A kind of off-grid distributed power station system based on methanol power storage

Abstract

The utility model provides a kind of off-grid distributed power station system based on methanol power storage, including methanol fuel module, power generation module, power conversion module, energy storage module, it is characterized in that, the methanol fuel module is used to store and supply methanol fuel;The power generation module is connected with methanol fuel module, for converting methanol fuel into electric energy;The power conversion module is connected with power generation module, for processing electric energy conversion;By utilizing the advantage that methanol liquid state is stored and transported, it can be stably and efficiently through methanol generator set to generate electricity, and methanol generator set does not directly respond to load fluctuation, but stable operation in the power topology structure of efficient interval, using intelligent controller according to load power and battery SOC state dynamic start-stop power generation module, when load is greater than 5kW and SOC is lower than 40%, start power generation, make system on-demand operation improve power generation efficiency, can long-term stable for off-grid distributed power station system provide cheap electric energy.

Description

Technical Field

[0001] This utility model relates to the field of off-grid distributed power station technology, and in particular to an off-grid distributed power station system based on methanol power generation and energy storage. Background Technology

[0002] Currently, off-grid power supply mainly relies on technologies such as diesel generators, pure battery energy storage, hybrid renewable energy systems, and hydrogen fuel cells. However, these solutions all have significant limitations. While diesel generators are technologically mature, they generate high levels of noise and emissions of pollutants such as nitrogen oxides. Furthermore, diesel fuel itself is a hazardous material, making storage and transportation inconvenient. Pure battery energy storage systems, in off-grid scenarios without grid support, suffer from high initial investment costs, severe performance degradation at low temperatures, and insufficient power supply duration due to limited energy density. Hybrid systems combining renewable energy sources such as photovoltaics and wind power experience highly volatile power output due to weather conditions. To ensure continuous power supply, they often require over-storage capacity, increasing the overall system cost. While hydrogen fuel cells are clean and efficient, they face industrialization bottlenecks such as high hydrogen storage and transportation costs and a lack of hydrogen refueling infrastructure, limiting their widespread application in remote areas or emergency scenarios. Therefore, a new type of off-grid distributed energy solution is needed that combines readily available fuel, economical operation, low emissions, and the ability to provide independent and stable power supply. Utility Model Content

[0003] In view of this, the present invention aims to provide an off-grid distributed power station system based on methanol power generation and energy storage to solve or alleviate the technical problems existing in the prior art, and at least provide a beneficial option.

[0004] The technical solution of this utility model embodiment is implemented as follows: an off-grid distributed power station system based on methanol power generation and energy storage, including a methanol fuel module, a power generation module, a power conversion module, and an energy storage module, characterized in that the power generation module is connected to the methanol fuel module, the power conversion module is connected to the power generation module, the energy storage module is connected to the power conversion module, the system is controlled by an intelligent controller, the intelligent controller is communicatively connected to the methanol fuel module, the power generation module, the power conversion module, and the energy storage module, and the power generation module is connected to a waste heat recovery module.

[0005] In some embodiments, the methanol fuel module includes a methanol storage tank equipped with an injection pump, an online purity / water content sensor, an electronic level gauge, and a filter.

[0006] In some embodiments, the power generation module includes a methanol engine and a permanent magnet generator, wherein the methanol engine is directly connected to the permanent magnet generator, and the methanol engine has a compression ratio of 18:1 and uses alcohol-resistant material seals.

[0007] In some embodiments, the power conversion module includes an AC / DC rectifier and a DC / AC inverter, wherein the AC / DC rectifier is a three-phase VIENNA rectifier and the DC / AC inverter is a three-level T-type inverter.

[0008] In some embodiments, the energy storage module is a lithium iron phosphate battery pack that supports 2C discharge and has a capacity of 50-100kWh.

[0009] In some embodiments, the intelligent controller includes an ARM+FPGA dual processor, a sensor network, and a communication network, and is configured with a methanol power generation start-up and shutdown strategy based on load forecasting and a SOC dynamic threshold control algorithm.

[0010] In some embodiments, the waste heat recovery module includes an exhaust gas heat exchanger and a cylinder liner water heat exchanger, and is connected to an absorption refrigeration or organic Rankine cycle (ORC) power generation module.

[0011] The present invention has the following advantages due to the adoption of the above technical solution: 1. An off-grid distributed power station system based on methanol power generation and storage, which utilizes the advantages of methanol liquid storage and transportation to generate electricity stably and efficiently through methanol generator sets. The methanol generator sets do not directly respond to load fluctuations, but rather operate stably in a power topology within an efficient range. The intelligent controller dynamically starts and stops the power generation modules based on the load power and battery SOC status. Power generation is started when the load is greater than 5kW and the SOC is less than 40%, enabling the system to operate on demand, improving power generation efficiency, and providing inexpensive electricity to the off-grid distributed power station system stably for a long period of time.

