JP7669966B2 - High Pressure Gas Charging System - Google Patents

Description

The technology disclosed in this specification relates to a high-pressure gas filling system that can increase the pressure of gas from a gas supply source and supply it to a tank.

Fuel cells that generate electricity using hydrogen and oxygen are accompanied by a tank that stores hydrogen. A device is required to fill the tank with hydrogen. Patent Document 1 discloses an example of a high-pressure gas filling system. In the high-pressure gas filling system of Patent Document 1, a large amount of liquefied gas is stored, and high-pressure hydrogen gas is supplied from the storage tank that stores the liquefied gas to the fuel cell tank.

JP 2009-144815 A

It costs money to produce high-pressure liquefied gas to store in a storage tank. It also costs money to have a storage tank that stores a large amount of liquefied gas. This specification provides a high-pressure gas filling system that increases the gas pressure of a gas supply source when filling a destination tank with gas. This system does not require a storage tank that stores a large amount of liquefied gas, and also reduces costs by using the thermal energy of the gas in the gas supply source when increasing the gas pressure.

The high-pressure gas filling system disclosed in this specification is a system that can increase the pressure of gas from a gas supply source and fill it into a tank, and is equipped with a liquefier, a vaporizer, a heat exchanger, and first, second, and third valves. The liquefier cools and liquefies the gas from the gas supply source. The vaporizer warms and vaporizes the liquefied gas liquefied by the liquefier. The heat exchanger is equipped in the vaporizer, and warms the liquefied gas in the vaporizer with the thermal energy of the gas sent from the gas supply source to the liquefier.

The first valve blocks the flow of gas from the gas source to the heat exchanger. The second valve blocks the flow of liquefied gas from the liquefier to the vaporizer. The third valve blocks the flow of gas from the vaporizer to the tank. The controller controls the first valve, the second valve, the third valve, and the liquefier.

The controller repeatedly executes steps 1 to 3 below. In step 1, the controller closes the second valve, opens the first valve, and sends gas from the gas supply source to the liquefier. In step 2, the controller closes the first valve after a predetermined amount of gas has been sent to the liquefier, and cools and liquefies the gas in the liquefier. In step 3, the controller closes the third valve, opens the second valve, and sends the liquefied gas in the liquefier in liquid form to the vaporizer.

The heat exchanger uses the gas passing through it in step 1 to heat and vaporize the liquefied gas sent to the vaporizer in step 3, and also increases the pressure of the vaporized gas to a pressure higher than the gas pressure of the gas supply source.Then, the controller opens the third valve to send the gas vaporized in the vaporizer to the tank.

The above-mentioned high-pressure gas filling system can increase the gas pressure of the gas supply source and send it to the tank. This system does not require a storage tank for storing large amounts of liquefied gas. In addition, this system can reduce operating costs because it uses the heat of the gas sent from the gas supply source to increase the gas pressure. The gas sent from the gas supply source releases thermal energy in a heat exchanger, so the cost of liquefying the gas can also be reduced.

By appropriately selecting the volume of the vaporizer, the liquefied gas can be vaporized using only the thermal energy of the gas passing through the heat exchanger. If the thermal energy of the gas passing through the heat exchanger alone may be insufficient to vaporize the liquefied gas, the vaporizer may be equipped with a heater to assist in the vaporization of the liquefied gas (or in increasing the pressure after vaporization).

The vaporizer is preferably positioned lower than the liquefier so that the liquefied gas flows from the liquefier to the vaporizer by gravity. This eliminates the need for power to send the liquefied gas from the liquefier to the vaporizer.

The high pressure gas filling system disclosed in this specification may include two sets of sub-units each consisting of a vaporizer, a heat exchanger, a first valve, a second valve, and a third valve. In this case, the controller may be configured to send liquefied gas, which is produced by liquefying gas that has passed through the heat exchanger of one sub-unit, to the vaporizer of the other sub-unit. By using the two sub-units alternately, the speed at which gas is filled into the tank can be increased. The liquefier is shared by the two sub-units.

When the gas pressure in the vaporizer becomes the same as the internal pressure of the tank, gas stops flowing from the vaporizer to the tank. In order not to waste the gas remaining in the vaporizer, it is preferable that the high-pressure gas filling system further includes a switching valve that switches the destination of the gas in the vaporizer from the tank to another tank. In this case, while the third valve is open, the controller controls the switching valve so that the destination of the gas in the vaporizer is switched from the tank to another tank when the gas pressure in the vaporizer becomes equal to the gas pressure in the tank. The gas in the vaporizer can be used effectively.

