WO2021254292A1 - 一种超临界水燃烧环境往复活塞式内燃机及其燃烧方法 - Google Patents

一种超临界水燃烧环境往复活塞式内燃机及其燃烧方法 Download PDF

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WO2021254292A1
WO2021254292A1 PCT/CN2021/099904 CN2021099904W WO2021254292A1 WO 2021254292 A1 WO2021254292 A1 WO 2021254292A1 CN 2021099904 W CN2021099904 W CN 2021099904W WO 2021254292 A1 WO2021254292 A1 WO 2021254292A1
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combustion
water
fuel
supercritical
supercritical water
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PCT/CN2021/099904
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English (en)
French (fr)
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刘金宏
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东莞宏大动力科技有限公司
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Publication of WO2021254292A1 publication Critical patent/WO2021254292A1/zh

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
    • F02M25/022—Adding fuel and water emulsion, water or steam
    • F02M25/025—Adding water
    • F02M25/03—Adding water into the cylinder or the pre-combustion chamber
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the invention relates to a reciprocating piston internal combustion engine, in particular to the combustion environment of the reciprocating piston internal combustion engine and a combustion method thereof.
  • the reciprocating piston internal combustion engine refers to a piston internal combustion engine in which the piston reciprocates linearly in the cylinder.
  • the working process of a four-stroke reciprocating piston engine is that the four orderly steps of the piston movement forming intake, air compression, combustion and expansion work, and exhaust form a working cycle, and the working process is formed by repeating the cycle continuously.
  • the reciprocating piston internal combustion engine uses air as the oxidant, and the fuel consumed is mainly oil or gas.
  • Reciprocating piston internal combustion engines can be divided into two types according to the ignition mode, namely ignition type and compression ignition type, mainly gasoline engine and diesel engine.
  • the thermal efficiency of current gasoline engines is generally about 35%, and the highest can reach about 40%, and the thermal efficiency of diesel engines is generally about 40%, and the highest can reach about 46%.
  • the reciprocating piston internal combustion engine has been developed for more than one hundred years, and various technologies are relatively mature, but the thermal efficiency is not high. It is very difficult to further improve the thermal efficiency.
  • the emissions of reciprocating piston internal combustion engines will cause environmental pollution.
  • the harmful substances emitted mainly include sulfur oxides (mainly sulfur dioxide SO 2 ), carbon monoxide (CO), nitrogen oxides (NO x ), hydrocarbons (HC), Particulate matter (PM), odor (mainly products of various incomplete combustion, such as various aldehydes), carbon dioxide (CO 2 ), etc., as well as noise pollution.
  • the main harmful emissions are nitrogen oxides (NO x ), carbon monoxide (CO), particulate matter (PM) and hydrocarbons (HC).
  • the compression ratio is the main factor affecting the thermal efficiency of reciprocating piston internal combustion engines.
  • the compression ratio of gasoline engines is generally between 8-12, and the highest compression ratio of Mazda engines even reaches 14; the compression ratio of diesel engines is currently generally between 11-22, and the maximum can even reach 25.
  • the reduction of the gas can indeed increase the cylinder pressure and reduce the production of nitrogen oxides.
  • due to the oxygen-deficient combustion it is easy to generate carbon monoxide and increase new harmful emissions. Therefore, with the increasingly stringent emission regulations, the existing technology Under the conditions, a proper reduction in the compression ratio is more conducive to reducing the production of nitrogen oxides and carbon monoxide, and a proper reduction in efficiency can effectively reduce harmful emissions. Therefore, there are many diesel engines designed with a compression ratio of about 16, and their compression ratios are compared with the previous ones. Decrease, in order to reduce the thermal efficiency of the internal combustion engine to achieve the purpose of reducing harmful emissions. Third, it is the limitation of power and power demand.
  • reciprocating piston internal combustion engines are generally designed with a fixed compression ratio, and the adjustable compression ratio engine is rarely used due to its complex structure.
  • the compression ratio In the fixed compression ratio mode, the compression ratio It is usually designed under the maximum load and power conditions. A too high compression ratio will result in less air being compressed during intake, which will limit the load of the engine and the amount of fuel each time, resulting in insufficient power and power, and low load. It is difficult to meet the design requirements, so generally the compression ratio of supercharged gasoline engines and diesel engines is usually lower to meet the requirements of greater power and greater power of the engine.
  • the intake water injection combustion technology can indeed reduce the production of nitrogen oxides in the engine, but it will also increase the emissions of carbon monoxide (CO), particulate matter (PM) and hydrocarbons (HC). It will also be very difficult to further reduce waste gas pollution to achieve the desired state.
  • CO carbon monoxide
  • PM particulate matter
  • HC hydrocarbons
  • the present invention provides a new internal combustion engine solution.
  • the thermal efficiency of reciprocating piston internal combustion engines can be greatly improved, and At the same time, it can significantly reduce the emission of harmful substances.
  • the solution of the present invention is that in addition to consuming air and fuel, reciprocating piston internal combustion engines also need to consume water; in the air compression process and the end of compression of the reciprocating piston internal combustion engine , Or before the fuel is burned, add a proper amount of water to the air of the internal combustion engine, so that the compressed air of the internal combustion engine is mixed with the proper amount of water; and before the fuel is burned, or before the main combustion of the fuel combustion, through direct gas compression, or after compression Pre-combustion makes the water in the combustion chamber of the internal combustion engine reach a supercritical state.
  • the compressed air and supercritical water dissolve in the gaseous state to form a supercritical water mixed gas environment; the fuel burns in the supercritical water mixed gaseous environment; in the fuel combustion process In this, the water in the combustion chamber of the internal combustion engine is maintained in a supercritical water state.
  • the so-called supercritical refers to the state when the pressure and temperature of the fluid exceed the critical pressure and critical temperature.
  • the critical temperature is that every substance has a specific temperature. Above this temperature, no matter how the pressure is increased, the gaseous substance will not liquefy. This temperature is the critical temperature.
  • the critical pressure is the minimum pressure required to liquefy the gas at the critical temperature.
  • the critical temperature of water is 374.3°C, and the critical pressure is 22.1mPa; water that exceeds the critical temperature and critical pressure is supercritical water.
  • the critical temperature of water is generally easy to reach; but because the critical pressure of supercritical water is relatively high, if the engine is restricted by various conditions, the compression ratio may be relatively small, and direct compression is difficult to achieve supercritical water state.
  • It can be pre-combusted with a small amount of fuel after compressing the air. Pre-combustion is to burn a small amount of fuel to preheat and heat, so that the working gas can generate high temperature and high pressure, and the water in the mixed gas can reach supercritical Water state, thus forming a supercritical water mixed gaseous environment.
  • Main combustion refers to the combustion of most or all of the fuel. Most or all of the fuel must be combusted in a supercritical water mixed gaseous environment, which is the core requirement of the solution of the present invention.
  • Supercritical water has many different characteristics. The main characteristics of supercritical water are:
  • the viscosity and diffusion coefficient of supercritical water are close to that of gas.
  • the low viscosity of supercritical water makes supercritical water molecules and solute molecules have a high mobility, solute molecules are easily diffused in supercritical water, so that supercritical water becomes a good reaction medium and has a high diffusion coefficient Conducive to mass transfer and heat exchange.
  • the density of supercritical water can continuously change from a density value similar to steam to a density value similar to liquid, especially near the critical point.
  • the density is very sensitive to changes in temperature and pressure, that is, small changes in temperature or pressure. It can cause greater changes in the density of supercritical water.
  • the constant volume heat capacity and constant pressure heat capacity of supercritical water are much larger than when water is below the critical value, and even the constant pressure heat capacity of supercritical water diverges to infinity at the critical point.
  • the number of hydrogen bonds has a linear relationship with temperature.
  • the ion product increases greatly, that is, it causes a strong dissociation effect.
  • Supercritical water with dissolved oxygen is even stronger than potassium permanganate; many combustible substances can spontaneously combust in supercritical water with dissolved oxygen. It is because supercritical water has extremely strong oxidation reaction characteristics, so supercritical water oxidation (SCWO) is often used in the treatment of sewage, waste, and especially organic waste.
  • SCWO supercritical water oxidation
  • Supercritical water can dissolve many substances (such as oil), and its volume will be greatly reduced when dissolved; supercritical water can be completely miscible with non-polar substances and other organic substances, and can also be completely miscible with air, oxygen, carbon dioxide, etc. in any ratio , Forming a single phase, but the solubility of inorganic substances, especially inorganic salts, in supercritical water is very low.
  • Supercritical water can change the phase behavior, diffusion rate and solvation effect, homogenize the reaction mixture and increase the diffusion coefficient, thereby affecting the phase separation process and product distribution, and accelerating the rate of chemical reactions.
  • Supercritical water has a strong solvent capacity for electrolytes, is conducive to the formation of hydrogen bonds and the generation of free radicals, and is especially suitable for ion reactions.
  • supercritical water When supercritical water is used as the reaction medium, its specific physical and chemical properties will affect the progress of the reaction.
