Photovoltaic heat storage and collection system

Abstract

The invention provides a photovoltaic heat storage and collection subsystem, and the subsystem comprises a DC energy supply system which is used for providing DC electric energy; the confluence control box is connected to the direct current energy supply device, and the junction box is connected to the confluence control box and used for circuit division and electric quantity transmission between the confluence control box and the heat storage water tank; and the heat storage water tank is connected to the confluence control box. The system has the beneficial effects that a roof distributed photovoltaic power generation system is directly connected into the residential user indoor heat storage and heat preservation water tank, a direct current heating and mains supply complementary mode system is utilized, a clean energy hot water system is achieved, and a new application mode of zero-carbon energy hot water is created; a centralized photovoltaic module array is adopted, specifically, photovoltaic modules are distributed on the roof of a building in a centralized mode, a certain number of modules are connected in series to form a group, then a plurality of groups of photovoltaic groups are connected in series and in parallel and converged to form a unit with a certain generating capacity, and the electricity utilization requirement of a user is met.

Description

Technical Field

[0001] The invention belongs to the technical field of photovoltaics, and in particular relates to a photovoltaic thermal storage subsystem. Background Art

[0002] The rational and effective use of photovoltaic power generation on the roof of residential buildings to drive indoor water tank electric heating or heat pump heating to provide users with domestic hot water. The hot water (heat storage) system has created a new energy supply model. The installation of photovoltaic systems not only reduces users' carbon emissions, but also effectively solves users' hot water needs. It has broad development prospects in the future.

[0003] At present, large-scale photovoltaic power generation on the market is connected to the grid or used after being inverted by inverters. The power generation efficiency of photovoltaic inverters is generally around 90%. The power generation efficiency of inverters of different models and brands is different, which seriously reduces the efficiency of photovoltaic power generation.

[0004] In the patent literature that has been published, for example, invention patent application number CN201610867565.9 discloses an invention named an all-weather multi-purpose photovoltaic heat storage system and method, wherein the system includes a solar photovoltaic system, a photovoltaic current intelligent distributor, a photovoltaic stove system, a power storage and transformation system, and a solid or liquid heat storage body with controllable release, wherein the photovoltaic power generation system is connected to the photovoltaic current intelligent distributor; the photovoltaic current intelligent distributor is a device that can use an electronic program to control the photovoltaic current to input into different systems at different times; the photovoltaic current intelligent distributor includes a photovoltaic current intelligent distribution host, a plurality of sensors and a plurality of intelligent distribution terminals; the electrically heated solid or liquid heat storage body is made of a mixture of carbon fiber and phase change material, and is made into different shapes under the wrapping of good thermal insulation materials, and then placed in a spatial position inside a building wall, underground, or on the ground.

[0005] For another example, the invention patent application number CN202010790431.8, the invention name is disclosed as a kind of photothermal and photovoltaic complementary synergistic power generation system and operation method, including a photovoltaic power station, a photothermal power station, an electric heating system, a convergence system, a control system and a power grid. The photovoltaic power station includes a photovoltaic array and an inverter, and the photothermal power station includes a photothermal collection system, a heat storage system and a power generation system; the output end of the photovoltaic array is connected to the power interface and the convergence system of the electric heating system through the inverter, the photothermal collection system is connected to the heat storage system, the heat storage system is connected to the power generation system, the output end of the power generation system is connected to the convergence system, the control system is connected to the control end of the convergence system, and the output end of the convergence system is connected to the power grid. The system and operation method can realize the complementary and synergistic power generation of photovoltaic and photothermal, and have strong self-regulation ability.

[0006] For another example, invention patent application number CN202011295593.0 discloses a maximum power point tracking circuit and method for an off-grid photovoltaic thermal storage system, wherein the system includes a photovoltaic panel, a photovoltaic inverter for converting direct current output by the photovoltaic panel into alternating current, and a thermal load, and the tracking circuit includes: a load controller, N contactors and M remote IO modules; wherein the first end of each of the contactors is connected to the output end of the photovoltaic inverter, and the second end of each contactor is connected to a thermal load; each remote IO module is connected to one or more contactors; the load controller is used to sample the output voltage of the photovoltaic inverter, and based on the comparison between the output voltage and a predetermined voltage, the remote IO module controls the connection and disconnection of the connected contactor to switch the thermal load on and off, thereby realizing the maximum power point tracking function of the off-grid photovoltaic thermal storage system.

