DESC:TECHNICAL FIELD
[0001] The present invention relates generally to the field of humidifiers. In particular, the present invention relates to an intelligent humidifier system and method for efficient air humidification.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] A humidifier is a device which helps to retain/increase the humidity/moisture content at a specific level in an environment or in a closed space. Humidifiers are required for maintaining the level/percentage of moisture in a particular device, system, building, area, etc. Humidifiers are required for various applications like, but not limited to, medical, pharmaceutical, automotive, HVAC, refrigeration, industrial applications, aviation, etc. Various types of mechanical, electrical, electro-mechanical humidifiers are currently being used. One such application where humidifiers are required to maintain the moisture level is a fuel cell.
[0004] A fuel cell is an electrochemical device that converts chemical energy into an electrical energy. Nowadays, fuel cells are being used as a power source for many applications like automotive vehicles, portable power supplies, etc. In a Proton Exchange Membrane (PEM) fuel cell the chemical energy of fuels such as hydrogen and oxidants such as oxygen/air is converted into electrical energy. A typical fuel cell comprises an anode, a cathode and a membrane. Such multiple fuel cells are stacked together to form a fuel cell stack. The performance of the PEM fuel cell depends on the ionic conductivity of the membrane. To protect the membranes from damage and to achieve a higher operating efficiency, the membranes of the individual fuel cells must be kept moist/hydrated during operation of the fuel cell stack. Without humidification, with usage, the fuel cell membrane becomes dry and thereby, reducing the proton transport in the fuel cell stack. This adversely affects the oxygen reduction reaction at cathode resulting in a poor fuel cell performance.
[0005] Fuel cell stack itself generates water during reaction which alone cannot fulfil the humidification requirement. Hence, in order to humidify/hydrate the polymer electrolyte membranes, various methods including internal humidification and external humidification are being used and explored. In case of external humidification, a device/humidifier which is placed external to the fuel cell assembly is used to humidify the reactant gases/air, thereby, hydrating the membrane. Some methods of extremal humidification are gas bubbling humidification, membrane humidifiers, direct water injection, exhaust gas recirculation. In gas bubbling humidifier, a bubbler is used to humidify the air, wherein a stream of air is passed underwater which forms bubbles at the surface of water, thereby, humidifying the air. In this technique, the water droplets maybe carried into the membrane which may obstruct the gas path, leading to inefficiency. Also, this method may lead to parasitic losses. Additionally, this method is suitable only for a small-scale operation, where a small amount of humidification is required. This method is not efficient for large scale commercial applications where large quantity of fuel/reactant gases/air needs to be humidified.
[0006] Another method of external humidification is use of membrane humidifiers. A membrane humidifier comprises multiple Nafion membrane tubes of very small dimensions carried inside a conduit, for example, a stainless-steel shell. In this technique, gas/air is passed through Nafion membrane tubes and water is passed through the shell, surrounding the Nafion membrane tubes. Due to H+ ion conductivity of Nafion membrane tubes, the air inside the Nafion tubes is humidified. However, as these Nafion tubes are very delicate they tend to wear out over time with usage. As they are not robust, they wear out due to the continuous pressure, leading to mixing of water. This reduces the humidification efficiency and degrades the fuel cell performance with time. Also, the membrane may be blocked due to impurities in a long term and a large-scale operation.
[0007] In case of internal humidification, a humidifier is placed internally in the fuel cell assembly or some internal mechanism is used to maintain the membrane in a hydrated state. Generally, physical methods and chemical methods are used for internal humidification. Some examples of physical methods of internal humidification are changing the physical structure like the flow fields, design features, etc. The chemical methods of internal humidification include changing the composition of membrane, changing the composition of the electrode, using additives, etc. The internal humidifying mechanisms eliminate the need of an additional component of a humidifier. However, the internal humidifying mechanisms are complicated in design and require precise control as they are placed internally. It is also difficult to control and regulate the humidifying amount with such mechanisms. Since they are placed internally, the repair and maintenance of these humidifiers is also tedious and complicated. Besides, the durability and stability of the internal humidifier is to be questioned. Internal humidifiers are more suitable for low power or portable PEMFC application like mobile devices.
[0008] Thus, there is a need for a simple and efficient solution which can obviate the above mentioned challenges in the art. Thus, there is a need for a simple, economical and an efficient humidifier which can be used for various applications, like, but not limited to, medical, pharmaceutical, transportation, automotive, HVAC, refrigeration, industrial applications, aviation, fuel cell, etc.
[0009] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0010] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the disclosure are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the disclosure may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0011] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0012] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of the disclosure otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the disclosure.
[0013] Groupings of alternative elements or embodiments of the disclosure disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

OBJECTS OF THE PRESENT INVENTION
[0014] A general object of the present invention to provide an intelligent air/gas humidifier system and method which is efficient, compact and economical.
[0015] Another object of the present invention is to provide an improved humidifier system and method with precisely controlled humification, wherein the humidity is controlled by monitoring various parameters of the system.
[0016] Yet another object of the present invention is to provide an intelligent humidifier system which can be easily repaired and maintained with minimum cost.
[0017] Yet another object of the present invention is to provide an intelligent humidifier system which is compact and economical.
[0018] Still another object of the present invention is to provide an intelligent humidification system and method to improve life of the fuel cell stack.
