Carbureted natural gas turbo charged engine

• US 8,713,935 B2
• Filed: 12/16/2010
• Issued: 05/06/2014
• Est. Priority Date: 06/01/2006
• Status: Active Grant

• Current Assignee: REM Technology Inc.
• Original Assignee: REM Technology Inc.
• Inventors: Malm, Howard Leigh, Mowat, Wade Larry
• Primary Examiner(s): Trieu, Thai Ba
• Application Number:
  US12/970,558
• Publication Number:
  US 20110174281A1
• Time in Patent Office: 1,237 Days
• Field of Search: 123/361, 123/571, 123/198.D, 123/399, 123352-355, 123/478, 123527-528, 123683-684, 123/335, 123/703, 123/438, 123/339.21, 606/02
• US Class Current: 60/602
• CPC Class Codes: F02B 37/18 by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
• CPC Class Codes: F02B 37/186 Arrangements of actuators or linkage for bypass valves
• CPC Class Codes: F02D 19/023 to adjust the fuel mass or volume flow
• CPC Class Codes: F02D 19/029 Determining density, viscosity, concentration or composition
• CPC Class Codes: F02D 2041/1409 using at least a proportional, integral or derivative controller
• CPC Class Codes: F02D 2041/141 using a feed-forward control element
• CPC Class Codes: F02D 41/1477 characterised by the regulation circuit or part of it,(e.g. comparator, PI regulator, output)
• CPC Class Codes: F02M 13/08 Carburettors adapted to use liquid and gaseous fuels, e.g. alternatively
• CPC Class Codes: F02M 21/02 for gaseous fuels
• CPC Class Codes: F02M 21/0203 characterised by the type of gaseous fuel
• 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 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A control system for a turbo charged natural gas engine. A butterfly valve used for fuel control upstream of a carburetor provides non-linear flow response during opening and closing and a flow compensator compensates for the non-linear response. A throttle valve position sensor acts in association with a controller which compares the throttle valve position signal with a predetermined set point and thereby opens or closes the waste gate of the turbo charger which affects oxygen content in the exhaust. A compensator for a throttle valve used with electronic engine controllers is also provided.

Claims

1. A method of controlling a natural gas engine system having a turbo charger having a compressor and a turbine connected to said natural gas engine;

a turbine wastegate valve;

an oxygen sensor associated with said natural gas engine to sense a quantity of oxygen in exhaust gas discharged from said natural gas engine;

an air/fuel throttle valve;

a fuel valve positioned upstream of said air/fuel throttle valve;

a position sensor to sense the position of said air/fuel throttle valve; and

a PID controller;

said method comprising;

sensing an air/fuel throttle valve position;

comparing said position signal with a predetermined user set point via said PID controller;

actuating said waste gate valve in response to an output signal as a result of said comparing said position signal with a predetermined user set point to regulate compressed air pressure in an intake duct.

2. A control system for a natural gas engine comprising:

a turbo charger having a compressor and a turbine connected to said natural gas engine;

a wastegate valve bypassing exhaust gas around said turbine;

an oxygen sensor associated with said natural gas engine to sense a quantity of oxygen in exhaust gas discharged from said natural gas engine;

an air/fuel throttle valve;

a fuel valve positioned upstream of said air/fuel throttle valve to adjust fuel being distributed into an air intake duct to form a compressed air/fuel mixture;

wherein said air/fuel throttle valve adjusts the compressed air/fuel mixture being delivered into said natural gas engine;

a position sensor to sense the position of said air/fuel throttle valve; and

a PID controller,

wherein said PID controller is to

receive a signal from said air/fuel throttle valve position sensor;

compare the signal from said air/fuel throttle valve position sensor to a predetermined user set point;

output a signal associated with said comparing the signal from said air/fuel throttle valve position sensor to a predetermined user set point; and

actuate said waste gate valve in response to said outputting a signal associated with said comparing the signal from said air/fuel throttle valve position sensor to a predetermined user set point thereby to regulate compressed air pressure in said air intake duct.