[0007] The above invention patent applications have not been able to reasonably solve the problem of photovoltaic systems reducing users' carbon emissions while effectively meeting users' hot water needs. Summary of the invention

[0008] The purpose of the present invention is to provide a photovoltaic thermal storage subsystem in view of the deficiencies of the prior art.

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

[0010] A photovoltaic thermal storage subsystem, comprising:

[0011] A DC power supply system is used to provide DC power;

[0012] A confluence control box is connected to the DC power supply device to increase the input power of the photovoltaic module array and intelligently distribute the DC power it provides;

[0013] A junction box, connected to the confluence control box, used for circuit division and power transmission between the confluence control box and the hot water storage tank;

[0014] The hot water storage tank is connected to the confluence control box, receives electric energy according to the distribution of the confluence control box, consumes the received electric energy, and stores it in the form of heat energy.

[0015] Furthermore, the DC energy supply system includes a photovoltaic component array and cables connected to the photovoltaic components, wherein the cables are connected to the convergence control box.

[0016] Furthermore, the convergence control box includes an MPPT controller, an integrated control board, a shunt circuit breaker, and a micro-electricity sensor. The MPPT controller is connected to the integrated control board, the integrated control board is connected to the shunt circuit breaker, and the shunt circuit breaker is connected to the micro-electricity sensor.

[0017] Furthermore, the hot water storage tank mainly includes: a rack, a shell, a DC heating tube, an AC heating tube, a temperature probe blind tube, an inspection port, an inspection cover, a sealing gasket, a leakage protection plug, a controller, a thermal insulation material layer, an inner tank, a hot water inlet, a magnesium rod, a cold water inlet, and an MC4 connector, wherein:

[0018] A cold water inlet pipe and a hot water outlet pipe are arranged inside the hot water storage tank, the cold water inlet pipe is arranged at the cold water outlet, and the hot water outlet pipe is arranged at the hot water outlet; the water inlet end of the cold water inlet pipe passes through the hot water storage tank and is connected with the water outlet end of the water inlet pipe, and the water outlet end of the hot water outlet pipe passes through the hot water storage tank and is connected with the water inlet end of the water pipe; a controller is arranged on the hot water storage tank; the controller is electrically connected to the DC heating pipe, and the AC heating pipe is electrically connected to the leakage protector arranged on the leakage protection plug of the shell through the controller.

[0019] An opening is provided at one end of the inner pot, an end cover for sealing the opening can be opened and closed at the opening, a sealing gasket is provided on the contact surface between the end cover and the inner pot, and the DC heating tube and the AC heating tube are both provided on the end cover;

[0020] The end cover is provided with a temperature probe blind tube, and the temperature probe blind tube is electrically connected to the controller.

[0021] The inner liner is arranged in the outer shell, and a heat-insulating material layer is arranged between the inner liner and the outer shell.

[0022] The shell body is provided with an inspection opening, and an inspection cover for sealing the inspection opening is provided at the inspection opening in an openable and closable manner.

[0023] The bottom of the hot water storage tank is provided with an installation groove, the bottom of the installation groove is provided with a through hole connected to the inside of the hot water storage tank, a detachable magnesium rod is provided at the through hole, and the main body of the detachable magnesium rod is located inside the hot water storage tank.

[0024] A hanging bracket is arranged on the back side of the hot water storage tank, which is used to fix the hot water storage tank on the wall.

[0025] Furthermore, the hot water storage tank includes an intelligent controller, and the intelligent controller is connected to the electric auxiliary heater and an AC power supply.

[0026] Furthermore, the heat storage tank is connected to the cold water pipeline and the hot water pipeline, and the cold water pipeline and the hot water pipeline are connected to the indoor water supply terminal.

[0027] Furthermore, the water storage tank is an electrically assisted heating water storage tank, and the electrically assisted heating is divided into direct current assisted heating and alternating current assisted heating.

[0028] Furthermore, the integrated control board includes: a control unit, a communication interface, a heat dissipation system, and a reactor, all of which are existing technologies.

[0029] Furthermore, the branch circuit breaker is of prior art, comprising: an operating mechanism, a contact system, and a release system, wherein the contact system is installed on an insulating base plate, and is composed of a static contact, a moving contact and a spring, a connecting rod, and a bracket. The arc extinguishing chamber uses a cardboard material and dozens of iron sheets as arc extinguishing grids to enhance the extinguishing of the arc; the operating mechanism is composed of a handle, an electromagnetic operating mechanism, and a powerful spring; the release system is provided with an overload long-delay release, a short-circuit instantaneous release, an undervoltage release, and a shunt release.

