Indoor heating system based on coupling of compost residual heat and photovoltaic energy storage and control method

Abstract

The present application belongs to the technical field of renewable energy utilization and building energy saving, and particularly relates to an indoor heating system based on compost waste heat and photovoltaic energy storage coupling and a control method, comprising a compost heat utilization unit, a heat storage water tank unit, a heat pump temperature raising unit, a phase change heat storage unit, a terminal heating unit, a photovoltaic energy storage unit and an intelligent control unit. The present application realizes deep coupling and intelligent collaboration of compost waste heat and photovoltaic energy storage, significantly improves energy utilization efficiency and fire safety level, and achieves all-weather, energy-saving heating effect without manual intervention.

Description

Technical Field

[0001] This invention belongs to the field of renewable energy utilization and building energy conservation technology, specifically involving an indoor heating system and control method based on the coupling of compost waste heat and photovoltaic energy storage. It utilizes the biomass heat energy generated by aerobic composting, combined with a photovoltaic power generation and energy storage system, to provide stable and continuous heating for buildings. It also features fire protection and safety monitoring functions and a collaborative energy storage strategy based on peak-valley electricity prices and weather forecasts. Background Technology

[0002] The global energy crisis is worsening, and environmental protection pressures are increasing, necessitating continuous optimization of building heating energy structures. The current state and limitations of existing technologies are as follows: Composting waste heat utilization technology: The aerobic fermentation process of organic waste releases a large amount of biomass heat energy. The core temperature of the compost can reach 60-70℃, and this high-temperature phase can last for several days or even weeks, making it an excellent low-carbon heat source. Existing composting technologies mainly focus on decomposition and do not recover waste heat; the heat is recovered through natural dissipation or forced ventilation. A few technologies use buried heat exchange pipes for heat recovery, but the heat generation is highly phased, with large temperature fluctuations, making it difficult to meet the stable heating needs of buildings.

[0003] Photovoltaic heating technology: Although photovoltaic-driven heat pump heating has been widely adopted, photovoltaic power generation is affected by the diurnal variation of weather and is intermittent. It requires the configuration of large-capacity energy storage batteries or relies on grid supplementation, resulting in large initial investment or uncontrollable operating costs.

[0004] Multi-energy complementarity and energy storage technology: Coupling multiple energy sources can complement each other, but current technologies mostly only use compost waste heat as a heat source for heat pumps, without utilizing the temperature gradient. Heat storage often uses water tanks, resulting in low energy density and unstable heat release temperatures. Phase change energy storage, on the other hand, has high energy density but is unsuitable for engineering applications. Furthermore, existing heating systems lack control over the composting process and integrated fire safety functions, posing fire hazards. Therefore, there is a strong need for a system that organically integrates compost waste heat, photovoltaic energy storage, heat pump temperature rise, and phase change energy storage, and possesses intelligent control, composting process optimization, fire-fighting linkage, and peak-valley electricity price and weather forecast-based energy storage capabilities. This would enable 24 / 7 unattended, energy-efficient, safe, and cost-effective heating. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an indoor heating system and control method based on the coupling of compost waste heat and photovoltaic energy storage.

[0006] This invention provides an indoor heating system based on the coupling of compost waste heat and photovoltaic energy storage, comprising a compost heat utilization unit, a hot water storage tank unit, a heat pump temperature boosting unit, a phase change heat storage unit, a terminal heating unit, a photovoltaic energy storage unit, and an intelligent control unit. The compost heat utilization unit includes a fermentation tank and a compost heat utilization heat exchange coil embedded inside the fermentation tank. The hot water storage tank unit includes a hot water storage tank with six ports. The inlet of the compost heat utilization heat exchange coil is connected to the second port of the hot water storage tank via a primary side return water main, and the outlet of the compost heat utilization heat exchange coil is connected to the first port of the hot water storage tank via a primary side supply water main. A primary circulation pump is installed on the primary side supply water main; the heat pump temperature boosting unit... The heat pump unit includes an evaporator, compressor, condenser, and expansion valve connected in sequence to form a closed loop. The inlet and outlet of the evaporator are connected to the fifth and sixth ports of the hot water storage tank, respectively. A sixth electric three-way valve is installed on the pipeline between the evaporator and the compressor, and a fifth electric three-way valve is installed on the pipeline between the evaporator and the expansion valve. An outdoor air-side heat exchanger is connected between the sixth and fifth electric three-way valves to switch between water source and air source heat pump modes. The inlet of the fifth electric three-way valve is connected to the outlet of the expansion valve, and the outlet of the fifth electric three-way valve is connected to the refrigerant inlets of both the evaporator and the outdoor air-side heat exchanger. The outlet of the sixth electric three-way valve is connected to the suction port of the compressor. The inlet of the three-way valve is connected to the refrigerant outlet of the evaporator and the outdoor air-side heat exchanger, respectively; the terminal heating unit includes an indoor heat exchange coil laid indoors, the third interface of the hot water storage tank is connected to the inlet of the indoor heat exchange coil through the first electric three-way valve, and the fourth interface is connected to the outlet of the indoor heat exchange coil through the second electric three-way valve. A two-stage circulation pump is installed on the pipeline between the second electric three-way valve and the indoor heat exchange coil. The outlet of the condenser is connected to one inlet of the first electric three-way valve, and the inlet of the condenser is connected to one outlet of the second electric three-way valve; the phase change heat storage unit includes a phase change heat storage tank, which is filled with phase change material and equipped with a phase change heat storage coil. The inlet of the phase change heat storage tank is connected to the fourth... An electric three-way valve is provided, with its outlet connected to a third electric three-way valve. Both the third and fourth electric three-way valves are connected to the pipeline between the first electric three-way valve and the indoor heat exchange coil. The photovoltaic energy storage unit includes a photovoltaic array, an energy storage battery, and a bidirectional energy storage converter. The DC side of the bidirectional energy storage converter is connected to the photovoltaic array and the energy storage battery, while the AC side is connected to the main distribution box. The main distribution box is connected to the power grid and supplies power to the indoor heating system through the main distribution box. The bidirectional energy storage converter has a built-in MPPT controller to monitor the real-time power P_pv of the photovoltaic array. The energy storage battery has a built-in battery management system to monitor the battery's state of charge (SOC) in real time. The MPPT controller and the battery management system are collectively referred to as the electrical parameter acquisition module.The intelligent control unit includes a central controller and several sensors electrically connected to it: a compost temperature sensor installed in the fermentation tank for real-time monitoring of compost temperature T1; a hot water tank temperature sensor installed in the hot water tank for monitoring the tank temperature T_tank; a phase change heat storage tank temperature sensor installed in the phase change heat storage tank for monitoring the phase change heat storage temperature T_pcm; a room temperature sensor installed indoors for monitoring the room temperature T_room; and a grid connection switch installed between the power grid and the main distribution box. The central controller is also electrically connected to the compressor, primary circulation pump, secondary circulation pump, first electric three-way valve, second electric three-way valve, third electric three-way valve, fourth electric three-way valve, fifth electric three-way valve, sixth electric three-way valve, bidirectional energy storage converter, MPPT controller, and battery management system.

[0007] Preferably, the fermentation tank is further provided with an electric auxiliary heating film, a forced ventilation fan and a stirring device. The electric auxiliary heating film is attached to the inner wall of the fermentation tank or the surface of the compost heat utilization heat exchange coil. The forced ventilation fan is connected to the inside of the fermentation tank through a duct. The stirring device is driven by a motor and extends into the inside of the fermentation tank. The central controller is also electrically connected to the electric auxiliary heating film, the forced ventilation fan and the stirring device respectively.

[0008] Preferably, it also includes a fire protection and safety monitoring unit, which includes a distributed fiber optic temperature measurement host, a thermal imaging temperature sensing camera, a multispectral image fire detector, a smoke detector, and a fire protection gateway, all electrically connected to the central controller. The temperature sensing fiber of the distributed fiber optic temperature measurement host is laid around the cable trench and composting tank. The thermal imaging temperature sensing camera is located near the heat pump compressor, distribution box, energy storage battery, and inverter. The multispectral image fire detector is located in the photovoltaic array, composting area, and heat storage tank area. The smoke detector is located in the power distribution room, control room, and battery room. The fire protection gateway is connected to the existing automatic fire alarm controller.

