Pressure or flow rate regulation method for hydrogen gas distribution system

Abstract

The present invention relates to a method for improving the stability of a hydrogen gas distribution system. An example of such a system is a fuel filling station for hydrogen fuel vehicles. Vehicles are filled with multiple high pressure hydrogen gas tubes, usually one tube at a time. For safety and reliability, the control requirement for such a system is to be able to deliver hydrogen at a constant rate to the fuel tank so that its rate of pressure rise remains constant during the entire filling process. To better maintain flow continuity and / or pressure during tube switching, the provision of a dual pressure regulator is proposed.

Description

[Technical Field]

[0001] The present disclosure relates to pressure stability management of pressurized gas streams, particularly hydrogen gas for refueling hydrogen fuel cell vehicles (FCEVs). [Background technology]

[0002] High-pressure hydrogen gas stored in multiple tubes (tube bundles) is distributed to a vehicle fuel tank (receiving tank) by the pressure difference between the tubes and the fuel tank. A strategy for maximizing the utilization of the tube bundle storage capacity is to minimize the average pressure difference between the tubes and the fuel tank during the filling process. The fuel tank is filled one tube at a time in a cascade fashion, starting with the tube with the lowest pressure difference. When the pressure in a tube reaches a preset limit relative to the fuel tank pressure, it switches to the tube with the next lowest pressure difference between the tube and the receiving tank. The switchover is performed by first opening the isolation valve of the inlet tube and then closing the isolation valve of the outlet tube. This sequence is repeated until the fuel tank reaches the desired pressure. Summary of the Invention [Problem to be solved by the invention]

[0003] A commonly accepted method of regulating the flow, and therefore the rate of pressurization, is by means of a pressure control valve (PCV). However, a steady flow to the receiving tank cannot be guaranteed with this single PCV installation. The receiving tank will likely experience a sudden increase in flow due to a sudden pressure spike upstream of the PCV during tube switching if the valve is kept in automatic mode. On the other hand, if the PCV is switched to inactive mode (i.e., closed position), the flow to the receiving tank will be obstructed. [Means for solving the problem]

[0004] The present invention may be understood with respect to the following embodiments: A system for adding pressurized gas to receptacle vessels fluidly connected to the system is disclosed, the system comprising: a) a plurality of banks of pressurized gas vessels, each bank having a plurality of pressurized gas vessels, each pressurized vessel of a bank fluidly connected to a common bank manifold and a common bank pressure control valve (PCV); b) a common bank PCV configured downstream of that bank and all of its pressurized gas vessels, the common bank PCV adapted to control the flow of pressurized gas from that bank to the receptacle vessels; c) the bank PCVs configured and adapted to operate sequentially in response to a computer control; and d) the computer control configured and specifically programmed to control the opening and closing of the bank PCVs in response to a pressure value representing the pressure of the pressurized gas in a first pressurized vessel of a first bank (Bank A). The computer control includes the steps of: A) detecting a first pressure in a first pressurized gas container of a first bank (Bank A); B) comparing the first pressure of the first pressurized gas container of the first bank (Bank A) with the receptacle vessel pressure; C) comparing the pressure value of each pressurized gas container of a second bank (Bank B) to identify a second pressurized gas container having the smallest pressure difference with the receptacle pressure vessel when the comparison of (B) reaches a predetermined minimum pressure difference; and D) comparing the pressure value of each pressurized gas container of a second bank (Bank B) to identify a second pressurized gas container having the smallest pressure difference with the receptacle pressure vessel. and (D) opening a second isolation valve of a second pressurized gas container of the second bank to establish fluid communication between the first bank PCV and the receptacle container; (E) proportionally opening the second bank PCV to maintain a minimum pressure of gas flow to the receptacle container based on a pressure decay of the pressurized gas flow through the first bank PCV; and (F) closing the first PCV when a first pressure of the first pressurized gas container reaches a second preset pressure difference with the pressure of the receptacle container.