[0019] Still another object of the present invention is to provide an intelligent humidifier system and method for an efficient humidification of reactant gas/air for an electrode of the fuel cell stack.
[0020] Still another object of the present invention is to provide an intelligent system and method for air/gas humidification for fuel cell stack that increases overall performance and efficiency of the fuel cell stack and provides maximum power.
[0021] Still another object of the present invention is to provide an intelligent humidifier system which can be conveniently used in various applications such as, but not limited to, automobiles, transportation, power generation systems, aviation, pharmaceutical, refrigeration, HVAC, consumer products, industrial applications, low power applications, backup power supplies, etc.

SUMMARY
[0022] Aspects of the present invention relate to humidifiers. In particular, the present invention relates to an intelligent humidifier system and method for efficient air humidification.
[0023] In an aspect, the present disclosure provides an improved humidifier apparatus comprises of a housing having a chamber enclosed by one or plurality of side walls and a pair of plates comprising a top plate and a bottom plate. In an embodiment, the chamber comprises of a first side wall, a second side wall and a third side wall (not shown) coupled to each other at corresponding side ends. In an alternate embodiment, the chamber comprises of a single side wall, forming a circular chamber. Thus, the chamber may be of various shapes, like, but not limited to, circle, square, rectangle, triangle, etc. The top plate and the bottom plate are coupled to opposite ends of the set of side walls. The humidifier apparatus comprises of an air inlet port movably configured with an air inlet coupled to the first side wall of the housing to allow change in angular position of the air inlet port with respect to the first side wall, the air inlet port being adapted to allow inflow of an air steam from an air source into the chamber of the housing between a predefined range of angles; and a baffle plate disposed in the chamber of the housing. The baffle plate is located in an axis of the air inlet port such that the air stream coming through the air inlet port in the chamber strikes on the baffle plate. The baffle plate is movably coupled to an inner surface of the second side wall of the housing to allow change in angular position of the baffle plate with respect to the inner surface of the second side wall based on an angle of the air stream entering into the chamber.
[0024] In an embodiment, the humidifier apparatus further comprises one or more water jet nozzles configured with the top plate of the housing. The water jet nozzles are adapted to spray water received from a water source into the chamber in an atomized form to enable humidification of the air in the chamber.
[0025] In an embodiment, the humidifier apparatus comprises a humidified air outlet port configured with an outlet on the second side wall of the housing to allow outflow of the humidified air from the chamber.
[0026] In an embodiment, the humidifier apparatus comprises a humidified air temperature sensor and a humidified air Relative humidity (Rh) sensor configured with the outlet to sense a temperature and Rh, respectively, of the humidified air at the outlet of the housing.
[0027] In an embodiment, the humidifier apparatus comprises a water pressure sensor, a water temperature sensor, and a water flow sensor configured with an water inlet of the housing to sense a pressure, a temperature and a flow rate of the water, respectively, at inlet of the one or more water jet nozzles.
[0028] In an embodiment, the humidifier apparatus comprises an air pressure sensor, an air Rh sensor, and an air temperature sensor configured with the air inlet of the housing to sense a pressure, Rh and a temperature, respectively, of the air at the air inlet.
[0029] In an embodiment, the humidifier apparatus comprises a pump to supply the water at a predefined water pressure to the one or more water jet nozzles from the water source.
[0030] In an embodiment, the air source is an air compressor which supplies the air at a predefined air pressure to the air inlet.
[0031] In an embodiment, the humidifier apparatus comprises a control unit comprising a processor and a memory storing a set of instructions. The control unit is operatively coupled to the water jet nozzles to control one or more attributes associated with the water jet nozzles. The one or more attributes comprises any or a combination of a duty cycle of the one or more water jet nozzles, an angle of water jets sprayed by the water jet nozzles, a length of water jets sprayed by the water jet nozzles, a pressure of the water jets, a level of atomization of the water droplets, a number of nozzles out of the one or more water jet nozzles to be operated, and the like.
[0032] In an embodiment, the humidifier apparatus comprises a purge valve configured with the bottom plate of the housing to allow outflow of condensed water from the chamber for recirculation.
[0033] In an embodiment, the humidifier apparatus comprises a heating element placed inside the chamber of the housing. The heating element is any knowing heating element in the art, like, but not limited to, heater coil, cartridge heater, IR heater, heat pump, etc. embedded into a container.
[0034] In an embodiment, the humidifier apparatus comprises a first rotary device to enable movement of the air inlet port to change position of the air inlet port, and a second rotary device to enable movement of the baffle plate to change position of the baffle plate. Each of the first rotary device and the second rotary device may be selected from a group comprising a servo motor, a stepper motor, an alternating current motor, and a direct current motor.
[0035] In another aspect, the present disclosure provides a method for air humidification including providing, a housing having a chamber enclosed by a set of side walls comprising at least a first side wall, a second side wall and a third side wall coupled to each other at corresponding side ends, and a pair of plates comprising a top plate and a bottom plate, the top plate and the bottom plate being coupled to opposite ends of the set of side walls; and providing, an air inlet port to allow inflow of an air steam from an air source into the chamber of the housing between a predefined range of angles. The air inlet port is movably configured with an air inlet coupled to the first side wall of the housing to allow change in angular position of the air inlet port with respect to the first side wall.
