阅读说明：本技术 基于实时状态诊断的变海拔增压系统自适应控制方法 (Real-time state diagnosis-based adaptive control method for variable-altitude supercharging system ) 是由 石磊 邓康耀 杨名洋 卢康博 杨震寰 张琨 于 2021-10-12 设计创作，主要内容包括：本发明公开了一种内燃机技术领域的基于实时状态诊断的变海拔增压系统自适应控制方法,包括以下步骤：第一,在涡轮入口前布置两个排气支管,在一个排气支管上布置一个旁通阀,在另外一个排气支管上布置一个旁通阀和一个中冷器；第二,在柴油机后排气总管上布置一个排温传感器,排温采集采用排温动态响应特性计算公式；第三,根据排温传感器实时检测判断是否超过增压器涡前温度限定值,若超过,则打开与中冷器在同一排气支管上的旁通阀,同时关闭另外一个排气支管上的旁通阀,并通过调整涡轮增压器旁通阀开度,使发动机在不同海拔下功率得到有效的恢复。本发明能够在高海拔条件下,破除增压器高温的限制,增加柴油机喷油量,提升其动力。(The invention discloses an adaptive control method of a variable-altitude supercharging system based on real-time state diagnosis in the technical field of internal combustion engines, which comprises the following steps of: firstly, two exhaust branch pipes are arranged in front of a turbine inlet, a bypass valve is arranged on one exhaust branch pipe, and a bypass valve and an intercooler are arranged on the other exhaust branch pipe; secondly, arranging a temperature exhaust sensor on a rear exhaust main pipe of the diesel engine, wherein a temperature exhaust dynamic response characteristic calculation formula is adopted for temperature exhaust collection; and thirdly, real-time detection is carried out according to a temperature exhaust sensor to judge whether the temperature exceeds a supercharger preswirl temperature limit value, if so, a bypass valve on the same exhaust branch pipe with the intercooler is opened, a bypass valve on the other exhaust branch pipe is closed, and the power of the engine is effectively recovered under different altitudes by adjusting the opening degree of the turbocharger bypass valve. The invention can break the limit of high temperature of the supercharger, increase the fuel injection quantity of the diesel engine and improve the power of the diesel engine under the condition of high altitude.)

1. A self-adaptive control method of a variable-altitude supercharging system based on real-time state diagnosis is characterized by comprising the following steps of:

firstly, arranging two exhaust branch pipes in front of a turbine inlet of a turbocharger, wherein inlets of the two exhaust branch pipes are connected with a rear exhaust main pipe of a diesel engine, outlets of the two exhaust branch pipes are connected with a front exhaust main pipe of the turbine, a bypass valve is arranged on one exhaust branch pipe, and a bypass valve and an intercooler are arranged on the other exhaust branch pipe;

secondly, arranging a temperature exhaust sensor on a rear exhaust main pipe of the diesel engine in front of inlets of the two exhaust branch pipes, connecting the temperature exhaust sensor with a diesel engine control device through a data acquisition device, and acquiring the front exhaust temperature of the turbine by adopting a temperature exhaust dynamic response characteristic calculation formula;

thirdly, detecting and judging whether the temperature exceeds a limit value of the temperature before the turbine of the supercharger or not in real time according to the exhaust temperature sensor, if so, opening a bypass valve on the same exhaust branch pipe with the intercooler, and closing a bypass valve on the other exhaust branch pipe; if the bypass valve does not exceed the bypass valve, closing the bypass valve on the same exhaust branch pipe as the intercooler, and simultaneously opening the bypass valve on the other exhaust branch pipe;

fourthly, the power of the engine can be effectively recovered under different altitudes by adjusting the opening degree of the waste gas bypass valve of the turbocharger.

2. The adaptive control method for a variable altitude boosting system based on real time status diagnosis according to claim 1, wherein the exhaust temperature dynamic response characteristic calculation formula is:

in the formula: m is the mass of the temperature sensor in kg; c is the specific heat capacity of the temperature sensor, and the unit J/(kg. K), T₁Is the temperature of the temperature sensor in units K, T₀The temperature of the environment medium is shown in the unit K, alpha is the heat exchange coefficient between the temperature sensor and the medium, A is the surface area of the temperature sensor and the unit mm²And epsilon is an altitude correction coefficient.

Technical Field

The invention relates to a supercharging regulation and control method in the technical field of internal combustion engines, in particular to an altitude-variable supercharging system self-adaptive control method based on real-time state diagnosis, wherein a device capable of reducing exhaust temperature is arranged in front of a turbine.

