阅读说明：本技术 一种可控冷、热egr系统 (Controllable cold and hot EGR system ) 是由 陈伟建 刘亚萌 李智 徐敏 陈珏 陈猛 于 2019-07-29 设计创作，主要内容包括：一种可控冷、热EGR系统,包括发动机、压气机、涡轮机、冷却器与混合器,所述发动机的内部设置有多个气缸,压气机的出气端经进气管与发动机的一端相连接,发动机的另一端与排气管的进气端相连接,排气管的出气端与冷却器的进气端、混合器的进气端、涡轮机的进气端相连接,冷却器的出气端、压气机的出气端均与混合器的进气端相连接,混合器的出气端经进气管与发动机相连接。本设计不仅对EGR温度和EGR率的调节范围更广,而且调控的精确度较高。(A controllable cold and hot EGR system comprises an engine, a gas compressor, a turbine, a cooler and a mixer, wherein a plurality of cylinders are arranged in the engine, the gas outlet end of the gas compressor is connected with one end of the engine through a gas inlet pipe, the other end of the engine is connected with the gas inlet end of a gas exhaust pipe, the gas outlet end of the gas exhaust pipe is connected with the gas inlet end of the cooler, the gas inlet end of the mixer and the gas inlet end of the turbine, the gas outlet end of the cooler and the gas outlet end of the gas compressor are connected with the gas inlet end of the mixer, and the gas outlet end of the mixer is connected with the engine through a gas inlet pipe. The design not only has wider adjusting range for the EGR temperature and the EGR rate, but also has higher regulating and controlling accuracy.)

1. The utility model provides a controllable cold, hot EGR system, includes engine (2), compressor (1) and turbine (3), the inside of engine (2) is provided with a plurality of cylinders (21), and the end of giving vent to anger of compressor (1) is connected with the one end of engine (2) through intake pipe (24), and the other end of engine (2) is connected with the inlet end of turbine (3) through blast pipe (25), its characterized in that:

the EGR system further comprises a cooler (4) and a mixer (5), the air outlet end of the exhaust pipe (25) is connected with the air inlet end of the cooler (4), the air inlet end of the mixer (5) and the air inlet end of the turbine (3), the air outlet end of the cooler (4) and the air outlet end of the compressor (1) are connected with the air inlet end of the mixer (5), and the air outlet end of the mixer (5) is connected with the engine (2) through an air inlet pipe (24).

2. A controlled cold and hot EGR system according to claim 1, wherein: the gas outlet end of the cooler (4) is connected with the gas inlet end of the mixer (5) through a one-way valve (51), and the gas outlet end of the exhaust pipe (25) is connected with the gas inlet end of the mixer (5) through a two-way valve (52).

3. A controlled cold and hot EGR system according to claim 2, wherein: the end of giving vent to anger of blast pipe (25) is connected with the inlet end of blender (5) after cold EGR valve (6), cooler (4), check valve (51) in proper order, the end of giving vent to anger of blast pipe (25) is connected with the inlet end of blender (5) after hot EGR valve (7), No. two check valve (52) in proper order, the end of giving vent to anger of blast pipe (25) is connected with the inlet end of turbine (3) through throttle valve (17) before the vortex.

4. A controlled cold, hot EGR system according to claim 1, 2 or 3 wherein: the EGR system also comprises a flow regulating valve (10), a radiator (9), a temperature regulator (11) and a water pump (12), under the working condition of small circulation, the cooler (4) takes water from a water sending and taking port (26) through the flow regulating valve (10), and the outlet water of the cooler (4) and the outlet water of the water sending port (23) flow back to a water sending and returning port (22) after passing through the temperature regulator (11) and the water pump (12); under the working condition of large circulation, the cooler (4) takes water from the water sending and taking port (26) through the flow regulating valve (10), and the outlet water of the cooler (4) and the outlet water of the water sending port (23) flow back to the water sending and returning port (22) after passing through the radiator (9), the temperature regulator (11) and the water pump (12).

5. A controlled cold and hot EGR system according to claim 4, wherein: the EGR system further comprises a fan (13) and an air cooler (14), the air compressor (1) is communicated with the air inlet end of the mixer (5) through the air cooler (14), and the temperature regulator (11) is located between the radiator (9) and the water pump (12).

