CN117552898A - Ammonia supply mechanism, ammonia internal combustion engine and ammonia supply control method - Google Patents

Abstract

The invention discloses an ammonia supply mechanism, an ammonia internal combustion engine and an ammonia supply control method, wherein the ammonia supply mechanism comprises a liquid ammonia tank, a temperature and pressure monitoring assembly, an ammonia supply assembly and a pressurizing assembly; the ammonia supply assembly comprises a high-pressure pump and an ammonia rail, an inlet of the high-pressure pump is communicated with an outlet of the liquid ammonia tank, an outlet of the high-pressure pump is communicated with one end of the ammonia rail, and the other end of the ammonia rail is communicated with a first feed inlet of the oil sprayer; the supercharging assembly comprises a flow-back valve, a heat exchanger, a regulating valve and a controller, one end of the flow-back valve is communicated with an outlet of the high-pressure pump, and the other end of the flow-back valve is communicated with a first medium inlet of the heat exchanger. The beneficial effects of the invention are as follows: through adopting the direct injection in the liquid ammonia jar, injection pressure is high, can reach higher combustion efficiency, simultaneously, when the pressure in the liquid ammonia jar was less than the setting value, opened and returned row valve and governing valve, made in the high-pressure ammonia heated gasification changed into high-pressure nitrogen gas back and discharged into the liquid ammonia jar to maintain the pressure in the liquid ammonia jar in predetermineeing the within range, thereby be convenient for control liquid ammonia injection quantity.

Description

Ammonia supply mechanism, ammonia internal combustion engine and ammonia supply control method

Technical Field

The invention relates to the technical field of automobile engines, in particular to an ammonia supply mechanism, an ammonia internal combustion engine and an ammonia supply control method.

Background

As shown in fig. 1, the current ammonia internal combustion engine has the technical route that liquid ammonia is stored and is supplied to the engine after being vaporized, is premixed with air in an air inlet manifold, enters a cylinder and is ignited by diesel oil, and the ammonia internal combustion engine belongs to a low-pressure fuel supply system and has low combustion heat efficiency.

Meanwhile, ammonia is gas at normal temperature and normal pressure, but the liquefaction pressure of ammonia is very low, and the ammonia can be liquefied at normal temperature (25 ℃) under 1 MPa. The liquid ammonia is unstable and is easily vaporized in the storage container under the influence of temperature. The pressure in the storage container can change along with the ambient temperature, can make ammonia change back and forth between gaseous state and liquid state, and the air feed pressure of ammonia is unstable, is unfavorable for the control of automobile-used internal-combustion engine to injection quantity.

Disclosure of Invention

In view of the foregoing, there is a need for an ammonia supply mechanism, an ammonia internal combustion engine, and an ammonia supply control method for solving the technical problems of low combustion heat efficiency of the ammonia internal combustion engine and unstable air supply pressure of ammonia, which are unfavorable for controlling injection quantity of the internal combustion engine for vehicles.

In order to achieve the above purpose, the invention provides an ammonia supply mechanism, which comprises a liquid ammonia tank, a temperature and pressure monitoring assembly, an ammonia supply assembly and a pressurizing assembly;

the temperature and pressure monitoring component is used for detecting the temperature and pressure in the liquid ammonia tank;

the ammonia supply assembly comprises a high-pressure pump and an ammonia rail, an inlet of the high-pressure pump is communicated with an outlet of the liquid ammonia tank, an outlet of the high-pressure pump is communicated with one end of the ammonia rail, and the other end of the ammonia rail is communicated with a first feed inlet of the oil sprayer;

the supercharging assembly comprises a flow-back valve, a heat exchanger and a regulating valve, one end of the flow-back valve is communicated with an outlet of the high-pressure pump, the other end of the flow-back valve is communicated with a first medium inlet of the heat exchanger, a first medium outlet of the heat exchanger is communicated with an inlet of the liquid ammonia tank, a second medium inlet of the heat exchanger is communicated with one end of the regulating valve, the other end of the regulating valve is communicated with one end of a cooling tube group of the engine, and a second medium outlet of the heat exchanger is communicated with the other end of the cooling tube group of the engine.

In some embodiments, the ammonia supply assembly further comprises a first filter having one end in communication with the outlet of the liquid ammonia tank and the other end in communication with the inlet of the high pressure pump.

In some embodiments, the pressurizing assembly further comprises a one-way valve and a return pipe, wherein an inlet of the one-way valve is communicated with a first medium outlet of the heat exchanger, an outlet of the one-way valve is communicated with an inlet of the liquid ammonia tank, one end of the return pipe is communicated with the ammonia rail, and the other end of the return pipe is communicated with one end of the return pipe valve.

