ENHANCEMENT OF HEAT TRANSFER RATE IN A RADIATOR USING CUO NANOFLUID

Transcription

1 International Journal of Advances in Applied Science and Engineering (IJAEAS) ISSN (P): ; ISSN (E): X Vol. 3, Issue 2, May 2016, IIST ENHANCEMENT OF HEAT TRANSFER RATE IN A RADIATOR USING CUO NANOFLUID AMRUTA P. BIRAR 1, SWAPNIL S. DARADE 2, ASHISH W. KHANDALKAR 3 1,2 Student, Dept. of mechanical engineering, KGCE, Karjat, India 3 Asst. Professsor,Dept. of production engineering, KGCE, Karjat, India biraramruta@gmail.com, swapnildarade3@gmail.com ABSTRACT - In the past decade more emphasis is placed on reduction in energy consumption by introducing various heat transfer enhancement techniques. The entry of nanofluid technology has provided a great alternative for the current methods of increasing heat. The nanofluids prove to be a phenomenal resource for enhancement of heat transfer which indirectly leads to the increase in the efficiency of engine. In this paper we discuss about various aspects of CuO nanofluid which includes the enhancement of heat transfer rate from the radiator and effects on thermophysical properties KEYWORD: Nanoparticles,radiator, thermal conductivity. I. INTRODUCTION The current trend in various industries demand micro-electronic devices with higher outputs. Such devices have high heat s and therefore proper thermal management of these devices is necessary to achieve desired performance. The conventional method of enhancing the heat transfer rate includes usage of extended heat transfer surfaces known as fins. But the heat to a certain extent. The objective of this project is to increase heat of a radiator thus increasing its efficiency. It can be achieved by Increasing temperature difference ( T),Increasing the area (A) and Increasing overall heat transfer coefficient (h). To achieve higher heat we are going to make use of CuO Nano fluid as coolant and by changing the concentration of particle in different percentage in the base fluid we can increase the thermal conductivity,overall heat transfer coefficient. This the heat by 35-45% and the radiator size can be decreased thus decreasing the overall weight of the component. It also the engine efficiency and decreases the fuel consumption. Nano fluids are prepared by dispersing and stably suspending nanometre sized solid particles in conventional heat transfer fluids. Nanofluids consist of nanoparticles and base fluids. Nanoparticles are Al 2 O 3, Fe, CuO, etc. Base fluids can be DI-water, ethylene glycol, pump oil, transformer oil. The use of nanofluids as coolants would allow for smaller size and better positioning of the radiators. Owing to the fact that there would be less fluid due to the higher efficiency, coolant pumps could be shrunk and truck engines could be operated at higher temperatures allowing for more horsepower while still meeting stringent emission standards. Nanofluids are prepared by mixing nanometer-sized particles of less than 100 nm in a base fluid such as ethylene glycol, water etc. These novel and advanced concepts of coolants offer intriguing heat transfer characteristics compared to conventional coolants. There are considerable researches on the superior heat transfer 9

