shortcomings in the prior art, the present application provides a method, an apparatus, a medium, a device and a fuel cell for estimating humidity of air entering a stack from a humidifier indirectly, comprising:
in a first aspect, the present application provides a method of estimating humidity of a humidifier, the humidifier comprising a membrane for diffusing water vapor from a wet side to a dry side of the humidifier; the wet side of the humidifier including a wet side inlet, the dry side of the humidifier including a dry side outlet, the method comprising:
acquiring a first water vapor partial pressure of the wet side inlet, a material parameter of the diaphragm and a gas parameter of the dry side;
and obtaining a third water vapor partial pressure of the dry side outlet according to the first water vapor partial pressure, the material parameter and the gas parameter.
By adopting the method, the first water vapor partial pressure of the wet side inlet of the humidifier, the material parameters of the diaphragm and the gas parameters of the dry side are utilized to determine the third water vapor partial pressure of the dry side outlet position, so that the air humidity of the dry side outlet position is estimated under the condition that the dry side outlet position is not directly detected by a humidity sensor.
As an optional implementation manner of the first aspect, the dry side of the humidifier further includes a dry side inlet, the gas parameter includes a total gas pressure of the dry side, a gas flow rate of the dry side, and a second water vapor partial pressure of the dry side inlet, and the obtaining, according to the first water vapor partial pressure, the material parameter, and the gas parameter, a third water vapor partial pressure of the dry side outlet includes:
and obtaining a third water vapor partial pressure of the dry side outlet according to the first water vapor partial pressure, the total air pressure, the air flow, the second water vapor partial pressure and the material parameter, wherein the pressure difference between the third water vapor partial pressure and the second water vapor partial pressure is positively correlated with the water diffusion flux diffused to the dry side.
In this implementation, the third water vapor partial pressure of the dry side outlet is indirectly solved based on a positive correlation between a pressure difference between the third water vapor partial pressure and the second water vapor partial pressure and a water diffusion flux that diffuses to the dry side.
As an alternative embodiment of the first aspect, the material parameter includes a diffusion rate of the membrane, a thickness of the membrane, and an area of the membrane.
In this implementation, the above parameters related to the diffusion flux are utilized to improve the accuracy of the calculation of the diffusion flux.
As an alternative implementation of the first aspect, the first water vapour partial pressure, the total gas pressure, the gas flow, the second water vapour partial pressure and the relation between the material parameter and the third water vapour partial pressure satisfy the following relation:
in the method, in the process of the invention,
representing a target diffusion rate of the membrane, +.>
Representing the area of the membrane, +.>
Represents the thickness of the membrane, < >>
Indicating said first water vapor partial pressure, +.>
Representing said third water vapor partial pressure, +.>
Representing the gas flow of the dry side, +.>
Indicating the total air pressure of the dry side, +.>
Representing the second partial pressure of water vapor.
In this implementation, a mathematical relationship is established between the first water vapor partial pressure, the total gas pressure, the gas flow, the second water vapor partial pressure, and the parameters such as the material parameter and the third water vapor partial pressure, so that the directly measured parameters are substituted into the above expression, and the third water vapor partial pressure as the unknown quantity is solved.
As an alternative implementation of the first aspect, the target diffusion rate of the membrane is an average diffusion rate of the membrane at a plurality of locations;
the average diffusion rate and the diffusion rate of the reference position of the diaphragm meet the preset proportional relation.
In this implementation, since diffusion rates of different positions of the diaphragm are different, the average diffusion rate is taken as the diffusion rate of all positions of the diaphragm to simplify the calculation process.
As an optional implementation manner of the first aspect, the obtaining the first water vapor partial pressure of the wet side inlet includes:
acquiring a target dew point of the wet side inlet;
and taking the target water vapor partial pressure matched with the target dew point as the first water vapor partial pressure of the wet side inlet according to the mapping relation between the dew point and the water vapor partial pressure.
In this implementation, the water vapor partial pressure at the wet side inlet position is indirectly measured using the mapping relationship between the dew point and the water vapor partial pressure.
As an optional implementation manner of the first aspect, the gas introduced by the dry side inlet is derived from an atmospheric environment, and the obtaining the second water vapor partial pressure of the dry side inlet includes:
acquiring the water vapor content in the atmosphere;
and determining a second water vapor partial pressure of the dry side inlet according to the water vapor content and the total air pressure of the dry side.
In this implementation, the second partial pressure of water vapor at the dry side inlet is determined indirectly from the atmospheric pressure using the relationship between the water vapor content and the partial pressure of water vapor.
In a second aspect, the present application provides a humidity estimation device for a humidifier comprising a membrane for diffusing water vapor from a wet side to a dry side of the humidifier; the wet side of the humidifier including a wet side inlet, the dry side of the humidifier including a dry side outlet, the apparatus including;
a parameter acquisition module for acquiring a first water vapor partial pressure of the wet side inlet, a material parameter of the diaphragm, and a gas parameter of the dry side;
and the partial pressure calculation module is used for obtaining a third partial pressure of the water vapor at the dry side outlet according to the first partial pressure of the water vapor, the material parameter and the gas parameter.
