JP2016155733A - Reforming system, fuel cell system and reformed gas production process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reforming system, fuel cell system and reformed gas production process in which the supply state of a reformed gas into the raw-material to be hydrodesulfurized is suitably detected.SOLUTION: Provided is a reforming system 50 including a desulfurization unit 11 for hydrodesulfurizing a raw-material Dr, a raw-material supply unit 20, a reforming unit 51 for reforming a desulfurized raw-material Df, a reformed gas supply unit 30 for mixing a reformed gas R into the raw-material Dr, a moisture level detection unit 43 for detecting the moisture level in a hydrogen-containing fluid HF, and a state detection unit 16 for detecting the supply state of the reformed gas R in the reformed gas supply unit 30 based on the detected moisture level; provided is a fuel cell system 1 including a reforming system 50, and a fuel cell 61 for generating power by introducing a reformed gas E and an oxidizer gas A; and provided is a reformed gas production process including the detection of the supply state of the reformed gas R to be mixed into the desulfurization target raw-material Dr based on the detected moisture level in the hydrogen-containing fluid HF during the formation of the reformed gas E and R by reforming the hydrodesulfurized raw-material Df.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a reforming system, a fuel cell system, and a method for producing a reformed gas, and in particular, a reforming system, a fuel cell system, and a reformed gas that suitably detect the supply state of the reformed gas to a raw material to be hydrodesulfurized. It relates to the manufacturing method.

  For example, a hydrogen-containing gas used for power generation in a fuel cell is often obtained by reforming a hydrocarbon-based raw material. Since hydrocarbon-based raw materials generally contain a sulfur content, desulfurization is performed before reforming into a hydrogen-containing gas. One of the desulfurization methods is hydrodesulfurization. In hydrodesulfurization, hydrogen is mixed with a raw material, the sulfur content in the raw material is reacted with hydrogen on a catalyst to convert to hydrogen sulfide, and this hydrogen sulfide is reacted with zinc oxide to be removed as zinc sulfide. . In the hydrodesulfurization, when hydrogen is insufficient, the desulfurization performance is deteriorated, which may adversely affect downstream equipment. Recycled gas that mixes a part of the hydrogen-containing gas produced by reforming the desulfurized raw material with a reformer into the raw material before desulfurization to suppress the shortage of hydrogen mixed with the raw material in hydrodesulfurization There is a circuit in which a thermometer is provided in a circuit to determine whether or not a recycle gas is supplied (for example, see Patent Document 1).

Japanese Patent No. 3718917

  However, the hydrogen-containing gas taken out from the reformer (partially recycle gas) is usually recovered in the reformer in order to suppress the decrease in efficiency due to heat dissipation, and near the temperature in the housing Extracted at a temperature of Therefore, the temperature change due to the presence or absence of the supply of the recycle gas in the recycle gas circuit is small, and it is difficult to accurately detect the presence or absence of the supply of the hydrogen-containing gas to the raw material before desulfurization.

  In view of the above-described problems, the present invention provides a reforming system, a fuel cell system, and a reformed gas manufacturing method that suitably detect a supply state of a reformed gas containing hydrogen mixed with a raw material to be hydrodesulfurized. The purpose is to do.

  In order to achieve the above object, the reforming system of the present invention includes a desulfurization unit that hydrodesulfurizes a desulfurization target raw material to generate a desulfurized raw material, and a raw material supply unit that supplies the desulfurization target raw material to the desulfurization unit. A reforming unit that introduces and reforms the desulfurized raw material to generate a reformed gas containing hydrogen, a reformed gas supply unit that mixes the reformed gas with the desulfurization target raw material, and the reformed gas A moisture level detection unit that directly or indirectly detects a moisture level of a hydrogen-containing fluid that is one of the reformed gas in the supply unit and a mixed fluid in which the raw material for desulfurization and the reformed gas are mixed; And a state detection unit that detects a supply state of the reformed gas in the reformed gas supply unit based on the moisture level of the hydrogen-containing fluid detected by the moisture level detection unit.

  In the reforming system of the present invention, the reformed gas supply unit may include a drainer that removes condensed water in the reformed gas.

  Further, the reforming system of the present invention includes a temperature detection unit that detects the temperature of the drainer or a temperature having a correlation with the temperature of the drainer, and the state detection unit corresponds to the temperature detected by the temperature detection unit. The reference for detecting the supply state of the reformed gas may be changed.

  In the reforming system of the present invention, the moisture level detection unit may be provided in the reformed gas supply unit downstream of the drainer as viewed in the flow direction of the reformed gas.

  In the reforming system of the present invention, the moisture level detector may detect the moisture level of the mixed fluid.

  Further, the reforming system of the present invention includes a pre-mixing raw material moisture level detection unit that detects a moisture level of the raw material to be desulfurized before the reformed gas is mixed, and the state detection unit is configured to detect the moisture level. The reformed gas in the reformed gas supply unit based on the difference between the moisture level of the hydrogen-containing fluid detected by the unit and the moisture level of the raw material for desulfurization detected by the raw material moisture level detection unit before mixing It is good also as detecting the supply state.

  In the reforming system of the present invention, the state detector may issue a command to perform an abnormality handling process when detecting an abnormality in the supply state of the reformed gas.

  In the reforming system of the present invention, the reformed gas supply unit includes a reformed gas flow rate adjusting unit that adjusts a flow rate of the reformed gas mixed with the desulfurization target raw material, and the reformed gas flow rate control A control unit that controls the control unit, and the state detection unit, as the abnormality handling process, issues a command to adjust the reformed gas flow rate control unit in order to suppress an abnormality in the supply state of the reformed gas. It may be sent to.

  The fuel cell system of the present invention includes the reforming system, and a fuel cell that generates power by introducing the reformed gas generated in the reforming unit and an oxidant gas containing oxygen. .

  In order to achieve the above object, the reformed gas production method of the present invention is produced in a desulfurization step of hydrodesulfurizing a raw material to be desulfurized after mixing a gas containing hydrogen, and the desulfurization step. A reforming step of reforming the desulfurized raw material to generate a reformed gas containing hydrogen, and the reformed gas generated in the reforming step mixed with the raw material to be desulfurized as the hydrogen-containing gas A reformed gas mixing step; a moisture level detecting step of detecting a moisture level of a hydrogen-containing fluid that is one of the reformed gas and a mixed fluid in which the raw material to be desulfurized and the reformed gas is mixed; And a state detection step of detecting a supply state of the reformed gas in the reformed gas mixing step based on the moisture level of the hydrogen-containing fluid detected in the moisture level detecting step.

