Abstract: A gas engine includes a generator coupled to an output shaft thereof, an intake passage to which a low-concentration methane gas (VAM gas) derived from mine venting is supplied, and a gas mixing unit mixing a high-concentration methane gas (CMM gas) to the low-concentration methane gas midway along the intake passage, so that a gas mixture of the low-concentration methane gas and the high-concentration methane gas is supplied to and burnt in a combustion chamber. A turbocharger is provided in the intake passage upstream of the gas mixing unit, and in the intake passage upstream of the turbocharger, is provided a mixture ratio adjusting unit adjusting a mixture ratio of the low-concentration methane gas and the air. The temperature or flow rate of intake gas flowing into the turbocharger is kept in a constant range by an intake controller.

Abstract: Provided is a seal air supply system including: a seal air compressor 73 provided separately from an exhaust gas turbine turbocharger 27 to generate compressed air; a seal air supply passage 77 through which the compressed air is supplied to a seal air supply part 79 as seal air of the exhaust gas turbine turbocharger 27; and a surplus air inlet passage 81 bifurcating from the seal air supply passage 77 and guiding surplus air of the seal air to an outlet side of an intake gas compressor 27a of the exhaust gas turbine turbocharger.

Abstract: A controller for a gas engine includes a cycle detection unit 67 configured to detect a crank angle period of a single combustion cycle of an engine including a plurality of cylinders based on a crank angle detection value inputted from a crank angle detector 75, a misfire detection unit 69 configured to detect a misfire in a combustion chamber 37 based on an in-cylinder pressure detection value inputted from the in-cylinder pressure detector 59, and a simultaneous misfire determination unit 73 configured to determine a simultaneous misfire of more than one cylinder when a total number of cylinders where the misfire is detected in the single combustion cycle by the misfire detection unit 69 is not less than a preset threshold value of a cylinder number. The fuel gas to all of the cylinders is shut of when the simultaneous misfire of more than one cylinder in the single combustion cycle is determined by the simultaneous misfire determination unit 73.

Abstract: An air supply device of a gas engine having a turbocharger includes a first intake passage configured to guide the mixture of outdoor air and unpurified gas into the turbocharger, a second intake passage configured to guide indoor air into the turbocharger, a filter configured to remove a solid impurity in the unpurified gas which is disposed in the first intake passage, a first damper capable of opening and closing the first intake passage disposed on the downstream side of the filter in the first intake passage, a heating unit for heating the indoor air disposed in the second intake passage, a second damper capable of opening and closing the second intake passage disposed on the downstream side of the heating unit in the second intake passage, and a damper control device configured to control the opening degree of each of the first and second dampers.

Abstract: In an gas engine provided with a gas supply pipe 35 branching into a supercharger-side gas supply pipe 33 and a cylinder-side gas supply pipe 37, a supercharger-side gas adjusting valve 43 and a cylinder-side gas adjusting valve 45 for controlling flow rates of passages, when gas concentration of the fuel gas changes, the cylinder-side gas adjusting valve 45 is controlled first to keep the output of the gas engine constant and then the supercharger-side gas adjusting valve 43 is controlled to achieve the fuel gas flow rate Q1 based on the constant flow ratio by means of a gas supply controller 63, while maintaining the flow rate ratio Q1/Q2 at a constant value where Q1 is a fuel gas flow rate in the supercharger-side gas supply pipe 33 and Q2 is a fuel gas flow rate in the cylinder-side gas supply pipe 37

Abstract: A method to control a gas engine system is disclosed, whereby the engine can be operated with an air-fuel-ratio controlled with high precision, even in using a low calorific fuel-gas that is prone to vary in calorific value; the engine system includes: a first gas line toward each cylinder via a first gas valve from a gas supply source line, the first gas valve regulating flow rates of the fuel-gas through a gas compressor on the line; a second gas line toward suction air, the line being branched from the gas supply source line and the line being provided with a gas air mixer and a second gas valve on the line. In the case when the fuel-gas is of a low calorific value or where the output of the engine is high, a part of the fuel-gas is supplied to the engine through the first and second lines.

