PEM hydrogen production energy-saving system and control method thereof

Abstract

The invention relates to the technical field of hydrogen production systems, and particularly discloses a PEM hydrogen production energy-saving system and a control method thereof.The system comprises a comprehensive safety water tank, a water adding pump, an oxygen separator, a pure water circulating pump, an ion filter, a PEM tank, a hydrogen separator, a buffer tank and a hydrogen production power source; a water supplementing opening is formed in the comprehensive safety water tank, the inner bottom side of the comprehensive safety water tank is connected with the inlet end of a water adding pump through a pipeline, and the outlet end of the water adding pump is connected with the first inlet end of an oxygen separator; the outlet end of the oxygen separator is connected with the inlet end of the ion filter through the pure water circulating pump, the outlet end of the ion filter is connected with the inlet end of the PEM groove, the outlet end of the PEM groove is connected with the inlet end of the hydrogen separator and the second inlet end of the oxygen separator, and the outlet end of the hydrogen separator is connected with the inlet end of the comprehensive safety water tank through the buffer tank. And the hydrogen production power supply is connected with the PEM groove. According to the invention, water on the hydrogen side can be recycled under a safe condition, so that the purpose of saving energy is achieved.

Description

Technical Field

[0001] This invention belongs to the technical field of hydrogen production systems, and more specifically, relates to a PEM hydrogen production energy-saving system and a control method for the PEM hydrogen production energy-saving system. Background Technology

[0002] PEM hydrogen production systems offer superior energy efficiency compared to other systems. Most commercially available PEM systems do not fully recycle and reuse the pure water on the hydrogen side to achieve energy savings. There are several reasons for this, but a major one is that hydrogen molecules are very small and easily dissolve in pure water. Direct recycling of this water can cause it to enter the oxygen side, resulting in excessive hydrogen levels in the oxygen. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a PEM hydrogen production energy-saving system. This invention eliminates the pre-pure water tank and direct drainage water seal tank of PEM, and is equipped with corresponding comprehensive safety water tank, pressure, liquid level, hydrogen concentration probe and other equipment to recycle and reuse water on the hydrogen side under safe conditions to achieve the purpose of energy saving.

[0004] As a first aspect of the present invention, a PEM hydrogen production energy-saving system is provided, the PEM hydrogen production energy-saving system comprising an integrated safety water tank, a water pump, an oxygen separator, a pure water circulation pump, an ion filter, a PEM tank, a hydrogen separator, a buffer tank, and a hydrogen production power supply. The integrated safety water tank is equipped with a water inlet, through which external pure water is added to the integrated safety water tank. The bottom of the integrated safety water tank is connected to the inlet of the water pump through a pipe, and the outlet of the water pump is connected to the first inlet of the oxygen separator, so as to add pure water from the integrated safety water tank to the oxygen separator. The outlet of the oxygen separator is connected to the inlet of the ion filter via the pure water circulation pump. The outlet of the ion filter is connected to the inlet of the PEM tank. The outlet of the PEM tank is connected to the inlet of the hydrogen separator and the second inlet of the oxygen separator. The outlet of the hydrogen separator is connected to the inlet of the buffer tank. The outlet of the buffer tank is connected to the inlet of the integrated safety water tank. The hydrogen production power supply is connected to the PEM tank.

[0005] As a further improvement of the present invention, the integrated safety water tank stores pure water for hydrogen production; the water pump is used to replenish the pure water in the integrated safety water tank to the oxygen separator; the oxygen separator is used to separate oxygen and pure water; a pure water cooler is provided between the oxygen separator and the pure water circulation pump, and the pure water cooler is used to cool the pure water discharged from the oxygen separator; the pure water circulation pump is used to provide the power source required for pure water circulation; a flow meter is provided between the pure water circulation pump and the ion filter, and the flow meter is used to monitor the flow rate of pure water circulation; the ion filter is used to filter ionic impurities in the pure water entering the PEM tank; the PEM tank is used to decompose pure water into oxygen and hydrogen under the action of the hydrogen production power source, and to transport oxygen and pure water to the oxygen separator, and to transport hydrogen and pure water to the hydrogen separator; the hydrogen separator is used to separate hydrogen and pure water; the buffer tank is used to buffer the pressure of the pure water discharged from the hydrogen separator; the hydrogen production power source is used to provide DC power to the PEM tank.

[0006] As a further improvement of the present invention, a first control valve is provided on the hydrogen separator, a second control valve is provided on the oxygen separator, a third control valve is provided between the hydrogen separator and the buffer tank, a fourth control valve is provided on the integrated safety water tank, a fifth control valve is provided between the water pump and the oxygen separator, a sixth control valve is connected between the water pump and the fifth control valve, and the outlet end of the buffer tank is connected to the inlet end of the integrated safety water tank through a pressure reducing valve.

