JP2012069493A - Fluid supply device, fuel cell system having the same, and fluid supply method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid supply device capable of lowering the temperature of the air to be supplied when the temperature in a fuel cell module rises without lowering the efficiency of a fuel cell system as much as possible.SOLUTION: A fluid supply device B1 comprising a high-temperature air piping 12 which supplies the low-temperature air boosted by a blower 11 to a fuel cell C1 as the high-temperature air elevated by a temperature rising part 14 is provided with a low-temperature air piping 22 which branches from the high-temperature air piping 12 on the upstream side of the temperature rising part 14 and is connected on the downstream side and a three-way valve 15 which is provided in a branching part and switches an airflow path in a step-by-step manner. If a temperature T in a fuel cell module exceeds a threshold temperature T, the fluid supply device B1 adjusts the three-way valve 15 to gradually increase the flow rate of the low-temperature air piping 22, thereby lowering the temperature of the air to be supplied to the fuel cell C1. Power consumption can also be reduced because a blower for low-temperature air supply is unnecessary.

Description

  The present invention relates to a fluid supply device that supplies air to a fuel cell module in a fuel cell system, a fuel cell system including the fluid supply device, and a fluid supply method, and more particularly, to suppress a temperature increase of the fuel cell module. Regarding processing.

  Conventionally, a fuel cell system has been developed as a cogeneration system. The fuel cell system is a power generation system that effectively uses exhaust heat when the fuel cell generates power. The fuel cell system is provided with a fluid supply device for supplying air to the fuel cell.

  FIG. 4 is a block diagram for explaining a fuel cell system including a conventional fluid supply apparatus. The fuel cell system A includes a fluid supply device B, a fuel cell module C, an inverter device D, and an exhaust heat recovery device E.

  The fluid supply device B supplies air to a fuel cell C1 (described later) of the fuel cell module C. The fluid supply device B raises the temperature of the air pressurized by the blower 11 at the temperature raising unit 14 and supplies the air to the fuel cell C1. In addition to the fluid supply device B, the fuel cell system A includes a fluid supply device that supplies raw fuel to a reformer C2 (described later) of the fuel cell module C. However, the description in FIG. Omitted.

  The fuel cell module C generates electricity using raw fuel supplied from a fluid supply device (not shown) and air supplied from the fluid supply device B. The fuel cell module C includes a fuel cell C1 that generates electric power using a chemical reaction between hydrogen and oxygen, and a reformer C2 that generates hydrogen from raw fuel and separately supplied water and supplies the hydrogen to the fuel cell C1. It has.

  Hydrogen is supplied from the reformer C2 to the fuel electrode (anode) of the fuel cell C1, and air is supplied from the fluid supply device B to the air electrode (cathode). The fuel cell C1 reacts hydrogen and oxygen in the air to generate electric energy and heat energy. The electrical energy extracted as DC power is output to the inverter device D. The generated thermal energy is recovered by the exhaust heat recovery device E. The fuel cell C1 is classified according to the type of electrolyte, and the operating temperature is set for each. For example, in the case of a solid oxide fuel cell, the operating temperature is set in the range of 750 to 1000 ° C. In order to maintain the set operating temperature, the air heated by the temperature raising unit 14 is used as the air supplied from the fluid supply device B to the fuel cell C1. As the temperature raising unit 14, a burner cooling jacket is generally used. The burner cooling jacket cools a burner (not shown) for raising the temperature of the reformer C2 and the fuel cell C1 to the operating temperature. The burner cooling jacket cools the burner by moving the heat of the burner to the air, and at the same time, raises the temperature of the air by the heat of the burner.

  The reformer C2 generates hydrogen by a chemical reaction (steam reforming) between hydrocarbons (such as methane) contained in the supplied raw fuel and separately supplied water. The reformer C2 supplies the generated hydrogen to the fuel electrode (anode) of the fuel cell C1.

  The inverter device D converts the DC power input from the fuel cell C1 into AC power and outputs the AC power. The inverter device D is linked to the power system, and the output AC power is supplied to the load. In addition, a part of the AC power output from the inverter device D and a part of the DC power before being input to the inverter device D are consumed inside the fuel cell system A. For example, AC power is consumed by the flow meters 13 and 23 or a solenoid valve (not shown), and DC power is consumed by the blowers 11 and 21, a mass flow (not shown), a gas detector, or the like. The exhaust heat recovery device E recovers heat generated by a chemical reaction in the fuel cell C1. The exhaust heat recovery device E uses the heat of the exhaust gas emitted from the fuel cell module C and uses it for hot water supply or the like.

