Sreyas International Journal of Scientists and Technocrats, Vol. 1(2) 2017, pp.15-19 RESEARCH ARTICLE UPS & Cell Tower Static Cooling System * Sainath Kasubha1, Suresh Akella1, Avinash2, Alurujyothsna2, Uday raj2, Prakash Nayak2 1Department of mechanical Engineering, Sreyas Institute of Engineering and Technology, Hyderabad, India. 2 U.G.Students, Department of mechanical Engineering, Sreyas Institute of Engineering and Technology, Hyderabad, India. Received- 11 November 2016, Revised- 31 December 2016, Accepted- 17 January 2017, Published- 27 January 2017 ABSTRACT The AC is installed with roll bond evaporator, newly designed, tube and fin condenser and rotary compressor. All these three are attached using copper tubes and the refrigerant is supplied which is rotated through this setup. The refrigerant which comes out of the compressor goes into the condenser which is initially at high temperature and then while coming out of the condenser the temperature of the refrigerant is reduced and now it enters the roll bond evaporator through capillary tube in which the low temperature refrigerant is evaporated and then the refrigerant again goes to compressor. The refrigerant used in this project is R-22, tube and fin condenser and 1 ton rotary compressor. Roll bond evaporator, copper tubes, expansion valve are used for assembling of mobile air conditioner and design of AC In the present work, we have attached 6 roll bond evaporators to cool the ups room and connected to throttle valve, compressor condenser with the help of copper tubes. When the AC is switched on the compressor get started and refrigerant enters into compressor condenser. It then enters into the roll bond evaporator and it helps to reduce the room temperature. There are many cell tower rooms in many companies and colleges ups rooms. For best efficiency, life and reliability the temperature needs to be uniformly constant at 23°Celsius. This project also provides a 3D uniform temperature as required by the set point. Keywords: Roll bond evaporator, Fin condenser, R-22 refrigerant, Mobile air conditioner, 3D uniform temperature. 1. INTRODUCTION OF medium receives heat from the condenser. REFRIGERATION PROCESS Basically the heat flow through a substance by The process of transferring heat particle contact is termed as conduction. between two locations can be termed as In our project we use six roll bond refrigeration. This heat transfer mechanism is evaporators which are fixed to the frame as carried out conventionally by means of shown in figure 1. mechanical work. Other sources of driving includes magnetism, heat, laser, electricity etc., [1] The above mentioned process corresponds to the primary principle of refrigeration. The main components in a refrigeration process include evaporator, refrigerant and condenser. The function of an evaporator is to transfer heat into the refrigerant. The role of the refrigerant is to transfer heat to the condenser. The cooling Figure 1.Six roll bond evaporators *Corresponding author. Tel.: Email address: [email protected] (S.Kasubha) https://dx.doi.org/10.24951/sreyasijst.org/2017021003 Double blind peer review under responsibility of Sreyas Publications ISSN© 2017 Sreyas Publications by Sreyas Institute of Engineering and Technology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 15 S.Kasubha et al./Sreyas International Journal of Scientists and Technocrats, Vol. 1(2), 2017 pp. 15-19 This frame is placed at the back side of compressor in a thermodynamic state also the rack. The racks are present inside the UPS referred as saturated vapor. Here it is room. Batteries are placed on the racks. Each compressed to higher pressure which inturn rack has got around four batteries in it. So result in higher temperature. Now, the vapor there are a number of batteries inside the room which is hot compressed is in a which leads to the production of more amount thermodynamic state. This state is known as of heat. Only one air Conditioner is fixed superheated vapor and is now predominantly at inside the room. During summer season due to a pressure and temperature at which its high temperature, more amount of heat is condensation with respect to cooling air and produced inside the room and the life of the cooling water across the tubes can be batteries may get reduced. So to overcome this facilitated. At this state, the circulating effect, we are using