[0007] As a further improvement of the present invention, a first pressure sensor and a first temperature sensor are respectively installed on the pipeline between the PEM tank and the hydrogen separator, a second pressure sensor and a second temperature sensor are respectively installed on the pipeline between the PEM tank and the oxygen separator, and a third pressure sensor is installed on the buffer tank. The integrated safety water tank is equipped with a fourth pressure sensor and a hydrogen concentration sensor. The fourth pressure sensor is used to monitor the pressure of the gas phase inside the integrated safety water tank, and the hydrogen concentration sensor is used to monitor the concentration of hydrogen inside the integrated safety water tank. The opening and closing of the fourth control valve are controlled according to the pressure of the gas phase inside the integrated safety water tank or the concentration of hydrogen inside the integrated safety water tank.

[0008] As a further improvement of the present invention, a first liquid level sensor is provided on the hydrogen separator, which is used to monitor the height of the liquid phase in the hydrogen separator; a second liquid level sensor is provided on the oxygen separator, which is used to monitor the height of the liquid phase in the oxygen separator; and a third liquid level sensor is provided on the integrated safety water tank, which is used to monitor the height of the liquid phase in the integrated safety water tank.

[0009] As a second aspect of the present invention, a control method for a PEM hydrogen production energy-saving system is provided, comprising the following steps: Step S1: First, open the first, second, and fifth control valves and the pressure reducing valve, while simultaneously closing the third, fourth, and sixth control valves and the water pump. Then, determine when the liquid level in the hydrogen separator is within the first preset range, the liquid level in the oxygen separator is within the second preset range, and the liquid level in the integrated safety water tank is within the third preset range. At this point, activate the control center, start the hydrogen production power supply, and control the PEM hydrogen production energy-saving system to begin hydrogen production, i.e., control the PEM hydrogen production energy-saving system to enter its initial state. The first preset range is: L2 < liquid 1 < L3; where liquid 1 is the height of the liquid phase in the hydrogen separator, L2 is the second preset liquid level value, and L3 is the third preset liquid level value. The second preset range is: L4 < liquid 2 < L5; where liquid 2 is the height of the liquid phase in the oxygen separator, L4 is the fourth preset liquid level value, and L5 is the fifth preset liquid level value. The third preset range is: L8 < liquid 3 < L9; where liquid 3 is the height of the liquid phase in the integrated safety water tank, L8 is the eighth preset liquid level value, and L9 is the ninth preset liquid level value. Step S2: After the PEM hydrogen production energy-saving system enters the initial state, determine whether the height of the liquid phase in the hydrogen separator is still within the first preset range. If so, control the third control valve to open and proceed to step S3. Step S3: Determine whether the liquid level in the integrated safety water tank is still within the third preset range. If so, turn on the water pump to add pure water to the oxygen separator and proceed to step S4. Step S4: Determine whether the height of the liquid phase in the oxygen separator is still within the second preset range. If so, control the PEM hydrogen production energy-saving system to enter the cycle energy-saving hydrogen production mode, that is, control the PEM hydrogen production energy-saving system to enter the normal working state.

[0010] As a further improvement of the present invention, step S2 includes: If the height of the liquid phase inside the hydrogen separator is L1 < liquid 1 < L2, where L1 is the first preset liquid level value, then there are two possibilities: (1) If the height of the liquid phase in the integrated safety water tank is: liquid 3 ≥ L9, then return to step S2; (2) If the height of the liquid phase in the integrated safety water tank is: L7 < liquid 3 < L9, where L7 is the seventh preset liquid level value, then control the third control valve to open and proceed to step S3.

[0011] As a further improvement of the present invention, step S3 includes: If the liquid level in the integrated safety tank is L7 < L3 < L8, then there are two possibilities: (1) If the height of the liquid phase in the hydrogen separator is: L2 < liquid 1 < L3, then return to step S3; (2) If the height of the liquid phase in the hydrogen separator is L1 < liquid 1 < L2, then water is added to the integrated safety water tank through the water inlet. After the height of the liquid phase in the integrated safety water tank rises, the water inlet is closed and the process returns to step S3.

[0012] As a further improvement of the present invention, step S4 includes: If the height of the liquid phase in the oxygen separator is: L5 < liquid 2 ≤ L6, then return to step S4; where L6 is the sixth preset liquid level value; If the liquid level in the oxygen separator is L2 > L6, then the sixth control valve is opened and the fifth control valve is closed to drain the water using a water pump. After the liquid level in the oxygen separator drops, the sixth control valve is closed and the fifth control valve is opened.

