JP2019044784A - Temperature control system having gas tank - Google Patents

Abstract

To provide a temperature control system having a gas tank which suppresses the lowering of the tensile strength of a resin constituting a liner by suppressing the lowering of a liner temperature resulting from the adiabatic expansion of a gas at the discharge of the gas, and as a result, can prevent the damage of the liner.SOLUTION: A temperature control system 1 having a gas tank 10 comprises the gas tank 10 which is coated with a carbon fiber reinforced resin 14 at an outer face of a resin-made liner 11 which is filled with a gas. The temperature control system 1 further comprises: a pair of electrode parts 31, 31 which are arranged at the carbon fiber reinforced resin 14 so that a current flows to the carbon fiber reinforced resin 14; a power supply part 32 for carrying a current between a pair of the electrode parts 31, 31; a temperature measurement part 33 for measuring a temperature of the gas in the gas tank; and a control part 34 for controlling the power supply part 32 so that the current is carried between a pair of the electrode parts 31, 31 when the gas temperature measured by the temperature measurement part 33 reaches a prescribed temperature or lower.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a temperature control system provided with a gas tank.

  For example, the following gas tanks have been proposed as gas tanks filled with gas at high pressure. This gas tank is made of a liner filled with resin gas, a reinforcing layer made of carbon fiber reinforced resin formed on the outer surface of the liner, and a fiber reinforced resin such as glass fiber formed on the surface of the reinforcing layer (See, for example, Patent Document 1).

JP, 2017-72244, A

  However, in the gas tank described above, when the gas filled in the tank is released, the adiabatic expansion of the gas lowers the temperature inside the tank. Since the liner is coated with a carbon fiber reinforced resin layer (hereinafter, "CFRP layer"), the thermal conductivity with the outside of the tank is low, and the lowered gas temperature is maintained at a low temperature. Exposure of the liner to such low temperature gases lowers the temperature of the liner, which causes a gap to be formed between the liner and the CFRP layer as the liner shrinks.

  When the gas tank is filled with gas in such a state that a gap is formed, the gas pressure acts on the liner before the temperature rise of the gas by adiabatic compression (that is, before the temperature rise of the liner). . The tensile strength of the resin constituting the liner decreases as the temperature decreases. Therefore, if there is a gap between the liner and the CFRP layer, the liner is subjected to gas pressure only by the liner, and it is assumed that the liner is damaged.

  In the present invention, by suppressing the decrease in liner temperature caused by the adiabatic expansion of gas at the time of gas release, it is possible to suppress the decrease in tensile strength of the resin that constitutes the liner, and as a result, prevent the liner from being damaged. To provide a temperature control system.

  In order to solve the above problems, a temperature control system comprising a gas tank according to the present invention comprises a gas tank in which a carbon fiber reinforced resin layer is coated on the outer surface of a resin liner filled with gas. It is. The temperature control system includes a pair of electrode units disposed on the carbon fiber reinforced resin layer, and a power supply unit configured to apply the current between the pair of electrode units so that the current flows through the carbon fiber reinforced resin layer. A temperature measurement unit that measures the gas temperature in the gas tank, and a current is supplied between the pair of electrode units when the gas temperature measured by the temperature measurement unit becomes equal to or lower than a predetermined temperature And a control unit configured to control the power supply unit.

  According to the present invention, when the gas temperature in the gas tank becomes equal to or lower than the predetermined temperature, the carbon fiber reinforced resin layer is formed by supplying a current between the pair of electrode parts disposed in the carbon fiber reinforced resin layer. It can cause fever. Thus, the liner whose outer surface is covered with the carbon fiber reinforced resin layer can be heated, so that it is possible to suppress the decrease in liner temperature caused by the decrease in gas temperature due to the adiabatic expansion of the gas at the time of gas release. For this reason, the reduction in the tensile strength of the resin constituting the liner can be suppressed, so that even if a gap is formed between the liner and the CFRP layer, damage to the liner when the gas tank is filled with gas can be prevented.

It is a figure explaining a typical composition of a temperature control system provided with a gas tank concerning this embodiment. (A) is a typical expanded sectional view near the 1st nozzle of a gas tank shown in FIG. (B) is a typical expanded sectional view of the 2nd nozzle cap vicinity of a gas tank shown in FIG. (A) is a graph which shows the change of the gas pressure at the time of the gas discharge which concerns on this embodiment and the conventional gas tank. (B) is a graph which shows change of gas temperature of a gas tank in the case of performing temperature control concerning this embodiment, and change of gas temperature of the conventional gas tank which does not perform temperature control. It is a flowchart which shows the temperature control process which concerns on the temperature control system provided with the gas tank of this embodiment.

