29results about How to "Improve cold start performance" patented technology

The utility model discloses a preheating system for low-temperature starting of a diesel automobile. The preheating system comprises a sensing module, a preheating module and a control module, wherein the sensing modules are fixedly arranged inside and / or outside a diesel automobile body respectively; the preheating modules are respectively and fixedly arranged near and / or inside a diesel automobile cooling system, an intake manifold and a gearbox; the control module is fixedly arranged in a vehicle-mounted electronic system of the diesel automobile; the control module is used for receiving input signals such as temperature and pressure obtained by the sensing module, automatically controlling the preheating module to preheat intake air, an engine cylinder body and a gearbox of the diesel automobile, and automatically adjusting the preheating time and strength, so that the low-temperature starting performance is effectively improved, and meanwhile, the low-temperature starting performance of the diesel automobile is improved. Waste of fuel oil and electric quantity of a storage battery caused by excessive preheating is avoided, in addition, it is ensured that lubricating oil reaches proper viscosity before starting, mechanical abrasion at the moment of starting is reduced, and safe and rapid starting is achieved.

The invention provides a methanol preheating and catalytic cracking system for a methanol engine, a ship and a control method, and belongs to the technical field of ship methanol engines. The problems that an existing methanol engine is difficult in cold start and methanol gasification are solved. The system comprises a methanol engine, a methanol storage tank, a water storage tank, a heat exchanger, an inlet temperature sensor and an outlet temperature sensor, one passage of a third three-way valve is connected with the waste gas output end of the methanol engine, the other passage of the third three-way valve is connected with another cooling water pipeline, and the methanol output end of the heat exchanger is connected with the methanol input end of the methanol engine. The methanol input end is connected with the methanol storage tank, a methanol pump is arranged on a methanol conveying pipeline between the methanol storage tank and the heat exchanger, two passages of the first three-way valve are arranged between the methanol conveying pipelines, and the inlet temperature sensor and the outlet temperature sensor are respectively arranged at a methanol inlet and a methanol outlet of the heat exchanger. The method is mainly used for starting the methanol engine.

The invention discloses a purging method and system of a fuel cell and electronic equipment. The purging method of the fuel cell comprises high-temperature purging, cooling purging and low-speed purging which are carried out in sequence, wherein the high-temperature purging comprises the steps of controlling the temperature of the galvanic pile to be a high-temperature purging temperature, controlling air to purge the galvanic pile, and controlling hydrogen to cyclically purge the galvanic pile; the step of cooling and purging is that the temperature of the electric pile is controlled to be reduced from a high-temperature purging temperature to a low-temperature purging temperature, and in the cooling process, purging of the electric pile by air is stopped, and circulating purging of the electric pile by hydrogen is kept; the low-speed purging is characterized in that the temperature of the electric pile is controlled to be a low-temperature purging temperature, and the gas flow of hydrogen circulating purging is reduced so as to perform low-speed purging on the electric pile. According to the fuel cell purging method and system and the electronic equipment provided by the invention, the liquid in the fuel cell system can be effectively discharged, and the cold start capability of the fuel cell system is improved.

The invention relates to an on-line evaluation system and an on-line evaluation method for the cold start-up capability of a fuel cell. The on-line evaluation system comprises a fuel cell stack, an on-line evaluation system and a DCDC, the on-line evaluation system specifically comprises an acquisition unit used for acquiring the voltage of a fuel cell stack and the current of a DCDC input end; the impedance spectrum measurement unit is used for carrying out impedance calculation; the impedance spectrum analysis unit is used for calculating polarization process information of impedance; the excitation signal unit is used for receiving an instruction of the impedance spectrum measurement unit and controlling the amplitude and the frequency of alternating current excitation superposed on the DCDC direct current; the storage unit internally comprises a maximum water capacity database; and the control unit is used for extracting the maximum water capacity database information, obtaining the maximum water capacity of the current state in combination with the calculated polarization process information, and further transmitting a control signal to the fuel cell stack. Compared with the prior art, the polarization process information can be acquired in real time, and the cold start capability of the fuel cell can be acquired and evaluated on line in combination with the maximum water capacity database.

