STUDY OF PERFORMANCE AND POSSIBLE CONFIGURATION OF HYBRID AIR CONDITIONING SYSTEM WITH AND WITHOUT COMBINED PELTIER MODULE AND EARTH HEAT EXCHANGER.

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1 STUDY OF PERFORMANCE AND POSSIBLE CONFIGURATION OF HYBRID AIR CONDITIONING SYSTEM WITH AND WITHOUT COMBINED PELTIER MODULE AND EARTH HEAT EXCHANGER. 1 Avinash B. Lohar, 2 Nitin V. Sali 1 M.E. Student, 2 Associate Professor, Department of Mechanical Engineering Govt. College of Engineering, Karad, Maharashtra, India. 1 avi.b.lohar@gmail.com, 2 nvsali@yahoo.co.in Abstract- A study was carried out to investigate the performance and effect of Earth Heat Exchangers (Heat Pipe), Peltier Module with and without combination with vapour compression air conditioning system with return air. The results show that the coefficient of performance of the system can be improved and the energy required by the compressor can be reduced when Peltier Module and Earth Heat Exchanger is used before cooling coil and provide supplementary cooling air to evaporator coil.in the present age with depleting sources of energy there will be minimum electric power consumption in operation of the air conditioning units so thatthere is always a target to get the best energy ratios. Individually the ideas like Earth heat exchanger cooling; Peltier Module(thermoelectric cooling) did not stand good but by combination of two or more concepts in a collaborative manner stands a possibility to develop an energy efficient method of air conditioning. By adopting proper design of Earth heat exchanger and modifying domestic refrigerator with Peltier Module can improve the COP as the best interesting alternative compared to other refrigerator system, for energy efficient applications based on the above concept experimental set-up is formulated. The Experimental set-up is tested with different combinations of VCC, Earth Heat Exchangers (Heat Pipe) and Peltier Module (thermoelectric module) for various performance parameters such as COP, compressor powerreduction,temperature drop,, Refrigerating effect, Energy saving etc. The COP of the conventional 0.05 TR window type air conditioner is found tobe increased from to and energy saving is observed to be 12.75% with the combination of conventional 0.05 TR window type air conditioner with heat pipe heat exchanger and thermoelectric module. Keywords: COP, Energy saving, Earth Heat exchanger (Heat Pipe), Peltier module (thermoelectric module), Temperature Gradient, VCC. I. INTRODUCTION The increasingly worldwide problem regarding rapid economy development and a relatively shortage of energy for residential homes, some countries set minimum requirements for energy efficiency. Air conditioning system is highly significant device for getting comfort to human being also in industry application. But this device is required of lager amount of electricity. The ever increasing energy requirement puts a great burden on the further economical development as India is poor in energy resources. In the present age with depleting sources of energy, there is always a target to get the best energy ratios so that there will be minimum electric power consumption in operation of the air conditioning units. How to reduce the energy consumption by using new energy saving technologies and equipment is an important task now days. Many methods and ideas like evaporative cooling, thermoelectric cooling, Earth heat exchanger etc. have been tried to keep the electricity consumption to a minimum in air conditioning applications.in air conditioning facilities with high outside air requirements such as clean room air conditioning systems, considerable energy savings is possible by using Peltier module and Earth Heat Exchanger( Heat Pipe). Ground temperature becomes more stable with depth; the temperature of earth at about 2 to 3m is nearly constant throughout the year. This undisturbed temperature remains higher than the outside temperature in winter and lower than the outside temperature in summer. When the atmospheric air is passed through the buried pipes, the air is cooled in summer and heated in winter.the Avinash B. Lohar and Nitin V. Sali ijesird, Vol. III, Issue III, September 2016/203

