WO2006075501A1

WO2006075501A1 - Degradation detection device and degradation detection method for hydrogen occlusion material in hydrogen storage tank, and hydrogen storage and supply system

Info

Publication number: WO2006075501A1
Application number: PCT/JP2005/023606
Authority: WO
Inventors: Katsuyoshi Fujita; Daigoro Mori
Original assignee: Kabushiki Kaisha Toyota Jidoshokki; Toyota Jidosha Kabushiki Kaisha
Priority date: 2004-12-24
Filing date: 2005-12-22
Publication date: 2006-07-20
Also published as: JP2006177535A; JP4575140B2

Abstract

A hydrogen storage tank (12) incorporates a hydrogen occlusion alloy (MH) and a heat exchanger (19). Based on a PCT curve of the hydrogen occlusion alloy, a microcomputer (31) determines, when the pressure inside the hydrogen storage tank (12) at the time of the start of hydrogen charging is in a state in a plateau region of the hydrogen occlusion alloy or is lower than the pressure in the plateau region, whether or not the hydrogen occlusion alloy is degraded. The microcomputer (31) calculates the amount of heat for cooling, which amount is a heat amount used for cooling in the charging of hydrogen into the hydrogen storage tank (12), based on heat medium temperatures at the entrance and exit of the heat exchanger and on the flow rate of the heat medium. The microcomputer (31) determines whether or not the hydrogen occlusion alloy (MH) is degraded, and the determination is made based on a standard amount of heat for cooling and on the calculated heat amount for cooling, the standard amount of heat is a heat amount required when hydrogen is charged up to a predetermined pressure from an empty state of the tank.

Description

Specification

Deterioration detection device and deterioration detection method for hydrogen storage material in hydrogen storage tank, and hydrogen storage and supply system

Technical field

TECHNICAL FIELD [0001] The present invention relates to a hydrogen storage material deterioration detection device, deterioration detection method, and hydrogen storage supply system in a hydrogen storage tank.

Background art

[0002] In recent years, awareness of suppressing global warming has increased, and hydrogen with hydrogen as fuel in electric vehicles and hydrogen engine automobiles driven by fuel cells, particularly for the purpose of reducing carbon dioxide emitted from vehicles. Automobile development is thriving. A hydrogen vehicle is generally equipped with a hydrogen storage tank filled with hydrogen as a hydrogen supply source.

[0003] As a method for storing and transporting hydrogen, it absorbs hydrogen under the conditions of a predetermined temperature and pressure and converts it into a hydride. When necessary, the hydrogen is stored under conditions of another temperature and pressure. A metal called “hydrogen storage alloy” is known. A hydrogen storage tank using a hydrogen storage alloy is attracting attention because it can increase the amount of hydrogen stored without increasing its volume.

[0004] The hydrogen storage tank is filled with hydrogen in a facility called a hydrogen station corresponding to a gas station or LP gas station. Therefore, it is necessary to fill with hydrogen before the remaining amount of hydrogen in the hydrogen storage tank becomes so small that it interferes with the supply to the fuel cell and the hydrogen engine. Need to be identified. In order to determine the amount of hydrogen, the relationship between the pressure and temperature in the hydrogen S storage tank and the hydrogen storage amount is obtained by preliminary experimentation, and the pressure and temperature in the hydrogen storage tank are measured and calculated. It is common to calculate the amount of hydrogen using a mathematical formula.

[0005] However, hydrogen storage alloys deteriorate due to repeated storage and release of hydrogen many times or poisoning. Therefore, if the hydrogen amount is calculated without taking into account the deterioration of the hydrogen storage alloy (decrease in the hydrogen storage amount), the error increases.

[0006] Conventionally, when a hydrogen storage alloy deteriorates, a specific flow rate change occurs when hydrogen is stored. A device is known that measures the flow rate of hydrogen supplied to a hydrogen storage tank (hydrogen storage device) using this, and determines the deterioration of the hydrogen storage alloy from that value (see Patent Document 1).

[0007] Further, as the hydrogen storage alloy deterioration detection means, the temperature of the hydrogen storage alloy detected by the temperature detection means at the time of the previous hydrogen filling is stored, and the temperature at the time of the current hydrogen filling is stored in the previous time. It has been proposed that when the temperature of the hydrogen storage alloy is higher than that of the hydrogen storage alloy, it is judged that the hydrogen storage alloy is deteriorated (see Patent Document 2).

Patent Document 1: Japanese Patent Laid-Open No. 2001-266915

Patent Document 2: Japanese Patent Laid-Open No. 2002-228098

Disclosure of the invention

[0008] However, the device of Patent Document 1 detects the deterioration of the hydrogen storage alloy stored in the hydrogen shell storage tank filled with hydrogen generated by reforming alcohol, gasoline, or the like with a reformer. To do. The main cause of deterioration of the equipment is CO, CO, o contained in reformed gas.

2 and other impurities adhere to the hydrogen storage alloy.

2

It is difficult to apply as it is. In addition, the reference data for obtaining a specific flow rate change when storing hydrogen varies depending on the pressure in the hydrogen storage tank at the start of hydrogen filling. Therefore, in order to cope with the case where the pressure in the hydrogen storage tank at the start of hydrogen filling is filled from an arbitrary state, it takes time to create a map of reference data indicating the relationship between the hydrogen filling amount and the pressure. And the map becomes complicated.

