Engine, engine control method, and vehicle

Abstract

An engine, an engine control method, and a vehicle related to the technical field of engines. The engine includes an engine block, a fuel injection system, and a piston, a cylinder formed in the engine block, the piston slidably disposed in the cylinder, a combustion chamber formed between the piston and an inner wall of the cylinder, the fuel injection system connected to the combustion chamber and used to inject fuel into the combustion chamber, wherein in a single engine operating cycle, total energy generated by combustion of the fuel in the combustion chamber is Q1, exhaust heat of the combustion chamber is Q2, and heat dissipated outward from the combustion chamber is Q3, wherein 35%≦Q2:Q1≦45%, and Q3:Q1≦20%.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This disclosure claims priority to Chinese Patent Application No. 202211731086.6, entitled "ENGINE, METHOD FOR CONTROLLING ENGINE, AND VEHICLE," filed on December 30, 2022. The entire contents of the above-referenced application are hereby incorporated by reference.

[0002] The present disclosure relates to the technical field of engines, and more particularly to engines, methods for controlling engines, and vehicles. [Background technology]

[0003] An engine typically includes an engine body, an intake system, and an exhaust system. The intake system and the exhaust system are typically connected to an exhaust utilization device. The exhaust system of an existing engine has a low temperature, so the exhaust utilization device hardly obtains or utilizes energy, and therefore cannot provide more effective service to the engine or other components.

[0004] Therefore, new technical solutions are needed to solve the above problems. Summary of the Invention

[0005] The present disclosure is intended to provide an engine, a method for controlling an engine, and a vehicle.

[0006] According to a first aspect of the present disclosure, there is provided an engine. The engine includes an engine body, a fuel injection system, and a piston. A cylinder is formed within the engine body. The piston is slidably disposed within the cylinder. A combustion chamber is formed between the piston and an inner wall of the cylinder. The fuel injection system is connected to the combustion chamber and configured to inject fuel into the combustion chamber. In an operating cycle of the engine, total energy generated from combustion of the fuel within the combustion chamber is Q1, waste heat of the combustion chamber is Q2, and heat released to the outside from the combustion chamber is Q3. 35%≦Q2:Q1≦45%, and Q3:Q1≦20%.

[0007] Optionally, an exhaust system and an exhaust utilization device are further included. The exhaust system is in communication with the interior of the combustion chamber. The exhaust utilization device is connected to the exhaust pipe.

[0008] Optionally, the exhaust utilization device includes a turbocharging module including a turbine, a rotating shaft, and a compressor wheel, both of which are drivingly coupled to the rotating shaft. The turbine is located within the exhaust system. The compressor wheel is located within the intake system.

[0009] Optionally, the exhaust utilization device includes a generator, the rotor of which is drivingly connected to the turbine.

[0010] Optionally, the exhaust utilization device includes an exhaust gas recirculation module. The exhaust gas recirculation module includes a gas return branch pipe and an exhaust gas cooler. The exhaust gas cooler is disposed in the gas return branch pipe. One end of the gas return branch pipe is connected to an exhaust system. The other end of the gas return branch pipe is connected to an intake system of the engine.

[0011] Optionally, the exhaust gas utilization device includes a Rankine circulation module. The Rankine circulation module includes a circulation pipeline, a heat exchanger, an expander, a condenser, and a pump body. The heat exchanger, the expander, the condenser, and the pump body are connected end-to-end through the circulation pipeline. The heat exchanger has a first heat exchange path and a second heat exchange path. The first heat exchange path is in communication with the exhaust gas system. The second heat exchange path is in communication with the circulation pipeline.

[0012] Optionally, the exhaust utilization device includes at least one of a thermoelectric power generation module, a cooling and air conditioning module, and a waste heat for heating module.

[0013] Optionally, a heat preservation apparatus is further included. The heat preservation apparatus is disposed in the engine body. The heat preservation apparatus is configured to provide heat preservation to the combustion chamber.

[0014] Optionally, the thermal device includes a thermal structure, the thermal chamber being formed in the thermal structure, the thermal structure being disposed around the cylinder outside the cylinder.

[0015] Optionally, the thermal insulation device includes a thermal insulation coating disposed on the inner wall of the cylinder, on the outside of the cylinder, around the cylinder, or on one end of the piston.

[0016] Optionally, the thermal barrier coating is made of silicon dioxide reinforced porous anodic alumina.

[0017] Optionally, the engine body includes a cylinder liner. The cylinder liner is disposed within the cylinder. An outer wall of the cylinder liner is attached to an inner wall of the cylinder. A piston is positioned within the cylinder liner.

[0018] Optionally, a thermal insulation device is further included. The thermal insulation device is disposed in the engine body. The thermal insulation device is configured to provide thermal insulation for the combustion chamber. The thermal insulation device includes a thermal barrier coating. The thermal barrier coating is disposed between the inner wall of the cylinder and the cylinder liner, or the thermal barrier coating is disposed on the inner wall of the cylinder liner.

[0019] Optionally, a heating device is further included, the heating device including an electric heating unit disposed between the inner wall of the cylinder and the outer wall of the cylinder liner.

[0020] Optionally, the fuel injection system is configured to inject fuel into the combustion chamber after the temperature within the combustion chamber reaches a set threshold, so as to heat the fuel within the combustion chamber and cause it to spontaneously combust, and when the temperature within the combustion chamber is equal to or greater than the set threshold, the temperature within the combustion chamber reaches the spontaneous combustion temperature of the fuel during the compression stroke.

[0021] Optionally, a heating device is further included, the heating device configured to heat the combustion chamber to cause a temperature within the combustion chamber to reach a set threshold.

[0022] Optionally, the heating device further comprises a spark plug and / or an electric heating unit, the spark plug configured to initiate fuel heating of the combustion chamber via heat of the fuel.

[0023] The electric heating unit is configured to electrically heat the combustion chamber.

[0024] Optionally, the engine has an excess air factor of 1 or greater.

[0025] According to a second aspect of the present disclosure, there is provided a method for controlling an engine as described above, the control method comprising the steps of:

[0026] Obtaining a temperature value characterizing the temperature within the combustion chamber.

[0027] A step in which the fuel injection system is controlled to inject fuel into the combustion chamber when the engine is in the compression stroke based on a preset rule, in which the fuel in the combustion chamber is heated and combusted spontaneously, and input parameters of the preset rule include a temperature value.

[0028] According to a third aspect of the present disclosure, there is provided a method for controlling an engine, the engine having a first operating state and a second operating state, the method comprising the steps of:

[0029] A temperature in a combustion chamber of the engine is increased to a set threshold during a first operating state, and when the temperature in the combustion chamber is equal to or greater than the set threshold, the temperature in the combustion chamber reaches a natural combustion temperature of the fuel during the compression stroke.

[0030] Injecting fuel into the combustion chamber during the second operating state, causing the fuel to heat and spontaneously combust within the combustion chamber.

[0031] According to a fourth aspect of the present disclosure, there is provided a vehicle, the vehicle including a vehicle body and the engine described above, the engine being disposed in the vehicle body.

[0032] In this embodiment of the present disclosure, the waste heat of the combustion chamber is 35% to 45% of the heat generated from the combustion of the fuel. The high waste heat provides sufficient energy for the utilization of the exhaust gas.

[0033] In addition, the heat released from the combustion chamber is less than 20% of the heat generated from the combustion of fuel, which effectively increases the heat rejection.

[0034] Other features and advantages of the present disclosure will become apparent through the following detailed description of exemplary embodiments of the present disclosure, which refer to the drawings.

[0035] The drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a cross-sectional view of an engine according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of another engine according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0037] Various exemplary embodiments of the present disclosure will be described in detail with reference to the drawings. It should be noted that unless otherwise specified, the opposing arrangements, numerical expressions, and numerical values ​​of components and steps described in the embodiments do not limit the scope of the present disclosure.

[0038] The following description of at least one exemplary embodiment is merely illustrative and is in no way construed as any limitation on the present disclosure and application or their uses.

[0039] Techniques, methods, and devices known to those skilled in the relevant art need not be discussed in detail, but, where appropriate, the techniques, methods, and devices should be considered part of this specification.

[0040] In all examples shown and discussed herein, any specific values ​​should be construed as exemplary only, and not as limiting, and thus other examples of exemplary embodiments may have different values.

[0041] It should be noted that in the following drawings, like reference numerals and letters represent like items, and therefore, once an item is defined in a drawing, that item need not be further discussed in subsequent drawings.

[0042] The engine provided in the embodiment of the present disclosure will be described in detail below by using a gasoline engine as an example. Those skilled in the art can understand that the engine provided in the embodiment of the present disclosure can also be an engine using other fuels such as natural gas, methanol, ethanol, and diesel. The engine can be applied to automobiles, ships, airplanes, compressors, construction machinery, etc.

[0043] In the related art, the exhaust system of the engine has a low temperature, so the exhaust utilization device does not obtain or utilize much energy and therefore cannot service the engine or other components more effectively.

