JP2013148197A - Gas filling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas filling system which is compact and has a high degree of flexibility in its installation, capable of efficiently cooling a fuel gas to be filled.SOLUTION: A gas filling system 1 for filling a fuel gas F into an on-vehicle tank which is mounted in a vehicle, is provided with a filling line 33 for filling the fuel gas F into the on-vehicle tank, and a cooling means to cool the filling line with a refrigerant. The cooling means has a carbon dioxide cooling section 4 that cools carbon dioxide with the refrigerant, and a gas piping cooling section 3 that cools the filling line 33 with the cooled carbon dioxide. The carbon dioxide cooling section 4 includes: a compressor 41 that compresses the gaseous refrigerant so as to produce a refrigerant of a higher temperature and pressure; a condenser 42 that liquefies the refrigerant of higher temperature and higher pressure; an expansion valve 43 that decompresses and expands the liquefied refrigerant; and an evaporator 44 that cools the carbon dioxide and liquefies it by way of a latent heat of the refrigerant.

Description

  The present invention relates to a gas filling system, and more particularly to a system for filling a vehicle-mounted tank mounted on a vehicle that travels using gas fuel.

  As vehicles that respond to environmental problems in recent years, CNG (Compressed Natural Gas), CNG vehicles using gas fuel such as hydrogen, fuel cell vehicles, hydrogen vehicles, and the like are being actively developed. In order to promote the widespread use of vehicles that run using such gas fuel, an apparatus that stably and efficiently fills the on-board tank mounted on the vehicle is required.

  Therefore, the applicant of the present invention has made it possible to preset high-pressure gas with high accuracy into a fuel tank of a vehicle that runs using gas fuel while minimizing the length of filling time and overrun as much as possible. An apparatus was proposed (see Patent Document 1).

  This high-pressure gas filling device is effective because it can suppress the lengthening of the filling time, etc., but when the fuel gas is hydrogen, heat is generated along with the high-pressure filling, and the filling efficiency to the vehicle is improved. There is a problem of lowering.

  Therefore, the present applicant has proposed a system for cooling the gas fuel flowing in the pipe for filling the fuel gas. This system includes a refrigerator and a gas filling device in which an antifreeze liquid tank that is a cooling device for cooling a pipe is provided, supplies refrigerant from the refrigerator to the antifreeze liquid tank, and The tank is filled while cooling the fuel gas with antifreeze.

  Further, the antifreeze liquid tank is provided with a stirring device such as a motor, and by stirring the antifreeze liquid inside the antifreeze liquid tank and making the temperature uniform, the gas fuel flowing in the pipe can be efficiently cooled. .

JP 2005-337439 A

  However, in the conventional gas filling system, since the antifreeze liquid tank which is a cooling device is provided in the gas filling device, there is a problem that the device itself becomes large and the installation place is limited.

  In addition, when the gas pipe is cooled by the antifreeze liquid, the viscosity of the antifreeze liquid is high, so that a stirring device for stirring is necessary. In this case, there is a problem that heat exchange efficiency is low, the gas piping to be cooled needs to be longer, and the apparatus may be increased in size.

  Furthermore, in the conventional gas filling system, the antifreeze liquid tank can be installed separately from the gas filling device. In this case, the diameter of the pipe is increased to circulate the antifreeze liquid having a high viscosity, There was a problem that it was necessary to provide a refrigerator in the vicinity of the filling device.

  Therefore, the present invention has been made in view of the above-described problems in the prior art, and is a gas filling system that is compact, has a high degree of freedom in installation, and can efficiently cool and fill fuel gas. The purpose is to provide.

  In order to achieve the above object, the present invention provides a gas filling system for filling an on-vehicle tank mounted on a vehicle with fuel gas, the filling line for filling the on-vehicle tank with the fuel gas, and the filling line. And a cooling means for cooling the liquid with a refrigerant.

  According to the present invention, the filling line for filling the on-vehicle tank with the fuel gas is cooled by the refrigerant, so that heat generation due to high-pressure filling is suppressed and the fuel gas is efficiently filled into the vehicle. Is possible.

