JP2012189108A - Tank valve with injector and fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the miniaturization and weight reduction of a tank valve mounted directly on a tank.SOLUTION: A main stop valve 10 includes a body 11 which is inserted partially and fixed inside a hydrogen tank 2, a first passage 15 so formed inside the body 11 as to communicate with the inside of the hydrogen tank 2, a second passage 17 so formed inside the body 11 as to communicate with the outside of the hydrogen tank 2, a main valve 18 which communicates or shuts off the first passage 15 and the second passage 17, a spring 27 which urges the main valve 18 in the valve-closing direction, a back pressure chamber 25 which communicates with the inside of the hydrogen tank 2 to give a fluid pressure in the valve-closing direction to the main valve 18, a third passage 29 which communicates the second passage 17 with the back pressure chamber 25, and an injector 30 so arranged on the third passage 29 as to regulate the pressure of the back pressure chamber 25. The main valve 18 is opened and closed using a pressure in the first passage 15, an elastic force of the spring 27, a pressure of the back pressure chamber 25 regulated by the injector 30, and a pressure in the second passage 17.

Description

  The present invention relates to a tank valve with an injector installed directly in a tank, and a fuel cell system including a fuel tank having the tank valve.

  In a fuel cell system that generates power by supplying fuel to a fuel cell from a high-pressure fuel tank, a shut-off valve and a regulator are generally provided downstream of the fuel tank, and the high-pressure fuel gas flowing out of the fuel tank is decompressed by the regulator. The fuel cell is supplied (for example, see Patent Document 1).

  There is also known a fuel cell system that controls the flow rate of the fuel gas supplied to the fuel cell to the required gas flow rate of the fuel cell by using an injector that operates using the pressure of the high-pressure fuel gas stored in the fuel tank as an operating pressure. (For example, refer to Patent Document 2).

JP 2005-216519 A JP 2010-54035 A

  However, if the flow rate of the fuel gas is directly controlled by the injector, since the operating pressure is high, it is difficult to increase the opening area of the injector due to the pressure resistance, and the opening area must be reduced. However, since the flow rate of fuel gas that can be circulated is small in an injector having a small opening area, a large number of injectors must be arranged in parallel in order to flow a large flow rate, which disadvantageously increases the installation space for the injector. There is also a cost increase.

  In particular, when a base with an injector is attached directly to the mouth of the fuel tank, the base having a plurality of injectors becomes large. As a result, the mouth of the fuel tank, which is an opening for attaching the base, also becomes large, and there is a problem that the weight of the fuel tank itself is increased in order to ensure the pressure strength of the fuel tank.

  Therefore, the present invention provides a tank valve that can be reduced in size while using an injector, and a fuel cell system that can be reduced in size.

The tank valve with an injector according to the present invention employs the following means in order to solve the above problems.
The invention according to claim 1 includes a body (for example, a body 11 in an embodiment described later) that is partially inserted into a tank (for example, a hydrogen tank 2 in an embodiment described later) and fixed to the tank, A first passage formed in the body and communicating with the inside of the tank (for example, a first passage 15 in an embodiment described later), and a second passage formed in the body and communicating with the outside of the tank (for example, an embodiment described later). A second passage 17) in the example, a main valve (for example, a main valve 18 in an embodiment described later) disposed between the first passage and the second passage to cut off the passage, and the main valve A spring (for example, a spring 27 in an embodiment to be described later) for energizing the valve in the valve closing direction, and fluid in the valve closing direction to the main valve through the inside of the tank A back pressure chamber (for example, a back pressure chamber 25 in an embodiment described later) for applying force, and a third passage (for example, a third passage 29 in an embodiment described later) that communicates the second passage and the back pressure chamber. , 29a, 29b) and an injector (for example, an injector 30 in an embodiment to be described later) disposed on the third passage and capable of regulating the pressure in the back pressure chamber, the pressure in the first passage A tank valve with an injector that opens and closes the main valve using the elastic force of the spring, the pressure in the back pressure chamber regulated by the injector, and the pressure in the second passage ( For example, it is the main stop valve 10) in the Example mentioned later.

  The invention according to claim 2 is the invention according to claim 1, wherein the injector includes an actuator part (for example, an actuator part 37 in an embodiment described later) and a fluid discharge part (for example, a fluid discharge part in an embodiment described later). 36), disposed at an end of the body facing the inside of the tank, the fluid discharge portion disposed toward the inside of the body, and the actuator portion disposed toward the inside of the tank. It is characterized by being.

  The invention according to claim 3 is the invention according to claim 1, wherein the injector includes an actuator part (for example, an actuator part 37 in an embodiment described later) and a fluid ejection part (fluid ejection part 36). The body is disposed at an end facing the outside of the tank, the fluid discharge section is disposed toward the inside of the body, and the actuator section is disposed toward the outside of the tank. .

