An internal combustion engine biomass slurry combustion energy conversion system

Abstract

This invention discloses a biomass combustion energy conversion system for internal combustion engines, using biomass as fuel. The system includes a biomass fuel delivery unit for delivering biomass fuel to an injection unit; an injection unit that injects biomass fuel and ignition fuel into the internal combustion engine cylinder via high-pressure atomization in a time-sharing manner; wherein the biomass fuel is atomized into droplets with a particle size of 10-200 μm, and the ignition fuel is atomized into oil droplets with a particle size of 10-150 μm; an ignition unit where the ignition fuel is first ignited by compression ignition or a spark plug to form a high-temperature ignition core, which then ignites the biomass droplets for combustion. The resulting high-temperature, high-pressure gas drives the piston in reciprocating motion, converting chemical energy into heat energy and then into mechanical energy, ultimately driving the ship's operation; and a control unit for real-time adjustment of the supply of biomass fuel and ignition fuel to achieve efficient combustion. This invention can adapt to different ship power requirements.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and more specifically, to an internal combustion engine biomass slurry combustion energy conversion system. Background Technology

[0002] The shipbuilding industry is facing profound pressure for energy transition and emission reduction, placing increasingly stringent requirements on the carbon emission intensity of marine propulsion systems. Currently, mainstream marine low- and medium-speed diesel engines mainly use heavy oil and marine diesel fuel. The large amounts of carbon dioxide, sulfur oxides, and particulate matter produced after combustion are significant factors contributing to regional air pollution and global climate change.

[0003] To achieve decarbonization of ship propulsion, the industry's current main research focus is on alternative fuels such as liquefied natural gas (LNG), methanol, ammonia, and hydrogen. However, these pathways all face significant bottlenecks. While LNG fuel can reduce carbon dioxide emissions by about 25%, it is still a fossil fuel, and methane escape issues may diminish its climate benefits. Green ammonia and green hydrogen fuels rely on immature and costly green production and offshore supply chains, and face serious challenges in storage security and engine technology compatibility.

[0004] Biomass-derived liquid fuels, such as biodiesel and biomethanol, are considered promising technological pathways. However, the large-scale production of these fuels generally faces the energy loss dilemma of "from solid to liquid." Converting solid biomass feedstocks into standard liquid fuels through complex chemical or biological processes requires significant energy consumption (such as hydrogen production and purification processes), resulting in a substantial reduction in life-cycle energy efficiency. Furthermore, the refining infrastructure for producing these fuels, similar to that for fossil fuels, presents systemic problems such as competition for land with food crops and a fragile supply chain.

[0005] Against this backdrop, developing a novel fuel form that can bypass energy-intensive chemical conversion processes and directly utilize biomass carbon sources has become crucial to overcoming current technological bottlenecks. This new fuel needs to simultaneously inherit the engineering advantages of traditional liquid fuels in terms of transportation, metering, and control, while possessing near-zero carbon cycle environmental characteristics. However, how to stably adapt high-solids-content slurry fuels to internal combustion engines with high requirements for transient response and combustion uniformity, and how to solve the potential wear, deposition, and injection control problems they may bring, constitute a pressing technological gap in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the aforementioned deficiencies in the existing technology and provide a biomass slurry combustion energy conversion system for internal combustion engines. Based on a comprehensive analysis of the atomization characteristics of heavy oil and the synergistic effect of tar and heavy oil, this invention designs a biochar slurry fuel as a multi-element composite fuel. It utilizes biomass tar with high oxygen content and low aromatic ring number to mix with heavy oil, forming a liquid carrier that can reduce viscosity and improve ignition and combustion. Then, this invention further designs a biomass slurry combustion energy conversion system for internal combustion engines. Through high-pressure injection, the slurry fuel is atomized into droplets of tens of micrometers in the cylinder, ensuring efficient combustion and realizing the clean and efficient co-conversion of biomass resources and heavy oil in the internal combustion engine.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: A bioslurry fuel for internal combustion engines, the bioslurry fuel comprising the following components in weight percentages: 40%–50% biochar, 20%–30% tar, 20%–30% heavy oil, and 0.1%–1% additives.

[0008] Optionally, the viscosity of the bio-slurry fuel is 500 mPa·s to 3000 mPa·s; the particle size of the bio-slurry fuel is 20 to 100 μm; and the calorific value of the bio-slurry fuel is 20 to 35 MJ / kg.

