Bypass flow rate control device for membrane humidifier and membrane humidifier having same

Abstract

A bypass flow rate control device for a membrane humidifier according to the present invention comprises: a flow rate control valve disposed on an inlet side of a housing through which wet gas enters; a first bypass flow path that branches upstream of the inlet of the housing to branch the wet gas before the wet gas enters the housing; and an opening and closing valve provided on the first bypass flow path to open and close the first bypass flow path. When the vehicle is under a predetermined initial starting condition, the opening and closing valve opens the first bypass flow path and the flow rate control valve is closed to block the wet gas from flowing into the housing. When the vehicle is not under the initial starting condition, the opening and closing valve closes the first bypass flow path and the flow rate control valve is opened to allow the wet gas to flow into the housing.

Description

Bypass flow control device for membrane humidifier and membrane humidifier equipped with same

[0001] The present invention relates to a bypass flow control device for a membrane humidifier and a membrane humidifier having the same, and more particularly, to a bypass flow control device for a membrane humidifier that controls the flow rate by bypassing humidified gas to prevent excessive humidification by preventing excessive humidification by preventing excessive humidification of air from flowing into a stack during the initial operation or low-power section of a vehicle, and to a membrane humidifier having the same.

[0002] Fuel cells generate electrical energy using the chemical energy generated by the combination of hydrogen and oxygen. Fuel cells are actively being researched as an environmentally friendly energy source with minimal pollutant emissions.

[0003] Fuel cells can be broadly classified into polymer electrolyte membrane fuel cells (PEMFC), phosphoric acid fuel cells (PAFC), molten carbonate fuel cells (MCFC), solid oxide fuel cells (SOFC), and alkaline fuel cells (AFC) depending on the type of electrolyte used.

[0004] While each of these fuel cells operates on fundamentally identical principles, they differ in the type of fuel used, operating temperature, catalyst, and electrolyte. Among these, polymer electrolyte membrane fuel cells (PEMFCs) are known to be the most promising, not only for small-scale stationary power generation but also for transportation systems, due to their low-temperature operation and high power density, which allows for miniaturization.

[0005] One of the most important factors in improving the performance of polymer electrolyte membrane fuel cells (PEMFCs) is maintaining the moisture content of the polymer electrolyte membrane (or proton exchange membrane: PEM) of the membrane electrode assembly (MEA) by supplying a certain amount of moisture or more. This is because power generation efficiency rapidly declines when the polymer electrolyte membrane dries.

[0006] Methods for humidifying a polymer electrolyte membrane include 1) a bubbler humidification method in which a pressure vessel is filled with water and the target gas is passed through a diffuser to supply moisture, 2) a direct injection method in which the amount of moisture required for the fuel cell reaction is calculated and moisture is directly supplied to the gas flow pipe through a solenoid valve, and 3) a humidification membrane method in which moisture is supplied to a gas fluidized bed using a polymer membrane. Among these, the membrane humidification method in which only water vapor contained in the exhaust gas is selectively transmitted and water vapor is supplied to the air supplied to the polymer electrolyte membrane to humidify the polymer electrolyte membrane is advantageous in that the humidifier can be made lighter and smaller.

[0007] The selectively permeable membrane used in membrane humidification is preferably a hollow fiber membrane with a large permeable area per unit volume when forming a module. Manufacturing a humidifier using hollow fiber membranes allows for high integration of the membranes with a large contact surface area, enabling sufficient humidification of fuel cells even with small capacities. Furthermore, the membranes are relatively inexpensive and can recover moisture and heat contained in the high-temperature off-gas discharged from the fuel cell for reuse in the humidifier.

[0008] Figure 1 is a schematic exploded perspective view of a conventional membrane humidifier for fuel cells. Referring to Figure 1, a conventional membrane humidifier includes a humidifying module (110) in which moisture exchange occurs between air supplied from the outside and exhaust gas discharged from a fuel cell stack (not shown), and first and second caps (120, 130) respectively connected to both ends of the humidifying module (110).

[0009] Outside air is introduced through the inlet (121) of the first cap (120) and delivered to the humidifying module (110), and air humidified by the humidifying module (110) is delivered to the stack of the fuel cell through the outlet (131) of the second cap (130). The humidifying module (110) includes a housing (111) having an off-gas inlet (111a) through which wet exhaust gas discharged from the stack is introduced and an off-gas outlet (111b) through which the exhaust gas is discharged, and a cartridge (100) arranged within the housing (111).

[0010] The above cartridge (100) is fastened to the fastening portion (112) of the housing (111). A plurality of the above cartridges (100) can be fastened to the fastening portion (112). The interior of the cartridge (100) is filled with a hollow fiber membrane, and both ends of the hollow fiber membrane are potted and fixed to both ends of the cartridge (100). The hollow fiber membrane can be potted by curing a liquid polymer such as a liquid polyurethane resin.

[0011] Air supplied from the outside is introduced into the first cap (120) and flows along the hollow fiber membranes. The exhaust gas introduced into the housing (111) through the exhaust gas wet gas inlet (111a) comes into contact with the outer surface of the hollow fiber membranes and then flows out of the housing (111) through the exhaust gas wet gas outlet (111b). When the exhaust gas comes into contact with the outer surface of the hollow fiber membranes, moisture contained in the exhaust gas permeates the hollow fiber membranes, thereby humidifying the air flowing along the hollow fiber membranes.

[0012] Humidification is achieved through a process in which wet gas introduced through the wet gas inlet (111a) comes into contact with the outer surface of the hollow fiber membrane (150) placed inside the cartridge (100). The cartridges (100) are arranged adjacent to each other in multiple numbers, and the wet gas is introduced between the cartridges (100) and is introduced into the interior through a window formed in the cartridge (100).

[0013] As described above, a membrane humidifier uses moist gas discharged from a stack to humidify outside air and then supplies it to the stack. However, if the outside air is excessively humidified, the over-humidified air flows into the stack, which reduces the power generation efficiency of the fuel cell. In particular, over-humidification by moist gas is a problem during the initial operation or at low engine output. Therefore, the present invention proposes an invention that bypasses moist gas during the initial operation or at low output.

