Crankcase ventilation system for ammonia-hydrogen engine and control method

Abstract

The invention relates to the technical field of engines, and provides a crankcase ventilation system and method for an ammonia-hydrogen engine. The system comprises an energy supply structure which communicates with an engine through a pipeline and is used for conveying fuel to the engine to serve as an energy source for operation of the engine; the gas supply structure communicates with the engine through a pipeline and is used for conveying a combustion-supporting gas source to the engine; the engine is provided with a sensing assembly electrically connected with the control unit; and the blow-by gas treatment structure communicates with a crankcase of the engine and the gas supply structure through pipelines and is used for separating impurities in blow-by gas in the crankcase and supplementing the separated blow-by gas back to the gas supply structure to participate in gas inlet circulation under the regulation and control of the control unit. According to the device, engine oil steam, water vapor and ammonia gas in blow-by gas of the crankcase can be separated, so that the problem of engine oil emulsification in the crankcase is solved, and meanwhile, the safety problem possibly caused by high-concentration enrichment of the ammonia gas is avoided.

Description

Technical Field

[0001] The present application relates to the field of engine technology, and in particular to a crankcase ventilation system and control method for an ammonia-hydrogen engine. Background Art

[0002] Ammonia and hydrogen are currently gaining widespread attention as fuels for combustion in internal combustion engines. Ammonia offers advantages such as zero carbon emissions, high volumetric energy density, and ease of storage and transportation. Its use in internal combustion engines can mitigate the risks of hydrogen storage and transportation, as well as abnormal hydrogen combustion. To address ammonia's slow combustion rate, using hydrogen to ignite ammonia can effectively increase the flame propagation speed, reduce ignition difficulty, and improve thermal efficiency.

[0003] Compared with traditional gasoline engines, the combustion products of ammonia and hydrogen contain a large amount of water. The higher water content in blowby gas will accelerate the emulsification and deterioration of the engine oil and the failure of working performance. When the engine is working, high-temperature and high-pressure fuel gas enters the crankcase through the gap between the piston ring and the cylinder to form blowby gas. Since the blowby gas contains oil droplets, water vapor, fuel gas, exhaust gas and other components, it will accelerate the emulsification and deterioration of the engine oil, thereby reducing its performance. Secondly, ammonia dissolves in water. The accumulation of ammonia water in the pipeline for a long time will cause corrosion of the pipeline and accelerate pipeline wear.

[0004] The current designs for the operation of ammonia-hydrogen engines mainly focus on traditional methods such as independent ammonia / hydrogen supply and control, ammonia-hydrogen injection strategy control methods, and ammonia-hydrogen intake injection. However, there is still a gap in the treatment of crankcase blowby in ammonia-hydrogen engines.

[0005] Therefore, it is urgent to design a crankcase ventilation system and control method suitable for ammonia-hydrogen engines to solve the problems of a large amount of water vapor generated by the combustion of ammonia-hydrogen, which aggravates the emulsification of the engine oil, alleviate the safety hazards caused by ammonia corrosion of the pipeline, shortening the working life, and leakage of the air supply pipeline causing a large amount of gas to accumulate in the crankcase. Summary of the Invention

[0006] The present invention aims to provide a crankcase ventilation system and control method for an ammonia-hydrogen engine, capable of separating oil vapor, water vapor, and ammonia from crankcase blowby gas, thereby improving the problem of oil emulsification in the crankcase while avoiding the safety issues that may arise from high ammonia concentrations. The specific solution is as follows:

[0007] A crankcase ventilation system for an ammonia-hydrogen engine, the system comprising:

[0008] An energy supply structure is connected to the engine through a pipeline and is used to deliver fuel to the engine as an energy source for the operation of the engine;

[0009] The gas supply structure is connected to the engine through a pipeline and is used to deliver a combustion-supporting gas source to the engine. The combustion-supporting gas source reacts with the fuel inside the engine to drive the engine to operate;

[0010] An engine, wherein the engine is provided with a sensing component electrically connected to a control unit for detecting blowby gas data in a crankcase; the blowby gas data includes at least: blowby gas concentration and blowby gas pressure;

[0011] The blowby gas treatment structure is connected to the engine crankcase and air supply structure through pipelines, and is used to separate impurities in the blowby gas in the crankcase and, under the control of the control unit, feed the separated blowby gas back to the air supply structure to participate in the intake cycle;

[0012] The control unit is configured to calculate the air supply volume of the air supply structure based on a preset control strategy and a preset algorithm.

[0013] Optionally, the air supply structure includes: an intake system, a supercharger and an intercooler connected in sequence; the outlet of the intercooler is connected to the engine, and an air flow meter is provided on the pipeline between the intercooler and the engine; wherein, the intercooler is connected to the blowby gas processing structure for transporting cooling medium to the blowby gas processing structure.

[0014] Optionally, the energy supply structure includes:

[0015] a liquid ammonia cylinder, connected to one end of the ammonia online cracking hydrogen production device and the first energy supply device through pipelines;

[0016] The other end of the ammonia online cracking hydrogen production device is connected to the engine, and is used to crack ammonia into hydrogen;

[0017] The other end of the first energy supply device can be connected to the engine or the supercharger.

