JP5151388B2 - Steam supply device - Google Patents

Description

  The present invention relates to a vapor supply device for supplying vapor generated by vaporizing a liquid.

  For example, in a water vapor supply device that supplies water vapor obtained by vaporizing the supplied water, the amount of water vapor generated may be changed depending on the demand of the water vapor consumption device on the downstream side. For example, when the amount of generated steam is increased, the pressure of the steam generator increases, that is, changes in the direction that inhibits steam generation (increase in boiling point) accompany an increase in pressure loss accompanying an increase in the flow rate of steam.

Further, a technique for controlling a flow rate adjustment valve provided in a steam line so as to keep the pressure of the steam separator constant is known (for example, see Patent Document 1). In the technique described in Patent Document 1, make-up water commensurate with the amount of steam supplied from the steam separator by heating with an electric heater is always supplied to the steam separator.
JP-A-8-250142 specification

  However, in the conventional technology as described above, for example, in order to simultaneously increase the supply amount of makeup water and the heating amount by the electric heater in response to a request for increase in steam, the time required to increase the amount of steam generated is long, and the amount of steam supply Cannot be changed rapidly.

  In view of the above fact, an object of the present invention is to obtain a steam supply device capable of changing the steam generation amount rapidly.

The steam supply device according to the invention of claim 1 is a steam generator for vaporizing a liquid, a flow resistor connected to the steam outlet side of the steam generator, and causing a flow resistance with the passage of gas, A gas supply means capable of supplying a gas between a steam outlet of the steam generator and a gas inlet of the flow resistor, a gas flow rate changing means capable of changing a gas supply amount by the gas supply means, and the steam when the time variation of the steam generation amount due to rapid steam generator to the extent that changes in response time of the gas supply means to the set liquid level of the generator upper or lower limit is required, of the steam generation amount and a, and control means for controlling the gas flow rate control means in response to the increasing decline the request.

  In the steam supply device according to claim 1, the steam generated by the steam generator passes through the flow resistor alone or together with the gas from the gas supply means and is supplied to the steam consumption device. For this reason, a pressure difference corresponding to the flow rate of the steam and gas is generated upstream and downstream of the flow resistor. In this steam supply apparatus, the control means controls the flow rate variable means according to the change in the amount of steam generated, thereby adjusting the amount of gas supplied between the steam generator and the flow resistor by the gas supply means. The pressure upstream of the flow resistor, that is, the pressure of the steam generator can be controlled. By changing the pressure of the steam generator, the boiling point of the liquid in the steam generator (the amount of heat required for evaporation) is changed. Thus, the amount of steam generated by the steam generator can be changed abruptly (with good response) as required.

  Thus, in the steam supply device according to claim 1, the amount of steam generated can be changed abruptly.

A steam supply apparatus according to a second aspect of the present invention is the steam supply apparatus according to the first aspect, wherein the control means changes the liquid level of the steam generator to the lower limit in response time of the gas supply means. to request to increase the steam generation amount by rapidly the steam generator, the gas supply amount of the gas supply means so as to reduce, for controlling the gas flow rate changing means.

  The steam supply device according to claim 2, wherein when a rapid (temporary) increase in the amount of steam generated by the steam generator is requested, the steam generation by the gas supply means is controlled by the control of the gas flow rate changing means by the control means. The gas supply between the vessel and the flow resistor is reduced. For this reason, since the pressure of the steam generator is lowered and the boiling point of the liquid in the steam generator is lowered, the superheated liquid in the steam generator is released as steam in a short time. That is, the amount of steam generated by the steam generator is rapidly increased.

The steam supply device according to a third aspect of the present invention is the steam supply device according to the first or second aspect, wherein the control means has a response time of the gas supply means up to a liquid level of the steam generator up to the upper limit. in response to a request to decrease little of the steam generation amount by rapidly the steam generator to the extent that changing, as gas supply amount of the gas supply means is increased, to control the gas flow rate changing means.

  In the steam supply device according to claim 3, when a rapid (temporary) decrease in the amount of steam generated by the steam generator is requested, the steam generation by the gas supply means is controlled by the control of the gas flow rate changing means by the control means. The gas supply between the vessel and the flow resistor is increased. For this reason, since the pressure of the steam generator is increased and the boiling point of the liquid in the steam generator is increased, a part of the steam (supercooled steam) in the steam generator is condensed. That is, the amount of steam generated by the steam generator is rapidly reduced.

A steam supply apparatus according to a fourth aspect of the present invention is the vapor supply apparatus according to any one of the first to third aspects, further comprising a liquid supply means for supplying the liquid to the steam generator. , wherein, in response to a request to increase the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to said lower limit, the gas supply A steam discharge mode for controlling the gas flow rate changing means so that a gas supply amount by the means is reduced, and after the execution of the steam discharge mode, the gas supply amount by the gas supply means is increased and the steam generator The recovery mode for controlling the gas flow rate changing means and the liquid supply means may be performed so that the supply amount of the liquid is increased.

  In the steam supply device according to the fourth aspect, the control means executes the steam discharge mode when a request for a rapid (temporary) increase in the amount of generated steam is made. In the steam discharge mode, the gas supply amount between the steam generator and the flow resistor by the gas supply means is reduced by the control of the gas flow rate changing means by the control means. For this reason, since the pressure of the steam generator is lowered and the boiling point of the liquid in the steam generator is lowered, the superheated liquid in the steam generator is released as steam in a short time. That is, the amount of steam generated by the steam generator is rapidly increased.

  The control means executes the recovery mode after executing the vapor discharge mode. In the recovery mode, the gas supply amount between the steam generator and the flow resistor by the gas supply means is increased by the control of the gas flow rate changing means and the liquid supply means by the control means, and the liquid to the steam generator is increased. Supply volume is increased. For this reason, the pressure of the steam generator rises compared to the steam discharge mode, and a part of the steam (supercooled steam) in the steam generator is condensed, and the amount of liquid in the steam generator increases in a short time. In other words, while maintaining the generation of steam, the amount of liquid in the steam generator can be recovered in a short time to the steady amount before the execution of the steam discharge mode.

The steam supply device according to a fifth aspect of the present invention is the vapor supply device according to any one of the first to fourth aspects, further comprising a liquid supply means for supplying the liquid to the steam generator. , the control means, the relative steam generator of the liquid level required to decrease little of the steam generation amount by rapidly the steam generator to the extent that changes in response time of the gas supply means to the upper limit, the gas supply After the execution of the vapor discharge suppression mode for controlling the gas flow rate changing means and the vapor discharge suppression mode, the gas supply amount by the gas supply means is reduced and the steam is supplied so that the gas supply amount by the means is increased. A recovery mode for controlling the gas flow rate changing means and the liquid supply means may be performed so that the supply amount of the liquid to the generator is reduced.

  In the steam supply device according to the fifth aspect, the control means executes the steam discharge suppression mode when a rapid (temporary) reduction request of the steam generation amount is requested. In the steam discharge suppression mode, the gas supply amount between the steam generator and the flow resistor by the gas supply means is increased by the control of the gas flow rate changing means by the control means. For this reason, the pressure of the steam generator is increased and the dew point of the steam in the steam generator is increased, so that the saturated steam in the steam generator is liquefied and the steam release is suppressed in a short time. That is, the amount of steam generated by the steam generator is rapidly reduced.

  The control means executes the recovery mode after executing the vapor release suppression mode. In the recovery mode, the gas supply amount between the steam generator and the flow resistor by the gas supply means is reduced by the control of the gas flow rate changing means and the liquid supply means by the control means, and the liquid to the steam generator is reduced. Supply is reduced. For this reason, the pressure of a steam generator falls compared with steam discharge mode, a part of superheated liquid in a steam generator evaporates, and the amount of liquids in a steam generator decreases in a short time. That is, while increasing the generation of steam, the amount of liquid in the steam generator can be recovered in a short time to the steady amount before the execution of the steam release suppression mode.

A steam supply device according to a sixth aspect of the present invention includes a steam generator for vaporizing a liquid, a flow resistor that is in communication with a steam outlet side of the steam generator and generates a flow resistance with the passage of gas. The first gas supply means capable of supplying gas between the steam outlet of the steam generator and the gas inlet of the flow resistor, and the first gas supply amount by the first gas supply means can be changed. A gas flow rate change means, a second gas supply means capable of supplying gas to the gas outlet side of the flow resistor, and a second gas flow rate change capable of changing a gas supply amount by the second gas supply means When the time change of the amount of steam generated by the steam generator is required to be rapid enough to change the liquid level of the steam generator to the set upper limit or lower limit with the response time of the gas supply means , depending on the increase decrease request of the steam generation amount The first gas flow rate change means and the second gas flow rate change means are controlled so that the vapor generation amount changes according to the increase / decrease request while the vapor concentration at the apparatus outlet is maintained at a predetermined concentration. Control means.

