About replacing antifreeze of diesel generator sets
RE:Diesel generator sets change antifreeze. Why do we need to change antifreeze? What kind of antifreeze should we choose? What are the precautions? What is the function of antifreeze?
Antifreeze is an indispensable heat dissipation medium for diesel generator sets: one is to prevent freezing of the generator set water tank, so that it will not freeze and expand and burst in winter; the other is to cool the engine. When the engine is running, the use of antifreeze as a circulating cooling liquid is very obvious. Therefore, in winter, it is recommended to add antifreeze to maintain the generator set to avoid unnecessary accidents to your equipment.
As for what kind of antifreeze to choose? Choose an antifreeze with a suitable freezing point. Generally speaking, the freezing point of the selected antifreeze is recommended to be 10℃ lower than the local minimum temperature, leaving more surplus to avoid sudden cooling in some places. For example, in Suzhou and Shanghai, the minimum temperature in winter is around -1℃, so it is enough to use antifreeze with a freezing point of -16℃.
In winter, use appropriate antifreeze to avoid corrosion of the heat dissipation pipe and leakage of sand holes; open the lid in a hot state, loosen the lid slowly first, and wait until all the steam is discharged before opening the lid to avoid burns; replace the antifreeze regularly and avoid leakage when adding.
Currently, there are many colors of antifreeze for diesel generator sets, mainly red, green and blue. The main component of red antifreeze is propylene glycol, the main component of green antifreeze is ethylene glycol, and the main component of blue is diethylene glycol. Different colors represent different main components and cannot be mixed. Before starting the diesel generator, it is necessary to check whether the cooling water or antifreeze in the diesel engine water tank is sufficient. If it is insufficient, fill it up.
Function of antifreeze:
1. Antifreeze function. Ensure that the diesel engine cooling system is not frozen when the temperature is too low. Under normal circumstances, the most common antifreeze temperature of coolant, that is, the freezing point, is between minus 20 degrees and 45 degrees. Scientifically select according to the actual needs of different regions.
2. Anti-boiling function. Ensure that premature boiling is not easy to occur under high temperature conditions. Under normal circumstances, the most common coolant boiling point is 104 to 108 degrees. When the coolant is added to the cooling system and pressure is generated, its boiling point will be higher.
3rd, anti-corrosion function. Professional coolant can reduce the corrosion of the cooling system, thereby avoiding the leakage caused by the rust corrosion of the cooling system.
4th, anti-rust function. High-quality coolant can avoid the rust of the cooling system. If the cooling system rusts, it will cause accelerated wear and reduce the heat transfer efficiency.
5th, anti-scaling function. Since the coolant uses deionized water, it can avoid the formation of scaling and precipitation, so as to achieve the purpose of protecting the engine.
In summary, the application of diesel generator coolant solves the problem of suboptimal cooling of diesel generators and excessive temperature of parts, avoids the occurrence of diesel generator operation failures, and its anti-corrosion, anti-rust and anti-listening functions create the most suitable operating conditions for diesel generators. Generator manufacturer Guangxi Zhengchai Generator Group would like to remind you that if the coolant is not replaced for a long time, its function will be reduced, so we usually replace the coolant every one and a half to two years.
Why does the diesel generator exhaust smoke abnormally?
RE:
柴油发电机组刚开始新机试车时,一般都会有一些黑烟冒出,这是因为新的柴油机在出厂时都经过了试车,里面留有一些机油等其它的东西,所以,在刚开机时会有黑烟冒出,而开机一段时间,带上负载后,发电机组冒出的烟的颜色就正常了,一般为淡蓝色,而且很少.
但是,当发电机组出现问题后,它冒出的烟的颜色就不正常了.这种原因有很多种.