[0012] 2. An off-grid distributed power station system based on methanol power generation and energy storage achieves efficient energy management through an intelligent controller. The controller is based on an ARM+FPGA dual processor and a load forecasting algorithm to optimize the start-up, shutdown, and power output of the power generation module, enabling the methanol engine to operate in its efficient range. The electrical energy generated by the power generation module is rectified and inverted by the power conversion module and then supplied to the load. Excess electrical energy is stored in the energy storage module, reducing the demand for lithium battery capacity, lowering initial investment, and improving the overall system operating efficiency by more than 12%.

[0013] 3. An off-grid distributed power station system based on methanol power generation and energy storage, which recovers heat energy during the power generation process through a waste heat recovery module, including a tail gas heat exchanger and a cylinder liner water heat exchanger, and uses the heat energy for absorption refrigeration or organic Rankine cycle power generation, thereby improving energy utilization efficiency. The total energy efficiency of the system reaches 70-75%, and the harmful emissions such as particulate matter are almost zero, which has significant environmental advantages.

[0014] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the power station system workflow of this utility model; Figure 2 This is a schematic diagram of the multi-unit parallel control of this utility model; Figure 3 This is a schematic diagram of the control strategy of the intelligent controller of this utility model.

[0017] Figure label: 1. Methanol fuel module; 2. Power generation module; 3. Power conversion module; 4. Energy storage module; 5. Intelligent controller; 6. Methanol storage tank; 7. Methanol engine; 8. Permanent magnet generator; 9. AC / DC rectifier; 10. DC / AC inverter; 11. Waste heat recovery module. Detailed Implementation

[0018] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0019] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0020] Example 1: As Figure 1-3 As shown, an off-grid distributed power station system based on methanol power generation and energy storage includes a methanol fuel module 1, a power generation module 2, a power conversion module 3, an energy storage module 4, an intelligent controller 5, and a waste heat recovery module 11. The methanol fuel module 1 includes a methanol storage tank 6 equipped with an injection pump, an online purity / water content sensor, an electronic level gauge, and a filter; The power generation module 2 includes a methanol engine 7 and a 10kW permanent magnet generator 8. Preferably, the methanol engine 7 has a compression ratio of 18:1 and uses alcohol-resistant material seals. The power conversion module 3 includes an AC / DC rectifier 9 and a DC / AC inverter 10, and the energy storage module 4 is a 100kWh lithium iron phosphate battery pack that supports 2C discharge. The intelligent controller 5 includes an ARM+FPGA dual processor, a sensor network, and a communication network. It performs real-time energy dispatching based on a methanol power generation start-up and shutdown strategy and a SOC dynamic threshold control algorithm. It can dynamically start and stop the methanol generator set and adjust the output power according to the load power demand and battery SOC status, and optimize the methanol generator set operating point based on the load curve of the next 15 minutes. Waste heat recovery module 11 includes an exhaust gas heat exchanger and a cylinder liner water heat exchanger, and the heat energy is supplied to an absorption refrigeration or ORC power generation module. Among them, AC / DC rectifier 9 is a three-phase VIENNA rectifier, and DC / AC inverter 10 is a three-level T-type inverter.

[0021] In this embodiment, the methanol fuel module 1 supplies power to the methanol engine 7 in the power generation module 2 and drives the permanent magnet generator 8, which is directly connected to the power output shaft of the methanol engine 7, to generate electricity. The intelligent controller 5 can adjust the injection parameters of the methanol engine 7 according to the methanol water content detected by the online purity sensor equipped in the methanol storage tank 6. The output of the permanent magnet generator 8 is connected to the AC / DC rectifier 9 of the power conversion module 3. The lithium battery pack in the energy storage module 4 is connected in parallel to the DC bus. The DC / AC inverter 10 converts the DC bus power into AC power for the load.