[0014] The present invention has been devised to improve the above-described problems, and its purpose is to provide a bypass flow control device for a membrane humidifier that controls the flow rate by bypassing humidified gas to prevent excessive humidification by preventing excessive humidification by preventing excessive humidification air from flowing into the stack during the initial operation or low-power section of a vehicle, and a membrane humidifier having the same.

[0015] According to one aspect of the present invention, a bypass flow control device for a membrane humidifier is a bypass flow control device for a membrane humidifier that controls the flow rate of a wet gas bypassed before the wet gas comes into contact with a hollow fiber membrane, the bypass flow control device comprising: a flow control valve arranged on an inlet side of a housing through which the wet gas flows; a first bypass flow path branching from a front end side of the inlet of the housing so as to branch the wet gas before it flows into the housing; And an on-off valve provided on the first bypass passage to open and close the first bypass passage; when the vehicle is under a predetermined initial starting condition, the on-off valve opens the first bypass passage and the flow control valve closes, thereby blocking the wet gas from flowing into the housing, and when the initial starting condition is out of the condition, the on-off valve closes the first bypass passage and the flow control valve opens, thereby allowing the wet gas to flow into the housing.

[0016] In addition, the flow control valve preferably includes a body part formed in a spherical shape; a first through-hole penetrating the body part in one direction to allow the wet gas to pass through; and a driving part rotating the body part, such that the body part is rotated by the driving part and the first through-hole is selectively connected to the inlet of the housing when the body part is stationary.

[0017] In addition, the invention includes a control unit that controls the opening and closing of the flow control valve and the opening / closing valve, and it is preferable that the control unit opens the opening / closing valve for a predetermined time after the vehicle is started, and closes the flow control valve.

[0018] In addition, it is preferable that the control unit opens the opening / closing valve and closes the flow rate control valve until the flow rate of the wet gas generated from the stack reaches a predetermined level.

[0019] In addition, the flow control valve preferably includes: a body portion formed in a spherical shape; a first through-hole penetrating the body portion in one direction to allow the wet gas to pass through; and a second through-hole formed in a direction different from the first through-hole and ventilated with the first through-hole; and a driving unit that rotates the body portion; wherein the body portion is rotated by the driving unit, and the first through-hole is selectively communicated with the inlet of the housing when the body portion is stationary, and when the first through-hole is communicated with the inlet, the wet gas is introduced into the interior of the housing through the first through-hole, and a portion of the wet gas is bypassed through the second through-hole.

[0020] In addition, it is preferable that a second bypass passage is formed inside the housing through which the wet gas bypassed through the second through hole passes.

[0021] Additionally, it is preferable that the cross-sectional area of ​​the first through hole is larger than the cross-sectional area of ​​the second through hole.

[0022] In addition, it is preferable that the control unit includes a control unit that controls the opening and closing of the flow control valve and the opening / closing valve, and the control unit opens the opening / closing valve for a predetermined time after the vehicle is started, and rotates the body unit so that the first through hole of the flow control valve does not communicate with the inlet.

[0023] In addition, it is preferable to include a control unit that controls the opening and closing of the flow control valve and the opening / closing valve, and to open the opening / closing valve until the flow rate of the wet gas generated from the stack reaches a predetermined level, and to rotate the body unit so that the first through hole of the flow control valve does not communicate with the inlet.

[0024]

[0025] Meanwhile, a membrane humidifier according to another aspect of the present invention comprises: a housing having an inlet formed on one side through which a humid gas is introduced and an outlet formed on the other side through which the humid gas introduced through the inlet is discharged; a first cap coupled to one side of the housing through which outside air is introduced; a plurality of hollow fiber membranes provided inside the housing through which outside air introduced through the first cap flows and through which the humid gas contacts an outer surface to humidify the outside air; a flow rate control valve disposed on the inlet side of the housing; a first bypass channel branching from a front end side of the inlet of the housing to branch the humid gas before it is introduced into the housing; and an opening / closing valve provided on the first bypass channel to open / close the first bypass channel. And a second cap coupled to the other side of the housing, wherein the outside air flows along the hollow fiber membrane and is humidified and discharged; when the vehicle is under a predetermined initial starting condition, the on-off valve opens the first bypass passage and the flow control valve closes, thereby blocking the wet gas from flowing into the housing, and when the initial starting condition is out of the range, the on-off valve closes the first bypass passage and the flow control valve opens, thereby allowing the wet gas to flow into the housing.

[0026] Here, the flow control valve comprises: a body part formed in a spherical shape; a first through-hole penetrating the body part in one direction to allow the wet gas to pass through; and a driving part that rotates the body part; wherein the body part is rotated by the driving part, and the first through-hole can be selectively connected to the inlet of the housing when the body part is stationary.

[0027] Here, a control unit for controlling the opening and closing of the flow control valve and the opening / closing valve is included, and the control unit can open the opening / closing valve for a predetermined time after the vehicle is started, and close the flow control valve.

[0028] Here, the control unit can open the opening / closing valve and close the flow rate control valve until the flow rate of the wet gas generated from the stack reaches a predetermined level.

[0029] Here, the flow control valve comprises: a body part formed in a spherical shape; a first through-hole penetrating the body part in one direction to allow the wet gas to pass through; and a second through-hole formed in a direction different from the first through-hole and ventilated with the first through-hole; and a driving part that rotates the body part; wherein the body part is rotated by the driving part, and the first through-hole is selectively communicated with the inlet of the housing when the body part is stationary, and when the first through-hole is communicated with the inlet, the wet gas is introduced into the interior of the housing through the first through-hole, and a portion of the wet gas can be bypassed through the second through-hole.

[0030] Here, it is preferable that a second bypass passage is formed inside the housing through which the wet gas bypassed through the second through hole passes.

