JP2006128063A - Forming method and forming device of humidified gas having target dew point - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently produce humidified gas having a target dew point required to a test bench or the like, for example, of a fuel cell at a relatively low cost and so as to save a space. <P>SOLUTION: Steam S having higher temperature than a target dew point is continuously mixed to a starting gas flow G having lower temperature than the target dew point K°, the temperature of the mixed gas is measured, and the supply amount of the steam to the starting gas flow is continuously controlled so that the measured mixed gas temperature becomes the same as that of the target dew point. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for generating a humidified gas having a target dew point, and although not limited thereto, to obtain an adjusted fuel gas or oxidant gas set at a target dew point in a fuel cell test bench. It is related with the production | generation method and production | generation apparatus of humidification gas with a suitable target dew point.

  In some fields such as thermal equipment, humidified gas with a preset dew point (target dew point) is continuously used to objectively evaluate the performance of the equipment or to obtain optimal operating conditions. Must be generated and used automatically. For example, in a bench test of a polymer electrolyte fuel cell stack, in order to objectively evaluate the performance of the electrolyte membrane, catalyst layer, gas diffusion layer, and drain separator constituting the stack, a desired dew point must be set in advance. It is necessary to generate a fuel gas and an oxidant gas that are adjusted to have, and supply them to the fuel electrode and the air electrode, respectively, to perform a bench test.

  Patent Document 1 describes a method and apparatus for humidifying a process gas stream used for such purposes, in which steam is added to the process gas stream so that the temperature is higher than the dew point target temperature. After being supersaturated and heated, the process gas at the target dew point is obtained by cooling to the dew point target temperature, and after removing excess water (condensation water) condensed from this process gas, the process gas at the target dew point is targeted. The process gas stream having the target dew point and the target gas temperature is generated by heating to the process gas temperature. The process gas stream produced here is a fuel gas stream and an oxidant gas stream and is sent to the fuel cell via a supply line.

  Patent Document 2 describes a fuel cell test apparatus capable of preventing fluctuations in dew point temperature when humidifying and supplying fuel gas to a fuel cell, in which the apparatus is supplied to the fuel cell. A humidifying means for humidifying the fuel gas to be humidified and a dew point temperature measuring means for measuring the dew point temperature of the humidified fuel gas, wherein the humidifying means is a fuel according to the dew point temperature of the fuel gas measured by the dew point temperature measuring means. The heating temperature when the gas is humidified is controlled.

JP-T-2004-505431 JP 2003-346855 A

  According to the method and apparatus described in Patent Document 1, a process gas flow having a target dew point and a target temperature can be generated with high accuracy. However, with this method, steam is first added so that the gas temperature is higher than the dew point target, and then the process gas is cooled to the dew point target, resulting in wasted energy and steam usage. Yes. There is also a problem that the apparatus needs to be improved in terms of space and cost, for example, because a steam generating boiler is increased in size to add excessive steam and a heat exchanger for gas cooling is required. The thing of patent document 2 presupposes use of an expensive dew point temperature measurement means, and has a cost subject.

  The present invention has been made in view of the circumstances as described above. For example, a humidified gas flow having a target dew point required for a fuel cell test bench or the like can be efficiently and relatively low-cost and space-saving. An object of the present invention is to provide a novel humidified gas production method and production apparatus that can be produced.

  The method for producing a humidified gas having a target dew point according to the present invention continuously mixes steam having a temperature higher than the target dew point into the starting gas stream having a temperature lower than the target dew point, and measures the temperature of the mixed gas after mixing. The supply amount of steam to the starting gas stream is controlled so that the measured mixed gas temperature becomes the same as the target dew point.

