FR2578581A1 - DIESEL ENGINE TURBOCHARGER AND METHOD OF CONTROLLING SUCH A TURBOCHARGER - Google Patents

Abstract

THIS TURBOCOMPRESSOR 2 FOR A DIESEL ENGINE 1 INCLUDES A CHAMBER 9 FOR THE EXHAUST GAS TURBINE, COMMUNICATING WITH THE EXHAUST PIPE 7 OF THE ENGINE AND INCLUDING A DRIVE WHEEL 14 OF THE TURBINE, A BLOWER CHAMBER 10 SHAPED BY A VOLUTE 19, COMMUNICATING WITH THE SWEEPING TUBING 8 OF THE MOTOR AND INCLUDING A COAXIAL BLOWER ROTOR 21 AND ROTATING WITH THE WHEEL 14, VARIABLE DELIVERY GUIDELINES 15 LOCATED IN CHAMBER 9, VARIABLE GUIDELINES 22 FOR AIR D 'ADMISSION INTO CHAMBER 10, VARIABLE BLADES FORMING OUTPUT DIFFUSER 25 IN CHAMBER 10 AND MEANS 16, 23, 26 SERVING TO CONTROL ALL THESE BLADES IN ACCORDANCE WITH THE OPERATING PARAMETERS OF THE TURBOCHARGER AND DIESEL ENGINE. APPLICATION IN PARTICULAR TO MARINE DIESEL ENGINES.

Description

[Diesel engine turbocharger and method of controlling such

turbocharger

  The present invention relates to a turbocompres-

  for a diesel engine and a method of controlling the turbocharger, and more particularly a turbocharger for a diesel engine, comprising a chamber housing

  an exhaust gas turbine and communicating with the

  exhaust system of a diesel engine and provided with a driving turbine wheel, and a chamber housing a blower and

  having a volute communicating with the tubing of

  motor assembly and provided with a blower wheel rotating in one piece with the driving turbine wheel being coaxial with the latter, and a control method of a

such turbocharger.

  A turbocharger of this type, which is intended to send high pressure air to a diesel engine, acts to increase the power output of the engine and

  to improve the combustion efficiency of the latter. How-

  during operation of the diesel engine under

  the operating point of the turbocharger

  to a pre-set operating point, resulting in reduced turbocharger efficiency as well as

  reduced combustion efficiency of the engine.

  Attempts, which have hitherto been made to eliminate such a difficulty, consist, for example, in providing a suction butterfly in the air passage,

  upstream of the blower chamber, the throttle valve

  being controlled through a unit of

  command as a function of the pressure detected in the pass-

  of air downstream of the blower chamber, and

  other operating parameters such as, for example,

  the speed of the diesel engine and the like. But with such an arrangement, one can not get an accurate control of the turbocharger since the flow and pressure

  air supply are regulated only by the butterfly

  lon suction. As a result, no significant success has been achieved in improving the efficiency of the turbocharger or

  combustion efficiency of the diesel engine.

  The main object of the present invention is to

  a diesel turbocharger, which removes

  the problem mentioned above, and a method of

this turbocharger.

  According to a first aspect of the invention,

  a turbocharger is planned for a diesel engine,

  characterized in that it comprises a chamber housing the tur-

  exhaust and communicating with the hose

  exhaust system of a diesel engine and equipped with a tur-

  motor, a chamber housing a blower and

  a volute communicating with the sweeping pipe of the diesel engine and provided with a fan rotor that can rotate in one piece with the drive turbine wheel being coaxially mounted to the latter, guide vanes

  discharge variables arranged in the accommodation chamber.

  turbine upstream of the turbine wheel,

  variable guide vanes for intake air,

  in the chamber housing the blower, upstream of the

  blower tor, variable blades forming diffuser

  outlet and arranged in the chamber housing the blower.

  te, between the fan rotor and the volute, and

  first, second and third driving means for

  order the guide vanes respectively

  the guide vanes for air and diffuser vanes in accordance with the operating parameters

  turbocharger and diesel engine.

  According to the arrangement mentioned above,

  it is possible to order the vanishing guide vanes

  The guide vanes for the air and the blades

  diffuser according to the specific requirements

  terminated by the operating parameters, so

  that the operating conditions of the turbocharger

  can be regulated in a precise and

  to maintain the diesel engine at all times in conditions

ideal operating conditions.