[0009] Optionally, the tar is a byproduct generated during the biochar production process.

[0010] Optionally, the heavy oil is selected from at least one of RF20, RF80, RF180, RF380 and RF500.

[0011] Optionally, the additive is selected from lignin sulfonate and carboxymethyl cellulose salt in a weight ratio of 1:1.

[0012] The present invention also discloses a method for preparing bio-slurry fuel for internal combustion engines as described above, comprising the following steps; (1) The biomass is subjected to slow pyrolysis reaction, and solid-liquid separation is performed after the reaction to obtain biochar and tar; (2) The biochar is ball-milled to obtain biochar powder; (3) The biochar powder, the tar, the heavy oil and the additives are mixed to obtain bio-slurry fuel.

[0013] Optionally, in step (1), the biomass includes one or more agricultural and forestry wastes such as rice husks, sawdust, and straw; the slow pyrolysis reaction specifically includes: converting biomass into biochar and tar by thermal decomposition at a temperature of 380-450°C under air-isolated conditions.

[0014] Optionally, in step (3), the mixing specifically includes: first, mixing the tar and heavy oil thoroughly under stirring to form a uniform oil phase; then, mixing the resulting mixed oil with biochar powder and additives at high speed to ensure full dispersion, thereby obtaining the bio-slurry fuel.

[0015] Optionally, in step (2), the ball milling specifically includes: mixing biochar with particle size a and particle size b in a mass ratio of 4:6 and then ball milling the mixture, wherein the ball milling speed is 300~500 r / min and the ball milling time is 10~20 h, to obtain biochar powder with a particle size of 10~40 μm; wherein 25 μm < a ≤ 45 μm, 45 μm < b ≤ 75 μm; or, in step (2), the ball milling specifically includes: mixing biochar with particle size a, particle size b and particle size c in a mass ratio of 1:8.5:0.5 and then ball milling the mixture, wherein the ball milling speed is 300~500 r / min and the ball milling time is 10~20 h, to obtain biochar powder with a particle size of 10~40 μm; wherein 25 μm < a ≤ 45 μm, 45 μm < b ≤ 75 μm, c ≤ 25 μm.

[0016] The present invention also discloses an internal combustion engine bioslurry combustion energy conversion system, wherein the system uses bioslurry fuel as described above, or bioslurry fuel prepared by the preparation method described above, as fuel. The system includes: a biomass fuel delivery unit, an injection unit, an ignition unit, and a control unit; The bioslurry fuel delivery unit is used to deliver bioslurry fuel to the injection unit; The injection unit includes a first inlet and a second inlet. The first inlet is connected to the outlet of the bioslurry fuel delivery unit and is used to receive the bioslurry fuel. The second inlet is used to receive the ignition fuel and injects the bioslurry fuel and the ignition fuel into the internal combustion engine cylinder after high-pressure atomization in a time-sharing manner. The bioslurry fuel is atomized into droplets with a particle size of 10~200μm under high pressure, and the ignition fuel is atomized into oil droplets with a particle size of 10~150μm under high pressure. The ignition unit is used for staged ignition by compression ignition or spark plug ignition; wherein, the ignition fuel is first ignited by compression ignition or spark plug to form a high-temperature ignition core, which then ignites the biological slurry droplets for combustion. The resulting high-temperature and high-pressure gas drives the piston to reciprocate, converting chemical energy into heat energy and then into mechanical energy, ultimately driving the ship's operation. The control unit receives sensor data from the internal combustion engine in real time and coordinates the bioslurry fuel delivery unit and the injection unit to adjust the supply of bioslurry fuel and ignition fuel in real time to achieve efficient combustion.

[0017] Optionally, when the injection unit injects biomass fuel, the flow rate is 100~2000 kg / h and the injection pressure is 200~1200 bar.

[0018] Optionally, when the injection unit injects ignition fuel, the flow rate is 5~200 kg / h and the injection pressure is 300~1000 bar.

[0019] Optionally, the ignition fuel includes one of diesel and methanol.

[0020] Optionally, in the ignition unit, the air-fuel ratio is 1.2:1 to 1.7:1, and the combustion temperature is 1200 to 1600℃.

[0021] Optionally, the bioslurry fuel delivery unit adjusts the bioslurry fuel delivery amount based on the real-time analysis of the internal combustion engine crankshaft position, load, temperature and / or pressure data by the control unit, so as to adjust the ratio of the bioslurry fuel to the ignition fuel, and delivers the bioslurry fuel and the ignition fuel to the injection unit.

