Gas filling method

Abstract

The present invention provides a gas filling method capable of filling gas under optimized filling conditions to minimize waste in terms of filling time and precooler power consumption. The gas filling method includes the following steps: an effective thermal mass calculation step, which uses the heat capacity of the pipe and the detection value of the pipe temperature sensor before starting gas filling to calculate the value of the effective thermal mass related to the temporary pressure loss generated in the pipe; a pressure loss parameter calculation step, which uses the detection value of the pressure sensor when the flow rate of gas in the pipe changes after starting gas filling to calculate the value of a pressure loss parameter related to the pressure loss generated in the pipe; and a filling condition changing step, which changes the filling condition to a condition specified based on the value of the pressure loss parameter and continues filling gas.

Description

Technical Field

[0001] The present invention relates to a gas filling method, and more particularly to a gas filling method comprising connecting a compressed gas supply source to a tank mounted on a mobile object using piping, and filling the gas into the tank of the mobile object. Background Art

[0002] In recent years, with the restrictions imposed by vehicle emissions regulations and CO2 / fuel efficiency regulations, there is a need to simultaneously clean engine exhaust and improve fuel efficiency. Strengthening the construction of safe cities and human settlements in all countries is crucial to enhancing inclusive and sustainable urban development and sustainable human settlement planning and management capabilities. Therefore, all countries need to strengthen the provision of safe, affordable, accessible, and sustainable transportation systems for all, improve road safety, particularly by expanding public transportation, and reduce the negative per capita environmental impact of cities, including by paying special attention to air quality and urban waste management. In the transportation sector, and in the vehicle manufacturing sector, there is an urgent need to take measures to address environmental issues and develop technologies that can increase the rate of improvement in global energy efficiency.

[0003] Fuel cell vehicles are driven by supplying oxygen-containing air and fuel gas, namely hydrogen, to a fuel cell, and using the electricity generated thereby to drive an electric motor. In recent years, fuel cell vehicles that use such fuel cells as an energy source for generating power have begun to be used in practice. Fuel cell power generation requires hydrogen, but in recent years, the mainstream fuel cell vehicle is to store a sufficient amount of hydrogen in a hydrogen tank with a high-pressure tank or storage alloy in advance and use the hydrogen in the tank for driving. In addition, correspondingly, many studies have been conducted on filling technology that can quickly fill a tank with as much hydrogen as possible at a hydrogen station.

[0004] Hydrogen generates heat within the tank due to compression. Therefore, in recent years, the mainstream technology for suppressing the temperature rise within the tank during hydrogen filling has been to use a precooler installed in the hydrogen flow path to cool the hydrogen to, for example, around -40°C. This lowering of the hydrogen temperature by the precooler also suppresses the temperature rise within the tank, allowing hydrogen filling to be accelerated accordingly.

[0005] For example, non-patent document 1 shows a filling method in which hydrogen can be filled while the pressure increase rate during filling is changed based on a specific formula. In the filling method described in non-patent document 1, a polynomial of a temperature parameter obtained by mass averaging the detection value of a temperature sensor provided on the downstream side of a precooler in a hydrogen flow channel is used to express the formula for specifying the pressure increase rate, and the values of the coefficients of each order of the temperature parameter are determined based on a map (see non-patent document 1). Furthermore, in the filling method described in non-patent document 1, a plurality of such maps are prepared, and a suitable map corresponding to the tank capacity and the initial pressure of the tank is selected from these plurality of maps, and the values of the aforementioned plurality of coefficients are determined using the selected map.

[0006] [Prior art literature]

[0007] [Non-Patent Document 1] Kei Hanta, Steve Mathison, Development of the MC Formula Hydrogen Filling System for FCVs, Preliminary Speech for the 2015 Autumn Conference of the Automotive Engineering Society

[0008] [Non-Patent Document 2] SAE J2601-2020, Fueling Protocols for Light Duty Gaseous Hydrogen Surface Vehicles Summary of the Invention

[0009] [Problems to be solved by the invention]

[0010] However, when filling hydrogen, as hydrogen flows through the piping connecting the hydrogen station's accumulator to the vehicle's hydrogen tank, significant pressure loss occurs, and the temperature of the hydrogen in the tank also rises accordingly. Therefore, in the aforementioned filling method, the image used to determine the pressure increase rate is constructed in anticipation of this pressure loss. Furthermore, the actual pressure loss incurred during filling varies depending on various factors, such as the shape of the piping at the station, the shape of the piping on the vehicle, and the condition of the dust filter inserted into the piping. However, with existing filling methods, it is impossible to estimate the actual pressure loss incurred during hydrogen filling. Therefore, the multiple images used to determine the pressure increase rate, as described above, are constructed based on the assumption that the largest pressure loss will occur.

[0011] As a result, conventional filling methods use a worst-case pressure loss assumption, resulting in wasted time and precooler set temperature. Specifically, if the pressure loss is estimated to be greater than the actual value, the filling rate is unnecessarily slowed, potentially increasing the time required to fill the hydrogen tank. Furthermore, using a worst-case pressure loss assumption as the pressure loss map is equivalent to assuming the most significant gas temperature rise due to pressure loss, thus providing an excess temperature margin, which means there is room to increase the precooler set temperature.

[0012] Furthermore, existing gas filling methods at hydrogen stations take into account various worst-case scenarios when filling fuel cell vehicles with hydrogen for fuel cell power generation. For example, when the piping temperature is low, the hydrogen station's gas filling system can also provide consumers with options for faster filling, such as using a cold dispenser.

[0013] Because various worst-case scenarios can coexist, margins (e.g., excess temperature margins) are often set higher than necessary. This forces slower filling rates or excessive hydrogen precooling, leading to wasted electricity. By utilizing appropriate technologies, unnecessary margins can be reduced and filling rates increased without compromising safety, or the margin for relaxing the precooler's set temperature can be increased.

[0014] Furthermore, in the prior art (Non-Patent Document 2), when a cold dispenser is used for filling gas, the cold dispenser does not display an accurate temperature detection position, so the control of the cold dispenser cannot be actually applied in the gas filling system.

[0015] In view of the above, an object of the present invention is to provide a gas filling method capable of filling gas under optimized filling conditions so as to reduce waste in terms of filling time and power consumption of a precooler.

[0016] [Technical means to solve the problem]

[0017] [1] In order to achieve the above-mentioned purpose, the present invention is a gas filling method, which uses a gas filling system to fill gas from a supply source into a tank, and the gas filling system comprises: a supply source storing compressed gas; a piping connecting the supply source to a tank mounted on a mobile body, and the piping is provided with a control valve, a pressure sensor, a gas temperature sensor and a flow sensor; and a control device operating the control valve under specific filling conditions and controlling the flow rate of gas flowing through the piping; the gas filling method includes the following steps: an effective thermal mass calculation step, before starting to fill the gas, using the heat capacity of the piping and the detection value of the gas temperature sensor, thereby calculating the value of the effective thermal mass related to the temporary pressure loss generated by the piping; a pressure loss parameter calculation step, after starting to fill the gas, using the detection value of the pressure sensor when the flow rate of the gas in the piping changes, thereby calculating the value of the pressure loss parameter related to the pressure loss generated by the piping; and a filling condition changing step, changing the filling condition to a condition specified based on the value of the pressure loss parameter, and continuing to fill the gas.