[0009] Further, in the deterioration detection means described in Patent Document 2, the temperature detection accuracy of the hydrogen storage alloy has a great influence on the deterioration determination. The temperature of the hydrogen storage alloy varies depending on the location, and in order to increase the accuracy of temperature measurement, it is necessary to measure at many locations, which complicates the structure.

[0010] The present invention has been made in view of the above problems, and an object of the present invention is to detect deterioration of the hydrogen storage material accommodated in the hydrogen storage tank with a simpler configuration than the prior art and with high accuracy. It is an object of the present invention to provide a deterioration detection device and deterioration detection method for a hydrogen storage material in a hydrogen storage tank that can be discharged. Another object of the present invention is to provide a hydrogen storage and supply system provided with a deterioration detection device for the hydrogen storage material.

In order to achieve the above object, according to the first aspect of the present invention, a hydrogen storage material deterioration detection device in a hydrogen storage tank that houses a hydrogen storage material and incorporates a heat exchanger. Is provided. The deterioration detector includes a pressure detection means for detecting a pressure in the hydrogen storage tank, a first temperature detection means for detecting a temperature in the hydrogen storage tank, and the heat exchanger for the heat medium flowing through the heat exchanger. Second temperature detecting means for detecting the temperature at the inlet and the outlet. Further, based on the temperature of the heat medium at the inlet and the outlet detected by the second temperature detecting means and the flow rate of the heat medium, it was used for cooling when filling the hydrogen storage tank with hydrogen. Based on the first calculation means for calculating the amount of heat and the PCT curve of the hydrogen storage material accommodated in the hydrogen storage tank, a second amount of hydrogen stored in the hydrogen storage material at the start of hydrogen filling is obtained. Computing means. Further, the deterioration detection device is configured so that the pressure in the hydrogen storage tank at the start of hydrogen filling is lower than the state of the plateau region of the hydrogen storage material or the plateau region based on the PCT curve at the temperature in the hydrogen storage tank. When the hydrogen storage tank is filled with hydrogen from an empty state to a predetermined pressure set in advance, and from a predetermined state at the start of hydrogen filling or after the start of hydrogen filling, Degradation determining means for determining whether or not the hydrogen storage material has deteriorated based on the amount of cooling heat required to fill hydrogen to a predetermined pressure.

Here, the “PCT curve of the hydrogen storage material” means a curve showing the relationship between the pressure, the amount of hydrogen stored and the temperature of the hydrogen storage material.

In the first aspect, the amount of heat used for cooling the hydrogen storage material (cooling heat amount) is calculated by the first calculation means when the hydrogen storage tank is filled with hydrogen. The amount of cooling heat is calculated based on the temperature of the heat medium flowing through the heat exchanger built in the hydrogen storage tank at the inlet and outlet of the heat exchanger and the flow rate of the heat medium. Then, the deterioration determination means determines whether the hydrogen storage material has deteriorated based on the reference cooling heat amount necessary for filling the hydrogen storage tank with hydrogen from an empty state to a predetermined pressure set in advance, and the cooling heat amount. Judgment is made. The deterioration judging means judges the deterioration when the pressure in the hydrogen storage tank at the start of hydrogen filling is lower than the state of the plateau region of the hydrogen storage material or the plateau region. Therefore, the deterioration of the hydrogen storage material accommodated in the hydrogen storage tank can be detected with a simpler configuration and with higher accuracy than in the prior art.

[0014] The predetermined pressure is determined when the hydrogen filling amount in the hydrogen storage tank reaches 100%. The pressure is desirable. In this case, the predetermined pressure when calculating the heat of cooling used to determine the deterioration of the hydrogen storage material is compared with the pressure at the time when hydrogen is stored in the hydrogen storage material by an amount less than 100%. Accuracy.

[0015] Preferably, the deterioration determining means determines whether or not the deterioration has occurred when hydrogen filling is started when the pressure in the hydrogen storage tank is lower than the plateau region of the hydrogen storage material. In this case, when determining the hydrogen storage amount at the start of hydrogen filling from the PCT curve of the hydrogen storage material, the accuracy in the low pressure region is higher than that in the plateau region. The accuracy of.

[0016] The predetermined state after the start of hydrogen filling is preferably a state in which the pressure and temperature in the hydrogen storage tank have reached preset values.

[0017] The hydrogen storage tank can be used as a hydrogen source for a hydrogen-fueled vehicle using hydrogen as fuel.

[0018] According to the second aspect of the present invention, there is provided a method for detecting deterioration of a hydrogen storage material in a hydrogen storage tank that contains a hydrogen storage material and incorporates a heat exchanger. According to the method, based on the PCT curve of the hydrogen storage material, when the pressure in the hydrogen storage tank at the start of hydrogen filling is lower than the state of the plateau region or lower than the plateau region of the hydrogen storage material, The amount of cooling heat required to fill the predetermined pressure with hydrogen at the start of hydrogen filling or after the start of hydrogen filling, and the hydrogen storage tank are charged with hydrogen from an empty state to a predetermined pressure set in advance. Degradation of the hydrogen storage material based on the required amount of cooling heat in the non-degraded state of the hydrogen storage material determined corresponding to the hydrogen filling amount that required the cooling heat amount from the reference cooling heat amount required for filling Determine the presence or absence.