  In the gas filling system, the cooling means includes a carbon dioxide cooling section that cools and liquefies carbon dioxide with a refrigerator, and a gas pipe cooling section that cools the filling line with the cooled and liquefied carbon dioxide. The carbon cooling section compresses the gaseous refrigerant to generate a higher-temperature and higher-pressure refrigerant, a condenser that liquefies the higher-temperature and high-pressure refrigerant, and an expansion that decompresses and expands the liquefied refrigerant. It can have a valve and an evaporator that cools and liquefies carbon dioxide by the latent heat of the refrigerant. Thus, since the filling line through which the fuel gas flows is cooled with carbon dioxide that has been liquefied by the refrigerator, the gas filling device can be downsized. Further, since the fuel gas is cooled by the liquefied carbon dioxide, the fuel gas can be efficiently cooled.

  In the gas filling system, the carbon dioxide cooling unit and the gas pipe cooling unit may be configured separately. Thereby, a gas filling apparatus can be reduced in size and it becomes possible to improve the freedom degree of installation of a system.

  In the gas filling system, the gas pipeline cooling section can be configured by a plurality of gas pipeline cooling means. Thereby, since the fuel gas which flows through a filling line can be cooled in steps, it becomes possible to improve the cooling efficiency of fuel gas.

  In the gas filling system, carbon dioxide from the carbon dioxide cooling unit is supplied to one gas line cooling means, and carbon dioxide from the one gas line cooling means is supplied to the other gas line cooling means. be able to. Thereby, it becomes possible to further improve the cooling efficiency of the fuel gas.

  In the gas filling system, the one gas pipe cooling means may be provided on the downstream side of the filling line, and the other gas pipe cooling means may be provided on the upstream side of the filling line. Thereby, the cooling efficiency of the fuel gas can be improved.

  In the gas filling system, the gas line cooling means can be constituted by a vacuum heat insulating container.

  In the gas filling system, the gas line cooling unit can cool the fuel gas flowing through the filling line by the latent heat of vaporization of the cooled and liquefied carbon dioxide.

  As described above, according to the present invention, it is compact and has a high degree of freedom in installation, and it becomes possible to efficiently cool and fill the fuel gas.

It is the schematic for demonstrating the gas filling system which concerns on this invention. It is a block diagram which shows one Embodiment of the gas filling system which concerns on this invention. It is a basic diagram which shows an example of a vacuum heat insulation container, (a) is a perspective view, (b) is a top view, (c) looked at the cross section by line segment XX 'shown in (b) from the arrow direction. It is sectional drawing. It is an approximate line figure for explaining filling operation of fuel gas. It is a flowchart for demonstrating operation | movement of the gas filling system which concerns on this invention. It is a flowchart for demonstrating operation | movement of the gas filling system which concerns on this invention. It is a flowchart for demonstrating operation | movement of the gas filling system which concerns on this invention.

  Next, an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view for explaining a gas filling system according to the present invention. This gas filling system 1 is a fuel gas F such as hydrogen gas filled in a curdle 10 loaded on a truck 9. It is provided to fill an in-vehicle tank (not shown) mounted on the vehicle while cooling via the gas compressor 7, the accumulator 8 and the gas filling device 2. The fuel gas F filled in the curdle 10 is not supplied via the pressure accumulator 8 but directly supplied from the gas compressor 7 to the gas filling device 2 or directly without going through the livestock pressure device 8 and the gas compressor 7. In some cases, the gas is supplied to the gas filling device 2.

The gas filling system 1 includes a carbon dioxide cooling unit 4, a gas pipe cooling unit 3 provided in the gas filling device 2, a POS (Point Of Sale system) 5 provided indoors and / or outdoors. And an outdoor input / output device 6 provided. Based on the control by the POS 5 and / or the outdoor input / output device 6, carbon dioxide (CO ₂ ) cooled and liquefied from the carbon dioxide cooling unit 4 is gas pipe of the gas filling device 2. The fuel tank F is supplied to the road cooling unit 3 and is filled into the vehicle tank while the fuel gas F is cooled by the gas pipe cooling unit 3.