Details and further improvements of the technology disclosed in this specification are explained in the "Description of Embodiments" below.

1 is a block diagram of a high-pressure gas filling system according to a first embodiment. FIG. FIG. 5 is a block diagram of a high-pressure gas filling system according to a second embodiment.

A high-pressure gas filling system 10 according to a first embodiment will be described with reference to the drawings. FIG. 1 shows a block diagram of the high-pressure gas filling system 10. The high-pressure gas filling system 10 can increase the pressure of the gas in the gas supply source 90 and then fill the gas into tanks 93a to 93c. The gas stored in the gas supply source 90 is, for example, oxygen or hydrogen. The gas stored in the gas supply source 90 may also be another type of gas.

The high pressure gas filling system 10 includes a liquefier 11, a vaporizer 24a, a first gas pipe 21a, a second gas pipe 22a, a liquid pipe 23a, a first valve 31a, a second valve 32a, a third valve 33a, a common gas pipe 13, a switching valve 14, and a controller 19. The vaporizer 24a, the first gas pipe 21a, the second gas pipe 22a, the liquid pipe 23a, the first valve 31a, the second valve 32a, and the third valve 33a are collectively referred to as the first subunit 20a. The high pressure gas filling system 10 also includes a second subunit 20b having the same configuration as the first subunit 20a.

The gas supply source 90 and the liquefier 11 are connected by a first gas pipe 21a. More specifically, a gas pipe 91 extends from the gas supply source 90, and the first gas pipe 21a is connected to the gas pipe 91. The gas pipe 91 is equipped with a check valve 92.

Gas from the gas supply source 90 is sent to the liquefier 11 through the first gas pipe 21a. A first valve 31a and a heat exchanger 25a are arranged in the middle of the first gas pipe 21a. The first valve 31a is arranged upstream (upstream of the gas flow) of the heat exchanger 25a. The first valve 31a stops the flow of gas from the gas supply source 90 to the heat exchanger 25a. The heat exchanger 25a is provided in the vaporizer 24a. The vaporizer 24a will be described later.

The liquefier 11 is equipped with a cooler 12. The liquefier 11 liquefies the gas sent from the gas supply source 90 by cooling it with the cooler 12. The cooler 12 is powerful enough to liquefy the gas at atmospheric pressure (or a pressure close to atmospheric pressure).

The liquefier 11 is connected to the vaporizer 24a by a liquid pipe 23a. The liquid pipe 23a sends the liquefied gas liquefied in the liquefier 11 to the vaporizer 24a. A second valve 32a is disposed midway along the liquid pipe 23a. The second valve 32a blocks the flow of liquefied gas from the liquefier 11 to the vaporizer 24a. The vaporizer 24a is disposed at a lower position than the liquefier 11. Therefore, when the second valve 32a is opened, the liquefied gas in the liquefier 11 flows to the vaporizer 24a by the action of gravity.

The vaporizer 24a does not expand the gas to vaporize it, but heats and vaporizes the liquefied gas. In addition to the heat exchanger 25a described above, the vaporizer 24a is equipped with a cooler 27a and a heater 26a. The cooler 27a is provided to lower the temperature of the vaporizer 24a to a temperature close to that of the liquefied gas before the liquefied gas flows in. The heat exchanger 25a warms the liquefied gas in the vaporizer 24a with the thermal energy of the gas (gas supplied from the gas supply source 90) passing through it. The vaporizer 24a vaporizes the liquefied gas with the thermal energy (thermal energy of the gas in the gas supply source 90) obtained from the heat exchanger 25a. The vaporizer 24a further heats the vaporized gas until the pressure of the vaporized gas becomes higher than the gas pressure of the gas supply source 90.

The heater 26a is provided to supplement the thermal energy when the thermal energy obtained from the heat exchanger 25a alone is insufficient to generate gas at a pressure equal to or greater than the gas pressure of the gas supply source 90. In other words, the vaporizer 24a is provided with a heater 26a that assists in the vaporization of the liquefied gas (or the increase in pressure of the vaporized gas).

The vaporizer 24a and the tanks 93a-93c are connected by the second gas pipe 22a and the common gas pipe 13. The second gas pipe 22a and the common gas pipe 13 send the gas vaporized by the vaporizer 24a to the tanks 93a-93c. A third valve 33a is disposed on the second gas pipe 22a. The third valve 33a blocks the flow of gas from the vaporizer 24a to the tanks 93a-93c.