In some embodiments, the pressurizing assembly further comprises a controller, wherein the controller is electrically connected with the temperature and pressure monitoring assembly, the flow back valve and the regulating valve, and is used for controlling the opening degrees of the flow back valve and the regulating valve according to the temperature and the pressure in the liquid ammonia tank.

In some embodiments, the cooling tube set includes a circulation pump, a first connecting tube and a second connecting tube, an inlet of the circulation pump is communicated with a second medium outlet of the heat exchanger, an outlet of the circulation pump is communicated with one end of the first connecting tube, the other end of the first connecting tube is communicated with one end of a liquid cooling cavity of the engine, one end of the second connecting tube is communicated with the other end of the liquid cooling cavity of the engine, one end of the regulating valve is communicated with a second medium inlet of the heat exchanger, and the other end of the regulating valve is communicated with the other end of the second connecting tube.

In some embodiments, the temperature and pressure monitoring assembly includes a temperature detecting member for detecting a temperature in the liquid ammonia tank and a pressure detecting member for detecting a pressure in the liquid ammonia tank.

The invention also provides an ammonia internal combustion engine, which comprises the ammonia supply mechanism, and further comprises an oil sprayer, an engine and an oil supply assembly, wherein a first feed inlet of the oil sprayer is communicated with the other end of the ammonia rail, a second feed inlet of the oil sprayer is communicated with the oil supply assembly, and an outlet of the oil sprayer is communicated with a combustion chamber of the engine.

In some embodiments, the oil supply assembly comprises a diesel tank, an oil delivery pump, a booster pump and an oil rail, wherein an inlet of the oil delivery pump is communicated with an outlet of the diesel tank, an outlet of the oil delivery pump is communicated with an inlet of the booster pump, an outlet of the booster pump is communicated with one end of the oil rail, and the other end of the oil rail is communicated with a second feed inlet of the oil injector.

In some embodiments, the oil supply assembly further comprises a second filter having one end in communication with the outlet of the diesel tank and the other end in communication with the inlet of the oil transfer pump.

The invention also provides an ammonia supply control method which is suitable for the ammonia supply mechanism and comprises the following steps:

s1, starting a high-pressure pump to suck liquid ammonia in a liquid ammonia tank to one end of an ammonia rail, and enabling the liquid ammonia to enter a first feed inlet of an oil sprayer from the other end of the ammonia rail;

s2, when the temperature and pressure monitoring assembly detects that the pressure in the liquid ammonia tank is lower than the preset pressure, the flow back valve and the regulating valve are opened, high-pressure liquid ammonia discharged from an outlet of the high-pressure pump enters the heat exchanger, the liquid ammonia in the heat exchanger absorbs heat of cooling liquid in a cooling pipe group of the engine and is gasified into high-pressure ammonia, and the high-pressure ammonia enters the liquid ammonia tank to increase the pressure in the liquid ammonia tank;

s3, controlling the opening degree of the regulating valve according to the pressure and temperature detected by the temperature and pressure monitoring assembly in the liquid ammonia tank, so as to control the temperature of high-pressure ammonia gas input into the liquid ammonia tank, and respectively keeping the pressure and the temperature in the liquid ammonia tank in a preset pressure range and a preset temperature range.

Compared with the prior art, the technical scheme provided by the invention has the beneficial effects that: when the device is used, the high-pressure pump is started to suck the liquid ammonia in the liquid ammonia tank to one end of the ammonia rail, and the liquid ammonia enters the first feed inlet of the fuel injector from the other end of the ammonia rail; when the temperature and pressure monitoring component detects that the pressure in the liquid ammonia tank is lower than the preset pressure, the flow back valve and the regulating valve are opened, high-pressure liquid ammonia discharged from an outlet of the high-pressure pump enters the heat exchanger, the liquid ammonia in the heat exchanger absorbs heat of cooling liquid in a cooling pipe group of the engine and is gasified into high-pressure ammonia, the high-pressure ammonia enters the liquid ammonia tank to increase the pressure in the liquid ammonia tank, so that the pressure in the liquid ammonia tank is increased, when the temperature and pressure monitoring component detects that the pressure in the liquid ammonia tank is higher than the other preset pressure, the flow back valve and the regulating valve are closed, so that the pressure in the liquid ammonia tank is kept in a certain range, and unstable air supply pressure of ammonia caused by gasification of the liquid ammonia tank due to the fact that the pressure in the liquid ammonia tank is too low is avoided, thereby being convenient for controlling the liquid ammonia injection quantity.