[0030] Furthermore, the release system is a universal circuit breaker with an electronic release. The universal circuit breaker with an electronic release can integrate the protection functions of overload long delay, short circuit instantaneous, short circuit short delay, undervoltage instantaneous and delayed tripping in one component, and use a shunt release to disconnect the circuit breaker, which are all existing technologies.

[0031] Furthermore, the micro-electric sensor is an AHKC-HAX solar-specific Hall current sensor, including: an input terminal, an output terminal, an indicator light, and a voltage sensor.

[0032] Furthermore, the photovoltaic thermal storage subsystem is provided with a junction box, including:

[0033] A power access port, used to access a power source;

[0034] Cable, used to connect to external power supply;

[0035] The output port is used to output power and connect the structural parts that need power to the output port;

[0036] LED indicator light, used to indicate whether the power is on;

[0037] The shell is prepared according to different industrial application requirements and meets the explosion-proof, leakage-proof, collision-proof, waterproof and anti-magnetic functions.

[0038] Furthermore, the DC energy supply device includes: a photovoltaic component, a power line, and an MC4 connector, and the photovoltaic component is connected to the MC4 connector via the power line.

[0039] Compared with the prior art in this technical field, the beneficial effects of the present invention are:

[0040] 1. The photovoltaic thermal storage collection and distribution system of the present invention utilizes the distributed photovoltaic power generation system on the rooftop to directly connect to the indoor heat storage and insulation water tank of the residential user, and utilizes direct current (or heat pump) heating to complement the city electricity system to realize a clean energy hot water system and create a new application model of zero-carbon energy hot water.

[0041] 2. The photovoltaic thermal storage subsystem of the present invention adopts a centralized photovoltaic module array: photovoltaic modules are centrally arranged on the roof of the building, and a certain number of modules are connected in series as a group, and then several groups of photovoltaic strings are connected in parallel to form a unit with a certain power generation capacity to meet the user's electricity demand.

[0042] 3. The photovoltaic thermal storage subsystem of the present invention adopts distributed electric heat storage: the direct current generated by photovoltaics is not connected to the grid, but is distributed and connected to the heat storage and insulation water tanks installed indoors by the residents after convergence. The DC heater in the water tank is used to heat the indoor water tank to a certain temperature to meet the user's daily hot water needs. When the light is insufficient, the mains electricity is used for supplementary heating.

[0043] 4. The photovoltaic thermal storage subsystem described in the present invention has the function of local photovoltaic power generation without grid access: In view of the fact that photovoltaic grid-connected to residential buildings has been largely abandoned due to issues such as property rights and profit distribution, the photovoltaic grid-connected solutions for residential buildings also have the problem of grid absorption capacity. The technical solution of the present invention effectively solves the reasonable interests of classified photovoltaic residential buildings, which not only saves energy but also reduces carbon emissions.

[0044] 5. The photovoltaic thermal storage subsystem of the present invention realizes the best power matching: the photovoltaic power generation is constantly changing with the light intensity. Under different irradiation intensities, to maintain the maximum power generation of the photovoltaic components, the DC load needs to be adjusted to achieve the best match between the photovoltaic string power generation power and the load power. The controller provided in the present invention has super computing power and can perform rapid data calculation and adjustment execution.

[0045] 6. The photovoltaic thermal storage collection and distribution system and the centralized and distributed controller described in the present invention are connected in series and parallel with a certain number of photovoltaic modules and connected to a centralized controller. The centralized controller realizes branch DC power supply and reasonably matches the load power (increase or decrease of household resistive load). The information of the indoor water tank is collected through the household controller, and instructions are sent to the household water tank controller, and the instructions are quickly executed according to the program.

[0046] 7. The photovoltaic thermal storage subsystem of the present invention has an information platform + remote monitoring function: a cloud database center is established, each system information is uploaded to the database, and rapid data processing and calculation are performed. The household work instruction plan of the project is executed according to the scientific management procedure, and the household end control program can be upgraded through the network to perform energy scientific operation and management of all household ends (indoor water tanks) under the jurisdiction of the system.