[0044] According to one embodiment of the present disclosure, an engine is provided. As shown in Figures 1 and 2, the engine includes an engine body 100, a fuel injection system, and a piston 104. A cylinder 101 is formed within the engine body 100. The piston 104 is slidably disposed within the cylinder 101. A combustion chamber 102 is formed between the piston 104 and an inner wall of the cylinder 101. The fuel injection system is connected to the combustion chamber 102 and configured to inject fuel into the combustion chamber 102.

[0045] In an engine operating cycle, the total energy generated from the combustion of fuel in the combustion chamber 102 is Q1, the exhaust heat of the combustion chamber 102 is Q2, and the heat released from the combustion chamber 102 is Q3.

[0046] 35%≦Q2:Q1≦45%, and Q3:Q1≦20%.

[0047] Specifically, the engine body 100 is made of a metal such as stainless steel, carbon steel, or cast iron. A fuel injection system is configured to inject fuel into the combustion chamber 102. The fuel may be, but is not limited to, gasoline, natural gas, methanol, or ethanol. The burned fuel pushes and moves the piston 104, converting thermal energy into mechanical energy. The engine further includes an intake system and an exhaust system. The intake system and the exhaust system are disposed in the engine body 100. The intake system is configured to supply air to the combustion chamber 102. The exhaust system is configured to discharge exhaust gases generated from the combustion of the fuel from the combustion chamber 102.

[0048] The fuel injection system may supply fuel to the combustion chamber 102 by direct injection. For example, fuel is injected into the combustion chamber 102 through a fuel injection nozzle 105. Within the combustion chamber 102, the fuel mixes with air entering the combustion chamber 102 through an intake passage to form a gas mixture for combustion.

[0049] Alternatively, the fuel injection system can supply fuel in an indirect manner. For example, the fuel injection system injects fuel into the intake tract. In the intake tract, the fuel premixes with air. The fuel then enters the combustion chamber 102 along with the air in the intake tract and mixes with the air to form a gas mixture for combustion. Methods for calculating the total energy Q1 generated from the combustion of fuel in the combustion chamber 102, the waste heat Q2 of the combustion chamber 102, and the heat Q3 emitted outside the combustion chamber 102 are common knowledge in the art and will not be described in detail herein.

[0050] In this embodiment of the present disclosure, the heat rejection of the combustion chamber 102 is 35% to 45% of the heat generated from the combustion of the fuel. The high heat rejection provides sufficient energy for the utilization of the exhaust gases.

[0051] In order to achieve 35% to 45% of the heat generated from the combustion of fuel as waste heat, the embodiment of the present disclosure reduces the heat emitted from the combustion chamber 102. In other words, the heat emitted from the combustion chamber 102 is 20% or less of the heat generated by the combustion of fuel. For a certain amount of heat generated from the combustion of fuel, after the heat emitted is reduced, the energy generated from the work performed by the piston 104 and the waste heat increase. However, the energy generated from the work performed by the piston 104 generally accounts for 40% to 50% of the energy produced by the combustion of fuel and is difficult to continue to increase. In this way, it is achieved that the waste heat is 35% to 45% of the heat generated from the combustion of fuel.

[0052] The heat dissipated from the combustion chamber 102 can be reduced in several ways. For example, the amount of cooling in the cooling system, i.e., the water jacket structure, may be reduced. In another example, the water jacket structure may be eliminated. In another example, a thermal insulation device may be placed to heat the combustion chamber. In another example, the temperature difference between the inside and outside of the combustion chamber 102 may be reduced by a heating device.

[0053] It should be noted that after the heat dissipated outward from the combustion chamber 102 is reduced, the temperature of the engine body outside the combustion chamber 102 is relatively high. The impact of high temperature on the strength of the engine body 100 can be overcome in several ways. For example, to reduce the heat dissipation outward from the combustion chamber 102, the engine body is configured as a one-piece engine body, the engine body is formed by using a material with higher heat resistance, or a heat insulating structure is arranged outside the combustion chamber 102. Under the guidance of this embodiment of the present disclosure, a specific way may be adaptively selected by those skilled in the art based on actual circumstances.

[0054] In one example, the engine further includes an exhaust system 107 and an exhaust utilization device. The exhaust system 107 is in communication with the interior of the combustion chamber 102. The exhaust utilization device is connected to the exhaust system 107.

[0055] An exhaust system 107 discharges exhaust gases from the combustion chamber 102. The exhaust system 107 is connected to an exhaust utilization device to deliver the exhaust gases to the exhaust utilization device. The exhaust utilization device can use the energy of the exhaust gases to improve the engine's energy utilization.

[0056] The exhaust utilization device may be, but is not limited to, a power generation device, a heating device, a turbocharger, etc. In this example, the exhaust utilization device has high efficiency due to the high exhaust heat of the combustion chamber 102.

[0057] In one example, the exhaust utilization device includes a turbocharging module. The turbocharging module includes a turbine 115, a rotating shaft 116, and a compressor wheel 117. Both the turbine 115 and the compressor wheel 117 are drivingly coupled to the rotating shaft 116. The turbine 115 is located within the exhaust system 107. The compressor wheel 117 is located within the intake system 106.

[0058] In this example, the turbine 115 is configured to convert the flow energy of the exhaust gas into rotational energy of the turbine 115. The exhaust gas drives the turbine 115 to rotate. The turbine 115 drives the rotating shaft 116 to rotate. The rotating shaft 116 drives the compressor wheel 117 to rotate. The compressor wheel 117 is located in the intake system 106, which can effectively increase the intake flow rate of air entering the combustion chamber 102, thereby improving the intake efficiency. A throttle valve 114 is located in the intake system 106. The throttle valve 114 is configured to adjust the intake flow of the intake system 106. Due to the high exhaust heat of the combustion chamber 102, the exhaust gas has a high flow rate and high air pressure, which can significantly improve the operating efficiency of the turbocharging module.

[0059] In one example, the intake system 106 further includes an intake branch 128. The intake branch 128 is connected in parallel with the turbocharging module. The intake branch 128 can ensure an intake air flow of the intake system 106. A second valve 129 is disposed in the intake branch 128. The second valve 129 is configured to control the intake air flow of the intake branch 128.

[0060] In one example, the exhaust utilization device includes a generator 118. The rotor of the generator 118 is drivingly coupled to the turbine 115.

[0061] In this example, the rotation of turbine 115 drives the rotor of generator 118 to rotate so as to convert the kinetic energy of the exhaust gases into electrical energy. Turbine 115 not only provides energy for the additional modules of turbine 115, but also provides energy for generator 118, thereby further improving the efficiency of engine exhaust gas utilization.

[0062] In one example, the exhaust utilization device includes an exhaust gas recirculation module. The exhaust gas recirculation module includes a gas return branch 119 and an exhaust gas cooler 120. The exhaust gas cooler 120 is disposed in the gas return branch 119. One end of the gas return branch 119 is connected to the exhaust system 107. The other end of the gas return branch is connected to the intake system 106 of the engine.

[0063] In this example, the gas return branch 119 delivers a portion of the exhaust gas to the intake system 106. The gas return branch 119 is provided with a third valve 130. The third valve 130 is configured to control the exhaust gas flow through the gas return branch 119. Because the exhaust gas has a high temperature, the air in the intake system 106 is heated, which can increase the temperature of the combustion chamber 102, resulting in more sufficient fuel combustion. However, if the intake air temperature is excessively high, the air is heated and expanded, resulting in a reduced intake air flow rate in the intake system 106 and insufficient fuel combustion. The exhaust gas cooler 120 can effectively prevent the exhaust gas from entering the intake system 106 from becoming too hot, thereby ensuring a sufficient intake air flow rate in the intake system 106.

[0064] Additionally, the amount of NOx emitted from the combustion chamber 102 via the exhaust gas in the gas return branch 119 can also be controlled, reducing nitrate emissions from the engine.

[0065] In one example, the exhaust gas utilization device includes a Rankine circulation module 121. The Rankine circulation module 121 includes a circulation pipeline, a heat exchanger, an expander, a condenser, and a pump body, the heat exchanger, the expander, the condenser, and the pump body being connected end to end through the circulation pipeline.

[0066] The heat exchanger has a first heat exchange path and a second heat exchange path, the first heat exchange path being in communication with the exhaust system 107, and the second heat exchange path being in communication with the circulation pipeline.

[0067] In this example, the exhaust system 107 includes an exhaust branch pipe 126. A first valve 127 is disposed in the exhaust branch pipe 126. The first valve 127 is configured to control the exhaust gas flow in the exhaust branch pipe 126. The exhaust branch pipe 126 is connected in parallel with the turbocharging module to ensure the exhaust gas flow to the Rankine circulation module 121. Heat from the exhaust system 107 is thermally exchanged with the first heat exchange path. The first heat exchange path and the second heat exchange path are coupled together to exchange heat. Heat is thermally exchanged from the first heat exchange path to the second heat exchange path. Water in the second heat exchange path is heated to generate high-pressure steam. The high-pressure steam reaches an expander through a circulation pipeline. The high-pressure steam expands in the expander to generate low-pressure steam. The high-pressure steam and the low-pressure steam create a pressure difference. The pressure difference pushes a steam turbine to generate electricity. The low-pressure steam is condensed into water by a condenser. The condensed water is transported by the pump body through the circulation pipeline to the second heat exchange passage, where it is heated to achieve circulation. During the circulation process, the working efficiency of the Rankine cycle can be significantly improved due to the high temperature of the engine exhaust gas.