[0036] In an embodiment, the method comprises disposing, a baffle plate in the chamber, wherein the baffle plate is located in an axis of the air inlet port such that the air stream coming through the air inlet port in the chamber strikes on the baffle plate. The baffle plate is movably coupled to an inner surface of the second side wall of the housing to allow change in angular position of the baffle plate with respect to the inner surface of the second side wall based on an angle of the air stream entering into the chamber.
[0037] In an embodiment, the method comprises controlling, by a control unit, one or more attributes associated with one or more water jet nozzles, wherein the one or more water jet nozzles are adapted to spray water received from a water source into the chamber in an atomized form to enable humidification of the air in the chamber of the housing.
[0038] In another aspect, the present disclosure provides a humidifier system for a fuel cell stack. The humidifier system comprises a humidifier apparatus as described above, and an air compressor fluidically coupled to an air inlet of the humidifier apparatus to supply compressed air to the humidifier apparatus for humidification. The humidifier apparatus is operatively coupled to a cathode inlet of the fuel cell stack to supply humidified air to the fuel cell stack on receipt of hydrogen from a hydrogen supply unit at an anode inlet of the fuel cell stack.
[0039] In another aspect, the present disclosure provides a method for air humidification for a fuel cell stack, the method comprises providing, a humidifier apparatus operatively coupled to a cathode inlet of the fuel cell stack to supply humidified air to the fuel cell stack on receipt of hydrogen from a hydrogen supply unit at an anode inlet of the fuel cell stack; supplying, by an air compressor, a compressed air stream to an air inlet port movably configured with an air inlet of a housing of the humidifier apparatus for humidification, wherein the air stream coming through the air inlet port in a chamber of the housing strikes on a baffle plate disposed in the chamber; and controlling, by a control unit, one or more attributes associated with one or more water jet nozzles of the humidifier apparatus. The one or more water jet nozzles are adapted to spray water received from a water source into the chamber in an atomized form to enable humidification of the air in the chamber of the housing of the humidifier apparatus.
[0040] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0042] FIG. 1 illustrates the proposed intelligent humidifier apparatus, in accordance with an embodiment of the present invention.
[0043] FIG. 2 illustrates a flow diagram of a method for air humidification, in accordance with an embodiment of the present invention.
[0044] FIG. 3 illustrates a block diagram of the proposed intelligent humidifier system for a fuel cell stack, in accordance with an embodiment of the present invention.
[0045] FIG. 4 illustrates a flow diagram of a method for air humidification for a fuel cell stack, in accordance with an embodiment of the present invention.
[0046] FIG. 5 illustrates an exemplary dashboard display of the control parameters monitored by an intelligent control unit of the fuel cell system, in accordance with an exemplary embodiment of the present invention.
[0047] FIG. 6 illustrates an exemplary graphical representation of a test observation data, in accordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION
[0048] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
[0049] Embodiments of the present invention include various steps, which will be described below. The steps may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, steps may be performed by a combination of hardware, software, and firmware and/or by human operators.
[0050] Embodiments of the present invention may be provided as a computer program product, which may include a machine-readable storage medium tangibly embodying thereon instructions, which may be used to program a computer (or other electronic devices) to perform a process. The machine-readable medium may include, but is not limited to, fixed (hard) drives, magnetic tape, floppy diskettes, optical disks, compact disc read-only memories (CD-ROMs), and magneto-optical disks, semiconductor memories, such as ROMs, PROMs, random access memories (RAMs), programmable read-only memories (PROMs), erasable PROMs (EPROMs), electrically erasable PROMs (EEPROMs), flash memory, magnetic or optical cards, or other type of media/machine-readable medium suitable for storing electronic instructions (e.g., computer programming code, such as software or firmware).
[0051] Various methods described herein may be practiced by combining one or more machine-readable storage media containing the code according to the present invention with appropriate standard computer hardware to execute the code contained therein. An apparatus for practicing various embodiments of the present invention may involve one or more computers (or one or more processors within a single computer) and storage systems containing or having network access to computer program(s) coded in accordance with various methods described herein, and the method steps of the invention could be accomplished by modules, routines, subroutines, or subparts of a computer program product.
[0052] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0053] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0054] Embodiment explained herein relate to humidifiers. In particular, the present invention relates to an intelligent system and method for efficient air humidification.
[0055] FIG. 1 illustrates the proposed intelligent humidifier apparatus 100, in accordance with an embodiment of the present invention. The disclosed humidifier apparatus 100 comprises of a housing 102 having a chamber 104 enclosed by one or a plurality of side walls and a pair of plates comprising a top plate 110 and a bottom plate 112. In an embodiment, the chamber 104 comprises of a first side wall 106, a second side wall 108 and a third side wall (not shown) coupled to each other at corresponding side ends. In an alternate embodiment, the chamber 104 comprises of a single side wall, forming a circular chamber. Thus, the chamber 104 may be of various shapes, like, but not limited to, circle, square, rectangle, triangle, etc. The top plate 110 and the bottom plate 112 are coupled to opposite ends of the set of side walls. The humidifier apparatus 100 also comprises an air inlet port 114 movably configured with an air inlet 116 coupled to the first side wall 106 of the housing to allow change in angular position of the air inlet port 114 with respect to the first side wall 106. The air inlet port 114 can be adapted to allow inflow of an air steam from an air source into the chamber of the housing between a predefined range of angles. The air inlet port 114 can be a motor assisted air inlet port to enable movement of the air inlet port 114. In an embodiment, the humidifier apparatus 100 may include a first rotary device (not shown) to enable movement of the air inlet port 114 to change position of the air inlet port with respect to air inlet 116 and/or the first side wall 106 to vary angle of the air stream entering in the chamber 104 based on requirement.