  According to the present invention, since the supply state of the reformed gas is detected based on the moisture level of the hydrogen-containing fluid containing the reformed gas with high humidity, the supply state of the reformed gas can be suitably detected.

1 is a schematic system diagram of a fuel cell system according to an embodiment of the present invention. It is a graph which shows the relationship between the flow volume of the raw material before desulfurization introduce | transduced into a desulfurization part, and the allowable range of the absolute humidity which the recycle gas hygrometer detected. It is a flowchart which shows the operation | movement procedure of a reforming system. (A) is a schematic system diagram of a fuel cell system according to a first modification of the embodiment of the present invention, and (B) is a flow rate of a raw material before desulfurization introduced into a desulfurization section and a mixed fluid hygrometer detected. It is a graph which shows the relationship with the tolerance | permissible_range of humidity. It is a typical systematic diagram of the fuel cell system which concerns on the 2nd modification of embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or similar members are denoted by the same or similar reference numerals, and redundant description is omitted.

  A reforming system 50 and a fuel cell system 1 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic system diagram of the fuel cell system 1. The fuel cell system 1 includes a fuel cell 61 and a reforming system 50 as components. First, the configuration of the reforming system 50 will be described. The reforming system 50 includes a desulfurization unit 11 that desulfurizes the raw material D, a raw material supply unit 20, a reforming unit 51, a recycle gas supply unit 30 (hereinafter referred to as “RG supply unit 30”), and a recycle gas hygrometer. 43 (hereinafter referred to as “RG hygrometer 43”) and a control device 15.

  The raw material D can be made into a gas rich in hydrogen (hydrogen-rich gas) that can be used for power generation in the fuel cell 61 by reforming, and a hydrocarbon-based raw material (hydrocarbon fuel) is used. Specific examples include hydrocarbons, alcohols, ethers, biofuels, and these hydrocarbon fuels are derived from fossil fuels such as petroleum and coal, those derived from synthetic fuels such as synthesis gas, Those derived from biomass can be used as appropriate. Examples of hydrocarbons include methane, ethane, propane, butane, natural gas, LPG, city gas, town gas, gasoline, naphtha, kerosene, and light oil. Examples of alcohols include methanol and ethanol. Examples of ethers include dimethyl ether. Examples of biofuels include biogas, bioethanol, biodiesel, and biojet. In the following description, the raw material D before being desulfurized in the desulfurization section 11 is referred to as a pre-desulfurization raw material Dr, and the raw material D after being desulfurized in the desulfurization section 11 is referred to as a desulfurized raw material Df. This is collectively referred to as raw material D. The raw material Dr before desulfurization corresponds to the raw material to be desulfurized.

  The desulfurization part 11 is a part which desulfurizes the raw material Dr before desulfurization with a hydrodesulfurization system. In the desulfurization part 11, the raw material Dr and hydrogen before desulfurization are introduced, and first, the sulfur component in the raw material Dr before desulfurization is converted into hydrogen sulfide. Next, hydrogen sulfide reacts with zinc oxide and is immobilized as zinc sulfide. In this way, the raw material Dr before desulfurization is desulfurized to become a desulfurized raw material Df. Hydrodesulfurization is generally performed at 200 ° C to 400 ° C. The desulfurization section 11 has a hydrodesulfurization catalyst (not shown) that converts the sulfur component in the raw material Dr before desulfurization into hydrogen sulfide, and a heater (not shown) that can heat the desulfurization atmosphere to about 400 ° C. doing.

  Connected to the desulfurization section 11 are a pre-desulfurization raw material line 21 that leads the raw material Dr before desulfurization to the desulfurization section 11 and a desulfurized raw material line 52 that guides the desulfurized raw material Df to the reforming section 51. Here, the “... line” is a fluid flow path, and is typically a tube that exclusively guides the fluid, but is a space formed between objects used for other purposes. It may be. A recycle gas line 31 (hereinafter referred to as “RG line 31”) for introducing a gas containing hydrogen used for hydrodesulfurization of the raw material D in the desulfurization section 11 is connected to the raw material line 21 before desulfurization. In the raw material line 21 before desulfurization, a feed pump 22 that sends a mixed fluid DR in which the raw material Dr before desulfurization and the recycle gas R are mixed to the desulfurization unit 11 is in the flow direction of the raw material Dr before desulfurization than the connection part with the RG line 31. A flow meter 23 that is disposed on the downstream side and that measures the flow rate of the raw material Dr before desulfurization flowing through the raw material line 21 before desulfurization is disposed on the upstream side. The recycle gas R is obtained by extracting a part of the reformed gas E generated in the reforming unit 51. The mixed fluid DR is a form of the hydrogen-containing fluid HF. The feed pump 22 is configured to be able to adjust the flow rate of the fluid to be discharged by changing the rotation speed. The flow meter 23 is disposed upstream of the feed pump 22 when viewed in the flow direction of the raw material Dr before desulfurization. In the present embodiment, the raw material supply unit 20 includes the pre-desulfurization raw material line 21, the feed pump 22, and the flow meter 23. When the raw material Dr before desulfurization introduced into the reforming system 50 is liquid, a vaporizer (not shown) for vaporizing the raw material Dr before desulfurization is provided in the raw material line 21 before desulfurization upstream of the flow meter 23. .

  The reforming unit 51 is a part that introduces and reforms the desulfurized raw material Df to generate a reformed gas E rich in hydrogen. The reformed gas may be generally referred to as fuel gas. The reformed gas E contains hydrogen that can be used for power generation in the fuel cell 61, and is a form of gas containing hydrogen. The reforming unit 51 has a reforming catalyst (not shown) that promotes reforming of the desulfurized raw material Df inside the casing. The reforming unit 51 is connected to the other end of a desulfurized raw material line 52 having one end connected to the desulfurization unit 11. In other words, the desulfurization unit 11 and the reforming unit 51 communicate with each other via the desulfurized raw material line 52. The desulfurized raw material line 52 is a flow path that guides the desulfurized raw material Df generated in the desulfurization unit 11 to the reforming unit 51. A moisture line 53 for introducing moisture S is connected to the desulfurized raw material line 52. The reforming unit 51 introduces the desulfurized raw material Df and the water S, and causes the reforming reaction of the hydrocarbon and the water S (steam) in the desulfurized raw material Df under the reforming catalyst. Is configured to generate A reformed gas line 56 for flowing the generated reformed gas E is also connected to the reforming unit 51. As described above, the reforming system 50 in the present embodiment includes the desulfurized raw material line 52, the moisture line 53, and the reformed gas line 56.