[0047] 8. The photovoltaic thermal storage subsystem described in the present invention can realize power information sensing and carbon emission reduction calculation: the water tank temperature and DC power related information collected by the indoor water tank controller and the power generation information and power transmission information of the photovoltaic components collected by the centralized controller are classified and written into the cloud database, and then the energy-saving and emission reduction effects are converted through the algorithm, and dynamic carbon management is achieved according to the carbon emission reduction. The carbon reduction value is calculated based on 0.5703kg of carbon dioxide reduction for every kilowatt-hour of electricity saved, and the economic benefits of emission reduction are significant. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the principle of the photovoltaic thermal storage subsystem described in an embodiment of the present invention;

[0049] Figure 2 It is a schematic diagram of the internal structure of the photovoltaic module array in the photovoltaic thermal storage subsystem in the embodiment of the present invention and the structure of the connection with the confluence control box;

[0050] Figure 3 Schematic diagram of the internal structure of the confluence control box in the photovoltaic thermal storage subsystem in the embodiment of the present invention;

[0051] Figure 4 Attached to the instruction manual Figure 1 The enlarged structural diagram at A in the middle;

[0052] Figure 5 It is a schematic diagram of the structure of the hot water storage tank in the photovoltaic thermal storage subsystem described in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0054] Example

[0055] A photovoltaic thermal storage subsystem, such as Figures 1 to 5 As shown, including:

[0056] A DC power supply system is used to provide DC power;

[0057] The confluence control box 2 is connected to the DC power supply device to increase the input power of the photovoltaic module array and intelligently distribute the DC power it provides;

[0058] A junction box, connected to the confluence control box 2, used for circuit division and power transmission between the confluence control box 2 and the hot water storage tank 3;

[0059] The hot water storage tank 3 is connected to the confluence control box 2, receives electric energy according to the distribution of the confluence control box 2, consumes the received electric energy, and stores it in the form of heat energy.

[0060] In a specific embodiment of the present invention, Figure 1-2 As shown, the DC energy supply system includes a photovoltaic component array 1 and cables connected to the photovoltaic component array 1, wherein the cables are connected to the convergence control box 2.

[0061] In a specific embodiment of the present invention, Figure 2-3 As shown, the confluence control box 2 includes an MPPT controller 2.1, an integrated control board 2.2, a shunt circuit breaker 2.3, and a micro-electricity sensor 2.4. The MPPT controller 2.1 is connected to the integrated control board 2.2, the integrated control board 2.2 is connected to the shunt circuit breaker 2.3, and the shunt circuit breaker 2.3 is connected to the micro-electricity sensor 24; wherein, Figure 3 The dotted line between the integrated control board 2.2 and the micro-electricity sensor 2.4 is a signal line used for signal transmission, which transmits the data detected by the micro-electricity sensor 24 to the integrated control board 2.2.

[0062] In a specific embodiment of the present invention, Figure 4-5 As shown, the hot water storage tank 3 mainly includes: a rack 3.1, a shell 3.2, a DC electric heating pipe 3.3, an AC electric heating pipe 3.4, a temperature probe blind pipe 3.5, a maintenance cover 3.6, a sealing gasket, a leakage protection plug 3.7, a controller 3.8, a thermal insulation material layer 3.9, an inner tank 3.10, a hot water inlet 3.11, a magnesium rod 3.12, a cold water inlet 3.13, and an MC4 connector; wherein:

[0063] The hot water storage tank 3 is provided with a cold water inlet pipe and a hot water outlet pipe inside, the cold water inlet pipe is arranged at the cold water inlet 3.13, and the hot water outlet pipe is arranged at the hot water inlet 3.11; the water inlet end of the cold water inlet pipe passes through the hot water storage tank and is communicated with the water outlet end of the water inlet pipe, and the water outlet end of the hot water outlet pipe passes through the hot water storage tank and is communicated with the water inlet end of the water pipe; the hot water storage tank 3 is provided with a controller 3.8; the controller 3.8 is electrically connected to the DC electric heating pipe 3.3, and the AC electric heating pipe 3.4 is electrically connected to the leakage protector arranged on the leakage protection plug 3.7 of the housing 3.2 through the controller 3.8;

[0064] The inner liner 3.10 is arranged in the outer shell 3.2, and a heat-insulating material layer 3.9 is arranged between the inner liner 3.10 and the outer shell 3.2;

