Method for regulating a gas engine

Patent metadata

Field	Value
Publication number	US-9273620-B2
Application number	US-201013382100-A
Country	US
Kind code	B2
Filing date	Jun 16, 2010
Priority date	Jul 3, 2009
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

The invention relates to a method for regulating a gas engine ( 1 ) having a generator ( 5 ), wherein a regulator torque is calculated by means of a speed regulator from a speed regulator deviation, wherein a target volume flow is calculated at least as a function of the regulator torque, wherein a fuel volume is determined as a proportion of a fuel-air mixture as a function of the target volume flow, and wherein a target receiver pipe pressure is also calculated as a function of the target volume flow as a guide parameter for a receiver pipe pressure regulating circuit for regulating the mixture pressure (pRRA, pRRB) of a fuel-air mixture in the receiver pipe ( 12, 13 ) above the inlet valves of the gas engine ( 1 ). The invention is characterized in that a deviation of the regulator torque from a generator torque is calculated and the target receiver pipe pressure is corrected using the deviation.

First claim

The invention claimed is:

1. A method for automatically controlling a gas engine, comprising the steps of: computing a controller torque (MR) from a speed control deviation by a speed controller; computing a set volume flow (V(SL)) at least as a function of the controller torque (MR); setting a fuel volume as a fraction of an air/fuel mixture as a function of the set volume flow (V(SL)) by adjusting a gas control device; computing a set intake manifold pressure (pRR(SL)) as a reference input for an intake manifold closed-loop pressure control system as a function of the set volume flow (V(SL)); automatically controlling a mixture pressure (pRRA, pRRB) of an air/fuel mixture in the intake manifold upstream of intake valves of the gas engine by adjusting a mixture control device of the intake manifold closed-loop pressure control system based on the set intake manifold pressure; computing a deviation (yS) of the controller torque (MR) from a generator torque (MGen); correcting the set intake manifold pressure (pRR(SL)) based on the deviation (yS), including correcting the set intake manifold pressure (pRR(SL)) by correcting input variables of the set intake manifold pressure by the deviation (yS), computing the set intake manifold pressure (pRR(SL)) at least from a corrected set volume flow (Vk(SL)), a corrected combustion air ratio (LAMk), and a corrected air requirement (LMINk), and computing the corrected set volume flow (Vk(SL)) by multiplying the set volume flow (V(SL)) by the square of the deviation (yS), and using the corrected set volume flow to adjust the gas control device and the mixture control device to respectively control the fuel volume flow and the mixture pressure.

2. A method for automatically controlling a gas engine, comprising the steps of: computing a controller torque (MR) from a speed control deviation by a speed controller; computing a set volume flow (V(SL)) at least as a function of the controller torque (MR); setting a fuel volume as a fraction of an air/fuel mixture as a function of the set volume flow (V(SL)) by adjusting a gas control device; computing a set intake manifold pressure (pRR(SL)) as a reference input for an intake manifold closed-loop pressure control system as a function of the set volume flow (V(SL)); automatically controlling a mixture pressure (pRRA, pRRB) of an air/fuel mixture in the intake manifold upstream of intake valves of the gas engine by adjusting a mixture control device of the intake manifold closed-loop pressure control system based on the set intake manifold pressure; computing a deviation (yS) of the controller torque (MR) from a generator torque (MGen); correcting the set intake manifold pressure (pRR(SL)) based on the deviation (yS), including correcting the set intake manifold pressure (pRR(SL)) by correcting input variables of the set intake manifold pressure by the deviation (yS), computing the set intake manifold pressure (pRR(SL)) at least from a corrected set volume flow (Vk(SL)), a corrected combustion air ratio (LAMk), and a corrected air requirement (LMINk), and computing the corrected combustion air ratio (LAMk) at least from a reference combustion air ratio (LAMr) and the deviation (yS), the reference combustion air ratio (LAMr) being computed by an input-output map as a function of the controller torque (MR) and actual speed (nM(IST)), and using the corrected set volume flow to adjust the gas control device and the mixture control device to respectively control the fuel volume flow and the mixture pressure.

3. A method for automatically controlling a gas engine, comprising the steps of: computing a controller torque (MR) from a speed control deviation by a speed controller; computing a set volume flow (V(SL)) at least as a function of the controller torque (MR); setting a fuel volume as a fraction of an air/fuel mixture as a function of the set volume flow (V(SL)) by adjusting a gas control device; computing a set intake manifold pressure (pRR(SL)) as a reference input for an intake manifold closed-loop pressure control system as a function of the set volume flow (V(SL)); automatically controlling a mixture pressure (pRRA, pRRB) of an air/fuel mixture in the intake manifold upstream of intake valves of the gas engine by adjusting a mixture control device of the intake manifold closed-loop pressure control system based on the set intake manifold pressure; computing a deviation (yS) of the controller torque (MR) from a generator torque (MGen); correcting the set intake manifold pressure (pRR(SL)) based on the deviation (yS), including correcting the set intake manifold pressure (pRR(SL)) by correcting input variables of the set intake manifold pressure by the deviation (yS), computing the set intake manifold pressure (pRR(SL)) at least from a corrected set volume flow (Vk(SL)), a corrected combustion air ratio (LAMk), and a corrected air requirement (LMINk), and computing the corrected air requirement (LMINk) by computing a first mixing parameter as a function of the deviation (yS), by computing an efficiency ratio (ETA) from the first mixing parameter and an ignition point (ZZP), by correcting the first mixing parameter recursively by the efficiency ratio (ETA), by setting a last mixing parameter computed as a valid mixing parameter on recognition of a termination criterion, and by multiplying the valid mixing parameter by constants and setting the result as the corrected air requirement (LMINk), and using the corrected set volume flow to adjust the gas control device and the mixture control device to respectively control the fuel volume flow and the mixture pressure.

4. The method in accordance with claim 3 , wherein a termination criterion is present if the recursive loop has been passed through i times or if a difference between two computed mixing parameters (xS(i), xS(i+1)) is less than a limit (GW).

5. The method in accordance with claim 3 , including filtering the valid mixing parameters.

6. The method in accordance with claim 1 , including computing the deviation (yS) by computing a quotient of the controller torque (MR) and the generator torque (MGen).

7. The method in accordance with claim 1 , including automatically controlling an A-side mixture pressure (pRRA) in an A-side intake manifold by a first intake manifold closed-loop pressure control system as a function of the set intake manifold pressure (pRR(SL)), and automatically controlling a B-side mixture pressure (pRRB) in an B-side intake manifold by a second intake manifold closed-loop pressure control system, also as a function of the set intake manifold pressure (pRR(SL)).

Assignees

• Kläser-Jenewein Ludwig
• Mtu Friedrichshafen Gmbh

Inventors

• Kläser-Jenewein Ludwig

Classifications

• F02M21/0215

  Mixtures of gaseous fuels; Natural gas; Biogas; Mine gas; Landfill gas · CPC title

• F02D2400/14

  Power supply for engine control systems · CPC title

• F02D41/0205

  using an auxiliary engine speed control (engine speed control per se F02D31/00) · CPC title

• F02D41/1497

  With detection of the mechanical response of the engine · CPC title

• F02D2250/18

  Control of the engine output torque · CPC title