[0009] Preferably, it also includes a remote operation and maintenance control platform and an energy storage fire protection subunit. The remote operation and maintenance control platform is deployed in the cloud or on a local server, and uses 4G / 5G, Ethernet or WiFi to establish a two-way data connection with the central controller. It is used to monitor the operating parameters of the indoor heating system in real time, perform fault prediction and analysis, push alarm information, and generate operation and maintenance work orders, and supports remote modification of control parameters. The energy storage fire protection subunit can be specifically classified by layer: Monitoring layer: Battery pack temperature sensor: Each battery module is equipped with a surface-mount NTC temperature sensor, which can monitor the surface temperature of the battery cell in real time.

[0010] Combustible gas detector: Installed on the top of the battery cabinet, its detection principle is catalytic combustion or semiconductor, and it can detect the concentration of hydrogen (H2), carbon monoxide (CO), and methane (CH4). The detection range of this detector is set to 0-100% LEL.

[0011] Smoke detector: Installed in the battery cabinet, its function is to detect smoke generated by the evaporation of electrolyte; Voltage monitoring process: The voltage of each battery string is collected in real time using a bidirectional energy storage converter, and then the voltage difference is calculated.

[0012] Early warning and coordination layer: After receiving the above monitoring signals, the central controller implements linkage operations according to the pre-set three-level threshold strategy (see the control method section for details).

[0013] Firefighting Execution Level: Automatic aerosol fire extinguishing device: It adopts a hot-start aerosol fire extinguisher, which is installed on the top or side of the battery cabinet. When the ambient temperature reaches or exceeds 90℃, or when it receives a start signal from the central controller, it will automatically spray aerosol to achieve the effect of total flooding fire extinguishing. Isolation and protective layers: Fireproof partition: A galvanized steel plate or Class A fireproof board with a thickness of not less than 1.5mm must be installed between the battery cabinet and adjacent equipment, such as distribution boxes, converters and other equipment, and its fire resistance limit should reach 1 hour or more. Explosion-proof pressure relief device: A pressure relief port is opened on the top or back of the battery cabinet, and a spring-type or rupture disc-type pressure relief valve is installed. When the internal pressure exceeds 300Pa, it will automatically open to release pressure in a safe direction.

[0014] A slope or drainage ditch can be installed on the floor of the battery cabinet to facilitate the collection and treatment of electrolyte leaks.

[0015] Further preferably, the remote operation and maintenance central control platform includes a data server (receiving and parsing data uploaded by the central controller), a real-time database (storing the latest operating parameters and historical data), a fault prediction engine (relying on built-in algorithms to perform trend analysis on the operating data of key components such as compressors, batteries, and circulating pumps, thereby predicting the remaining service life and potential faults), a web server, and a mobile application server (providing a visual interface and API interface, supporting access from computer browsers and mobile applications). It displays the real-time operating parameters, historical trend curves, health scores, and fault prediction results of the indoor heating system through a graphical dashboard. When abnormal parameters are detected or potential faults are predicted, an alarm is automatically generated and pushed to the operation and maintenance personnel via SMS and App. At the same time, an operation and maintenance work order is created for closed-loop management.

[0016] The present invention also provides a control method for the indoor heating system based on the coupling of compost waste heat and photovoltaic energy storage, comprising the following steps: Step 1: The central controller collects the compost temperature T1, the temperature inside the hot water storage tank T_tank, the indoor temperature T_room, the phase change thermal storage temperature T_pcm, the indoor preset temperature T_set, the real-time photovoltaic power P_pv, and the state of charge (SOC) of the energy storage battery; Step 2: The central controller automatically adjusts the composting process according to T1: when T1>60℃, the forced ventilation fan is started until T1≤55℃; when T1<50℃, the electric auxiliary heating film is started until T1≥50℃; the stirring device operates according to a preset cycle (running for 5-10 minutes every 6-8 hours), and the operating frequency is increased when there is a surplus of photovoltaic power generation; Step 3: The central controller selects the heating mode based on T_tank and T_room: If T_tank≥40℃ and T_room is lower than the set temperature, enter the direct water tank supply mode: turn off the compressor, switch the first electric three-way valve to the hot water storage tank side, switch the second electric three-way valve to the hot water storage tank side, and start the first-stage circulation pump and the second-stage circulation pump; at this time, the outlet of the indoor heat exchange coil is directly connected to the hot water storage tank through the second-stage circulation pump, and the hot water heated by the hot water storage tank enters the room through the inlet of the indoor heat exchange coil; If 25℃≤T_tank<40℃ and T_room is lower than the set temperature, enter the heat pump water source mode: start the compressor, switch the first electric three-way valve to the condenser side, switch the second electric three-way valve to the condenser side, switch the fifth electric three-way valve and the sixth electric three-way valve to the evaporator side, start the first-stage circulation pump and the second-stage circulation pump. At this time, the evaporator absorbs heat from the hot water storage tank, and then the refrigerant enters the compressor and is compressed into a high-temperature and high-pressure gas. Finally, it enters the condenser to condense and release heat to heat the cold water coming out of the indoor heat exchange coil. The heated water comes out from the condenser outlet, passes through the first electric three-way valve, the fourth electric three-way valve, and the third electric three-way valve in sequence, and finally enters the room through the water inlet of the indoor heat exchange coil. If T_tank < 25℃ and T_room is lower than the set temperature, the system enters the air source heat pump mode: the compressor is started and the fifth and sixth electric three-way valves are switched to the outdoor air-side heat exchanger so that the outdoor air-side heat exchanger can extract heat from the air. The first electric three-way valve is switched to the outlet side of the condenser, and the second electric three-way valve is switched to the inlet side of the condenser. The first-stage circulation pump is turned off, and the second-stage circulation pump is started, thereby extracting heat from the air to provide indoor heating in the form of an air source heat pump. At this time, the outdoor air-side heat exchanger absorbs heat from the air, and then the refrigerant enters the compressor and is compressed into a high-temperature and high-pressure gas. Subsequently, it enters the condenser to condense and release heat to heat the cold water coming out of the indoor heat exchange coil. Then, the heated water comes out from the condenser outlet, passes through the first electric three-way valve, the fourth electric three-way valve, and the third electric three-way valve in sequence, and finally enters the room through the inlet of the indoor heat exchange coil. Step 4: The central controller performs power dispatch: when P_pv ≥ the power required by the indoor heating system load, photovoltaic direct supply is prioritized, and excess power is stored in the energy storage battery; if SOC ≥ 95% and P_pv still has a surplus, then: If the current mode is heat pump water source mode or heat pump air source mode, increase the compressor frequency and switch the fourth electric three-way valve and the third electric three-way valve to the heat storage path to charge the phase change heat storage tank. If the current mode is direct water supply from the water tank, the surplus electrical energy will be allocated to the forced ventilation fan, the stirring device, or the electric auxiliary heating film to enhance composting fermentation. When P_pv < the power required by the indoor heating system load, it is supplemented by the energy storage battery; if SOC ≤ 20%, it automatically switches to the grid power supply. Step 5: The central controller switches the fourth electric three-way valve and the third electric three-way valve to the bypass, heat storage or heat release path according to the temperature of the phase change heat storage tank and the heating demand, so as to realize the storage and release of heat. Step 6: The central controller acquires real-time electricity price information and weather forecast data for the next 24-48 hours. When it is during off-peak electricity hours at night and low sunshine is predicted for the next day, if the SOC is less than 95%, it automatically switches to grid power supply, prioritizing heating loads, and using the remaining power to charge the energy storage battery. If the SOC is greater than or equal to 95% and there is still surplus power, the compressor is started and the fourth and third electric three-way valves are switched to the heat storage path to charge the phase change heat storage tank. When the SOC reaches 100% and the temperature of the phase change heat storage tank reaches the set upper limit, the off-peak electricity storage mode is stopped. Step 7: The central controller executes linkage based on fire monitoring data: When the distributed fiber optic temperature measurement host, the thermal imaging temperature sensing camera, the smoke detector, and the multispectral image fire detector alarm, it automatically cuts off the power supply to the corresponding area equipment, turns on emergency lighting, unlocks access control, pushes alarm information, and links video verification.

[0017] Preferably, step 3 further includes the coordinated control of the phase change thermal storage tank: when the water supply temperature is lower than the set value in heat pump water source mode or heat pump air source mode, the central controller switches the fourth electric three-way valve to the heat release path, so that the secondary side water flows through the phase change thermal storage tank to absorb heat before entering the indoor heat exchange coil.

