Compression ignition type diesel engine system and using method thereof

Abstract

The invention relates to a compression ignition type diesel engine system and a using method thereof.The compression ignition type diesel engine system comprises an engine system, a diesel direct injection supply system, a methanol direct injection supply system and a methanol pyrolysis gas device, and the diesel direct injection supply system is arranged at the bottom of one side of the engine system; the methanol pyrolysis gas device is arranged on the other side of the engine system, and a methanol direct injection supply system is arranged on one side of the methanol pyrolysis gas device. The influence of ignition type easy knocking is avoided, and the safety fatigue period of the air cylinder is prolonged.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of engine systems, in particular to a compression ignition diesel engine system and a method of using the same. BACKGROUND

[0002] Methanol has high octane value, low cost, environmental protection, and is widely used in engine alternative fuel selection; high oxygen content improves combustion efficiency and reduces CO and HC emissions; but methanol has high latent heat of vaporization, making it difficult to start the engine, so the exhaust heat can be used to heat the catalytic cracking, and then directly injected into the cylinder through the nozzle, which can effectively utilize the waste heat and reduce the influence of high latent heat of methanol on the cylinder combustion temperature.

[0003] Currently, most of the methanol is added from the intake manifold or mixed with gaseous fuel pipeline, which is not conducive to pipeline processing; direct injection of liquid methanol into the cylinder at too early or too late will result in poor combustion effect; spark-ignition engines can cause knock phenomenon, causing damage to the engine.

[0004] A spark-ignition methanol cracking gas engine is disclosed in Chinese patent application No. "CN202211599644.8", which evaporates methanol and water through an evaporator, applies a methanol cracker for cracking reaction, and mixes methanol cracking gas and air in a gas mixing tank to enter a spark-ignition engine for ignition. It can solve the problems of low and medium load heat efficiency of the original spark-ignition methanol cracking gas engine and high load prone to knock, improve the combustion speed by using plasma at low load, improve the hydrogen production rate by using methanol water vapor cracking and adding hot EGR at medium load, and reduce the tendency of knock and improve the thermal efficiency at high load. However, direct injection of liquid methanol into the cylinder too early will cause fuel wetting, too late will cause uneven mixing of the mixture, and poor combustion effect; at the same time, the engine uses spark-ignition, which can cause knock phenomenon due to sudden increase of local temperature and pressure in the cylinder, which can easily damage the engine cylinder.

[0005] A marine dual direct injection engine system and its control method are disclosed in Chinese patent application No. "CN202211599644.8", which is applied to the field of engine technology. The system includes a methanol supply module, a diesel supply module, an engine, a methanol cracking module, and an exhaust gas recirculation module. By controlling the methanol supply module and the diesel supply module, the combustion mode and fuel ratio of the engine can be flexibly controlled to meet the needs of different sailing conditions.

[0006] External exhaust gas recirculation is carried out through the exhaust gas recirculation module to regulate the combustion rate, reduce the combustion rate, prevent the explosion pressure from exceeding the limit and knock; the input methanol is cracked by the methanol cracking module to realize methanol cracking hydrogen-doped combustion, effectively accelerate the combustion rate, and thus realize clean, efficient and controllable combustion of the engine in a wide operating condition range, and effectively alleviate the problem of limited operating conditions.

[0007] However, methanol mixed with methanol cracking gas is pre-mixed with air into the cylinder by adding a mixed gaseous fuel pipeline in the intake manifold, the structure is not simple enough, and the pipeline processing is complex, and thus a compression ignition diesel engine system and a use method thereof are provided. SUMMARY

[0008] This section is intended to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, the abstract and the title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0009] In view of the following technical problems in the prior art: methanol mixed with methanol cracking gas is pre-mixed with air into the cylinder by adding a mixed gaseous fuel pipeline in the intake manifold, the structure is not simple enough, and the pipeline processing is complex.

[0010] To solve the above technical problems, the present application provides the following technical solutions: a compression ignition diesel engine system and a use method thereof, comprising an engine system, a diesel direct injection supply system, a methanol direct injection supply system and a methanol cracking gas device, the bottom of one side of the engine system is provided with the diesel direct injection supply system, the other side of the engine system is provided with the methanol cracking gas device, and one side of the methanol cracking gas device is provided with the methanol direct injection supply system.

[0011] As a preferred technical solution of the compression ignition diesel engine system and the use method thereof, the engine system comprises an intake pipe, a compressor, an intake cutoff valve, a cylinder, a coaxial double-channel fuel nozzle, an exhaust pipe, an exhaust temperature measuring instrument, an exhaust cutoff valve, a supercharger and a rotating shaft;

[0012] The methanol cracking gas device comprises a methanol input end, an exhaust output end and a cracking gas tank;

[0013] The upper side of the input section of the intake pipe is connected to the lower side of the compressor;

[0014] The left side of the middle section of the intake pipe is connected to the right side of the compressor, and the right side of the middle section of the intake pipe is connected to the left side of the intake cutoff valve;

