A source-load matching control device and method for photovoltaic direct current water electrolysis hydrogen production system

Abstract

The present invention proposes a source-load matching control device and method for a photovoltaic direct current water electrolysis hydrogen production system, comprising: a control system, a photovoltaic array, a heat exchange system, an adjustable heater, an energy storage system water electrolyzer, an electrodialysis device and a photovoltaic inverter; the control system comprises a controller and a sensor, the controller is installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, and mainly collects all parameters of the sensor and the photovoltaic water electrolysis hydrogen production system; the radiator comprises an indoor radiator and a molecular sieve dryer radiator, which are respectively installed on the indoor wall of the photovoltaic water electrolysis hydrogen production system room and in the molecular sieve dryer; and also comprises a temporary storage tank containing wet hydrogen, which is placed between the water electrolyzer and the molecular sieve dryer, and the hydrogen generated by the full-load electrolysis of the photovoltaic power generation water electrolyzer is temporarily stored in the temporary storage tank, and when the photovoltaic power generation power is less than the lower limit power of the water electrolyzer, the wet hydrogen in the temporary storage tank is dried again to make full use of the photovoltaic power generation energy.

Description

Technical Field

[0001] The present invention relates to the field of electric power and new energy, and in particular to a source-load matching control device and method for a photovoltaic direct current water electrolysis hydrogen production system. Background Art

[0002] Hydrogen energy is the best energy carrier to solve national energy security and environmental problems. Fuel cell technology has significant advantages in high-power and long-distance applications and has huge market potential. The main energy source at this stage is still fossil energy, which not only has limited reserves but is also unclean. As a clean energy, hydrogen energy will gradually replace the current energy because of its unique advantages, and it can also solve the energy crisis. It is predicted that we will fully enter the hydrogen energy society around 2050. The hydrogen energy society will surely bring revolutionary changes to the entire automobile and even energy industry, and will also be the commanding heights of future industries, with a great industry-leading effect.

[0003] Its significance:

[0004] 1) Strategic significance: Hydrogen energy is a medium for energy conversion and a carrier of secondary energy;

[0005] 2) Practical significance: Large-scale energy storage and regulation capabilities promote the development of new energy. The fluctuations in power generation from new energy sources such as photovoltaics and wind power restrict the rapid development of new energy. At the same time, the rapid advancement of new energy sources such as photovoltaics and wind power has made consumption a new problem. Hydrogen production can consume electricity and generate electricity when there is a shortage of electricity, which essentially plays a role in peak shaving and valley filling.

[0006] However, water electrolysis is also a high-energy-consuming device, so it is imperative to introduce new energy to produce hydrogen. The efficiency of new energy power generation and water electrolysis hydrogen production has become a key issue: for example, photovoltaic power generation, mainly the load matching problem of photovoltaic power generation power curve and water electrolysis hydrogen production process.

[0007] For example, the current basic hydrogen production process electricity time sequence distribution: electrodialysis device to produce pure water - water electrolyzer - regeneration heater - molecular sieve dryer - pure hydrogen output. Since the water electrolyzer electricity consumption accounts for more than 80% of the system electricity consumption in the water electrolysis hydrogen production process, and the regeneration heater electricity consumption accounts for more than 10% of the system electricity consumption, and the water electrolysis hydrogen production and regeneration heater electricity consumption rate is quite high, in the water electrolysis hydrogen production process, photovoltaic power generation is mainly used for water electrolysis hydrogen production + regeneration heater power, and the water electrolyzer has upper and lower power limits. When the photovoltaic power generation power is lower than the lower limit power of water electrolysis hydrogen production, it cannot be effectively utilized. The greater the system power, the lower the effective utilization rate of photovoltaic power generation, and the water electrolysis hydrogen production process and the photovoltaic power generation curve have a low matching degree.

[0008] At the same time, the following links also affect the efficiency of hydrogen production by water electrolysis:

[0009] Issues such as the power size of the water electrolyzer, the temperature of the water electrolyzer, the temperature inside the molecular sieve dryer and the indoor ambient temperature, the photovoltaic power generation efficiency, and the matching degree between the photovoltaic maximum power point and the water electrolyzer power. Summary of the invention

[0010] In order to solve the problem of low matching degree between photovoltaic water electrolysis hydrogen production process and photovoltaic power generation curve, and at the same time solve the problems of hydrogen production tank temperature and ambient temperature, comprehensive utilization of photovoltaic power generation and other issues that affect the efficiency of photovoltaic water electrolysis hydrogen production, the present invention proposes a source-load matching control device and method for photovoltaic direct current water electrolysis hydrogen production system to ensure efficient photovoltaic water electrolysis hydrogen production.

[0011] The device of the present invention adopts direct coupling connection: it does not consider introducing large energy storage devices and DC / DC converters into the system. In order to solve the mismatch problem between the maximum power point directly output by the photovoltaic array and the optimal water photovoltaic electrolysis hydrogen production, and to efficiently utilize the photovoltaic maximum power point output power, it is proposed to add a temporary storage tank containing wet hydrogen between the water electrolyzer and the molecular sieve dryer, separate the hydrogen purification process from the water electrolyzer process, and use an adjustable heater + energy storage system to participate in the regulation of the matching degree between the photovoltaic maximum power point and the optimal hydrogen production of the water electrolyzer.

[0012] The technical solution of the present invention is: a source-load matching control device for a photovoltaic direct current water electrolysis hydrogen production system, characterized in that it comprises: a control system, a photovoltaic array, a heat exchange system, an adjustable heater, an energy storage system water electrolyzer, an electrodialysis device and a photovoltaic inverter;

[0013] The control system includes a controller and a sensor. The controller is installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, and mainly collects all parameters of the sensor and the photovoltaic water electrolysis hydrogen production system;

[0014] The photovoltaic array includes multiple photovoltaic modules, which are installed around the photovoltaic water electrolysis hydrogen production system to provide energy for photovoltaic water electrolysis hydrogen production; the photovoltaic array output is respectively connected to the water electrolyzer, electrodialysis device, adjustable heater, energy storage system and photovoltaic inverter input end.

[0015] The heat exchange system includes: phase change heat storage material, heat exchanger, and radiator, wherein the phase change heat storage material is filled in a sealed box and placed in the photovoltaic water electrolysis hydrogen production system room or other indoor surroundings; the heat exchanger is installed in the phase change heat storage material. The purpose of the heat exchanger is to release the heat energy of the heat source in the phase change heat storage material through different radiators.

[0016] The radiator comprises an indoor radiator and a molecular sieve dryer radiator, which are respectively installed on the indoor wall of the photovoltaic water electrolysis hydrogen production system and in the molecular sieve dryer. According to the temperature requirement, the temperature of the heat exchanger is switched by a valve, and the heat is exchanged to the indoor environment through the indoor radiator to ensure the indoor temperature; the heat is exchanged to the molecular sieve dryer environment through the molecular sieve dryer radiator to provide the basic temperature of the molecular sieve dryer and improve the speed of hydrogen purification of the molecular sieve dryer.

[0017] The energy storage system includes: a bidirectional converter and an energy storage battery, which are installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, wherein the capacity of the energy storage system is to maintain the short-term and startup operation requirements of the hydrogen production auxiliary equipment.

[0018] The photovoltaic inverter is installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, mainly providing AC power for photovoltaic water electrolysis hydrogen production auxiliary equipment, including air compressors, water pumps, etc.

[0019] The adjustable heater is installed in the phase change material. The adjustable heater cooperates with the phase change material to store the excess photovoltaic power through the phase change material or directly use it for dry hydrogen.