[0056] In an embodiment, the first rotary device may be selected from a group comprising a servo motor, a stepper motor, an alternating current motor, and a direct current motor.
[0057] In an embodiment, the air source is an air compressor (shown in FIG. 3) which supplies the air at a predefined air pressure to the air inlet 116.
[0058] In an embodiment, the disclosed humidifier apparatus 100 comprises a baffle plate 118 disposed in the chamber 104. The baffle plate 118 is located in an axis of the air inlet port 114 such that the air stream coming through the air inlet port 114 in the chamber 104 strikes on the baffle plate 118. The baffle plate is movably coupled to an inner surface of the second side wall 108 which is located opposite to the first side wall 106 of the housing 102 to allow change in angular position of the baffle plate 118 with respect to the inner surface of the second side wall 108 based on an angle of the air stream entering into the chamber 104.
[0059] In an embodiment, the disclosed humidifier apparatus 100 comprises a second rotary device (not shown) to enable movement of the baffle plate 118 to change position of the baffle plate 118. The second rotary device may be selected from a group comprising a servo motor, a stepper motor, an alternating current motor, and a direct current motor.
[0060] In an embodiment, the humidifier apparatus 100 further comprises one or more water jet nozzles such as, but not limited to, water jet nozzles 120-1, and 120-2 (collectively referred to as nozzles 120) configured with the top plate 110 of the housing 102. The water jet nozzles 120 are adapted to spray water received from a water source into the chamber 104 in an atomized form to enable humidification of the air in the chamber 104.
[0061] In an embodiment, the humidifier apparatus 100 comprises a humidified air outlet port 122 configured with an outlet 124 on the second side wall 108 of the housing 102 to allow outflow of the humidified air from the chamber 104 for further use.
[0062] In an embodiment, the humidifier apparatus 100 comprises a humidified air temperature sensor 126 and a humidified air Relative humidity (Rh) sensor 128 configured with the outlet to sense a temperature and Rh, respectively, of the humidified air at the outlet 124 of the housing 102.
[0063] In an embodiment, the humidifier apparatus 100 comprises a water pressure sensor 130, a water temperature sensor 132, and a water flow sensor 134 configured with an water inlet 136 of the housing 102 to sense a pressure, a temperature and a flow rate of the water, respectively, at an inlet of the water jet nozzles 120.
[0064] In an embodiment, the humidifier apparatus 100 comprises an air pressure sensor 138, an air Rh sensor 140, and an air temperature sensor 142 configured with the air inlet 116 to sense a pressure, Rh and a temperature, respectively, of the air at the air inlet 116.
[0065] In an embodiment, the humidifier apparatus 100 comprises a pump (not shown) to supply water at a predefined water pressure to the one or more water jet nozzles from the water source.
[0066] In an embodiment, the humidifier apparatus 100 comprises a control unit (shown in FIG. 3) comprising a processor and a memory storing a set of instructions executed by the processors. The control unit is operatively coupled to the water jet nozzles to control one or more attributes associated with the water jet nozzles 120. The one or more attributes can include any or a combination of a duty cycle of the one or more water jet nozzles 120, an angle of water jets sprayed by the water jet nozzles 120, a length of water jets sprayed by the water jet nozzles 120, a pressure of the water jets, a level of atomization of the water droplets, a number of nozzles out of the water jet nozzles 120 to be operated, and the like.
[0067] In an embodiment, the control unit can control the one or more attributes associated with the water jet nozzles 120 on the basis of, but not limited to, the sensed water temperature, sensed water pressure, sensed water flow rate, sensed inlet air temperature, sensed inlet air pressure, sensed inlet air Rh, an angle of air inlet port, etc.
[0068] In an embodiment, the humidifier apparatus 100 comprises a purge valve 144 configured with the bottom plate 112 of the housing 102 to allow outflow of condensed water from the chamber 104 for recirculation to the nozzles 120.
[0069] In an embodiment, the humidifier apparatus 100 may comprise a heating element (not shown) placed inside the chamber 104. The heating element is any knowing heating element in the art, like, but not limited to, heater coil, cartridge heater, IR heater, heat pump, etc. embedded into a container. The heating element provides an additional humidification effect, thereby, increasing the relative humidity of the air in the chamber 104.
[0070] FIG. 2 illustrates a flow diagram for a method for air humidification, in accordance with an embodiment of the present invention. In an embodiment, the method can be implemented by using the above disclosed humidifier apparatus 100 in FIG. 1.
[0071] In an embodiment, the disclosed method 200 comprises at a step 202, providing, a housing having a chamber that is enclosed by a set of side walls comprising at least a first side wall, a second side wall and a third side wall coupled to each other at corresponding side ends, and a pair of plates comprising a top plate and a bottom plate. The top plate and the bottom plate are coupled to opposite ends of the set of side walls.
[0072] In an embodiment, the disclosed method 200 comprises at step 204, providing, an air inlet port to allow inflow of an air steam from an air source into the chamber of the housing between a predefined range of angles. The air inlet port is movably configured with an air inlet coupled to the first side wall of the housing to allow change in angular position of the air inlet port with respect to the first side wall.