[0013] As a further improvement of the present invention, after the PEM hydrogen production energy-saving system enters the initial state, it further includes: (1) The opening and closing of the fourth control valve are controlled according to the pressure of the gas phase in the integrated safety water tank; wherein, When the pressure of the gas phase in the integrated safety water tank is: pressure 4 ≤ P10, the fourth control valve is opened for 2 seconds, and then the fourth control valve is closed; where pressure 4 is the pressure of the gas phase in the integrated safety water tank, and P10 is the tenth preset pressure value; When the pressure of the gas phase in the integrated safety water tank is: P10 < pressure 4 < P11, the fourth control valve is controlled to close; where P11 is the eleventh preset pressure value; When the pressure of the gas phase in the integrated safety water tank is: pressure 4 = P11, then the fourth control valve is closed. When the pressure of the gas phase in the integrated safety water tank is: P11 < pressure 4 < P12, the fourth control valve is closed; where P12 is the twelfth preset pressure value. When the pressure of the gas phase in the integrated safety water tank is: pressure 4 ≥ P12, then control the fourth control valve to open for 2 seconds, and then control the fourth control valve to close. (2) The opening and closing of the fourth control valve are controlled according to the hydrogen concentration in the integrated safety water tank; wherein, When the concentration of hydrogen in the integrated safety water tank is: Measure 1 ≤ H1, then the fourth control valve is closed; where Measure 1 is the concentration of hydrogen in the integrated safety water tank, and H1 is the first preset concentration value; When the concentration of hydrogen in the integrated safety water tank is: H1 < H1 < H2, then the fourth control valve is closed; where H2 is the second preset concentration value. When the concentration of hydrogen in the integrated safety water tank is: H2≤Measure1<H3, the fourth control valve is opened for 2 seconds, and then the fourth control valve is closed; where H3 is the third preset concentration value; When the concentration of hydrogen in the integrated safety water tank is: 1 ≥ H3, the fourth control valve is opened, and then the PEM hydrogen production energy-saving system is shut down.

[0014] The positive and progressive effects of this application are as follows: 1. This invention eliminates the PEM hydrogen production water tank and replaces it with a comprehensive safety water tank, allowing for the safe recycling of water from the hydrogen side to achieve energy conservation; 2. This invention minimizes safety hazards before full-load hydrogen production; 3. This invention fully utilizes the fact that hydrogen production is greater than oxygen production (oxygen production is always half that of hydrogen); 4. This invention is highly feasible and applicable to various types of electrolyzers. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the PEM hydrogen production energy-saving system provided by the present invention.

[0016] Figure 2 A functional illustration diagram of the PEM hydrogen production energy-saving system provided by the present invention.

[0017] Figure 3 A flowchart of the control method for the PEM hydrogen production energy-saving system provided by the present invention.

[0018] Figure 4 A flowchart illustrating a specific implementation method for the control method of the PEM hydrogen production energy-saving system provided by the present invention.

[0019] Figure 5 This is a schematic diagram illustrating the control of the opening and closing of the fourth control valve provided by the present invention.

[0020] Figure 6 This is a schematic diagram of the preset values ​​for each sensor provided by the present invention. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, terms such as "comprising" and "having" mean that in addition to those already listed in "comprising" and "having," other unlisted contents may also be included; for example, a process, method, system, product, or device may include a series of steps or units, not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0024] like Figure 1 As shown, the present invention is a PEM hydrogen production energy-saving system, which includes a comprehensive safety water tank, a water pump, an oxygen separator, a pure water circulation pump, an ion filter, a PEM tank, a hydrogen separator, a buffer tank, and a hydrogen production power supply. The integrated safety water tank is equipped with a water inlet, through which external pure water is added to the integrated safety water tank. The bottom of the integrated safety water tank is connected to the inlet of the water pump through a pipe, and the outlet of the water pump is connected to the first inlet of the oxygen separator, so as to add pure water from the integrated safety water tank to the oxygen separator. The outlet of the oxygen separator is connected to the inlet of the ion filter via the pure water circulation pump. The outlet of the ion filter is connected to the inlet of the PEM tank. The outlet of the PEM tank is connected to the inlet of the hydrogen separator and the second inlet of the oxygen separator. The outlet of the hydrogen separator is connected to the inlet of the buffer tank. The outlet of the buffer tank is connected to the inlet of the integrated safety water tank. The hydrogen production power supply is connected to the PEM tank.