  The RG line 31 is branched from the reformed gas line 56, and a part of the reformed gas E output from the reforming section 51 can be supplied as the recycled gas R toward the raw material line 21 before desulfurization. It is configured as follows. The recycle gas R is a hydrogen-containing gas generated in the reforming section 51 as with the reformed gas E, and has the same composition as the reformed gas E. This is the name. The recycle gas R is a form of the hydrogen-containing fluid HF. The RG line 31 branched from the reformed gas line 56 is connected to the raw material line 21 before desulfurization between the feed pump 22 and the flow meter 23. The RG line 31 guides the recycle gas R (as described above, one of the reformed gas E that is circulated toward the desulfurization section 11) to the raw material line 21 before desulfurization. The RG line 31 includes an on-off valve 32 that can shut off the flow path, a recycle gas pump 33 that pumps the recycle gas R (hereinafter referred to as “RG pump 33”), and water in the recycle gas R is reduced (water level is reduced). And a drainer 34 to be lowered). The RG pump 33 is configured to be able to adjust the flow rate of the fluid to be discharged by changing the rotation speed. The RG pump 33 corresponds to a reformed gas flow rate control unit. The drainer 34 is configured to reduce moisture in the recycle gas R by removing condensed water contained in the recycle gas R. In the present embodiment, the RG supply unit 30 includes the RG line 31, the on-off valve 32, the RG pump 33, and the drainer 34. The RG supply unit 30 corresponds to a reformed gas supply unit.

  The RG line 31 is provided with an RG hygrometer 43 that detects the internal absolute humidity. The RG hygrometer 43 is a device that can detect the degree of wetness (moisture level) in the gas, and corresponds to a moisture level detection unit. The RG hygrometer 43 typically uses a meter that detects the dew point and calculates the absolute humidity from the dew point. In the present embodiment, the RG hygrometer 43 is disposed in the RG line 31 on the downstream side of the drainer 34 when viewed in the flow direction of the recycle gas R. Therefore, in the present embodiment, the RG hygrometer 43 is configured to detect the absolute humidity of the recycled gas R from which condensed water has been removed by the drainer 34. By providing the RG hygrometer 43 on the downstream side of the drainer 34, it is possible to prevent the condensed water from being conveyed to the RG hygrometer 43 and to protect the RG hygrometer 43. The reformed gas E exiting the reformer 51 is hot and humid, and the recycle gas R flowing downstream of the drainer 34 is typically saturated steam at the temperature of the drainer 34 (in a state where the relative humidity is 100%). ). Therefore, typically, when the recycle gas R is flowing through the RG line 31, the RG hygrometer 43 detects high humidity because there is almost no temperature drop in the RG line 31. On the other hand, when the flow of the recycle gas R in the RG line 31 is lost, the temperature in the RG line 31 is reduced to generate condensed water, and the RG hygrometer 43 detects low humidity. The drainer 34 has a discharge pipe 35 that discharges condensed water c in which moisture in the recycle gas R is condensed to the outside. One end of the discharge pipe 35 is typically connected to the bottom of the drainer 34. A discharge valve 36 that opens and closes the flow path is disposed in the discharge pipe 35. The drainer 34 has a liquid level meter 37 that detects the liquid level of the condensed water c stored inside. The liquid level meter 37 is configured to detect a high liquid level and a low liquid level in the drainer 34. The drainer 34 is provided with a drainer thermometer 48 that detects the internal temperature.

  Since the control device 15 controls the operation of the devices that constitute the reforming system 50 and also controls the operation of the devices that constitute the fuel cell system 1, details will be described later.

  Next, the configuration of the fuel cell system 1 will be described. The fuel cell system 1 includes a fuel cell 61 in addition to the reforming system 50 described above. The fuel cell system 1 in the present embodiment further includes an air line 62, a blower 65, a combustion unit 68, and an exhaust gas line 69. The fuel cell 61 is connected to the reforming unit 51 via a fuel gas line 56. An air line 62 for introducing air A is also connected to the fuel cell 61. Air A contains oxygen and corresponds to an oxidant gas. A blower 65 that pumps air A toward the fuel cell 61 is disposed in the air line 62. The blower 65 is configured so that the flow rate of the fluid to be discharged can be adjusted by changing the rotation speed. In the present embodiment, the oxidant gas supply unit is configured including the air line 62 and the blower 65.

  The fuel cell 61 is configured to introduce the reformed gas E and air A, and to generate DC power by an electrochemical reaction between hydrogen or the like in the reformed gas E and oxygen in the air A. In general, it may be called a cell stack. As the fuel cell 61, a cylindrical type (including a flat plate cylindrical type) solid oxide fuel cell (SOFC) is used in the present embodiment, but a SOFC such as a solid polymer fuel cell (PEFC) is used. Other fuel cells may be used. The reformed gas E and air A supplied to the fuel cell 61 for power generation in the fuel cell 61 are not all used for power generation, but the amount corresponding to the power generation current of the fuel cell 61 is used. The portion not used for power generation is discharged as off-gas F. In the present embodiment, a burner (not shown) for burning off-gas F flowing out from the fuel cell 61 is provided on the downstream side of the fuel cell 61, and the off-gas F is burned by the burner (not shown). The reforming part 51 can be heated by the heat generated at the time. Separately, combustion air is supplied to the burner (not shown).

  The fuel cell system 1 includes a combustion unit 68 downstream of the fuel cell 61. The combustion unit 68 introduces the off-gas F that has been discharged from the fuel cell 61 and burned by a burner (not shown), and burns unburned combustible components contained in the off-gas F after the primary combustion. It is configured. The combustion unit 68 is mainly for burning unburned components in the off-gas F after the primary combustion, and is disposed adjacent to the reforming unit 51 to heat the reforming catalyst in the reforming unit 51. May be provided. The combustion unit 68 is configured to discharge the exhaust gas G generated by the combustion of the off-gas F after the primary combustion. An exhaust gas line 69 for flowing exhaust gas G is connected to the combustion unit 68.

