A hydrogen concentration calculating process calculates a hydrogen concentration in a specific portion of a target region based on an operating state of an internal combustion engine. The internal combustion engine uses hydrogen as fuel. A downstream passage is a portion of an intake passage of the internal combustion engine that is downstream of a throttle valve. A connecting passage connects a crank chamber of the internal combustion engine to the downstream passage. The target region is a region including the crank chamber and the connecting passage. When a condition is met, in which the hydrogen concentration is greater than or equal to a predetermined determination value, a pressure reduction process causes a pressure in the downstream passage to be lower than that at a point in time when the condition is met.

This disclosure includes engines that are capable of controlling an air-fuel ratio responsive to rapid changes in the calorific value of a fuel gas. Some engines include an A/F valve (22), a solenoid valve (21), and a control unit (10) configured to close the A/F valve when an average opening degree of the solenoid valve is lower than a preset target opening degree, and open the A/F valve when the average opening degree is equal to or higher than the target opening degree. In some engines, when the opening degree of the solenoid valve has been an upper limit opening degree or a lower limit opening degree of the solenoid valve over a predetermined number of times, the control unit is configured to compare with the upper or lower limit opening degree, in lieu of the average opening degree, against the target opening degree to open or close the A/F valve.

A system and method for determining the quality of natural gas is provided. The system includes a fuel line for communicating natural gas to an engine. An infrared light source is disposed along the fuel line and is configured to emit a beam of infrared light into the fuel line having a wavelength of 6 to 10 micrometers. An infrared light detector detects a transmission value of the natural gas as the beam of infrared light passes through the fuel line. A natural gas quality module receives the transmission value from the infrared light detector and determines a quality value of the natural gas based on an amount of infrared light absorbed by methane in the natural gas. An engine control module, including a feed-forward control loop, receives the quality value from the natural gas quality module and alters an operating parameter of the engine in response thereto.

Embodiments of the present invention include a method and computer readable memory for supplying conditioned natural gas to dual fuel engines. Some embodiments of the present invention include an apparatus and process for controlling and optimizing the heating value or BTU per cubic foot of gas (BTU/cf) of the natural gas substituted for diesel fuel in the operation of transport vehicles and field equipment such as generators.

Embodiments of the present invention include a method and apparatus for supplying conditioned natural gas to dual fuel engines.

A Volatile Organic Compound (VOC) mitigation system employs a combination of technologies coupling VOC laden exhaust with a reciprocating engine and generator system (Combined Heat & Power (CHP) System) with heat recovery to destroy the VOC emissions and generate electric power and useful thermal energy.

A system for determining properties of fuel supplied to an internal combustion (IC) engine and for adjusting operations of the IC engine based on the determined properties. The system includes an air-flow throttle configured to control the air supplied to the IC engine; a fuel-flow throttle configured to control the fuel supplied to the IC engine; and an engine control module (ECM) configured to receive readings from and control operation of the throttles. The ECM is configured to perform a fuel-air determination program where the ECM determines a percent-error air-to-fuel ratio (AF) based on a true AF ratio compared to an ideal AF ratio. The ECM is configured to perform a fuel property determination and adjustment program in which the ECM is configured to adjust operations of the IC engine based on a fuel property value determined using the percent-error AF ratio.

A method and system for recycling permeated gas is disclosed. A container encapsulating a pressure vessel defines a containment volume. Gas permeating through the pressure vessel is captured in the containment volume. When a sensor detects a threshold level of permeated gas captured within the containment volume, a control module sends a command to open a purge valve. The open purge valve allows permeated gas captured within the containment volume to be supplied to an engine, a repressurization unit, or a secondary container.

A system for sensing and controlling a fuel gas composition may include a plurality of micro-sensors mounted in a single chamber, with each of the micro-sensors being configured to sense a characteristic of a mixture of gaseous fuel introduced into the chamber. The system may also include a plurality of heating elements, with each of the heating elements being associated with one of the plurality of micro-sensors, and the plurality of heating elements being configured to implement a different temperature level at each of the micro-sensors. The system may also include a microprocessor configured to determine a thermodynamic property of the mixture of gaseous fuel at the different temperature levels at each of the micro-sensors as a function of the characteristic sensed by each micro-sensor, correlate the thermodynamic property to a fuel gas composition of the mixture of gaseous fuel, and control an amount of at least one constituent in the mixture of gaseous fuel as a function of the fuel gas composition determined by the correlation.

A Volatile Organic Compound (VOC) mitigation system employs a combination of technologies coupling VOC laden exhaust with a reciprocating engine and generator system (Combined Heat & Power (CHP) System) with heat recovery to destroy the VOC emissions and generate electric power and useful thermal energy.