2 earth has high heat storage capacity and low thermal conductivity. Due to low thermal conductivity, it transports heat slowly; its temperature changes slowly on the order of month even years, depending on depth of measurement. That's why the Earth is warmer than the ambient air in the winter and cooler than ambient air in summer. This constant temperature of the Earth provides a free renewable source of energy that can easily provide enough energy round to cool an average suburban home. The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice-versa. Once it is decided that thermoelectric cooler is to be considered for cooling system, the next step is to select the thermoelectric module or cooler that can satisfy a particular set of requirements. Modules are available in great variety of sizes, shapes, operating currents, operating voltages and ranges of heat pumping capacity. In the longitudinal direction, the heat pipe is made up of an evaporator section and a condenser section. Should external geometrical requirements make this necessary; a further, adiabatic, section can be included to separate the evaporator and condenser. The cross-section of the heat pipe consists of the container wall, the wick structure and the vapour space.the performance of a heat pipe is often expressed in terms of equivalent thermal conductivity. The Hait book states that as a general rule, the ground temperature at 5 m down does not vary over the year, and that it is equal to the average yearly air temperature at that location. This probably varies with the soil type, moisture content, and ground cover, but may be generally helpful ground rule. The Sharan paper did a careful survey of ground temperatures in their location and found that at 3 m the yearly variation in ground temperature was about 2.5 C they felt that 3m depth was a good compromise between cost and yearly temperature variation. One of the most promising options to improve a refrigerator s system efficiency and reduce the energy consumption is to develop a more efficient refrigeration cycle. Current studies include improving cycle component efficiency, minimizing cycle losses and building alternative refrigeration cycles that are more efficient than conventional ones. Therefore by combination of PM and EHEX with VCC, i.e. Hybrid Air Conditioning which is one of the best alternative suggested for improve the performance and reduce the electricity consumption. We can say that conjunction of vapour compression air conditioning with thermoelectric cooling (Peltier Module) to provide supplemental heating and cooling for air supplied to conditioned space, and Earth heat exchanger in which energy consumption can significantly reduce and improve both the indoor thermal comfort and air quality. The power handling figures are for heat pipe working in Vertical position. Length 500mm long evaporator length 250 mm condenser length 250 mm working fluid water II. EXPERIMENTAL SETUP The set up of hybrid air conditioner is as shown in figure 1. Experimental setup consists of with combination of Earth heat exchanger, Peltier module with conventional vapour compression system, which is placed before evaporator to provide supplemental cooling air to conditioned space. From fresh air side, first condensing portion of two EHEXs mounted vertically in black cotton soil as shown in figure 1. EHEX consist of copper tube heat pipe having water as a working fluid and sintered powder is wick structure The main function of the wick is to generate capillary pressure and to distribute the liquid around the evaporator area. This is possible because the heat transport inside the heat pipe is based on evaporation, transport and condensation of a suitable working fluid, and thereby also obtaining an apparent thermal conductivity several hundred times that of solid materials such as copper. The heat pipe interior contains a wick, in which the condensate returns from the condenser section to the evaporator section. The driving force in the condensate transport process is the capillary pressure created by the wick and working fluid interaction, in some cases the capillary pressure is supported by the gravity force. The gravity force contributes to the transport process Avinash B. Lohar and Nitin V. Sali ijesird, Vol. III, Issue III, September 2016/204

3 when the condenser section is located above the evaporator section, i.e., the heat pipe is gravityassisted. The heat pipe is gravity-opposed when the condenser section is located below the evaporator. Using the Earth as a heat sink, a connection made between the object which is to be cooled the earth. The earth connection begins as piping starting from the object being cooled and ultimately returns as piping into the object being cooled. This connection is called as Ground Heat Exchanger" and the system used to harness the energy from ground called as Ground Source Heat Pump or Geothermal Heat Pump. This ambient temperature air is passed through via EHEX toward second stage where PM module mounted. Peltier module consists of two bonded semiconductors, and power provides to module by AC or DC voltage. Peltier cooling causes heat to be absorbed from the vicinity of the cooling plate and to move to the heat sink. The heat is carried through the cooler by electron transport and released on the hot side as the electrons move from a high to low energy state. Current passing across the junction results in either a forward or reverse bias, resulting in a temperature gradient. A. PERFORMANCE INVESTIGATION WILL BE CARRIED OUT FOR FOLLOWING COMBINATIONS WITH VCC. 1. Without Earth heat exchanger and Peltier module. 2. With Earth heat exchanger module. 3. With Peltier module. 4. With combined Earth heat exchanger and Peltier module. A. Mathematical relations. Actual C.O.P Figure 1 DESIGN DEVELOPMENT &TESTING OF HYBRID AIRCONDITIONER USING CONVENTIONAL VAPOR COMPRESSION CYCLE +PELTIER MODULE +EARTH HEAT EXCHANGER Here, ma = mass of air Ma =velocity of air X area of duct X density of air By using anemometer we can find out velocity of air. Cpa = Specific heat of air=1.005kj/kg K Velocity of air = 1.2 m/s Mass of air=0.09kg/sec Avinash B. Lohar and Nitin V. Sali ijesird, Vol. III, Issue III, September 2016/205