[0022] The present invention also discloses a marine bioslurry fuel engine, including the above-described internal combustion engine bioslurry combustion energy conversion system.

[0023] Optionally, the engine is a two-stroke compression-ignition engine or a four-stroke spark-ignition engine, with a typical output power range of 1MW to 50MW for marine engines.

[0024] Implementing the embodiments of the present invention will have the following beneficial effects: This invention innovatively utilizes biochar and tar, a byproduct of biochar production, and combines them with heavy oil and additives to form a bio-slurry with a particle size of 20-100 μm as fuel. This bio-slurry fuel has a calorific value of 20-35 MJ / kg, higher than methanol's 19.9 MJ / kg, exhibiting excellent energy density and combustion characteristics. Based on the properties of the bio-slurry fuel, this invention further proposes to atomize it under high pressure into droplets with a particle size of 10-200 μm, then inject it into the cylinder of an internal combustion engine. Employing a time-sharing injection and staged ignition strategy, this achieves highly efficient energy release and mechanical energy conversion of the biofuel. This not only avoids multi-stage energy conversion losses and significantly improves carbon utilization efficiency but also optimizes combustion, reduces incomplete combustion, and improves combustion efficiency, thereby enhancing engine power. Engines using this system can cover low-speed, medium-speed, and high-speed ranges, adapting to different ship power requirements and providing a new approach for the application of carbon-neutral fuels in power plants. Furthermore, this invention features renewable fuel sources, high energy conversion efficiency, and environmental friendliness. Attached Figure Description

[0025] Figure 1This is a process flow diagram for preparing the bio-slurry fuel of the present invention.

[0026] Figure 2 This is a flowchart of the internal combustion engine bio-slurry combustion energy conversion system of the present invention. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments, but this does not limit the present invention in any way.

[0028] This invention discloses a biomass fuel for internal combustion engines, comprising the following components by weight percentage: 40%–50% biochar, 20%–30% tar, 20%–30% heavy oil, and 0.1%–1% additives.

[0029] Specifically, the bio-slurry fuel of this invention has a high solids content, with biochar content reaching 40%–50%, which can significantly improve the energy density of the fuel, enabling the bio-slurry fuel to achieve a calorific value of 20–35 MJ / kg. Simultaneously, utilizing biochar as a renewable resource reduces costs and promotes the resource utilization of waste. However, the inventors have discovered that the high solids content presents challenges in preparation, particularly the tendency of biochar particles to aggregate and settle, leading to uneven dispersion and affecting the stability and combustion efficiency of the slurry. Therefore, this invention simultaneously adds tar and heavy oil to the system, utilizing the synergistic compounding of tar and heavy oil to improve its dispersibility.

[0030] Specifically, this invention utilizes the synergistic ratio of tar and heavy oil to optimize slurry performance, which is manifested in the following ways: The tar used in this invention originates from the biomass pyrolysis process. Its core chemical characteristics are high oxygen content and fewer aromatic rings. This means that its molecular structure is relatively lightweight, with high reactivity and a certain degree of polarity. In the bio-slurry fuel of this invention, it plays multiple roles: (1) Natural emulsifier and solvent: Due to the amphiphilic properties brought by its oxygen-containing functional groups (such as phenolic hydroxyl groups), its oxygen-containing functional groups and amphiphilic properties promote the wetting of the oil phase and biochar particles, reduce phase separation, and are the basis for forming a stable slurry. (2) Light active component: Fewer aromatic rings mean that its viscosity is relatively low and its boiling point range is narrow. When burning in the cylinder, it can act as a "light fraction" in the slurry, which will first vaporize and form an initial ignition nucleus, igniting the subsequent more difficult-to-volatilize biochar particles and heavy oil components, thereby significantly improving the ignition performance of the slurry.

[0031] The heavy oil used in this invention is a traditional petroleum-based residue fuel, characterized by a high carbon-to-hydrogen ratio, high viscosity, and extremely high calorific value, but it also contains a large amount of asphaltenes and heavy metals. In the bio-slurry fuel formulation of this invention, its main functions are: (1) providing basic calorific value: as one of the main contributors to the energy of the slurry, its high calorific value ensures that the entire fuel system has sufficient total energy density. (2) acting as a continuous phase matrix: together with tar, it constitutes the liquid oil phase of the slurry, impregnating and encapsulating the solid biochar particles, effectively adjusting the viscosity, forming a uniform suspension system, and improving fluidity and atomization characteristics.