The fuel cell system according to the present invention employs the following means in order to solve the above problems.
The invention according to claim 4 is a fuel cell (for example, a fuel cell stack 1 in an embodiment described later) and a fuel tank (for example, a hydrogen tank 2 in an embodiment described later) for storing fuel gas supplied to the fuel cell. And a tank pressure sensor (for example, a tank pressure sensor 8 in an embodiment described later) for detecting the pressure inside the tank of the fuel tank, and a control unit (for example, a control device 100 in the embodiment described later). The fuel tank is provided with the injector-equipped tank valve according to claim 1 (for example, a main stop valve 10 in an embodiment to be described later), and the control unit determines the required power generation amount of the fuel cell and the From the tank internal pressure detected by the tank pressure sensor, the preset required power generation amount, the tank internal pressure, and the duty ratio of the injector With engaging value to determine the duty ratio of the injector is a fuel cell system and controls the duty ratio of the injector with the duty ratio.

  The invention according to claim 5 is the invention according to claim 4, further comprising a flow rate sensor (for example, a flow rate sensor 4 in an embodiment described later) for measuring the flow rate of the fuel gas supplied to the fuel cell, The control unit performs feedback control by correcting the duty ratio of the injector based on the difference between the required gas flow rate obtained from the required power generation amount of the fuel cell and the actual gas flow rate measured by the flow rate sensor. It is characterized by.

  According to the first aspect of the invention, the main valve is opened by the operation of the injector, and the flow of the required flow rate can be ensured by the main valve. Here, the operation purpose of the injector is not to secure the required flow rate by the injector itself but to adjust the pressure in the back pressure chamber to open the main valve, so that there is one injector that operates with a high fluid pressure. The tank valve can be reduced in size and weight. In addition, because the tank valve can be made smaller and lighter, the inner diameter of the tank opening, which is the tank valve mounting part, can be reduced, which is advantageous in terms of pressure resistance of the tank and the weight of the tank itself can be reduced. Can do. Further, since the injector has a function of adjusting the pressure in the second passage by adjusting the pressure in the back pressure chamber, it is possible to simplify the decompression system downstream of the second passage.

  According to the invention which concerns on Claim 2, since the internal pressure of a tank can be applied also to the actuator part of an injector, the enlargement accompanying the pressure | voltage resistant structure provision of an actuator part can be prevented.

  According to the invention of claim 3, access to the injector is facilitated, and the injector can be maintained without removing the tank valve with the injector from the tank. In addition, when an injector fails, it can be easily replaced.

  According to the invention which concerns on Claim 4, a fuel cell system can be made compact by the size reduction and weight reduction of a tank valve with an injector, and simplification of the downstream pressure reduction system accompanying the pressure regulation function of an injector. Further, the fuel gas can be supplied according to the required power generation amount by controlling the duty ratio of the injector.

  According to the invention of claim 5, the responsiveness to the required gas flow rate is improved.

It is a schematic block diagram of a fuel cell system provided with a hydrogen tank equipped with a tank valve with an injector according to the present invention. It is sectional drawing of the tank valve with an injector in Example 1 of this invention. It is a principal part expanded sectional view of the fluid discharge part of an injector. It is an enlarged view of a main valve. It is a figure which shows the relationship between a tank pressure, the exit pressure of an injector, and a gas flow rate. It is a flow characteristic figure of an injector. It is an example of the duty ratio map of an injector. It is a flowchart which shows the feedback control of the duty ratio of an injector. It is a figure explaining the effect at the time of carrying out feedback control of the duty ratio of an injector. It is sectional drawing of the tank valve with an injector in Example 2 of this invention.

Hereinafter, an embodiment of a fuel cell system including a tank valve with an injector according to the present invention and a hydrogen tank equipped with the tank valve will be described with reference to the drawings of FIGS.
<Example 1>
First, a tank valve with an injector (hereinafter abbreviated as a tank valve) and a fuel cell system according to a first embodiment of the present invention will be described with reference to the drawings of FIGS.
FIG. 1 is a schematic configuration diagram of a fuel cell system, and the fuel cell system according to the first embodiment is a mode that is mounted on a fuel cell vehicle and supplies electric power to a motor or the like as a drive source.
In FIG. 1, reference numeral 1 denotes a fuel cell stack (fuel cell) that generates electricity by being supplied with hydrogen as fuel and oxygen as oxidant. The fuel cell stack 1 is, for example, a polymer electrolyte fuel cell (PEFC), and includes a plurality of single cells in which an MEA (Membrane Electrode Assembly) is sandwiched between separators (not shown). It is configured by stacking.

The fuel cell stack 1 is supplied with hydrogen at a predetermined pressure and a predetermined flow rate from a hydrogen tank 2 that stores high-pressure hydrogen via a hydrogen supply flow path 3 and air containing oxygen via an air supply device (not shown). Is supplied at a predetermined pressure and a predetermined flow rate.
The hydrogen tank 2 has a substantially hemispherical cylindrical shape at both ends in the longitudinal direction, one end in the longitudinal direction opens, and the opening 2a is blocked by a main stop valve (tank valve with injector) 10 being attached. It is. The main stop valve 10 is a valve for communicating / blocking the inside of the hydrogen tank 2 and the hydrogen supply flow path 3. The main stop valve 10 will be described in detail later.