[0025] Preferably, such as Figure 2As shown, the integrated safety water tank stores pure water for hydrogen production; the water pump replenishes the pure water in the integrated safety water tank to the oxygen separator; the oxygen separator separates oxygen and pure water; a pure water cooler is installed between the oxygen separator and the pure water circulation pump to cool the pure water discharged from the oxygen separator; the pure water circulation pump provides the power source required for pure water circulation; a flow meter is installed between the pure water circulation pump and the ion filter to monitor the flow rate of pure water circulation; the ion filter filters out ionic impurities from the pure water entering the PEM tank; the PEM tank decomposes pure water into oxygen and hydrogen under the action of the hydrogen production power source, and delivers the oxygen and pure water to the oxygen separator, and the hydrogen and pure water to the hydrogen separator; the hydrogen separator separates hydrogen and pure water; the buffer tank buffers the pressure of the pure water discharged from the hydrogen separator; the hydrogen production power source provides DC power to the PEM tank.

[0026] Preferably, the hydrogen separator is provided with a first control valve, the oxygen separator is provided with a second control valve, a third control valve is provided between the hydrogen separator and the buffer tank, a fourth control valve is provided on the integrated safety water tank, a fifth control valve is provided between the water pump and the oxygen separator, a sixth control valve is connected between the water pump and the fifth control valve, and the outlet end of the buffer tank is connected to the inlet end of the integrated safety water tank through a pressure reducing valve.

[0027] Preferably, a first pressure sensor and a first temperature sensor are respectively installed on the pipeline between the PEM tank and the hydrogen separator, a second pressure sensor and a second temperature sensor are respectively installed on the pipeline between the PEM tank and the oxygen separator, and a third pressure sensor is installed on the buffer tank. The integrated safety water tank is equipped with a fourth pressure sensor and a hydrogen concentration sensor. The fourth pressure sensor is used to monitor the pressure of the gas phase inside the integrated safety water tank, and the hydrogen concentration sensor is used to monitor the concentration of hydrogen inside the integrated safety water tank. The opening and closing of the fourth control valve are controlled according to the pressure of the gas phase inside the integrated safety water tank or the concentration of hydrogen inside the integrated safety water tank.

[0028] Preferably, the hydrogen separator is equipped with a first liquid level sensor for monitoring the height of the liquid phase inside the hydrogen separator; the oxygen separator is equipped with a second liquid level sensor for monitoring the height of the liquid phase inside the oxygen separator; and the integrated safety water tank is equipped with a third liquid level sensor for monitoring the height of the liquid phase inside the integrated safety water tank.

[0029] In embodiments of the present invention, such as Figure 1 As shown, the integrated safety water tank is equipped with a fourth control valve (referred to as valve 4). When the pressure of the gas phase inside the integrated safety water tank is too high or too low, the fourth control valve can be opened to restore the pressure of the gas phase inside the integrated safety water tank to 1 atmosphere. In addition, the fourth control valve can also safely release any residual hydrogen gas. The hydrogen concentration in the integrated safety water tank is monitored by a hydrogen concentration sensor (referred to as sensor 1). When the concentration reaches a certain level, the fourth control valve is opened to release the residual hydrogen gas (a flame arrester must be installed on the fourth control valve when releasing hydrogen gas), ensuring the safety of pure water entering the PEM hydrogen production energy-saving system.

[0030] In this embodiment of the invention, the hydrogen production power supply provides direct current, with its positive and negative electrodes connected to the PEM tank. Under the action of the direct current, pure water decomposes into corresponding protons, generating a certain amount of heat. The pure water is consumed, producing oxygen + pure water at the positive electrode and hydrogen + pure water at the negative electrode.

[0031] In this embodiment of the invention, the oxygen and pure water generated by the electrolysis of the PEM cell pass through an oxygen separator. The oxygen is discharged through the second control valve (hereinafter referred to as valve 2), and the pure water, due to its weight, flows from the outlet of the oxygen separator to the pure water cooler (cooling) → pure water circulation pump (circulation power source) → pure water flow meter (hereinafter referred to as flow) → ion filter (absorbing impurity ions) → back to the PEM cell.

[0032] In this embodiment of the invention, the oxygen separator has a second liquid level sensor (hereinafter referred to as liquid 2) to monitor the height of the liquid phase in the oxygen separator, so as to control the ratio of the gas phase space and the liquid phase space, and to a certain extent, it can also adjust the pressure of the second pressure sensor (hereinafter referred to as pressure 2). The flow rate of pure water must also be taken into account to ensure that there is sufficient circulation volume of pure water.

[0033] In this embodiment of the invention, the bottom of the hydrogen separator drains water through a third control valve, which then passes through a buffer tank and a pressure reducing valve to lower the hydrogen content in the water. The water then enters a comprehensive safety water tank for temporary storage, where it can also perform a small-scale gas-liquid separation. Excess water in the comprehensive safety water tank is piped to a water pump at the bottom to replenish the PEM hydrogen production energy-saving system with pure water.