[0031] Here, the cross-sectional area of ​​the first through hole can be formed to be larger than the cross-sectional area of ​​the second through hole.

[0032] Here, a control unit for controlling the opening and closing of the flow control valve and the opening / closing valve is included, and the control unit can open the opening / closing valve for a predetermined time after the vehicle is started, and rotate the body unit so that the first through hole of the flow control valve does not communicate with the inlet.

[0033] Here, a control unit that controls the opening and closing of the flow control valve and the on-off valve is included, and the on-off valve can be opened until the flow rate of the wet gas generated from the stack reaches a predetermined level, and the body part can be rotated so that the first through hole of the flow control valve does not communicate with the inlet.

[0034] A bypass flow control device for a membrane humidifier according to an embodiment of the present invention and a membrane humidifier having the same provide an effect of preventing over-humidification by bypassing the wet gas flowing into the housing during the initial operation of a vehicle or in a low-power section so that it flows into the hollow fiber membrane side.

[0035] In addition, it provides the effect of easily controlling the flow rate of wet gas flowing into the housing by a spherical rotary valve.

[0036] In addition, since a certain amount of wet gas can be bypassed even in normal operation mode, it is possible to suppress rapid pressure fluctuations inside the housing, thereby preventing damage to the hollow fiber membrane and improving humidification efficiency.

[0037] Figure 1 is a perspective view of a conventional membrane humidifier.

[0038] Figure 2 is a drawing showing a bypass flow control device according to one embodiment of the present invention.

[0039] Figure 3 is a drawing showing the operating state of Figure 2.

[0040] Figure 4 is a drawing showing a bypass flow control device according to another embodiment of the present invention.

[0041] Figure 5 is a drawing showing the operating state of Figure 4.

[0042] Figure 6 is a block diagram of a bypass flow control device according to the present invention.

[0043] Hereinafter, various embodiments of the present invention will be described in connection with the accompanying drawings. Various embodiments of the present invention may have various modifications and various embodiments, and thus specific embodiments are illustrated in the drawings and related detailed descriptions are provided. However, this is not intended to limit the various embodiments of the present invention to specific embodiments, but should be understood to include all modifications and / or equivalents or substitutes included in the spirit and technical scope of the various embodiments of the present invention. In connection with the description of the drawings, similar reference numerals have been used for similar components.

[0044] Expressions such as “includes” or “may include” that may be used in various embodiments of the present invention indicate the existence of the disclosed function, operation, or component, etc., and do not limit one or more additional functions, operations, or components, etc. In addition, in various embodiments of the present invention, it should be understood that terms such as “includes” or “has” are intended to specify the existence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and do not exclude in advance the possibility of the existence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0045] When a component is referred to as being "connected" to another component, it should be understood that the component may be directly connected to the other component, but that there may also be a new component between the component and the other component. Conversely, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that no new component exists between the component and the other component.

[0046] The terms used in the various embodiments of the present invention are used solely to describe specific embodiments and are not intended to limit the various embodiments of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0047] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the present invention belong.

[0048] Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in various embodiments of the present invention.

[0049]

[0050] The present invention relates to a membrane humidifier that uses moist gas discharged from a fuel cell stack to humidify dry gas supplied from an external source. In particular, the present invention relates to a membrane humidifier for vehicles, and relates to a flow control device that bypasses moist gas flowing into the membrane humidifier, and a membrane humidifier equipped with the same.

[0051] The membrane humidifier according to the present invention may include a housing (40) and first and second caps (50, 60), as illustrated in FIG. 2. The housing (40) may have a hollow fiber membrane (3) disposed therein as in the prior art, and the first and second caps (50, 60) may be coupled to both ends of the housing (40). The housing (40) has a wet gas inlet (41) formed on one side through which wet gas is introduced, and a wet gas outlet (42) formed on the other side through which wet gas introduced through the inlet (41) is discharged. The first cap (50) is coupled to one side of the housing (40), and external air is introduced through the inlet hole (51) of the first cap (50). The second cap (60) is coupled to the other side of the housing (40), and the outside air flows along the hollow fiber membrane (3), is humidified, and then discharged. The hollow fiber membrane (3) can be filled in a cartridge (100) and detachably coupled to the housing (40). Meanwhile, the wet exhaust gas discharged from the stack flows into the cartridge (100) inside the housing (40), and when the outside air flows through the hollow fiber membrane (3), the wet gas flows along the outer surface of the hollow fiber membrane (3). When the wet gas comes into contact with the outer surface of the hollow fiber membrane (3), moisture is transferred to the inside of the hollow fiber membrane (3), so that the outside air is humidified, and the humidified outside air can be supplied to the fuel cell stack through the discharge hole (61) of the second cap (60). A plurality of cartridges (100) filled with the hollow fiber membrane (3) can be provided. Of course, the hollow fiber membrane (3) is not limited to being provided in the form of a cartridge (100), and both ends of the hollow fiber membrane (3) may be provided by being potted and fixed to both ends of the housing (40).

[0052]

[0053] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The present invention relates to a flow control device that controls the flow rate of wet gas bypassed before the wet gas comes into contact with a hollow fiber membrane (3).

[0054]

[0055] A flow control device according to one embodiment of the present invention includes a flow control valve (10), a first bypass path (20), and an opening / closing valve (30), as shown in FIG. 2.

[0056]

[0057] The above flow control valve (10) is arranged on the inlet (41) side of the housing (40) into which the wet gas flows. According to an embodiment of the present invention, the flow control valve (10) is rotatably arranged inside the inlet (41). Specifically, the flow control valve (10) includes a body portion (11), a first through hole (12), and a driving portion (13).

[0058] The body part (11) is rotatably arranged inside the inlet (41). According to the present embodiment, the body part (11) is formed in a spherical shape. The outer circumferential surface of the body part (11) is in contact with the inner circumferential surface of the inlet (41). According to the present embodiment, the body part (11) is arranged so that wet gas can selectively pass through it depending on the rotated position inside the inlet (41). For example, when the body part (11) is in the first position, the wet gas can flow through the body part (11) and be introduced into the interior of the housing (40). In addition, when the body part (11) is in the second position, the wet gas cannot pass through the body part (11) and can flow toward the bypass path.

