Grid-connected heat and power cogeneration system based on photovoltaic and building hydrogen storage cooperation and operation method

Abstract

The invention discloses a grid-connected heat and power cogeneration system based on photovoltaic and building hydrogen storage cooperation and an operation method. The system comprises a solar module array, a hydrogen energy storage subsystem, a hydrogen fuel cell heat and power cogeneration subsystem and an intelligent control unit. The solar module array and the periphery of the building are integrally designed, one path of the solar module array is connected to the hydrogen energy storage subsystem to supply power to hydrogen production of the hydrogen energy storage subsystem, and the other path of electric energy is input into a power grid or the building to supply power; the hydrogen fuel cell cogeneration subsystem comprises a fuel cell and a heat recovery system, the fuel cell is connected with the hydrogen energy storage subsystem, hydrogen generated by the hydrogen energy storage subsystem is used for generating power, and the heat recovery system recovers heat energy generated in the power generation process of the hydrogen energy storage subsystem and supplies heat. According to the invention, a zero-carbon-emission energy closed-loop system which takes renewable energy as a source and hydrogen as an energy carrier and is completely completed in a local building is constructed, so that the dependence of the building on a fossil energy power grid and a traditional heat supply mode is remarkably reduced.

Description

Technical Field

[0001] This application relates to the field of photovoltaic-hydrogen storage combined heat and power technology, specifically to a grid-connected combined heat and power system and its operation method based on the synergy of photovoltaic and building hydrogen storage. Background Technology

[0002] The construction industry is currently facing significant decarbonization pressures, and the combination of distributed photovoltaic (PV) and hydrogen energy storage technologies provides direction for the energy transition in buildings. However, PV power generation is intermittent and volatile, and building thermal loads exhibit daily peak-valley and seasonal variations, leading to a mismatch between power generation and consumption. Existing PV-hydrogen storage systems primarily focus on electricity storage and supply, lacking adaptation to combined heat and power (CHP) scenarios. Furthermore, a single power / heat following strategy is insufficient to address the mismatch between user thermal loads, easily resulting in energy waste and supply-demand imbalances.

[0003] In existing technologies, grid-connected photovoltaic (PV) systems involve installing solar photovoltaic modules on building rooftops or exterior walls. The generated electricity is directly connected to the public power grid or used to supply part of the building's load via a DC / AC inverter. However, when there is sufficient sunlight but the building's electricity demand is low or the grid's absorption capacity is limited, a large amount of surplus PV power cannot be effectively utilized or is forcibly discarded, resulting in a huge waste of renewable energy. This prevents the maximization of PV capacity utilization, causing the system to lack energy storage or only be equipped with a small number of short-term batteries for stable output, lacking long-term energy storage and heating functions.

[0004] Off-grid photovoltaic (PV) systems with lithium-ion batteries (or other types of electrochemical batteries) serve as the energy storage core, building upon PV modules. When sunlight is abundant and PV power generation exceeds the building's immediate load demand, surplus electricity flows to the batteries for charging and storage. During periods of insufficient sunlight (such as at night or on cloudy days) or when PV output cannot meet load demands, the batteries release their stored energy to continuously power the building's load. However, lithium batteries have high initial purchase costs, and the cost of ultra-large capacity configurations required to meet long-term energy storage needs spanning days and even weeks increases linearly, making the unit energy storage cost uncompetitive in the long run. Furthermore, frequent deep charging and discharging, especially in high-capacity demand scenarios, significantly accelerates capacity degradation, necessitating periodic replacement and increasing the total lifecycle cost. In addition, lithium batteries rely excessively on organic electrolytes and the use of nickel, cobalt, and manganese, further increasing the environmental burden.

[0005] Traditional combined heat and power (CHP) systems rely on fossil fuels, such as natural gas / diesel-driven CHP systems: using natural gas internal combustion engines, micro gas turbines, or diesel generators as prime movers to drive generators to generate electricity, and recovering waste heat such as exhaust gas and cylinder liner water for building heating or driving absorption chillers for refrigeration. However, these systems usually need to be connected to the city's gas pipeline network or rely on diesel storage tanks.

[0006] Although hydrogen fuel cell combined heat and power technology exists, it is not deeply integrated with photovoltaic-building hydrogen storage and lacks a dynamic adjustment mechanism for the heat-to-power ratio based on user load characteristics. It cannot simultaneously solve the problems of intermittent photovoltaic power generation, long-term energy storage, and matching of heat and power supply and demand. It still needs to rely on fossil fuel boilers or electric heating, which are high-carbon emission / high-cost heating methods. It cannot utilize local free renewable resources, and its energy supply is not sustainable or independent.

[0007] Therefore, it is urgent to integrate photovoltaic-hydrogen energy storage with the heat-to-power ratio following strategy to build an efficient, zero-carbon grid-connected combined heat and power system. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a grid-connected combined heat and power system and its operation method based on the synergy of photovoltaic and building hydrogen storage.