Drawings

FIG. 1 is a schematic diagram of a hydraulic control system of a prior art ammonia internal combustion engine;

FIG. 2 is a schematic diagram of an embodiment of an ammonia internal combustion engine provided by the present invention;

FIG. 3 is a schematic diagram of the liquid ammonia tank of FIG. 2;

FIG. 4 is a schematic view of the cooling tube set of FIG. 2;

in the figure: 100-ammonia supply mechanism, 110-liquid ammonia tank, 120-warm-pressure monitoring assembly, 121-temperature detecting assembly, 122-pressure detecting assembly, 130-ammonia supply assembly, 131-high pressure pump, 132-ammonia rail, 133-first filter, 140-pressurizing assembly, 141-back flow valve, 142-heat exchanger, 143-regulating valve, 144-controller, 145-check valve, 146-back flow pipe, 200-injector, 300-engine, 310-cooling pipe group, 311-circulating pump, 312-first connecting pipe, 313-second connecting pipe, 400-oil supply assembly, 410-diesel tank, 420-oil delivery pump, 430-booster pump, 440-oil rail, 450-second filter.

Detailed Description

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and together with the description serve to explain the principles of the invention, and are not intended to limit the scope of the invention.

Referring to fig. 2-4, the present invention provides an ammonia supply mechanism 100, which includes a liquid ammonia tank 110, a temperature and pressure monitoring assembly 120, an ammonia supply assembly 130, and a pressurizing assembly 140.

The liquid ammonia tank 110 stores liquid ammonia therein at a pressure of 3 to 4MPa and a temperature of normal temperature (about 25 ℃). As shown in fig. 3, an outlet is provided at the lower end of the liquid ammonia tank 110, an inlet is provided at the top end of the liquid ammonia tank 110, and when liquid ammonia is filled into the liquid ammonia tank 110 and the liquid ammonia tank 110 is not filled with liquid ammonia, the liquid ammonia tank 110 is provided at the lower end and the volatilized gaseous ammonia (ammonia gas) is provided at the upper end.

The temperature and pressure monitoring component 120 is used for detecting the temperature and pressure in the liquid ammonia tank 110; in some embodiments, the temperature and pressure monitoring assembly 120 may be a temperature and pressure monitoring module of the liquid ammonia tank 110, and in other embodiments, the liquid ammonia tank 110 may be an additional temperature sensor and pressure sensor, which is not limited in the present invention.

The ammonia supply assembly 130 comprises a high-pressure pump 131 and an ammonia rail 132, wherein an inlet of the high-pressure pump 131 is communicated with an outlet of the liquid ammonia tank 110, an outlet of the high-pressure pump 131 is communicated with one end of the ammonia rail 132, and the other end of the ammonia rail 132 is communicated with a first feed inlet of the fuel injector 200; in this embodiment, the high-pressure pump 131 is used for pressurizing the liquid ammonia discharged from the outlet of the liquid ammonia tank 110, so that the pressure of the liquid ammonia is increased to above 30MPa, and the liquid ammonia enters the first feed inlet of the fuel injector 200 from the other end of the ammonia rail 132. In this embodiment, the ammonia rail 132 is used as a channel for delivering liquid ammonia, and a liquid ammonia delivering channel is formed inside the ammonia rail 132, one end of the liquid ammonia delivering channel is communicated with the outlet of the high-pressure pump 131, and the other end of the liquid ammonia delivering channel is communicated with the first feed port of the fuel injector 200. In this embodiment, the side portion of the ammonia rail 132 is further provided with a bypass port communicating with the liquid ammonia delivery channel.

The pressurizing assembly 140 includes a flow back valve 141, a heat exchanger 142, a regulating valve 143, and a controller 144, one end of the flow back valve 141 is communicated with the outlet of the high pressure pump 131, the other end of the flow back valve 141 is communicated with the first medium inlet of the heat exchanger 142, in this embodiment, one end of the flow back valve 141 is communicated with the bypass port, the first medium outlet of the heat exchanger 142 is communicated with the inlet of the liquid ammonia tank 110, the second medium inlet of the heat exchanger 142 is communicated with one end of the regulating valve 143, the other end of the regulating valve 143 is communicated with one end of the cooling tube bank 310 of the engine 300, the second medium outlet of the heat exchanger 142 is communicated with the other end of the cooling tube bank 310 of the engine 300, and the controller 144 is electrically connected with the temperature and pressure monitoring assembly 120, the flow back valve 141, and the regulating valve 143, and is used for controlling the opening degrees of the flow back valve 141 and the regulating valve 143 according to the temperature and the pressure in the liquid ammonia tank 110.