FIG. 2 shows an embodiment of a gas filling system 1 according to the present invention. This gas filling system 1 includes a gas pipe cooling unit 3 and a carbon dioxide cooling unit 4 provided in a gas filling device 2. The gas line cooling unit 3 includes the supplied fuel gas F, which is cooled by the cooled liquefied CO ₂ supplied from the carbon dioxide cooling unit 4 and filled in the vehicle tank.

  The gas line cooling unit 3 includes one or a plurality of vacuum heat insulating containers 31 as gas line cooling means, and detection means 32 provided for each vacuum heat insulating container 31, and fills the curdle 10 shown in FIG. A filling line 33 for supplying the fuel gas F thus supplied to an in-vehicle tank (not shown) mounted on the vehicle is disposed so as to pass through the vacuum heat insulating container 31. The example shown in FIG. 2 shows a case where two vacuum heat insulating containers 31A and 31B are provided, and detection means 32A and 32B are provided for each vacuum heat insulating container.

The vacuum heat insulation container 31 has a built-in heat exchanger, supplied with CO ₂ liquefied from a carbon dioxide cooling unit 4 described later, and cools the fuel gas F flowing through the filling line 33 by this CO ₂ . When a plurality of vacuum heat insulating containers 31 </ b> A and 31 </ b> B are provided as the vacuum heat insulating container 31, the vacuum heat insulating container 31 </ b> A is provided on the downstream side of the filling line 33, and the vacuum heat insulating container 31 </ b> B is provided on the upstream side of the filling line 33. Then, the cooled and liquefied CO ₂ supplied from the carbon dioxide cooling unit 4 is supplied to the vacuum heat insulating container 31A, and then the CO ₂ discharged from the vacuum heat insulating container 31A is supplied to the vacuum heat insulating container 31B. The CO ₂ discharged from the vacuum heat insulating container 31B is returned to the carbon dioxide cooling unit 4.

Here, the CO ₂ is supplied to the vacuum insulated container 31B, the temperature is higher than the CO ₂ to be supplied to the vacuum insulated container 31A. This is because when the fuel gas F flowing through the filling line 33 is cooled by the vacuum heat insulating container 31A, the CO ₂ in the vacuum heat insulating container 31A whose temperature has been raised by heat exchange is supplied to the vacuum heat insulating container 31B.

That is, the high-temperature fuel gas F flowing through the filling line 33 includes CO ₂ having a slightly increased temperature in the vacuum heat insulating container 31B provided on the upstream side of the filling line 33, and a vacuum provided on the downstream side of the filling line 33. The fuel gas F can be efficiently cooled by being cooled in stages by the cooled CO ₂ in the heat insulating container 31A.

The vacuum heat insulating container 31 has a built-in heat exchanger, and as shown in FIG. 3, for example, a CO ₂ inlet and a CO ₂ outlet are provided on the upper part of a cylindrical container having a vacuum wall surface. A fuel gas inlet and a fuel gas outlet are provided.

The CO ₂ inlet pipe for injecting the CO ₂ is inserted, one end of the pipe is arranged so as to be positioned below the inner container. Further, a pipe for discharging CO ₂ is inserted into the CO ₂ discharge port, and one end of the pipe is disposed above the inside of the container.

A filling line is connected to the heat exchanger inside the vacuum heat insulating container 31 at the fuel gas inlet and the fuel gas outlet. With such a configuration, heat exchange is performed between the filling line fuel gas in the vacuum heat insulating container and the CO ₂ injected into the container through the heat transfer tube, and the fuel gas F flowing through the filling line is cooled.

Returning to FIG. 2, the detection means 32 detects the temperature of CO ₂ inside the vacuum heat insulating container 31. As the detection means 32, for example, a temperature sensor or a pressure sensor can be used. When a pressure sensor is used as the detection means 32, the temperature of CO ₂ inside the vacuum heat insulating container 31 is converted by converting the pressure into a temperature. Can be detected.