[0009] The present invention adopts the following technical solution.

[0010] The first aspect of the present invention discloses a grid-connected combined heat and power system based on photovoltaic and building hydrogen storage synergy, comprising: a solar module array, a hydrogen energy storage subsystem, a hydrogen fuel cell combined heat and power subsystem, and an intelligent control unit; The solar panel array is integrated with the building envelope and is used to convert light energy into electrical energy. One source of electrical energy is connected to the hydrogen energy storage subsystem via a DC / DC converter to power the hydrogen production of the hydrogen energy storage subsystem. The other source of electrical energy is input to the power grid or the building via a DC / AC inverter to power the building. The hydrogen fuel cell combined heat and power subsystem includes: a fuel cell and a heat recovery system. The fuel cell is connected to a hydrogen energy storage subsystem and generates electricity using hydrogen produced by the hydrogen energy storage subsystem. The heat recovery system recovers the heat generated during the power generation process of the hydrogen energy storage subsystem and supplies heat to the building. The intelligent control unit includes a thermoelectric ratio control module, a data acquisition module, and a method execution module. The data acquisition module is used to collect system parameters in real time, the thermoelectric ratio control module is used to calculate the parameters, and the method execution module adjusts the system to switch operating methods according to the calculation results.

[0011] Preferably, the hydrogen energy storage subsystem includes: an electrolyzer, a compressor, and a hydrogen storage tank; After being powered by electricity, the electrolyzer electrolyzes water to produce hydrogen. The hydrogen is then transported to a compressor, processed by the compressor, and stored in a hydrogen storage tank. The hydrogen storage tank is equipped with a pressure sensor and a hydrogen concentration alarm. The data is uploaded to the intelligent control unit in real time. Hydrogen production stops when the pressure is detected to be ≥40MPa.

[0012] Preferably, the heat recovery system includes a heat exchanger and a water tank; The heat exchanger is connected in series with the cooling water circuit of the fuel cell and the heating water circuit of the building. The water tank stores excess heat energy by adjusting the opening of the three-way valve between the heat exchanger and the water tank.

[0013] The second aspect of the present invention discloses an operating method for implementing the grid-connected combined heat and power system based on photovoltaic and building hydrogen storage synergy described in the first aspect, comprising the following steps: Step 1, collect photovoltaic power generation data Pressure value of hydrogen energy storage subsystem Building electrical load requirements Heat load demand Based on the fuel cell output parameters, the required heat-to-power ratio is calculated. and output thermoelectric ratio ; Step 2, calculate photovoltaic power generation. With electricity load demand Difference The size, if If less than or equal to 0, proceed to step 3. If the value is greater than 0, proceed to step 4; Step 3, when When the required heat-to-electricity ratio is less than or equal to 0, determine the required heat-to-electricity ratio. With output thermoelectric ratio The size of the fuel cell determines its operating method; Step 4, when When the pressure is greater than 0, the hydrogen storage subsystem is activated to produce hydrogen through water electrolysis, based on the pressure of the hydrogen storage tank in the hydrogen storage subsystem. The size determines the start and stop of the hydrogen production process.

[0014] Preferably, in step 1, the electrical load demand Heat load demand is collected through building electricity meters and equipment current sensors. Data is collected through heat meters in the building's heating pipes and flow meters and temperature sensors in the hot water pipes. The fuel cell output parameters include: output thermal power. With net output power ; According to the formula Calculate the required heat-to-electricity ratio According to the formula Calculate the output thermoelectric ratio of the fuel cell .

[0015] Preferably, in step 3, when When less than or equal to 0, photovoltaic power generation ≤Building Real-Time Electrical Load Demand Photovoltaic power generation All power is supplied to the building load, and any shortfall is supplemented by the fuel cell using a power-following method based on the thermoelectric ratio.

[0016] Preferably, the fuel cell operation method includes: an electrical power follower method and a thermal power follower method; When the demand heat-to-electricity ratio Greater than the output thermoelectric ratio When selecting the thermal power follower method for operation; When the demand heat-to-electricity ratio Less than the output thermoelectric ratio The power follower method is selected for operation.

[0017] Preferably, the power tracking method involves obtaining the net power MAP of the fuel cell through experimental testing, and then adjusting the electrical load demand. The input is fed into the fuel cell net power MAP, which controls the operation of the fuel cell to ensure that the electrical power it generates meets the electrical load demand. By adjusting the opening of the three-way valve, excess heat power is stored in the water tank.

[0018] Preferably, the heat power following method involves using a water tank to output heat power to meet the heat load demand. After the water tank temperature drops, the fuel cell is turned on, and the fuel cell output thermal power MAP is obtained through experimental testing, along with the input heat load demand. The output thermal power MAP controls the operation of the fuel cell, ensuring that the thermal power it generates meets the thermal load requirements. The fuel cell supplies the building's load demand with its electrical power; the net power of the fuel cell is related to the load demand. The difference is supplemented or absorbed by the external power grid.