  The control device 15 includes a state detection unit 16, a control unit 17, and a storage unit 18. The state detection unit 16 is a part that detects the supply state of the recycle gas R to the raw material line 21 before desulfurization. Specifically, in this embodiment, the state detection unit 16 is configured to detect whether or not there is an abnormality in the supply state of the recycle gas R to the raw material line 21 before desulfurization. The state detection unit 16 is connected to the flow meter 23 with a signal cable, and is configured to receive the flow rate measured by the flow meter 23 as a signal. Moreover, the state detection part 16 is connected with the desulfurization part 11 by the signal cable, and is comprised so that the temperature of the desulfurization part 11 can be grasped | ascertained. Moreover, the state detection part 16 is connected with the liquid level meter 37 with the signal cable, and is comprised so that the liquid level which the liquid level meter 37 detected can be received as a signal. Moreover, the state detection part 16 is connected with the RG hygrometer 43 with the signal cable, and is comprised so that the value which the RG hygrometer 43 detected can be received as a signal. Moreover, the state detection part 16 is connected with the drainer thermometer 48 with the signal cable, and is comprised so that the temperature which the drainer thermometer 48 detected can be received as a signal. Details of a method for determining whether or not there is an abnormality in the supply state of the recycle gas R to the raw material line 21 before desulfurization in the state detection unit 16 will be described later. The state detection unit 16 is configured to issue a command for performing an abnormality handling process when it is determined that the supply state of the recycle gas R to the raw material line 21 before desulfurization is abnormal. As an example of the abnormality handling process, the fuel cell system 1 (including the reforming system 50) is stopped, an alarm is output, and the output of the RG pump 33 so that the recycle gas R is supplied to the raw material line 21 before desulfurization. For example. Since the state detection unit 16 issues a command to perform an abnormality handling process, the raw material Dr before desulfurization can be prevented from being supplied downstream of the desulfurization unit 11 in an incomplete desulfurization state, and is provided downstream of the desulfurization unit 11. Equipment can be protected.

  The control unit 17 is a part that controls the operation of the devices constituting the fuel cell system 1. The control unit 17 is connected to the feed pump 22, the RG pump 33, and the blower 65 through signal cables, and is configured to be able to adjust the flow rate of the fluid to be discharged by adjusting the rotation speed of each device. ing. The control unit 17 is connected to the open / close valve 32 and the discharge valve 36 by signal cables, respectively, and is configured to be able to individually switch the open / close of the open / close valve 32 and the discharge valve 36. Further, the state detection unit 16 and the control unit 17 are configured to be able to exchange signals with each other. The storage unit 18 includes a memory and the like, and a reference value (threshold value) for determining whether there is an abnormality in the supply state of the recycle gas R to the raw material line 21 before desulfurization is set. The state detection unit 16 is configured to be able to refer to the reference value stored in the storage unit 18 when determining whether there is an abnormality in the supply state of the recycle gas R to the raw material line 21 before desulfurization. Yes. In the present embodiment, from the viewpoint of function, for convenience, the state detection unit 16, the control unit 17, and the storage unit 18 are shown as independent configurations, but the control device 15 does not physically distinguish them. It may be provided integrally. The state detection unit 16 is configured to be able to grasp the respective outputs (rotational speeds) of the feed pump 22, the RG pump 33, and the blower 65.

  FIG. 2 shows the relationship between the flow rate of the raw material Dr before desulfurization introduced into the desulfurization section 11 and the absolute humidity detected by the RG hygrometer 43. In FIG. 2, a line segment SV is a reference value that is preset in the storage unit 18 to determine whether or not the supply state of the recycle gas R to the raw material line 21 before desulfurization is abnormal. In the present embodiment, the flow rate of the raw material Dr before desulfurization introduced into the desulfurization section 11 is the raw material Dr before desulfurization necessary for generating the reformed gas E having a flow rate required for the generated power in the fuel cell 61. (Hereinafter referred to as “predetermined flow rate”). The flow rate of the recycle gas R mixed with the raw material Dr before desulfurization is set to a flow rate suitable for appropriately performing hydrodesulfurization in the desulfurization section 11, and the absolute value of the recycle gas R mixed with the raw material Dr before desulfurization The humidity is typically constant regardless of the flow rate of the raw material Dr before desulfurization introduced into the desulfurization section 11. Therefore, the line segment SV (reference value) shown in FIG. 2 is set constant.

  During operation of the fuel cell system 1 (reforming system 50), the flow rate of the recycle gas R mixed with the raw material Dr before desulfurization may change due to some factor. As an example of the change in the flow rate of the recycle gas R mixed with the raw material Dr before desulfurization and the factor thereof, the recycle gas R is introduced into the raw material line 21 before desulfurization due to the blockage of the RG line 31 due to condensed water in the recycle gas R. For example, the supply is stopped or the supply flow rate is decreased. When the flow rate of the recycle gas R mixed with the raw material Dr before desulfurization decreases, the flow rate of the recycle gas R flowing through the RG line 31 also decreases, and the RG hygrometer 43 is accompanied by a temperature drop in the RG line 31. The absolute humidity detected by the is decreasing. In the hydrodesulfurization in the desulfurization part 11, if there is little hydrogen introduced, appropriate hydrodesulfurization cannot be performed. Therefore, the absolute humidity detected by the RG hygrometer 43 when the lower flow rate of the recycle gas R capable of stably performing hydrodesulfurization flows through the RG line 31 is set as a reference value. This is indicated by a line segment SV. When the absolute humidity detected by the RG hygrometer 43 is above or above the line segment SV obtained by referring to the storage unit 18, the state detection unit 16 generates a recycle gas R having an appropriate flow rate. It is determined that the raw material Dr is mixed with the raw material Dr before desulfurization, and when it is below the line segment SV, it is determined that the recycle gas R having an appropriate flow rate is not mixed with the raw material Dr before desulfurization.

  With continued reference to FIG. 1, the operation of the fuel cell system 1 will be described. As part of the description of the operation of the fuel cell system 1, the operation of the reforming system 50 will also be described. First, the operation around the reforming system 50 will be described with reference to the flowchart of FIG. 3 and FIG. While the reforming system 50 is stopped, both the on-off valve 32 and the discharge valve 36 are closed. When the state detection unit 16 detects that the reforming system 50 is activated and the temperature of the desulfurization unit 11 has reached a temperature suitable for hydrodesulfurization, the control unit 17 activates the feed pump 22, The raw material Dr before desulfurization is introduced into the reforming system 50 from the outside (S1). The control unit 17 opens the on-off valve 32 and activates the RG pump 33 to mix the recycle gas R as a gas containing hydrogen with the raw material Dr before desulfurization (recycle gas mixing step: S2). In FIG. 3, the raw material Dr before desulfurization is introduced (S1), and then the recycle gas R is mixed (S2). However, the introduction of the raw material Dr before desulfurization (S1) and the mixing of the recycle gas R ( S2) may be performed simultaneously, or the recycle gas R may be mixed at the timing when the reformed gas E is generated by the reforming process in the reforming unit 51. The mixed fluid DR in which the recycle gas R is mixed with the raw material Dr before desulfurization is supplied to the desulfurization unit 11 by the feed pump 22 (S3). When the mixed fluid DR is supplied to the desulfurization unit 11, the state detection unit 16 monitors the flow rate of the raw material Dr before desulfurization detected by the flow meter 23 so that the flow rate of the raw material Dr before desulfurization becomes a predetermined flow rate. In addition, the rotational speed of the feed pump 22 is adjusted via the controller 17.