  • the working fluid of the reciprocating piston internal combustion engine is a mixture of supercritical water before and after combustion, and it also possesses the characteristics of supercritical water to varying degrees, especially for a wide range of And extremely strong dissolving ability and compressibility, large constant volume heat capacity and constant pressure heat capacity, extremely strong oxidation ability, accelerating chemical reaction, can be used as a reaction medium and can directly participate in the reaction and other characteristics.
  • the combustion environment of the scheme of the present invention is supercritical water mixed gas.
  • the mixed gas in the combustion chamber contains an appropriate amount of water, and the state of the water in the combustion chamber reaches the supercritical state, making the compressed air and supercritical water a mixed and compatible single-phase gaseous environment;
  • the fuel is directly injected into the combustion chamber at high pressure.
  • the fuel quickly dissolves into the supercritical water mixed gas, and spontaneous combustion occurs in the supercritical water state, making the fuel burn in the supercritical water mixed gas state
  • Supercritical combustion in the environment is a single-phase gaseous (homogeneous gas phase) or supercritical oxidation reaction combustion that tends to a single-phase gaseous state in the mixed gas synthesized by supercritical water dissolution.
  • HCCI homogeneous charge compression ignition
  • the combustion solution of the present invention is to build and form The mixed gaseous environment of supercritical water, and supercritical combustion in this environment is enough, there is no need to particularly consider the mixing process of the fuel, of course, the uniform distribution of the fuel in the mist will make the fuel dissolution process faster, and the effect will definitely be better .
  • the intake port does not need water injection; part of the water is injected and added during the compression process after the valve is closed.
  • the amount of water injection should be such that the compression pressure at the end of compression is the lowest or the critical pressure of water is reached at the latest.
  • the air density is increased by spraying water to cool down. And reduce the pressure to achieve the goal of minimizing the power consumption of the compression process; a part of the water is injected into the cylinder at the end of compression until the fuel is burned, so that the mixed gas working fluid cools and reaches the critical pressure of water, or cools and dissolves, and reaches the critical point of water. After pressure, part of the water and air dissolve each other, converting temperature heat energy into internal energy potential energy.
  • Part of the water can be injected into the cylinder during the combustion process.
  • the temperature or pressure of the combustion working fluid gas is too high, an appropriate amount of water is directly injected into the combustion chamber at high pressure, and the water in the combustion chamber mixed gas remains supercritical
  • the water state and its characteristics do not affect the fuel combustion in the combustion chamber, thereby cooling the combustion working fluid gas, and transforming the working fluid heat energy into supercritical water mixed gas working fluid potential energy storage, increasing the energy storage capacity of the working fluid mixed gas, so that During the combustion process and after the combustion is completed, the temperature of the working fluid gas can be kept relatively low, and the exhaust gas temperature can be lowered.
  • an appropriate amount of water can be injected again.
  • the water does not participate in the combustion, but is only used for cooling, converting the temperature heat energy into the internal energy of the working fluid, and can reduce it The temperature of the exhaust gas.
  • Water has a wide range of sources, relatively cheap, non-toxic and harmless, and water is only used as a medium or equivalent catalyst, which will not cause pollution, and the use of supercritical water can help complete combustion and remove polluting harmful substances, which is beneficial Increase the compression ratio and thermal efficiency; adding more water is conducive to the internal energy storage of the working fluid mixture, enhances the internal energy storage capacity, and reduces the maximum combustion temperature, but too much water will absorb a lot of heat, especially the evaporation of water Heat consumes a lot of heat energy, but it may cause a decrease in the thermal efficiency of the engine.
  • the use of appropriate amount of water refers to the use of water corresponding to this design according to different designs, so that the ability to form a supercritical water mixed gaseous combustion environment and appropriate mixed gas energy storage can be achieved; but too little water will result in temperature and The pressure will be too high, and the maximum combustion temperature and the maximum working fluid gas pressure should be reduced to an appropriate range, so as not to generate excessive pollution and harmful substances and damage the body; and make the thermal efficiency of this design reach a better state, The thermal efficiency will not decrease due to excessive use of water.
  • the exhaust heat and the body's cooling waste heat should be used to preheat the water before spraying, so that the temperature of the water before spraying is increased, the heat consumption is reduced, and the water injected into the cylinder is easier to vaporize; Part of the tail gas can also be directly added to use when inhaling.
  • the waste heat, moisture and even pressure of the tail gas can be used to directly increase the temperature, pressure and moisture of the compressed air, and reduce the loss of water absorption and evaporation heat. Humidity and moisture in the air have a slight impact on the environment where the engine forms a supercritical water mixture.
  • Too much humidity will cause a little more moisture, but the impact will not be too great; but when it rains, the raindrops in the air will cause more moisture in the air. The large impact will cause the air to mix too much moisture, which may affect the formation of the supercritical water state, so the water injection volume of the engine should be properly adjusted in rainy days.
  • the working medium of the reciprocating piston internal combustion engine of the present invention is a mixture of supercritical water, so that the working medium of the internal combustion engine also has the characteristics of supercritical water to varying degrees, which makes the reciprocating piston internal combustion engine of the present invention comparable to previous internal combustion engines. Compared with different advantages, features, functions and effects.
  • the first is the energy storage characteristics of the working fluid. Since the working fluid mixture has the same compressibility and large constant volume heat capacity and constant pressure heat capacity as supercritical water, and because the supercritical water can completely dissolve the compressed air in any proportion, the working fluid mixture gas with appropriate water volume can even It is more compressible than pure supercritical water, so after the mixed gas working medium absorbs a large amount of heat released by fuel combustion, the temperature, pressure and volume of the mixed gas working medium will not change much, or relatively The change is smaller, and almost all heat is converted into the internal energy of the working fluid. The mixed gas working fluid actually becomes an internal energy storage body with little change in temperature, pressure and volume. It can be used under the condition of little change in temperature, pressure and volume.
  • the second is to effectively prevent the occurrence of deflagration and knocking.
  • Deflagration is the rapid and rapid spontaneous combustion of mixed gas, which leads to a sharp rise in local temperature and pressure, resulting in shock waves and knocking combustion phenomena.
  • the occurrence of deflagration is closely related to the rate of pressure increase during combustion, and the occurrence of deflagration is determined by the explosive concentration limit.
  • the mixed gas working fluid of supercritical water has a large constant volume heat capacity and constant pressure heat capacity, so when the fuel is burned, the mixed gas working fluid can absorb a lot of heat under the condition of little change in temperature, pressure, and volume, and supercritical
  • the heat conduction performance of the mixed gas in the water state is extremely strong, so that the pressure rise of the mixed gas working medium is relatively small, that is, the pressure rise rate is not large, so the supercritical water mixed gas working medium can effectively suppress and prevent deflagration and explosion. The occurrence of the earthquake.
  • the third is a higher compression ratio, combustion starting compression pressure (initial combustion pressure) and thermal efficiency.
  • the water before the fuel is burned, the water must reach a supercritical state, that is, the temperature of the mixed gas and water in the combustion chamber must reach the critical temperature of water above 374.3°C, and the pressure must reach the critical pressure of water above 22.1mPa, then If calculated by pure air compression, it is equivalent to a compression ratio of 48 or more.
  • the amount of water calculated as one-tenth of the amount of air by mass gasoline air-fuel ratio is 14.8, diesel air-fuel ratio is 14.3, but diesel engine Generally use an excessive air-fuel ratio, such as 20), and in the state of supercritical water, air can be completely dissolved in water, and water absorbs part of the heat, but when the pressure reaches the critical state of water, it contains a mixture of one-tenth of the amount of water
  • the actual compression ratio of the gas should be around 53. When the compression ratio reaches 53, according to the constant volume heating mode, its theoretical thermal efficiency can reach 72%, and its actual thermal efficiency can reach more than 60%. If the Miller cycle and a larger compression ratio are used, the actual thermal efficiency will be even higher.
  • the adiabatic index of the mixed gas of the working fluid After adding part of the water in the solution of the present invention, the adiabatic index of the mixed gas of the working fluid will be reduced.
  • the adiabatic index of the polyatomic gas is small, and under the same conditions, its thermal efficiency will be reduced;
  • the constant volume heat capacity and constant pressure heat capacity of the working gas It has greater thermal efficiency, and after the supercritical state changes to a non-supercritical state, when the working fluid is released from the dissolved gas, the working fluid will release more internal energy, which cannot be measured by an ideal gas.
  • the compression ratio of gasoline engines is generally between 8-12, the combustion compression pressure (initial combustion pressure) is generally about 0.8-1.3mPa, and the maximum thermal efficiency is 40%; the compression ratio of diesel engines is generally between 11-22. It can reach a maximum of 25, and its combustion compression pressure (initial combustion pressure) before ignition can reach about 3-5mPa, and the pressure before ignition (initial combustion pressure) of a turbocharged diesel engine can even reach 5-10mPa, and its maximum thermal efficiency is about 46%.