[0019] Preferably, step 4 is when When it is greater than 0, the photovoltaic power generation is Building electrical load demand The excess electricity generated by the solar panel array after supplying the building load is input into the hydrogen storage subsystem for hydrogen production through water electrolysis. When the pressure value of the hydrogen energy storage subsystem When the pressure is greater than or equal to 40 MPa, the hydrogen storage subsystem is shut down and hydrogen production is stopped; when When the pressure is less than 40 MPa, continue hydrogen production.

[0020] Compared with the prior art, the beneficial effects of the present invention include at least the following: (1) Achieve a zero-carbon closed loop of "source-load-storage" and achieve deep decarbonization.

[0021] By following the main path of solar photovoltaic power generation (green electricity) → water electrolysis to hydrogen production (green hydrogen) → fuel cell power generation (green electricity), and combining it with the building's own energy needs (electricity and heat), a zero-carbon emission closed-loop energy system is constructed, using renewable energy as the source and hydrogen as the energy carrier, and completed entirely within the local building. This significantly reduces the building's dependence on fossil fuel grids and traditional heating methods, providing an effective technical path to achieve building carbon neutrality. It effectively solves the intermittency and instability problems of photovoltaic power generation in existing technologies. Because solar power generation depends on weather and time, its output is unstable, and it does not generate electricity at night when there is no sunlight, resulting in a mismatch between the power generation curve and the building's electricity consumption curve. This invention converts the "surplus" electricity generated by photovoltaics (when there is sufficient sunlight but the building's electricity demand is low) into hydrogen for storage. When photovoltaic output is insufficient (such as at night or on cloudy days) or during peak electricity consumption, the stored hydrogen is used to generate electricity through fuel cells, providing a stable and continuous power supply to the building. This achieves energy conversion and time shifting from "green electricity → green hydrogen → green electricity".

[0022] (2) Make efficient use of fluctuating renewable energy sources and significantly improve the self-consumption rate of photovoltaic power generation.

[0023] By utilizing hydrogen energy as a large-scale, long-term energy storage medium, the inherent defects of intermittent and fluctuating photovoltaic power generation are overcome. Surplus electricity generated during peak photovoltaic periods (the portion that cannot be immediately consumed by the building) is efficiently converted into hydrogen for storage. During periods of insufficient photovoltaic power generation or peak building electricity consumption (such as at night or on cloudy or rainy days), the hydrogen is released to generate electricity. This maximizes the building's ability to absorb its own photovoltaic power locally, effectively avoiding the waste of renewable energy. Furthermore, using hydrogen as an energy carrier for storage offers advantages such as high hydrogen energy density (especially compared to lithium batteries), long-term storage (with little or no self-discharge loss), and the invention incorporates mature technologies such as compression and storage tanks, making it more suitable for medium-to-large-scale, medium-to-long-term (across days / seasons) energy storage needs at the building level.

[0024] (3) Achieve high-quality combined heat and power, and significantly improve the overall energy efficiency of the system.

[0025] Building heating and domestic hot water are major energy consumers. Traditional methods (such as gas boilers and electric heating) typically consume fossil fuels or high-grade electricity, resulting in high costs and significant carbon emissions. This invention efficiently recovers a large amount of high-quality waste heat (accounting for 40-50% of the fuel energy) generated during the power generation process of fuel cells through a heat exchanger, directly using it to meet the building's heating and domestic hot water needs. Simultaneously, this heat recovery effectively reduces the operating temperature of the fuel cell system, ensuring its stable and efficient operation. This achieves cascaded energy utilization: high-grade electrochemical energy is used for power generation, while medium- and low-grade thermal energy is used for heating, increasing the overall energy utilization rate of the system to over 70%, far exceeding traditional standalone power generation (efficiency ~40-60%) or standalone heating solutions. This significantly reduces overall energy costs, substantially lowers heating energy costs and overall carbon emissions, achieving combined heat and power (CHP).

[0026] (4) Promote the integrated design of buildings with renewable energy.