[0073] In an embodiment, the disclosed method 200 comprises at step 206, disposing, a baffle plate in the chamber. The baffle plate is located in an axis of the air inlet port such that the air stream coming through the air inlet port in the chamber strikes on the baffle plate.
[0074] In an embodiment, the disclosed method 200 comprises at step 208, controlling, by a control unit, one or more attributes associated with one or more water jet nozzles. The one or more water jet nozzles are adapted to spray water received from a water source, like but not limited to, water tank, water container, direct water supply, etc. into the chamber in an atomized form to enable humidification of the air in the chamber.
[0075] FIG. 3 illustrates a block diagram of the proposed intelligent humidifier system for a fuel cell stack, in accordance with an exemplary embodiment of the present invention. The disclosed system comprises a humidifier apparatus 100, as disclosed above in FIG. 1, that is fluidically connected to a cathode inlet 302 of a fuel cell stack 350 to supply humidified air to the fuel cell stack 350, an air compressor 306 fluidically coupled to an air inlet 116 of the humidifier apparatus 100 to supply compressed air for humidification, and a control unit 308 operatively coupled with the humidifier apparatus 100. A hydrogen supply unit 304 is connected to an anode inlet 310 of the fuel cell stack 350. The fuel cell stack 350 receives hydrogen from the hydrogen supply unit 304 at the anode inlet 310 and humidified air/oxygen at cathode inlet 302 from the humidifier apparatus 100. The air compressor 306 supplies the compressed air at a required pressure to the humidifier apparatus 100. The humidified air/oxygen coming out from the outlet 124 of the humidifier apparatus 100 is further supplied to the cathode inlet 302 of the fuel cell stack 350. The control unit 308 controls the humidification of air/ oxygen based on various parameters of the system.
[0076] In an embodiment, the air pressure sensor 138, air Rh sensor 140 and the air temperature sensor 142 sense the pressure, relative humidity (Rh) and temperature at the air inlet 116 of the humidifier apparatus 100. The variable angle air inlet port 114 configured with chamber (hereinafter, also referred to as humidification chamber) 104 may assists homogeneous mixing of air and water vapour in the chamber 104. In a fuel cell application, this homogenous mixture is fed to the cathode inlet 302 of the fuel cell stack 350. Angle variation of the air inlet port 114 can be achieved by means of a motor assist. With the motor assist air inlet port 114, the air enters into the chamber at a specific angle to achieve maximum efficiency of the system. Additionally, angle of the air inlet port 114 maybe prefixed or changed runtime based on the system requirement.
[0077] Angle of the baffle plate 118 mounted inside the humidification chamber 104 is variable and it can be titled to various degrees based on requirement. The baffle plate 118 angle can be adjusted such that when air enters through the air inlet port 114, it strikes the baffle plate 118. The angle of the baffle plate 118 can be optimized to ensure maximum efficiency of the system. The angle of the baffle plate 118 maybe prefixed or may be varied during run time based on the system requirement. In an alternate embodiment, the baffle plate 118 may be perforated to improve the performance of the system.
[0078] Water is supplied by a water pump at required pressure to the water jet nozzles 120 mounted on the top end plate 110 of the humidifier apparatus 100. The water pressure sensor 130, water temperature sensor 132 and water flow sensor 134 measures the pressure, temperature and flow rate at the inlet of the water jet nozzles 120. The water jet nozzles 120 transforms the liquid water into very fine water droplets/vapour or in an atomized form to be fed into the humidification chamber 104 for efficient air humidification.
[0079] In an embodiment, the air is fed into the humidification chamber 104 as per the demand from the fuel cell stack 350 and at the same time the water jet nozzles 120 deliver atomized water inside the humidification chamber 104 to achieve optimum humidity required for the target air flow rate. The humidified air temperature sensor 126 and the humidified air Rh sensor 128 measure the temperature and Rh of the humidified air at the outlet 124 of the humidifier apparatus 100. The condensed water collected during the process in the humidification chamber 104 is recirculated to the water bath through the purge valve 144, which is further supplied to the water jet nozzles 120 using the water pump.
[0080] In an embodiment, the water jet nozzles 120 are controlled by pulse width modulation (PWM) signal received from the control unit 308. The control unit 308 can vary the water jet nozzle duty cycle/ opening as per the required air flow rate for the fuel cell stack 350. To achieve optimum efficiency and power, an intelligent control logic of the control unit 308 controls multiple features of the water jet nozzles 120, including, but not limited to the duty cycle of the nozzles 120, a length of the water jet sprayed by the water jet nozzles 120, the angle of the water jet sprayed by the water jet nozzles 120, the pressure of the water jet sprayed by the water jet nozzles 120, the level of atomization of the droplets, the number of water jet nozzles to be actuated for spraying water in the chamber 104, etc. The intelligent control logic of the control unit 308 may considers multiple system parameters, fuel cell stack parameters, and power requirement of a vehicle in which the fuel cell stack 350 is implanted to control the water jet nozzles 120.
[0081] In an embodiment, various system parameters monitored by the control unit 308 for controlling the water jet nozzles 120 can include, but are not limited to, water temperature, water pressure, water flow rate, inlet air temperature, inlet air pressure, inlet air Rh, angle of air inlet port 114, etc. Various parameters of the fuel cell stack 350 monitored include, but are not limited to, stack voltage, stack current, stack temperature, stack pressure, etc. Further, water jet nozzles 120 are controlled by the intelligent control unit 308 based on the drive and power requirement of the vehicle.