[0018] Preferably, the preset cycle of the stirring device in step 2 is 5-10 minutes every 6-8 hours; when the photovoltaic power generation is abundant and the battery is full and in the direct water supply mode, the stirring cycle is shortened to once every 3-4 hours.

[0019] Preferably, step 6 further includes an energy management strategy: the central controller acquires weather forecast data, and when it is predicted that the next day will be a low-sunlight day, it will overclock the compressor in advance and switch the fourth electric three-way valve to the heat storage path during the peak period of photovoltaic power generation on that day, so as to store the excess heat in the phase change heat storage tank.

[0020] Preferably, the system also includes intelligent operation and maintenance and fault prediction steps: the central controller uploads the operating data of the indoor heating system to the remote operation and maintenance control platform at a constant cycle; the remote operation and maintenance control platform stores the received data in a real-time database and performs the following analysis: Real-time monitoring: An alarm will be issued immediately if the parameter exceeds the limit range; Fault prediction: Analyze the rate of increase of compressor exhaust temperature, the degree of inconsistency of battery voltage, and the downward trend of inverter efficiency. If the predicted value exceeds the preset threshold, issue an early warning and indicate the possible causes of the fault. Health score: Generates a health score for each device in the indoor heating system. The score ranges from 0 to 100. When the score is lower than the preset threshold, a maintenance work order will be automatically generated. Maintenance personnel can use a web interface or mobile app to view the status of the indoor heating system, historical curves and alarm information, remotely modify control parameters, and send the modified parameters to the central controller. It also includes the fire alarm linkage procedure for the energy storage battery cabinet: The central controller collects real-time data on battery pack temperature (T_cell), combustible gas concentration (C_gas), and smoke concentration (C_smoke), and executes a three-level linkage strategy: Level 1 warning: When T_cell ≥ 60℃ or battery voltage difference ≥ 50mV, reduce the charging power of the bidirectional energy storage converter to 50%, start the exhaust fan linkage controller for forced ventilation, and push the Level 1 warning. Level 2 alarm: When T_cell≥70℃ or C_gas≥10%LEL or smoke alarm, immediately disconnect the DC side and AC side of the bidirectional energy storage converter, start the aerosol automatic fire extinguishing device, shut down the exhaust fan linkage controller, unlock the battery cabinet access control, and push the level 2 alarm. Level 3 Emergency: When thermal imaging or video confirms an open flame, execute all Level 2 actions, automatically dial the alarm number, activate the evacuation broadcast, cut off the main power supply to the indoor heating system, and retain the power supply to the central controller.

[0021] Compared with the prior art, the advantages of the present invention are as follows: 1. Cascaded utilization of energy: Based on the temperature of the hot water storage tank, the system automatically selects whether to supply heat directly or raise the temperature through a heat pump, thereby achieving efficient utilization of waste heat from composting. During high-temperature periods, it achieves zero-power heating, while during medium-temperature periods, it can significantly improve the coefficient of performance of the heat pump.

[0022] 2. Optimization of composting process: Through intelligent control of electric heating, forced ventilation and stirring device, the composting temperature is kept stable in the optimal range, thereby extending the high-temperature stage and increasing the heat generation. The surplus photovoltaic power can be fed back to enhance the composting process, thus forming a positive feedback mechanism of "electricity to heat".

[0023] 3. Multi-energy storage synergistic operation: The sensible heat storage function of the hot water storage tank is combined with the latent heat storage function of the phase change heat storage tank to take into account both heat buffering and quality improvement. It also works in conjunction with photovoltaic energy storage batteries to achieve a dual time-shifting effect in terms of both electricity and heat.

[0024] 4. Achieve fully automatic and unattended operation: With the fusion of multi-source sensors and intelligent decision-making algorithms, the system can automatically switch heating modes, schedule power, and regulate composting without human intervention.

[0025] 5. For integrated fire safety, by integrating various active fire protection measures such as distributed fiber optic temperature measurement, thermal imaging, and multispectral flame detection, early warning functions and protection mechanisms for fires can be realized, thereby improving the safety of the system during operation.

[0026] 6. Economic optimization measures: By introducing a strategy that combines off-peak electricity period identification with weather forecasting, the battery can be charged and phase change heat storage can be achieved by utilizing the low-priced grid electricity at night before the arrival of low sunshine weather. This can efficiently transfer peak electricity demand, thereby reducing operating costs and improving the system's power supply reliability under continuous rainy weather conditions.

[0027] 7. The grid-friendly characteristics are reflected in the fact that photovoltaic power is prioritized for its own use, and excess power is consumed or stored locally. The grid is only used in extremely special circumstances, which reduces the impact on the grid. This is in line with the development concept of distributed energy.

[0028] 8. Intelligent Operation and Maintenance Capabilities: This invention achieves intelligent operation and maintenance capabilities through a central controller and a remote operation and maintenance control platform, enabling real-time remote monitoring of all equipment within the system, historical data analysis, and fault prediction and alarm. Maintenance personnel can anticipate abnormal equipment conditions and conduct planned maintenance, thereby avoiding downtime losses caused by sudden failures and extending the equipment's lifespan.

[0029] 9. Comprehensive Fire Protection for Energy Storage: This invention provides comprehensive fire protection for the energy storage battery cabinet, constructing a five-layer protection system of "monitoring → early warning → linkage → fire extinguishing → isolation." This includes cell-level temperature monitoring, combustible gas detection, automatic aerosol fire extinguishing, fireproof partition isolation, explosion-proof pressure relief devices, and tiered linkage strategies. This system can detect early signs of battery thermal runaway, automatically cut off power, and initiate fire extinguishing procedures to prevent the spread of fire and explosions, thereby improving the intrinsic safety level of the energy storage system and meeting the extremely stringent fire safety requirements of energy storage power stations. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the thermal piping connection of the system of the present invention; Figure 2 This is a schematic diagram of the power line connection of the system of the present invention; Figure 3 This is the control logic diagram (heat distribution) of the present invention. Figure 4 This is the control logic diagram (power distribution) of the present invention. Figure 5 This is a schematic diagram showing the connection relationship between the fire protection and safety monitoring unit of the present invention; Figure 6 This is a schematic diagram of the remote operation and maintenance control platform architecture of the present invention; Figure 7 This is a schematic diagram of the connection relationship of the energy storage fire protection subunit of the present invention.

[0031] The components are: 1-Fermentation tank, 2-Composting heat exchange coil, 3-Room temperature sensor, 4-Primary side water supply main pipe, 5-Primary side return water main pipe, 6-Evaporator, 7-Compressor, 8-Condenser, 9-Expansion valve, 10-Third electric three-way valve, 11-First-stage circulation pump, 12-Second-stage circulation pump, 13-Phase change heat storage tank, 14-Indoor heat exchange coil, 15-Outdoor air-side heat exchanger, 16-Temperature sensing fiber optic cable, 17-Fire protection gateway, 18-Photovoltaic array, 19-Bidirectional energy storage converter, 20-Energy storage battery, 21-Main distribution box, 22-Central controller, 23-Composting temperature sensor, 24-Fourth electric three-way valve, 25-Sixth electric three-way valve, 2 6-Power grid, 27-Hot water storage tank, 28-First electric three-way valve, 29-Second electric three-way valve, 30-Electric auxiliary heating film, 31-Forced ventilation fan, 32-Stirring device, 33-Hot water storage tank temperature sensor, 34-Phase change thermal storage tank temperature sensor, 35-Distributed fiber optic temperature measurement host, 36-Thermal imaging temperature sensing camera, 37-Multispectral image fire detector, 38-Smoke detector, 39-Remote operation and maintenance central control platform, 40-Battery pack temperature sensor, 41-Combustible gas detector, 42-Automatic aerosol fire extinguishing device, 43-Explosion-proof pressure relief device, 44-Fireproof partition, 45-Exhaust fan linkage controller, 46-Fifth electric three-way valve. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] Example 1 An office building (200 square meters) in an ecological agricultural park 2 An underground heating system based on this invention will be constructed. Specific parameters are as follows: Composting heat utilization unit: Construct a 20m³ closed aerobic fermentation tank 1. The tank body is made of reinforced concrete, and the inner wall is treated with waterproofing and anti-corrosion. DN25 PE-RT composting heat utilization heat exchange coils 2 are evenly laid on the bottom and side walls of fermentation tank 1, with a coil spacing of 200mm, and a total heat exchange area of ​​approximately 30m². 2The inlet and outlet of the coil are respectively connected to the primary side return water main 5 and the primary side supply water main 4. An electric auxiliary heating film 30 with a power of 3kW is attached to the inner wall of the fermentation tank 1; a forced ventilation fan 31 with an air volume of 500m³ / h 3 / h; the stirring device has a power of 1.5kW and runs automatically for 8 minutes every 6 hours.