1.接通起动机开关后，发电机组排气管大量排黑烟，但发电机不能起动。首先检查进、排气通道是否畅通，如空气滤清器有无堵塞、进气胶管是否凹瘪或其内孔壁脱层阻塞、排气制动间是否全部打开。
b.若发动机有敲击声并排黑烟，说明喷油时间过早，应重新调整喷油正时。通常这种情况是由喷油泵联轴节螺钉松动、轴键损坏或被动盘错位所致。如未发现问题，可按下述方法检查喷油正时：拆下第一缸高压油管，使喷油系出油阀压紧座中心孔的油液液面清晰可见，将供油齿条置于供油位置，从放气螺塞处泵出油路中的空气，缓慢转动曲轴，仔细观察油泵出油阀液面的变化，只要液面有所变化，即说明供油开始，立即停转曲轴，检查喷油提前角是否正确。此时，喷油泵联结盘的定时刻线应与泵体上的刻线重合。
2.发动机运转均匀无高速且排烟过少
从故障现象可以判定，发动机转速提不高是由于得不到最大供油量。诊断时，应按供油系排除空气的顺序先行排气，然后再按以下程序进行检查。
a.检查油门拉杆行程。将油门踏到底，扳动喷油泵油量调节臂，如还能向加油方向推进则说明油门拉杆不能使喷油泵达到最大供油量，应予调整。
b.检查供油量。首先，检查并调整调速器高速限制螺钉的最大供油量限制螺钉。旋进高速限制螺钉则高速降低，反之增高；旋进最大油量限制螺钉则供油量增加，反之减少。当将两调节螺钉向增加的方向旋进时，发动机感到有力，说明此处即为症结所在。应调整供油量，直到急加速时排气管排黑烟为宜。其次，应检查喷油泵、调速器等高压油路部分。
拆下喷油器盖，查看油量调节齿杆能否达到最高速位置，喷油泵挺杆或柱塞是否粘滞，柱塞、挺杆滚轮及凸轮是否磨损过甚，柱塞弹簧是否折断，以及出油间是否密封等。若均正常，再检查喷油器有无泄露，调速器弹簧力是否符合标准。如断定故障不在高压油路，应检查低压油路。主要是油箱通气孔及管路有无堵塞，输油泵滤网有无堵塞，柴油滤清器有无堵塞，输油泵油阀有无渗漏或粘滞，整个油路有无渗漏等。
c.检查发动机运动件，如活塞、曲轴及连杆轴承、凸轮轴轴承、正时齿轮及惰轮等有无粘滞。
d.在寒冷季节，还应检查所用的柴油标号是否符合要求。
3.发动机运转不均匀，排气管排黑烟
首先，在发动机运转时进行逐缸断油试验。当某缸断油时，若发动机转速显著降低，黑烟减少，敲击声变弱或消失，说明该缸供油量过多；若发动机无变化或变化甚微，则说明该缸供油量过少；若发动机转速变化小而黑烟消失，说明该缸喷油器喷雾质量差。找出有故障的单缸后，再进一步检查故障原因，如该缸喷油泵柱塞副情况、扇形齿轮固定螺钉有无松动及柱塞弹簧有无断裂等。若均正常，可拆检喷油器，必要时可换装新喷油器进行对比，若用新喷油器时故障消失，说明原喷油器有故障。
其次，对喷油泵柱塞挺杆带有调整螺钉的，应检查各缸喷油正时是否一致。
若以上各项均无问题，可对有故障的单缸测试压力，以判断是否因气缸、活塞、活塞环等磨损漏气或气门密封不良。
只有正确认识发电机组排烟不正常的原因,才能正确处理发电机组的各项故障,以免盲目操作,造成不可挽回的损失.
What are the power selection tips for diesel generator sets?