  According to a second aspect of the invention, there is provided a method for controlling the turbocharger defined above, characterized in that it consists in sending to a control unit programmed in advance, parameters

  of operation including the respective positions of the

  heads of discharge, guide vanes of

  air and vanes forming the diffuser, the speed of the tur-

  bocompressor, the pressure and the outlet temperature of the chamber housing the blower, the internal pressure in the volute, on the outer circumference of the latter, the pressure difference in the volute between its external and internal periphery the intake temperature in the chamber housing the exhaust gas turbine, the internal pressure in an air cooler connected to the diesel engine sweep tube, the speed of the diesel engine and the fuel flow to that engine, and to control the vanes the guide vanes for air and diffuser vanes in accordance with the instructions

  delivered by the control unit.

  The control method mentioned above is based on

  on the fact that three types of blades make it possible

  accurate and variable turbocharger, and is planned

  for the use of different operating parameters

  compatible with increased freedom of order.

  Other features and advantages of the pre-

  invention will emerge from the description given below.

  after a preferred embodiment, taken in

  the attached drawings, in which: -

  - Figure 1 is a diagram of a turbocharger

  according to the invention, shown in connection with a

diesel engine;

  FIG. 2 is a front view showing the

  driving instructions of this turbocharger;

  FIG. 3 is a front view showing the

  directions for the air of this turbocharger;

  FIG. 4 is a front view showing the

  forming diffuser of this turbocharger; FIG. 5 is a timing diagram illustrating a mode of operation, given by way of example, of the diesel engine; and - Figure 6 is a flowchart illustrating a

  command method, given as an example, turbocomprom-

sor.

  In FIG. 1 a diesel engine 1 and a turbocharger

  presser 2, which is connected to it, are controlled

  optimal by a control unit 3.

  The diesel engine i has in itself an arrangement

  known and is arranged so that the alternating movement

  natives6 (only one of which is represented)

  cylinders5 is transformed into the rotational movement

  a crankshaft 4 located below the pistons. Reference 7 designates an exhaust pipe, the reference 8

  a sweep tubing and the reference 8a a cooler

  air supply connected to the sweep tubing 8.

  The turbocharger 2, which constitutes the main part of the present invention, comprises a chamber 9 housing an exhaust gas turbine and a chamber 10 housing a fan. Chamber 9 housing the turbine

  comprises an inlet 11 which communicates with the pipe of

  7 of the engine 1 via a channel

  13 of the exhaust pipe connection, and one

  12.Unercuemotrioe 14 of the turbine is arranged so as to

  see turning inside room 9 housing the tur-

  and has an output shaft 14a protruding from

  the interior of the chamber 10 housing the blower. Others

  pushing guides 14, which extend radially

  each of which can be rotated about a perpendicular axis

  14a to the axis 14a of the turbine, are arranged in a ring arrangement, as shown in Figure 2, inside the chamber 9 housing the turbine, upstream of the wheel 14 of the turbine. The blades 15 are rotated by first drive devices 16. The rotational angular position of the blades 15 is detected by a first angle of rotation detector A1a. The chamber 10 housing the fan comprises an intake 18 and a volute 19 having an outlet 19a which communicates with the sweep pipe 8 of the engine 1 via an air supply pipe 20. A rotor 21 of the fan, which is fixed to the shaft 14a of the turbine, is disposed within the chamber 10 housing

  the blower. Guide vanes 22 for the admission air

  which extend radially and each of which can

  around an axis perpendicular to the shaft 14a of the tur-

  are arranged in a ring arrangement, as shown in FIG. 3e inside the chamber 10

  housing the blower, upstream of the rotor 21 of this

  Niere. The blades 22 are rotated by means of

  conds driving devices 23. The angular position

  in rotation of the blades 22 is detected by a second detection

  angle of rotation A2. In addition, blades 25 which form

  outlet diffuser and each of which can rotate

  turn of an axis parallel to the shaft 14a of the turbine, are arranged in a ring arrangement (Figure 4) in the chamber 10 housing the fan, between the rotor 21 and the volute 19. The blades 25 can be driven by of the

  third training devices 26. The angular position

  rotation of the vanes forming a diffuser 25 is de-

  tected by a third angle of rotation detector A3.

