EFFECT OF INLET TEMPERATURE ON REYNOLDS NUMBER AND NUSSELT NUMBER WITH MIXED REFRIGERANTS FOR INDUSTRIAL APPLICATIONS

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 7, July 2017, pp , Article ID: IJMET_08_07_172 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed EFFECT OF INLET TEMPERATURE ON REYNOLDS NUMBER AND NUSSELT NUMBER WITH MIXED REFRIGERANTS FOR INDUSTRIAL APPLICATIONS Veeranki Srikanth Research Scholar, Lovely Professional University, Punjab, India. Seepana PraveenKumar Research Scholar, Lovely Professional University, Punjab, India. Raja Sekhar Dondapati Associate Professor, Lovely Professional University, Punjab, India. Gaurav Vyas Assistant Professor, Lovely Professional University, Punjab, India. Preeti Rao Usurumarti Assistant Professor, P.V.K. Institute of Technology, Andhra Pradesh, India. ABSTRACT In present scenario, the concept of mixed refrigerant plays major role due to its thermophysical properties to increase the Coefficient of performance (COP). It is widely used in the application for domestic refrigerators, water cooler, Automobile A/Cs, Cold storages, Ice plants etc.; in the present context, a mixed refrigerant such as Propane and Iso-Butane are chosen for the analysis at constant pressure of 3MPa and temperature range of 300k to 330K. A fluent based analysis has done along the evaporator pipe and Reynolds number and Nusslet number with respect to mass flow rate are evaluated. The results show that as the flow rate increases Reynolds number and Nusslet number were also increased. Moreover, it is also evaluated that as the Nusslet number increase with increase in Reynolds operated pressure at 3MPa and temperature varies from 300K to 330K. Key words: Thermophysical properties, Coefficient of Performance, Reynolds Number, Nusselt Number. Cite this Article: Veeranki Srikanth, Seepana PraveenKumar, Raja Sekhar Dondapati, Gaurav Vyas and Preeti Rao Usurumarti Effect of Inlet Temperature on Reynolds Number and Nusselt Number with Mixed Refrigerants for Industrial Applications editor@iaeme.com

2 Veeranki Srikanth, Seepana PraveenKumar, Raja Sekhar Dondapati, Gaurav Vyas and Preeti Rao Usurumarti International Journal of Mechanical Engineering and Technology, 8(7), 2017, pp INTRODUCTION In present scenario studies on mixed refrigerants has become versatile all over the universe, so for these reasons vapour compression refrigeration systems (VCRS) are used for cooling purposes. In general, Figure 1 represents VCRS cycle consists of four major parts such as compressor, condenser, expansion valve and evaporator. The compressor is the process where the low temperature and low pressure gaseous refrigerant is compressed is entropically to obtain high pressure super-heated vapour region this process is also predominately known as Win process. From process 1-2 Figure 1, represents the work given by the compressor (1 3). From the process 2-3 condenser process takes place in condenser the high pressure and high temperature superheated vapour is converted to high pressure and high temperature liquid refrigerant this process takes at constant pressure (P=C) and within the dome there will be occurrence of constant temperature process (T=C). In this process heat rejection will take place Qout in the Figure 1, represents process 2-3 (4-6). Expansion valve is the process takes place at takes place from 3-4 in this neither. heat input nor rejection of heat occur or neither supply of work or nor rejection of work takes it is the process enthalpy is the process where narrow cut junction will occur to supply the liquid from high pressure and temperature liquid to low pressure and temperature liquid and vapour region (7-8) Figure 1, represents process 3-4. Evaporator is the process where the object gets cooled this process generally takes place from 3-4 is the process represents In Figure 1, where low pressure and low temperature liquid and vapour refrigerant is converted to Vapour refrigerant. This process is also widely known as heat supply process (Qin) (9). Figure 1 Representation of VCRS System editor@iaeme.com

3 Effect of Inlet Temperature on Reynolds Number and Nusselt Number with Mixed Refrigerants for Industrial Applications Figure 2 Show P-h plot of VCRS System 2. METHODOLOGY PHASE 1: Modelling: In the present context, fluent model created in ANSYS workbench 15.0 with diameter m and extrude for length 1m. A fluent parameters of mixed refrigerant such as propane and Iso-butane are evaluated computationally at different inlet temperatures and at different mass flow rates varies from 0.05 to 0.1 (kg/s). PHASE 2:computational analysis: ρν D Reynolds Number can be estimated as (Re) = υ. [1] ρ = Density of refrigerant mixture (kg/m 3 ), ν = Velocity of liquid mixed refrigerant (m/s) D= Diameter of the pipe (m), υ = Viscosity of base fluid (kg/m-s) Nusselt Number can be estimated as Nu= hd k h = heat transfer coefficient (w/m 2.K), d= diameter of pipe (m), k bf = thermal conductivity of fluid (w/m.k) bf [2] 3. EXPERIMENTAL RESULTS In the present research work, effect of Reynolds number and Nusselt number are evaluated at different inlet temperatures varies from K for a mixed refrigerant at different compositions for a refrigerant mixture such as Propane and ISO-butane Effect of Reynolds number at different in let temperatures for mixed refrigerant: editor@iaeme.com