  • the lowest compression ratio of the present invention is approximately equivalent to 53, the lowest combustion compression pressure (initial combustion pressure) is 22.1mPa or more, the theoretical thermal efficiency can reach more than 72%, and the actual thermal efficiency can reach More than 60%, each item has been greatly improved, and because the combustion compression pressure (initial combustion pressure) of the engine of the present invention has been maintained above the critical pressure of water, its thermal efficiency is Both can be maintained at a relatively high level, which is especially the advantage of the engine of the present invention over previous engines.
  • the fourth is to have a relatively lower maximum combustion temperature, reducing the production of nitrogen oxides.
  • the production of nitric oxide changes exponentially with temperature. When the temperature is lower than 1800K, the production rate of nitric oxide is extremely low.
  • the initial temperature and compression pressure before the fuel combustion are relatively high, because part of the water is added and the water is in the state of supercritical water, the constant volume heat capacity and constant pressure heat capacity of supercritical water The temperature of the supercritical water mixed gas working fluid will not rise significantly.
  • the quantity of the working fluid has increased, and its specific heat capacity has increased a lot, and its combustion is equivalent to Because of the autoclave heating model, the combustion temperature must be increased relatively less, and it can have a relatively lower maximum combustion temperature, thereby reducing the generation of nitrogen oxides and reducing the emission of harmful substances.
  • the fifth is more complete fuel combustion.
  • Supercritical water with dissolved oxygen has a strong oxidizing ability.
  • the supercritical water mixed gas used as a working fluid also has a strong oxidizing ability. It is easier to chemically react with fuel, and the combustion reaction will be faster and more complete. thorough.
  • hydrocarbons, carbon crystal particles, carbon monoxide, etc. are all prone to spontaneous combustion and combustion, and it is almost impossible to leave residues. It can effectively reduce carbon monoxide (CO), carbon crystal particles (PM) and hydrocarbons.
  • the generation of pollutants such as chemical compounds (HC) reduces harmful emissions.
  • Supercritical water's strong oxidizing ability will not increase the emission of nitrogen oxides.
  • Supercritical water oxidation is usually used for waste treatment and does not generate harmful emissions of nitrogen oxides.
  • SCWO Supercritical water oxidation
  • the supercritical water mixture has strong oxidizing properties, it may cause oxidative corrosion to the engine body. Therefore, the materials of the engine need to have oxidation and corrosion resistance, which will increase the cost of the engine.
  • the sixth is lower exhaust temperature. Due to the decrease in the maximum combustion temperature and the increase in the amount of the working fluid, the heat energy can be greatly converted into the working fluid potential energy to perform work, so that the exhaust gas temperature is relatively reduced.
  • the seventh is stronger motivation.
  • the highest pressure of the fuel engine generally does not exceed 16mPa.
  • the highest pressure of the engine of the present invention is not lower than the critical pressure of water 22.1mPa, which is much higher than the previous engine, so the average pressure of the engine of this program is also much higher. , Especially for low-speed engine power will be more obvious enhancement.
  • the eighth is greater power per liter. Since the combustion compression pressure (initial combustion pressure) of the engine of the present invention is relatively much larger, the compressed air contained in the engine of the present invention for the same compressed space (or the same compression ratio) in each working cycle Much more, so much more fuel can be burned, and its power per cycle is also greater.
  • the proposed engine of the present invention runs in a supercritical water mixed gas environment and high pressure, and the combustion reaction is more rapid, the combustion time can be greatly shortened, and the engine speed can be increased, and the engine power per liter can be increased. Engines with a higher liter power are especially suitable for the aviation field and are of great significance.
  • the ninth is the wide variety of available fuels. Due to the strong oxidation, compressibility and storage internal energy characteristics of the supercritical water mixed gas working medium, the internal combustion engine of the present invention can use different kinds of fuels and fuels, gasoline, diesel, methanol gasoline, and even Mixed fuel of various fuels. Of course, since the combustion characteristics of different fuels are also different, the characteristics of the internal combustion engine should be adjusted and controlled according to the characteristics of the fuel. For example, different fuels require different combustion times and their engine speeds should also have different limits. Especially for heavy oil fuel oil engines used in ships, the solution of the present invention is of great significance to its improvement, and can obviously increase its speed and power.
  • the strong oxidizing properties of the supercritical water mixed gas working fluid can make the use of fuels also broad. Carbon powder, coal powder, even starch, cellulose and other biomass can be directly used as fuel after being crushed or made into liquid. The burning substances in the supercritical water mixed gas working medium can be used as the fuel of the engine, opening up a wide range of fuel sources.
  • the tenth is a fuel case that needs special explanation.
  • the engine designed and manufactured using the scheme of the present invention can be used as an ideal fuel with liquid ammonia, which can achieve zero pollution and zero carbon emissions.
  • liquid ammonia is used as fuel
  • the cost of the engine designed and manufactured using the scheme of the present invention is equivalent to that of fuel.
  • liquid ammonia fuel After the combustion of liquid ammonia fuel, only water and nitrogen will be generated, which can truly achieve zero pollution and no carbon emissions, and the liquid ammonia fuel can be Through water and air production, liquid ammonia is easy to safely transport and store.
  • the use of liquid ammonia fuel engines can efficiently and ideally realize pollution-free energy circulation, and can easily, efficiently and widely carry out energy conversion, transportation and storage.
  • the engine generates electricity to form a pollution-free and ideal energy storage energy cycle, which has high energy storage efficiency, safety and reliability, and greatly saves space in use.
  • liquid ammonia will become an ideal fuel.
  • the internal combustion engine of the scheme technology of the present invention using liquid ammonia fuel can truly achieve zero pollution and no carbon emissions, and the liquid ammonia fuel is easy to manufacture, safe and transportable.
  • Storage is an ideal energy cycle fuel. Its manufacturing and transportation costs are much cheaper than hydrogen fuel, and transportation and storage are relatively more convenient and safer.
  • future gas stations only need to drill a well and power source to continuously produce liquid ammonia fuel on demand, no longer need long-distance transportation like fuel oil, and even future technological development can realize home-based liquid ammonia production. In this way, the liquid ammonia fuel can completely get rid of the dependence on petroleum fuels and expensive batteries, and the use is safer and more reliable, more environmentally friendly, and cheaper.
  • the energy storage characteristics of the supercritical water mixed gas working medium make the fuel combustion and working medium work process similar to, or even better than, the isobaric heating mode, with relatively greater thermal efficiency.
  • the engine power per liter is greater.
  • a wide variety of fuels can be used, opening up a wide range of fuel sources.
  • liquid ammonia can be used as an ideal fuel, zero pollution and zero carbon emissions can be realized at low cost, and safe, reliable, low-cost, high-efficiency, and convenient energy conversion, transportation, storage and use cycles can be realized.
  • the implementation example of the present invention uses a turbocharged diesel engine as an engine prototype, and design improvements are made on this basis.
  • the specific design and manufacturing improvement of this example is based on the existing exhaust turbocharged diesel engine, the engine is a 1.6-liter displacement four-cylinder reciprocating piston engine, 0.4 liter displacement per cylinder, and an electric turbocharger is added.
  • the engine adopts a cast iron alloy body, which can withstand a pressure of more than 30mPa.
  • the piston is flexible
  • the piston elastic initial compression pressure to 22.5mPa
  • the maximum piston elastic compression pressure to 26mPa
  • the static compression ratio to 60 (the compression ratio when the piston does not become elastically longer).
  • the dynamic compression ratio before combustion can be The air intake is automatically adjusted between 8--60 as needed. After the fuel is burned, it can expand to 3/8 of the piston stroke (that is, the maximum compression length of the piston is 43/120 of the cylinder volume).
  • the initial expansion ratio (pre-expansion ratio or pre-expansion ratio) at the minimum compression ratio is 3, that is, the maximum expansion of combustion at the minimum compression ratio is 3 times;
  • the use of an elastic variable-length piston on the one hand helps prevent the body from pressure overload.
  • the amount of injected water involved in combustion is one-tenth of the mass of compressed air, and the water is injected during the air compression process after the intake valve is closed.
  • the amount of water injected before the fuel is burned is one-tenth of the mass of air. 1. No more water spray after the combustion starts; the total spray volume is one-tenth of the air volume. If the air-fuel ratio is 20, the total spray water quality is twice the fuel quality.
  • the engine of this example must work in a supercritical water mixed gaseous environment, so a supercritical water mixed gas environment must be formed before each combustion, and the intake air volume and water injection volume for each cycle of combustion have the lowest requirements.
  • the minimum intake air volume is equivalent to the actual compression ratio should not be lower than 54 (by calculation, it should be approximately 53, but considering the mechanical precision and cylinder seal For reasons such as performance, the actual intake air volume should be slightly more), that is, the intake air volume per cylinder per cycle should not be less than:
  • the minimum amount of spray water each time is approximately:
  • the maximum intake air volume is when the minimum compression ratio is equal to 8, its compression pressure (pre-combustion pressure) is 23.56mPa, the volume is 0.05 liters, the air volume is approximately 3.28 grams, the water injection volume is approximately 0.328 grams, and the available fuel volume is approximately 0.164 gram.