  The above generation method is characterized in that steam is added to the starting gas stream while controlling the flow rate so that the gas temperature after mixing becomes the target dew point. Therefore, waste of steam can be reduced and cost reduction can be achieved. In addition, equipment such as a steam generating boiler can be reduced in size, and space can be saved. In the method of the present invention, a) a part of the added steam remains as steam, and the temperature is lowered to the starting gas temperature which is lower than the target dew point, and the energy released at this time is the mixed gas temperature (and surrounding pipes). B) the remainder of the steam (supersaturated) releases latent heat of condensation and raises the temperature of the mixed gas (and the surrounding tube temperature, etc.) to become a drain (condensation water). The two phenomena occur, and finally, the humidified mixed gas reaches a saturation state at “gas temperature = dew point”. That is, by continuously measuring the mixed gas temperature after mixing and controlling the amount of steam mixed in the starting gas stream so that the mixed gas temperature becomes the target dew point, the humidified gas having the target dew point is removed from the useless steam. It can be produced without using a large amount.

  In the method of the present invention, the target dew point is higher than the temperature of the starting gas stream because of the mechanism. Therefore, when it is required to generate a humidified gas having a relatively low dew point, it is necessary to cool the starting gas stream with an appropriate heat exchanger or the like. That is, in the present invention, when the temperature of the starting gas stream is higher than the target dew point, a step of lowering the temperature of the starting gas stream to a temperature lower than the target dew point is further performed. Thereby, the target dew point range can be expanded in actual operation. Further, in the method of the present invention, even if a large amount of condensed water is not by-produced during the generation process of the humidified gas, the by-product condensed water can be separated by means such as a drain separator. Preferably, further energy saving can be achieved by returning the separated water to the boiler feed water.

  The humidified gas generation method according to the present invention can be used in many technical fields such as semiconductor and chemical product manufacturing processes. Among them, it is effective to adopt as a method for generating a humidified gas used in a fuel cell test bench. At this time, the generated humidified gas is a fuel gas used in the fuel cell (for example, hydrogen as a main component). A mixed gas of dry gas and steam) and / or an oxidant gas (mixed gas of air and steam). In this case, the generated humidified gas is heated to a predetermined target temperature by an appropriate heating means such as a heater after removing the by-product condensed water as described above, and then the fuel cell stack is heated. It is sent to the fuel electrode or the air electrode.

  The present invention is further connected to a gas pipe through which the starting gas flows and a gas pipe through which steam is mixed into the starting gas as a device for suitably carrying out the method for generating the humidified gas having the target dew point. A steam line, a flow rate adjusting valve provided in the steam line, a gas-vapor mixing region downstream of the connection portion of the gas line with the steam line, and humidification in the gas-vapor mixing region A temperature sensor for measuring the temperature of the mixed gas, and a control means for controlling the opening of the flow rate adjusting valve based on information from the temperature sensor so as to obtain a steam flow rate such that the temperature of the humidified mixed gas becomes a target dew point; and Also disclosed is a humidified gas generator.

  In the above generation device, the temperature of the humidified mixed gas in the gas-vapor mixing region is measured using a normal temperature sensor, and the opening degree of the flow rate adjusting valve is controlled based on the temperature information. The amount of steam (that is, the amount of gas mixture = target dew point) is mixed into the starting gas stream, and expensive equipment such as a dew point thermometer is not used. Can be planned. In addition, since the intended purpose can be achieved with the minimum amount of steam, excessive capital investment is not required for boilers as a steam generation source. It is done.

  In order to operate the apparatus of the present invention more efficiently, it is desirable to efficiently transfer steam energy to the starting gas stream. One aspect for that purpose is to configure the connection of the steam line in the gas line so that the starting gas flow flowing through the gas line and the vapor flow supplied from the vapor line can be parallel flows. . With this configuration, it is possible to prevent the steam flow from the steam line from strongly colliding with the wall surface of the gas line, and it is possible to prevent loss of steam energy due to local heating of the gas line.