[0068] In one example, the exhaust utilization device includes at least one of a thermoelectric power generation module, a cooling and air conditioning module, and a heating waste heat module, all of which can use the energy of the exhaust gases to provide services to devices in which the engine is located.

[0069] In one example, the engine further includes a heat retention device disposed on the engine body, the heat retention device being configured to provide heat retention to the combustion chamber.

[0070] In this example, the heat preservation device can effectively prevent the heat in the combustion chamber from escaping. The heat preservation device can effectively increase the temperature of the combustion chamber, resulting in a significant increase in the temperature of the exhaust heat and an increase in the heat of the exhaust gas. Thus, 35%≦Q2:Q1≦45%, and Q3:Q1≦20%.

[0071] Additionally, the thermal insulation device is able to maintain higher temperatures within the combustion chamber 102, which significantly improves the thermal efficiency of the engine.

[0072] In one example, the thermal insulation device includes a thermal structure. An insulating chamber is formed in the thermal structure. The thermal structure is disposed outside and around the cylinder 101.

[0073] For example, a hollow chamber is disposed in the engine body 100. The hollow chamber constitutes a heat insulating chamber. The heat insulating chamber can effectively isolate the combustion chamber 102.

[0074] Alternatively, the thermal insulation structure may include the original water jacket structure of the engine body 100. The water jacket structure forms an insulating chamber. The water jacket structure is disposed outside the cylinder 101 and is disposed around the cylinder 101. The engine removes coolant, so that the water jacket structure can effectively insulate the combustion chamber 102.

[0075] In this example, insulating cotton may be placed in the insulating chamber, which can effectively perform the insulating function.

[0076] Alternatively, the insulating chamber may be evacuated to maintain a set level of vacancy within the insulating chamber. The evacuated insulating chamber can perform a heat retention function, so that the combustion chamber 102 can be effectively insulated.

[0077] Alternatively, only the cavity structure of the cylinder 101 is cast into the engine body 100, and the cavity structure of the water jacket structure is no longer cast, so that the engine body 100 is directly used to insulate the combustion chamber 102.

[0078] Of course, the thermal structure is not limited to the above embodiments, and may be configured by those skilled in the art based on actual requirements.

[0079] 1, the thermal insulation device includes a thermal insulation coating 113. The thermal insulation coating 113 is disposed on the inner wall of the cylinder 101, on the outside of the cylinder 101, around the cylinder 101, or at one end of the piston 104.

[0080] The thermal barrier coating 113 is configured to prevent heat from diffusing from within the combustion chamber 102 to the outside. For example, the thermal barrier coating 113 is made of porous anodic alumina. Porous anodic alumina is an aluminum oxide material prepared by anodizing aluminum metal under acidic conditions. The material has good thermal insulation properties. For example, the thermal barrier coating 113 is formed on the engine body, cylinder, cylinder liner, or exhaust pipe by a powder metallurgy process.

[0081] Optionally, the thermal barrier coating 113 is made of silicon dioxide reinforced porous anodic alumina. A micron-thick silica coating is formed on the surface of the porous anodic alumina. The silica coating can effectively improve the wear resistance of the porous anodic alumina. The material has excellent thermal insulation properties, which can effectively prevent engine heat from escaping.

[0082] Of course, the material of the thermal barrier coating 113 is not limited to the above embodiments, and may be selected by those skilled in the art based on actual requirements.

[0083] A thicker thickness of the thermal barrier coating 113 indicates a better thermal insulation effect. However, a thicker thickness may cause the thermal barrier coating 113 to easily fall off from the engine body 100. Optionally, the thickness of the thermal barrier coating 113 is in the range of 10 μm to 100 μm. Within this range, the thermal barrier coating 113 can effectively prevent the heat in the combustion chamber 102 from diffusing outward, and the thermal barrier coating 113 has high bonding strength with the engine body 100.

[0084] The thermal barrier coating 113 is attached to the inner wall of the cylinder 101, or the thermal barrier coating 113 is located in the engine body 100 and arranged around the cylinder 101. The thermal barrier coating 113 has a good thermal insulation effect in the above-mentioned positions.

[0085] Alternatively, the thermal barrier coating 113 is disposed on one end of the piston 104. In this example, the thermal barrier coating 113 located on one end of the piston 104 can effectively prevent the heat of the combustion chamber 102 from dissipating through the piston 104.

[0086] In a specific example, the thermal barrier coating 113 is attached to the original water jacket of the engine body 100. The water jacket is disposed around the combustion chamber 102. The thermal barrier coating 113 is disposed on the inner wall of the water jacket. The thermal barrier coating 113 can provide good thermal insulation.

[0087] 2, the engine body 100 includes a cylinder liner 103. The cylinder liner 103 is disposed within the cylinder 101. The outer wall of the cylinder liner 103 is attached to the inner wall of the cylinder 101. The piston 104 is positioned within the cylinder liner 103.

[0088] The material of the cylinder liner 103 is harder and has better wear resistance than the material of the inner wall of the cylinder 101. The cylinder liner 103 can effectively improve the service life of the engine.

[0089] In one example, the engine further includes a thermal insulation device. The thermal insulation device is disposed in the engine body 100. The thermal insulation device is configured to provide thermal insulation for the combustion chamber 102. The thermal insulation device includes a thermal barrier coating 113. The thermal barrier coating 113 is disposed between the inner wall of the cylinder 101 and the cylinder liner 103, or the thermal barrier coating 113 is disposed on the inner wall of the cylinder liner 103.

[0090] For example, the material and thickness of the thermal barrier coating 113 are as described above. The thermal barrier coating 113 is disposed on at least one of the outer wall of the cylinder liner 103 and the inner wall of the cylinder 101. The thermal barrier coating 113 can effectively perform the function of heat insulation. In addition, the thermal barrier coating 113 in this position is less susceptible to external impacts and has good durability.

[0091] Alternatively, the thermal barrier coating 113 may be disposed on the inner wall of the cylinder liner, where it is closer to the combustion chamber 102 and can therefore more effectively perform its thermal and insulating functions.

[0092] In one example, the engine further includes a heating device, the heating device including an electric heating unit disposed between an inner wall of the cylinder and an outer wall of the cylinder liner.

[0093] The electric heating unit heats the combustion chamber 102, so that the temperature of the combustion chamber 102 is significantly increased. The exhaust gas temperature can be higher, which effectively improves the exhaust gas utilization rate. Thus, 35%≦Q2:Q1≦45%.

[0094] In addition, the electric heating unit is disposed between the inner wall of the cylinder 101 and the cylinder liner 103, which can avoid the impact from external forces, thereby significantly improving the durability of the engine.

[0095] In addition, the electric heating unit blocks the path for heat in the combustion chamber to escape, further reducing the amount of heat released from the engine. Thus, Q3:Q1≦20%.

[0096] In a preferred embodiment, the water jacket structure is eliminated or the cooling capacity of the water jacket structure is reduced to reduce the heat emitted out of the combustion chamber.

[0097] Based on this preferred embodiment, the inventor further finds that the temperature of the inner wall of the combustion chamber 102 in this case is relatively high, even exceeding the natural combustion temperature of the fuel in the combustion chamber 102 under the current conditions. Based on the above and further considering that the related art's method of igniting fuel for combustion by a spark plug may cause engine knocking when the compression ratio is high, the inventor takes the lead in combining improved exhaust gas energy with reduced knocking risk and finds a method of directly igniting fuel through the inner wall of the combustion chamber 102 to achieve fuel combustion. In this way, the heat released from the combustion chamber is reduced, which improves exhaust gas utilization efficiency. In addition, the stored heat may be used to heat the inner wall of the combustion chamber 102 to naturally combust the fuel at a high temperature, which reduces the risk of engine knocking. Therefore, the compression ratio of the engine may reach 16 or more, or even 18 or more, or 20 or more.

[0098] In one example, the fuel injection system is configured to inject fuel into the combustion chamber 102 after the temperature in the combustion chamber 102 reaches a set threshold to heat the fuel and allow it to spontaneously combust within the combustion chamber 102. When the temperature in the combustion chamber 102 is equal to or greater than the set threshold, the temperature in the combustion chamber 102 can reach the spontaneous combustion temperature of the fuel during the compression stroke.

[0099] Although the inventors conceive of an embodiment in which the fuel is ignited by high temperature to spontaneously combust based on a preferred embodiment in which the water jacket structure is removed or the cooling capacity of the water jacket structure is reduced, it should be noted that the embodiment in which the fuel is ignited by high temperature to spontaneously combust does not necessarily need to be implemented based on an embodiment in which the water jacket structure is removed or the cooling capacity of the water jacket structure is reduced. Other methods, such as disposing a corresponding insulation or heating device, may be used to increase the temperature in the combustion chamber 102 to spontaneously combust the fuel without removing the water jacket structure and without changing the cooling capacity of the water jacket structure.