[0018] Optionally, when the other end of the first energy supply device is directly connected to the engine, the first energy supply device delivers fuel directly to the engine. In this case, the first energy supply device includes: a coarse filter, a low-pressure pump, a fine filter, and a high-pressure pump connected in sequence; wherein the inlet end of the coarse filter is connected to the liquid ammonia bottle, and the outlet end of the high-pressure pump is connected to the engine;

[0019] When the other end of the first energy supply device is connected to the supercharger, the first energy supply device converts the liquid fuel into gaseous fuel and transports it to the engine through the air supply structure. At this time, the first energy supply device includes: a pressure reducing valve, a liquid ammonia vaporizer, an ammonia pressure regulating tank and a third electronically controlled pressure regulating valve connected in sequence; wherein, one end of the pressure reducing valve is connected to the liquid ammonia bottle, and the outlet of the third electronically controlled pressure regulating valve is connected to the pipeline between the intake system and the supercharger.

[0020] Optionally, the blowby gas processing structure includes:

[0021] An oil-gas separator in communication with the engine, the oil-gas separator being used to separate oil from crankcase blowby gas; a first liquid level sensor connected to a control unit for monitoring the oil depth inside the oil-gas separator is provided inside the oil-gas separator;

[0022] The first interface of the oil-gas separator is connected to the water-gas separator through a pipeline, and the second interface is connected to the oil storage tank through a pipeline; wherein, a first auxiliary suction pump and a blowby check valve are provided on the pipeline between the oil-gas separator and the water-gas separator; and an oil return check valve is provided on the pipeline between the oil-gas separator and the oil storage tank;

[0023] The first inlet of the water-gas separator is connected to the intercooler, and a coolant flow sensor and a coolant electric control valve are set on the pipeline between the two; the first outlet of the water-gas separator is connected to the water tank; wherein a second liquid level sensor is arranged at the bottom of the water tank.

[0024] Optionally, when the other end of the first energy supply device is directly connected to the engine, the blowby gas treatment structure further includes: an ammonia spray device and an SCR treatment system; wherein the water-gas separator is connected to the SCR treatment system via the ammonia spray device; the ammonia spray device is used to remove ammonia in the blowby gas; the ammonia spray device is connected to the water storage tank via a pipeline, and a spray water supply valve and a second auxiliary suction pump are provided on the pipeline between the two; the outlet of the ammonia spray device is connected to the pipeline between the intake system and the supercharger; wherein a first electronically controlled pressure regulating valve and an air supply flow meter are provided on the outlet pipeline of the ammonia spray device; wherein the first electronically controlled pressure regulating valve and the air supply flow meter are both connected to the control unit signal;

[0025] An ammonia pressure regulating valve connected to the control unit signal is provided on the pipeline between the ammonia spray device and the SCR treatment system; wherein, an ammonia concentration sensor connected to the control unit signal is also provided inside the ammonia spray device.

[0026] Optionally, when the other end of the first energy supply device is connected to the supercharger, the second outlet of the water-gas separator is directly connected to the pipeline between the intake system and the supercharger; wherein, a second electronically controlled pressure regulating valve and an ammonia flowmeter are provided on the second outlet pipeline of the water-gas separator; wherein, the blowby gas separated by the water-gas separator includes at least ammonia and other gases.

[0027] A crankcase ventilation control method for an ammonia-hydrogen engine is applied to the above system; the method comprises the following steps:

[0028] Step 1: Obtain engine operating parameters; wherein the operating parameters include at least: engine speed, coolant temperature, intake air temperature, throttle opening, crankshaft position, manifold pressure, crankcase blowby concentration and pressure, oil-gas separator liquid level, oil tank liquid level, water tank liquid level and ammonia spray device liquid level;

[0029] Step 2: When the acquired engine operating parameters meet a first preset condition, a first strategy is invoked to control the engine and first operating data of the engine is output, where the first operating data includes a first operating condition and a first operating state.

[0030] Step 3: In response to the first operating data of the engine, triggering the second strategy and determining whether the operating condition of the engine has entered the second operating condition from the first operating condition;

[0031] Step 4: If the engine operating condition is the second operating condition, the third strategy is triggered to determine whether the engine operating condition has entered the target operating condition from the second operating condition, and based on the target operating condition and its corresponding operating state, the preset control strategy and preset algorithm are used to control the purified blowby gas to replenish the air supply structure.

[0032] Optionally, the step 4 includes:

[0033] Obtaining throttle opening and manifold pressure values, and comparing them with a second preset calibration range respectively;

[0034] When the throttle opening and the manifold pressure values ​​both fall within a second preset calibration range, it is determined that the engine is in the third operating condition;

[0035] Based on the engine being in the third operating condition, concentration values ​​in the oil-gas separator, the oil storage tank, the water storage tank, and the ammonia spray device are monitored in real time with a preset first unit time as a period, so as to adjust the concentration values ​​in the oil-gas separator, the oil storage tank, the water storage tank, and the ammonia spray device to below corresponding preset first thresholds, thereby obtaining a third state corresponding to the third operating condition;

[0036] When the engine enters the third operating condition and the third state, the preset first unit time is adjusted to the preset second unit time, and the throttle opening, the manifold pressure value, and the liquid level values ​​in the oil-gas separator, the oil storage tank, the water storage tank and the ammonia spray device are regularly monitored;

[0037] If the throttle opening and manifold pressure values ​​fall within the third preset calibration range, and the liquid level values ​​in the oil-gas separator, oil storage tank, water storage tank and ammonia spray device are less than the third threshold, the engine enters the target operating condition and target state, triggering the air replenishment strategy, and calculating the air replenishment amount for the air supply structure through the preset algorithm.

[0038] Optionally, the air supply volume is calculated according to the preset algorithm The formula is: ,

[0039] For real-time monitoring of crankcase pressure, is the intake air mass flow rate, is the excess air coefficient measured by the oxygen sensor, is the engine speed, is the oil-gas separation efficiency, is the ammonia removal rate of the spray tower;

[0040] Based on the supplementary air volume, the excess coefficient deviation obtained by the second algorithm Correct the excess air coefficient; the formula of the second algorithm is as follows:

[0041] ; in, Instant feedback coefficient, Cumulative steady-state coefficient, is the target excess air coefficient, is the actual excess air coefficient.