Background

The plateau environmental conditions have great influence on the performance of each subsystem and the whole diesel engine. According to statistics, the diesel engine dynamic of the elevation of 1000m per liter is reduced by 4.0-13.0%, and the economical efficiency is reduced by 2.7-12.9%. This is because the atmospheric pressure is reduced, the amount of air entering the cylinder is reduced, and the pressure and temperature of the mixed air in the cylinder at the end of compression are reduced, so that the fuel injected into the cylinder cannot be ignited in time, resulting in combustion lag, reduced isochoricity, and backward shift of the center of gravity of the combustion heat release rate, resulting in reduced power of the diesel engine, increased fuel consumption rate, increased exhaust temperature, and deteriorated emission performance.

Especially in high altitude areas, the intake pressure and density are lower, the combustion of the diesel engine is further worsened, the exhaust temperature is higher, and the higher exhaust temperature of the diesel engine leads to the increase of the heat load of the turbocharger, thereby bringing harm to the operation of the turbocharger. The traditional method reduces the exhaust temperature by limiting the oil injection quantity of the diesel engine, but simultaneously reduces the power of the diesel engine, and further limits the recovery of the power of the variable-altitude diesel engine, so that how to solve the problem that the exhaust temperature of the variable-altitude supercharged diesel engine is too high is one of the difficulties which limit the power recovery at present.

Disclosure of Invention

Aiming at the defects of the technology, the invention provides a self-adaptive control method of a variable-altitude supercharging system based on real-time state diagnosis, which can break the limitation of high temperature of a supercharger, increase the fuel injection quantity of a diesel engine and improve the power of the diesel engine under the condition of high altitude.

The invention is realized by the following technical scheme, and the invention comprises the following steps: firstly, arranging two exhaust branch pipes in front of a turbine inlet of a turbocharger, wherein inlets of the two exhaust branch pipes are connected with a rear exhaust main pipe of a diesel engine, outlets of the two exhaust branch pipes are connected with a front exhaust main pipe of the turbine, a bypass valve is arranged on one exhaust branch pipe, and a bypass valve and an intercooler are arranged on the other exhaust branch pipe; secondly, arranging a temperature exhaust sensor on a rear exhaust main pipe of the diesel engine in front of inlets of the two exhaust branch pipes, connecting the temperature exhaust sensor with a diesel engine control device through a data acquisition device, and acquiring the front exhaust temperature of the turbine by adopting a temperature exhaust dynamic response characteristic calculation formula; thirdly, detecting and judging whether the temperature exceeds a limit value of the temperature before the turbine of the supercharger or not in real time according to the exhaust temperature sensor, if so, opening a bypass valve on the same exhaust branch pipe with the intercooler, and closing a bypass valve on the other exhaust branch pipe; if the bypass valve does not exceed the bypass valve, closing the bypass valve on the same exhaust branch pipe as the intercooler, and simultaneously opening the bypass valve on the other exhaust branch pipe; fourthly, the power of the engine can be effectively recovered under different altitudes by adjusting the opening degree of the bypass valve of the turbocharger.

Further, in the present invention, the calculation formula of the exhaust temperature dynamic response characteristic is:

in the formula: m is the mass of the temperature sensor in kg; c is the specific heat capacity of the temperature sensor, and the unit J/(kg. K); t is₁Is the temperature of the temperature sensor, in units of K; t is₀Is the temperature of the ambient medium, in K; alpha is the heat exchange coefficient between the temperature sensor and the medium; a is the surface area of the temperature sensor in mm²(ii) a Epsilon is an altitude correction coefficient which mainly influences the heat exchange coefficient between the temperature sensor and the medium.

According to the invention, two exhaust branches of the diesel engine are respectively provided with an exhaust bypass valve, the bypass valves are controlled to be opened and closed by a valve control device, one bypass valve is connected with an exhaust intercooler and can be used for cooling high-temperature gas, a turbine front temperature sensor is used for detecting the front exhaust temperature of the turbine in real time, a calculation formula of exhaust temperature dynamic response characteristics is provided aiming at the influence of the altitude on the temperature sensor, the response time considers the influence factor of the altitude, and the temperature distribution and the heat conduction in the temperature sensor are ignored when the dynamic characteristics of the temperature sensor are described. According to the energy balance equation, a heat balance equation of the temperature sensor when the ambient temperature changes, namely a calculation formula of the exhaust temperature dynamic response characteristic can be obtained. The thermal response time of the variable altitude temperature sensor is denoted by K:

detecting and judging whether the temperature exceeds a limit value of the temperature before the turbine of the supercharger or not in real time according to the exhaust temperature sensor, if so, opening a bypass valve on the same exhaust branch pipe with the intercooler, and closing a bypass valve on the other exhaust branch pipe; if not, the bypass valve on the same exhaust branch pipe with the intercooler is closed, and the bypass valve on the other exhaust branch pipe is opened at the same time.

After the technical scheme is adopted, compared with the prior art, the invention has the following advantages: the invention can prevent the supercharger from being damaged by overhigh exhaust temperature when the variable altitude diesel engine runs, and can break the limitation of high temperature of the supercharger, increase the fuel injection quantity of the diesel engine and improve the dynamic property of the diesel engine under the condition of high altitude.