The invention discloses a hydrogen hybrid power locomotive thermal management system which comprises a hydrogen fuel cell thermal management system, a power cell thermal management system and an intermediate heat exchange device, the intermediate heat exchange device comprises a fuel cell cooling liquid flow channel and a power cell cooling liquid flow channel, the fuel cell cooling liquid flow channel is communicated with a fuel cell cooling liquid circulation loop, and the power cell cooling liquid flow channel is communicated with a power cell cooling liquid circulation loop. The power battery cooling liquid flow channel is communicated with the power battery cooling liquid circulation loop. When the fuel cell stack is in a low-temperature environment, the power cell operates normally and the hydrogen power fuel cell is started, the fuel cell stack needs to be heated, the cooling liquid in the power cell cooling liquid flow channel can heat the cooling liquid in the fuel cell cooling liquid flow channel at the moment, and the heated cooling liquid can heat the fuel cell stack. The cooling liquid of the fuel cell cooling liquid circulation loop is heated by utilizing the heat of the power cell, so that the cold start effect of the hydrogen fuel cell can be effectively improved, and the energy utilization rate can also be improved.

The invention discloses a two-stroke heavy oil aviation piston engine, and belongs to the technical field of unmanned aerial vehicle engines, the two-stroke heavy oil aviation piston engine comprises an engine body, a spark plug, an exhaust pipe, a fuel oil supply system, a crank connecting rod mechanism, two pistons and an auxiliary heating system, the engine body is composed of a crankcase and two piston cylinders, and the two piston cylinders are horizontally and oppositely distributed on the two sides of the crankcase; the two sides of the crankcase are connected with the short output shaft and the long output shaft in a penetrating and coupling mode, and a rotating cavity opposite to the crankshaft connecting disc is formed in the crankcase. The opposed crankshaft connecting disc is provided with two crank throws in an opposed 180-degree working phase, and the structure of the opposed crankshaft connecting disc without a central shaft neck can reduce the centrifugal force of rotation and improve the operation stability; the crank throw is connected with the piston through a connecting rod, and the joint can rotate; the two pistons are respectively positioned in the two piston cylinders; and the auxiliary heating system is dispersedly arranged on the engine body, consists of a temperature switch and a heating rod, and is used for heating the purified oil-gas mixture provided by the fuel oil supply system.

This utility model discloses an engine cylinder head and its electronic fuel injection system, including a cylinder head body. The cylinder head body has an intake manifold, an exhaust manifold, and a connecting surface for connection and mating with the engine block. The cylinder head body has a fuel jet channel communicating with the intake manifold. A cylinder head fuel jet clearance groove is provided on the inner wall of the intake manifold near the inner end of the fuel jet channel. An intake valve is installed on the cylinder head body, with its valve head installed in an intake valve seat hole. An intake pipe is installed on the cylinder head body on one side of the intake manifold. An injector seat is provided on the intake pipe, and an injector mounting hole communicating with the fuel jet channel is provided on the injector seat. An injector is installed in the injector mounting hole, and the linear distance between the injector nozzle and the center of the valve head is 70mm to 110mm. By precisely defining the position and mating relationship between the components, the overall performance of the engine is maximized.

The invention relates to a dual-module intercooler type fuel cell cathode inlet temperature and humidity cooperative control method. The method comprises the steps that fuel cell cathode air inlet real-time state parameters and operation parameters are obtained, a multivariable coupling prediction model is constructed after preprocessing, and a temperature and humidity reference and an oxygen stoichiometric ratio target reference are set in combination with heat exchange characteristics of a dual-module intercooler; then the core body heat exchange distribution proportion is regulated and controlled, humidification adjustment is matched, and the core body heat exchange distribution proportion and the humidification adjustment intensity are dynamically adjusted according to the real-time working condition; comparing the deviation between the adjusted actual temperature and humidity and the target temperature and humidity reference, and correcting the heat exchange distribution proportion and the humidifying adjustment parameter through a dynamic constraint correction model; cooperative regulation and control of cathode inlet temperature and humidity are realized, dynamic change of working conditions is adapted, and stable operation of the fuel cell is guaranteed.

The present invention discloses a spiral coil heating flame preheating plug and a diesel engine, belonging to the technical field of engine cold start auxiliary system. The spiral coil heating flame preheating plug comprises a flame cover, a shell, an electromagnetic induction evaporation net, an oil inlet pipe and an electromagnetic induction spiral coil, wherein the wall of the flame cover is provided with ventilation holes, and is coaxially arranged in the inner cavity of the lower part of the shell; the electromagnetic induction evaporation net is sandwiched between the inner wall of the shell and the outer wall of the flame cover; one end of the oil inlet pipe is connected to the electromagnetic induction evaporation net, and the other end can be connected to the oil pump; the electromagnetic induction wire spiral coil is spirally wound on the outer wall of the shell and the position corresponding to the electromagnetic induction evaporation net; the inner cavity of the upper part of the shell forms a mixed gas cavity. The spiral coil heating flame preheating plug can significantly improve the cold start performance of the diesel engine in extremely cold and harsh environments.

