EXPERIMENTAL INVESTIGATION OF COMPARISION OF AIR COOLED AND WATER COOLED CONDENSER ATTACHED WITH COOLING TOWER Gourav Roy; Taliv Hussain; Rahul Wandra Department of Mechanical Engineering, Lovely Professional University Phagwara, Punjab (India) -144402 Email:gouravroy2@gmail.com Abstract-This paper presents an experimental investigation of comparison of air cooled and water cooled with cooling tower. Water cooled is attached to cooling tower in vapour compression refrigeration system. The VCRS system is made with the component of refrigerator to check the performance of air cooled and water cooled with cooling tower. Data is noted after steady state condition is achieved in the system and the properties of refrigerant (R143a) and air remained constant after (20min). Experimental test are performed at two ambient air temperatures 27 and 30.At 27 ambient temperature the COP of air cooled is 4.59 which is increases up to 4.817 when VCRS attached with cooling tower. Similarly at 30 ambient temperature the COP varies from 4.49 to 4.58 when we move from air cooled to water cooled attached with cooling tower. There is an increase in the COP of VCRS attached with cooling tower as compare to air cooled. Keywords-Air cooled, Water cooled, vapour compression refrigeration system, evaporative cooling pad. Nomenclature-COP Coefficient of performance h1 Enthalpy of refrigerant at inlet of compressor in kj/kg h2 Enthalpy of refrigerant at exit of compressor in kj/kg h3 Enthalpy of refrigerant at exit of the kj/kg h4 Enthalpy of refrigerant at entry of evaporator in kj/kg mref Mass flow rate of refrigerant Qr Cooling effect Wc Compressor work T1 T2 T3 T4 I V Suction temperature of refrigerant into the compressor Discharge temperature of refrigerant into the compressor Condenser outlet temperature of refrigerant temperature of refrigerant from capillary tube Inlet current Inlet voltage I.INTRODUCTION The key to nation building lies in the optimum and proper use of energy and capital. Research on refrigeration and air conditioning has facilitated the correction of human vision; it has given us vast technology such as VCRS, VARS, psychometry etc.india Scientific Policy Resolution (SPR) of 1958 emphasis use of the scientific approach toward development of nation building which remains valid even today. In refrigeration and air conditioning domain, several scientists have contributed greatly to our understanding of VCRS. During 1834 the first mechanical device cooling system have been develop later it become vapour compressor. The major objective of our experiment involved compare between the air cooled and water cooled attached with cooling tower. Water cooled has some special advantage in order to increase the performance as compared to air. We can increase the COP of system by attached with it cooling tower. By taking two different ambient temperature 27 and 30,calculate following parameter such discharge pressure, suction pressure, Condenser, Condenser Inlet etc. As we increase the ambient temperature COP get decrease for air as well as water with cooling tower.for air cooled at 27 and 30, COP is 4.59 and 4.49.Similarly for water cooled at 27 and 30, COP is 4.817 and 4.58 respectively. II.LITERATURE SURVEY S.S. Hu, B.J. Huang et al. [1] conducted an experimental investigation on a split air conditioner having water cooled. They developed a simple watercooled air conditioner utilizing a cooling tower with cellulose pad filling material to cool the water for condensing operation. The experimental investigation verified that the water-cooled and cooling tower
results in decreasing the power consumption of the compressor. Sreejith K et al. [2] Heat can be recovered by using the water-cooled and the system can work as a waste heat recovery unit. The recovered heat from the can be used for bathing, cleaning, laundry, dish washing etc. The modified system can be used both as a refrigerator and also as a water heater. Therefore by retrofitting a water cooled it produce hot water and even reduce the utility bill of a small family. In this system the water-cooled is designed as a tube in tube heat exchanger of overall length of 1m. It consists of an inlet for the cooling water and an exit for collecting the hot water. The hot water can be used instantly or it can be stored in a thermal storage tank for later use. Adarsh Mohan Dixit, Aditya Desai, Akshay Vyas et al.[3] They made setup of 1.5 ton air conditioner was constructed and tested in the present study. The experimental results show the coefficient of performance (COP) reaches 8.03 that are higher than the standard value (5.98) of those conventional residential split air conditioners. Kulkarni and Rajput [4] theoretically analyzed the performance of indirect-direct two stages cooler with cellulose and aspen media in direct stage. They selected the most frequently occurring inlet condition of 39.9 0 C DBT and 32.8 % RH for the analysis. The saturation efficiency ranged from 121.5 to 106.7 % for two stages cooler. Fig.1 Air Cooled Condenser After calculated different parameter by using air, now is dipped in water tank which is attached to cooling tower as shown in (Fig.2). III EXPERIMENTAL SETUP In the present work we have concentrated toward the comparison of air cooled and water cooled which is attached to cooling tower. Here cellulose pad are used in cooling tower cool the warm water discharged from the and feed the cooled water back to the. The COP varies from 27 to 30 as the ambient