[0018] [2] Furthermore, in the present invention, the control device operates the control valve under the filling condition specified by a filling control image selected from a plurality of predetermined filling control images, and in the filling condition changing step, the filling control image selected by the control device is replaced by an image specified based on the value of the pressure loss parameter among the plurality of filling control images.

[0019] [3] In addition, in the present invention, in the pressure loss parameter calculation step, the value of the pressure loss parameter is calculated based on the following formula (1-1), in which "k0" is the pressure loss parameter, "dP loss " is the pressure difference in the pipe before and after the gas flow rate is reduced, "ρ" is the density of the gas in the pipe, "dm" is the mass flow rate of the gas in the pipe,

[0020] [Formula (1-1)]

[0021]

[0022] [4] Furthermore, in the present invention, the control device operates the control valve under the filling condition specified by a filling control image selected from a plurality of predetermined filling control images, and in the filling condition changing step, the filling control image selected by the control device is replaced by an image specified based on the value of the thermal mass related to the temporary pressure loss generated by the piping among the plurality of filling control images.

[0023] [5] In addition, in the present invention, in the effective thermal mass calculation step, the value of the effective thermal mass is calculated based on the following formula (1-2), in which “T tube " is the temperature detected by the gas temperature sensor, "T amb " is the atmospheric temperature, "T HE " is the heat exchanger temperature, "T amb " is the atmospheric temperature, m i " is the mass of the pipe, " Cp i " is the specific heat capacity of the pipe, "m i x Cp i " is the heat capacity of the pipe,

[0024] [Formula (1-2)]

[0025]

[0026] [6] In addition, in the present invention, in the effective thermal mass calculation step, the value of the effective thermal mass is calculated based on the following formula (1-3), in which “T tube " is the temperature detected by the gas temperature sensor, "T amb " is the atmospheric temperature, "T HE " is the heat exchanger temperature, "T amb " is the atmospheric temperature, m i " is the mass of the pipe, " Cp i " is the specific heat capacity of the pipe, "m i x Cp i " is the heat capacity of the pipe, "k0" is the pressure loss parameter,

[0027] [Formula 1-3]

[0028]

[0029] [7] Furthermore, in the present invention, in the pressure loss parameter calculation step, the detection value of the pressure sensor when the flow rate of the gas in the piping decreases from a flow rate greater than 0 to 0 or near 0 is used to calculate the value of the pressure loss parameter.

[0030] [Effects of the Invention]

[0031] Based on the above, the gas filling method of the present invention includes, among the multiple selectable filling control maps during gas filling, a map based on the thermal mass of the piping, in addition to the map based on the pressure loss parameter. Taking the thermal mass of the piping into account allows for a wider margin in the precooler's set temperature, thereby reducing precooler power consumption. Furthermore, this increased margin in the precooler's set temperature extends the life of components such as the piping and piping seals, and reduces piping and precooler specifications, thereby reducing equipment costs.

[0032] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a diagram showing the structure of a hydrogen filling system to which a hydrogen filling method according to an embodiment of the present invention is applied.

[0034] Figure 2 This is a functional block diagram showing the configuration of a control circuit for filling flow rate control implemented by a station ECU.

[0035] Figure 3A This is a diagram for explaining the order of selecting a fill control image in the image selection unit.

[0036] Figure 3B This is a diagram for explaining another order of selecting a fill control image in the image selection unit.

[0037] Figure 4 is a flowchart showing the sequence of filling hydrogen gas in the hydrogen filling system.

[0038] Figure 5 : is a flowchart showing the specific procedure of the pressure loss coefficient calculation process.

[0039] Figure 6 It is schematically shown by Figure 4 The flowchart shows the timing diagram of the hydrogen filling process.

[0040] [Explanation of Symbols]

[0041] S: Hydrogen filling system

[0042] M: Vehicle (moving object)

[0043] 8: Site ECU

[0044] 9: Hydrogen Station

[0045] 31: Hydrogen tank (tank)

[0046] 71: Flow sensor

[0047] 72: Station temperature sensor (gas temperature sensor) (pipe temperature sensor)

[0048] 73: Site pressure sensor (pressure sensor)

[0049] 74: Atmospheric temperature sensor

[0050] 75: Heat exchanger temperature sensor

[0051] 81: Mass average temperature calculation unit

[0052] 82: Pressure loss coefficient calculation section

[0053] 83: Effective thermal mass calculation department

[0054] 84: Target boost rate setting unit

[0055] 841: Image Selection Department

[0056] 842: Boost rate calculation unit

[0057] 85: Target filling pressure calculation unit

[0058] 86: Feedback Controller

[0059] 87: Filling completion judgment unit

[0060] 91: Accumulator (supply source)

[0061] 93: Site piping (piping)

[0062] 94: Shut-off valve

[0063] 95: Flow control valve (control valve)

[0064] 96: Precooler DETAILED DESCRIPTION

[0065] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0066] Figure 1 This figure shows the structure of a hydrogen filling system S to which the hydrogen filling method of this embodiment is applied. The hydrogen filling system S is composed of a hydrogen station 9 having a compressed hydrogen supply source and a fuel cell vehicle M (hereinafter referred to as "vehicle M"), wherein the hydrogen station 9 has a hydrogen tank for storing hydrogen supplied by the hydrogen station 9. The hydrogen filling method of this embodiment is a method of filling hydrogen from the hydrogen station 9 to the tank of the vehicle M, and is implemented using this hydrogen filling system S. Below, the structure of the vehicle M side is described first, and then the structure of the hydrogen station 9 side is described.

[0067] Vehicle M is a fuel cell vehicle equipped with a tank storing hydrogen gas and a fuel cell system (not shown) that generates electricity using the hydrogen gas stored in the tank and air as fuel gas. Vehicle M uses the electricity generated by the fuel cell system to drive a motor for travel. The following description focuses on the case where vehicle M is a fuel cell vehicle, but the present invention is not limited to this embodiment. The present invention is applicable to any mobile vehicle equipped with a tank storing hydrogen gas.

[0068] The vehicle M includes: a hydrogen tank 31 that stores hydrogen supplied from a hydrogen station 9; a vehicle piping 39 extending from the hydrogen tank 31; a fuel cell system (not shown) that generates electricity using the hydrogen stored in the hydrogen tank 31 and travels using the generated electricity; an infrared communicator 5 that transmits data signals related to the hydrogen tank 31 to the hydrogen station 9; and a communication algorithm ECU 6 that generates the data signals transmitted by the infrared communicator 5. The following description will focus on a vehicle M equipped with an infrared communicator 5 and a communication algorithm ECU 6, but the present invention is not limited to this. The present invention can also be applied to a vehicle M that does not include an infrared communicator 5 and a communication algorithm ECU 6.