A switching valve 14 is provided between the common gas pipe 13 and the tanks 93a-93c. The switching valve 14 is provided with stop valves 15a-15c. The stop valve 15a stops the flow of gas into the tank 93a. The stop valve 15b (15c) stops the flow of gas into the tank 93b (93c). The switching valve 14 can select one of the three tanks 93a-93c as the destination for the gas supplied from the vaporizer 24a by opening one of the three stop valves 15a-15c and closing the remaining two.

The controller 19 controls the first/second/third valves 31a/32a/33a, the liquefier 11 (cooler 12), the vaporizer 24a (cooler 27a, heater 26a), and the switching valve 14.

As mentioned above, the high-pressure gas filling system 10 includes the second subunit 20b having the same configuration as the first subunit 20a. The second subunit 20b includes the vaporizer 24b (heat exchanger 25b, cooler 27b, heater 26b), the first gas pipe 21b, the second gas pipe 22b, the liquid pipe 23b, the first valve 31b, the second valve 32b, and the third valve 33b. The vaporizer 24b (heat exchanger 25b, cooler 27b, heater 26b), first gas pipe 21b, second gas pipe 22b, liquid pipe 23b, first valve 31b, second valve 32b, and third valve 33b correspond to the vaporizer 24a (heat exchanger 25a, cooler 27a, heater 26a), first gas pipe 21a, second gas pipe 22a, liquid pipe 23a, first valve 31a, second valve 32a, and third valve 33a of the first subunit 20a, respectively.

The controller 19 controls the first, second and third valves 31b, 32b and 33b and the vaporizer 24b (cooler 27b, heater 26b). The liquefier 11 (cooler 12) is shared by the first subunit 20a and the second subunit 20b.

The operation of the high-pressure gas filling system 10 will be explained. First, the operation using only the first subunit 20a will be explained.

The controller 19 repeatedly executes the following three steps. (Step 1) The controller 19 closes the second valve 32a, opens the first valve 31a, and sends gas from the gas supply source 90 to the liquefier 11. (Step 2) After a predetermined amount of gas has been sent to the liquefier 11, the controller 19 closes the first valve 31a, and cools and liquefies the gas in the liquefier 11. (Step 3) The controller 19 closes the third valve 33a, opens the second valve 32a, and sends the liquefied gas in the liquefier 11 in liquid form to the vaporizer 24a.

Before step 3, the controller 19 uses the cooler 27a to lower the temperature of the vaporizer 24a to the temperature of the liquefied gas (a temperature close to the temperature of the liquefied gas). By lowering the temperature of the vaporizer 24a to the temperature of the liquefied gas, the liquefied gas flows in liquid form from the liquefier 11 to the vaporizer 24a.

When step 1 is executed for the second time, the gas in the gas supply source 90 passes through the heat exchanger 25a. At this time, the heat exchanger 25a warms and vaporizes the liquefied gas sent to the vaporizer 24a in the previous step 3 with the gas passing through the heat exchanger 25a in the previous step 1. Furthermore, the heat exchanger 25a increases the pressure of the vaporized gas to a pressure higher than the internal gas pressure of the gas supply source 90. Note that, if the thermal energy of the gas passing through the heat exchanger 25a is insufficient to increase the gas pressure in the vaporizer 24a, the controller 19 operates the heater 26a to supplement the thermal energy. In this way, gas with a pressure higher than the gas pressure in the gas supply source 90 is obtained. Note that, if the capacity of the vaporizer 24a is appropriately selected, the liquefied gas can be vaporized using only the thermal energy of the gas in the gas supply source 90, and the pressure can be increased to be higher than the internal pressure of the gas supply source 90.

After the liquefied gas in the vaporizer 24a is vaporized, the controller 19 opens the third valve 33a and sends the gas vaporized in the vaporizer 24a to the tank 93a. In this way, the high-pressure gas filling system 10 can fill the tank 93a with gas at a gas pressure higher than the internal gas pressure of the gas supply source 90 through the action of the liquefier 11, the vaporizer 24a, and the heat exchanger 25a. The controller 19 controls the vaporizer 24a so that the gas pressure of the vaporizer 24a is higher than the gas pressure of the tank 93a. In this way, gas can be filled until the internal pressure of the tank 93a reaches the target pressure. The target pressure is higher than the gas pressure of the gas supply source 90.