[0032] Furthermore, this invention employs a synergistic fusion of tar and heavy oil: tar with high oxygen content and low aromatic ring number is mixed with heavy oil. This is not a simple physical dilution, but a functional compounding: (1) Viscosity adjustment: The introduction of tar can effectively reduce the viscosity of the entire oil phase mixture, which greatly improves the fluidity, pumpability, and atomization characteristics of the slurry, enabling it to meet the requirements of the high-pressure injection system. (2) Promoting combustion: The oxygen element in tar can play an "internal oxygen supply" effect during combustion, promoting combustion in the local oil-rich area, which helps to reduce the emissions of soot and particulate matter caused by the incomplete combustion of heavy oil and biochar. (3) Optimizing component gradient: The mixture forms a continuous distribution from easily volatile oxygen-containing light components (tar) to difficult-to-volatile high-calorific-value heavy components (heavy oil). This gradient is very beneficial for achieving a stable, stratified, and efficient combustion process in the engine cylinder.

[0033] In one specific embodiment, the viscosity of the bioslurry fuel is 500 mPa·s to 3000 mPa·s; the particle size of the bioslurry fuel is 20 to 100 μm; and the calorific value of the bioslurry fuel is 20 to 35 MJ / kg.

[0034] In one specific embodiment, tar is a byproduct generated during the biochar production process.

[0035] In one specific embodiment, the heavy oil is selected from at least one of RF20, RF80, RF180, RF380 to RF500. Preferably, the heavy oil is selected from at least one of RF20, RF80, RF180, RF380 and RF500.

[0036] Specifically, according to the ISO 8217 standard, the core models of marine residual fuel (RF) constitute a continuous spectrum from light to extra-heavy, with their key indicators exhibiting systematic changes. Specifically, from RF20, RF80, RF180, RF380 to RF500, the upper limit of fuel viscosity increases from 20 cSt to 500 cSt, and the upper limit of density increases from 955 kg / m³. 3 Relaxed to 1010 kg / m 3Meanwhile, the trace carbon residue (MCR), which characterizes coking tendency, increased from 10% to 20%, and the limits for metallic elements such as vanadium, sodium, aluminum, and silicon also increased significantly, which may lead to an increase in ash content after fuel combustion. This index gradient directly determines the trade-off between its application economy and technical complexity: RF20 and RF80 have the highest quality and simplest pretreatment but are the most engine-friendly, and are also the most expensive; RF180 is a balanced choice; while RF380 and RF500 are the most economical choices, but they must rely on powerful preheating and purification systems and meticulous engine maintenance to cope with the risks of carbon deposits, wear, and corrosion caused by their high viscosity, high density, and high impurity content.

[0037] In one specific embodiment, the additive is selected from lignin sulfonate and carboxymethyl cellulose salt in a weight ratio of 1:1.

[0038] The present invention also discloses a method for preparing bio-slurry fuel for internal combustion engines as described above, comprising the following steps; (1) The biomass is subjected to slow pyrolysis reaction, and solid-liquid separation is performed after the reaction to obtain biochar and tar.

[0039] (2) The biochar was ball-milled to obtain biochar powder.

[0040] (3) Biochar powder, tar, heavy oil and additives are mixed to obtain bio-slurry fuel.

[0041] In one specific embodiment, in step (1), the biomass includes one or more agricultural and forestry wastes such as rice husks, sawdust, and straw; the slow pyrolysis reaction specifically includes: converting the biomass into biochar and tar by thermal decomposition at a temperature of 380-450°C under air-isolated conditions.

[0042] In one specific embodiment, step (2) specifically includes: mixing biochar with particle size a and particle size b in a mass ratio of 4:6 and then ball milling the mixture. The ball milling speed is 300~500 r / min and the ball milling time is 10~20 h to obtain biochar powder with a particle size of 10~40 μm; wherein, 25 μm < a ≤ 45 μm and 45 μm < b ≤ 75 μm.

[0043] In a specific embodiment, step (2) specifically includes: mixing biochar with particle size a, particle size b and particle size c in a mass ratio of 1:8.5:0.5 and then ball milling them. The ball milling speed is 300~500 r / min and the ball milling time is 10~20 h to obtain biochar powder with a particle size of 10~40 μm; wherein, 25 μm < a ≤ 45 μm, 45 μm < b ≤ 75 μm, and c ≤ 25 μm.