  • the fuel injection volume can be 0 to one twentieth of the air volume.
  • the fuel can be liquid ammonia, gasoline, diesel, kerosene, methanol gasoline, etc., or a mixed fuel mixed with a variety of fuels.
  • the operation of the engine in this example The four stages of the engine cycle process are intake, air compression, combustion and expansion, and exhaust.
  • the intake phase the exhaust valve is closed and the intake valve is opened.
  • the piston descends to perform the intake process; when the minimum intake volume is used, the equivalent compression ratio is 54 and the intake volume is 0.36 liters; specific requirements
  • the gas volume can be adjusted by exhaust turbocharger and electric turbocharger.
  • the intake valve is closed first, and then the corresponding amount of water is sprayed according to the amount of intake air, and then the air is compressed until the piston reaches the top dead center at the end of compression, forming a supercritical water state mixed gas environment;
  • the compression ratio is 54
  • the air intake is 0.36 liters
  • the water injection volume is 0.042 g.
  • the temperature of the mixture is about 1218.5K and the pressure is about 22.1mPa, reaching the state of supercritical water.
  • the fuel is injected first (when the minimum air intake is used, the fuel can be 0-0.021g), the fuel is quickly dissolved in the mixed gas, and supercritical combustion is carried out in the supercritical water mixed gas environment ,
  • the heat energy of combustion is quickly converted into the internal energy of the gas working fluid (if cooling and pressure reduction are required, you can continue to spray an appropriate amount of water to cool down the temperature and pressure and increase the capacity of the working fluid to store energy).
  • the combustion products include water and carbon dioxide. Dissolve quickly in the working fluid mixture, the temperature of the working fluid rises, the pressure also increases, and the length of the elastic piston is quickly compressed; as the fuel burns and the crankshaft rotates, the piston moves linearly to push the connecting rod and crankshaft to do work.
  • the length of the piston elastically recovers, before reaching the critical point of water, it is equivalent to a similar isobaric heating process; after the pressure of the working fluid mixture reaches the critical point of water, the mixed gas is dissolved out, and the working fluid gas continues to push the piston to do work.
  • the piston is close to reaching bottom dead center.
  • the exhaust valve In the exhaust phase, when the piston approaches the bottom dead center, the exhaust valve is opened, and the working fluid gas is pushed by the piston to perform an exhaust process. At this point, the engine completes a working cycle process, and continues to circulate to continue the operation of the engine.
  • the thermal efficiency estimate can be calculated according to the compression ratio; according to the compression ratio of 54 and the isobaric heating mode, the theoretical thermal efficiency can reach more than 72%, and the actual maximum thermal efficiency can reach more than 60%; while the current maximum thermal efficiency of gasoline engines is about 40%.
  • the maximum thermal efficiency of the diesel engine is about 46%; and different from the previous engine, because the actual compression ratio of this example is not less than 54, and the compression pressure is maintained above the critical pressure of water, the engine of this example is in most operating conditions.
  • the internal energy is not much different from the maximum thermal efficiency, and it maintains a relatively high thermal efficiency under most working conditions (this is also mainly due to the application of the dynamic compression ratio in this example), which is especially useful for the use under diversified working conditions such as automobiles
  • the benefits will be particularly significant.
  • the maximum power increase can be estimated based on the maximum intake air volume and maximum speed per cycle; in the past, the pressure before ignition of gasoline engines is generally between 0.8-1.3mPa, and the compression ratio is generally between 8-12. This is to simplify the calculation. , Take the pressure before ignition of 1.3mPa and the minimum compression ratio of 8 as the maximum intake air volume; diesel engines generally have a pressure of 3-5mPa before ignition, and a compression ratio of 11-22.
  • the pressure before ignition is 5mPa