[0042] Through the above solution, the following beneficial technical effects are achieved:

[0043] The present application provides a crankcase ventilation system and control method for an ammonia-hydrogen engine, in which ammonia-hydrogen fuel is delivered to the engine through an energy supply structure; when the engine is operating, high-temperature and high-pressure combustion gas enters the crankcase through the gap between the piston ring and the cylinder to form blowby gas; the blowby gas treated by the blowby gas treatment structure avoids the problems of oil emulsification caused by the mixing of water and oil, corrosion of pipelines by ammonia water, and accelerated wear of parts by particulate matter; at the same time, the treated blowby gas is also used to replenish the gas supply structure to achieve fuel recycling; the concentration and pressure of the blowby gas in the crankcase are detected in real time by a sensing component provided on the engine, and after the data is transmitted to the control unit, the separation strength and replenishment amount of the blowby gas treatment structure can be dynamically adjusted. If the concentration or pressure exceeds the standard, the safety hazard is avoided by enhancing emissions, diluting inert gases, etc.; under normal operating conditions, the replenished fuel and the new fuel delivered by the energy supply structure work together to accurately match the intake volume to optimize the air-fuel ratio, thereby achieving the coordination of efficient combustion and clean emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Structural connection diagram of the crankcase ventilation system for direct input of liquid ammonia as fuel into the engine;

[0045] Figure 2 A structural connection diagram of the crankcase ventilation system in which gaseous ammonia is fed into the engine through the air supply structure as fuel;

[0046] Figure 3The figure is a flow chart of a crankcase ventilation control method for an ammonia-hydrogen engine according to one embodiment. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of this application clearer, the following Figure 1-Figure 3 This application is further described in detail. Obviously, the embodiments described are only a part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0048] The terms used in the examples of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a," "the," and "the" used in the examples of this application and the appended claims are also intended to include plural forms, and unless the context clearly indicates otherwise, "a plurality" generally includes at least two.

[0049] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0050] It should be understood that although the terms first, second, third, etc. may be used to describe in the embodiments of the present application, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, without departing from the scope of the embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0051] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0052] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or device. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or device comprising the element.

[0053] It should be noted in particular that any symbols and / or numbers in the specification that are not marked in the accompanying drawings are not drawing marks.

[0054] Figure 1 : 1-intake system; 2-supercharger; 3-intercooler; 4-air flow meter; 5-engine; 6-exhaust system; 7-oil storage tank; 8-oil and gas separator; 9-first auxiliary suction pump; 10-air brake air tank; 11-water and gas separator; 12-water storage tank; 13-liquid ammonia bottle; 14-ammonia online cracking hydrogen production device; 15-coarse filter; 16-low-pressure pump; 17-fine filter; 18-high-pressure pump; 19-ammonia spray device; 20-first electronically controlled pressure regulating valve; 21-air supply flow Meter; 22-Ammonia concentration sensor; 23-Second liquid level sensor; 24-Compressed air valve; 25-Blowby check valve; 26-Gas concentration sensor; 27-Gas pressure sensor; 28-First liquid level sensor; 29-Oil return check valve; 30-Oil return level sensor; 31-Coolant flow sensor; 32-Coolant electric control valve; 34-Second auxiliary suction pump; 35-Spray water supply valve; 36-Ammonia pressure regulating valve; 37-SCR treatment system; 38-Control unit;

[0055] Figure 2 : 100-second electronically controlled pressure regulating valve; 101-ammonia flow meter; 102-pressure reducing valve; 103-liquid ammonia vaporizer; 104-ammonia pressure regulating tank; 105-third electronically controlled pressure regulating valve.

[0056] like Figure 1 A crankcase ventilation system for an ammonia-hydrogen engine is shown, the system comprising:

[0057] An energy supply structure is connected to the engine through a pipeline and is used to deliver fuel to the engine as an energy source for the operation of the engine;

[0058] The gas supply structure is connected to the engine through a pipeline and is used to deliver a combustion-supporting gas source to the engine. The combustion-supporting gas source reacts with the fuel inside the engine to drive the engine to operate;

[0059] An engine, wherein the engine is provided with a sensing component electrically connected to the control unit for detecting blowby gas data in the crankcase; the blowby gas data includes at least: blowby gas concentration and blowby gas pressure; the sensing component includes: a gas concentration sensor and a gas pressure sensor;

[0060] The blowby gas treatment structure is connected to the engine crankcase and air supply structure through pipelines, and is used to separate impurities in the blowby gas in the crankcase and, under the control of the control unit, feed the separated blowby gas back to the air supply structure to participate in the intake cycle;

[0061] The control unit is configured to calculate the air supply volume of the air supply structure based on a preset control strategy and a preset algorithm.

[0062] It can be understood that the energy supply structure can directly deliver liquid ammonia fuel to the engine through a pipeline, or it can convert the liquid ammonia fuel into gaseous ammonia and deliver it to the engine through the air supply structure, and at the same time it can deliver ignition fuel, such as hydrogen, to the engine.