[0044] In one specific embodiment, a planetary ball mill is used for ball milling.

[0045] In one specific embodiment, the grinding media used in the ball milling is zirconia balls.

[0046] In one specific embodiment, step (3) specifically includes: first, mixing tar and heavy oil thoroughly under stirring to form a uniform oil phase; then, mixing the resulting mixed oil with biochar powder and additives at high speed to ensure full dispersion, thereby obtaining bio-slurry fuel. Specifically, in the preparation method of this invention, by first stirring tar and heavy oil to form a uniform oil phase, and then mixing it with ball-milled biochar powder (controlling the particle size distribution to 10~40μm) and additives at high speed to ensure full dispersion and form a stable suspension system, the uniformity and pumpability of the high solids content slurry are achieved.

[0047] This invention also discloses a bioslurry combustion energy conversion system for an internal combustion engine. The system uses bioslurry fuel as described above, or bioslurry fuel prepared by the method described above, as fuel. The system includes: a bioslurry fuel delivery unit, an injection unit, an ignition unit, and a control unit. The bioslurry fuel delivery unit delivers the bioslurry fuel to the injection unit. The injection unit includes a first inlet and a second inlet. The first inlet is connected to the outlet of the bioslurry fuel delivery unit and is used to receive the bioslurry fuel. The second inlet is used to receive ignition fuel, and the bioslurry fuel and ignition fuel are injected into the internal combustion engine cylinder after high-pressure atomization in a time-sharing manner. The bioslurry fuel is then atomized by high pressure. The fuel is atomized into droplets with a particle size of 10~200μm, and the ignition fuel is atomized into oil droplets with a particle size of 10~150μm under high pressure. The ignition unit is used for staged ignition by compression ignition or spark plug ignition. The ignition fuel is first ignited by compression ignition or spark plug to form a high-temperature flame core, which then ignites the bio-slurry droplets for combustion. The resulting high-temperature and high-pressure gas drives the piston to reciprocate, converting chemical energy into heat energy and then into mechanical energy, ultimately driving the ship's operation. The control unit receives data from sensors installed on the internal combustion engine in real time and coordinates the bio-slurry fuel delivery unit and injection unit to adjust the supply of bio-slurry fuel and ignition fuel in real time to achieve efficient combustion.

[0048] In one specific embodiment, when the injection unit injects biomass fuel, the flow rate is 100~2000 kg / h and the injection pressure is 200~1200 bar.

[0049] In one specific embodiment, when the injection unit injects ignition fuel, the flow rate is 5~200 kg / h and the injection pressure is 300~1000 bar.

[0050] In one specific embodiment, the ignition fuel includes one of diesel oil and methanol.

[0051] In one specific embodiment, the air-fuel ratio in the ignition unit is 1.2:1 to 1.7:1, and the combustion temperature is 1200 to 1600°C.

[0052] In one specific embodiment, the bioslurry fuel delivery unit delivers bioslurry fuel to the injection unit via a high-pressure oil pump.

[0053] In one specific embodiment, biomass fuel and ignition fuel are atomized under high pressure and injected into the cylinder of an internal combustion engine using a high-pressure nozzle.

[0054] In one specific embodiment, the bioslurry fuel delivery unit adjusts the bioslurry fuel delivery amount based on real-time analysis of the crankshaft position, load, temperature and / or pressure data of the internal combustion engine by the control unit, so as to adjust the ratio of bioslurry fuel to ignition fuel, and delivers the bioslurry fuel and ignition fuel to the injection unit.

[0055] The present invention also discloses a marine bioslurry fuel engine, including the above-described internal combustion engine bioslurry combustion energy conversion system.

[0056] In one specific embodiment, the engine is a two-stroke compression-ignition engine or a four-stroke spark-ignition engine, and the typical output power range of the marine engine is 1MW to 50MW.

[0057] In one specific embodiment, the engine of the engine system of the present invention can cover low-speed, medium-speed and high-speed ranges, and can adapt to different ship power requirements.

[0058] In one specific embodiment, the marine flow-carrying engine is suitable for one of the following: diesel engine, hydrogen fuel engine, ammonia fuel engine, and methanol fuel engine.

