Integrated system for drying, collecting water and producing hydrogen

Abstract

The invention discloses an integrated system for drying, water collection and hydrogen production, which comprises a drying box system provided with an air inlet and an air outlet and used for accommodating materials to be dried; the heat pump system comprises an evaporator and a condenser, an inlet of the evaporator is connected with the drying box air outlet, and an outlet of the condenser is connected with the drying box air inlet to form an air circulation loop; a condensate water collector is arranged at the lower part of the evaporator; the photovoltaic-PEM direct coupling hydrogen production system comprises a PEM electrolytic bath, and a water inlet of the PEM electrolytic bath is connected with a condensate water collector; the solar photovoltaic power supply system comprises a photovoltaic array, and the output end of the photovoltaic array is directly connected to the input end of the PEM electrolytic bath; the control unit is used for dynamically adjusting the series-parallel structure of the photovoltaic array and the number of working units of the PEM electrolytic cell according to the illumination intensity; according to the scheme, as an integrated, intelligent, modularized and multi-output system, the synergistic effect is achieved by organically integrating solar photovoltaic, heat pump drying and PEM electrolytic hydrogen production technologies.

Description

Technical Field

[0001] This invention relates to the field of new energy and energy-saving technology, specifically to an integrated system for drying and collecting water to produce hydrogen. Background Technology

[0002] In the drying and processing of agricultural products, traditional Chinese medicinal materials, and other materials, traditional drying methods mainly include natural sun-drying and conventional hot air drying. Natural sun-drying depends on weather conditions, has low drying efficiency and a long cycle, and the moisture is directly lost into the atmosphere, resulting in water waste. Conventional hot air drying mostly uses coal or electric heating, which is energy-intensive, polluting, and similarly does not recycle the moisture generated during the drying process.

[0003] Heat pump drying technology significantly reduces drying energy consumption by recovering the waste heat of humid air. However, existing heat pump drying devices usually discharge condensate directly, failing to achieve high-value utilization of water resources. Furthermore, their driving energy still relies on grid electricity, resulting in limited cleanliness.

[0004] While solar drying technology is clean, it is severely affected by the intermittent nature of sunlight, requiring heat storage or auxiliary heat sources, resulting in low system reliability. Photovoltaic water electrolysis for hydrogen production is an important method for producing "green hydrogen," but it typically requires an external supply of purified water and necessitates the configuration of energy storage batteries and DC-DC converters to smooth out power fluctuations, leading to high system costs, complex structures, and significant energy losses.

[0005] Currently, there is no system that deeply integrates solar-driven heat pump drying, condensate recovery, and photovoltaic-PEM direct coupling hydrogen production. This results in the separation of drying and hydrogen production processes, and the failure to form a closed loop for efficient utilization of energy and water resources, thus failing to achieve the synergistic efficiency goal of "treating waste with waste and turning waste into treasure". Summary of the Invention

[0006] To address the aforementioned shortcomings of existing technologies, this invention provides an integrated system for drying, collecting water, and producing hydrogen, which solves the problems of high energy consumption and serious water waste in the agricultural product drying process, as well as the high raw material costs and low energy coupling efficiency of independent clean energy production systems.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An integrated system for drying and collecting water to produce hydrogen is provided, comprising: A drying oven is a closed or semi-closed box with a humid air outlet at the top and a dry air inlet at the bottom. The heat pump system includes an evaporator and a condenser. The air inlet of the evaporator is connected to the air outlet of the drying chamber through a first air duct, the air outlet of the evaporator is connected to the air inlet of the condenser through a second air duct, and the air outlet of the condenser is connected to the air inlet of the drying chamber through a third air duct, forming a loop that allows air to circulate between the drying chamber and the heat pump. A condensate collector is installed at the bottom of the evaporator to collect the liquid water that is cooled and precipitated when the air flows through the evaporator. A photovoltaic PEM direct-coupled hydrogen production system includes at least one PEM electrolyzer. The feed water inlet of the PEM electrolyzer is connected to a condensate collector through a water supply pipeline. The PEM electrolyzer is composed of multiple independent PEM electrolysis units stacked or connected in parallel. The solar photovoltaic power supply system includes a photovoltaic array and a solar controller. The DC output terminal of the photovoltaic array is directly connected to the DC power input terminal of the PEM electrolyzer via a first cable, and is simultaneously connected to the compressor power input terminal of the heat pump system via a second cable through the solar controller. The control unit is used to dynamically adjust the series and parallel structure of the photovoltaic array and the number of working units of the PEM electrolyzer according to the light intensity.