  An embodiment according to the present invention will be described below with reference to FIGS.

1. Configuration of Temperature Control System 1 Having Gas Tank 10 FIG. 1 is a view for explaining a schematic configuration of the temperature control system 1 having the gas tank 10 according to the present embodiment. In the drawing, the gas tank 10 shows a side cross-sectional structure in which the gas tank 10 is cut along a plane including the central axis CX in the longitudinal direction, and the gas tank 10 is fitted in the opening of the first mouthpiece 12. The part is shown in cross section. Further, (a) and (b) of FIG. 2 are schematic enlarged cross-sectional views in the vicinity of the first base 12 and the second base 13, respectively.

  As shown in FIG. 1, the temperature control system 1 according to the present embodiment includes at least a gas tank 10. Such a temperature control system 1 can be used for a fuel cell system provided with the gas tank 10, a vehicle equipped with the fuel cell system, or the like.

1-1. Gas Tank 10 The gas tank 10 is a hollow container centered on the central axis CX, and is a hydrogen gas, and various compressed gases such as CNG (compressed natural gas), LNG (liquefied natural gas), LPG (liquefied petroleum gas) Etc., and other various pressurized substances.

  The gas tank 10 is configured such that the outer surface of the liner 11 is coated with a CFRP layer (carbon fiber reinforced resin layer) 14, and a first base 12 and a second base 13 are provided at both ends thereof. The liner 11 is made of a resin having appropriate gas barrier properties. A thermoplastic resin or a thermosetting resin can be used as a resin material. The liner 11 includes a cylindrical tubular portion 11b and spherical dome portions 11a and 11a on both sides in the direction along the central axis CX, and includes an internal space 15 for storing gas.

  As shown in FIGS. 1 and 2, the CFRP layer 14 includes a hoop layer 14a covering the outer surface of the liner 11 and the outer surface near the inner space 15 side of the first base 12, and a helix covering the outer surface of the hoop layer 14a. And a layer 14b. The hoop layer 14a is a layer wound around the circumference of the liner 11, while the helical layer 14b is placed on the hoop layer 14a along the central axis CX from the one dome portion 11a side to the other dome portion It is a layer wound over 11a side. The hoop layer 14a and the helical layer 14b are layers in which a carbon fiber is oriented as a reinforcing fiber and a thermosetting resin or a thermoplastic resin is impregnated as a matrix resin for bonding the carbon fiber.

  The first mouthpiece 12 and the second mouthpiece 13 are formed of a metal such as aluminum or an alloy thereof, and provided on the dome portions 11 a and 11 a of the liner 11 respectively. The opening of the first mouthpiece 12 communicates with the internal space 15 of the gas tank 10, and a valve 20 for discharging and flowing the gas is attached to the opening. On the other hand, the opening of the second base 13 is shielded from the inner space 15, and the second base 13 seals the inner space 15.

  The valve 20 is provided with a solenoid valve (not shown) for releasing and flowing gas. Further, the valve 20 is provided with a nozzle 22 extending from the valve 20 in the direction of the internal space 15. The nozzle 22 is connected to the gas discharge port 21 via a pipe in the valve 20, and discharges the gas stored in the internal space 15 to the outside. Note that the gas discharge port 21 may be used as a gas filling port for filling the gas into the internal space 15 after gas release, or even if a separate gas filling system flow path for filling the gas into the valve 20 is provided. good.

Here, with reference to FIGS. 3A and 3B, first, the gas pressure and temperature change of the conventional gas tank 10 at the time of gas release will be described.
FIG. 3A is a graph showing a change in gas pressure at the time of gas release according to the present embodiment and the conventional gas tank 10. In this graph, the X axis and the Y axis respectively indicate the release time of the gas filled in the internal space 15 and its pressure.