[0034] In this embodiment of the invention, industrial processes do not involve recycling to prevent residual hydrogen in the pure water from permeating to the oxygen side and forming a hydrogen-oxygen mixture. This invention adds a pressure reducing valve (referred to as "reducing valve 1") before the integrated safety water tank, which can significantly reduce the amount of residual hydrogen in the pure water (the principle is that the higher the pressure, the higher the solubility of residual hydrogen in pure water. At 0.1-0.2 MPa, the residual hydrogen is very little, almost negligible).

[0035] It should be noted that, to prevent the accumulation of residual hydrogen, a hydrogen concentration sensor (referred to as Sensor 1) is installed on the integrated safety water tank. When the residual hydrogen evaporated in the gas phase reaches the alarm value, the fourth control valve (referred to as Valve 4) is opened, releasing the residual hydrogen and reducing the gas phase pressure in the integrated safety water tank, making the residual hydrogen negligible. This ensures that no hydrogen is present when pure water enters the oxygen side. Hence the name "integrated safety water tank." Under normal operation, the pressure is the same as atmospheric pressure. The pressure changes when pure water is recovered and replenished. When the liquid level rises, the gas phase pressure increases; when the liquid level falls, a certain negative pressure is created. According to regulations, 1 meter of water height is approximately equal to 0.098 MPa. Assuming a liquid level fluctuation of 0.5 meters, the corresponding pressure is 0.049 MPa < 0.1 MPa. Within this very safe range, residual hydrogen can be ignored.

[0036] In this embodiment of the invention, although some pure water can be recovered from the integrated safety water tank through the liquid phase of the hydrogen separator, over time, the pure water still needs to be replenished externally. An external water inlet is provided. Pure water is drawn from the integrated safety water tank and added to the oxygen separator of the PEM hydrogen production energy-saving system via a water pump.

[0037] In this embodiment of the invention, the initial state of the PEM hydrogen production energy-saving system is as follows: L2 < Liquid 1 < L3 (at a higher liquid level); L4 < Liquid 2 < L5 (at a lower liquid level); L8 < liquid 3 < L9 (at a higher liquid level).

[0038] In this embodiment of the invention, the normal operating state of the PEM hydrogen production energy-saving system is as follows: ◆Normal pure water circuit route: Water inlet → Integrated safety water tank → Water pump → Oxygen separator → Pure water cooler → Pure water circulation pump → Flow rate → Ion filter → PEM tank ◆→PEM tank→ Oxygen + pure water→ Oxygen separator ◆→PEM tank→ Hydrogen + pure water→ Hydrogen separator→ Valve 3→ Buffer tank (pressure stabilizer)→ Reduce 1→ Integrated safety water tank.

[0039] In this embodiment of the invention, the limiting state of the PEM hydrogen production energy-saving system is as follows: When the oxygen separator liquid level is high and the comprehensive safety water tank liquid level is high, only valve 5 can be closed and valve 6 can be opened to drain pure water.

[0040] This embodiment also provides a control method for a PEM hydrogen production energy-saving system, such as... Figure 3 As shown, the control method of the PEM hydrogen production energy-saving system includes the following steps: Step S1: First, open the first, second, and fifth control valves and the pressure reducing valve, while simultaneously closing the third, fourth, and sixth control valves and the water pump. Then, determine when the liquid level in the hydrogen separator is within the first preset range, the liquid level in the oxygen separator is within the second preset range, and the liquid level in the integrated safety water tank is within the third preset range. At this point, activate the control center, start the hydrogen production power supply, and control the PEM hydrogen production energy-saving system to begin hydrogen production, i.e., control the PEM hydrogen production energy-saving system to enter its initial state. The first preset range is: L2 < liquid 1 < L3; where, for example Figure 6 As shown, L1 is the height of the liquid phase inside the hydrogen separator, L2 is the second preset liquid level value, and L3 is the third preset liquid level value. The second preset range is: L4 < liquid 2 < L5; where, for example Figure 6 As shown, L2 is the height of the liquid phase in the oxygen separator, L4 is the fourth preset liquid level value, and L5 is the fifth preset liquid level value. The third preset range is: L8 < liquid 3 < L9; where, for example Figure 6 As shown, L3 is the height of the liquid phase in the integrated safety water tank, L8 is the eighth preset liquid level value, and L9 is the ninth preset liquid level value. Step S2: After the PEM hydrogen production energy-saving system enters the initial state, determine whether the height of the liquid phase in the hydrogen separator is still within the first preset range. If so, control the third control valve to open and proceed to step S3. Preferably, such as Figure 4 As shown, step S2 includes: If the height of the liquid phase inside the hydrogen separator is: L1 < liquid1 < L2; where, as Figure 6 As shown, L1 is the first preset liquid level value, then there are the following two cases: (1) If the height of the liquid phase in the integrated safety water tank is: liquid 3 ≥ L9, then return to step S2; (2) If the height of the liquid phase in the integrated safety water tank is: L7 < liquid 3 < L9, where, as Figure 6 As shown, L7 is the seventh preset liquid level value, so the third control valve is opened and the process proceeds to step S3.