  It is also preferable that the starting gas stream and the steam are mixed together at a short distance so that the energy of the steam can be efficiently transmitted to the starting gas stream and the apparatus can be downsized. For this purpose, in a preferred embodiment of the device according to the invention, a vapor diffusing means for diffusing the vapor flowing into the upstream region of the gas-vapor mixing region is arranged. Specific examples of the vapor diffusion means include an appropriate vapor collision body, vapor diffusion body, and the like that prevent the vapor from going straight. In another preferred embodiment, a mixing facilitating means for promoting the mixing of the humidified gas mixture flowing therethrough is arranged in the gas-vapor mixing zone. The mixing accelerating means may be arbitrary, and more preferably means such as a swirling flow of the humidified mixed gas flow, such as an impeller-shaped gas diffusion plate. This mixing promoting means may be arranged alone or in addition to the vapor diffusion means described above.

  In the apparatus of the present invention, the steam pipe may be provided with one flow rate adjustment valve, a large flow rate adjustment valve is attached to the main flow path, and a fine adjustment dedicated valve is attached to the branch line arranged in parallel. It may be. What is necessary is just to select suitably in an actual machine in consideration of the total amount of steam required or the required control accuracy. As another preferable aspect, an aspect in which at least one or more ON-OFF valves and at least one regulating valve are arranged in parallel can also be mentioned. In general, an ON-OFF valve is less expensive than a flow rate adjustment valve. By adopting this mode, for example, three flow rates can be achieved while having an inexpensive configuration of one adjustment valve and two ON-OFF valves. It becomes possible to appropriately control the flow rate in the same flow range as that provided with the adjusting valve.

  In the apparatus according to the present invention, for the same reason as described in the description of the method for generating the humidified gas, a device for adjusting the temperature of the starting gas is further provided, or the humidified gas is included in the gas-vapor mixing region. Providing a drain separator that separates the condensed water by-produced during the production process is a preferable mode. When the drain separator is provided, the temperature sensor for measuring the temperature of the humidified mixed gas is desirably arranged immediately before or after the drain separator. Further, when the humidified mixed gas passes through the drain separator, the temperature of the drain separator rises due to heat transfer from the humidified mixed gas, and the mixed gas temperature becomes lower than the target dew point because of the heat radiation. When the target dew point accuracy is not high, the target dew point may be used in this state, or the target gas temperature may be set higher in advance in view of the drop. By taking heat retention measures such as wrapping a band heater around the drain separator and keeping the temperature at the target dew point temperature to prevent condensation, the target dew point accuracy can be further increased.

  The apparatus according to the present invention can be used in many technical fields. Among them, it is effective to be used as a humidifying gas generating apparatus used in a fuel cell test bench. As described in the method invention, it is one or both of the fuel gas and the oxidant gas used in the fuel cell. In that case, the apparatus is provided with a heating means for heating and raising the humidified gas of the generated target dew point to a target predetermined temperature after removing the by-product condensed water, and more preferably, A baffle member is provided on the downstream side of the humidified gas heating means for turbulent flow of the humidified gas generated. By providing such a baffle member, the generated humidified gas can be soaked in a short pipe line, which contributes to further space saving of the apparatus.

  When the apparatus of the present invention is used for a fuel cell test bench, the target dew point may be frequently changed, particularly when it is required to shorten the switching time from the high dew point to the low dew point. It is desirable to further provide a means for rapidly cooling the drain separator. An example of the rapid cooling means is a means of winding a copper pipe around a drain separator and passing cooling water therethrough.

  According to the present invention, it is possible to efficiently generate a humidified gas flow having a target dew point, such as that required for a test bench of a fuel cell, at low cost and in a space-saving manner.

  Hereinafter, the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a conceptual diagram for explaining a generation process in a method for generating a humidified gas having a target dew point according to the present invention, and FIG. 2 is a schematic diagram showing an example of an apparatus for that purpose. FIG. 3 is a system when the method and apparatus according to the present invention are used in a fuel cell test bench, and FIGS. 4 and 5 are diagrams for explaining the vicinity of the gas-vapor mixing region. Further, FIG. 6 is a graph for explaining one mode in the case of adjusting the steam flow rate, and FIG. 7 shows the test results when the humidifying gas generating method according to the present invention is carried out using the apparatus shown in FIG. It is a graph to show.