By adopting the method, the first water vapor partial pressure of the wet side inlet of the humidifier, the material parameters of the diaphragm and the gas parameters of the dry side are utilized to determine the third water vapor partial pressure of the dry side outlet position, so that the air humidity of the dry side outlet position is estimated under the condition that the dry side outlet position is not directly detected by a humidity sensor.
As an optional implementation manner of the second aspect, the dry side of the humidifier further includes a dry side inlet, the gas parameter includes a total gas pressure of the dry side, a gas flow rate of the dry side, and a second water vapor partial pressure of the dry side inlet, and the partial pressure calculating module obtains a third water vapor partial pressure of the dry side outlet according to the first water vapor partial pressure, the material parameter and the gas parameter, where the method includes:
determining a third water vapor partial pressure of the dry side outlet from the first water vapor partial pressure, the total gas pressure of the dry side, the gas flow of the dry side, the second water vapor partial pressure, and the material parameter, wherein a pressure difference between the third water vapor partial pressure and the second water vapor partial pressure is positively correlated with a water diffusion flux that diffuses to the dry side.
In this implementation, the third water vapor partial pressure of the dry side outlet is indirectly solved based on a positive correlation between a pressure difference between the third water vapor partial pressure and the second water vapor partial pressure and a water diffusion flux that diffuses to the dry side.
As an alternative embodiment of the second aspect, the material parameter includes a diffusion rate of the membrane, a thickness of the membrane, and an area of the membrane.
In this implementation, the above parameters related to the diffusion flux are utilized to improve the accuracy of the calculation of the diffusion flux.
As an alternative implementation of the first aspect, the first water vapour partial pressure, the total gas pressure, the gas flow, the second water vapour partial pressure and the relation between the material parameter and the third water vapour partial pressure satisfy the following relation:
in the method, in the process of the invention,
representing a target diffusion rate of the membrane, +.>
Representing the area of the membrane, +.>
Represents the thickness of the membrane, < >>
Indicating said first water vapor partial pressure, +.>
Representing said third water vapor partial pressure, +.>
Representing the gas flow of the dry side, +.>
Indicating the total air pressure of the dry side, +.>
Representing the second partial pressure of water vapor.
In this implementation, a mathematical relationship is established between the first water vapor partial pressure, the total gas pressure, the gas flow, the second water vapor partial pressure, and the parameters such as the material parameter and the third water vapor partial pressure, so that the directly measured parameters are substituted into the above expression, and the third water vapor partial pressure as the unknown quantity is solved.
As an alternative embodiment of the second aspect, the target diffusion rate of the membrane is an average diffusion rate of the membrane at a plurality of locations;
the average diffusion rate and the diffusion rate of the reference position of the diaphragm satisfy a preset proportional relationship, wherein the reference position is close to the wet-side inlet.
In this implementation, since diffusion rates of different positions of the diaphragm are different, the average diffusion rate is taken as the diffusion rate of all positions of the diaphragm to simplify the calculation process.
As an optional implementation manner of the second aspect, the manner in which the parameter obtaining module obtains the first water vapor partial pressure of the wet side inlet includes:
acquiring a target dew point of the wet side inlet;
and taking the target water vapor partial pressure matched with the target dew point as the first water vapor partial pressure of the wet side inlet according to the mapping relation between the dew point and the water vapor partial pressure.
In this implementation, the water vapor partial pressure at the wet side inlet position is indirectly measured using the mapping relationship between the dew point and the water vapor partial pressure.
As an optional implementation manner of the second aspect, the gas introduced by the dry side inlet is derived from an atmospheric environment, and the mode of obtaining the second water vapor partial pressure of the dry side inlet by the parameter obtaining module includes:
acquiring the water vapor content in the atmosphere;
and determining a second water vapor partial pressure of the dry side inlet according to the water vapor content and the total air pressure of the dry side.
In this implementation, the second partial pressure of water vapor at the dry side inlet is determined indirectly from the atmospheric pressure using the relationship between the water vapor content and the partial pressure of water vapor.
In a third aspect, the present application provides a computer readable storage medium storing a computer program which, when executed by a processor, implements the method of estimating humidity of a humidifier.
In a fourth aspect, the present application provides a control apparatus, the control apparatus comprising a processor and a memory, the memory storing a computer program which, when executed by the processor, implements the method of estimating humidity of a humidifier.
In a fifth aspect, the present application provides a fuel cell comprising a humidifier, a stack, and the control apparatus.
The technical solutions provided in the third, fourth and fifth aspects of the present application may refer to the beneficial effects of the technical solution in the first aspect, and are not described herein again.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of a fuel cell structure according to an embodiment of the present disclosure;
FIG. 2 is a schematic diagram of a membrane property analysis provided in an embodiment of the present application;
FIG. 3 is a schematic diagram of the relationship between partial pressures of water vapor on two sides of a diaphragm according to an embodiment of the present disclosure;
FIG. 4 is a schematic flow chart of a method according to an embodiment of the present disclosure;
FIG. 5 is a graph showing the relationship between the diffusion rate and the position of a diaphragm according to an embodiment of the present disclosure;
fig. 6 is a schematic structural diagram of a virtual device according to an embodiment of the present application;
fig. 7 is a schematic structural diagram of a control device according to an embodiment of the present application.