[0059] The first through hole (12) is formed to penetrate the body part (11) in one direction so that the wet gas can pass through it. When the body part (11) is in the first position, the first through hole (12) is arranged to communicate the inlet (41) and the interior of the housing (40), and when the body part (11) is in the second position, the first through hole (12) closes the inlet (41) to block internal communication with the housing (40).

[0060] The above driving unit (13) is provided to rotate the body part (11). The driving unit (13) may be a motor, and according to the present embodiment, may be disposed outside the inlet (41). The driving unit (13) may be configured to be connected to the body part (11) and a rotation shaft to transmit power. The body part (11) is rotated by the driving unit (13), and the first through-hole (12) is selectively connected to the inlet (41) of the housing (40) depending on the state in which the body part (11) is stationary. The state in which the body part (11) is stationary may be, for example, a first position or a second position.

[0061] The first bypass flow path (20) is provided to branch the wet gas before it flows into the housing (40). The first bypass flow path (20) branches from the front end side of the inlet (41) of the housing (40). Branching from the front end side of the inlet (41) means that the flow path branches so that the wet gas can bypass through the first bypass flow path (20) before flowing into the inlet (41).

[0062] As illustrated in Fig. 2, the first bypass passage (20) is connected to a discharge line that discharges wet gas from an outlet (42) formed in the housing (40). Of course, the first bypass passage (20) may be configured to be discharged separately to the outside without being connected to the discharge line.

[0063] The above-mentioned opening / closing valve (30) is provided on the first bypass passage (20) and opens / closes the first bypass passage (20). When it is necessary to bypass the wet gas under predetermined conditions, the opening / closing valve (30) opens the first bypass passage (20) to allow the flow of the wet gas, and when the driving conditions of the vehicle deviate from the predetermined conditions, the first bypass passage (20) is closed to allow the wet gas to flow into the housing (40).

[0064] According to an embodiment of the present invention, when the vehicle is under a predetermined initial starting condition, the opening / closing valve (30) opens the first bypass valve and the flow control valve (10) closes to block the wet gas from flowing into the housing (40). On the other hand, when the initial starting condition is out of the range, the opening / closing valve (30) closes the first bypass passage (20) and the flow control valve (10) opens to allow the wet gas to flow into the housing (40).

[0065]

[0066] As illustrated in FIG. 3, according to an embodiment of the present invention, a control unit (80) is included that controls the opening and closing of the flow control valve (10) and the on-off valve (30). The control unit (80) can open the on-off valve (30) and close the flow control valve (10) until a predetermined time after the vehicle is started. In addition, the control unit (80) can open the on-off valve (30) and close the flow control valve (10) until the flow rate of the wet gas generated from the stack reaches a predetermined level.

[0067] The above-described predetermined time may be set to a time point of, for example, 30 seconds or more and 1 minute or less after starting. For example, if the above-described time is set to a time point of 1 minute after starting, the control unit (80) may open the opening / closing valve (30) and close the flow control valve (10) for 1 minute after starting the vehicle so that the wet gas is bypassed through the first bypass passage (20) before flowing into the housing (40).

[0068] The above-mentioned predetermined time is not limited to the above range, but if the humid gas is not introduced into the housing (40) but bypassed in a situation where the initial operation section is exceeded after 1 minute from the start, the humidification efficiency of the membrane humidifier is lowered, and since preventing over-humidification as an initial operation condition in less than 30 seconds from the start increases the efficiency of the stack, it is preferable to set the above-mentioned predetermined time within the above range.

[0069] In addition, the predetermined level of the wet gas flow rate can be set to a point where the flow rate of the wet gas flowing toward the inlet (41) after startup reaches a predetermined volume. The predetermined volume can be set to a flow rate of the wet gas of 2000 slpm (Standard Liter Per Minute) or less. That is, the flow rate of the wet gas flowing into the inlet (41) of the housing (40) from the stack increases after startup, and in a low output section where the flow rate of the wet gas reaches 2000 slpm, the control unit (80) can open the on-off valve (30) and close the flow rate control valve (10) to control the wet gas to be bypassed through the first bypass passage (20) before flowing into the housing (40).

[0070] The predetermined level of the above wet gas flow rate is not limited to 2000 slpm or less, but until the point where the wet gas inflow rate reaches 2000 slpm, the efficiency of the stack is improved by reducing the inflow of wet gas into the interior of the housing (40) as an initial operation section to prevent over-humidification, and after the initial operation section has passed, the wet gas is allowed to flow into the housing (40) to provide sufficient humidified air.

[0071] In addition, according to an embodiment of the present invention, the control unit (80) can control to gradually reduce the flow rate of the wet gas bypassed through the first bypass passage (20) until the above-described predetermined condition is reached. That is, the control unit (80) can gradually reduce the flow rate of the wet gas bypassed through the first bypass passage (20) until a predetermined time after the vehicle is started. For example, the control unit (80) can gradually reduce the flow rate of the wet gas discharged through the first bypass passage (20) by adjusting the opening degree of the on-off valve (30) until a time of 1 minute from the time of starting the vehicle. At this time, the control unit (80) can control the opening degree of the flow rate control valve (10) in conjunction with the on-off valve (30) in order to gradually increase the flow rate of the wet gas flowing into the housing (40).

[0072] In addition, the control unit (80) can control to gradually reduce the flow rate of the wet gas bypassed through the first bypass passage (20) until the flow rate of the wet gas flowing into the inlet (41) side after the vehicle is started reaches a predetermined set value. For example, the control unit (80) can gradually reduce the flow rate of the wet gas discharged through the first bypass passage (20) by adjusting the opening degree of the on-off valve (30) until the flow rate of the wet gas generated in the stack and flowing into the housing (40) after the vehicle is started reaches 2000 slpm. At this time, the control unit (80) can control the opening degree of the flow rate control valve (10) in conjunction with the on-off valve (30) in order to gradually increase the flow rate of the wet gas flowing into the housing (40).