  The control unit 3 receives detection signals

  issued by the first, second and third

  rotation angles A1 to A3. In addition, the communication unit

  mande 3 receives detection signals delivered by a first

  first rotational speed sensor S1 for detecting the rotational speed of the turbine shaft 14a, by means of a

  second rotation speed detector S2 for detecting

  the speed of rotation of the crankshaft 4 of the engine, by a first pressure detector PI for detecting the pressure at the outlet 19a of the fan, by a first

  temperature detector T1 for detecting the time

  at the outlet 19a of the blower, by a second pressure detector P2 for detecting the

  internal pressure at the outer circumference of the

  19 housing the blower, by a differential pressure detector PD for detecting the pressure difference in the volute 19 housing the blower, between the outer periphery and the inner periphery of this volute, by a

  second temperature detector T2 for detecting the time

  Exhaust gas temperature at intake level 11

  in the chamber housing the turbine, by a third detection

  pressure sensor P3 for detecting the pressure in the air cooler 8a of the engine 1, and by a flow sensor F for detecting the flow of the fuel to the engine 1. The control unit 3 is programmed in advance for

  optimum operation of the diesel engine 1 in general

  the speed range of the latter.

  The turbocharger comprising the indi-

  above works in the following manner. When the engine 1 is running, the exhaust gases enter

  the chamber 9 housing the turbine through the channeling

  13 of the exhaust gas transfer and inlet 11 so as to rotate the rotor 14 of the turbine, the gases then being discharged through the outlet 12. Therefore, the rotor 21 of the fan, which is fixed to the turbine shaft 14a rotates so that outside air is sucked into the chamber 10 housing the fan through the inlet 18 thereof and

  compressed air is delivered to the engine 1 through the medium of

  of the volute 19, the outlet 19a of the blower and

  the pipe 20 for supplying air for combustion. Pen

  In this process, the signals delivered by the individual detectors A1, A2, A3, S2, P1 'P2' P38 PD, T1, T2 and F

  sent to the control unit 3 which, in turn,

  control signals C1, C2, C3 for respectively driving the first, second and third drive devices 16, 23, 26 to rotate the discharge guide vanes 15, the guide vanes 22 for the air and the diffuser vanes 25 as required by the preset program of the control unit 3, so that the flow rate and pressure of the air supply to the engine 1 are optimally controlled,

  turbocharger 2 being simultaneously prevented from

  with excessive speed and have a

  sawing, and being controlled simultaneously so as to function

with maximum yield.

  FIG. 5 illustrates an operating mode, given by way of example, of a marine diesel engine. After starting, the motor runs at the traveling speed

  in the harbor, while the ship is in the harbor.

  When the ship enters an expanse of sea, the ship

  is operating at full speed or at cruising speed.

  re. When the vessel is on a canal, the speed of the

  is reduced to idle speed. Once the

  the vessel entered the port of destination, the engine

  again according to the speed of travel to the in-

  inside a port, and the engine is stopped when the navi-

re is docked.

  Fig. 6 shows the flowchart illustrating a typical control mode performed by the control unit

  3. When engine 1 is started, the engine unit

  command 3 is switched either automatically or manually in a waiting state (block a). In this standby state (ie while the engine 1 is running at speed

  movement in a port), the guide vanes of

  15, the guide vanes 22 for the air and the

  the diffuser 25 of the turbocharger 2 are

  in predetermined specific angular positions

  related to the maximum continuous output speed (hereinafter referred to as the "MCO" speed) of

  driver 1 (block b). In the case of an order entirely

  tomatic, the second speed detector S2 detects the

  motor 1 (block c) and the value detected is

  to a reference value that can be changed manually.

  (eg 50% of the MCO value) to establish whether the detected value is not less than the value of

  reference (block d). If "YES", it is estimated that the speed of the

  has entered a range of control and the com-

  command 3 begins to carry out its command (block e). If "NO", the control unit 3 is kept in the waiting state until the motor speed reaches the value of

  reference. Otherwise, you can manually start the uni-

  control unit 3 (block f) before the engine speed has

ring the reference value.