[0059] In one specific embodiment, the engine system of the present invention can be applied to engine platforms provided by various internal combustion engine manufacturers, including but not limited to MAN, Wärtsilä, WINGD, Shanghai Diesel Engine Co., Ltd., Dalian Diesel Engine Co., Ltd., Guangzhou Diesel Engine Co., Ltd., Zibo Diesel Engine Co., Ltd., Weichai Diesel Engine Co., Ltd., etc.

[0060] The following are specific embodiments. Example 1 The bioslurry fuel for internal combustion engines in this embodiment comprises the following components by weight percentage: 45% biochar, 24.5% tar, 30% heavy oil (RF180), and 0.5% additives. The additives are selected from lignin sulfonate and carboxymethyl cellulose salt in a 1:1 weight ratio.

[0061] The viscosity of the bio-slurry fuel in this embodiment is 500 mPa·s to 3000 mPa·s; the particle size of the bio-slurry fuel is 20 to 100 μm; and the calorific value of the bio-slurry fuel is 20 to 35 MJ / kg.

[0062] The method for preparing bio-slurry fuel for internal combustion engines in this embodiment includes the following steps; (1) The straw was subjected to slow pyrolysis at 380-450℃ under air-isolated conditions. After the reaction, solid-liquid separation was carried out to obtain biochar and tar.

[0063] (2) Mix biochar with particle size a and particle size b at a mass ratio of 4:6 and then ball mill them. The ball milling speed is 300~500 r / min and the ball milling time is 10~20 h to obtain biochar powder with a particle size of 10~40 μm; wherein 25 μm < a ≤ 45 μm and 45 μm < b ≤ 75 μm to obtain biochar powder.

[0064] (3) First, mix the tar and heavy oil thoroughly under stirring to form a uniform oil phase; then mix the resulting mixed oil with biochar powder and additives at high speed to ensure full dispersion and obtain biomass fuel.

[0065] This embodiment uses the aforementioned bioslurry fuel as fuel and discloses a bioslurry combustion energy conversion system for an internal combustion engine. The system includes: a bioslurry fuel delivery unit, an injection unit, an ignition unit, and a control unit. The bioslurry fuel delivery unit is used to deliver the bioslurry fuel to the injection unit via a high-pressure oil pump. The injection unit includes a first inlet and a second inlet. The first inlet is connected to the outlet of the bioslurry fuel delivery unit and is used to receive the bioslurry fuel. The second inlet is used to receive the ignition fuel. The bioslurry fuel and the ignition fuel are injected into the internal combustion engine cylinder through a high-pressure atomization process using a high-pressure nozzle in a time-sharing manner. The bioslurry fuel is atomized into granules under high pressure. The system consists of droplets with a diameter of 10-200 μm, which ignite the fuel and atomize it into oil droplets with a diameter of 10-150 μm under high pressure; an ignition unit for staged ignition via compression ignition or spark plug ignition; where the igniter fuel is first ignited by compression ignition or spark plug to form a high-temperature ignition core, which then ignites the bio-slurry droplets for combustion. The resulting high-temperature, high-pressure gas drives the piston to reciprocate, converting chemical energy into heat energy and then into mechanical energy, ultimately driving the ship's operation; and a control unit that receives real-time data from sensors installed on the internal combustion engine and coordinates the bio-slurry fuel delivery unit and injection unit to adjust the supply of bio-slurry fuel and igniter fuel in real time to achieve efficient combustion.

[0066] When the injection unit injects biomass fuel, the flow rate is 100~2000 kg / h and the injection pressure is 200~1200 bar. When the injection unit injects ignition fuel, the flow rate is 5~200 kg / h and the injection pressure is 300~1000 bar. The ignition fuel includes either diesel or methanol.

[0067] The air-fuel ratio in the ignition unit is 1.2:1 to 1.7:1, and the combustion temperature is 1200 to 1600℃.

[0068] The bioslurry fuel delivery unit adjusts the bioslurry fuel delivery volume based on real-time analysis of the crankshaft position, load, temperature and / or pressure data of the internal combustion engine by the control unit, so as to adjust the ratio of bioslurry fuel to ignition fuel, and delivers the bioslurry fuel and ignition fuel to the injection unit.

[0069] Example 2 The bioslurry fuel for internal combustion engines in this embodiment comprises the following components by weight percentage: 49% biochar, 30% tar, 20% heavy oil (RF180), and 1% additives. The additives are selected from lignin sulfonate and carboxymethyl cellulose salt in a 1:1 weight ratio.