  FIG. 3B is a graph showing a change in gas temperature of the gas tank 10 when temperature control is performed according to the present embodiment and a change in gas temperature of the conventional gas tank 10 without temperature control. In this graph, the X axis and the Y axis respectively indicate the release time of the gas filled in the internal space 15 and its pressure. The solid line L1 and the broken line L2 are graphs of the gas temperature when temperature control is performed and when the temperature control is not performed, respectively, and from time 0 to time T1 shown in FIG. And overlap.

  When the gas is released from the gas tank 10 to the outside through the nozzle 22, the valve 20, and the gas release port 21, as shown in FIG. 3A, the gas release start time (time 0) to the gas release completion time The gas pressure gradually decreases until (time T2).

  With the adiabatic expansion of the gas in the gas tank 10 caused by such a decrease in gas pressure, as shown by the broken line L2 in FIG. 3B, in the conventional gas tank, the gas is released from the gas release start time (time 0) The temperature also begins to fall. While the tensile strength of resin which comprises the liner 11 falls with the fall of gas temperature, the liner 11 shrink | contracts and a clearance gap will be formed between the liner 11 and the CFRP layer 14. As a result, when the gas tank 10 is filled with the gas again in a short time after the discharge is completed, the liner 11 directly receives the gas pressure before the temperature rise of the gas due to the adiabatic expansion, and the liner 11 is damaged. .

  In particular, when the gas temperature is lower than the glass transition temperature (Tg) of the resin that constitutes the liner 11, the liner 11 tends to become brittle and the possibility of breakage of the liner 11 further increases.

  Therefore, the temperature control system 1 according to the present embodiment includes the pair of electrode units 31 and 31, the power supply unit 32, and the temperature measurement unit in order to perform temperature control described later in order to avoid such damage to the liner 11. And 33 and a control unit 34. Below, the detail of each part is demonstrated.

1-2. About a pair of electrode parts 31 and 31 In this embodiment, a pair of electrode parts 31 and 31 are arranged on the CFRP layer 14 so that current flows in the CFRP layer 14. As shown in FIGS. 2A and 2B, the pair of electrode portions 31, 31 is preferably disposed inside the helical layer 14b. In the helical layer 14b, since carbon reinforced fibers are wound so as to pass the carbon reinforced fiber on both sides of the liner 11, providing the respective electrode portions 31 on the helical layer 14b enables the liner to be energized when the power supply unit 32 described later is energized. The whole of 11 can be heated more uniformly.

  In the present embodiment, one electrode portion 31 of the pair of electrode portions 31 is disposed on the helical layer 14 b in the vicinity of the first mouthpiece 12 and along the first mouthpiece 12 on the outer surface of the gas tank 10. Exposed (see Fig. 2 (a)). On the other hand, the other electrode portion 31 is disposed on the helical layer 14b in the vicinity of the second mouthpiece 13 and exposed along the second mouthpiece 13 on the outer surface of the gas tank 10 (see FIG. 2B) .

  Although not shown in the drawings, the surface of the first base 12 has an insulating layer formed by alumite treatment. As described above, by providing the insulating layer on the surface of the first mouthpiece 12, it is possible to suppress the flow of current from the first mouthpiece 12 to the solenoid valve of the valve 20 through the piping in the valve 20, Malfunctions and the like can be avoided.

  The positions of the pair of electrode portions 31 disposed in the tank 10 may be any positions at which the liner 11 can be sufficiently heated by causing the CFRP layer 14 to generate heat, as shown in FIGS. 2 (a) and 2 (b). It is not limited to the position.

1-3. Regarding the Power Supply Unit 32 In the present embodiment, the power supply unit 32 receives a control signal from the control unit 34 to perform current conduction or non-current conduction between the pair of electrode units 31. When the power supply unit 32 performs this energization, the current flows to the carbon fibers of the CFRP layer 14 and the carbon fibers generate heat, and as a result, the CFRP layer 14 generates heat. Thereby, the liner 11 can be heated. The power supply unit 32 may be either a DC power supply or an AC power supply as long as it can generate heat in the CFRP layer 14.

  The magnitude of the current to be supplied is preferably determined in consideration of the energy radiated to the outside of the CFRP layer 14, the energy for heating the CFRP layer 14, and the energy for heating the liner 11. . Here, the energy for heating the liner 11 is preferably energy that compensates for the temperature decrease of the liner 11 due to the gas temperature decrease due to the adiabatic expansion so as not to pass a current of excessive magnitude.