  In the steam supply device according to the sixth aspect, the steam generated by the steam generator passes through the flow resistor alone or together with the gas from the gas supply means and is supplied to the steam consumption device. For this reason, a pressure difference corresponding to the flow rate of the steam is generated upstream and downstream of the flow resistor. In this steam supply apparatus, the control means controls the first and second flow rate variable means according to the change in the amount of steam generated, so that the steam supply by the gas supply means is supplied between the flow generator and the flow resistor. The vapor concentration upstream of the flow resistor, that is, the pressure of the steam generator is controlled to maintain the vapor concentration at the outlet of the device (the concentration of the vapor with respect to the vapor / gas mixer) at a predetermined concentration. Can do. Since the boiling point of the liquid in the steam generator (the amount of heat required for evaporation) is changed by changing the pressure of the steam generator, when there is a request for rapid increase or decrease in the amount of steam generated, the first and second The flow rate variable means can be controlled to change the amount of steam generated by the steam generator abruptly (with good response) as required while maintaining the steam concentration at the outlet of the apparatus.

  Thus, in the steam supply device according to the sixth aspect, the amount of steam generated can be changed abruptly.

A steam supply apparatus according to a seventh aspect of the present invention is the steam supply apparatus according to the sixth aspect, wherein the control means changes the liquid level of the steam generator to the lower limit in response time of the gas supply means. as to the request to increase the steam generation amount by rapidly the steam generator, with a gas supply amount is reduced by the gas supply means, the vapor concentration at the device outlet is maintained at a predetermined concentration, The first gas flow rate changing means and the second gas flow rate changing means are controlled.

  In the steam supply device according to claim 7, when a rapid (temporary) increase in the amount of steam generated by the steam generator is requested, the first gas flow rate changing means is controlled by the control means to control the first gas flow rate changing means. The gas supply amount between the steam generator and the flow resistor by the gas supply means is decreased, and the gas supply amount by the second gas supply means is increased by the control of the second gas flow rate changing means by the control means. Is done. As a result, the pressure in the steam generator is lowered while the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration, and the boiling point of the liquid in the steam generator is lowered, so that the superheated liquid in the steam generator is short as vapor. Released in time. That is, the amount of steam generated by the steam generator is rapidly increased.

The steam supply device according to an eighth aspect of the present invention is the steam supply device according to the sixth or seventh aspect, wherein the control means has a response time of the gas supply means up to the upper limit of the liquid level of the steam generator. in response to a request to decrease little of the steam generation amount by rapidly the steam generator to the extent of changing, with a gas supply amount is increased by the first gas supply means, the concentration vapor concentration of a predetermined in the apparatus outlet The first gas flow rate changing means and the second gas flow rate changing means are controlled so as to be maintained.

  In the steam supply device according to claim 8, when a rapid (temporary) reduction in the amount of steam generated by the steam generator is requested, the first gas flow rate changing means is controlled by the control means. The gas supply amount between the steam generator and the flow resistor by the gas supply means is increased, and the gas supply amount by the second gas supply means is decreased by the control of the second gas flow rate changing means by the control means. Is done. This increases the pressure in the steam generator while maintaining the vapor concentration at the outlet of the apparatus at a predetermined concentration, and raises the boiling point of the liquid in the steam generator. Cooling steam) condenses. That is, the amount of steam generated by the steam generator is rapidly reduced.

A steam supply device according to a ninth aspect of the present invention is the vapor supply device according to any one of the sixth to eighth aspects, further comprising a liquid supply means for supplying the liquid to the steam generator. , wherein, in response to a request to increase the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to said lower limit, the gas supply A vapor discharge mode for controlling the first gas flow rate changing means and the second gas flow rate changing means so that the gas supply amount by the means is reduced and the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration. After the execution of the vapor discharge mode, the gas supply amount by the gas supply means is increased, the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration, and the liquid supply amount to the vapor generator As will be increased, the first gas flow rate control means, the second gas flow rate control means, and a recovery mode for controlling the liquid supply unit may perform.

  In the steam supply device according to the ninth aspect, the control means executes the steam discharge mode when a rapid (temporary) increase request for the amount of generated steam is made. In the vapor discharge mode, the amount of gas supplied between the steam generator and the flow resistor by the first gas supply means is reduced by the control of the first gas flow rate changing means by the control means, and the first by the control means. The gas supply amount by the second gas supply means is increased by the control of the second gas flow rate changing means. As a result, the pressure in the steam generator is lowered while the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration, and the boiling point of the liquid in the steam generator is lowered, so that the superheated liquid in the steam generator is short as vapor. Released in time. That is, the amount of steam generated by the steam generator is rapidly increased.

  The control means executes the recovery mode after executing the vapor discharge mode. In the recovery mode, by the control of the first gas flow rate changing means, the second gas flow rate changing means, and the liquid supply means by the control means, between the steam generator and the flow resistor by the first gas supply means. As the gas supply amount increases, the gas supply amount by the second gas supply means decreases, and the liquid supply amount to the steam generator increases. For this reason, while the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration, the pressure of the vapor generator rises compared to the vapor discharge mode, and a part of the vapor (supercooled vapor) in the vapor generator is generated. Condensation increases the amount of liquid in the steam generator in a short time. In other words, while maintaining the generation of steam, the amount of liquid in the steam generator can be recovered in a short time to the steady amount before the execution of the steam discharge mode.

A steam supply device according to a tenth aspect of the present invention is the vapor supply device according to any one of the sixth to ninth aspects, further comprising a liquid supply means for supplying the liquid to the steam generator. , the control means, the relative steam generator of the liquid level required to decrease little of the steam generation amount by rapidly the steam generator to the extent that changes in response time of the gas supply means to the upper limit, the gas supply Vapor emission suppression for controlling the first gas flow rate change means and the second gas flow rate change means so that the gas supply amount by the means is increased and the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration And after the execution of the vapor emission suppression mode, the gas supply amount by the gas supply means is reduced, the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration, and the liquid to the vapor generator is As the amount of feed is reduced, the first gas flow rate control means, the second gas flow rate control means, and a recovery mode for controlling the liquid supply unit may perform.

  In the steam supply device according to the tenth aspect, the control means executes the steam discharge suppression mode when a rapid (temporary) reduction request of the steam generation amount is requested. In the steam release suppression mode, the control unit controls the first gas flow rate changing unit to increase the gas supply amount between the steam generator and the flow resistor by the first gas supply unit, and also by the control unit. The amount of gas supplied by the second gas supply means is reduced by the control of the second gas flow rate changing means. This increases the pressure in the steam generator while maintaining the steam concentration at the outlet of the apparatus at a predetermined concentration, and the steam outdoor in the steam generator rises, so that the saturated steam in the steam generator is liquefied. Vapor emission is suppressed in a short time. That is, the amount of steam generated by the steam generator is rapidly reduced.

  The control means executes the recovery mode after executing the vapor release suppression mode. In the recovery mode, by the control of the first gas flow rate changing means, the second gas flow rate changing means, and the liquid supply means by the control means, between the steam generator and the flow resistor by the first gas supply means. The gas supply amount is reduced, the gas supply amount by the second gas supply means is increased, and the liquid supply amount to the steam generator is reduced. For this reason, while the vapor concentration at the outlet of the device is maintained at a predetermined concentration, the pressure of the vapor generator decreases compared to the vapor discharge mode, and a part of the vapor (superheated liquid) in the vapor generator evaporates. As a result, the amount of liquid in the steam generator decreases in a short time. In other words, while maintaining the generation of steam, the amount of liquid in the steam generator can be recovered in a short time to the steady amount before the execution of the steam discharge mode.

  As described above, the steam supply apparatus according to the present invention has an excellent effect that the amount of steam generated can be changed abruptly.

  A steam supply apparatus 10 according to a first embodiment of the present invention will be described with reference to FIGS. First, the overall configuration of the steam supply apparatus 10 will be described, and then an application example in which the steam supply apparatus 10 is applied to the fuel cell system 100 will be described, and effects of the steam supply apparatus 10 in this application example will be described.

(Overall configuration of steam supply device)
FIG. 1 shows a system configuration diagram of the steam supply apparatus 10. As shown in FIG. 1, the steam supply device 10 includes a steam generator 12. The steam generator 12 is configured to evaporate the liquid supplied from the liquid tank 14 by a pump 16 as a liquid supply means and generate steam. In this embodiment, the steam generator 12 is a heating type evaporator that vaporizes a liquid by heating (supply of latent heat). The steam generated by the steam generator 12 is supplied to a steam consuming device (not shown) through a steam supply line 18. That is, the downstream end 18A of the steam supply line 18 corresponds to the apparatus outlet in the present invention.

  A flow resistor 20 is arranged in series on the steam supply line 18. The flow resistor 20 is configured, for example, as a porous body or a sintered body, or a resistor body formed as a fibrous filler or a filter is disposed in the case, and the flow resistor 20 A pressure loss is generated according to the flow rate. The resistor body and the case constituting the flow resistor 20 are made of a heat resistant material such as metal or ceramic.

  The first gas supply line 22 joins between the steam outlet 12A of the steam generator 12 and the gas inlet 20A of the flow resistor 20 in the steam supply line 18. A gas supply port 24 </ b> A of the first gas supply device 24 is connected to the upstream end of the first gas supply line 22. In addition, a flow rate control valve 26 as a first gas flow rate change means is provided between the gas supply port 24A of the first gas supply device 24 in the first gas supply line 22 and the junction J1 of the steam supply line 18. It is arranged. The flow rate control valve 26 is controlled by a controller 36 described later to change (increase / decrease) the flow rate of the gas supplied to the junction portion J1.

