CN105317532A - Opening control method for air valve of sequential supercharging system - Google Patents

Abstract

The invention provides an opening control method for an air valve of a sequential supercharging system. The opening control method comprises the steps that the pressure of an outlet of an air compressor and the pressure of an air inlet pipe are monitored in real time; pressure signals are transmitted to an air valve controller; the pressure of the outlet of the air compressor is further increased along with the operation of a controlled supercharger; and when it is judged by the air valve controller that the difference value between the pressure of the outlet of the air compressor and the pressure of the air inlet pipe exceeds a set value, the air valve controller sends out an opening signal and transmits the opening signal to the air valve, the air valve is kept being in an opened state according to the received opening signal, and air enters the air inlet pipe from the outlet of the air compressor. By the adoption of the opening control method for the air valve of the sequential supercharging system, the problems of surging, backflow and the like of the air compressor caused when the air valve is opened too early or too late can be solved.

Description

A method for controlling the opening of an air valve in a sequential supercharging system

technical field

The invention relates to a method for controlling an engine, in particular to a method for controlling a sequential supercharging system of an engine.

Background technique

Sequential supercharging technology is an effective measure to improve the performance of supercharged diesel engines in low working conditions. It can effectively expand the operating range of diesel engines, improve its economy, and improve emission performance. When sequential supercharging diesel engines are switched from one supercharger to two superchargers When the supercharger is used, it is necessary to open the gas valve and air valve of the controlled supercharger. In order to realize the fast response of the supercharger, the gas valve of the controlled supercharger is opened first, and the gas in the exhaust pipe pushes the controlled supercharger to work. When the compressor in the controlled supercharger starts to work, the outlet of the compressor pressure started to rise. At this time, if the air valve is opened too early, the pressure in the intake pipe will be higher than the pressure at the outlet of the compressor, and the air will flow back into the compressor from the intake pipe, causing the compressor to stop or even reverse, destroying the stability of the diesel engine. . If the air valve is opened too late, the pressure at the outlet of the compressor will be too high and the flow rate will be too small, which will cause the compressor to surge, and the controlled supercharger will work unstable, which may seriously cause the supercharger damaged.

Therefore, the timing of the air valve opening is very important. At present, the sequential supercharged diesel engine adopts the time delay method, that is to say, after the gas valve is opened, after a period of time, the air valve is opened again. This period of time was previously determined in sequential supercharged diesel engine tests. Although this method can avoid opening the air valve of successively supercharged diesel engines too early and too late, it does not touch the essence of fluid movement, so it can be regarded as an empirical method; It is also different, which means that each model of successive supercharged diesels needs to be tested to determine, which means a lot of time and money is wasted.

Contents of the invention

The object of the present invention is to provide a sequential supercharging system air valve opening control method that can effectively avoid compressor reverse flow and surge, and adapt itself to any sequential supercharging diesel engine.

The purpose of the present invention is achieved like this:

A method for controlling the opening of an air valve in a sequential supercharging system of the present invention is characterized in that: the controlled turbocharger is connected with the engine, that is, the turbine is connected with the exhaust pipe of the engine, the compressor is connected with the intake pipe of the engine, and the compressor An air valve is installed between the outlet and the inlet pipe, and a pressure sensor is installed at the outlet of the compressor and the inlet pipe respectively, and the two pressure sensors and the air valve are connected to the air valve controller;

When the sequentially supercharged diesel engine is switched from single supercharging to dual supercharging, the controlled supercharger starts to work, the gas valve is opened first, and the gas enters the turbine of the controlled supercharger from the exhaust pipe, and works through the turbine to push the controlled supercharger. Control the rotation of the compressor in the supercharger, the air is compressed in the compressor, so that the pressure at the outlet of the compressor begins to rise, and the two pressure sensors monitor the pressure at the outlet of the compressor and the inlet pipe in real time, and transmit the pressure signal to the air valve Controller, with the operation of the controlled supercharger, the pressure at the outlet of the compressor rises further. When the air valve controller judges that the difference between the outlet pressure of the compressor and the pressure of the intake pipe exceeds the set value, the air valve controller sends an open signal. The signal is transmitted to the air valve, and the air valve remains open according to the received opening signal, and the air enters the intake pipe from the outlet of the compressor.