temperature increase. Initially our setup is air cooled.through with the help of external fan air is circulated to air in VCRS system. Air passes horizontally through and takes latent heat from the refrigerant which further helps to condense the refrigerant. Our experiment setup consists of single stage vapour compression system which contains different components parts such as expansion device, compressor, evaporator and evaporative cooled. The compressor of volume (cc) 4.5 are used to increase the pressure and temperature of refrigerant (R134a).Here the capillary tube is used, made up of a copper tube of very small diameter. Capillary tube used as expansion device. The evaporator is used to reduce the pressure, dissipating heat and making liquid refrigerant to much cooler. Evaporator used in this experiment setup is tube and fin type. Fig.2 Water Cooled with cooling tower Different measuring devices are used in this experiment setup such as Digital Thermometer TPM-10, which gives the temperature at various points within the system. Pressure gauge is also used; first pressure gauge measures the suction pressure before the compressor and second pressure gauge measure the discharge pressure after the compressor. Similarly ammeter and voltmeter are used to measure the current and voltage to input to the system. A cellulose pad of 2 inch thickness is installed in the cooling tower. The main function of cellulose pad is to provide the
evaporative action by transferring the latent heat of water coming from water dip. Fig.3 Cellulose pad within cooling tower IV. EXPERIMENT RESULT AND DISCUSSION Compressor Inlet 9.1 11.1 19.1 21.1 PARAMETERS UNIT Air Cooled Water cooled with cooling tower Compressor Evaporator Inlet 44.4 46.4 40.1 42.1 23.4 22.7 22.5 21.8 At 27 At 30 At 27 At 30 Evaporator -13.1-12.4-17.6-16.9 Suction Pressure Psi 12 12 8 8 urrent Ampere A 1.2 1.2 1.2 1.2 Discharge Pressure Psi 215 215 150 150 Voltage Volt V 200 200 200 200 Condenser Inlet 40.1 42.3 37.2 39.4 Dry Bulb 27 27 25 25 Condenser 36.2 38.4 28.9 31.1 Wet Bulb 20 20 15 15 Table 1: Result of the experiment of air cooled and water cooled with cooling tower
The above table at an ambient temperature 27 and 30 respectively. Our experiment was carried out in two consequent steps. In initial step we have taken air cooled and calculated COP. Further that we dipped the in water and is attached with cooling tower. While performing the experiment refrigerant and air remained constant in order to achieve steady state also current and voltage is constant for both the ambient temperature 27 and 30 in air cooled and water cooled with cooling tower. Fig 5: Pressure-Enthalpy diagram for air cooled and water cooled with cooling tower at an ambient temperature 30 V. CALCULATION AND RESULT Fig 4: Pressure-Enthalpy diagram for air cooled and water cooled with cooling tower at an ambient temperature 27 While performing the experiment, the result obtained. Based on this result thermodynamic properties of refrigerant R134a are obtained at the different point of the system. In order to calculate the enthalpy, using the P-h chart of the refrigerant R134a and we are getting different parameter at air cooled and water cooled attached with cooling tower. a. Compressor Work Wc = V * I = m ref* (h2 h1) Parameter Air Cooled Water Cooled 27 30 27 30 b. Mass flow rate of refrigerant m ref c. Cooling effect produced Qr=m ref* (h1 h4) d. COP = COP 4.59 4.49 4.817 4.58 Where, h1 = enthalpy of refrigerant at inlet of compressor in kj/kg (1) h2 = enthalpy of refrigerant at exit of compressor in kj/kg (2) h3 = enthalpy of refrigerant at exit of the kj/kg (3) h4 = enthalpy of refrigerant at entry of evaporator in kj/kg (4) Table 2: Result of the experiment at ambient air temperature 27 and 30
[4] Kulkarni R.K., Rajput S.P.S.,(2011) : Theoretical Performance Analysis of Indirect-Direct Evaporative Cooler in Hot and Dry Climates, International Journal of Engineering Science and Technology, 3, pp.1239-1251. Graph 1: cop variation with ambient temperature From the above graph it is clear shown that as the ambient temperature increase COP of system in both cases 27 and 30 decrease.as the COP decrease cooling capacity of system is also decrease. But COP in water cooled with cooling tower have higher COP than simple air in both ambient temperature 27 and 30. VI CONCLUSION This air cooled design is very simple and easy to use. We used same and dipped in water it became water cooled, further it is attached to normal cooling tower. The hot water from after taking latent heat from refrigerant with the help of pump it circulate to cooling tower where it became to cooled down and again circulate to. From(graph 1) which shown that the COP of system decrease as the ambient temperature goes on increase. The test result shown that at an ambient temperature 27 when we move from air cooled to water cooled with cooing tower there is 4.94% COP gain. Similarly at an ambient temperature 30 there is 2% rise in COP as we move from air to water with cooling tower. REFERENCES [1] S.S. Hu, B.J. Huang, Study of a high efficiency residential split watercooled air conditioner, Applied Thermal Engineering 25 (2005) 1599 1613 [2] Experimental Investigation of A Domestic Refrigerator Having water cooled using various compressor oils, Sreejith K, Assistant Professor, Dept.Of Mechanical. [3] Improving efficiency of air conditioner by cellulose pad/international journal of engineering science & humanities ISSN 2250-3552