  The hydrogen supply flow path 3 is provided with a pressure reducing valve 5, a relief valve 6, and an intermediate pressure device 7 from the upstream side. High-pressure (for example, 35 MPa or 70 MPa) hydrogen released from the hydrogen tank 2 is reduced to a predetermined pressure (for example, 1 MPa or less) by the main stop valve 10 and the pressure reducing valve 5 and supplied to the intermediate pressure device 7. . Here, the intermediate pressure device 7 is a general term for devices arranged between the pressure reducing valve 5 and the fuel cell stack 1, and includes an ejector, a humidifier, and the like. The ejector is a device that returns the hydrogen off gas to the hydrogen supply flow path 3 in order to circulate and use the hydrogen off gas discharged from the fuel cell stack 1, and the humidifier is a device that humidifies the hydrogen supplied to the fuel cell stack 1. It is. Which device is incorporated as the intermediate pressure device 7 is determined by the overall configuration of the fuel cell system.

The main stop valve 10 is provided with a tank pressure sensor 8 for detecting the pressure in the hydrogen tank 2, and the hydrogen supply flow path 3 is provided with a pressure sensor 9 between the pressure reducing valve 5 and the relief valve 6, Between the low-pressure device 7 and the fuel cell stack 1, a flow rate sensor 4 that measures the flow rate of hydrogen gas supplied to the fuel cell stack 1 is provided.
These sensors 4, 8, 9 output an electrical signal corresponding to the detected value to the control device (control unit) 100. The control device 100 controls the duty ratio of the injector 30 of the main stop valve 10 and controls the flow rate or pressure of the hydrogen gas supplied to the fuel cell stack 1 as will be described later.

Next, the main stop valve 10 will be described in detail with reference to FIGS. 2 and 3. In the following description, the vertical direction is the vertical direction in the drawing in FIG. 2, and the horizontal direction is the horizontal direction in the drawing in FIG.
The main stop valve 10 includes a body 11 fixed to the opening 2 a of the hydrogen tank 2, and the body 11 is inserted into the hydrogen tank 2 (hereinafter referred to as an interior portion) 12, and the hydrogen tank 2. Part (hereinafter referred to as an exterior part) 13 exposed to the outside. The interior portion 12 has a cylindrical shape, and is inserted into and fixed to the circular opening 2 a of the hydrogen tank 2. The exterior part 13 is larger than the outer diameter of the interior part 12.

  A first passage 15 that communicates with the inside of the hydrogen tank 2 and a second passage 17 that communicates with the outside of the hydrogen tank 2 are formed inside the body 11. More specifically, the first passage 15 opens in the end surface 14 disposed toward the inner center of the hydrogen tank 2 in the interior portion 12. The second passage 17 opens to the right end surface 13a of the exterior portion 13, and the hydrogen supply flow path 3 is connected thereto. A main valve 18 is provided between the first passage 15 and the second passage 17 to communicate and block the passages 15 and 17.

The main valve 18 includes a cylindrical valve chamber 19 formed in the body 11 and a valve body 20 accommodated in the valve chamber 19 so as to be movable in the vertical direction.
The valve body 20 has a substantially cylindrical shape, and the upper surface 22 is formed as a convex curved surface forming a part of a spherical shell. An orifice ring 23 that forms a ring-shaped gap 28 between the valve body 20 and the inner peripheral surface of the valve chamber 19 is attached to the outer peripheral portion of the valve body 20. The orifice ring 23 moves up and down in the valve chamber 19 integrally with the valve body 20 while holding a ring-shaped gap 28 between the orifice ring 23 and the inner peripheral surface of the valve chamber 19. The valve chamber 19 is partitioned vertically by an orifice ring 23, and a high pressure chamber 24 is above the orifice ring 23 and a back pressure chamber 25 is below the orifice ring 23. The high pressure chamber 24 and the back pressure chamber 25 communicate with each other through a ring-shaped gap 28.
One end of the second passage 17 opens in the ceiling wall portion of the valve chamber 19 facing the high-pressure chamber 24, and the periphery of this opening is a valve seat 26 in which the upper surface of the valve body 20 is seated and separated.

Further, one end of the first passage 15 is opened at the upper end of the inner peripheral surface of the valve chamber 19 which is always the inner peripheral surface of the high pressure chamber 24 regardless of the vertical movement of the valve body 20. That is, the first passage 15 communicates the inside of the hydrogen tank 2 and the high pressure chamber 24 of the main valve 18, and the first passage 15 and the second passage 17 are main when the valve body 20 is separated from the valve seat 26. It communicates via the valve 18. Although not shown in FIG. 2, the tank pressure sensor 8 described above is attached so as to detect the hydrogen gas pressure in the first passage 15. Since the pressure in the hydrogen tank 2 and the gas pressure in the first passage 15 are equal, it can be said that the tank pressure sensor 8 detects the pressure in the hydrogen tank 2.
The valve body 20 is urged in a direction approaching the valve seat 26 (in other words, a valve closing direction) by a spring 27 disposed in the back pressure chamber 25.

A third passage 29 that connects the back pressure chamber 25 and the second passage 17 is formed in the body 11. Since it is sufficient that a small flow rate of hydrogen gas flows through the third passage 29, the inner diameter of the third passage 29 is smaller than the inner diameters of the first passage 15 and the second passage 17. Further, the body 11 has an injector mounting hole 50 opened in the left end surface 13 b of the exterior portion 13 that is recessed toward the inside of the body 11 and continues to the third passage 29.
An electromagnetically driven injector 30 disposed on the third passage 29 and capable of adjusting the pressure in the back pressure chamber 25 is fixed to the injector mounting hole 50. The injector 30 mainly includes a body 31, a needle valve 32, a plunger 33, a coil 34 constituting a solenoid, and a spring 35.