The controller 19 may continue step 1 after opening the third valve 33a. Even after opening the third valve 33a, the heat of the gas from the gas supply source 90 continues to warm the gas inside the vaporizer 24a (24b), forcing the gas out of the vaporizer 24a and into the tank 93.

So far, the operation using only the first subunit 20a has been explained. The operation using both the first and second subunits 20a/20b will now be explained. Note that the configuration of the second subunit 20b is the same as that of the first subunit 20a. Therefore, the operation of the first subunit 20a described above can also be achieved directly with the second subunit 20b.

When the first/second subunits 20a/20b are used, the controller 19 closes the second valve 32a of the first subunit 20a in step 1, opens the first valve 31a, and then closes the third valve 33b of the second subunit 20b and opens the second valve 32b in step 3. Note that the controller 19 uses the cooler 27b to lower the temperature of the vaporizer 24b to a temperature close to that of the liquefied gas before opening the second valve 32b. When the second valve 32b is opened, the liquefied gas in the liquefier 11 is sent to the vaporizer 24b as a liquid. Conversely, the controller 19 closes the second valve 32b of the second subunit 20b in step 1, opens the first valve 31b, and then closes the third valve 33a of the first subunit 20a in step 3, opens the second valve 32a, and sends the liquefied gas in the liquefier 11 as a liquid to the vaporizer 24a. Simply put, the controller 19 liquefies the gas that has passed through the heat exchanger of one subunit, and sends the liquefied gas to the vaporizer of the other subunit. By alternating between the two subunits in this way, the gas filling speed of the tank 93a can be increased.

The use of the switching valve 14 will be explained. As mentioned above, by using the switching valve 14, the controller 19 can select one of the three tanks 93a-93c as the destination of the gas supplied from the vaporizer 24a/24b. For example, the controller 19 opens the stop valve 15a and closes the remaining two stop valves 15b and 15c. Then, the first tank 93a is selected as the destination of the gas supplied from the vaporizer 24a (24b). When the third valve 33a (33b) of the vaporizer 24a (24b) is opened, high-pressure gas flows from the vaporizer 24a (24b) to the first tank 93a. When the internal pressure of the vaporizer 24a (24b) becomes equal to the internal pressure of the first tank 93a, gas stops flowing from the vaporizer 24a (24b) to the first tank 93a. At this time, gas still remains in the vaporizer 24a (24b). The controller 19 switches the destination of the gas from the first tank 93a to another tank (e.g., the second tank 93b) to effectively utilize the gas remaining in the vaporizer 24a (24b). Since the internal pressure of the second tank 93b is lower than the internal pressure of the first tank 93a, the gas in the vaporizer 24a (24b) flows to the second tank 93b.

When the internal pressure of the vaporizer 24a (24b) becomes equal to the internal pressure of the second tank 93b, gas stops flowing from the vaporizer 24a (24b) to the second tank 93b. The controller 19 then switches the destination of the gas from the second tank 93b to another tank (in this case, the third tank 93c). Since the internal pressure of the third tank 93c is lower than the internal pressure of the second tank 93b, the gas in the vaporizer 24a (24b) flows to the third tank 93c. In this way, the vaporized gas can be effectively filled into the tank 93. In the above explanation, the pressure loss in the gas pipe between the vaporizer 24a (24b) and the tank 93 was ignored. In reality, when the internal pressure of the vaporizer 24a (24b) becomes equal to [tank internal pressure + loss pressure], gas stops flowing from the vaporizer 24a (24b) to the tank 93a.

As described above, the high-pressure gas filling system 10 increases the pressure of the gas in the gas supply source 90 when filling the tank 93 with high-pressure gas. The high-pressure gas filling system 10 uses the thermal energy of the gas in the gas supply source 90 to increase the gas pressure. This makes it possible to reduce the cost of increasing the gas pressure. In addition, the temperature of the gas in the gas supply source 90 decreases while passing through the heat exchanger 25a (25b). Because the temperature of the gas decreases before being sent to the liquefier 11, the cost of liquefying the gas in the liquefier 11 can also be reduced.

Furthermore, by placing the vaporizer 24a (24b) below the liquefier 11, liquefied gas can be transferred from the liquefier 11 to the vaporizer 24a (24b) without the need for power (pump). This also contributes to cost reduction.

