Performance Analysis of Solar Water Heating System using PCM

Performance Analysis of Solar Water Heating System using PCM

Mohammed Aslam. A

Department of Mechanical Engineering Bharathidasan Engineering College, Natrampalli, Tirupattur, Tamil Nadu India

Abstract:- In the contemporary era, phase change material (PCM) is used in the solar water heaters to store the extra amount of heat energy available during the full sunshine hours. The primary purpose of this study is to examine the performance of PCM incorporated solar water heating system using the flat plate collector as a heat source. In this study, a cylindrical aluminium PCM tank acts as the thermal energy storage unit. Paraffin wax is used as the PCM. Water is used as heat transfer fluid (HTF) to transfer heat from the flat plate collector to the storage tank. The charging has been carried out on clear days without and with PCM under actual operating conditions. It shows that from the experiments, the PCM improves the performance on the system by bettering the charging energy efficiency and thermal efficiency of the Storage tank.

Keywords: Component, Sensible Heat, Latent Heat, PCM

1. INTRODUCTION

   1.1. SENSIBLETHERMAL ENERGY STORAGE

   That is, the internal energy of the storages material is influencing by the energy going stored, which would raise the temperature of the materials [1].

   Expressed equation

   Q= mCp (T1-T2)

   Where Q is heat transfer

   Cp is specific heat of water

   1.2 LATENT THERMAL ENERGY STORAGE

   In latent TES, the heat storages material undergoes a phase transformation process for storing or discharging the heat energy [2]. The phase change material either from solid to liquid or near isothermal condition.

   Latent heat energy Q = m Cp + mH

   Q= mCp (T1 T2) mH

2. PHASE CHANGING MATERIALS

   Thermal energy storage through PCM is capable of storing and releasing large amount of energy. The system depends on the shift in phase of the material for holding and releasing the energy [6].

   1. PARAFFIN WAX

      Paraffin wax refers to a mixed of alkanes that fall with 20 n 40 range. They are found in the solid state at room temperature and begin to either liquid phase approximately 37°C.

      Fig.1 Thermal energy storage using PCM

3. EXPERIENTAL SETUP

   COMPONENTS

   1. Thermal storage tank

   2. RTD

   3. Temperature indicator

   4. Insulation material

   5. Phase change material

   6. Flow meter

   7. Pressure gauge

   1. THERMAL STORAGE TANK

      Fig.2 Thermal storage tank

      Thermal storage tank is heat water storage in occupies space. Tank has manufacturing stainless steel. The tank is two position one outer tank and other inner tank. There are two physical systems namely LHS system and SHS system considered in the present analysis [3]. The LHS system considered for the analysis is a cylindrical storage system

      of height 1100 mm and diameter 500 mm. It consists of three zones.

   2. RTD

      RTD is a temperature sensor which measure temperature using the principles that the resistance of the metal charge with temperature.

      Fig.3 PT100 RTD Sensor of Platinum Resistance Eelement

      • Outer diameter: 6 mm

      • Length of platinum element: 4 inch or 101.6 mm

      • Cable length or lead wire: 4 meter

      • Cable insulation: pt fe insulation

      • Configuration: 3 wire configuration

        S.NO	DESCRIPTION	VALUE
        1	Melting temperature	65°C
        2	Thermal conductivity (solid)	0.1383 W/m°C
        3	Thermal conductivity (liquid)	0.1383 W/m°C
        4	Specific heat (solid)	2890 J/kg.K
        5	Specific heat (liquid)	2890 J/kg.K
        6	Density (solid)	947 kg/m3
        7	Density (liquid)	750 kg/m3
        8	Latent heat	190 J/kg

        S.NO	DESCRIPTION	VALUE
        1	Melting temperature	65°C
        2	Thermal conductivity (solid)	0.1383 W/m°C
        3	Thermal conductivity (liquid)	0.1383 W/m°C
        4	Specific heat (solid)	2890 J/kg.K
        5	Specific heat (liquid)	2890 J/kg.K
        6	Density (solid)	947 kg/m3
        7	Density (liquid)	750 kg/m3
        8	Latent heat	190 J/kg

      • Temperature range: 20°C TO 540°C Table: 1 Variation Values of PCM

        Fig.4 Thermal Insulation

   3. INSULATION MATERIAL

      Thermal insulation is blocking or reducing heat transfer between two objects (heat transfer is energy moving from one thing to another because of a difference in temperature) [4]. Thermal conductivity is 0.028 W/m.k

   4. PUMPS

      C.R.I. Self priming mono block pump sets is power-driven by a totally enclosed fan cooled AC induction two pole motor, suitable for continuous duty.

   5. PRESSURE GAUGE

      Pressure gauge, instrument for measuring the condition of a fluid (liquid or gas) that is specified by the force that the fluid would exert, when at rest, on a unit area, such as pounds per square inch or new tons per square centimeter. Pressure gauge ranges from 0 to 5bar.

