6.3 Technical performance of the set:
*6.3.1 Adaptability of gas engine set to changes in methane contents.
Where the methane content is between 30% and 50%, gas engine sets could operate at rating parameters. Where the ambient temperature is at 40℃ or below and the altitude is lower than 1,000m, its power output will be 4,000kW. Data of power output related to changes in methane content is listed in Table below.
6.3.2 Adaptability of gas engine sets to abnormal working conditions
1) The shafting of the sets shall be able to bear the torque caused by the conditions under which the generator outlet bus is suddenly occurred to two-phase or three-phase short circuit, or single-phase short circuit reclosure, or non-synchronous reclosure.
2) The set is allowed to be with an idle time of one minute after load rejection.
3) The sets is allowed to operated at no-load condition, and the permitted time of no-load must satisfy the time to adjust generator testing after starting up the engine.
4) The gas engine will be allowed to operate for long time if the offgas reaches the maximum temperature and maintains this temperature.
5) When the gas engine genset is undergoing over-speed test, if it is operated with no-load under 115% rated revolution for a short time, at this moment, any component shall not be allowed to exceed its permissible stress and the vibration of various shafting shall also not exceed its permissible values.
6) When the automatic gas valve is closed suddenly while the sets are still jointed with the grid, there shall be no damages to any equipment.
7) Loads of gas engine sets shall conform to the requirements of load changes provided by manufacturer.
8) If the grid or system is occurred with emergent accident which causes the plant unable to deliver electricity, jointing system could be capable of automatically shutting down most gensets and of maintaining few gensets in order to meet electricity demands from the plant.
6.3.3 Under the normal working conditions, the system of gas engine gensets will require:
1) Gensets are allowed to normally, continually operate at the load range required by tender documents.
2) Under the rated revolution, when the engine is operating with full loads, the engine shall be capable of providing rated output power to the gensets.
3) Under the normal configuration and maintenance, the engine shall be capable of starting up and reaching the rated voltage and frequency within 30 seconds and of operating with loads.
4) The sets shall be capable of operating continually and smoothly with the frequency range of 48.5~50.5Hz.
5) The sets shall operate at permissible maximum backing pressure and rated loads. The permissible maximum backing pressure of the sets shall be 50 mbar.
6) The sets shall be capable of loading and unloading 10% bulk load; and in case of suddenly loading or unloading, the voltage and frequency excursion as well as the recovery time shall be in accordance with ISO8528-5 Standard.
6.3.4 Requirements for maintenance of gas engine sets
1) Maintenance shall be implemented in terms of repair and maintenance schedule for gas engine sets prepared by manufacturer, and the time interval for overhaul of the sets could be 70,000 hours.
2) Maintenance schedule for gensets, including activities, contents, schedule and frequency of maintenance, can be found in Article 3.6.3.4 Activities, Contents and Costs of Maintenance to Gas Engine Genset, the Specification. Components, prices and working hours of maintenance and replacement can be found in the List of Spare Parts and Sub-item quotation.
4) Designed useful life of main components and parts (wearing parts exclusive) of gas engine gensets shall not be less than 30 years, and they must bear various operating modes during their life.
6.3.5 Average sound pressure level of surface noise measured at the place 1m away from the gas engine shall conform to the provisions of DIN45635 Standards. Noise level of engine and the noise level of gas inlet and outlet are shown in the Table below.
6.3.6 NOx emission of engine sets is less than 500mg/nm3 (about 1.50g/kWh).
6.3.7 The Seller shall be responsible for the vibration of shafting of gas engine and gensets, and for unified design of lubricating oil system, control instrumentation, couplings and all auxiliary systems, so as to ensure the integrality and operational reliability of gas engine gensets.
6.3.8 The Seller shall be responsible for integrality of gas engine gensets, auxiliary equipments and systems.
6.3 机组系统技术性能：
*6.3.1 燃气发动机组对瓦斯甲烷浓度变化的适应性能。
燃气发动机组在瓦斯的甲烷浓度为30% ~ 55%范围内，机组能在额定参数运行。燃气发动机组在环境温度40摄氏度以下及海拔1000米下功率输出为4000kW。功率输出相对甲烷含量变化数据见下表。
6.3.2 燃气发动机发电机组对非正常运行工况的适应性能
1）机组的轴系能承受发电机出口母线突然发生两相或三相短路或单相短路重合闸或非同期合闸时所产生的扭矩．
2）机组甩负荷后，允许空转时间不少于1分钟。
3）机组在额定转速下空负荷运行，允许持续空负荷运行时间，满足发动机启动后进行发电机试验调整的时间。
4）燃气发动机排气温度达到421高温度下允许长期运行，并提供机组最高的排气温度。
5）燃气发动机发电机组超速试验时，在不低于115%额定转速下作短期空负荷运行，这时任何部件都不超允许应力，各轴系振动不超过允许值。
6）当自动燃气阀突然关闭，机组仍与电网并列时，不引起设备上的任何损坏。
7）燃气机组负载应符合制造商负荷变化表要求。
8)电网或系统发生突然事故全厂不能对外供电时，并机系统能自动停止大部分机组发电，保留满足厂用电负荷的机组继续运行。
6.3.3 燃气发动机发电机组的系统在正常工况下运行要求
1）机组允许可以在招标文件要求的负荷范围内正常连续运行。
2）额定转速下，发动机带所有负载时，发动机能够为发电机组提供额定的输出功率。
3）在正常配置和维护下，发动机在30秒内起动达到额定电压与频率，并有能力接受负载。
4）机组能在频率为48.5~50.5Hz的范围内持续稳定运行。
5）机组在允许的最大背压值下、在额定负载下持续运行。机组运行允许的最大背压值为50 mbar。
6）机组具备分步加载和卸载10%大块负载的能力，在突加或突减负载时，电压的偏移、频率的偏移与恢复时间满足ISO8528—5的标准。
6.3.4 燃气发动机组对维修的要求
1）按照制造商对燃气发动机组制定的维护保养计划维护，机组的大修间隔可以达7万小时。
2）机组维修计划，包括维修活动、维修内容、维修时间及维修频率见本规格书3.6.3.4 燃气发动机发电机组的维修活动内容和成本。维护更换的部件、价格、工时见备件清单及分项报价。
4）燃气发动机发电机组的主要零部件（不包括易损件）设计使用寿命不少于30年，在寿命期内应能承受各种运行方式。
6.3.5 距燃气发动机1m处测量的表面噪音平均声压级符合DIN45635标准的规定。发动机的噪声以及进气、排气的噪声值见下表。
6.3.6 发动机组NOx排放小于500mg/nm3（约1.50g/kWh）。
6.3.7卖方对燃气发动机和发电机组整个轴系的振动值负责，对润滑油系统、控制仪表以及联轴节和所有辅助系统，负责统一设计，保证燃气发动机发电机组的整套性和运行的稳定性。
6.3.8 卖方对燃气发动机和发电机组、辅助设备和系统的整套性负责。 原件下载： 
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