roll bond evaporator along refrigerant removes the system heat and carries with the air conditioner. Hence the load on the away the heat by means of air or water air conditioner will reduce and life of the depending upon the case. batteries increases. Now the liquid refrigerant which is condensed is in the thermodynamic state. This 2. VAPOUR COMPRESSION state is comprised of the saturated liquid which REFRIGERATION CYCLE is next guided to the throttle valve. Here Vapour-compression refrigeration sudden decrease in pressure is done which steam (VCRS) is the one which exhibits results in a part of the liquid refrigerant being refrigerant phase changes. Air-conditioning of adiabatically flash evaporated. The auto- automobiles, buildings etc., uses refrigeration refrigeration effect of the adiabatic flash cycles for their accurate design. Other evaporation lowers the liquid and vapor applications include commercial and domestic refrigerant mixture temperature. Next the refrigerators, cold storages for storing mixture which is in a cold sate is routed vegetables, grains, meat etc., large ware through the evaporator coil. Parallel, the houses, transportable storages, rail, air and circulating air gets cooled thereby lowering the water transport, and a large number of enclosed space temperature to the desired industrial and commercial services. Chemical temperature. Next it is the evaporator, where plants, oil processing industries, natural gas the liquid refrigerant absorbs the haeat and plants etc., are some examples which removes them which is consequently rejected extensively make use of these vapour- in the condenser and carried to other places by compression refrigeration systems the air or water present in the condenser. [2, 3] Refrigeration as defined earlier may simply be viewed as lowering of 2.1. Stages of the vapor-compression temperature in a space which is enclosed by a refrigeration cycle medium by eliminating the heat from that Basically four steps comprise the space by passing to other regions of interest. refrigeration cycle. The conceptual figure The instruments which perform these functions shown in figure 2 shows the PV changes are commonly called as refrigerators, air during each part [4, 5]. conditioners, geothermal heat pump, air source pumps or chillers. Liquid refrigerant is used as the tool or a medium which circulates through the system, facilitating vapour compression. This liquid absorbs the heat from the enclosed space which is the region of interest for cooling and consequently disperses the heat elsewhere. Figure shows a conventional single stage vapor compression system. The main components include a condenser, a compressor, a throttle valve (thermal expansion valve or metering device), in addition to an evaporator. The Figure 2.PV diagram of vapor compression liquid refrigerant medium makes its way in to refrigeration cycle the compressor initially. It enters in to the 16 S.Kasubha et al./Sreyas International Journal of Scientists and Technocrats, Vol. 1(2), 2017 pp. 15-19 2.1.1. Compression 3.1. Refrigerant development Here the refrigerant enters the The refrigerators and air compressor part in gaseous state under low conditioners employed flammable or toxic pressure and temperature. Next the, adiabatic gases, such as methyl chloride, ammonia compression of refrigerant takes place, leaving propane etc., which could lead to fatal the compressor under high temperature and accidents on their leakage. Thomas Midgley pressure. Jr created the first non-flammable and non- toxic chlorofluorocarbon gas, Freon, in 1928. 2.1.2. Condensation The name is a trademark name owned This resulting high pressure and by DuPont for any chlorofluorocarbon temperature releases heat and condenses inside (CFC), hydrochlorofluorocarbon (HCFC) the condenser. The hot reservoir and condenser and hydro fluorocarbon (HFC) refrigerant. The of the refrigeration system is in contact with refrigerant names include the number each other. Due to the external work added to indicating the molecular composition (e.g., R- the gas the hot reservoir releases the gas. Now 11, R-12, R-22, R-134A). HCFC is the blend the refrigerant can be viewed as a liquid with which is most commonly used in building high pressure. comfort cooling and direct-expansion home and is an HCFC referred 2.1.3. Throttling as chlorodifluoromethane (R-22). Now the high pressure