[0019] With this method, the deterioration of the hydrogen storage material can be detected more easily and accurately than in the prior art.

[0020] According to the third aspect of the present invention, the hydrogen storage material deterioration detection device of the hydrogen storage tank according to the first aspect, the hydrogen storage tank containing the hydrogen storage material and incorporating the heat exchanger, There is provided a hydrogen storage and supply system comprising a supply means for supplying a heat medium for heating or cooling the hydrogen storage material to the heat exchanger. This hydrogen storage and supply system can accurately detect the deterioration of the hydrogen storage material. Brief Description of Drawings

FIG. 1 is a configuration diagram of a fuel cell system.

FIG. 2 is a flowchart showing a procedure for judging deterioration of a hydrogen storage alloy.

FIG. 3 is a diagram showing a PCT curve of a hydrogen storage alloy.

[FIG. 4] (a) is a diagram showing the relationship between the filling time at 100% hydrogen filling and the amount of cooling heat, and (b) is a diagram showing the relationship between the filling time at hydrogen filling and the amount of cooling heat.

BEST MODE FOR CARRYING OUT THE INVENTION

[0022] (First embodiment)

Hereinafter, the present invention is embodied in a fuel cell system configured to be used as a hydrogen source for a fuel cell and a heat medium for cooling the fuel cell as a heat medium for heating and cooling the hydrogen storage material. Such an embodiment will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a fuel cell system.

The fuel cell system includes a fuel cell 11, a hydrogen storage tank 12, a compressor 13, and a radiator 14. The hydrogen storage tank 12, the fuel cell 11 and the radiator 14 are connected through a heat medium flow path 15.

[0024] The fuel cell 11 is composed of, for example, a polymer electrolyte fuel cell. The fuel cell 11 reacts with hydrogen supplied from the hydrogen storage tank 12 and oxygen in the air supplied from the compressor 13 to generate direct current electric energy ( DC power). In order to allow the fuel cell 11 to be cooled during the steady operation, a part of the heat medium flow path 15 is arranged in the fuel cell 11 as a heat exchanging portion 15a.

The hydrogen storage tank 12 includes a tank body 16, a hydrogen storage unit 17 containing a hydrogen storage alloy MH as a hydrogen storage material therein, and a support body that supports the hydrogen storage unit 17 in the tank body 16. 18 and. In the hydrogen storage tank 12, a heat exchanger 19 for exchanging heat with the hydrogen storage alloy MH is provided. The heat exchanger 19 forms a part of the hydrogen storage unit 17 and includes a large number of fins 20 for increasing the efficiency of heat exchange with the hydrogen storage alloy MH. The flow path of the heat exchanger 19 forms part of the heat medium flow path 15. In this embodiment, LLC (Long Life Coolant) is used as the heat medium. A known material can be used as the hydrogen storage alloy MH. The hydrogen storage tank 12 is connected to a hydrogen supply port (not shown) of the fuel cell 11 via a conduit 21 and supplies hydrogen to the fuel cell 11. The hydrogen storage tank 12 stores hydrogen in the tank body 16 at a pressure higher than the pressure in the plateau region of the hydrogen storage alloy MH, for example, about 35 MPa, and reduces the pressure with a valve (not shown) to the fuel cell 11. Supply at a constant pressure (for example, about 0.3 MPa). The plateau region is a region where the pressure in the tank main body 16 hardly increases even if the amount of occluded hydrogen increases, and is kept almost constant.

[0027] The hydrogen storage tank 12 is connected to a pipe line 22 having a hydrogen filling port 22a, and the hydrogen storage tank 12 can be filled with hydrogen gas from the pipe line 22. The hydrogen storage tank 12 is provided with a pressure sensor 23a as a pressure detection means for detecting the pressure in the tank body 16 and a temperature sensor 23b as a first temperature detection means for detecting the temperature in the tank body 16. ing

[0028] The compressor 13 is connected to an oxygen supply port (not shown) of the fuel cell 11 via a pipe line 24, and supplies compressed air to the fuel cell 11. The compressor 13 compresses the air from which dust and the like have been removed by an air cleaner (not shown) and discharges the compressed air to the conduit 24.

[0029] The radiator 14 includes a fan 25a that is rotated by a motor 25 so that heat is efficiently radiated from the radiator 14.

[0030] The heat medium flow path 15 is provided with a pump 26 located on the inlet side of the radiator 14.

The pump 26 is provided to send the heat medium in the heat medium flow path 15 to the inlet of the radiator 14. The heat medium flow path 15 is branched at a branch portion provided between the inlet of the heat exchanging portion 15a and the outlet of the radiator 14, and has a bypass portion 15b connected to the inlet of the radiator 14, and the branch portion includes An electromagnetic three-way valve 27 is provided. The outlet side of the heat exchange part 15a is connected to the bypass part 15b. The electromagnetic three-way valve 27 is configured to be switchable between a state in which the heat medium is supplied to the inlet side of the heat exchange part 15a of the fuel cell 11 and a state in which the heat medium flows through the bypass part 15b without being supplied to the heat exchange part 15a. ing.