[0063] Specifically, the present application delivers fuel and combustion-supporting gas sources to the engine through an energy supply structure and an air supply structure respectively. During the combustion process in the engine, some high-temperature and high-pressure combustion gas enters the crankcase through the gap between the piston rings to form blowby gas. The present application adopts a dual mechanism to precisely control the blowby gas: first, the concentration and pressure of ammonia and hydrogen in the blowby gas in the crankcase are directly detected by a sensing component, and the data is transmitted to the control unit in real time to avoid safety hazards such as excessive hydrogen concentration and explosion, and excessive pressure causing pipeline rupture; secondly, the blowby gas treatment structure is used to first separate the liquid water, oil vapor and particulate matter in the blowby gas, so as to avoid emulsification of water and oil, corrosion of pipelines by ammonia water and wear of parts by particulate matter from the source; the control unit then calculates and controls the amount of purified blowby gas replenished to the air supply structure based on a preset control strategy and algorithm to achieve fuel recovery; finally, the replenished fuel and the new fuel delivered by the energy supply structure work together to accurately match the intake volume of the combustion-supporting gas source to optimize the air-fuel ratio, thereby achieving the synergy of efficient combustion and clean emissions.

[0064] Furthermore, the air supply structure includes: an intake system, a supercharger and an intercooler connected in sequence; the outlet of the intercooler is connected to the engine, and an air flow meter is provided on the pipeline between the intercooler and the engine; wherein, the intercooler is connected to the blowby gas processing structure for transporting cooling medium to the blowby gas processing structure.

[0065] Specifically, the present application provides cooling for the blowby gas processing structure by reusing the intercooler in the air supply structure, eliminating the need for an additional independent cooling system, simplifying the pipeline layout while reducing costs.

[0066] Furthermore, the energy supply structure includes:

[0067] a liquid ammonia cylinder, connected to one end of the ammonia online cracking hydrogen production device and the first energy supply device through pipelines;

[0068] The other end of the ammonia online cracking hydrogen production device is connected to the engine, and is used to crack ammonia into hydrogen;

[0069] The other end of the first energy supply device can be connected to the engine or the supercharger.

[0070] It can be understood that the on-site conversion of liquid ammonia to hydrogen can be achieved through the online ammonia cracking hydrogen production device, without the need for high-pressure hydrogen storage, thus reducing the storage safety risks of hydrogen fuel from the source; since liquid ammonia is used as a single raw material, the complexity of the pipelines for independent storage of hydrogen and ammonia dual fuels is reduced, and the probability of leakage is reduced; further, when the first energy supply device is connected to the engine: the first energy supply device filters and pressurizes the liquid ammonia, and the fuel does not pass through the air supply structure, but is directly transported to the engine for combustion; when the first energy supply device is connected to the supercharger: the first energy supply device processes and reduces the pressure of the liquid ammonia to form a stable gaseous ammonia, and sends it into the engine through the air supply structure for combustion reaction. Through these two fuel path designs, the fuel supply is more flexible and adaptable to multiple working conditions.

[0071] Combine Figure 1 As shown, when the other end of the first energy supply device is directly connected to the engine, the first energy supply device directly delivers liquid ammonia fuel to the engine. In this case, the first energy supply device includes: a coarse filter, a low-pressure pump, a fine filter, and a high-pressure pump connected in sequence; wherein the inlet end of the coarse filter is connected to the liquid ammonia bottle, and the outlet end of the high-pressure pump is connected to the engine;

[0072] Combine Figure 2 As shown, when the other end of the first energy supply device is connected to the supercharger, the first energy supply device converts the liquid fuel into gaseous fuel and transports it to the engine through the air supply structure. At this time, the first energy supply device includes: a pressure reducing valve, a liquid ammonia vaporizer, an ammonia pressure regulating tank and a third electronically controlled pressure regulating valve connected in sequence; wherein, one end of the pressure reducing valve is connected to the liquid ammonia bottle, and the outlet of the third electronically controlled pressure regulating valve is connected to the pipeline between the intake system and the supercharger.

[0073] It can be understood that the dual paths of high-pressure direct injection of liquid ammonia and low-pressure mixing of gaseous ammonia not only utilize the high energy density of liquid ammonia, but also give play to the mixing advantages of gaseous ammonia. At the same time, the system reliability is guaranteed through precise component configuration, ultimately achieving a balance between power, economy and emissions.

[0074] Furthermore, the blowby gas processing structure includes:

[0075] An oil-gas separator is connected to the engine, and is used to separate oil from crankcase blowby gas. A first liquid level sensor is provided inside the oil-gas separator and is electrically connected to the control unit for signal transmission. The oil depth inside the oil-gas separator is monitored by the first liquid level sensor.

[0076] The first interface of the oil-gas separator is connected to the water-gas separator through a pipeline, and the second interface is connected to the oil storage tank through a pipeline; wherein, a first auxiliary suction pump and a blowby check valve are provided on the pipeline between the oil-gas separator and the water-gas separator; and an oil return check valve is provided on the pipeline between the oil-gas separator and the oil storage tank;

[0077] The first inlet of the water-gas separator is connected to the intercooler, and a coolant flow sensor and a coolant electric control valve are set on the pipeline between the two; the intercooler is used to transport coolant to the water-gas separator; the water-gas separator is used to separate water vapor in the blowby gas; the first outlet of the water-gas separator is connected to the water tank; wherein, a second liquid level sensor electrically connected to the control unit signal is arranged at the bottom of the water tank; the water-gas separator is provided with a second outlet for discharging the blowby gas after separation treatment; the blowby gas check valve and the oil return check valve are both electrically connected to the control unit.

[0078] The water-gas separator adopts a water-gas separator of a same-direction sleeve-type structure; an oil return level sensor electrically connected to the control unit is arranged inside the oil storage tank.