  On the other hand, the second gas supply line 28 is joined to a portion of the steam supply line 18 downstream of the gas outlet 20B of the flow resistor 20. A gas supply port 30 </ b> A of the second gas supply device 30 is connected to the upstream end of the second gas supply line 28. Further, a flow rate control valve 32 as a second gas flow rate changing means is provided between the gas supply port 30A of the second gas supply device 30 in the second gas supply line 28 and the junction J2 of the steam supply line 18. It is arranged. The flow rate control valve 32 is controlled by a controller to be described later to change the flow rate of the gas supplied to the junction portion J1. The first gas supply device 24 and the second gas supply device 30 are configured, for example, as a wind generator such as a blower or a compressor, or a gas reservoir such as a gas cylinder.

  Further, the steam supply device 10 includes a mixer 34 provided in series on the downstream side of the junction J2 in the steam supply line 18. In the mixer 34, the steam generated by the steam generator 12 and the gas joined from the first gas supply line 22 and the second gas supply line 28 to the steam supply line 18 are mixed substantially uniformly as they pass. It is comprised so that. Therefore, the steam supply device 10 is configured to supply a mixture of steam and gas to the steam consuming device. Specifically, the steam supply device 10 supplies, for example, an air-fuel mixture of fuel vapor and air to the combustor, or an air-fuel mixture of steam and reforming raw material gas such as hydrocarbons to the reforming hydrogen generator. The present invention can be applied to an application in which the fuel cell is supplied or a mixture of humidified water vapor and cathode air or anode hydrogen is supplied to the fuel cell. From another viewpoint, the steam supply device 10 can be grasped as an air-fuel mixture supply device for supplying an air-fuel mixture to an air-fuel mixture consuming device containing steam.

  And the steam supply apparatus 10 is set as the structure which can change the vapor | steam quantity supplied to various steam consumption apparatuses as illustrated above. That is, the steam supply device 10 is configured to supply an amount of steam corresponding to (a change in) the required steam amount from the steam consuming device. Specifically, the steam supply apparatus 10 includes a controller 36 as control means. The controller 36 controls the steam generator 12 and the pump 16 in order to change the heating amount in the steam generator 12 and the supply amount of the liquid, which is the raw material of the steam, to the steam generator 12, and also the steam generator. In order to change the gas supply amount to the steam supply line 18 in accordance with the amount of steam generated at 12, the flow control valves 26 and 32 are controlled.

  In this embodiment, the controller 36 is configured to control the steam generation amount of the steam generator 12 in response to a steam consumption increase / decrease request from the steam consumption device side, and to release steam in response to a temporary steam rapid increase request. The steam discharge mode for temporarily increasing the amount temporarily and the liquid amount recovery mode for recovering the liquid amount in the steam generator 12 that has decreased in the steam discharge mode can be executed.

  In the normal mode, the controller 36 sets the steam concentration (partial pressure) of the air-fuel mixture supplied to the steam consuming device so that the internal pressure Pin of the steam generator 12 becomes substantially constant (within a predetermined range). The flow control valves 26 and 32 are controlled so as to be substantially constant. Therefore, the controller 36 is electrically connected to the steam generator 12 (heater not shown), the pump 16, and the flow rate control valves 26 and 32, and outputs a signal corresponding to the internal pressure Pin of the flow resistor 20. The pressure gauge (sensor) 38 is electrically connected. In this embodiment, the controller 36 is also electrically connected to a thermometer (sensor) 40 that outputs a signal corresponding to the internal temperature Tin of the flow resistor 20. Further, the controller 36 is electrically connected to a steam flow meter 42 that outputs a signal corresponding to the steam flow rate (a generated steam amount per unit time) of the steam generator 12 in order to execute the liquid amount recovery mode. Yes.

  In the normal mode, when the controller 36 receives a request for increasing the steam flow rate Vs from the steam consuming device, basically, the controller 36 supplies the steam generator 12 with an amount corresponding to the increase ΔVsi of the requested steam flow rate Vs. The pump 16 is controlled so as to increase the liquid supply amount Vp, and the gas supply amount to the junction J1 between the steam generator 12 and the flow resistor 20 by the required increase ΔVsi of the steam flow rate Vs. The flow control valve 26 is controlled so that V1 decreases. Thereby, in the steam supply apparatus 10, the increase in pressure loss in the flow resistor 20 accompanying the increase in the amount of generated steam is offset, and the pressure Pin of the steam generator 12 is kept substantially constant.

  Further, in the normal mode, when the controller 36 receives a request for increasing the steam flow rate Vs from the steam consuming apparatus, basically, the controller 36 is substantially the same rate as the requested increase rate of the steam flow rate Vs ((Vs + ΔVsi) / Vs). Thus, the flow rate control valves 26 and 32 are controlled so that the total gas amount (V1 + V2) supplied to the steam supply line 18 from the junction J1 and the junction J2 increases. That is, in the steam supply device 10 in which the gas supply amount V1 at the junction portion J1 is limited as described above, the total gas supply amount (V1 + V2) in the entire steam supply line 18 is the junction portion controlled by the flow control valve 32. It is adjusted by the gas supply amount V2 to J2.

  On the other hand, in the normal mode, when the controller 36 receives a request to reduce the steam flow rate Vs from the steam consuming device, basically, the steam generator 12 is an amount corresponding to the required decrease ΔVsi of the steam flow rate Vs. The pump 16 is controlled so as to reduce the liquid supply amount V1 to the gas, and the gas to the junction J1 between the steam generator 12 and the flow resistor 20 is reduced by the required decrease ΔVsi of the steam flow rate Vs. The flow control valve 26 is controlled to increase the supply amount V1. Thereby, in the steam supply device 10, the decrease in the pressure loss in the flow resistor 20 accompanying the decrease in the amount of generated steam is offset, and the pressure Pin of the steam generator 12 is kept substantially constant.

  Further, in the normal mode, when the controller 36 receives a request to reduce the steam flow rate Vs from the steam consuming device, the controller 36 is basically substantially the same as the requested reduction rate ((Vs−ΔVsi / Vs) of the steam flow rate Vs. The flow rate control valves 26 and 32 are controlled such that the total gas amount (V1 + V2) supplied from the merging portion J1 and the merging portion J2 to the steam supply line 18 is reduced at a ratio. In the steam supply device 10 in which the gas supply amount V1 at J1 is limited as described above, the total gas supply amount (V1 + V2) in the entire steam supply line 18 is the gas to the junction J2 under the control of the flow control valve 32. It is adjusted by the supply amount V2.

It supplements about the calculation method by the controller 36 of the variation | change_quantity of the gas supply amount V1 to the junction J1 by control with respect to the flow control valve 26. FIG. Assuming that the change in the gas supply amount V1 to the junction J1 is ΔV1, the changed gas supply amount (V1 + ΔV1) is the gas supply amount V1 before the change and the pump after the change as shown in the following equation (1). The liquid supply amount (Vp + ΔVp) after the change by 16 (may be the steam generation amount (Vs + ΔVsi) in the steam generator 12), the internal temperature Tin of the steam generator 12, and the target value Pt of the internal pressure of the steam generator 12 And a function of the difference e between the actual internal pressure Pin.
V1 + ΔV1 = f (V1, (Vs + ΔVsi), Tin, e) (1)

  More specifically, if the relationship between the flow rate V of the gas passing through the flow resistor 20 and the pressure loss ΔP as shown in the diagram R in FIG. 3B is known, the internal pressure of the steam generator 12 From the difference between the target value Pt and the actual internal pressure Pin, an increase ΔV1 in the gas supply amount to the junction J1 can be obtained. Here, the relationship between the flow rate V of the gas passing through the flow resistor 20 and the pressure loss ΔP indicates that the resistor body 20D in which a large number of pores 20C are formed as shown in FIG. The relationship between the flow rate V of the gas passing through the flow resistor 20 and the pressure loss ΔP in the case of the built-in model is exemplified as follows.

The pressure loss ΔP of the flow resistor 20 is caused by the loss (microchannel internal loss) ΔPc associated with the passage of the large number of pores 20C and the gas inflow into the large number of pores 20C, as shown in the following equation (2). It can be grasped as the sum of a loss (reduction loss) ΔPin and a loss (expansion loss) ΔPout associated with gas outflow from a large number of pores 20C.
ΔP = ΔPc + ΔPin + ΔPout (2)

The internal loss ΔPc of the fine flow path is expressed by the density of the air-fuel mixture passing through the flow resistor 20, the length of the resistor body 20D as L, the flow velocity of the air-fuel mixture passing through the numerous pores 20C, and the kinematic viscosity coefficient. Denote that u, ν, the diameter of each pore 20C is de, the inner diameter of the steam supply line 18 (the diameter of the case constituting the flow resistor 20) is De, and the Reynolds number is Re (= u × de / ν), f = ( 64 / Re), it can be obtained from the following formula (3). The flow velocity u can be calculated from the flow rate of steam (Vs + ΔVsi) passing through the flow resistor 20, the flow rate V1 of gas, and the flow path shape. Although not described, the density ρ and the Reynolds number Re (dynamic viscosity coefficient ν) are also functions of the temperature Tin and are selected or calculated according to a signal from the thermometer 40.
ΔPc = (ρ × L × u ² ) × f / (2 × de) (3)

Further, when the contraction coefficient of the resistor body 20D is Cc (ε) and the aperture ratio is ε, the reduction loss ΔPin and the expansion loss ΔPout can be obtained from the following equations (4) and (5), respectively.
ΔPin = ½ × ρ × u ² × {(1 / Cc (ε) −1)} ² (4)
ΔPout = 1/2 × ρ × u ² × (1-ε) ² (5)

  As described above, the relationship between the flow rate V of the flow resistor 20 and the pressure loss ΔP represented by the equation (2) can be calculated, so that the target value Pt of the internal pressure of the steam generator 12 and the actual internal pressure Pin are A change ΔV1 in the gas supply amount can be obtained from the difference e. For example, in an application operated at a substantially constant operating temperature, the controller 36 may store the relationship between the flow rate V and the pressure loss ΔP as shown in FIG.