[0020] The electrodialysis device is installed with a pure water container, and the pure water prepared by the electrodialysis device enters the pure water container, and the outlet of the pure water container provides water for hydrogen production in the water electrolyzer. The electrodialysis device is installed in the photovoltaic water electrolysis hydrogen production system room or other indoor surroundings;

[0021] The water electrolyzer is the main equipment of the photovoltaic water electrolysis hydrogen production system, is mainly used for water electrolysis hydrogen production, and is installed indoors in the photovoltaic water electrolysis hydrogen production system.

[0022] Installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, it mainly collects all parameters of the photovoltaic water electrolysis hydrogen production equipment.

[0023] The control system is composed of a controller and a sensor. The controller is installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, and mainly collects all parameters of the sensor and the photovoltaic water electrolysis hydrogen production system.

[0024] The controller's input interface is connected to all sensor output ports through data lines to monitor the operating status of all devices and systems, and execute corresponding control strategies after analysis and judgment. The controller's output interface is connected to all actuators and equipment through control lines to control the corresponding equipment to work or stop, thus achieving efficient operation of photovoltaic water electrolysis hydrogen production.

[0025] The temporary storage tank containing wet hydrogen of the present invention is placed between the water electrolyzer and the molecular sieve dryer, and the hydrogen generated by the full-load electrolysis of the photovoltaic water electrolyzer is temporarily stored in the temporary storage tank. When the photovoltaic power generation power is less than the lower limit power of the water electrolyzer, the wet hydrogen in the temporary storage tank is dried again to fully utilize the photovoltaic power generation energy.

[0026] The wet hydrogen temporary storage tank is composed of a pressure tank, an air inlet pipe, an air outlet pipe, a safety valve and a drainage pipe. One end of the air inlet pipe is installed on the upper left side of the pressure tank, an air inlet check valve is installed on the air inlet pipe, and the other end of the air inlet pipe is connected to the hydrogen outlet of the electrolyzer; one end of the air outlet pipe is installed on the upper right side of the pressure tank, an air outlet check valve is installed on the air outlet pipe, and the other end of the air outlet pipe is connected to the air inlet of the molecular sieve dryer; one end of the drainage pipe is installed on the lower end of the pressure tank, and a valve is installed on the drainage pipe for regular drainage; one end of the safety valve is installed on the upper end of the pressure tank, and the outlet of the safety valve is connected to a special hydrogen discharge and venting pipe.

[0027] According to another aspect of the present invention, a source-load matching control method for a photovoltaic direct current water electrolysis hydrogen production system is provided, comprising the following steps:

[0028] The electrodialysis device prepares pure water, which is then supplied to the water electrolyzer for hydrogen production through pipelines;

[0029] The wet hydrogen produced by the water electrolyzer is stored in a wet hydrogen temporary storage tank between the photovoltaic water electrolyzer and the molecular sieve dryer;

[0030] Source-load matching control is performed based on lighting conditions. The photovoltaic power generation curve under ideal lighting conditions is divided into three stages:

[0031] The first stage is before the photovoltaic power generation reaches the lower power limit of the water electrolyzer;

[0032] The second stage is to start the water electrolyzer to produce hydrogen when the photovoltaic power generation meets the lower limit of hydrogen power of the electrolytic hydrogen production electrolyzer, and store the wet hydrogen;

[0033] The third stage is in the afternoon when the photovoltaic power generation power is from the lower limit power of the water electrolyzer to the minimum working load of the photovoltaic water electrolysis hydrogen production system;

[0034] In the three stages, the power combination vector P of the auxiliary equipment for photovoltaic water electrolysis hydrogen production is used to control the power P of the electrodialysis device respectively. s 、Energy storage system charging power P c , air compressor compressed gas power P g , Regeneration heater power P kThe system starts and stops the system, and cooperates with the adjustable heater phase change heat storage to time-share the photovoltaic water electrolysis hydrogen production, the wet hydrogen stored in the temporary tank, the regeneration heater heating and the molecular sieve dryer to prepare pure hydrogen for compression storage and filling, thereby realizing the load decoupling of the water electrolyzer and the molecular sieve dryer and effectively utilizing the photovoltaic power generation power.

[0035] The original basic hydrogen production process is: electrodialysis device to produce pure water - water electrolyzer - regeneration heater - molecular sieve dryer - pure hydrogen output. Since the water electrolyzer hydrogen production and regeneration heater have power supply requirements at the same time, accounting for 85-90% of the electrolytic hydrogen production power, 85-90% of the photovoltaic power generation is used for water electrolyzer hydrogen production + regeneration heater power supply, and the photovoltaic power generation power less than the lower limit of photovoltaic water electrolyzer hydrogen production cannot be effectively utilized. When the light is weak, the time to meet the power supply of water electrolyzer hydrogen production + regeneration heater is short, the utilization rate of photovoltaic power generation further decreases, and the matching degree with the photovoltaic power generation curve is low. At the same time, in order to meet more hydrogen production needs, it is necessary to increase the installation capacity of the photovoltaic array to participate in power generation.

[0036] The improved basic hydrogen production process of the present invention is to add a temporary storage tank for wet hydrogen before hydrogen purification, thereby realizing the separation of the power supply requirements of hydrogen production in the water electrolyzer and the regeneration heater. The improved basic hydrogen production process is as follows:

[0037] Electrodialysis device to produce pure water - water electrolyzer - temporary storage tank for wet hydrogen - regeneration heater - molecular sieve dryer - pure hydrogen output. Due to the addition of a temporary storage tank for wet hydrogen before hydrogen purification, the wet hydrogen at the outlet of the water electrolyzer is temporarily stored, and the power supply requirements of the water electrolyzer hydrogen production and the regeneration heater are separated, so that the photovoltaic power generation power greater than or equal to the lower limit power of the water electrolyzer is used for hydrogen production in the water electrolyzer, and the photovoltaic power generation power less than the lower limit power of the water electrolyzer is used according to priority for the preparation of pure water by the electrodialysis device, the drying and purification of gas by the regeneration heater, and the compression of gas by the air compressor. In this way, through the method of load migration, the photovoltaic power generation power is improved to match the time and load power of the water electrolysis device, and the operation time of the electrolyzer is extended, while the installation capacity of the photovoltaic array is reduced. The photovoltaic installed capacity is reduced relative to the original basic hydrogen production process requirements.

[0038] Furthermore, the present invention defines the power combination vector P of photovoltaic water electrolysis hydrogen production auxiliary equipment:

[0039] The control system converts the electrodialysis device power P s 、Energy storage system charging power P c , air compressor compressed gas power P g , Regeneration heater power P k The start and stop states of the auxiliary equipment are encoded by binary numbers to generate an auxiliary equipment operation state array, which is then combined with the electrodialysis device power P s 、Energy storage system charging power P c , air compressor power Pg , Regeneration heater power P k The power vectors of the auxiliary equipment composed are multiplied to generate a complete enumeration of the power combination vector P of the photovoltaic water electrolysis hydrogen production auxiliary equipment.

[0040]

[0041] Among them, P x belongs to P0, P1, ..., P 15 Any combination of one or more, that is, P x ∈P.