2 properties of nanofluids especially on thermal conductivity and convective heat transfer. II. LITERATURE SURVEY A greater temperature difference can lead to increase the heat flow, but it is often limited by process or materials constraints. For example, the maximum temperature in a nuclear reactor must be kept below a certain value to avoid runaway reactions and meltdown. Therefore increased temp difference can only be achieved by decreasing the temperature of the coolant. However, this would reduce the rate of the nuclear reaction and decrease the efficiency of the process. Maximizing the heat transfer area A is a common strategy to improve heat transfer, and many heat exchangers such as radiators and plate-andframe heat exchangers are designed to maximize the heat transfer area. However, this strategy cannot be employed in microprocessors and micro electro mechanical systems (MEMS) because the area cannot be increased. In aerospace and automotive systems, increasing the heat transfer area can only be achieved by increasing the size of the heat exchanger which can lead to unwanted in weight.the conventional base fluid ethylene glycol used with water displayed poor conductivity. Table1: Thermal conductivity of different materials SR NO MATERIAL THERMAL CONDUCTIVITY 1 WATER ETHYLENE GLYCOL 3 ALUMINIUM 40 4 COPPER SILVER NANO TUBES WATER/Al EG/Al2O EG WATER/Al2O3 10 WATER/CuO The first results on the improved thermal conductivity of nanofluids were reported by Eastman et al.[1]. By dispersing CuO nanoparticles in water there was a phenomenal increase of 60% in thermal conductivity for a nanoparticle volume concentration of 5%. In case of Cu/oil-based nanofluids, it was found that there was an increase of 44% in thermal conductivity by dispersing vol% of Cu nanoparticles in HE-200 oil. Also for the same CuO nanoparticle dispersed in water and ethylene glycol, it displayed a moderate enhancement of thermal conductivity[2]. For 4% of volume of CuO nanoparticles, 20% enhancement was observed in thermal conductivity of ethylene glycol. A 17% increase in thermal conductivity for 0.4 % of volume of 50 nm sized CuO nanoparticles was reported by Wang et al[3]. Li and Peterson measured the thermal conductivity for 29 nm CuO nanofluid[4]. They reported that the thermal conductivity increased by 52% at a volume fraction of 6% at 34 degrees. K. Y. Leong et. al (2010) found that about 3.8% of heat transfer enhancement could be achieved by adding 2% copper particles in base fluid (ethylene glycol) at the Reynolds number 6000 for air and 5000 for coolant. Also, reduction in air frontal area was estimated. III. METHODOLOGY EXPERIMENTAL REVIEW ON CAR RADIATOR: Experimental Review on nano fluid used in Car radiator at different concentration,different inlet temperature &different flow rate for CuO nanofluid: Table 2: Working conditions and result WORKING CONDITIONS (0to0.4%) Volume flow rate Inlet temperature (60to80 degree) (0.15 to 0.65 %) RESULT If then Heat If flow rate heat If inlet temperature heat transfer rate decreases If then Heat 10

3 Flow rate Effect of different parameters: 1. Effect of fluid temperature: transfer increase rate If flow rate then Heat increase increasing the volume concentration of nano fluid the heat and heat is enhanced from 31% to 46 % when volume concentration from 1% to 2.5%[8] Fluid temperature has a significant role in enhancing the effective thermal conductivity of CuO nanofluid. Das et al[5] conducted an experiment to investigate the effect of temperature on thermal conductivity of nanofluids containing 38.4 nm sized Al 2 O 3 nanoparticles and 28.6 nm sized CuO nanoparticles in water. The thermal conductivity was determined by using a temperature oscillation technique. It was observed that CuO/water-based nanofluid showed greater enhancement of thermal conductivity than Al 2 O 3 nanoparticles. Das et al concluded that Brownian motion of nanoparticles was responsible for the strong temperature dependence of thermal conductivity. 2. Convective heat transfer studies of nanofluids: Eastman et al[6] showed that convective heat of water under dynamic flow conditions was increased by more than 15% with 1% vol of CuO nanoparticles. Heris et al checked heat transfer coefficient of CuO/water-based nanofluid under laminar flow conditions through an annular copper tube[7]. It was found that thermal conductivity increased with increasing volume fraction of nanoparticles. S. M. Peyghambarzadeh (2012) evaluated heat transfer performance experimentally. Copper oxide and iron oxide nanoparticles were added to the water & effect of these variables on overall heat transfer coefficient was studied. Results displayed that both Nano fluids show greater overall heat transfer coefficient In comparison with water up to 9%. 3. Enhancement of heat transfer by using volume concentration: Adnan M.Hussein (2014) ) studied the effect of Volume concentration. Figure shows that heat of car radiator depends on nano fluid volume concentration. it shows that with the Fig 1: Effect of volume concentration on heat transfer rate 4. Enhancement of heat transfer on the basis of inlet temperature: Adnan M.Hussein (2014) ) investigated the effect of inlet temperature on enhancement rate. it displayed that heat of car radiator is depend on nano fluid inlet temperature of car radiator it is shows that the heat transfer enhancement from 39% to56% from if increase the temperature from 60 to 80 degree Celsius. Fig2: The effect of nanofluid inlet temperature on the heat Fig. above compares the results for nanofluid at the concentration of 0.4 vol.% and at different inlet temperatures in order to study the effect of temperature variation on the overall heat transfer coefficient of the automobile radiator. It is clear from Fig that with the increasing in fluid inlet 11