  The filling line 33 includes a meter 34 for measuring the flow rate of the fuel gas F, and a nozzle 35 for supplying the fuel gas F to an in-vehicle tank (not shown) at one end. Since the high-pressure fuel gas F flows in the filling line 33, the connection portion does not exist particularly in the portion that passes through the inside of the vacuum heat insulating container 31 in consideration of leakage of the fuel gas F inside the vacuum heat insulating container 31. It is preferable to configure as described above.

The carbon dioxide cooling unit 4 includes a compressor 41 that compresses a low-temperature / low-pressure gaseous refrigerant (hereinafter referred to as “refrigerant vapor”) and generates a high-temperature / high-pressure liquefied refrigerant vapor. The generated high-temperature and high-pressure refrigerant vapor is liquefied to produce a condenser 42, an expansion valve 43 for reducing and expanding the pressure of the refrigerant liquid produced by the condenser 42, and decompression by the expansion valve 43. The evaporator 44 that cools and liquefies CO ₂ by the latent heat of the expanded refrigerant, the pump 45 that feeds the cooled and liquefied CO ₂ to the gas line cooling unit 3, and the pressure of CO ₂ in the evaporator 44 And a pressure sensor 46 for measuring. As the refrigerant, for example, chlorofluorocarbon or ammonia can be used.

Next, operation | movement of the gas filling system 1 which has the said structure is demonstrated roughly with reference to FIG. As shown in FIG. 4, in the gas filling system 1, when a filling setting signal for filling the vehicle gas tank with the fuel gas F is input to the POS 5 by the operator, the POS 5 is sent to the carbon dioxide cooling unit 4. Output a forced operation signal. Next, the carbon dioxide cooling unit 4 starts an operation for cooling and liquefying CO ₂ based on the forced operation signal supplied from the POS 5, and a filling OK signal indicating that the CO ₂ can be filled at the stage where the CO ₂ is cooled and liquefied. Is output to POS5.

  When a filling OK signal is supplied from the carbon dioxide cooling unit 4, the POS 5 outputs a filling permission signal for starting filling of the fuel gas F to the gas filling device 2. When the gas filling device 2 receives the filling permission signal, the on-vehicle tank is filled with the fuel gas F. When the filling of the fuel gas F is completed, a filling end signal indicating that the filling is completed is output to the POS 5.

  Next, operation | movement of the gas filling system 1 is demonstrated with reference to the flowchart shown in FIGS. In addition, the operation | movement shown below shall be performed by control of the control part etc. which are provided in the gas filling apparatus 2 and are not shown.

First, the operation of the carbon dioxide cooling unit 4 at the time of non-filling (when opening a store where the gas filling system 1 is installed) will be described with reference to FIG. In step S 1, the pressure sensor 46 measures the pressure of CO ₂ in the evaporator 44. Next, the temperature T of CO ₂ is calculated based on the pressure measured in step S1, and it is determined whether or not the temperature T is equal to or higher than a predetermined temperature T ₁ set in advance (step S2).

In step S2, when it is determined that the temperature T of CO ₂ is lower than the temperature T ₁ (step S2; No), the process returns to step S1, and the pressure of the evaporator 44 is measured again. On the other hand, when it is determined that the temperature T of the CO ₂ is equal to or higher than the temperature T ₁ (step S2; Yes), the capacity control of the compressor 41 is controlled so that the CO ₂ is cooled to a lower pressure. The high drive to be controlled is operated (step S3). Then, the pressure of the CO ₂ in the evaporator 44 is measured by the pressure sensor 46 (step S4).

Next, based on the pressure measured in step S4, the temperature T of CO ₂ is calculated, and it is determined whether or not the temperature T has reached a predetermined temperature T ₂ set in advance (step S5). The temperature T ₂ is set to a temperature lower than the temperature T ₁ described above.