The advantage of the present invention is that the present invention can solve the problems of compressor surge, compressor reverse flow and the like caused by early or late opening of the air valve.

Description of drawings

Fig. 1 is the structure schematic diagram of the present invention.

detailed description

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

Combined with Figure 1, the compressor outlet 3 is connected with the air valve 2 and the intake pipe 1. Only when the air valve 2 is opened, the air can flow from the compressor outlet 3 to the intake pipe 1. When the air valve 2 is closed, the compressor outlet The air in 3 and the air in intake pipe 1 cannot be exchanged. Pressure sensors 4 and 8 are respectively installed on the compressor outlet 3 and the inlet pipe 1, and they monitor the pressure of the compressor outlet 3 and the inlet pipe 1 at any time. The signal transmission lines 5 and 7 are connected with the pressure sensors 4 and 8 and the air valve controller 6 , and transmit the pressure signal to the air valve controller 6 . The signal transmission line 9 connects the air valve controller 6 and the air valve 2 , and transmits the control signal of the air valve controller 6 to the air valve 2 .

The control process of the present invention is as follows: when the gas valve in front of the controlled supercharger is opened, the gas drives the supercharger to operate, and the compressor starts to work, so that the outlet pressure of the compressor starts to rise, and the pressure sensor transmits the pressure signal to the air valve When the air valve controller judges that the pressure at the outlet of the compressor is higher than the pressure of the intake pipe by a certain value, the air valve controller controls the opening of the air valve, and the air enters the intake pipe from the outlet of the compressor to complete the opening process of the air valve.

When the sequential supercharging diesel engine is switched from single supercharging to dual supercharging, the controlled supercharger will start to work. First, the control system of the sequential supercharging diesel engine will open the gas valve, and the gas will enter the controlled supercharger from the exhaust pipe. in the turbo. Through the work of the turbine, the compressor in the controlled supercharger is driven to rotate, and the air is compressed in the compressor, so that the pressure 3 at the outlet of the compressor begins to rise, and the pressure sensor 4 and pressure sensor 8 monitor the compressor outlet 3 and the intake pipe in real time 1, and the pressure signal is transmitted to the air valve controller 6 through the signal transmission line 5 and the signal transmission line 7. With the operation of the controlled supercharger, the pressure at the outlet of the compressor rises further. When the air valve controller 6 When it is judged that the pressure of the compressor outlet 3 is higher than the pressure of the intake pipe 1 by a certain value, the air valve controller 6 sends an opening signal, which is transmitted to the air valve 2 through the signal transmission line 9, and the air valve 2 opens the air valve according to the received opening signal 2 and keep it open, air enters the intake pipe 1 from the compressor outlet 3. The air valve opening process is complete.

Claims (1)

1. A method for controlling the opening of the air valve of a sequential supercharging system, characterized in that: the controlled turbocharger is connected to the engine, that is, the turbine is connected to the exhaust pipe of the engine, the air compressor is connected to the intake pipe of the engine, and the air compressor An air valve is installed between the outlet and the inlet pipe, and a pressure sensor is installed at the outlet of the compressor and the inlet pipe respectively, and the two pressure sensors and the air valve are connected to the air valve controller; When the sequentially supercharged diesel engine is switched from single supercharging to dual supercharging, the controlled supercharger starts to work, the gas valve is opened first, and the gas enters the turbine of the controlled supercharger from the exhaust pipe, and works through the turbine to push the controlled supercharger. Control the rotation of the compressor in the supercharger, the air is compressed in the compressor, so that the pressure at the outlet of the compressor begins to rise, and the two pressure sensors monitor the pressure at the outlet of the compressor and the inlet pipe in real time, and transmit the pressure signal to the air valve Controller, with the operation of the controlled supercharger, the pressure at the outlet of the compressor rises further. When the air valve controller judges that the difference between the outlet pressure of the compressor and the pressure of the intake pipe exceeds the set value, the air valve controller sends an open signal. The signal is transmitted to the air valve, and the air valve remains open according to the received opening signal, and the air enters the intake pipe from the outlet of the compressor.