The intelligent bilateral air agreement device of a kind of supercharged engine
Technical field
The present invention relates to a kind of air inlet system of supercharged engine, specifically, relate to a kind of intelligent bilateral air agreement device of supercharged engine that has adopted the SCR exhaust gas post-treatment device.
Background technique
Along with the demand of market to the engine power performance Economy, turbocharging technology becomes the technology that diesel engine generally adopts.Turbosupercharger can increase suction pressure, increases air inflow, improves engine power performance, and HP, hp/litre and specific fuel consumption all are greatly improved.Refrigeration technique has further strengthened the effect of turbosupercharger in the thing followed air inlet, and gas temperature after the reduction supercharging improves the air inlet charge.Yet the dynamic response of supercharged engine is denounced by people always, the bus that particularly uses in the operating mode of city now, postal car, city special car etc., owing to reasons such as traffic light and traffic congestions, make the driver require more and more higher to the dynamic response performance of vehicle.In addition, at arctic weather, the engine start warming-up process is slow, causes engine warm-up Economy and emission performance relatively poor, and the rapid warming-up technology also is subject to people's attention.Therefore, the dynamic performance and the cold starting performance that how to improve supercharged engine become hot subject.
On the other hand, along with Abgasgesetz is more and more stricter, after-treatment system becomes the indispensable part of motor.For the state's four directions case that is about to carry out comprehensively, domestic large-scale Vehicle Turbocharged Diesel Engines producer generally adopts the post processing mode of SCR to reduce the technology path of NOx discharging.The developed countries such as the China Diesel quality is American-European are low, sulphur content is higher, reach 20ppm, for the diesel engine that has increased the SCR exhaust gas post-treatment device, in-cylinder combustion produces sulphate and discharges with tail gas, during through the reprocessing catalyst converter, part is attached on the coating of catalyzer, cause and contain a large amount of sulphate in the exhaust, these sulphate have covered the coating of catalyzer soon, thereby after-treatment system is sharply descended to the transformation efficiency of NOx, make the NOx discharging surpass national OBD rules to the limit value of NOx, and then cause that motor limit turns round, have a strong impact on driving.Generally speaking, when the temperature of catalyst converter was higher than 280 ℃, sulphate can produce decomposition and discharge with tail gas, can not affect the transformation efficiency of catalyst converter.But, find by market user's collection in worksite data, vehicle is under the downtown roads operating mode, and motor is in a kind of instantaneous conditions for a long time, and traffic light are a lot of and road conditions are bad, motor operates in middle low velocity zone for a long time, add that load is on the low side, engine exhaust temperature is not high, when arriving the reprocessing catalyst converter through outlet pipe, delivery temperature is very low, and the delivery temperature at catalyst converter place is not higher than 240 ℃.Therefore improve delivery temperature solution sulfur poisoning problem imperative.
China Patent Publication No.: CN 202108580U, open day: on January 11st, 2012, model utility title: " turbosupercharger residual air reclaims gas storage moment making-up air device ", comprise exhaust-gas turbocharger, motor and the ICS intercooler system that is connected with exhaust-gas turbocharger with motor, be connected the inlet end of gas holder on the connecting pipeline of described ICS intercooler system and exhaust-gas turbocharger by another arm; The outlet side connecting engine of gas holder and the pipeline between the ICS intercooler system.Do not use other power sources, directly utilize the unnecessary tolerance of turbosupercharger to store, add solenoid valve on the pipeline of gas holder outlet side, solenoid valve controls opening an account or cutting out of its after gathering accelerator pedal signal by ECU (Electrical Control Unit) ECU.Set up gas holder in the anxious accelerating process of diesel engine, can open rear moment tonifying Qi by the moment of solenoid valve, solve the emission problem of the anxious accelerating process of diesel engine.But because the high temperature compressed air of turbosupercharger output can cool off after entering gas holder gradually, cause moment to fill into the gas temperature of motor lower, be difficult to solve the problem of engine warm-up and raising cold starting performance, particularly after diesel engine generally adopts the SCR exhaust gas post-treatment device, because the gas temperature of moment tonifying Qi is lower, the switching of solenoid valve and the exhaust gas temperature change of motor and onrelevant easily cause the sulfur poisoning problem of catalyzer in the SCR exhaust gas post-treatment device.This model utility can't be monitored the temperature variation of SCR exhaust gas post-treatment device exhaust, also can't improve the intake temperature of motor, and then can't solve simultaneously the problem that engine cold-start poor performance, warming-up speed are slow, the motor dynamic responding speed is low and the SCR exhaust gas post-treatment device easily lost efficacy.