When it is determined in step S5 that the temperature T of CO ₂ has reached the temperature T ₂ (step S5; Yes), the capacity control of the compressor 41 is set to the low load side so as to maintain the pressure of CO _2. The controlled LOW drive is operated (step S6). On the other hand, when it is determined that the temperature T of CO ₂ has not reached the temperature T ₂ (step S5; No), the process returns to step S3, and the compressor 41 is operated so that the CO ₂ is further reduced in pressure. Let

Thereafter, the above-described operation is repeated until CO ₂ reaches a predetermined temperature T ₂ . As a result, CO ₂ for cooling the fuel gas F can be sufficiently cooled and liquefied, and the temperature of CO ₂ can be maintained.

Next, the operation of the carbon dioxide cooling unit 4 at the time of filling (when filling the vehicle-mounted tank with the fuel gas F) will be described with reference to FIG. When the forced operation signal from the POS 5 is supplied to the carbon dioxide cooling unit 4, the electromagnetic valve is opened and the pump 45 is driven, and the cooled and liquefied CO ₂ is supplied to the gas line cooling unit 3. Then, filling of the vehicle gas tank with the fuel gas F is started (step S11).

Next, it is determined whether or not the temperature T of CO ₂ is equal to or higher than the temperature T ₁ (step S12). When it is determined that the temperature T of CO ₂ is lower than the temperature T ₁ (step S12; No), the process returns to step S12, and the temperature T of CO ₂ is determined again.

On the other hand, when it is determined that the temperature T of CO ₂ is equal to or higher than the temperature T ₁ (step S12; Yes), the compressor 41 is operated to cool the CO ₂ to a lower pressure (step S13). . Then, the pressure of the CO ₂ in the evaporator 44 is measured by the pressure sensor 46 (step S14).

Next, based on the pressure measured in step S14, the temperature T of CO ₂ is calculated, and it is determined whether or not the temperature T has reached a predetermined temperature T ₂ set in advance (step S15). When it is determined that the temperature T of CO ₂ has reached the temperature T ₂ (step S15; Yes), the compressor 41 is operated so as to maintain the pressure of CO ₂ (step S16).

On the other hand, when it is determined that the temperature T of CO ₂ has not reached the temperature T ₂ (step S15; No), the process returns to step S13, and the compressor is cooled so that the CO ₂ is cooled to a lower pressure. 41 is operated.

Next, it is determined whether or not filling of the vehicle gas tank with the fuel gas F has been completed (step S17). If it is determined that the filling of the fuel gas F has been completed (step S17; Yes), the process returns to step S12, the operations of steps S12 to S16 are repeated, and the temperature T of CO ₂ is maintained at the temperature T ₂ . To do. On the other hand, when it is determined that the filling of the fuel gas F has not been completed (step S17; No), the electromagnetic valve is opened and the pump 45 is driven, and the filling of the fuel gas F is continued.

As described above, when the fuel gas F is filled, the fuel gas F can be appropriately cooled and filled by maintaining the CO ₂ temperature T at the predetermined temperature T ₂ .

Next, the operation of the carbon dioxide cooling unit 4 during non-filling (when the store where the gas filling system 1 is installed is closed) will be described with reference to FIG. In step S21, the pressure of the CO ₂ in the evaporator 44 is measured by the pressure sensor 46. Next, based on the pressure measured in step S21, the temperature T of CO ₂ is calculated, and it is determined whether or not the temperature T is equal to or higher than a predetermined temperature T ₃ set in advance (step S22). The temperature T ₃ is set to a temperature higher than the above-described temperatures T ₁ and T ₂ .

In step S22, when it is determined that the temperature T of CO ₂ is lower than the temperature T ₃ (step S22; No), the process returns to step S21, and the pressure of the evaporator 44 is measured again. On the other hand, when it is determined that the temperature T of CO ₂ is equal to or higher than the temperature T ₃ (step S22; Yes), the compressor 41 is operated so as to make CO ₂ at a lower pressure (step S23). Then, the pressure of the CO ₂ in the evaporator 44 is measured by the pressure sensor 46 (step S24).

Next, based on the pressure measured in step S24, the temperature T of CO ₂ is calculated, and it is determined whether or not the temperature T has reached a predetermined temperature T ₄ set in advance (step S25). The temperature T ₄ is set to a temperature higher than the above-described temperatures T ₁ and T ₂ and lower than the temperature T ₃ .