[0070] The viscosity of the bio-slurry fuel in this embodiment is 500 mPa·s to 3000 mPa·s; the particle size of the bio-slurry fuel is 20 to 100 μm; and the calorific value of the bio-slurry fuel is 20 to 35 MJ / kg.

[0071] The method for preparing bio-slurry fuel for internal combustion engines in this embodiment includes the following steps; (1) The straw was subjected to slow pyrolysis at 380-450℃ under air-isolated conditions. After the reaction, solid-liquid separation was carried out to obtain biochar and tar.

[0072] (2) Biochar with particle size a, particle size b and particle size c are mixed in a mass ratio of 1:8.5:0.5 and then ball-milled. The ball milling speed is 300~500 r / min and the ball milling time is 10~20 h to obtain biochar powder with a particle size of 10~40 μm; wherein, 25 μm < a ≤ 45 μm, 45 μm < b ≤ 75 μm and c ≤ 25 μm.

[0073] (3) First, mix the tar and heavy oil thoroughly under stirring to form a uniform oil phase; then mix the resulting mixed oil with biochar powder and additives at high speed to ensure full dispersion and obtain biomass fuel.

[0074] This embodiment uses the aforementioned bioslurry fuel as fuel and discloses a bioslurry combustion energy conversion system for an internal combustion engine. The system includes: a bioslurry fuel delivery unit, an injection unit, an ignition unit, and a control unit. The bioslurry fuel delivery unit is used to deliver the bioslurry fuel to the injection unit via a high-pressure oil pump. The injection unit includes a first inlet and a second inlet. The first inlet is connected to the outlet of the bioslurry fuel delivery unit and is used to receive the bioslurry fuel. The second inlet is used to receive the ignition fuel. The bioslurry fuel and the ignition fuel are injected into the internal combustion engine cylinder through a high-pressure atomization process using a high-pressure nozzle in a time-sharing manner. The bioslurry fuel is atomized into granules under high pressure. The system consists of droplets with a diameter of 10-200 μm, which ignite the fuel and atomize it into oil droplets with a diameter of 10-150 μm under high pressure; an ignition unit for staged ignition via compression ignition or spark plug ignition; where the igniter fuel is first ignited by compression ignition or spark plug to form a high-temperature ignition core, which then ignites the bio-slurry droplets for combustion. The resulting high-temperature, high-pressure gas drives the piston to reciprocate, converting chemical energy into heat energy and then into mechanical energy, ultimately driving the ship's operation; and a control unit that receives real-time data from sensors installed on the internal combustion engine and coordinates the bio-slurry fuel delivery unit and injection unit to adjust the supply of bio-slurry fuel and igniter fuel in real time to achieve efficient combustion.

[0075] When the injection unit injects biomass fuel, the flow rate is 100~2000 kg / h and the injection pressure is 200~1200 bar. When the injection unit injects ignition fuel, the flow rate is 5~200 kg / h and the injection pressure is 300~1000 bar. Ignition fuel includes either diesel or methanol.

[0076] The air-fuel ratio in the ignition unit is 1.2:1 to 1.7:1, and the combustion temperature is 1200 to 1600℃.

[0077] The bioslurry fuel delivery unit adjusts the bioslurry fuel delivery volume based on real-time analysis of the crankshaft position, load, temperature and / or pressure data of the internal combustion engine by the control unit, so as to adjust the ratio of bioslurry fuel to ignition fuel, and delivers the bioslurry fuel and ignition fuel to the injection unit.