The invention discloses an environment-friendly multifunctional oil composition for agricultural machinery and a preparation method of the environment-friendly multifunctional oil composition, and belongs to the field of oil for agricultural machinery. The lubricating oil is prepared from the following components in parts by mass: 3 to 5 parts of an extreme pressure anti-wear agent, 2 to 4 parts of an antioxidant, 0.1 to 2 parts of a preservative, 1 to 2 parts of a clearing agent, 0.1 to 3 parts of a dispersing agent, 0.1 to 2 parts of an anti-rust agent, 1 to 2 parts of a viscosity index improver, 0.1 to 0.5 part of an anti-foaming agent, 0.3 to 0.5 part of a pour point depressant and 79 to 92.3 parts of base oil, wherein the base oil is formed by combining rapeseed oil and synthetic ester base oil PALMESTER 2083; the preparation method comprises the following steps: sequentially adding the base oil, the anti-wear reagent at extreme pressure, the antioxidant, the preservative, the clearing agent, the dispersing agent, the viscosity index improver and the anti-foaming agent at the temperature of 50-70 DEG C according to the proportion, and mixing until the materials are completely dissolved to form a transparent precipitate-free solution. According to the multifunctional oil composition for the agricultural machinery, the influence on the environment is reduced, the wear resistance and the extreme pressure property are improved, and the service life is prolonged.

The present invention relates to the field of compressor lubrication technology, and specifically to a scroll compressor and air conditioner, which includes a compressor body, an oil pool space for accommodating lubricating oil is provided at the bottom of the compressor body, a positive displacement oil pump is provided in the oil pool space, the positive displacement oil pump is connected to the oil supply channel in the crankshaft of the compressor body, the positive displacement oil pump includes a pump body, the pump body includes an oil pumping part, the oil pumping part is connected to the oil supply channel in the crankshaft of the compressor body, a primary oil suction channel and a secondary oil suction channel are provided on the pump body, the primary oil suction channel and the secondary oil suction channel extend out of the surface of the pump body to form a primary suction port and a secondary suction port, the height of the primary suction port is higher than the height of the secondary suction port, and the oil pumping part is selectively connected to the primary oil suction channel and the secondary oil suction channel. The present invention can effectively avoid the aggravation of the contact parts such as the bearings in the compressor, thereby effectively improving the low temperature starting performance and reliability of the compressor.

The present invention relates to a structure for improving the weak piece of the end plate of a fuel cell stack, comprising a power generation cell, a pseudo cell, an end plate, an insulating plate and a current collecting plate, wherein the width of the plate flow channel of the power generation cell is L1, the depth is H1, and the width of the flow channel ridge is R1, and the width of the plate flow channel of the pseudo cell is L2, the depth is H2, and the width of the flow channel ridge is R2, wherein L2=1.1-1.3L1, H2=1.1-1.3H1, and R2=0.7-0.9R1. Compared with the prior art, the present invention provides pseudo cells without power generation function at both ends of the fuel cell stack as transmission channels for reaction gas and cooling water, which is conducive to discharging excess liquid water generated during the operation of the stack, and at the same time improves the phenomenon of low voltage of single cells at both ends of the end plate of the stack, thereby improving the output performance, cold start performance and durability of the stack.

The invention relates to the technical field of lead-acid storage batteries, in particular to tubular lead-carbon battery positive and negative plates and a preparation method thereof. The positive and negative pole plates of the tubular lead-carbon battery comprise positive and negative pole plate grids and filled active substance powder, the positive and negative pole plate grids are of a fence structure formed by cross beams and conductive cores perpendicular to the cross beams, and a sleeve layer is arranged outside the positive and negative pole plate grids; the active substance powder is filled in a gap between the sleeve layer and the conductive core; the active substance is prepared from the following substances in percentage by weight: 1 to 25 weight percent of lead powder, 1 to 50 weight percent of capacitive carbon material, 0.1 to 0.5 weight percent of carbon black, 2 to 97 weight percent of barium sulfate, 0 to 1.2 weight percent of sodium lignin sulfonate, 0.5 to 2 weight percent of humic acid and 0.05 to 0.1 weight percent of short fiber. The manufacturing process is simple and easy to implement, solves the problems that the lead paste is poor in stability and easy to fall off, stabilizes the structure of the lead paste, prevents the lead paste from falling off, and prolongs the service life of the battery.