[0065] An opening (not shown) is provided at one end of the inner pot 3.10, and an end cover (not shown) for sealing the opening can be opened and closed. A sealing gasket is provided on the contact surface between the end cover and the inner pot 3.10, and the DC heating tube 3.3 and the AC heating tube 3.4 are both provided on the end cover;

[0066] The end cover is provided with a temperature probe blind tube 3.5, and the temperature probe blind tube 3.5 is electrically connected to the controller 3.8;

[0067] The housing 3.2 is provided with an inspection port (not shown in the figure), and a maintenance cover 3.6 for blocking the inspection port is provided at the inspection port so as to be openable and closable;

[0068] The bottom of the hot water storage tank 3 is provided with a mounting groove (not shown in the figure), the bottom of the mounting groove is provided with a through hole connected to the inside of the hot water storage tank 3, a detachable magnesium rod 3.12 is provided at the through hole, and the main body of the detachable magnesium rod 3.12 is located inside the hot water storage tank 3;

[0069] A hanger 3.1 is provided on the back side of the hot water storage tank 3, and the hanger 3.1 is used to fix the hot water storage tank 3 on the wall.

[0070] In a specific embodiment of the present invention, the hot water storage tank 3 includes an intelligent controller, and the intelligent controller is connected to the electric auxiliary heater and the AC power supply.

[0071] In a specific embodiment of the present invention, the hot water storage tank 3 is connected to a cold water pipeline and a hot water pipeline, and the cold water pipeline and the hot water pipeline are connected to the indoor water supply terminal.

[0072] In a specific embodiment of the present invention, the hot water storage tank 3 is an electrically assisted heating hot water storage tank, and the electrically assisted heating is divided into direct current assisted heating and alternating current assisted heating.

[0073] In a specific embodiment of the present invention, the integrated control board includes: a control unit, a communication interface, a heat dissipation system, and a reactor, all of which are prior art.

[0074] In a specific embodiment of the present invention, the branch circuit breaker is of prior art, including: an operating mechanism, a contact system, and a release system, wherein the contact system is installed on an insulating base plate, and is composed of a static contact, a moving contact and a spring, a connecting rod, and a bracket. The arc extinguishing chamber uses a cardboard material and dozens of iron sheets as an arc extinguishing grid to enhance the extinguishing of the arc; the operating mechanism is composed of a handle, an electromagnetic operating mechanism, and a powerful spring; the release system is provided with an overload long-delay release, a short-circuit instantaneous release, an undervoltage release, and a shunt release.

[0075] In a specific embodiment of the present invention, the release system is a universal circuit breaker with an electronic release. The universal circuit breaker with an electronic release can integrate the protection functions of overload long delay, short circuit instantaneous, short circuit short delay, undervoltage instantaneous and delayed tripping in one component, and use a shunt release to disconnect the circuit breaker, which are all existing technologies.

[0076] In a specific embodiment of the present invention, the micro-electricity sensor is an AHKC-HAX solar-specific Hall current sensor, which includes: an input terminal, an output terminal, an indicator light, and a voltage sensor.

[0077] In a specific embodiment of the present invention, the photovoltaic thermal storage subsystem is provided with a junction box, which is a terminal of a distribution cable or an optical cable, connects the distribution cable or the optical cable and the user line, branches the main line, and converts a power signal into multiple outputs, including:

[0078] A power access port, used to access a power source;

[0079] Cable, used to connect to external power supply;

[0080] The output port is used to output power and connect the structural parts that need power to the output port;

[0081] LED indicator light, used to indicate whether the power is on;

[0082] The housing 3.2 is made of suitable materials according to different industrial applications to meet the functions of explosion-proof, leakage-proof, collision-proof, waterproof and anti-magnetic.

[0083] In a specific embodiment of the present invention, a DC energy supply device includes: a photovoltaic component, a power line, and an MC4 connector, wherein the photovoltaic component is connected to the MC4 connector via the power line.

[0084] Application examples:

[0085] Taking a residential area as an example, the practical application of the photovoltaic thermal storage subsystem of the present invention is briefly introduced below:

[0086] There are 108 households in the 1# residential building in a certain community, with 3 units in total, 2 households per elevator, 18 floors, and an available installation area of ​​about 500 square meters on the roof;

[0087] 550W photovoltaic module electrical performance parameters: maximum output power is 550w, open circuit voltage is 49.83V, maximum power voltage is 41.31V, short circuit current is 13.8A, maximum power current is 13.32V, and module conversion power is 21.19%.