  The body 31 has a stepped cylindrical shape, the tip side is a small diameter fluid discharge portion 36, and the base side is a large diameter actuator portion 37, and the fluid discharge portion 36 is inserted into the small diameter hole 50a in the injector mounting hole 50 without a gap. The actuator portion 37 is inserted into the large-diameter hole 50b of the injector mounting hole 50 without a gap. That is, the injector 30 is disposed at the end of the exterior portion 13 facing the outside of the hydrogen tank 2 in the body 11 of the main stop valve 10, and the fluid discharge portion 36 is disposed inward of the body 11 (in the internal structure direction of the body 11). ), The actuator portion 37 is arranged to face outward of the hydrogen tank 2 (in a direction away from the hydrogen tank 2).

  The body 31 of the injector 30 is formed with a cylindrical valve chamber 39 and a ring-shaped coil housing portion 40 that is concentric with the valve chamber 39 and disposed outside thereof. Both the valve chamber 39 and the coil storage portion 40 open to the end surface 38 of the body 31 arranged toward the outside of the hydrogen tank 2, but the valve chamber 39 is sealed with a lid 45. The valve chamber 39 extends linearly to the vicinity of the right end of the fluid discharge portion 36, and the coil storage portion 40 extends linearly to the vicinity of the right end of the actuator portion 37. The valve chamber 39 and the coil storage part 40 are separated by a partition wall 44.

  An inlet hole 41 is formed in the outer periphery of the fluid discharge part 36, and an injection hole 42 is formed in the right end part, both of which communicate with the valve chamber 39. The inlet hole 41 is connected to the back pressure chamber 25 via a third passage (hereinafter referred to as an upstream third passage) 29 a upstream of the injector 30, and the injection hole 42 is downstream of the injector 30. Is connected to the second passage 17 through a third passage (hereinafter referred to as a downstream third passage) 29b. As shown in FIG. 3, the valve chamber 39 is provided with a taper portion 43 that is reduced in cross section as it approaches the tip near the right end of the fluid discharge portion 36, and the tip of the taper 43 is continuous with the injection hole 42. ing.

In the valve chamber 39, a needle valve 32 and a plunger 33 which are connected in series and integrated are accommodated so as to be movable in the left-right direction. As shown in FIG. 3, the tip portion of the needle valve 32 includes a tapered portion 46 whose cross section is reduced as it approaches the tip, and a rod-like pintle 47 that protrudes further forward from the tip of the tapered portion 46. . The tapered portion 46 of the needle valve 32 can be brought into contact with and separated from the tapered portion 43 of the valve chamber 39, and the upstream third passage 29 a and the downstream third passage when the tapered portion 46 comes into contact with the tapered portion 43. 29b is blocked, and when the taper portion 46 is separated from the taper portion 43, the upstream third passage 29a and the downstream third passage 29b communicate with each other. The pintle 47 is inserted into the nozzle hole 42 with a gap, and the tip of the pintle 47 is slightly forward from the nozzle hole 42 when the tapered portion 46 of the needle valve 32 contacts the tapered portion 43 of the valve chamber 39. Protruding.
The needle valve 32 and the plunger 33 are urged in a direction approaching the taper portion 43 of the valve chamber 39 (in other words, the valve closing direction) by a spring 35 accommodated in the valve chamber 39. The spring 35 is supported by a lid body 45 of the valve chamber 39.

  A coil 34 that constitutes a solenoid is disposed in the coil housing portion 40 of the actuator portion 37, and when a current is passed through the coil 34, the plunger 33 is attracted to the left by an electromagnetic attractive force, and the needle valve 32 is tapered. The upstream third passage 29a and the downstream third passage 29b communicate with each other. At this time, the inside of the hydrogen tank 2 and the second passage 17 are connected to the first passage 15, the high pressure chamber 24 of the main valve 18, the ring-shaped gap 28, the back pressure chamber 25, the third passage 29, and the valve chamber of the injector 30. 39 to communicate.

The valve opening operation of the main stop valve 10 configured as described above will be described.
When the main stop valve 10 is closed, no current flows through the coil 34 of the injector 30, so that the needle valve 32 of the injector 30 urged by the spring 35 abuts against the tapered portion 43 of the valve chamber 39, and the upstream side The third passage 29a is blocked from the downstream third passage 29b. The main valve 18 is also closed by the needle valve 20 biased by the spring 27 seated on the valve seat 26. At this time, the pressure in the hydrogen tank 2 is conducted to the back pressure chamber 25 via the first passage 15, the high pressure chamber 24 of the main valve 18, and the ring-shaped gap 28, and further via the upstream third passage 29 a. The region is electrically connected to the valve chamber 39 of the injector 30, and these regions have the same pressure as the pressure in the hydrogen tank 2 and are at a high pressure. On the other hand, since the main valve 18 and the injector 30 are closed, the pressure in the hydrogen tank 2 is not applied to the downstream side third passage 29b and the second passage 17, and the pressure is low.