Icon: 101-a humidifier; 102-pile; 103-a membrane; 104-wet side inlet; 105-wet side outlet; 106-dry side inlet; 107-dry side outlet; 108-proton exchange membrane; 201-a parameter acquisition module; 202-a partial pressure calculation module; 301-memory; 302-a processor; 303-a communication unit; 304-a system bus.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
In the description of the present application, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships that are conventionally put in use of the inventive product, are merely for convenience of description of the present application and simplification of description, and do not indicate or imply that the apparatus or element to be referred to must have a specific direction, be configured and operated in a specific direction, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
Furthermore, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Based on the above statement, in order to make the embodiments of the present application more clear, the operation of the fuel cell will be exemplified with reference to fig. 1. In order to ensure the stability of long-term operation of the fuel cell, the proton exchange membrane 108 currently used in the stack 102 of the fuel cell needs to be kept wet by water vapor continuously during operation, because only hydrated protons can freely pass through the proton exchange membrane 108 to reach the electrode cathode end from the electrode anode end to participate in electrochemical reaction.
Otherwise, when a large amount of dry air enters and leaves the stack 102, water molecules in the proton exchange membrane 108 are easily taken away, so that protons cannot smoothly pass through the proton exchange membrane 108, and then the internal resistance of the electrode is increased sharply, and the battery performance is reduced sharply; therefore, the air supplied to the fuel cell generally needs to be humidified to increase the relative humidity of the air entering the interior of the stack 102 so as not to dehydrate the proton exchange membrane 108.
As further shown in fig. 1, the related art may be used to maintain the humidity of the gas entering the inside of the stack 102 by externally connecting a corresponding humidifier 101 at the air inlet position of the stack 102. The humidifier 101 includes a membrane 103 dividing the humidifier 101 into a wet side and a dry side, and water vapor on the wet side in the humidifier 101 diffuses through the membrane to the dry side to humidify the air on the dry side. In some embodiments, the membrane 103 may be made of membrane tube material for convenience in controlling the water vapor flux through the membrane.
Continuing with fig. 1, the wet side of humidifier 101 includes wet side outlet 105 and wet side inlet 104 connected to the drain of stack 102; while the dry side of humidifier 101 includes a dry side inlet 106 and a dry side outlet 107. In this way, the steam generated when the stack 102 operates is made to enter the humidifier 101 through the wet side inlet 104, wherein a part of the steam entering the wet side is diffused to the dry side of the humidifier 101 through the diaphragm 103, and the other part of the steam is discharged out of the humidifier 101 through the wet side outlet 105.
The dry side inlet 106 of the dry side of the humidifier 101 communicates with the atmosphere and the dry side outlet 107 communicates with the air inlet of the stack 102. Thus, a portion of the water vapor entering the stack 102 is from the atmospheric environment, and another portion is from the water vapor diffusing from the wet side to the dry side of the humidifier 101.
Therefore, based on the structure shown in fig. 1, in order to enable the electric pile 102 to be in a better stable state for continuous operation, the humidity information of the position of the dry side outlet 107 can be obtained, and when the humidity actually entering the electric pile 102 is detected to be too low, corresponding adjustment can be performed in time to raise the air humidity of the dry side, so that the humidity of the dry side outlet 107 is restored to be within a proper range; similarly, when the humidity actually entering the pile 102 is detected to be too high, corresponding adjustment can be timely performed to reduce the air humidity of the dry side, so that the humidity of the dry side outlet 107 is restored to be in a proper range, and reliable operation of the pile 102 is protected.
In addition, in some embodiments, after detecting that the humidity drops to a certain extent according to the humidity of the position of the dry side outlet 107, relevant faults can be timely identified, so as to remind maintenance personnel to check and repair, and avoid larger losses caused by further expanding the faults.
Currently, in the phase technology for detecting the humidity of the air entering the electric pile 102, a humidity sensor (or dew point sensor) is directly arranged at the position of the dry side outlet 107, and the humidity of the air entering the electric pile 102 is obtained by the humidity sensor; however, the position of the dry side outlet 107 is in a high-temperature and high-humidity environment for a long time, the existing humidity sensor is difficult to work normally for a long time in the environment, and the price of the humidity sensor is expensive; accordingly, it is desirable to provide a method for indirectly estimating the humidity of the gas at the dry side outlet 107.
It should be noted that the above prior art solutions have all the drawbacks that the inventors have obtained after practice and careful study, and thus the discovery process of the above problems and the solutions to the problems that the embodiments of the present application hereinafter propose should not be construed as what the inventors have made in the invention creation process to the present application, but should not be construed as what is known to those skilled in the art.
In view of this, the present embodiment provides a humidity estimation method of a humidifier. In the method, a mathematical model is established on the wet and dry side outlet position of the humidifier based on the conclusion that the difference of the partial pressures of water vapor at any position of the diaphragm in the humidifier is approximately equal, so that the air humidity at the dry side outlet position is indirectly estimated.
The method can be applied to a control device of the fuel cell, wherein the control device can be an electronic device integrated with the fuel cell for controlling the normal operation of the fuel cell or a central control device on an electric vehicle carrying the fuel cell.