[0015] The left side of the air intake pipe output section is connected with the right side of the air intake stop valve, and the right side of the air intake pipe output section is connected with the air cylinder air intake input end;

[0016] The exhaust pipe is two parts, one part is located below the methanol cracking gas device, and the other part is located above the methanol cracking gas device;

[0017] The lower side of the exhaust pipe input section is connected with the upper side of the air cylinder exhaust output end, and the upper side of the exhaust pipe input section is connected with the lower side of the exhaust temperature measuring instrument;

[0018] The right side of the middle section of the exhaust pipe is connected with the upper side of the exhaust output end, and the left side of the middle section of the exhaust pipe is connected with the right side of the exhaust stop valve;

[0019] The left side of the exhaust pipe rear section is connected with the right side of the supercharger, and the right side of the exhaust pipe rear section is connected with the left side of the exhaust stop valve;

[0020] The lower side of the exhaust pipe output section is connected with the upper side of the supercharger;

[0021] The lower side of the rotating shaft is connected with the upper side of the air compressor, and the upper side of the rotating shaft is connected with the lower side of the supercharger.

[0022] As a preferred technical scheme of a compression ignition diesel engine system and a method for using the same, the diesel direct injection fuel supply system comprises a diesel storage bottle, a diesel fuel supply pipe, a diesel flow measuring instrument, a diesel pump and a diesel stop valve;

[0023] The left side of the diesel fuel supply pipe input section is connected with the diesel storage bottle, and the right side of the diesel fuel supply pipe input section is connected with the left side of the diesel flow measuring instrument;

[0024] The left side of the diesel fuel supply pipe rear section is connected with the right side of the diesel pump, and the right side of the diesel fuel supply pipe rear section is connected with the left side of the diesel stop valve;

[0025] The left side of the diesel fuel supply pipe output section is connected with the right side of the diesel stop valve, and the right side of the diesel fuel supply pipe output section is connected with the upper side of the coaxial double-channel fuel nozzle.

[0026] As a preferred technical scheme of a compression ignition diesel engine system and a method for using the same, the methanol direct injection fuel supply system comprises a methanol storage bottle, a methanol fuel supply pipe, a methanol flow measuring instrument, a methanol pump and a methanol stop valve, the left side of the methanol fuel supply pipe input section is connected with the methanol storage bottle, and the right side of the methanol fuel supply pipe input section is connected with the left side of the methanol flow measuring instrument;

[0027] The left side of the middle section of the methanol fuel supply pipe is connected with the right side of the methanol flow measuring instrument, the right side of the middle section of the methanol fuel supply pipe is connected with the left side of the methanol pump;

[0028] The left side of the rear section of the methanol fuel supply pipe is connected with the right side of the methanol pump, and the right side of the rear section of the methanol fuel supply pipe is connected with the left side of the methanol stop valve;

[0029] The left side of the output section of the methanol fuel supply pipe is connected with the right side of the methanol stop valve, and the right side of the output section of the methanol fuel supply pipe is connected with the methanol input end.

[0030] As a preferred technical scheme of a compression ignition diesel engine system and a method for using the same, the methanol cracking gas device comprises a methanol input end, an exhaust gas output end, a cracking gas tank, a baffle, a cracking gas heating catalytic pipe, a cracking gas output end, a pressure regulating valve, a methanol cracking gas pipe, a pressure detector and an exhaust gas input end;

[0031] The left side of the cracking gas tank is connected with the right side of the methanol input end, and the upper side of the cracking gas tank is connected with the lower side of the exhaust gas output end;

[0032] The right side of the cracking gas tank is connected with the left side of the cracking gas output end, the left side of the input section of the methanol cracking gas pipe is connected with the right side of the cracking gas output end, the right side of the input section of the methanol cracking gas pipe is connected with the upper side of the pressure regulating valve, the right side of the middle section of the methanol cracking gas pipe is connected with the lower side of the pressure regulating valve, and the left side of the middle section of the methanol cracking gas pipe is connected with the right side of the pressure detector;

[0033] The right side of the output section of the methanol cracking gas pipe is connected with the left side of the pressure detector, and the left side of the output section of the methanol cracking gas pipe is connected with the upper side of the coaxial double-channel fuel nozzle;

[0034] The lower side of the cracking gas tank is connected with the upper side of the exhaust gas input end, and the lower side of the exhaust gas input end is connected with the upper side of the exhaust gas temperature measuring instrument.

[0035] As a preferred technical scheme of a compression ignition diesel engine system and a method for using the same, the following steps are included:

[0036] S1, the speed and working torque of the engine are measured according to a dynamometer;

[0037] S2, the relationship between the working torque of the engine and the rated torque is judged to determine the working mode of the engine;

[0038] S3, different fuel injection supply strategies are adopted according to the working mode of the engine under different loads.