[0042] According to an embodiment of the present invention, the control process based on the improved basic hydrogen production process and the photovoltaic power generation curve matching is as follows:

[0043] The photovoltaic power generation curve under ideal lighting conditions is divided into three stages:

[0044] The first stage is the morning photovoltaic power generation before reaching the lower limit power of the water electrolyzer. During this period, the electrodialysis device prepares pure water and the photovoltaic power generation process has a relatively high matching degree. When the photovoltaic power generation meets the conditions for the electrodialysis device to prepare pure water, the electrodialysis device is started to prepare pure water. By defining the power combination vector P of the photovoltaic water electrolysis hydrogen production auxiliary equipment, the matching combination vector P is found. x Auxiliary equipment such as adjustable heaters, air compressors, and energy storage participate in photovoltaic maximum power point tracking to ensure the maximum photovoltaic power output;

[0045] The second stage is when photovoltaic power generation meets the hydrogen power limit of the electrolytic hydrogen production electrolyzer, the water electrolyzer is started to produce hydrogen, and the wet hydrogen is stored, and the electrodialysis device to prepare pure water, air compressor, energy storage and adjustable heater are stopped.

[0046] As the sunlight increases, the photovoltaic power generation power increases, and the water electrolyzer power increases synchronously. Due to the voltage clamping effect of the electrolytic hydrogen production electrolyzer, the maximum power point of photovoltaic power generation may deviate at this time. However, when the photovoltaic array is installed and designed, the local seasonal changes and the impact of the environment on sunlight are taken into consideration, as well as the need for hydrogen production throughout the year. The deviation between the maximum power point of photovoltaic power generation and the hydrogen production power of the electrolyzer is relatively small.

[0047] When the photovoltaic power generation is greater than the limited hydrogen power on the water electrolyzer, the matching combination vector P is found based on the difference between the current photovoltaic power generation and the limited hydrogen power on the water electrolyzer and by defining the power combination vector P of the photovoltaic water electrolysis hydrogen production auxiliary equipment. x The corresponding load power equipment is started respectively, such as the adjustable heater phase change heat storage or regeneration heating, electrodialysis device water production, energy storage, air compressor, etc., to match the photovoltaic power generation power with the photovoltaic water electrolysis hydrogen production load.

[0048] When the photovoltaic power generation is less than the limited hydrogen power of the water electrolyzer, the relevant equipment will be stopped, such as the adjustable heater phase change heat storage or regenerative heating, electrodialysis device water production, and energy storage air compressor, to ensure the maximum hydrogen production by photovoltaic water electrolysis.

[0049] The third stage is the afternoon when the photovoltaic power generation power is from the lower limit power of the water electrolyzer to the minimum working load of the photovoltaic water electrolysis hydrogen production system. During this period, the main tasks are: according to the definition of the photovoltaic water electrolysis hydrogen production auxiliary equipment power combination vector P, find the matching combination vector P x The combination of regeneration heater power is used to output the gas in the wet hydrogen storage tank through the regeneration heater-molecular sieve dryer-pure hydrogen, and participates in the photovoltaic maximum power point tracking and adjustment through auxiliary equipment such as adjustable heaters to ensure the maximum photovoltaic power output;

[0050] Based on the above-mentioned photovoltaic power generation curve under ideal lighting conditions, which is divided into three stages, the control device of the present invention has the following specific control process:

[0051] The improved basic hydrogen production process is adopted: electrodialysis device to produce pure water - water electrolyzer - wet hydrogen temporary storage tank - regeneration heater - molecular sieve dryer - pure hydrogen output. Due to the addition of a wet hydrogen temporary storage tank before hydrogen purification, the wet hydrogen at the outlet of the water electrolyzer is temporarily stored, the power supply requirements of the water electrolyzer hydrogen production and the regeneration heater are separated, and the operating time of each load is set independently. Therefore, the lower limit power P of the water electrolyzer under the original process el_ymin Adjust down to the lower limit power P of the water electrolyzer with improved process el_min ; The upper limit power P of the water electrolyzer under the same original process el_ymax Reduce to the upper limit power P of the water electrolyzer under improved process el_max ; Photovoltaic water electrolysis hydrogen production time is reduced from the original process t 1_y ~t 2_y Increase to t 1_n ~t 2_n Based on the reduction of the upper and lower power limits of the water electrolyzer of the original process, the installed capacity of the photovoltaic array of the improved process was reduced.

[0052] Therefore, the control system will be greater than or equal to the lower limit power P of the water electrolyzer el_min Photovoltaic power generation power P v , used for water electrolyzer hydrogen production power P el , and through the photovoltaic water electrolysis hydrogen production auxiliary equipment power combination P in the photovoltaic water electrolysis hydrogen production auxiliary equipment power combination vector P x , find the hydrogen production power P of the water electrolyzer el The best match is close to the maximum power point P of photovoltaic power generation pv Power combination of auxiliary equipment P x , and then through the adjustable heater load P rFine-tuning to maximize the integration of photovoltaic water electrolysis hydrogen production and photovoltaic power generation maximum power point P pv match.

[0053] The control system will be less than the lower limit power P of the water electrolyzer according to the priority el_min Photovoltaic power generation power P v , used for preparing pure water power P in electrodialysis device s , Regeneration heater for gas drying and purification power P k , air compressor compressed gas power P g 、Energy storage system charging power P c Etc. And through the photovoltaic water electrolysis hydrogen production auxiliary equipment power combination P in the photovoltaic water electrolysis hydrogen production auxiliary equipment power combination vector P x , determine the maximum power point power P of photovoltaic power generation pv The equipment power combination P is approaching zero x , start all the equipment in the combination, and adjust the adjustable heater power to make the load power close to the maximum power point power P of photovoltaic power generation pv , thereby ensuring the maximum efficiency of photovoltaic water electrolysis hydrogen production.

[0054] Therefore, through the method of load migration, the photovoltaic power generation is improved, the photovoltaic water electrolysis device time and load power are matched, the water electrolysis tank operation time is extended, and the installation capacity of the photovoltaic array is reduced. Relative to the original basic hydrogen production process, the photovoltaic installed capacity is reduced.

[0055] The priority design of the present invention is as follows: in the morning period, electrodialysis, energy storage system, air compressor, regeneration heater, etc. are used in sequence; in the afternoon period, regeneration heater, energy storage system, air compressor, electrodialysis, etc. are used in sequence.

[0056] Among them, P el_min is the lower limit power of the water electrolyzer; P el_max is the upper limit power of the water electrolyzer; P pv is the maximum power point of photovoltaic output; I v is the maximum power point current of photovoltaic output; U v P is the maximum power point voltage of photovoltaic output; v is the photovoltaic output power (variable); P r P is the adjustable heater power (0~100% adjustable variable); s is the power of the electrodialysis device (constant power); P el is the power of the hydrogen production water electrolyzer; P c Charging power for energy storage system; P g P is the power of compressed gas by air compressor; k is the regeneration heater power;

[0057] According to an embodiment of the present invention, the photovoltaic power generation curve under ideal lighting conditions is divided into three stages:

[0058] The first period t0~t 1_n is the photovoltaic power generation power P in the morning v Less than the lower power limit P of the water electrolyzer el_min , that is, P p <P el_min In the interval between t0 and t 1_n During this period, the electrodialysis device produces pure water, which is highly compatible with photovoltaic power generation. v Greater than or equal to the power P of the electrodialysis device to prepare pure water s , that is, P v ≥P s When the electrodialysis device is started to prepare pure water, the control system monitors and calculates the maximum power point P of photovoltaic power generation. pv =I v *U v , and according to the definition of photovoltaic water electrolysis hydrogen production auxiliary equipment power combination vector P, through the photovoltaic power generation maximum power point power P pv The vector P contains the power P of the electrodialysis device for preparing pure water s Equipment power combination P x Compare and find the equipment power combination P whose difference is approaching zero x ,Right now Start all the equipment in the combination and adjust the adjustable heater power P r , so that the starting photovoltaic water electrolysis hydrogen production load power is close to the photovoltaic power generation maximum power point power P pv Therefore, the photovoltaic maximum power point tracking is carried out by combining auxiliary equipment such as adjustable heaters, air compressors, and energy storage systems to ensure the maximum efficiency of photovoltaic water electrolysis hydrogen production. x ∈P.