Drawings

FIG. 1 is a flow chart of the present invention;

FIG. 2 is a schematic structural diagram of an embodiment of the present invention;

wherein: 1. the system comprises an air inlet main pipe, a gas compressor, a first intercooler, a second intercooler, a diesel engine rear exhaust main pipe, a first exhaust branch pipe, a second intercooler, a first exhaust branch pipe, a first bypass valve, a second bypass valve, a valve control device, a data acquisition device, a diesel engine control device, a gas compressor front temperature and pressure sensor, a first bypass valve, a second intercooler, a second bypass valve control device, a second intercooler, a third intercooler, a fourth intercooler, a.

Detailed Description

The following embodiments of the present invention are described in detail with reference to the accompanying drawings, and the embodiments and specific operations of the embodiments are provided on the premise of the technical solution of the present invention, but the scope of the present invention is not limited to the following embodiments. The flow scheme which can be obtained by logic analysis, reasoning or limited experiments based on the prior art by the technical personnel in the technical field is within the protection scope determined by the claims of the invention.

Examples

The specific implementation example is shown in fig. 1 and fig. 2, the invention includes an air inlet manifold 1, an air compressor 2, a first intercooler 3, a diesel engine 4, a diesel engine rear exhaust manifold 5, a second exhaust branch pipe 6, a first exhaust branch pipe 7, a turbine front exhaust manifold 8, a turbine 9, a first bypass valve 10, a second bypass valve 11, a second intercooler 12, a valve control device 13, a data acquisition device 14, a diesel engine control device 15, an air compressor front temperature and pressure sensor 16, an intercooling front temperature and pressure sensor 17, an intercooling rear temperature and pressure sensor 18, a turbine front temperature and pressure sensor 19, a turbine rear temperature and pressure sensor 20, a wiring harness 21, and a turbine rear exhaust manifold 22, an air outlet of the air inlet manifold 1 is connected with an air inlet of the diesel engine 4, the air compressor 2 and the first intercooler 3 are sequentially connected in series on the air inlet manifold 1 along the air flow direction, an air inlet of the diesel engine rear exhaust manifold 5 is connected with an air outlet of an exhaust passage of the diesel engine 4, the air inlets of the first exhaust branch pipe 6 and the second exhaust branch pipe 7 are connected with the air outlet of the rear exhaust main pipe 5 of the diesel engine, the air outlets of the first exhaust branch pipe 6 and the second exhaust branch pipe 7 are connected with the air inlet of the front exhaust main pipe 8 of the turbine, the air outlet of the front exhaust main pipe 8 of the turbine is connected with the air inlet of the turbine 9, and the air inlet of the rear exhaust main pipe 22 of the turbine is connected with the air outlet of the turbine 9; the first bypass valve 10 is connected in series with the first exhaust branch pipe 7, the second bypass valve 11 and the second intercooler 12 are connected in series with the second exhaust branch pipe 6 in sequence along the exhaust flow direction, the compressor front temperature and pressure sensor 16 is arranged on the air inlet header pipe 1 in front of the compressor 2, the intercooler front temperature and pressure sensor 17 and the intercooler rear temperature and pressure sensor 18 are respectively arranged on the air inlet header pipe 1 in front of and behind the compressor 2, the turbine front temperature and pressure sensor 19 is arranged on the diesel engine rear exhaust header pipe 5, the turbine rear temperature and pressure sensor 20 is arranged on the turbine rear exhaust header pipe 22, the compressor front temperature and pressure sensor 16, the intercooler front temperature and pressure sensor 17, the intercooler rear temperature and pressure sensor 18, the turbine front temperature and pressure sensor 19 and the turbine rear temperature and pressure sensor 20 are all connected with the data acquisition device 14 through a wire harness 21, and the data acquisition device 14 is connected with the diesel engine control device 15 through a wire harness 21, the first bypass valve 10 and the second bypass valve 11 are both connected to a valve control device 13 through a wire harness 21, and the valve control device 13 is connected to a diesel engine control device 15 through the wire harness 21.

In the invention, whether the temperature limit value before the turbine of the supercharger is exceeded is judged according to real-time detection of a temperature exhaust sensor, if so, a second bypass valve 11 is opened, and a first bypass valve 10 is closed; if not, the first bypass valve 10 is opened while the second bypass valve 11 is closed. If the power of the diesel engine 4 is not recovered, the power of the engine is effectively recovered under different altitudes by adjusting the opening degree of the bypass valve of the turbocharger.

In the invention, the first bypass valve 10 and the second bypass valve 11 are electrically controlled valves and are not limited to butterfly valves and spherical valves; a bypass valve may also be added to the rear of the second charge air cooler 12.