[0041] Step S3: Determine whether the liquid level in the integrated safety water tank is still within the third preset range. If so, turn on the water pump to add pure water to the oxygen separator and proceed to step S4. Preferably, such as Figure 4 As shown, step S3 includes: If the liquid level in the integrated safety tank is L7 < L3 < L8, then there are two possibilities: (1) If the height of the liquid phase in the hydrogen separator is: L2 < liquid 1 < L3, then return to step S3; (2) If the height of the liquid phase in the hydrogen separator is L1 < liquid 1 < L2, then water is added to the integrated safety water tank through the water inlet. After the height of the liquid phase in the integrated safety water tank rises, the water inlet is closed and the process returns to step S3.

[0042] Step S4: Determine whether the height of the liquid phase in the oxygen separator is still within the second preset range. If so, control the PEM hydrogen production energy-saving system to enter the cycle energy-saving hydrogen production mode, that is, control the PEM hydrogen production energy-saving system to enter the normal working state.

[0043] Preferably, such as Figure 4 As shown, step S4 includes: If the liquid phase height in the oxygen separator is L5 < liquid 2 ≤ L6, then return to step S4; where, if Figure 6 As shown, L6 is the sixth preset liquid level value; If the liquid level in the oxygen separator is L2 > L6, then the sixth control valve is opened and the fifth control valve is closed to drain the water using a water pump. After the liquid level in the oxygen separator drops, the sixth control valve is closed and the fifth control valve is opened.

[0044] Preferably, such as Figure 5 As shown, after the PEM hydrogen production energy-saving system enters the initial state, it also includes: (1) The opening and closing of the fourth control valve are controlled according to the pressure of the gas phase in the integrated safety water tank; wherein, When the pressure of the gas phase inside the integrated safety water tank is: pressure 4 ≤ P10, then the fourth control valve is opened for 2 seconds, and then closed; wherein, if Figure 6 As shown, pressure 4 is the pressure of the gas phase inside the integrated safety water tank, and P10 is the tenth preset pressure value; When the pressure of the gas phase inside the integrated safety water tank is: P10 < P4 < P11, then the fourth control valve is closed; wherein, if Figure 6 As shown, P11 is the eleventh preset pressure value; When the pressure of the gas phase in the integrated safety water tank is: pressure 4 = P11, the fourth control valve is closed. At this time, the pressure of the gas phase in the integrated safety water tank is the normal value, that is, one atmosphere. When the pressure of the gas phase inside the integrated safety water tank is: P11 < P4 < P12, then the fourth control valve is closed; wherein, if Figure 6As shown, P12 is the twelfth preset pressure value; When the pressure of the gas phase in the integrated safety water tank is: pressure 4 ≥ P12, then control the fourth control valve to open for 2 seconds, and then control the fourth control valve to close. (2) The opening and closing of the fourth control valve are controlled according to the hydrogen concentration in the integrated safety water tank; wherein, When the hydrogen concentration in the integrated safety water tank is: H1 ≤ H1, then the fourth control valve is closed; wherein, if Figure 6 As shown, Measure 1 is the concentration of hydrogen in the integrated safety water tank, and H1 is the first preset concentration value; When the hydrogen concentration in the integrated safety water tank is: H1 < H1 < H2, then the fourth control valve is closed; wherein, if Figure 6 As shown, H2 is the second preset concentration value; When the hydrogen concentration in the integrated safety water tank is: H2 ≤ H1 < H3, then the fourth control valve is opened for 2 seconds, and then closed; wherein, if Figure 6 As shown, H3 is the third preset concentration value; When the concentration of hydrogen in the integrated safety water tank is: 1 ≥ H3, the fourth control valve is opened, and then the PEM hydrogen production energy-saving system is shut down.

[0045] The present invention provides a control method for a PEM hydrogen production energy-saving system, which can recycle and reuse water on the hydrogen side under safe conditions to achieve energy saving.

