夜雨聆风4-2 Start and Stop
4-2.1 Starting Procedure4-2.1 启动流程
When the urea water injection switch is turned on, this SCR system will automatically start according to the exhaust gas temperature and engine load conditions.
开启尿素喷射开关后，选择性催化还原（SCR）系统会根据排气温度及发动机负荷工况自动启动
A. Checking the power switches
A检查电源开关
Check that the power switch of each urea water control & metering cabinet is on. ( : 4-1.1 “How to Turn on Power”)
确认各尿素控制计量柜的电源开关处于合闸状态。
（详见4-1.1《电源开启操作方法》）
Keep the SCR system powered on even while the engine is stopped. It will recover from the standby state at the same time when the engine is started and will automatically
即使发动机停机，也需保持SCR系统通电。发动机启动时，系统会从待机状态同步恢复，并自动投入运行
start operation.
When starting the engine without supplying power to the SCR system, remove the urea water injector from the exhaust pipe. When the SCR system power is off, compressed air is not supplied to the urea water injector, and the injector is not cooled. Therefore, high temperature exhaust gas may damage the nozzle, nozzle valve and seal. After stopping the power supply to the SCR system and restoring the power, check the functions. Care must be taken particularly for several hours after the restoration.
若发动机启动前未给SCR系统供电，必须先将尿素喷射器从排气管上拆下。SCR系统断电时，压缩空气无法供给至喷射器，喷射器失去冷却，高温废气易损坏喷嘴、喷嘴阀及密封件。切断SCR系统电源后再次恢复供电时，务必检查各项功能，且恢复供电后的数小时内需重点留意设备状态
B. Setting up the piping
B. 管路检查
Check that all manual valves on the urea water system and compressed air system are open.
( : 2-3.1 “Urea Water System”, 2-3.2 “Compressed Air System”) 确认尿素系统与压缩空气系统上所有手动阀门均已全开。（详见2-3.1《尿素供给系统》、2-3.2《压缩空气系统》
If the compressed air for urea water injection is not supplied, the urea water in the urea water injector will crystallize and block the injector. If the supply of compressed air is stopped for any reason, supply compressed air from a substitute line. 若尿素喷射用压缩空气中断，喷射器内的尿素溶液会结晶并造成管路堵塞。一旦压缩空气供给因故停止，需启用备用管路临时供气
Check that the urea water inlet line is filled with urea water. If it is not filled with urea water, the pump may suck air and be damaged. ( : 4.1.2 "Manual Operation of Urea Water Pump and Confirmation of Rotation Direction")检查尿素进液管路，确保管路内已充满尿素溶液。若管路缺液，尿素泵会吸入空气，进而导致泵体损坏。（详见4.1.2《尿素泵手动操作及转向确认》）
C. Switching the fuel oil C. 燃油切换
This system is designed for use with fuel oil with a sulfur content of 0.1% or less. When using the SCR system, switch the fuel oil to low-sulfur fuel with a sulfur content of 0.1% and keep the engine running 1 or 1.5 hours before entering an ECA. The use of high-sulfur fuel during SCR operation can cause catalyst clogging. 本系统适配硫含量≤0.1% 的燃油。启用SCR系统时，需将燃油切换为低硫燃油（硫含量0.1%及以下）；驶入排放控制区（ECA）前，需使用该低硫燃油持续运行发动机1~1.5小时。SCR系统运行期间若使用高硫燃油，会造成催化剂堵塞。
D. Injection of urea water D. 尿素喷射作业
After switching the fuel to low-sulfur fuel with a sulfur content of 0.1% or less, turn on the urea water injection switch on the display panel. When the urea water injection switch turns on and the ECA signal turns on (when the ECA switch function is used), the SCR system will turn on. When the SCR system is on, if the exhaust gas temperature rises above the specified value, the by-pass damper will be switched to the catalyst side to increase the catalyst temperature. When the catalyst temperature is within the normal operation range and the engine load/speed is higher than the preset value, the urea water pump will start. At the same time, the shutoff valve of urea water control & metering unit and the 3-way valve of the urea water injector will open to start the injection of urea water.
切换至硫含量0.1%及以下的低硫燃油后，操作控制面板开启尿素喷射开关。若同时启用排放控制区（ECA）开关功能，当尿素喷射开关、ECA信号均处于开启状态时，SCR系统正式启动。系统启动后，若排气温度升至规定值，旁通风门会切换至催化剂侧，提升催化剂温度。当催化剂温度处于正常运行区间，且发动机负荷、转速高于设定值时，尿素泵开始运转；同时尿素控制计量单元截止阀、喷射器三通阀相继开启，系统开始喷射尿素溶液。
<Display panel operation procedure>控制面板操作步骤
1. Open the main screen, and press AE1. 1. 进入主界面，按下AE1按键；
2. Turn on the urea water injection switch on the engine display screen.
2. 在发动机显示界面开启尿素喷射开关
3. Press Prev to return to the main screen. 3. 按下返回键（Prev）回到主界面；
4. When multiple engines are mounted, repeat Steps 1 to 3 for each of AE2 to AE5, and turn on the urea water injection switch for each SCR system.
4. 若设备配备多台发动机，依次对AE2至AE5重复上述1-3步骤，分别开启各套SCR系统的尿素喷射开关。
4-2.3 Normal Stop
Turn off the urea water injection switch on the display panel. The urea water injection will be
stopped, and the by-pass damper will switch to open the by-pass side. ( :8-1.3 “Engine Display Screen”) When the ECA switch function is used, the urea water injection will be automatically stopped when the ECA signal is not received, and the by-pass damper will be switched to open the by-pass side. Also when the engine stops and when the engine load/speed lowers to such a degree that the operation of the SCR system is not required, the by-pass damper will be automatically switched to open the by-pass side and stop the urea water injection. 关闭控制面板上的尿素喷射开关，尿素喷射即刻停止，旁通风门切换至旁通侧。若启用了ECA开关功能，未接收到ECA信号时，系统会自动停止尿素喷射，旁通风门同步切至旁通侧。此外，发动机停机，或发动机负荷、转速降至无需SCR系统运行的工况时，旁通风门也会自动切换至旁通侧，并停止尿素喷射。（详见8-1.3《发动机显示界面》）