[0022] In this embodiment, the workflow is as follows: First, the intelligent controller 5 issues a start command based on the load demand and battery status, controlling the fuel in the methanol storage tank 6 to be supplied to the dedicated high-efficiency methanol engine 7 through the injection pump and filter. Then, the methanol engine 7 burns the fuel, driving the permanent magnet synchronous generator 8 directly connected to it to rotate and generate three-phase alternating current. Subsequently, the generated three-phase alternating current is converted into stable direct current through the AC / DC rectifier 9 and sent to the DC bus of the system. Second, the electrical energy on the DC bus is preferentially supplied directly to the DC / AC inverter 10, which converts the DC power into standard and stable AC power to immediately meet the needs of the current load (such as equipment, buildings or microgrids). When the power generation exceeds the load demand, the excess electrical energy will charge the lithium battery pack of the energy storage module 4 to store the energy. When the load demand suddenly increases or the generator module 2 fails to start, the lithium battery pack of the energy storage module 4 will discharge rapidly, releasing electrical energy to the DC bus, which can support the load in parallel or independently with the permanent magnet generator 8, ensuring the stability and response speed of the power supply. III. The intelligent controller 5 continuously monitors the entire system and makes decisions based on preset strategies. Its core logic is as follows: 1. When the real-time load power is high (e.g., >5kW) and the lithium battery power of energy storage module 4 is low (e.g., SOC <40%), the power generation module 2 will be activated. 2. When the real-time load power is very low (e.g., <2kW) and the lithium battery of energy storage module 4 has sufficient power (e.g., SOC>80%), turn off generator module 2. The code is: defpower_management(): load_power = get_real_time_load() Real-time load power bat_soc = read_battery_soc() Current battery SOC ifload_power>5kWandbat_soc<40%: start_methanol_genset() Start the methanol generator set set_genset_power(min(load_power,10kW)) Power generation capacity ≤ unit upper limit elifload_power<2kWandbat_soc>80%: stop_methanol_genset() Shut down the unit ifgenset_running: waste_heat_recovery() Activate waste heat recovery; Meanwhile, the intelligent controller 5 also has a built-in load prediction algorithm, which can predict load changes in the next 15 minutes in advance, so as to start and stop the generator more smoothly and economically. IV. Waste Heat Recovery: During the operation of power generation module 2, heat energy recovery is carried out simultaneously. Through the exhaust gas heat exchanger and cylinder liner water heat exchanger in waste heat recovery module 11, the high-temperature exhaust gas emitted by the engine and the waste heat in the coolant are collected. This heat energy can be used to provide heating or domestic hot water for the site, and by driving the Organic Rankine Cycle (ORC) power generation system, the low-grade heat energy is converted back into electrical energy, further improving the overall system efficiency. Organic Rankine Cycle power generation is a technology that uses a low-boiling-point organic working fluid to effectively convert medium and low temperature heat sources of 80℃ to 300℃ into electrical energy. After absorbing waste heat in the evaporator, the organic working fluid evaporates into high-pressure steam, which drives the expander to do work, thereby driving the generator to generate electricity. The low-pressure steam after doing work is cooled back into liquid in the condenser, and then pumped back to the evaporator by the working fluid to complete a closed cycle, which can convert low-grade heat energy into high-grade electrical energy, and is very suitable for the 550℃ heat energy generated in power generation module 2. Fifth, the intelligent controller 5 can connect multiple systems in parallel via the CAN bus. The intelligent controller 5 with the best performance can be used as the master controller, while the controllers of other units can be used as slave controllers. The role of the master controller is the "commander-in-chief" of the system. It is responsible for monitoring the total voltage and total load power demand of the DC bus in real time, calculating the total power of the generators that need to be put into operation, and issuing power commands to each slave controller according to the preset strategy. The master controller broadcasts the calculated power setpoint to each slave controller via the CAN bus in the form of data frames. After receiving the instruction, the slave controller immediately adjusts the throttle of the local methanol engine and the excitation of the generator to accurately stabilize the output power at the instruction value. While executing the power output, each slave controller continuously monitors the actual output power, speed, temperature and other parameters of the system. This real-time status information is encapsulated into CAN data frames and periodically sent back to the master controller. Meanwhile, the CAN bus ensures clock and command synchronization among all 5 nodes of the intelligent controller, keeping their actions consistent within milliseconds and avoiding power oscillations caused by response delays.

[0023] An off-grid distributed power station system based on methanol power generation and storage is a high-efficiency, low-carbon energy solution using methanol as fuel and intelligent control as its core. At the fuel level, the system uses liquid methanol, fully utilizing its compatibility with existing diesel infrastructure for convenient storage and transportation, safely and efficiently overcoming the dependence of clean energy sources like hydrogen on dedicated infrastructure. At the system architecture level, it creatively introduces the power topology technology of range-extended electric vehicles, using the methanol engine generator set as a stable and efficient power source. It primarily operates in the high-efficiency range to charge the DC bus, rather than directly responding to load fluctuations. This "on-demand power generation" mode fundamentally reduces the need for expensive lithium battery energy storage capacity, significantly reducing initial investment costs. Regarding control strategies… At the power level, the system is equipped with an intelligent energy manager based on load forecasting algorithms, which can proactively and dynamically coordinate the start-up, shutdown, and power output of the methanol generator, enabling it to deeply coordinate with the charging and discharging behavior of the lithium battery, thereby improving the overall system operating efficiency by more than 12%. In terms of environmental protection and economy, the system not only achieves a 25% reduction in CO2 emissions compared to diesel by burning methanol, but also maximizes the overall energy utilization rate of fuel by integrating exhaust gas and cylinder liner water waste heat recovery devices, achieving an exhaust gas waste heat utilization rate of >65%. Ultimately, it forms a disruptive off-grid power supply system that combines the advantages of fuel availability, economical architecture, high operating efficiency, and clean emissions, making it suitable for various scenarios such as remote areas, emergency power supply, and smooth complementarity of renewable energy.