  • the minimum compression ratio is 11 as the maximum intake air volume.
  • the maximum speed of a gasoline engine is usually twice as large as that of a diesel engine.
  • the maximum pressure before fire is 23.56mPa and the minimum compression ratio is 8 as the maximum intake air volume.
  • the maximum speed is basically the same as that of the gasoline engine; rough calculation (calculated based on the ideal gas pure air) can get the ratio of the maximum air intake of the gasoline engine, the diesel engine and the engine of this example is 12.63:24.03:100, if you simply press the same air Fuel ratio calculation, the ratio of the three liters of power is approximately 12.63:12.02:100; that is to say, the maximum air intake in this example is more than 7.9 times that of a gasoline engine, which is more than 4 times that of a diesel engine, and the maximum power of this example is also It is more than 7.9 times that of gasoline engines and 8.3 times that of diesel engines.
  • the power comparison can be roughly based on the highest pressure; the highest pressure of a general gasoline engine is 3-8.5mPa, and the highest pressure of a diesel engine is 7-16mPa.
  • the initial combustion pressure of this example will not be lower than 22.1mPa, and the highest pressure can even be Up to 26mPa, the average pressure of the engine is closely related to its maximum pressure.
  • the maximum pressure of this example is much higher than that of gasoline and diesel engines, so the power of this example engine is also much greater than that of gasoline and diesel engines.
  • the solution of the present invention requires the use of various materials that are resistant to oxidation, corrosion and high strength.
  • the corresponding materials are widely used in supercritical water sewage and waste treatment, and do not exceed the standards of existing materials; on the basis of existing internal combustion engines, the design And process reform is relatively simple and easy, the manufacturing cost is not high, it can greatly improve the compression ratio, thermal efficiency, power performance and power of the internal combustion engine, can reduce and control the maximum temperature and pressure of combustion, and can greatly reduce the harmful substances at the same time. Emissions can even achieve zero pollution and zero carbon emissions, and can use a wide variety of fuels, suitable to replace existing internal combustion engines, and have strong practicability.
  • the technical solution of the present invention will definitely be the development direction of internal combustion engines.

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Abstract

本发明是一种超临界水燃烧环境往复活塞式内燃机及其燃烧方法，通过建造超临界水混合气体燃烧环境和使用超临界燃烧的燃烧方案，使得往复活塞式内燃机大幅度提高压缩比、燃烧压缩压力、热效率和升功率，大幅度增强发动机的动力，实现更完全的燃料燃烧，有效减少污染有害物排放，并且可以使用广泛的多种燃料；本发明技术方案，液氨可以作为理想的燃料，可以低成本实现零污染、零碳排放，可以实现安全可靠、低成本、高效率、便利的能量转换、运输、存储和使用循环。

Description

一种超临界水燃烧环境往复活塞式内燃机及其燃烧方法 技术领域
本发明涉及一种往复活塞式内燃机，尤其是涉及往复活塞式内燃机的燃烧环境及其燃烧方法。
 背景技术
往复活塞式内燃机是指活塞在气缸内作往复直线运动的活塞式内燃机。四冲程往复活塞式发动机的工作过程是，由活塞运动形成进气、空气压缩、燃烧和膨胀做功、排气四个有序步骤形成一个工作循环，不断重复循环就形成其工作过程。往复活塞式内燃机以空气为氧化剂，消耗的燃料主要是燃油或燃气。往复活塞式内燃机按着火方式可以分为点燃式和压燃式两类，主要分别是汽油机和柴油机。
现在的汽油机热效率一般为35%左右，最高可达到40%左右，柴油机热效率一般为40%左右，最高可达到46%左右。往复活塞式内燃机发展了一百多年，各项技术相对成熟，但热效率却不高，想要进一步提高热效率十分困难。
往复活塞式内燃机的排放物会造成环境污染，排放的有害物质主要有：硫氧化物（主要为二氧化硫SO 2）、一氧化碳（CO）、氮氧化物（NO x）、碳氢化合物（HC）、颗粒物（PM）、臭气（主要为各种不完全燃烧的产物，如各种醛类）、二氧化碳（CO 2）等，还有噪音污染。对于汽油机和柴油机，主要的有害排放物是氮氧化物(NO x)、一氧化碳（CO）、颗粒物（PM）和碳氢化合物（HC）等。国际上很多国家为了减少环境污染和保护环境，制定和实施了各自的排放标准，并且排放标准的要求越来越严格。排放标准的实施对发动机的热效率和设计等有所限制。
理论上压缩比是影响往复活塞式内燃机热效率的主要因素，压缩比越大，热效率就越高。目前汽油机的压缩比普遍在8—12之间，最高的马自达发动机压缩比甚至达到14；柴油机的压缩比目前普遍为11—22之间，最大甚至可达到25。
但要增大压缩比受到多方面的限制。首先，是机体材料的限制；特别是汽油机，较大的压缩比会导致汽油燃烧更加剧烈，并产生高温高压，容易产生爆燃，引起发动机爆震，从而损害发动机的机体。第二，是在高温高压环境下，容易产生有害污染物；高温更容易产生氮氧化物（NO x），有研究表明，当温度低于1800K时，氮氧化物（NO x）的生成速率极低，因此有的设计为了能达到更高的气缸压力，使用了排气后处理的催化还原技术（SCR），甚至使用了降低空燃比和排气再循环技术（EGR），随着燃烧氧气量的减少，确实可以提高气缸压力和减少氮氧化物的产生，但由于缺氧燃烧却又容易生成一氧化碳，增加了新的有害排放物，所以，随着排放法规的日益严格，在现有的技术条件下，压缩比适当下调才更有利于降低氮氧化物和一氧化碳的生成，适当降低效率才能有效减少有害排放，故而现在有很多柴油机设计其压缩比在16左右，其压缩比与以前比较有所下降，以降低内燃机热效率来达到减少有害排放的目的。第三，是升功率和动力需求的限制；当前，往复活塞式内燃机一般设计为固定压缩比的方式，可调节压缩比发动机由于结构复杂而较少得到应用；在固定压缩比方式下，压缩比通常要考虑最大负载和动力情况下进行设计，过高的压缩比会导致进气时压缩的空气量较少，从而限制发动机的负载量和每次燃油量，导致功率和动力不足，负载过低就很难达到设计的要求，所以一般带有增压的汽油机和柴油机的压缩比通常都较低一些，以满足发动机较大功率和较大动力的要求。
在实际发动机的设计中，主要是受限于最高温度和最高压强的限制，以符合越来越严格的排放标准，同时对发动机的升功率和动力也存在较大的要求，这些限制和需求使得内燃机热效率的提高变得极为困难。特别是往复活塞式发动机技术相对成熟，很多新技术都得到了应用，在符合越来越严格排放标准的情况下，即使想要内燃机热效率作一点点的提高也变得极为艰难。
通过改善往复活塞式内燃机的燃烧可以减少废气污染物。为了改善内燃机的燃烧，出现了各种各样的燃烧技术，比如柴油机的直喷式油膜雾化燃烧，柴油机进气道喷水燃烧技术，将燃料以超临界状态供给到内燃机的燃烧技术，还有将燃料以水乳化后供给到内燃机的燃烧技术，以及将燃料混合水达到超临界状态后供给到内燃机的燃烧技术等等，都能够在一定程度上有所改善了燃烧效果，但总的结果仍难以达到理想的状况，比如进气道喷水燃烧技术，确实可以减少发动机氮氧化物的生成，但又会提高一氧化碳（CO）、颗粒物（PM）和碳氢化合物（HC）的排放，想要进一步减少废气污染以达到理想状态也将会十分困难。