  In the method for generating a humidified gas having a target dew point according to the present invention, first, a target dew point K ° is set. A dew point k1 lower than the target dew point K °, a starting gas (dry gas) G having a gas temperature (for example, room temperature) t1, and a gas temperature (for example, 165 °) t2 higher than the target dew point K °. Steam S is mixed (see also FIG. 2). At the moment of mixing, a part S1 of the added steam S is lowered to the starting gas temperature t1 which is lower than the target dew point K °, and the energy released at this time raises the gas temperature. Further, the remainder (supersaturated portion) of the steam S releases condensed latent heat, and the gas temperature is raised to become condensed water (drain) D. The two phenomena occur, and in the process, the temperature of the mixed gas is continuously measured, and the supply amount (mixing amount) of steam S so that the temperature of the mixed gas becomes K ° which is the same temperature as the target dew point. Adjust. Finally, as indicated by R in FIG. 1, a humidified gas that has reached a saturation state of mixed gas temperature = dew point (K °) is generated.

  As described above, in the humidified gas generation method of the present invention, the humidified gas that has finally reached the saturation state in a state where the amount of the supplied steam is controlled and the temperature of the mixed gas of the gas and the steam is maintained at the target dew point temperature. Since the gas is generated and, in theory, the mixed gas is not oversaturated, wasteful steam (that is, steam that is finally produced as a by-product from condensed water) is minimized. Can be operated at low cost. In addition, the boiler equipment for generating steam may be small-scale, and space saving can be achieved.

  More specifically, as shown in FIG. 2, a starting gas (dry gas) G is supplied to the gas pipeline 1. A steam line 2 is connected to the gas line 1, and the steam S from the boiler flows into the gas line 1 from the steam line 2. The steam line 2 is provided with a flow rate adjusting valve 3, and the amount of steam supplied is controlled by adjusting the opening degree of the flow rate adjusting valve 3. In the illustrated example, the steam line 2 has parallel branch lines 2a, a large capacity adjustment valve 3 is disposed in the main steam line 2, and a fine adjustment valve is provided in the branch line 2a. Although 3a is arranged, it is of course possible to perform a required flow rate adjustment with one flow rate adjustment valve.

  A region after the connection portion of the steam line 2 in the gas line 1 is referred to as a “gas-vapor mixing region” 4, and the mixing of gas and steam proceeds in the region 4. The temperature of the mixed gas in the gas-vapor mixing region 4 is measured by the temperature sensor T, and temperature information is sent to the control means 5. The position of the temperature sensor T is preferably a place where mixing has sufficiently progressed, that is, the downstream side of the flow. The control means 5 passes the amount of steam necessary to fill the difference from the relationship between the target dew point, the measured gas mixture temperature difference, and the amount of steam (energy amount) necessary to fill the difference. It has a function of sending as much valve opening signal as possible to the flow rate adjusting valves 3 and 3a, and this type of conventionally known control mechanism may be used as it is. By performing appropriate feedback control when necessary, the mixed gas temperature can be controlled with higher accuracy. By performing this control, as described above, humidified gas is generated with gas temperature = target dew point. If necessary, the generated humidified gas is supplied to appropriate equipment after removing condensed water generated as a by-product from the humidified gas generated by the drain separator 7.

  An appropriate heat exchanger 8 for cooling the starting gas G can also be provided in the gas line 1. If the temperature of the starting gas G is higher or lower than the target dew point and the temperature difference is slight, the method of the present invention cannot be performed. In such a case, the temperature of the starting gas G is previously lowered to a temperature lower than the target dew point by a required width by using the heat exchanger 8, and the starting gas G and the steam S thus lowered are mixed. To do.