[0100] In this disclosure, so-called spontaneous combustion means that fuel burns naturally. Conditions required for spontaneous combustion include fuel concentration, combustion aids, and temperatures reaching or exceeding the spontaneous combustion temperature. In the related art, engines typically ignite fuel in the combustion chamber using a spark plug. In this disclosure, so-called ignition means that fuel burns under the action of a hot spot such as a spark or an electric arc.

[0101] When the engine is in the compression stroke, the piston 104 moves from bottom dead center to top dead center. During this process, mechanical energy is converted into internal energy. During the compression stroke, the fuel injection system is controlled to inject fuel into the combustion chamber 102. When the temperature in the combustion chamber 102 reaches a set threshold, the fuel is heated and spontaneously combusts under this condition. The spontaneous combustion of the fuel generates a large amount of gas, which pushes the piston 104 to move from top dead center to bottom dead center. Therefore, during the power stroke, the crank is driven to rotate by the piston 104, thereby converting internal energy into mechanical energy. When the engine is in the compression stroke, the intake and exhaust valves are closed.

[0102] In this example, the temperature in the combustion chamber 102 reaches a set threshold before the fuel injection system injects fuel into the combustion chamber 102. In this case, the temperature in the combustion chamber 102 can reach the spontaneous combustion temperature of the fuel during the compression stroke, resulting in the fuel spontaneously combusting. In this disclosure, a combustion mode that heats and spontaneously combusts the fuel is adopted, so that when the engine is in the compression stroke, the fuel gradually mixes with air and is heated after being injected through the fuel injection nozzle 105. A flame in the combustion chamber 102 begins to burn from one end of the fuel injection spray (i.e., the end closest to the piston) and gradually spreads upward. In essence, the heat and spontaneously combust combustion mode completely avoids knocking.

[0103] The set thresholds are related to factors such as the type of fuel, the air pressure of the gas mixture, the amount of injected fuel, and the intake air flow rate, etc. Of course, those skilled in the art may select the set thresholds depending on the actual operating conditions.

[0104] In one example, the engine further includes a heating device configured to heat the combustion chamber 102 to cause the temperature therein to reach a set threshold.

[0105] To avoid the problem of fuel not being able to burn naturally due to the low temperature of the combustion chamber, the engine is equipped with a heating device, for example, the heating device can heat the cylinder so that the inner wall of the combustion chamber is warm, thereby increasing the temperature of the combustion chamber and allowing the fuel to burn naturally.

[0106] Additionally, the heating device generally increases the temperature within the combustion chamber 102. In this manner, the flame in the combustion chamber 102 begins to burn at one end of the fuel injection beam (i.e., the end closest to the piston) and spreads upward more quickly, thereby avoiding engine knock.

[0107] In one example, the heating device includes a spark plug configured to initiate fuel heating of the combustion chamber via heat of the fuel, and / or an electric heating unit configured to electrically heat the combustion chamber.

[0108] In this example, in a warm-up state, the spark plug 110 can be used to start the fuel to heat the temperature in the combustion chamber of the engine to a set threshold. When the fuel burns, heat is generated. The heat is used to heat the combustion chamber 102. In this way, the original engine's spark plug 110 is used to heat the combustion chamber 102. If the temperature of the combustion chamber 102 is higher than the set threshold, the fuel injected by the fuel injection system can combust naturally. In a non-warm-up state, the spark plug 110 does not need to be started again, and the temperature of the combustion chamber 102 is maintained directly by using the heat from the combustion chamber 102, so that the fuel injected into the combustion chamber 102 by the fuel injection system can combust naturally.

[0109] It should be noted that the warm-up and non-warm-up states in this embodiment of the present disclosure are different from the warm-up and non-warm-up states in the related art. In the related art, the period after the engine is started in which the engine components are raised to a temperature at which the components have a relatively high operating efficiency is commonly referred to as the engine warm-up period or preheat period. Typically, during the compression stroke, the temperature in the combustion chamber 102 can only reach temperatures below 250°C, and usually only below 200°C. In this embodiment of the present disclosure, the warm-up state refers to the warm-up stage in which the temperature in the engine's combustion chamber 102 rises to approximately 300°C or approximately 400°C during the compression stroke to ensure that fuel can enter the non-warm-up combustion chamber 102 and be heated to spontaneous combustion.

[0110] It should be noted that the heating method of using the heat of fuel to heat the combustion chamber 102 by igniting the fuel with the spark plug 110 is only applicable to heating the engine in a warm-up state. In a non-warm-up state, if the combustion chamber 102 needs to be heated by using the spark plug to ignite the fuel, the control of the engine becomes complicated. Different operating cycles output different power and torque, which affects the smoothness of the engine operation.

[0111] Alternatively, the engine body 100 is provided with an electric heating device. The electric heating device is configured to heat the combustion chamber 102. Specifically, the combustion chamber 102 can be heated by the electric heating device to raise the temperature in the combustion chamber 102 of the engine above a set threshold in a warmed-up or non-warmed-up state.

[0112] For example, an electric heating device is disposed around the combustion chamber 102. The combustion chamber 102 can be heated more quickly by the electric heating device. Heating by the electric heating device can effectively control the temperature in the combustion chamber 102, which ensures that the fuel injected into the combustion chamber 102 from the fuel injection system can be combusted naturally.

[0113] For example, the electric heating device includes a power supply, a switch, and a heating resistor. The power supply is electrically connected to the switch and the heating resistor. The power supply is configured to supply power to the heating resistor. The switch is configured to control the on and off of the heating current. The electric heating device can quickly heat the combustion chamber 102.

[0114] The electric heating device can be operated to raise and maintain the temperature of the combustion chamber 102 when the temperature in the combustion chamber 102 drops unexpectedly during a non-warm-up phase of the engine. The electric heating device can also heat the combustion chamber 102 during a warm-up phase of the engine so that a characterizing temperature reaches a set temperature.

[0115] Of course, the manner of heating the combustion chamber is not limited to the above embodiment, and may be configured by those skilled in the art based on actual requirements.

[0116] In one example, the engine has an excess air factor of 1 or greater.

[0117] The air excess coefficient is the ratio of the amount of air actually provided to burn the fuel to the amount of air theoretically required. As the temperature of the combustion chamber increases, the air pressure in the combustion chamber increases, which leads to a decrease in the amount of air entering the combustion chamber when the intake valve opens.

[0118] In this example, the excess air factor is greater than or equal to 1 so as to avoid insufficient combustion of fuel caused by insufficient intake air flow rate, effectively ensure sufficient combustion of fuel, and improve fuel utilization.

[0119] According to another embodiment of the present disclosure, there is provided a method for controlling an engine, the method comprising the steps of:

[0120] A characterizing temperature is obtained that characterizes the temperature within the combustion chamber.

[0121] The fuel injection system is controlled based on a preset rule to inject fuel into the combustion chamber when the engine is in the compression stroke, where the fuel is heated and spontaneously combusted. Input parameters of the preset rule include a characterization temperature.

[0122] The temperature inside the combustion chamber 102 is mainly characterized by the temperature of the inner wall of the combustion chamber, which fluctuates within a certain range due to the heat generated from the combustion of fuel during the engine's operating cycle. During the compression stroke, the temperature of the inner wall of the combustion chamber becomes higher than the temperature of the gas inside the combustion chamber 102. When the fuel is injected, after the fuel comes into contact with the inner wall of the combustion chamber 102, which has a relatively high temperature, the fuel is heated and combusts naturally, thereby avoiding the risk of knocking.

[0123] In this embodiment of the present disclosure, to ensure that at least a portion of the fuel can fall to the top of the piston 104 after being injected, the fuel injection nozzle 105 of the fuel injection system faces the top of the piston 104, so that the fuel naturally begins to burn from above the top of the piston 104 and gradually diffuses and burns upward.

[0124] For example, a characterization temperature is obtained that characterizes the temperature in the combustion chamber 102. During the compression stroke, when the characterization temperature reaches a set value, the fuel injection system is controlled to inject fuel into the combustion chamber 102, thereby causing the fuel to combust naturally. The control method can accurately control the fuel injection system to inject fuel, thereby ensuring that the fuel is fully combusted.

[0125] In addition, before the fuel injection system injects fuel into the combustion chamber 102, the temperature in the combustion chamber 102 must reach a set threshold, and combustion occurs through spontaneous combustion of the fuel. In this way, the engine knocking phenomenon that occurs when the fuel is compressed and ignited by the spark plug 110 can be effectively avoided, resulting in a smoother engine start.

[0126] Specifically, as shown in Figure 2, a temperature sensor 111 is disposed in the engine. The temperature sensor 111 is configured to obtain a characterizing temperature that characterizes the temperature within the combustion chamber 102. For example, the characterizing temperature is a temperature at a predetermined location. The predetermined location that is closer to the combustion chamber 102 has a temperature that more closely resembles the temperature within the combustion chamber 102.

