کنفرانس مبدل های گرمایی
سال:1391 | دوره:5 |تعداد مقالات:2

THIS PAPER CONTAINS A CONDENSED DESCRIPTION OF RECENT DEVELOPMENTS IN HEAT EXCHANGERS AND IMPROVE EFFICIENCY IN HEAT TRANSFERRING. THE SUPERCHANGER HEAT EXCHANGER IS DESIGNED TO PROVIDE MAXIMUM EFFICIENCY IN TRANSFERRING HEAT FROM ONE LIQUID TO ANOTHER OR FROM STEAM TO LIQUID. [2] THEIR APPLICATIONS ARE IN ENERGY EXCHANGES, PULP & PAPER, METALS, CHEMICALS, FOOD & BEVERAGE, OIL & GAS AND MISCELLANEOUS MANUFACTURING. THE REFRIGERATION PROCESSES CAN FUNCTION AS FLOODED EVAPORATORS, DIRECT EXPANSION EVAPORATORS, LIQUID COOLED CONDENSERS, DESUPERHEATED, SUBCOOLERS AND OIL COOLERS. WE'VE DISCUSSED ABOUT EVERY 6 CASES IN THIS PAPER. EFFICIENCY, COST EFFECTIVENESS, HIGH PERFORMANCE, MINIMAL MAINTENANCE AND SERVICE ARE DEMANDED BY EVERY INDUSTRY AND COMMERCIAL OR GOVERNMENTAL ENTITY IN TODAY'S HIGHLY COMPETITIVE, TECHNOLOGICAL WORLD. PLATE AND FRAME HEAT EXCHANGERS HAVE DEMONSTRATED THEIR SUPERIORITY IN SATISFYING THESE DEMANDING NEEDS OVER OTHER TYPES OF HEAT EXCHANGERS – AND THE BEST OF PLATE AND FRAME ARE TRANTER SUPERCHANGER UNITS. SUPERCHANGER HEAT EXCHANGERS ARE DAILY PERFORMING CRITICAL DUTIES IN A WIDE VARIETY OF APPLICATIONS AROUND THE WORLD. TRANTER'S SUPERMAX AND MAXCHANGER WELDED HEAT EXCHANGERS OFFER DISTINCT ADVANTAGES OF PLATE HEAT TRANSFER EFFICIENCY, DUE IN LARGE MEASURE TO THE TURBULENT FLOW CREATED BY THE CORRUGATED PATTERNS OF THEIR PLATES. [4] THE SUPERMAX WELDED PLATE HEAT EXCHANGER HANDLES LIQUIDS, GASES AND TWO-PHASES MIXTURES AT PERSSURES TO 1,000-PLUS PSIG (68-PLUS BARG) AND AT VERY LOW AND HIGH TEMPRETURES. IF PRIME APPLICATION CONSIDERATIONS INCLUDE A VARIETY OF CONNECTION LOCATIONS, SPACE AND SINGLE-MATERIAL DESIGN, THE MAXCHANGER IS EXTREMELY VERSATILE. [4]

THE OBJECTIVE OF THE PRESENT PAPER IS TO INVESTIGATE DIAMOND/OIL NANOFLUID NATURAL CONVECTION IN PARTIALLY HEATED CYLINDRICAL ENCLOSURE NUMERICALLY. FOR THIS PURPOSE NUMERICAL SIMULATION IF NATURAL CONVECTION IN PARTIALLY HEATED CYLINDRICAL IS CARRIED OUT WITH PURE OIL AND DIAMOND/OIL NANOFLUID. CALCULATION IS PERFORMED BASED ON THE FINITE VOLUME TECHNIQUE FOR THREE DIFFERENT GRASHOF NUMBERS (104 £GR£105) AND THE VOLUME FRACTION OF 0.04 (F=0.04). RESULTS SHOW THAT ADDING NANO DIAMOND TO PURE OIL NOT ONLY CHANGES THE TEMPERATURE FIELD, BUT ALSO ALTERS THE FLOW FIELD SIGNIFICANTLY. IT IS DEMONSTRATED THAT BY ADDING NANO DIAMOND TO THE PURE OIL, THERMAL DIFFUSION ENHANCES TO GREAT EXTEND WHICH LEADS TO THE UNIFORM RADIAL DISTRIBUTION OF TEMPERATURE THROUGHOUT THE NANOFLUID IN COMPARISON TO THE PURE OIL. MOREOVER, THERMAL DIFFUSION AUGMENTATION LEADS TO THE INTENSIFICATION OF NATURAL HEAT TRANSFER AND INCREASING OF NUSSELT NUMBER. IT IS ALSO CONCLUDED THAT NANO DIAMOND INCREASES THE VISCOSITY OF THE NANOFLUID THAT RESULTS IN THE REDUCTION OF THE VERTICAL VELOCITY ESPECIALLY AT LOWER GRASHOF NUMBERS.