Hydrogen supply device

Abstract

To keep a temperature of hydrogen gas to be supplied to a power device in a predetermined temperature range.SOLUTION: A hydrogen supply device includes a heater 20, a vaporizer 40, a circulation flow path 30 for circulating a heat medium between the heater 20 and the vaporizer 40, a circulation pump 34, and a control part 70. The control part 70, to which output of a power device for hydrogen gas flowing out of the vaporizer 40 to be supplied thereto and a temperature of the heat medium flowing out of the vaporizer 40 are input, calculates a drive duty command value for the circulation pump 34 on the basis of the temperature of the heat medium flowing out of the vaporizer 40 and the output of a hydrogen engine 15 and drives the circulation pump 34 on the basis of the calculated drive duty command value.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to temperature control of hydrogen gas in a hydrogen supply device that vaporizes liquid hydrogen to supply hydrogen gas.

Background Art

[0002] Patent Document 1 discloses a technique for maintaining a rotating electric machine within a predetermined temperature range by changing the flow rate of a coolant flowing into a heat exchanger that cools the coolant of the rotating electric machine according to the rotational speed of the rotating electric machine.

Prior Art Document

[0007] As a result, It is possible to calculate the drive duty cycle command value according to the output of the power unit. Even if the output of the power unit changes, the temperature of the hydrogen gas supplied to the power unit can be maintained within a predetermined temperature range.

[0010] In the hydrogen supply device of this disclosure, the control unit may calculate the base drive duty cycle such that the base drive duty cycle decreases as the temperature of the heat transfer medium flowing out of the vaporizer increases, and calculate the correction coefficient such that the correction coefficient increases as the output of the power unit increases.

[0011] This allows the flow rate of the circulation pump to be increased or decreased in advance of changes in the temperature of the hydrogen gas flowing out of the vaporizer, so that even if the output of the power unit changes, the temperature of the hydrogen gas supplied to the power unit can be maintained within a predetermined temperature range. [Effects of the Invention]

[0012] The hydrogen supply device of this disclosure can maintain the temperature of the hydrogen gas supplied to the power unit within a predetermined temperature range. [Brief explanation of the drawing]

[0013] [Figure 1] This is a system diagram showing the configuration of the hydrogen supply device of the embodiment and the hydrogen engine vehicle equipped with the hydrogen supply device. [Figure 2]Figure 1 shows the base drive duty cycle calculation map stored in the control unit's memory. [Figure 3] Figure 1 shows the correction coefficient calculation map stored in the control unit's memory. [Figure 4] Figure 1 is a flowchart showing the operation of the hydrogen supply device. [Modes for carrying out the invention]

[0014] The hydrogen supply device 100 of this embodiment will be described below with reference to the drawings. In the following description, the hydrogen supply device 100 will be described as supplying hydrogen gas to the hydrogen engine 15, which is a power unit mounted on the hydrogen engine vehicle 200.

[0015] As shown in Figure 1, the hydrogen supply device 100 includes a heating circuit 10 that heats a heat transfer medium and supplies it to the vaporizer 40, a hydrogen circuit 50 that supplies the hydrogen gas vaporized in the vaporizer 40 to the hydrogen engine 15, and a control unit 70. First, the heating circuit 10 will be described. The heating circuit 10 consists of a heater 20, a vaporizer 40, a circulation channel 30, and a circulation pump 34.

[0016] The heater 20 is equipped with a cooling water channel 21 and a heat transfer medium channel 31. High-temperature cooling water that has flowed through the internal channel 17 of the hydrogen engine 15 flows through the cooling water channel 21. Low-temperature heat transfer medium that has flowed through the inside of the casing 41 of the vaporizer 40 flows through the heat transfer medium channel 31. The heater 20 heats the heat transfer medium by exchanging heat between the high-temperature cooling water flowing through the cooling water channel 21 and the low-temperature heat transfer medium. Here, the heat transfer medium is a liquid, and may be, for example, a long-life coolant (LLC).