[0127] When the engine is in the compression stroke, the piston 104 moves from bottom dead center to top dead center. During this process, mechanical energy is converted into internal energy. During the compression stroke, the fuel injection system is controlled to inject fuel into the combustion chamber 102. Under this condition, the temperature in the combustion chamber 102 reaches a set threshold, and the fuel is heated and spontaneously combusts. The spontaneous combustion of the fuel generates a large amount of gas, which pushes the piston 104 to move from top dead center to bottom dead center. Therefore, during the power stroke, the crank is driven to rotate by the piston 104, thereby converting internal energy into mechanical energy.

[0128] The preset rule is a rule for controlling the engine to inject fuel so that the fuel can combust naturally. Based on the input parameters, it may be determined whether the input parameters satisfy appropriate conditions. Then, a result indicating whether to inject fuel, the amount of injected fuel, the fuel injection timing, the fuel injection frequency, etc. is output. The preset rule may be preset based on the compression ratio of the engine, the type of fuel, the engine operating parameters, etc.

[0129] For example, the input parameters of the preset rule include a characterizing temperature that characterizes the temperature in the combustion chamber. The determination condition for the characterizing temperature is to determine whether the characterizing temperature is higher than a set temperature. If the characterizing temperature is higher than the set temperature, the output result is to inject fuel. If the characterizing temperature is not higher than the set temperature, the output result is to not inject fuel. If the characterizing temperature is equal to the set temperature, it indicates that the temperature in the combustion chamber 102 has reached a set threshold. Under the set threshold, the temperature in the combustion chamber 102 can reach the spontaneous combustion temperature of the fuel during the compression stroke, so that the fuel can be heated and spontaneously combusted.

[0130] To take advantage of the high temperature in the combustion chamber 102 to allow fuel injected into the combustion chamber 102 to combust naturally during the compression stroke, a method for controlling an engine is provided according to a third embodiment of the present disclosure. The engine has a first operating state and a second operating state. The control method includes the following steps:

[0131] The temperature in the combustion chamber 102 of the engine is raised to a set threshold by heating during a first operating state. If the temperature in the combustion chamber 102 is equal to or greater than the set threshold, the temperature in the combustion chamber 102 can reach the spontaneous combustion temperature of the fuel during the compression stroke.

[0132] Fuel is injected into the combustion chamber 102 during the second operating state, such that the fuel is heated and spontaneously combusts within the combustion chamber 102 .

[0133] During actual operation of the engine, the engine in this embodiment of the present disclosure has a first operating state (also referred to as a warm-up state, a warm-up phase, or a first operating phase) into which the engine can be switched, and a second operating state (also referred to as a non-warm-up state, a non-warm-up phase, or a second operating phase). A method for controlling an engine in this embodiment of the present disclosure includes the following steps: The temperature in the combustion chamber 102 of the engine is raised to a set threshold by heating during the first operating state. If the temperature in the combustion chamber 102 is equal to or greater than the set threshold, the temperature in the combustion chamber 102 can reach the spontaneous combustion temperature of the fuel during the compression stroke. Fuel is injected into the combustion chamber 102 during the second operating state, so that the fuel is heated and spontaneously combusted in the combustion chamber 102.

[0134] The characterizing temperature characterizing the temperature in the combustion chamber 102 may be obtained during the first operating state or the second operating state. When the engine is in the compression stroke, the fuel injection system is controlled to inject fuel into the combustion chamber based on preset rules. The fuel in the combustion chamber 102 heats up and spontaneously combusts, which occurs during the second operating state.

[0135] It should be noted that the warm-up and non-warm-up states in this embodiment of the present disclosure are different from the warm-up and non-warm-up states in the related art. In the related art, the period after the engine is started in which the engine components are raised to a temperature at which the components have a relatively high operating efficiency is commonly referred to as the engine warm-up period or preheat period. Typically, during the compression stroke, the temperature in the combustion chamber 102 can only reach temperatures below 250°C, and usually only below 200°C. In this embodiment of the present disclosure, the warm-up state refers to the warm-up stage in which the temperature in the engine's combustion chamber 102 rises to approximately 300°C or approximately 400°C during the compression stroke to ensure that fuel can enter the non-warm-up combustion chamber 102 and be heated to spontaneous combustion.

[0136] It should be noted that the effect of high temperature on the strength of the engine body can be overcome in several ways. For example, to reduce heat dissipation outside the combustion chamber 102, the engine body is constructed as a one-piece engine body, the engine body is formed by using a material with higher heat resistance, or a heat insulating structure is arranged outside the combustion chamber 102. Under the guidance of this embodiment of the present disclosure, a specific way may be adaptively selected by those skilled in the art based on actual circumstances.

[0137] In a warm-up state, the temperature in the combustion chamber 102 does not reach a set threshold. In this case, the output result based on the preset rule is not to inject fuel. In other words, in this case, the fuel cannot spontaneously combust in the combustion chamber 102. Therefore, the preset rule is not satisfied. In a warm-up state, the fuel injection system may inject fuel under the action of a different rule. For example, to ensure consistent power output, the method for controlling an engine in this embodiment of the present disclosure may heat the combustion chamber 102 while the engine is controlled to ignite fuel normally using a spark plug as usual to implement normal engine operation.

[0138] In a non-warmed state, the fuel can undergo spontaneous combustion in the combustion chamber 102. Thus, the preset rule is satisfied. The fuel injection system is controlled to inject fuel into the combustion chamber 102 based on the preset rule. The fuel in the combustion chamber 102 is heated and spontaneously combusts.

[0139] It should be noted that the spontaneous combustion temperature of fuel in this embodiment of the present disclosure refers to the spontaneous combustion temperature of fuel in the combustion chamber 102 in the current state, which is related to factors such as pressure, temperature, air flow rate, and fuel amount in the combustion chamber 102, and may be obtained by real-time calculation after collecting relevant data, or by looking up a table containing calibrated spontaneous combustion temperatures under various operating conditions.

[0140] The engine can be controlled to switch between a warm-up state and a non-warm-up state in multiple ways. For example, in the method for controlling an engine in this embodiment of the present disclosure, the engine's operating state may be switched based on the engine's operating time. For example, when the engine is started, the engine initially enters a warm-up state. After the engine is started and operates for a set period of time, the engine is controlled to enter a non-warm-up state. After the engine is started and operates for a set period of time, the temperature in the combustion chamber 102 rises to a set threshold. In this case, the warm-up is considered to be complete.

[0141] In the method for controlling an engine in this embodiment of the present disclosure, the operating state of the engine may further be switched based on the temperature in the combustion chamber 102. For example, a characterizing temperature that characterizes the temperature in the combustion chamber 102 is obtained. If the characterizing temperature is equal to a set temperature, it indicates that the temperature in the combustion chamber 102 is at a set threshold. If the characterizing temperature is less than the set temperature, the engine enters a warm-up state and operates. If the characterizing temperature is equal to or greater than the set temperature, the engine enters a non-warm-up state and operates.

[0142] When the engine is in a warm state, the characterizing temperature is obtained at a first frequency.

[0143] When the engine enters and operates in a non-warm state, the characterizing temperature characterizing the temperature within the combustion chamber 102 may not be acquired. The engine continues to operate in the non-warm state before the engine is shut down. Alternatively, the characterizing temperature characterizing the temperature within the combustion chamber 102 may be reacquired at a second frequency to determine whether the engine needs to re-enter the warm state or remain in the non-warm state to heat the combustion chamber 102. The second frequency may be less than the first frequency. In the method for controlling an engine in this embodiment of the present disclosure, when the characterizing temperature is below a set temperature during a non-warm state, the temperature within the engine's combustion chamber 102 is raised to a set threshold by heating to ensure that the combustion chamber can be reheated to a temperature above the set threshold if the engine's combustion chamber 102 cools.

[0144] Optionally, the input parameters of the preset rule further include at least one of a compression ratio of the engine, a crank angle of the engine, a camshaft phase of the engine, a rotational speed of the engine, a pressure value in the combustion chamber 102, an intake air flow rate of the combustion chamber 102, an amount of fuel injected from the combustion chamber 102, and a type of fuel. Under conditions where the preset rule is satisfied, the fuel injection system injects fuel into the combustion chamber 102, whereupon the fuel is heated and spontaneously combusted.

[0145] The compression ratio indicates the degree to which the gas in the cylinder 101 is compressed when the piston 104 moves from bottom dead center to top dead center. For example, the compression ratio is the ratio of the total volume of the cylinder 101 before compression to the volume of the cylinder 101 after compression.

[0146] A higher rotation speed of the engine means a higher fuel injection frequency. For example, in a four-stroke engine, every two revolutions of the crank, the combustion chamber 102 completes one combustion charge and the fuel injection nozzle injects one fuel charge. In other words, the fuel injection frequency is equal to half the rotation speed.