[0027] Solar panel arrays are directly installed on the building envelope (exterior walls, roof), transforming the building itself into an energy producer. Core equipment (electrolyzers, hydrogen storage tanks, fuel cells, etc.) can be flexibly arranged in usable building spaces (such as basements, equipment rooms, roofs, etc.), achieving deep integration of energy production, storage, and utilization with the building structure and efficient space utilization, in line with the design concepts of modern green buildings and "productive energy buildings". Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the combined heat and power system in this invention; Figure 2 This is a schematic diagram of the combined heat and power fuel cell system in this invention; Figure 3 This is a block diagram of the electrical system in this invention; Figure 4 This is a schematic diagram of the intelligent control unit operation judgment method of the present invention; In the diagram: 1. Solar panel array; 2. DC / DC converter; 3. Electrolyzer; 4. Compressor; 5. Hydrogen storage tank; 6. Fuel cell; 7. DC / AC inverter; 8. Heat exchanger; 9. Water pump; 10. Water tank; 11. Building; 12. Three-way valve. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0030] like Figure 1-3 As shown, Embodiment 1 of the present invention provides a grid-connected combined heat and power system based on photovoltaic and building hydrogen storage synergy, including: a solar module array 1, a DC / DC converter 2, a hydrogen energy storage subsystem, a hydrogen fuel cell combined heat and power subsystem, a DC / AC inverter 7, and an intelligent control unit; The solar panel array 1 uses lightweight double-glass BIPV modules, integrated with the building envelope, covering the south-facing facade and roof (roof angle 15°~30°), with a total area ≥100m². 2 Peak power ≥20kW, output voltage range 200V–600VDC. The electricity generated by the solar module array 1 is connected to the system through a lightning protection combiner box, which not only meets the power generation needs but also requires no additional land, conforming to the concept of green building. It is a key design for combining the "source" of the grid-connected combined heat and power system with the building carrier.

[0031] In a preferred but non-limiting embodiment of the present invention, according to the photovoltaic power collection and thermoelectric ratio operation method, the high-voltage direct current (120-500VDC) generated by the solar module array 1 can be stepped down to 48VDC through the DC / DC converter 2 to power the hydrogen energy storage subsystem; or the high-voltage direct current generated by the solar module array 1 can be input to the power grid or building 11 for power supply through the DC / AC inverter 7.

[0032] The hydrogen energy storage subsystem, as the core of "green electricity to green hydrogen" and long-term energy storage, includes: an electrolyzer 3, a compressor 4, and a hydrogen storage tank 5; The electrolyzer 3 has a rated power of 15kW and a hydrogen production capacity of ≥3.0Nm³ / h. It includes a 50L water storage tank (with a liquid level sensor that automatically replenishes water when the liquid level is <30%) and nickel mesh electrodes. After being supplied with 48VDC power, it electrolyzes water to produce hydrogen (purity ≥99.5%) and oxygen. The oxygen is discharged through a check valve, and the hydrogen is delivered to the compressor 4. The compressor 4 adopts an oil-free piston design, with an inlet pressure of 1.5 bar, an outlet pressure of 35 MPa, and a power of 1.5 kW. Downstream, a dual-tower adsorption dryer (dew point ≤ -40℃) is connected in series to remove moisture from the hydrogen produced by the electrolysis cell 3, thus preventing corrosion of subsequent equipment. The hydrogen storage tank 5 is made of 35MPa carbon fiber wound type IV bottle with a capacity of ≥200L. It has the advantages of high strength and lightweight. The hydrogen gas processed by the compressor 4 is stored in the hydrogen storage tank 5. The hydrogen storage tank 5 is equipped with a pressure sensor (range 0-45MPa) and a hydrogen concentration alarm (range 0-‰). The data is uploaded to the intelligent control unit in real time. Hydrogen production is stopped when the pressure is ≥40MPa to ensure the safety of hydrogen storage.

[0033] The hydrogen fuel cell cogeneration subsystem realizes "green hydrogen to heat and electricity" and includes fuel cell 6 and a series heat recovery system: In a preferred but non-limiting embodiment of the present invention, the fuel cell 6 is a proton exchange membrane fuel cell stack with a rated power of 150kW and a hydrogen inlet pressure of 16bara; an inlet excess ratio of 1.8 to ensure sufficient reactants; and an inlet relative humidity of 100% to improve the conductivity of the proton exchange membrane.

[0034] More preferably, the fuel cell 6 includes a hydrogen system (electromagnetic valve controls on / off, proportional valve regulates flow, hydrogen circulation pump improves utilization), an air system (air filter filters impurities, air compressor pressurizes, humidifier humidifies, intercooler cools), and a cooling circuit (expansion tank stabilizes pressure, water pump drives circulation), ensuring stable output of the fuel cell 6; The heat recovery system includes a heat exchanger 8 and a water tank 10; In a preferred but non-limiting embodiment of the present invention, the heat exchanger 8 is a brazed plate heat exchanger, the water tank 10 has a volume ≥ 4.5 m³, and the heat exchanger 8 is connected in series with the cooling water circuit (water temperature 60°C) of the fuel cell 6 and the heating water circuit (water temperature 40°C–55°C) of the building 11.

[0035] The waste heat generated during the power generation process of fuel cell 6 (accounting for 40-50% of the fuel energy) is absorbed by cooling water and transferred to the heating water circuit of building 11 through water pump 9 and heat exchanger 8 to meet the building's heating and domestic hot water needs. At the same time, the opening of the three-way valve 12 between heat exchanger 8 and water tank 10 can be adjusted to allow the hot water storage tank 10 to store excess heat energy to cope with fluctuations in building heat demand.