1-4. About Temperature Measurement Unit 33 The temperature measurement unit 33 is a sensor that detects the gas temperature in the gas tank 10, and transmits a signal of the detected temperature to the control unit 34. In the present embodiment, a temperature sensor is disposed on the side of the internal space 15 of the valve 20 as the temperature measurement unit 33. Thus, it is possible to constantly detect the temperature that changes in accordance with the released gas. In addition, the position which arrange | positions the temperature measurement part 33 will not be specifically limited if it is a position which can always detect the temperature of the gas of the internal space 15. FIG.

1-5. Regarding Control Unit 34 Based on the gas temperature acquired from the temperature measurement unit 33, the control unit 34 performs energization control or non-energization control on the power supply unit 32. In the present embodiment, when the control unit 34 determines that the gas temperature is equal to or lower than a predetermined temperature (preset temperature set in advance), the control unit 34 outputs a control signal to the power supply unit 32 to make the power supply unit 32 a pair. The power supply unit 32 is controlled so that a current flows between the electrode units 31.

  On the other hand, when the control unit 34 determines that the gas temperature exceeds the predetermined temperature, the control unit 34 outputs a control signal to the power supply unit 32 so that the power supply unit 32 generates a current between the pair of electrode units 31. The power supply unit 32 is controlled so as not to supply power.

  Here, the set temperature is preferably a temperature equal to or higher than the Tg of the resin constituting the liner 11. Thereby, in the control part 34 mentioned later, the temperature of the liner 11 can start electricity supply at the temperature more than Tg. As a result, heating can be performed before the temperature of the liner 11 falls below Tg, and this can be maintained, so damage to the liner 11 caused by the tensile strength of the resin constituting the liner 11 can be avoided more preferably.

  The control unit 34 includes, as hardware, a storage device (not shown) such as a RAM and a ROM, and an arithmetic device (not shown) such as a CPU. For example, the storage device stores the set temperature by inputting the set temperature described above via an input device such as a keyboard. The arithmetic device compares, for example, the set temperature stored in the storage device as software with the magnitude of the gas temperature measured by the temperature measurement unit 33, and the power supply unit 32 supplies power based on the measured gas temperature or the like. The magnitude of the current or the like is calculated, and this is output to the power supply unit 32 as a control signal.

2. Regarding Temperature Control Processing According to the Present Embodiment Based on the configuration of the present embodiment described above, the flow of temperature control processing according to the temperature control system 1 including the gas tank 10 of the present embodiment will be described with reference to FIG. . FIG. 4 is a flowchart showing temperature control processing according to the temperature control system 1 including the gas tank 10 of the present embodiment. Hereinafter, description will be made along each step of FIG.

  In step S1 shown in FIG. 4, the gas filled in the internal space 15 is discharged to the outside through the nozzle 22, the piping of the valve 20, and the gas discharge port 21. Next, the process proceeds to step S2.

  In step S2, the control unit 34 acquires the gas temperature from the temperature measurement unit 33 which constantly detects the gas temperature, and determines whether the acquired gas temperature is equal to or lower than a set temperature (predetermined temperature). If the control unit 34 determines that the set temperature is exceeded, the process proceeds to step S3. If the control unit 34 determines that the set temperature is equal to or less than the set temperature, the process proceeds to step S4.

  In step S <b> 3, the control unit 34 outputs a control signal of non-energization to the pair of electrode units 31, 31 to the power supply unit 32. Specifically, when the energization control by the power supply unit 32 has already been performed on the pair of electrode units 31, the control signal for stopping (terminating) the energization is sent to the power supply unit 32 in step S3. Output. When the power supply unit 32 has already stopped the energization, the control signal is output to the power supply unit 32 so as to continue the non-energization. The power supply unit 32 to which the control signal is input does not energize the pair of electrode units 31. When step S3 is completed, the process returns to step S2.

  In step S4, the control unit 34 outputs, to the power supply unit 32, a control signal for energizing the pair of electrode units 31, 31. Specifically, when the power supply unit 32 does not energize the pair of electrode units 31, 31, in step S3, a control signal to execute (start) the energization is output to the power supply unit 32. Do. When the power supply unit 32 has already performed (started) the energization, the control signal is output to the power supply unit 32 so as to continue the energization. The power supply unit 32 to which the control signal is input passes a current to the pair of electrode units 31. When step S4 is completed, the process returns to step S2. The above-described flow may be ended after the gas release is completed.