  With reference to FIG. 3, an example in which the above-described humidified gas generating method and apparatus according to the present invention is actually used will be described using a fuel cell test bench. In a fuel cell test bench, it is necessary to supply a fuel cell and an oxidant gas controlled to a target dew point and a target gas temperature to the fuel cell. In the example of FIG. 3, hydrogen (H2), Air (Air) is used as the starting gas for the oxidant gas, and the humidified gas generation method according to the present invention is applied to both starting gases to generate the fuel gas and the oxidant gas controlled to the target dew point and target gas temperature. And supplying it to the fuel cell FC. In FIG. 3, members having the same functions as the members of the apparatus shown in FIG.

  In the system shown in FIG. 3, pure water PW is prepared, and the hydrogen gas flow flowing through the gas pipe line 1H and the air flow flowing through the gas pipe line 1A are exchanged with the pure water PW by the heat exchangers 8 and 8. And cooled (cooled down). The cooled hydrogen gas and air are controlled to a constant flow rate by the mass flow controllers 10 and 10 and flow down through the respective gas pipelines. The pure water PW heated by the heat exchangers 8 and 8 is sent to the pure water tank 11. The cooling water HW of the fuel cell FC circulates in the pure water tank 11 and exchanges heat with the pure water PW.

  The pure water heated by heat exchange is sent to the boilers 12 and 12, for example, steam of about 165 ° and 0.7 MPa is produced. The steam from one boiler 12 flows into the hydrogen gas line 1H through the steam line 2H provided with the flow control valve 3 to form a mixed gas of hydrogen and steam. The steam from the other boiler 12 flows into the air gas pipe 1A through the steam pipe 2A provided with the flow control valve 3 to form a mixed gas of air and steam. Each mixed gas passes through the gas-vapor mixing regions 4H and 4A in each pipe line.

  In the illustrated system example, drain separators 7H and 7A are attached to the ends of the gas-vapor mixing regions 4H and 4A. The drain separators 7H and 7A have temperature sensors TH and TA for measuring the temperature of the mixed gas. Is provided. And the information of each temperature sensor TH and TA is sent to the flow control valve 3 and 3 side via the control means 5, and as already demonstrated in the apparatus shown in FIG. The valve opening is adjusted, and a controlled amount of steam S is supplied to the gas-steam mixing regions 4H, 4A. As a result, each mixed gas is generated as a fuel gas and an oxidant gas controlled to a target dew point.

  The generated fuel gas and oxidant gas are heated to the target gas temperature by the heaters 13 and 13 and then sent to the fuel cell FC to be tested. The fuel cell FC is provided with a back pressure control valve 14 to adjust the operating environment, and the high-temperature cooling water is sent to the pure water tank 11 to exchange heat with the pure water. In the system diagram shown in FIG. 3, the steam pipe is provided with one flow rate adjusting valve. However, like the apparatus shown in FIG. 2, two flow rate adjusting valves 3, 3a are arranged in parallel. You may make it do. Further, as described above, when there is a sufficient gap between the temperature of the starting gas, hydrogen and air, and the target dew point, the heat exchanger 8 may be omitted or not operated. Further, when the drain separator 7 is used, the drain separator 7 is wound around with a band heater 15 or the like and kept at the target dew point temperature, so that undesired dew condensation can be prevented, and the target dew point has higher accuracy. Humidified gas generation is possible. Although not shown, water energy can be saved by returning the water separated by the drain separator 7 to the boiler feed water.

  In the apparatus shown in FIG. 2 or FIG. 3, the mode in which the steam S is mixed in the starting gas G is basically arbitrary on the condition that both are uniformly mixed at the temperature-measured location. However, a) When heat is excessively transferred to the surrounding tube wall and the like, the energy of the steam is wasted correspondingly, and b) When the gas G and the steam S are mixed by natural diffusion, the flow rate of the steam S is large. Therefore, a long pipe length is required until uniform mixing, resulting in inconveniences such as an increase in size of the apparatus.