[0069] The vehicle piping 39 includes: a socket 38 into which a filling nozzle 92 of the hydrogen station 9 described later is fitted; and a check valve 36 provided near the socket 38 in the vehicle piping 39 to prevent hydrogen gas from flowing back from the hydrogen tank 31 toward the socket 38 .

[0070] The communication and calculation ECU 6 is connected to a tank temperature sensor 41 and a tank pressure sensor 42 as a means of obtaining information related to the hydrogen tank 31. The tank temperature sensor 41 detects the temperature of the hydrogen gas in the hydrogen tank 31 and transmits a signal corresponding to the detected value to the communication and calculation ECU 6. The tank pressure sensor 42 detects the pressure in the hydrogen tank 31 and transmits a signal corresponding to the detected value to the communication and calculation ECU 6.

[0071] The communication calculation ECU 6 is a microcomputer composed of the following: an interface for performing A / D conversion on the detection signals of the above-mentioned sensors 41, 42, a CPU for executing the signal generation processing described later, a driving circuit for driving the infrared communication device 5 in the form determined by the above-mentioned processing, and a storage device for storing various data.

[0072] The storage device of the communication calculation ECU 6 stores a program for executing the data signal generation process described later, as well as unique information including the volume value of the hydrogen tank 31 installed at the time of manufacturing the vehicle M. In addition to the volume value of the hydrogen tank, this unique information also includes information related to the hydrogen tank 31 that can be identified at the time of manufacturing, such as the capacity derived from the volume value using known conversion rules and the material of the hydrogen tank.

[0073] The CPU of the communication and calculation ECU 6 starts signal generation processing, i.e., generates a signal to be transmitted from the communication device 5 to the hydrogen station 9, when, for example, the fuel lid protecting the receptacle 38 is opened. Furthermore, the CPU of the communication and calculation ECU 6 ends signal generation processing when, for example, the nozzle is removed from the receptacle 38, rendering hydrogen filling impossible.

[0074] In the signal generation process, a temperature transmission value T corresponding to the current value of the temperature in the hydrogen tank is obtained in each specific cycle. IR , the pressure transmission value P corresponding to the current value of the pressure in the hydrogen tank IR , and the volume transmission value V corresponding to the current value of the volume of the hydrogen tank IR , and generate the values ​​(T IR ,P IR ,V IR ) corresponding data signal. Temperature transmission value T IR The detection value of the tank temperature sensor 41 at this time is used. The pressure transmission value P IR The detection value of the tank pressure sensor 42 at this time is used. And the volume transmission value V IR The value recorded in the above-mentioned storage device is used.

[0075] The driving circuit of the communication calculation ECU 6 drives the infrared communication device 5 (to make it flash) according to the data signal and interrupt signal generated by the above signal generation process. As a result, the state information related to the state inside the hydrogen tank (that is, the temperature value T IR And pressure sending value P IR etc.) and inherent information (ie, volume transmission value V IR The data signal (etc.) is sent to the hydrogen station 9.

[0076] The hydrogen station 9 includes: a pressure accumulator 91 that stores hydrogen at high pressure for supply to the vehicle M; a station piping 93 that extends from the pressure accumulator 91 to a filling nozzle 92 for discharging hydrogen; a shut-off valve 94 and a flow control valve 95 that are provided on the station piping 93; and a station ECU 8 that controls these valves 94, 95.

[0077] The station ECU8 is an electronic computer that operates the shut-off valve 94 and the flow control valve 95 under specific filling conditions after the filling nozzle 92 is connected to the socket 38 provided on the vehicle M, thereby controlling the flow of hydrogen flowing through the station piping 93 and filling the high-pressure hydrogen stored in the accumulator 91 into the hydrogen tank 31 of the vehicle M.

[0078] In the hydrogen filling system S, after the filling nozzle 92 is connected to the socket 38, a pipe is formed by the part constituting the hydrogen station 9, that is, the station pipe 93, and the part constituting the vehicle M, that is, the vehicle pipe 39. As a result, the hydrogen tank 31 and the accumulator 91 mounted on the vehicle M are connected using this pipe.

[0079] A precooler (i.e., heat exchanger) 96 for cooling hydrogen gas is provided between the flow control valve 95 and the filling nozzle 92 in the station piping 93. Specifically, the precooler 96 promotes heat exchange between the refrigerant and the hydrogen gas flowing through the station piping 93. The precooler 96 cools the hydrogen gas, which has been decompressed by the flow control valve 95, to a predetermined temperature (e.g., approximately -40°C). By using this precooler 96 to cool the hydrogen gas immediately prior to filling into the hydrogen tank 31, the hydrogen gas temperature rise within the tank 31 can be suppressed, allowing for faster filling.

[0080] The station ECU 8 is connected to various sensors 71 , 72 , 73 , 74 , and 75 to grasp the state of hydrogen gas at a position immediately before filling the hydrogen tank 31 .

[0081] The flow sensor 71 is installed between the shutoff valve 94 and the flow control valve 95 in the station piping 93 , and sends a signal corresponding to the mass per unit time of hydrogen gas flowing through the station piping 93 , that is, the mass flow rate, to the station ECU 8 .

[0082] The station temperature sensor 72 is provided on the downstream side of the precooler 96 in the station piping 93 and measures the temperature of the hydrogen in the station piping 93 (which can be used as the piping temperature T tube Or site temperature T ST )The corresponding signal is sent to the station ECU8.

[0083] The station pressure sensor 73 is provided on the downstream side of the precooler 96 in the station piping 93 , and transmits a signal corresponding to the pressure of the hydrogen gas in the station piping 93 to the station ECU 8 .

[0084] The atmospheric temperature sensor 74 detects the atmospheric temperature and transmits a signal corresponding to the detected value to the station ECU 8. The atmospheric temperature detected by the atmospheric temperature sensor 74 may be regarded as the temperature of the hydrogen gas in the fuel tank of the vehicle M at the start of filling.

[0085] The heat exchanger temperature sensor 75 is installed on the downstream side of the precooler 96 in the station piping to detect the temperature of the precooler 96 and compare it with the detected value T HE The corresponding signal is sent to the station ECU 8. In addition, the temperature of the precooler 96 detected by the heat exchanger temperature sensor 75 is used as a parameter for calculating the effective thermal mass of the pipe 93.

[0086] The filling nozzle 92 is provided with an infrared communicator 98 for communicating with the vehicle M. By connecting the filling nozzle 92 to the jack 38 , the infrared communicator 98 faces the infrared communicator 5 provided on the vehicle M, and data signals can be sent and received between these communicators 98 and 5 via infrared rays.

