Method and device for water injection

Patent metadata

Field	Value
Publication number	US-10801400-B2
Application number	US-201916258855-A
Country	US
Kind code	B2
Filing date	Jan 28, 2019
Priority date	Jan 26, 2018
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

A method and device for water injection, wherein a water injector ( 104 ) is activated in accordance with an activation ( 200 ) to open at a first time (t 1 ) and to close at a second time (t 2 ), wherein a water pressure profile ( 300 ) is measured and a change in the water pressure profile ( 400 ) is determined on the basis of the water pressure profile ( 300 ), wherein, depending on the water pressure profile ( 300 ) and on the change in the water pressure profile ( 400 ), it is determined whether the water injector ( 104 ) has been opened as a result of the activation ( 200 ), and/or wherein, depending on the water pressure profile ( 300 ) and on the change in the water pressure profile ( 400 ), it is determined whether the water injection ( 104 ) has been closed as a result of the activation ( 200 ).

First claim

What is claimed is:

1. A method for water injection, comprising:
a first step of providing a water injector ( 104 ) operable between an open state and a closed state;
a second step of measuring a water pressure profile ( 300 ) to confirm whether the water injector is in the closed state;
a third step of activating the water injector ( 104 ) in accordance with an activation ( 200 ) to open at a first time (t 1 ) and to close at a second time (t 2 ),
a fourth step of confirming the water injector is in the open state by at least one of:
measuring a water pressure profile ( 300 ) at the first time (t 1 ) to determine if the water pressure profile ( 300 ) exceeds a first limiting value (G 1 ) and the water injector ( 104 ) is in the open state or if the water pressure profile ( 300 ) is less than the first limiting value (G 1 ) and the water injector ( 104 ) is in the closed state,
determining whether a pressure gradient in the course of a change in the water pressure profile ( 400 ) fall below a second limiting value (G 2 ) within a first time window (Z 1 ), and
confirming whether the water pressure profile ( 300 ) falls below a third limiting value (G 3 ) following the opening of the water injector ( 104 ), and

a fifth step of determining whether the water injector ( 104 ) has been closed by at least one of:
determining if the pressure gradient in the course of the change in the water pressure profile ( 400 ) exceed a fourth limiting value (G 4 ) within a second time window (Z 2 ), and
determining if the water pressure profile ( 300 ) exceed a fifth limiting value (G 5 ) following the closure of the water injector ( 104 ).

2. The method of claim 1 , further comprising detecting a fault if the water injector ( 104 ) has been opened too early or too late.

3. The method of claim 1 , further comprising detecting a fault if the water injector ( 104 ) has not been opened completely.

4. The method of claim 1 , further comprising detecting a fault if the water injector ( 104 ) has been closed too early or too late.

5. The method of claim 1 , further comprising detecting a fault if the water injector ( 104 ) has not been closed completely.

6. The method of claim 1 , further comprising recording the water pressure profile ( 300 ) as a water pressure signal by means of a pressure sensor ( 116 ), wherein the water pressure signal is low-pass filtered, and wherein the change in the water pressure profile ( 400 ) is determined as a first derivative of the low-pass filtered water pressure signal.

7. The method of claim 1 , wherein the step of measuring the water pressure profile ( 300 ) comprises measuring a water rail pressure profile in a water rail ( 106 ).

8. A device for water injection, comprising a water injector ( 104 ), a pressure sensor ( 116 ) and a control device ( 118 ), wherein the control device ( 118 ) is configured to receive a water pressure signal from the pressure sensor ( 116 ) and to activate the water injector ( 104 ) in accordance with the method of claim 1 .

Assignees

• Porsche Ag

Inventors

• Jost Philip
• Poggemann Timo

Classifications

• F02D19/12

  peculiar to engines working with non-fuel substances or with anti-knock agents, e.g. with anti-knock fuel · CPC title

• F02D41/0025

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title

• F02M25/028

  into the charge intakes · CPC title

• F02D41/22 Primary

  Safety or indicating devices for abnormal conditions {(in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809)} · CPC title

• F02M25/0221

  Details of the water supply system, e.g. pumps or arrangement of valves · CPC title