[0034] Photovoltaic energy storage unit: A 20kWp monocrystalline silicon photovoltaic array 18 is installed on the roof of the office building at a 30° angle. It is equipped with a 30kW bidirectional energy storage inverter 19 and a set of 30kWh lithium iron phosphate batteries as energy storage batteries 20. The batteries adopt a modular design and are installed in a dedicated battery cabinet. The battery cabinet has a width of 800 mm, a depth of 600 mm, and a height of 2000 mm. The cabinet body is made of 2.0 mm thick cold-rolled steel plate, and the inner wall is lined with 1.5 mm thick Class A fireproof board. The battery cabinet is equipped with the following fire-fighting equipment: Each battery module contains a total of 6 battery modules, each with an NTC battery pack temperature sensor mounted on its surface. This sensor has an accuracy of ±1℃ and can monitor the cell temperature in real time.

[0035] A combustible gas detector 41 is installed in the center of the top of the cabinet. This detector is used to detect hydrogen, carbon monoxide and methane, and its range is set to 0-100% LEL.

[0036] An automatic aerosol fire extinguishing device 42 is installed on the top of the cabinet. This device adopts a dual-mode system combining thermal and electric start, and is equipped with 1 kg of extinguishing agent, capable of protecting a volume of not less than 2 m³. 3 ; An explosion-proof pressure relief port is installed on the back of the cabinet, and a rupture disc type pressure relief valve is installed. The opening pressure of the pressure relief valve is set to 300Pa.

[0037] The electromagnetic lock is installed on the cabinet door, and the electromagnetic lock is linked with the central controller 22.

[0038] A fan control unit 45 is installed on the side of the cabinet. Its air volume is 200 cubic meters per hour. The start and stop of the fan is controlled by the central controller.

[0039] A galvanized steel fireproof partition 44 with a thickness of 2.0mm is installed between the battery cabinet and the adjacent distribution box. The width of the partition is 200mm wider than the cabinet body, and its height is flush with the cabinet body.

[0040] Hot water storage tank unit: Hot water storage tank 27, volume 5m³ 3 The insulation thickness is 100mm, and the six interfaces are connected as designed.

[0041] Heat pump heating unit: Utilizes a 15kW rated heating capacity variable frequency water / air source heat pump, internally comprising a variable frequency scroll compressor 7, plate evaporator 6, plate condenser 8, electronic expansion valve 9, outdoor air-side heat exchanger 15, and two electric three-way valves. Rated heating capacity COP 4.5.

[0042] Phase change thermal energy storage unit: Phase change thermal energy storage tank 13, capacity 2m³ 3 It is filled with paraffin-based phase change material (phase change temperature 48℃, latent heat 200kJ / kg), and has an internal stainless steel heat exchange coil with a heat exchange area of ​​5m². 2 Use two electric three-way valves. Connect the phase change thermal storage tank 13 and the indoor water supply pipe in parallel.

[0043] Terminal heating unit: 14 PE-RT indoor heat exchange coils are laid indoors, with a pipe spacing of 200mm, divided into six loops. Stainless steel manifolds and collectors are configured, and each loop is equipped with a manual regulating valve.

[0044] Intelligent Control Unit: The central controller 22 is a programmable logic controller, equipped with analog / digital input / output modules and communication interfaces. The remote operation and maintenance central control platform 39 is deployed via a cloud server and has a time-series database and fault prediction scripts installed internally. A large-screen display is located in the park's monitoring room, which can display system operation data in real time. Maintenance personnel can log in to the platform using a computer or mobile application interface to conduct remote monitoring and effective control operations.

[0045] Fire protection unit: 500m of temperature-sensing optical fiber 16 is laid along the cable trench and connected to the distributed optical fiber temperature measurement host 35; 4 thermal imaging temperature-sensing cameras 36 are installed in front of the heat pump compressor 7, the distribution box, and the battery cabinet; 2 multispectral image fire detectors 37 are installed in the photovoltaic array 18 area; 3 smoke detectors 38 are installed in the power distribution room and the control room; the fire gateway 17 is connected to the existing fire alarm controller.

[0046] System connection relationships: To ensure that those skilled in the art can accurately implement this invention, the specific connection relationships of each component are now described in detail: 1. Connection of heating pipes (e.g.) Figure 1 (As shown) 1. Primary side circulation (compost → hot water storage tank → heat pump evaporator) Composting heat generation loop: Outlet of composting heat exchange coil 2 → Primary side water supply main 4 → First interface (inlet) of hot water storage tank 27 → Inside hot water storage tank 27 → Second interface (outlet) of hot water storage tank 27 → Primary side return water main 5 → Inlet of composting heat exchange coil 2. This loop transfers composting heat to the hot water storage tank 27, driven by a primary circulation pump 11. The primary circulation pump 11 is installed on the primary side water supply main 4.

[0047] Heat pump heat extraction loop: Water storage tank 27 fifth interface (outlet) → Evaporator 6 inlet → Evaporator 6 outlet → Water storage tank 27 sixth interface (return port). In heat pump water source mode, this loop sends the heat from the water storage tank 27 to the heat pump evaporator 6, driven by the primary circulation pump 11 (which shares the same circulation pump with the composting heat generation loop and is achieved through parallel pipeline connection).

[0048] 2. Secondary side circulation (heat source → indoor terminal) Water supply switching: The common outlet of the first electric three-way valve 28 is connected to the inlet of the fourth electric three-way valve 24; the inlet A of the first electric three-way valve 28 is connected to the third interface (water tank supply) of the hot water storage tank 27, and the inlet B is connected to the outlet of the condenser 8.

[0049] Return water switching: The common inlet of the second electric three-way valve 29 is connected to the outlet of the indoor heat exchange coil 14; the outlet A of the second electric three-way valve 29 is connected to the inlet of the condenser 8, and the outlet B is connected to the fourth interface of the hot water storage tank 27.

[0050] The phase change thermal storage tank (13) is connected in parallel: the common outlet of the third electric three-way valve 10 is connected to the inlet (distributor) of the indoor heat exchange coil 14; the inlet A of the third electric three-way valve 10 is connected to the outlet A of the fourth electric three-way valve 24. The inlet B of the third electric three-way valve 10 is connected to the outlet of the phase change thermal storage tank 13, and the inlet of the phase change thermal storage tank 13 is connected to the other outlet B of the fourth electric three-way valve 24, and the outlet is connected to the inlet B of the third electric three-way valve 10. The inlet of the fourth electric three-way valve 24 is connected to the common outlet of the first electric three-way valve 28. The secondary circulation pump 12 is installed between the indoor heat exchange coil 14 and the second electric three-way valve 29.

[0051] Secondary side standard circulation (taking heat pump water source mode as an example): Condenser 8 outlet → Port B of the first electric three-way valve 28 → Common port of the first electric three-way valve 28 → Inlet of the fourth electric three-way valve 24 → Bypass or through the phase change heat storage tank 13 according to the valve position → Third electric three-way valve 10 → Inlet of indoor heat exchange coil 14 → Outlet of indoor heat exchange coil 14 → Secondary circulation pump 12 → Common port of the second electric three-way valve 29 → Port A of the second electric three-way valve 29 → Inlet of condenser 8.

[0052] 3. Refrigerant circulation (inside the heat pump) Heat pump water source mode: Evaporator 6 refrigerant outlet → A inlet of the sixth electric three-way valve 25 → outlet of the sixth electric three-way valve 25 → compressor 7 suction port → compressor 7 discharge port → condenser 8 refrigerant inlet → condenser 8 refrigerant outlet → expansion valve 9 → inlet of the fifth electric three-way valve 46 → A outlet of the fifth electric three-way valve 46 → evaporator 6 refrigerant inlet.