In this embodiment, the flow back valve 141 is an electromagnetic valve, so that the flow back valve 141 is conveniently controlled by a controller, and the specific model of the flow back valve 141 is not limited in the present invention.

In this embodiment, the heat exchanger 142 is a convection heat exchanger, a first medium inlet of the heat exchanger 142 is communicated with a first medium outlet of the heat exchanger 142, a second medium inlet of the heat exchanger 142 is communicated with a second medium outlet of the heat exchanger 142, and the flow directions of the first medium and the second medium are opposite in the heat exchanger, so that heat exchange between the first medium and the second medium is realized through convection. In the present invention, the specific type of the heat exchanger 142 is not limited.

In this embodiment, the adjusting valve 143 is an electromagnetic valve, so that the control is conveniently performed by the controller, and the specific model of the adjusting valve 143 is not limited in the present invention.

In the present embodiment, the controller 144 is an ECU (electronic control unit for an automobile), which is a comprehensive control device for an engine. The function of the engine is to calculate, process, judge and then output instructions to various information input by various sensors of the engine according to the stored programs, and control the related executors to act, thus achieving the purpose of controlling the engine to work rapidly, accurately and automatically. When the engine is started, the electronic control unit enters a working state, and certain programs and steps are taken out of the ROM and enter the CPU. These programs may be control of ignition timing, control of gasoline injection, control of idle speed, etc. By the control of the CPU, each instruction is looped one by one. Engine information required in the execution of the program comes from various sensors. The signal from the sensor first enters the input loop and is processed. If the signal is a digital signal, the signal directly enters the microcomputer through the I/O interface according to the arrangement of the CPU. If the analog signal is converted into a digital signal by an A/D converter, the digital signal can enter the microcomputer through the I/O interface. Most of the information is temporarily stored in the RAM and sent to the CPU from the RAM according to the instruction. The next step is to introduce the reference data in the memory ROM into the CPU to compare the information input to the sensor with it. Each signal from the relevant sensor is sampled in turn and compared to the reference data. After comparing and calculating the data, the CPU makes a decision and sends out an output instruction signal, the output instruction signal is amplified through an I/O interface, necessary signals are changed into analog signals through a D/A converter, and finally the action of an actuator is controlled through an output loop.

When in use, the high-pressure pump 131 is started to suck the liquid ammonia in the liquid ammonia tank 110 to one end of the ammonia rail 132, the high-pressure pump 131 pressurizes the liquid ammonia to more than 30MPa, and the liquid ammonia enters the first feed inlet of the fuel injector 200 from the other end of the ammonia rail 132; with the use of the liquid ammonia, the liquid ammonia in the liquid ammonia tank 110 gradually decreases, the pressure is reduced, when the temperature and pressure monitoring component 120 detects that the pressure in the liquid ammonia tank 110 is lower than a preset pressure (for example, 3 Mpa), the flow back valve 141 and the regulating valve 143 are opened, so that the high-pressure liquid ammonia discharged from the outlet of the high-pressure pump 131 enters the heat exchanger 142, the liquid ammonia in the heat exchanger 142 absorbs the heat of the cooling liquid (the temperature of which is usually higher than 80 ℃) in the cooling tube set 310 of the engine 300 and is gasified into high-pressure ammonia, the high-pressure ammonia enters the liquid ammonia tank 110, the pressure in the liquid ammonia tank 110 is increased, and when the temperature and pressure monitoring component 120 detects that the pressure in the liquid ammonia tank 110 is higher than another preset pressure (for example, 4 Mpa), the flow back valve 141 and the regulating valve 143 are closed, so that the pressure in the liquid ammonia tank 110 is kept within a certain range, the air supply pressure of the liquid ammonia in the liquid ammonia tank 110 is prevented from being gasified due to the low pressure in the liquid ammonia tank 110, and the liquid ammonia injection amount is controlled conveniently.

