Latvian Maritime academy

Table 2. MAN B&W 7S50MC-C alarm boundary values and optimum operating parameters of central coolingsystemCautionI - ALYMeasuring PointOptimum OperatingValuesCylinder Cooling Water Inlet 3.5 - 4.5ALARM VALUE UNIT SLD SHD2 Bar1.5 Bar LZ Cylinder Cooling Water Inlet 3.5 - 4.5 x Bar LI - AL57 º CCylinder Cooling Water Inlet 65 - 70I - AH 75 º CI - AH85 º CY Cylinder Cooling Water Outlet 78 - 8290 º C HZ 95 º C HI - AH Cylinder Cooling Water Outlet 1.0 - 1.5 2 BarI - AH30 º CM/E Preheating 35 - 50Z 25 º CI - AH Cooling Water T/C Outlet 75 - 80 85 º CI - AH LT Cooling Water 30 - 36 44 º CI - AH5.5 BarLT Cooling Water 2.0 - 4.5I - AL 1.0 BarI - AHI - ALYI - AHSea Water 1.9 - 2.5LTFW Air Cooler Inlet3.5 Bar1.0 Bar0.5 Bar L•Sea Water Cooling System 2.0 – 2.5 3.5 Bar•Central Cooling System 2.0 – 4.5 5.5 BarAL 1 BarI - AHILTFW Air Cooler Inlet•Sea Water Cooling System >10 - 32 40 º C•Central Cooling System >10 - 36 40 º CLTFW Air Cooler Outlet•Sea Water Cooling System >10 - 50 º C•Central Cooling System >10 - 63 º CA: ALARM Z: SHUT DOWN AL: LOW ALARMI: INDICATION Z: SLOW DOWN AH: HIGH ALARMH: HIGHL: LOWIf the working parameters in Figure 5 are out of optimal range, it can be observed that all the alarmsare active as given in Figure 7. Several alarm conditions can be seen related with the input data.The alarms enabled are colored in red as shown in Figure 7 and a warning symbol appears beneathit, denoting that the alarm is enabled. If none of the alarms are enabled (the entered values are parallel tothe ideal running values of the system), the trouble-free condition shown in Figure 8 will be monitored.As seen, the system has returned to the normal condition and this can be understood from the text of thealarm system written in black and from the symbols beneath the alarm.68