[0079] Specifically, the blowby gas treatment structure provided by this application addresses the unique pain points of blowby gas in ammonia-hydrogen engines through multi-stage, precise oil-gas and water-gas separation. For example, an oil-gas separator separates the oil and gas, which are then recovered via a return oil check valve to the oil storage tank, preventing the oil from participating in subsequent circulation and causing carbon deposits or emulsification. The water-gas separator then uses the coolant from the intercooler to lower the blowby gas temperature, causing the water vapor to condense into liquid water, which is then collected in the water storage tank. This effectively eliminates the risk of water-oil emulsification and ammonia corrosion at the source. Simultaneously, first and second liquid level sensors monitor the oil and water levels in real time, and the blowby and return oil check valves prevent backflow. Dynamic regulation of the first auxiliary suction pump adapts to different operating conditions, leveraging existing coolant resources to reduce energy consumption while enabling oil recovery and reuse, thereby precisely adapting to the specific combustion requirements of ammonia-hydrogen fuel.

[0080] Combine Figure 1When the other end of the first energy supply device is directly connected to the engine, the blowby gas treatment structure further includes: an ammonia spray device and an SCR treatment system; wherein the water-gas separator is connected to the SCR treatment system through the ammonia spray device; the ammonia spray device is used to remove ammonia in the blowby gas; the ammonia spray device is connected to the water storage tank through a pipeline, and a spray water supply valve and a second auxiliary suction pump are provided on the pipeline between the two; the outlet of the ammonia spray device is connected to the pipeline between the intake system and the supercharger; wherein the outlet pipeline of the ammonia spray device is provided with a first electronically controlled pressure regulating valve and an air supply flow meter; wherein the first electronically controlled pressure regulating valve and the air supply flow meter are both connected to the control unit signal;

[0081] An ammonia pressure regulating valve connected to the control unit signal is provided on the pipeline between the ammonia spray device and the SCR treatment system; wherein, an ammonia concentration sensor connected to the control unit signal is also provided inside the ammonia spray device.

[0082] It can be understood that the ammonia spray device absorbs ammonia in the blowby gas by using water to avoid direct emission causing odor and environmental pollution, and uses the dilute ammonia water formed by absorption as a reducing agent for SCR to replace traditional urea, thereby reducing the operating cost of the SCR system; further, the blowby gas without ammonia, water vapor and oil droplets is replenished to the intake system, and burns in conjunction with the liquid ammonia fuel of the first energy supply device to avoid fuel waste caused by excessive emissions; further, the present application uses an ammonia water concentration sensor to monitor the absorption effect in real time, and the control unit adjusts the water volume through the spray water supply valve to ensure that the ammonia is completely removed, and accurately controls the replenishment gas volume through the first electronically controlled pressure regulating valve and the air supply flowmeter, and cooperates with the air flow meter of the intake system to optimize the air-fuel ratio, avoids combustion fluctuations caused by excessive replenishment, and improves the combustion effect.

[0083] It can be understood that the present application separates the oil vapor, water vapor, ammonia and unburned hydrogen in the crankcase blowby gas: recovers the oil back to the storage tank, replenishes hydrogen to the intake pipe, realizes fuel reuse, separates water vapor to avoid oil emulsification, converts ammonia into SCR reducing agent, realizes the reuse of resources, and achieves the advantages of cost reduction and efficiency improvement; it not only solves the problem of oil emulsification of water-oil mixture, but also eliminates the safety hazards of high concentration enrichment of ammonia.

[0084] Furthermore, the control unit uses a first algorithm to calculate the coolant flow rate delivered from the intercooler to the water separator based on the workload of the intercooler, the liquid level of the water storage tank, the ammonia concentration in the ammonia spray device, and the crankcase blowby pressure, so as to ensure efficient condensation and removal of moisture in the blowby gas without affecting sufficient cooling of the intake air. The coolant flow rate is affected by a combination of factors such as the water storage tank level, the ammonia concentration, the blowby pressure, the basic requirements of the intercooler, the maximum coolant distribution flow rate, and the spray water volume.

[0085] The formula of the first algorithm is as follows: ;in, ; ; Where, Represents the water tank level, Represents the real-time measurement of ammonia concentration. , represents the crankcase blowby pressure, Represents the target blowby pressure; represents the intercooler base flow, Represents the maximum distributable flow rate of coolant; Represents the coolant flow rate of the water-gas separator; in addition, in order to ensure that the ammonia concentration formed by ammonia spraying is basically consistent with the urea concentration required for efficient operation of SCR, the spraying water consumption needs to be calibrated.

[0086] Among them, the heat dissipation performance of the intercooler should be guaranteed first, and the constraints are: ; Liquid level weight , concentration weight Ensure ammonia concentration , pressure weight , to prevent the crankcase pressure from exceeding the limit;

[0087] The calculation of ammonia spraying amount is obtained by the following formula: ; is the amount of ammonia spray water; is the dissolution efficiency coefficient; for example, =32.5%.

[0088] Combine Figure 2 As shown, when the other end of the first energy supply device is connected to the supercharger, the second outlet of the water-gas separator is directly connected to the pipeline between the intake system and the supercharger; wherein, a second electronically controlled pressure regulating valve and an ammonia flowmeter are provided on the second outlet pipeline of the water-gas separator; wherein, the blowby gas separated by the water-gas separator includes at least ammonia and other gases (such as hydrogen, nitrogen, carbon dioxide, etc.).

[0089] Combine Figure 1 and Figure 2 As shown, the blowby gas processing structure also includes: an air brake air tank and several compressed air valves; wherein, the air brake air tank is respectively connected to the first auxiliary suction pump and the second auxiliary suction pump, wherein, a compressed air valve is provided on the pipeline between the air brake air tank and the first auxiliary suction pump and the second auxiliary suction pump.