[0073] In this way, the control unit (80) prevents air over-humidified by the membrane humidifier from flowing into the stack by gradually reducing the flow rate of the humid gas bypassed in the initial start-up and low-output sections, and smoothly changes the operating state of the membrane humidifier to enable normal humidification when the initial start-up section is over, thereby providing the effect of stable system operation.

[0074]

[0075] According to another embodiment of the present invention, the flow control valve (10) may include a body portion (11), a first through hole (12), a second through hole (14), and a driving portion (13). Components that are substantially the same as the flow control valve (10) described above in this embodiment are given the same reference numbers.

[0076] The body part (11) is rotatably arranged on the side of the inlet (41). According to the present embodiment, the body part (11) is formed in a spherical shape. The outer circumferential surface of the body part (11) is in contact with the inlet (41). The body part (11) is arranged so that wet gas can selectively pass through it depending on the rotational position. For example, when the body part (11) is in the first position, the wet gas can flow through the body part (11) and be introduced into the interior of the housing (40). In addition, when the body part (11) is in the second position, the wet gas cannot pass through the body part (11) and can flow toward the bypass path.

[0077] The first through hole (12) is formed to penetrate the body part (11) in one direction so that the wet gas can pass through it. When the body part (11) is in the first position, the first through hole (12) is arranged to communicate the inlet (41) and the interior of the housing (40), and when the body part (11) is in the second position, the first through hole (12) closes the inlet (41) to block internal communication with the housing (40).

[0078] The second through hole (14) is formed in a different direction from the first through hole (12) and is formed to be ventilated with the first through hole (12). According to the present embodiment, as illustrated in FIG. 5, the second through hole (14) is formed in a direction perpendicular to the direction of the first through hole (12) and is formed at an eccentric position away from the center of the spherical body portion (11). In addition, the second through hole (14) is formed so that its cross-sectional area is smaller than that of the first through hole (12).

[0079] According to the present embodiment, a second bypass passage is formed inside the housing (40) through which the wet gas bypassed through the second through hole (14) passes. The second bypass passage is provided by forming a bypass hole (71) in a mounting portion (70) for mounting a cartridge (100) in which the hollow fiber membrane (3) is accommodated. The wet gas introduced into the inside of the housing (40) is bypassed to a certain extent without contacting the hollow fiber membrane (3) through the second bypass passage, and the hollow fiber membrane (3) is prevented from being damaged by the pressure of the wet gas flowing into the hollow fiber membrane (3) due to the bypass of the wet gas, and the pressure difference between the inlet (41) side and the outlet (42) side of the housing (40) can be eliminated.

[0080] According to the present embodiment, the second through hole (14) is formed to have a diameter smaller than that of the first through hole (12), so that the flow rate flowing through the second through hole (14) is smaller than that flowing through the first through hole (12), thereby efficiently achieving the effects of relieving the pressure difference and preventing damage to the hollow fiber membrane (3) as described above without lowering the humidification efficiency by the wet gas.

[0081] The above driving unit (13) is provided to rotate the body part (11). The driving unit (13) may be a motor, and according to the present embodiment, may be disposed outside the inlet (41). The driving unit (13) may be configured to be connected to the body part (11) and a rotation shaft to transmit power. When the body part (11) is rotated by the driving unit (13), the first through-hole (12) may be selectively connected to the inlet (41) of the housing (40) depending on the state in which the body part (11) is stationary. The state in which the body part (11) is stationary may be, for example, the first position or the second position. When the first through hole (12) is connected to the inlet (41), the wet gas flows into the interior of the housing (40) through the first through hole (12), and a portion of the wet gas is bypassed through the second bypass passage through the second through hole (14).

[0082] According to the present embodiment, similar to the embodiment of FIG. 2, it includes a control unit (80) that controls the opening and closing of the flow control valve (10) and the on-off valve (30). The control unit (80) can open the on-off valve (30) for a predetermined time after the vehicle is started and rotate the body part (11) so that the first through-hole (12) of the flow control valve (10) does not communicate with the inlet (41). In addition, the control unit (80) can open the on-off valve (30) until the flow rate of the wet gas generated from the stack (1) reaches a predetermined level and rotate the body part (11) so that the first through-hole (12) of the flow control valve (10) does not communicate with the inlet (41). At this time, the second through-hole (14) is aligned toward the second bypass path.

[0083] The above control unit (80) is intended to prevent over-humidification by bypassing the wet gas during the initial start-up and low-power sections of the vehicle. The level of flow rate of the wet gas generated from the stack (1) after start-up toward the inlet (41) within a predetermined time range after start-up can be set to be substantially the same as in the embodiment of Fig. 2 described above. The operation process of the above control unit (80) has already been described above, so a repetitive description will be omitted.

[0084] In addition, the control unit (80) can gradually reduce the flow rate of the wet gas bypassed in the initial startup and low-power sections. That is, the flow rate of the wet gas bypassed through the first bypass passage (20) can be gradually reduced in a predetermined time range (initial startup section) after startup, and the flow rate of the wet gas flowing into the housing (40) can be gradually increased. In addition, the flow rate of the wet gas bypassed through the first bypass passage (20) can also be gradually reduced in a predetermined low-power section after startup, and the flow rate of the wet gas flowing into the housing (40) can be gradually increased. When the bypass flow rate is gradually changed in this way, the opening degrees of the flow control valve (10) and the on-off valve (30) can be gradually changed. Since this is substantially the same as the embodiment of FIG. 3, a repeated explanation is omitted.

[0085]

[0086] Meanwhile, according to another aspect of the present invention, a membrane humidifier having a flow control device is provided. According to the present embodiment, the membrane humidifier includes a housing (40), a hollow fiber membrane (3), a first cap (50), a second cap (60), and a flow control device.