6. A controlled cold, hot EGR system according to claim 1, 2 or 3 wherein: the air inlet end of the air compressor (1) is connected with an air filter (15), and the air outlet end of the turbine (3) is connected with an exhaust aftertreatment device (16).

Technical Field

The invention relates to an EGR (exhaust gas recirculation) system, belongs to the technical field of engine exhaust gas recirculation, in particular to a controllable cold and hot EGR system, which is particularly suitable for improving the regulation range and the regulation accuracy of EGR rate and EGR temperature.

Background

EGR, an exhaust gas recirculation system, is a system that introduces a portion of the exhaust gas of an engine into a cylinder to lower the in-cylinder combustion temperature and thereby reduce NOx emissions. EGR is divided into cold EGR and hot EGR, wherein the cold EGR refers to that partial exhaust gas is cooled by a cooler and then is introduced into a cylinder, the hot EGR refers to that the exhaust gas directly enters the cylinder without passing through the cooler, the temperature of the cold EGR is lower than that of the hot EGR, the lower in-cylinder combustion temperature can be realized, and the NOx emission is further reduced.

The invention discloses a controllable leading-in device for realizing cold and hot EGR, which is disclosed by the invention with the application publication number of CN105422323A and the application publication date of 2016, 3 and 23, and comprises an engine, a turbine, an EGR valve, a gas compressor, a cooler and a throttle valve, wherein the gas inlet end of the turbine is connected with the gas outlet end of an exhaust manifold in the engine through a pipeline, the gas inlet A of the EGR valve is connected with the gas outlet end of the engine through a pipeline, the gas outlet C of the EGR valve is connected with the gas inlet end of the cooler through a pipeline, the gas outlet end of the gas compressor is connected with the gas inlet end of the cooler through a pipeline, the gas outlet of the cooler is connected with one end of the throttle valve through a pipeline, the other end of the throttle valve is connected with the gas inlet end of the gas inlet manifold in the engine through a pipeline, the. Although the design has two EGR application modes of cold EGR and hot EGR, the design has the following defects:

firstly, the design can only realize cold EGR or hot EGR, and cold EGR and hot EGR cannot be adopted at the same time, so that the regulation range of EGR temperature is limited, and the regulation accuracy is poor;

secondly, this design does not have a pre-vortex throttling function, and cannot adjust the EGR driving pressure difference, so that a higher EGR rate cannot be achieved.

The information disclosed in this background section is only for enhancement of understanding of the general background of the patent application and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to overcome the defects and problems of smaller regulation range and lower regulation and control accuracy of EGR temperature and EGR rate in the prior art, and provides a controllable cold and hot EGR system with wider regulation range and higher regulation and control accuracy of EGR temperature and EGR rate.

In order to achieve the above purpose, the technical solution of the invention is as follows: a controllable cold and hot EGR system comprises an engine, a gas compressor and a turbine, wherein a plurality of cylinders are arranged in the engine, the gas outlet end of the gas compressor is connected with one end of the engine through a gas inlet pipe, and the other end of the engine is connected with the gas inlet end of the turbine through a gas outlet pipe;

the EGR system also comprises a cooler and a mixer, wherein the air outlet end of the exhaust pipe is connected with the air inlet end of the cooler, the air inlet end of the mixer and the air inlet end of the turbine, the air outlet end of the cooler and the air outlet end of the air compressor are connected with the air inlet end of the mixer, and the air outlet end of the mixer is connected with the engine through an air inlet pipe.

The gas outlet end of the cooler is connected with the gas inlet end of the mixer through a one-way valve, and the gas outlet end of the exhaust pipe is connected with the gas inlet end of the mixer through a two-way valve.

The end of giving vent to anger of blast pipe is connected with the inlet end of blender behind cold EGR valve, cooler, the check valve in proper order, the end of giving vent to anger of blast pipe is connected with the inlet end of blender behind hot EGR valve, No. two check valves in proper order, the end of giving vent to anger of blast pipe is connected with the inlet end of turbine through whirlpool front throttle valve.

