Performance Evaluation of A Low Heat Rejection Diesel Engine for Different Insulation Levels

Abstract

This experimental study focuses on investigating of effects of low heat rejection engine application to a diesel engine at different insulation levels. For this purpose cylinder head and valves of the test engine were thermally insulated with yttria-stabilized zirconia (Y2O3–ZrO2) layer at first stage. Then in addition to cylinder head and valves, pistons of the test engine were coated with the same material. Brake specific fuel consumption (BSFC), exhaust gas temperature (EGT), brake thermal efficiency and volumetric efficiency of the test engine were investigated for two different insulation levels. After the engine tests it was determined that BSFC was improved by 4 - 7.1 %, EGT was increased by 3.5 - 6.8 %, brake thermal efficiency was improved by 4.1-7.9 % and volumetric efficiency was increased by 0.9 - 2.6 % with LHR application. It was also determined that these improvements in engine performance are proportional with the insulation levels of the test engine.

Keywords

• Low heat rejection engine, Thermal barrier coating, Diesel engine, Engine performance.

Farklı İzolasyon Seviyeleri İçin Düşük Isı Kayıplı Bir Dizel Motorunun Performans Değerlendirmesi

Abstract

Bu deneysel çalışma bir dizel motoruna farklı izolasyon seviyelerindeki düşük ısı kayıplı motor uygulamasının etkilerinin incelenmesine yöneliktir. Bu amaçla ilk aşamada deney motorunun silindir kapağı ve supapları termal bariyer oluşturmak için yitriya ile stabilize zirkonya (Y2O3–ZrO2) ile kaplanmıştır. Daha sonra silindir kapağı ve supaplara ilaveten deney motorunun pistonları da aynı malzeme ile kaplanmıştır. Deney motorunun özgül yakıt tüketimi, egzoz gaz sıcaklığı, fren ısıl verimi ve hacimsel verimi iki farklı izolasyon durumu için incelenmiştir. Düşük ısı kayıplı motor uygulaması ile motor testlerinin sonucunda özgül yakıt tüketiminde % 4-7,1 iyileşme, egzoz gazı sıcaklıklarında % 3,5–6,8 artış, fren ısıl verimde % 4,1–7,9 iyileşme ve hacimsel verimde % 0,9–2,6 artış tespit edilmiştir. Ayrıca motor performansındaki bu iyileşmelerin deney motorunun izolasyon seviyesi ile orantılı olduğu belirlenmiştir.

Keywords

• Düşük ısı kayıplı motor, Termal bariyer kaplama, Dizel motoru, Motor performansı.

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