[0005] A method for adding pressurized gas to a container fluidly connected to the system is also disclosed. The method includes the following steps: a) detecting a first pressure in a first pressurized gas container of a first bank (Bank A); b) comparing the first pressure of the first pressurized gas container of the first bank (Bank A) with a receptacle container pressure; c) comparing the pressure values ​​of each pressurized gas container of a second bank (Bank B) to identify a second pressurized gas container having the smallest pressure difference from the receptacle pressure container when the comparison of (B) reaches a predetermined minimum pressure difference; d) opening a second isolation valve of a second pressurized gas container of the second bank to establish fluid communication between the second pressurized gas container and the second bank PCV; and e) proportionally opening the second bank PCV to maintain a minimum pressure for gas flow to the receptacle container based on the pressure decay of the pressurized gas flow through the first bank PCV. f) The first PCV is closed when the first pressure in the first pressurized gas container reaches a second preset pressure difference with the pressure in the receptacle container.

[0006] The above system and / or method may include one of the following aspects. The first isolation valve of the first pressurized gas container is closed simultaneously with (F) or after (F). The computer control is further configured and particularly programmed to perform a set point exchange process, wherein the set point of the second PCV is set to a predetermined value below the set point of the first PCV, and then the predetermined set point value is reduced to zero. The computer control is configured and specifically programmed to repeat (A) through (F) for the second pressurized vessel and the third pressurized vessel of the first bank. g) the first isolation valve of the first pressurized gas container is closed simultaneously with or after step f). In the setpoint exchange process, the setpoint of the second PCV is set to a predetermined value below the setpoint of the first PCV, and then the predetermined setpoint value is reduced to zero. Steps a) to f) are repeated for the second and third pressurized vessels of the first bank. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 shows a prior art system for generating a flow of pressurized gas. [Figure 2] FIG. 2 shows an embodiment of the invention having two independent banks of pressurized gas storage vessels, each bank having a pressure control valve connected to a common outlet conduit. [Figure 3] FIG. 3 shows a diagram of the pressure set point exchange process. DETAILED DESCRIPTION OF THE INVENTION

[0008] The object of the present invention is to overcome the above drawbacks by dividing the tubes (1-14) into two banks (Bank A and Bank B), each having one common PCV (PCV-A, PCV-B) so that filling can be performed alternatively between the banks.

[0009] The tube switching sequence is managed by a computer (not shown) as follows. Filling begins with the tube in bank A (tube 1) with the lowest pressure differential to the vehicle fuel tank, with PCV-A controlling the rate of pressurization. When the pressure difference between tube 1 in bank A and the receiving tank decays to a preset limit, the sequence selects the next fill tube (tube 2) from bank B with the lowest pressure differential to the vehicle fuel tank and opens the corresponding isolation valve to pressurize the pipe and manifold header to PCV-B. After the isolation valve opens, PCV-B switches to active mode (automatic mode) with a setting that tracks the current setting of PCV-A, and its upstream is pressurized. As the pressure difference between bank A and the receiving tank continues to decay until PCV-A can no longer maintain full flow, PCV-B begins opening to provide additional flow, and bank B is brought online in stages (Figure 3). When the pressure difference reaches the preset limit, bank A is taken offline, followed by the ramped closure of its isolation valve. The cycle repeats between banks A and B until the receiving tank reaches its desired pressure.

[0010] The transition can be further improved by adapting the setpoint exchange strategy: PCV-B is switched to automatic with an offset below the setpoint of PCV-A, where the offset is gradually reduced to zero. [Industrial Applicability]

[0011] The present invention is industrially applicable at least to refueling hydrogen FCEVs.

[0012] While the present invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, all such alternatives, modifications, and variations are intended to be within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist of, or consist essentially of disclosed elements, and may be practiced in the absence of undisclosed elements. Furthermore, any reference to an order, such as first and second, should be understood in an illustrative sense and not in a limiting sense. For example, one skilled in the art may recognize that certain steps can be combined into a single step.

[0013] The singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise.

[0014] "Comprising" in a claim is an open transitional term meaning that the claim elements that follow it are a non-exclusive list (i.e., things other than those listed may additionally be included within and remain within the scope of the "comprising"). As used herein, "comprising" may be interchanged with the more restrictive transitional terms "consisting essentially of" and "consisting of," unless otherwise indicated herein.

[0015] "Providing" in the claims is defined to mean equipping, supplying, making available, or preparing something. Steps may be performed by any actor in the absence of express language unless otherwise indicated in the claims.