Based on the above related description, since this embodiment uses the conclusion that the difference of the partial pressures of water vapor at two sides of any position of the diaphragm in the humidifier is approximately equal, in order to make the technical solution of this embodiment more clear, before describing the humidity estimation method of the humidifier in detail, an inference process of this conclusion is provided:
firstly, the humidifier is taken as a whole, and the substance exchange process carried out on the dry side and the wet side of the humidifier mainly comprises the steps that the vapor on the wet side passes through a diaphragm made of water-permeable and air-impermeable materials such as a membrane tube and the like in the humidifier, and the diffusion transmission of the vapor is carried out under the drive of the partial pressure difference of the water on the two sides. Thus, according to the phillips law, the water diffusion flux across the membrane material of the humidifier
The method comprises the following steps:
in the method, in the process of the invention,
representing the diffusion coefficient of the membrane, +.>
Represents the partial pressure of water vapor on the wet side, +.>
Represents the water vapor partial pressure on the dry side, +.>
Representing the area of the diaphragm, +.>
The thickness of the separator is shown.
It should be understood herein that the air humidity includes three basic expressions of water vapor pressure, relative humidity, dew point temperature, and the present embodiment selects water vapor pressure as a measure of air humidity. Wherein the gas component in the air comprises oxygen, nitrogen, water vapor, carbon dioxide and the like; the water pressure, also known as the water vapor partial pressure, represents the portion of the air overall pressure that is generated by the water vapor.
Next, as shown in fig. 1, the flow direction of the gas on the wet side enters from the wet side inlet 104 near the stack 102, flows through the wet side of the humidifier 101, and then flows out from the wet side outlet 105 far from the stack 102; and the gas flow direction on the dry side enters away from the dry side inlet 106 of the stack 102, flows through the dry side of the humidifier 101, and then flows out from the dry side outlet close to the stack 102. Therefore, the gas flow direction on the dry side and the gas flow direction on the wet side inside the humidifier 101 are opposite to each other.
During the study, it was found that the pressure drop of the gas inside the humidifier 101 was small when it flowed through the dry or wet side of the humidifier 101, and the gas pressure on the dry side could be considered
And gas pressure on the wet side->
Each being substantially stable during flow on both wet and dry sides.
Based on the above findings, as shown in fig. 2, 3 minute segments of equal length and successively adjacent positions were arbitrarily cut from the separator in the gas flow direction for analysis. Selecting the wet side of the humidifier in the figure as a reference, and distributing serial numbers of 1-3 to three micro segments along the gas flow direction of the wet side, wherein the water vapor partial pressures of the three micro segments on the wet side of the humidifier are respectively expressed as
The method comprises the steps of carrying out a first treatment on the surface of the On the dry side of the humidifier, the partial pressure of water vapor at the corresponding positions of the three micro-segments is expressed as +.>
。
According to Phak's law, the water transport flux of the 2 nd micro-segment diffused to the dry side can be obtained
The method comprises the following steps:
in the method, in the process of the invention,
represents the diffusion coefficient of the 2 nd micro-segment, ">
Represents the area of the 2 nd micro-segment, +.>
Represents the membrane thickness of the 2 nd micro-segment, < >>
Represents the partial pressure of water vapor on the wet side of the 2 nd micro-segment,/-, and>
the water vapor partial pressure of the 2 nd minute fragment on the dry side is shown.
Further, it is assumed that the humidifier is divided in the direction of water vapor diffusion from the position of the 2 nd minute section to obtain the humidifier section corresponding to the 2 nd minute section, and the gas flow rate on the wet side of the section is assumed to be
The gas flow on the dry side is +.>
The method comprises the steps of carrying out a first treatment on the surface of the According to the law of conservation of mass, the section of the humidifier corresponding to the 3 rd micro segment can be obtained, and the gas flow rate at the wet side is as follows:
the humidifier section corresponding to the 1 st micro segment has the dry side gas flow rate of:
the above-mentioned pressures on the wet and dry sides are substantially stable, and the partial pressure of water vapor in the adjacent section to the wet side of the 2 nd minute section
Can be further expressed as:
in the method, in the process of the invention,
represents the water vapor partial pressure of the 3 rd micro segment on the wet side,/>
Indicating the total gas pressure of the wet side gas,
the flow of gas representing the corresponding section of the 2 nd minute section on the wet side, (-)>
Represents the partial pressure of water vapor of the 2 nd micro-segment on the wet side,/>
Water transport flux indicating diffusion of the 2 nd micro-segment to the dry side, < >>
Indicating the water vapor content in the gas flow.
Further, consider the water transport flux of the 2 nd micro-segment diffusing to the dry side
Is far below the order of +.>
The above formula can be simplified as:
based on the same reasoning as above, the water vapor partial pressure of the 3 rd micro segment on the dry side can be obtained:
further, considering that the ratio of the pressure to the flow rate of the fuel cell cathode system stack in and stack out is close (pressure/flow rate), that is, in the above expression
And->
Proximity, therefore, assume
The->
The expression of (2) can be further reduced to:
also because the 3 micro-segments are very close in spatial position, this means that the water diffusion flux at the position where the 3 micro-segments are located
Approaching equality, the above-mentioned relation +.>
The two expressions can be further transformed into:
water diffusion flux according to the positions of 3 micro-fragments
Approaching equality conditions, further reduces to:
the physical meaning of the expression is that the pressure difference of the water vapor partial pressure at the two sides of the 3 rd micro segment is equal to the water vapor partial pressure at the two sides of the 2 nd micro segment. Thus, as shown in fig. 3, the difference in partial pressure of water vapor across the membrane at any position in the humidifier is approximately equal.