The EGR system also comprises a flow regulating valve, a radiator, a temperature regulator and a water pump, under the working condition of small circulation, the cooler takes water from a water generating and taking port through the flow regulating valve, and the outlet water of the cooler and the outlet water of the water generating port flow back to a water generating and returning port after passing through the temperature regulator and the water pump; under the working condition of large circulation, the cooler takes water from the water sending and taking port through the flow regulating valve, and the outlet water of the cooler and the outlet water of the water sending port flow back to the water sending and returning port after passing through the radiator, the temperature regulator and the water pump.

The EGR system also comprises a fan and an air cooler, the air compressor is communicated with the air inlet end of the mixer through the air cooler, and the temperature regulator is positioned between the radiator and the water pump.

The air inlet end of the air compressor is connected with an air filter, and the air outlet end of the turbine is connected with an exhaust aftertreatment device.

Compared with the prior art, the invention has the beneficial effects that:

1. in the controllable cold and hot EGR system of the invention, the gas exhausted from the exhaust pipe is divided into three parts, namely cold EGR gas, hot EGR gas and exhaust gas flowing into a turbine, and the cold EGR gas and the hot EGR gas finally flow into an engine through an air inlet pipe for recycling, and the design has the advantages that: firstly, the exhaust gas flowing to an air inlet pipe and a turbine can be integrally regulated and controlled to adjust the EGR temperature and the EGR rate; secondly, the gas flowing to the air inlet pipe can be further refined and regulated, namely, the cold EGR gas and the hot EGR gas are respectively regulated and controlled independently or simultaneously, so that the regulation and control range and the regulation and control accuracy of the EGR temperature and the EGR rate are improved; thirdly, when the design is used for controlling the opening/closing of the cold EGR gas, the hot EGR gas and the exhaust gas flowing to the turbine and controlling the opening/closing degree, the control method belongs to online operation, has strong adjustability and can be adjusted according to various different working conditions or requirements in practical application. The three advantages are combined, the adjusting range of the EGR temperature and the EGR rate can be larger, the adjusting and controlling precision is higher, and therefore the requirements of different engine working conditions on the EGR are met. Therefore, the invention can adopt a mode of combining cold EGR and hot EGR to adjust, has wider adjusting range of EGR temperature and EGR rate and higher adjusting and controlling precision.

2. In the controllable cold and hot EGR system, the final flow direction of the exhaust gas of the exhaust pipe is an air inlet pipe and a turbine, and at the moment, when the flow rate of the exhaust gas flowing to the turbine is adjusted, the pressure at the exhaust pipe, namely the vortex front pressure, is changed, so that the pressure difference between the vortex front pressure and the air inlet pressure, namely the driving pressure difference of EGR is changed, the EGR driving capacity and the EGR rate are adjusted, and higher EGR driving capacity and EGR rate are obtained. Therefore, the invention can realize the vortex front throttling technology and adjust the driving pressure difference of the EGR so as to obtain better EGR driving capability and EGR rate.

3. In the controllable cold and hot EGR system, cold EGR gas is connected with the gas inlet end of the mixer through the one-way valve, hot EGR gas is connected with the gas inlet end of the mixer through the two-way valve, gas sources of the cold EGR gas and the hot EGR gas are all from the exhaust pipe, the exhaust pipe has pulse energy, and the one-way valve can prevent gas backflow, so that the combination of the pulse energy and the one-way valve can improve the EGR driving capability and increase the EGR rate, and meanwhile, the use frequency of the vortex front throttling technology can be reduced, so that the pump gas loss can be reduced on the basis of improving the EGR rate, and the economy of an engine is improved. Therefore, the invention not only can improve the EGR driving capability and the EGR rate, but also can reduce the pumping loss and improve the economy of the engine.

4. The invention relates to a controllable cold and hot EGR system, which is additionally provided with a flow regulating valve, a radiator, a temperature regulator and a water pump, and a special cooling liquid loop is constructed among an engine, the flow regulating valve, the radiator, the temperature regulator and the water pump on the basis of the flow regulating valve, the radiator, the temperature regulator and the water pump. Therefore, the accuracy of the cold EGR control is higher.

Drawings

Fig. 1 is a schematic structural view of the present invention.