[0036] The DC / AC inverter 7 is used to boost the low-voltage DC power (such as 48VDC) generated by the fuel cell 6 or the solar module array 1 to 220VAC, so that it meets the power distribution system requirements of building 11, and is finally connected to the power distribution system of building 11 to power loads such as lighting, computers, and elevators, realizing the conversion of hydrogen energy into electrical energy.

[0037] The intelligent control unit, serving as the "brain" of the grid-connected combined heat and power system, incorporates a heat-to-power ratio control module, a data acquisition module, and a method execution module.

[0038] The data acquisition module collects real-time data such as photovoltaic output, building thermal power load, fuel cell parameters, and hydrogen storage tank status; the thermoelectric ratio control module calculates the required thermoelectric ratio and the output thermoelectric ratio; the method execution module controls the fuel cell 6 to switch operating methods based on the thermoelectric ratio comparison results, while coordinating the work of each subsystem to ensure system stability and efficiency.

[0039] like Figure 2-3As shown, the system architecture of this invention takes the building's external solar panel array 1 as the sole primary energy input starting point. By converting surplus green electricity into green hydrogen through electrolyzer 3 (hydrogen production system), compressor 4, and hydrogen storage tank 5 (hydrogen storage system), the hydrogen is generated by fuel cell 6 (fuel cell system) when needed. The generated electricity is then supplied to the building via DC / AC 7 and heat recovery through heat exchanger 8 and water tank 10. This forms a physically and logically clear and self-consistent closed-loop energy flow of "photovoltaic power generation → hydrogen energy storage → power generation and heat supply".

[0040] This invention provides a grid-connected combined heat and power system based on photovoltaic and building-integrated hydrogen storage. This specific embodiment fully discloses the technical solution of this invention, enabling those skilled in the art to implement the system functions. In practical applications, the equipment capacity (such as the volume of the hydrogen storage tank and the photovoltaic power) can be adjusted according to the building scale, but all remain within the scope of this patent protection. It should be noted that the specific embodiments described herein are only for explaining this invention and do not constitute a limitation on the scope of protection.

[0041] The core innovation of this invention lies in integrating the heat-to-power ratio following mechanism into the photovoltaic-building hydrogen storage synergistic process. By dynamically switching operating modes, it achieves heat and power supply-demand matching. Embodiment 2 of this invention provides an operating method based on the grid-connected cogeneration system based on photovoltaic and building hydrogen storage synergy described in Embodiment 1. The method and specific steps are as follows: 1. Heat and electricity load acquisition and heat-to-electricity ratio calculation The intelligent control unit collects real-time data on the building's thermal and electrical loads and fuel cell output parameters from sensors deployed within the building. Thermal and electrical load acquisition: electrical load demand Heat load demand is collected through electricity meters and equipment current sensors (covering lighting, computers, air conditioning, elevators, etc.). Data is collected through a heat meter for heating pipes and a flow meter and temperature sensor for hot water pipes. Calculation of demand heat-to-power ratio: According to the formula calculate.

[0042] Output thermoelectric ratio calculation: The output thermal power of hydrogen fuel cell 6 was collected experimentally. With net output power According to the formula Calculate the output thermoelectric ratio of fuel cell 6.

[0043] 2. Power Follower Methods and Thermal Power Follower Methods for Fuel Cell 6 ① Power Follower Method: The current, temperature, and net power MAP of fuel cell 6 were obtained through experimental testing, and the electrical load demand was calculated. The input is fed into the fuel cell net power MAP, which controls the fuel cell 6 to operate at its preset point, ensuring that the electrical power it generates meets the electrical load demand. By adjusting the opening of the three-way valve 12 (increasing the opening of valves a and b, and decreasing the opening of valve c) and increasing the speed of the water pump 9, excess heat power is stored in the water tank 10.

[0044] ② Thermal power following method: Adjust the opening of the three-way valve 12 (increase the opening of valves a and b, and decrease the opening of valve c) and increase the speed of the water pump 9 to prioritize the use of the heat storage tank 10 to output heat power to meet the heat load demand. When the water tank temperature drops to 60℃, close the three-way valve (port b) and turn on fuel cell 6.

[0045] The current, temperature, and output thermal power (MAP) of fuel cell 6 were obtained through experimental testing, along with the input heat load demand. The output thermal power MAP controls the fuel cell 6 to operate at its preset point, ensuring that the thermal power it generates meets the thermal load requirements. The power output of fuel cell 6 is prioritized to meet the user's electrical load demand. The net power output of the fuel cell is related to the electrical load demand. The difference is supplemented or absorbed by the external power grid.

[0046] 3. Photovoltaic power collection and heat-to-power ratio operation methods Solar panel array 1 converts solar energy into DC power, which is then input to DC / DC converter 2 via a surge protector. The intelligent control unit monitors the photovoltaic power generation and the building's real-time load power. If photovoltaic power generation ≤Building Real-Time Electrical Load Demand The solar panel array 1 provides electricity to the building 11 load first, and the remaining power is supplied by the fuel cell 6.