[0031] The inlet 19a of the heat exchanger 19 of the hydrogen storage tank 12 is connected to the bypass portion 15b via an electromagnetic three-way valve 28. The outlet 19b of the heat exchanger 19 is connected to the downstream side of the electromagnetic three-way valve 28 of the bypass portion 15b. The electromagnetic three-way valve 28 has a first state in which the heat medium flowing through the bypass portion 15b can pass only to the inlet 19a of the heat exchanger 19, and the bypass portion 15b. The flowing heat medium is configured to be switchable to a second state in which the flowing heat medium can pass only to the downstream side of the bypass portion 15b instead of the inlet 19a of the heat exchanger 19.

[0032] A temperature sensor T1 for detecting the temperature of the heat medium is provided at the inlet 19a of the heat exchanger 19, and a temperature sensor T2 for detecting the temperature of the heat medium is provided at the outlet 19b of the heat exchanger 19, respectively. Both temperature sensors Tl and T2 constitute second temperature detecting means for detecting temperatures at the inlet 19a and outlet 19b of the heat exchanger 19 of the heat medium. Further, a flow meter 29 for measuring the flow rate of the heat medium is provided between the inlet 19a and the electromagnetic three-way valve 28.

[0033] The control device 30 housed in the hydrogen storage tank 12 includes a microcomputer ₃₁ as a means for calculating a cooling heat amount, a means for calculating a hydrogen storage amount at the start of filling, and a deterioration determining means. The microcomputer 31 includes a memory (ROM and RAM) 32. Pressure sensor 23a, temperature sensor 23b, temperature sensors Tl and T2, flow meter 29, and temperature sensor (not shown) for detecting the temperature of fuel cell 11 are connected to the input side (input interface) of control device 30. Each is electrically connected. The compressor 13, the motor 25, the pump 26, and the electromagnetic three-way valves 27 and 28 are electrically connected to the output side (output interface) of the control device 30, respectively. The compressor 13, the motor 25, the pump 26, and the electromagnetic three-way valves 27 and 28 are operated or switched by commands from the control device 30. The pump 26 is driven, stopped and the flow rate is changed based on the command signal from the control device 30.

[0034] The memory 32 stores a PCT curve of a hydrogen storage alloy as shown in FIG. 3 as a map. The memory 32 stores a reference cooling heat quantity Q0 necessary for filling the hydrogen storage tank 12 with hydrogen from an empty state to a predetermined pressure set in advance. In this embodiment, the pressure and heat quantity when the hydrogen storage tank 12 is filled with 100% hydrogen are set as the reference cooling heat quantity Q0 at a predetermined pressure. Further, as shown in FIG. 4 (a), the reference cooling heat quantity Q0 is stored as a map indicating the relationship between the cooling heat quantity and the filling time.

[0035] The microcomputer 31 includes the temperature T (° C) of the heat medium at the inlet 19a of the heat exchanger 19 detected by the temperature sensors Tl and Τ2, and the temperature T (° C) of the heat medium at the outlet 19b. The heat

in out

When the hydrogen storage tank 12 is filled with hydrogen based on the flow rate Q (L / min) of the medium The cooling heat quantity W (kW) used for cooling is calculated by the following equation (1). At this time, the microcomputer 31 functions as a first calculation means.

[0036] W = (T -T) p-Q / 1000/60---(1)

out in

Where C is the specific heat of the heat medium (kjZ (kg- ° C)) and p is the specific gravity of the heat medium (kgZm ³ ). In addition, “Z60” in the equation (1) is used to make the output value of the flow meter in “minute” units correspond to the sampling process in “one second unit”.

[0037] The microcomputer 31 calculates the PCT curve of the hydrogen storage alloy from the pressure in the hydrogen storage tank 12 and the temperature in the hydrogen storage tank 12 based on the amount of hydrogen stored in the hydrogen storage alloy MH at the start of hydrogen filling. Use to calculate. At this time, the microcomputer 31 functions as first calculation means for obtaining the amount of hydrogen stored in the hydrogen storage alloy MH stored in the hydrogen storage tank 12 at the start of hydrogen filling.

[0038] When the pressure in the hydrogen storage tank 12 at the start of hydrogen filling is the state of the plateau region of the hydrogen storage alloy MH or lower than the plateau region, the microcomputer 31 starts to store the reference cooling heat Q0 and the hydrogen storage. Whether or not the hydrogen storage alloy MH has deteriorated is determined based on the amount of cooling heat W required from the time until the predetermined pressure is filled with hydrogen. At this time, the microcomputer 31 functions as a deterioration determining means for determining whether or not the hydrogen storage alloy MH has deteriorated.

[0039] In this embodiment, the heat exchange part 15a of the fuel cell 11 and the radiator 14 constitutes a supply means for supplying a heat medium for heating or cooling the hydrogen storage alloy MH built in the hydrogen storage tank 12. The hydrogen storage tank 12, the radiator 14, the heat exchange part 15a of the fuel cell 11, and the hydrogen storage material deterioration detector configured as described above constitute a hydrogen storage and supply system. .

Next, the operation of the apparatus configured as described above will be described.

The fuel cell 11 is normally operated when the environmental temperature is equal to or higher than a preset temperature (set temperature) at which the fuel cell 11 can generate power. Based on a detection signal of a temperature sensor (not shown) that measures the environmental temperature, the control device 30 performs normal operation from the start if the environmental temperature is equal to or higher than the set temperature, and the environmental temperature is less than the set temperature. In some cases, after warming up, the system shifts to normal operation. During normal operation, hydrogen is supplied from the hydrogen storage tank 12 to the anode electrode side of the fuel cell 11. Further, the compressor 13 is driven, and the air is pressurized to a predetermined pressure and supplied to the power sword electrode side of the fuel cell 11.