3. Operation and Effect of this Embodiment The operation and effect of this embodiment will be described with reference to FIGS. 3 (a) and 3 (b). Here, a temperature equal to or higher than the Tg of the resin of the liner 11 will be described as a set temperature determined by the control unit 34.

  As shown in FIG. 3A, when the gas is released from the gas tank 10 to the outside through the nozzle 22, the valve 20, and the gas discharge port 21 (see step S1), the release of the gas is started (time 0). The gas pressure gradually decreases from the time t2 to the time t2 when the gas release is completed.

  In FIG. 3B, as indicated by a solid line L1, which is a graph of the present embodiment in which temperature control is performed, the gas temperature also starts to gradually decrease due to the adiabatic expansion of the gas caused by the gas pressure drop. Before reaching the set temperature (before time T1), the control unit 34 determines that the gas temperature acquired from the temperature measurement unit 33 exceeds the set temperature, and performs non-energization control on the power supply unit 32. As a result, the power supply unit 32 does not energize the pair of electrode units 31 (see step S2 and step S3 in FIG. 4). Therefore, until the time T1, the temperature of the liner 11 continues to decrease as the gas temperature decreases.

  At time T1 at which the gas temperature reaches the set temperature, the control unit 34 determines that the gas temperature detected by the temperature measurement unit 33 is equal to or lower than the set temperature, and controls the power supply unit 32 to be energized. Thereby, the power supply unit 32 energizes the pair of electrode units 31 with a current of a predetermined magnitude (see step S2 and step S4 in FIG. 4). In this embodiment, by starting energization at a temperature of Tg or higher, the CFRP layer 14 starts to be heated before the temperature of the liner 11 becomes lower than the Tg, and then the liner 11 starts to be heated.

  After time T1, the gas temperature lower than the set temperature continues until the gas release completion time (time T2), so the control unit 34 continues the energization control by the power supply unit 32, and the power supply unit 32 transmits the pair of electrode units 31, 31. The current supply of a predetermined magnitude is continued.

  As a result, when the gas temperature in the gas tank 10 becomes equal to or lower than the set temperature, a current flows in the carbon fiber by supplying a current between the pair of electrode parts 31 disposed in the CFRP layer 14 , And the CFRP layer 14 can generate heat.

  Thereby, since the liner 11 can be heated by the heat generation of the CFRP layer 14, it is possible to suppress the decrease in the temperature of the liner 11 caused by the decrease in the gas temperature due to the adiabatic expansion of the gas at the time of gas release. For this reason, by suppressing the reduction in the tensile strength of the resin constituting the liner 11, even if a gap is formed between the liner 11 and the CFRP layer 14 due to the thermal contraction of the liner 11, gas release After completion, when the gas tank 10 is filled with gas again, damage to the liner 11 due to gas pressure can be prevented.

  As mentioned above, although one embodiment of the present invention was explained in full detail, the present invention is not limited to the above-mentioned embodiment, It is a range which does not deviate from the spirit of the present invention indicated in a claim. It is possible to make design changes.

  For example, the temperature measurement unit 33 is not limited to one that detects temperature, such as a temperature sensor, and may estimate temperature. Specifically, the temperature measurement unit 33 may detect the amount of released gas with a gas flow meter to estimate the gas temperature in the gas tank 10, and measure the gas pressure in the gas tank 10 with a gas pressure measuring device. Then, the gas temperature may be estimated from the pressure in the gas tank 10 as shown in FIG. 3 (a).

1: Temperature control system 10: Gas tank 11: Liner 14: CFRP layer (carbon fiber reinforced resin layer) 31: electrode unit 32: power supply unit 33: temperature measurement unit 34: control unit

Claims (1)

A temperature control system comprising a gas tank having a carbon fiber reinforced resin layer coated on the outer surface of a gas-filled resin liner,
The temperature control system includes a pair of electrode portions disposed on the carbon fiber reinforced resin layer such that current flows through the carbon fiber reinforced resin layer;
A power supply unit for supplying the current between the pair of electrode units;
A temperature measurement unit that measures the gas temperature in the gas tank;
Further comprising: a control unit that controls the power supply unit so that current flows between the pair of electrode units when the gas temperature measured by the temperature measurement unit becomes lower than or equal to a predetermined temperature. A temperature control system with a gas tank that is characterized.

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