In the figure: the system comprises a compressor 1, an engine 2, a cylinder 21, a water sending and returning port 22, a water sending and taking port 23, an air inlet pipe 24, an exhaust pipe 25, a water sending and taking port 26, a turbine 3, a cooler 4, a mixer 5, a first check valve 51, a second check valve 52, a cold EGR valve 6, a hot EGR valve 7, a radiator 9, a water sending and taking port 91, a water sending and taking port 92, a flow regulating valve 10, a temperature regulator 11, a water pump 12, a fan 13, an air cooler 14, an air filter 15, an exhaust gas aftertreatment device 16 and a pre-vortex throttle valve 17.

Detailed Description

The present invention will be described in further detail with reference to the following description and embodiments in conjunction with the accompanying drawings.

Referring to fig. 1, a controllable cold and hot EGR system comprises an engine 2, a compressor 1 and a turbine 3, wherein a plurality of cylinders 21 are arranged in the engine 2, an air outlet end of the compressor 1 is connected with one end of the engine 2 through an air inlet pipe 24, and the other end of the engine 2 is connected with an air inlet end of the turbine 3 through an air outlet pipe 25;

the EGR system further comprises a cooler 4 and a mixer 5, the air outlet end of the exhaust pipe 25 is connected with the air inlet end of the cooler 4, the air inlet end of the mixer 5 and the air inlet end of the turbine 3, the air outlet end of the cooler 4 and the air outlet end of the compressor 1 are both connected with the air inlet end of the mixer 5, and the air outlet end of the mixer 5 is connected with the engine 2 through an air inlet pipe 24.

The air outlet end of the cooler 4 is connected with the air inlet end of the mixer 5 through a first check valve 51, and the air outlet end of the exhaust pipe 25 is connected with the air inlet end of the mixer 5 through a second check valve 52.

The end of giving vent to anger of blast pipe 25 is connected with the inlet end of blender 5 behind cold EGR valve 6, cooler 4, check valve 51 in proper order, the end of giving vent to anger of blast pipe 25 is connected with the inlet end of blender 5 behind hot EGR valve 7, No. two check valves 52 in proper order, the end of giving vent to anger of blast pipe 25 is connected with the inlet end of turbine 3 through vortex front throttle valve 17.

The EGR system also comprises a flow regulating valve 10, a radiator 9, a temperature regulator 11 and a water pump 12, under the working condition of small circulation, the cooler 4 takes water from a water sending and taking port 26 through the flow regulating valve 10, and the outlet water of the cooler 4 and the outlet water of the water sending port 23 flow back to a water sending and returning port 22 after passing through the temperature regulator 11 and the water pump 12; under the large circulation working condition, the cooler 4 takes water from the water sending and taking port 26 through the flow regulating valve 10, and the outlet water of the cooler 4 and the outlet water of the water sending and taking port 23 flow back to the water sending and returning port 22 after passing through the radiator 9, the temperature regulator 11 and the water pump 12.

The EGR system also comprises a fan 13 and an air cooler 14, the compressor 1 is communicated with the air inlet end of the mixer 5 through the air cooler 14, and the temperature regulator 11 is positioned between the radiator 9 and the water pump 12.

The air inlet end of the compressor 1 is connected with an air filter 15, and the air outlet end of the turbine 3 is connected with an exhaust gas post-treatment device 16.

The principle of the invention is illustrated as follows:

the invention aims to provide a controllable cold and hot EGR system aiming at the problem that the prior art can not realize the accurate control of the EGR rate and the EGR temperature of an engine in the full working condition range so as to meet the requirements of different working conditions on the adjustment of the EGR rate and the EGR temperature, and the specific operation method comprises the following steps:

(1) when the post-treatment working temperature is lower, hot EGR can be adopted and the vortex front throttling is increased, so that the working temperature of an engine and the post-treatment is quickly increased, the post-treatment conversion efficiency is improved, and the emission performance is improved;

(2) when the post-processing working temperature is higher, cold and hot EGR and vortex front throttling can be comprehensively adjusted, so that the accurate adjustment of the EGR temperature and the EGR rate is realized, and the purpose of optimally controlling the performance and the emission of the engine is achieved.

The cold EGR valve 6 and the hot EGR valve 7 adopted in the invention are of a two-way structure which can control the opening/closing degree.