  Further, in the steam discharge mode, the controller 36 determines that the control target value Pt of the internal pressure Pin of the steam generator 12 is the target of the internal pressure in the normal mode and the liquid amount recovery mode, as shown in FIG. The flow control valves 26 and 32 are controlled so that the Pt1 is lower than the value Pt (hereinafter referred to as the internal pressure Pt2), and the vapor concentration (partial pressure) of the air-fuel mixture supplied to the vapor consuming device is substantially constant. It is supposed to be configured. Thereby, in the steam supply device 10 in the steam discharge mode, the amount of steam generated is temporarily reduced by the amount corresponding to the decrease in the boiling point of the liquid (increase in superheated liquid) mainly based on the internal pressure decrease (Pt2-Pt1) of the steam generator 12. It is configured to increase. Note that the internal pressure Pt1 (lower limit) in the vapor discharge mode can be set to an arbitrary pressure, but in this embodiment, is set to a predetermined constant value.

  On the other hand, in the liquid amount recovery mode, the controller 36 controls the pump 16 so that the liquid supply amount to the steam generator 12 is increased, the internal pressure of the steam generator 12 rises above Pt1, and the steam The flow control valves 26 and 32 are controlled so that the vapor concentration (partial pressure) of the air-fuel mixture supplied to the consuming device is substantially constant. Therefore, in the liquid amount recovery mode, the liquid storage amount (liquid level) of the steam generator 12 is increased while the predetermined steam supply amount (required in the normal mode) from the steam generator 12 is maintained. Yes.

(Application example for fuel cell system)
FIG. 2 is a schematic system configuration diagram showing an application example of the steam supply device 10 to the fuel cell system 100. As shown in this figure, the steam supply device 10 constitutes a part of a fuel supply device 104 for supplying a fuel gas containing hydrogen at a high concentration to the fuel cell 102. The fuel supply device 104 modifies a fuel mainly composed of hydrocarbons (for example, propane and butane) into a reformed gas containing hydrogen and carbon monoxide by a reforming reaction including a steam reforming reaction and a partial oxidation reaction. The reforming reaction part 106 to be processed is included. The steam supply device 10 generates water vapor from the water stored in the liquid tank 14 by the steam generator 12, and air from the first gas supply device 24 and the second gas supply device 30 that are blowers is used for the water vapor. And a mixture of water vapor used for the steam reforming reaction and air used for the partial oxidation reaction is supplied to the reforming reaction unit 106 of the fuel supply device 104.

  In addition, as shown in FIG. 2, the fuel supply device 104 sprays water from the liquid tank 14 by the water pump 108 onto the reformed gas to form a mixed gas composed of water vapor and the reformed gas, and at a predetermined range of temperatures. The heat exchange unit 110 that cools the mixed gas, the shift reaction unit 112 that shifts carbon monoxide in the mixed gas into hydrogen and carbon dioxide by a shift reaction, and the carbon monoxide that could not be shifted by the shift reaction unit 112 And a carbon monoxide purifying unit 116 that is oxidized using oxygen in the air supplied by the blower 114 to form a fuel gas rich in hydrogen and having a low carbon monoxide concentration. The fuel supply device 104 supplies the outlet gas of the carbon monoxide purification unit 116 to the fuel cell 102 as the fuel gas described above.

  As shown in FIG. 2, hydrocarbon fuel is supplied from the fuel tank 120 to the mixer 34 of the steam supply apparatus 10 by the fuel pump 118. The fuel may be sprayed to the mixer 34 by an injector (not shown) or the like, and may be supplied to the mixer 34 after being vaporized by a vaporizer (not shown). Therefore, the mixer 34 of the steam supply device 10 is configured to supply the reforming raw material gas mixed with fuel, water vapor, and air to the reforming reaction unit 106 of the fuel supply device 104.

  The controller 36 of the steam supply device 10 increases or decreases the amount of water vapor generation while maintaining the water vapor concentration substantially constant in the normal mode based on the water vapor amount required from the main controller that controls the entire fuel cell system 100. It has become. Further, the controller 36 is configured to execute the vapor discharge mode based on the heat spot cooling request from the main controller and then execute the liquid amount recovery mode.

  Here, it supplements about a heat spot. In the fuel supply device 104 of the fuel cell system 100, heat spots can be generated in the reforming reaction unit 106 and the shift reaction unit 112 that involve an exothermic reaction. In the reforming reaction unit 106, an exothermic reaction such as a partial oxidation reaction, a shift reaction, and a methanation reaction and a steam reforming reaction that is an endothermic reaction proceed in parallel. The steam reforming reaction maintains the reaction by utilizing a part of the heat generated by the exothermic reaction. On the other hand, in the partial oxidation reaction, the amount of air supplied is controlled so that the calorific value and the endothermic amount are balanced at a temperature at which a reforming reaction including a steam reforming reaction can be maintained (by the steam supply device 10). The water vapor concentration of the mixture of water vapor and air is constant). However, since the reaction rate of the partial oxidation reaction is higher than that of the steam reforming reaction, the distributions of both reactions in the gas flow direction do not completely coincide with each other, and the reforming reaction unit 106 in which partial oxidation reactions having a high reaction rate are concentrated. A strong temperature distribution occurs on the inlet side of the. By the way, when the amount of power generation by the fuel cell 102 is increased, an increase control of the supply amount of reforming raw materials (fuel, water vapor, air) to the fuel supply device 104 is performed in response to a request for an increase in the supply amount of fuel gas from the fuel cell 102. Done. Even during the transition period of this reaction amount change, the reaction rate of the partial oxidation reaction is faster than the steam reforming reaction as described above, so that the temporary amount of heat is reduced until the reaction in the reforming reaction unit 106 reaches a steady state. In some cases, a portion having a high temperature, that is, a heat spot is generated in the vicinity of the inlet of the reforming reaction unit 106 where the balance occurs and the partial oxidation reaction concentrates.

  On the other hand, in the shift reaction section 112, exothermic reactions such as shift reaction and methanation reaction proceed, and the heat generated by these exothermic reactions is caused by the temperature rise (sensible heat) of the reformed gas (and the mixed gas of water vapor). By being absorbed, the shift reaction is maintained within a predetermined temperature range. Thereby, the concentration of carbon monoxide in the mixed gas is reduced. In the reforming reaction section 106 located on the upstream side of the shift reaction section 112, the S / C ratio (the amount of water vapor relative to the amount of carbon in the hydrocarbon gas) due to the difference in the change rate of the supply amount of fuel and water vapor. May temporarily drop (water vapor may be insufficient). In this case, since the concentration of carbon monoxide at the outlet of the reforming reaction unit 106 temporarily increases, the amount of heat generated in the shift reaction unit 112 exceeds the endothermic amount. Can occur.

  The main controller of the fuel cell system 100 detects a heat spot at the reforming reaction unit 106 and the shift reaction unit 112, predicts the occurrence of a heat spot, or operates under an operating condition with a high probability of heat spot (for example, A heat spot cooling request is output to the controller 36 of the steam supply device 10 during a transition period when the power generation amount is increased.

  Next, the operation of the first embodiment will be described with reference to the flowcharts shown in FIGS.

  In the steam supply apparatus 10 applied to the fuel cell system 100 having the above-described configuration, after the operation is started, the controller 36 determines whether or not a heat spot cooling request is issued from the main controller in step S100 as shown in FIG. Judging. The controller 36 that has determined that a heat spot cooling request has not been issued from the main controller sets the target value Pt of the internal pressure of the steam generator 12 to Pt2 in step S102, proceeds to step S104, and executes normal mode control.

  On the other hand, if the controller 36 determines that a heat spot cooling request has been made from the main controller, the target value Pt of the internal pressure of the steam generator 12 is set to Pt1 in step S106, and the process proceeds to step S108. Execute the control. Further, after executing the control of the steam discharge mode, the controller 36 sets the set value of the target value Pt of the internal pressure of the steam generator 12 as Pt2 in step S110, proceeds to step S112, and executes the control of the liquid amount recovery mode. After executing step S104 or step S112, the controller 36 returns to step S100. Hereinafter, each control in the normal mode, the vapor discharge mode, and the liquid amount recovery mode will be described.

(Normal mode)
In the normal mode, the flow shown in FIG. 5 is executed. That is, in the normal mode, in step S10, the controller 36 receives information corresponding to the required steam amount and concentration from the steam consuming apparatus that is the target of steam supply. Next, the controller 36 proceeds to step S12, the amount of liquid supplied to the steam generator 12 by the pump 16 according to the required steam amount and concentration, the heating amount in step S12, the upstream and downstream junction J1 of the flow resistor 20, The amount of gas supplied to J2 is calculated. Note that the processing in step S12 includes information necessary for calculation of each control amount (for example, input of temperature Tin). In step S14, the pump 16, the flow control valve 26, the flow control valve 32, and the heater in step S12 are based on the supply liquid amount, the heating amount, and the supply gas amount to the junctions J1 and J2 calculated in step S12. A signal corresponding to the amount of power supplied to is output. Thereby, the vapor | steam supply apparatus 10 produces | generates the mixer of the vapor | steam and gas of required vapor | steam amount and density | concentration, and supplies it to a vapor | steam consumption apparatus.