[0053] Heat pump air source mode: Outdoor air-side heat exchanger 15 refrigerant outlet → sixth electric three-way valve 25 B inlet → sixth electric three-way valve 25 outlet → compressor 7 suction port → compressor 7 discharge port → condenser 8 refrigerant inlet → condenser 8 refrigerant outlet → expansion valve 9 → fifth electric three-way valve 46 inlet → fifth electric three-way valve 46 B outlet → outdoor air-side heat exchanger 15 refrigerant inlet.

[0054] II. Power line connections (e.g.) Figure 2 (As shown) 1. Main Power Supply Architecture: Photovoltaic array 18 DC output → Bidirectional energy storage converter 19 DC input. Energy storage battery 20 is bidirectionally electrically connected to the DC terminal of bidirectional energy storage converter 19. Bidirectional energy storage converter 19 AC output → Main distribution box 21 incoming line (AC bus). Grid 26 is connected to the main distribution box 21 incoming line via an automatic grid connection switching unit (grid connection switch). Main distribution box 21 is bidirectionally connected to bidirectional energy storage converter 19 and grid 26. This allows for the storage of electricity from grid 26 in off-peak hours, which can then be stored in battery 20.

[0055] 2. Load Power Distribution: The main distribution box 21 supplies power to the following devices via its branch circuits: heat pump compressor 7 (power terminal); primary circulation pump 11 (power terminal); secondary circulation pump 12 (power terminal); first electric three-way valve 28 (power terminal); second electric three-way valve 29 (power terminal); third electric three-way valve 10 (power terminal); fourth electric three-way valve 24 (power terminal); fifth electric three-way valve 46 (power terminal); sixth electric three-way valve 25 (power terminal); electric auxiliary heating film 30 (power terminal); forced ventilation fan 31 (power terminal); stirring device motor 32 (power terminal); central controller 22 (power terminal); distributed fiber optic temperature measurement host 35 (power terminal); thermal imaging temperature sensing camera 36 (power terminal); multispectral image fire detector 37 (power terminal); smoke detector 38 (power terminal); fire gateway 17 (power terminal); and various temperature sensor power terminals and fire protection equipment in the energy storage battery cabinet.

[0056] 3. Power Flow Description: During normal operation, photovoltaic power is prioritized for the load, and excess power is stored in the energy storage battery 20 via the bidirectional energy storage converter 19. When photovoltaic power is insufficient, the energy storage battery 20 supplies power to the load after being inverted by the bidirectional energy storage converter 19. When the energy storage battery 20's charge level falls below a set threshold (SOC≤20%) or when the off-peak electricity storage strategy is implemented, the central controller 22 controls the automatic grid connection switching unit to close, and the power grid 26 connects to the main distribution box 21 to supply power to the load and charge the energy storage battery 20.

[0057] III. Signal Line Connection 1. Sensor Input The signal line of the compost temperature sensor 23 monitoring T1 is connected to the analog input module of the central controller 22.

[0058] The signal line of sensor 33 for monitoring the temperature of the hot water storage tank of T_tank is connected to the analog input module of the central controller 22.

[0059] The room temperature sensor 3 signal line of monitoring T3 is connected to the analog input module of the central controller 22.

[0060] The signal line of the phase change thermal storage tank temperature sensor 34, which monitors T_pcm, is connected to the analog input module of the central controller 22.

[0061] Electrical parameter acquisition module communication line (RS485 / CAN) → Central controller 22 communication interface.

[0062] 2. Actuator control output Central controller 22 analog output module → primary circulating pump 11 frequency converter control terminal.

[0063] Central controller 22 analog output module → secondary circulating pump 12 frequency converter control terminal.

[0064] Central controller 22 analog output module → heat pump compressor 7 frequency converter control terminal.

[0065] Central controller 22 digital output module → first electric three-way valve 28 control terminal.

[0066] Central controller 22 digital output module → Second electric three-way valve 29 control terminal.

[0067] Central controller 22 digital output module → control terminal of third electric three-way valve 10 and fourth electric three-way valve 24.

[0068] Central controller 22 digital output module → fifth electric three-way valve 46, sixth electric three-way valve 25 control terminal.

[0069] Central controller 22 digital output module → electric auxiliary heating film 30 solid-state relay control terminal.

[0070] Central controller 22 digital output module → forced ventilation fan 31 frequency converter / contactor control terminal.

[0071] Central controller 22 digital output module → stirring device 32 motor contactor control terminal.

[0072] Central controller 22 digital output module → Automatic grid-connected switching unit (grid-connected switch) control terminal.

[0073] 3. Fire protection wiring connection (e.g.) Figure 5 , 7 (As shown) The distributed fiber optic temperature monitoring host 35 communicates with the central controller 22 via an RS485 bus, and its temperature-sensing fiber optic cable 16 is laid along the cable trench, cable tray, and around the composting tank. The thermal imaging temperature-sensing camera 36 is connected to the local area network of the central controller 22 via an Ethernet cable and is located near the heat pump compressor 7, distribution box 21, energy storage battery cabinet 20, and energy storage converter 19. The multispectral image fire detector 37 is connected to the digital input module or communication interface of the central controller 22 via a switch signal line or RS485 bus and is located in the photovoltaic array 18 area, fermentation tank 1, and thermal storage tank area 13. The smoke detector 38 is connected to the digital input module of the central controller 22 via a switch signal line and is located in the power distribution room, control room, and battery room. The fire gateway 17 is connected to the central controller 22 via an RS485 bus or Ethernet and also communicates with the existing automatic fire alarm controller on site. All of the above devices upload alarm signals or real-time monitoring data to the central controller 22.

[0074] Battery pack temperature sensor 39 signal line (one line per module) → Central controller 22 analog input module (or via CAN bus / RS485 acquisition module). Combustible gas detector 41 signal line → central controller 22 analog input module or communication interface; Aerosol automatic fire extinguishing device 42 start signal line → central controller 22 digital output module (relay output, normally open contact); Arrangement of the thermal wire in the automatic aerosol fire extinguishing device 42: It surrounds the inner wall of the battery cabinet and contacts the surface of the battery cell. When the temperature is ≥90℃, the thermal wire spontaneously combusts and triggers the fire extinguishing device (independent of the controller, as a backup). Exhaust fan linkage controller 45 control line → Central controller 22 digital output module (control contactor); Battery cabinet access control electromagnetic lock control line → Central controller 22 digital output module; The explosion-proof pressure relief device 43 is a purely mechanical structure and does not require a signal cable connection; Fireproof partition 44 is a passive component and does not require signal cable connection.

[0075] 4. Connection to the remote operation and maintenance control platform (e.g.) Figure 6 (as shown) The central controller 22 establishes a bidirectional data connection with the remote operation and maintenance control platform 39 via a wireless network (4G / 5G or Ethernet). It uploads all collected equipment operating data (including compost temperature T1, hot water tank temperature T_tank, indoor temperature T_room, compressor exhaust temperature, current of each circulating pump, battery module voltage and temperature, photovoltaic power P_pv, battery SOC, valve status, fire sensor status, etc.) to the platform at fixed intervals (e.g., every 5 seconds). The remote operation and maintenance control platform 39 is deployed on a cloud server and includes a data server, real-time database, fault prediction engine, web server, and mobile application server. Data processed by the platform is pushed to a large-screen display, the computer browser of maintenance personnel, and a mobile app, enabling real-time monitoring, alarm push notifications, historical queries, remote parameter modification, and maintenance work order management. Control parameters modified by maintenance personnel on their computers or mobile phones take effect after being sent to the central controller 22 by the platform.

[0076] Example 2: Operational Case: High Temperature Period + Sunny Day - Direct Water Supply from Tank + Surplus Electricity for Enhanced Composting Scenario: During the high-temperature period of composting, the temperature T1 reaches 58℃, the temperature of the hot water storage tank T_tank is 52℃, the photovoltaic power P_pv is 18kW at noon on a sunny day, the system load includes the circulation pump and controller, the total load is 1.5kW, the state of charge of the battery is 98%, the current room temperature is 20℃, and there is a need to raise it to 22℃.

[0077] The operation process is as follows: When the central controller 22 determines that T_tank is greater than or equal to 40℃, the direct water supply mode is implemented. Specifically, the compressor 7 is turned off, the first electric three-way valve 28 is switched to the water tank side, and the second electric three-way valve 29 is also switched to the water tank side. At the same time, the primary and secondary circulation pumps 12 are started to run. Since the battery is full, there is a surplus of 16.5kW of power. The central controller 22 distributes this power to the composting tank: the speed of the forced ventilation fan 31 is increased from 1000 rpm to 2000 rpm, the operating frequency of the stirring device 32 is changed from once every 6 hours to once every 3 hours, and the electric heating film 30 is turned on intermittently, thereby maintaining T1 between 58 and 60℃.