[0087] Figure 2 : is a functional block diagram showing the structure of the control circuit of the filling flow control implemented by the station ECU 8. The station ECU 8 performs the filling flow control, that is, specifies the target pressure increase rate according to the state of the vehicle's hydrogen tank and operates the flow control valve 95 to achieve this target pressure increase rate. Figure 2 , only modules 81 to 87 in the station ECU 8 that are relevant to the implementation of this filling flow control are shown.

[0088] The mass average temperature calculation unit 81 calculates the mass average temperature MAT of the hydrogen gas after passing through the precooler 96 based on the detection values of the station temperature sensor 72 and the flow rate sensor 71. This mass average temperature MAT is used to set the target pressure increase rate in the target pressure increase rate setting unit 84. However, immediately after the start of hydrogen filling, it takes several tens of seconds for the detection value of the station temperature sensor 72 to actually reach the temperature of the gas flowing out of the precooler 96. Therefore, the mass average temperature calculation unit 81 does not use the detection value of the station temperature sensor 72 for a period of several tens of seconds (more specifically, for example, 30 seconds) after the start of filling, and instead outputs a preset value as the mass average temperature MAT.

[0089] The pressure loss coefficient calculation unit 82 calculates the pressure loss coefficient k0, which is a parameter related to the pressure loss generated in the station piping 93 and the vehicle piping 39 (hereinafter collectively referred to as "connecting piping") when hydrogen flows through these pipings. Here, pressure loss refers to the pressure difference between a specific location on the upstream side of the connecting piping (e.g., the detection location of the station pressure sensor 73) and a specific location on the downstream side (e.g., inside the hydrogen tank 31) when hydrogen flows through these connecting pipings.

[0090] Below, we explain the definition and calculation method of effective thermal mass (e.g., the thermal mass of the piping system of the gas filling system). In typical hydrogen station piping systems, efforts are made to minimize the thermal mass of the piping during design, with the designed thermal mass of the piping being a fixed value. However, as the continuous filling process lowers the temperature of the piping (e.g., when used as a cold dispenser), the amount of heat imparted to the hydrogen by the piping system decreases, and the situation thus changes moment by moment.

[0091] In this embodiment, during the gas filling process, the piping temperature sensor 72 (i.e., the station temperature sensor 72) is used to detect the temperature of the piping, that is, to detect the temperature of the flowing gas being filled. Among them, the piping temperature sensor 72 used to obtain the temperature of the piping can generally be a sensor that can also serve as a gas temperature sensor, so it is also called a gas temperature sensor 72. When a shared gas temperature sensor is not used, different sensors (gas temperature sensor and piping temperature sensor) can also be set at the most appropriate positions. After the filling is completed, the temperature of the gas inside the piping is detected, but since the thermal conductivity of hydrogen is very high, it can be almost equal to the temperature of the piping. Therefore, the temperature T of the piping detected by the gas temperature sensor 72 can be tube As the temperature of hydrogen gas, the temperature T tube The actual thermal mass value is calculated based on the temperature of the pipe at the beginning of gas filling.

[0092] In addition, the temperature T of the precooler 96 is also detected by the heat exchanger temperature sensor 75. HE , is used as the expected value of the temperature of the gas flowing in the future. tube , the heat exchanger temperature T detected by the heat exchanger temperature sensor 75 HE , atmospheric temperature T amb As a parameter, the value of the effective thermal mass of the piping system is calculated.

[0093] In other words, before gas filling begins, the effective thermal mass value related to the temporary pressure loss generated in the piping is calculated using the piping's heat capacity, the piping temperature sensor's detection value, the atmospheric temperature detection value, and the heat exchanger temperature sensor's detection value.

[0094] In this way, when gas filling is performed, in the filling condition change step, the filling control image selected by the control device can be replaced with an image specified based on a value related to the temporary pressure loss generated by the piping (that is, the value of the effective thermal mass of the piping) among multiple filling control images.

[0095] In addition, the piping system is composed of different sizes, shapes and specifications. After the gas filling is completed, the temperature of the piping system pipes changes all the time. For the temperature detection of many types of piping, it is not easy to detect the actual temperature. Therefore, in order to convert the piping temperature T detected by the gas temperature sensor 72 into the temperature of the piping system, the temperature of the piping system is changed from time to time. tube As the representative piping system temperature, the structure of the heat insulation material arranged in other piping in the piping system can be adjusted in advance so that the temperature of other components is lower than the piping temperature Ttube .

[0096] Alternatively, the temperature sensor may not directly detect the temperature of the gas, but may detect the temperature of a portion related to the temperature of the gas (for example, the temperature of the piping through which the gas circulates, and / or the temperature of the refrigerant that cools the gas in the precooler 96).

[0097] In the following formula (1), “T tube " is the temperature detected by the pipe temperature sensor, which can be measured by the gas temperature sensor 72, "T amb " is the atmospheric temperature, which can be measured using the atmospheric temperature sensor 74, "T HE " is the heat exchanger temperature, which can be measured using the heat exchanger temperature sensor 75, "T amb " is the atmospheric temperature, m i " is the mass of the pipe, which can be obtained from the specifications of the pipe, "Cp i " is the specific heat capacity of the pipe, which can be obtained from the specifications of the pipe (such as the material used to make the pipe)," m i x Cp i " is the heat capacity of the pipe, as shown in the following formula (1). However, when the temperature of each component is non-uniform, this method may not be used, for example, the value of the heat capacity actually measured may be used. Based on this, after starting the hydrogen filling, the effective thermal mass calculation unit 83 uses the hydrogen detection values of the gas temperature sensor 72 connected to the pipe, the atmospheric temperature sensor 74, and the heat exchanger temperature sensor 75 to perform the calculation shown in the following formula (1), thereby calculating the value of the effective thermal mass Heat mass.

[0098] [Formula 1]

[0099]

[0100] The following is an explanation of the definition and calculation method of the pressure loss coefficient k0. The following is only an example, and other appropriate calculation methods can also be used. The pressure loss dP generated in the flow channel of a general gas is loss , is expressed as shown in the following formula (2) using the dimensionless loss coefficient ζ, gas density ρ, and flow velocity v.

[0101] [Formula 2]

[0102]

[0103] In the above equation (2), the flow velocity v is not measured in a typical hydrogen station 9. Therefore, this flow velocity v, rewritten as the mass flow rate dm, which can be measured by the flow sensor 71, is expressed by the following equation (3). In the following equation (3), "A" is the cross-sectional area of the flow channel.

[0104] [Formula 3]

[0105]

[0106] Here, the pressure loss coefficient k0 in this embodiment is defined by the following equation (4) using the loss coefficient ζ in equations (2) and (3) and the flow channel cross-sectional area A. As shown in equation (4), the value of this pressure loss coefficient k0 is determined by the shape of the hydrogen flow channel formed in the connecting pipe. Equation (4) is merely an example of calculating the value of the pressure loss coefficient k0, and the present invention is not limited to this calculation method.