[0017] The cooling water passage 21 is connected to the internal passage 17 by a cooling water supply pipe 22 and a cooling water return pipe 23. The internal passage 17, the cooling water passage 21, the cooling water supply pipe 22, and the cooling water return pipe 23 form a cooling water circulation passage 25 that circulates cooling water between the hydrogen engine 15 and the heater 20. The cooling water circulation passage 25 circulates the cooling water, whose temperature has risen in the hydrogen engine 15, back to the cooling water passage 21 of the heater 20.

[0018] The vaporizer 40 consists of a casing 41 and hydrogen tubes 45 housed inside the casing 41. A high-temperature heat transfer medium heated by the heater 20 flows through the inside of the casing 41. Low-temperature liquid hydrogen or hydrogen gas flows through the inside of the hydrogen tubes 45. The heat transfer medium flowing through the inside of the casing 41 flows along the outside of the hydrogen tubes 45, heating and vaporizing the liquid hydrogen inside to produce hydrogen gas.

[0019] The circulation channel 30 consists of the heat transfer medium channel 31 of the heater 20, the heat transfer medium supply pipe 32, the casing 41 of the vaporizer 40, and the heat transfer medium return pipe 33. The heat transfer medium supply pipe 32 connects the outlet of the heat transfer medium channel 31 to the heat transfer medium inlet 42 of the vaporizer 40. The heat transfer medium return pipe 33 connects the heat transfer medium outlet 43 of the vaporizer 40 to the inlet of the heat transfer medium channel 31. The heat transfer medium supply pipe 32 is also equipped with a circulation pump 34 that pressurizes the heat transfer medium into the circulation channel 30. A heat transfer medium temperature sensor 38 for detecting the vaporizer outlet heat transfer medium temperature TL is provided near the heat transfer medium outlet 43 of the heat transfer medium return pipe 33.

[0020] The heat transfer medium, pressurized by the circulation pump 34, flows into the casing 41 through the heat transfer medium supply pipe 32 and into the casing 41 from the heat transfer medium inlet 42. Inside the casing 41, the heat transfer medium flows along the outer surface of the hydrogen tube 45 and exchanges heat with the low-temperature liquid hydrogen flowing inside the hydrogen tube 45, causing its temperature to decrease. The cooled heat transfer medium flows out of the heat transfer medium outlet 43 of the vaporizer 40 into the heat transfer medium return pipe 33. The heat transfer medium flows from the heat transfer medium return pipe 33 into the heat transfer medium flow path 31 of the heater 20. There, the heat transfer medium exchanges heat with the high-temperature cooling water flowing in the cooling water flow path 21, and the increased temperature of the heat transfer medium is returned to the circulation pump 34 from the heat transfer medium supply pipe 32.

[0021] Next, the hydrogen circuit 50 will be described. The hydrogen circuit 50 is composed of a liquid hydrogen tank 51, a liquid hydrogen pump inlet pipe 52, a liquid hydrogen pump 53, a liquid hydrogen inlet pipe 54, a hydrogen tube 45, a hydrogen gas outlet pipe 56, a pressure reducing valve 57, and a hydrogen gas supply pipe 59.

[0022] The liquid hydrogen tank 51 is a tank that stores low-temperature liquid hydrogen inside. The liquid hydrogen pump inlet pipe 52 connects the liquid hydrogen tank 51 and the suction port of the liquid hydrogen pump 53. The liquid hydrogen inlet pipe 54 connects the discharge port of the liquid hydrogen pump 53 and the inlet of the hydrogen tube 45. The hydrogen gas outlet pipe 56 connects the outlet of the hydrogen tube 45 and the pressure reducing valve 57. A hydrogen gas temperature sensor 58 for detecting the temperature TH of the hydrogen gas at the vaporizer outlet is attached to the hydrogen gas outlet pipe 56. The hydrogen gas supply pipe 59 connects the pressure reducing valve 57 and the injector 16 of the hydrogen engine 15.