[0088] The system design is: 6 groups of components are connected in series, and the average daily power generation is 550W*6*4H=13.2KWH;

[0089] Open circuit voltage: 298.98V, maximum power voltage is 247.86V, maximum power current is 13.32V, short circuit current is 13.8A;

[0090] When the solar illumination changes, the power supply voltage is basically stable, and the power supply current fluctuates between 5.3A and 13.3A, with large current fluctuations. When the light intensity is 1000W, the current is 13.32A, and when the light intensity is 400W, the current is 5.3A. The design calculation can be carried out according to the light intensity fluctuating between 400-1100W.

[0091] Functional parameter description of the present invention:

[0092] (I) About detection and measurement: The parameters that the indoor water tank controller needs to detect and measure are: water tank temperature, current time, photovoltaic voltage, current, power, mains power, cumulative power, converted into: daily carbon emission reduction, cumulative carbon emission reduction.

[0093] (II) Indoor household controller function:

[0094] 1. Display function: display water tank temperature, Beijing time, photovoltaic power supply of the day, cumulative carbon emission reduction; Status indication function: indicate DC heating working indication, mains heating working indication, alarm reminder (over-temperature, fault, leakage, etc.), mode status indication;

[0095] 2. Button function: set temperature adjustment button, mode selection button, timing parameter modification button. Timely heating button, 3. Mode selection function:

[0096] (1) Energy-saving mode: The AC heating function can only be started manually and stops when the set temperature is reached;

[0097] (2) Constant temperature mode: Use AC power to maintain the lowest temperature of the water tank, keep the temperature adjustable, the factory default is 45℃;

[0098] (3) Timing mode: 3 times a day, fixed temperature, the factory timing function is turned off;

[0099] (4) Away mode: The electric heating function is turned off, and the maximum limit of photovoltaic heating is 45 degrees;

[0100] 4. Parameter setting: temperature parameters are adjustable, timing is adjustable;

[0101] 5. One-click factory reset;

[0102] 6. Remote OTA (flash): The indoor controller can be upgraded through the remote network;

[0103] 7. Wireless communication function: through WIFI (users need to be connected to the Internet to access the control platform), ZigBee (self-built local area network), power carrier (no need to lay lines, transmitters and receivers), etc., timely communication between the indoor controller and the main controller on the roof can be achieved, and the information and status of the indoor water tank can be transmitted to the cloud control program center in time for centralized management;

[0104] 8. Remote monitoring: The controller can be remotely controlled by APP, and can monitor the energy consumption of each household, record and display the photovoltaic output voltage, current, power and power generation, and can collect the start and stop number of load users, the voltage, current, power, resistance value and other data of each household. It can count the photovoltaic usage of each household, the photovoltaic usage, and can adjust the water temperature set value, timed mains heating and other parameters.

[0105] (III) Outdoor centralized controller:

[0106] 1. MPPT tracking function: Track the maximum power of strings with different numbers of parallel connections, and increase or decrease the number of user heating by continuously adjusting the load resistance value, so as to ensure the maximum voltage at the working point of the photovoltaic cell and achieve the maximum power generation under different light intensities.

[0107] 2. Convergence function: Converge the currents of 3-6 strings and finally distribute them to 2 DC power supply circuits.

[0108] 3. Centralized control function: collate and analyze the data of all online users’ indoor water tanks, group them according to the heating strategy, and continue the cycle continuously until the photovoltaic power generation stops working.

[0109] 4. 4G communication function: upload the information collected by the photovoltaic centralized controller and the indoor water tank to the cloud data platform for analysis and processing, and establish a heating database according to the optimal cycle heating method.

[0110] 5. Communication and contact with indoor water tanks: The centralized controller can communicate with indoor water tanks in real time to collect, organize and classify data.

[0111] 6. Electrical protection function: The centralized controller has protection functions such as current, voltage, leakage, overload, lightning protection, DC arcing, etc. Rainproof function: The centralized controller installed outdoors should have rainproof function.

[0112] 7. Calculation and data analysis function: The centralized controller should have the ability to quickly calculate data information and execute commands; 8. Metering function: The current, voltage, power and other information of each photovoltaic string should be detected and measured, and each load at the user's load end should have the functions of current, voltage, power detection and measurement.