The present invention discloses a disc-type coil heating type flame preheating plug and a diesel engine, belonging to the technical field of engine cold start auxiliary system. The disc-type coil heating type flame preheating plug comprises a flame cover, a disc-shaped electromagnetic induction coil, a disc-shaped electromagnetic induction heating element, an evaporation net and an oil pipe, wherein the wall of the flame cover is provided with ventilation holes, and the bottom of the flame cover is coaxially provided with a disc-shaped electromagnetic induction coil; the disc-shaped electromagnetic induction heating element is coaxially provided on the top surface of the disc-shaped electromagnetic induction coil; the evaporation net is coaxially provided on the top surface of the disc-shaped electromagnetic induction heating element; one end of the oil pipe passes through the flame cover and is inserted into the evaporation net, and the other end can be connected to the oil pump; the inner cavity of the flame cover forms a mixed gas cavity. The disc-type coil heating type flame preheating plug can significantly improve the cold start performance of the diesel engine in extremely cold and harsh environments.

The utility model belongs to the technical field of engines, and particularly relates to a cylinder cover and an engine. The cylinder cover comprises a cylinder cover body, a fuel injector mounting hole, two air inlets and two air outlets are formed in the cylinder cover body, the two air inlets and the two air outlets are located at one axial end of the fuel injector mounting hole, and the two air inlets are arranged on one side of the fuel injector mounting hole at intervals. The cylinder cover body is provided with two air inlets and two exhaust ports, the two exhaust ports are spaced from each other and arranged on the other side of the fuel injector mounting hole, an inlet nose bridge area is formed between the two air inlets and provided with a glow plug hole, and the cylinder cover body is further provided with an unloading groove which is formed in the inlet nose bridge area and arranged on the side, away from the fuel injector mounting hole, of the glow plug hole. According to the air cylinder cover, the cold starting effect is improved, the risk of fatigue cracks of the air cylinder cover caused by deformation of the feeding nose bridge area can be reduced through the unloading grooves, the reliability of the air cylinder cover is improved, and the service life of the air cylinder cover is prolonged.

The invention discloses an air supply system for low-temperature starting of a fuel cell automobile and a control method of the air supply system, and the air supply system mainly comprises a fuel cell air supply system branch, a vortex tube branch and a passenger compartment branch. The vortex tube branch heats the fuel cell air supply system branch and the passenger compartment branch through the three-way valve. According to the invention, interconnection and intercommunication of gas heating loops of the fuel cell automobile are realized by using a set of integrated air supply loop, and meanwhile, non-auxiliary heating of the vortex tube on a fuel cell stack and a passenger compartment is realized by controlling loop mode switching, so that the system efficiency is improved.

The invention discloses a low-temperature starting method, device and equipment and a computer readable storage medium, and relates to the technical field of display terminals, the low-temperature starting method is applied to scalp massage equipment, the method comprises the steps that working information of the scalp massage equipment is acquired, and the working information comprises the motor temperature of a motor in the scalp massage equipment; the motor duty ratio and the actual motor rotating speed correspond to the equipment gear; determining a motor control instruction according to the motor temperature and the motor duty ratio, and determining an incremental duty ratio according to the motor control instruction and the actual motor rotating speed; and controlling the motor according to the incremental duty ratio and the actual rotating speed of the motor. The low-temperature starting effect of the scalp massage equipment is improved.

The present invention discloses an engine start control method, device, electronic device and vehicle. The method comprises: obtaining the ambient temperature of the engine, the engine water temperature, and the voltage of the power supply device that drives the engine to start; obtaining the running state of the engine and the speed change rate of the engine within a preset time period; when the ambient temperature, engine water temperature, voltage, running state and speed change rate all meet preset conditions, determining that the engine is in a pseudo-idle condition, and performing an intake heating operation on the engine. The present invention solves the technical problem of poor engine starting performance in a low temperature environment.

This invention relates to the field of engines, providing an engine intake air preheating method, system, device, and engine. The method includes: acquiring ambient temperature and atmospheric pressure values ​​after the engine is powered on; if the ambient temperature is less than 0 degrees Celsius, heating the air entering the engine through a heating rod, and injecting fuel onto the surface of the heating rod based on a pre-constructed MAP map; after starting the engine, acquiring the engine speed, and if the engine speed is higher than a first set speed, completing the engine intake air preheating. This invention addresses the shortcomings of existing diesel engines in cold starts at high altitudes, enabling the minimum intake air preheating power to adaptively adjust with engine speed, altitude, and ambient temperature during diesel engine startup. It supplements the deficiencies of existing design methods and improves the environmental adaptability of diesel engines.