  The fluid supply device B has a configuration for lowering the temperature when the temperature in the fuel cell module C rises excessively in order to maintain the operating temperature set for the fuel cell C1. The blower 21 and the pipe 22 are for lowering the temperature of the supplied air when the temperature in the fuel cell module C becomes a predetermined temperature or higher. The blower 21 pressurizes and sends out air outside the fuel cell system A. The pipe 22 is connected to the pipe 12 on the downstream side of the temperature raising unit 14, and supplies the external air sent from the blower 21 to the fuel cell module C. The fluid supply device B mixes external air through the pipe 22, thereby lowering the temperature of the air supplied to the fuel cell module C and lowering the temperature inside the fuel cell module C.

JP 2008-218277 A

  However, if the blower 21 is started to mix external air into the air supplied to the fuel cell module C, DC power for operating the blower 21 is consumed excessively. Therefore, the AC power output from the inverter device D is reduced accordingly, and the efficiency of the fuel cell system A is reduced.

  The present invention has been conceived under the circumstances described above, and can reduce the temperature of air supplied when the temperature in the fuel cell module rises without reducing the efficiency of the fuel cell system as much as possible. The object is to provide a fluid supply device.

  In order to solve the above problems, the present invention takes the following technical means.

  A fluid supply device provided by a first aspect of the present invention is a fluid supply device that supplies air to a fuel cell module, and includes a booster that raises the pressure of air, and air that has been pressurized by the booster. It is characterized by comprising low temperature air supply means for supplying to the fuel cell module, and high temperature air supply means for increasing the temperature of the air boosted by the pressure increasing means and supplying it to the fuel cell module.

  In a preferred embodiment of the present invention, the high-temperature air supply means includes a temperature raising means for raising the temperature of air passing therethrough, and air sent from the pressure raising means is passed through the temperature raising means, A high-temperature air pipe for supplying to the fuel cell module, and the low-temperature air supply means branches from the high-temperature air pipe before allowing the temperature raising means to pass therethrough, and the air sent from the pressure raising means is This is a low-temperature air pipe supplied to the fuel cell module.

  In a preferred embodiment of the present invention, a flow rate adjusting means that is arranged at a position where the low temperature air pipe branches from the high temperature air pipe and adjusts a flow rate of air flowing through the low temperature air pipe, and the measured fuel cell. Control means for causing the flow rate adjusting means to adjust the flow rate of air based on the temperature of the module is further provided.

  In a preferred embodiment of the present invention, the control means adjusts the flow rate adjusting means so that the flow rate of the air flowing through the low-temperature air pipe becomes zero when the measured temperature is a predetermined value or less, When the measured temperature is higher than the predetermined value, the flow rate adjusting means is adjusted so that air flows through the low temperature air pipe.

  In a preferred embodiment of the present invention, when the measured temperature is higher than the predetermined value, the control means controls the flow of air flowing through the low-temperature air pipe until the measured temperature becomes equal to or lower than the predetermined value. The flow rate adjusting means is adjusted to increase the flow rate by a predetermined amount.

  In a preferred embodiment of the present invention, the apparatus further comprises a low-temperature air flow measuring means for measuring a flow rate of air flowing through the low-temperature air pipe or a high-temperature air flow measuring means for measuring a flow rate of air flowing through the high-temperature air pipe. The flow rate adjusting means is a three-way valve, and adjusts the flow rate of air flowing through the low temperature air pipe based on the opening degree indicated by the control means, and the control means increases the indicated opening degree. When the flow rate increase amount measured by the low temperature air flow rate measurement unit is less than the predetermined amount, or the flow rate decrease amount measured by the high temperature air flow rate measurement unit is greater than or equal to the predetermined amount. In this case, the pressure of the air sent out by the pressure raising means is further increased.

  In a preferred embodiment of the present invention, the control means increases the pressure of the air sent out by the boosting means before increasing the flow rate of the air flowing through the low-temperature air pipe, and After increasing the flow rate, the pressure of the air sent out by the pressure increasing means is decreased.

  In a preferred embodiment of the present invention, the low temperature air supply means further includes a temperature lowering means for lowering the temperature of the air passing through the low temperature air pipe.

  The fuel cell system provided by the second aspect of the present invention includes the fuel cell module and the fluid supply device provided by the first aspect of the present invention.

  A fluid supply method provided by the third aspect of the present invention is a method of supplying air to a fuel cell module, wherein high-temperature air in which a part of air whose pressure has been increased is heated, and the pressure Of the air whose temperature has been raised, other low-temperature air that has not been heated is supplied to the fuel cell module.

  In a preferred embodiment of the present invention, the temperature of the fuel cell module is measured, and the amount of the low-temperature air is adjusted based on the measured temperature.

  In a preferred embodiment of the present invention, when the measured temperature is not more than a predetermined value, the amount of the low-temperature air is adjusted to be zero.

  In a preferred embodiment of the present invention, when the measured temperature is larger than the predetermined value, the amount of the low-temperature air is increased by a predetermined amount until the measured temperature becomes equal to or lower than the predetermined value. adjust.