[0023] The extremely low-temperature liquid hydrogen stored in the liquid hydrogen tank 51 is pressurized by the liquid hydrogen pump 53 and flows into the hydrogen tube 45 from the liquid hydrogen pump inlet pipe 52. The liquid hydrogen flowing through the hydrogen tube 45 exchanges heat with the high-temperature heat medium flowing through the outer surface of the hydrogen tube 45 and vaporizes into hydrogen gas. The hydrogen gas flowing through the hydrogen tube 45 exchanges heat with the high-temperature heat medium flowing through the outer surface of the hydrogen tube 45 and becomes hydrogen gas at a predetermined temperature and flows out from the outlet of the hydrogen tube 45 to the hydrogen gas outlet pipe 56. The hydrogen gas is depressurized to the supply pressure to the hydrogen engine 15 by the pressure reducing valve 57 and then supplied to the injector 16 of the hydrogen engine 15 through the hydrogen gas supply pipe 59. The hydrogen gas burns inside the hydrogen engine 15 to generate driving force and raises the temperature of the cooling water flowing through the internal flow path 17.

[0024] The hydrogen engine 15 is controlled by the engine control unit 60. The engine control unit 60 is a computer that includes a CPU 61, which is a processor that performs information processing, and a memory 62, which stores control programs and control data. The engine control unit 60 adjusts the output of the hydrogen engine 15 by adjusting the opening degree of the injector 16. The engine control unit 60 is connected to a start switch 18 attached to the hydrogen engine vehicle 200. When the start switch 18 is turned ON, the engine control unit 60 starts the hydrogen engine 15, and when the start switch 18 is turned OFF, it stops the hydrogen engine 15. The engine control unit 60 also communicates with the control unit 70, which will be described later, to exchange information. The engine control unit 60 outputs the output of the hydrogen engine 15 and the ON / OFF signal of the start switch 18 to the control unit 70.

[0025] The control unit 70 is a computer equipped with a CPU 71, which is a processor that performs information processing, and a memory 72 that stores control programs and control data. The circulation pump 34 and the liquid hydrogen pump 53 are connected to the control unit 70 and operate according to commands from the control unit 70. The heat transfer medium temperature sensor 38 is also connected to the control unit 70, and the vaporizer outlet heat transfer medium temperature TL detected by the heat transfer medium temperature sensor 38 is input to the control unit 70. The control unit 70 also exchanges information with the engine control unit 60. The control unit 70 receives the output of the hydrogen engine 15 and the on / off signal of the start switch 18 from the engine control unit 60.

[0026] The control unit 70 stores a base drive duty calculation map 75 shown in Figure 2 and a correction coefficient calculation map 76 shown in Figure 3 in its memory 62. The base drive duty calculation map 75 is a map that defines the base drive duty D for the vaporizer outlet heat transfer medium temperature TL. The base drive duty D is D2 until the vaporizer outlet heat transfer medium temperature TL is TL1. Between TL1 and TL2 (TL2 > TL1), the base drive duty D decreases from D2 to D1 as the vaporizer outlet heat transfer medium temperature TL increases. Then, when the vaporizer outlet heat transfer medium temperature TL exceeds TL2, the base drive duty D becomes constant at D1. Note that the base drive duty D is set between the minimum drive duty of the circulation pump 34 and 100%, so the maximum value of D2 is 100%, and the minimum value of D1 is the minimum drive duty of the circulation pump 34, for example, 10%.

[0027] Furthermore, the correction coefficient calculation map 76 is a map that defines a correction coefficient C that corrects the base drive duty cycle D of the circulation pump 34 for the output of the hydrogen engine 15. The correction coefficient C is the minimum value C1 when the output of the hydrogen engine 15 is less than W1. Then, as the output of the hydrogen engine 15 increases from W1 to W2, the correction coefficient C increases from C1 to C2. When the output of the hydrogen engine 15 exceeds W2, the correction coefficient C becomes constant at C2. In this embodiment of the hydrogen supply device 100, the correction coefficient C is set to 1.0 or more, for example, between 1.0 and 2.0. In this case, the minimum value of C1 is 1.0 and the maximum value of C2 is 2.0.

[0028] The control unit 70 calculates the drive duty command value DS using the following equation 1, based on the base drive duty D calculated using the base drive duty calculation map 75 and the correction coefficient C calculated using the correction coefficient calculation map 76. Drive duty cycle command value DS = Base drive duty cycle D × Correction coefficient C ... (Equation 1) The drive duty command value DS is the command value used when controlling the flow rate of the circulation pump 34. When the vaporizer outlet heat transfer medium temperature TL decreases, the control unit 70 increases the base drive duty D to increase the flow rate of the heat transfer medium flowing through the circulation channel 30. As a result, the amount of heat exchanged between the heat transfer medium and hydrogen in the vaporizer 40 increases, and the vaporizer outlet hydrogen gas temperature TH rises.

