CN103352754A - Multi-mode large and small turbocharger diesel engine sequential supercharging structure - Google Patents

Abstract

The purpose of the present invention is to provide the sequential supercharging structure of multi-mode size turbocharger diesel engine, including small supercharger and large supercharger, the turbine of the small supercharger communicates with the exhaust port of the diesel engine through the A row exhaust pipe, and the large supercharger is connected to the exhaust port of the diesel engine. The turbine of the supercharger is connected to the exhaust port of the diesel engine through the exhaust pipe of row B, the compressor of the small supercharger is connected to the intercooler through the intake pipe of row A, and the compressor of the large supercharger is connected to the intercooler through the inlet pipe of row B The exhaust pipes of row A and row B are connected through the exhaust connecting pipe, and the first gas is set between the connection of the exhaust connecting pipe and the exhaust pipe of row A and the turbine of the small supercharger. Valve, the second gas valve is set between the connection between the exhaust communication pipe and the exhaust pipe of row B and the turbine of the large supercharger, the first air valve is set on the intake pipe of row A, and the second gas valve is set on the intake pipe of row B air valve. The invention can make the diesel engine switch to the non-supercharging mode at idle speed, and improve the air intake efficiency at idle speed.

Description

Sequential supercharging structure of multi-mode size turbocharger diesel engine

technical field

The invention relates to a diesel engine, in particular to a supercharging structure of the diesel engine.

Background technique

Sequential supercharging technology is the technology first adopted by German MTU company in the late 1970s. Its design is mainly to expand the working range of low compression ratio and high supercharging engine, increase the low-speed torque of the engine and reduce the part-load running time. Fuel consumption. Its basic principle is to use multiple turbochargers, which are sequentially put into operation as the engine speed and load increase, so as to ensure that the working turbochargers are always running in the high-efficiency zone, so that the engine's The fuel consumption rate is low throughout the operating range, and the low-speed high-torque performance is good. Its principle is similar to the variable section turbine, but it is different. The sequential supercharging system not only changes the area of the turbine nozzle, but also changes the flow area of the compressor, improving the overall efficiency of the supercharger at low load.

With the development of sequential supercharging technology of diesel engines, the technology of sequential supercharging of large and small superchargers has appeared, that is, in the structure of sequential supercharging of diesel engines with two superchargers, the sizes of the two superchargers are different. The engine can adjust the supercharging system in three operating regions, such as only using a small supercharger at low load, only using a large supercharger at medium load, and using both large and small superchargers at high load.

When the supercharged diesel engine is idling, the intake air of the cylinder passes through the compressor inlet, the compressor impeller, the intercooler, the intake pipe, and finally enters the cylinder. The exhaust gas passes through the engine exhaust pipe, the turbine intake pipe, the turbine, the exhaust duct, and then enters the atmosphere. During this process, due to the existence of the supercharger, the intake and exhaust of the engine are subjected to the resistance of the supercharger. When idling, the exhaust energy is very small, the supercharger works in the ultra-low efficiency zone, the existence of the compressor impeller increases the intake resistance, and the existence of the turbine blade increases the exhaust resistance, which affects the intake of the engine at idle from a negative angle. gas efficiency.

Among the patents that have been applied for are "Series and Parallel Adjustable Boosting System of Large and Small Turbochargers" (200510025774.0), "Three-stage Sequential Turbocharging Device for Large and Large Turbochargers" (200820157308.7), " Series-Parallel Boiler Adjustable Supercharging System" (200910072418.2), which involves the content of turbocharger supercharging system. However, these 3 patents do not relate to the content of improving the idling performance of the supercharged diesel engine.

Contents of the invention

The object of the present invention is to provide a sequential supercharging structure of a multi-mode size turbocharger diesel engine that can switch the diesel engine to a non-supercharging mode at idle speed, thereby improving the air intake efficiency at idle speed.

The purpose of the present invention is achieved like this:

The multi-mode size turbocharger diesel engine sequential supercharging structure of the present invention includes a diesel engine, an intercooler, and the intercooler communicates with the air inlet of the diesel engine, and is characterized in that it also includes a small supercharger and a large supercharger, The turbine of the small supercharger is connected to the exhaust port of the diesel engine through the exhaust pipe of row A, the turbine of the large supercharger is connected to the exhaust port of the diesel engine through the exhaust pipe of row B, and the compressor of the small supercharger is connected to the intake pipe of row A Connected to the intercooler, the compressor of the large supercharger is connected to the intercooler through the intake pipe of row B, the exhaust pipe of row A and the exhaust pipe of row B are connected through the exhaust connecting pipe, and the exhaust connecting pipe and the A The first gas valve is set between the connection of the exhaust pipes of row B and the turbine of the small supercharger, and the second gas valve is set between the connection of the exhaust communication pipe and the exhaust pipe of row B and the turbine of the large supercharger , The first air valve is set on the air intake pipe of column A, and the second air valve is set on the air intake pipe of column B.

The present invention may also include:

1. An intake valve is set between the intercooler and the intake port of the diesel engine, and an exhaust valve is set on the exhaust connecting pipe. Both the intake valve and the exhaust valve are connected to the atmosphere.