In order to facilitate removal of impurities in the liquid ammonia, referring to fig. 2, in a preferred embodiment, the ammonia supply assembly 130 further includes a first filter 133, one end of the first filter 133 is in communication with the outlet of the liquid ammonia tank 110, and the other end of the first filter 133 is in communication with the inlet of the high pressure pump 131. In this embodiment, the first filter 133 is a filter, which is a fitting that functions to filter foreign substances or gas through a filter paper. Generally refers to an automotive filter, which is an accessory for an engine. The filtering device is divided into: oil filters, fuel filters (gasoline filters, diesel filters, oil-water separators, hydraulic filters), air filters, air conditioning filters, and the like. The engine has three filters, namely air, engine oil and fuel oil, commonly called as three filters, and an air conditioner filter commonly called as four filters. Respectively, the filtering of a lubricating system, a medium in a combustion system, an engine air inlet system and a carriage air circulation system. The fuel filter includes three types of diesel filter, gasoline filter and natural gas filter. The gasoline filter is divided into a carburetor type and an electric injection type, a gasoline engine using the carburetor is arranged on one side of an inlet of an oil delivery pump, the working pressure is smaller, a nylon shell is generally adopted, the gasoline filter of the electric injection type engine is arranged on one side of an outlet of the oil delivery pump, the working pressure is higher, and a metal shell is generally adopted. The filter element of the gasoline filter is mostly made of filter paper, and nylon cloth and polymer materials are also used. The fuel filter is connected in series on a pipeline between the fuel pump and the oil inlet of the throttle valve body. The fuel filter has the function of filtering ferric oxide contained in fuel, and the structure of the fuel filter consists of an aluminum shell and a bracket with stainless steel inside, and a high-efficiency filter paper sheet is arranged on the bracket and is in a chrysanthemum shape so as to increase the flow area. The electrospray filter cannot be commonly used with an oil filter. Because electrospray filters often withstand fuel pressures of 200-300 KPA, the filter is generally required to have a compressive strength of above 500KPA, whereas chemical fuel filters are not required to achieve such high pressures. In this embodiment, a general gasoline filter may be used as the first filter 133.

In order to prevent the gaseous ammonia from flowing back into the ammonia rail 132 to affect the injection quantity, referring to fig. 2, in a preferred embodiment, the pressurizing assembly 140 further includes a check valve 145, an inlet of the check valve 145 is communicated with the first medium outlet of the heat exchanger 142, an outlet of the check valve 145 is communicated with the inlet of the liquid ammonia tank 110, and the gaseous ammonia in the liquid ammonia tank 110 and the heat exchanger 142 does not flow back into the ammonia rail 132 to affect the injection quantity due to the check valve 145. In this embodiment, the check valve is also called a check valve, and can make fluid flow along only one direction, and no backflow phenomenon occurs, and the check valve has the following several kinds: (1) The spring check valve is characterized in that the valve is opened by utilizing the pressure of a spring from bottom to top to stop the liquid in the pipeline from flowing back. (2) The gravity check valve regulates the pipeline pressure by the self weight of the valve. When the pressure is high, the valve automatically falls and closes, and when the pressure is low, the valve automatically withdraws. (3) The rotary-opening pressure valve is opened by the flow of liquid in the pipeline. (4) The diaphragm type pressure valve is the same as a waterwheel, and can eliminate reverse pressure when liquid flows, and open and close the pipeline liquid reflux. In this embodiment, a spring check valve is preferred.

To specifically implement the mounting of the flowback valve 141, referring to fig. 2, in a preferred embodiment, the supercharging assembly 140 further includes a flowback pipe 146, one end of the flowback pipe 146 communicates with the ammonia rail 132, and the other end of the flowback pipe 146 communicates with one end of the flowback valve 141.

In order to specifically implement the function of the cooling tube set 310, referring to fig. 2 and 4, in a preferred embodiment, the cooling tube set 310 includes a circulation pump 311, a first connection tube 312 and a second connection tube 313, where an inlet of the circulation pump 311 is communicated with a second medium outlet of the heat exchanger 142, an outlet of the circulation pump 311 is communicated with one end of the first connection tube 312, another end of the first connection tube 312 is communicated with one end of a liquid cooling chamber of the engine 300, one end of the second connection tube 313 is communicated with another end of the liquid cooling chamber of the engine 300, one end of the regulating valve 143 is communicated with a second medium inlet of the heat exchanger 142, another end of the regulating valve 143 is communicated with another end of the second connection tube 313, during operation of the engine 300, heat is generated to heat a cooling liquid in the liquid cooling chamber, the cooling liquid enters the second medium inlet of the heat exchanger 142 through the second connection tube 313, after heating the cooling liquid in the heat exchanger 142, is discharged from the second medium outlet of the heat exchanger 142, and enters the first connection tube 312 through the circulation pump 311, and the cooling liquid ammonia is further cooled by the cooling tube 300.