  When the main stop valve 10 in the closed state is opened, a current is passed through the coil 34 of the injector 30. Then, as a result of the needle valve 32 being attracted to the left together with the plunger 33 by the electromagnetic attractive force generated by energizing the coil 34, the needle valve 32 is separated from the tapered portion 43 of the valve chamber 39, and the upstream third passage 29a communicates with the downstream third passage 29b, the hydrogen gas in the back pressure chamber 25 of the main valve 18 is discharged to the second passage 17 through the third passage 29, and the pressure in the second passage 17 rises. On the other hand, the pressure in the back pressure chamber 25 decreases due to the outflow of hydrogen gas to the second passage 17, but the back pressure chamber 25 has a ring-shaped gap 28 between the orifice ring 23 and the inner peripheral surface of the valve chamber 19. Since the hydrogen gas stored in the hydrogen tank 2 flows into the back pressure chamber 25 through the first passage 15, the high pressure chamber 24, and the gap 28, the hydrogen pressure stored in the hydrogen tank 2 flows into the back pressure chamber 25. Increase the pressure. However, since the opening area of the gap 28 is small, it is not possible to replenish all of the pressure drop in the back pressure chamber 25. As a result, the pressure P2 in the back pressure chamber 25 is smaller than the pressure P1 in the pressure chamber 24 (that is, the pressure in the hydrogen tank 2) P1 and larger than the pressure P3 in the second passage 17. (P1> P2> P3).

Based on this pressure difference, a force that pushes the valve body 20 downward acts on the valve body 20 of the main valve 18. When this force exceeds the urging force of the spring 27 in the valve closing direction, the valve body 20 The main valve 18 opens after separating from the valve seat 26.
When the main valve 18 is opened, the hydrogen gas in the hydrogen tank 2 flows from the first passage 15 to the second passage 17 via the high pressure chamber 24. The flow rate of the hydrogen gas flowing through the main valve 18 when the main valve 18 is opened is much larger than the flow rate of the hydrogen gas flowing from the back pressure chamber 25 to the second passage 17 through the injector 30.

The operating principle of the main valve 18 will be described in detail. As shown in FIG. 4, the pressure receiving area on the back pressure chamber 25 side of the valve body 20 of the main valve 18 is S1, and the pressure receiving area in the second passage 17 of the valve body 20 is Assuming S2, the main valve 18 is opened when the following inequality (1) is established. Note that F _S is the elastic force of the spring 27.
(S1-S2) · P1 + S2 · P3> S1 · P2 + F _S (1)

Then, after the valve body 20 is separated from the valve seat 26, when the following equation (2) is established, the movement of the valve body 20 in the valve opening direction is stopped, and the stroke amount of the valve body 20 is determined.
(S1−S2) · P1 + S2 · P3 = S1 · P2 + F _S (2)
Therefore, the stroke amount when the main valve 18 is opened is determined by the pressure P 1 in the hydrogen tank 2, the pressure P 2 in the back pressure chamber 25, and the pressure P 3 in the second passage 17. The opening area when the valve is opened is determined, and the flow rate of the hydrogen gas flowing through the main valve 18 is determined.

By the way, in this main stop valve 10, the pressure in the back pressure chamber 25 can be adjusted by controlling the duty ratio of the energization to the coil 34 of the injector 30. Therefore, it is possible to control the supply amount of hydrogen gas to the fuel cell stack 1 by controlling the duty ratio of energization to the coil 34 of the injector 30.
For example, when the supply amount of hydrogen gas to the fuel cell stack 1 may be small, in other words, when the consumption amount of hydrogen gas is small, the pressure of the back pressure chamber 25 is controlled by controlling the duty ratio of the injector 30 to be low. P2 is set to a value close to the pressure P1 in the hydrogen tank 2, the opening stroke of the main valve 18 is reduced (including zero), and the opening area of the main valve 18 is reduced.
On the other hand, when the supply amount of hydrogen gas to the fuel cell stack 1 is large, in other words, when the consumption amount of hydrogen gas is large, the pressure P2 of the back pressure chamber 25 is controlled by controlling the duty ratio of the injector 30 high. A value sufficiently lower than the pressure P1 in the hydrogen tank 2 is set, and the opening stroke of the main valve 18 is increased to ensure a necessary opening area.

  The hydrogen gas flow rate required for the fuel cell stack 1 (hereinafter referred to as the required flow rate) can be determined from the required power generation amount for the fuel cell stack 1, but is discharged from the fuel cell stack 1 to the outside of the system. If the hydrogen gas purge amount is added, the required flow rate of hydrogen gas can be determined more accurately.

Next, the relationship between the required flow rate of hydrogen gas, the pressure in the hydrogen tank 2 (hereinafter referred to as tank pressure) P1, and the duty ratio of the injector 30 is stored in advance in a map, and the injector is used using this map. A method for determining the duty ratio of 30 will be described.
First, the relationship between the pressure in the second passage 17 (hereinafter, abbreviated as the outlet pressure) P3 and the flow rate of the gas flowing through the main stop valve 10 is obtained for each tank pressure P1 by experiment. FIG. 5 shows an example of the relationship between the tank pressure P1, the outlet pressure P3, and the gas flow rate. When compared at the same gas flow rate, the outlet pressure P3 can be increased as the tank pressure P1 increases.