  The controller 36 inputs a signal from the pressure gauge 38 in step S16, and determines in step S18 whether or not the internal pressure Pin of the steam generator 12 is below 90% of the target value Pt. When it is determined that the internal pressure Pin of the steam generator 12 is lower than 90% of the target value Pt, the process proceeds to step S20. In step S20, the flow control valves 26 and 32 are controlled to increase the amount of gas supplied to the junction portion J1 and increase Pin, while the amount of gas supplied to the junction portion J2 is decreased to supply the steam supply line 18 to the steam supply line 18. Maintain total gas supply.

  When the controller 36 determines in step S18 that the internal pressure Pin of the steam generator 12 is 90% or more of the target value Pt, the controller 36 proceeds to step S22. In step S22, it is determined whether or not the internal pressure Pin of the steam generator 12 exceeds 110% of the target value Pt. If it is determined that the internal pressure Pin of the steam generator 12 exceeds 110% of the target value Pt, the process proceeds to step S24. In step S24, the flow control valves 26 and 32 are controlled to reduce the amount of gas supplied to the junction J1 to reduce Pin, while the amount of gas supplied to the junction J2 is increased to provide a total to the steam supply line 18. Maintain gas supply at

  If the controller 36 determines in step S24 that the internal pressure Pin of the steam generator 12 is 110% or less of the target value Pt, the controller 36 proceeds to step S26. In step S26, it is determined whether a condition for ending control by the controller 36 is satisfied. When it is determined that the condition for ending the control by the controller 36 is satisfied, the present control is terminated, and when it is determined that the condition for ending the control by the controller 36 is not satisfied, the process returns to step S10.

In step S <b> 10, the controller 36 receives again information corresponding to the required steam amount and concentration from the steam consuming apparatus. Accordingly, when the supply steam amount fluctuates, the information input in step S10 is different from the previous information, and in step S12, the supply liquid to the steam generator 12 according to the changed required steam amount. The amount, the heating amount, and the amount of gas supplied to the junctions J1 and J2 are calculated. At this time, the change amount ΔV1 of the gas supply amount V1 to the junction portion J1 is calculated as the change amount of the gas flow rate enough to eliminate the pressure difference shown in FIG. 3 as described above, and further the junction portion J1 changed in this way. The gas amount V2rev (or the change ΔV2 relative to the gas supply amount V2) corresponding to the change in the required steam amount supplied to the junction J2 in order to maintain the vapor concentration is calculated using the gas supply amount (V1 + ΔV1) Is done. That is, the gas amount V2 is determined so as to satisfy the following formula (6).
(Vs + ΔVsi) / (V2rev + (V1 + ΔV1)) = Vs / (V2 + V1)
(6)

  Similarly to the above, the controller 36 controls in step S26 while correcting the gas supply amount in steps S20 and S24 when it is determined in steps S18 and S22 that the pressure of the steam generator 12 is fluctuated. The flow of FIG. 5 is repeated until it is determined that the processing is finished.

  Here, in the steam supply apparatus 10, the flow resistor 20 is disposed in the steam supply line 18 whose upstream end is connected to the steam outlet 12 </ b> A of the steam generator 12, and the gas inlet 20 </ b> A of the flow resistor 20 is connected to the steam supply line 18. Since the flow rate control valve 26 that can change the amount of gas supplied to the junction J1 between the steam generator 12 and the steam outlet 12A is provided in the first gas supply line 22, it is highly responsive to changes in the required amount of generation. The amount of supplied (generated) steam can be made to follow.

  This point will be supplemented with reference to the example shown in FIG. FIG. 7A shows steam supply when the required steam amount is changed between Sr1 and Sr2 (= Sr1 / 5) so that the steam concentration at the downstream end 18A of the steam supply line 18 is constant. The pressure of each part which comprises the apparatus 10 is shown. The thick solid line (open circle plot) is the pressure of each part when the required steam amount is Sr1, and the thin solid line (black paint plot) is the pressure of each part when the required steam amount is Sr2, and the broken line (black paint) The circle plot) shows the pressures of the respective parts in the comparative example in which the required steam amount is Sr2 and there is no change in the gas supply amount to the merging portion J1.

  From this figure, the gas flow rate supplied to the junction J1 (immediately upstream of the gas inlet 20A of the flow resistor 20) is higher than that when the required steam amount is Sr2 when the required steam amount is Sr1. The difference in generated amount (Sr1-Sr2) is reduced. In other words, when the required steam amount is Sr2, only the difference in steam generation amount (Sr1-Sr2) is compared with the case where the required steam amount is Sr1. It can be seen that by increasing the pressure, the internal pressure Pin of the steam generator 12 is kept constant regardless of the amount of steam generated. Thereby, in the steam supply apparatus 10, as shown in FIG. 7 (B), the boiling point Tb can be made constant, and the steam generation amount is controlled well by increasing / decreasing the heating amount of the steam generator 12 (heater). be able to.

  For example, in the configuration in which the gas supply amount to the merging portion J1 is not changed as shown as a comparative example by a broken line in FIG. 7A, the internal pressure Pin of the steam generator 12 is reduced when the required generation amount decreases from Sr1 to Sr2. It turns out that becomes low. Since this action is qualitatively the same as that in the steam supply device that does not include the flow resistor 20 shown in FIG. 12, supplementary explanation will be given based on FIG. FIG. 12A shows a comparative example when the required steam amount is changed between Sr1 and Sr2 (= Sr1 / 5) so that the steam concentration at the downstream end 18A of the steam supply line 18 is constant. The pressure of each part of the structure which concerns on is shown. From this figure, when the required steam amount (generated amount) is large, the supply gas amount also increases, so the pressure in each part of the device is high. Conversely, when the required steam amount (generated amount) is small, the supply gas amount is also high. It can be seen that the pressure becomes lower in each part of the apparatus because it becomes smaller, and the internal pressure Pin of the steam generator 12 changes (approximately proportionally) according to the required steam amount. In this case, as shown in FIG. 12B, the boiling point Tb changes in the steam generator 12 according to the pressure Pin. Specifically, the boiling point Tb3 when the required steam amount Sr1 is large is higher than the boiling point Tb4 when the required steam amount Sr2 is set. For this reason, for example, when the required amount of steam is changed (increased) from Sr2 to Sr1, the boiling point becomes higher, so that the steam tends to be insufficient, and conversely, the required amount of steam is changed (decreased) from Sr1 to Sr2. In this case, since the boiling point is lowered, the vapor tends to become excessive. That is, it becomes difficult to follow the change in the required steam amount due to the change in the internal pressure Pin of the steam generator 12.

  On the other hand, in the steam supply device 10, the internal pressure Pin of the steam generator 12 is kept constant even when the required steam amount fluctuates as described above, so that the pump 16 (supply liquid amount), the flow resistor 20 (heater) By controlling the heating amount), the steam supply amount can be changed with good response according to the required steam amount.

  Here, in the steam supply device 10, the first gas supply line 22, the first gas supply device 24, and the flow rate control valve 26 that supply gas to the junction J <b> 1 in order to keep the internal pressure Pin of the steam generator 12 constant. In addition, since the second gas supply line 28, the second gas supply device 30, and the flow rate control valve 32 for supplying gas to the joining portion J2 downstream of the flow resistor 20 are provided, the steam generator 12 of the steam generator 12 is provided as described above. While maintaining the internal pressure Pin constant, it is possible to increase the supply steam amount according to the change in the required steam amount and maintain the steam concentration in the air-fuel mixture supplied to the steam consuming device. That is, the steam supply device 10 can obtain a stable output with high responsiveness (amount of gas mixture, steam concentration). Hereinafter, this point will be confirmed based on experimental results.

  FIG. 9 shows the experimental results when the required steam amount is rapidly increased. FIG. 9A shows changes over time in the amount of liquid supplied to the steam generator 12 of the steam supply device 10 and the amount of gas supplied to the junctions J1 and J2. At time 0, an instruction to increase the required steam amount is input, and as the amount of liquid supplied to the steam generator 12 (the amount of generated steam) increases, the amount of gas supplied to the junction J1 is reduced and to the junction J2. It can be seen that the amount of gas supplied is increased. FIG. 9B shows the pressure at the inlet of the steam consuming apparatus (downstream end 18A of the steam supply line 18) and the change over time (response) of the steam concentration. From time 0, it can be seen that the pressure increases as the amount of steam supplied increases. From this figure, it was confirmed that in the steam supply device 10, the steam concentration in the gas mixture was substantially constant regardless of the change in the steam supply amount (pressure). In other words, it can be seen that the steam is generated with high responsiveness to the increased gas supply amount. Although not shown in the drawing, the gas pressure 20A side of the flow resistor 20, that is, the internal pressure Pin in the steam generator 12, is requested to increase the amount of steam due to a decrease in the amount of gas supplied to the junction J1. It has been confirmed that it is kept substantially constant from the set time 0.