[0113] 9. Carbon emission reduction calculation function: data calculation and analysis functions such as the photovoltaic power supply of the day, the carbon emission reduction of the day, and the cumulative carbon emission reduction.

[0114] 10. Display indication function: Beijing time, working status indication function of each channel: alarm reminder of over-temperature, fault, leakage, etc.

[0115] 11. Remote OTA (flashing): The centralized controller can be upgraded through the remote network. It can be monitored by mobile phones and computers. It can display information such as water temperature, DC power supply and AC power consumption of each household. The built-in parameters of the system are adjustable.

[0116] 12. Wireless communication function: Through WIFI (users need to be connected to the Internet to access the control platform), ZigBee (self-built local area network) and power carrier (no need to lay lines, transmitters and receivers), etc., timely communication between the indoor controller and the rooftop main controller is achieved, and the information and status of the indoor water tank are transmitted to the cloud control program center in a timely manner for centralized management.

[0117] (IV) Indoor water tank heating control strategy:

[0118] 1. According to the installation space on the roof, the number of photovoltaic installations is limited, and it is unlikely that each household will be equipped with a photovoltaic module. The photovoltaic power generation system distributes energy evenly, and the following heating grouping method is adopted:

[0119] Reasonably match the number of technical components and the number of users of each independent system according to certain design rules, as shown in the following example:

[0120] Building 1# of a residential building is planned to install a solar photovoltaic centralized water heating system on the roof. It has 18 floors, 3 units, 2 households in each unit, and a total of 108 households. 90 sets of solar photovoltaic modules can be installed on the roof, and the maximum power of the modules is 580W. The solar photovoltaic water heating system designed for this building is divided into 3 independent systems on the roof. Each unit is equipped with a set of photovoltaic water heating system. Each system is configured with 30 sets of modules and 36 users. Each system supplies power vertically downward in 2 ways from the roof of the unit, or 1 way is laid on the ground from the power well to the household. The following Table 1 is simulated according to the 2-way access.

[0121] Table 1

[0122]

[0123] Each time the photovoltaic heating power reaches the start value: above 120V, it is grouped by indoor water tank number. Each system selects 10 households according to the heating strategy and rules to be included in the heating sequence. The control range of the number of households heated by each channel is 2-5 households. When the maximum power is generated, the maximum number of heating households matched by each channel is 5 households; the maximum number of heating households matched by two channels is 10 households in total, as shown in Table 2 below.

[0124] Table 2

[0125]

[0126]

[0127] 2. Adopt the method of increasing or decreasing the number of households in heating groups: according to the start and stop conditions of users, realize maximum power tracking, maximize the use of photovoltaics, and reasonably allocate output:

[0128] (1) When the irradiance is 1000W, the maximum power generation of the system is 17400W; the maximum heating power of each line is 8700W; the heating queue is 5 households / line, 2 lines, and the total heating queue of each system is 10 households. The heating power of each household's indoor water tank is 1740W.

[0129] (2) When the irradiance is 800 W, the maximum power generation of the system is 13920 W; the maximum power generation of each channel is 6960 W, the heating queue is 4 households / channel, and there are a total of 8 households in the heating queue. The average heating power per household is 1740 W / household, and the heating strategy is the same.

[0130] (3) When the irradiance is 600W, the maximum power generation of the system is 10440W; the maximum power generation of each line is 5220W; the heating queue is 3 households / line, with a total of 6 households in the heating queue, and the average heating power per household is 1740W / household.

[0131] (4) When the irradiance is 400W, the maximum power generation capacity of the system is 6960W; the maximum power generation capacity of each line is 3480W; the heating queue is 2 households / line, with a total of 4 households in the heating queue, and the average heating power per household is 1740W / household.

[0132] The above indoor water tank heating control strategy can realize variable adjustment of power changes and load power following changes of photovoltaic components under different irradiation intensities.

[0133] The present invention is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and improvements, which are within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A photovoltaic thermal storage subsystem, characterized in that: include: A DC power supply system is used to provide DC power; A confluence control box is connected to the DC energy supply system to increase the input power of the photovoltaic module array and intelligently distribute the DC power it provides; the DC energy supply system includes: a photovoltaic module, a power line, and an MC4 connector, and the photovoltaic module is connected to the MC4 connector through the power line; A junction box, connected to the confluence control box, used for circuit division and power transmission between the confluence control box and the hot water storage tank; The hot water storage tank is connected to the confluence control box, receives electric energy according to the distribution of the confluence control box, consumes the received electric energy, and stores it in the form of heat energy.