[0043] In addition, solid polymer fuel cells generate power efficiently at about 80 ° C, but the chemical reaction between hydrogen and oxygen is an exothermic reaction. The temperature rises above an appropriate temperature of about 80 ° C. In order to prevent this temperature rise, the heat medium cooled by the radiator 14 circulates in the heat medium flow path 15. In addition, since the release of hydrogen from the hydrogen storage alloy MH is an endothermic reaction, it is necessary to heat the hydrogen storage alloy MH in order to make the reaction proceed smoothly. Used for heating alloy MH.

[0044] During operation of the fuel cell 11, the control device 30 holds the electromagnetic three-way valve 27 in a state where the heat medium is supplied to the inlet of the heat exchange unit 15a, and detects the pressure in the hydrogen storage tank 12. Based on the detection signal of the pressure sensor 23a, the electromagnetic three-way valve 28 is switched and controlled. When the pressure in the hydrogen storage tank 12 becomes equal to or lower than a first preset pressure, the control device 30 is in a state where the heat medium heats the hydrogen storage tank 12, that is, the heat medium flows through the heat exchanger 19. A command signal for switching the electromagnetic three-way valve 28 is output to the state. Further, when the pressure in the hydrogen storage tank 12 becomes equal to or higher than a second preset pressure set in advance, the electromagnetic three-way valve is brought into a state where the heat medium does not flow through the heat exchanger 19, that is, does not flow through the hydrogen storage tank 12. A command signal for switching 28 is output. The control device 30 determines that hydrogen filling is necessary when the first set pressure is not reached even if heating with the heat medium continues for a preset time. Then, the notification means (for example, a display unit such as a lamp) is driven.

[0045] When the hydrogen storage tank 12 is filled with hydrogen gas, that is, stored, the control device 30 sends a command signal for switching to a state in which the heat medium flows through the bypass portion 15b without being supplied to the heat exchange portion 15a of the fuel cell 11. Is output to the electromagnetic three-way valve 27, and a command signal for switching the state in which the heat medium is supplied to the heat exchanger 19 of the hydrogen storage tank 12 is output to the electromagnetic three-way valve 28. Accordingly, the heat medium cooled by the radiator 14 is supplied to the heat exchanger 19 of the hydrogen storage tank 12 without passing through the heat exchange section 15a of the fuel cell 11.

[0046] And, for example, a dispenser coupler of a hydrogen station (not shown) is filled with hydrogen. The hydrogen storage tank 12 is filled with hydrogen gas by the pressure difference between the hydrogen curdle of the hydrogen station and the hydrogen storage tank 12 connected to the port 22a.

[0047] The hydrogen gas supplied from the hydrogen curdle into the hydrogen storage tank 12 reacts with the hydrogen storage alloy MH to become a hydride and is stored in the hydrogen storage alloy MH. Since the hydrogen occlusion is an exothermic reaction, the occlusion does not proceed smoothly unless the heat generated by the hydrogen occlusion is removed. Therefore, when filling with hydrogen, the heat medium flowing through the heat medium flow path 15 does not flow through the fuel cell 11, passes through the bypass portion 15b and the heat exchanger 19, and between the hydrogen storage tank 12 and the radiator 14. The electromagnetic three-way valves 27 and 28 are switched so as to circulate at

[0048] The microcomputer 31 makes a deterioration determination when the pressure in the hydrogen storage tank 12 at the start of hydrogen filling is lower than the state of the plateau region of the hydrogen storage alloy MH or lower than the plateau region.

Next, a procedure for determining the deterioration of the hydrogen storage alloy MH will be described based on the flowchart of FIG.

[0050] The control device 30 outputs a command signal for switching to a state in which the heat medium flows through the bypass portion 15b without being supplied to the heat exchanging portion 15a of the fuel cell 11 to the electromagnetic three-way valve 27 at the time of hydrogen filling, and the electromagnetic three-way valve A command signal for switching to a state in which the heat medium is supplied to the heat exchanger 19 of the hydrogen storage tank 12 is output to 28. Thereafter, the microcomputer 31 executes the process for determining the deterioration of the hydrogen storage alloy MH according to the procedure shown in the flowchart of FIG.

The microcomputer 31 first inputs detection signals from the pressure sensor 23a and the temperature sensor 23b in step S1. Next, in step S2, it is determined whether the pressure in the hydrogen storage tank 12 is in the state of the plateau region of the hydrogen storage alloy MH or whether it is lower than the plateau region. Then, if the pressure in the hydrogen storage tank 12 is not lower than the state of the plateau region of the hydrogen storage alloy MH or the plateau region in step S2, the deterioration determination process is terminated, and if the pressure is lower than the state of the plateau region or the plateau region, step is performed. Proceed to S3 and continue the deterioration judgment process.

[0052] The microcomputer 31 fills 100% of the amount of hydrogen stored in the hydrogen storage alloy MH at the start of hydrogen charging in step S3 based on the pressure and temperature in the hydrogen storage tank 12 and the PCT curve. Calculated as a percentage (%) with respect to time (fully filled). Next, microcode The computer 31 proceeds to step S4, inputs the output signals of the temperature sensors Tl and T2 and the flow meter 29 every second, calculates the cooling heat amount W by the above equation (1), and stores the value in the memory 32. To do.