[0047] The power supply for fuel cell 6 is as follows: the high-pressure hydrogen in hydrogen storage tank 5 is reduced to 8 bar by a pressure reducing valve and then transported to the anode side of fuel cell 6 through the hydrogen system; at the same time, air is processed by the air system (filtered, pressurized to 1.2 bar, humidified to 100%, and cooled to 60°C) and then enters the cathode side. Hydrogen and oxygen undergo an electrochemical reaction in the stack to generate direct current, which is boosted to 220VAC by DC / AC inverter 7 and connected to the building's power distribution system 11 to supplement the power supply. In the above process, the intelligent control unit selects whether to follow the thermal power or the electrical power by comparing the required thermoelectric ratio with the output thermoelectric ratio.

[0048] The selection logic is: when the demand heat-to-electricity ratio is... Greater than or equal to the fuel cell output thermoelectric ratio In this mode, the heat-following mode is adopted, and the difference between the net power output of the fuel cell and the electrical load demand is supplemented or absorbed by the external power grid. When the demand heat-to-power ratio... Less than the fuel cell output thermoelectric ratio This indicates that electricity is the primary demand at this time. The fuel cell 6 operates using the power follower method and recovers excess heat through the hot water storage tank 10. 3.2 If the photovoltaic power generation capacity Building electrical load demand Excess electrical energy is reduced to 48VDC by DC / DC converter 2 and then input into electrolyzer 3 for water electrolysis to produce hydrogen. After being compressed to 35MPa by compressor 4 and dehumidified by dryer, it is stored in hydrogen storage tank 5; when the pressure of hydrogen storage tank reaches a certain level... When the pressure reaches 40 MPa, the intelligent control unit issues a command to shut down electrolyzer 3 and compressor 4, thus stopping hydrogen production.

[0049] like Figure 4 As shown, Embodiment 3 of the present invention provides an operating method based on the grid-connected combined heat and power system based on photovoltaic and building hydrogen storage synergy described in Embodiment 1. The specific steps are as follows: Step 1: Collect the hydrogen storage tank pressure value, building thermal and electrical load data, and fuel cell output parameters, and calculate the heat-to-power ratio.

[0050] Specifically, the thermoelectric load data includes: electrical load demand. and heat load demand ; Electricity load demand Heat load demand is collected through building electricity meters and equipment current sensors (covering lighting, computers, air conditioning, elevators, etc.). Data is collected through heat meters in the building's heating pipes and flow meters and temperature sensors in the hot water pipes. The fuel cell output parameters include: output thermal power. With net output power ; According to the formula The required heat-to-power ratio is calculated according to the formula. The output thermoelectric ratio of the fuel cell is calculated.

[0051] Step 2, calculate photovoltaic power generation. With electricity load demand Difference Size, if If less than or equal to 0, proceed to step 3. If the value is greater than 0, proceed to step 4.

[0052] Step 3, when When the required heat-to-electricity ratio is less than or equal to 0, determine the required heat-to-electricity ratio. With output thermoelectric ratio The size of the fuel cell determines the different operating methods.

[0053] Specifically, when When less than or equal to 0, photovoltaic power generation ≤Building Real-Time Electrical Load Demand The electrical energy generated by the solar panel array, i.e., photovoltaic power generation. All power is supplied to the building load, and any shortfall is supplemented by fuel cells using a power-following method determined by the thermoelectric ratio. The fuel cell operation method includes: an electrical power follower method and a thermal power follower method; When the demand heat-to-electricity ratio Greater than the output thermoelectric ratio When selecting the thermal power follower method for operation; When the demand heat-to-electricity ratio Less than the output thermoelectric ratio The power follower method is selected for operation.

[0054] Step 4, when When the pressure is greater than 0, the hydrogen storage subsystem is activated to produce hydrogen through water electrolysis, based on the pressure of the hydrogen storage tank. The size determines the start and stop of the hydrogen production process.

[0055] Specifically, when When it is greater than 0, the photovoltaic power generation is Building electrical load demand The excess electricity generated by the solar panel array after supplying the building load is input into the hydrogen storage subsystem for hydrogen production through water electrolysis. when When the pressure is greater than or equal to 40 MPa, shut down the electrolyzer and compressor to stop hydrogen production; when When the pressure is less than 40 MPa, continue hydrogen production.

[0056] Compared with the prior art, the beneficial effects of the present invention include at least the following: (1) Achieve a zero-carbon closed loop of "source-load-storage" and achieve deep decarbonization.