[0107] [Formula 4]

[0108]

[0109] And according to the above formulas (2) to (4), the pressure loss coefficient k0 is based on the pressure loss dP loss , gas density ρ and mass flow rate dm and is expressed by the following formula (5). As shown in the following formula (5), the larger the pressure loss coefficient k0, the greater the pressure loss dP loss And in the following formula (5), the pressure loss dP loss The calculation can be performed using the detection value of the station pressure sensor 73 when the hydrogen flow rate in the connecting pipe decreases. Furthermore, the mass flow rate dm can be measured by the flow sensor 71. Furthermore, since the gas density ρ can be expressed as a function of the pressure and temperature of the hydrogen gas, it can be calculated based on the detection values of the station temperature sensor 72 and the station pressure sensor 73. Therefore, after hydrogen filling begins, the pressure loss coefficient calculation unit 82 uses the detection values of the station pressure sensor 73 and the detection values of the flow sensor 71 when the hydrogen flow rate in the connecting pipe decreases, and performs the calculation shown in the following equation (5) to calculate the value of the pressure loss coefficient k0.

[0110] [Formula 5]

[0111]

[0112] The target pressure increase rate setting unit 84 is based on the mass average temperature MAT calculated by the mass average temperature calculation unit 81, the pressure loss coefficient k0 calculated by the pressure loss coefficient calculation unit 82, and the atmospheric temperature T detected by the atmospheric temperature sensor 74. amb , and the tank volume V of the hydrogen tank 31, etc., to set the target pressure increase rate ΔP ST, the target boost rate △P ST More specifically, the target pressure increase rate setting unit 84 uses the map selection unit 841 and the pressure increase rate calculation unit 842 to set the target pressure increase rate ΔP ST .

[0113] The storage medium of the map selection unit 841 stores a plurality of filling control maps. The filling control map sets the atmospheric temperature T amb and characterize the target boost rate △P ST The values of the multiple coefficients (a, b, c, d) of the model equation (see equation (6) described later) used when filling is associated. In other words, the filling control map is a map that specifies the filling conditions in the filling flow control.

[0114] Figure 3A This is a diagram for explaining the order of selecting the filling control image in the image selection unit 841. The filling conditions for filling the hydrogen tank as quickly as possible vary depending on the tank volume of the connected hydrogen tank and the size of the pressure loss coefficient of the connecting piping. Therefore, in this embodiment, the tank volume is divided into i stages (i is an integer greater than 2), and the pressure loss coefficient is further divided into j stages (j is an integer greater than 2). i×j filling control images M11, M12, ..., M1j, M21, M22, ..., M2j, ..., Mi1, Mi2, ..., Mij suitable for the combination of these volumes and pressure loss coefficients are pre-constructed, and these i×j filling control images are stored in the storage medium of the image selection unit 841.

[0115] Figure 3B This is a diagram for explaining another order of selecting the filling control image in the image selection unit 841. The filling conditions for filling the hydrogen tank as quickly as possible vary depending on the tank volume of the connected hydrogen tank, the pressure loss coefficient of the connecting piping, and the size of the heat capacity of the connecting piping. Therefore, in this embodiment, the tank volume is divided into i stages (i is an integer greater than 2), and the pressure loss coefficient and heat capacity are further divided into j stages (j is an integer greater than 2). i×j filling control images M11, M12, ..., M1j, M21, M22, ..., M2j, ..., Mi1, Mi2, ..., Mij suitable for these combinations of volume, pressure loss and heat capacity are pre-constructed, and these i×j filling control images are stored in the storage medium of the image selection unit 841.

[0116] Figure 3A and Figure 3B The difference is that Figure 3A is based on the pressure loss coefficient of the connecting pipes, and Figure 3BIn addition to the pressure loss coefficient of the connecting piping, the heat capacity of the connecting piping is also taken into account. For large vehicles, the pressure loss of the connecting piping will have a significant impact on the filling conditions of the hydrogen tank, but the influence of the heat capacity of the connecting piping is also present and cannot be ignored.

[0117] Therefore, for large vehicles, another embodiment is proposed in which the value of the pressure loss coefficient k0 is also taken into account in the formula (1) for calculating the effective heat mass value. When both pressure loss and heat capacity are taken into account, it is expressed as shown in the following formula (1A). For example, after starting the hydrogen filling, the effective heat mass calculation unit 83 uses the hydrogen detection values of the gas temperature sensor 72, the atmospheric temperature sensor 74, and the heat exchanger temperature sensor 75 of the connecting pipe and the value of the pressure loss coefficient to perform the calculation shown in the following formula (1A) to calculate the value of the effective heat mass value.

[0118] [Formula 1A]

[0119]

[0120] The map selection unit 841 obtains the volume V and pressure loss coefficient k0 values of the hydrogen tank 31, selects a filling control map corresponding to these volume V and pressure loss coefficient k0 values from the aforementioned i×j filling control maps, and transmits the selected filling control map to the pressure increase rate calculation unit 842. However, as the pressure loss coefficient increases, the pressure loss in the connecting piping also increases, and the temperature rise of the hydrogen gas within the piping also increases. Therefore, as the pressure loss coefficient k0 value calculated by the pressure loss coefficient calculation unit 82 increases, the map selection unit 841 selects a map that slows the filling speed to suppress the temperature rise caused by pressure loss.

[0121] As described above, in order to select an appropriate filling control map in the map selection unit 841, the value of the volume V of the hydrogen tank 31 and the value of the pressure loss coefficient k0 are required. The value of the volume V of the hydrogen tank 31 can be obtained by using, for example, the volume transmission value V transmitted by the infrared communication device 5 of the vehicle M. IR , is acquired by the image selection unit 841 immediately after filling begins. In contrast, the value of the pressure loss coefficient k0 is calculated by utilizing the period after hydrogen filling begins, when the flow rate of hydrogen gas flowing through the connecting pipe temporarily decreases, as described above. Therefore, the image selection unit 841 can only acquire the value of the pressure loss coefficient k0 after a period of time has passed since filling began.

[0122] Therefore, immediately after filling begins and when the value of the pressure loss coefficient k0 has not been acquired, the map selection unit 841 selects a filling control map based on the value of the volume V of the hydrogen tank 31 acquired by infrared communication as described above and the predetermined value of the pressure loss coefficient k0. Furthermore, in this case, the map selection unit 841 assumes an estimated value greater than the actual value of the pressure loss coefficient k0, more specifically, the maximum value within the range expected at the station in use, selects the filling control map corresponding to the value of the volume V of the hydrogen tank 31 as a temporary map, and performs filling under this temporary map.

[0123] Afterwards, if the value of the pressure loss coefficient k0 has been obtained, the map selection unit 841 selects a filling control map corresponding to the value of the pressure loss coefficient k0 as the official map, and continues filling under this official map. This allows the selection of an appropriate filling control map corresponding to the actual pressure loss, allowing the hydrogen tank 31 to be filled as quickly as possible.