[0059] The second period t 1_n ~t 2_n is the photovoltaic power generation power P v Greater than or equal to the lower limit hydrogen power P of the water electrolyzer el_min , that is, P v ≥P el_min The interval is mainly the process of hydrogen production in the water electrolyzer, and the wet hydrogen is stored in the temporary storage tank. v Greater than or equal to the lower limit hydrogen power P of the water electrolyzer el_min , that is, P v ≥P el_min When the water electrolyzer is started to produce hydrogen, the electrodialysis device to prepare pure water, the air compressor, the energy storage system, the adjustable heater and other equipment are stopped.

[0060] As the light increases, the photovoltaic power generation power P v Increase, water electrolyzer power P el Increase synchronously, due to the voltage clamping effect of the water electrolyzer, the maximum photovoltaic power generation power P pv The point may deviate, but when designing the photovoltaic array installation, the local seasonal changes and the impact of the environment on the light are taken into consideration, as well as the need to ensure hydrogen production throughout the year, and the maximum photovoltaic power generation power P is set. pv The point has a small deviation from the hydrogen production power of the water electrolyzer.

[0061] When the photovoltaic power generation power P v Greater than the limiting hydrogen power P on the water electrolyzer el_max , that is, P p >P el_max When the control system monitors and calculates the maximum power point P of photovoltaic power generation pv =I v *U v , and according to the definition of the power combination vector P of the auxiliary equipment for photovoltaic water electrolysis hydrogen production, the equipment power combination P x As a result, the maximum power point power P of photovoltaic power generation pv With the current water electrolyzer power P el The difference is calculated and then compared with the equipment power combination P in the power combination vector P of the photovoltaic water electrolysis hydrogen production auxiliary equipment x Difference calculation, find the equipment power combination P that is approaching zero x ,Right now At this time, the control system starts all the devices in the combination and adjusts the adjustable heater power P r , so that the load power is close to the maximum power point power P of photovoltaic power generation pv , thus, the photovoltaic maximum power point tracking is participated in by the combination of auxiliary equipment such as adjustable heater, air compressor, energy storage system, etc., to ensure the maximum efficiency of photovoltaic water electrolysis hydrogen production to the greatest extent. Among them, P x ∈P.

[0062] The third period t 2_n ~t e is the photovoltaic power generation power P in the afternoon v Less than the limiting hydrogen power P of the water electrolyzer el_min , photovoltaic power generation power P v Greater than the minimum workload P for photovoltaic water electrolysis hydrogen production min , that is, P min <P v <P el_min This period of time is mainly for hydrogen purification, and the gas in the wet hydrogen storage tank is passed through the molecular sieve dryer under the action of the regeneration heater to output pure hydrogen.

[0063] At the same time, the control system monitors and calculates the maximum power point P of photovoltaic power generation pv =I v *U v , and according to the definition of photovoltaic water electrolysis hydrogen production auxiliary equipment power combination vector P, through the photovoltaic power generation maximum power point power P pv The vector P contains the regenerative heater power P k Equipment power combination P x Compare and find the equipment power combination P whose difference is approaching zero x ,Right now Start all devices in the combination and adjust the adjustable heater power P r , so that the starting photovoltaic water electrolysis hydrogen production load power is close to the photovoltaic power generation maximum power point power P pv Therefore, the photovoltaic maximum power point tracking is carried out through the combination of auxiliary equipment such as adjustable heaters, air compressors, and energy storage systems, so as to ensure the maximum efficiency of photovoltaic water electrolysis hydrogen production to the greatest extent.

[0064] Among them, P min The minimum working load for hydrogen production by water electrolysis; P x ∈P.

[0065] Beneficial effects:

[0066] The present invention adopts a photovoltaic array directly coupled to a water electrolysis hydrogen production system. In order to solve the mismatch problem between the maximum power point directly output by the photovoltaic array and the optimal water electrolysis hydrogen production, as well as the efficient use of the photovoltaic maximum power point output power and photovoltaic power generation, it is proposed to separate the hydrogen purification process from the water electrolyzer process, and use an adjustable heater + energy storage system to participate in the regulation of the matching degree between the photovoltaic maximum power point and the optimal water electrolyzer hydrogen production. Therefore, the present invention has the following advantages over traditional technologies:

[0067] ① Comprehensive utilization of energy.

[0068] ② Migrate and separate the regeneration heater load to extend the operating time of the water electrolyzer.

[0069] ③The photovoltaic power generation characteristics are optimally matched with the water electrolysis hydrogen production characteristics.

[0070] ④ Realize load time matching between photovoltaic power generation and photovoltaic water electrolysis hydrogen production system through load migration method. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 The structure diagram of the photovoltaic water electrolysis hydrogen production system of the present invention;

[0072] Figure 2 The photovoltaic array of the present invention is a schematic diagram of power supply for the photovoltaic water electrolysis hydrogen production system;

[0073] Figure 3Structural diagram of the wet hydrogen temporary storage tank of the photovoltaic water electrolysis hydrogen production system of the present invention;

[0074] Figure 4 A comparison curve of power generation and load before and after the improved process of the photovoltaic water electrolysis hydrogen production system of the present invention;

[0075] Figure 5 Flow chart of the control process of the present invention. DETAILED DESCRIPTION

[0076] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0077] According to an embodiment of the present invention, a source-load matching control device for a photovoltaic direct current water electrolysis hydrogen production system is provided. Figure 1 and Figure 2 As shown,

[0078] It comprises: a control system, a photovoltaic array, a water electrolyzer (1), a heat exchange system, an electrodialysis device (2), an adjustable heater (3), an energy storage system (11) and a photovoltaic inverter (14);

[0079] The photovoltaic array comprises a plurality of photovoltaic modules (7) which are installed around the photovoltaic water electrolysis hydrogen production system to provide energy for photovoltaic water electrolysis hydrogen production; the photovoltaic array output is respectively connected to the water electrolyzer (1), the electrodialysis device (2), the adjustable heater (3), the energy storage system (11) and the photovoltaic inverter (14) input end.

[0080] The heat exchange system comprises: a phase change heat storage material (4), a heat exchanger (5), and a radiator; wherein the phase change heat storage material (4) is filled in a sealed box (15) and placed in the photovoltaic water electrolysis hydrogen production system room or other indoor surroundings;

[0081] The heat exchanger (5) is installed in the phase change heat storage material. The purpose of the heat exchanger (5) is to release the heat energy of the heat source in the phase change heat storage material (4) through different heat sinks.

[0082] The radiator comprises an indoor radiator (13) and a molecular sieve dryer radiator (18), which are respectively installed on the wall of the photovoltaic water electrolysis hydrogen production system room and in the molecular sieve dryer (9). According to the temperature requirement, the temperature of the heat exchanger (5) is switched through the valve (16), and the heat is exchanged to the indoor of the photovoltaic water electrolysis hydrogen production system through the radiator (13) to ensure the indoor temperature; the heat is exchanged to the environment of the molecular sieve dryer (9) through the molecular sieve dryer radiator (31), providing the basic temperature of the molecular sieve dryer (9), thereby improving the speed of hydrogen purification of the molecular sieve dryer (9).

[0083] The energy storage system (11) comprises: a bidirectional converter and an energy storage battery, which are installed in the room of the photovoltaic water electrolysis hydrogen production system or other rooms, wherein the capacity of the energy storage system (11) is sufficient to maintain the short-term and startup operation requirements of the hydrogen production auxiliary equipment.