[0082] In an embodiment, a heating element such as a heater coil embedded in a container, for example, a metal pipe can be placed inside the humidification chamber 104. The heater coil provides an additional humidification effect, thereby, increasing the relative humidity of the air fed to the cathode inlet of the fuel cell stack 350.
[0083] In an embodiment, condensed air at the outlet 124 of the humidification chamber 104 is recirculated to the air inlet 116 for humidification and is further fed to the cathode of the fuel cell stack 350.
[0084] In an embodiment, for an automotive application, the intelligent humidifier system of the present disclosure may be activated only during a cold start of the engine to meet the high-power cranking requirement of the vehicle. When the vehicle is running, the intelligent humidifier system may be activated and/or deactivated depending on the power requirement of the vehicle.
[0085] The intelligent humidifier system of the present disclosure can be used in various applications, including, but not limited to, transportation, automobiles, power generation, aviation, pharmaceutical, refrigeration, HVAC, consumer products, industrial applications, low power applications, backup power supplies, etc.
[0086] FIG. 4 illustrates a flow diagram for a method for air humidification for a fuel cell stack, in accordance with an embodiment of the present invention. In an embodiment, disclosed method 400 can be implemented by using the above mentioned system in FIG. 3.
[0087] In an embodiment, the method 400 comprises at a step 402, providing, a humidifier apparatus operatively coupled to a cathode inlet of the fuel cell stack to supply humidified air to the fuel cell stack on receipt of hydrogen from a hydrogen supply unit at an anode inlet of the fuel cell stack.
[0088] In an embodiment, the method 400 comprises at a step 404, supplying, by an air compressor, a compressed air stream to an air inlet port movably configured with an air inlet of a housing of the humidifier apparatus for humidification. The air stream coming through the air inlet port in a chamber of the housing strikes on a baffle plate disposed in the chamber.
[0089] In an embodiment, the method 400 comprises at a step 406, controlling, by a control unit, one or more attributes associated with one or more water jet nozzles of the humidifier apparatus. The one or more water jet nozzles are adapted to spray water received from a water source into the chamber in an atomized form to enable humidification of the air in the chamber of the housing of the humidifier apparatus.
[0090] FIG. 5 illustrates an exemplary dashboard display of the system parameters monitored by the intelligent control unit 308 of the fuel cell system, in accordance to an embodiment of the present invention. As illustrated in FIG. 5, a dashboard display is provided to monitor various temperatures and pressures at both, the inlet and the outlet, along with the difference in the two. Readings for current, voltage and temperature of the individual fuel cell along with the temperature readings for multiple stacks are monitored. Various other parameters like load cell, cathode flow rate, hydrogen leak sensor readings, etc. are also monitored.
[0091] Test data and results for an exemplary embodiment of the intelligent humidifier of the present invention implemented in a fuel cell have been mentioned below-
[0092] A compressor was used to supply air to humidifier, attributes of the air compressor are as below:
Max flow : 800 lpm
Max speed : 4000 rpm
Rated power : 1.2 kW
Rated current : 25A
Motor : 48V brushless DC
[0093] Gasoline fuel injector was used for water injection purpose; attributes for the injector are as follows:
Supply Voltage : 12V
Orifice diameter : 0.3mm
No. of orifice : 4 nos.
Working fuel pressure : 150kpa to 400kpa
Working temperature : -30 deg.C to 120 deg.C
Open time : < 20ms
Close time : < 10ms
[0094] Tap water used for humidification was at ambient temperature of 27 deg.C. The water pump used to deliver the water is a diaphragm type positive displacement pump; and attributes as mentioned below:
Suction lift: self-priming to 10ft.
Motor : Permanent Magnet
Duty cycle : Continuous
Flow : 12 lpm
Fluid Temperature : 55 deg.C (Max)
Fluid viscosity : 250 centipoises.
[0095] A standard Rh sensor is connected to a circuit board for signal processing and the value (% Rh and temperature) is displayed on a standard 1” x 3” LED display. To measure temperature and pressure, ‘J’ type thermocouple and pressure transducer were used respectively. Ambient temperature and Rh are measured during testing at regular time intervals as per below Table 1.
Time (H:MM)
1:15 1:50 2:17 2:50
Ambient Temp. deg.C 25 26 26.5 25
Ambient Rh % 30 33 34 37
Table 1
[0096] Test Observations: Observations of the tests carried out to see the overall effect of air flow rate, air temperature, air pressure and water pressure on the relative humidity (Rh) of the air coming out of the humidifier are shown in FIG. 6.
[0097] Additional data points are stated below in a table 2 which are subset of the above the graph shown in FIG. 6.
Inlet Airflow in (lpm)
Unit 50 100 150 200 250 300
Rh (%) % 56 57 60 63 70 72
Air inlet temp. deg.C 45 55 75 90 120 135
Air outlet temp. deg.C 40 40 50 55 70 80
Air inlet press. kPa 10 20 35 45 70 80
Table 2
[0098] From the Table 2, we can see that the air inlet temperature and flow rate has a direct relation with the change in % Rh. Air compressor compresses more air to satisfy the increased air flow demand which increases the temperature of the compressed air entering into the humidifier chamber. Heated air entering in the humidifier, losses its heat to vaporize the water droplet injected by water injector. Thus, creating a homogeneous mixture of air and water vapour to be supplied to cathode side of the fuel cell stack. With increased flow rate, air has very small residence time in humidifier, but with the help of elevated temperature it vaporizes the water in order to supply humidified air to the fuel cell stack. It was also noted that once the inlet air temperature goes beyond 100 deg.C (superheated temperature) then rate of change in % Rh also increases.