[0147] The pressure value in the combustion chamber 102 is related to parameters such as the compression ratio, the intake air flow rate, the exhaust gas flow rate, the amount of injected fuel, and the temperature. In the present disclosure, considering the pressure value in the combustion chamber 102 actually comprehensively considers parameters such as the compression ratio, the intake air flow rate, the exhaust gas flow rate, the amount of injected fuel, and the temperature in the combustion chamber.

[0148] The intake air flow rate and exhaust gas flow rate are related to the amount of injected fuel: a higher intake air flow rate and a higher exhaust gas flow rate indicate a higher amount of injected fuel.

[0149] Higher fuel injection pressure means a faster fuel injection velocity, allowing the fuel to enter the combustion chamber and be heated more quickly. In addition, higher fuel injection pressure means a wider range of fuel injection timing options.

[0150] The camshaft phase of an engine and the crank angle of the engine are used to control the timing of opening and closing of the intake valves and / or exhaust valves of the engine. The camshaft phase refers to the rotation phase at which the cams on the camshaft open and close the intake valves and / or exhaust valves. The crank angle refers to the angle of rotation of the crank. The crank and the camshaft may be rotated synchronously by a timing mechanism. By controlling the camshaft phase of an engine and the crank angle of the engine, the timing of opening and closing of the intake valves and / or exhaust valves of the engine can be effectively controlled, resulting in higher engine operating efficiency. The engine rotation speed is the rotation speed of the crank.

[0151] Different types of fuel and different fuel injection pressures indicate different spontaneous combustion temperatures. The type of fuel may be gasoline, natural gas, methanol, ethanol, etc. The fuel injection pressure value may be determined based on the compression ratio, the intake air flow rate, and the amount of injected fuel.

[0152] The above description of the preset rules is merely an example. In specific work processes, those skilled in the art can specifically set the types of input parameters of the preset rules under the guidance of the present disclosure, and correspondingly set the judgment conditions corresponding to the input parameters, so as to correspondingly output results.

[0153] In one example, obtaining a characterizing temperature that characterizes the temperature in the combustion chamber 102 includes the following steps: obtaining a temperature at a specified position on the engine body 100 of the engine, the distance between the specified position and the combustion chamber 102 being in the range of 4 mm to 10 mm;

[0154] For example, the engine body 100 is made of a metal material such as carbon steel, stainless steel, and cast iron. Metal materials transfer heat quickly. A temperature sensor 111 is disposed at a predetermined position on the engine body 100. The proximity of the predetermined position to the combustion chamber 102 indicates that the temperature sensed by the temperature sensor 111 is closer to the temperature inside the combustion chamber 102. Within the above-mentioned scale range, it may be ensured that the characterization temperature acquired by the temperature sensor 111 is closer to the temperature inside the combustion chamber 102.

[0155] In one example, the engine in this embodiment of the present disclosure may be provided with a cooling water jacket for cooling the combustion chamber 102. After the cooling water jacket is in place, the combustion chamber 102 has an outer wall. Obtaining a characterizing temperature that characterizes the temperature inside the combustion chamber 102 includes the following steps: obtaining the temperature of the outer wall of the combustion chamber 102; and the distance between the outer wall of the combustion chamber 102 and the inner wall of the combustion chamber 102 is typically in the range of 4 mm to 10 mm.

[0156] Of course, the distance between the specified position and the combustion chamber 102 is not limited to the above embodiment, and may be selected by those skilled in the art based on actual requirements.

[0157] In one example, obtaining a characterization temperature characterizing the temperature inside the combustion chamber 102 includes the following steps: obtaining a characterization temperature characterizing the temperature of the inner wall of the combustion chamber 102; generally, the space inside the combustion chamber 102 is limited. If a temperature sensor 111 is additionally disposed, combustion will be affected; therefore, the temperature sensor 111 cannot be disposed directly inside the combustion chamber 102; in other words, the temperature inside the combustion chamber 102 cannot be measured directly; therefore, in this example, the temperature inside the combustion chamber 102 is obtained indirectly by obtaining a temperature at another position to characterize the temperature inside the combustion chamber 102. When the characterization temperature is converted to the temperature inside the combustion chamber 102, the characterization temperature may be converted by consulting calibration data or may be calculated and converted by combining parameters such as thermal conductivity.

[0158] Optionally, the temperature of the engine body 100 may be obtained by the temperature sensor 111 and used as a characterization temperature, which is close to the characterization temperature of the combustion chamber 102, thereby allowing for more accurate timing of fuel injection and more sufficient spontaneous combustion of the fuel.

[0159] The engine body 100 may be provided with a plurality of temperature sensors 111. The plurality of temperature sensors 111 acquire temperatures of different parts of the engine body 100 corresponding to the combustion chamber 102. An average value of the plurality of temperatures is used as a characterizing temperature that characterizes the temperature in the combustion chamber 102. In this way, the characterizing temperature that characterizes the temperature in the combustion chamber 102 can be acquired more accurately.

[0160] In another example, a temperature at another location may also be obtained by the temperature sensor 111 and used as the characterizing temperature. For example, the temperature at a location where the engine's intake tract is proximate to the combustion chamber 102 may be obtained and used as the characterizing temperature, or the temperature at a location where the engine's exhaust tract is proximate to the combustion chamber 102 may be obtained and used as the characterizing temperature, or the dimension proximate to the fuel injection nozzle may be obtained and used as the characterizing temperature.

[0161] In one example, the preset rule includes that the temperature in the combustion chamber 102 is greater than 300° C. In other words, when the temperature in the combustion chamber 102 is equal to or greater than a set threshold, the temperature in the combustion chamber 102 can reach a temperature greater than 300° C. during the compression stroke.

[0162] In one example, the preset rule includes that the temperature in the combustion chamber 102 is greater than 400° C. In other words, when the temperature in the combustion chamber 102 is equal to or greater than a set threshold, the temperature in the combustion chamber 102 can reach a temperature greater than 400° C. during the compression stroke.

[0163] Specifically, it can be determined whether the temperature in the combustion chamber 102 satisfies a preset rule based on the actual situation. Before the piston 104 reaches top dead center, the air pressure in the combustion chamber 102 gradually increases as the piston 104 moves. A higher pressure in the combustion chamber 102 indicates a lower combustion point. Conversely, a lower pressure indicates a higher combustion point. A specific temperature value that satisfies the preset rule may be selected based on the actual situation to ensure that the fuel can combust naturally in the combustion chamber 102. Generally, to ensure that the fuel can combust naturally in the combustion chamber 102, the temperature in the combustion chamber 102 needs to be higher than 300°C. In some operating conditions, the temperature in the combustion chamber 102 needs to be higher than 400°C to ensure that the fuel can combust naturally.

[0164] In one example, the pre-set rules include the temperature within the combustion chamber 102 being greater than the natural combustion temperature of the fuel within the combustion chamber 102 under current conditions.

[0165] The spontaneous combustion temperature is the lowest temperature at which fuel can spontaneously combust in an aerobic atmosphere without spark initiation. Note that the spontaneous combustion temperature is related to several factors, such as the fuel injection rate, the air pressure in the combustion chamber 102, the oxygen content in the combustion chamber 102, and the type of fuel. In this example, the temperature in the combustion chamber 102 is higher than the spontaneous combustion temperature of the fuel in the combustion chamber 102 at the current conditions, so that the fuel injected into the combustion chamber 102 from the fuel injection system can spontaneously combust without spark initiation.

[0166] In one example, the preset rule includes that the temperature in the combustion chamber 102 characterized by the characterizing temperature is greater than 1.2 times the natural combustion temperature of the fuel in the combustion chamber 102. In other words, if the temperature in the combustion chamber 102 is greater than or equal to the set threshold, the temperature in the combustion chamber 102 can reach 1.2 times the natural combustion temperature of the fuel during the compression stroke.

[0167] Under that condition, the control method can ensure that the fuel injected into the combustion chamber 102 from the fuel injection system burns quickly.

[0168] For example, if the spontaneous combustion temperature of the fuel is 300° C., the preset rule includes that the temperature characterized by the characterizing temperature in the combustion chamber 102 is higher than 360° C. In this way, it can be ensured that the fuel injected from the fuel injection system into the combustion chamber 102 can spontaneously combust quickly.

[0169] For example, if the spontaneous combustion temperature of the fuel is 400° C., the preset rule includes that the temperature characterized by the characterizing temperature in the combustion chamber 102 is higher than 480° C. In this way, it can be ensured that the fuel injected from the fuel injection system into the combustion chamber 102 can spontaneously combust quickly.

[0170] Of course, the ratio of the temperature in the combustion chamber 102 characterized by the characterizing temperature to the spontaneous combustion temperature included in the preset rule is not limited to the above embodiment, and may be selected by those skilled in the art based on actual requirements.

[0171] In one example, the input parameters of the pre-defined rule further include the crank angle of the engine.