[0087] The housing (40) has an inlet (41) formed on one side through which wet gas is introduced, and an outlet (42) formed on the other side through which the wet gas introduced through the inlet (41) is discharged. The housing (40) provides a space in which a hollow fiber membrane (3) is placed inside, and provides a space in which wet gas is introduced inside to transfer moisture of the wet gas to the outside air. Referring to Fig. 3, the inlet (41) and the outlet (42) are provided on the upper surface of the housing (40). Of course, the formation positions of the inlet (41) and the outlet (42) are not limited thereto.

[0088] The hollow fiber membrane (3) is accommodated inside the housing (40). Outside air flows through the inside of the hollow fiber membrane (3), and wet gas comes into contact with the outer surface. As the wet gas comes into contact with the outer surface of the hollow fiber membrane (3), moisture penetrates into the inside, and the outside air is humidified. According to the present embodiment, the hollow fiber membrane (3) is provided in the form of a cartridge (100), as shown in Fig. 1. The cartridge (100) having the hollow fiber membrane (3) coupled thereto can be detachably mounted on the housing (40).

[0089] The hollow fiber membrane (3) is placed inside the cartridge (100), and both ends of the cartridge (100) and the hollow fiber membrane (3) are potted to form a potting layer and are fixed. The potting layer can be formed by curing a liquid polymer such as a liquid polyurethane resin. The cartridge (100) can be detachably coupled to the mounting portion (70) of the housing (40). According to the present embodiment, a plurality of cartridges (100) can be mounted inside the housing (40).

[0090] The hollow fiber membrane (3) is formed of a material through which moisture of the wet gas can penetrate. For example, the hollow fiber membrane (3) may be formed of a polymer membrane formed of polysulfone resin, polyethersulfone resin, sulfonated polysulfone resin, polyvinylidene fluoride (PVDF) resin, polyacrylonitrile (PAN) resin, polyimide resin, polyamideimide resin, polyesterimide resin, or a mixture of two or more thereof. The hollow fiber membrane (3) is potted and fixed to the cartridge (100), so that it can be integrally attached to and detached from the housing (40).

[0091] The cartridge (100) according to the present embodiment, similar to FIG. 1, has a first window (101) formed on one side to introduce wet gas, and a second window (102) formed on the other side to discharge the wet gas introduced into the interior of the cartridge (100). The first window (101) and the second window (102) may be formed in a plurality of rows in the vertical direction. The size of the first window (101) and the number of rows, etc., of the second window (102) may vary. The wet gas introduced into the interior of the cartridge (100) through the first window (101) may flow to the rear end and then be discharged to the outside through the second window (102). The wet gas discharged through the second window (102) may be discharged to the outside through the discharge hole (61) of the housing (40).

[0092] The first cap (50) is coupled to one side of the housing (40). An inlet hole (51) is formed in the first cap (50) through which external air is introduced. The second cap (60) is coupled to the other side of the housing (40), and external air introduced through the first cap (50) flows along the hollow fiber membrane (3), is humidified, and then is discharged to the stack. An exhaust hole (61) is formed in the second cap (60) to discharge the humidified air.

[0093] The above flow control device can be adopted as is, as described above with reference to FIGS. 2 to 5. That is, the flow control device may include a flow control valve (10) arranged on the inlet (41) side of the housing (40), a first bypass passage (20) branching from the front side of the inlet (41) of the housing (40) to branch the wet gas before it flows into the housing (40), and an on-off valve (30) provided on the first bypass passage (20) to open and close the first bypass passage (20), and when the vehicle is under a predetermined initial starting condition, the on-off valve (30) opens the first bypass passage (20) and the flow control valve (10) is closed, thereby blocking the wet gas from flowing into the housing (40), and when the initial starting condition is out of the range, the on-off valve (30) closes the first bypass passage (20) and the flow control valve (10) It can be opened to allow the wet gas to flow into the housing (40).

[0094] In addition, according to a membrane humidifier according to one embodiment, the flow control valve (10) may adopt the configuration of FIG. 2 as it is. That is, the flow control valve (10) may include a body part (11), a first through-hole (12), and a driving unit (13), and by rotating the body part (11) by the driving unit (13), the first through-hole (12) may be selectively connected to the inlet (41) of the housing (40) while the body part (11) is stationary. The configuration of the body part (11), the first through-hole (12), and the driving unit (13) is substantially the same as the configuration of the embodiment of FIG. 2. In addition, according to this embodiment, the flow control valve (10) may include a control unit (80) that controls the opening and closing of the flow control valve (10) and the opening / closing valve (30). The above control unit (80) can open the on-off valve (30) for a predetermined time after the vehicle is started and close the flow rate control valve (10), or can open the on-off valve (30) and close the flow rate control valve (10) until the flow rate of the wet gas generated from the stack (1) reaches a predetermined level. Since this configuration and operation can be adopted substantially the same as the control unit (80) according to the embodiments of FIGS. 2 and 3, a repeated description thereof will be omitted. In addition, the control unit (80) can gradually reduce the bypass flow rate of the wet gas under predetermined initial driving conditions, and at this time, can control the opening degrees of the flow rate control valve (10) and the on-off valve (30) to gradually change.

[0095] Meanwhile, according to a membrane humidifier according to another embodiment, the flow control valve (10) may adopt the configuration of FIG. 4 as is. That is, the flow control valve (10) may include a body (11), a first through-hole (12), a second through-hole (14), and a driving unit (13), and when the body (11) is rotated by the driving unit (13), the first through-hole (12) is selectively connected to the inlet (41) of the housing (40) depending on the stationary state of the body (11). When the first through-hole (12) is connected to the inlet (41), the wet gas flows into the interior of the housing (40), and a portion of the wet gas may be bypassed through the second through-hole (14). The configuration of the body portion (11), the first through-hole (12), the second through-hole (14), and the driving portion (13) is substantially the same as that of the embodiment of FIG. 4. In addition, this embodiment may also include a control unit (80) that controls the opening and closing of the flow control valve (10) and the on-off valve (30). The control unit (80) may open the on-off valve (30) for a predetermined time after the vehicle is started and close the flow control valve (10), or open the on-off valve (30) and close the flow control valve (10) until the flow rate of the wet gas generated from the stack (1) reaches a predetermined level. Since these configurations and operations may be employed substantially the same as those of the control unit (80) according to the embodiments of FIGS. 2 and 3, a repeated description thereof will be omitted. In addition, the control unit (80) can gradually reduce the bypass flow rate of the wet gas under predetermined initial operating conditions, and at this time, control the opening degree of the flow control valve (10) and the opening / closing valve (30) to gradually change.