Abstract: Provided is a seal air supply system including: a seal air compressor 73 provided separately from an exhaust gas turbine turbocharger 27 to generate compressed air; a seal air supply passage 77 through which the compressed air is supplied to a seal air supply part 79 as seal air of the exhaust gas turbine turbocharger 27; and a surplus air inlet passage 81 bifurcating from the seal air supply passage 77 and guiding surplus air of the seal air to an outlet side of an intake gas compressor 27a of the exhaust gas turbine turbocharger.

Abstract: In a gas engine 1 that uses a gas having a lower specific gravity than air and has a pre-mixing device before a turbocharger, a pre-mixed gas mixture compressed by a turbocharger 3 is cooled by an intercooler 4 located downstream of the turbocharger 3 in the intake system. Condensed water produced as the gas is cooled and the pre-mixed gas mixture discharged with the condensed water are separated into condensed water, air, and fuel gas in a vapor-liquid separator 7. The fuel gas is returned to the intake system upstream of the turbocharger 3, while the condensed water is discharged to atmosphere.

Abstract: A gas engine includes a generator coupled to an output shaft thereof, an intake passage to which a low-concentration methane gas (VAM gas) derived from mine venting is supplied, and a gas mixing unit mixing a high-concentration methane gas (CMM gas) to the low-concentration methane gas midway along the intake passage, so that a gas mixture of the low-concentration methane gas and the high-concentration methane gas is supplied to and burnt in a combustion chamber. A turbocharger is provided in the intake passage upstream of the gas mixing unit, and in the intake passage upstream of the turbocharger, is provided a mixture ratio adjusting unit adjusting a mixture ratio of the low-concentration methane gas and the air. The temperature or flow rate of intake gas flowing into the turbocharger is kept in a constant range by an intake controller.

Abstract: In a gas engine system, air fed through a turbocharger is mixed with fuel gas flowing through a fuel gas supply line and supply into a combustion chamber is controlled. In case that the fuel gas has a low calorie or the engine output power is high, a portion of the fuel gas is diverged from the fuel gas supply line, and the flow rate thereof is set to a constant rate less than that of the diverged side fuel gas. The diverging fuel gas is fed into the combustion chamber through a divergence control valve while the remainder of the fuel gas is fed into the fuel flow control valve. In case that the fuel gas has a high calorie or the engine output power is low, the divergence control valve is closed so as to feed the fuel gas only into the gas supply main pipe.

Abstract: What is disclosed is a micro-pilot injection ignition type gas engine, whereby an air fuel ratio control in starting the engine is executed with enhanced precision, by means of introducing skip-firing intermittent operations which reflect the engine operation conditions, while an idling time span can be shortened or omitted.

Abstract: Provided are a method controlling a gas engine system capable of controlling an air-fuel ratio with a high degree of accuracy even through fuel gas has a low calorie so that the calorific value thereof is likely to vary, and the gas engine system.

Abstract: A method to control a gas engine system is disclosed, whereby the engine can be operated with an air-fuel-ratio controlled with high precision, even in using a low calorific fuel-gas that is prone to vary in calorific value; the engine system includes: a first gas line toward each cylinder via a first gas valve from a gas supply source line, the first gas valve regulating flow rates of the fuel-gas through a gas compressor on the line; a second gas line toward suction air, the line being branched from the gas supply source line and the line being provided with a gas air mixer and a second gas valve on the line. In the case when the fuel-gas is of a low calorific value or where the output of the engine is high, a part of the fuel-gas is supplied to the engine through the first and second lines.

Abstract: What is disclosed is a micro-pilot injection ignition type gas engine, whereby an air fuel ratio control in starting the engine is executed with enhanced precision, by means of introducing skip-firing intermittent operations which reflect the engine operation conditions, while an idling time span can be shortened or omitted.