[0078] The results showed that the room temperature had risen to 22°C and remained stable, the heat generation rate during the composting process had increased, the temperature in the water tank remained at or above 52°C, and no electricity supplied by the grid was used throughout the day.

[0079] Example 3: Mid-temperature period + cloudy weather - heat pump water source mode + phase change thermal storage Scenario: The composting process is in the mesophilic stage. At this time, the temperature T1 is 38℃, the temperature T_tank in the hot water storage tank 27 is 32℃, the weather is cloudy, the photovoltaic power P_pv reaches 8kW, the state of charge (SOC) of the battery is 80%, the room temperature is 18℃, and the room temperature needs to be raised to 22℃.

[0080] Operation Process: When the central controller 22 detects that the water tank temperature T_tank is between 25℃ (inclusive) and 40℃ (exclusive), it activates the heat pump water source mode. At this time, the compressor 7 is started, the first electric three-way valve 28 and the second electric three-way valve 29 are switched to the heat pump side, the fifth electric three-way valve 46 and the sixth electric three-way valve 25 are switched to the evaporator 6 side, the primary circulation pump 11 and the secondary circulation pump 12 start running, and the heat pump obtains heat from the water tank. At this time, the coefficient of performance (COP) of the heat pump is approximately 4.2. The total load is approximately 4.5kW. After the photovoltaic system provides 8kW of direct supply, there is a surplus of 3.5kW. The battery is fully charged (SOC=98%). The central controller 22 increases the frequency of the compressor 7 to 55Hz and switches the fourth electric three-way valve 24 and the third electric three-way valve 10 to the heat storage path, storing the excess heat in the phase change heat storage tank 13. The temperature of the phase change tank rises from 45℃ to 52℃.

[0081] The results showed that the room temperature successfully rose to 22°C, the phase change tank absorbed and stored the extra heat, and was able to release the stored heat at night to assist in the heating work.

[0082] Example 4: Low Temperature Period + Cloudy Day - Heat Pump Air Source Mode + Phase Change Heat Release Scenario: When the compost is in the maturation stage, the temperature of T1 is 18℃, the temperature of the hot water storage tank 27 T_tank is 15℃, the weather is cloudy, the photovoltaic power P_pv is 1.2kW, the state of charge of the battery is 45%, and the room temperature is 16℃, but the room temperature needs to be maintained at 18℃.

[0083] Operation Process: The central controller 22 detects that T_tank is less than 25℃ and therefore executes the heat pump air source mode: First, compressor 7 is started, switching the fifth electric three-way valve 46 and the sixth electric three-way valve 25 to the outdoor air-side heat exchanger 15, allowing the outdoor air-side heat exchanger 15 to extract heat from the air. Simultaneously, the first-stage circulation pump 11 is shut down. At this time, the heat pump extracts heat from the air, with a coefficient of performance (COP) of approximately 2.5. The total load is 3.8 kW, and the 1.2 kW of power provided by the photovoltaic system is insufficient; the battery supplements 2.6 kW of power through discharge. When the water supply temperature is only 38℃ (the required temperature for underfloor heating is 40℃), the central controller 22 switches the fourth electric three-way valve 24 and the third electric three-way valve 10 to the heat release path, utilizing the 48℃ heat stored in the phase change heat storage tank 13 to raise the water supply temperature to 42℃ before delivering it indoors.

[0084] The results showed that the room temperature remained stable at 18°C, the temperature inside the phase change tank dropped to 40°C, the battery charge also decreased to 30%, and no power was supplied from the grid.

[0085] Example 5: Extreme working conditions + fire protection linkage Scenario: The continuous rainy weather prevents the composting process from generating heat, and the battery is completely depleted, relying on the power grid 26 for power. One day, aging occurs at the joints in the cable trench. The distributed fiber optic temperature monitoring host 35 detects that the temperature has risen to 75℃ at a distance of 120 meters from the starting point, exceeding the set threshold of 70℃.

[0086] The operation process is as follows: Upon receiving the alarm signal, the central controller 22 automatically retrieves the footage captured by the thermal imaging camera in that area. Inspection reveals overheating on the cable surface. After confirming overheating, the power supply to that circuit is immediately disconnected (i.e., the corresponding inverter is disconnected), and an alarm message is pushed to the maintenance personnel's mobile phone. After remote verification, the maintenance personnel take a spare cable to the site for handling, thus preventing a fire.

[0087] At the same time, the system will automatically switch to other circuits to maintain basic heating, thereby ensuring that the room temperature is not lower than 12°C and thus preventing damage from freezing.

[0088] Example 6: Off-peak electricity storage at night + cloudy weather the next day Scenario: On a winter day, the weather forecast indicates that the next day will be cloudy. Under these conditions, the photovoltaic power generation is predicted to be only 10% of its rated power. The time is 23:00 at night, which is during off-peak hours. The indoor temperature needs to be maintained at 18℃, the energy storage battery 20 has a state of charge (SOC) of 30%, and the phase change thermal storage tank 13 has a temperature of 40℃.

[0089] Operation process: When the central controller 22 detects that it is during off-peak electricity hours and the next day is expected to have low sunshine, the automatic grid-connected switching unit immediately connects to the grid 26 for power supply; the indoor heating load (in heat pump air source mode, with a power of 3.5kW) is given priority to be powered by the grid 26, and the room temperature is maintained at 18℃; the remaining capacity of the grid 26 (according to the preset charging power of 5kW) is used to charge the energy storage battery 20, and its SOC gradually increases from 30% to 95%; when the battery is fully charged (around 2:00 AM), the central controller 22 starts the heat pump compressor 7, switches the third electric three-way valve 10 to the heat storage path, and charges the phase change heat storage tank 13. The phase change tank temperature rises from 40℃ to 55℃ and then the charging stops; at 5:00 AM, the off-peak electricity hours end, the central controller 22 stops charging, and the system switches back to photovoltaic / battery power supply mode.

[0090] The results showed that the next day was cloudy, and the state of charge (SOC) of the battery remained at 85% or above. The phase change thermal storage tank 13 stored enough heat. When the photovoltaic power supply was insufficient, the system relied on the battery and thermal storage tank to ensure heating throughout the day, and did not use the grid power 26 during peak hours, thus greatly reducing operating costs.

[0091] Example 7: Demonstration of Fault Prediction and Energy Storage Fire Protection Linkage in Remote Operation and Maintenance Control Platform Scenario: One winter day, the system had been running stably for eight months. At 2:00 AM, the remote maintenance control platform 39 detected a continuous rise in the temperature (T_cell) of battery module 3 in the energy storage battery cabinet, from the normal 25°C to 62°C, and the voltage difference between adjacent battery strings increased from 10mV to 55mV. The platform's fault prediction engine, after analyzing historical trends, issued a yellow warning: "The internal resistance of battery module 3 has increased, which is highly likely to indicate an internal micro-short circuit. It is recommended to implement equalization charging measures or replace the module." Maintenance personnel received the warning via a mobile application in the early morning, checked the detailed curves, and confirmed the anomaly. However, since it was nighttime and not an emergency, they decided to handle it during the day.

[0092] At 9:00 AM that day, one hour before the maintenance personnel arrived on site, the temperature of the battery module had already climbed to 69°C, and the combustible gas detector detected an H2 concentration of 8% LEL. The central controller 22 automatically initiated a level-two alarm, cutting off the energy storage converter, activating the aerosol fire suppression system, and shutting down the exhaust fan. When the maintenance personnel arrived, there was no voltage inside the battery cabinet, the aerosol spraying operation had been completed, and the temperature had begun to decrease. Inspection revealed that a minor short circuit in module 3 had triggered thermal runaway; the aerosol had effectively suppressed combustion, successfully preventing a fire.

[0093] After the maintenance personnel completed the replacement of the faulty module, they reset the alarm status using the remote maintenance control platform 39 and filled out a work order processing record. The platform processed this event through automatic learning, and then optimized the battery health model.