  According to the present invention, the air boosted by the boosting means is supplied to the fuel cell module by the low temperature air supply means, and the high temperature air supply means raises the temperature and supplies the fuel cell module. Therefore, the temperature of the air supplied to the fuel cell module can be adjusted by adjusting the amount of air supplied by the low temperature air supply means and the amount of air supplied by the high temperature air supply means. Thereby, the temperature of the air supplied to the fuel cell module can be lowered by increasing the amount of air supplied by the low-temperature air supply means when the temperature in the fuel cell module rises. Further, since the low-temperature air supply means and the high-temperature air supply means use the air boosted by the common boosting means, they are consumed by the boosting means as compared with the case where the air boosted by the separate boosting means is used. The total amount of power can be suppressed. Therefore, it can suppress that the efficiency of a fuel cell system falls. Further, since the number of necessary boosting means is suppressed, the fluid supply device and the fuel cell system using the fluid supply device can be reduced in size, and the manufacturing cost can be suppressed.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

It is a block diagram for demonstrating 1st Embodiment of the fluid supply apparatus which concerns on this invention. It is a flowchart for demonstrating the process for adjusting the opening degree of a three-way valve. It is a block diagram for demonstrating 2nd Embodiment of the fluid supply apparatus which concerns on this invention. It is a block diagram for demonstrating a fuel cell system provided with the conventional fluid supply apparatus.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

  FIG. 1 is a block diagram for explaining a first embodiment of a fluid supply apparatus according to the present invention. The fluid supply device B1 corresponds to the fluid supply device B in the fuel cell system A shown in FIG. In FIG. 1, the same or similar elements as those of the fluid supply device B are denoted by the same reference numerals.

  The fluid supply device B1 supplies air to the cathode side of the fuel cell C1 of the fuel cell module C (see FIG. 4). In the present embodiment, a case where a solid oxide fuel cell is used as the fuel cell C1 will be described. The fluid supply device B <b> 1 includes a blower 11, pipes 12 and 22, flow meters 13 and 23, a temperature raising unit 14, a three-way valve 15, and a control unit 3.

  The blower 11 pressurizes and sends out air. The blower 11 increases the pressure increase degree of the air by increasing the rotation speed, and increases the flow rate of the air to be sent out. Moreover, the pressure increase degree of air is reduced by reducing the rotation speed, and the flow rate of the air to be sent out is reduced. In the present embodiment, air that has been heated in advance through the exhaust heat recovery device E (see FIG. 4) is sent out by the blower 11. Note that air outside the fuel cell system A may be boosted and sent out. In any case, since the air sent out from the blower 11 has a lower temperature than the air heated in the temperature raising unit 14 described later, the air sent out from the blower 11 will be described as “cold air” below. . On the other hand, the air heated by the temperature raising unit 14 is referred to as “hot air”. In addition, the capacity | capacitance of the blower 11 is made into the capacity | capacitance according to the flow volume of the air used at the time of the normal rated driving | operation of the fuel cell C1.

  The pipe 12 is a pipe that connects the outlet of the blower 11 and the inlet of the fuel cell C1. Since the pipe 12 constitutes a flow path for converting the low-temperature air sent from the blower 11 into the high-temperature air by passing through the temperature raising unit 14, it may be referred to as “high-temperature air pipe” 12 hereinafter. The pipe 22 is a pipe branched from the high temperature air pipe 12 on the upstream side of the temperature raising unit 14 and connected to the high temperature air pipe 12 on the downstream side of the temperature raising unit 14. Since the pipe 22 constitutes a flow path for supplying the low-temperature air sent from the blower 11 to the fuel cell C1 as it is (without increasing the temperature), hereinafter, it will be described as “low-temperature air pipe” 22 There is.

The flow meters 13 and 23 measure the flow rate of air flowing through the pipes 12 and 22, respectively, and output the measured flow value to the control unit 3. The flow meter 13 measures the flow rate V _{1 of the} high-temperature air supplied to the fuel cell C 1 by measuring the flow rate of the air flowing through the high-temperature air pipe 12. On the other hand, the flow meter 23 measures the flow rate V _{2 of the} low-temperature air supplied to the fuel cell C 1 by measuring the flow rate of the air flowing through the low-temperature air pipe 22.

  The temperature raising unit 14 raises the temperature of the air flowing through the high-temperature air pipe 12 to a temperature for maintaining the operating temperature set in the fuel cell C1. In this embodiment, the burner cooling jacket is used as the temperature raising unit 14. The burner cooling jacket cools a reformer C2 (see FIG. 4) and a burner (not shown) for raising the temperature of the fuel cell C1 to the operating temperature. The burner cooling jacket cools the burner by moving the heat of the burner to the air, and at the same time, raises the temperature of the air by the heat of the burner. In the case where the blower 11 is configured to pressurize and send air outside the fuel cell system A, the exhaust heat recovery device E and the burner cooling jacket are considered to be the temperature raising unit 14. That is, the temperature raising unit 14 is configured to raise the temperature of the low-temperature air flowing through the high-temperature air pipe 12 to a temperature for maintaining the operating temperature.