The principle of the engine cooling system is as follows: during the process of converting chemical energy into mechanical energy, the engine releases a large amount of heat, and the engine itself is heated, and a cooling system is required to keep the engine within a proper temperature unit under each operating condition. The cooling system is used for ensuring that the engine cannot be overheated or supercooled and needs to be quickly warmed up after starting, so that the normal working range is reached. The maximum combustion temperature can reach 2500 ℃ when the engine is normally operated, and the temperature of the combustion chamber can reach 1000 ℃ even at idle speed or medium speed. The engine cooling system usually uses water cooling as the main part, and uses circulating water cooling in a water channel of a cylinder to lead the water heated in the water channel into a radiator (a water tank), and returns the water to the water channel after being cooled by wind. The common water cooling medium is a liquid (and a certain amount of antirust agent, foam inhibitor and the like are added) formed by mixing ethylene glycol and water according to a certain proportion, so that the boiling point temperature can be increased, the freezing point temperature can be reduced, scale and rust can be prevented, the tightness of a cooling system is improved, and the generation of foam in the water circulation process is inhibited. The radiator is a heat exchanger, and can be divided into a longitudinal flow type radiator and a transverse flow type radiator according to the flowing direction of cooling liquid, and a transverse flow type radiator is adopted in most cars. The radiator has various structural forms, and common ones include flat tube sheets, round tube sheets, tube belts, plates and the like. The cooling fan is mainly used for enhancing the heat radiation capability of the radiator, accelerating cooling of cooling liquid, and can be divided into axial flow type and centrifugal type, and the automobile engine is mainly provided with low-pressure head, large-air-quantity and high-efficiency axial flow fans, and the air quantity of the fans is mainly related to the diameter, the rotating speed, the shape of blades, the installation angle of the blades and the number of the blades. The thermostat can be divided into a wax type structure and a bellows type structure according to the valve body structure by opening or closing a channel of cooling liquid passing through the radiator according to the temperature of the cooling liquid, but the wax type structure is common, but in order to save temperature and reduce emission, the warm-up time is shortened, the emission of a cold machine is reduced, and the electronic thermostat is mostly adopted. The water pump pressurizes the coolant, guarantees that it flows in the cooling cycle, and automobile engine adopts centrifugal mechanical water pump mostly, generally through bent axle drive, therefore water pump rotational speed is directly proportional with the engine rotational speed. In order to reduce the warm-up time, an electronic water pump is generally adopted, and the water pump is separated through a clutch during low-speed operation, so that the water circulation is reduced, the heat loss is reduced, the warm-up time is shortened, and the emission of a cooler is reduced. When the vehicle starts, the engine starts to run, the water pump drives the crank pulley to rotate, the pressure of the cooling liquid is increased, and the cooling liquid is forced to circulate in the engine. The circulating low-temperature cooling liquid is contacted with the wall of the water jacket, so that heat generated in the running process of the engine is taken away, the temperature of the engine cylinder body, the cylinder sleeve, the cylinder cover and other parts is reduced, the heated cooling liquid is cooled by the fan and then reenters the cooling circulation, and the whole cooling process enables the engine to be at a proper working temperature.

In order to specifically implement the function of the temperature and pressure monitoring assembly 120, referring to fig. 2, in a preferred embodiment, the temperature and pressure monitoring assembly 120 includes a temperature detecting member 121 and a pressure detecting member 122, wherein the temperature detecting member 121 is used for detecting the temperature in the liquid ammonia tank 110, and the pressure detecting member 122 is used for detecting the pressure in the liquid ammonia tank 110.

Referring to fig. 2, the present invention further provides an ammonia internal combustion engine, which includes the ammonia supply mechanism 100, and further includes an injector 200, an engine 300, and an oil supply unit 400, wherein a first feed port of the injector 200 is communicated with the other end of the ammonia rail 132, a second feed port of the injector 200 is communicated with the oil supply unit 400, and an outlet of the injector 200 is communicated with a combustion chamber of the engine 300. In use, liquid ammonia provided by ammonia supply mechanism 100 enters fuel injector 200 from the first feed inlet, diesel oil provided by oil supply assembly 400 enters fuel injector 200 via the second feed inlet, and after liquid ammonia and diesel oil are uniformly mixed, the liquid ammonia is ejected from the outlet of fuel injector 200 into the combustion chamber of engine 300 for combustion.

The fuel injector 200 is a dual fuel injector, and can mix liquid ammonia and diesel oil uniformly and then spray the mixture into a combustion chamber of the engine 300 for combustion.