[0008] Furthermore, the drying chamber also includes a chamber wall made of insulating material and at least one drying plate disposed inside the chamber and having evenly distributed air vents, the drying plates being arranged in parallel to form a multi-layer material carrying space through which airflow passes.

[0009] Furthermore, the photovoltaic array of the solar photovoltaic power supply system is fixedly installed on a photovoltaic tracking bracket, and the photovoltaic tracking bracket includes a robotic arm or turntable with multiple degrees of rotational freedom located on the top of the drying box. The robotic arm or turntable is electrically connected to the control unit to adjust the orientation of the photovoltaic array and track the sun's position.

[0010] Furthermore, the control unit is electrically connected to the light sensor, the array switching switch group of the photovoltaic array, and the electrolysis unit switching switch group of the PEM electrolyzer. The control unit is configured to control the array switching switch group to change the series and parallel combination mode of the photovoltaic modules according to the real-time light intensity signal, and synchronously control the electrolysis unit switching switch group to adjust the number of PEM electrolysis units put into operation, so as to perform dynamic electrical matching between photovoltaic output and electrolysis load.

[0011] Furthermore, the control unit also includes a microprocessor, which is electrically connected to the light sensor. The light sensor is electrically connected to the array switching switch group and the electrolysis unit switching switch group respectively through the driving circuit. The array switching switch group includes several relays to change the series or parallel topology between photovoltaic modules.

[0012] Furthermore, each PEM electrolysis unit has an independent power input contact, and the electrolysis unit switching group consists of multiple contactors to independently connect or disconnect the power supply to the PEM electrolysis unit.

[0013] Furthermore, the solar controller's energy storage battery interface is electrically connected to the energy storage battery, and the solar controller is configured to supply power to various electrical components from the energy storage battery when the photovoltaic output power is insufficient.

[0014] Furthermore, the solar photovoltaic power supply system includes an inverter, which is electrically connected to the load output terminal of the solar controller or the energy storage battery. The AC output terminal of the inverter is connected to the compressor of the heat pump system and the internal circulation fan in the drying box via a third cable.

[0015] Furthermore, a water treatment device for improving water quality is installed on the water supply pipeline between the condensate collector and the PEM electrolyzer. The water treatment device includes at least one of a filter, an ion exchange resin column, or a reverse osmosis membrane assembly.

[0016] Furthermore, the air circulation loop consisting of the drying chamber, the first air duct, the evaporator, the second air duct, the condenser, and the third air duct is either a closed loop that is isolated from the outside world during the drying process or a semi-closed loop equipped with an adjustable fresh air inlet and a dehumidification outlet.

[0017] The beneficial effects of this invention are as follows: 1. This solution achieves deep coupling between the drying process and the hydrogen production process, constructing a closed-loop system of "drying-water collection-hydrogen production", converting the waste water vapor in traditional drying into hydrogen production feedstock, and realizing zero-consumption recovery and high-value utilization of water resources.

[0018] 2. This solution uses solar photovoltaic as the sole driving energy source, combined with the high efficiency and energy-saving characteristics of heat pumps, which significantly reduces carbon emissions and operating energy consumption in the drying process, achieving clean production.