[0124] The pressure increase rate calculation unit 842 uses the mass average temperature MAT and the atmospheric temperature T amb , and the filling control map selected by the map selection unit 841, perform the calculation shown in the following formula (6), thereby calculating the filling control map from the specific filling start time t ini The filling time t corresponds to the time until the specific filling end time. final .

[0125] [Formula 6]

[0126] t final =a(T amb )MAT 3 +b(T amb )MAT 2 +c(T amb )MAT+d(T amb ) (6)

[0127] In the above equation (6), the values of the four coefficients (a, b, c, d) are respectively based on the atmospheric temperature T detected by the atmospheric temperature sensor 74. amb , to retrieve the filling control map selected by the map selection unit 841 and calculate it. And the boost rate calculation unit 842 is based on the filling start time t ini To the above filling time t fiinal Then fill the hydrogen tank 31 to set the target pressure increase rate ΔP ST .

[0128] The target filling pressure calculation unit 85 uses the target pressure increase rate ΔP set by the target pressure increase rate setting unit 84. ST The detection value P of the site pressure sensor 73ST (hereinafter also referred to as "filling pressure"), thereby calculating the target filling pressure P corresponding to the target value of the filling pressure after a specific time. TRGT .

[0129] The feedback controller 86 determines the filling pressure P based on the known feedback control law. ST The target filling pressure P TRGT The indicated opening of the flow control valve is input to the drive device (not shown) of the flow control valve 95. The drive device adjusts the opening of the flow control valve 95 to achieve the indicated opening. As a result, hydrogen is filled in the hydrogen tank 31 to achieve the target pressure increase rate ΔP set by the target pressure increase rate setting unit 84. ST .

[0130] The filling completion judgment unit 87 judges whether the filling of hydrogen gas is completed. When it is judged that the filling is completed, the indicated opening is set to 0 to complete the filling of hydrogen gas. More specifically, the filling completion judgment unit 87, when the filling pressure P detected by the station pressure sensor 73 is ST When the filling exceeds a specific completion threshold value, it is determined that the hydrogen tank 31 is fully filled, and the indicated opening is set to 0 to complete the hydrogen filling.

[0131] Next, a specific procedure for filling the hydrogen tank 31 with hydrogen gas in the hydrogen filling system S described above will be described.

[0132] Figure 4 The flowchart shows the procedure of filling hydrogen gas in the hydrogen filling system S. This process starts when the filling nozzle 92 of the hydrogen station 9 is connected to the inlet 38 of the vehicle M and the vehicle M is ready for hydrogen gas filling.

[0133] In step S0, first, the station ECU 8 performs startup filling. More specifically, while the flow control valve 95 provided on the station piping 93 is tightly closed, the shut-off valve 94 provided on the upstream side thereof is opened, and the pressure in the station piping 93 is increased until the detection value of the station pressure sensor 73 provided on the downstream side of the flow control valve 95 shows a specific value, and then the shut-off valve 94 is closed. As a result, the storage interval between the flow control valve 95 and the shut-off valve 94 in the station piping 93 is filled with hydrogen in an amount corresponding to the pressure. Next, the flow control valve 95 is opened while the shut-off valve 94 is closed. As a result, the hydrogen compressed in the above-mentioned storage interval flows into the hydrogen tank 31 instantaneously, so that the inside of the hydrogen tank 31 and the inside of the station piping 93 become uniform. And in step S0, the startup filling is performed as described above, and the time of starting this startup filling is set to the filling time t determined in the above-mentioned target pressure increase rate setting unit 84. final The required filling start time t ini , but the present invention is not limited thereto.

[0134] In step S1, the station ECU 8 calculates the effective thermal mass Heat mass ( Figure 2 After calculating the effective thermal mass of the value of HM (in the figure), move to step S2 and select the appropriate image.

[0135] In step S2, the station ECU 8 uses infrared communication to obtain the value of the volume V of the hydrogen tank 31 and selects a temporary map corresponding to this value of volume V from the predetermined i×j filling control maps. In order to select the appropriate map as described above, the value of the pressure loss coefficient k0 is required in addition to the value of volume V. However, at this time, the station ECU 8 cannot obtain the value of the pressure loss coefficient k0. Therefore, as described above, the station ECU 8 assumes an estimated value greater than the actual value as the value of the pressure loss coefficient k0, more specifically, the maximum value within the range expected at the station in use, and selects the filling control map corresponding to the value of the volume V of the hydrogen tank 31 as the temporary map and sends it to the pressure increase rate calculation unit 842.

[0136] In step S3, the station ECU 8 starts the actual filling process under the filling control map selected as the temporary map in step S2. More specifically, the target pressure increase rate ΔP is set under the temporary map selected in step S2. ST , and fill with hydrogen to achieve this target pressure increase rate △P ST In step S3, the detection value of the station temperature sensor cannot be used for a period of several tens of seconds (for example, 30 seconds) after the start of formal filling. Therefore, from the start of filling to the time period mentioned above, the target pressure increase rate setting unit 84 retrieves the filling control map based on the predetermined mass average temperature MAT, thereby determining the filling time t final , and target boost rate △P ST .

[0137] In step S4 , the station ECU 8 executes a pressure loss coefficient calculation process for calculating the value of the pressure loss coefficient k0 , and then moves to step S5 .

[0138] Figure 5 : is a flowchart showing the specific procedure of the pressure loss coefficient calculation process.

[0139] First, in step S41, the station ECU 8 uses the station pressure sensor 73, the station temperature sensor 72, and the flow rate sensor 71 to obtain the pressure P in the connecting pipe immediately before the hydrogen filling is stopped in step S42 described later. ST (i) Temperature T ST (i) and the flow rate dm(i), and moves to step S42.

[0140] In step S42, the station ECU 8 temporarily stops hydrogen filling to perform a leak check to confirm any filling leaks, and then proceeds to step S43. More specifically, the station ECU 8 completely closes the shutoff valve 94, thereby temporarily stopping hydrogen filling. The following description focuses on the case where hydrogen filling is temporarily stopped while calculating the pressure loss coefficient k0, specifically reducing the hydrogen flow rate in the connecting pipe to zero. However, the present invention is not limited to this. In step S42, hydrogen filling does not need to be completely stopped. In other words, the hydrogen flow rate can be reduced to near zero.

[0141] In step S43, after the station ECU 8 stops filling hydrogen in step S42 and a specific measurement waiting time (for example, about 3 seconds) has passed, the station ECU 8 uses the station pressure sensor 73 to obtain the pressure P in the connecting pipe from the time when filling is stopped to the time when the specific waiting time has passed. ST The value of (i+n) is obtained and the process moves to step S44.