  A diagram indicated by a broken line in FIG. 9B shows a response of the vapor concentration when controlled by the control method according to the comparative example. In this control method, as shown in FIG. 9C, the gas supply to the junction J1 is always set to 0, and the vapor concentration is kept constant only by the gas supply to the junction J2. In the control according to this comparative example, as shown in FIG. 9B, the steam concentration is remarkably reduced immediately after the change in the required steam amount, and the steam supply becomes unstable. That is, in this comparative example, the gas supply amount increases corresponding to the increase in the required steam amount, but as the internal pressure Pin of the steam generator 12 increases due to this, the boiling point Tb becomes lower as shown in FIG. As a result, the generation of steam (increase in amount) is suppressed, and the above-described decrease in the vapor concentration occurs. In this experimental example, it takes approximately 100 seconds for the vapor concentration to recover to the predetermined concentration. By comparison with this comparative example, it was confirmed that the steam supply device 10 showed extremely high responsiveness and was able to maintain the steam concentration following the change in the required steam amount.

  In the steam supply device 10, the above-described effects can be obtained with the configuration in which the flow resistor 20 is provided in the steam supply line 18 and the gas supply units are provided on the upstream and downstream sides of the flow resistor 20. That is, since it is not necessary to use a high-temperature, heat-resistant and expensive sealing material in the steam supply line 18 that is at a high temperature to generate steam and to provide a flow control valve that is enlarged for cooling the drive unit, etc. The steam supply apparatus 10 can be configured inexpensively and compactly. In addition, in the configuration provided with the flow rate adjusting valve as described above, starting at a high temperature is not permitted due to the limitation of the heat resistant temperature of the material, so that it takes a long time to raise the temperature of the device (steam generator 12) at the initial starting. It will be. On the other hand, the steam supply device 10 that does not include the flow rate adjusting valve in the steam supply line 18 can be started at a high temperature, and the temperature of the device (steam generator 12) is increased at an early stage, that is, the normal operation is performed. be able to.

(Vapor release mode)
In the vapor release mode, the same control as in the normal mode shown in FIG. 5 is performed except that Pin = Pt1 and the control end condition in step S26 are different. For this reason, it supplements about a different point from above-mentioned normal mode.

  In the steam discharge mode, the target value Pt of the internal pressure of the steam generator 12, which is the control target of the steam generator 12, is switched from Pt2 to Pt1, so first the process proceeds from step S22 to step S24, and the amount of gas supplied to the junction J1 Is reduced, the internal pressure Pin is rapidly reduced. For this reason, inside the steam generator 12, as shown in FIG. 8B, the boiling point Tb of water decreases from Tb1 to Tb2, and the superheated water at the pressure Pt1 evaporates momentarily to temporarily vaporize water vapor. The amount of emissions increases. Thereafter, the flow of FIG. 5 is repeated until it is determined in step S26 that the control (steam discharge mode) is finished. In this case, the target value Pt of the internal pressure of the steam generator 12 is Pt = Pt1, so that the steam generator 12 has a larger amount of water vapor compared to the normal mode (constant heating amount). Further, in the steam supply device 10 in which the steam supply concentration to the fuel cell system 100 is constant (set in step S10), the gas supply amount to the junction J2 increases as the amount of water vapor released increases.

  By increasing the supply amount of water vapor and air in this vapor discharge mode, the reforming reaction unit 106 and the shift reaction unit 112 suppress the temperature rise by the sensible heat cooling effect due to the increase in water vapor and air and the effect of increasing the heat capacity flow rate. Is done. In particular, since the gas to be supplied to the reforming reaction unit 106 and the shift reaction unit 112 includes water vapor as a main gas, for example, reforming compared to the case of introducing air (only) that promotes an exothermic reaction. The temperature rise suppression effect of the reaction unit 106 and the shift reaction unit 112 is high. Further, since water vapor generated by evaporating water in the steam generator 12 is used as a refrigerant, the water vapor can be instantaneously released by rapidly decreasing the pressure of the steam generator 12 from Pin2 to Pin1. That is, it is possible to effectively suppress the temperature rise of the reforming reaction unit 106 and the shift reaction unit 112 by releasing water vapor in a short time from the hot spot cooling request.

  In addition, in the steam supply device 10, the S / C ratio is temporarily increased by increasing the amount of steam supplied to the reforming reaction section 106, so that the steam reforming reaction, which is an endothermic reaction, is promoted and reforming is performed. The temperature rise of the reaction unit 106 is suppressed. Moreover, since the concentration of carbon monoxide discharged from the reforming reaction unit 106 is temporarily reduced by promoting the steam reforming reaction, heat generation due to the shift reaction in the shift reaction unit 112 is suppressed, The temperature rise in the shift reaction unit 112 is further suppressed.

  As described above, when the steam supply device 10 is operated in the steam discharge mode, a heat spot cooling effect can be obtained.

(Liquid recovery mode)
For example, in step S26 in the steam release mode, when the cooling request for the heat spot is canceled, the controller 36 determines that the control is finished, and finishes the steam release mode. The controller 36 switches the target value Pt of the internal pressure of the steam generator 12 from Pt1 to Pt2 (> Pt1) in step S110 of FIG. 4, and executes the liquid amount recovery mode shown in FIG.

  In the liquid amount recovery mode, in step S30, the controller 36 responds to the required steam amount (Vs), the concentration, and the amount of liquid to be stored in the steam generator 12 (ΔVsd in terms of steam) from the steam consuming apparatus that is the target of steam supply. Receive information. Next, the controller 36 proceeds to step S32, and the amount of liquid supplied to the steam generator 12 by the pump 16 (Vs + ΔVsd in terms of steam) according to the required steam amount, stored liquid amount, and concentration, heating amount in step S12, and flow resistance The amount of gas supplied to the upstream and downstream junctions J1 and J2 of the body 20 is calculated. Note that the processing in step S12 includes information necessary for calculation of each control amount (for example, input of temperature Tin). In step S34, the pump 16, the flow control valve 26, the flow control valve 32, and the heater in step S12 are based on the supply liquid amount, the heating amount calculated in step S32, and the supply gas amount to the junctions J1 and J2. A signal corresponding to the amount of power supplied to is output.

  As a result, the steam supply device 10 generates a mixer of the required steam amount and concentration of steam and gas and supplies it to the steam consuming device, while the target value Pt of the internal pressure of the steam generator 12 is Pt2 (> Pt1). ), The steam in the steam generator 12 (supercooled steam at the pressure Pt2) is condensed by the amount corresponding to the increase in pressure (boiling point) and stored in the steam generator 12 as a liquid. That is, as shown in FIG. 8B, the liquid reduced in the vapor discharge mode is stored in the steam generator 12.

  The controller 36 inputs a signal from the steam flow meter 42 in step S36, and determines in step S38 whether or not the steam amount (steam flow rate) Vs of the steam generator 12 is less than 90% of the target value Vt. . When it is determined that the steam flow rate Vs of the steam generator 12 is less than 90% of the target value Vt, the process proceeds to step S40. In step S40, the flow rate control valves 26 and 32 are controlled to reduce the amount of gas supplied to the junction J1 and increase Vs, while increasing the amount of gas supplied to the junction J2 to the steam supply line 18. Maintain total gas supply.

  When the controller 36 determines in step S38 that the steam flow rate Vs of the steam generator 12 is 90% or more of the target value Vt, the process proceeds to step S42. In step S42, it is determined whether or not Vs of the steam generator 12 exceeds 110% of the target value Vt. When it is determined that the steam flow rate Vs of the steam generator 12 exceeds 110% of the target value Vt, the process proceeds to step S44. In step S44, the flow control valves 26 and 32 are controlled to increase the amount of gas supplied to the junction J1 and decrease Vs, while the amount of gas supplied to the junction J2 is decreased to supply the steam supply line 18 to the steam supply line 18. Maintain total gas supply.

  If the controller 36 determines in step S44 that the steam flow rate Vs of the steam generator 12 is 110% or less of the target value Pt, the controller 36 proceeds to step S46. In step S46, it is determined whether or not an end condition for control by the controller 36 (liquid amount recovery mode) is satisfied. As the control end condition, for example, the elapse time of the steam discharge mode and the set time set according to the capacity of the steam generator 12, the output signal of the liquid level meter when the liquid level meter is provided become the set value. It can be the case when it arrives. When it is determined that the condition for ending the control by the controller 36 is satisfied, the present control is terminated. When it is determined that the condition for ending the control by the controller 36 is not satisfied, the process returns to step S30.

  In step S <b> 30, the controller 36 receives again information corresponding to the required steam amount and concentration from the steam consuming apparatus. Therefore, when the supply steam flow rate Vs fluctuates, the controller 36 calculates the supply gas amount to J1 and J2 according to the supply steam amount in the same manner as the normal mode described above, and changes the supply steam flow rate Vs. The amount of liquid in the steam generator 12 is increased while following and maintaining the concentration of the supply gas. Similarly to the above, when it is determined in steps S38 and S42 that the steam flow rate Vs of the steam generator 12 is varied, the controller 36 corrects the steam flow rate Vs in steps S40 and S44 while step S26. 6 is repeated until it is determined that the control is finished.