  In order to avoid the inconvenience of a), the steam line in the gas line 1 is preferably such that the starting gas flow flowing in the gas line 1 and the vapor flow supplied from the vapor line 2 are parallel flows. Two connections are configured. FIG. 4 shows one form thereof. The gas pipe 1 is provided with an insertion port 31 for the steam pipe 2, and the steam pipe 2 inserted therein is extended in the gas flow direction. The direction and the axial center direction of the gas pipe 1 are made to coincide with each other. In FIG. 4, another insertion port 33 is formed, and the main steam line 2 to which the large capacity valve 3 shown in FIG. 2 is attached is inserted into the insertion port 31, and the other insertion port 33 is inserted into the other insertion port 33. A branch steam line 2a fitted with a fine adjustment dedicated valve 3a is inserted. Naturally, the axial direction of the extension 34 of the branch steam line 2a is also made coincident with the axial direction of the gas pipe 1. By setting it as this form, the vapor | steam S does not hit the surrounding wall of the gas pipe line 2 strongly, and it can prevent effectively that the energy of a vapor | steam is wasted on the surrounding wall side.

  In order to avoid the inconvenience of b), the vapor diffusion means for diffusing the vapor flow entering the upstream region of the gas-vapor mixing region as a parallel flow is preferably provided in the upstream region of the gas-vapor mixing region. To place. FIGS. 5a and 5b show one form thereof. As shown in FIG. 5b, a diffusing member 50 having a diffusing plate 51 that assists the vapor collision and diffusion is shown in FIG. It is made to attach near the front-end | tip of the extension part of the steam pipe line shown in (4). By attaching the member for forcibly diffusing the vapor in this way, the length of the gas-vapor mixing region can be shortened, and the apparatus can be downsized. The diffusion member 50 shown in the figure also diffuses the gas flow as a result, so that the mixing of the gas flow and the vapor flow is further promoted. Although not shown, even if an appropriate diffusion member is attached only to the distal end portion of the extension portion of the steam line, that is, in a place where the gas flow is not actively diffused, the desired effect can be sufficiently achieved.

  The inconvenience of b) can also be avoided by arranging in the gas-vapor mixing area 4 means for positively mixing the mixed gas and vapor flowing in the gas-vapor mixing area 4. FIGS. 6a and 6b show one form thereof. Here, as shown in FIG. 6b, an impeller-shaped gas diffusion plate 60 having a plurality of blades 61 spreading in the radial direction is shown in FIG. 6a. In the gas-vapor mixing region 4, one or more, three in the illustrated example, are attached. Each time the mixed gas passes through the gas diffusion plate 60, it becomes a swirling flow corresponding to the opening angle of the blade 61, and the mixing of the gas flow and the vapor flow is reliably promoted. Therefore, the starting gas and the steam can be uniformly mixed at a short distance, and the length of the gas-vapor mixing region 4 can be shortened, resulting in further miniaturization of the apparatus. 6a, the diffusion member 50 shown in FIG. 5b is used at the same time. However, depending on the operating environment of the apparatus, only the gas diffusion plate 60 is used in the gas-vapor mixing region 4 without using the diffusion member 50. Even if placed, the intended purpose can be achieved. Furthermore, as described above, the use of the impeller-shaped gas diffusion plate 60 to turn the mixed gas flow into the swirl flow is the most preferable aspect from the viewpoint of promoting the mixing, but is not limited thereto, and is not limited to this. The intended purpose can be achieved even if the mixing promoting means having the shape as shown in FIG.

  Although not shown in the figure, compared to the tube diameter provided on the inner wall of the gas line, for example, a baffle member for turbulently generating the humidified gas in the gas line on the downstream side of the heater 13 shown in FIG. It is also preferable to dispose a plurality of sufficiently large protrusions, a plurality of bar members that cross in the diameter direction, a plate member having a large number of through holes, and the like. By arranging such a baffle member, it is possible to equalize the humidified gas heated with a short pipe length, and the pipe length can be shortened to reduce the size of the entire apparatus.