Based on the conclusion that the difference of the partial pressures of the water vapor at the two sides of the membrane at any position in the humidifier is approximately equal, the embodiment selects the first partial pressure of the water vapor at the wet side inlet and the third partial pressure of the water vapor at the dry side outlet as the partial pressures of the water vapor at the two sides of the whole membrane, and provides the following embodiments of the humidity estimation method of the humidifier. The steps of the method are described in detail below in conjunction with fig. 4, the method comprising:
s101, acquiring a first water vapor partial pressure of a wet side inlet, material parameters of a diaphragm and gas parameters of a dry side.
It will be appreciated that since the partial pressure of water vapor at the dry side outlet location is correlated to the water diffusion flux that diffuses through the membrane to the dry side, it is embodied that the water diffusion flux is positively correlated to the partial pressure of water vapor at the dry side outlet location; and the material parameters affecting the water diffusion flux include the diffusion rate of the membrane, the thickness of the membrane, and the area of the membrane; the diffusion rate of the diaphragm is determined by the material characteristics of the diaphragm pipe material of the diaphragm, and the larger the diffusion rate is, the better the diffusion effect of the diaphragm is. On this basis, the area and thickness of the membrane also affect the diffusion effect of the water vapor.
S102, obtaining a third water vapor partial pressure of the dry side outlet according to the first water vapor partial pressure, the material parameter and the gas parameter.
The dry side of the humidifier further comprises a dry side inlet, and the gas parameters comprise total gas pressure of the dry side, gas flow of the dry side and second water vapor partial pressure of the dry side inlet. At this time, the control device of the fuel cell obtains the third water vapor partial pressure of the dry-side outlet according to the first water vapor partial pressure, the total air pressure, the air flow, the second water vapor partial pressure and the material parameter.
In this way, the control device of the fuel cell obtains the control parameters, and determines the third water vapor partial pressure at the dry side outlet position by utilizing the characteristic that the pressure difference between the third water vapor partial pressure and the second water vapor partial pressure of the humidifier and the water diffusion flux diffused to the dry side are positively correlated, so that the air humidity at the dry side outlet position is estimated under the condition that the humidity sensor is not directly used for detecting the dry side outlet position.
By utilizing the characteristic that the pressure difference between the third water vapor partial pressure and the second water vapor partial pressure of the humidifier is positively correlated with the water diffusion flux diffused to the dry side, as an alternative embodiment, the first water vapor partial pressure, the total air pressure, the air flow, the second water vapor partial pressure and the material parameter and the third water vapor partial pressure satisfy the following relations:
in the method, in the process of the invention,
indicating the target diffusion rate of the membrane,/-)>
Representing the area of the diaphragm, +.>
Represents the thickness of the diaphragm, +.>
Indicating a first partial pressure of water vapour,/->
Indicating the third partial pressure of water vapor, ">
Air flow on the dry side, +.>
Indicating total air pressure on the dry side, +.>
Indicating a second partial pressure of water vapor.
As shown in fig. 5, it is found that there is a certain difference in diffusion rate at different positions of the diaphragm, and the diffusion characteristic curve thereof is embodied as that the diffusion rate at the center position of the diaphragm is maximum, and gradually decreases in a direction away from the center position; in order to simplify the operation process, the diffusion rates of all the positions of the diaphragm are uniformly set as target diffusion rates; the target diffusion rate may be a diffusion rate at a specific location in the membrane or an average diffusion rate at a plurality of locations of the membrane.
It was further found that when the target diffusion rate is the average diffusion rate, the average diffusion rate of the diaphragm and the diffusion rate of the diaphragm reference position satisfy a preset proportional relationship.
As further shown in fig. 5, when the position of the diaphragm corresponding to the wet-side inlet is selected as the reference position in combination with the diffusion characteristic curve of the diaphragm in the drawing, the diffusion rate thereof is expressed as
The method comprises the steps of carrying out a first treatment on the surface of the At this time, according to the proportional relation (generally between 1.25 and 0.75) calibrated by the working condition, the average diffusion rate can be obtained and used as the target diffusion rate +.>
。
In addition, for a first partial pressure of water vapor at the wet side inlet, the present example provides the following alternative embodiments of step S101:
s101-1, the control device can acquire a target dew point of the wet side inlet.
It should be understood that the dew point/dew point temperature refers to the temperature at which the air is cooled to saturation, called the dew point temperature for short, under the condition that the water vapor content in the air is unchanged and the air pressure is kept constant; thus, the control device may take the stack gas temperature as the target dew point.
S101-2, taking the water vapor partial pressure matched with the target dew point as the first water vapor partial pressure of the wet side inlet according to the mapping relation between the dew point and the water vapor partial pressure.
Because the specific mapping relation exists between the dew point and the water vapor partial pressure, the first water vapor partial pressure at the wet side inlet position of the humidifier can be indirectly obtained through the mapping relation.