[0142] In step S44, the station ECU 8 uses the pressure P obtained before and after the flow rate of hydrogen gas in the connecting pipe is reduced from a flow rate greater than 0 to 0 as described above. ST (i) P ST The value of the pressure loss coefficient k0 is calculated by using the values of (i+n), the temperature Tst(i) and the flow rate dm(i) and the above-mentioned formula (5), and the process proceeds to step S45.

[0143] More specifically, regarding the pressure loss dP in the above formula (5), loss The value of is as shown in the following formula (7-1), from the pressure P after filling is stopped ST Subtract the pressure P before stopping from (i+n) ST (i) is used to calculate. And regarding the value of gas density ρ in the above formula (5), the pressure P is used ST (i) P ST The value of (i+n) and temperature Tst(i) is calculated by inputting the function of pressure x and temperature y, that is, the density function ρ[x, y]. More specifically, as shown in the following formula (7-2), the pressure P before the flow rate is reduced is used. ST (i) Pressure P after flow reduction ST The gas density ρ is calculated from the average value of (i+n).

[0144] [Formula 7]

[0145] dP loss =P ST (i)-P ST (i+n) (7-1)

[0146]

[0147] In step S45, the ECU 8 performs a leak check to check whether there is a filling leak, and then moves to step S46. Figure 4 Step S5.

[0148] Back to Figure 4 In step S5, the station ECU 8 selects the map corresponding to the value of the pressure loss coefficient k0 calculated in step S4 from the multiple filling control maps as the official map, and then moves on to step S6. As described above, in step S2, the station ECU 8 selects the map with the greatest pressure loss, namely, filling control map Mkj, from among the j filling control maps (Mk1, ..., Mkj) ("k" is an arbitrary integer from 1 to i) corresponding to the volume V of the hydrogen tank 31 as the temporary map. Therefore, in step S5, the station ECU 8 selects the map corresponding to the value of the pressure loss coefficient k0 from among the aforementioned j filling control maps (Mk1, ..., Mkj) as the official map. This allows the selection of an appropriate filling control map corresponding to the pressure loss in the connecting piping.

[0149] In step S6, the station ECU 8 performs the formal filling again under the filling control map selected as the formal map in step S5. More specifically, the target pressure increase rate ΔP is set under the formal map selected in step S5. ST , and fill with hydrogen to achieve this target pressure increase rate ΔP ST .

[0150] In step S7, the station ECU 8 determines whether hydrogen filling is complete, that is, whether the hydrogen tank 31 is fully filled. If the determination result in step S7 is NO, the station ECU 8 returns to step S6 and continues the actual filling process. If the determination result in step S7 is YES, the hydrogen filling process ends.

[0151] Figure 6 It is schematically shown by Figure 4 The flow chart of the hydrogen filling process is implemented in the timing diagram. Figure 6 In FIG. 1 , the solid line shows the temporal variation of the pressure detected by the site pressure sensor 73 , the dotted line shows the temporal variation of the pressure in the hydrogen tank 31 , and the single-dot chain line shows the temporal variation of the flow rate detected by the flow rate sensor 71 .

[0152] First, the station ECU 8 performs the priming filling from time t0 to t1 (refer to Figure 4 Step S1), and set the time t0 of starting pre-injection filling as the filling start time t iniAt time t1, the station ECU 8 selects a temporary image based on the volume V of the hydrogen tank 31, and during the period from time t1 to t3, the actual filling is performed under the temporary image. ST In addition, due to the pressure loss in the connecting pipe, the pressure at the detection position of the station pressure sensor 73 in the connecting pipe (at the time of hydrogen flow) is reduced during the period from time t1 to time t3. Figure 6 The solid line in the middle) is higher than the pressure in the hydrogen tank on the downstream side (in Figure 6 In the following, the time t0 at which the pre-injection filling is started is taken as the filling start time t ini After the start filling is completed, the time t1 at which the formal filling starts under the temporary image can also be set as the filling start time t ini .

[0153] Then, at time t2, the station ECU 8 obtains the pressure P in the connecting pipe immediately before the temporary stop of hydrogen filling. ST (i), flow rate dm(i) and temperature T ST (i) value, then, at time t3, the hydrogen filling is temporarily stopped to perform a leak check. Then, at time t4, the station ECU 8 obtains the pressure P in the connecting pipe again according to the elapsed measurement waiting time. ST The station ECU8 uses the pressure P obtained before and after the temporary stop of hydrogen filling at time t3. ST (i) P ST (i+n), temperature Tst(i) and flow rate dm(i), and thereby calculate the value of the pressure loss coefficient k0.

[0154] Then, at time t5, the station ECU 8 selects the filling control map as the official map based on the value of the pressure loss coefficient k0 calculated by the pressure loss coefficient calculation process between times t2 and t5, and performs official filling again using this official map. This replaces the filling control map with an appropriate map appropriate for the current state of the connected piping.

[0155] According to the hydrogen filling method of this embodiment, the following effects are achieved.

[0156] (1) Using the hydrogen filling method, before starting to fill the gas and before selecting the temporary image, the piping temperature detected by the gas temperature sensor 72 and the existing set values of the piping (such as the mass and specific heat capacity of the piping) are used to calculate the value of the effective heat mass related to the temporary pressure loss generated by the piping. In the hydrogen filling method, the effective heat mass of the piping system is taken into consideration to change the filling control image, select an appropriate temporary image, and perform the formal filling step under the temporary image. As a result, the power consumption of the precooler can be reduced. In addition, since the margin for relaxing the set temperature of the precooler is increased, the life of parts such as the piping and piping seals can be extended, and the equipment cost can be reduced by reducing the specifications of the piping and precooler. After starting to fill the hydrogen under the temporary image, the detection value of the station pressure sensor 73 when the hydrogen flow rate in the connecting piping is reduced is used to calculate the value of the pressure loss coefficient k0. In the hydrogen filling method, the detection value of the station pressure sensor 73 during a period of reduced hydrogen flow is used to accurately calculate the value of the pressure loss coefficient k0. Furthermore, the hydrogen filling method modifies the filling control map based on the calculated value of the pressure loss coefficient k0, and hydrogen filling is continued under the modified filling control map. In the hydrogen filling method, by modifying the filling control map based on the value of the pressure loss coefficient k0, the filling control map can be optimized to reduce waste in filling time and the set temperature of the precooler 96, and gas filling can be performed under this optimized filling control map.

[0157] (2) The station ECU 8 used in the hydrogen filling method selects an appropriate filling control map from a plurality of predetermined maps M11, ..., Mij, and further operates the flow control valve 95 under the filling conditions specified by the filling control map to control the flow rate of hydrogen flowing through the connecting pipe. Furthermore, in the hydrogen filling method, the filling control map selected as a temporary map by the station ECU 8 is replaced with a filling control map specified based on the value of the pressure loss coefficient k0 calculated as described above, thereby changing the filling conditions. In this way, in the hydrogen filling method, the filling control map is replaced based on the value of the pressure loss coefficient k0. Therefore, since the plurality of filling control maps predetermined in the station ECU 8 can be optimized based on the value of the pressure loss coefficient k0, the filling time can be shortened as much as possible based on the actual pressure loss, and the set temperature of the precooler 96 can be further increased.