[0039] As a kind of compression ignition diesel engine system and its use method preferred technical scheme, according to the size relationship between engine working torque and rated torque, engine working state is determined, including:

[0040] 1), engine cold start control:

[0041] Engine cold start refers to the engine starts working from zero speed;

[0042] Engine low load refers to engine working torque less than or equal to the rated torque first threshold value, i.e. engine working torque ≤ engine rated torque 40%;

[0043] 2), engine non-cold start control:

[0044] Engine medium load refers to engine working torque greater than the rated torque first threshold value, less than or equal to the second threshold value, i.e. engine rated torque 40% < engine working torque ≤ engine rated torque 70%;

[0045] Engine high load refers to engine working torque greater than the rated torque second threshold value, i.e. engine rated torque 70% < engine working torque ≤ engine rated torque 100%.

[0046] As a kind of compression ignition diesel engine system and its use method preferred technical scheme, when the engine cold start, open the diesel stop valve, close the methanol stop valve;

[0047] The flow and flow rate of diesel are adjusted by the diesel stop valve.

[0048] As a kind of compression ignition diesel engine system and its use method preferred technical scheme, when the engine non-cold start, open the diesel stop valve and the methanol stop valve;

[0049] The mass and flow rate of diesel are adjusted by the diesel stop valve, and the rate of methanol cracking gas is adjusted by the pressure regulating valve.

[0050] The compression ignition diesel engine system and its use method of the application have the following beneficial effects: the engine adopts compression ignition, avoids the influence of knock of spark ignition, and improves the cylinder safety fatigue cycle;

[0051] In-cylinder direct injection of methanol and cracking gas can improve the uniformity of mixture distribution faster than direct injection of liquid fuel through pressure regulating valve, and there is no wall sticking and uneven mixing phenomenon, compared with intake manifold injection fuel, the engine system can be simplified, only the nozzle structure is changed, and it is easy to realize;

[0052] The exhaust waste heat is utilized to improve energy utilization rate and reduce the influence of methanol vaporization latent heat on engine in-cylinder combustion temperature;

[0053] Methanol mixed combustion cracking gas can effectively reduce the high emission effect caused by burning diesel, and better realize the combustion effect of high efficiency and low emission of the engine, and the combustion efficiency is high. BRIEF DESCRIPTION OF DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0055] ATTACHMENT Fig. 1 The structure schematic diagram of the compression ignition diesel micro-injection methanol mixed combustion cracking gas engine system;

[0056] ATTACHMENT Fig. 2 The control method flow chart of the compression ignition diesel micro-injection methanol mixed combustion cracking gas engine system;

[0057] ATTACHMENT Fig. 3 The structure schematic diagram of the coaxial double-channel fuel nozzle;

[0058] ATTACHMENT Fig. 4 The structure schematic diagram of the methanol cracking gas device.

[0059] Reference signs: 11, air inlet pipe; 12, air compressor; 13 is air inlet stop valve; 14, cylinder; 15, coaxial double-channel fuel nozzle; 16, exhaust pipe; 17, exhaust temperature measuring instrument; 18, exhaust stop valve; 19, supercharger; 20, rotating shaft; 21, diesel storage bottle; 22, diesel fuel supply pipe; 23, diesel flow measuring instrument; 24, diesel pump; 25, diesel stop valve; 31, methanol storage bottle; 32, methanol fuel supply pipe; 33, methanol flow measuring instrument; 34, methanol pump; 35, methanol stop valve; 4, methanol cracking gas device; 41, methanol input end; 42, exhaust output end; 43, cracking gas tank; 44, baffle; 45, cracking gas heating catalytic pipe; 46, cracking gas output end; 47, pressure regulating valve; 48, methanol cracking gas pipe; 49, pressure detector; 410, exhaust input end; 151, nozzle shell; 152, diesel injection pipeline; 153, methanol injection pipeline; 154, methanol nozzle; 155, diesel nozzle. DETAILED DESCRIPTION

[0060] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings of the specification.

[0061] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details set forth in this disclosure. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present application.

[0062] Second, the "one embodiment" or "an embodiment" as used herein means a specific implementation, or example, that can include features that are not included in other implementations or examples of the present application. Various instances of "in one embodiment" or "in an embodiment" that can appear in various places in this specification are not necessarily all referring to the same embodiment.

[0063] Third, the present application is described in connection with exemplary embodiments, schematics, and drawings. In the interest of clarity, not all features of an actual implementation can be described in this specification. It will of course be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions can be made to achieve the development goal, which will vary from one implementation to another. Moreover, it will often be the case that a design contains structural and / or functional limitations that simply cannot be expressed in simple or single-minded fashion. Accordingly, the features illustrated (and consequently discussed in this specification) can not be exhaustive, but instead represent a typical or representative example of the present application. It should be noted that, in some alternative implementations, full software simulation, other implementation, or fabrication can be realized. Also, it is intended that the scope of the present application extend to such and similar implementations and uses, and that the scope is not limited to the specific embodiments described in this specification.

[0064] As shown in Figs. 1-4 The present application provides a compression ignition diesel engine system and a method thereof, comprising an engine system 1, a diesel direct injection supply system 2, a methanol direct injection supply system 3 and a methanol cracking gas device 4, wherein the bottom of one side of the engine system 1 is provided with the diesel direct injection supply system 2, the other side of the engine system 1 is provided with the methanol cracking gas device 4, and one side of the methanol cracking gas device 4 is provided with the methanol direct injection supply system 3.