  The three-way valve 15 is provided at a portion where the low-temperature air pipe 22 branches from the high-temperature air pipe 12 and switches the flow path of the air sent from the blower 11 step by step. Air sent from the blower 11 flows into the inlet of the three-way valve 15. The air sent out from one delivery port of the three-way valve 15 flows through the high-temperature air pipe 12 as it is, and is heated by the temperature raising unit 14 and then supplied to the fuel cell C1. The air sent from the other delivery port of the three-way valve 15 flows through the low temperature air pipe 22 and is supplied to the fuel cell C1 without being heated. The three-way valve 15 is an electric proportional control valve, for example, and can proportionally control the opening degree. Therefore, the three-way valve 15 can adjust the amount of air supplied directly from the blower 11 to the fuel cell C1 without increasing the temperature. In the following, the opening is the opening on the low-temperature air pipe 22 side. That is, when the opening degree is 0% (fully closed), the entire flow rate of the inflowed air is sent to the high-temperature air pipe 12 side, and when the opening degree is 100% (fully open), the total flow rate of the inflowing air is low temperature air. It is sent out to the piping 22 side.

The control unit 3 controls the fluid supply device B1. The fluid supply device B1 adjusts the ratio of the high temperature air and the low temperature air supplied to the fuel cell C1 according to the temperature T in the fuel cell module C input from a temperature detection means (not shown). That is, the fluid supply device B1, when the temperature T is below the threshold temperature T _0, and supplying only hot air, if the temperature T has exceeded the threshold temperature T _0, the start of the supply of cold air, the temperature T is The ratio of low-temperature air is gradually increased until the temperature becomes lower than the threshold temperature T ₀ . The threshold temperature T ₀ is a value set in advance based on the upper limit value of the allowable operating temperature range of the fuel cell C1, and is set according to the specification of the fuel cell C1. The control unit 3 adjusts the ratio of the high temperature air and the low temperature air supplied to the fuel cell C1 by adjusting the opening degree of the three-way valve 15 and the rotation speed of the blower 11. The controller 3 receives the temperature T in the fuel cell module C from the temperature detection means, receives the flow rate V _{1 of} high-temperature air from the flow meter 13, and receives the flow rate V _{2 of} low-temperature air from the flow meter 23. Further, the control unit 3 outputs a control signal to the blower 11 to adjust the rotational speed of the blower 11, and outputs an opening / closing control signal to the three-way valve 15 to adjust the opening degree of the three-way valve 15.

When the temperature T is equal to or lower than the threshold temperature T ₀ , the control unit 3 sets the opening of the three-way valve 15 to 0%. Thereby, all the low temperature air sent out from the blower 11 is heated up by the temperature raising part 14, and is supplied to the fuel cell C1 as high temperature air. On the other hand, when the temperature T exceeds the threshold temperature T ₀ , the control unit 3 increases the opening degree of the three-way valve 15. As a result, the proportion of the low-temperature air delivered from the blower 11 that is directly supplied to the fuel cell C1 is increased. Therefore, the flow rate of the high-temperature air supplied to the fuel cell C1 decreases and the flow rate of the low-temperature air increases, so that the temperature in the fuel cell module C decreases. The opening degree of the three-way valve 15 is increased until the temperature T becomes equal to or lower than the threshold temperature T _0, and the ratio of the low-temperature air supplied to the fuel cell C1 is increased.

  In the present embodiment, in order to avoid a shortage of the total flow rate of air supplied to the fuel cell C1 (the sum of the flow rates of high temperature air and low temperature air) due to the backflow of air when the opening of the three-way valve 15 is changed. In addition, the total flow rate of the air supplied to the fuel cell C1 is increased by increasing the rotational speed of the blower 11 before the opening degree of the three-way valve 15 is changed. After the opening degree of the three-way valve 15 is changed, the rotational speed of the blower 11 is returned to the original value, and the total flow rate of the air supplied to the fuel cell C1 is returned to the rated flow rate. In addition, when the reduction | decrease of the total flow rate of the air at the time of change of the opening degree of the three-way valve 15 is an allowable range, you may make it change the opening degree of the three-way valve 15, without changing the rotation speed of the blower 11. . In this case, since the rotational speed of the blower 11 is not increased, power consumption can be reduced.

If the opening degree of the three-way valve 15 is 100% (even if all the air supplied to the fuel cell C1 is low-temperature air) and the temperature T exceeds the threshold temperature T ₀ , the control unit 3 11 is increased to increase the supply amount of low-temperature air. Even in this case, if the temperature T exceeds the threshold temperature T ₀ , there is a possibility that the fuel cell module C has an abnormality, so the control unit 3 stops the operation of the fuel cell system A.