4 N = No. of impulse. t = time taken for N impulse III. RESULT AND DISCUSSION Observation Table 1 VCC EMC = Energy meter Constant = 3200 W-hr Sr. No. Time (Outlet) c To+ Tr (Inlet)Ti c Impulse Compressor Power Refrigerant Effect VCC COP actual (Min) Dry Wet Dry Wet KW KW Observation Table 2 VCC combined with PM (VCC + PM) Sr. No. Time (Outlet) c To + Tr Temperature ng the Peltier el (Inlet)Ti c Impu lse Compressor Power ( v+p) Refrigerant Effect V+P W COP (Min) Dry Wet Dry Wet KW KW KW actual V + P Avinash B. Lohar and Nitin V. Sali ijesird, Vol. III, Issue III, September 2016/206

5 Sr. No. Time (Outlet) c To+Tr Temperat leaving the Heat Pipe Observation Table 3 VCC combined with EHEX (VCC + EHEX) (Inlet)Ti c Impulse Compre or Power Refrigera Effect V+H (Min) Dry Wet Dry Wet KW KW VCC+H COP actual) Observation Table 4 VCC combined with PM and EHEX (VCC + PM + EHEX) Sr. No. Time (Outlet)To c Return Air Heat Pipe ving Temp. Peltier odule leaving Temp. (Inlet)Ti c Impul se Compresso r Power (V+P+H) Refrigerant Effect (V+P+H) COP actual (VCC+H+P) (Min) Dry Wet c c c Dry Wet KW From above results various performance parameters such as COP, compressor power, Refrigerating effect, Compressor power KW/ Ton, Temperature gradient plotted with time (Min). Avinash B. Lohar and Nitin V. Sali ijesird, Vol. III, Issue III, September 2016/207

6 Fig.2. C.O.P Vs Time (min) Fig.6. Inlet Temperature Vs Time (min) Fig3. Refrigerating effect Vs Time (min) Fig.4. Input power Vs Time (min) Fig. 5 Compressor Power KW/ Ton Vs Time (Min) The first setup of operation in which air conditioner is operated only is considered as the base case. The Performances of other setups are compared with the VCC, which is purely a active cooling system without combination of PM and EHEX. (Since in first case it is not coupled with heat pipe or Peltiercooler) Fig 2 shows the variation of COP with time for different combination. COP of VCC+PM+HP is maximum and thus most effective of the three combinations hence it isrecommended that all three combinations of the hybrid system be used for best results. Comparison of the COP of VCC+PM & VCC+HP represents that VCC +PM show better COP as compared to the VCC+HP over delayed duty cycle i.e., from 12 to 15min, hence will be recommended if the temperature cycling is to done over a range above 12minutes time. Comparison of the COP of VCC+PM &VCC+HP shows that VCC+HP shows better COP as compared to the VCC+PM over short Avinash B. Lohar and Nitin V. Sali ijesird, Vol. III, Issue III, September 2016/208