[0065] The engine system 1 comprises an air inlet pipe 11, a compressor 12, an air inlet cutoff valve 13, a cylinder 14, a coaxial double-channel fuel nozzle 15, an exhaust pipe 16, an exhaust temperature measuring instrument 17, an exhaust cutoff valve 18, a supercharger 19 and a rotating shaft 20.

[0066] The methanol cracking gas device 4 comprises a methanol input end 41, an exhaust output end 42 and a cracking gas tank 43.

[0067] The upper side of the input section of the air inlet pipe 11 is connected with the lower side of the compressor 12.

[0068] The left side of the middle section of the air inlet pipe 11 is connected with the right side of the compressor 12, and the right side of the middle section of the air inlet pipe 11 is connected with the left side of the air inlet cutoff valve 13.

[0069] The left side of the output section of the air inlet pipe 11 is connected with the right side of the air inlet cutoff valve 13, and the right side of the output section of the air inlet pipe 11 is connected with the air inlet input end of the cylinder 14.

[0070] The exhaust pipe 16 is two parts, one part is located in the lower side of the methanol cracking gas device 4, the other part is located in the upper side of the methanol cracking gas device 4;

[0071] The lower side of the input section of the exhaust pipe 16 is connected with the exhaust output end of the cylinder 14, and the upper side of the input section of the exhaust pipe 16 is connected with the lower side of the exhaust temperature measuring instrument 17;

[0072] The right side of the middle section of the exhaust pipe 16 is connected with the upper side of the exhaust output end 42, and the left side of the middle section of the exhaust pipe 16 is connected with the right side of the exhaust cutoff valve 18;

[0073] The left side of the rear section of the exhaust pipe 16 is connected with the right side of the supercharger 19;

[0074] The upper side of the supercharger 19 is connected with the lower side of the output section of the exhaust pipe 16;

[0075] The upper side of the supercharger 19 is connected with the lower side of the output section of the exhaust pipe 16;

[0076] As a preferred technical scheme of a compression ignition diesel engine system and a method for using the same, the diesel direct injection fuel supply system 2 comprises a diesel storage bottle 21, a diesel fuel supply pipe 22, a diesel flow measuring instrument 23, a diesel pump 24 and a diesel cutoff valve 25;

[0077] The left side of the input section of the diesel fuel supply pipe 22 is connected with the diesel storage bottle 21, and the right side of the input section of the diesel fuel supply pipe 22 is connected with the left side of the diesel flow measuring instrument 23;

[0078] The left side of the rear section of the diesel fuel supply pipe 22 is connected with the right side of the diesel pump 24, and the right side of the rear section of the diesel fuel supply pipe 22 is connected with the left side of the diesel cutoff valve 25;

[0079] The right side of the output section of the diesel fuel supply pipe 22 is connected with the upper side of the coaxial double-channel fuel nozzle 15.

[0080] The methanol direct injection fuel supply system 3 comprises a methanol storage bottle 31, a methanol fuel supply pipe 32, a methanol flow measuring instrument 33, a methanol pump 34 and a methanol cutoff valve 35, the left side of the input section of the methanol fuel supply pipe 32 is connected with the methanol storage bottle 31, and the right side of the input section of the methanol fuel supply pipe 32 is connected with the left side of the methanol flow measuring instrument 33;

[0081] The left side of the middle section of the methanol fuel supply pipe 32 is connected with the right side of the methanol flow measuring instrument 33, and the right side of the middle section of the methanol fuel supply pipe 32 is connected with the left side of the methanol pump 34;

[0082] The left side of the rear section of the methanol fuel supply pipe 32 is connected with the right side of the methanol pump 34, and the right side of the rear section of the methanol fuel supply pipe 32 is connected with the left side of the methanol stop valve 35;

[0083] The left side of the output section of the methanol fuel supply pipe 32 is connected with the right side of the methanol stop valve 35, and the right side of the output section of the methanol fuel supply pipe 32 is connected with the methanol input end 41.

[0084] The methanol cracking gas device 4 comprises a methanol input end 41, an exhaust gas output end 42, a cracking gas tank 43, a baffle 44, a cracking gas heating catalytic pipe 45, a cracking gas output end 46, a pressure regulating valve 47, a methanol cracking gas pipe 48, a pressure detector 49 and an exhaust gas input end 410;

[0085] The left side of the cracking gas tank 43 is connected with the right side of the methanol input end 41, and the upper side of the cracking gas tank 43 is connected with the lower side of the exhaust gas output end 42;

[0086] The right side of the cracking gas tank 43 is connected with the left side of the cracking gas output end 46, the left side of the input section of the methanol cracking gas pipe 48 is connected with the right side of the cracking gas output end 46, and the right side of the input section of the methanol cracking gas pipe 48 is connected with the upper side of the pressure regulating valve 47; the right side of the middle section of the methanol cracking gas pipe 48 is connected with the lower side of the pressure regulating valve 47, and the left side of the middle section of the methanol cracking gas pipe 48 is connected with the right side of the pressure detector 49;

[0087] The right side of the output section of the methanol cracking gas pipe 48 is connected with the left side of the pressure detector 49, and the left side of the output section of the methanol cracking gas pipe 48 is connected with the upper side of the coaxial double-channel fuel nozzle 15;

[0088] The lower side of the cracking gas tank 43 is connected with the upper side of the exhaust gas input end 410, and the lower side of the exhaust gas input end 410 is connected with the upper side of the exhaust gas temperature measuring instrument 17.