  FIG. 7 shows other steam flow control when one or more branch pipes are arranged in parallel as in the case where the branch pipe 2a is provided in parallel with the steam pipe 2 shown in FIG. It is a graph which shows the relationship between the amount of valve opening (CV value) explaining the aspect of, and a steam flow rate. In this example, the steam pipe 2 is branched into three parallel pipes, and a small flow rate adjusting valve 3b is attached to one branch circuit, and the opening degree of the regulating valve 3C is fully opened to the two branch circuits. ON-OFF valves 41 and 42 of a size corresponding to the above are respectively attached. In this embodiment, first, on the small flow rate side, the flow rate of steam is controlled only by the regulating valve 3C with the two ON-OFF valves 41 and 42 closed (A region in FIG. 7). When the regulating valve 3C is in the vicinity of full opening, one ON-OFF valve 41 is opened and the regulating valve 3C is fully closed (point B in FIG. 7). When a higher flow rate is required, control is performed by opening the ON-OFF valve 41 + regulating valve 3C (C region in FIG. 7), and when the regulating valve 3C becomes close to full opening again, the second ON- The OFF valve 42 is opened and the regulating valve 3C is fully closed (point D in FIG. 7). Further, when a higher flow rate is required, control is performed by the ON-OFF valves 41, 42 opening + regulating valve 3C (E region in FIG. 7). As can be seen from FIG. 7, by doing so, it is possible to perform arbitrary steam flow rate adjustment in a flow rate range corresponding to three expensive adjustment valves with an inexpensive valve configuration using an ON-OFF valve.

  FIG. 8 is a graph showing test results when the humidified gas generating method according to the present invention is carried out using the apparatus shown in FIG. In the graph, the horizontal axis represents time, and in the test, the target dew point K ° was set to 50 ° for the first stage S1, and 75 ° for the second stage S2 that follows. Curve A is the dew point temperature of the mixed gas, and was measured using a conventional dew point thermometer. Curve B is the temperature of the mixed gas measured in the gas-vapor mixing region described above, and was measured with a normal temperature sensor. As shown in the graph, even if the set target dew point K ° changes, the mixed gas temperature (curve B) changes to substantially the same temperature following the change. Although the measured dew point temperature is also shifted to a lower level, it changes almost in line with the target dew point. The reason why the shift is lower than the target dew point is presumed to be that dew condensation occurred in the apparatus used in the test because the heat retention mechanism was not applied to the drain separator.

The conceptual diagram for demonstrating the production | generation process in the production | generation method of the humidification gas with the target dew point by this invention. The schematic diagram which shows an example of the apparatus for enforcing the production | generation method of the humidification gas with the target dew point by this invention. A system for using a method and apparatus for humidified gas with a target dew point according to the present invention in a fuel cell test bench. The figure for demonstrating an example of the gas-vapor | steam mixing area | region vicinity with the apparatus shown in FIG. 2 or FIG. The figure for demonstrating the other example of the gas-vapor | steam mixing area | region in the apparatus shown in FIG. 2 or FIG. The figure for demonstrating the further another example of the gas-vapor | steam mixing area | region in the apparatus shown in FIG. 2 or FIG. The graph explaining one aspect in the case of adjusting a steam flow rate. The graph which shows a test result when the production | generation method of the humidification gas by this invention is implemented using the apparatus shown in FIG.