RE:
常用发电机组持续工作时间长，负荷曲线变化较大，机组容量、台数、型式的选择及机组的进行控制方式与应急机组不同。
1、容量的确定：按机组长期持续运行输出功率能满足全工程计算负荷选择,并应根据负荷的重要性确定发电机组备用机组容量。柴油机持续进行的输出功率，一般为标定功率的0.9倍。
2、台数的确定：一般设置通常为2台以上，以保证供电的连续性及适应用电负荷曲线的变化。机组台数多，才可以根据用电负荷的变化确定投入发电机组的进行台数，使柴油机经常是在经济负荷下运行，以减少燃油消耗率,降低发电成本。柴油机的经济运行状态是在标定功率的75%-90%之间。为保证供电的连续性，常用机组本身应考虑设置备用机组。
3、转速的确定：一般民用上宜选用转速为1000～1500转/分的高速机组，而转速为300～350转/分的低速机组适用为船用主机。
4、电压的确定：发电机输出电压的确定与应急发电机组相同，一般为400V，个别用电量大，输电距离远的工程可选用高压发电机组。
一、注意事项
1、发电机功率有KVA和KW之分。KVA是视在功率，KW是有效功率，他们之间的关系是1KVA=0.8KW，进口机组一般用KVA表示功率单位，而国内用电设备一般都用KW表示，所以核算功率时应注意单位，如果是KVA,应按照公式换算成KW。
2、功率有长行（额定）功率和后备功率之分，一般备用功率都是大于常用功率。
a、长行功率（常用功率）：一台柴油发电机组在12个小时内连续运行可以达到的功率数值
b、后备功率（备用功率）：在12个运行小时内有一个小时达到的最高功率数值。
例如：一台常用100kw柴油发电机，常用功率为100kw，那么备用功率就可达到110kw，如果是备用100kw柴油发电机，那么常用功率大概只有80kw-90kw。
3、 柴油机功率与发电机的功率不能配置成一样大。业内一般规定柴油机功率≥发电机功率10%，如果配置成一样大，会降低机组寿命，导致维修频繁，使用费居高不下。
4、业内一般规定10KW以上的机组必须带全仪表（俗称五表）及空气开关；大型机组及自动化机组必须带有自四保护功能。
5、确定发电机组的功率并非把所有用电器功率简单相加，还需要考虑用电器的启动方式。一般启动方式分为直接启动和降压启动或变频启动，前者启动电流为工作电流6倍左右，瞬间功率也会达到额定功率6倍；后者启动电流为3倍左右，瞬间功率也为额定功率3倍。因此，选择发电机组功率时，除了需要考虑所有用电器功率之和，还需要考虑每台用电器的启动功率。
二、具体方式
1、如果用户负载的最大值，每天超过8小时运行，所选用的机组的常用功率应为负载的最大值的1.25倍；
2、如果用户负载的最大值，每天4-8小时运行，所选用的机组常用功率应为负载的最大值的1.2倍；
3、如果用户负载的最大值，每天2-4小时运行，所选用的机组常用功率应为负载的最大值的1.15倍；
4、如果用户负载的最大值，每天1-2小时运行，所选用的机组常用功率应为负载的最大值的1.1倍；
5、如果用户负载的最大值，每天低于1小时运行，所选用的机组的常用功率和负载的最大值相等。
控制机组的负载在机组的常用功率以下运行，可以保证机组的工作寿命和正常的工作状态，节省机组的维护费用。
Why must the generator room be kept clean and free of loose sand on the ground?
RE:If the diesel engine inhales dirty air, the power will decrease; if the generator inhales impurities such as sand, the insulation between the stator and rotor gap will be damaged, and in severe cases, it will burn out.
Why do we require customers to tighten all electrical contacts after every 200 hours of operation?
RE:Diesel generator sets are vibrating machines. Moreover, many domestically produced or assembled units do not use double nuts or spring washers. Once the electrical fasteners are loose, a large contact resistance will be generated, causing the unit to operate abnormally.
What is the power factor of a three-phase generator? Can a power compensator be added to improve the power factor?
RE:The power factor is 0.8. No, because the charging and discharging of capacitors will cause fluctuations in the small power supply and unit oscillation.
What are the conditions for parallel operation of two generator sets? What equipment is used to complete the parallel operation?
RE:The condition for parallel operation is that the voltage, frequency and phase of the two generators are the same at the moment. It is commonly known as "three simultaneous". Use a special parallel device to complete the parallel work. It is generally recommended to use a fully automatic parallel cabinet. Try not to use manual paralleling. Because the success or failure of manual paralleling depends on human experience. With more than 20 years of experience in power work, the author dares to say that the reliable success rate of manual paralleling of diesel generators is equal to 0. The concept of manual paralleling for large power systems of the mains must not be applied to small power systems, because the protection levels of the two are completely different.
中文版
English