[0019] 3. This solution eliminates the need for large-capacity energy storage batteries and DC-DC conversion stages by using direct coupling and dynamic matching strategies between photovoltaic PEMs. This reduces system costs, energy conversion losses, and maintenance complexity, while improving the overall efficiency of photovoltaic-hydrogen conversion and the stability of system operation.

[0020] 4. The heat pump system in this solution also serves as an "energy amplifier" and a "water resource recovery device," recovering high-quality condensate while efficiently drying it, making it widely applicable to areas with scarce water resources.

[0021] 5. This solution generates new income through by-product hydrogen production, thereby improving the overall economic benefits of agricultural processing. At the same time, the use of an intelligent dynamic matching method broadens the effective working range of the system under varying light conditions, enabling continuous and efficient hydrogen production from weak light to strong light.

[0022] 6. The system features a modular design, which facilitates expansion and adjustment. It can be widely applied to the drying and processing of various agricultural and sideline products and Chinese medicinal materials, as well as distributed green hydrogen production scenarios, and has good promotional value and social benefits. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The above and other objects, features, and advantages of the present invention will become clearer through the accompanying drawings. The same reference numerals indicate the same parts in all the drawings. The drawings are not intentionally drawn to scale to actual dimensions; the focus is on illustrating the main points of the invention.

[0024] Figure 1 This is a schematic diagram of an integrated system for drying and collecting water to produce hydrogen.

[0025] Figure 2 This is a schematic diagram of the drying oven.

[0026] Figure 3 This is a schematic diagram of a heat pump system.

[0027] Figure 4 This is a schematic diagram of a photovoltaic PEM direct-coupled hydrogen production system.

[0028] Figure 5 Circuit connection diagram for a solar photovoltaic power supply system.

[0029] The components include: 1. Drying chamber; 11. Humid and hot air outlet; 12. Dry and hot air inlet; 13. Drying plate; 14. Viewing window; 2. Heat pump system; 21. Evaporator; 22. Condenser; 23. First air duct; 24. Second air duct; 25. Third air duct; 26. Compressor; 27. Expansion valve; 3. Photovoltaic PEM direct coupling hydrogen production system; 31. PEM electrolyzer; 32. Hydrogen storage tank; 33. Oxygen storage tank; 4. Solar photovoltaic power supply system; 41. Photovoltaic array; 42. Solar controller; 43. Photovoltaic tracking bracket; 44. Battery; 45. Inverter; 5. Control unit. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0032] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0033] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0034] like Figures 1 to 5 As shown, the integrated system for drying and collecting water to produce hydrogen includes: a drying chamber 1, which is a closed or semi-closed chamber with a humid hot air outlet 11 at the top and a dry hot air inlet 12 at the bottom. Multiple layers of drying plates 13 for supporting materials are arranged inside the chamber, and a viewing window 14 is provided on one side of the chamber; a heat pump system 2, including an evaporator 21 and a condenser 22. The air inlet of the evaporator 21 is connected to the air outlet of the drying chamber 1 through a first air duct 23, the air outlet of the evaporator 21 is connected to the air inlet of the condenser 22 through a second air duct 24, and the air outlet of the condenser 22 is connected to the air inlet of the drying chamber 1 through a third air duct 25, forming a loop for air circulation between the drying chamber 1 and the heat pump; condensate is provided at the bottom of the evaporator 21. A water collector is used to collect liquid water that is cooled and precipitated when air flows through the evaporator 21; a photovoltaic PEM direct-coupled hydrogen production system 3 includes at least one PEM electrolyzer 31, the raw water inlet of the PEM electrolyzer 31 is connected to the condensate collector through a water supply pipeline, and the PEM electrolyzer 31 is composed of multiple independent PEM electrolysis units stacked or connected in parallel; a solar photovoltaic power supply system 4 includes a photovoltaic array 41 and a solar controller 42, the DC output terminal of the photovoltaic array 41 is directly connected to the DC power input terminal of the PEM electrolyzer 31 through a first cable, and is connected to the heat pump system 2 through a second cable via the solar controller 42; a control unit 5 is used to dynamically adjust the series and parallel structure of the photovoltaic array 41 and the number of working units of the PEM electrolyzer 31 according to the light intensity.