The advantages of the present invention are: the present invention considers the intake and exhaust characteristics of the diesel engine at idle speed, and installs an intake valve after the intercooler and between the intake pipe, and installs an exhaust valve in the middle of the exhaust communication pipe, so that the engine can Switch to a non-supercharged diesel engine at idle speed to improve the intake efficiency of the engine, improve combustion, reduce emissions, and reduce fuel consumption. At the same time, due to the existence of the sequential supercharging structure of the large and small superchargers, the diesel engine can work in 4 working areas. The non-supercharged mode is used when idling, the small supercharger is used when the load is small, and the large supercharger is used when the load is medium. When the load is high, the large and small superchargers work at the same time. In this way, the engine can have better air intake efficiency under all working conditions.

Description of drawings

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

Detailed ways

The present invention is described in more detail below in conjunction with accompanying drawing example:

In conjunction with Fig. 1, the multi-mode diesel engine size turbocharger sequence supercharging structure involved in the present invention is composed of diesel engine 1, supercharger 9,12, intercooler 4, diesel engine intake and exhaust pipe 3,16,17, control valve and so on, wherein the sizes of the two superchargers are different. One end of the intake valve 2 is connected to the atmosphere, and the other end is connected to the intake pipe 17 . One end of the exhaust valve 18 is connected to the atmosphere, and the other end is connected to the exhaust communication pipe 5 . Gas valve A7 one end links to each other with small supercharger turbine 8, and the other end links to each other with A column exhaust pipe 3. One end of the air valve A6 is connected with the small supercharger compressor 10 , and the other end is connected with the intercooler 4 . One end of the gas valve B14 is connected to the large supercharger turbine 13, and the other end is connected to the B row exhaust pipe 16. One end of the air valve B15 is connected with the large supercharger compressor 11 , and the other end is connected with the intercooler 4 .

During the operation of the sequential supercharging diesel engine, the diesel engine sequential supercharging control system collects the operating parameters of the engine. When the engine starts, that is, in the idle state, the gas valve A, air valve A, gas valve B, and air valve B are all closed, and the intake valve And the exhaust valve is opened, the engine is in the non-boost mode at this time, the intake resistance and exhaust resistance are small, which is conducive to engine combustion. When the running state of the engine reaches the switching condition of the small turbocharger, the gas valve A and the air valve A are opened, the intake valve and the exhaust valve are closed, and the supercharging system enters the small turbocharger mode. When the operating condition of the engine is further improved and the switching condition of the large supercharger is reached, the gas valve B and the air valve B are opened, the gas valve A and the air valve A are closed, and the intake valve and the exhaust valve are also closed. , the supercharger system enters the large supercharger mode. The operating condition of the engine is further improved, and when the switching condition of both large and small turbochargers is reached, the gas valve A and air valve A are also opened. device mode.

Similarly, when the operating condition of the engine decreases, according to the switching conditions of various modes, it is sufficient to maintain the switching states of the valves in each mode. That is, in the idle mode, the gas valve A, the air valve A, the gas valve B, and the air valve B are closed, and the intake valve and the exhaust valve are opened. In the small supercharger mode, the intake valve, exhaust valve, gas valve B, and air valve B are closed, and the gas valve A and air valve A are opened. In the supercharger mode, the intake valve, exhaust valve, gas valve A, and air valve A are closed, and the gas valve B and air valve B are opened. In the supercharger mode, the gas valve A, air valve A, gas valve B, and air valve B are opened, and the intake valve and exhaust valve are closed.

The invention mainly protects the "non-supercharging" scheme for improving the idling performance of the turbocharger sequentially supercharging the diesel engine. That is, an intake valve is installed between the intercooler and the intake pipe, and an exhaust valve is installed in the middle of the exhaust communication pipe, so that the diesel engine can be switched to a non-supercharged mode at idle speed, and the intake efficiency at idle speed can be improved.

Claims (2)

1. Multi-mode size turbocharger diesel engine sequential supercharging structure, including diesel engine, intercooler, intercooler is connected with the intake port of diesel engine, and its characteristics are: it also includes small supercharger and large supercharger, The turbine of the small supercharger is connected to the exhaust port of the diesel engine through the exhaust pipe of row A, the turbine of the large supercharger is connected to the exhaust port of the diesel engine through the exhaust pipe of row B, and the compressor of the small supercharger is connected to the intake pipe of row A Connected to the intercooler, the compressor of the large supercharger is connected to the intercooler through the intake pipe of row B, the exhaust pipe of row A and the exhaust pipe of row B are connected through the exhaust connecting pipe, and the exhaust connecting pipe and the A The first gas valve is set between the connection of the exhaust pipes of row B and the turbine of the small supercharger, and the second gas valve is set between the connection of the exhaust communication pipe and the exhaust pipe of row B and the turbine of the large supercharger , The first air valve is set on the air intake pipe of column A, and the second air valve is set on the air intake pipe of column B. 2. The multi-mode size turbocharger diesel engine sequential supercharging structure according to claim 1 is characterized in that: an intake valve is set between the intercooler and the intake port of the diesel engine, and an air intake valve is set on the exhaust communication pipe. The exhaust valve, the intake valve and the exhaust valve are all connected to the atmosphere.

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