[0096]

[0097] Hereinafter, the bypass flow control device for a membrane humidifier according to the above configuration and the operation and effect of a membrane humidifier equipped with the same will be described in detail.

[0098] In a vehicle fuel cell, when the vehicle engine operates, hydrogen and oxygen react in the stack to generate wet gas. The wet gas is introduced into the housing (40) of the membrane humidifier to humidify the air supplied to the stack. Referring to FIG. 1, the wet gas introduced into the inlet (41) of the housing (40) flows into the first window (101) of the cartridge (100), flows along the outer surface of the hollow fiber membrane (3) provided in a bundle shape inside the cartridge (100), and is discharged toward the second window (102). The wet gas discharged through the second window (102) is discharged to the outside through the outlet (42) of the housing (40). Meanwhile, the blower (2) introduces outside air into the housing (40) through the first cap (50), and the outside air moves along the inside of the hollow fiber membrane (3), receives moisture from the wet gas, and is humidified. Humidified outside air is discharged through the second cap (60) and supplied to the stack.

[0099] The present invention prevents over-humidification in the initial driving conditions of a vehicle, i.e., by bypassing the humid gas generated in the stack before it flows into the housing (40) until a predetermined point in time after starting or until the flow rate of the humid gas reaches a predetermined range after starting. That is, in the initial driving or low-power environment, if excessive humidified air is supplied to the stack, the power generation efficiency of the stack is lowered, so in the initial driving or low-power environment, the humidification rate is reduced by bypassing the humid gas through the first bypass passage (20).

[0100] In addition, according to an embodiment of the present invention, the flow rate of the wet gas flowing into the housing (40) can be easily controlled by a spherical rotary valve. The spherical rotary valve can be used to easily open or close the inlet (41), and by controlling the degree of rotation, the degree to which the first through-hole communicates with the inlet (41) can be controlled so that the flow rate of the wet gas flowing in through the first through-hole can be continuously changed. Therefore, the flow rate of the wet gas bypassed from the outside of the housing (40) and the flow rate of the wet gas flowing into the housing (40) can be changed smoothly rather than abruptly, thereby improving the performance of the membrane humidifier.

[0101] In addition, since a certain amount of wet gas can be bypassed even in normal operation mode, it is possible to suppress rapid pressure fluctuations inside the housing (40), thereby preventing damage to the hollow fiber membrane (3) and providing the effect of improving humidification efficiency.

[0102] In addition, it can provide the effect of preventing the outside air from being additionally humidified and over-humidified by the condensate present inside the membrane humidifier during the initial operation and low-power section. The condensate is generated inside the membrane humidifier during the process in which the wet gas comes into contact with the housing (40), the outer surface of the hollow fiber membrane (3), and the surface of the cartridge (100). During the initial operation section of the vehicle, when the wet gas flows into the inside of the housing (40), the condensate present inside the housing (40) may transfer moisture to the outside air flowing through the hollow fiber membrane (3) together with the wet gas, thereby causing over-humidification. The present invention can additionally prevent the moisture of the condensate remaining inside the housing (40) from being transferred to the outside air by bypassing the wet gas through the first bypass passage (20). Through this series of processes, the membrane humidifier according to the present invention contributes to improving the efficiency of the fuel cell stack.

[0103]

[0104] Above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and many modifications can be provided within a range that does not depart from the scope of the present invention.

Claims

1. In a bypass flow control device for a membrane humidifier that controls the flow rate of the wet gas bypassed before the wet gas comes into contact with the hollow fiber membrane, A flow control valve (10) arranged on the inlet (41) side of the housing (40) into which the above wet gas is introduced; A first bypass path (20) branching from the front end side of the inlet (41) of the housing (40) to branch the wet gas before it flows into the housing (40); It includes an opening / closing valve (30) provided on the first bypass passage (20) to open / close the first bypass passage (20); When the vehicle is under a predetermined initial starting condition, the opening / closing valve (30) opens the first bypass path (20), and the flow control valve (10) is closed, thereby blocking the wet gas from flowing into the housing (40). A bypass flow control device for a membrane humidifier, characterized in that when the above initial starting conditions are exceeded, the opening / closing valve (30) closes the first bypass flow path (20), and the flow control valve (10) opens to allow the wet gas to flow into the housing (40).

2. In paragraph 1, The above flow control valve (10) is A body part (11) formed in a spherical shape; and A first through hole (12) that penetrates the body part (11) in one direction and allows the wet gas to pass through; Including a driving part (13) that rotates the above body part (11); A bypass flow control device for a membrane humidifier, characterized in that the body part (11) is rotated by the driving part (13), and the first through hole (12) is selectively connected to the inlet (41) of the housing (40) while the body part (11) is stationary.

3. In paragraph 1, It includes a control unit (80) that controls the opening and closing of the flow control valve (10) and the opening and closing valve (30); A bypass flow control device for a membrane humidifier, characterized in that the control unit (80) opens the opening / closing valve (30) for a predetermined time after the vehicle is started and closes the flow control valve (10).

4. In paragraph 1, It includes a control unit (80) that controls the opening and closing of the flow control valve (10) and the opening and closing valve (30); A bypass flow control device for a membrane humidifier, characterized in that the control unit (80) opens the opening / closing valve (30) and closes the flow control valve (10) until the flow rate of the wet gas generated from the stack (1) reaches a predetermined level.