liquid refrigerant enters the expansion valve thereby 3.2. Refrigerants causing its expansion. The resulting refrigerant This colourless gas is better known now has lower temperature and pressure while as HCFC-22 or R-22.It is commonly used as remaining at liquid phase. Thin slit or a plug a propellant and refrigerant. These applications with holes cvan be used as the thermal valve. are being phased out in some developed Once the refrigerant is forced through the countries due to the compound’s high Global throttle, the pressure gets reduced causing Warming Potential (GWP) and Ozone liquid expansion. Depletion Potential (ODP), although R-22 refrigerant global use continues to increase 2.1.4. Evaporation because of high demand in developing The refrigerant which is now in a low countries. R-22 is a versatile intermediate in temperature and pressure state enters the industrialorganofluorine chemistry, e.g. as a evaporator. The cold reservoir is connected to precursor to tetrafluoroethylene. R-22 the evaporator. As low pressure is maintained, cylinders are coloured light green. at the same temperatures the refrigerant is able to boil. So, the liquid rejects the heat from the 4. PRODUCTION AND CURRENT reservoir and evaporates. This leaves the APPLICATIONS evaporator at a low temperature and pressure Worldwide production of R-22 in 2008 which is now taken back to the compressor was about 800 Gg per year, up from about 450 thereby continuing the cycle. Ggper year in 1998, with most production in developing countries. [6, 7] R-22 use is 3. AIR CONDITIONING increasing in developing countries, largely for The process of changing the air air conditioning applications. Air conditioning properties to more comfortable conditions is sales are growing 20% annually in India and called air conditioning. The primary aim is to China. R-22 is prepared from chloroform: distribute the conditioned air to any occupied sopace such as vehicle or building so that the indoor air quality and thermal comfort are improved. Commonly referred, an air An important application of R-22 is as conditioner is a device which removes heat a precursor to tetrafluoroethylene. This from inside the vehicle or building, thereby conversion involves pyrolysis to give lowering the air temperature. The cooling difluorocarbene, which dimerizes: [8] effect is typically achieved through refrigeration cycle, but sometimes free cooling or evaporation is used. 17 S.Kasubha et al./Sreyas International Journal of Scientists and Technocrats, Vol. 1(2), 2017 pp. 15-19 The compound also yields at 30 °C (86 °F) difluorocarbene upon treatment with strong Heat capacity ratio (γ) 1.178253 base and is used in the laboratory as a source at 30 °C (86 °F) of this reactive intermediate. [9, 10] The Compressibility 0.9831 factor (Z) pyrolysis of R-22 in the presence of at 15 °C chlorofluoromethane gives hexafluorobenzene. Acentric factor (ω) 0.22082  True ranges of 20 to 50˚F. It works with Molecular dipole 1.458 D MO, AB, and POE oils. moment  R-427A is for use in air conditioning and Viscosity (η) at 0 °C 12.56 µPa.s (0.1256 cP) refrigeration applications.It does not require Ozone depletion 0.055 (CCl F = 1) 3 all the mineral oil to be removed. It works potential (ODP) with MO, AB, and POE oils [11, 12]. Global warming 1810 (CO = 1) 2  R-434A is for use in water cooled and potential (GWP) process chillers for air conditioning and medium- and low-temperature applications. 4.2. Calculation  It works with MO, AB, and POE oils. Temperature and its specification are  R-438A is for use in low-, medium-, and given in table 2. high-temperature applications. It is compatible with all lubricants. Table 2.Temperature range Temperature Range 4.1. Physical properties Average initial 33 temperatures T The physical properties are tabulated Average of Return 27 in table 1. temperatures T1 Average temperature of 28 Table 1.Physical properties discharge T2 Property Value Average temperature of 26 Density (ρ) at -69 °C 1.49 g.cm−3 liquid line T3 (liquid) Average temperature of 30 Density (ρ) at -41 °C 1.413 g.cm−3 shell top T4 (liquid) Density (ρ) at -41 °C 4.706 kg.m−3 When h = enthalpy T = temperature, (gas) Density (ρ) at 15 °C 3.66 kg.m−3 their specifications are given in table 3. (gas) Specific gravity at 3.08 (air = 1) Table 3.Enthalpy vs. temperature 21 °C (gas) h1 at T1 236.6KJ/KG Specific volume (ν) 0.275 m3.kg−1 h 