Summary of the invention
The objective of the invention is for existing supercharged engine dynamic responding speed low, cold starting performance is poor, warming-up speed slow and the SCR exhaust gas post-treatment device easily lost efficacy defective and deficiency, a kind of intake resistance is proposed little, dynamic responding speed is high, cold starting performance is good, and warming-up speed is fast and can guarantee the intelligent bilateral air agreement device of the efficient supercharged engine that moves of SCR exhaust gas post-treatment device.
For realizing purpose of the present invention, technical solution of the present invention is: the intelligent bilateral air agreement device of a kind of supercharged engine, be communicated with pressurized machine on the exhausting waste gas pipeline of engine block, the compressed air outlet of pressurized machine is connected with the engine block suction tude through intercooler, the waste gas outlet of pressurized machine is connected with the SCR exhaust gas post-treatment device, there is an end of a by-pass line to be connected with the admission line of described intercooler, the other end is connected with the outlet pipe of described intercooler, be provided with the bypass electric control valve on the described by-pass line, the control end of described bypass electric control valve is connected with the output terminal of ECU electronic control unit, have a SCR temperature transducer to be connected with the input end of described ECU electronic control unit, described SCR temperature transducer is arranged on the relief opening of SCR exhaust gas post-treatment device.
Described bypass electric control valve is Proportional valve or servovalve.
Compared with prior art, the invention has the beneficial effects as follows:
1. the invention provides a kind of novel supercharged engine intelligent two-way gas handling system, at vehicle launch or accelerating process bypass intercooler, fast air inlet improves the engine charge dynamic response; When underrun, improve the delivery temperature of motor, reach the decomposition temperature of sulphate, OBD warning and the motor limit avoiding producing owing to the inefficacy of SCR exhaust gas post-treatment device are turned round problem.In the engine cold-start process, by improving intake temperature, increase the in-cylinder combustion temperature, help the motor rapid warming-up.
2. reduce intake resistance after the pressurization gas bypass, accelerated the air inlet in the engine accelerating course, improved the air inlet dynamic response characteristic of supercharged engine, thereby improved the dynamic characteristic in vehicle launch and the accelerating process.The conformability of motor when each operating mode operation improves.
3. under the prerequisite of not sacrificing the motor Economy, solve motor and in medium and small load operation, arranged the excessively low SCR sulfur poisoning problem that causes of temperature, improved SCR exhaust gas post-treatment device reliability of operation.Be in the heat engine process at motor, improve the in-cylinder combustion temperature, accelerate the engine warm-up process.
4. the intelligent bilateral air agreement device of a kind of supercharged engine of the present invention not only is suitable for being equipped with the supercharged diesel engine of SCR exhaust gas post-treatment device, also is suitable for being equipped with the gasoline supercharging engine of SCR exhaust gas post-treatment device.
Description of drawings
Fig. 1 is the fundamental diagram of the present invention when intercooler 2 is supplied gas.
Fig. 2 is the simultaneously fundamental diagram when intercooler 2 and by-pass line 4 are supplied gas of the present invention.
Among the figure: radiator 1, intercooler 2, bypass electric control valve 3, by-pass line 4, admission line 5, ECU electronic control unit 6, SCR temperature transducer 7, outlet pipe 8, SCR exhaust gas post-treatment device 9, pressurized machine 10, cooling water channel 11, engine block 12.
Embodiment
The present invention is described in further detail below in conjunction with description of drawings and embodiment.
Referring to Fig. 1, Fig. 2, the intelligent bilateral air agreement device of a kind of supercharged engine of the present invention, be communicated with pressurized machine 10 on the exhausting waste gas pipeline of engine block 12, the compressed air outlet of pressurized machine 10 is connected with engine block 12 suction tude through intercooler 2, the waste gas outlet of pressurized machine 10 is connected with SCR exhaust gas post-treatment device 9, there is an end of a by-pass line 4 to be connected with the admission line 5 of described intercooler 2, the other end is connected with the outlet pipe 13 of described intercooler 2, be provided with bypass electric control valve 3 on the described by-pass line 4, the control end of described bypass electric control valve 3 is connected with the output terminal of ECU electronic control unit 6, have a SCR temperature transducer 7 to be connected with the input end of described ECU electronic control unit 6, described SCR temperature transducer 7 is arranged on the relief opening of SCR exhaust gas post-treatment device 9.
