Sensors Monitoring Systems. Crank-Case Protection System (CPS)

Transcription

1 Sensrs Mnitring Systems Dr.E Hrn GmbH & C. KG Im Vgelsang Schönaich Germany Tel: inf@dr-hrn.rg DK Rev /6 Crank-Case Prtectin System (CPS) The Crank-Case Prtectin System (CPS) is designed fr mnitring f bearings f 4-strke Diesel engines. A thermelectric measurement between the rtating shaft (e.g. via brushes) and the engine blck is transfrmed int a signal (CPS signal) designated fr engine cnditin mnitring. The basic principle f the system is t measure the therms-vltage prduced by a steel crankshaft when it slides n the metal surface f its bearing shells. The CPS signal prvides infrmatin, at an early stage, abut upcming damages caused by frictin, especially f bearings. Operatrs get infrmed thrugh the display abut the cnditin. Thus, it helps t diagnse failures in thse mving parts at early stages, preventing the engine frm serius damages. The system is, in parallel, cnnected t the AMS system - by pre-alarm and main-alarm relay utputs. The CPS, its psitin encder (ptinal) and the pressure sensr (ptinal), is cnnected t the CPS Master unit that calculates and mnitrs the measured values. Depending n engine specific settings and parameters, limits fr alarm levels are set. The CPS Master Unit is directly cnnected t the AMS. The CPS Slave Unit is used fr displaying live-data at the ECR where the measured values are displayed and the signal evaluatin is perfrmed. CPS Sensr is installed n the husing n a free end f the crankshaft. Main Characteristics Thermelectric measurement Engine speed measurement (ptinal) Engine lad measurement (under preparatin) Crankcase pressure measurement (ptinal) Oil temperature measurement (under preparatin) Oil pressure measurement (under preparatin) Mnitring f bearing cnditin CPS Advantages Simple and easy assembly Assembly by crew pssible Easy maintenance Early initialisatin f an alarm if bearing anmalies ccur Tw independent external supply vltages, ne frm the 24V net and ne frm the safety battery (under preparatin) Technische Änderungen und Irrtümer vrbehalten. / Mit diesem Datenblatt verlieren alle vrherigen Datenblätter ihre Gültigkeit. Technical mdificatins and errrs reserved. / Prir data sheets lse validity.

2 Sensrs Mnitring Systems Dr.E Hrn GmbH & C. KG Im Vgelsang Schönaich Germany Tel: inf@dr-hrn.rg DK Rev /6 Technical Data Pwer supply: 24VDC +30%/-25% Pwer cnsumptin: Over current prtectin: Operating temperature: Strage temperature: Relative humidity: Current Cnsumptin: Prtectin acc. t DIN 40050: Cnnectin terminals: Cnnectin crss sectin: Data Interface apprx.125w by fuse 0 C C fr sensr 0 C C fr cmputing unit -10 C C fr sensr C fr cmputing unit < 90%, nt cndensing < 500mA fr sensr IP68 fr cmputing unit IP67 frm frnt panel and IP 20 fr rear side plug in multiple cage tensins spring terminal cnnectin screw able 0,14-1,5 mm² acc. IEC Under preparatin CPS munted n engine / in engine rm Technische Änderungen und Irrtümer vrbehalten. / Mit diesem Datenblatt verlieren alle vrherigen Datenblätter ihre Gültigkeit. Technical mdificatins and errrs reserved. / Prir data sheets lse validity.