The invention discloses a fuel-saving and emission-reducing diesel purification synergist and a preparation method thereof. The formula of the synergist comprises isooctanol, dodecenylsuccinic acid and other components. Wherein the nonylphenol polyoxyethylene ether is a demulsifier, the light aromatic solvent oil and the like are solvent oil, the polyisobutylene succinimide and the like are compounded into a purification dispersant, the cobalt iso-octoate and the like are synergists, and the hexadecanoic acid butyl ester and the like are lubrication emission reduction agents. During preparation, the raw materials are metered by a mass flow meter, are respectively heated and compounded, are continuously blended by a pipeline reactor and are subjected to pressure-limited filtration, and a finished product is stored in an N2 sealed storage tank. During heating and compounding, all the components are stirred at different temperatures. The synergist disclosed by the invention can be used for effectively removing sediments such as carbon deposit of an engine and improving tail gas emission, the fuel saving rate reaches 10-15%, the CO emission is reduced by 60-80%, the smoke value is reduced by 50-60%, the NOX is reduced by 40-60%, the wear of parts can be reduced, the power is enhanced, the cold start performance is improved, and the energy consumption is reduced.

The invention discloses a methanol engine cold start heating device which comprises a fuel injector and a high-pressure fuel pipe connected to the fuel injector, a fuel injector heating coil is arranged on the fuel injector and connected to a fuel injector heating controller, a high-pressure fuel pipe heating coil is arranged on the high-pressure fuel pipe and connected to a fuel injector heating controller, and a fuel injector heating coil is arranged on the high-pressure fuel pipe. And the high-pressure oil pipe heating coil is connected to a high-pressure oil pipe heating controller. The invention further provides a control method of the methanol engine cold start heating device, and the control method comprises the steps that relevant temperature conditions are obtained, which condition is met is judged, and the heating step corresponding to the condition is entered. Heating coils are arranged on the high-pressure oil pipe and the oil sprayer at the same time, and it is ensured that the temperature of methanol fuel can be increased in time in the low-temperature environment. When parameters such as the environment temperature and the engine water temperature reach preset conditions, the system can automatically judge whether the heating device needs to be started or not, so that the fuel temperature is rapidly increased, the fuel atomization effect is improved, and the ignition and combustion efficiency is improved.

The invention relates to the technical field of diesel engines, and particularly discloses a quick starting device for a multi-cylinder diesel engine, the diesel engine and a method. The quick starting device is suitable for the multi-cylinder diesel engine comprising a first cylinder and a second cylinder, and comprises a connecting pipe which is arranged to be communicated with a first air inlet channel of the first cylinder and a second combustion chamber in the second cylinder; and the stop valve is connected to the connecting pipe and is arranged to selectively open and close a gas passage in the connecting pipe. According to the quick starting device, a part of pipelines and a stop valve are additionally arranged on the basis of the structure of an existing multi-cylinder diesel engine, gas in the exhaust stroke of the diesel engine can be secondarily utilized, the gas inlet temperature is increased in a self-heating mode, and then the low-temperature starting capacity is improved.

The invention relates to a system and a method for converting parallel input and output of positive and negative assembled batteries, which are applied to a special vehicle powered by the positive and negative assembled batteries, and are characterized in that the positive and negative assembled batteries respectively supply power to positive and negative assembled loads during normal work; the parallel input and output of the positive and negative batteries can be realized by operating the change-over switch on the instrument board, and meanwhile, the load connected with the original negative battery is cut off, so that the safety during parallel connection is ensured, and the influence on the load is avoided; when the original vehicle main switch is independently turned on, the electric equipment on the vehicle can keep the original vehicle electric state unchanged; when the change-over switch and the main switch are switched on simultaneously, only the positive battery pack is kept to supply power to the vehicle, and the safety of series-parallel connection switching of the positive and negative battery packs is ensured through the self-locking design.