[0029] Furthermore, when the vaporizer outlet heat transfer medium temperature TL rises, the control unit 70 reduces the base drive duty cycle D, thereby decreasing the flow rate of the heat transfer medium through the circulation channel 30. This reduces the amount of heat exchanged between the heat transfer medium and hydrogen in the vaporizer 40, and lowers the vaporizer outlet hydrogen gas temperature TH.

[0030] Furthermore, as the output of the hydrogen engine 15 increases, the hydrogen gas flow rate increases, causing the vaporizer outlet hydrogen gas temperature TH to decrease. On the other hand, as the output of the hydrogen engine 15 decreases, the vaporizer outlet hydrogen gas temperature TH increases. In this case, if the drive duty command value DS = base drive duty D, the delay in the control response may cause a large decrease / increase in the vaporizer outlet hydrogen gas temperature TH due to the increase / decrease in the output of the hydrogen engine 15. Therefore, in the hydrogen supply device 100 of this embodiment, a pre-control is performed to change the drive duty command value DS according to the output of the hydrogen engine 15 using the correction coefficient calculation map 76 and Equation 1. This suppresses large fluctuations in the vaporizer outlet hydrogen gas temperature TH. In other words, when the output of the hydrogen engine 15 increases, the correction coefficient C is increased so that the drive duty command value DS increases by the amount expected to decrease in the vaporizer outlet hydrogen gas temperature TH due to the increase in output. Also, when the output of the hydrogen engine 15 decreases, the correction coefficient C is decreased so that the drive duty command value DS decreases by the amount expected to increase in the vaporizer outlet hydrogen gas temperature TH due to the decrease in output. This makes it possible to maintain the vaporizer outlet hydrogen gas temperature TH within a predetermined temperature range even when there are fluctuations in the output of the hydrogen engine 15 using a simple method.

[0031] Next, the operation of the hydrogen supply device 100 will be described with reference to Figure 4. When the start switch 18 is turned on, the hydrogen engine 15 and the hydrogen supply device 100 start up. In step S101 of Figure 4, the control unit 70 of the hydrogen supply device 100 obtains the vaporizer outlet heat transfer medium temperature TL from the heat transfer medium temperature sensor 38. The control unit 70 then proceeds to step S102 of Figure 4 and calculates the base drive duty cycle D corresponding to the vaporizer outlet heat transfer medium temperature TL by referring to the base drive duty cycle calculation map 75 stored in the memory 72.

[0032] In step S103 of Figure 4, the control unit 70 receives the output of the hydrogen engine 15 from the engine control unit 60. Then, in step S104 of Figure 4, the control unit 70 calculates a correction coefficient C corresponding to the output of the hydrogen engine 15 by referring to the correction coefficient calculation map 76 shown in Figure 3.

[0033] Next, the control unit 70 proceeds to step S105 in Figure 4 and calculates the drive duty command value DS using equation 1 described earlier.

[0034] Next, the control unit 70 proceeds to step S106 in Figure 4, where it controls the drive of the circulation pump 34 using the calculated drive duty command value DS.

[0035] Next, after executing step S106 in Figure 4, the control unit 70 proceeds to step S107 in Figure 4. In step S107, the control unit 70 determines whether it has received an OFF signal for the start switch 18 from the engine control unit 60. If the control unit 70 determines NO in step S107 in Figure 4, it returns to step S101 in Figure 4 and repeats the operation from step S101 to step S107. On the other hand, if the control unit 70 determines YES in step S107 in Figure 4, it terminates the process.