4 temperature it decreases the overall heat transfer coefficient of nanofluid. 5. effect of nanofluid inlet temperature on overall heat transfer co-efficient: IV. RESULT AND CONCLUSION: 1) The overall heat transfer coefficient decreases with increasing inlet temperature of the nanofluid. 2) The overall heat transfer coefficient enhances with the addition of nanoparticles to the base fluid with a concentrations of 0.15 and 0.4 vol.% of CuO nanoparticles, the overall heat transfer coefficient enhancements compared with the pure water are 6% and 8%. 3)for a certain range of fluid temperature, the thermal conductivity with increasing temperature. NOMENCLATURE h k m heat transfer coefficient, W/m 2 C thermal conductivity, W/mC mass flow rate, Kg/sec Fig 3. Effect of inlet nanofluid temperature on the overall heat transfer coefficient with nanofluid. CALCULATION OF HEAT TRANSFER COEFFICIENT: The nanofluid flowing inside the tube transfers heat to the outside air flowing in the air flow channel. The air-side and the tube-side heat transfer rates can be calculated as: Nu Nusselt number Q heat s, KW Re Reynolds number U overall heat transfer coefficient W/C ρ density, kg/m 3 ACKNOLEDGEMENT where Qa and Qnf are the heat s at the air and nanofluid flows, respectively. This decrease in the overall heat transfer coefficient of the nanofluid with increase in nanofluid inlet temperature is mainly because of two factors: 1- Rapid alignment of nanoparticles in lower viscosity fluids whichleads to less contact between nanoparticles. 2- When the temperature, a very small decrease occurred in the nanofluid density while its viscosity drops greater, leading to a higher Reynolds number in hightemperature nanofluid. We would like to acknowledgement the whole hearted support extended to us by Department of mechanical engineering, KONKAN GYANPEETH COLLEGE OF ENGINEERING, KARJAT. We take this opportunity to express our sincere gratitude to project co-ordinator Prof. N.A.Meshram for his valuable guidance in this project. Special thanks to the facilities provided by the mechanical engineering department. We are also grateful for the active cooperation and valuable suggestion rendered by Prof. K.A.Chaudhari as a Head of Department and all other teaching staff of mechanical department. We are indeed obliged by constant support and encouragement of our principal Dr. M.J.Lengare. 12

5 REFERENCES [1] J.A. Eastman, S.U.S. Choi, S. Li, L.J. Thompson, Enhanced thermal conductivity through the development of nanofluids, Proceedings of the Symposium on Nanophase and Nanocomposite Materials II, vol. 457, Materials Research Society, USA, 1997 [2] S. Lee, S.U.S. Choi, S. Li, J.A. Eastman, Measuring thermal conductivity of fluids containing oxide nanoparticles, Journal of Heat Transfer 121 (1999). [3] B.-X. Wang, L.-P. Zhou, X.-F. Peng, A fractal model for predicting the effective thermal conductivity of liquid with suspension of nanoparticles, International Journal of Heat and Mass Transfer 46 (2003). [4] C.H. Li, G.P. Peterson, Experimental investigation of temperature and volume fraction variations on the effective thermal conductivity of nanoparticle suspensions (nanofluids), Journal of Applied Physics 99 (2006). [5] S.K. Das, N. Putra, P. Thiesen, W. Roetzel, Temperature dependence of thermal conductivity enhancement for nanofluids, Journal of Heat Transfer 125 (2003). [6] J.A. Eastman, S.U.S. Choi, S. Li, G. Soyez, L.J. Thompson, R.J. Dimelfi, Novel thermal properties of nanostructured materials, Materials Science Forum (1999). [7] S.Z. Heris, S.G. Etemad, M.S. Esfahany, Experimental investigation of oxide nanofluids laminar flow convective heat transfer, International Communications in Heat and Mass Transfer 3 (2006). [8] S.M. Peyghambarzadeh, S.H. Hashemabadi, M. Naraki, Y. Vermahmoudi ; Experimental study of overall heat transfer coefficient in the application of dilute nanofluids in the car radiator Applied Thermal Engineering, Volume 52, Issue 1, 5 April [9] M. Naraki, S.M. Peyghambarzadeh, S.H. Hashemabadi, Y. Vermahmoudi, Parametric study of overall heat transfer coefficient of CuO/water nanofluids in a car radiator, International Journal of Thermal Sciences, Volume 66, April