[0053] Next, the microcomputer 31 proceeds to step S5, and from the output signal of the pressure sensor 23a, it is determined whether or not the pressure in the hydrogen storage tank 12 has reached a predetermined pressure (pressure at 100% filling: for example, 35 MPa). to decide. If the predetermined pressure has not been reached, the process returns to step S4 to execute step S4. The relationship between the cooling heat quantity W and the elapsed time from the start of filling is, for example, as shown in Fig. 4 (b). Whether or not the predetermined pressure has been reached in step S5 is determined by whether or not the predetermined pressure is maintained even after a preset time has elapsed, and is maintained at the predetermined pressure even after a predetermined time has elapsed. It is determined that the predetermined pressure has been reached.

[0054] On the other hand, if the predetermined pressure has been reached in step S5, it is determined that the filling has ended, and the process proceeds to step S6. The microcomputer 31 integrates the value of the cooling heat amount W stored in the memory 32 so far in step S6, and calculates the total cooling heat amount Wa used for cooling when filling with hydrogen. Then, the process proceeds to step S7, and the amount of cooling heat necessary for cooling at the time of hydrogen filling when the hydrogen storage alloy MH is not deteriorated from the reference cooling heat amount Q0 and the hydrogen storage amount of the hydrogen storage alloy MH at the start of filling. Find Qs. Specifically, the cooling heat quantity Qs is calculated by multiplying the reference cooling heat quantity Q0 by subtracting the percentage (%) of the hydrogen storage quantity of the hydrogen storage alloy MH at the start of filling from 100%. For example, if the amount of hydrogen stored in the hydrogen storage alloy MH at the start of hydrogen filling in step S3 is 30%, the cooling heat quantity Q s is based on 70% of 100% minus 30%. Calculated as the value multiplied by the cooling heat quantity Q0 (Qs = 0.7 X Q0).

[0055] Next, in step S8, the microcomputer 31 compares the cooling heat quantity Qs with the total cooling heat quantity Wa, and if the total cooling heat quantity Wa is less than the cooling heat quantity Qs, the microcomputer 31 proceeds to step S9 and proceeds to step S9. After determining that has deteriorated, the deterioration determination process is terminated. If the total cooling heat amount Wa is not less than the cooling heat amount Qs, the process proceeds to step S10, and it is determined that the hydrogen storage alloy MH has not deteriorated, and then the deterioration determination process ends.

Therefore, when the microcomputer 31 calculates the amount of hydrogen remaining in the hydrogen storage tank 12 based on the pressure and temperature in the hydrogen storage tank 12 and the PCT curve, By calculating the presence or absence of gold MH degradation, it is possible to accurately calculate the amount of residual hydrogen. For example, the difference between the total cooling heat Wa calculated in Steps S6 and S7 and the cooling heat Qs (Qs-Wa) is obtained, and the amount of hydrogen that is no longer stored in the hydrogen storage alloy MH due to the deterioration of the hydrogen storage alloy MH is estimated from that value. To do. Then, the remaining hydrogen amount is calculated to be smaller by the amount of hydrogen.

This embodiment has the following effects.

[0058] (1) The microcomputer 31 determines that the hydrogen storage alloy MH deteriorates when the pressure in the hydrogen storage tank 12 at the start of hydrogen filling is in the state of the hydrogen storage alloy MH plateau region or lower than the plateau region. Determine the presence or absence. Whether the hydrogen storage alloy MH is in a non-deteriorated state or not is determined based on the reference cooling calorie QO required when the hydrogen storage tank 12 is filled with hydrogen from an empty state to a predetermined pressure, and the hydrogen storage alloy MH. This is based on the amount of cooling heat used for cooling (total cooling heat amount Wa). Therefore, it is possible to detect the deterioration of the hydrogen storage alloy MH accommodated in the hydrogen storage tank 12 with a simpler configuration than the prior art and with high accuracy.

[0059] (2) The amount of cooling heat necessary for the hydrogen storage tank 12 to reach 100% is used as the reference cooling heat quantity QO used to determine the deterioration of the hydrogen storage alloy MH. Therefore, the accuracy of deterioration determination is higher than when using a value until hydrogen is charged to a smaller amount.

[0060] (3) The amount of heat generated by the hydrogen storage alloy MH when the hydrogen storage tank 12 is filled with hydrogen is the amount of heat given to the heat medium flowing through the heat exchanger 19, that is, the amount of heat used for cooling the hydrogen storage alloy MH. The total cooling heat amount Wa is obtained by calculating every predetermined time based on the above and integrating the values. Therefore, the accuracy is higher than when the temperature of the hydrogen storage alloy MH is directly measured and the total calorific value of the hydrogen storage alloy MH is calculated.

The embodiment of the present invention is not limited to the above, and may be configured as follows, for example.