[0057] By following the main path of solar photovoltaic power generation (green electricity) → water electrolysis to hydrogen production (green hydrogen) → fuel cell power generation (green electricity), and combining it with the building's own energy needs (electricity and heat), a zero-carbon emission closed-loop energy system is constructed, using renewable energy as the source and hydrogen as the energy carrier, and completed entirely within the local building. This significantly reduces the building's dependence on fossil fuel grids and traditional heating methods, providing an effective technical path to achieve building carbon neutrality. It effectively solves the intermittency and instability problems of photovoltaic power generation in existing technologies. Because solar power generation depends on weather and time, its output is unstable, and it does not generate electricity at night when there is no sunlight, resulting in a mismatch between the power generation curve and the building's electricity consumption curve. This invention converts the "surplus" electricity generated by photovoltaics (when there is sufficient sunlight but the building's electricity demand is low) into hydrogen for storage. When photovoltaic output is insufficient (such as at night or on cloudy days) or during peak electricity consumption, the stored hydrogen is used to generate electricity through fuel cells, providing a stable and continuous power supply to the building. This achieves energy conversion and time shifting from "green electricity → green hydrogen → green electricity".

[0058] (2) Make efficient use of fluctuating renewable energy sources and significantly improve the self-consumption rate of photovoltaic power generation.

[0059] By utilizing hydrogen energy as a large-scale, long-term energy storage medium, the inherent defects of intermittent and fluctuating photovoltaic power generation are overcome. Surplus electricity generated during peak photovoltaic periods (the portion that cannot be immediately consumed by the building) is efficiently converted into hydrogen for storage. During periods of insufficient photovoltaic power generation or peak building electricity consumption (such as at night or on cloudy or rainy days), the hydrogen is released to generate electricity. This maximizes the building's ability to absorb its own photovoltaic power locally, effectively avoiding the waste of renewable energy. Furthermore, using hydrogen as an energy carrier for storage offers advantages such as high hydrogen energy density (especially compared to lithium batteries), long-term storage (with little or no self-discharge loss), and the invention incorporates mature technologies such as compression and storage tanks, making it more suitable for medium-to-large-scale, medium-to-long-term (across days / seasons) energy storage needs at the building level.

[0060] (3) Achieve high-quality combined heat and power, and significantly improve the overall energy efficiency of the system.

[0061] Building heating and domestic hot water are major energy consumers. Traditional methods (such as gas boilers and electric heating) typically consume fossil fuels or high-grade electricity, resulting in high costs and significant carbon emissions. This invention efficiently recovers a large amount of high-quality waste heat (accounting for 40-50% of the fuel energy) generated during the power generation process of fuel cells through a heat exchanger, directly using it to meet the building's heating and domestic hot water needs. Simultaneously, this heat recovery effectively reduces the operating temperature of the fuel cell system, ensuring its stable and efficient operation. This achieves cascaded energy utilization: high-grade electrochemical energy is used for power generation, while medium- and low-grade thermal energy is used for heating, increasing the overall energy utilization rate of the system to over 70%, far exceeding traditional standalone power generation (efficiency ~40-60%) or standalone heating solutions. This significantly reduces overall energy costs, substantially lowers heating energy costs and overall carbon emissions, achieving combined heat and power (CHP).

[0062] (4) Promote the integrated design of buildings with renewable energy.

[0063] Solar panel arrays are directly installed on the building envelope (exterior walls, roof), transforming the building itself into an energy producer. Core equipment (electrolyzers, hydrogen storage tanks, fuel cells, etc.) can be flexibly arranged in usable building spaces (such as basements, equipment rooms, roofs, etc.), achieving deep integration of energy production, storage, and utilization with the building structure and efficient space utilization, in line with the design concepts of modern green buildings and "productive energy buildings".