[0089] The method comprises the following steps:

[0090] S1, measuring the speed and working torque of the engine according to the dynamometer;

[0091] S2, judging the size relationship between the working torque and the rated torque of the engine to determine the working mode of the engine;

[0092] S3, adopting different fuel injection supply strategies according to the working mode of the engine under different loads.

[0093] According to the relationship between the engine working torque and the rated torque, the engine working state is determined, including:

[0094] 1. Engine cold start control:

[0095] Engine cold start refers to the engine starting to work from zero speed;

[0096] Engine low load refers to the engine working torque being less than or equal to the first threshold of the rated torque, i.e. engine working torque ≤ engine rated torque 40%;

[0097] 2. Engine non-cold start control:

[0098] Engine medium load refers to the engine working torque being greater than the first threshold of the rated torque and less than or equal to the second threshold, i.e. engine rated torque 40% < engine working torque ≤ engine rated torque 70%;

[0099] Engine high load refers to the engine working torque being greater than the second threshold of the rated torque, i.e. engine rated torque 70% < engine working torque ≤ engine rated torque 100%.

[0100] When the engine is cold started, the diesel cut-off valve 25 is opened and the methanol cut-off valve 35 is closed;

[0101] The flow rate and flow velocity of diesel are adjusted through the diesel cut-off valve 25.

[0102] When the engine is not cold started, the diesel cut-off valve 25 and the methanol cut-off valve 35 are opened;

[0103] The mass and flow velocity of diesel are adjusted through the diesel cut-off valve 25, and the rate of methanol cracking gas is adjusted through the pressure regulating valve 47.

[0104] High combustion efficiency refers to the thermal efficiency reaching 43.96%, and the nitrogen oxide emission being as low as 0.97g / kW·h, which is superior to Tier III standard.

[0105] The embodiment is specific: methanol is heated and catalytically cracked into methanol cracking gas through a methanol cracking gas device, methanol cracking gas and methanol steam are directly injected into the same coaxial fuel nozzle of the engine, the pressure of the fuel entering the cylinder is adjusted through the pressure regulating valve, which can directly affect the distribution of methanol fuel in the cylinder, make the mixture in the cylinder uniform, and then form better combustion effect; The engine is also less changed, only the structure of the fuel injector is changed, and the engine intake manifold structure is not changed, which is simple in structure and easy to realize. Compared with diesel fuel, burning methanol and cracking gas can effectively reduce the emission of nitrogen oxides and hydrocarbons and other pollutants, and improve the combustion efficiency.

[0106] The in-cylinder direct injection compression ignition engine system comprises an engine system 1, a diesel direct injection fuel supply system 2, a methanol direct injection fuel supply system 3 and a methanol cracking gas device 4.

[0107] The engine system 1 comprises an air intake pipe 11, a compressor 12, an air intake stop valve 13, a cylinder 14, a coaxial double-channel fuel nozzle 15, an exhaust pipe 16, an exhaust temperature measuring instrument 17, an exhaust stop valve 18, a supercharger 19 and a rotating shaft 20. Ambient air enters the engine system from the air intake pipe 11, and in-cylinder combustion exhaust gas is discharged from the engine system from the exhaust pipe 16; the compressor 12 and the supercharger 19 can provide the required pressure difference when gas enters or is discharged; the coaxial double-channel fuel nozzle 15 has a double-channel design to meet the requirement of separate injection of diesel and methanol fuel into the cylinder 14; the rotating shaft 20 with a turbine end and a compressor end in a symmetrical design transmits mechanical energy from the turbine end driven by exhaust gas to the compressor end to drive the compressor impeller to rotate at high speed, thereby compressing air to improve engine air intake efficiency.

[0108] The diesel storage bottle 21 can provide diesel fuel; the diesel flow measuring instrument 23 can monitor the real-time injection amount of diesel fuel to observe the difference in in-cylinder combustion conditions under different injection amounts; and the diesel pump 24 provides power for fuel injection.

[0109] The diesel stop valve 25 adjusts the diesel injection amount according to the actual working condition requirement based on the methanol injection amount measured by the measuring instrument, for example, if the actual working condition requirement is greater than the theoretical diesel injection amount, the stop valve opening degree needs to be increased to inject more fuel to meet the working condition requirement, and if the actual working condition requirement is less than the theoretical diesel injection amount, the stop valve opening degree needs to be reduced to inject less diesel to meet the working condition requirement.