总而言之，如何提高往复活塞式内燃机的热效率和减少有害物的排放以达到理想状况仍然是当前难以解决的问题。
 
参考文献：
1. 《超临界水的特性及应用》 ，化学工业与工程 第20卷第1期，作者：天津大学理学院----张丽莉，陈丽，赵雪峰，于琳，田宜灵。
2.  《内燃机及其设计制造方法》 ，专利申请文件，申请国别：中国，申请号：2018112190950，发明人：刘金宏，公告号：CN110344939A，公告日期：2019年10月18日。
 技术问题
如何提高内燃机热效率和有效减少有害排放是当前内燃机设计和制造难以解决的难题。
 技术解决方案
为了解决往复活塞式内燃机热效率低下和减少有害物排放的难题，本发明提供了一种内燃机的新方案，通过建造完全不同的新式燃烧环境和燃烧方案，可以大幅度提升往复活塞式内燃机热效率，并且能够同时有效地大幅度降低有害物的排放。
与传统的往复活塞式内燃机只消耗空气和燃料有所不同，本发明方案是，往复活塞式内燃机除了需要消耗空气和燃料之外，还需要消耗水；在往复活塞式内燃机空气压缩过程和压缩末期，或者在燃料燃烧之前，在内燃机空气中加入适量的水，使得内燃机的压缩空气与适量水混合；并且在燃料燃烧之前，或者是燃料燃烧的主燃烧之前，通过直接气体压缩，或者压缩后再预燃烧，使得内燃机燃烧室内的水达到超临界状态，压缩空气与超临界水在气态下相溶，形成超临界水混合气体环境；燃料在超临界水混合气态环境中进行燃烧；在燃料燃烧过程中，内燃机燃烧室内的水保持为超临界水状态。
所谓超临界是指流体所处的压力和温度均超过临界压力和临界温度时的状态。临界温度就是，每种物质都有一个特定的温度，在这个温度以上，无论怎样增大压强，气态物质都不会液化，这个温度就是临界温度。临界压力是在临界温度时使气体液化所需要的最小压力。水的临界温度为374.3℃，临界压力为22.1mPa；超过临界温度和临界压力的水就是超临界水。
可以通过对空气和水的混合气体直接压缩，使混合气体中的水达到超临界水状态，形成超临界水混合气态环境。通过空气压缩，水的临界温度一般都容易达到；但由于超临界水的临界压力比较高，如果发动机由于各种条件的限制，可能导致压缩比相对较小，直接压缩难以达到超临界水状态时，可以通过在压缩空气后，以少量部分燃料进行预燃烧，预燃烧就是先用少量的燃料燃烧进行预热加温，使工质气体产生高温和高压，并使得混合气体中的水达到超临界水状态，从而形成超临界水混合气态环境。主燃烧是指主要大部分燃料或全部燃料所进行的燃烧。主要大部分或全部燃料的燃烧必须在超临界水混合气态环境中进行，这是本发明方案的核心要求。
超临界水具有很多不同的特性，超临界水主要特性有：
1、高扩散系数和极低粘度。
超临界水的粘度和扩散系数接近于气体。超临界水的低粘度使超临界水分子和溶质分子具有较高的迁移率，溶质分子很容易在超临界水中扩散，从而使超临界水成为一种很好的反应媒介，并且高的扩散系数有利于传质和热交换。
2、可压缩性。
超临界水的密度可从类似于蒸汽的密度值连续地变到类似于液体的密度值，特别是在临界点附近，密度对温度和压力的变化十分敏感，也就是温度或压力的较小变化可引起超临界水的密度发生较大的变化。
3、恒容热容和恒压热容很大。
超临界水的恒容热容和恒压热容比水处于临界值之下时大得多，甚至超临界水的恒压热容在临界点时几乎发散到无穷大。
4、氢键数量与温度呈线性关系。
在超临界情况下，温度的升高能快速地降低氢键的总数，水在超临界状态时，大部分的氢键都断裂了，氢键不到常温的三分之一。
5、极强导热性。
超临界水具有极强的导热性能。
6、离子积大增，即引起很强的离解作用。
即使在中等温度和密度条件下，超临界水的离子积也比标准状态下水的离子积高出几个数量级。
7、极强的氧化能力。
溶解了氧气的超临界水，其氧化性甚至强于高锰酸钾；很多可燃物质都可以在溶解了氧气的超临界水中发生自燃。正是超临界水具备极强的氧化反应特性，所以超临界水氧化法(SCWO)常用于污水、废物、特别是有机废物的处理。
8、广泛和极强的溶解能力。
超临界水可以溶解很多物质（比如油），且在溶解时体积会大大缩小；超临界水能与非极性物质和其他有机物完全互溶，也能与空气、氧气、二氧化碳等以任意比例完全互溶，形成单一相，但无机物特别是无机盐类在超临界水中的溶解度很低。
9、加快化学反应速率。
超临界水可改变相行为、扩散速率和溶剂化效应，使反应混合物均相化，增大扩散系数，从而影响相分离过程和影响产物分布，加快化学反应的速率。
10、既可作反应介质，又可以直接参加反应。
超临界水对电解质具有很强的溶剂能力，有利于氢键的形成和游离基的生成，特别适合于离子反应。超临界水作为反应介质时，其特定的物理和化学性质都会影响反应的进行。
以上说明了超临界水的特性，在本发明方案中，往复活塞式内燃机工质在燃烧前后都是超临界水的混合气体，也同样不同程度具备了超临界水的各项特性，特别是广泛和极强的溶解能力和可压缩性、很大的恒容热容和恒压热容、极强的氧化能力、加快化学反应、既可作反应介质又可以直接参加反应等特性。
本发明方案的燃烧环境是超临界水混合气体。往复活塞式内燃机在燃料燃烧之前，燃烧室的混合气含有适量的水，并且燃烧室内水的状态达到超临界状态，使得压缩空气与超临界水成为混合相溶的单一相气态环境；在燃料燃烧过程中，将燃料直接高压喷入燃烧室，由于超临界水的特性，燃料迅速溶解进入超临界水混合气体中，并且在超临界水状态下发生自燃，使得燃料在超临界水的混合气态燃烧环境中进行超临界燃烧，是在超临界水溶合成的混合气体中进行单一相气态(气相均相)或趋向单一相气态的超临界氧化反应燃烧。
以往的内燃机燃烧方案都是以均质充量压燃(HCCI)作为燃烧的标准终极目标，各种燃烧技术方法都是以燃料均匀分布的均质预混合作为追求目标，不均质的燃烧容易形成不完全燃烧，生成碳晶颗粒、一氧化碳等污染物。本发明方案则无需以追求燃料的预均匀分布作为目标，由于超临界水混合气体具有极强的溶解能力和极强的氧化能力，还有极强的扩散特性，本发明的燃烧方案就是建造形成超临界水的混合气态环境，并在此环境进行超临界燃烧就可以了，不需要特别考虑燃料的混合过程，当然燃料以雾状均匀分布会使得燃料的溶解过程更加迅速，效果肯定会更好。
喷水的时机、方案和策略。进气道不需要喷水；一部分水在关闭气门后的压缩过程中进行喷射加水，喷水量应当使得压缩末期压缩压力最低或者使得最迟达到水的临界压强，通过喷水降温来增加空气密度和减少压力，以达到压缩过程功耗最小的目标；一部分水在压缩末期至燃料燃烧前喷入气缸，使得混合气体工质降温并达到水的临界压力，或者降温并溶解，在达到水的临界压力后，部分水与空气互溶，将温度热能转化为内能势能。
一部分水可在燃烧过程中喷入气缸。在往复活塞式内燃机燃烧室的燃烧过程中，当燃烧工质气体的温度过高时或压强过高时，在燃烧室直接高压喷入适量水，并使得燃烧室混合气体中的水保持超临界水状态及其特性，不影响燃烧室的燃料燃烧，从而对燃烧工质气体降温，并将工质热能转化为超临界水混合气体工质势能存储，增加工质混合气体储能的能力，使得燃烧过程中和燃烧完成后能够保持相对较低的工质气体温度，并且使得排放的尾气温度更低。
在燃料燃烧完成后，或者压力降低到水临界点附近时，可以再次喷入适量水，此时的水不参与燃烧，只是用于降温，将温度热能转化为工质内能势能，并可以减低尾气的温度。
水来源广泛，相对价格便宜，无毒无害，而且水只是作为中介质或相当催化剂使用，不会造成污染，而且使用超临界水有助于完全燃烧和去除有污染性的有害物，有利于增加压缩比和热效率；加入较多的水有利于工质混合气的内能存储，增强内能存储的能力，降低最高燃烧温度，但过多的水会吸收大量的热量，特别是水的蒸发热会消耗大量热能，反而可能会导致发动机热效率的下降。使用适量的水是指，根据不同的设计，使用与此设计相对应的用水量，使得可以达到形成超临界水混合气态燃烧环境和适当的混合气体储能的能力；但水量过少则温度和压力就会过高，并且要使得最高燃烧温度和最高工质气体压力降低到在适当的范围内，不至于生成过量的污染有害物和损坏机体；并且使得此设计的热效率达到比较好的状态，不会由于使用过量的水而导致热效率的下降。为了充分利用热能，在喷水前，应当利用尾气热量和机体的降温余热对水进行预加热，使得喷水前的水温度提升，减少消耗热量，使得喷射进气缸的水更容易汽化；发动机在吸气时也可以直接加入部分尾气使用，可以利用尾气的余热和水分甚至压力，直接提高压缩空气的温度、压力和水分，减少水吸收蒸发热的损耗。空气中的湿度水分对发动机形成超临界水混合气体状态环境有轻微的影响，湿度太大会造成水分稍多，但影响不会太大；但下雨时空气中的雨滴对空气的水分会造成较大的影响，会导致空气混合水分过多，可能会影响超临界水状态的形成，所以在下雨天应当对发动机的喷水量进行适当的调节。
 有益效果
本发明方案往复活塞式内燃机的工质是超临界水的混合气体，使得内燃机工质也不同程度地具备超临界水的各项特性，也就使得本发明方案往复活塞式内燃机与以往的内燃机相比具有不同的优势特性、功能和效果。
第一是工质的储能特性。由于工质混合气体与超临界水一样具有可压缩性和很大的恒容热容和恒压热容，并且由于超临界水可以完全以任意比例溶解压缩空气，适当水量的工质混合气体甚至要比纯超临界水的可压缩性更高，所以混合气体工质在吸收燃料燃烧放出的大量热量后，混合气体工质的温度、压强和体积并不会有很大的改变，或者说相对变化更小，热量几乎都转化为工质内能，混合气体工质实际上成为了温度、压强和体积都变化不大的内能存储体，在温度、压强和体积变化不大的情况下可以吸收很多热能并转化为内能；燃料燃烧一般会生成水和二氧化碳，在超临界水的混合气体环境状态下，燃烧生成的水和二氧化碳会在工质超临界水的混合气体中相互溶解融合，使得整体工质温度、压强、体积变化不大，但工质内能增加；根据可压缩性，反过来，当工质体积增大时，其压强变化也相对不那么大，并释放内能做功；当工质状态低于水的临界值时，工质中相互溶解融合的空气、水和二氧化碳等气体从溶解中释出，工质会在相对较高压强情况下进一步释放内能做功，在非超临界水状态下，其他气体与水汽难以相溶，相当于气体中物质的量增加了，必定能以更大的压强做功；在超临界水的混合气体环境情况下，燃料燃烧和工质做工过程类似于、甚至更优越于等压加热模式，具有相对更加大的热效率。
第二是有效防止爆燃和爆震的发生。爆燃是混合气体快速急剧自燃的剧烈燃烧，导致局部温度和压力的急剧陡升，产生冲击波和爆震的燃烧现象。爆燃的发生与燃烧时的压力升高率密切相关，并且爆燃发生由爆炸浓度极限所决定。超临界水的混合气体工质具有很大的恒容热容和恒压热容，故燃料燃烧时混合气体工质可以在温度、压强、体积变化不大的情况下吸收很多热量，并且超临界水状态下的混合气体导热性能极强，使得混合气体工质压强升高相对并不多，也就是其压力升高率不大，所以超临界水混合气体工质能够有效抑制和防止爆燃和爆震的发生。