(Second embodiment) Figure 2 shows a block diagram of the high-pressure gas filling system 110 of the second embodiment. The high-pressure gas filling system 110 differs from the high-pressure gas filling system 10 of the first embodiment in that it is equipped with a return path 29a (29b) and a fourth valve 34a (34b). After opening the third valve 33a (33b), when the internal pressure of the vaporizer 24a (24b) becomes lower than the internal pressure of any of the tanks 93a-93c, the controller 19 closes the switching valve 14 (all stop valves 15a-15c) and opens the third valve 33a (33b) and the fourth valve 34a (34b). Then, the gas remaining in the vaporizer 24a (24b) is returned to the liquefier 11 through the return path 29a (29b). The high-pressure gas filling system 110 of the second embodiment can reuse the gas remaining in the vaporizer 24a (24b). In addition, by discharging the gas remaining in the vaporizer 24a (24b), there is also the advantage that the internal pressure and temperature of the vaporizer 24a are reduced.

Notes regarding the technology described in the embodiment are as follows. The high-pressure gas filling system may include three or more subsystems. The three or more subsystems are used in sequence. High-pressure gas can be supplied to the tank sequentially from the vaporizers of the three or more subsystems.

Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exert technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of those objectives is itself technically useful.

10, 110: High pressure gas filling system 11: Liquefier 12: Cooler 13: Common gas pipe 14: Switching valve 15a-15c: Stop valve 19: Controller 20a, 20b: First subunit 21a, 21b: First gas pipe 22a, 22b: Second gas pipe 23a, 23b: Liquid pipe 24a, 24b: Vaporizer 25a, 25b: Heat exchanger 26a, 26b: Heater 27a, 27b: Cooler 29a, 29b: Circulation path 31a, 31b: First valve 32a, 32b: Second valve 33a, 33b: Third valve 34a, 34b: Fourth valve 90: Gas supply source 91: Gas pipe 92: Check valve 93a-93c: Tank

Claims (5)

This is a high-pressure gas filling system that increases the pressure of the gas from the gas supply source and fills it into a tank.
a liquefier for cooling and liquefying the gas from the gas supply source;
a vaporizer that heats and vaporizes the liquefied gas liquefied by the liquefier;
a heat exchanger provided in the vaporizer, through which gas flows from the gas supply source to the liquefier, the heat exchanger warming the liquefied gas in the vaporizer with thermal energy of the gas flowing from the gas supply source to the liquefier;
a first valve for blocking the flow of gas from the gas source to the heat exchanger;
a second valve for blocking the flow of liquefied gas from the liquefier to the vaporizer;
a third valve that blocks the flow of gas from the vaporizer to the tank;
a controller for controlling the first valve, the second valve, the third valve, and the liquefier;
Equipped with
The controller includes:
Step 1: closing the second valve and opening the first valve to send gas from the gas source to the liquefier;
Step 2: closing the first valve after a predetermined amount of gas has been sent to the liquefier, and cooling and liquefying the gas in the liquefier;
Step 3: closing the third valve, opening the second valve, and sending the liquefied gas in the liquefier to the vaporizer in liquid form;
Repeatedly execute
The heat exchanger warms and vaporizes the liquefied gas sent to the vaporizer in the previous step 3 with the gas passing through the heat exchanger in the current step 1, and increases the pressure of the vaporized gas to a pressure higher than the gas pressure in the gas supply source,
The controller opens a third valve after the liquefied gas in the vaporizer is vaporized, and sends the gas vaporized in the vaporizer to the tank.
High pressure gas filling system. The high-pressure gas filling system of claim 1, wherein the vaporizer is positioned lower than the liquefier, and when the second valve is opened, liquefied gas flows from the liquefier to the vaporizer by gravity. The system includes two sets of subunits each including the vaporizer, the heat exchanger, the first valve, the second valve, and the third valve,
3. The high-pressure gas filling system according to claim 1, wherein the controller sends the liquefied gas, which is liquefied from gas that has passed through the heat exchanger of one of the subunits, to the vaporizer of the other subunit. The high pressure gas filling system of claim 1, wherein the vaporizer is equipped with a heater that assists in vaporizing the liquefied gas. The high-pressure gas filling system of claim 1 further comprises a switching valve that switches the destination of the gas in the vaporizer from the tank to another tank, and the controller controls the switching valve to switch the destination of the gas in the vaporizer from the tank to another tank when the gas pressure in the vaporizer becomes equal to the gas pressure in the tank while the third valve is open.

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