In the above embodiment, it is described that the gas parameter of the dry side includes the water vapor partial pressure of the dry side inlet, and since the gas introduced into the dry side inlet in this embodiment is derived from the atmospheric environment, the content of water vapor in the gas introduced into the dry side inlet is equivalent to the atmospheric environment, and thus in this embodiment, step S101 may further include the following specific embodiments for obtaining the second water vapor partial pressure of the dry side inlet:
s101-3, acquiring the water vapor content in the atmosphere.
S101-4, determining a second water vapor partial pressure of the dry side inlet according to the water vapor content and the total air pressure of the dry side inlet.
It should be understood herein that in some embodiments, the dry side inlet is in direct communication with the atmosphere, where the total air pressure of the dry side inlet is atmospheric pressure; in other embodiments, in order to increase the intake air amount of the fuel cell, the pressurizing device is connected to the dry side inlet, and the total air pressure of the dry side inlet is the air pressure after the pressurizing device pressurizes.
In this way, the second partial pressure of water vapor generated by water vapor in the total dry-side gas pressure can be indirectly determined by the ratio of water vapor in the atmospheric environment, as found that the content of water vapor in the gas introduced from the dry-side inlet is equivalent to that in the atmospheric environment.
The above description of the humidity estimation method of the humidifier is based on the same inventive concept, and the embodiment also provides a humidity estimation device of the humidifier. The humidity estimation means of the humidifier comprises at least one software functional module which may be stored in the memory 301 in the form of software or solidified in the Operating System (OS) of the control device. The processor 302 in the control device is used to execute executable modules stored in the memory 301. For example, a humidity estimation device of the humidifier includes a software function module, a computer program, and the like. Referring to fig. 6, functionally divided, the humidity estimation apparatus of the humidifier may include:
the parameter acquisition module 201 is configured to acquire a first water vapor partial pressure of the wet side inlet, a material parameter of the diaphragm, and a gas parameter of the dry side.
In the present embodiment, the parameter obtaining module 201 is configured to implement step S101 in fig. 4, and a detailed description of the parameter obtaining module 201 may be referred to as a detailed description of step S101.
The partial pressure calculation module 202 is configured to obtain a third partial pressure of water vapor at the dry side outlet according to the first partial pressure of water vapor, the material parameter and the gas parameter.
In the present embodiment, the partial pressure calculating module 202 is used to implement step S102 in fig. 4, and the detailed description of the partial pressure calculating module 202 can be referred to as the detailed description of step S102.
It should be noted that, since the humidity estimation method of the humidifier and the humidity estimation device of the humidifier have the same inventive concept, the above parameter obtaining module 201 and the partial pressure calculating module 202 may also be used to implement other steps or sub-steps of the method, which will not be described in detail in this embodiment.
In addition, the functional modules in the embodiments of the present application may be integrated together to form a single part, or each module may exist alone, or two or more modules may be integrated to form a single part.
It should also be appreciated that the above embodiments, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored on a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application.
Accordingly, the present embodiment also provides a computer-readable storage medium storing a computer program which, when executed by a processor, implements the humidity estimation method of the humidifier provided by the present embodiment. The computer readable storage medium may be any of various media capable of storing a program code, such as a usb (universal serial bus), a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk.
Referring to fig. 7, a control apparatus provided in this embodiment may include a processor 302 and a memory 301. The processor 302 and the memory 301 may communicate via a system bus 304. The memory 301 stores a computer program, and the processor reads and executes the computer program corresponding to the above embodiment in the memory 301 to realize the method for estimating the humidity of the humidifier according to the present embodiment.
As further shown in fig. 7, the control device may further comprise a communication unit 303. The memory 301, the processor 302 and the communication unit 303 are electrically connected directly or indirectly to each other to realize data transmission or interaction. For example, the components may be electrically connected to each other via one or more communication buses or signal lines.
The memory 301 may be an information recording device based on any electronic, magnetic, optical or other physical principle for recording execution instructions, data, etc. In some embodiments, the memory 301 may be, but is not limited to, volatile memory, non-volatile memory, storage drives, and the like.
Therein, by way of example only, the volatile memory may be random access memory (Random Access Memory, RAM). The nonvolatile Memory may be Read Only Memory (ROM), programmable Read Only Memory (Programmable Read-OnlyMemory, PROM), erasable Read Only Memory (Erasable ProgrammableRead-Only Memory, EPROM), electrically erasable Read Only Memory (Electric Erasable Programmable Read-Only Memory, EEPROM), flash Memory, etc.; the storage drive may be a magnetic disk drive, a solid state disk, any type of storage disk (e.g., optical disk, DVD, etc.), or a similar storage medium, or a combination thereof, etc.
The communication unit 303 is used for transmitting and receiving data through a network. In some embodiments, the network may include a wired network, a Wireless network, a fiber optic network, a telecommunications network, an intranet, the internet, a Local area network (Local Area Network, LAN), a wide area network (Wide Area Network, WAN), a Wireless Local area network (Wireless Local AreaNetworks, WLAN), a metropolitan area network (Metropolitan Area Network, MAN), a wide area network (Wide Area Network, WAN), a Public Switched network (Public Switched TelephoneNetwork, PSTN), a bluetooth network, a ZigBee network, a near field communication (Near Field Communication, NFC) network, or the like, or any combination thereof. In some embodiments, the network may include one or more network access points. For example, the network may include wired or wireless network access points, such as base stations and/or network switching nodes, through which one or more components of the service request processing system may connect to the network to exchange data and/or information.
