Heat Transfer and Pressure Drop Characteristics of Compact Heat Exchangers for Turbo Charged Diesel Engines

Abstract

The medium and large sized turbo-charged automotive diesel engines or stationary turbo-charged diesel engines adopted from automotive designs are associated with three compact heat exchangers, namely, radiators, oil coolers newlineand after-coolers. These exchangers are used for cooling the engine body newlinecooling water, lubricating oil and turbo-charged air respectively. Engine manufacturers offer the base engines which are used in a variety of applications thereby necessitating the changes in layout and configuration of these heat exchangers. The heat exchangers are generally supplied by vendors and engine manufacturers are keen to know whether an optimum configuration has been supplied thereby ensuring lower newlinecosts. Further, the materials used in building the heat exchangers would also be applied in a variety of combinations to determine the low cost options for meeting a newlineparticular duty. newlineThe main aim of the present investigation is to formulate an analytical tool and to use it to achieve the objectives mentioned above. The complete design of a heat exchanger involves thermal aspects, the mechanical design and the design for manufacture. The present work has considered only thermal aspects. The heat exchanger thermal design problems are further categorized as rating and sizing problems. The rating or performance problem involves analysis for predicting the performance of a known configuration while the sizing problem involves the design of a new configuration for specified performance within known constraints and minimum objective functions. The objectives set forth in the present investigation have been achieved by considering rating problem. Essentially, the heat transfer and pressure drop newlinecharacteristics of radiator, oil-cooler and after-cooler of turbo-charged diesel engines have been evaluated based on the methods available in literature.