[0158] (3) Using the hydrogen filling method, the hydrogen flow rate is used to reduce the pressure difference dP before and after loss, the gas density ρ in the pipe, and the mass flow rate dm of the gas in the connecting pipe, thereby calculating the value of the pressure loss coefficient k0 defined in the above formula (5). Therefore, using the hydrogen filling method, the value of the pressure loss coefficient k0 can be calculated by simple calculation.

[0159] (4) The hydrogen filling method calculates the pressure loss coefficient k0 using the detection value of the station pressure sensor 73 when the flow rate of hydrogen gas in the connecting pipe decreases from a flow rate greater than 0 to 0 or near 0. Therefore, the hydrogen filling method can calculate the pressure loss coefficient k0 with high accuracy and can also replace the filling control map appropriately according to the state of the connecting pipe.

[0160] While one embodiment of the present invention has been described above, the present invention is not limited thereto and the detailed structure may be appropriately modified within the scope of the gist of the present invention.

[0161] For example, in the above embodiment, the case where the pressure loss coefficient calculation process is performed by temporarily stopping the hydrogen filling to perform a leak check after the hydrogen filling is started is described (see Figure 5 ), and calculate the pressure loss dP loss and the value of the pressure loss coefficient k0, but calculate the pressure loss dP loss The timing of calculating the value of the pressure loss coefficient k0 is not limited to this. loss The timing of adjusting the value of the pressure loss coefficient k0 may be any timing, regardless of the reason, when the flow rate of hydrogen gas in the connecting pipe is temporarily reduced after the start of hydrogen filling or when it is increased after reduction.

[0162] For example, the above-mentioned leak check process is not mandatory in some countries. In such countries, leak checks are sometimes not performed during hydrogen filling, and therefore, the pressure loss dP may be calculated incorrectly. loss However, even when the leak check process is not mandatory, hydrogen filling may be temporarily stopped during the main filling period to replace the hydrogen tank on the hydrogen station 9 side. Therefore, in this case, the pressure loss dP can be calculated by using the time when the tank is replaced on the hydrogen station 9 side. loss and the value of the pressure loss coefficient k0.

[0163] In the above embodiment, for example, the following situation is described, that is, the tank volume V, the pressure loss coefficient k0 and the atmospheric temperature T amb The value of and the values of the four coefficients (a, b, c, d) are used Figure 3A and Figure 3BThe tank volume V, pressure loss coefficient k0 and atmospheric temperature T are related to each other. amb The value of and the values of the four coefficients (a, b, c, d) can also be associated using means other than mapping, more specifically, using mathematical expressions and neural networks.

[0164] In summary, the gas filling method of the present invention allows the gas filling system to be configured to calculate the effective thermal mass of the piping system using the parameters of existing components and parts (e.g., existing piping, heat exchangers, and temperature sensors) within the existing control system. This allows the effective thermal mass of the piping to be taken into account. In the step of selecting a temporary image, a map defined based on the effective thermal mass of the piping can be selected for gas filling, thereby reducing power consumption in the precooler. Furthermore, by increasing the margin for relaxing the set temperature of the precooler, the life of components such as the piping and piping seals can be extended, and equipment costs can be reduced by reducing the specifications of the piping and precooler.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gas filling method, characterized in that: Using the gas filling system, the tank is filled with gas from the supply source. The gas filling system comprises: A supply source containing compressed gas; a pipe connecting the supply source to a tank mounted on a mobile body, wherein the pipe is provided with a control valve, a pressure sensor, a gas temperature sensor, and a flow sensor; and a control device for operating the control valve under specific filling conditions and controlling the flow rate of the gas flowing through the pipe; The gas filling method comprises the following steps: an effective thermal mass calculation step of calculating a value of the effective thermal mass associated with a temporary pressure loss generated in the pipe by using the heat capacity of the pipe and a detection value of the gas temperature sensor before starting to fill the pipe with gas; a pressure loss parameter calculation step of calculating a value of a pressure loss parameter related to pressure loss generated in the pipe by using a detection value of the pressure sensor when a flow rate of gas in the pipe changes after gas filling is started; and The filling condition changing step changes the filling condition to a condition specified based on the value of the pressure loss parameter and the value of the effective thermal mass, and continues filling the gas.

2. The gas filling method according to claim 1, characterized in that: The control device operates the control valve under a filling condition specified by a filling control map selected from a plurality of predetermined filling control maps, Furthermore, in the filling condition changing step, the filling control map selected by the control device is replaced with a map defined based on the value of the pressure loss parameter among the plurality of filling control maps.

3. The gas filling method according to claim 1, characterized in that: In the pressure loss parameter calculation step, the value of the pressure loss parameter is calculated based on the following formula (1-1): In the following formula (1-1), "k0" is the pressure loss parameter, "dP loss " is the pressure difference in the pipe before and after the gas flow rate is reduced, "ρ" is the density of the gas in the pipe, "dm" is the mass flow rate of the gas in the pipe, [Formula 1-1] 4. The gas filling method according to claim 1, characterized in that: The control device operates the control valve under a filling condition specified by a filling control map selected from a plurality of predetermined filling control maps, Furthermore, in the filling condition changing step, the filling control map selected by the control device is replaced with a map defined based on the value of the thermal mass associated with the temporary pressure loss generated in the pipe, among the plurality of filling control maps.

5. The gas filling method according to claim 1, characterized in that: In the effective thermal mass calculation step, the value of the effective thermal mass is calculated based on the following formula (1-2): In the following formula (1-2), "T tube " is the temperature detected by the gas temperature sensor, "T amb " is the atmospheric temperature, "T HE " is the heat exchanger temperature, "m i " is the mass of the piping, " Cp i " is the specific heat capacity of the pipe, "m i x Cp i " is the heat capacity of the pipe, [Formula 1-2] 6. The gas filling method according to claim 5, characterized in that: In the effective thermal mass calculation step, the value of the effective thermal mass is calculated based on the following formula (1-3): In the following formula (1-3), "T tube " is the temperature detected by the gas temperature sensor, "T amb " is the atmospheric temperature, "T HE " is the heat exchanger temperature, "m i " is the mass of the piping, " Cp i " is the specific heat capacity of the pipe, "m i x Cp i " is the heat capacity of the pipe, "k0" is the pressure loss parameter, [Formula 1-3] 7. The gas filling method according to any one of claims 1 to 6, characterized in that: In the pressure loss parameter calculation step, the pressure loss parameter is calculated using a detection value of the pressure sensor when the flow rate of the gas in the pipe decreases from a flow rate greater than 0 to 0 or near 0.

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