Turbocharger flow control

Patent metadata

Field	Value
Publication number	US-9291093-B2
Application number	US-201313762549-A
Country	US
Kind code	B2
Filing date	Feb 8, 2013
Priority date	Feb 8, 2013
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A method for controlling a turbocharger is provided. The turbocharger has a turbine operatively connected to an exhaust of an internal combustion engine, and a compressor operatively connected to an intake of the engine. The method includes determining a boost pressure command for the compressor. The boost pressure command is configured to provide sufficient combustion reactant for the engine. The method includes calculating a compressor power from the determined boost pressure command, and calculating a turbine flow from the calculated compressor power. The method commands the turbocharger to operate at the calculated turbine flow.

First claim

The invention claimed is:

1. A method for controlling a turbocharger having a turbine operatively connected to an exhaust of an internal combustion engine and having a compressor operatively connected to an intake of the engine, the method comprising:
determining, via an electronic control unit, engine operating conditions based on air intake flow at at least one of the intake of the engine or a compressor inlet and based on engine exhaust flow at at least one of a turbine inlet or a turbine outlet;
calculating a boost pressure command P i for the compressor from the equation:
<Equation 1: P i >
wherein R is the ideal gas constant, T i is a current temperature at the intake, {dot over (m)} c is a current charge flow command determined by the electronic control unit, n is a determined rotational speed of the engine, D is a displacement of the engine, and η is engine volumetric efficiency, which is calculated as a function of EGRf and the current rotational speed of the engine n, wherein EGRf is an exhaust gas recirculation fraction;
calculating a compressor flow Q c from the equation:
<Equation 2: Q c >
wherein {dot over (m)} a is a determined mass flow to the compressor, T a is atmospheric temperature, and P a is atmospheric pressure;
calculating a compressor pressure ratio P rc from the equation:
<Equation 3: P rc >
wherein, P i is the calculated boost pressure command and P a is atmospheric pressure;
calculating a compressor power E c from the equation:
<Equation 4: E c >
wherein T ex is exhaust temperature, P to is a pressure at an output of the turbine, {dot over (m)} a is the mass flow to the compressor, C p is specific heat of the engine exhaust, T a is atmospheric temperature, a 1 through a 6 are constants specific to the turbocharger, P rc is the calculated pressure ratio across the compressor, and Q c is the calculated compressor flow;
calculating a turbine flow from the equation:
<Equation 5: Q t >
wherein E j is a calculated inertial power and E c is the calculated compressor power; and
commanding the turbocharger to operate at the calculated turbine flow Q t .

Assignees

• Gm Global Tech Operations Inc

Inventors

• Wang Yue-Yun
• Haskara Ibrahim
• Gady Kevin Andrew

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02D41/0072

  Estimating, calculating or determining the EGR rate, amount or flow (sensors in EGR systems F02M26/45) · CPC title

• F02B37/18 Primary

  by bypassing exhaust {from the inlet to the outlet of turbine or to the atmosphere} · CPC title

• F02B37/12 Primary

  Control of the pumps · CPC title

• F02D41/0007

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title