By the way, since the pressure reducing valve 5 and the intermediate pressure device 7 are provided downstream of the main stop valve 10, the outlet pressure P3 is restricted by the pressure conditions of these downstream devices. That is, the outlet pressure P3 must be between the lower limit pressure and the upper limit pressure of the downstream device. Therefore, the range of the duty ratio of the injector 30 is determined for each tank pressure P1 so as not to deviate from this pressure range.
For example, when the tank pressure P1 is high and the outlet pressure P3 sometimes exceeds the upper limit pressure when the gas flow rate is decreased, the outlet pressure P3 at the tank pressure P1 has the upper limit pressure. The gas flow rate is controlled within a range not exceeding, the gas flow rate when the outlet pressure P3 becomes equal to the upper limit pressure is set as the minimum flow rate at the tank pressure P1, and the duty ratio of the injector 30 at that time is set as the duty ratio. The lower limit value of.
Similarly, when the tank pressure P1 is low and the outlet pressure P3 may fall below the lower limit pressure when the gas flow rate is increased, the outlet pressure P3 is lower than the lower limit pressure at the tank pressure P1. The gas flow rate is controlled within a range that does not fall below, the gas flow rate when the outlet pressure P3 becomes equal to the lower limit pressure is set as the maximum flow rate at the tank pressure P1, and the duty ratio of the injector 30 at that time is set to the duty rate The upper limit of the ratio.

Next, within the duty ratio range of the injector 30 determined for each tank pressure P1 in this way, as shown in FIG. 6, it corresponds to each gas flow rate when the gas flow rate is changed for each tank pressure P1. The duty ratio of the injector 30 is measured. FIG. 6 shows an example of the relationship between the gas flow rate obtained for each tank pressure P1 and the duty ratio.
Next, based on the measurement result, as shown in FIG. 7, a duty ratio map in which the tank pressure P1, the gas flow rate, and the duty ratio of the injector 30 are associated with each other is created.

  When such a duty ratio map is stored in the control device 100, based on the tank pressure P1 detected by the tank pressure sensor 8 and the required flow rate of hydrogen gas calculated from the required power generation amount of the fuel cell stack 1, The duty ratio of the injector 30 can be determined. When the required flow rate is between the gas flow rate value and the gas flow rate value described in the duty ratio map shown in FIG. 7, the duty ratio is determined using an interpolation method or the like. Further, since the fuel cell system in the first embodiment is mounted on the fuel cell vehicle, the required power generation amount is calculated by the control device 100 based on the depression amount of an accelerator pedal (not shown).

By the way, when the duty ratio of the injector 30 is determined by using the duty ratio map of FIG. 7 based on the tank pressure P1 and the required flow rate of hydrogen gas and controlling the duty ratio of the injector 30 as shown in FIG. As shown in FIG. 9B, when the required flow rate of the hydrogen gas changes rapidly, the actual flow rate and the required flow rate of the hydrogen gas actually flowing through the main stop valve 10 as shown in FIG. A large error may occur between the flow rate. In particular, in a fuel cell system mounted on a vehicle, a sudden change in required power generation is an event that can occur more frequently due to a vehicle acceleration / deceleration request or the like. 9A is a diagram showing a change in the required flow rate and the actual flow rate, and FIG. 9B is a diagram showing a temporal change in the difference between the required flow rate and the actual flow rate, and FIG. The broken line indicates a difference of 0, and the alternate long and short dash line indicates an allowable upper and lower limit.
Accordingly, if feedback control is performed by correcting the duty ratio of the injector 30 based on the difference between the required flow rate and the actual flow rate, the responsiveness to the required flow rate can be improved.

  Next, feedback control of the duty ratio of the injector 30 will be described according to the flowchart shown in FIG. This feedback control of the duty ratio is repeatedly performed by the control device 100 at regular intervals.

  First, in step S101, based on the tank pressure P1 of the hydrogen tank 2 detected by the tank pressure sensor 8 and the required flow rate of hydrogen gas required for the fuel cell stack 1, an injector is used using the duty ratio map shown in FIG. A duty ratio command value of 30 is determined. The required flow rate of hydrogen gas is calculated based on the required power generation amount for the fuel cell stack 1.

Next, proceeding to step S102, it is determined whether or not the absolute value of the difference between the actual flow rate measured by the flow rate sensor 4 and the required flow rate exceeds a predetermined value (allowable range).
If the determination result in step S102 is “NO” (difference is within the allowable range), the duty ratio is appropriate and the process returns without correction.

On the other hand, if the determination result in step S102 is “YES” (difference is outside the allowable range), the process proceeds to step S103, the correction amount of the duty ratio is calculated, and the duty ratio command value set in step S101 is calculated. Correction is made by this correction amount, a corrected duty ratio command value (duty ratio correction command value) is determined, and the process returns.
As shown in the following equation (3), the duty ratio correction amount depends on the difference between the actual flow rate and the required flow rate, the pipe volume from the main stop valve 10 to the fuel cell stack 1, the response performance of the injector 30, and the like. It can be calculated by multiplying by a constant A determined by.
Duty ratio correction amount = A · (Actual flow rate-Required flow rate) (3)

  FIG. 9C is a diagram comparing temporal changes in the duty ratio of the injector 30 before and after correction, and FIG. 9D is a diagram showing temporal changes in the difference between the required flow rate and the actual flow rate. In FIG. 9D, the broken line indicates a difference of 0, and the alternate long and short dash line indicates an allowable upper and lower limit. When the duty ratio is corrected in this manner, the difference between the required flow rate and the actual flow rate can be kept within an allowable range even when the required flow rate of hydrogen gas changes abruptly.