4 Veeranki Srikanth, Seepana PraveenKumar, Raja Sekhar Dondapati, Gaurav Vyas and Preeti Rao Usurumarti Figure 3 Effect of Reynolds Number withrespect to Massflowrate Figure 3 Shows reveals that Reynolds number(re) with respect to mass flow rate at different inlet temperatures ( K).Moreover, it is observed that as the mass flow rate increased at different temperatures Reynolds number is also increased at different compositions of refrigerant mixtures. Effect of Nusselt number with respect to mass flow rate at different inlet temperatures: Figure 4:reveals that Nusselt number with respect to mass flow rate at different inlet temperatures for a mixed refrigerant propane and ISO-butane at different compositions. It was also observed that, as the mass flow rate increases Nusselt number is also increases editor@iaeme.com

5 Effect of Inlet Temperature on Reynolds Number and Nusselt Number with Mixed Refrigerants for Industrial Applications Figure 4 Nusselt Number with respect to mass flow rate Effect of Nusselt number with respect to Reynold number at different inlet temperatures: Figure 5: represents that variation of Nusselt number with respect to Reynolds number of Propane and ISO-butane at different composition at different inlet temperatures ( K). Moreover, it is also observed that as the Nusselt number increased with respect to Reynolds at different inlet temperatures. Figure 5 Nusselt Number with respect to Reynolds number editor@iaeme.com

6 Veeranki Srikanth, Seepana PraveenKumar, Raja Sekhar Dondapati, Gaurav Vyas and Preeti Rao Usurumarti 4. CONCLUSION From the above results and discussions hence we can conclude that as the mass flow rate increases both Nusselt number and Reynolds number is also increase at different inlet temperatures of evaporator pipe. Moreover, it is also observed that Nusselt number is also increases with increase in Reynolds number at different temperature of evaporator pipe at different compositions of mixed refrigerant. Hence it is evident that for heat transfer gives the better results for mixed refrigerant at different compositions REFERENCES [1] Conditioning, AlternativeRefrigerantsandCyclesforCompressionRefrigerationSystems, [2] M. Duminil, A Brief History of Refrigeration, Int. Inst. Regrigeration, pp. 1 5,2010. [3] R. Cycles,C.P. Equipment, H. Rejection, and C. P.Design, Cooling Production Equipment and [4] C. Guide,Airconditioningandrefrigeration,vol.266,no [5] S.K. Wang, Handbook of Air Conditioning and Refrigeration [6] H. Uchida, Refrigeration and Air-Conditioning, Trans. JapanSoc. Mech. Eng.,vol. 25,pp ,1959. [7] M. Holt, Air-conditioning and refrigeration equipment, EC MElectr. Constr. Maint., vol.112,no.8,2013 [8] A.S.Gow, Amodifiedclausiusequationofstateforcalculationofmulticomponentrefrigerantva por-liquidequilibria, FluidPhase Equilib., vol.90, no.2, pp ,1993. [9] R.N.RichardsonandJ.S.Butterworth, Vapour- CompressionRefrigerationSystemPROPa, no.july1993,1994. [10] Dondapati RS, Ravula J, ThadelaS, UsurumartiPR. Analytical approximations for thermophysical properties of super critical nitrogen(scn) to be used in futuristic high temperature superconducting (HTS)cables. PhysC Supercondits Appl [Internet]. 2015;519:53 9. [11] C.S. Rajamanickam and P. Tamilselvan. Multiphase Simulation of Automotive HVAC Evaporator using R134A and R1234YF Refrigerants. International Journal of Mechanical Engineering and Technology, 8(2), 2017, pp [12] Ajeet Kumar Rai and Salem Alabd Mohamed, Study of Performance Evaluation of Domestic Refrigerator working with Mixture of Propane, butane and isobutene Refrigerant (LPG). International Journal of Mechanical Engineering and Technology, 7(3), 2016, pp editor@iaeme.com