[0090] The air brake air tank is used to provide a source for the air pump; the compressed air valve is used to control the on / off of the air source and the air source pressure.

[0091] See Figure 3 As shown, the present application provides a crankcase ventilation control method for an ammonia-hydrogen engine, which is applied to the above system; the method comprises the following steps:

[0092] Step 1: Obtain engine operating parameters; wherein the operating parameters include at least: engine speed, coolant temperature, intake air temperature, throttle opening, crankshaft position, manifold pressure, crankcase blowby concentration and pressure, oil-gas separator liquid level, oil tank liquid level, water tank liquid level, and ammonia spray device liquid level and concentration;

[0093] Step 2: When the acquired engine operating parameters meet a first preset condition, a first strategy is invoked to control the engine and first operating data of the engine is output, where the first operating data includes a first operating condition and a first operating state.

[0094] Step 2 specifically includes: comparing the coolant temperature and the intake air temperature with preset values ​​respectively; if the coolant temperature and the intake air temperature are both lower than the preset values, determining that the operating condition is a cold start condition; wherein the preset value range of the cold start condition is determined by an engine bench calibration test;

[0095] Based on the engine cold start condition, the blowby gas concentration and pressure are obtained and compared with the minimum preset values ​​respectively;

[0096] If the blowby gas concentration and pressure are both lower than the minimum preset values, it is determined that the engine is operating normally (corresponding to the first operating state);

[0097] If the blowby gas concentration and pressure are greater than the minimum preset value and less than the maximum preset value, it is determined that the hydrogen concentration or blowby gas pressure in the crankcase exceeds the safe operating range. The control unit (ECU) controls the first auxiliary suction pump to operate at high power to suck the high-concentration and high-pressure blowby gas from the engine crankcase, thereby improving the separation capacity of the oil-gas separator.

[0098] If the blowby gas concentration and pressure are both greater than the maximum preset values, it is determined that the engine is not working properly or the gas supply pipeline is leaking. At this time, the ECU controls the first auxiliary suction pump to run at high power to suck out the high-concentration / pressure blowby gas in the engine crankcase and issues an alarm to remind the user to stop the vehicle for inspection and maintenance.

[0099] It can be understood that under cold start conditions, the operating conditions are identified by the coolant and intake air temperatures, the engine status is determined by combining the blowby gas concentration and pressure classification, and the auxiliary suction pump and alarm are linked to ensure cold start safety and operating efficiency.

[0100] Step 3: In response to the first operating data of the engine, trigger the second strategy and determine whether the operating condition of the engine has entered the second operating condition from the first operating condition. Specifically:

[0101] Based on a first operating condition and a first running state of the engine, obtaining a throttle opening and an engine speed, and comparing the measured values ​​with a first preset calibration range;

[0102] If the throttle opening and the engine speed fall within a first preset calibration range, it is determined that the engine is in an idle operating condition (a second operating condition);

[0103] It is understood that the first preset calibration range for idle conditions is determined by engine bench calibration testing. During idle conditions, the engine speed is higher than during cold start conditions, which slightly increases the combustion chamber pressure, increases the proportion of gas burned in the cylinder, and reduces the amount of blowby. During this period, the piston ring clearance improves slightly due to thermal expansion, but still does not achieve optimal sealing. Therefore, the crankcase blowby concentration or pressure continues to follow the same determination logic and preset value range as during cold start conditions.

[0104] Step 4: If the engine operating condition is the second operating condition, the third strategy is triggered to determine whether the engine operating condition has entered the target operating condition from the second operating condition. Based on the target operating condition and its corresponding operating state, a preset control strategy and a preset algorithm are used to control the purified blowby gas to replenish the air supply structure, specifically including:

[0105] Obtaining throttle opening and manifold pressure values, and comparing them with a second preset calibration range respectively;

[0106] When the throttle opening and the manifold pressure values ​​both fall within a second preset calibration range, it is determined that the engine is in a small to medium load operating condition (a third operating condition);

[0107] Based on the engine being in the third operating condition, the liquid levels of the oil-gas separator, the oil storage tank, the water storage tank, and the ammonia spray device are monitored in real time with a preset first unit time as a period, so as to adjust the liquid levels of the oil-gas separator, the oil storage tank, the water storage tank, and the ammonia spray device to below corresponding first thresholds, respectively, to obtain a third state corresponding to the third operating condition;

[0108] Specifically, after a cold start and idle warm-up, the piston rings achieve optimal expansion and sealing performance under low-to-medium load conditions, achieving optimal performance. This results in higher combustion efficiency and faster engine speeds, significantly reducing blowby. Furthermore, a slight negative pressure or near-atmospheric pressure forms within the crankcase, actively pumping the blowby gas into the oil / gas separator for separation.

[0109] It should be noted that, since a certain amount of oil may already exist in the oil-gas separator and oil storage tank after a long period of operation under the engine's low-load operating conditions, a certain liquid level should also be formed at the bottom of the water storage tank and ammonia spray device;

[0110] Based on the engine being in the third operating condition, with a preset first unit time as a period, the liquid levels of the oil-gas separator, the oil storage tank, and the water storage tank, as well as the ammonia concentration in the ammonia spray device, are monitored in real time to timely drain the stored liquids and further determine whether the liquid contents in the oil-gas separator, the oil storage tank, and the water storage tank are within the normal operating range;

[0111] When the liquid levels of the separator, the oil storage tank, the water storage tank, and the concentration value in the ammonia spraying device are all less than the first threshold value, it is determined that the operating state of the engine is normal (third state);

[0112] When the liquid level of the separator, oil storage tank, or water storage tank is greater than a first threshold and less than a second threshold, it is determined that the device needs to be emptied, and the user is reminded to empty the device in time;

[0113] When the concentration value in the ammonia spray device is greater than the first threshold value and less than the second threshold value, the ammonia water in the ammonia spray device is transported to the SCR treatment system through the pipeline to achieve energy recovery and utilization.