  As a result, the steam supply apparatus 10 recovers the amount of liquid supplied as steam for cooling the heat spot while supplying steam (mixed gas of air and air) according to the request from the fuel cell system 100. can do. In the liquid amount recovery mode, the target value Pt = Pt2 (> Pt1) of the internal pressure of the steam generator 12 is set while increasing the amount of liquid supplied to the steam generator 12 by ΔVsd. In other words, FIG. ), The boiling point Tb rises from Tb1 to Tb2, so that the liquid amount of the steam generator 12 is instantaneously recovered. That is, it returns to the state which can perform vapor | steam discharge | release mode in a short time according to the next heat spot cooling request | requirement.

  As described above, in the steam supply device 10, the water vapor discharge amount can be rapidly changed by changing the internal pressure of the steam generator 12 to change the boiling point (dew point) of the liquid. Here, in this embodiment, rapid means that the liquid level (stored amount) of the steam generator 12 is set to the internal pressure in the vapor discharge time and storage time (several seconds) defined by the response time of the flow control valves 26 and 32. This refers to the case where the rate of change in the amount of steam generated is changed to the corresponding liquid level. In this embodiment, as the change range of the liquid level, a change from 20% to 80% of the total liquid level of the steam generator 12 is set as the upper and lower limits. More specifically, for example, when 50% of the total liquid level of the steam generator 12 is a normal liquid level, the liquid level is reduced from 50% to 20% with the response time of the flow control valves 26 and 32. The target value Pt of the internal pressure of the steam generator 12 is set to such an extent that the steam generation amount is increased or the liquid level is increased from 50% to 80% in response time of the flow control valves 26 and 32. When the liquid level of the steam generator 12 is less than 20%, there is a concern about a decrease in steam generation due to insufficient heat transfer area, and when the liquid level of the steam generator 12 exceeds 80%, there is a concern about overflow of superheated liquid. By setting the target value Pt of the internal pressure of the steam generator 12 to be changed in the range of 20% to 80% of the total liquid level of the steam generator 12 as described above, it is sufficient to follow a sudden change in internal pressure. An increased amount of steam generation can be obtained over a predetermined time, and overflow of the superheated liquid can be prevented.

(Second Embodiment)
Next, a steam supply device 50 according to a second embodiment of the present invention will be described with reference to FIGS. Note that parts and portions that are basically the same as those in the first embodiment described above are denoted by the same reference numerals as those in the first embodiment described above, and a description thereof is omitted.

  In FIG. 10, the steam supply apparatus 50 is shown by the flowchart corresponding to FIG. As shown in this figure, the steam supply device 50 does not include the second gas supply device 30, the flow rate control valve 32, and the second gas supply line 28, and the merging portion J <b> 2 is not provided in the steam supply line 18. Thus, it is different from the steam supply apparatus 10 according to the first embodiment. Further, the steam supply device 50 includes a controller 52 as a control means instead of the controller 36.

  When the controller 52 receives a request to increase the steam flow rate Vs from the steam consuming device, basically, the amount of liquid supplied to the steam generator 12 by an amount corresponding to the required increase ΔVsi of the steam flow rate Vs. The pump 16 is controlled so as to increase Vp, and the gas supply amount V1 to the junction J1 between the steam generator 12 and the flow resistor 20 is decreased by the required increase ΔVsi of the steam flow rate Vs. Thus, the flow control valve 26 is controlled. Thereby, in the steam supply apparatus 10, the increase in pressure loss in the flow resistor 20 accompanying the increase in the amount of generated steam is offset, and the pressure Pin of the steam generator 12 is kept substantially constant.

  On the other hand, when the controller 52 receives a request to reduce the steam flow rate Vs from the steam consuming device, basically, the controller 52 supplies liquid to the steam generator 12 by an amount corresponding to the requested decrease ΔVsi of the steam flow rate Vs. The pump 16 is controlled so that the supply amount V1 is reduced, and the gas supply amount V1 to the junction J1 between the steam generator 12 and the flow resistor 20 by the required decrease ΔVsi of the steam flow rate Vs. The flow rate control valve 26 is controlled so as to increase. Thereby, in the steam supply device 10, the decrease in the pressure loss in the flow resistor 20 accompanying the decrease in the amount of generated steam is offset, and the pressure Pin of the steam generator 12 is kept substantially constant.

  The method of obtaining the change amount of the gas supply amount V1 to the junction J1 by the control of the flow control valve 26 by the controller 52 is the same as that of the controller 36 in the first embodiment. And the control flow by the controller 52 of the variation | change_quantity of the gas supply amount V1 is based on the flow shown in FIG. 5 except not performing control with respect to the junction part J2 by step S20, S24 shown in FIG.

  When the controller 52 receives a heat spot cooling request from the main controller of the fuel cell system 100, the controller 52 instantaneously reduces the target value Pt of the internal pressure of the steam generator 12 from Pt2 to Pt1. It is set as the structure which performs the vapor | steam discharge | release mode which increases discharge | release amount. Further, the controller 52 maintains the steam supply amount to the fuel cell system 100 by increasing the target value Pt of the internal pressure of the steam generator 12 from Pt1 to Pt2 and increasing the amount of liquid supplied to the steam generator 12. However, the liquid amount recovery mode for recovering the liquid amount of the steam generator 12 decreased in the steam discharge mode is executed. The other configuration of the steam supply device 50 is the same as the corresponding configuration of the steam supply device 10.

  Therefore, the steam supply device 50 according to the second embodiment also has the effect of changing the gas supply amount to the junction J2 and maintaining the steam concentration at the downstream end 18A of the steam supply line 18 constant. The same effect as the steam supply apparatus 10 according to the embodiment can be obtained. That is, in the steam supply device 50, the flow resistor 20 is disposed in the steam supply line 18 whose upstream end is connected to the steam outlet 12 </ b> A of the steam generator 12, and the gas inlet 20 </ b> A of the flow resistor 20 and the steam are connected. Since the first gas supply line 22 is provided with a flow rate control valve 26 capable of changing the amount of gas supplied to the junction J1 between the steam outlet 12A of the generator 12 and supplied with high response to changes in the required amount of generation. (Generation) The amount of steam can be followed. This effect will be supplemented with reference to FIG.

  FIG. 11 shows the experimental results when the required steam amount is rapidly increased. FIG. 11A shows changes over time in the amount of liquid supplied to the steam generator 12 of the steam supply device 50 and the amount of gas supplied to the junction J1. An instruction to increase the required steam amount is input at time 0, and it can be seen that the amount of gas supplied to the junction J1 is reduced as the amount of liquid supplied to the steam generator 12 (the amount of generated steam) increases. FIG. 11B shows a change with time (response) of the steam flow rate to the inlet of the steam consuming apparatus (downstream end 18A of the steam supply line 18). From this figure, it is confirmed that in the steam supply device 10, the steam flow rate increases (sets) in a short time (about 4 seconds) from the required steam volume increase command (time 0), and then the stable steam flow rate is maintained. It was. Although illustration is omitted, it has been confirmed that the inlet pressure of the steam consuming apparatus becomes constant in a short time.

  A diagram indicated by a broken line in FIG. 11B shows the response of the vapor concentration when controlled by the control method according to the comparative example. In this control method, the gas supply to the junction J1 is always zero. In the control according to this comparative example, as shown in FIG. 11 (B), the steam flow rate is remarkably reduced immediately after the change of the required steam amount, and the steam supply becomes unstable. That is, in this comparative example, the internal pressure Pin of the steam generator 12 increases as the required steam amount increases, and the boiling point Tb increases as shown in FIG. Then, since steam generation (increase in amount) is suppressed, the above-described decrease in the steam flow rate occurs. In this experimental example, it takes approximately 120 seconds for the steam flow rate to recover to the predetermined flow rate. By comparison with this comparative example, it was confirmed that the steam supply device 10 showed extremely high responsiveness and was able to maintain the steam concentration following the change in the required steam amount.

  Further, in the steam supply device 50, when the heat spot cooling request is received from the main controller of the fuel cell system 100, the steam release mode is executed to instantaneously increase the amount of water vapor released. In addition, the temperature increase of the shift reaction unit 112 can be effectively suppressed. Further, in the steam supply device 50, after executing the steam discharge mode, the liquid amount recovery mode is executed to instantaneously recover the liquid amount of the steam generator 12 while maintaining the supply of steam to the fuel cell system 100. Can do. That is, it returns to the state which can perform vapor | steam discharge | release mode in a short time according to the next heat spot cooling request | requirement.

  In each of the above-described embodiments, the steam supply devices 10 and 50 applied to the fuel supply device 104 of the fuel cell system 100 are exemplified. However, the present invention is not limited to this, and the steam consuming device preferably uses steam, preferably The present invention can be applied to various uses for supplying a mixture of steam and gas. Therefore, for example, the present invention can also be applied to a fuel mixture supply device for mixing fuel vapor with air and supplying it to combustion equipment. In such various applications, the control of steam supply suppression (steam emission suppression) is realized by increasing the gas supply amount to the junction J1 and increasing the internal pressure Pin of the steam generator 12 suddenly. Mode). In this case, in the configuration including the second gas supply line 28, the second gas supply device 30, and the flow rate control valve 32, the gas supply amount to the junction portion J2 is increased in accordance with the increase in the gas supply amount to the junction portion J1. By reducing it, it is possible to make the concentration of the fuel mixture supplied to the combustion equipment constant. Further, in this case, if the supply of steam is suddenly decreased (stopped) instantaneously, the amount of liquid in the steam generator 12 increases. However, by the operation opposite to the recovery mode described above (the operation similar to the steam discharge mode for the normal mode). The amount of liquid can be recovered.