The processor 302 may be an integrated circuit chip with signal processing capabilities and may include one or more processing cores (e.g., a single-core processor or a multi-core processor). By way of example only, the Processor may include a central processing unit (Central Processing Unit, CPU), application specific integrated circuit (Application SpecificIntegrated Circuit, ASIC), special instruction set Processor (Application Specific Instruction-set Processor, ASIP), graphics processing unit (Graphics Processing Unit, GPU), physical processing unit (Physics Processing Unit, PPU), digital signal Processor (Digital Signal Processor, DSP), field programmable gate array (Field Programmable gateway array, FPGA), programmable logic device (Programmable Logic Device, PLD), controller, microcontroller unit, simplified instruction set computer (Reduced Instruction SetComputing, RISC), microprocessor, or the like, or any combination thereof.
On the basis of the above, the present embodiment also provides a fuel cell including a stack, a humidifier for maintaining the humidity of the stack, and a control device.
It should be understood that the apparatus and method disclosed in the above embodiments may be implemented in other manners. The apparatus embodiments described above are merely illustrative, for example, flow diagrams and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
The foregoing is merely various embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered in the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (10)
1. A method of estimating humidity of a humidifier, the humidifier comprising a membrane for diffusing water vapor from a wet side to a dry side of the humidifier; the wet side of the humidifier including a wet side inlet, the dry side of the humidifier including a dry side outlet and a dry side inlet, the method comprising:
acquiring a first water vapor partial pressure of the wet side inlet, a material parameter of the diaphragm and a gas parameter of the dry side, wherein the gas parameter comprises total gas pressure of the dry side, gas flow of the dry side and a second water vapor partial pressure of the dry side inlet;
and obtaining a third water vapor partial pressure of the dry side outlet according to the first water vapor partial pressure, the total air pressure, the air flow, the second water vapor partial pressure and the material parameter, wherein the pressure difference between the third water vapor partial pressure and the second water vapor partial pressure is positively correlated with the water diffusion flux diffused to the dry side.
2. The method of claim 1, wherein the material parameters include a diffusion rate of the membrane, a thickness of the membrane, and an area of the membrane.
3. The method of humidity estimation of a humidifier according to claim 2, wherein the first water vapor partial pressure, the total gas pressure, the gas flow rate, the second water vapor partial pressure, and the relationship between the material parameter and the third water vapor partial pressure satisfy the following relationship:
in the method, in the process of the invention,
representing a target diffusion rate of the membrane, +.>
Representing the area of the membrane, +.>
Represents the thickness of the membrane, < >>
Indicating said first water vapor partial pressure, +.>
Representing said third water vapor partial pressure, +.>
Representing the gas flow of the dry side, +.>
Indicating the total air pressure of the dry side, +.>
Representing the second partial pressure of water vapor.
4. A method of estimating humidity of a humidifier according to claim 3, wherein the target diffusion rate of the membrane is an average diffusion rate of the membrane at a plurality of positions;
the average diffusion rate and the diffusion rate of the reference position of the diaphragm meet the preset proportional relation.
5. The method of claim 1, wherein the gas introduced at the dry side inlet is derived from an atmospheric environment, and wherein obtaining the second partial pressure of water vapor at the dry side inlet comprises:
acquiring the water vapor content in the atmosphere;
and determining a second water vapor partial pressure of the dry side inlet according to the water vapor content and the total air pressure of the dry side.
6. The method of claim 1, wherein said obtaining a first partial pressure of water vapor at said wet side inlet comprises:
acquiring a target dew point of the wet side inlet;
and taking the target water vapor partial pressure matched with the target dew point as the first water vapor partial pressure of the wet side inlet according to the mapping relation between the dew point and the water vapor partial pressure.
7. A humidity estimation device of a humidifier, the humidifier comprising a membrane for diffusing water vapor from a wet side to a dry side of the humidifier and a dry side inlet; the wet side of the humidifier including a wet side inlet, the dry side of the humidifier including a dry side outlet, the apparatus including;
a parameter acquisition module for acquiring a first water vapor partial pressure of the wet side inlet, a material parameter of the diaphragm, and a gas parameter of the dry side, the gas parameter including a total gas pressure of the dry side, a gas flow of the dry side, a second water vapor partial pressure of the dry side inlet;
and the partial pressure calculation module is used for obtaining a third partial pressure of the dry side outlet according to the first partial pressure of the water vapor, the total air pressure, the air flow, the second partial pressure of the water vapor and the material parameter, wherein the pressure difference between the third partial pressure of the water vapor and the second partial pressure of the water vapor is positively correlated with the water diffusion flux diffused to the dry side.
8. A computer readable storage medium, characterized in that the computer readable storage medium stores a computer program which, when executed by a processor, implements the method of estimating humidity of a humidifier according to any one of claims 1-6.