[0064] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0065] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0066] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0067] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1.A grid-connected combined heat and power system based on the synergy of photovoltaic and building hydrogen storage, characterized in that it comprises: a solar module array (1), a hydrogen storage subsystem, a hydrogen fuel cell combined heat and power subsystem, and an intelligent control unit; the solar module array (1) is designed in an integrated manner with the building envelope, and is used to convert light energy into electrical energy, one of which is connected to the hydrogen storage subsystem through a DC / DC converter (2) to provide power for hydrogen production, and the other is input to the power grid or the building through a DC / AC inverter (7) for power supply; the hydrogen fuel cell combined heat and power subsystem comprises a fuel cell (6) and a heat recovery system, the fuel cell (6) is connected with the hydrogen storage subsystem and generates electricity by using hydrogen generated by the hydrogen storage subsystem, and the heat recovery system recovers the heat energy generated in the power generation process of the hydrogen storage subsystem and provides heat for the building; the intelligent control unit comprises a heat-to-power ratio control module, a data acquisition module and a method execution module, the data acquisition module is used to acquire system parameters in real time, the heat-to-power ratio control module is used to calculate parameters, and the method execution module adjusts the system switching operation method according to the calculation results. 2.The grid-connected combined heat and power system based on the synergy of photovoltaic and building hydrogen storage according to claim 1, characterized in that: the hydrogen storage subsystem comprises an electrolytic cell (3), a compressor (4) and a hydrogen storage tank (5); the electrolytic cell (3) electrolyzes water to generate hydrogen after being supplied with electrical energy, the hydrogen is transported to the compressor (4), the hydrogen is treated by the compressor (4) and then enters the hydrogen storage tank (5) for storage, the hydrogen storage tank (5) is provided with a pressure sensor and a hydrogen concentration alarm instrument, and data is uploaded to the intelligent control unit in real time, and hydrogen production is stopped when the detected pressure is greater than or equal to 40 MPa. 3.The grid-connected combined heat and power system based on the synergy of photovoltaic and building hydrogen storage according to claim 1, characterized in that: the heat recovery system comprises a heat exchanger (8) and a water tank (10); the heat exchanger (8) is connected in series in the cooling water circuit of the fuel cell (6) and the heating water circuit of the building, and the opening degree of a three-way valve (12) between the heat exchanger (8) and the water tank (10) is adjusted to make the water tank (10) store surplus heat energy. 4.An operation method for the grid-connected combined heat and power system based on the synergy of photovoltaic and building hydrogen storage according to any one of claims 1-3, characterized in that it comprises the following steps: 5.The operation method according to claim 4, characterized in that: 6.The operation method according to claim 4, characterized in that: 7.The operation method according to claim 6, characterized in that: the fuel cell operation method comprises an electric power following method and a thermal power following method; 8.The operation method according to claim 7, characterized in that: 9.The operation method according to claim 7, characterized in that: 10.The operation method according to claim 4, characterized in that: ​ ​ ​ ​ Step 1, collecting photovoltaic power generation , hydrogen energy storage subsystem pressure value , electrical load demand in the building , thermal load demand and fuel cell (6) output parameters, calculate the required heat-to-power ratio and output heat-to-power ratio ; Step 2, calculate photovoltaic power generation with the electrical load demand difference the size, if less than or equal to 0, then go to step 3, if greater than 0, then go to step 4; Step 3, when if the required heat / electricity ratio is less than or equal to 0, the operation method of the fuel cell (6) is determined based on the magnitude of the output heat / electricity ratio if the required heat / electricity ratio is less than or equal to 0, the operation method of the fuel cell (6) is determined based on the magnitude of the output heat / electricity ratio the magnitude of Step 4, when greater than 0, start the hydrogen storage energy subsystem to electrolyze water to produce hydrogen, according to the pressure of the hydrogen storage tank in the hydrogen storage energy subsystem determine the size to start or stop the hydrogen production process. ​ The electric load demand in step 1 The heat load demand is collected by the electric meter and equipment current sensor in the building The heat load demand is collected by the heat meter and flow meter and temperature sensor in the heating pipe in the building The fuel cell (6) output parameters include: output thermal power with net output electric power ; The required heat power ratio is calculated according to the formula The required heat power ratio is calculated according to the formula The output heat power ratio of the fuel cell is calculated according to the formula The output heat power ratio of the fuel cell is calculated according to the formula . ​ In step 3, when PV power is less than or equal to 0 ≤ building real-time electric load demand power , PV power All building loads are supplied, and the insufficient part is supplemented by the fuel cell (6) through judging the size of the thermal power ratio to determine the power following method. ​ ​ selecting a thermal power following method to operate when the demand heat-to-power ratio is greater than the output heat-to-power ratio ; The electrical power following method is selected to operate when the demand heat-to-power ratio is less than the output heat-to-power ratio . ​ The electric power following method is that the net electric power MAP of the fuel cell (6) is obtained by experiment test, the electric load demand is input into the fuel cell net electric power MAP, the fuel cell (6) is controlled to work so that the electric power emitted by it satisfies the electric load demand , and the excess heat power is stored in the water tank (10) by regulating the opening of the three-way valve (12). ​ The heat power following method involves using a water tank (10) to output heat power to meet the heat load demand. When the temperature of the water tank (10) drops, the fuel cell (6) is turned on. The output thermal power MAP of the fuel cell (6) is obtained through experimental testing, and the input thermal load demand is calculated. The output thermal power MAP controls the operation of the fuel cell (6) to ensure that the thermal power it generates meets the thermal load requirements. The electric power of the fuel cell (6) supplies the building load demand, and the net electric power of the fuel cell (6) is related to the electric load demand. The difference is supplemented or absorbed by the external power grid. ​ The step 4 is, when > Photovoltaic power generation power > Building electrical load demand power The excess electrical energy of the solar module array (1) after supplying the building load is input into the hydrogen energy storage subsystem to produce hydrogen by electrolyzing water. When the pressure value of the hydrogen energy storage subsystem When the pressure is greater than or equal to 40 MPa, the hydrogen storage subsystem is shut down and hydrogen production is stopped; when When the pressure is less than 40 MPa, continue hydrogen production.

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