[0035] The power connection in this scheme is as follows: the solar photovoltaic power supply system 4 is the main power source of the system. The solar controller 42 has multiple outputs: one is connected to the energy storage battery 44 for charging and discharging management; the other directly supplies power to the system load; the DC power drawn from the main output terminal of the solar controller 42 is directly connected to the DC power input terminal of the PEM electrolysis cell 31 through the first cable. This is the core direct coupling path, and no DC-DC converter is set in between. Its core function is to simplify the system structure, reduce equipment costs, and reduce energy loss caused by multiple power conversions. At the same time, this output also supplies power to the compressor 26 of the heat pump system 2, the circulating fan in the drying box 1, and the control unit 5. If the compressor 26 or the fan is an AC motor, the power needs to be converted to AC power by the inverter 45 before being supplied.

[0036] The control connection relationship of this scheme is as follows: the control unit 5 can be an STM32 series microcontroller, which is the brain of the system. Its I / O port is electrically connected to the mechanical arm drive motor installed on the top of the drying chamber 1 for adjusting the angle of the photovoltaic panel, and is used to execute the solar tracking program; its I / O port is electrically connected to the array switching switch group and the switching switch group of the PEM electrolyzer 31 in the photovoltaic PEM direct coupling hydrogen production system 3, and is used to dynamically adjust the electrical structure of the system according to the light intensity; its analog input port can be connected to light sensors, temperature sensors, humidity sensors, etc., for collecting environmental and operating parameters.

[0037] The structure of this scheme will be explained in detail below: The drying chamber 1 of this solution includes a chamber body, a circulating fan, and a photovoltaic tracking bracket 43. The chamber body uses a stainless steel inner liner and is covered with a polyurethane insulation layer with a thickness of not less than 50mm to minimize heat loss and reduce energy consumption. Several layers of perforated stainless steel drying plates 13 are arranged inside the chamber, with a hole diameter of about 5mm and a hole spacing of about 15mm. The material is spread flat on the drying plates 13, which allows the hot dry air entering from the bottom to penetrate the material layer evenly, achieving efficient convection drying. The circulating fan is installed on the air inlet duct of the drying chamber 1 and is driven by a motor. Its function is to force air to circulate within the system and provide a stable air volume. The photovoltaic tracking bracket 43 includes a two-degree-of-freedom robotic arm fixed to the top of the drying chamber 1. Multiple photovoltaic panels are installed on the platform of the robotic arm. Its function is to track the sun so that the photovoltaic array 41 always receives maximum irradiance, thereby improving power generation efficiency.

[0038] The heat pump system 2 in this scheme uses a closed-loop air source heat pump dryer unit with a rated heating capacity of 50kW as its core. It includes an evaporator 21, a condenser 22, a compressor 26, an expansion valve 27, and a condensate collector. The evaporator 21 adopts a finned tube heat exchanger. The low-temperature, low-pressure liquid refrigerant flowing through it absorbs the heat of the humid air outside the tube and evaporates, causing the air temperature to drop below the dew point and water to be separated. Its core function is to recover condensate and recover the sensible and latent heat of the air. The compressor 26 adopts a fully enclosed scroll compressor 26. Its function is to compress the low-temperature, low-pressure refrigerant vapor from the evaporator 21 into a high-temperature, high-pressure gas, creating conditions for the refrigerant to release heat in the condenser 22. The condenser 22 also uses a finned tube heat exchanger, in which the high-temperature, high-pressure refrigerant gas condenses and releases heat to the dry, cold air from the evaporator 21, raising its temperature. Its core function is to reuse the recovered heat in the drying process. The expansion valve 27 is a thermostatic expansion valve. Its function is to throttle and reduce the pressure of the high-pressure liquid refrigerant from the condenser 22, turning it back into a low-temperature, low-pressure vapor-liquid mixture, which then enters the evaporator 21 to start a new cycle. The condensate collector is located at the bottom of the evaporator 21 and is used to collect condensate. It is equipped with a water level sensor and a drain pump to deliver water to the photovoltaic PEM direct-coupled hydrogen production system 3 as needed.