  Further, in each of the above-described embodiments, an example in which the controller 36 performs control for keeping the internal pressure Pin of the steam generator 12 constant in the normal mode has been described. However, the present invention is not limited thereto. As the amount of steam increases, in order to promote steam generation, the gas supply amount to the junction J1 may be controlled so as to be reduced more than the increase in steam generation amount.

  Furthermore, in the above-described first embodiment, the control example in which the gas supply amount to the junctions J1 and J2 is calculated according to the required steam amount in the normal mode is shown, but the present invention is not limited to this, With this control, the internal pressure Pin of the steam generator 12 can be kept substantially constant. Therefore, for example, a steam concentration meter is provided downstream of the mixer 34 in the steam supply line 18, and the internal pressure Pin of the steam generator 12 and the steam supply line 18 are controlled by feedback control based on signals from the steam concentration meter and the pressure gauge 38. Control for maintaining the vapor concentration at the downstream end 18A may be employed.

  Furthermore, in each of the above-described embodiments, an example in which a mixture of steam and gas is supplied to the steam consuming device has been described. However, the present invention is not limited to this. For example, instead of the mixer 34, steam supply A vapor separation membrane or the like may be provided in the line 18 so that only the vapor is supplied to the vapor consuming device.

1 is a system flow diagram showing a schematic overall configuration of a steam supply apparatus according to a first embodiment of the present invention. 1 is a block diagram showing a schematic overall configuration of a fuel cell system to which a steam supply device according to a first embodiment of the present invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which concerns on the flow resistance body which comprises the steam supply apparatus which concerns on the 1st Embodiment of this invention, Comprising: (A) is a perspective view which shows a schematic structure typically, (B) is the gas amount-pressure which passes. It is a diagram which shows a loss characteristic. It is a flowchart which shows the main control flow by the controller which comprises the steam supply apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the control flow of the normal mode by the controller which comprises the steam supply apparatus which concerns on the 1st Embodiment of this invention, and a vapor | steam discharge mode. It is a flowchart which shows the control flow of the liquid quantity recovery | restoration mode by the controller which comprises the steam supply apparatus which concerns on the 1st Embodiment of this invention. (A) is a diagram which shows the pressure of each part in the driving | running state of the steam generator which concerns on the 1st Embodiment of this invention, (B) is a steam pressure line of a steam generator. (A) is a diagram which shows the difference in the pressure of each part of the vapor | steam discharge mode and liquid quantity recovery mode of the steam generator which concerns on the 1st Embodiment of this invention, (B) is the vapor pressure of a steam generator Is a line. It is a figure which shows the experimental result at the time of increasing the request | requirement steam volume by the steam generator which concerns on the 1st Embodiment of this invention, Comprising: (A) is the supply liquid quantity to a steam generator, and a steam supply line A diagram showing the change over time in the amount of gas supplied, (B) is a diagram showing the change over time in the inlet pressure and the vapor concentration of the steam consuming device, and (C) is a steam generator when the control according to the comparative example is performed. It is a diagram which shows the time change of the amount of supply liquids to and the amount of gas supply to a steam supply line. It is a system flow figure which shows the schematic whole structure of the steam supply apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the experimental result at the time of increasing the request | requirement steam volume by the steam generator which concerns on the 2nd Embodiment of this invention, Comprising: (A) is the supply liquid quantity to a steam generator, and a steam supply line FIG. 4B is a diagram showing a change over time in the amount of supplied gas, and FIG. 5B is a diagram showing a change over time in the amount of generated steam. (A) is a diagram which shows the pressure of each part in the operation state of the steam generator which concerns on the comparative example with embodiment of this invention, (B) is the vapor | steam pressure line of the steam generator in this comparative example.

Explanation of symbols

10 Steam supply device 12 Steam generator 16 Pump (liquid supply means)
20 Flow resistor 22 First gas supply line (gas supply means, first gas supply means)
24 1st gas supply apparatus (gas supply means, 1st gas supply means)
26 Flow control valve (gas flow rate changing means, first gas flow rate changing means)
28 Second gas supply line (second gas supply means)
30 Gas supply device (second gas supply means)
32 Flow control valve (second gas flow rate changing means)
36 controller (control means)
50 Steam supply device 52 Controller (control means)

Claims (10)

A steam generator for vaporizing the liquid;
A flow resistor that is in communication with the steam outlet side of the steam generator and generates a flow resistance as the gas passes;
Gas supply means capable of supplying gas between a steam outlet of the steam generator and a gas inlet of the flow resistor;
A gas flow rate changing means capable of changing a gas supply amount by the gas supply means;
When the time variation of the steam generation amount due to rapid steam generator is required to the extent that changes in response time of the gas supply means to the set upper limit or lower limit liquid level in the steam generator, the steam generator and control means for controlling the gas flow rate changing means in accordance with the amount of increase decrease request,
A steam supply device comprising: Wherein, in response to a request to increase the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to said lower limit, the gas supply means The steam supply device according to claim 1, wherein the gas flow rate changing means is controlled so that the gas supply amount by the gas is reduced. It said control means, in response to a request to decrease little of the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to the upper limit, the gas supply means The steam supply device according to claim 1, wherein the gas flow rate changing unit is controlled so that the gas supply amount by the gas is increased. A liquid supply means for supplying the liquid to the vapor generator;
The control means includes
To request to increase the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to said lower limit, the gas supply amount of the gas supply means A vapor discharge mode for controlling the gas flow rate changing means to be reduced;
After the execution of the vapor discharge mode, the gas flow rate changing means and the liquid supply means are arranged such that the gas supply amount by the gas supply means is increased and the liquid supply amount to the steam generator is increased. Recovery mode to control,
The steam supply device according to any one of claims 1 to 3, wherein A liquid supply means for supplying the liquid to the vapor generator;
The control means includes
To request to decrease little of the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to the upper limit, gas supply amount of the gas supply means A vapor emission suppression mode for controlling the gas flow rate changing means to be increased; and
The gas flow rate changing means and the liquid supply means so that the gas supply amount by the gas supply means is reduced and the supply amount of the liquid to the steam generator is reduced after the execution of the vapor emission suppression mode. Recovery mode to control,
The steam supply apparatus according to any one of claims 1 to 4, wherein A steam generator for vaporizing the liquid;
A flow resistor that is in communication with the steam outlet side of the steam generator and generates a flow resistance as the gas passes;
First gas supply means capable of supplying gas between a steam outlet of the steam generator and a gas inlet of the flow resistor;
First gas flow rate changing means capable of changing a gas supply amount by the first gas supply means;
Second gas supply means capable of supplying gas to the gas outlet side of the flow resistor;
Second gas flow rate changing means capable of changing a gas supply amount by the second gas supply means;
When the time variation of the steam generation amount due to rapid steam generator is required to the extent that changes in response time of the gas supply means to the set upper limit or lower limit liquid level in the steam generator, the steam generator depending on the amount of increase down requests, so that the steam generation amount vapor concentration being maintained at a predetermined concentration at the device outlet is changed according to the increase or decrease request, the first gas flow rate control means and said second Control means for controlling the gas flow rate changing means of 2;
A steam supply device comprising: Wherein, in response to a request to increase the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to said lower limit, the gas supply means 7. The first gas flow rate changing means and the second gas flow rate changing means are controlled so that the gas supply amount due to the gas is reduced and the vapor concentration at the apparatus outlet is maintained at a predetermined concentration. The steam supply device described. Said control means, in response to a request to decrease little of the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to the upper limit, the first The first gas flow rate changing means and the second gas flow rate changing means are controlled so that the gas supply amount by the gas supply means is increased and the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration. The steam supply apparatus according to claim 6 or 7. A liquid supply means for supplying the liquid to the vapor generator;
The control means includes
To request to increase the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to said lower limit, the gas supply amount of the gas supply means A vapor discharge mode for controlling the first gas flow rate changing means and the second gas flow rate changing means so that the vapor concentration at the outlet of the apparatus is reduced and maintained at a predetermined concentration;
After execution of the vapor discharge mode, the gas supply amount by the gas supply means is increased, the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration, and the supply amount of the liquid to the vapor generator is increased. A recovery mode for controlling the first gas flow rate changing means, the second gas flow rate changing means, and the liquid supply means;
The steam supply device according to any one of claims 6 to 8, wherein A liquid supply means for supplying the liquid to the vapor generator;
The control means includes
To request to decrease little of the steam generation amount by rapidly the steam generator liquid level of the steam generator to the extent that changes in response time of the gas supply means to the upper limit, gas supply amount of the gas supply means A vapor discharge suppression mode for controlling the first gas flow rate change means and the second gas flow rate change means so that the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration,
After execution of the vapor emission suppression mode, the gas supply amount by the gas supply means is decreased, the vapor concentration at the outlet of the apparatus is maintained at a predetermined concentration, and the liquid supply amount to the vapor generator is decreased. A recovery mode for controlling the first gas flow rate changing means, the second gas flow rate changing means, and the liquid supply means;
The steam supply device according to any one of claims 6 to 9, wherein

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