  As is apparent from FIG. 5, the outlet pressure P3 decreases as the gas flow rate increases between the gas flow rate flowing through the main stop valve 10 and the outlet pressure (pressure in the second passage 17) P3. There is a correlation that the outlet pressure P3 increases as the gas flow rate decreases. Therefore, it is also possible to perform feedback control by replacing the required flow rate with the target outlet pressure, replacing the actual flow rate with the actual outlet pressure, and correcting the duty ratio of the injector 30 based on the difference between the target outlet pressure and the actual outlet pressure. is there. In that case, the process in step S102 may be replaced with whether or not the absolute value of the difference between the target outlet pressure and the actual outlet pressure exceeds a predetermined value (allowable range).

  In the main stop valve 10, the main valve 18 is opened by the operation of the injector 30, and the flow of the required flow rate can be secured by the main valve 18. Here, the operation purpose of the injector 30 is not to secure the required flow rate by the injector 30 itself, but to adjust the pressure of the back pressure chamber 25 of the main valve 18 to open the main valve 18. Only one injector 30 is required to operate with fluid pressure. Therefore, the main stop valve 10 which is a tank valve can be reduced in size and weight.

  Moreover, the internal diameter of the opening part 2a of the hydrogen tank 2 used as the attachment part of the main stop valve 10 can be made small by size reduction and weight reduction of the main stop valve 10. FIG. In particular, in the main stop valve 10 of the first embodiment, since the injector 30 is provided in the exterior portion 13 of the body 11, the interior portion 12 that is a portion inserted into the opening 2a of the hydrogen tank 2 is made to have a smaller diameter. As a result, the inner diameter of the opening 2a of the hydrogen tank 2 can be made smaller. The reduction in the diameter of the opening 2a is advantageous in terms of pressure resistance of the hydrogen tank 2, and the weight of the hydrogen tank 2 can be reduced.

  Furthermore, since the injector 30 has a function of adjusting the pressure in the second passage 17 as a result of adjusting the pressure in the back pressure chamber 25, the pressure reducing system downstream of the second passage 17 can be simplified. It becomes. Specifically, the primary pressure of the pressure reducing valve 5 can be reduced or the pressure reducing valve 5 can be reduced.

  The injector 30 is disposed at the end of the exterior portion 13 of the body 11 of the main stop valve 10, with the fluid discharge portion 36 facing inward of the body 11 and the actuator portion 37 facing outward of the hydrogen tank 2. Therefore, the injector 30 can be easily accessed, and maintenance of the injector 30 can be performed without removing the main stop valve 10 from the hydrogen tank 2. Further, it is possible to easily replace the injector 30 when it fails.

  Further, in this fuel cell system, the fuel cell system can be made compact by reducing the size and weight of the main stop valve, and simplifying the downstream pressure reducing system associated with the pressure adjusting function of the injector 30, thereby reducing the cost. Can be planned. Furthermore, the supply of fuel gas according to the required power generation amount can be realized by the duty ratio control of the injector 30. In particular, when feedback control is performed by correcting the duty ratio of the injector 30 based on the difference between the required flow rate and the actual flow rate, the responsiveness to the required flow rate can be improved.

<Example 2>
Next, a second embodiment of the tank valve with an injector of the present invention will be described with reference to the drawing of FIG.
The main stop valve (tank valve with an injector) 10 of the second embodiment is different from the main stop valve 10 of the first embodiment in the attachment position of the injector 30. In the main stop valve 10 of the first embodiment, the injector 30 is installed in the exterior portion 13 of the body 11 of the main stop valve 10. However, in the main stop valve 10 of the second embodiment, the injector 30 is the body of the main stop valve 10. 11 is installed in the interior part 12.
Hereinafter, with respect to the main stop valve 10 of the second embodiment, the same reference numerals are given to the same aspects as the main stop valve 10 of the first embodiment, the description thereof will be omitted, and differences will be described in detail.

  In the main stop valve of the second embodiment, an injector mounting hole 60 is opened in the end surface 14 of the interior portion 12 and is recessed toward the inside of the body 11. The fluid discharge portion 36 is provided in the injector mounting hole 60. Is inserted and fixed in the injector mounting hole 60 without a gap. In the second embodiment, the actuator portion 37 protrudes from the end surface 14 of the interior portion 12 into the hydrogen tank 2. That is, the injector 30 is disposed at the end of the interior portion 12 facing the inside of the hydrogen tank 2 in the body 11 of the main stop valve 10, and the actuator portion 37 is directed toward the inside of the body 11. It is arranged toward the inside of the hydrogen tank 2 (in the direction of the internal space of the hydrogen tank 2). The injector 30 is disposed on the third passage 29 and can adjust the pressure in the back pressure chamber 25 as in the first embodiment. The actuator portion 37 is set so as to fit inside the interior portion 12 in the radial direction.