In order to specifically implement the function of the oil supply unit 400, referring to fig. 2, in a preferred embodiment, the oil supply unit 400 includes a diesel tank 410, an oil pump 420, a booster pump 430 and an oil rail 440, wherein an inlet of the oil pump 420 is communicated with an outlet of the diesel tank 410, an outlet of the oil pump 420 is communicated with an inlet of the booster pump 430, an outlet of the booster pump 430 is communicated with one end of the oil rail 440, and the other end of the oil rail 440 is communicated with a second feed port of the injector 200. In this embodiment, the fuel rail 440 is also called a fuel rail (fuel rail), i.e., a high-pressure accumulator, which is an oil path pipe in front of a fuel injector for supplying fuel to a cylinder of the internal combustion engine. It contains a fuel inlet (inlet) with a seat cover (pocket or seat) for a plurality of fuel injectors. Some fuel rails have a fuel pressure regulator at one end. Solenoid or piezo valves may provide fine electronic control of fuel injection timing and quantity, and higher pressures provided by common rail technology may provide better fuel atomization. To reduce engine noise, the electronic control unit of the engine may inject a small amount of diesel fuel prior to the main injection event ("pilot" injection), thereby reducing its explosiveness and vibration, and optimizing the injection time and the amount of fuel quality variation, cold start, etc. Some advanced common rail fuel systems may perform up to five injections per stroke.

In order to facilitate filtering impurities in diesel fuel, referring to fig. 2, in a preferred embodiment, the oil supply assembly 400 further includes a second filter 450, one end of the second filter 450 is in communication with the outlet of the diesel tank 410, and the other end of the second filter 450 is in communication with the inlet of the oil transfer pump 420. In this embodiment, the second filter 450 is a filter.

The invention also provides an ammonia supply control method, which is suitable for the ammonia supply mechanism 100 and comprises the following steps:

s1, starting a high-pressure pump 131 to pump liquid ammonia in a liquid ammonia tank 110 to one end of an ammonia rail 132, pressurizing the liquid ammonia to more than 30MPa by the high-pressure pump 131, and enabling the liquid ammonia to enter a first feed inlet of an oil sprayer 200 from the other end of the ammonia rail 132;

s2, as the liquid ammonia is used, the liquid ammonia in the liquid ammonia tank 110 gradually decreases, the pressure is reduced, when the temperature and pressure monitoring component 120 detects that the pressure in the liquid ammonia tank 110 is lower than the preset pressure (such as 3 Mpa), the back flow valve 141 and the regulating valve 143 are opened, high-pressure liquid ammonia discharged from the outlet of the high-pressure pump 131 enters the heat exchanger 142, the cooling liquid (the temperature of which is usually higher than 80 ℃) in the cooling tube group 310 of the liquid ammonia absorption engine 300 in the heat exchanger 142 is gasified into high-pressure ammonia, the high-pressure ammonia enters the liquid ammonia tank 110 so as to increase the pressure in the liquid ammonia tank 110, the pressure in the liquid ammonia tank 110 is increased, and when the temperature and pressure monitoring component 120 detects that the pressure in the liquid ammonia tank 110 is higher than the other preset pressure (such as 4 Mpa), the back flow valve 141 and the regulating valve 143 are closed, so that the pressure in the liquid ammonia tank 110 is kept within a certain range, the air supply pressure of the liquid ammonia in the liquid ammonia tank 110 is prevented from being excessively low, and the air supply pressure of the liquid ammonia in the liquid ammonia tank 110 is not stable, and the liquid ammonia injection amount is controlled conveniently;

s3, controlling the opening degree of the regulating valve 143 according to the pressure and the temperature in the liquid ammonia tank 110 detected by the temperature and pressure monitoring assembly 120, so as to control the temperature of the high-pressure ammonia gas input into the liquid ammonia tank 110, and respectively keeping the pressure and the temperature in the liquid ammonia tank 110 within a preset pressure range and a preset temperature range.

In summary, according to the technical scheme provided by the invention, by adopting the direct injection in the liquid ammonia tank, the injection pressure is high, so that higher combustion efficiency can be achieved, and simultaneously, when the pressure in the liquid ammonia tank 110 is lower than a set value, the flowback valve 141 and the regulating valve 143 are opened, so that high-pressure ammonia gas is heated and gasified to be converted into high-pressure nitrogen gas and then discharged into the liquid ammonia tank 110, and the pressure in the liquid ammonia tank 110 is maintained within a preset range, so that the injection quantity of the liquid ammonia can be conveniently controlled.

The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the technical scope of the present invention should be included in the scope of the present invention.