  In the desulfurization section 11, when the mixed fluid DR is introduced, the hydrodesulfurization of the raw material Dr before desulfurization is performed, and the desulfurized raw material Df is generated (desulfurization step: S4). The desulfurized raw material Df generated in the desulfurization unit 11 flows through the desulfurized raw material line 52 and is introduced into the reforming unit 51. The desulfurized raw material Df is combined with the moisture S flowing through the moisture line 53 before flowing into the reforming section 51 or after flowing into the reforming section 51. The desulfurized raw material Df that has flowed into the reforming unit 51 together with the moisture S is reformed in the reforming unit 51 to generate a reformed gas E rich in hydrogen (reforming step: S5). A part of the reformed gas E flowing out from the reforming section 51 flows into the RG line 31 as the recycle gas R and flows toward the raw material line 21 before desulfurization. Usually, the raw material before desulfurization flows through the raw material line 21 before desulfurization. It is mixed with Dr (recycle gas supply process: S6). This recycle gas supply process (S6) is the same process as the recycle gas mixing process (S2) described above, and is described redundantly for convenience of explanation. Both the recycle gas mixing step (S2) and the recycle gas supply step (S6) correspond to the reformed gas mixing step. During the operation of the reforming system 50, the process is continuously performed from the pre-desulfurization raw material Dr introduction step (S1) to the recycle gas supply step (S6). The recycle gas R flowing through the RG line 31 is a gas having a relative humidity of approximately 100% because condensed water is removed when passing through the drainer 34. By removing the condensed water in the recycle gas R by the drainer 34, it is possible to avoid the RG line 31 from being clogged with the condensed water. The condensed water c removed from the recycle gas R is stored in the drainer 34. The state detection unit 16 receives a liquid level signal from the liquid level meter 37 at any time, and when the liquid level meter 37 detects a high liquid level, the discharge valve 36 is opened via the control unit 17 and the condensed water c is discharged to the outside. When the liquid level meter 37 detects a low liquid level, the discharge valve 36 is closed via the control unit 17.

  When the recycle gas R flows through the RG line 31 and is supplied to the raw material line 21 before desulfurization, the state detection unit 16 receives the value detected by the RG hygrometer 43 to thereby determine the moisture level of the recycle gas R. It is detected (moisture level detection step: S7). Then, the state detection unit 16 determines whether or not the value detected by the RG hygrometer 43 is appropriate in view of the reference value stored in the storage unit 18 (state detection step: S8). In other words, in the state detection step (S8), it is determined whether or not the value detected by the RG hygrometer 43 is equal to or greater than the reference value indicated by the line segment SV in the graph shown in FIG. As described above, since the recycle gas R has a relative humidity of about 100%, the RG hygrometer 43 disposed in the RG line 31 on the downstream side of the drain 34 has a flow of the recycle gas R in the RG line 31. When the high humidity above the line segment SV is detected, the detected value decreases as the flow rate of the recycle gas R flowing through the RG line 31 decreases. Thus, according to the RG hygrometer 43, it is easy to detect a change in the flow rate of the recycle gas R in the RG line 31. Therefore, the reforming system 50 can detect with higher accuracy than the conventional case where the presence or absence of the supply of the recycle gas R is detected by measuring the temperature of the recycle gas R.

  Note that the reference value indicated by the line segment SV in FIG. 2 is preferably corrected based on the temperature detected by the drainer thermometer 48. The recycle gas R that has passed through the drainer 34 has a relative humidity of approximately 100% as described above, but the absolute humidity of the recycle gas R detected by the RG hygrometer 43 varies depending on the temperature of the recycle gas R. If the temperature detected by the drain thermometer 48 is lower than the standard value and the absolute humidity of the recycle gas R is lower than the standard value at the standard time, the flow of the recycle gas R is present. If there is an abnormality in the supply of the recycle gas R, there is a possibility that it is erroneously detected. When the temperature detected by the drainer thermometer 48 is lower than the standard value, the state detector 16 lowers the reference value indicated by the line segment SV in FIG. 2 in accordance with the deviation from the standard value, and the drainer thermometer 48 2 is higher than the standard value, the flow rate of the recycle gas R in the RG line 31 is changed by increasing the reference value indicated by the line segment SV in FIG. 2 according to the deviation from the standard value. Can be detected appropriately. As described above, the temperature of the drain 34 that affects the moisture level of the recycle gas R on the downstream side of the drain 34 is reflected in the reference value indicated by the line segment SV in FIG. The supply state of the recycle gas R can be detected with higher accuracy.

  In the flowchart shown in FIG. 3, in the state detection step (S8), if the value detected by the RG hygrometer 43 is equal to or greater than the reference value, a command to stop the reforming system 50 (reforming in the reforming unit 51). It is determined whether or not there is (S9). When there is no command (S9) for stopping the reforming system 50, the process returns to the step (S1) of introducing the raw material Dr before desulfurization again, and the above-described flow is continued. If there is a command (S9) to stop the reforming system 50, the reforming system 50 is stopped. On the other hand, in the state detection step (S8), when the value detected by the RG hygrometer 43 is not greater than or equal to the reference value, the state detection unit 16 determines that the supply state of the recycled gas R is abnormal (S10). When the state detection unit 16 determines that the supply state of the recycle gas R is abnormal, the state detection unit 16 issues a command for performing the abnormality handling process, and the abnormality handling process is performed in the reforming system 50 (S11).