When the temperature T becomes equal to or lower than the threshold temperature T ₀ by increasing the proportion of the low-temperature air supplied to the fuel cell C1, and the state continues for a predetermined time (for example, 1 minute), the control unit 3 Decrease the opening and return to 0%. That is, all the air supplied to the fuel cell C1 is made high temperature air, and the supply of low temperature air is stopped. When the opening degree of the three-way valve 15 is decreased, the control unit 3 decreases the rotational speed of the blower 11 before the opening degree is changed, and returns the rotational speed of the blower 11 to the original state after the opening degree is changed. In this case, power consumption can be reduced while the rotation speed of the blower 11 is being reduced. The opening degree of the three-way valve 15 may be changed without changing the rotation speed of the blower 11. The condition for returning the opening degree of the three-way valve 15 to 0% may be that the temperature T has become a predetermined temperature or lower, or that the state in which the temperature T is lower than the predetermined temperature has continued for a predetermined time. .

In addition, the detail of the adjustment method of the opening degree of the three-way valve 15 when the temperature T exceeds the threshold temperature T ₀ performed by the control unit 3 will be described later.

  Although not shown in FIG. 1, each of the pipes 12 and 22 includes a pressure gauge for detecting the pressure in the pipe, a solenoid valve for adjusting the flow rate of the pipe, and preventing air from flowing backward. A check valve is provided. Since these are not directly related to the description of the present invention, descriptions and explanations in each figure are omitted.

FIG. 2 is a flowchart for explaining processing for adjusting the opening of the three-way valve 15 (hereinafter referred to as “opening adjustment processing”) performed by the control unit 5. The opening degree adjusting process is performed when the fluid supply device B1 is activated, and when the three-way valve 15 is adjusted by opening degree, the temperature T is lowered to a threshold temperature T ₀ or less and a predetermined time has elapsed, and the opening degree of the three-way valve 15 is reached. Is started when is returned to 0%.

When the opening degree adjusting process is started, first, the variable n is initialized to “1” (S1). In the present embodiment, when the temperature T exceeds the threshold temperature T ₀ , the flow rate of the high-temperature air is decreased by a predetermined flow rate ΔV (hereinafter referred to as “changed flow rate ΔV”), and the flow rate of the low-temperature air is decreased. Increase the change flow rate by ΔV. The variable n counts the number of times the flow rate is changed and indicates how many times the flow rate is changed in the opening adjustment process.

Next, it is determined whether or not the temperature T is higher than the threshold temperature T ₀ (S2). When the temperature T is higher than the threshold temperature T ₀ (S2: YES), the process proceeds to step S3, and the opening degree of the three-way valve 15 is adjusted. On the other hand, when the temperature T is equal to or lower than the threshold temperature T ₀ (S2: NO), the process returns to step S2. That is, while the temperature T is equal to or lower than the threshold temperature T ₀ , the opening degree of the three-way valve 15 is not adjusted (the opening degree remains 0%), and the determination in step S2 is repeated. During this time, all of the rated air flow rate V ₀ of the blower 11 flows through the high-temperature air pipe 12, so the flow rate of hot air V ₁ detected by the flow meter 13 = V ₀ and the flow rate of low-temperature air detected by the flow meter 23 V ₂ = 0.

In step S3, the flow rate V ₁ is whether changing the flow rate ΔV or more is determined (S3). If the flow rate V ₁ is greater than or equal to the changed flow rate ΔV (S3: YES), the flow rate V ₁ can be reduced by the changed flow rate ΔV, so the flow rate changing process of steps S4 to S8 is performed. On the other hand, when the flow rate V ₁ is smaller than the changed flow rate ΔV (S3: NO), the flow rate V ₁ cannot be reduced by the changed flow rate ΔV, so the flow rate changing process of steps S4 to S8 is not performed and the process proceeds to step S10.

In step S4, the rotation speed of the blower 11 is increased, the total flow rate is increased by changing the flow rate ΔV is the sum of the flow rate V ₂ of the flow rate V ₁ and the low-temperature air of the hot air (S4). That is, the rotation speed of the blower 11 is increased so that the state of V ₁ + V ₂ = V ₀ + ΔV continues for a predetermined time (for example, 10 seconds) or longer.

Next, the opening degree of the three-way valve 15 is adjusted (S5). Here, after the opening degree of the three-way valve 15 is increased by a predetermined amount (for example, 30%), it is adjusted so that V ₁ = V ₀ − (n−1) · ΔV and V ₂ = n · ΔV. The For example, in the case of the first flow rate change (n = 1), V ₁ = V ₀ and V ₂ = ΔV are adjusted, and in the case of the second flow rate change (n = 2), V ₁ = Adjustment is made so that V ₀ −ΔV and V ₂ = 2 · ΔV. As a result of the adjustment, there is a case where V ₁ + V ₂ <V ₀ + ΔV and the flow rate becomes insufficient. In this case (S6: YES), the process returns to step S4, the rotational speed of the blower 11 is increased (S4), and the opening degree of the three-way valve 15 is adjusted. In this case (step S6: YES and return to step S4), it is not necessary to increase the rotational speed of the blower 11 until the total flow rate is further increased by the changed flow rate ΔV. By adjusting the opening degree of the three-way valve 15, steps S4 to S4 are performed until V ₁ ≧ V ₀ − (n−1) · ΔV and V ₂ ≧ n · ΔV are satisfied and the shortage of flow is resolved (S6: NO). S6 is repeated.