The present invention increases by a roadside to thread a pipe 4 in parallelly with intercooler 2 after pressurized machine 10, and increase a bypass electric control valve 3 in bypass admission line 4., open bypass electric control valve 3 under certain condition, cold in the pressurization gas part, can improve the engine aspirating system responsiveness; Can improve motor row temperature, prevent that SCR9 from the sulfur poisoning phenomenon occuring; Can accelerate engine warm-up.
Vehicle is in startup or accelerating process, motor needs to spray into great amount of fuel oil rapidly in cylinder, this makes gas handling system need at short notice to provide a large amount of air inlets, and under the impact of pressurized machine 10 and intercooler 2, tolerance can not reach rapidly requirement, but hysteresis phenomenon for some time, and a large amount of black smokes appear in motor under this operating mode, Engine ECU 6 volitional check fuel injection quantitys make vehicle launch and accelerate slow.Use bilateral air agreement of the present invention system, can open the bypass electric control valve 3 of by-pass line 4 in each process, because the resistance of 2 pairs of air-flows of intercooler is larger, gas enters cylinder by by-pass line 4 after the part supercharging, realizes bilateral air agreement.This mode can reduce intake resistance, in the short time a large amount of gases is sent into the cylinder of engine block 12, improves the gas handling system dynamic response performance of motor.
At little load or instantaneous conditions, the temperature that engine exhaust arrives in the SCR exhaust gas post-treatment device 9 is excessively low, the sulphate that high sulfur content fuel produces easily is adsorbed on the catalyst surface in the SCR exhaust gas post-treatment device 9, be difficult for decomposing, the transformation efficiency of SCR exhaust gas post-treatment device 9 is reduced greatly.The present invention can by opening the bypass electric control valve 3 on the by-pass line 4, improve intake temperature, thereby improve row's temperature by the delivery temperature in the SCR temperature transducer 7 monitoring SCR exhaust gas post-treatment devices 9, and sulphate is decomposed immediately, guarantees the activity of catalyzer.Test shows, uses bilateral air agreement, although because intake temperature improves, and air inflow slightly has minimizing, because the air fuel ratio of supercharged diesel engine under little load up to 30-40, almost do not have much affect to oil consumption; Although have increased slightly owing to the cylinder temperature rising causes the NOx discharging of outlet pipe 8, can be remedied by the transformation efficiency that the present invention is built the efficient stable that is suitable for 9 operations of SCR exhaust gas post-treatment device by the raising delivery temperature.
At arctic weather, motor rubs larger in warming-up process, and engine efficiency is reduced, and economic performance is relatively poor, and emission performance also is affected.The present invention is by by-pass line 4, improve the temperature of part pressurization gas, the mean temperature that enters gas in the jar is increased, therefore improved the temperature of engine cylinder internal combustion, make engine cooling water after radiator 1 heat radiation behind cooling water channel 11 and engine block 12, the temperature of engine block 12 can improve rapidly, so that accelerate engine warm-up.
Among Fig. 1, described bypass electric control valve 3 is closed namely cut-off, and through admission line 5, the intercooler 2 of all flowing through is sent in each cylinder in the engine block 12 by pipeline again by the pressurization gas of pressurized machine 10 outputs.When this state is suitable for the middle and high load operation of motor.
Among Fig. 2, it is conducting that described bypass electric control valve 3 is opened, and through admission line 5, flow through respectively intercooler 2 and by-pass line 4 are sent in each cylinder in the engine block 12 by pipeline again by the pressurization gas of pressurized machine 10 outputs.This state is suitable for engine cold-start, instantaneous acceleration or engine low load operation, delivery temperature is crossed when hanging down.Described bypass electric control valve 3 can adopt automatically controlled switch valve, because the resistance of gas flow when intercooler 2 be greater than by-pass line 4, in order to regulate the flow of gas in the by-pass line 4, preferably described bypass electric control valve 3 is Proportional valve or servovalve.
The intelligent bilateral air agreement device of a kind of supercharged engine of the present invention and air inlet method not only are suitable for being equipped with the supercharged diesel engine of SCR exhaust gas post-treatment device 9, also can be suitable for being equipped with the supercharging gasoline engine of SCR exhaust gas post-treatment device 9.