[0062] In the above embodiment, assuming that the amount of heat taken out from the hydrogen storage alloy MH side by the heat exchanger 19 at the time of hydrogen filling is all used for cooling the hydrogen storage alloy MH, the power for determining the deterioration of the hydrogen storage alloy MH To be precise, the hydrogen storage alloy MH stores in the tank body 16. It is also used to cool the hydrogen gas that is present. This is because when the hydrogen gas is filled in the hydrogen storage tank 12, the temperature of the hydrogen gas in the tank body 16 rises due to adiabatic compression, and is used to suppress the temperature rise. Therefore, in order to determine the deterioration of the hydrogen storage alloy MH with higher accuracy, it is necessary to correct the reference cooling heat amount Q0 and the total cooling heat amount Wa only to the heat amount used for cooling the hydrogen storage alloy MH. In this case, from the reference cooling heat quantity Q0 and the total cooling heat quantity Wa, it is necessary to calculate the heat quantity used for cooling the hydrogen gas not filled in the hydrogen storage alloy MH but filled in the tank body 16. If the hydrogen storage alloy MH that has deteriorated and the hydrogen storage alloy MH that has not deteriorated have the same pressure and temperature at the start of filling and at the end of filling, the amount of heat is the same. Therefore, the heat quantity is calculated in advance for the hydrogen storage alloy MH that is not deteriorated, and the heat quantity is calculated in the calculation of the total cooling heat quantity Wa in step S6 and the reference cooling heat quantity Q0 in step S7 of the flowchart. You can deduct.

[0063] Deterioration determining means, that is, the microcomputer 31 determines that the hydrogen storage alloy MH deteriorates only when hydrogen filling is started when the pressure in the hydrogen storage tank 12 is lower than the plateau region of the hydrogen storage alloy MH. It may be determined whether or not there is. When calculating the amount of hydrogen stored in the hydrogen storage alloy MH at the start of hydrogen filling from the PCT curve of the hydrogen storage alloy MH, the pressure change in the hydrogen storage tank 12 with respect to the change in the amount of hydrogen at a constant temperature in the plateau region It may be difficult to accurately determine the small amount of hydrogen. However, in the region where the pressure is lower than the plateau region of the PCT curve, the pressure change in the hydrogen storage tank 12 with respect to the change in the hydrogen amount at a constant temperature is larger than the change in the plateau region, so hydrogen filling starts. The amount of hydrogen at the time can be determined with high accuracy, and the accuracy of determining the deterioration of the hydrogen storage alloy MH is increased.

[0064] When the conditions for determining the presence or absence of deterioration of the hydrogen storage alloy MH are satisfied, the processing after step S4 in the embodiment is immediately executed regardless of the pressure and temperature values in the hydrogen storage tank 12. However, after the start of filling with hydrogen, after the pressure and temperature in the hydrogen shell storage tank 12 reach preset values, the processing after step S4 may be performed. However, if the pressure and temperature values in the hydrogen storage tank 12 are larger than the preset values at the start of hydrogen filling, the processing after step S4 is immediately performed. This In this case, the reference cooling heat quantity Q0 corresponding to the preset value is stored in the memory 32, so that the reference cooling heat quantity Q0 corresponds to the pressure and temperature in the hydrogen storage tank 12 at the start of hydrogen filling. You don't have to calculate every time.

[0065] When calculating the amount of cooling heat W when determining the deterioration of the hydrogen storage alloy MH, the interval at which the output signals of the temperature sensors T1, T2 and the flow meter 29 are input (sampled) is not limited to 1 second. Sampling may be performed at intervals longer than 1 second and at intervals (for example, at intervals of several seconds), or may be sampled at intervals shorter than 1 second. In that case, change the “Z60” part of equation (1) and use it to calculate the cooling heat quantity W.

[0066] When the hydrogen storage tank 12 is filled with hydrogen so that the pressure at the time of full filling of hydrogen is higher than the pressure in the plateau region of the hydrogen storage alloy MH, the pressure is the pressure (35 MPa). For example, it may be higher than 35 MPa or lower than 35 MPa.

[0067] The hydrogen storage tank 12 is not limited to a configuration in which hydrogen is stored at a pressure higher than the pressure in the plateau region of the hydrogen storage alloy MH, for example, at a high pressure of about 35 MPa. Hydrogen may be stored at the pressure in the region. In this case, the pressure resistance of the hydrogen storage tank 12 can be lowered.

[0068] The fuel cell system has a configuration in which the heat medium used for heating and cooling the hydrogen storage tank 12 is the same as the heat medium for cooling the fuel cell 11, the electromagnetic three-way valve 27 is omitted, and the heat medium is A configuration may be adopted in which the fuel cell 11 is always supplied to the heat exchanger 19 of the hydrogen storage tank 12 via the heat exchanger 15a and then returned to the radiator 14. In this case, only the heat medium that has passed through the heat exchanger 15a of the fuel cell 11 is supplied to the heat exchanger 19 of the hydrogen storage tank 12, but the hydrogen filling is performed in a state where the fuel cell 11 is not operated. Therefore, the hydrogen storage alloy MH has no problem in cooling. In this case, since the electromagnetic three-way valve 27 can be omitted, the configuration of the heat medium circulation system is simplified.

[0069] The fuel cell 11 is not limited to a polymer electrolyte fuel cell, but may be a fuel cell that uses a heat medium to cool the fuel cell, such as a phosphoric acid fuel cell or an alkaline fuel cell.

[0070] The fuel cell system is not limited to a configuration in which the fuel cell 11 and one hydrogen storage tank 12 are connected, but a system that supplies hydrogen from the plurality of hydrogen storage tanks 12 to the fuel cell 11. May be.