[0024] Example 2: An off-grid distributed power station system based on methanol power generation and energy storage, taking a 10kW off-grid power station as an example, methanol engine 7: rated power 10kW@3000rpm, methanol consumption rate 1.8kg / kWh; Energy storage module 4: 50kWh LFP battery, cycle life > 6000 cycles; Heat recovery efficiency: 30kW of heat energy can be recovered from the exhaust gas (550℃→150℃); The control strategy is as follows: Battery SOC maintenance range: 30%-85%; Load > 7kW for 5 minutes → start the unit; Load < 3kW for 10 minutes → shut down the unit. Power generation efficiency: 35-40%, total energy efficiency (including heat recovery): 70-75%, emissions of particulate matter, sulfur compounds, and aromatic compounds are almost zero, no particulate filter is required, and fuel costs are about 20-30% lower than diesel. Compared with diesel generator sets and photovoltaic + energy storage systems of the same power load, it has the advantages of high efficiency, long and stable power supply time, low operating costs, and high adaptability to extreme environments.

[0025] System efficiency 35-40% (with the overall efficiency reaching 70-75% after heat recovery) 30-45% 16-20.7% Heat recovery 30kW of heat energy can be recovered none none Power supply duration Long-lasting (depends on fuel reserves, can operate continuously for several days). Long-lasting (depends on fuel reserves, can operate continuously for several days). Shorter duration (depending on capacity design, typically 2-4 hours) Fuel / Operating Costs Approximately 1.2 yuan / kWh 2.1 yuan / kWh 0.05-0.1 yuan / kWh Adaptability to extreme environments Excellent performance at low temperatures and high altitudes, strong combustion stability, and no preheating required. Poor performance at low temperatures and high altitudes; requires additional preheating. Power generation capacity decreases during cloudy or rainy weather, dependent on sunlight conditions. Total life cycle cost Low fuel and maintenance costs High fuel and maintenance costs High initial investment, low long-term costs The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this utility model, and these should all be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An off-grid distributed power station system based on methanol power generation and energy storage, comprising a methanol fuel module (1), a power generation module (2), a power conversion module (3), and an energy storage module (4), characterized in that, The power generation module (2) is connected to the methanol fuel module (1), and the power conversion module (3) is connected to the power generation module (2); the energy storage module (4) is connected to the power conversion module (3). The system is controlled by an intelligent controller (5), which is communicatively connected to the methanol fuel module (1), the power generation module (2), the power conversion module (3), and the energy storage module (4). The power generation module (2) is connected to a waste heat recovery module (11). The power generation module (2) includes a methanol engine (7) and a permanent magnet generator (8). The methanol engine (7) is directly connected to the permanent magnet generator (8). The compression ratio of the methanol engine (7) is 18:1, and it uses alcohol-resistant material seals. The power conversion module (3) includes an AC / DC rectifier (9) and a DC / AC inverter (10). The AC / DC rectifier (9) is a three-phase VIENNA rectifier. The lithium battery pack in the energy storage module (4) is connected in parallel to the DC bus. The DC / AC inverter (10) converts the DC bus power into AC power for the load. The DC / AC inverter (10) is a three-level T-type inverter. The intelligent controller (5) includes an ARM+FPGA dual processor, a sensor network, and a communication network. The intelligent controller (5) collects the load power signal and the SOC status signal of the energy storage module (4) through the sensor network, and outputs start-stop control signals to the power generation module (2) through the communication network.

2. The off-grid distributed power station system based on methanol power generation and energy storage according to claim 1, characterized in that: The methanol fuel module (1) includes a methanol storage tank (6) equipped with an injection pump, an online purity / water content sensor, an electronic level gauge and a filter.

3. The off-grid distributed power station system based on methanol power generation and energy storage according to claim 2, characterized in that: The energy storage module (4) is a lithium iron phosphate battery pack that supports 2C discharge and has a capacity of 50-100kWh.

4. An off-grid distributed power station system based on methanol power generation and energy storage according to claim 3, characterized in that: The waste heat recovery module (11) includes an exhaust gas heat exchanger and a cylinder liner water heat exchanger, and is connected to an absorption refrigeration or organic Rankine cycle power generation module.

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