[0039] The photovoltaic PEM direct-coupled hydrogen production system 3 of this scheme includes a PEM electrolyzer 31 and a photovoltaic array 41 composed of multiple monocrystalline silicon modules. The series and parallel structure of the modules can be changed by the array switching switch group. The hydrogen and oxygen produced by the PEM electrolyzer 31 are stored in hydrogen storage tank 32 and oxygen storage tank 33, respectively. The PEM electrolyzer 31 adopts a modular design, for example, it is composed of 10 PEM electrolysis units with a rated operating voltage of 2V and a rated current of 500A. The number of electrolysis units in operation can be controlled by the electrolyzer switching switch group.

[0040] The control unit 5 is electrically connected to the light sensor, the array switching switch group of the photovoltaic array 41, and the electrolysis unit switching switch group of the PEM electrolysis cell 31. The control unit 5 is configured to control the array switching switch group to change the series-parallel combination mode of the photovoltaic modules according to the real-time light intensity signal, and synchronously control the electrolysis unit switching switch group to adjust the number of PEM electrolysis units in operation, so as to perform dynamic electrical matching between photovoltaic output and electrolysis load. The control unit 5 also includes a microprocessor, which is electrically connected to the light sensor. The light sensor is electrically connected to the array switching switch group and the electrolysis unit switching switch group through a drive circuit. The array switching switch group includes several relays to change the series or parallel topology between the photovoltaic modules. Each PEM electrolysis unit has an independent power input contact. The electrolysis unit switching switch group is composed of multiple contactors to independently connect or disconnect the power supply of the PEM electrolysis unit.

[0041] When the light intensity is below the set threshold, the control unit 5 controls the array switching switch group to adjust the photovoltaic array 41 to a mainly parallel mode, and at the same time controls the electrolysis unit switching switch group to reduce the number of PEM electrolyzers 31 units in operation, so that the system operating point can still be located in the effective power output range of the photovoltaic curve under low power, maintaining low-flow continuous hydrogen production. When the light intensity is above the set threshold, the control unit 5 controls the array switching switch group to adjust to a mainly series mode and increases the number of PEM electrolyzers 31 units in operation. At this time, the system operating point is close to the maximum power point of the photovoltaic array 41, realizing high peak efficiency hydrogen production. The purpose of this dynamic matching method is to broaden the effective operating range of the system and improve the overall solar energy utilization efficiency and hydrogen production stability throughout the day.

[0042] This scheme selects a specific number of photovoltaic arrays 41 connected in series and parallel, so that the voltage / current range of their maximum power point has a good overlap with the operating voltage / current requirements of the PEM electrolyzer 31 under typical illumination conditions, in order to achieve efficient direct coupling.

[0043] In this solar photovoltaic system, the solar controller 42 is a YJSS10 intelligent controller. Its function is to manage the charging and discharging of the energy storage battery 44, prevent overcharging and over-discharging, and distribute power to the DC load. The interface of the solar controller 42 is electrically connected to the energy storage battery 44, and the solar controller 42 is configured to supply power to various electrical components by the energy storage battery 44 when the photovoltaic output power is insufficient. The energy storage battery 44 can be two sets of 24V, 55AH gel lead-acid energy storage batteries 44 connected in series. Its main function is to provide backup power for the control unit 5, sensors, and control circuits at night or in extreme weather. At the same time, it provides starting current for equipment such as the compressor 26 at the moment of system startup. In particular, the energy storage battery 44 is not used to supply power to the PEM electrolyzer 31 in the absence of light, which reflects the fundamental difference between the direct coupling system and the traditional photovoltaic energy storage hydrogen production system.