In step S6, if not insufficient flow rate (S6: NO), the rotational speed of the blower 11 is reduced, the total flow rate is returned to the nominal flow rate V ₀ (S7). Next, the opening degree of the three-way valve 15 is adjusted (S8). Here, the opening degree of the three-way valve 15 is adjusted so that V ₁ = V ₀ −n · ΔV and V ₂ = n · ΔV. For example, in the case of the first flow rate change (n = 1), V ₁ = V ₀ −ΔV and V ₂ = ΔV are adjusted. In the second flow rate change (n = 2), V 1 Adjustments are made so that ₁ = V ₀ −2 · ΔV and V ₂ = 2 · ΔV.

After the opening degree of the three-way valve 15 is adjusted, the variable n is increased by “1” and the process returns to step S2. If the temperature T remains higher than the threshold temperature T ₀ (S2: YES), steps S3 to S9 are repeated. On the other hand, when the flow rate of the high temperature air and the low temperature air is changed, the temperature T becomes equal to or lower than the threshold temperature T ₀ (S2: NO), and when the predetermined time elapses after step S2 is repeated, the opening degree adjusting process ends. Then, after the opening degree of the three-way valve 15 is returned to 0%, the opening degree adjusting process is started again. However, if the temperature T exceeds the threshold temperature T ₀ before the predetermined time has elapsed (S2: YES), steps S3 to S9 are repeated. In the case where the flow rate is changed only by adjusting the opening degree of the three-way valve 15 without changing the rotational speed of the blower 11, the processes in steps S4 to S7 may be omitted.

In step S3, when the flow rate V ₁ is smaller than change rate ΔV (S3: YES), and the opening of the three-way valve 15 is in the 100% (S10), determines whether or not the temperature T is higher than the threshold temperature T ₀ is (S11). That is, the temperature T is compared with the threshold temperature T _{0 in} a state where all the air supplied to the fuel cell C1 is low-temperature air (V ₁ = 0, V ₂ = V ₀ ). When the temperature T becomes equal to or lower than the threshold temperature T ₀ (S11: NO), the process returns to step S2. Step S2: When NO is repeated and a predetermined time elapses, the opening degree adjusting process is terminated, and the opening degree adjusting process is started again after the opening degree of the three-way valve 15 is returned to 0%. However, if the temperature T exceeds the threshold temperature T ₀ before the predetermined time has elapsed (S2: YES), the opening degree of the three-way valve 15 has already been fully opened, so step S3: NO, step S11: It becomes YES and progresses to step S12.

In step S11, if the temperature T is higher than the threshold temperature T ₀ (S11: YES), the rotation speed of the blower 11 is increased (S12), whether or not the temperature T is higher than the threshold temperature T ₀ is determined ( S13). That is, the temperature T is compared with the threshold temperature T ₀ in a state where the flow rate V _{2 of the} low-temperature air supplied to the fuel cell C 1 is larger than the rated flow rate V ₀ . When the temperature T becomes equal to or lower than the threshold temperature T ₀ (S13: NO), the process returns to step S2. Step S2: When NO is repeated and a predetermined time elapses, the opening degree adjusting process is terminated, and the opening degree adjusting process is started after the opening degree of the three-way valve 15 is returned to 0%. However, if the temperature T exceeds the threshold temperature T ₀ before the predetermined time has elapsed (S2: YES), the opening degree of the three-way valve 15 is already fully opened, and the flow rate V of the low-temperature air supplied to the fuel cell C1. _{Since 2} is larger than the rated flow rate V ₀ , Step S3: NO, Step S11: YES, Step S13: YES, and the process proceeds to Step S14.

In step S13, if the temperature T is higher than the threshold temperature T ₀ (S13: YES), it is determined that there is an abnormality in the fuel cell module C, operation of the fuel cell system A is stopped, the opening adjustment process is terminated The In the case of step S13: YES, the operation of the fuel cell system A may not be stopped but may be notified by an alarm or the like. In the case of step S13: YES, the temperature T may be compared with the threshold temperature T ₀ after further increasing the rotational speed of the blower 11.

  In addition, the flowchart of the opening degree adjustment process shown in FIG. 2 is an example, and is not limited to this.