[0078] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A biomass slurry combustion energy conversion system for internal combustion engines, characterized in that, The system uses bioslurry fuel as fuel; The system includes: a biomass fuel delivery unit, an injection unit, an ignition unit, and a control unit; The bioslurry fuel delivery unit is used to deliver bioslurry fuel to the injection unit; The injection unit includes a first inlet and a second inlet. The first inlet is connected to the outlet of the bioslurry fuel delivery unit and is used to receive the bioslurry fuel. The second inlet is used to receive the ignition fuel and injects the bioslurry fuel and the ignition fuel into the internal combustion engine cylinder after high-pressure atomization in a time-sharing manner. The bioslurry fuel is atomized into droplets with a particle size of 10~200μm under high pressure, and the ignition fuel is atomized into oil droplets with a particle size of 10~150μm under high pressure. The ignition unit is used for staged ignition by compression ignition or spark plug ignition; wherein, the ignition fuel is first ignited by compression ignition or spark plug to form a high-temperature ignition core, which then ignites the biological slurry droplets for combustion. The resulting high-temperature and high-pressure gas drives the piston to reciprocate, converting chemical energy into heat energy and then into mechanical energy, ultimately driving the ship's operation. The control unit receives sensor data from the internal combustion engine in real time and coordinates the bioslurry fuel delivery unit and the injection unit to adjust the supply of bioslurry fuel and ignition fuel in real time to achieve efficient combustion. When the injection unit injects bio-slurry fuel, the flow rate is 100~2000 kg / h and the injection pressure is 200~1200 bar; When the injection unit injects ignition fuel, the flow rate is 5~200 kg / h and the injection pressure is 300~1000 bar; In the ignition unit, the air-fuel ratio is 1.2:1 to 1.7:1, and the combustion temperature is 1200 to 1600°C; The biomass fuel comprises the following components by weight percentage: 40%–50% biochar, 20%–30% tar, 20%–30% heavy oil, and 0.1%–1% additives; The viscosity of the bio-slurry fuel is 500 mPa·s to 3000 mPa·s; the particle size of the bio-slurry fuel is 20 to 100 μm; and the calorific value of the bio-slurry fuel is 20 to 35 MJ / kg. The additive is selected from lignin sulfonate and carboxymethyl cellulose salt in a weight ratio of 1:1; The method for preparing bio-slurry fuel for internal combustion engines includes the following steps; (1) The biomass is subjected to slow pyrolysis reaction, and solid-liquid separation is performed after the reaction to obtain biochar and tar; (2) The biochar is ball-milled to obtain biochar powder; (3) The biochar powder, the tar, heavy oil and additives are mixed to obtain bio-slurry fuel; In step (3), the mixing specifically includes: first, mixing the tar and heavy oil thoroughly under stirring to form a uniform oil phase; then, mixing the resulting mixed oil with biochar powder and additives at high speed to ensure full dispersion, thereby obtaining the bio-slurry fuel.

2. The internal combustion engine bio-slurry combustion energy conversion system according to claim 1, characterized in that, The tar is a byproduct of biochar production. The heavy oil is selected from at least one of RF20, RF80, RF180, RF380 and RF500.

3. The internal combustion engine bio-slurry combustion energy conversion system according to claim 1, characterized in that, In step (1), the biomass includes one or more agricultural and forestry wastes such as rice husks, sawdust, and straw; the slow pyrolysis reaction specifically includes: converting biomass into biochar and tar by thermal decomposition at a temperature of 380-450°C under air-isolated conditions.

4. The internal combustion engine bio-slurry combustion energy conversion system according to claim 1, characterized in that, In step (2), the ball milling specifically includes: mixing biochar with particle size a and particle size b at a mass ratio of 4:6 and then ball milling the mixture. The ball milling speed is 300~500 r / min, and the ball milling time is 10~20 h, to obtain biochar powder with a particle size of 10~40 μm; wherein, 25 μm < a ≤ 45 μm, 45 μm < b ≤ 75 μm; or, In step (2), the ball milling specifically includes: mixing biochar with particle size a, particle size b and particle size c in a mass ratio of 1:8.5:0.5 and then ball milling them. The ball milling speed is 300~500 r / min and the ball milling time is 10~20 h to obtain biochar powder with a particle size of 10~40 μm; wherein, 25 μm < a ≤ 45 μm, 45 μm < b ≤ 75 μm, and c ≤ 25 μm.

5. The internal combustion engine bio-slurry combustion energy conversion system according to claim 1, characterized in that, The ignition fuel includes either diesel or methanol.

6. The internal combustion engine bio-slurry combustion energy conversion system according to claim 1, characterized in that, The bioslurry fuel delivery unit adjusts the bioslurry fuel delivery volume based on the real-time analysis of the internal combustion engine crankshaft position, load, temperature and / or pressure data by the control unit, so as to adjust the ratio of the bioslurry fuel to the ignition fuel, and delivers the bioslurry fuel and the ignition fuel to the injection unit.

7. A marine bioslurry fuel engine, characterized in that, Including the internal combustion engine bioslurry combustion energy conversion system as described in any one of claims 1-6.

8. The marine bioslurry fuel engine according to claim 7, characterized in that, The engine is a two-stroke compression-ignition engine or a four-stroke spark-ignition engine, with a typical output power range of 1MW to 50MW for marine engines.

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