The invention discloses a fuel cell purging control method, device, equipment and system, a vehicle and a medium, is applied to the technical field of fuel cells, and is used for solving the problems that the shutdown time is prolonged, the shutdown power consumption is increased, a hydrogen circulating pump is easy to freeze and the cold start performance is poor in an anode purging scheme in the prior art. The current optimal opening frequency of a target valve at the current environment temperature is determined on the basis of the pre-calibrated optimal opening frequency, enabling the water accumulation amount of the anode system to be minimum, of the target valve in the anode system at different environment temperatures, and the target valve is controlled to operate to purge the anode system on the basis of the current optimal opening frequency. Therefore, the overall purging strategy of the anode system is executed by utilizing the pre-calibrated optimal purging condition of the target valve in the anode system, it can be ensured that the hydrogen circulating pump is not frozen in the low-temperature environment, and then the cold start performance can be improved while the shutdown time is not prolonged and the shutdown power consumption is not increased.

The application provides a high-compression-ratio ethanol fuel gasoline engine combustion system and a control method thereof, wherein the system comprises: a high-compression-ratio combustion structure with a compression ratio of 14-15, the combustion structure comprises a piston top with an omega-shaped shallow pit structure, and the surface of the piston top is provided with a silicon nitride ceramic coating; a cold start enhancement system comprising a PTC ceramic heating module and a high-energy ignition device; a fuel injection system comprising a high-pressure common rail system and a multi-hole swirl oil injector; and a control system comprising an ECU control unit and a UEGO wide-range oxygen sensor. The high-compression-ratio ethanol fuel gasoline engine combustion system and the control method thereof can realize high thermal efficiency, reliable start at low temperature, stable combustion and low emission.

The present invention discloses a valve system for a vehicle fuel pump, which includes: a liquid storage cup, a fuel pump, an injection pump and an injection pump control valve, wherein the liquid storage cup is arranged in a fuel tank that stores fuel in the liquid storage cup; the fuel pump is configured to pump fuel from the liquid storage cup to an engine and simultaneously supply fuel to the injection pump through a first discharge port; the injection pump is configured to fill the liquid storage cup with fuel by drawing fuel from a fuel tank using the pressure of the fuel supplied by the fuel pump; the injection pump control valve is arranged on the first discharge port and is configured to control the flow of fuel discharged from the fuel pump to the injection pump.

The invention discloses a cooperative control method for a glow plug and a fuel injection quantity in a cylinder in a cold starting process of a diesel engine, which relates to the technical field of cold starting of diesel engines and comprises the following steps: firstly, judging a cold starting condition, and calculating the fuel injection quantity required by the glow plug according to a starting stage (an injection starting period / Ramp period); secondly, through iterative calculation, the final oil injection quantity of the glow plug and the air inlet oxygen content decline value caused by the final oil injection quantity are synchronously determined, and then the effective oxygen mass capable of being used for in-cylinder combustion is obtained; and finally, accurately calculating and executing the in-cylinder fuel injection quantity after collaborative correction according to the effective oxygen mass. According to the method, dynamic accurate matching of the preheating process and the oil injection process is achieved, the first-time starting success rate and the starting speed of the low-compression-ratio and high-supercharge-ratio diesel engine in the low-temperature environment are remarkably increased, and smoking and pollutant emission in the cold starting stage are effectively reduced.

The present invention relates to a valve system for a fuel pump of a vehicle. The valve system for a fuel system of a vehicle can close an injection pump side flow path when the pressure of fuel supplied from a fuel pump to an engine is lower than a prescribed fuel pressure at engine startup, and open the injection pump side flow path when the fuel pressure is equal to or higher than the prescribed fuel pressure at engine startup, thereby improving the cold start performance of the engine, and can also allow the injection pump side flow path to remain in an open state between a low load region and a high load region of the engine after the engine is started, thereby smoothly maintaining the function of the injection pump after the engine is started.

The invention provides a light diesel engine tail gas after-treatment system and a control method thereof, which can solve the problems of high cold start emission, catalyst poisoning caused by HC, N2O generation and difficulty in reaching the standard of PN10 emission in the prior art, meet the requirements of a new generation of emission regulations, and improve the emission efficiency. Comprising a ccDOC unit, a first urea injection unit, a ccSCR unit, a DPF unit, a second urea injection unit, a second SCR unit and an ASC unit which are sequentially arranged in the tail gas direction of an engine. The controller is electrically connected with the first urea spraying unit and the second urea spraying unit; and the controller controls the first urea injection unit to inject a first urea amount U1 into the tail gas in front of the ccSCR unit and controls the second urea injection unit to inject a second urea amount U2 into the tail gas in front of the second SCR unit according to a preset control method.