[0071] The fuel cell system is not limited to a vehicle. For example, the present invention may be applied to a fuel cell system for a moving body other than a vehicle, or may be applied to a home cogeneration system. In this case as well, it becomes possible to accurately detect the amount of hydrogen remaining in the hydrogen storage tank 12 in consideration of the deterioration of the hydrogen storage alloy MH, and the inconvenience due to the delay of the hydrogen filling timing in the hydrogen storage tank 12 is achieved. Can be suppressed.

[0072] The heating medium used for heating or cooling the hydrogen storage alloy MH of the hydrogen storage tank 12 is not limited to the configuration shared with the cooling medium of the fuel cell 11, but in the fuel cell 11 and the hydrogen storage tank 12. An independent heat medium circulation system may be provided.

[0073] The hydrogen storage and supply system is not limited to a configuration that is used as a hydrogen supply means to the fuel cell 11, but may be a configuration that is used as a hydrogen supply means to a device that uses other hydrogen. In that case, a heat medium supplying means for supplying a heat medium for heating or cooling the hydrogen storage alloy MH incorporated in the hydrogen storage tank 12 is provided separately.

[0074] The heat medium is not limited to LLC, and may be, for example, simple water.

[0075] The hydrogen storage tank 12 is not limited to a fuel cell system, and may be used as a hydrogen source for a hydrogen engine vehicle equipped with a hydrogen engine.

[0076] The hydrogen storage tank 12 may contain a hydrogen storage material other than a hydrogen storage alloy, for example, an activated carbon fiber or a single-walled carbon nanotube.

Claims

The scope of the claims

[1] A device for detecting deterioration of a hydrogen storage material in a hydrogen storage tank containing a hydrogen storage material and incorporating a heat exchanger,

Pressure detecting means for detecting the pressure in the hydrogen storage tank;

First temperature detecting means for detecting the temperature in the hydrogen storage tank;

Second temperature detecting means for detecting the temperature of the heat medium flowing through the heat exchanger at the inlet and outlet of the heat exchanger;

The amount of heat used for cooling when filling the hydrogen storage tank with hydrogen based on the temperature of the heat medium at the inlet and outlet detected by the second temperature detecting means and the flow rate of the heat medium. A first computing means for computing

Second computing means for determining the amount of hydrogen stored in the hydrogen storage material at the start of hydrogen filling based on the PCT curve of the hydrogen storage material stored in the hydrogen storage tank; and Based on the PCT curve at temperature, when the pressure in the hydrogen storage tank at the start of hydrogen filling is lower than the state of the plateau region of the hydrogen storage material or lower than the plateau region, the hydrogen storage tank is The reference cooling heat amount necessary for filling hydrogen to a predetermined pressure set in advance and the cooling required for filling hydrogen from the predetermined state after the start of hydrogen filling or after the start of hydrogen filling to the predetermined pressure. A deterioration detection device for a hydrogen storage material in a hydrogen storage tank, comprising: deterioration determination means for determining whether or not the hydrogen storage material has deteriorated based on the amount of heat.

2. The deterioration detection device for a hydrogen storage material in a hydrogen storage tank according to claim 1, wherein the predetermined pressure is a pressure at the time when the hydrogen filling amount in the hydrogen storage tank reaches 100%.

[3] The deterioration judging means judges the presence or absence of the deterioration when the filling of hydrogen is started when the pressure in the hydrogen storage tank is lower than the plateau region of the hydrogen storage material. The hydrogen storage material deterioration detection device in the hydrogen storage tank according to 1.

[4] In the hydrogen storage material deterioration detection device in the hydrogen storage tank according to claim 1, the predetermined state after the start of the hydrogen filling is a value in which the pressure and temperature in the hydrogen storage tank are set in advance. Deterioration detection device for hydrogen storage material in the hydrogen storage tank in the reached state.

[5] In the hydrogen storage material deterioration detection device for a hydrogen storage tank according to any one of claims 1 to 4, the hydrogen storage tank is used as a hydrogen source for a hydrogen fueled automobile using hydrogen as fuel. For detecting deterioration of hydrogen storage material in a hydrogen storage tank.

[6] A method for detecting deterioration of a hydrogen storage material in a hydrogen storage tank containing a hydrogen storage material and incorporating a heat exchanger,

Based on the PCT curve of the hydrogen storage material, when the pressure in the hydrogen storage tank at the start of hydrogen filling is lower than the state of the plateau region of the hydrogen storage material or lower than the plateau region, The amount of cooling heat required for filling hydrogen from a predetermined state after the start of filling to the predetermined pressure, and necessary for filling the hydrogen storage tank from the empty state to a predetermined pressure set in advance. Based on the reference cooling heat amount and the required cooling heat amount in the non-deteriorated state of the hydrogen storage material determined from the reference cooling heat amount corresponding to the hydrogen filling amount that requires the cooling heat amount, the presence or absence of deterioration is determined. To detect deterioration of hydrogen storage material in the hydrogen storage tank.

[7] In the hydrogen storage and supply system,

A hydrogen storage tank containing a hydrogen storage material and incorporating a heat exchanger; and a heat medium supply means for supplying a heat medium for heating or cooling the hydrogen storage material to the heat exchanger;

A hydrogen storage and supply system comprising: the hydrogen storage material deterioration detection device in the hydrogen storage tank according to any one of claims 1 to 5.