[0046] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A PEM hydrogen production energy-saving system, characterized in that, The PEM hydrogen production energy-saving system includes a comprehensive safety water tank, a water pump, an oxygen separator, a pure water circulation pump, an ion filter, a PEM tank, a hydrogen separator, a buffer tank, and a hydrogen production power supply. The integrated safety water tank is equipped with a water inlet, through which external pure water is added to the integrated safety water tank. The bottom of the integrated safety water tank is connected to the inlet of the water pump through a pipe, and the outlet of the water pump is connected to the first inlet of the oxygen separator, so as to add pure water from the integrated safety water tank to the oxygen separator. The outlet of the oxygen separator is connected to the inlet of the ion filter via the pure water circulation pump. The outlet of the ion filter is connected to the inlet of the PEM tank. The outlet of the PEM tank is connected to the inlet of the hydrogen separator and the second inlet of the oxygen separator. The outlet of the hydrogen separator is connected to the inlet of the buffer tank. The outlet of the buffer tank is connected to the inlet of the integrated safety water tank. The hydrogen production power supply is connected to the PEM tank.

2. The PEM hydrogen production energy-saving system as described in claim 1, characterized in that, The integrated safety water tank stores pure water for hydrogen production; the water pump replenishes the pure water in the integrated safety water tank to the oxygen separator; the oxygen separator separates oxygen and pure water; a pure water cooler is installed between the oxygen separator and the pure water circulation pump to cool the pure water discharged from the oxygen separator; the pure water circulation pump provides the power source for pure water circulation; a flow meter is installed between the pure water circulation pump and the ion filter to monitor the flow rate of pure water circulation; the ion filter filters out ionic impurities from the pure water entering the PEM tank; the PEM tank decomposes pure water into oxygen and hydrogen under the action of the hydrogen production power source, and delivers the oxygen and pure water to the oxygen separator, and the hydrogen and pure water to the hydrogen separator; the hydrogen separator separates hydrogen and pure water; the buffer tank buffers the pressure of the pure water discharged from the hydrogen separator; the hydrogen production power source provides DC power to the PEM tank.

3. The PEM hydrogen production energy-saving system as described in claim 1, characterized in that, The hydrogen separator is equipped with a first control valve, the oxygen separator is equipped with a second control valve, a third control valve is installed between the hydrogen separator and the buffer tank, a fourth control valve is installed on the integrated safety water tank, a fifth control valve is installed between the water pump and the oxygen separator, a sixth control valve is connected between the water pump and the fifth control valve, and the outlet end of the buffer tank is connected to the inlet end of the integrated safety water tank through a pressure reducing valve.

4. The PEM hydrogen production energy-saving system as described in claim 3, characterized in that, A first pressure sensor and a first temperature sensor are respectively installed on the pipeline between the PEM tank and the hydrogen separator, a second pressure sensor and a second temperature sensor are respectively installed on the pipeline between the PEM tank and the oxygen separator, and a third pressure sensor is installed on the buffer tank. The integrated safety water tank is equipped with a fourth pressure sensor and a hydrogen concentration sensor. The fourth pressure sensor is used to monitor the pressure of the gas phase inside the integrated safety water tank, and the hydrogen concentration sensor is used to monitor the concentration of hydrogen inside the integrated safety water tank. The opening and closing of the fourth control valve are controlled according to the pressure of the gas phase inside the integrated safety water tank or the concentration of hydrogen inside the integrated safety water tank.

5. The PEM hydrogen production energy-saving system as described in claim 1, characterized in that, The hydrogen separator is equipped with a first liquid level sensor, which is used to monitor the height of the liquid phase inside the hydrogen separator; the oxygen separator is equipped with a second liquid level sensor, which is used to monitor the height of the liquid phase inside the oxygen separator; and the integrated safety water tank is equipped with a third liquid level sensor, which is used to monitor the height of the liquid phase inside the integrated safety water tank.