[0044] The inverter 45 is a YS-1600H sine wave inverter 45 with an input of 48VDC, an output of 220VAC / 50Hz, and a power of 1600W. Its function is to convert the DC power output from the energy storage battery 44 or the controller into AC power for use by loads, such as the AC motor driven compressor 26 and the internal circulation fan in the drying chamber 1.

[0045] The following example, using the drying of a batch of grapefruit peels, illustrates the specific workflow of this solution in chronological order: S1: System Initialization and Material Loading S11: Open the door of drying oven 1, spread 200kg of fresh grapefruit peel evenly on the multi-layer drying plate 13, and close the door; S12: Power on the system, control unit 5 performs self-test, and the light sensor starts working; S2: Solar energy harvesting and distribution: S21: Photovoltaic array 41 generates direct current under sunlight; S22: The solar controller 42 prioritizes supplying electrical energy to the compressor 26, fan and PEM electrolyzer 31 of the heat pump system 2, and the excess electrical energy is used to charge the energy storage battery 44. S23: Control unit 5 executes a dynamic matching strategy for direct photovoltaic PEM coupling based on light intensity to optimize hydrogen production efficiency; S3: Heat pump drying and moisture recovery cycle: S31: The circulating fan starts, driving air to circulate within the system; S32: First cycle: The hot and humid air in the drying chamber 1 is drawn out by the circulating fan and enters the evaporator 21. The air is cooled to below the dew point, and most of the water vapor condenses into liquid water, which flows into the condensate collector, and the air becomes dry and cold air. S33: The dry, cold air then flows through the condenser 22, absorbs the heat released by the refrigerant condensation, and is heated to the target drying temperature, becoming dry, hot air; S34: Dry, hot air enters the drying chamber 1 from the bottom, penetrates the grapefruit peel layer, takes away the moisture, and then becomes humid, hot air again, completing a cycle.

[0046] S35: This process continues until the moisture content of the material reaches the target value; during the drying process, moisture is continuously transferred from the material to the air and then condensed and recovered at the evaporator 21. S4: Hydrogen production by condensate electrolysis: S41: After the condensate in the condensate collector reaches a certain level, it is pumped into the pure water treatment unit of the PEM electrolysis cell 31. S42: PEM electrolyzer 31 electrolyzes water under the direct current drive from photovoltaic array 41, and produces oxygen and high-purity hydrogen. The produced hydrogen is dried and purified, and then compressed or directly stored in hydrogen storage tank 32. S5: Night or Rain Mode: S51: When there is insufficient sunlight, the photovoltaic power generation cannot drive the main load, the solar controller 42 automatically switches to the discharge mode of the energy storage battery 44. S52: The energy storage battery 44 supplies power to the control unit 5, control circuit and sensors to maintain the system monitoring status; at this time, high-power loads such as PEM electrolysis cell 31 and compressor 26 stop working. S53: Once the light is restored, the system will automatically switch back to the daytime working mode of step S2.

[0047] The beneficial effects of this plan are explained in detail below: 1. This solution offers significant energy-saving and environmental benefits: Taking a county in Hunan Province as an example, during the pomelo harvest season (September-November), the system's photovoltaic power generation can reach 7296.13 kW·h. If this clean electricity is used to replace traditional coal-fired drying, it is equivalent to reducing the consumption of 2332.76 kg of standard coal. The high-efficiency heating characteristics of the heat pump technology itself (coefficient of performance (COP) is much greater than 1) further amplify the energy-saving effect of solar power, making the overall energy consumption per unit of material drying much lower than that of direct electric heating or coal-fired drying. At the same time, by using clean electricity and avoiding coal combustion, emissions of 1077.01 kg CO2 (greenhouse gas) and 78.04 kg SO2 (acid gas) can be reduced simultaneously during the above operation period. After conversion, this emission reduction is equivalent to the carbon absorption of 59 mature trees for one year, and the environmental contribution is intuitive and considerable.