[0114] When the liquid level is greater than the second threshold, it is determined that the separator, oil storage tank, water storage tank is operating abnormally or the sensor is operating abnormally, and the user is reminded to stop the vehicle for inspection and maintenance.

[0115] When the engine enters the third operating condition and the third state, the preset first unit time is adjusted to the preset second unit time, and the throttle opening, manifold pressure value, and the liquid level values ​​in the oil-gas separator, oil tank, water tank and ammonia spray device are monitored regularly to shorten the liquid level monitoring time interval and achieve faster feedback response.

[0116] If the throttle opening and manifold pressure values ​​fall within a third preset calibration range, and the liquid level values ​​in the oil-gas separator, oil storage tank, water storage tank and ammonia spray device are less than a third threshold, the engine enters the target operating condition and target state, triggers the air replenishment strategy, and calculates the air replenishment amount for the air supply structure through a preset algorithm; wherein the third threshold is greater than the first threshold.

[0117] For example, when the throttle opening and manifold pressure values ​​fall within the third preset calibration range, the engine is determined to be operating under medium-to-high load, full load, or acceleration conditions (target operating conditions). Due to the dramatic increase in cylinder pressure under medium-to-high load, full load, or acceleration conditions, the high gas pressure and mass may prevent the piston rings from fully sealing. Furthermore, the high engine speed causes metal components to agitate the oil, and the volume expansion of the mixture further increases crankcase blowby. Under these conditions, the crankcase blowby pressure is high, and the large positive pressure causes the blowby gas to quickly enter the oil-gas separator for separation, eliminating the need for the first auxiliary suction pump to assist in extracting the blowby gas.

[0118] Furthermore, the gas replenishment volume is calculated according to the preset algorithm The formula is: , For real-time monitoring of crankcase pressure, is the intake air mass flow rate, is the excess air coefficient measured by the oxygen sensor, is the engine speed, is the oil-gas separation efficiency, is the ammonia removal rate of the spray tower;

[0119] Based on the supplementary air volume, the excess coefficient deviation obtained by the second algorithm Correct the excess air coefficient; the formula of the second algorithm is as follows: , in, Instant feedback coefficient, Cumulative steady-state coefficient, is the target excess air coefficient, is the actual excess air coefficient.

[0120] The ECU dynamically adjusts the air flow distribution ratio between the air supply line and the intake duct based on the corrected air supply volume, and synchronously and cooperatively controls the throttle opening and the air supply pressure regulating valve to bring the actual air flow close to the target value calibrated on the test bench.

[0121] Specifically, in this application, under the basic premise of repeating the above-mentioned working condition judgment, the ECU controls the air flow distribution ratio of the air supply pipeline and the intake duct, so as to meet the air flow for stable operation of each working condition. The ECU controls the throttle opening and the pressure regulating valve opening according to the air flow under the standard test bench conditions to provide the required air flow, and then flexibly distributes the air flow to ensure stable combustion under all working conditions such as cold start and high load.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A crankcase ventilation system for an ammonia-hydrogen engine, characterized in that: The system comprises: An energy supply structure is connected to the engine through a pipeline and is used to deliver fuel to the engine as an energy source for the operation of the engine; The gas supply structure is connected to the engine through a pipeline and is used to deliver a combustion-supporting gas source to the engine. The combustion-supporting gas source reacts with the fuel inside the engine to drive the engine to operate; An engine, wherein the engine is provided with a sensing component electrically connected to a control unit for detecting blowby gas data in a crankcase; the blowby gas data includes at least: blowby gas concentration and blowby gas pressure; The blowby gas treatment structure is connected to the engine crankcase and air supply structure through pipelines, and is used to separate impurities in the blowby gas in the crankcase and, under the control of the control unit, feed the separated blowby gas back to the air supply structure to participate in the intake cycle; The control unit is configured to calculate the air supply volume of the air supply structure based on a preset control strategy and a preset algorithm.

2. The system according to claim 1, wherein: The air supply structure includes: an intake system, a supercharger and an intercooler connected in sequence; the outlet of the intercooler is connected to the engine, and an air flow meter is provided on the pipeline between the intercooler and the engine; wherein, the intercooler is connected to the blowby gas treatment structure for conveying cooling medium to the blowby gas treatment structure.

3. The system according to claim 2, characterized in that The energy supply structure includes: a liquid ammonia cylinder, connected to one end of the ammonia online cracking hydrogen production device and the first energy supply device through pipelines; The other end of the ammonia online cracking hydrogen production device is connected to the engine, and is used to crack ammonia into hydrogen; The other end of the first energy supply device can be connected to the engine or the supercharger.

4. The system according to claim 3, characterized in that When the other end of the first energy supply device is directly connected to the engine, the first energy supply device delivers fuel directly to the engine. In this case, the first energy supply device includes: a coarse filter, a low-pressure pump, a fine filter, and a high-pressure pump connected in sequence; wherein the inlet end of the coarse filter is connected to the liquid ammonia bottle, and the outlet end of the high-pressure pump is connected to the engine; When the other end of the first energy supply device is connected to the supercharger, the first energy supply device converts the liquid fuel into gaseous fuel and transports it to the engine through the air supply structure. At this time, the first energy supply device includes: a pressure reducing valve, a liquid ammonia vaporizer, an ammonia pressure regulating tank and a third electronically controlled pressure regulating valve connected in sequence; wherein, one end of the pressure reducing valve is connected to the liquid ammonia bottle, and the outlet of the third electronically controlled pressure regulating valve is connected to the pipeline between the intake system and the supercharger.