2at T2 231.5KJ/KG at 21 °C (gas) h3 at T3 234.1KJ/KG Density (ρ) 3.66 kg.m−3 h4 at T4 232.8KJ/KG at 15 °C (gas) Triple The relations for heat rejection, heat point temperature (T) addition and coefficient of performance are t Critical 96.2 °C (369.3 K) stated below, temperature (Tc) Heat rejected (QR) Critical pressure (p) 4.936 MPa (49.36 bar) c QR = (h2-h3) + (h3-h4) KJ/KG Vapor pressure 0.9384 MPa (9.384 bar) QR = (234.1-231.5) + (231.5-232.6) at 21.1 °C (pc) [10] QR = 1.5KG/KJ Critical density (ρ) 6.1 mol.l−1 c Heat addition (QS) Latent heat of 233.95 kJ.kg−1 QS = h1-h4 KJ/KGK vaporization QS = 236.6-232.8 (lv) at boiling point (-40.7 °C) QS = 3.8 KJ /KGK Heat capacity at 0.057 kJ.mol−1.K−1 Coefficient of performance (COP) constant pressure (Cp) COP = QS/ (QS - QR) at 30 °C (86 °F) COP = 3.8 / (3.8-1.5) Heat capacity at 0.048 kJ.mol−1.K−1 COP = 1.65 constant volume (Cv) 18 S.Kasubha et al./Sreyas International Journal of Scientists and Technocrats, Vol. 1(2), 2017 pp. 15-19 5. CONCLUSION Analysis of Roll Bond Evaporator and After conducting the experimentation Geyser, Universe of Emerging and testing, we understood the future scope of Technologies and Science, Vol. 1, No. our work. We can with stand-up room with 23 6, 2015, pp. 1-9. degrees.Hence, we can say that ups cell tower [7] N.Austin, Different Refrigerants and static cooling system and very economical their Impact on Vapour-Compression when compared to traditional split or window Refrigeration Systems, Journal of air conditioner. Advances in Mechanical Engineering and Science, Vol. 2, No. 3, 2016, pp. REFERENCES 29-39, [1] Kasuba Sainath and Suresh Akella, http://dx.doi.org/10.18831/james.in/20 Aluminium Roll Bond- A Single 16031004. Innovative Circuit for Air Conditioner, [8] Kasuba Sainath, P.S.Ravi, Rajan Saini Car Radiator, Refrigerator and Water and Suresh Akella, Estimation of Heater, International Journal & Refrigeration side Heat Transfer Magazine of Engineering, Technology, Coefficient of Zero Ozone Depletion Management and Research, Vol. 1, Refrigerant R134a used in Mobile AC No. 9, 2014. in comparison with R22 Refrigerant, [2] Kasuba Sainath, T.Kishen Kumar International Journal of Latest Trends Reddy and Suresh Akella, Overview of in Engineering and Technology, Vol. HVAC Systems in General Aspects, 6, No. 4, 2016. International Journal for Research in [9] Kasuba Sainath, Akshay Hemanth, Applied Science and Engineering, Vol. T.Kishen Kumar Reddy and Suresh 2, No. 12, 2014, pp. 558-569. Akella, Controlling and Calibration of [3] N.Austin, Experimental Performance Psychrometric Room, International Comparison of R134a and R600a Journal of Latest Trends in Refrigerants in Vapour Compression Engineering and Technology, Vol. 7, Refrigeration System at Steady State No. 1, 2016, Condition, Journal of Advances in http://dx.doi.org/10.21172/1.71.093. Mechanical Engineering and Science, [10] Kasuba Sainath, Suresh Akella and Vol. 2, No. 3, 2016, pp. 14-20, T.Kishen Kumar Reddy, Experimental http://dx.doi.org/10.18831/james.in/20 and Computational Analysis of 16031002. Radiator and Roll Bond Evaporator, [4] Kasuba Sainath, T.Kishen Kumar 4th International Conference on Reddy and Suresh Akella, Materials Processing and Experimental and Theoretical Analysis Characterization, India, 2014. of Roll Bond Evaporator as Air [11] M.A.Aravindh, C.Veerakumar, Conditioner, International Journal of Sustainable Technologies for Cutting Advanced Research in Computer down Energy Requirements for Science and Software Engineering, Lighting and Air Conditioning in Vol. 5, No. 6, 2015, pp. 798-803. Buildings, Advances in Mechanical [5] S.Muthuraman, S.Kathirvel and Hafiz Engineering and Science, Vol. 2, No. Zafar Sherif, Investigation of 2, 2016, pp. 31-41, Evaporative-Vapour Compression http://dx.doi.org/10.18831/james.in/20 Refrigeration (VCR) based Air 16021003. Conditioning (AC) Framework for [12] Kasuba Sainath, V.Prashanth Reddy, Warm and Dry Climatic Conditions, G.Nikhil and Yasho Vardhan, Flow Journal of Advances in Mechanical and Thermal Analysis of Mobile Air Engineering and Science, Vol. 2, No. Conditioning by using Roll Bond 5, 2016, pp. 1-17, Evaporator, National Conference on http://dx.doi.org/10.18831/james.in/20 Recent Trends & Innovations in 16051001. Mechanical Engineering, 2016. [6] Kasuba Sainath, Nagendra Babu, Suresh Akella and T.K.K.Reddy, Experimental and Computational 19