7 duty cycle i.e., from 0 to 12min, hence will be recommended if the temperature cycling is to done over a range below 12minutes time. The maximum COP of combinations (VCC, VCC+PM, VCC+ HP, VCC+ PM+ HP) are2.18, 2.57, 2.62, 2.85 respectively. From fig.6 it is clear that Temperature reduction is maximum with Combination with VCC + PM + HP. When compared with the base case i.e. VCC, values of maximum temperature percentage reductions are 5%, 12% and 13.2% for different combination respectively. The maximum energy saving is also one of the important parameter that should also to be considered. Fig.6 shows the variation of energy saving with time when compared with the VCC setup. The maximum energy saving is observed to be 20.8% with VCC+ HP since heat pipe is a passive cooling enhancement. The values with VCC + HP + PM and VCC + PM are 33.3% and 25 % when compared with the base case respectively. Fig.3 shows the variation of refrigerating effect with time. Figure shows that VCC with heat pipe and Peltiermodule shows very promising results. For the same time period the refrigerating effect with the VCC + PM + HP will increase but for considering temperature before cooling coil as a out let temperature and after crossing the cooling coil as a inlet temperature as per this basis refrigerating effect decreases by all combination, Due to this compressor power Fig.4 shows variation of input power with time. From the figure it is very clear that compressor input power required over a period of time reduces considerably with various combinations as compared with the base case. IV. CONCLUSIONS The experimental study of air conditioner working on VCC with combination of heat pipe (EHEX) and Peltier module lead to following conclusion: [1] The maximum COP with all combination will rise to 2.85 ascompared to the base case with [2] The Maximum percentage temperature reduction with all combination is 13.2% compared to the VCC with total energy saving slightly (negligibly) less than VCC + HP. [3] The maximum energy saving is observed to be 33.3% with VCC + HP since heat pipe is a passive cooling enhancement. [4] The refrigerating effect with all combinations will increase for the same time period Nomenclature Qr: Refrigeration effect in Kw. Qi: Input Power in Kw. m: Mass of air in Kg/s. Cp: Specific heat of air in KJ/kg K. ΔT: Temperature change in K. COP: Coefficient of performance. TEC: Thermoelectric cooler. VCC: Vapor Compression Cycle. SHR: Heat sensible Ratio. EHEX: Earth heat exchanger. HP: Heat pipe. PM: Peltier module. TR: Tonne of Refrigeration ACKNOWLEDGMENT I would like to give my special thanks and appreciation to Mechanical Department of GEC, Karad,. Iwould also like to thank Prof. Nitin V. Sali for valuable support and Mr. SharadPatil. REFERANCE [1] ASHRAE Handbook of Fundamentals SI Version, American Society of Heating; Refrigerating; and Air- Conditioning Engineers, Inc., Atlanta, GA. [2] Ballaney, P.L., Refrigeration and Air Conditioning.Khanna Publishers, Delhi [3] J.W. Wan, J.L. Zhang, W.M. Zhang, The effect of heatpipe air-handling coil on energy consumption in central air-conditioning system, Received 31 July [4] A.M. Alklaibi, Evaluating the possible configurations of incorporating the loop heat pipe into the air-conditioning systems international journal of refrigeration 3 1, [5] Yat H. Yau, Application of a heat pipe heat exchanger to dehumidification enhancement in a HVAC system for tropical climates a baseline performance characteristics study,8 June [6] Manoj Kumar Rawat, On Developments of Thermoelectric Refrigeration And Air Conditioning Systems: A Novel Potential Green Refrigeration And Air Conditioning Technology, International Journal of Emerging Technology and Advanced Engineering, Volume 3, Special Issue 3: ICERTSD 2013, Feb [7] Y.H. Yau, Experimental thermal performance study of an inclined heat pipe heat exchanger operating in high humid Avinash B. Lohar and Nitin V. Sali ijesird, Vol. III, Issue III, September 2016/209

8 tropical HVAC systems, International Journal of Energy Research 30 (2007). [8] Judith Koetzsch, Mark Madden, Thermoelectric Cooling for Industrial Enclosures, Mark Corcoran, Editor. [9] C. K. Loh, Daniel T. Nelson, D. J. Chou, Investigation into the use of Thermoelectric Devices as Heat Source for Heat Sink Characterization. [10] GirjSharan, RatanJadhav, Performance of Single Pass earth-tube Heat Exchanger: An Experimental Study. Patent No.: US 7,779,639 B2, Aug.24, [11] LakhiNandlalGoenka, HVAC System for Hybrid Vehicles Using Thermoelectric Deive, [12] Daniel A. Spurgeon, Mahmoud A. Taher, Thermoelectric Enhanced HVAC System And Method, United States Patent Application Publication, Pub. No.: US 2006/ A1, Jul.31, 2006 UğurKemiklioğlu, SelimSolmaz Avinash B. Lohar and Nitin V. Sali ijesird, Vol. III, Issue III, September 2016/210