[0172] One rotation of the engine crank spans 360°. Based on the obtained crank angle, the fuel injection system can be effectively controlled to inject fuel when the crank is rotated to a set crank angle. In this way, the control method can precisely control the timing of fuel injection, so that the fuel can be heated for a sufficient time in the combustion chamber 102 and can be more fully spontaneously combusted.

[0173] In one example, the pre-set rules include that the engine crank angle be in the range of 30° to 130° before top dead center of the compression stroke.

[0174] As the piston 104 moves from bottom dead center to top dead center, the crank rotates 180°. In this example, fuel injection is completed between the time when the crank rotates 50° from bottom dead center and the time when the crank rotates 150°. In other words, the fuel injection system injects fuel before the piston 104 reaches top dead center. In this way, the fuel is heated in the combustion chamber 102 for a sufficient time so that the fuel can be combusted when the piston 104 is near top dead center.

[0175] It should be noted that the engine camshaft rotates synchronously with the crank, so the engine crank angle in this embodiment of the present disclosure may be equivalently replaced with camshaft phase information to adjust the heating time of the combustion in the combustion chamber 102.

[0176] In one example, the control method further includes heating the combustion chamber 102 to allow the temperature within the combustion chamber 102 to reach a set threshold. In this example, during a warm-up condition, the temperature within the combustion chamber 102 can be heated to a set threshold.

[0177] In this example, the engine includes a heating device. The heating device can heat the combustion chamber 102 by electrical heating or combustion heating. The heating device heats the combustion chamber 102 to meet the temperature conditions for spontaneous combustion of fuel. In other words, the engine is allowed to complete warm-up. After heating, the temperature in the combustion chamber 102 is such that spontaneous combustion occurs when fuel is injected into the combustion chamber 102.

[0178] In one example, if the characterizing temperature is below the set temperature, the combustion chamber 102 is heated. If the characterizing temperature is below the set temperature, the fuel injected into the combustion chamber 102 does not spontaneously combust. If the characterizing temperature reaches or exceeds the set temperature, the fuel injected into the combustion chamber 102 can spontaneously combust.

[0179] For example, if the characterizing temperature is equal to or greater than the set temperature, the combustion chamber 102 is stopped from heating. In other words, the engine warm-up is completed. The engine has a condition for switching from a warm-up state to a non-warm-up state. If the characterizing temperature is equal to or greater than the set temperature, the temperature in the combustion chamber 102 is equal to or greater than a set threshold. The temperature in the combustion chamber 102 can reach the spontaneous combustion temperature of the fuel during the compression stroke.

[0180] In this example, if the characterizing temperature is equal to or greater than the set temperature, the combustion chamber 102 is turned off. The spontaneous combustion of fuel generates heat, which can ensure that the characterizing temperature of the combustion chamber 102 is equal to or greater than the set temperature. In other words, the heat can ensure that the temperature in the combustion chamber 102 always reaches the spontaneous combustion temperature of the fuel during the compression stroke, so that the fuel spontaneously combusts.

[0181] Therefore, in this example, in the non-warmed state, the characterizing temperature may no longer be acquired. In other words, during the second operating state, the acquisition of the characterizing temperature is stopped, and the temperature in the combustion chamber 102 initially satisfies the preset rule. Because the temperature in the combustion chamber 102 can always be maintained at a value that satisfies the preset rule by the heat of spontaneous combustion of the fuel, when the engine operates in the non-warmed state, fuel can be directly injected into the combustion chamber 102 during the compression stroke. The fuel enters the combustion chamber 102, is heated, and spontaneously combusts. Therefore, the method for controlling the engine in this embodiment of the present disclosure may be simplified to ensure efficient operation of the engine.

[0182] Of course, in this example, in a non-warmed state, the characterization temperature may still be obtained at a certain frequency so that the temperature in the combustion chamber 102 can be heated and increased while the temperature decreases, thereby ensuring natural combustion of the fuel. However, the frequency may be relatively low to account for the heat generated when the fuel is burned, thereby somewhat simplifying the method of controlling the engine in this embodiment of the present disclosure.

[0183] In one example, heating the combustion chamber 102 includes the following steps: fuel is ignited by the spark plug 110, and the heat of the fuel heats the combustion chamber 102. In other words, in a warm-up state, fuel can be ignited by the spark plug, and the heat of the fuel can heat the combustion chamber in order to raise the temperature in the combustion chamber of the engine to a set threshold.

[0184] In this example, fuel is ignited by a spark plug 110. When the fuel burns, heat is generated. The heat is used to heat the combustion chamber 102. In this way, the spark plug 110 of the original engine is used to heat the combustion chamber 102. If the temperature in the combustion chamber 102 is above a set threshold, the fuel injected by the fuel injection system can combust naturally. If the obtained characterization temperature reaches the set temperature, the spark plug 110 does not need to be re-activated. The temperature in the combustion chamber 102 is maintained directly by using the heat generated from the combustion in the combustion chamber 102, so that the fuel injected by the fuel injection system into the combustion chamber 102 can combust naturally.

[0185] In this example, the heating method of using the heat of fuel to heat the combustion chamber 102 by igniting the fuel with the spark plug 110 is only applicable to heating the engine when the engine is warmed up. In the non-warmed state, if the combustion chamber 102 needs to be heated by igniting the fuel using the spark plug, the control of the engine becomes complicated. Different operating cycles output different power and torque, which affects the smoothness of the engine operation.

[0186] In one example, heating the combustion chamber 102 includes the following steps: The combustion chamber 102 is heated by an electric heating device. Specifically, the combustion chamber 102 can be heated by an electric heating device to raise the temperature within the combustion chamber 102 of the engine above a set threshold during a warmed-up or unwarmed-up state.

[0187] In this example, the engine body 100 is provided with an electric heating device. The electric heating device is configured to heat the combustion chamber 102. For example, the electric heating device is arranged around the combustion chamber 102. The combustion chamber 102 is heated more quickly by the electric heating device. By heating with the electric heating device, the temperature in the combustion chamber 102 can be effectively controlled, which ensures that the fuel injected into the combustion chamber 102 from the fuel injection system can be combusted naturally.

[0188] For example, the electric heating device includes a power source, a switch, and a heating resistor. The power source is electrically connected to the switch and the heating resistor. The power source is configured to supply power to the heating resistor. The switch is configured to control the on and off of the heating current. The electric heating device can quickly heat the combustion chamber 102. In another example, the electric heating device includes a power source and a switch. A cylinder configured to define the combustion chamber 102 is electrically connected to the power source. The power source is configured to supply power to the cylinder to directly heat the cylinder. The switch is configured to control the on and off of the heating current.

[0189] In one example, as shown in FIG. 2 , the engine body 100 includes a cylinder liner 103. The cylinder liner 103 is disposed within the cylinder 101. The outer wall of the cylinder liner 103 is attached to the inner wall of the cylinder 101. The piston 104 is positioned within the cylinder liner 103. The material of the cylinder liner 103 is harder than the material of the inner wall of the cylinder 101 and has good wear resistance. The cylinder liner 103 can effectively improve the service life of the engine. In one example, the electric heating device includes an electric heating unit. The electric heating unit is disposed between the inner wall of the cylinder 101 and the cylinder liner 103. The electric heating unit heats the combustion chamber 102, so that the temperature within the combustion chamber 102 is maintained above the spontaneous combustion temperature of the fuel. By disposing the electric heating unit between the inner wall of the cylinder 101 and the cylinder liner 103, the impact of external forces can be avoided, thereby significantly improving the durability of the engine.

[0190] The electric heating device can be operated to raise and maintain the temperature in the combustion chamber when the temperature in the combustion chamber unexpectedly drops during a non-warm-up phase of the engine. The electric heating device can also heat the combustion chamber 102 during a warm-up phase of the engine so that the characterization temperature reaches a set temperature.

[0191] In one example, controlling the fuel injection system to inject fuel into the combustion chamber 102 includes the following steps: Fuel is injected into the combustion chamber 102 multiple times.

[0192] Compared with injecting fuel once, injecting fuel into the combustion chamber 102 multiple times after the acquired characterization temperature reaches the set temperature can allow the fuel to be more thoroughly mixed with air, so that the injected fuel can spontaneously combust quickly. In this way, the starting speed of the engine can be significantly increased.

[0193] In one example, before the fuel injection system is controlled to inject fuel into the combustion chamber 102 based on preset rules, the method includes the following steps: When the engine is in the intake stroke or the compression stroke, the fuel injection system is controlled to inject a first set amount of fuel into the combustion chamber 102.

