应急柴油发电机房的设计（五） Design of Emergency Diesel Generator Room (V)

柴油发电机是一种小型发电设备，系指以柴油等为燃料，以柴油机为原动机带动发电机发电的动力机械。整套机组一般由柴油机、发电机、控制箱、燃油箱、起动和控制用蓄电瓶、保护装置、应急柜等部件组成。可用于各种家庭、办公室、大中小型企业日常发电以及应急发电。

  柴油发电机组是柴油发动机与发电机（通常是交流发电机）的组合以产生电能。 柴油压燃式发动机通常设计成在燃油上运行，但是有一些类型适用于其他液体燃料或天然气。发电机是将其他形式的能源转换成电能的机械设备。

  随着社会的发展，人民生活水平的提高，在现代民用建筑当中，用电设备的种类和数量越来越多，在这些用电设备当中，不仅有消防泵、喷淋泵等消防设备，还有需要可靠供电的生活泵、电梯等用电设备，为满足这些设备用电的可靠性，当市政电网无法提供两路独立电源时，在设计中采用柴油发电机组作为备用电源的方法被普遍采用。

  虽然柴油燃点较高，发生火灾危险性相对较小，但是在民用建筑中是将柴油发电机组设置在建筑物主体内，从理论上来说肯定还是有危险性的，再考虑到机组运行过程中通风、噪音、振动等问题，无疑需要我们全面考虑并采取充分的防范措施。

基础的设计

  据发电机相关厂家样本可知，发电机组的重量约在4~8吨，而其中的柴油机转速一般为1500转/分，这么沉重的东西在高速运行时，必须采取一定的减振措施。为了减低振动，根据柴油机组尺寸，设置一个高20cm的混凝土基础基础各边应超出机组最宽处15~30cm，当进行机组安装时，在基础相对于机组底架上的固定螺栓位置钻孔，然后用膨胀螺栓将机组固定。采取这一措施，机组的振动被混凝士吸收一部分。电气专业向结构专业提荷载时，除了要提供机组的静负荷，混凝土基础的体积，还应考虑机组的动负荷，动负荷可向相关的厂家索取，也可按机组静负荷的1.5倍考虑。

钢筋混凝土基础必须保证一定的养护期，设备才可就位。基础四周应设计10cm的油槽，可以方便清理设备滴漏的燃油或润滑油。

机房接地

柴油发电机房一般应有三种接地：

工作接地：发电机中性点接地；

保护接地：电气设备正常不带电的金属外壳接地；

防静电接地：燃油系统的设备及管道接地。

各种接地与建筑物的其它接地共用接地装置，即采用联合接地方式。设计时应在机房设接地预埋件。

A diesel generator is a small power generation device that refers to a power machinery that uses diesel or other fuels and a diesel engine as the prime mover to drive the generator to generate electricity. The entire unit is generally composed of components such as a diesel engine, generator, control box, fuel tank, starting and control battery, protective device, emergency cabinet, etc. Can be used for daily power generation and emergency power generation in various households, offices, large, medium and small enterprises.

A diesel generator set is a combination of a diesel engine and a generator (usually an AC generator) to generate electrical energy. Diesel compression ignition engines are typically designed to run on fuel, but there are some types that are suitable for other liquid fuels or natural gas. A generator is a mechanical device that converts other forms of energy into electrical energy.

With the development of society and the improvement of people's living standards, there are more and more types and quantities of electrical equipment in modern civil buildings. Among these electrical equipment, there are not only fire-fighting equipment such as fire pumps and sprinkler pumps, but also electrical equipment such as domestic pumps and elevators that require reliable power supply. In order to meet the reliability of power supply for these equipment, when the municipal power grid cannot provide two independent power sources, the method of using diesel generator sets as backup power sources in the design is widely adopted.

Although diesel has a high ignition point and a relatively low risk of fire, it is theoretically still dangerous to install diesel generator sets inside the main structure of civil buildings. Considering issues such as ventilation, noise, and vibration during unit operation, it is undoubtedly necessary for us to comprehensively consider and take sufficient preventive measures.

Basic design

According to samples from generator manufacturers, the weight of the generator set is about 4-8 tons, and the diesel engine speed is generally 1500 revolutions per minute. When such a heavy object is running at high speeds, certain vibration reduction measures must be taken. In order to reduce vibration, a concrete foundation with a height of 20cm should be set up according to the size of the diesel unit. Each side of the foundation should exceed the widest part of the unit by 15-30cm. When installing the unit, drill holes at the fixed bolt positions on the foundation relative to the unit frame, and then fix the unit with expansion bolts. By taking this measure, the vibration of the unit is partially absorbed by the concrete. When the electrical profession applies loads to the structural profession, in addition to providing the static load of the unit and the volume of the concrete foundation, the dynamic load of the unit should also be considered. The dynamic load can be obtained from relevant manufacturers or considered at 1.5 times the static load of the unit.

The reinforced concrete foundation must ensure a certain curing period before the equipment can be in place. A 10cm oil tank should be designed around the foundation to facilitate the cleaning of leaking fuel or lubricating oil from the equipment.

Computer room grounding

Diesel generator rooms generally have three types of grounding:

Working grounding: neutral point grounding of the generator;

Protective grounding: Grounding the metal casing of electrical equipment that is normally non electrified;

Anti static grounding: grounding of equipment and pipelines in the fuel system.

Various grounding devices are shared with other grounding devices of the building, that is, a joint grounding method is adopted. Grounding embedded parts should be installed in the computer room during design.