If it is determined in step S25 that the temperature T of CO ₂ has reached the temperature T ₄ (step S25; Yes), the drive of the compressor 41 is stopped (step S26). On the other hand, when it is determined that the temperature T of CO ₂ has not reached the temperature T ₄ (step S25; No), the process returns to step S23, and the compressor 41 is operated so that the CO ₂ is further reduced in pressure. Let

Thereafter, the above-described operation is repeated until CO ₂ reaches a predetermined temperature T ₄ . In this way, at the time of non-filling such as when the store is closed, the temperature of the CO ₂ is maintained at a temperature T ₄ higher than the temperature T ₂ at the time of filling, so that the CO ₂ is not unnecessarily cooled and liquefied, and the fuel gas F Can be provided at the time of filling.

As described above, according to the present embodiment, the filling line through which the fuel gas flows is cooled using the vacuum heat insulating container filled with the liquefied CO _2, so that the gas filling device can be downsized. it can. In addition, since the gas pipeline cooling unit for cooling the filling line and the carbon dioxide cooling unit for cooling and liquefying CO ₂ when cooling the filling line can be installed separately, the installation of the system Can increase the degree of freedom.

Furthermore, since CO ₂ is cooled and liquefied to a predetermined temperature by the carbon dioxide cooling section, and the fuel gas filling line is cooled by the cooled liquefied CO ₂ , the fuel gas can be efficiently cooled.

  Furthermore, according to the present embodiment, the fuel gas is cooled by carbon dioxide that has a viscosity lower than that of the antifreeze liquid and that can use latent heat. The cooling time can be shortened as compared with the case of cooling.

1 Gas Filling System 2 Gas Filling Device 3 Gas Pipeline Cooling Unit 4 Carbon Dioxide Cooling Unit 5 POS
6 Outdoor input / output device 7 Gas compressor 8 Accumulator 9 Track 10 Cardle 31 (31A, 31B) Vacuum insulation container 32 (32A, 32B) Detection means 33 Filling line 34 Meter 35 Nozzle 41 Compressor 42 Condenser 43 Expansion valve 44 Evaporator 45 Pump 46 Pressure sensor

Claims (8)

A gas filling system for filling an on-vehicle tank mounted on a vehicle with fuel gas,
A filling line for filling the on-board tank with fuel gas;
A gas filling system comprising: cooling means for cooling the filling line with a refrigerant. The cooling means is
A carbon dioxide cooling section for cooling and liquefying carbon dioxide with a refrigerator;
A gas pipe line cooling part for cooling the filling line with carbon dioxide cooled and liquefied,
The carbon dioxide cooling part is
A compressor that compresses the gaseous refrigerant to produce a higher temperature and higher pressure refrigerant;
A condenser for liquefying the high-temperature and high-pressure refrigerant;
An expansion valve that decompresses and expands the pressure of the liquefied refrigerant;
The gas filling system according to claim 1, further comprising an evaporator that cools and liquefies carbon dioxide by latent heat of the refrigerant.   The gas filling system according to claim 2, wherein the carbon dioxide cooling unit and the gas pipeline cooling unit are configured separately.   4. The gas filling system according to claim 2, wherein the gas pipeline cooling unit includes a plurality of gas pipeline cooling means. Carbon dioxide from the carbon dioxide cooling section is supplied to one gas pipe cooling means,
The gas filling system according to claim 4, wherein carbon dioxide from said one gas line cooling means is supplied to the other gas line cooling means. The one gas line cooling means is provided on the downstream side of the filling line,
6. The gas filling system according to claim 5, wherein the other gas line cooling means is provided on the upstream side of the filling line.   The gas filling system according to claim 6, wherein the gas pipe cooling means is constituted by a vacuum heat insulating container.   The gas filling system according to any one of claims 1 to 7, wherein the gas line cooling unit cools the fuel gas flowing through the filling line by latent heat of vaporization of the liquefied carbon dioxide.

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