[0094] This example demonstrates that the fault prediction function of the remote operation and maintenance control platform enables operation and maintenance personnel to be aware of battery anomalies in advance, while the three-level linkage of energy storage fire protection effectively suppresses thermal runaway accidents and ensures system safety.

[0095] As can be seen from the above embodiments, the system of the present invention can intelligently switch operating modes according to composting status, weather, indoor load, and electricity price period under fully automatic and unmanned intervention. It can efficiently utilize composting waste heat and photovoltaic power, use low-priced electricity at night for pre-energy storage, and actively provide early warning and linkage when fire hazards occur. It has significant energy saving, safety, economy and intelligence.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An indoor heating system based on the coupling of waste heat from composting and photovoltaic energy storage, characterized in that, The system includes a composting heat utilization unit, a hot water storage tank unit, a heat pump heating unit, a phase change heat storage unit, a terminal heating unit, a photovoltaic energy storage unit, and an intelligent control unit. The composting heat utilization unit includes a fermentation tank (1) and a composting heat utilization heat exchange coil (2) buried inside the fermentation tank (1). The hot water storage tank unit includes a hot water storage tank (27), which has six ports. The inlet of the composting heat utilization heat exchange coil (2) is connected to the second port of the hot water storage tank (27) through the primary side return water main pipe (5). The outlet of the composting heat utilization heat exchange coil (2) is connected to the first port of the hot water storage tank (27) through the primary side supply water main pipe (4). A primary circulation pump (11) is installed on the primary side supply water main pipe (4). The heat pump heating unit includes a composting heat utilization unit, a hot water storage tank (27), a heat pump heating unit, a phase change heat storage unit, a terminal heating unit, a photovoltaic energy storage unit, and an intelligent control unit. The composting heat utilization unit includes a composting tank (27), a hot water storage tank (27), a heat pump heating unit, ... The system includes an evaporator (6), a compressor (7), a condenser (8), and an expansion valve (9) connected in sequence to form a closed loop. The inlet and outlet of the evaporator (6) are connected to the fifth and sixth ports of the hot water storage tank (27), respectively. A sixth electric three-way valve (25) is installed on the pipeline between the evaporator (6) and the compressor (7), and a fifth electric three-way valve (46) is installed on the pipeline between the evaporator (6) and the expansion valve (9). An outdoor air-side heat exchanger (15) is connected between the sixth electric three-way valve (25) and the fifth electric three-way valve (46). The terminal heating unit includes an indoor heat exchange coil (14) laid indoors. The third port of the hot water storage tank (27) is connected to the indoor heat exchange coil through the first electric three-way valve (28). The inlet of pipe (14) and the fourth interface are connected to the outlet of indoor heat exchange coil (14) through the second electric three-way valve (29). A secondary circulation pump (12) is provided on the pipeline between the second electric three-way valve (29) and indoor heat exchange coil (14). The outlet of condenser (8) is connected to one inlet of the first electric three-way valve (28), and the inlet of condenser (8) is connected to one outlet of the second electric three-way valve (29). The phase change heat storage unit includes a phase change heat storage tank (13). The phase change heat storage tank (13) is filled with phase change material and is equipped with a phase change heat storage heat exchange coil. The inlet of the phase change heat storage tank (13) is connected to the fourth electric three-way valve (24), and the outlet is connected to the third electric three-way valve (10). The third electric three-way valve (10) The first electric three-way valve (24) and the fourth electric three-way valve (28) are both connected to the pipeline between the first electric three-way valve (28) and the indoor heat exchange coil (14); the photovoltaic energy storage unit includes a photovoltaic array (18), an energy storage battery (20) and a bidirectional energy storage converter (19). The DC side of the bidirectional energy storage converter (19) is connected to the photovoltaic array (18) and the energy storage battery (20), and the AC side is connected to the main distribution box (21). The main distribution box (21) is connected to the power grid (26) and supplies power to the indoor heating system through the main distribution box (21). The bidirectional energy storage converter (19) has a built-in MPPT controller to monitor the real-time power P_pv of the photovoltaic array (18) in real time. The energy storage battery (20) has a built-in battery management system to monitor the battery state of charge (SOC) in real time.The intelligent control unit includes a central controller (22) and a compost temperature sensor (23) installed in the fermentation tank (1) for real-time monitoring of compost temperature T1, a hot water tank temperature sensor (33) installed in the hot water tank (27) for monitoring the tank temperature T_tank, a phase change heat storage tank temperature sensor (34) installed in the phase change heat storage tank (13) for monitoring the phase change heat storage temperature T_pcm, a room temperature sensor (3) installed indoors for monitoring the indoor temperature T_room, and a grid connection switch installed between the power grid (26) and the main distribution box (21). The central controller (22) is also electrically connected to the compressor (7), the first-stage circulating pump (11), the second-stage circulating pump (12), the first electric three-way valve (28), the second electric three-way valve (29), the third electric three-way valve (10), the fourth electric three-way valve (24), the fifth electric three-way valve (46), the sixth electric three-way valve (25), the bidirectional energy storage converter (19), the MPPT controller, and the battery management system. ; 2. The indoor heating system based on the coupling of compost waste heat and photovoltaic energy storage according to claim 1, characterized in that, The fermentation tank (1) is also equipped with an electric auxiliary heating film (30), a forced ventilation fan (31) and a stirring device (32). The electric auxiliary heating film (30) is attached to the inner wall of the fermentation tank (1) or the surface of the compost heat exchange coil (2). The forced ventilation fan (31) is connected to the inside of the fermentation tank (1) through a duct. The stirring device (32) is driven by a motor and extends into the inside of the fermentation tank (1). The central controller (22) is also electrically connected to the electric auxiliary heating film (30), the forced ventilation fan (31) and the stirring device (32).

3. The indoor heating system based on the coupling of compost waste heat and photovoltaic energy storage according to claim 1, characterized in that, It also includes a fire protection and safety monitoring unit, which includes a distributed fiber optic temperature measurement host (35), a thermal imaging temperature sensing camera (36), a multispectral image fire detector (37), a smoke detector (38), and a fire gateway (17), all of which are electrically connected to the central controller (22).

4. The indoor heating system based on the coupling of compost waste heat and photovoltaic energy storage according to claim 1, characterized in that, It also includes a remote operation and maintenance central control platform (39) and an energy storage fire protection subunit. The remote operation and maintenance central control platform (39) is bidirectionally connected to the central controller (22) through a wireless communication network. It is used to monitor the operating parameters of the indoor heating system in real time, perform fault prediction analysis, push alarm information and generate operation and maintenance work orders, and support remote modification of control parameters. The energy storage fire protection subunit is set in the battery cabinet where the energy storage battery (20) is located. It includes battery pack temperature sensors (40) installed inside each battery module to monitor the cell temperature and connected to the central controller (22), and combustible gas sensors installed on the top of the battery cabinet to detect the concentration of hydrogen, carbon monoxide and methane. Detector (41), smoke detector (38) installed in the battery cabinet to detect smoke generated by electrolyte evaporation, automatic aerosol fire extinguishing device (42) installed on the top or side of the battery cabinet to automatically start fire extinguishing when the temperature or gas concentration exceeds the threshold, explosion-proof pressure relief device (43) installed on the back of the battery cabinet to directionally release pressure when the internal pressure exceeds the limit, fireproof partition (44) installed between the battery cabinet and adjacent equipment to prevent the spread of fire, exhaust fan linkage controller (45) installed on the top of the battery cabinet to start forced ventilation to exhaust combustible gas during the early warning stage, and central controller (22) to perform hierarchical linkage control according to the received signal.

5. The indoor heating system based on the coupling of compost waste heat and photovoltaic energy storage according to claim 4, characterized in that, The remote operation and maintenance control platform (39) includes a data server, a real-time database, a fault prediction engine, a web server and a mobile application server. It displays the real-time operating parameters, historical trend curves, health scores and fault prediction results of the indoor heating system through a graphical dashboard. When abnormal parameters are detected or potential faults are predicted, an alarm is automatically generated and pushed to the operation and maintenance personnel via SMS and App. At the same time, operation and maintenance work orders are created for closed-loop management.