3 Sensrs Mnitring Systems Dr.E Hrn GmbH & C. KG Im Vgelsang Schönaich Germany Tel: inf@dr-hrn.rg DK Rev /6 Test measurements During the last years, the fllwing applicatin tests have been carried ut: 1. 9 Cylinder Engine Field evaluatin test n a pwer plant using a 4-strke diesel engine Test duratin n a live engine: apprximately 1 year Lng term tests f the measuring principle under live cnditins Mechanical tests n a live engine Gathering infrmatin abut systems (mechanic/electrnic) stability Lng term data recrding t evaluate system stability Imprvement f the crankcases il sealing and cncentricity f rtating parts Cylinder Engine Data n different engines during engine start & stp Data n different il temperatures Preliminary setup f alarm levels (pre and main alarm) Tests with different freign materials t simulate impure lubricatin il Tests with squeezed main bearings t simulate bearing wear / malfunctin by increased bearing temperature Alarm speed cmparisns between Oil Mist Detectr and CPS Imprved mechanics t allw a bigger crankshaft clearance Cylinder Engine 3.1 Field evaluatin test n a cruise ship s main generatr engine Test duratin n a live engine: apprximately 1 year Test with imprved mechanics Imprved electrnical cnnectin t reduce applicatin and system nise Lng term data recrding t evaluate alarm levels & system stability Alarm level ptimizatin. 3.2 Field evaluatin test n a secnd main generatr engine Test duratin: apprximately 6 mnths Test t experience engine tlerance impact n system Alternative electrnical cnnectin t reduce system csts withut interfering with system accuracy Lng term data recrding t evaluate (engine specific) alarm levels & system stability Alarm level ptimizatin. Technische Änderungen und Irrtümer vrbehalten. / Mit diesem Datenblatt verlieren alle vrherigen Datenblätter ihre Gültigkeit. Technical mdificatins and errrs reserved. / Prir data sheets lse validity.

4 Sensrs Mnitring Systems Dr.E Hrn GmbH & C. KG Im Vgelsang Schönaich Germany Tel: inf@dr-hrn.rg DK Rev /6 Results f measurements During the abve field tests the data prcessing and as a result the signal-t-nise rati has been vastly imprved (Figure 1, 2, 3). By that, alarm levels had been defined mre accurate, s that functinal distance between nrmal peratin and alarm limits exists. Therefre, false alarms had nt ccurred and had been highly avided. Figure 1: Alarming signal n engine during crash tests Technische Änderungen und Irrtümer vrbehalten. / Mit diesem Datenblatt verlieren alle vrherigen Datenblätter ihre Gültigkeit. Technical mdificatins and errrs reserved. / Prir data sheets lse validity.

5 Sensrs Mnitring Systems Dr.E Hrn GmbH & C. KG Im Vgelsang Schönaich Germany Tel: inf@dr-hrn.rg DK Rev /6 Figure 2: Cmparing Respnse Time f CPS (red) versus OMD (brwn) Graph is shwing a main bearing damage Figure 3: Signal at nrmal peratin (Cruise vessel DG4) with engine start and stp. Technische Änderungen und Irrtümer vrbehalten. / Mit diesem Datenblatt verlieren alle vrherigen Datenblätter ihre Gültigkeit. Technical mdificatins and errrs reserved. / Prir data sheets lse validity.

6 Sensrs Mnitring Systems Dr.E Hrn GmbH & C. KG Im Vgelsang Schönaich Germany Tel: inf@dr-hrn.rg DK Rev /6 Out view fr further develpments fr CPS Additinally t the actual develpment additinal features can be added by using an added encder detecting the engine speed, psitin infrmatin and speed changes ver ne revlutin. Infrmatin like cylinder balancing and engine perfrmance may be calculated ut f such sensr data. Crankcase pressure sensrs cnnected t the system are available and supply further infrmatin fr example abut blw-by f the engine. Cnclusin On the basis f the abve tests and field evaluatins the fllwing cnclusins can be made: 1. The mechanics is stable n cntinuus and lng-term peratin. All rtatin parts are suitable fr lng time f peratin withut maintenance. 2. The electrnics is fail safe. It des nt interrupt nrmal peratin due t false alarms. 3. Enugh memry fr data recrding f all input signals. Technische Änderungen und Irrtümer vrbehalten. / Mit diesem Datenblatt verlieren alle vrherigen Datenblätter ihre Gültigkeit. Technical mdificatins and errrs reserved. / Prir data sheets lse validity.