2. The photovoltaic thermal storage subsystem according to claim 1, characterized in that: The DC energy supply system includes: a photovoltaic component array and cables connected to the photovoltaic components, wherein the cables are connected to the convergence control box.

3. The photovoltaic thermal storage subsystem according to claim 1, characterized in that: The confluence control box includes: an MPPT controller, an integrated control board, a shunt circuit breaker, and a micro-electricity sensor. The MPPT controller is connected to the integrated control board, the integrated control board is connected to the shunt circuit breaker, and the shunt circuit breaker is connected to the micro-electricity sensor.

4. The photovoltaic thermal storage subsystem according to claim 1, characterized in that: The hot water storage tank mainly includes: a rack, a shell, a DC electric heating tube, an AC electric heating tube, a temperature probe blind tube, an inspection port, an inspection cover, a sealing gasket, a leakage protection plug, a controller, a thermal insulation material layer, an inner tank, a hot water inlet, a magnesium rod, a cold water inlet, and an MC4 connector, wherein: A cold water inlet pipe and a hot water outlet pipe are arranged inside the hot water storage tank, the cold water inlet pipe is arranged at the cold water outlet, and the hot water outlet pipe is arranged at the hot water outlet; the water inlet end of the cold water inlet pipe passes through the hot water storage tank and is connected with the water outlet end of the water inlet pipe, and the water outlet end of the hot water outlet pipe passes through the hot water storage tank and is connected with the water inlet end of the water pipe; a controller is arranged on the hot water storage tank; the controller is electrically connected to the DC heating pipe, and the AC heating pipe is electrically connected to the leakage protector arranged on the leakage protection plug of the shell through the controller.

5. The photovoltaic thermal storage subsystem according to claim 1, characterized in that: An opening is provided at one end of the inner pot, an end cover for sealing the opening can be opened and closed, a sealing gasket is provided on the contact surface between the end cover and the inner pot, and the DC heating tube and the AC heating tube are both provided on the end cover; The end cover is provided with a temperature probe blind tube, and the temperature probe blind tube is electrically connected to the controller; The inner liner is arranged in the outer shell, and a heat-insulating material layer is arranged between the inner liner and the outer shell; The shell body is provided with an inspection opening, and an inspection cover which can be opened and closed and is used to block the inspection opening is provided at the inspection opening.

6. The photovoltaic thermal storage subsystem according to claim 1, characterized in that: The bottom of the hot water storage tank is provided with an installation groove, the bottom of the installation groove is provided with a through hole connected to the inside of the hot water storage tank, a detachable magnesium rod is provided at the through hole, and the main body of the detachable magnesium rod is located inside the hot water storage tank.

7. The photovoltaic thermal storage subsystem according to any one of claims 1 to 6, characterized in that: A bracket is provided on the back side of the hot water storage tank for fixing the hot water storage tank on the wall; the hot water storage tank includes an intelligent controller, which is connected to the electric auxiliary heater and an AC power supply; the hot water storage tank is connected to a cold water pipeline and a hot water pipeline, which are connected to the indoor water supply terminal; the hot water storage tank is an electrically assisted heating hot water storage tank, and the electrically assisted heating is divided into direct current assisted heating and alternating current assisted heating.

8. The photovoltaic thermal storage subsystem according to claim 3, characterized in that: The integrated control board includes: a control unit, a communication interface, a heat dissipation system, and a reactor.

9. The photovoltaic thermal storage subsystem according to claim 3, characterized in that: The shunt circuit breaker includes: an operating mechanism, a contact system, and a release system, wherein the contact system is installed on an insulating base plate and consists of a static contact, a moving contact and a spring, a connecting rod, and a bracket; the operating mechanism consists of an operating handle, an electromagnetic operating mechanism, and a strong spring; the release system is provided with an overload long-delay release, a short-circuit instantaneous release, an undervoltage release, and a shunt release; the micro-electric sensor is an AHKC-HAX solar-specific Hall current sensor, including: an input terminal, an output terminal, an indicator light, and a voltage sensor.

10. According to the photovoltaic thermal storage subsystem of claim 1, the junction box comprises: A power access port, used to access a power source; Cable, used to connect to external power supply; The output port is used to output power and connect the structural parts that need power to the output port; LED indicator light to indicate whether the power is on.

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