The generator set is precisely a complete set of mechanical equipment that converts other forms of energy into electric energy. It is composed of power system, control system, silencing system, damping system and exhaust system. It is driven by water turbine, steam turbine, diesel engine or other power mechanical drives to convert the energy generated by water flow, air flow, fuel combustion or nuclear fission into mechanical energy and transmit it to the generator, Then it is converted into electric energy by the generator and output to the electrical equipment for use.

而發電機組又分為單燃料發電機組和雙燃料發電機組。

The generator set is divided into single fuel generator set and dual fuel generator set.

單燃料發電機組：單燃料發電機組又稱為全燒式發電機組，在沼氣產量大的場合可連續穩定地運行，適合在大、中型沼氣工程中使用，可以使用天然氣發電機組，亦可由柴油機改裝而成。由于氣體燃料的組分、熱值、物理性能、著火溫度、爆炸極限、燃燒特性存在很大差異。

Single fuel generator set: single fuel generator set, also known as full fired generator set, can operate continuously and stably in occasions with large biogas output. It is suitable for large and medium-sized biogas projects. It can use natural gas generator set or be refitted from diesel engine. There are great differences in composition, calorific value, physical properties, ignition temperature, explosion limit and combustion characteristics of gaseous fuel.

當利用天然氣發電機組燃燒沼氣時，需對發電機組的相關部件進行必要的調整或改裝，例如發電機組的空氣-燃氣混合器，在改裝時，空氣閥的通徑需擴大1.4倍左右；此外，還應根據發電機組對空燃比和調節特性的要求，確定燃氣閥芯的型號，設計若干組閥座與閥芯的配合方案，以備篩選。

When using natural gas generator set to burn biogas, it is necessary to adjust or refit the relevant components of the generator set, such as the air-gas mixer of the generator set. During refitting, the diameter of the air valve needs to be expanded by about 1.4 times; In addition, the model of gas valve core shall be determined according to the requirements of generator set for air-fuel ratio and regulation characteristics, and several groups of matching schemes of valve seat and valve core shall be designed for screening.

也就是說，單燃料發電機組只能用一種材料發電，而雙燃料則能用兩種燃料，這就是他們的區別。

In other words, a single fuel generator set can only use one material for power generation, while a dual fuel generator set can use two fuels, which is the difference between them.