Claims (10)

1. The ammonia supply mechanism is characterized by comprising a liquid ammonia tank, a temperature and pressure monitoring assembly, an ammonia supply assembly and a pressurizing assembly;

the temperature and pressure monitoring component is used for detecting the temperature and pressure in the liquid ammonia tank;

the ammonia supply assembly comprises a high-pressure pump and an ammonia rail, an inlet of the high-pressure pump is communicated with an outlet of the liquid ammonia tank, an outlet of the high-pressure pump is communicated with one end of the ammonia rail, and the other end of the ammonia rail is communicated with a first feed inlet of the oil sprayer;

the supercharging assembly comprises a flow-back valve, a heat exchanger and a regulating valve, one end of the flow-back valve is communicated with an outlet of the high-pressure pump, the other end of the flow-back valve is communicated with a first medium inlet of the heat exchanger, a first medium outlet of the heat exchanger is communicated with an inlet of the liquid ammonia tank, a second medium inlet of the heat exchanger is communicated with one end of the regulating valve, the other end of the regulating valve is communicated with one end of a cooling tube group of the engine, and a second medium outlet of the heat exchanger is communicated with the other end of the cooling tube group of the engine.

2. The ammonia supply mechanism of claim 1, wherein the ammonia supply assembly further comprises a first filter having one end in communication with the outlet of the liquid ammonia tank and the other end in communication with the inlet of the high pressure pump.

3. The ammonia supply mechanism of claim 1, wherein the pressurizing assembly further comprises a one-way valve and a return line, an inlet of the one-way valve is communicated with a first medium outlet of the heat exchanger, an outlet of the one-way valve is communicated with an inlet of the liquid ammonia tank, one end of the return line is communicated with the ammonia rail, and the other end of the return line is communicated with one end of the return line valve.

4. The ammonia supply mechanism of claim 1, wherein the pressurization assembly further comprises a controller electrically connected to the temperature and pressure monitoring assembly, the flow back valve and the regulating valve and configured to control the opening of the flow back valve and the regulating valve according to the temperature and pressure in the liquid ammonia tank.

5. The ammonia supply mechanism according to claim 1, wherein the cooling tube group includes a circulation pump, a first connecting tube and a second connecting tube, an inlet of the circulation pump is communicated with a second medium outlet of the heat exchanger, an outlet of the circulation pump is communicated with one end of the first connecting tube, the other end of the first connecting tube is communicated with one end of a liquid cooling chamber of the engine, one end of the second connecting tube is communicated with the other end of the liquid cooling chamber of the engine, one end of the regulating valve is communicated with a second medium inlet of the heat exchanger, and the other end of the regulating valve is communicated with the other end of the second connecting tube.

6. The ammonia supply mechanism of claim 1, wherein the temperature and pressure monitoring assembly comprises a temperature detecting member for detecting a temperature in the liquid ammonia tank and a pressure detecting member for detecting a pressure in the liquid ammonia tank.

7. An ammonia internal combustion engine, characterized by comprising the ammonia supply mechanism as claimed in any one of claims 1-6, and further comprising an oil injector, an engine and an oil supply assembly, wherein a first feed port of the oil injector is communicated with the other end of the ammonia rail, a second feed port of the oil injector is communicated with the oil supply assembly, and an outlet of the oil injector is communicated with a combustion chamber of the engine.

8. The ammonia internal combustion engine of claim 7, wherein the oil supply assembly comprises a diesel tank, an oil transfer pump, a booster pump and an oil rail, wherein an inlet of the oil transfer pump is communicated with an outlet of the diesel tank, an outlet of the oil transfer pump is communicated with an inlet of the booster pump, an outlet of the booster pump is communicated with one end of the oil rail, and the other end of the oil rail is communicated with a second feed port of the oil injector.

9. The ammonia internal combustion engine of claim 8, wherein the oil supply assembly further comprises a second filter having one end in communication with the outlet of the diesel tank and the other end in communication with the inlet of the oil delivery pump.

10. An ammonia supply control method, adapted to an ammonia supply mechanism as claimed in any one of claims 1 to 6, comprising the steps of:

s1, starting a high-pressure pump to suck liquid ammonia in a liquid ammonia tank to one end of an ammonia rail, and enabling the liquid ammonia to enter a first feed inlet of an oil sprayer from the other end of the ammonia rail;

s2, when the temperature and pressure monitoring assembly detects that the pressure in the liquid ammonia tank is lower than the preset pressure, the flow back valve and the regulating valve are opened, high-pressure liquid ammonia discharged from an outlet of the high-pressure pump enters the heat exchanger, the liquid ammonia in the heat exchanger absorbs heat of cooling liquid in a cooling pipe group of the engine and is gasified into high-pressure ammonia, and the high-pressure ammonia enters the liquid ammonia tank to increase the pressure in the liquid ammonia tank;

s3, controlling the opening degree of the regulating valve according to the pressure and temperature detected by the temperature and pressure monitoring assembly in the liquid ammonia tank, so as to control the temperature of high-pressure ammonia gas input into the liquid ammonia tank, and respectively keeping the pressure and the temperature in the liquid ammonia tank in a preset pressure range and a preset temperature range.