[0048] 2. This solution achieves closed-loop and high-value utilization of water resources: it recovers water vapor, which is inevitably generated during the drying process and traditionally discarded. Processing 200 kg of grapefruit peel with an initial moisture content of 75% yields 144.8 kg of condensate. This not only solves the problem of requiring an external water source for independent photovoltaic hydrogen production but also achieves internal water recycling and "zero net consumption" during the production process. The aforementioned 144.8 kg of water, through efficient PEM electrolysis (approximately 86% efficiency), can produce 16.09 kg of hydrogen with a purity of up to 99.999%. Converted to energy, this is equivalent to producing approximately 536.28 kW·h of clean energy (based on the high calorific value of hydrogen). This directly transforms a byproduct of agricultural waste processing into high-quality green hydrogen energy suitable for industrial, transportation, and other fields.

[0049] 3. This solution boasts significantly improved integration and coupling efficiency, resulting in more stable and economical operation: Employing a direct photovoltaic PEM coupling and dynamic matching strategy eliminates the intermediate links of the battery 44 and DC-DC converter, reducing unnecessary energy conversion losses. The microcontroller intelligently adjusts the operating mode based on sunlight, ensuring a good match between the output of the photovoltaic array 41 and the operating point of the electrolyzer under all-weather conditions, thereby improving the overall energy utilization efficiency and system stability from solar to hydrogen energy. Simultaneously, the heat pump system 2, while dehumidifying and condensing, uses the recovered latent heat to heat the air, resulting in higher air temperature and lower humidity entering the drying chamber 1. This process significantly shortens the drying time of the materials and facilitates drying at lower temperatures, better preserving heat-sensitive active ingredients in the materials (such as flavonoids and polysaccharides in grapefruit peel), thus improving the quality of the dried products.

[0050] 4. This solution offers clear economic benefits and has broad application prospects: Based on the calculation that each mu (approximately 0.16 acres) of pomelo peel in a county in Hunan Province can produce 160.48 kg of hydrogen, estimated at the current market price (approximately RMB 30 / kg), the hydrogen alone could generate a potential income of approximately RMB 4814 per mu per year. The system generates 7296.13 kW·h / year of electricity, which, based on an industrial electricity price of RMB 0.86-1.80 / kW·h, can save RMB 6274-13133 in electricity costs annually. Meanwhile, China's annual pomelo production is approximately 3 million tons, producing about 1.2 million tons of peel. If 10% of the pomelo peel were processed using this solution, theoretically, it could generate hundreds of millions of yuan in hydrogen production value, while simultaneously saving huge amounts of drying energy costs and environmental remediation costs, demonstrating its enormous potential for large-scale application.

[0051] In summary, this solution, as an integrated, intelligent, modular, and multi-output system, achieves synergistic efficiency by organically combining solar photovoltaic, heat pump drying, and PEM electrolysis hydrogen production technology. It represents a highly resilient and economically efficient distributed production solution oriented towards a circular economy and a carbon-neutral future, possessing both technological depth and strategic significance.

[0052] Although the specific embodiments of the invention have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent; various modifications and variations that can be made by a person skilled in the art without inventive effort within the scope described in the claims are still within the scope of protection of this patent.