[0084] The photovoltaic inverter (14) is installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, and mainly provides AC power for photovoltaic water electrolysis hydrogen production auxiliary equipment, including air compressors (6), water pumps, etc.

[0085] The adjustable heater (3) is installed in the phase change heat storage material (4). The adjustable heater (3) cooperates with the phase change heat storage material (4) to store the excess photovoltaic power through the phase change heat storage material (4) or directly use it for dry hydrogen.

[0086] The electrodialysis device (2) is equipped with a pure water container (21), and the pure water produced by the electrodialysis device (2) enters the pure water container, and the pure water container outlet (32) provides water for hydrogen production in the water electrolysis cell. The electrodialysis device (2) is installed in the photovoltaic water electrolysis hydrogen production system room or other indoor surroundings;

[0087] The water electrolyzer (1) is the main equipment of the photovoltaic water electrolysis hydrogen production system, is mainly used for water electrolysis hydrogen production, and is installed in the photovoltaic water electrolysis hydrogen production system room.

[0088] The control system is composed of a controller (12) and a sensor. The controller is installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, and mainly collects all parameters of the sensor and the photovoltaic water electrolysis hydrogen production system. The input interface of the controller (12) is connected to all sensor output ports through a data line to monitor the operating status of all devices and systems, and executes the corresponding control strategy after analysis and judgment. The output interface of the controller is connected to all actuators, equipment, etc. through a control line to control the corresponding equipment to work or stop, so as to realize the efficient operation of photovoltaic water electrolysis hydrogen production.

[0089] The temporary storage tank (8) containing wet hydrogen of the present invention is placed between the water electrolyzer (1) and the molecular sieve dryer (9), and the hydrogen generated by the photovoltaic power generation water electrolyzer (1) at full load is temporarily stored in the temporary storage tank (8). When the photovoltaic power generation power is less than the lower limit power of the water electrolyzer (1), the wet hydrogen in the temporary storage tank (8) is dried again, so as to fully utilize the photovoltaic power generation energy.

[0090] like Figure 3 As shown, the wet hydrogen temporary storage tank (8) includes a pressure tank body (22), an air inlet pipeline (27), an air outlet pipeline (23), a safety valve (25) and a drainage pipeline (29). One end of the air inlet pipe (27) is installed at the upper left end of the pressure tank (22), an air inlet check valve (26) is installed on the air inlet pipe (27), and the other end of the air inlet pipe (27) is connected to the hydrogen production outlet (19) of the water electrolyzer; one end of the air outlet pipe (23) is installed at the upper right end of the pressure tank (22), an air outlet check valve (24) is installed on the air outlet pipe (23), and the other end of the air outlet pipe (23) is connected to the air inlet (20) of the molecular sieve dryer; one end of the drainage pipe (29) is installed at the lower end of the pressure tank (22), and a valve (28) is installed on the drainage pipe (29) for regular drainage; one end of the safety valve (25) is installed at the upper end of the pressure tank (22), and the outlet of the safety valve (25) is connected to a special hydrogen discharge and venting pipe.

[0091] Since the hydrogen pipeline between the conventional power grid rectifier water electrolyzer and the molecular sieve dryer is directly connected, the loads of the water electrolyzer and the molecular sieve dryer are tightly coupled. The water electrolyzer and the molecular sieve dryer cannot adopt a time-sharing operation mode to realize the load shifting in the time dimension, resulting in a 100% simultaneous power consumption rate of the water electrolyzer and the molecular sieve dryer.

[0092] The improved basic process of hydrogen production of the present invention is described as follows:

[0093] The present invention designs a temporary storage tank for wet hydrogen between the photovoltaic power generation water electrolyzer and the molecular sieve dryer, so as to temporarily store the hydrogen generated by the full-load electrolysis of the water electrolyzer when the photovoltaic power is relatively large. When the photovoltaic power generation power is less than the lower limit power of the water electrolyzer, the wet hydrogen in the temporary storage tank is dried again, so as to realize the load decoupling of the water electrolyzer and the molecular sieve dryer and make full use of the photovoltaic power generation energy.

[0094] The electrodialysis device prepares pure water, which is then supplied to the water electrolyzer through a pipeline for hydrogen production. The wet hydrogen produced by the water electrolyzer is stored in a wet hydrogen temporary storage tank. The wet hydrogen stored in the temporary storage tank is heated by a regeneration heater and then passed through a molecular sieve dryer to prepare pure hydrogen. That is, the electrodialysis device prepares pure water → the water electrolyzer produces hydrogen → the wet hydrogen temporary storage tank is stored → the regeneration heater is heated → the molecular sieve dryer prepares pure hydrogen.

[0095] Working principle of the present invention:

[0096] Photovoltaic water electrolysis hydrogen production is to connect the DC power generated by the photovoltaic array to the positive and negative electrodes of the electrolyzer through an inverter or directly, and produce oxygen and hydrogen at the positive and negative electrodes of the water electrolyzer through DC electrolysis of pure water or electrolyte water solution. The wet hydrogen is stored in a temporary storage tank. When the photovoltaic power is lower than the minimum hydrogen production power of the water electrolyzer, the hydrogen with the required purity is obtained through the purification process for compression, storage and refueling. Photovoltaic water electrolysis hydrogen production uses renewable energy, without environmental pollution and carbon emissions, so this hydrogen product is called "green hydrogen". Since the photovoltaic array is most efficient when the output is at the maximum power point, such as the maximum power point of the photovoltaic maximum output is close to the working curve of the hydrogen production system, the efficient use of photovoltaic water electrolysis hydrogen production can be achieved.

[0097] According to an embodiment of the present invention, the relevant device information of the present invention is as follows:

[0098] Pure water preparation generally adopts electrodialysis device, which is generally 5% of the hydrogen production power of water electrolyzer, operating pressure: 0.5~3.0kg / cm2, operating DC voltage 100~250V;

[0099] The adjustable range of hydrogen production power of the electrolyzer is 40%-120% for alkaline water and 5%-150% for PEM. After the structure of the water electrolyzer is processed, when the temperature of the water electrolyzer is constant, the IV curve of hydrogen production by the water electrolyzer is relatively fixed;

[0100] Purification stage: The gas containing a certain amount of humidity produced by the water electrolyzer is heated by the regeneration heater and then dehumidified by the molecular sieve dryer to produce dry hydrogen. The power of the regeneration heater is 10-15% of the power of the water electrolyzer hydrogen production;

[0101] Since the efficiency of photovoltaic water electrolysis hydrogen production is related to temperature, the adjustable heater is combined with the phase change material to match the excess photovoltaic power generation through phase change material heat storage or directly used for dry hydrogen. The power of the adjustable heater is adjustable from 0 to 100%.

[0102] The power output of the photovoltaic cell is related to the amount of sunlight that hits the solar panel, and the efficiency is related to the electronic characteristics of the load. When the sunlight changes, the load curve of the maximum power transmission efficiency of the photovoltaic cell also changes accordingly. The maximum power output is achieved through load coordination and adjustment, and the system obtains the best efficiency. After the photovoltaic array is installed, under the condition of a certain temperature (without considering attenuation), the photovoltaic power generation light output IV curve is relatively fixed, and the maximum power point of photovoltaic power generation is fixed, so that the power generation efficiency is highest when the load characteristics are maintained at this power point.

[0103] Since photovoltaic water electrolysis hydrogen production requires high-power DC power support during the hydrogen production process, photovoltaic water electrolysis hydrogen production can be achieved by using solar photovoltaic + DC / DC converter to output power at the maximum power point, but the loss in the conversion process is large and the cost is high. Therefore, photovoltaic array direct water electrolysis hydrogen production is proposed.