5. The system according to claim 4, characterized in that The blowby gas processing structure includes: An oil-gas separator in communication with the engine, the oil-gas separator being used to separate oil from crankcase blowby gas; a first liquid level sensor connected to a control unit for monitoring the oil depth inside the oil-gas separator is provided inside the oil-gas separator; The first interface of the oil-gas separator is connected to the water-gas separator through a pipeline, and the second interface is connected to the oil storage tank through a pipeline; wherein, a first auxiliary suction pump and a blowby check valve are provided on the pipeline between the oil-gas separator and the water-gas separator; and an oil return check valve is provided on the pipeline between the oil-gas separator and the oil storage tank; The first inlet of the water-gas separator is connected to the intercooler, and a coolant flow sensor and a coolant electric control valve are provided on the pipeline between the two; the first outlet of the water-gas separator is connected to the water storage tank; wherein a second liquid level sensor is arranged at the bottom of the water storage tank; The water-gas separator is provided with a second outlet for discharging blowby gas after separation treatment.

6. The system according to claim 5, characterized in that When the other end of the first energy supply device is directly connected to the engine, the blowby gas treatment structure further includes: an ammonia spray device and an SCR treatment system; wherein the water-gas separator is connected to the SCR treatment system via the ammonia spray device; the ammonia spray device is used to remove ammonia from the blowby gas; the ammonia spray device is connected to the water storage tank via a pipeline, and a spray water supply valve and a second auxiliary suction pump are provided on the pipeline between the two; the outlet of the ammonia spray device is connected to the pipeline between the intake system and the supercharger; wherein the outlet pipeline of the ammonia spray device is provided with a first electronically controlled pressure regulating valve and an air supply flow meter; wherein the first electronically controlled pressure regulating valve and the air supply flow meter are both connected to the control unit signal; An ammonia pressure regulating valve connected to the control unit signal is provided on the pipeline between the ammonia spray device and the SCR treatment system; wherein, an ammonia concentration sensor connected to the control unit signal is also provided inside the ammonia spray device.

7. The system according to claim 5, characterized in that When the other end of the first energy supply device is connected to the supercharger, the second outlet of the water-gas separator is directly connected to the pipeline between the intake system and the supercharger; wherein, a second electronically controlled pressure regulating valve and an ammonia flowmeter are provided on the second outlet pipeline of the water-gas separator; wherein, the blowby gas separated by the water-gas separator includes at least ammonia and other gases.

8. A crankcase ventilation control method for an ammonia-hydrogen engine, characterized in that: Applicable to the system according to any one of claims 1 to 7; the method comprises the following steps: Step 1: Obtain engine operating parameters; wherein the operating parameters include at least: engine speed, coolant temperature, intake air temperature, throttle opening, crankshaft position, manifold pressure, crankcase blowby concentration and pressure, oil-gas separator liquid level, oil tank liquid level, water tank liquid level and ammonia spray device liquid level; Step 2: When the acquired engine operating parameters meet a first preset condition, a first strategy is invoked to control the engine and first operating data of the engine is output, where the first operating data includes a first operating condition and a first operating state. Step 3: In response to the first operating data of the engine, triggering the second strategy and determining whether the operating condition of the engine has entered the second operating condition from the first operating condition; Step 4: If the engine operating condition is the second operating condition, the third strategy is triggered to determine whether the engine operating condition has entered the target operating condition from the second operating condition, and based on the target operating condition and its corresponding operating state, the preset control strategy and preset algorithm are used to control the purified blowby gas to replenish the air supply structure.

9. The method according to claim 8, characterized in that The fourth step comprises: Obtaining throttle opening and manifold pressure values, and comparing them with a second preset calibration range respectively; When the throttle opening and the manifold pressure values ​​both fall within a second preset calibration range, it is determined that the engine is in the third operating condition; Based on the engine being in the third operating condition, concentration values ​​in the oil-gas separator, the oil storage tank, the water storage tank, and the ammonia spray device are monitored in real time with a preset first unit time as a period, so as to adjust the concentration values ​​in the oil-gas separator, the oil storage tank, the water storage tank, and the ammonia spray device to below corresponding preset first thresholds, thereby obtaining a third state corresponding to the third operating condition; When the engine enters the third operating condition and the third state, the preset first unit time is adjusted to the preset second unit time, and the throttle opening, the manifold pressure value, and the liquid level values ​​in the oil-gas separator, the oil storage tank, the water storage tank and the ammonia spray device are regularly monitored; If the throttle opening and manifold pressure values ​​fall within the third preset calibration range, and the liquid level values ​​in the oil-gas separator, oil storage tank, water storage tank and ammonia spray device are less than the third threshold, the engine enters the target operating condition and target state, triggering the air replenishment strategy, and calculating the air replenishment amount for the air supply structure through the preset algorithm.

10. The method according to claim 9, characterized in that Calculate the gas supplement volume according to the preset algorithm The formula is: ， For real-time monitoring of crankcase pressure, is the intake air mass flow rate, is the excess air coefficient measured by the oxygen sensor, is the engine speed, is the oil-gas separation efficiency, is the ammonia removal rate of the spray tower; Based on the supplementary air volume, the excess coefficient deviation obtained by the second algorithm Correct the excess air coefficient; the formula of the second algorithm is as follows: ;in, Instant feedback coefficient, Cumulative steady-state coefficient, is the target excess air coefficient, It is the actual excess air coefficient.

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