[0099] The effect of the injector inlet pressure on the water jet length and jet angle is illustrated in Table 3 below. Pressurized water passes through injector nozzle/orifice and converts into tiny vapor particle. Data presented below in Table 3 indicates that the jet angle varies as we increase the injector inlet pressure.

Injector Inlet pressure (barg)
1.8 2 2.2 2.5 2.8 3.5
Jet Angle deg 100 100 100 125 140 140
Jet length mm 205 210 212 212 215 250
Table 3
[00100] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the disclosure is determined by the claims that follow. The disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the disclosure when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES
[00101] The present disclosure provides an intelligent air/gas humidifier system and method which is efficient, compact and economical.
[00102] The present disclosure provides an improved humidifier system and method with precisely controlled humification, wherein the humidity is controlled by monitoring various parameters of the system.
[00103] The present disclosure provides an intelligent humidifier system which can be easily repaired and maintained with minimum cost.
[00104] The present disclosure provides an intelligent humidifier system which is compact and economical. The present disclosure provides an intelligent humidification system and method to improve life of the fuel cell stack.
[00105] The present disclosure provides an intelligent humidifier system and method for an efficient humidification of reactant gas/air for an electrode of the fuel cell stack.
[00106] The present disclosure provides an intelligent system and method for air/gas humidification for fuel cell stack to increases overall performance and efficiency of the fuel cell stack.
[00107] The present disclosure provides an intelligent humidifier system which can be conveniently used in various applications such as, but not limited to, automobiles, power generation systems, aviation, pharmaceutical, consumer products, industrial applications, low power applications, backup power supplies, etc.
,CLAIMS:1. A humidifier apparatus (100) comprising:
a housing (102) having a chamber (104) enclosed by a set of side walls comprising at least a first side wall (106), a second side wall (108) and a third side wall coupled to each other at corresponding side ends, and a pair of plates comprising a top plate (110) and a bottom plate (112), the top plate (110) and the bottom plate (112) being coupled to opposite ends of the set of side walls;
an air inlet port (114) movably configured with an air inlet (116) coupled to the first side wall (106) of the housing (102) to allow change in angular position of the air inlet port (114) with respect to the first side wall (106), the air inlet port (114) being adapted to allow inflow of an air steam from an air source into the chamber (104) of the housing (102) between a predefined range of angles;
a baffle plate (118) disposed in the chamber (104) of the housing (102), the baffle plate (118) being located in an axis of the air inlet port (114) such that the air stream coming through the air inlet port (114) in the chamber (104) strikes on the baffle plate (118); and
one or more water jet nozzles (120) configured with the top plate (110) of the housing (102), the one or more water jet nozzles (120) being adapted to spray water received from a water source into the chamber (104) in an atomized form to enable humidification of the air in the chamber (104),
wherein the baffle plate (118) is movably coupled to an inner surface of the second side wall (108) of the housing (102) to allow change in angular position of the baffle plate (118) with respect to the inner surface of the second side wall (108) based on an angle of the air stream entering into the chamber (104).
2. The humidifier apparatus (100) as claimed in claim 1, wherein the humidifier apparatus (100) comprises a humidified air outlet port (122) configured with an outlet (124) on the second side wall of the housing (102) to allow outflow of the humidified air from the chamber (104), wherein the humidifier apparatus (100) comprises a humidified air temperature sensor (126) and a humidified air Relative humidity (Rh) sensor (128) configured with the outlet (124) to sense a temperature and Rh, respectively, of the humidified air at the outlet (124) of the housing (102), wherein the humidifier apparatus (100) comprises a water pressure sensor (130) , a water temperature sensor (132), and a water flow sensor (134) configured with an water inlet (136) of the housing (102) to sense a pressure, a temperature and a flow rate of the water, respectively, at inlet of the one or more water jet nozzles (120), and wherein the humidifier apparatus (100) comprises an air pressure sensor (138), an air Rh sensor (140), and an air temperature sensor (142) configured with the air inlet (116) of the housing (102) to sense a pressure, Rh and a temperature, respectively, of the air at the air inlet (116).
3. The humidifier apparatus (100) as claimed in claim 1, wherein the humidifier apparatus (100) comprises a pump to supply the water at a predefined water pressure to the one or more water jet nozzles (120) from the water source, and wherein the air source is an air compressor (306) which supplies the air at a predefined air pressure to the air inlet (116).
4. The humidifier apparatus (100) as claimed in claim 1, wherein the humidifier apparatus (100) comprises a control unit (308) comprising a processor and a memory storing a set of instructions, the control unit (308) is operatively coupled to the one or more water jet nozzles (120) to control one or more attributes associated with the one or more water jet nozzles (120), and wherein one or more attributes comprises any or a combination of a duty cycle of the one or more water jet nozzles (120), an angle of water jets sprayed by the water jet nozzles (120), a length of water jets sprayed by the water jet nozzles (120), a pressure of the water jets, a level of atomization of the water droplets, and a number of nozzles out of the one or more water jet nozzles (120) to be operated.