[0110] The diesel stored in the diesel storage bottle 21 is pressurized by the diesel pump 24 and injected into the coaxial double-channel fuel nozzle 15 of the cylinder 14.

[0111] The methanol storage bottle 31 can provide methanol fuel; the methanol flow measuring instrument 33 can monitor the real-time injection amount of methanol fuel to observe the difference in in-cylinder combustion conditions under different injection amounts; and the methanol pump 34 provides power for fuel injection.

[0112] Methanol cut-off valve 35 adjusts the amount of methanol injection according to the actual working condition requirements by measuring the amount of methanol injection measured by the meter. For example, if the actual working condition requirement is greater than the theoretical methanol injection amount, the cut-off valve opening needs to be increased to inject more fuel to meet the working condition requirement. If the actual working condition requirement is less than the theoretical methanol injection amount, the cut-off valve opening needs to be reduced to inject less methanol to meet the working condition requirement. The methanol stored in the methanol storage bottle 31 is injected into the methanol cracking gas device 4 through the methanol pump 34. After being heated by the waste heat of the exhaust gas in the methanol cracking gas device 4 and catalyzed by the catalyst laid on the cracking gas heating catalyst pipe 45, the methanol cracking gas mainly generates CO and H2 and vaporized methanol steam, which is injected into the coaxial double-channel fuel nozzle 15 of the cylinder 14 through the methanol cracking gas pipe 48.

[0113] The methanol cracking gas device 4 includes a methanol input end 41, an exhaust gas output end 42, a cracking gas tank 43, a baffle 44, a cracking gas heating catalyst pipe 45, a cracking gas output end 46, a pressure regulating valve 47, a methanol cracking gas pipe 48, a pressure detector 49, and an exhaust gas input end 410.

[0114] The methanol input end 41 is connected to the methanol fuel supply pipe 32 for injecting methanol into the methanol cracking gas device 4.

[0115] The exhaust gas input end 410 is connected to the exhaust pipe 16 to provide combustion exhaust gas into the cracking gas device 4.

[0116] The exhaust gas output end 42 discharges exhaust gas from the cracking gas device 4. The cracking gas heating catalyst pipe 45 is covered with methanol cracking catalyst. The injected methanol is cracked under the action of the catalyst and the waste heat of the exhaust gas. The cracking gas output end 46 is connected to the methanol cracking gas pipe 48 to inject cracking gas and vaporized methanol steam into the cylinder 14. The baffle 44 is arranged at both ends of the cracking gas heating catalyst pipe 45 to prevent combustion exhaust gas from flowing into the cracking gas heating catalyst pipe 45, affecting the methanol cracking effect.

[0117] Control method of compression ignition diesel micro-injection methanol blending combustion cracking gas engine:

[0118] S1, measure the speed and torque of the engine according to the dynamometer;

[0119] S2, determine the working mode of the engine by judging the size relationship between the engine working torque and the rated torque;

[0120] S3, adopt different fuel injection supply strategies according to different working modes of the engine under different loads.

[0121] Among them, the speed measurement: through the speed sensor built-in the dynamometer, the mechanical signal is converted into an electrical signal to monitor the rotation speed of the engine output shaft, the unit is r / min.

[0122] Torque measurement: dynamometer through the strain gauge on the shaft, when the torque, the strain gauge due to deformation caused by resistance changes, through the wheatstone bridge circuit will change in resistance into a voltage signal, reflecting the shaft shear strain.

[0123] Torque and shear strain conversion formula:

[0124] Wherein, the shear strain, the distance from the measuring point to the center of the circle, unit m, T for torque, unit N.m, G for shear modulus, unit Pa, the section polar moment of inertia, unit m4.

[0125] According to the engine working torque and rated torque size relationship, determine the engine working state:

[0126] Engine cold start refers to the engine starts working from zero speed;

[0127] Engine low load is the engine working torque is less than or equal to the rated torque of the first threshold, that is, the engine working torque ≤ engine rated torque 40%;

[0128] Engine medium load is the engine working torque is greater than the rated torque of the first threshold, less than or equal to the second threshold, that is, engine rated torque 40% < engine working torque ≤ engine rated torque 70%;

[0129] Engine high load is the engine working torque is greater than the rated torque of the second threshold, that is, engine rated torque 70% < engine working torque ≤ engine rated torque 100%.

[0130] The intake pipe 11 is connected to the air supply pipeline.

[0131] According to the engine working state, determine the fuel supply mode:

[0132] When the engine is cold started, open the diesel cut-off valve 25 and close the methanol cut-off valve 35.

[0133] Air is compressed into the intake pipe 11 by the air compressor 12, flows through the intake cut-off valve 13 into the cylinder 14, and is compressed under the reciprocating motion of the engine piston; the diesel in the diesel storage bottle 21 is injected into the nozzle 15 by the diesel pump 24, and then is injected into the cylinder 14 to be compressed and burned in the high compression ratio cylinder pressure environment, and the CO2 and other exhaust emissions generated by the cylinder combustion reaction are introduced into the exhaust pipe 16, and then are discharged to the outside through the turbine 19.

