Method for regulating a stationary gas engine

• US 8,683,983 B2
• Filed: 11/17/2008
• Issued: 04/01/2014
• Est. Priority Date: 11/23/2007
• Status: Active Grant

• Current Assignee: Rolls-Royce Solutions GmbH (Rolls-Royce Holdings Plc)
• Original Assignee: MTU Friedrichshafen GmbH (Rolls-Royce Holdings Plc)
• Inventors: Baldauf, Johannes, Smuda, Peer, Klaeser-Jenewein, Ludwig
• Primary Examiner(s): Cronin, Stephen K
• Assistant Examiner(s): STAUBACH, CARL C
• Application Number:
  US12/744,122
• Publication Number:
  US 20100242937A1
• Time in Patent Office: 1,961 Days
• Field of Search: 123/704, 123/352, 123/359, 123/361, 123/399, 123/438, 123/436, 123/480, 123/494, 123/674, 123/679, 123/681, 123/683, 701/103, 701/104, 701/192, 701/106, 701/109, 701/110, 701/113
• US Class Current: 123/527
• CPC Class Codes: F02D 19/023 to adjust the fuel mass or volume flow
• CPC Class Codes: F02D 2250/26 by applying a torque limit
• CPC Class Codes: F02D 2400/14 Power supply for engine control systems
• CPC Class Codes: F02D 31/002 controlling air supply
• CPC Class Codes: F02D 41/0027 the fuel being gaseous non-electrical control F02D19/02
• CPC Class Codes: F02M 21/0215 Mixtures of gaseous fuels; Natural gas; Biogas; Mine gas; Landfill gas
• CPC Class Codes: F02M 21/04 Gas-air mixing apparatus
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

The invention relates to a method for regulating a stationary gas motor (1). In said method, a deviation of the regulated speed is calculated from a desired speed and an actual speed, a desired moment is determined as an adjustable variable from the deviation of the regulated speed by means of a speed governor, said desired moment being limited to an air ratio-limiting moment by limiting the moment, and a desired volume flow (VSL) is determined from the limited desired moment in order to define an angle (DKW1, DKW2) of the mixture throttle valve and an angle of the gas throttle valve.

Claims

1. A method for automatically controlling a stationary gas engine, comprising the steps of:

computing a speed control deviation (dn) from a set speed (nSL) and an actual speed (nIST);

using the speed control deviation (dn) in a speed controller to determine a set torque (MSL) as a correcting variable;

limiting the set torque (MSL) by a torque limiter to an air ratio limit torque (MLAM); and

determining a set volume flow (VSL) from the limited set torque (MSLB) in order to determine a mixture throttle angle (DKW1, DKW2) and a gas throttle angle.

2. The method in accordance with claim 1, including computing the air ratio limit torque (MLAM) from a minimum lambda value (LAM(MIN)) and an actual mixture volume (VGM(IST)).

3. The method in accordance with claim 2, including computing the minimum lambda value (LAM(MIN)) by an engine map as a function of an old value (MSLBA) of the limited set torque (MSLB) and the actual speed (nIST), where the old value (MSLBA) is equal to the limited set torque (MSLB) computed during a previous run through the program.

4. The method in accordance with claim 2, including computing the actual mixture volume (VGM(IST)) at least as a function of a mixture temperature (T1) in a receiver tube of the engine, an actual mixture pressure (p1(IST), p2(IST)), and the actual speed (nIST).

5. The method in accordance with claim 4, including determining the actual mixture pressure as a representative actual mixture pressure (pR(IST)) from a first actual mixture pressure (p1(IST)) or a second actual mixture pressure (p2(IST)).

6. A method in accordance with claim 2, including measuring the actual mixture volume (VGM(IST)) in a receiver tube of the engine.

7. The method in accordance with claim 1, including setting the air ratio limit torque (MLAM) to a starting torque during a starting operation.

8. The method in accordance with claim 1, including setting the limited set torque (MSLB) by a minimum value selector to a smallest value of the set torque (MSL), a fault torque (MFM), the air ratio limit torque (MLAM), or a maximum torque (MMAX), where the maximum torque (MMAX) is determined at least from a permissible mechanical maximum torque and a limit-speed-dependent torque.