[0104] Furthermore, the optimal matching design of the volt-ampere characteristics of the electrolytic cell of the present invention and the maximum power operation characteristics of the photovoltaic array is as follows:

[0105] After the water electrolyzer structure is processed, when the temperature of the electrolyzer is constant, the IV curve of hydrogen production by the water electrolyzer is relatively fixed, the power demand range in the hydrogen production process is 40% to 120%, and the relative voltage is relatively stable. The photovoltaic array design can refer to the voltage and upper and lower power limits of the water electrolyzer, consider factors such as season and environment, and determine the series and parallel configuration mode and quantity of photovoltaic modules, so that the maximum power curve of the photovoltaic array under different light conditions coincides with the corresponding volt-ampere characteristics of the water electrolyzer, and achieves the best relative match.

[0106] Therefore, it is possible to use photovoltaic arrays to directly power the water electrolyzer. In order to meet the system's efficient hydrogen production, the load of auxiliary equipment is adjusted by time-sharing and dynamic allocation during the hydrogen production process, so as to achieve the fitting of the photovoltaic power generation maximum power curve and the photovoltaic water electrolysis hydrogen production process curve, and ensure the efficiency of photovoltaic power generation hydrogen production.

[0107] According to an embodiment of the present invention, the control process of the above photovoltaic direct current water electrolysis hydrogen production system source-load matching control device is as follows: Figure 5 As shown, including:

[0108] First, define the power combination vector P of photovoltaic water electrolysis hydrogen production auxiliary equipment:

[0109] The control system sets the power P of the electrodialysis device (2) s 、Energy storage system (11) Charging power P c 、Air compressor (6) compressed gas power P g , Regeneration heater (17) power P k The start and stop states are encoded by binary numbers to generate an auxiliary equipment operation state array, which is then combined with the power P of the electrodialysis device (2). s 、Energy storage system (11) Charging power P c 、Air compressor (6) power P g , Regeneration heater (17) power P k The power vectors of the auxiliary equipment composed are multiplied to generate a complete enumeration of the power combination vector P of the photovoltaic water electrolysis hydrogen production auxiliary equipment.

[0110]

[0111] Among them, Px belongs to P0, P1, ..., P 15 Any combination of P x ∈P.

[0112] The device of the embodiment of the present invention improves the traditional basic hydrogen production process. The control process based on the improved basic hydrogen production process and the photovoltaic power generation curve matching is as follows:

[0113] See also Figure 1 Figure 2 and Figure 4 The basic hydrogen production process after improvement is: electrodialysis device (2) produces pure water - water electrolyzer (1) - wet hydrogen temporary storage tank (8) - regeneration heater (17) - molecular sieve dryer (9) - pure hydrogen output. Due to the addition of wet hydrogen temporary storage tank (8) before hydrogen purification, the wet hydrogen at the outlet of the water electrolyzer (1) is temporarily stored, the power supply requirements of hydrogen production in the water electrolyzer (1) and the regeneration heater (17) are separated, and the operating time of each load is independently set. Therefore, the lower limit power P of the water electrolyzer (1) under the original process is el_ymin Adjust down to the lower limit power P of the water electrolyzer (1) with improved process el_min ; The upper limit power P of the water electrolyzer (1) under the same original process el_ymax Reduce to the upper limit power P of the water electrolyzer (1) under the improved process el_max ; Photovoltaic water electrolysis hydrogen production time is reduced from the original process t 1_y ~t 2_y Increase to t 1_n ~t 2_n Based on the reduction of the upper and lower power limits of the water electrolyzer (1) of the original process, the installed capacity of the photovoltaic array of the improved process is reduced.

[0114] Therefore, the control system will be greater than or equal to the lower limit power P of the water electrolyzer (1). el_min Photovoltaic power generation power P v , used for water electrolyzer (1) hydrogen production power P el , and through the photovoltaic water electrolysis hydrogen production auxiliary equipment power combination P in the photovoltaic water electrolysis hydrogen production auxiliary equipment power combination vector P x , find the hydrogen production power P of the water electrolyzer (1) el The best match is close to the maximum power point P of photovoltaic power generation pv Power combination of auxiliary equipment P x , and then through the adjustable heater (3) load P r Fine-tuning to maximize the integration of photovoltaic water electrolysis hydrogen production and photovoltaic power generation maximum power point P pv match.

[0115] The control system will be less than the lower limit power P of the water electrolyzer (1) according to the priority el_min Photovoltaic power generation power Pv , used in electrodialysis device (2) to prepare pure water power P s , the regeneration heater (17) has a power P for drying and purifying the gas k 、Air compressor (6) compressed gas power P g 、Energy storage system (11) Charging power P c Etc. And through the photovoltaic water electrolysis hydrogen production auxiliary equipment power combination P in the photovoltaic water electrolysis hydrogen production auxiliary equipment power combination vector P x , determine the maximum power point power P of photovoltaic power generation pv The equipment power combination P is approaching zero x , start all the equipment in the combination, and adjust the power of the adjustable heater (3) to make the load power close to the maximum power point power P of photovoltaic power generation pv , thereby ensuring the maximum efficiency of photovoltaic water electrolysis hydrogen production.

[0116] Thus, by means of load migration, the photovoltaic power generation is improved to match the photovoltaic water electrolysis device time and load power, and the operation time of the water electrolysis cell (1) is extended, while the installation capacity of the photovoltaic array is reduced. The photovoltaic installed capacity required by the original basic hydrogen production process is reduced.

[0117] Priority: In the morning, electrodialysis (2), energy storage system (11), air compressor (6), regeneration heater (17), etc.; in the afternoon, regeneration heater (17), energy storage system (11), air compressor (6), electrodialysis (2), etc. el_min is the lower power limit of the water electrolyzer (1); P el_max is the upper limit power of the water electrolyzer (1); P pv is the maximum power point of photovoltaic output; I v is the maximum power point current of photovoltaic output; U v P is the maximum power point voltage of photovoltaic output; v is the photovoltaic output power (variable); P r P is the power of the adjustable heater (3) (0-100% adjustable variable); s is the power of the electrodialysis device (2) (constant power); P el P is the power of the hydrogen production water electrolyzer (1); c is the charging power of the energy storage system (11); g P is the air compressor power for compressing gas; k is the power of the regeneration heater (17);

[0118] The photovoltaic power generation curve under ideal lighting conditions is divided into three stages:

[0119] 1) The first period t0~t 1_n is the photovoltaic power generation power P in the morningv Less than the lower power limit P of the water electrolyzer (1) el_min , that is, P p <P el_min In the interval between t0 and t 1_n During this period, the electrodialysis device (2) produces pure water, which is highly compatible with photovoltaic power generation. v Greater than or equal to the power P of the electrodialysis device (2) for preparing pure water s , that is, P v ≥P s When the electrodialysis device (2) is started to prepare pure water, the control system monitors and calculates the maximum power point P of photovoltaic power generation. pv =I v *U v , and according to the definition of photovoltaic water electrolysis hydrogen production auxiliary equipment power combination vector P, through the photovoltaic power generation maximum power point power P pv The vector P contains the electrodialysis device (2) to prepare pure water power P s Equipment power combination P x Compare and find the equipment power combination P whose difference is approaching zero x ,Right now Start all the equipment in the combination. And adjust the power P of the adjustable heater (3) r , so that the starting photovoltaic water electrolysis hydrogen production load power is close to the photovoltaic power generation maximum power point power P pv Therefore, the photovoltaic maximum power point tracking is performed by combining auxiliary equipment such as the adjustable heater (3), the air compressor (6), and the energy storage system (6), thereby ensuring the maximum efficiency of photovoltaic water electrolysis hydrogen production to the greatest extent. x ∈P.

