نوع مقاله : مقاله مکانیک
نویسندگان
1 ، دانشکده مهندسی مکانیک، دانشگاه تربیت دبیر شهیدرجایی
2 دانشکده مهندسی مکانیک- دانشگاه تربیت دبیر شهید رجایی تهران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The addition of nanoparticles to the base fluid has adverse consequences, including a greater pressure drop than the base fluid, which leads to an increase in pump work, which is not economical. To improve the efficiency, we must look for a suitable range of particle volume fraction so that by adding this amount to the base fluid, the increase in heat transfer is greater than the increase in pressure drop. In this study, by introducing the criterion ratio of PEC performance evaluation, this suitable range of volume fraction for several types of individual particles and mixed particles in a part of an evaporator tube has been determined by numerical calculations and Eulerian-Lagrangian approach. The results showed that the use of mixed nanoparticles in the volume percentage range of less than 1% has better feedback than the nanofluid with single type particles. For water-ethylene glycol/Co nanofluid, this optimal volume percentage range is between 0.01 and 0.2 percent, and for water-ethylene glycol/CuO it is 0.01 to 0.14, and for the combined nanoparticle water-ethylene glycol/ Al2O3+TiO2 is equal to 0.01 to 0.04, for water-ethylene glycol/Al2O3 up to 0.03 percent by volume. Water-ethylene glycol/SiO2 nanofluid always has a PEC ratio of nanofluid and fluid less than 1, and from this point of view, its use in heat exchanger is not economical.
کلیدواژهها [English]
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