  An example of the abnormality handling process is to issue an alarm notifying that an abnormality has occurred. By issuing an alarm, an opportunity for inspection by the maintenance staff can be evoked. When an alarm is issued, the reforming system 50 may be temporarily stopped because an abnormality in the supply state of the recycle gas R is not solved in principle. By stopping the reforming system 50, it is possible to suppress adverse effects on the reforming unit 51 and the fuel cell 61 disposed on the downstream side of the desulfurization unit 11. The operation of the fuel cell system 1 may be stopped when the reforming system 50 is stopped. On the other hand, adjusting the rotational speed of the RG pump 33 is another example of the abnormality handling process. In this case, typically, the rotational speed of the RG pump 33 is increased according to the value detected by the RG hygrometer 43. When the rotational speed of the RG pump 33 is adjusted as an abnormality handling process, there is a possibility that an abnormality in the supply state of the recycle gas R may be eliminated, so that the operation of the reforming system 50 may be continued. In other words, when the rotational speed of the RG pump 33 is adjusted as an abnormality handling process, the operation of the reforming system 50 can be continued.

  When the abnormality handling process of the reforming system 50 is performed (S11), the state detection unit 16 determines whether to temporarily stop the reforming system 50 (S12). Typically, when the rotational speed of the RG pump 33 is adjusted as the abnormality handling process, the reforming system 50 is temporarily stopped without returning to the moisture level detection step (S7). On the other hand, in the step (S12) of determining whether or not to temporarily stop the reforming system 50, typically, when an alarm is issued as an abnormality handling process, or the rotation speed of the RG pump 33 is adjusted. If the abnormality in the supply state of the recycle gas R is not resolved even once or several times, the reforming system 50 is temporarily stopped (S13).

  Next, the operation of the fuel cell system 1 will be described with reference to FIG. Of the reformed gas E flowing out from the reforming section 51, the reformed gas E that has not flowed into the RG line 31 flows through the reformed gas line 56 and flows into the fuel cell 61. When the reformed gas E is supplied to the fuel cell 61, the control unit 17 activates the blower 65. When the blower 65 is activated, air A flows into the fuel cell 61 via the air line 62. In the fuel cell 61 into which the reformed gas E and air A are introduced, power generation is performed by an electrochemical reaction between hydrogen or the like in the reformed gas E and oxygen in the air A. The electric power generated in the fuel cell 61 is supplied to electric equipment (each pump 22, 33, blower 65, etc.) in the fuel cell system 1 and / or an electric power load (not shown) outside the fuel cell system 1. The reformed gas E and air A that have flowed into the fuel cell 61 are discharged as off-gas F after being used for power generation, are primarily burned by a burner (not shown), give heat to the reforming unit 51, and then burned. Part 68 is reached. The off-gas F after the primary combustion that has flowed into the combustion unit 68 is burned by the combustion catalyst. The combustion heat generated by the combustion of the off-gas F after the primary combustion in the combustion unit 68 may be used for the reforming reaction in the reforming unit 51. The exhaust gas G generated by the combustion of the off-gas F after the primary combustion in the combustion unit 68 flows through the exhaust gas line 69 and is discharged from the fuel cell system 1.

  As described above, according to the reforming system 50 included in the fuel cell system 1 according to the present embodiment, whether or not the supply state of the recycle gas R is abnormal is determined in the RG line 31 of the reformed gas E. Since the absolute humidity of the recycle gas R flowing in and mixed with the raw material Dr before desulfurization is detected by the value of the RG hygrometer 43, it is supplied to the desulfurization section 11 as compared with the case where it is detected by measuring the temperature of the recycle gas R. It is easy to distinguish whether or not the recycle gas R (reformed gas) is contained in the fluid to be detected, and the fluid can be accurately detected. Further, since an abnormality handling process is performed when an abnormality in the supply state of the recycle gas R is detected, it is possible to prevent the raw material D that is insufficiently desulfurized from flowing into the reforming unit 51 and the fuel cell 61. This contributes to the protection of the mass part 51 and the fuel cell 61.

  Next, with reference to FIG. 4A, a fuel cell system 1A including a reforming system 50A according to a first modification of the embodiment of the present invention will be described. FIG. 4A is a schematic system diagram of the fuel cell system 1A. Hereinafter, differences between the reforming system 50A and the fuel cell system 1A including the reforming system 50A, the reforming system 50 (see FIG. 1), and the fuel cell system 1 including the reforming system 50 (see FIG. 1) will be described. The common points of the two are not particularly mentioned in order to avoid redundant explanations unless necessary to explain the differences. In the configuration of the fuel cell system 1A including the reforming system 50A shown in FIG. 4A, refer to the configuration common to the fuel cell system 1 (see FIG. 1) including the reforming system 50 (see FIG. 1). The same reference numerals are assigned without changing the reference numerals. The configuration of the fuel cell system 1A other than the reforming system 50A is the same as the configuration of the fuel cell system 1 (see FIG. 1) other than the reforming system 50 (see FIG. 1), and a description thereof will be omitted.

  In the reforming system 50A, the RG hygrometer 43 (see FIG. 1) provided in the reforming system 50 (see FIG. 1) is not provided. On the other hand, the reforming system 50A is provided with a mixed fluid hygrometer 42 for detecting the internal absolute humidity between the connection part of the RG line 31 and the desulfurization part 11 on the raw material line 21 before desulfurization. The mixed fluid hygrometer 42 is a device capable of detecting the degree of wetness (moisture level) in the gas, and corresponds to a moisture level detection unit. The mixed fluid hygrometer 42 is typically a meter that calculates absolute humidity by detecting the dew point. In this modification, the mixed fluid hygrometer 42 is disposed in the raw material line 21 before desulfurization between the connection portion of the RG line 31 with respect to the raw material line 21 before desulfurization and the feed pump 22. The mixed fluid hygrometer 42 is configured to detect the absolute humidity of the mixed fluid DR in which the recycle gas R (reformed gas E containing hydrogen) is mixed with the raw material Dr before desulfurization. The raw material Dr before desulfurization has a relative humidity of, for example, 10% or less, and the recycle gas R typically has a relative humidity of approximately 100%. The raw material Dr before desulfurization introduced into the reforming system 50 </ b> A is adjusted to a predetermined flow rate according to the generated power in the fuel cell 61. On the other hand, the absolute humidity of the recycle gas R mixed with the raw material Dr before desulfurization is substantially constant regardless of the change in the flow rate of the raw material Dr before desulfurization. Therefore, as the flow rate of the mixed fluid DR (and thus the flow rate of the raw material Dr before desulfurization) increases, the amount of water per unit weight decreases and the absolute humidity decreases.

  In the reforming system 50A, the state detection unit 16A of the control device 15A is connected to the mixed fluid hygrometer 42 through a signal cable, and can receive a value detected by the mixed fluid hygrometer 42 as a signal. It is configured to be able to. The state detection unit 16A has a function that the state detection unit 16 (see FIG. 1) has, except for a function related to the RG hygrometer 43 (see FIG. 1) that the reforming system 50A does not have. In the storage unit 18A, a reference value different from the reference value shown in FIG. 2 is set as a reference value for determining whether or not the supply state of the recycle gas R to the raw material line 21 before desulfurization is abnormal.