5. The humidifier apparatus (100) as claimed in claim 1, wherein the humidifier apparatus (100) comprises a purge valve (144) configured with the bottom plate (112) of the housing (102) to allow outflow of condensed water from the chamber (104) for recirculation.
6. The humidifier apparatus (100) as claimed in claim 1, wherein housing (102) has a circular chamber (104) comprising of a single side wall.
7. The humidifier apparatus (100) as claimed in claim 1, wherein the humidifier apparatus (100) comprises a heating element placed inside the chamber (104) of the housing (102), and wherein the heating element is embedded in a container.
8. The humidifier apparatus (100) as claimed in claim 1, wherein the humidifier apparatus (100) comprises a first rotary device to enable movement of the air inlet port (114) to change position of the air inlet port (114), and a second rotary device to enable movement of the baffle plate (118) to change position of the baffle plate (118), and wherein each of the first rotary device and the second rotary device is selected from a group comprising a servo motor, a stepper motor, an alternating current motor, and a direct current motor.
9. A method for air humidification comprising:
providing, a housing (102) having a chamber (104) enclosed by a set of side walls comprising at least a first side wall (106), a second side wall (108) and a third side wall coupled to each other at corresponding side ends, and a pair of plates comprising a top plate (110) and a bottom plate (112), the top plate (110) and the bottom plate (112) being coupled to opposite ends of the set of side walls;
providing, an air inlet port (114) to allow inflow of an air steam from an air source into the chamber (104) of the housing (102) between a predefined range of angles, the air inlet port (114) being movably configured with an air inlet (116) coupled to the first side wall (106) of the housing (102) to allow change in angular position of the air inlet port (114) with respect to the first side wall (106);
disposing, a baffle plate (118) in the chamber (104), the baffle plate (118) being located in an axis of the air inlet port (114) such that the air stream coming through the air inlet port (114) in the chamber (104) strikes on the baffle plate (118), wherein the baffle plate (118) is movably coupled to an inner surface of the second side wall of the housing (102) to allow change in angular position of the baffle plate (118) with respect to the inner surface of the second side wall (108) based on an angle of the air stream entering into the chamber (104); and
controlling, by a control unit (308), one or more attributes associated with one or more water jet nozzles (120), wherein the one or more water jet nozzles (120) are adapted to spray water received from a water source into the chamber (104) in an atomized form to enable humidification of the air in the chamber (104) of the housing (102).
10. A humidifier system for a fuel cell stack (350), the humidifier system comprising:
a humidifier apparatus (100) operatively coupled to a cathode inlet (302) of the fuel cell stack (350) to supply humidified air to the fuel cell stack (350) on receipt of hydrogen from a hydrogen supply unit (304) at an anode inlet (310) of the fuel cell stack (350); and
an air compressor (306) fluidically coupled to an air inlet (116) of the humidifier apparatus (100) to supply compressed air to the humidifier apparatus (100) for humidification,
wherein the humidifier apparatus (100) comprises:
a housing (102) having a chamber (104) enclosed by a set of side walls comprising at least a first side wall (106), a second side wall (108) and a third side wall coupled to each other at corresponding side ends, and a pair of plates comprising a top plate (110) and a bottom plate (112), the top plate (110) and the bottom plate (112) being coupled to opposite ends of the set of side walls;
an air inlet port (114) movably configured with the air inlet (116) coupled to the first side wall (106) of the housing (102) to allow change in angular position of the air inlet port (114) with respect to the first side wall (106), the air inlet port (114) being adapted to allow inflow of an air steam from the compressor into the chamber (104) of the housing (102) between a predefined range of angles;
a baffle plate (118) disposed in the chamber (104) of the housing (102), the baffle plate (118) being located in an axis of the air inlet port (114) such that the air stream coming through the air inlet port (114) in the chamber (104) strikes on baffle plate (118), wherein the baffle plate (118) is movably coupled to an inner surface of the second side wall of the housing (102) to allow change in angular position of the baffle plate (118) with respect to the inner surface of the second side wall (108) based on an angle of the air stream entering into the chamber (104); and
one or more water jet nozzles (120) configured with the top plate (110) of the housing (102), wherein the one or more water jet nozzles (120) are adapted to spray water received from a water source into the chamber (104) in an atomized form to enable humidification of the air in the chamber (104).
11. A method for air humidification for a fuel cell stack (350), the method comprising:
providing, a humidifier apparatus (100) operatively coupled to a cathode inlet (302) of the fuel cell stack (350) to supply humidified air to the fuel cell stack (350) on receipt of hydrogen from a hydrogen supply unit (304) at an anode inlet (310) of the fuel cell stack (350);
supplying, by an air compressor (306), a compressed air stream to an air inlet port (114) movably configured with an air inlet (116) of a housing (102) of the humidifier apparatus (100) for humidification, wherein the air stream coming through the air inlet port (114) in a chamber (104) of the housing (102) strikes on a baffle plate (118) disposed in the chamber (104); and
controlling, by a control unit (308), one or more attributes associated with one or more water jet nozzles (120) of the humidifier apparatus (100), wherein the one or more water jet nozzles (120) are adapted to spray water received from a water source into the chamber (104) in an atomized form to enable humidification of the air in the chamber (104) of the housing (102) of the humidifier apparatus (100).