第三是更高的压缩比、燃烧起始压缩压力(始燃压)和热效率。在本发明方案中，在燃料燃烧前，水必须达到超临界状态，也就是燃烧室混合气体和水的温度必须达到水的临界温度374.3℃以上，压力必须达到水的临界压力22.1mPa以上，那么如果以纯空气压缩计算，就相当于压缩比为48以上，如果加入小部分水，比如以质量计算为空气量十分之一的水量(汽油的空燃比为14.8，柴油空燃比为14.3，但柴油机一般使用过量的空燃比，比如20)，并且在超临界水状态下，空气可完全溶于水，并且水吸收了一部分热量，但当压强达到水临界状态时，包含十分之一水量的混合气体实际压缩比应当在53左右。当压缩比达到53时，按等容加热模式，其理论热效率可以达到72%，其实际热效率可达60%以上，如果使用米勒循环和更大的压缩比，实际热效率还要更高。在本发明方案加入部分水后，工质的混合气体的绝热指数会减小，一般来说，在理想气体状态下，多原子气体的绝热指数较小，在同等条件下，其热效率会降低；但在超临界水混合气体状态下，其工质气体恒容热容和恒压热容很大，在温度和压强变化不大的情况下，其压缩率和膨胀率很大，所以工质气体有更大的热效率，并且在超临界状态变化为不是超临界状态后，工质气体从溶解气体释出时，工质会释放更多的内能，这不能以理想气体来衡量。相比以往的发动机，汽油机的压缩比一般为8—12之间，燃烧压缩压力(始燃压)一般为0.8—1.3mPa左右，最高热效率为40%；柴油机的压缩比一般为11—22之间，最大可达到25，其着火前燃烧压缩压力(始燃压)可达3—5mPa左右，增压柴油机的着火前压强(始燃压)甚至可以达到5—10mPa，最高热效率为46%左右；但与本发明方案的水临界状态相比，本发明方案最低压缩比约相当于53，最低燃烧压缩压力(始燃压)为22.1mPa以上，理论热效率可达72%以上，实际热效率可达60%以上，各项都有了极大的提高，并且由于本发明方案发动机的燃烧压缩压力(始燃压)一直都保持在水的临界压力之上，在大部分的工况下，其热效率都可以保持在比较高的水平，这尤其是本发明方案发动机比以往发动机更显优势之处。
第四是具有相对更低的最高燃烧温度，减少氮氧化物的生成。一氧化氮的生成随温度呈指数函数变化关系，当温度低于1800K时一氧化氮的生成率极低。在本发明方案中，虽然在燃料燃烧前的起始温度和压缩压力都比较高，但由于加入了部分水，并且水处于超临界水状态，超临界水的恒容热容和恒压热容都很大，所以超临界水混合气体工质的温度不会大幅上升，相对于同样条件的以往内燃机来说，工质的物质的量增加了，而且其比热容增加很多，并且其燃烧相当于等压加热模型，故其燃烧温度必定增加得比较少，也就可以有相对更低的最高燃烧温度，从而减少氮氧化物的生成，减少有害物的排放。
第五是更完全的燃料燃烧。溶解了氧气的超临界水具有极强的氧化能力，同样地，作为工质的超临界水混合气体也具有很强的氧化能力，更容易与燃料产生化学反应，燃烧反应会更迅速、更完全彻底。在超临界水混合气体环境下，碳氢化合物、碳晶颗粒、一氧化碳等都很容易发生自燃和燃烧，几乎不可能残留剩余，可以有效减少一氧化碳（CO）、碳晶颗粒物（PM）和碳氢化合物（HC）等污染物的生成，减少有害排放。超临界水极强的氧化能力不会增加氮氧化物的排放，超临界水氧化法(SCWO)通常用于废物处理，并不会生成氮氧化物的有害排放。但由于超临界水混合气体具有强氧化性，可能对发动机的机体造成氧化腐蚀，所以发动机的材料需要具备抗氧化腐蚀性，这会增加发动机的成本。
第六是更低的排气温度。由于最高燃烧温度的降低，以及工质的物质的量增加，可以极大地将热能转化为工质势能做功，使得排气温度相对降低得多。
第七是动力更强。以往的燃油发动机最高压强一般不超过16mPa，本发明方案发动机最高压强不低于水的临界压力22.1mPa，相比以往的发动机要高得多，故本方案发动机的平均压强压力也要高得多，特别地对于低速时发动机的动力会有更明显的增强。
第八是升功率更大。由于本发明方案发动机的燃烧压缩压力(始燃压)相对要大得多，所以在每工作循环，对于相同的压缩后空间(或者说是相同压缩比)，本发明方案发动机所容纳的压缩空气要多得多，可以燃烧的燃油也就多得多，其每循环功率也就更大。本发明方案发动机运行在超临界水混合气体环境和高压下，燃烧反应更加迅速，可以极大地缩短燃烧时间，从而可以提高发动机转速，增加发动机升功率。升功率更大的发动机尤其适用于航空领域，意义重大。
第九是广泛多样的可用燃料。由于超临界水混合气体工质的强氧化性、可压缩性和存储内能的特性，本发明方案内燃机可以使用不同的各种燃油和燃料，可以使用汽油，也可以使用柴油、甲醇汽油、甚至各种燃油的混合燃料。当然，由于各种不同燃料的燃烧特性也有不同，应该根据燃料的特性来调整和控制内燃机的各项特性，比如不同燃料其燃烧需用时间不同，其发动机转速也应有不同的限制。特别地对于船舶使用的重油燃油发动机，本发明方案对其改进有重大意义，可以明显增加其转速和升功率。超临界水混合气体工质的强氧化性可以使得燃料的使用也具备广泛性，碳粉、煤粉、甚至淀粉、纤维素等生物质粉碎或制成液体后也可以直接作为燃料，只要可以在超临界水混合气体工质中进行燃烧的物质都可以作为发动机的燃料，开辟了燃料来源的广泛途径。
第十是需要特别说明的燃料案例，使用本发明方案设计制造的发动机，液氨可以作为理想的燃料，可以实现零污染、零碳排放。使用液氨作为燃料时，使用本发明方案设计制造的发动机，其使用成本与燃油相当，液氨燃料燃烧后只会生成水和氮气，能够真正实现零污染、无碳排放，并且液氨燃料可以通过水和空气制造，液氨容易安全运输和存储，使用液氨燃料发动机可以高效地、理想地实现无污染的能量循环，可以很容易地、高效率、广泛地进行能量的转换、运输、存储和使用循环(现有技术在使用液氨作燃料时，容易生成氮氧化物，并不能实现零污染燃烧。)。比如储能，现有的储能系统很多是通过抽水储能发电，需要很广阔的空间并形成水位差，在白天电能用量大时用水发电，在夜晚用电量少时进行抽水蓄能，效率也不高；但如果使用本发明方案技术，可以在夜晚用电量少时利用电能生产制造液氨，其原料是水和空气，材料来源经济广泛、随手可得，在白天时使用液氨燃料发动机进行发电，形成无污染的、理想的储能能量循环，储能效率高，安全可靠，极大地节省使用空间。当本发明方案技术得到推广后，液氨将会成为理想的燃料，使用液氨燃料的本发明方案技术内燃机，其能够真正实现零污染、无碳排放，并且液氨燃料容易制造、安全运输和存储，是理想的能量循环燃料，其制造和运输成本比氢燃料要便宜得多，运输和存储也相对要方便安全得多。试想一下，以后的加油站只需要打一口井和电源，就可以源源不断地按需生产出液氨燃料，不再需要像燃油一样的长途运输，甚至将来的技术发展可以实现家庭式制造液氨，这样通过液氨燃料就可以完全摆脱对石油燃料和昂贵电池的依赖，并且使用更加安全可靠，更加环保，成本更加低廉。
本发明方案有储多的有益效果，有益效果都取得了显著的进步，现将前面所述的有益效果归纳如下：
1、 大幅度提高压缩比、燃烧压缩压力(始燃压)和热效率。
2、 超临界水混合气体工质储能特性，使得燃料燃烧和工质做工过程类似于、甚至更优越于等压加热模式，具有相对更加大的热效率。
3、 有效防止爆燃和爆震的发生。
4、 更完全的燃料燃烧，有效减少有害废物排放。
5、 具有相对更低的最高燃烧温度，减少氮氧化物的生成。
6、 更低的排气温度，更有效利用热能。
7、 发动机的动力更强。
8、 发动机升功率更大。
9、 可使用广泛的多种燃料，开辟了燃料来源的广泛途径。
10、本发明技术方案，液氨可以作为理想的燃料，可以低成本实现零污染、零碳排放，可以实现安全可靠、低成本、高效率、便利的能量转换、运输、存储和使用循环。
 本发明的最佳实施方式
超临界水燃烧环境往复活塞式燃料发动机。
本发明方案实施实例以涡轮增压柴油机为发动机原型，并在此基础上进行设计改进。本实例具体设计制造改进是，以现有的尾气涡轮增压柴油机为基础，发动机为1.6升排量的四缸往复活塞式发动机，每气缸0.4升排量，并增加一级电动涡轮增压器，发动机采用铸铁合金机体，可承受30mPa以上的压强压力，由于超临界水混合气体带有强氧化腐蚀性，气缸、气缸盖、活塞等燃烧室组成部件都需要采取防氧化腐蚀措施；活塞使用弹性可变长活塞，设定活塞弹性起始压缩压强为22.5mPa，最大活塞弹性压缩压强为26mPa，静态压缩比为60(活塞不发生弹性变长时的压缩比)，燃烧前动态压缩比可以在8--60之间按需通过进气量进行自动调节，燃料燃烧后最大可膨胀到活塞行程的3/8(即最大活塞压缩长度为气缸容积长的43/120)。
    3/8-1/60 = 43/120
也就是在最小压缩比时的初始膨胀比(预胀比或预膨胀比)为3，即最小压缩比时燃烧最大可膨胀3倍；使用弹性可变长活塞一方面有利于防止机体压强压力过载，另一方面有利于实现发动机接近于等压加热模型，还有就是有利于实现按需动态的压缩比；气缸内加装高压喷水喷嘴，可以按需要进行按量高压雾状喷水。
在本实例中，参与燃烧的喷水量为压缩空气质量的十分之一，在进气门关闭后的空气压缩过程进行喷入水，在燃料燃烧之前的喷水量为空气质量的十分之一，在开始燃烧后不再喷水；总的喷水量为空气量的十分之一，如果按空燃比为20计算，总的喷水质量为燃料质量的二倍。
本实例发动机必须工作在超临界水混合气态环境，所以每次燃烧前必须形成超临界水混合气体状态环境，每循环燃烧的进气量和喷水量就有最低的要求。按本实例最高压缩比为60和前面所述用水等条件计算，其最小的进气量为相当实际压缩比不应低于54(通过计算大约应该为53，但考虑到机械精密度、气缸密封性等原因，实际进气量应稍多)，也就是每气缸每循环进气量不应少于：
0.4/60*54=0.36升(常压状态下)。
每次最少喷水量约为：
0.36*1.1691/10=0.042克(常压下空气密度约为1.1691g/L)。
也就是说，最少压缩0.36升空气，并加入0.042克水，压缩到：
0.4/60=0.0067升。
就可以达到超临界水混合气体状态环境。最高进气量为压缩比最小等于8时，其压缩压力(燃烧前压强)为23.56mPa，容积为0.05升，空气量约为3.28克，喷水量约为0.328克，可用燃料量约为0.164克。燃料喷量可以为0至空气量的二十分之一。当发动机在怠速运转时，为保持低速运行和节省燃料，可以通过间隔循环停止空气压缩、喷水、喷油和燃烧，或部分熄缸以控制发动机的低速运转。
燃料可以使用液氨、汽油、柴油、煤油、甲醇汽油等，或者是多种燃料混合的混合燃料。