  FIG. 4B shows the relationship between the flow rate of the raw material Dr before desulfurization introduced into the desulfurization section 11 and the absolute humidity detected by the mixed fluid hygrometer 42. In FIG. 4B, the line segment SVA is a reference value that is preset in the storage unit 18A and determines whether or not the supply state of the recycle gas R to the raw material line 21 before desulfurization is abnormal. As described above, when the recycle gas R is appropriately mixed with the raw material Dr before desulfurization, the absolute humidity of the mixed fluid DR decreases as the flow rate of the mixed fluid DR increases. Therefore, the line segment SVA (reference value) shown in FIG. During operation of the fuel cell system 1A (reforming system 50A), the flow rate of the recycle gas R mixed with the raw material Dr before desulfurization may change due to factors such as blockage of the RG line 31 due to condensed water in the recycle gas R. . When the flow rate of the recycle gas R mixed with the raw material Dr before desulfurization decreases, the absolute humidity detected by the mixed fluid hygrometer 42 decreases. As described above, in the hydrodesulfurization in the desulfurization section 11, when there is little hydrogen to be introduced, it is impossible to perform proper hydrodesulfurization. Therefore, the recycle gas R that can stably perform hydrodesulfurization is used. The lower limit of the absolute humidity of the mixed fluid DR to be included is set as a reference value when detected by the mixed fluid hygrometer 42, and is indicated by a line segment SVA in FIG. When the absolute humidity detected by the mixed fluid hygrometer 42 is above or above the line segment SVA stored in the storage unit 18A, the state detection unit 16A desulfurizes the recycle gas R at an appropriate flow rate. It is determined that the raw material Dr is mixed, and when it is below the line segment SVA, it is determined that the recycle gas R having an appropriate flow rate is not mixed with the raw material Dr before desulfurization. As described above, the reforming system 50A detects the moisture level of the mixed fluid DR in which a change in the moisture level is likely to occur, so that the supply state of the recycled gas R to the raw material line 21 before desulfurization can be detected with higher accuracy. .

  The reference value indicated by the line segment SVA in FIG. 4B is preferably corrected by the temperature detected by the drainer thermometer 48. As described above, the recycle gas R that merges with the raw material Dr before desulfurization after passing through the drainer 34 has a relative humidity of approximately 100%, and the absolute humidity varies depending on the temperature. The fluctuation of the absolute humidity of the recycle gas R affects the absolute humidity of the mixed fluid DR after mixing with the raw material Dr before desulfurization. When the temperature detected by the drainer thermometer 48 is lower than the standard value, the reference value indicated by the line segment SVA in FIG. 4B is lowered according to the deviation from the standard value, and the drainer thermometer 48 detects the temperature. When the measured temperature is higher than the standard value, the reference value indicated by the line segment SVA in FIG. 4B is raised in accordance with the deviation from the standard value, thereby supplying the recycle gas R to the raw material line 21 before desulfurization. It is possible to appropriately detect whether there is an abnormality in the state.

  Next, a fuel cell system 1B including a reforming system 50B according to a second modification of the embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic system diagram of the fuel cell system 1B. The reforming system 50B and the fuel cell system 1B including the reforming system 50B are different from the configurations of the reforming system 50A (see FIG. 4A) and the fuel cell system 1A including the reforming system 50A (see FIG. 4A) before mixing. The difference is that a raw material hygrometer 41 is further provided. The raw material hygrometer 41 before mixing is provided on the upstream side of the connecting portion with the RG line 31 on the raw material line 21 before desulfurization. The raw material hygrometer 41 before mixing is a device that can detect the degree of wetness (moisture level) in the raw material Dr before desulfurization before the recycle gas R is mixed, and corresponds to the raw material moisture level detection unit before mixing. The raw material hygrometer 41 before mixing is typically a meter that calculates absolute humidity by detecting the dew point.

  In the reforming system 50B, the state detection unit 16B of the control device 15B is connected to the raw material hygrometer 41 before mixing with a signal cable, and receives the value detected by the raw material hygrometer 41 before mixing as a signal. It is configured to be able to. The function of the state detection unit 16B other than the above is the state detection unit 16A (see FIG. 4A) except for the point of determining whether there is an abnormality in the supply state of the recycle gas R to the raw material line 21 before desulfurization described later. The function is the same as When the reforming system 50B determines whether there is an abnormality in the supply state of the recycle gas R to the raw material line 21 before desulfurization, the mixed fluid hygrometer 42 is used as a value to be checked against the reference value stored in the storage unit 18B. And the difference between the value detected by the raw material hygrometer 41 before mixing is used. In this respect, the reforming system 50A (see FIG. 4A) is different from the value detected by the mixed fluid hygrometer 42 as the value to be compared with the reference value SVA stored in advance. The storage unit 18B has a right-downward line similar to the line segment SVA shown in FIG. 4B as a reference value for determining whether or not there is an abnormality in the supply state of the recycle gas R to the raw material line 21 before desulfurization. Although the figure is set, the reference value is set below the line segment SVA (see FIG. 4B) by the amount subtracted from the value detected by the raw material hygrometer 41 before mixing. The other points of the reforming system 50B are the same as those of the reforming system 50A (see FIG. 4A). The configuration of the fuel cell system 1B other than the reforming system 50B is the same as the configuration of the fuel cell system 1A (see FIG. 4A) other than the reforming system 50A (see FIG. 4A).

  The fuel cell system 1B including the reforming system 50B configured as described above is stored in the storage unit 18B when determining whether there is an abnormality in the supply state of the recycle gas R to the raw material line 21 before desulfurization. Since the difference between the value detected by the mixed fluid hygrometer 42 and the value detected by the raw material hygrometer 41 before mixing is used as a value to be compared with the reference value, there is a disturbance in the supply system of the raw material Dr before desulfurization. Even if it occurs and the absolute humidity of the raw material Dr before desulfurization varies, the influence of disturbance can be reduced and the presence or absence of an abnormality in the supply state of the recycle gas R to the raw material line 21 before desulfurization can be accurately detected. it can.

  In the description of the reforming systems 50A and 50B according to the above modified examples, the mixed fluid hygrometer 42 is included in the reforming system 50A, and the mixed fluid hygrometer 42 and the raw material hygrometer 41 before mixing are respectively included in the reforming system 50B. Although the absolute humidity is detected, the relative humidity may be detected.