[0120] 2) The second period t 1_n ~t 2_n is the photovoltaic power generation power P v Greater than or equal to the lower limit hydrogen power P of the water electrolyzer (1) el_min , that is, P v ≥P el_min The interval is mainly the hydrogen production process of the water electrolyzer (1), and the wet hydrogen is stored in the temporary storage tank (8). v Greater than or equal to the lower limit hydrogen power P of the water electrolyzer (1) el_min , that is, P v ≥P el_min When the water electrolyzer (1) is started to produce hydrogen, the electrodialysis (2) device for preparing pure water, the air compressor (6), the energy storage system (11) and the adjustable heater (3) are stopped.

[0121] As the light increases, the photovoltaic power generation power P vIncrease, water electrolyzer (1) power P el Increase synchronously, due to the voltage clamping effect of the water electrolyzer (1), the maximum photovoltaic power generation power P pv The point may deviate, but when designing the photovoltaic array installation, the local seasonal changes and the impact of the environment on the light are taken into consideration, as well as the need to ensure hydrogen production throughout the year, and the maximum photovoltaic power generation power P is set. pv The point has a small deviation from the hydrogen production power of the water electrolyzer (1).

[0122] When the photovoltaic power generation power P v Greater than the limiting hydrogen power P of the water electrolyzer (1) el_max , that is, P p >P el_max When the control system monitors and calculates the maximum power point P of photovoltaic power generation pv =I v *U v , and according to the definition of the power combination vector P of the auxiliary equipment for photovoltaic water electrolysis hydrogen production, the equipment power combination P x As a result, the maximum power point power P of photovoltaic power generation pv With the current water electrolyzer (1) power P el The difference is calculated and then compared with the equipment power combination P in the power combination vector P of the photovoltaic water electrolysis hydrogen production auxiliary equipment x Difference calculation, find the equipment power combination P that is approaching zero x ,Right now At this time, the control system starts all the devices in the combination and adjusts the power P of the adjustable heater (3). r , so that the load power is close to the maximum power point power P of photovoltaic power generation pv , thus, the photovoltaic maximum power point tracking is participated in by the combination of auxiliary equipment such as the adjustable heater (3), the air compressor (6), the energy storage system (11), etc., so as to ensure the maximum efficiency of photovoltaic water electrolysis hydrogen production to the greatest extent. Among them, P x ∈P.

[0123] 3) The third period t 2_n ~t e is the photovoltaic power generation power P in the afternoon v Less than the lower limiting hydrogen power P of the water electrolyzer (1) el_min , photovoltaic power generation power P v Greater than the minimum workload P for photovoltaic water electrolysis hydrogen production min , that is, P min <P v <P el_min This period is mainly for hydrogen purification, where the gas in the wet hydrogen temporary storage tank (8) is passed through the molecular sieve dryer (9) and under the action of the regeneration heater (17), pure hydrogen is output.

[0124] At the same time, the control system monitors and calculates the maximum power point P of photovoltaic power generation pv =I v *U v , and according to the definition of photovoltaic water electrolysis hydrogen production auxiliary equipment power combination vector P, through the photovoltaic power generation maximum power point power P pv The vector P contains the power P of the regeneration heater (17) k Equipment power combination P x Compare and find the equipment power combination P whose difference is approaching zero x ,Right now Start all the equipment in the combination and adjust the power P of the adjustable heater (3) r , so that the starting photovoltaic water electrolysis hydrogen production load power is close to the photovoltaic power generation maximum power point power P pv Thus, the photovoltaic maximum power point tracking is participated in by the combination of auxiliary equipment such as the adjustable heater (3), the air compressor (6), the energy storage system (11), etc., so as to ensure the maximum efficiency of photovoltaic water electrolysis hydrogen production to the greatest extent.

[0125] Among them, P min The minimum working load for hydrogen production by water electrolysis; P x ∈P.

[0126] Although the above describes the illustrative specific embodiments of the present invention to facilitate those skilled in the art to understand the present invention, and it should be clear that the present invention is not limited to the scope of the specific embodiments, for those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. A source-load matching control device for a photovoltaic direct current water electrolysis hydrogen production system, characterized in that: include: Control system, photovoltaic array, heat exchange system, adjustable heater (3), energy storage system (11) water electrolyzer (1), electrodialysis device (2) and photovoltaic inverter (14); The control system comprises a controller (12) and a sensor, wherein the controller is installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, and mainly collects all parameters of the sensor and the photovoltaic water electrolysis hydrogen production system; The photovoltaic array comprises a plurality of photovoltaic modules (7) which are installed around the photovoltaic water electrolysis hydrogen production system to provide energy for photovoltaic water electrolysis hydrogen production; the photovoltaic array output is respectively connected to the voltage input terminals of the water electrolyzer (1), the electrodialysis device (2), the adjustable heater (3), the energy storage system (11) and the photovoltaic inverter (14); The heat exchange system comprises: a phase change heat storage material (4), a heat exchanger (5), and a radiator; wherein the phase change heat storage material (4) is filled in a sealed box (15) and placed in the photovoltaic water electrolysis hydrogen production system room or other indoor surroundings; the heat exchanger (5) is installed in the phase change heat storage material and is used to release heat energy from the heat source in the phase change heat storage material (4) through different radiators; The radiator comprises an indoor radiator (13) and a molecular sieve dryer radiator (18), which are respectively installed on the wall of the photovoltaic water electrolysis hydrogen production system room and in the molecular sieve dryer (9). According to the temperature requirement, the temperature of the heat exchanger (5) is switched through the valve (16) to exchange heat to the indoor of the photovoltaic water electrolysis hydrogen production system through the radiator (13) to ensure the indoor temperature; and heat is exchanged to the environment of the molecular sieve dryer (9) through the molecular sieve dryer radiator (31) to provide the basic temperature of the molecular sieve dryer (9) and improve the speed of hydrogen purification of the molecular sieve dryer (9); The energy storage system (11) comprises: a bidirectional converter and an energy storage battery, which are installed in the room of the photovoltaic water electrolysis hydrogen production system or other rooms, wherein the capacity of the energy storage system (11) is to maintain the short-term and startup operation requirements of the hydrogen production auxiliary equipment; The photovoltaic inverter (14) is installed in the photovoltaic water electrolysis hydrogen production system room or other rooms, and mainly provides AC power for photovoltaic water electrolysis hydrogen production auxiliary equipment; The adjustable heater (3) is installed in the phase change heat storage material (4). The adjustable heater (3) cooperates with the phase change heat storage material (4) to store the excess photovoltaic power through the phase change heat storage material (4) or directly use it for drying hydrogen; The electrodialysis device (2) is provided with a pure water container (21), and the pure water produced by the electrodialysis device (2) enters the pure water container, and the pure water container outlet (32) provides water for hydrogen production in the water electrolysis cell; It also includes a temporary storage tank (8) containing wet hydrogen, which is placed between the water electrolyzer (1) and the molecular sieve dryer (9), and temporarily stores the hydrogen generated by the photovoltaic power generation water electrolyzer (1) at full load in the temporary storage tank (8). When the photovoltaic power generation power is less than the lower limit power of the water electrolyzer (1), the wet hydrogen in the temporary storage tank (8) is dried again, so as to fully utilize the photovoltaic power generation energy. The wet hydrogen temporary storage tank (8) comprises a pressure tank body (22), an air inlet pipe (27), an air outlet pipe (23), a safety valve (25) and a drainage pipe (29); wherein one end of the air inlet pipe (27) is installed at the upper left end of the pressure tank body (22), an air inlet check valve (26) is installed on the air inlet pipe (27), and the other end of the air inlet pipe (27) is connected to the hydrogen production outlet (19) of the water electrolyzer; one end of the air outlet pipe (23) is installed at the pressure tank body ( 22), an exhaust check valve (24) is installed on the exhaust pipe (23), and the other end of the exhaust pipe (23) is connected to the air inlet (20) of the molecular sieve dryer; one end of the drainage pipe (29) is installed at the lower end of the pressure tank (22), and a valve (28) is installed on the drainage pipe (29) for regular drainage; one end of the safety valve (25) is installed at the upper end of the pressure tank (22), and the outlet of the safety valve (25) is connected to a dedicated hydrogen discharge vent pipe; The electrodialysis device (2) is installed in the photovoltaic water electrolysis hydrogen production system room or other indoor surroundings; The water electrolyzer (1) is the main equipment of the photovoltaic water electrolysis hydrogen production system, mainly used for water electrolysis hydrogen production, and is installed in the photovoltaic water electrolysis hydrogen production system room; The input interface of the controller (12) is connected to all sensor output ports via data lines to monitor the operating status of all devices and systems, and execute corresponding control strategies after analysis and judgment; the output interface of the controller is connected to all actuators and devices via control lines to control the corresponding devices to work or stop, thereby achieving efficient operation of photovoltaic water electrolysis to produce hydrogen.