[0036] In this way, when the vaporizer outlet heat transfer medium temperature TL decreases, the control unit 70 increases the base drive duty cycle D to increase the flow rate of the heat transfer medium through the circulation channel 30. This increases the amount of heat exchanged between the heat transfer medium and hydrogen in the vaporizer 40, causing the vaporizer outlet hydrogen gas temperature TH to rise. Conversely, when the vaporizer outlet heat transfer medium temperature TL increases, the control unit 70 decreases the base drive duty cycle D to decrease the flow rate of the heat transfer medium through the circulation channel 30. This reduces the amount of heat exchanged between the heat transfer medium and hydrogen in the vaporizer 40, causing the vaporizer outlet hydrogen gas temperature TH to decrease. As a result, the hydrogen supply device 100 can maintain the vaporizer outlet hydrogen gas temperature TH within a predetermined range, thereby suppressing a decrease in the output of the hydrogen engine 15 due to high hydrogen gas temperature and damage to the hydrogen piping due to low hydrogen gas temperature.

[0037] Furthermore, the control unit 70 increases the correction coefficient C so that the drive duty cycle command value DS increases by the amount expected to decrease in the vaporizer outlet hydrogen gas temperature TH due to an increase in the output of the hydrogen engine 15, and decreases the correction coefficient C so that the drive duty cycle command value DS decreases by the amount expected to increase in the vaporizer outlet hydrogen gas temperature TH due to a decrease in the output of the hydrogen engine 15. This makes it possible to maintain the vaporizer outlet hydrogen gas temperature TH within a predetermined temperature range even when there are fluctuations in the output of the hydrogen engine 15 using a simple method.

[0038] In the above description, the hydrogen supply device 100 was described as supplying hydrogen gas to the hydrogen engine 15 of the hydrogen engine vehicle 200, but it is not limited to this. For example, it may also supply hydrogen gas to a fuel cell, which is a power unit mounted on the vehicle. [Explanation of symbols]

[0039] 10 Heating circuit, 15 Hydrogen engine, 16 Injector, 17 Internal flow path, 18 Start switch, 20 Heater, 21 Cooling water flow path, 22 Cooling water supply pipe, 23 Cooling water return pipe, 25 Cooling water circulation flow path, 30 Circulation flow path, 31 Heat transfer medium flow path, 32 Heat transfer medium supply pipe, 33 Heat transfer medium return pipe, 34 Circulation pump, 38 Heat transfer medium temperature sensor, 40 Vaporizer, 41 Casing, 42 Heat transfer medium inlet, 43 Heat transfer medium outlet, 45 Hydrogen tube, 50 Hydrogen circuit, 51 Liquid hydrogen tank, 52 Liquid hydrogen pump inlet pipe, 53 Liquid hydrogen pump, 54 Liquid hydrogen inlet pipe, 56 Hydrogen gas outlet pipe, 57 Pressure reducing valve, 58 Hydrogen gas temperature sensor, 59 Hydrogen gas supply pipe, 60 Engine control unit, 61, 71 CPU, 62, 72 Memory, 70 Control unit, 75 Map for calculating base drive duty cycle, 76 Map for calculating correction coefficient, 100 Hydrogen supply system, 200 Hydrogen engine vehicle.

Claims

1. A heater for heating the heat transfer medium, A vaporizer that vaporizes liquid hydrogen into hydrogen gas using the heated heat transfer medium, A circulation channel for circulating the heat transfer medium is provided between the heater and the vaporizer, A circulation pump provided in the circulation channel for pressurizing the heat transfer medium, A hydrogen supply device including a control unit for adjusting the operation of the circulation pump, The control unit, The output of the power unit to which the hydrogen gas flowing out of the vaporizer is supplied, and the temperature of the heat transfer medium flowing out of the vaporizer are input, Based on the temperature of the heat transfer medium flowing out of the vaporizer, the base drive duty cycle of the circulation pump is calculated. A correction coefficient is calculated based on the output of the aforementioned power unit. The drive duty command value is calculated by multiplying the base drive duty by the correction coefficient. The circulation pump is driven based on the calculated drive duty command value. A hydrogen supply device characterized by the following features.

2. A hydrogen supply device according to claim 1, The control unit, The base drive duty cycle is calculated such that the base drive duty cycle decreases as the temperature of the heat transfer medium flowing out of the vaporizer increases. The correction coefficient is calculated such that it increases as the output of the power unit increases. A hydrogen supply device characterized by the following features.

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