  When starting the order made by the

  control unit 3, the fuel supply flow rate

  trip to engine 1 is first detected by means of the

  flowmeter F (block 2) and, based on the feed rate

  detected, the angular positions of vanes 15, 22 and 25 are adjusted by means of the devices

  drive 16, 23 and 26 (block h). Then, the differences

  The operating parameters are measured completely by means of the detectors A1, A2, A3, S1, S2, P2, P2, P3, PD, T1, T2, and F (block i), and the flow rate of the air sent. at the intake 18 of the blower is calculated in the control unit 3 on the basis of the different values detected through the use of a known method of calculating the flow (block j). The calculated value is examined to determine whether or not it falls within the allowable limits

  of a fan curve, obtained by means of internal tests

  dependents previously made with the turbocharger 2 (block k). If the calculated value is within the limits

  admissible, it is considered that there is no excess of

  se, or no sawing effect of the turbocharger 2, and advance to the next step of control is allowed. Inversely, if the air flow of the blower is

  within the permissible limits, the

  of the blades 15, 22, 25 are readjusted by means of the drive devices 16, 23, 26 (block 1), and the steps

  1 to 1 are repeated until the air flow of the

  flante is within the allowable limits of the blower curve. In the next step,

  the air supply rate sent to the engine 1 is again

  calf detected by means of the fuel flow sensor F

  (block m), to know if it is less than the value of

  fuel level detected during step _ (block m). Yes

  "YES", the value detected during step m is memorized

  as a minimum fuel flow. If "NO", the vanes 15, 22, 25 are adjusted again according to the fuel supply rate (block o), and steps i to o are repeated until the result of the comparison provides " YES". Then, the speed of the motor is again detected by the second speed detector S 2 (block p) for

  make a comparison with the reference value mentioned

  born above (block _ $. If the engine speed is not

  below the reference value, it is estimated that the

  He still maintains a normal walking speed. In order to obtain a more economical flow of fuel, the steps i to q are repeated, which has the effect that the memory of the minimum fuel flow is regenerated successively. When

  engine speed falls below the reference value

  the vanes 15, 22, 25 are locked in their posi-

  pre-set respective angular angles as in the case of starting the engine. It should be noted, on this subject, that even

  after the engine speed has been reduced as indicated

  previously, the order procedure may be

  born imposed, manually, step _ (block s).

  In general, we will implement a

  fully automatic while the vessel is in a harbor or canal.

Claims (5)

  1. Turbocharger for a diesel engine (1),   characterized in that it comprises a chamber (9) housing an exhaust gas turbine and communicating with the exhaust pipe (7) of a diesel engine (1) and provided with a wheel   driving turbine (14); a chamber (10) housing a blow-   flante and having a volute (19) communicating with the sweep neck (8) of the diesel engine (1) and provided with a rotor rotor (21) rotatable in one piece   with the driving turbine wheel (14) being coaxially mounted   to the latter; steering vanes   (15) disposed in the chamber (9) for housing the turbine upstream of the wheel (14) of the turbine; dawns   (22) for intake air,   in the chamber (10) housing the blower, upstream   blower rotor (21); variable vanes (25) form   output diffuser mant and arranged in the chamber (10) housing the blower, between the fan rotor (21) and the volute (19); and first, second and third means   drive (16, 23, 26) for respectively controlling   the guide vanes (15), the vanes   (22) for air and diffusing vanes   (25), in accordance with the operating parameters of the   turbocharger (2) and diesel engine (1).   2. Turbocharger according to claim 1,   characterized in that the discharge guide vanes (15) are arranged in a ring arrangement and in that each of them is rotatable about an axis transverse to the axis of rotation of the drive wheel (14) of the turbine.   3. Turbocharger according to one of the claims   1 or 2, characterized in that the guide vanes (22) are   laid in a ring arrangement and that each of them   can rotate around a transverse axis with respect to   the axis of rotation of the rotor (21) of the fan.   4. Turbocharger according to any one of the   Claims 1 to 3, characterized in that the diffuser blades (25) are arranged in a ring arrangement and in that each of them can rotate about an axis parallel to the axis of rotation of the rotor (21). the blower.   5. Method for controlling the turbocharger (2) se-   according to one of claims 1 to 4, characterized   in that it consists of sending to a control unit (3)   programmed in advance, operating parameters in-   the respective positions of the guide vanes (15), the vanes (22) for the air and   diffuser vanes (25), the speed of the turbocharger   pressure (2), the pressure and the outlet temperature of the chamber (10) housing the blower, the internal pressure in the volute (19) on the outer periphery of the latter,   the pressure difference in the volute (19) between the   outside tower and the inner periphery of the latter, the inlet temperature in the chamber (9) housing the exhaust gas turbine, the internal pressure in an air cooler connected to the sweep pipe (8) of the engine diesel (1), the speed of the diesel engine (1) and the fuel flow rate sent to that engine; and to order the   guide vanes (15), the guide vanes   these (22) for air and diffuser vanes (25),   in accordance with the instructions issued by the Mande (3).