[0016] Optional or optionally means that the subsequently described event or circumstance may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

[0017] Ranges may be expressed herein as from about one particular value and / or to about another particular value. When such a range is expressed, it should be understood that another embodiment is from the one particular value and / or to the other particular value, along with all combinations within said ranges.

[0018] All references identified herein, along with the specific information to which each cites them, are each incorporated by reference in their entirety into this application.

Claims

1. A system for applying pressurized gas to a receptacle container, said receptacle container being fluidly connected to said system; a) a plurality of banks of pressurized gas containers, each bank having a plurality of pressurized gas containers, each pressurized gas container of a bank fluidly connected to a common bank manifold and a common bank pressure control valve (PCV); b) each common bank PCV configured downstream of said bank and all of its pressurized gas vessels, each common bank PCV adapted to control the flow of said pressurized gas from each bank to said receptacle vessel; c) a first bank PCV of a first bank (Bank A) and a second bank PCV of a second bank (Bank B) of the plurality of banks, configured and adapted to operate in sequence in response to computer control; d) a specifically programmed computer control configured to control the opening and closing of the bank PCVs in response to a pressure value representative of the pressure of the pressurized gas in a first pressurized vessel of the first bank (Bank A), (A) detecting a first pressure in a first pressurized gas container of the first bank (Bank A); (B) comparing the first pressure of the first pressurized gas container of the first bank (Bank A) with the pressure in the receptacle container; (C) comparing the pressure values ​​of each pressurized gas container in the second bank (Bank B) to identify a second pressurized gas container having the smallest pressure difference from the pressure in the receptacle container when the comparison in (B) reaches a predetermined minimum pressure difference; (D) opening a second isolation valve of the second pressurized gas container of the second bank to establish fluid communication between the second pressurized gas container and the second bank PCV; (E) proportionally opening the second bank PCVs to maintain a minimum pressure of gas flow to the receptacle vessel based on a pressure decay of the pressurized gas flow through the first bank PCVs; (F) the first pressure of the first pressurized gas container is equal to the pressure of the receptacle container. closing the first bank PCV when a second preset pressure difference is reached between the first bank PCV and the second bank PCV; and a computer control specifically programmed to carry out Equipped with system.

2. (G) simultaneously with (F) or after (F), closing the first isolation valve of the first pressurized gas container. further comprising: The system of claim 1 .

3. the computer control is configured and particularly programmed to further perform a set point exchange process; the set point of the second bank PCV is set to a predetermined set point value below the set point of the first bank PCV, and then the predetermined set point value is reduced to zero; The system of claim 1 .

4. the computer control is configured and specifically programmed to repeat (A) through (F) for the second pressurized gas container and the third pressurized gas container of the first bank; The system of claim 1 .

5. 10. A method of adding pressurized gas to a container fluidly connected to the pressurized gas delivery system of claim 1, comprising: a) detecting a first pressure in a first pressurized gas container of the first bank (Bank A); b) comparing the first pressure of the first pressurized gas container of the first bank (Bank A) with the pressure in the receptacle container; c) comparing the pressure values ​​of each pressurized gas container in a second bank (Bank B) to identify a second pressurized gas container having the smallest pressure difference from the pressure in the receptacle container when the comparison in (B) reaches a predetermined minimum pressure difference; d) opening a second isolation valve of the second pressurized gas container of the second bank to establish fluid communication between the second pressurized gas container and the second bank PCV; e) proportionally opening the second bank PCVs to maintain a minimum pressure of gas flow to the receptacle vessel based on a pressure decay of the pressurized gas flow through the first bank PCVs; f) closing the first bank PCV when the first pressure in the first pressurized gas container reaches a second predetermined pressure difference with the pressure in the receptacle container; Including, method.

6. g) simultaneously with or after step f), closing the first isolation valve of the first pressurized gas container. further comprising: The method of claim 5.

7. Setpoint Exchange Process further comprising the set point of the second bank PCV is set to a predetermined set point value below the set point of the first bank PCV, and then the predetermined set point value is reduced to zero; The method of claim 5.

8. repeating steps a) through f) for a second pressurized gas container and a third pressurized gas container of said first bank. further comprising: The method of claim 5.

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