Claims

1. An integrated system for drying and collecting water to produce hydrogen, characterized in that, include: A drying oven is a sealed or semi-sealed box with a humid and hot air outlet at the top and a dry and hot air inlet at the bottom. The heat pump system includes an evaporator and a condenser. The air inlet of the evaporator is connected to the air outlet of the drying chamber through a first air duct, the air outlet of the evaporator is connected to the air inlet of the condenser through a second air duct, and the air outlet of the condenser is connected to the air inlet of the drying chamber through a third air duct, forming a loop that circulates air between the drying chamber and the heat pump. A condensate collector is provided at the bottom of the evaporator to collect the liquid water that is cooled and precipitated when the air flows through the evaporator. A photovoltaic PEM direct-coupled hydrogen production system includes at least one PEM electrolyzer. The feed water inlet of the PEM electrolyzer is connected to a condensate collector through a water supply pipeline. The PEM electrolyzer is composed of multiple independent PEM electrolysis units stacked or connected in parallel. A solar photovoltaic power supply system includes a photovoltaic array and a solar controller. The DC output terminal of the photovoltaic array is directly connected to the DC power input terminal of the PEM electrolyzer via a first cable, and is simultaneously connected to a heat pump system via a second cable through the solar controller. The control unit is used to dynamically adjust the series and parallel structure of the photovoltaic array and the number of working units of the PEM electrolyzer according to the light intensity.

2. The system according to claim 1, characterized in that, The drying chamber also includes a chamber wall made of thermal insulation material and at least one drying plate disposed inside the chamber and having evenly distributed air vents, the drying plates being arranged in parallel to form a multi-layer material carrying space through which airflow passes.

3. The integrated system for drying and collecting water to produce hydrogen according to claim 1, characterized in that, The photovoltaic array of the solar photovoltaic power supply system is fixedly installed on a photovoltaic tracking bracket, and the photovoltaic tracking bracket includes a robotic arm or turntable with multiple degrees of rotation freedom located on the top of the drying box. The robotic arm or turntable is electrically connected to the control unit to adjust the orientation of the photovoltaic array and track the sun's position.

4. The integrated system for drying and collecting water to produce hydrogen according to claim 1, characterized in that, The control unit is electrically connected to the light sensor, the array switching switch group of the photovoltaic array, and the electrolysis unit switching switch group of the PEM electrolyzer. The control unit is configured to control the array switching switch group to change the series and parallel combination mode of the photovoltaic modules according to the real-time light intensity signal, and synchronously control the electrolysis unit switching switch group to adjust the number of PEM electrolysis units put into operation, so as to perform dynamic electrical matching between photovoltaic output and electrolysis load.

5. The integrated system for drying and collecting water to produce hydrogen according to claim 4, characterized in that, The control unit further includes a microprocessor, which is electrically connected to a light sensor. The light sensor is electrically connected to the array switching switch group and the electrolysis unit switching switch group respectively through a driving circuit. The array switching switch group includes several relays to change the series or parallel topology between photovoltaic modules.

6. The integrated system for drying and collecting water to produce hydrogen according to claim 4, characterized in that, Each PEM electrolysis unit has an independent power input contact, and the electrolysis unit switching group consists of multiple contactors to independently connect or disconnect the power supply to the PEM electrolysis unit.

7. The integrated system for drying and collecting water to produce hydrogen according to claim 1, characterized in that, The solar controller's energy storage battery interface is electrically connected to the energy storage battery, and the solar controller is configured to supply power to various electrical components from the energy storage battery when the photovoltaic output power is insufficient.

8. The integrated system for drying and collecting water to produce hydrogen according to claim 7, characterized in that, The solar photovoltaic power supply system includes an inverter, which is electrically connected to the load output terminal of the solar controller or the energy storage battery. The AC output terminal of the inverter is connected to the compressor of the heat pump system and the internal circulation fan in the drying box through a third cable.

9. The integrated system for drying and collecting water to produce hydrogen according to claim 1, characterized in that: A water treatment device for improving water quality is installed on the water supply pipeline between the condensate collector and the PEM electrolysis cell. The water treatment device includes at least one of a filter, an ion exchange resin column, or a reverse osmosis membrane assembly.

10. The integrated system for drying and collecting water to produce hydrogen according to claim 1, characterized in that, The air circulation loop consisting of the drying chamber, the first air duct, the evaporator, the second air duct, the condenser, and the third air duct is either a closed loop that is isolated from the outside world during the drying process or a semi-closed loop with adjustable fresh air inlet and exhaust outlet.

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