Abstract: A gas engine drive system includes: a gas engine including combustion chamber; a turbocharger including a compressor and turbine; a fuel injection system that injects fuel gas into intake air that is supplied from compressor to combustion chamber via an intake passage; a pressure detector detecting a charge air pressure; a temperature detector detecting the intake air's temperature; and controller controlling the fuel injection system. The controller: when required output decreases, determines the charge air pressure's lean limit based on target injection amount corresponding to required output that has decreased; if the charge air pressure is lower than or equal to the lean limit, decreases fuel injection amount to target injection amount; if the charge air pressure is higher than lean limit, brings fuel injection amount to zero. When the charge air pressure becomes lower than or equal to the lean limit, increases fuel injection amount to target injection amount.

Abstract: A gas engine system controller: calculates a delay calculation value of a knocking occurrence ratio; determines a primary target ignition timing; sets the primary target ignition timing as a current ignition timing if the occurrence ratio difference is positive and an ignition timing does not exceed a converted value of a first advance rate; determines whether a rapid advance condition is satisfied if the occurrence ratio difference is positive and the ignition timing difference exceeds the converted value of the first advance rate; sets a secondary target ignition timing as the current ignition timing if the rapid advance condition is not satisfied, the secondary target ignition timing obtained by adding the converted value of the first advance rate to the previous ignition timing; and determines the current ignition timing so as to achieve a second advance rate greater than the first advance rate if the rapid advance condition is satisfied.

Abstract: A method of controlling a gas engine that is operated under lean-burn conditions, the method adjusting ignition timing such that a delay calculation value of an actual knocking occurrence ratio becomes a target occurrence ratio, the method comprising: when a delay calculation value of a maximum pressure in a cylinder of the gas engine is greater than or equal to a reference value, converting the delay calculation value into a virtual knocking occurrence ratio greater than or equal to a value greater than the target occurrence ratio; and either adding the virtual knocking occurrence ratio to the delay calculation value of the actual knocking occurrence ratio and then comparing the resulting delay calculation value of the actual knocking occurrence ratio with the target occurrence ratio, or comparing the virtual knocking occurrence ratio instead of the delay calculation value of the actual knocking occurrence ratio with the target occurrence ratio.

Abstract: A gas engine drive system includes: a gas engine; a turbocharger including a compressor and a turbine connected to the gas engine; a fuel injection valve provided on the gas engine; a fuel supply line leading a fuel gas to the fuel injection valve, the fuel supply line having a pressure regulating valve; a first pressure meter detecting an intake air pressure; a second pressure meter detecting a fuel supply pressure being a pressure at a pressure regulating valve downstream side; and a controller controlling the pressure regulating valve such that a pressure difference between the fuel supply pressure and the intake air pressure is a target value. The controller changes the target value from a first to a second setting value higher than the first when a load on the gas engine increases rapidly or when a calorific value of the fuel gas is less than a threshold.

Abstract: A method of controlling a gas engine connected to a turbocharger including a compressor and a turbine includes: performing a knocking control operation of optimizing an ignition timing as a steady operation; and in a case where a load of the gas engine increases during the steady operation, when a degree of increase in the load is relatively small, gradually increasing an actual fuel injection amount while keeping the ignition timing, and when the degree of increase in the load is relatively great, retarding the ignition timing and then gradually increasing the actual fuel injection amount.

Abstract: A method of controlling a gas engine connected to a turbocharger including a compressor and a turbine includes: performing a knocking control operation of optimizing an ignition timing as a steady operation; and in a case where a load of the gas engine increases during the steady operation, when a degree of increase in the load is relatively small, gradually increasing an actual fuel injection amount while keeping the ignition timing, and when the degree of increase in the load is relatively great, retarding the ignition timing and then gradually increasing the actual fuel injection amount.

Abstract: A gas engine drive system includes: a gas engine including combustion chamber; a turbocharger including a compressor and turbine; a fuel injection system that injects fuel gas into intake air that is supplied from compressor to combustion chamber via an intake passage; a pressure detector detecting a charge air pressure; a temperature detector detecting the intake air's temperature; and controller controlling the fuel injection system. The controller: when required output decreases, determines the charge air pressure's lean limit based on target injection amount corresponding to required output that has decreased; if the charge air pressure is lower than or equal to the lean limit, decreases fuel injection amount to target injection amount; if the charge air pressure is higher than lean limit, brings fuel injection amount to zero. When the charge air pressure becomes lower than or equal to the lean limit, increases fuel injection amount to target injection amount.

Abstract: A gas engine system controller: calculates a delay calculation value of a knocking occurrence ratio; determines a primary target ignition timing; sets the primary target ignition timing as a current ignition timing if the occurrence ratio difference is positive and an ignition timing does not exceed a converted value of a first advance rate; determines whether a rapid advance condition is satisfied if the occurrence ratio difference is positive and the ignition timing difference exceeds the converted value of the first advance rate; sets a secondary target ignition timing as the current ignition timing if the rapid advance condition is not satisfied, the secondary target ignition timing obtained by adding the converted value of the first advance rate to the previous ignition timing; and determines the current ignition timing so as to achieve a second advance rate greater than the first advance rate if the rapid advance condition is satisfied.

Abstract: A gas engine drive system includes: a gas engine; a turbocharger including a compressor and a turbine connected to the gas engine; a fuel injection valve provided on the gas engine; a fuel supply line leading a fuel gas to the fuel injection valve, the fuel supply line having a pressure regulating valve; a first pressure meter detecting an intake air pressure; a second pressure meter detecting a fuel supply pressure being a pressure at a pressure regulating valve downstream side; and a controller controlling the pressure regulating valve such that a pressure difference between the fuel supply pressure and the intake air pressure is a target value. The controller changes the target value from a first to a second setting value higher than the first when a load on the gas engine increases rapidly or when a calorific value of the fuel gas is less than a threshold.

Abstract: A method of controlling a gas engine that is operated under lean-burn conditions, the method adjusting ignition timing such that a delay calculation value of an actual knocking occurrence ratio becomes a target occurrence ratio, the method comprising: when a delay calculation value of a maximum pressure in a cylinder of the gas engine is greater than or equal to a reference value, converting the delay calculation value into a virtual knocking occurrence ratio greater than or equal to a value greater than the target occurrence ratio; and either adding the virtual knocking occurrence ratio to the delay calculation value of the actual knocking occurrence ratio and then comparing the resulting delay calculation value of the actual knocking occurrence ratio with the target occurrence ratio, or comparing the virtual knocking occurrence ratio instead of the delay calculation value of the actual knocking occurrence ratio with the target occurrence ratio.