| 摘要 |
A combined heat and power system including a 4 cylinder reciprocating internal combustion engine fuelled by a fuel gas, for example natural gas, and operating at a substantially constant speed and at a substantially constant air to fuel ratio. Operation of a spark generator and distributor device (44) is under control of an ignition spark duration control (10) whereby the duration of an ignition spark between the electrodes of the plug (16) is automatically variable to bring the spark duration closer to a predetermined minimum duration over which predetermined minimum duration there would be supplied to the electrodes of the plugs in turn a minimum level of electrical ignition energy to substantially avoid misfire in the cylinders provided with the plugs. The minimum level of the electrical ignition energy is variable according to the size of the gap between the electrodes of the plug (16). The duration of the ignition spark of the plug (16) is observed by a monitor (62) in the lead which inputs the observed duration time into the control (10). |