9. A control device comprising a processor and a memory storing a computer program which, when executed by the processor, implements the method of estimating humidity of a humidifier according to any one of claims 1-6.
10. A fuel cell comprising a humidifier, a stack, and the control apparatus of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310065514.4A CN115810773B (en) | 2023-02-06 | 2023-02-06 | Method, device, medium, equipment and fuel cell for estimating humidity of humidifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310065514.4A CN115810773B (en) | 2023-02-06 | 2023-02-06 | Method, device, medium, equipment and fuel cell for estimating humidity of humidifier |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115810773A CN115810773A (en) | 2023-03-17 |
| CN115810773B true CN115810773B (en) | 2023-05-09 |
Family
ID=85487534
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310065514.4A Active CN115810773B (en) | 2023-02-06 | 2023-02-06 | Method, device, medium, equipment and fuel cell for estimating humidity of humidifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115810773B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113193213A (en) * | 2021-04-29 | 2021-07-30 | 一汽解放汽车有限公司 | Method and device for controlling gas humidity of fuel cell, vehicle and storage medium |
| DE102020119137A1 (en) * | 2020-07-21 | 2022-01-27 | Audi Aktiengesellschaft | Method for the model-based humidity control of a fuel cell device, fuel cell device and fuel cell vehicle |
| CN114220995A (en) * | 2022-02-21 | 2022-03-22 | 中国汽车技术研究中心有限公司 | Fuel cell humidifier modeling method, apparatus, and medium |
| CN115577529A (en) * | 2022-10-10 | 2023-01-06 | 武汉雄韬氢雄燃料电池科技有限公司 | Modeling simulation method for humidifier of fuel cell system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8470479B2 (en) * | 2005-12-15 | 2013-06-25 | GM Global Technology Operations LLC | Sensorless relative humidity control in a fuel cell application |
-
2023
- 2023-02-06 CN CN202310065514.4A patent/CN115810773B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102020119137A1 (en) * | 2020-07-21 | 2022-01-27 | Audi Aktiengesellschaft | Method for the model-based humidity control of a fuel cell device, fuel cell device and fuel cell vehicle |
| CN113193213A (en) * | 2021-04-29 | 2021-07-30 | 一汽解放汽车有限公司 | Method and device for controlling gas humidity of fuel cell, vehicle and storage medium |
| CN114220995A (en) * | 2022-02-21 | 2022-03-22 | 中国汽车技术研究中心有限公司 | Fuel cell humidifier modeling method, apparatus, and medium |
| CN115577529A (en) * | 2022-10-10 | 2023-01-06 | 武汉雄韬氢雄燃料电池科技有限公司 | Modeling simulation method for humidifier of fuel cell system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115810773A (en) | 2023-03-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Liu et al. | Anode purge management for hydrogen utilization and stack durability improvement of PEM fuel cell systems | |
| Yan et al. | Investigation of water transport through membrane in a PEM fuel cell by water balance experiments | |
| Liso et al. | Modeling and experimental validation of water mass balance in a PEM fuel cell stack | |
| US8470479B2 (en) | Sensorless relative humidity control in a fuel cell application | |
| Husar et al. | Experimental characterization methodology for the identification of voltage losses of PEMFC: Applied to an open cathode stack | |
| Tolj et al. | Maintaining desired level of relative humidity throughout a fuel cell with spatially variable heat removal rates | |
| US20020180448A1 (en) | Method for measuring water content of fuel cell based on conductivity of electrolyte | |
| JP2001256988A (en) | Fuel cell system and fuel cell operating method | |
| Casalegno et al. | Quantitative characterization of water transport and flooding in the diffusion layers of polymer electrolyte fuel cells | |
| KR20100128124A (en) | Control method for air supply amount of fuel cell | |
| Park et al. | An experimental investigation of electro-osmotic drag coefficients in a polymer electrolyte membrane fuel cell | |
| CN115810773B (en) | Method, device, medium, equipment and fuel cell for estimating humidity of humidifier | |
| CN113991149B (en) | Fuel cell stack inlet air temperature testing method and device and storage medium | |
| JP4590819B2 (en) | Fuel cell system and fuel cell operating method | |
| US8647783B2 (en) | Auto-learning of base stack resistance for HFR based RH control | |
| CN113540506A (en) | Fuel cell water management and control method | |
| CN115954509B (en) | Method for calculating humidity of electric pile inlet | |
| CA2386881A1 (en) | Method and device for determining the concentration of fluid fuels to be used in fuel cells | |
| Gu et al. | A study of water adsorption and desorption by a PBI-H3PO4 membrane electrode assembly | |
| US20140199605A1 (en) | Transient Inlet Relative Humidity Estimation Via Adaptive Cathode Humidification Unit Model And High Frequency Resistance | |
| JP2008258040A (en) | Humidifying water amount estimation device | |
| CN101820070A (en) | Two stages, no HFR freeze to prepare shutdown strategy | |
| KR101937826B1 (en) | Apparatus for measuring oxygen permeability of ion exchange membranes and method for measuring oxygen permeability of ion exchange membranes using the same | |
| Novotny et al. | On/off cycling test of low-temperature PEM fuel cell at fully humidified conditions | |
| Carter et al. | Spatially resolved electrode diagnostic technique for fuel cell applications |
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 |