6. A control method for a PEM hydrogen production energy-saving system as described in any one of claims 1-5, characterized in that, The control method of the PEM hydrogen production energy-saving system includes the following steps: Step S1: First, open the first, second, and fifth control valves and the pressure reducing valve, while simultaneously closing the third, fourth, and sixth control valves and the water pump. Then, determine when the liquid level in the hydrogen separator is within the first preset range, the liquid level in the oxygen separator is within the second preset range, and the liquid level in the integrated safety water tank is within the third preset range. At this point, activate the control center, start the hydrogen production power supply, and control the PEM hydrogen production energy-saving system to begin hydrogen production, i.e., control the PEM hydrogen production energy-saving system to enter its initial state. The first preset range is: L2 < liquid 1 < L3; where liquid 1 is the height of the liquid phase in the hydrogen separator, L2 is the second preset liquid level value, and L3 is the third preset liquid level value. The second preset range is: L4 < liquid 2 < L5; where liquid 2 is the height of the liquid phase in the oxygen separator, L4 is the fourth preset liquid level value, and L5 is the fifth preset liquid level value. The third preset range is: L8 < liquid 3 < L9; where liquid 3 is the height of the liquid phase in the integrated safety water tank, L8 is the eighth preset liquid level value, and L9 is the ninth preset liquid level value. Step S2: After the PEM hydrogen production energy-saving system enters the initial state, determine whether the height of the liquid phase in the hydrogen separator is still within the first preset range. If so, control the third control valve to open and proceed to step S3. Step S3: Determine whether the liquid level in the integrated safety water tank is still within the third preset range. If so, turn on the water pump to add pure water to the oxygen separator and proceed to step S4. Step S4: Determine whether the height of the liquid phase in the oxygen separator is still within the second preset range. If so, control the PEM hydrogen production energy-saving system to enter the cycle energy-saving hydrogen production mode, that is, control the PEM hydrogen production energy-saving system to enter the normal working state.

7. The control method for the PEM hydrogen production energy-saving system as described in claim 6, characterized in that, Step S2 includes: If the height of the liquid phase inside the hydrogen separator is L1 < liquid 1 < L2, where L1 is the first preset liquid level value, then there are two possibilities: (1) If the height of the liquid phase in the integrated safety water tank is: liquid 3 ≥ L9, then return to step S2; (2) If the height of the liquid phase in the integrated safety water tank is: L7 < liquid 3 < L9, where L7 is the seventh preset liquid level value, then control the third control valve to open and proceed to step S3.

8. The control method for the PEM hydrogen production energy-saving system as described in claim 6, characterized in that, Step S3 includes: If the liquid level in the integrated safety tank is L7 < L3 < L8, then there are two possibilities: (1) If the height of the liquid phase in the hydrogen separator is: L2 < liquid 1 < L3, then return to step S3; (2) If the height of the liquid phase in the hydrogen separator is L1 < liquid 1 < L2, then water is added to the integrated safety water tank through the water inlet. After the height of the liquid phase in the integrated safety water tank rises, the water inlet is closed and the process returns to step S3.

9. The control method for the PEM hydrogen production energy-saving system as described in claim 6, characterized in that, Step S4 includes: If the height of the liquid phase in the oxygen separator is: L5 < liquid 2 ≤ L6, then return to step S4; where L6 is the sixth preset liquid level value; If the liquid level in the oxygen separator is L2 > L6, then the sixth control valve is opened and the fifth control valve is closed to drain the water using a water pump. After the liquid level in the oxygen separator drops, the sixth control valve is closed and the fifth control valve is opened.

10. The control method for the PEM hydrogen production energy-saving system as described in claim 6, characterized in that, After the PEM hydrogen production energy-saving system enters its initial state, it also includes: (1) The opening and closing of the fourth control valve are controlled according to the pressure of the gas phase in the integrated safety water tank; wherein, When the pressure of the gas phase in the integrated safety water tank is: pressure 4 ≤ P10, the fourth control valve is opened for 2 seconds, and then the fourth control valve is closed; where pressure 4 is the pressure of the gas phase in the integrated safety water tank, and P10 is the tenth preset pressure value; When the pressure of the gas phase in the integrated safety water tank is: P10 < pressure 4 < P11, the fourth control valve is controlled to close; where P11 is the eleventh preset pressure value; When the pressure of the gas phase in the integrated safety water tank is: pressure 4 = P11, then the fourth control valve is closed. When the pressure of the gas phase in the integrated safety water tank is: P11 < pressure 4 < P12, the fourth control valve is closed; where P12 is the twelfth preset pressure value. When the pressure of the gas phase in the integrated safety water tank is: pressure 4 ≥ P12, then control the fourth control valve to open for 2 seconds, and then control the fourth control valve to close. (2) The opening and closing of the fourth control valve are controlled according to the hydrogen concentration in the integrated safety water tank; wherein, When the concentration of hydrogen in the integrated safety water tank is: Measure 1 ≤ H1, then the fourth control valve is closed; where Measure 1 is the concentration of hydrogen in the integrated safety water tank, and H1 is the first preset concentration value; When the concentration of hydrogen in the integrated safety water tank is: H1 < H1 < H2, then the fourth control valve is closed; where H2 is the second preset concentration value. When the concentration of hydrogen in the integrated safety water tank is: H2≤Measure1<H3, the fourth control valve is opened for 2 seconds, and then the fourth control valve is closed; where H3 is the third preset concentration value; When the concentration of hydrogen in the integrated safety water tank is: 1 ≥ H3, the fourth control valve is opened, and then the PEM hydrogen production energy-saving system is shut down.

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