  In addition, the coil storage portion 40 in the actuator portion 37 opens toward the inside of the hydrogen tank 2, and the pressure in the hydrogen tank 2 is applied to the coil storage portion 40. Therefore, the inside and outside of the actuator unit 37, in other words, the entire actuator unit 37 receives the pressure in the hydrogen tank 2. On the other hand, a pressure equal to or close to the pressure in the hydrogen tank 2 is applied to the valve chamber 39 of the injector 30 regardless of the open / closed state of the main stop valve 10. As a result, the pressure difference between the inside and outside of the actuator portion 37 can be reduced, and an increase in size associated with the provision of a pressure resistant structure of the actuator portion 37 can be prevented. Further, the thickness of the partition wall 44 that separates the coil housing portion 40 and the valve chamber 39 in the actuator portion 37 can be reduced, and the separation dimension between the coil 34 and the plunger 33 can be reduced. The suction force (thrust) can be increased. Therefore, the actuator part 37 can be reduced in size.

  And since this reduced-sized actuator part 37 is attached to the end surface 14 of the interior part 12 in the body 11 and installed so that it may fit in the radial inside of the interior part 12, it is in the hydrogen tank 2 in the main stop valve 10. The radial dimension of the portion to be inserted (that is, the interior portion 12 and the actuator portion 37) can be reduced. As a result, the inner diameter of the opening 2a of the hydrogen tank 2 that is the mounting portion of the main stop valve 10 can be reduced. Thereby, the pressure receiving area of the hydrogen gas at the opening 2a can be reduced, the screw length to be screwed into the hydrogen tank 2 is not increased, and the main stop valve 10 is reduced in size and weight. Can be planned. Further, the diameter reduction of the opening 2a of the hydrogen tank 2 is advantageous in terms of pressure resistance, and the weight of the tank itself can be reduced.

The injector 30 is disposed at the end of the interior part 12 in the body 11 of the main stop valve 10, and only the fluid discharge part 36 is accommodated in the body 11, and the actuator part 37 is accommodated in the end surface 14 of the interior part 12. Therefore, it is easy to attach the injector 30 to the body 11.
Of course, the hydrogen tank 2 having the main stop valve 10 of the second embodiment can be applied to the fuel cell system shown in FIG.

[Other Examples]
The present invention is not limited to the embodiment described above.
For example, the fuel cell system is not limited to a vehicle and may be a stationary one.
Further, the structure of the injector 30 is not limited to that of the above-described embodiment.
In the embodiment described above, the time interval is constant in the duty ratio control of the injector 30, but the time interval may be variable. If this time interval is shortened, controllability can be improved, but on the other hand, since the number of operations increases, attention must be paid to durability. Therefore, depending on the power generation state (power generation mode) of the fuel cell, for example, when the output of the fuel cell fluctuates greatly, the time interval is shortened, and when the output is stable, the time interval is lengthened to increase controllability and durability. Thus, a fuel cell system that achieves compatibility can be configured.

1 Fuel cell stack (fuel cell)
2 Hydrogen tank (tank)
4 Flow sensor 8 Tank pressure sensor 10 Main stop valve (tank valve with injector)
11 Body 15 1st passage 17 2nd passage 18 Main valve 25 Back pressure chamber 27 Spring 29, 29a, 29b 3rd passage 30 Injector 36 Fluid discharge part 37 Actuator part 100 Control device (control part)

Claims (5)

A body that is partially inserted into the tank and fixed to the tank;
A first passage formed in the body and leading to the inside of the tank;
A second passage formed in the body and leading to the outside of the tank;
A main valve disposed between the first passage and the second passage to cut off communication between the passages;
A spring for urging the main valve in the valve closing direction;
A back pressure chamber that passes through the inside of the tank and applies a fluid pressure in the valve closing direction to the main valve;
A third passage communicating the second passage and the back pressure chamber;
An injector disposed on the third passage and capable of regulating the pressure in the back pressure chamber;
The main valve is opened and closed using the pressure in the first passage, the elastic force of the spring, the pressure in the back pressure chamber regulated by the injector, and the pressure in the second passage. A tank valve with an injector.   The injector includes an actuator portion and a fluid discharge portion, and is disposed at an end portion of the body facing the inside of the tank. The fluid discharge portion is disposed toward the inside of the body. The tank valve with an injector according to claim 1, wherein the tank valve is disposed toward an inner side of the tank.   The injector includes an actuator portion and a fluid discharge portion, and is disposed at an end of the body facing the outside of the tank, the fluid discharge portion is disposed toward the inside of the body, and the actuator portion is The tank valve with an injector according to claim 1, wherein the tank valve is disposed toward the outside of the tank. A fuel cell system comprising a fuel cell, a fuel tank for storing fuel gas to be supplied to the fuel cell, a tank pressure sensor for detecting a tank internal pressure of the fuel tank, and a control unit,
The tank valve with an injector according to claim 1 is installed in the fuel tank,
The control unit uses a predetermined relationship between the required power generation amount, the tank internal pressure, and the duty ratio of the injector from the required power generation amount of the fuel cell and the tank internal pressure detected by the tank pressure sensor. Then, a duty ratio of the injector is determined, and the duty ratio of the injector is controlled by the duty ratio. A flow rate sensor for measuring a flow rate of the fuel gas supplied to the fuel cell;
The control unit performs feedback control by correcting the duty ratio of the injector based on the difference between the required gas flow rate obtained from the required power generation amount of the fuel cell and the actual gas flow rate measured by the flow rate sensor. The fuel cell system according to claim 4.

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