  In the present embodiment, the fluid supply device B1 includes a low-temperature air pipe 22 branched from the high-temperature air pipe 12 on the upstream side of the temperature raising unit 14 and connected to the high-temperature air pipe 12 on the downstream side of the temperature raising part 14. By adjusting the opening degree of the three-way valve 15 provided at the branched portion, the flow rate of the high-temperature air supplied to the fuel cell C1 can be reduced and the flow rate of the low-temperature air can be increased. Therefore, when the temperature in the fuel cell module C rises, the temperature of the air supplied to the fuel cell C1 can be lowered, and the temperature in the fuel cell module C can be lowered. Further, since the fluid supply device B1 can supply high temperature air and low temperature air to the fuel cell C1 with one blower 11, a blower for supplying high temperature air and a blower for supplying low temperature air are provided. Compared with the case where it is provided separately, the power consumed by the blower can be suppressed. Therefore, it can suppress that the efficiency of the fuel cell system A falls. Moreover, since the number of necessary blowers is suppressed, the fluid supply device B1 and the fuel cell system A using the same can be reduced in size, and the manufacturing cost can be suppressed.

  In the first embodiment, the case where the low-temperature air sent from the blower 11 flows through the low-temperature air pipe 22 and is supplied to the fuel cell C1 as it is is described, but the present invention is not limited to this. For example, the low temperature air flowing through the low temperature air pipe 22 may be cooled before being supplied to the fuel cell C1. The fluid supply apparatus according to the second embodiment described below is provided with a configuration for lowering the temperature of the low-temperature air flowing through the low-temperature air pipe 22.

  FIG. 3 is a block diagram for explaining a fluid supply device B2 according to the second embodiment. The fluid supply device B2 corresponds to the fluid supply device B in the fuel cell system A shown in FIG. In FIG. 3, the same or similar elements as those of the fluid supply device B1 (see FIG. 1) according to the first embodiment are denoted by the same reference numerals.

  The fluid supply device B2 is different from the fluid supply device B1 according to the first embodiment in that a low temperature air pipe 22 includes a temperature lowering unit 24. The temperature lowering unit 24 further cools the low temperature air flowing through the low temperature air pipe 22. In the present embodiment, a heat exchanger with a water supply pipe (not shown) is used as the temperature lowering unit 24. Water flows through the water supply pipe, and the heat exchanger moves the temperature of the low-temperature air by moving the heat of the low-temperature air to the water flowing through the pipe for water supply. Note that the temperature lowering unit 24 is not limited to this, and any unit that absorbs the heat of the low-temperature air and lowers the temperature of the low-temperature air may be used.

  Since the fluid supply device B2 can supply the fuel cell C1 after lowering the low temperature air, the effect of lowering the temperature of the air supplied to the fuel cell C1 when the temperature in the fuel cell module C rises is the first effect. This can be achieved more significantly than the fluid supply device B1 according to the embodiment. That is, when the temperature of the air supplied to the fuel cell C1 is lowered by the same amount, the change amount of the flow rate of the high temperature air and the low temperature air can be made smaller in the fluid supply device B2 than in the fluid supply device B1. Further, the fluid supply device B2 can lower the temperature in the fuel cell module C than the fluid supply device B1 when all the air supplied to the fuel cell C1 is low-temperature air.

  When the temperature of the high-temperature air becomes too high due to the temperature rise of the air by the burner cooling jacket as the temperature raising unit 14, a heat exchanger with a water supply pipe is installed downstream of the burner cooling jacket of the high-temperature air pipe 12. It may be arranged to lower the temperature of the hot air.

In the above-described first and second embodiments, the opening of the three-way valve 15 when the temperature T is below the threshold temperature T ₀ is 0% only three-way valve when the temperature T exceeds the threshold temperature T ₀ Although the case where the opening degree of 15 is increased was demonstrated, it is not restricted to this. For example, the temperature T in the fuel cell module C may be feedback controlled by adjusting the opening of the three-way valve 15. That is, the target temperature T ₁ of the temperature T is set, and the opening degree of the three-way valve 15 is adjusted so that the deviation ΔT (= T−T ₁ ) between the temperature T and the target temperature T ₁ is zero. It may be. Since the hot air on one blower 11 even in this case the cold air supplied to the fuel cell C1, without reducing as much as possible the efficiency of the fuel cell system A, it is possible to control the temperature T in the target temperature T ₁ .

  Note that two control valves may be used instead of the three-way valve 15, and the opening degree of the other control valve may be changed according to the opening degree of the one control valve. That is, when the opening of one control valve is 100%, the opening of the other control valve is 0%, and when the opening of one control valve is 0%, the opening of the other control valve is 100%. You may make it adjust so.

  In the first and second embodiments, the fuel cell C1 is a solid oxide fuel cell. However, the present invention is not limited to this. The present invention can also be applied to the case where air is supplied to a fuel cell module using a fuel cell having a high operating temperature, such as a molten carbonate fuel cell.