2. A source-load matching control method for a photovoltaic direct current water electrolysis hydrogen production system, using the device of claim 1, characterized in that: The steps include: The electrodialysis device prepares pure water, which is then supplied to the water electrolyzer for hydrogen production through pipelines; The wet hydrogen produced by the water electrolyzer is stored in a wet hydrogen temporary storage tank between the photovoltaic water electrolyzer and the molecular sieve dryer; Source-load matching control is performed based on lighting conditions. The photovoltaic power generation curve under ideal lighting conditions is divided into three stages: The first stage is before the photovoltaic power generation reaches the lower power limit of the water electrolyzer; The second stage is to start the water electrolyzer to produce hydrogen when the photovoltaic power generation meets the lower limit of hydrogen power of the electrolytic hydrogen production electrolyzer, and store the wet hydrogen; The third stage is in the afternoon when the photovoltaic power generation power is from the lower limit power of the water electrolyzer to the minimum working load of the photovoltaic water electrolysis hydrogen production system; Power combination vector of auxiliary equipment for hydrogen production based on photovoltaic water electrolysis in three stages , respectively control the power of the electrodialysis device , Energy storage system charging power , Air compressor compressed gas power , Regeneration heater power The system starts and stops the system, and cooperates with the adjustable heater phase change heat storage to time-share the photovoltaic water electrolysis hydrogen production, the wet hydrogen stored in the temporary tank, the regeneration heater heating and the molecular sieve dryer to prepare pure hydrogen for compression storage and filling, thereby realizing the load decoupling of the water electrolyzer and the molecular sieve dryer and effectively utilizing the photovoltaic power generation power.

3. A source-load matching control method for a photovoltaic direct current water electrolysis hydrogen production system according to claim 2, characterized in that: Define the power combination vector of photovoltaic water electrolysis hydrogen production auxiliary equipment : The control system converts the electrodialysis unit power , Energy storage system charging power , Air compressor compressed gas power , Regeneration heater power The start and stop states of the auxiliary equipment are encoded by binary numbers to generate an array of auxiliary equipment operation states, which is then combined with the power of the electrodialysis device. , Energy storage system charging power , air compressor power , Regeneration heater power The power vectors of the auxiliary equipment composed are multiplied to generate a complete enumeration of the power combination vectors of photovoltaic water electrolysis hydrogen production auxiliary equipment : ， in, belong Any combination of one or more of .

4. A source-load matching control method for a photovoltaic direct current water electrolysis hydrogen production system according to claim 2, characterized in that: Source-charge matching control is performed based on light conditions, where: The photovoltaic power generation curve under ideal lighting conditions is divided into three stages: The first stage is before the photovoltaic power generation reaches the lower limit power of the water electrolyzer. When the photovoltaic power generation meets the conditions for the electrodialysis device to prepare pure water, the electrodialysis device is started to prepare pure water, and the power combination vector of the photovoltaic water electrolysis hydrogen production auxiliary equipment is defined. , find the matching combination vector The adjustable heater, air compressor and energy storage auxiliary equipment participate in the photovoltaic maximum power point tracking to ensure the maximum photovoltaic power output; The second stage is when the photovoltaic power generation meets the lower limit of hydrogen power of the electrolytic hydrogen production cell, the electrolytic cell is started to produce hydrogen, the wet hydrogen is stored, and the electrodialysis device to prepare pure water, the air compressor, the energy storage and the adjustable heater are stopped; when the photovoltaic power generation is greater than the upper limit of the hydrogen power of the water electrolyzer, according to the difference between the current photovoltaic power generation and the upper limit of the hydrogen power of the water electrolyzer, and by defining the power combination vector of the photovoltaic water electrolysis hydrogen production auxiliary equipment , find the matching combination vector The corresponding load power equipment is started, such as the adjustable heater phase change heat storage or regeneration heating, the electrodialysis device water production, energy storage, and air compressor, so that the photovoltaic power generation power matches the photovoltaic water electrolysis hydrogen production load; The third stage is the afternoon when the photovoltaic power generation power is from the lower limit power of the water electrolyzer to the minimum working load of the photovoltaic water electrolysis hydrogen production system. During this period of time, it is mainly: according to the definition of the power combination vector of the photovoltaic water electrolysis hydrogen production auxiliary equipment , find the matching combination vector The combination of regenerative heater power is used to output the gas in the wet hydrogen storage tank through the regenerative heater-molecular sieve dryer-pure hydrogen, and the adjustable heater auxiliary equipment is used to track and adjust the photovoltaic maximum power point to ensure the maximum photovoltaic power output.

5. A source-load matching control method for a photovoltaic direct current water electrolysis hydrogen production system according to claim 4, characterized in that: In the second stage, as the light increases, the photovoltaic power generation increases, and the water electrolyzer power increases synchronously. Due to the voltage clamping effect of the electrolytic hydrogen production electrolyzer, the maximum power point of photovoltaic power generation may deviate at this time. When designing the photovoltaic array installation, the local seasonal changes and the impact of the environment on light, as well as the need to ensure hydrogen production throughout the year, are considered, and the deviation between the relative photovoltaic maximum power point and the electrolyzer hydrogen production power is less than the predetermined value; When the photovoltaic power generation is greater than the hydrogen power limit on the water electrolyzer, the power combination vector of the photovoltaic water electrolysis hydrogen production auxiliary equipment is defined based on the difference between the current photovoltaic power generation and the hydrogen power limit on the water electrolyzer. , find the matching combination vector The corresponding load power equipment is started, such as the adjustable heater phase change heat storage or regeneration heating, the electrodialysis device water production, energy storage, and air compressor, so that the photovoltaic power generation power matches the photovoltaic water electrolysis hydrogen production load; When the photovoltaic power generation is less than the limited hydrogen power of the water electrolyzer, the relevant equipment will be stopped, such as the adjustable heater phase change heat storage or regenerative heating, electrodialysis device water production, and energy storage air compressor, to ensure the maximum hydrogen production by photovoltaic water electrolysis.

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