  In the above description, the moisture level detector (RG hygrometer 43, mixed fluid hygrometer 42) directly detects the moisture level of the fluid, but indirectly detects the moisture level of the fluid. There may be. As an example of a configuration for indirectly detecting the moisture level of the fluid, the time interval at which the discharge valve 36 is opened is measured, and the reforming is performed when the time interval at which the discharge valve 36 is opened is equal to or greater than a predetermined interval. For example, it may be determined that an abnormality may have occurred in the supply state of the reformed gas (recycle gas R) in the gas supply unit (RG supply unit 30). In this configuration, when the recycle gas R flows through the RG line 31, the condensed water c is accumulated in the drain 34 and should be discharged from the discharge pipe 35, but the condensed water c is not discharged from the discharge pipe 35. Is based on the assumption that the condensate c does not accumulate, that is, it can be estimated that the recycle gas R does not flow through the RG line 31.

  In the above description, the RG pump 33 (reformed gas flow rate adjusting unit) is disposed in the RG line 31. However, the raw material before desulfurization at the pressure when the reformed gas E is discharged from the reforming unit 51. When the recycle gas R can be supplied to the line 21, the RG pump 33 (reformed gas flow rate adjusting unit) may be omitted. Further, when the reformed gas flow rate adjusting unit is omitted, an orifice may be provided in order to set the flow rate of the reformed gas flowing in the reformed gas line such as the RG line 31 to a desired flow rate. If the moisture in the reformed gas does not have to be reduced, the drainer 34 may be omitted.

  In the above description, the reference value for determining whether there is an abnormality in the supply state of the reformed gas (recycle gas R) to the raw material Dr before desulfurization according to the temperature of the drainer 34 detected by the drainer thermometer 48. (Threshold value) was corrected, but in addition to the temperature of the drainer 34, the temperature mixed in the raw material Dr before desulfurization such as the temperature inside the reforming system or the casing (not shown) of the fuel cell system, the outside air temperature, etc. The temperature having a correlation with the temperature of the drainer 34 that may affect the moisture content of the quality gas (recycle gas R) may be detected, and the reference value (threshold value) may be corrected according to the detected temperature. . In addition, when the temperature of the drainer 34 or a temperature change correlated therewith is considered to have a small influence on the determination of whether or not there is an abnormality in the supply state of the reformed gas (recycle gas R) to the raw material Dr before desulfurization. The control may be simplified by not correcting the reference values (SV, SVA).

1, 1A, 1B Fuel cell system 11 Desulfurization unit 16, 16A, 16B State detection unit 17 Control unit 18, 18A, 18B Storage unit 20 Raw material supply unit 30 Reformed gas supply unit 33 RG pump 34 Drainer 41 Raw material hygrometer before mixing 42 Mixed fluid hygrometer 43 RG hygrometer 48 Drain thermometer 50, 50A, 50B Reforming system 51 Reforming unit 61 Fuel cell A Air Dr Raw material before desulfurization Df Desulfurized raw material DR Mixed fluid E Reformed gas HF Hydrogen-containing fluid R Recycled gas (reformed gas)

Claims (10)

A desulfurization section for producing a desulfurized raw material by hydrodesulfurizing a raw material to be desulfurized;
A raw material supply unit that supplies the desulfurization target raw material to the desulfurization unit;
A reforming section that introduces and reforms the desulfurized raw material to generate a reformed gas containing hydrogen;
A reformed gas supply unit for mixing the reformed gas with the raw material to be desulfurized;
Moisture level detection that directly or indirectly detects the moisture level of the hydrogen-containing fluid that is one of the reformed gas in the reformed gas supply unit and the mixed fluid in which the raw material to be desulfurized and the reformed gas are mixed. And
A state detection unit that detects a supply state of the reformed gas in the reformed gas supply unit based on the moisture level of the hydrogen-containing fluid detected by the moisture level detection unit;
Reforming system. The reformed gas supply unit has a drainer that removes condensed water in the reformed gas,
The reforming system according to claim 1. A temperature detector for detecting the temperature of the drainer or a temperature correlated with the temperature of the drainer;
The state detection unit changes a reference for detecting the supply state of the reformed gas according to the temperature detected by the temperature detection unit.
The reforming system according to claim 2. The moisture level detection unit is provided in the reformed gas supply unit downstream of the drainer when viewed in the flow direction of the reformed gas.
The reforming system according to claim 2 or claim 3. The moisture level detector detects the moisture level of the mixed fluid;
The reforming system according to any one of claims 1 to 3. A pre-mixing raw material moisture level detection unit that detects the moisture level of the raw material to be desulfurized before the reformed gas is mixed;
The state detection unit is based on the difference between the moisture level of the hydrogen-containing fluid detected by the moisture level detection unit and the moisture level of the raw material to be desulfurized detected by the raw material moisture level detection unit before mixing. Detecting the supply state of the reformed gas in the reformed gas supply unit,
The reforming system according to claim 5. The state detection unit issues an instruction to perform an abnormality handling process when detecting an abnormality in the supply state of the reformed gas,
The reforming system according to any one of claims 1 to 6. The reformed gas supply unit has a reformed gas flow rate adjusting unit that adjusts the flow rate of the reformed gas to be mixed with the desulfurization target raw material,
A control unit for controlling the reformed gas flow rate control unit;
The state detection unit sends a command to the control unit to adjust the reformed gas flow rate adjusting unit in order to suppress an abnormality in the supply state of the reformed gas as the abnormality handling process.
The reforming system according to claim 7. The reforming system according to any one of claims 1 to 8,
A fuel cell that generates power by introducing the reformed gas generated in the reforming unit and an oxidant gas containing oxygen; and
Fuel cell system. A desulfurization step of hydrodesulfurizing the raw material to be desulfurized after mixing a gas containing hydrogen;
A reforming step of reforming the desulfurized raw material generated in the desulfurization step to generate a reformed gas containing hydrogen;
A reformed gas mixing step of mixing the reformed gas generated in the reforming step with the raw material to be desulfurized as the gas containing hydrogen;
A moisture level detection step of detecting a moisture level of a hydrogen-containing fluid that is one of the reformed gas and a mixed fluid in which the raw material to be desulfurized and the reformed gas are mixed;
A state detection step of detecting a supply state of the reformed gas in the reformed gas mixing step based on the moisture level of the hydrogen-containing fluid detected in the moisture level detection step.
A method for producing reformed gas.

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