5. In paragraph 1, The above flow control valve (10) is A body part (11) formed in a spherical shape; A first through hole (12) that penetrates the body part (11) in one direction and allows the wet gas to pass through; A second through hole (14) formed in a different direction from the first through hole (12) and ventilated with the first through hole (12); and Including a driving part (13) that rotates the above body part (11); The body part (11) is rotated by the driving part (13), and the first through hole (12) is selectively connected to the inlet (41) of the housing (40) while the body part (11) is stationary. A bypass flow control device for a membrane humidifier, characterized in that when the first through-hole (12) is connected to the inlet (41), the wet gas flows into the interior of the housing (40) through the first through-hole (12), and a portion of the wet gas is bypassed through the second through-hole (14).

6. In paragraph 5, A bypass flow control device for a membrane humidifier, characterized in that a second bypass path is formed inside the housing (40) through which the wet gas bypassed through the second through hole (14) passes.

7. In paragraph 5, A bypass flow control device for a membrane humidifier, characterized in that the cross-sectional area of ​​the first through hole (12) is larger than the cross-sectional area of ​​the second through hole (14).

8. In paragraph 5, It includes a control unit (80) that controls the opening and closing of the above flow control valve (10) and the above opening and closing valve (30), A bypass flow control device for a membrane humidifier, characterized in that the control unit (80) opens the opening / closing valve (30) for a predetermined time after the vehicle is started and rotates the body part (11) so that the first through-hole (12) of the flow control valve (10) does not communicate with the inlet (41).

9. In paragraph 5, It includes a control unit (80) that controls the opening and closing of the above flow control valve (10) and the above opening and closing valve (30), A bypass flow control device for a membrane humidifier, characterized in that the opening / closing valve (30) is opened until the flow rate of the wet gas generated from the stack (1) reaches a predetermined level, and the body part (11) is rotated so that the first through-hole (12) of the flow control valve (10) does not communicate with the inlet (41).

10. A housing (40) having an inlet (41) formed on one side through which a wet gas is introduced and an outlet (42) formed on the other side through which the wet gas introduced through the inlet (41) is discharged; A first cap (50) coupled to one side of the housing (40) and through which external air is introduced; A plurality of hollow fiber membranes (3) provided inside the housing (40) so that external air introduced through the first cap (50) flows and the wet gas comes into contact with the outer surface to humidify the external air; A flow control device including a flow control valve (10) arranged on the inlet (41) side of the housing (40); a first bypass path (20) branching from the front end side of the inlet (41) of the housing (40) to branch the wet gas before the wet gas flows into the housing (40); and an opening / closing valve (30) provided on the first bypass path (20) to open / close the first bypass path (20); and Including a second cap (60) coupled to the other side of the housing (40) so that the external air flows along the hollow fiber membrane (3) and is humidified and discharged; When the vehicle is under a predetermined initial starting condition, the opening / closing valve (30) opens the first bypass path (20), and the flow control valve (10) is closed, thereby blocking the wet gas from flowing into the housing (40). A membrane humidifier characterized in that when the above initial starting conditions are exceeded, the opening / closing valve (30) closes the first bypass path (20) and the flow control valve (10) opens, allowing the wet gas to flow into the housing (40).

11. In paragraph 10, The above flow control valve (10) is A body part (11) formed in a spherical shape; A first through hole (12) that penetrates the body part (11) in one direction to allow the wet gas to pass through; and Including a driving part (13) that rotates the above body part (11); A membrane humidifier characterized in that the body part (11) is rotated by the driving part (13), and the first through hole (12) is selectively connected to the inlet (41) of the housing (40) while the body part (11) is stationary.

12. In paragraph 10, It includes a control unit (80) that controls the opening and closing of the flow control valve (10) and the opening and closing valve (30); A membrane humidifier characterized in that the control unit (80) opens the opening / closing valve (30) for a predetermined time after the vehicle is started and closes the flow control valve (10).

13. In paragraph 10, It includes a control unit (80) that controls the opening and closing of the flow control valve (10) and the opening and closing valve (30); A membrane humidifier characterized in that the control unit (80) opens the opening / closing valve (30) and closes the flow rate control valve (10) until the flow rate of the wet gas generated from the stack (1) reaches a predetermined level.

14. In paragraph 10, The above flow control valve (10) is A body part (11) formed in a spherical shape; A first through hole (12) that penetrates the body part (11) in one direction to allow the wet gas to pass through; and A second through hole (14) formed in a different direction from the first through hole (12) and ventilated with the first through hole (12); and Including a driving part (13) that rotates the above body part (11); The body part (11) is rotated by the driving part (13), and the first through hole (12) is selectively connected to the inlet (41) of the housing (40) while the body part (11) is stationary. A membrane humidifier characterized in that when the first through-hole (12) is connected to the inlet (41), the wet gas flows into the interior of the housing (40) through the first through-hole (12), and a portion of the wet gas is bypassed through the second through-hole (14).

15. In paragraph 14, A membrane humidifier characterized in that a second bypass path is formed inside the housing (40) through which the wet gas bypassed through the second through hole (14) passes.

16. In paragraph 14, A membrane humidifier characterized in that the cross-sectional area of ​​the first through hole (12) is larger than the cross-sectional area of ​​the second through hole (14).

17. In paragraph 14, It includes a control unit (80) that controls the opening and closing of the above flow control valve (10) and the above opening and closing valve (30), A membrane humidifier characterized in that the control unit (80) opens the opening / closing valve (30) for a predetermined time after the vehicle is started and rotates the body part (11) so that the first through-hole (12) of the flow control valve (10) does not communicate with the inlet (41).

18. In paragraph 14, It includes a control unit (80) that controls the opening and closing of the above flow control valve (10) and the above opening and closing valve (30), A membrane humidifier characterized in that the opening / closing valve (30) is opened until the flow rate of the wet gas generated from the stack (1) reaches a predetermined level, and the body part (11) is rotated so that the first through-hole (12) of the flow rate control valve (10) does not communicate with the inlet (41).

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