[0134] When the engine is not cold started, the diesel and methanol injection device stop valves 25 and 35 are opened. Air is compressed into the intake passage 11 by the compressor 12, flows into the cylinder 14 through the intake stop valve 13, and the diesel in the diesel storage bottle 21 is injected into the cylinder 14 through the nozzle 15 and is compressed and combusted under the reciprocating motion of the engine piston. The exhaust gas produced by the combustion is guided into the two-end baffle 44 of the methanol cracking device 4 through the exhaust passage 16, is used to heat only the methanol cracking gas pipe 48, does not participate in the combustion reaction process, and is guided out of the outside world through the turbine 19. The exhaust temperature measuring instrument 17 on the exhaust passage 16 measures the exhaust temperature to measure the degree of heating and cracking of the methanol. The methanol in the methanol storage bottle 31 is injected into the methanol cracking gas device 4 through the methanol pump 34, and after the waste heat and the cracking gas heat the catalyst on the catalyst pipe 45, the methanol cracking gas and the vaporized methanol steam flow into the methanol cracking gas pipe 48. The methanol fuel pressure value measured by the pressure detector 49 is used to adjust the pressure regulating valve 47 to meet the fuel demand of different engine loads, and then is injected into the cylinder 14 through the nozzle 15 and is combusted after being ignited by a small amount of diesel injected into the cylinder 14.

[0135] The methanol cracking hydrogen and carbon monoxide cracking gas heating catalyst pipe 45 generally uses a copper-based catalyst (such as TF109 catalyst), and the core component is copper oxide. The catalyst has the characteristics of high activity and high selectivity, is suitable for methanol steam reforming reaction, and can realize high-efficiency conversion of methanol at a temperature of 220 to 260°C.

[0136] It should be understood that, during the development of any actual implementation, numerous implementation-specific decisions can be made. Such development efforts, while possibly complex and time-consuming, would nevertheless be routine undertaking for those of ordinary skill in the art having the benefit of this disclosure, without undue experimentation.

[0137] It should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A compression ignition diesel engine system and its method of use, characterized in that: It includes an engine system (1), a diesel direct injection supply system (2), a methanol direct injection supply system (3) and a methanol cracking gas device (4). The diesel direct injection supply system (2) is provided at the bottom of one side of the engine system (1), the methanol cracking gas device (4) is provided on the other side of the engine system (1), and the methanol direct injection supply system (3) is provided on one side of the methanol cracking gas device (4).

2. The compression ignition diesel engine system and its method of use according to claim 1, characterized in that: The engine system (1) includes an intake manifold (11), a compressor (12), an intake shut-off valve (13), a cylinder (14), a coaxial dual-channel fuel injector (15), an exhaust manifold (16), an exhaust temperature measuring instrument (17), an exhaust shut-off valve (18), a turbocharger (19), and a shaft (20). The methanol cracking gas device (4) includes a methanol input terminal (41), an exhaust output terminal (42), and a cracking gas box (43); The upper side of the inlet section of the air inlet pipe (11) is connected to the lower side of the compressor (12); The left side of the middle section of the intake pipe (11) is connected to the right side of the compressor (12), and the right side of the middle section of the intake pipe (11) is connected to the left side of the intake shut-off valve (13). The left side of the output section of the intake pipe (11) is connected to the right side of the intake shut-off valve (13), and the right side of the output section of the intake pipe (11) is connected to the intake input end of the cylinder (14). The exhaust pipe (16) consists of two parts, one part located below the methanol cracking gas device (4) and the other part located above the methanol cracking gas device (4). The lower side of the input section of the exhaust pipe (16) is connected to the exhaust output end of the cylinder (14), and the upper side of the input section of the exhaust pipe (16) is connected to the lower side of the exhaust temperature measuring instrument (17). The right side of the middle section of the exhaust pipe (16) is connected to the upper side of the exhaust output end (42), and the left side of the middle section of the exhaust pipe (16) is connected to the right side of the exhaust shut-off valve (18). The right side of the rear section of the exhaust pipe (16) is connected to the left side of the exhaust shut-off valve (18), and the left side of the rear section of the exhaust pipe (16) is connected to the right side of the turbocharger (19). The lower side of the exhaust pipe (16) is connected to the upper side of the turbocharger (19); The lower side of the rotating shaft (20) is connected to the upper side of the compressor (12), and the upper side of the rotating shaft (20) is connected to the lower side of the booster (19). The methanol direct injection supply system (3) includes a methanol storage bottle (31), a methanol fuel supply pipe (32), a methanol flow meter (33), a methanol pump (34), and a methanol shut-off valve (35).