6. The control method for an indoor heating system based on the coupling of compost waste heat and photovoltaic energy storage according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: The central controller (22) collects the composting temperature T1, the temperature inside the hot water storage tank (27) T_tank, the indoor temperature T_room, the phase change heat storage temperature T_pcm, the indoor preset temperature T_set, the real-time photovoltaic power P_pv, and the state of charge (SOC) of the energy storage battery (20); Step 2: The central controller (22) automatically adjusts the composting process according to T1: when T1 > 60℃, the forced ventilation fan (31) is started until T1 ≤ 55℃; when T1 < 50℃, the electric auxiliary heating film (30) is started until T1 ≥ 50℃; the stirring device (32) operates according to a preset cycle, and the operating frequency is increased when there is a surplus of photovoltaic power generation; Step 3: The central controller (22) selects the heating mode based on T_tank and T_room: If T_tank≥40℃ and T_room is lower than the set temperature, enter the direct water supply mode: turn off the compressor (7), switch the first electric three-way valve (28) to the hot water storage tank (27) side, switch the second electric three-way valve (29) to the hot water storage tank (27) side, and start the first-stage circulation pump (11) and the second-stage circulation pump (12); at this time, the outlet of the indoor heat exchange coil (14) is directly connected to the hot water storage tank (27) through the second-stage circulation pump (12), and the hot water heated by the hot water storage tank (27) enters the room through the inlet of the indoor heat exchange coil (14); If 25℃≤T_tank<40℃ and T_room is lower than the set temperature, enter the heat pump water source mode: start the compressor (7), switch the first electric three-way valve (28) to the condenser (8) side, switch the second electric three-way valve (29) to the condenser (8) side, switch the fifth electric three-way valve (46) and the sixth electric three-way valve (25) to the evaporator (6) side, start the first-stage circulation pump (11) and the second-stage circulation pump (12), at this time the evaporator (6) absorbs heat from the hot water storage tank (27), and then the refrigerant enters the compressor (7) and is compressed into a high-temperature and high-pressure gas, and finally enters the condenser (8) to condense and release heat to heat the cold water coming out of the indoor heat exchange coil (14). The heated water comes out from the outlet of the condenser (8), passes through the first electric three-way valve (28), the fourth electric three-way valve (24), and the third electric three-way valve (10) in sequence, and finally enters the room through the inlet of the indoor heat exchange coil (14); If T_tank < 25℃ and T_room is lower than the set temperature, enter the heat pump air source mode: start the compressor (7) and switch the fifth electric three-way valve (46) and the sixth electric three-way valve (25) to the outdoor air side heat exchanger (15) so that the outdoor air side heat exchanger (15) can extract heat from the air. Switch the first electric three-way valve (28) to the outlet side of the condenser (8) and switch the second electric three-way valve (29) to the inlet side of the condenser (8). Close the first-stage circulation pump (11) and start the second-stage circulation pump (12) to extract heat from the air. The heat pump extracts heat from the air to heat the room. At this time, the outdoor air heat exchanger (15) absorbs heat from the air, and then the refrigerant enters the compressor (7) and is compressed into a high temperature and high pressure gas. Then it enters the condenser (8) to condense and release heat to heat the cold water coming out of the indoor heat exchange coil (14). After that, the heated water comes out from the outlet of the condenser (8), passes through the first electric three-way valve (28), the fourth electric three-way valve (24), and the third electric three-way valve (10) in sequence, and finally enters the room through the inlet of the indoor heat exchange coil (14). Step 4: The central controller (22) performs power dispatch: when P_pv ≥ the power required by the indoor heating system load, photovoltaic direct supply is given priority, and excess power is stored in the energy storage battery (20); if SOC ≥ 95% and P_pv still has a surplus, then: If the current mode is heat pump water source mode or heat pump air source mode, increase the frequency of compressor (7) and switch the fourth electric three-way valve (24) and the third electric three-way valve (10) to the heat storage path to charge the phase change heat storage tank (13) with heat; If the current mode is direct water supply from the water tank, the surplus electrical energy will be allocated to the forced ventilation fan (31), the stirring device (32), or the electric auxiliary heating film (30) to enhance composting fermentation; When P_pv < the power required by the indoor heating system load, it is supplemented by the energy storage battery (20); if SOC ≤ 20%, it automatically switches to the power grid (26) for power supply. Step 5: The central controller (22) switches the fourth electric three-way valve (24) and the third electric three-way valve (10) to the bypass, heat storage or heat release path according to the temperature of the phase change heat storage tank (13) and the heat supply demand, so as to realize the storage and release of heat. Step 6: The central controller (22) obtains real-time electricity price information and weather forecast data for the next 24-48 hours. When it is during the off-peak electricity period at night and the forecast is that the next day will be a low sunshine period, if the SOC is less than 95%, it will automatically switch to the power grid (26) to supply electricity, giving priority to the heating load, and the remaining electricity will be used to charge the energy storage battery (20). If the SOC is greater than or equal to 95% and there is still surplus electricity, the compressor (7) will be started and the fourth electric three-way valve (24) and the third electric three-way valve (10) will be switched to the heat storage path to charge the phase change heat storage tank (13). When the SOC reaches 100% and the temperature of the phase change heat storage tank (13) reaches the set upper limit, the off-peak electricity storage mode will be stopped. Step 7: The central controller (22) performs linkage based on fire monitoring data: When the distributed fiber optic temperature measurement host (35), the thermal imaging temperature sensing camera (36), the smoke detector (38), and the multispectral image fire detector (37) alarm, it automatically cuts off the power supply of the corresponding area equipment, turns on the emergency lighting, unlocks the access control, pushes alarm information, and links video verification.

7. The control method according to claim 6, characterized in that, Step 3 also includes the coordinated control of the phase change heat storage tank (13): when the water supply temperature is lower than the set value in heat pump water source mode or heat pump air source mode, the central controller (22) switches the fourth electric three-way valve (24) to the heat release path, so that the secondary side water flows through the phase change heat storage tank (13) to absorb heat and then enters the indoor heat exchange coil (14).

8. The control method according to claim 6, characterized in that, The preset cycle of the stirring device (32) in step 2 is 5-10 minutes every 6-8 hours; when the photovoltaic power generation is in surplus, the battery is full and in the direct water supply mode, the stirring cycle is shortened to once every 3-4 hours.

9. The control method according to claim 6, characterized in that, Step 7 also includes an energy management strategy: the central controller (22) acquires weather forecast data, and when it is predicted that the next day will be a low sunshine day, during the peak period of photovoltaic power generation on that day, the compressor (7) will be overclocked in advance and the fourth electric three-way valve (24) will be switched to the heat storage path to store excess heat in the phase change heat storage tank (13).

10. The control method according to claim 6, characterized in that, It also includes intelligent operation and maintenance and fault prediction steps: the central controller (22) will upload the operation data of the indoor heating system to the remote operation and maintenance control platform (39) at a constant cycle; the remote operation and maintenance control platform (39) will store the received data in the real-time database and perform the following analysis: Real-time monitoring: An alarm will be issued immediately if the parameter exceeds the limit range; Fault prediction: Analyze the rate of increase of compressor exhaust temperature, the degree of inconsistency of battery voltage, and the downward trend of inverter efficiency. If the predicted value exceeds the preset threshold, issue an early warning and indicate the possible causes of the fault. Health score: Generates a health score for each device in the indoor heating system. The score ranges from 0 to 100. When the score is lower than the preset threshold, a maintenance work order will be automatically generated. Maintenance personnel can use the web or mobile app to view the status of the indoor heating system, historical curves and alarm information, remotely modify control parameters, and send the modified parameters to the central controller (22). It also includes the fire alarm linkage procedure for the energy storage battery cabinet: The central controller (22) collects the battery pack temperature T_cell, combustible gas concentration C_gas, and smoke concentration C_smoke in real time, and executes a three-level linkage strategy: Level 1 warning: When T_cell ≥ 60℃ or battery voltage difference ≥ 50mV, reduce the charging power of the bidirectional energy storage converter (19) to 50%, start the exhaust fan linkage controller (45) for forced ventilation, and push the Level 1 warning; Level 2 alarm: When T_cell≥70℃ or C_gas≥10%LEL or smoke alarm, immediately cut off the DC side and AC side of the bidirectional energy storage converter (19), start the aerosol automatic fire extinguishing device (42), turn off the exhaust fan linkage controller (45), unlock the battery cabinet access control, and push the level 2 alarm; Level 3 Emergency: When thermal imaging or video confirms an open flame, execute all Level 2 actions, automatically dial the alarm phone, start the evacuation broadcast, cut off the main power supply of the indoor heating system, and retain the power supply of the central controller (22).

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