Explanation of symbols

  K ° ... target dew point, G ... starting gas (dry gas), S ... steam, D ... condensation water (drain), T, TH, TA ... temperature sensor, R ... humidification that has reached saturation state where gas temperature = dew point Gas, FC ... Fuel cell, PW ... Pure water, HW ... Fuel cell cooling water, 1 ... Gas pipe, 1H ... Hydrogen gas pipe, 1A ... Air gas pipe, 2, 2H, 2A ... Steam pipe, 2a ... Branch pipe parallel to the steam pipe, 3 ... (Large capacity) flow rate adjustment valve, 3a ... Fine adjustment valve, 4, 4H, 4A ... Gas-vapor mixing region, 5 ... Control means, 7, 7H , 7A ... drain separator, 8 ... heat exchanger, 10 ... mass flow controller, 11 ... pure water tank, 12 ... boiler, 13 ... heater, 14 ... back pressure control valve, 15 ... band heater, 31, 33 ... steam line , 32, 34 ... extension of steam line, 41, 42 ... ON- FF valve, 50 ... diffusing member, 51 ... diffusion plate, 60 ... gas diffusion plate as mixing promotion means, 61 ... blade of the gas diffusion plate

Claims (16)

  A method for generating a humidified gas having a target dew point, in which a steam having a temperature higher than the target dew point is continuously mixed in a starting gas stream having a temperature lower than the target dew point, and the temperature of the mixed gas after the mixing is measured, A method for generating a humidified gas, wherein the supply amount of steam to the starting gas stream is continuously controlled so that the measured mixed gas temperature is equal to the target dew point.   The method of generating a humidified gas according to claim 1, further comprising the step of lowering the temperature of the starting gas stream to a temperature lower than the target dew point when the temperature of the starting gas stream is higher than the target dew point.   The method for generating a humidified gas according to claim 1, further comprising a step of separating condensed water by-produced in the process of generating the humidified gas.   The method for producing a humidified gas according to any one of claims 1 to 3, wherein the humidified gas is a fuel gas and / or an oxidant gas used in a fuel cell.   The method for generating a humidified gas according to claim 4, further comprising a step of raising the temperature of the humidified gas that has reached the target dew point to a predetermined temperature.   A humidifying gas generating device having a target dew point, a gas pipe through which a starting gas flows, a steam pipe connected to a gas pipe for mixing steam into the starting gas, and a flow rate adjustment provided in the steam pipe A gas-steam mixing region downstream of the connection between the valve and the steam line in the gas line, a temperature sensor for measuring the temperature of the humidified gas mixture in the gas-steam mixing field, and the humidified gas mixture And a control means for controlling the opening degree of the flow rate adjustment valve based on information from the temperature sensor so that a steam flow rate is obtained in such an amount that the target temperature becomes the target dew point.   The steam pipe connecting portion in the gas pipe is configured so that the starting gas flow flowing through the gas pipe and the steam supplied from the steam pipe can be parallel flows. The humidified gas generating device as described.   The humidified gas generating device according to claim 6, wherein a vapor diffusing means for diffusing the inflowing vapor is disposed in an upstream region of the gas-vapor mixing region.   The humidified gas generating device according to claim 6, wherein mixing promotion means for promoting mixing of the humidified mixed gas flowing therethrough is arranged in the gas-vapor mixing region.   10. The humidified gas generating device according to claim 9, wherein the mixing promoting means is means for turning the humidified mixed gas flow into a swirl flow.   The humidified gas generating device according to claim 6, wherein the flow rate adjusting valve provided in the steam line is composed of at least one ON-OFF valve and at least one adjusting valve arranged in parallel.   The humidified gas generator according to any one of claims 6 to 11, further comprising means for adjusting the temperature of the starting gas.   The humidified gas generation device according to any one of claims 6 to 11, further comprising a drain separator that separates dew condensation water by-produced in the generation process of the humidified gas.   The humidified gas generator according to any one of claims 6 to 13, wherein the humidified gas is a fuel gas and / or an oxidant gas used in a fuel cell.   The humidified gas generator according to claim 14, further comprising a humidified gas heating means for raising the humidified gas that has reached the target dew point to a predetermined temperature.   The humidified gas generating device according to claim 15, further comprising a baffle member for turbulent flow of the humidified gas on the downstream side of the humidified gas heating means.

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