3. The compression ignition diesel engine system and its method of use according to claim 2, characterized in that: The diesel direct injection supply system (2) includes a diesel storage bottle (21), a diesel fuel supply pipe (22), a diesel flow meter (23), a diesel pump (24), and a diesel shut-off valve (25); The left side of the input section of the diesel fuel supply pipe (22) is connected to the diesel storage bottle (21), and the right side of the input section of the diesel fuel supply pipe (22) is connected to the left side of the diesel flow meter (23). The left side of the middle section of the diesel fuel supply pipe (22) is connected to the right side of the diesel flow meter (23), and the right side of the middle section of the diesel fuel supply pipe (22) is connected to the left side of the diesel pump (24); the left side of the rear section of the diesel fuel supply pipe (22) is connected to the right side of the diesel pump (24), and the right side of the rear section of the diesel fuel supply pipe (22) is connected to the left side of the diesel shut-off valve (25). The left side of the output section of the diesel fuel supply pipe (22) is connected to the right side of the diesel shut-off valve (25), and the right side of the output section of the diesel fuel supply pipe (22) is connected to the upper side of the coaxial dual-channel fuel nozzle (15).

4. The compression ignition diesel engine system and its method of use according to claim 2, characterized in that: The left side of the input section of the methanol fuel supply pipe (32) is connected to the methanol storage bottle (31), and the right side of the input section of the methanol fuel supply pipe (32) is connected to the left side of the methanol flow meter (33). The methanol cracking gas device (4) includes a methanol input terminal (41); The left side of the middle section of the methanol fuel supply pipe (32) is connected to the right side of the methanol flow meter (33), and the middle section and right side of the methanol fuel supply pipe (32) are connected to the left side of the methanol pump (34). The left side of the rear section of the methanol fuel supply pipe (32) is connected to the right side of the methanol pump (34), and the right side of the rear section of the methanol fuel supply pipe (32) is connected to the left side of the methanol shut-off valve (35). The left side of the output section of the methanol fuel supply pipe (32) is connected to the right side of the methanol shut-off valve (35), and the right side of the output section of the methanol fuel supply pipe (32) is connected to the methanol input end (41).

5. The compression ignition diesel engine system and its method of use according to claim 4, characterized in that: The methanol cracking gas device (4) also includes an exhaust outlet (42), a cracking gas box (43), a baffle (44), a cracking gas heating catalytic tube (45), a cracking gas outlet (46), a pressure regulating valve (47), a methanol cracking gas pipe (48), a pressure detector (49), and an exhaust inlet (410). The left side of the cracked gas box (43) is connected to the right side of the methanol input terminal (41), and the upper side of the cracked gas box (43) is connected to the lower side of the exhaust output terminal (42). The right side of the cracked gas box (43) is connected to the left side of the cracked gas output end (46), the left side of the input section of the methanol cracked gas pipe (48) is connected to the right side of the cracked gas output end (46), the right side of the input section of the methanol cracked gas pipe (48) is connected to the upper side of the pressure regulating valve (47); the right side of the middle section of the methanol cracked gas pipe (48) is connected to the lower side of the pressure regulating valve (47), and the left side of the middle section of the methanol cracked gas pipe (48) is connected to the right side of the pressure detector (49). The right side of the output section of the methanol cracking gas pipe (48) is connected to the left side of the pressure detector (49), and the left side of the output section of the methanol cracking gas pipe (48) is connected to the upper side of the coaxial dual-channel fuel nozzle (15). The lower side of the pyrolysis gas box (43) is connected to the upper side of the exhaust inlet (410), and the lower side of the exhaust inlet (410) is connected to the upper side of the exhaust temperature measuring instrument (17).

6. The compression ignition diesel engine system and its method of use according to claim 3, characterized in that: Includes the following steps: S1. Measure the engine speed and operating torque using a dynamometer; S2. Determine the relationship between the engine's operating torque and its rated torque to determine the engine's operating mode; S3. Different fuel injection supply strategies are adopted according to the different operating modes of the engine under different loads.

7. A compression ignition diesel engine system and its method of use according to claim 6, characterized in that, The engine operating state is determined based on the relationship between the engine's operating torque and its rated torque, including: 1) Engine cold start control: Engine cold start refers to the engine starting from zero speed; Engine low load refers to the engine operating torque being less than or equal to the first threshold of rated torque, that is, engine operating torque ≤ 40% of engine rated torque; 2) Engine non-cold start control: Medium load on an engine refers to an engine operating torque that is greater than the first threshold of rated torque and less than or equal to the second threshold, i.e., 40% of the engine rated torque < engine operating torque ≤ 70% of the engine rated torque; High engine load refers to the engine's operating torque being greater than the second threshold of the rated torque, i.e., 70% of the engine's rated torque < engine operating torque ≤ 100% of the engine's rated torque.

8. The compression ignition diesel engine system and its method of use according to claim 7, characterized in that: When the engine is cold-started, the diesel shut-off valve (25) is opened and the methanol shut-off valve (35) is closed; The flow rate and velocity of diesel fuel are regulated by the diesel shut-off valve (25).

9. A compression ignition diesel engine system and its method of use according to claim 7, characterized in that: When the engine is not cold-started, the diesel shut-off valve (25) and the methanol shut-off valve (35) are opened; The quality and flow rate of diesel fuel are regulated by the diesel shut-off valve (25), and the rate of methanol cracking gas is regulated by the pressure regulating valve (47).

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