  In the first and second embodiments, the case where the fluid supply device B1 (B2) for supplying air to the fuel cell C1 has only one system has been described. However, the present invention is not limited to this, and the fluid supply device B1 ( A plurality of systems B2) may be provided.

  The fluid supply device, the fuel cell system, and the fluid supply method according to the present invention are not limited to the above-described embodiments. The specific configuration of each part of the fluid supply device, the fuel cell system, and the fluid supply method according to the present invention can be varied in design in various ways.

A Fuel cell system B, B1, B2 Fluid supply device 11, 21 Blower (pressure increase means)
12 High-temperature air piping (low-temperature air supply means)
22 Low temperature air piping (High temperature air supply means)
13 Flowmeter (High-temperature air flow measurement means)
23 Flowmeter (Cryogenic air flow rate measuring means)
14 Temperature riser (high temperature air supply means, temperature rise means)
24 Temperature drop unit (low temperature air supply means, temperature drop means)
15 Three-way valve (flow rate adjusting means)
3 Control Unit C Fuel Cell Module C1 Fuel Cell C2 Reformer D Inverter Device E Waste Heat Recovery Device

Claims (13)

A fluid supply device for supplying air to a fuel cell module,
A pressure increasing means for increasing the pressure of the air;
Low-temperature air supply means for supplying air boosted by the boosting means to the fuel cell module;
High temperature air supply means for raising the temperature of the air boosted by the pressure boosting means and supplying it to the fuel cell module;
A fluid supply device comprising: The high temperature air supply means includes
A temperature raising means for raising the temperature of the passing air;
High-temperature air piping for supplying the fuel cell module with air sent from the pressure-increasing means and passing the temperature-increasing means;
With
The low-temperature air supply means is a low-temperature air pipe that branches from the high-temperature air pipe before passing the temperature raising means and supplies the fuel cell module with the air sent from the pressure-increasing means.
The fluid supply apparatus according to claim 1. A flow rate adjusting means that is arranged at a position where the low temperature air pipe branches from the high temperature air pipe, and adjusts a flow rate of air flowing through the low temperature air pipe;
Control means for causing the flow rate adjusting means to adjust the flow rate of air based on the measured temperature of the fuel cell module;
The fluid supply device according to claim 2, further comprising: The control means includes
When the measured temperature is equal to or lower than a predetermined value, the flow rate adjusting means is adjusted so that the flow rate of air flowing through the low temperature air pipe becomes zero,
If the measured temperature is greater than the predetermined value, the flow rate adjusting means is adjusted so that air flows through the low-temperature air pipe.
The fluid supply apparatus according to claim 3.   When the measured temperature is greater than the predetermined value, the control means increases the flow rate of air flowing through the low-temperature air pipe by a predetermined amount until the measured temperature becomes equal to or lower than the predetermined value. The fluid supply apparatus according to claim 4, wherein the fluid flow adjusting means is adjusted. A low-temperature air flow measurement means for measuring the flow rate of air flowing through the low-temperature air pipe, or a high-temperature air flow measurement means for measuring the flow rate of air flowing through the high-temperature air pipe,
The flow rate adjusting means is a three-way valve, and adjusts the flow rate of air flowing through the low temperature air pipe based on the opening degree instructed by the control means,
When the control means is changed to increase the indicated opening, the increase in the flow rate measured by the low-temperature air flow measurement means is less than the predetermined amount, or the high-temperature air flow measurement means When the amount of decrease in the measured flow rate is equal to or greater than the predetermined amount, the pressure of the air sent out by the pressure increasing means is further increased;
The fluid supply apparatus according to claim 5. The control means increases the pressure of the air sent out by the boosting means before increasing the flow rate of the air flowing through the low-temperature air pipe, and increases the flow rate of air flowing through the low-temperature air pipe. Reduce the pressure of the air to be sent out,
The fluid supply apparatus according to claim 4.   The fluid supply device according to any one of claims 1 to 7, wherein the low temperature air supply means further includes a temperature drop means for lowering the temperature of the air passing through the low temperature air pipe.   A fuel cell system comprising the fuel cell module and the fluid supply device according to claim 1. A method for supplying air to a fuel cell module, comprising:
Supplying the fuel cell module with high-temperature air in which part of the air whose pressure has been increased has been heated and other low-temperature air which has not been heated in the air whose pressure has been increased. A fluid supply method.   The fluid supply method according to claim 10, wherein the temperature of the fuel cell module is measured, and the amount of the low-temperature air is adjusted based on the measured temperature.   The fluid supply method according to claim 11, wherein when the measured temperature is equal to or lower than a predetermined value, the amount of the low-temperature air is adjusted to be zero.   13. The fluid according to claim 12, wherein when the measured temperature is larger than the predetermined value, the amount of the low-temperature air is adjusted to increase by a predetermined amount until the measured temperature becomes equal to or lower than the predetermined value. Supply method.

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