[0194] Controlling the fuel injection system to inject fuel into the combustion chamber 102 based on preset rules includes the steps of: controlling the fuel injection system to inject a second set amount of fuel into the combustion chamber 102, the second set amount being greater than the first set amount;

[0195] In a specific embodiment, when the engine is in the intake stroke, fuel pre-injection is performed, i.e., a first set amount of fuel is injected. When the engine is in the compression stroke, main fuel injection is performed, i.e., a second set amount of fuel is injected. The amount of pre-injected fuel is less than the amount of main-injected fuel. Specifically, when the engine is in the intake stroke, the fuel injection system is controlled to inject a first set amount of fuel into the combustion chamber 102. In this case, the first set amount is the amount of pre-injected fuel. The first set amount is relatively small. Therefore, after the first set amount of fuel is diluted in the combustion chamber, the spontaneous combustion condition is never met. In this case, the pre-injected fuel does not spontaneously combust. However, the pre-injected fuel can be sufficiently mixed with air, so that the main-injected fuel can be quickly and sufficiently mixed with the gas mixture in the combustion chamber 102. When the engine is in the compression stroke, the fuel injection system is controlled to inject a second set amount of fuel into the combustion chamber 102. In this case, the second set amount is the amount of main-injected fuel. After the main injection, the fuel burns spontaneously in the combustion chamber 102 as the characterization temperature reaches the set temperature.

[0196] In another specific embodiment, when the engine is in the compression stroke, fuel pre-injection is performed first, followed by main fuel injection. The amount of pre-injected fuel is less than the amount of main-injected fuel. Specifically, when the engine is in the compression stroke, the fuel injection system is controlled to inject a first set amount of fuel into the combustion chamber 102. In this case, the first set amount is the amount of pre-injected fuel. The first set amount is relatively small. Therefore, after the first set amount of fuel is diluted in the combustion chamber, the spontaneous combustion condition is never met. However, the pre-injected fuel can be sufficiently mixed with the air, so that the main-injected fuel can be quickly and sufficiently mixed with the gas mixture in the combustion chamber 102. Next, the fuel injection system is controlled to inject a second set amount of fuel into the combustion chamber 102. In this case, the second set amount is the amount of main-injected fuel. After the main injection, the fuel spontaneously combusts in the combustion chamber 102 because the characterization temperature reaches the set temperature.

[0197] In this example, the pre-injected fuel can be quickly mixed with the air, and the main-injected fuel can be quickly and thoroughly mixed with the gas mixture in the combustion chamber 102, thereby achieving rapid combustion without knocking.

[0198] According to a fourth embodiment of the present disclosure, there is provided a vehicle, the vehicle including a vehicle body and the engine described above, the engine being disposed in the vehicle body.

[0199] The vehicle has the advantages of fuel economy and high thermal efficiency.

[0200] The above-mentioned embodiments focus on the differences between the embodiments. As long as the different optimization features between the embodiments are not contradictory, the different optimization features may be combined to form a better embodiment. In consideration of the concise description, the details will not be described again in this specification.

[0201] Although several specific embodiments of the present disclosure have been described in detail as examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Those skilled in the art should appreciate that modifications may be made to the above-described embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is limited only by the appended claims. [Explanation of symbols]

[0202] 100 Engine body 101 Cylinder 102 Combustion chamber 103 Cylinder liner 104 Piston 105 Fuel injection nozzle 106 Intake System 107 Exhaust System 108 Control device 109 Cooling device 110 Spark Plug 111 Temperature Sensor 113 Thermal insulation coating 114 Throttle valve 115 Turbine 116 Rotation axis 117 Compressor Wheel 118 Generator 119 Gas return branch pipe 120 Exhaust gas cooler 121 Rankine Circulation Module 126 Exhaust manifold 127 First Valve 128 Intake branch pipe 129 Second Valve 130 Third Valve

Claims

1. An engine comprising: an engine body, a fuel injection system, and a piston; a cylinder formed within the engine body; the piston slidably disposed within the cylinder; a combustion chamber formed between the piston and an inner wall of the cylinder; the fuel injection system connected to the combustion chamber and configured to inject fuel into the combustion chamber; During an operating cycle of the engine, the total energy generated from the combustion of the fuel in the combustion chamber is Q1, the exhaust heat of the combustion chamber is Q2, and the heat released from the combustion chamber is Q3; An engine wherein 35%≦Q2:Q1≦45% and Q3:Q1≦20%.

2. 10. The engine of claim 1, further comprising an exhaust system and an exhaust utilization device, said exhaust system communicating with the interior of said combustion chamber and said exhaust utilization device connected to an exhaust pipe.

3. 3. The engine of claim 2, wherein the exhaust utilization device comprises a turbocharging module comprising a turbine, a rotating shaft, and a compressor wheel, the turbine and the compressor wheel both drivingly coupled to the rotating shaft, the turbine being located within the exhaust system, and the compressor wheel being located within the intake system.

4. 4. The engine of claim 3, wherein the exhaust utilization device comprises a generator, the rotor of the generator being drivingly connected to the turbine.

5. the exhaust utilization device comprises an exhaust gas recirculation module; 5. An engine according to claim 2, wherein the exhaust gas recirculation module comprises a gas return branch and an exhaust gas cooler, the exhaust gas cooler being arranged in the gas return branch, one end of the gas return branch being connected to the exhaust system and the other end of the gas return branch being connected to the intake system of the engine.

6. the exhaust gas utilization device comprises a Rankine circulation module, the Rankine circulation module comprising a circulation pipeline, a heat exchanger, an expander, a condenser, and a pump body, the heat exchanger, the expander, the condenser, and the pump body being connected end-to-end through the circulation pipeline; 6. An engine according to claim 2, wherein the heat exchanger has a first heat exchange path and a second heat exchange path, the first heat exchange path being in communication with the exhaust system, and the second heat exchange path being in communication with the circulation pipeline.

7. 7. An engine according to claim 2, wherein the exhaust utilization device comprises at least one of a thermoelectric power generation module, a cooling and air conditioning module, and a heating waste heat module.

8. 8. The engine of claim 1, further comprising a heat retention device, the heat retention device being disposed on the engine body and configured to provide heat retention to the combustion chamber.

9. The heat retention device is 9. The engine of claim 8, further comprising a thermal structure, wherein an insulating chamber is formed in the thermal structure, the thermal structure being disposed outside of and around the cylinder.

10. The heat retention device is 10. An engine according to claim 8 or 9, comprising a thermal barrier coating, the thermal barrier coating being disposed on the inner wall of the cylinder, on the outside of the cylinder, around the cylinder, or on one end of the piston.

11. 11. The engine of claim 10, wherein the thermal barrier coating is made of silicon dioxide reinforced porous anodic alumina.

12. 8. An engine according to claim 1, wherein the engine body comprises a cylinder liner, the cylinder liner is disposed within the cylinder, an outer wall of the cylinder liner is attached to the inner wall of the cylinder, and the piston is positioned within the cylinder liner.

13. The engine further includes a heat retention device, the heat retention device being disposed on the engine body and configured to provide heat retention to the combustion chamber, the heat retention device including a thermal insulation coating; The engine of claim 12 , wherein the thermal barrier coating is disposed between the inner wall of the cylinder and the cylinder liner, or the thermal barrier coating is disposed on the inner wall of the cylinder liner.

14. 14. The engine of claim 12 or 13, further comprising a heating device, said heating device comprising an electric heating unit, said electric heating unit being disposed between said inner wall of said cylinder and said outer wall of said cylinder liner.

15. 15. An engine according to any one of claims 1 to 14, wherein the fuel injection system is configured to inject the fuel into the combustion chamber after a temperature within the combustion chamber reaches a set threshold to heat the fuel and cause it to spontaneously combust within the combustion chamber, and wherein if the temperature within the combustion chamber is equal to or greater than the set threshold, the temperature within the combustion chamber reaches the spontaneous combustion temperature of the fuel during a compression stroke.

16. 16. The engine of claim 15, further comprising a heating device, the heating device configured to heat the combustion chamber to cause the temperature within the combustion chamber to reach the set threshold.

17. The heating device is a spark plug, the spark plug configured to initiate heating of the combustion chamber via the fuel's heat; and / or 17. The engine of claim 16, comprising an electric heating unit, the electric heating unit configured to electrically heat the combustion chamber.

18. 18. An engine according to any one of claims 1 to 17, wherein the engine has an air excess factor of 1 or greater.

19. 19. A method of controlling an engine according to any one of claims 1 to 18, comprising the steps of: obtaining a temperature value characterizing a temperature within the combustion chamber; 19. A method of controlling an engine according to any one of claims 1 to 18, comprising controlling the fuel injection system to inject fuel into the combustion chamber when the engine is in a compression stroke based on a preset rule, wherein the fuel in the combustion chamber is heated and combusts spontaneously, and wherein an input parameter of the preset rule comprises the temperature value.

20. 19. A method of controlling an engine according to any one of claims 1 to 18, wherein the engine has a first operating state and a second operating state, the method comprising: During the first operating state, increasing the temperature within the combustion chamber of the engine to a set threshold; If the temperature in the combustion chamber is equal to or greater than the set threshold, the temperature in the combustion chamber reaches a spontaneous combustion temperature of the fuel during the compression stroke; 19. A method of controlling an engine as claimed in any one of claims 1 to 18, comprising injecting the fuel into the combustion chamber during the second operating state and causing the fuel to heat and combust spontaneously within the combustion chamber.

21. A vehicle, said vehicle comprising a vehicle body and an engine according to any one of claims 1 to 18, said engine being disposed in said vehicle body.

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