本实例发动机的运行。发动机循环过程的四个阶段步骤为进气、空气压缩、燃烧和膨胀做功、排气。在进气阶段，关闭排气气门并打开进气气门，活塞下行，进行吸气进气过程；当用最小进气量时，相当压缩比为54，进气量为0.36升；具体的需要进气量，可以通过尾气涡轮增压器和电动涡轮增压器进行调节。在空气压缩阶段，先关闭进气门，然后根据进气量以雾状喷入相应的水量，然后进行空气压缩，直到压缩末期，活塞到达上止点，形成超临界水状态混合气体环境；当用最小进气量时，压缩比为54，进气量0.36升，喷水量0.042克，在压缩末期，混合气温度约为1218.5K，压强约为22.1mPa，达到超临界水状态。在燃烧和膨胀做功阶段，先喷入燃料(当用最小进气量时，燃料可用0—0.021克)，燃料迅速溶解于混合气体中，并且在超临界水状态混合气体环境中进行超临界燃烧，燃烧的热能迅速转化为燃气工质的内能（如果需要降温、降压，可以继续喷入适量水进行降温降压并增加工质储能的能力），燃烧生成物包括水和二氧化碳等也迅速溶解于工质混合气体中，工质温度有所上升，压强也有所增大，弹性活塞的长度迅速被有所压缩；随着燃料燃烧和曲轴的转动，活塞直线运动推动连杆和曲轴做功，活塞长度弹性恢复，在到达水的临界点前，相当于类似等压加热过程；在工质混合气体压力到达水的临界点后，混合气体溶解释出，工质气体继续推动活塞做功，直到活塞接近到达下止点。在排气阶段，在活塞接近到达下止点时，打开排气气门，工质气体在活塞的推动下进行排气过程。至此，发动机完成一个工作循环过程，不断循环以继续发动机的运行。
本实例发动机关键指标和性能估算。热效率估算可以按照压缩比进行计算；按压缩比为54，以等压加热模式估算，理论热效率可达72%以上，实际最大热效率可达60%以上；而当前汽油机的最大热效率为40%左右，柴油机的最大热效率为46%左右；并且与以往发动机不同的是，由于本实例的实际压缩比不小于54，压缩压力都保持在水的临界压力之上，所以本实例发动机在大多数工况范围内都能与最大热效率相差不大，多数工况下都保持比较高的热效率(这也主要得益于本实例的动态压缩比应用)，这特别是对于汽车等工况多样化情况下的使用效益会特别显著。最大升功率的估算可以按每循环最大进气量与最大转速进行大概的估算；以往的汽油机一般在点火前压强为0.8—1.3mPa之间，压缩比一般为8—12之间，为简化计算，取着火前压强为1.3mPa、最小压缩比为8时作为最大进气量；柴油机一般着火前压强为3—5mPa之间，压缩比一般为11—22之间，取着火前压强为5mPa、最小压缩比为11作为最大进气量，汽油机的最大转速通常比柴油机要大一倍；本实例以着火前最大压强为23.56mPa、压缩比最小为8作为最大进气量，在使用汽油或柴油的情况下，最大转速与汽油机基本相同；粗略计算(按理想气体纯空气计算)可得到汽油机、柴油机和本实例发动机的最大进气量之比为12.63:24.03:100，如果简单按相同的空燃比计算，则三者升功率之比大约为12.63:12.02:100；也就是说，本实例最大进气量是汽油机的7.9倍多，是柴油机的4倍多，本实例的最大升功率同样是汽油机的7.9倍多，是柴油机的8.3倍多。动力比较可以根据最高压强以作大概的比较；一般汽油机的最高压强为3—8.5mPa，柴油机的最高压强为7—16mPa，而本实例的燃烧初始压强不会低于22.1mPa，最高压强甚至可达26mPa，发动机的平均压力与其最大压力密切相关，本实例的最大压强压力比汽油机和柴油机都高得多，所以本实例发动机的动力也比汽油机和柴油机都要大得多。
特别是，当本实例发动机使用液氨作为燃料时，可以实现零污染、零碳排放。
 工业实用性
本发明方案需要使用耐氧化腐蚀和高强度的各种材料，相应材料在超临界水的污水和废物处理中都有广泛使用，没有超出现有材料的标准；在现有内燃机的基础上，设计及工艺改革相对简单容易，制造成本不高，可以大幅度提高内燃机的压缩比、热效率、动力性能和升功率，可以降低和控制燃烧的最高温度和最高压力，并且能够同时大幅度降低有害物的排放，甚至可以实现零污染、零碳排放，并且可以使用广泛的多种燃料，适合代替现有的内燃机，实用性强，本发明技术方案必将是内燃机的发展方向。

Claims (3)

  1. 一种往复活塞式内燃机，其特征是：往复活塞式内燃机除了需要消耗空气和燃料之外，还需要消耗水；在往复活塞式内燃机空气压缩过程和压缩末期，或者在燃料燃烧之前，在内燃机空气中加入适量的水，使得内燃机的压缩空气与适量水混合；并且在燃料燃烧之前，或者是燃料燃烧的主燃烧之前，通过直接气体压缩，或者压缩后再预燃烧，使得内燃机燃烧室内的水达到超临界状态，压缩空气与超临界水在气态下相溶，形成超临界水混合气体环境；燃料在超临界水混合气态环境中进行燃烧；在燃料燃烧过程中，内燃机燃烧室内的水保持为超临界水状态。
  2. 根据权利要求1所述往复活塞式内燃机的燃烧方法，其特征是：往复活塞式内燃机在燃料燃烧之前，燃烧室的混合气含有适量的水，并且燃烧室内水的状态达到超临界状态，使得压缩空气与超临界水成为混合相溶的单一相气态环境；在燃料燃烧过程中，将燃料直接高压喷入燃烧室，由于超临界水的特性，燃料迅速溶解进入超临界水混合气体中，并且在超临界水状态下发生自燃，使得燃料在超临界水的混合气态燃烧环境中进行超临界燃烧，是在超临界水溶合成的混合气体中进行单一相气态(气相均相)或趋向单一相气态的超临界氧化反应燃烧。
  3. 根据权利要求2所述的往复活塞式内燃机燃烧方法，其特征是：在往复活塞式内燃机燃烧室的燃烧过程中，当燃烧工质气体的温度过高时或压强过高时，在燃烧室直接高压喷入适量水，并使得燃烧室混合气体中的水保持超临界水状态及其特性，不影响燃烧室的燃料燃烧，从而对燃烧工质气体降温，并将工质热能转化为超临界水混合气体工质势能存储，增加工质混合气体储能的能力，使得燃烧过程中和燃烧完成后能够保持相对较低的工质气体温度，并且使得排放的尾气温度更低。
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6240859B1 (en) * 2000-05-05 2001-06-05 Four Corners Group, Inc. Cement, reduced-carbon ash and controlled mineral formation using sub- and supercritical high-velocity free-jet expansion into fuel-fired combustor fireballs
CN101438035A (zh) * 2004-10-27 2009-05-20 托马斯·C·马加讷斯 在富含甲烷的环境中安全运行柴油机的方法和系统
CN103732904A (zh) * 2011-06-14 2014-04-16 Wsc斯利有限公司 超临界的柴油燃烧用的方法
JP2017089554A (ja) * 2015-11-12 2017-05-25 マツダ株式会社 エンジンの制御装置
US20180058383A1 (en) * 2016-09-01 2018-03-01 Mazda Motor Corporation Homogeneous charge compression ignition engine
WO2020021564A1 (en) * 2018-07-23 2020-01-30 Seth, Chandan Kumar Mechanism for amplification of energy
CN111648878A (zh) * 2020-06-15 2020-09-11 东莞宏大动力科技有限公司 一种超临界水燃烧环境往复活塞式内燃机及其燃烧方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040003781A1 (en) * 2001-04-06 2004-01-08 Akihiro Yuki Method of operating internal combustion engine injected with critical water
US20070022977A1 (en) * 2005-07-27 2007-02-01 Crower H B Method and apparatus for operating an internal combustion engine
CN1740532A (zh) * 2005-08-12 2006-03-01 叶友清 定容燃烧内冷式内燃机
WO2014132125A2 (en) * 2013-02-27 2014-09-04 Wsc Three S.A. Method for superheated glycerin combustion
CN104481741A (zh) * 2014-11-30 2015-04-01 李启山 一种水气增压燃料发动机技术

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6240859B1 (en) * 2000-05-05 2001-06-05 Four Corners Group, Inc. Cement, reduced-carbon ash and controlled mineral formation using sub- and supercritical high-velocity free-jet expansion into fuel-fired combustor fireballs
CN101438035A (zh) * 2004-10-27 2009-05-20 托马斯·C·马加讷斯 在富含甲烷的环境中安全运行柴油机的方法和系统
CN103732904A (zh) * 2011-06-14 2014-04-16 Wsc斯利有限公司 超临界的柴油燃烧用的方法
JP2017089554A (ja) * 2015-11-12 2017-05-25 マツダ株式会社 エンジンの制御装置
US20180058383A1 (en) * 2016-09-01 2018-03-01 Mazda Motor Corporation Homogeneous charge compression ignition engine
WO2020021564A1 (en) * 2018-07-23 2020-01-30 Seth, Chandan Kumar Mechanism for amplification of energy
CN111648878A (zh) * 2020-06-15 2020-09-11 东莞宏大动力科技有限公司 一种超临界水燃烧环境往复活塞式内燃机及其燃烧方法

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