   6. MASS FLOW METER

      A mass flow meter, also known as an inertial flow meter is a device that measures mass flow rate of a fluid traveling through a tube. The mass flow rate is the mass of the fluid traveling past a fixed point per unit time.

   7. TEMPERATURE INDICATOR:

   Temperature indicators used to indicate or measuring the temperature at corresponding area. Using thermal indicators are 12 cable connections with two segments (red and white). Temperature range measure 20°C to 550°C. Digital temperature is measured.

   Fig.5 Temperature Indicator

   Sensible Heat energy	Time	Mass flow meter reading	Ta	Ti	To	T1	T2	T3
   	10 AM	12 LPM	40oC	42oC	40oC	40oC	40oC	40oC
   	11 AM	12 LPM	48oC	49oC	48oC	48oC	48oC	48oC
   	12 NOON	12 LPM	58oC	60oC	59oC	58oC	58oC	58oC
   	1 PM	12 LPM	70oC	71oC	70oC	70oC	70oC	70oC
   	2 PM	12 LPM	74oC	75oC	74oC	7oC	73oC	74oC
   	3 PM	12 LPM	76oC	77oC	76oC	76oC	75oC	76oC
   	4 PM	12 LPM	76oC	77oC	76oC	76oC	75oC	76oC

   Sensible Heat energy	Time	Mass flow meter reading	Ta	Ti	To	T1	T2	T3
   	10 AM	12 LPM	40oC	42oC	40oC	40oC	40oC	40oC
   	11 AM	12 LPM	48oC	49oC	48oC	48oC	48oC	48oC
   	12 NOON	12 LPM	58oC	60oC	59oC	58oC	58oC	58oC
   	1 PM	12 LPM	70oC	71oC	70oC	70oC	70oC	70oC
   	2 PM	12 LPM	74oC	75oC	74oC	74oC	73oC	74oC
   	3 PM	12 LPM	76oC	77oC	76oC	76oC	75oC	76oC
   	4 PM	12 LPM	76oC	77oC	76oC	76oC	75oC	76oC

4. EXPERIMENTAL ANALYSIS Table: 2 Analysis of Sensible Heat

   1. EFFICIENCY PARAMETER WITHOUT PCM

      Table: 3 Variations of Values without PCM

      PARAMETER	SYMBOL	VALUE
      VOLUME	V	215 litres
      INITIAL TEMPERATURE	Ti	28°C
      HEAT RADIATION	Rin	945.28 W/m²
      TIME ELAPSED		1 hr
      FINAL TEMPERATURE	To	76°C

   2. LATENT HEAT ENERGY

   PARAMETER	SYMBOL	VALUE
   VOLUME	V	215- 8.835 = 206.165
   INITIAL TEMPERATURE	Ti	28
   HEAT RADIATION	Rin	910.58 W/m²
   TIME ELAPSED		1 hr
   FINAL TEMPERATURE	To	78

   PARAMETER	SYMBOL	VALUE
   VOLUME	V	215- 8.835 = 206.165
   INITIAL TEMPERATURE	Ti	28
   HEAT RADIATION	Rin	910.58 W/m²
   TIME ELAPSED		1 hr
   FINAL TEMPERATURE	To	78

   Table: 4 Analysis of Latent Heat Energy

   1. CALCULATION

      VOLUME OF THE TANK:

      VOLUME= AREA* LENGTH

      Area (A) = ¶/4 *D2

      V tank= 0.200 m³ (or) 200 litres

      VOLUME OF PCM:

      = (4/3) ¶(D/2)3(4) ()³

      9. CONCLUSION

      Paraffin wax is a good PCM for energy storages in latent heat storages system. It has a suitable storages system. It has a suitable transition temperature range of 28 °C to 78

      °C and relatively high latent heat of 190 KJ/kg. So that sensible heat is 35.11KJ is compare to latent heat energy is 44.724 KJ it is greater than of sensible heat. Comparing

      = (4/3) ¶(0.075

      3 2

      /2)3

      with SHE and LTES is 9.614 KJ of energy is excess energy storage.

      = 0.22 m per single PCM ball

      TOTAL VOLUME OF THE PCM = 40 *0.22

      PCM = 8.83 mm or 8.83 litre

      SENSIBLE HEAT ENERGY

      ENERGY ABSORBED PER ONE HOUR

      Q = m Cp (Tf-Tw)

      m = 215 litre or 0.215m Cp = 4.18 KJ/kg

      Final temp Tf = 40.4°C

      Initial temp Ti =34°C

      Q= 0.200 4.18 (40.4 -34)

      = 5.7516 KJ

      HEAT STORAGE PER HOUR IS 5.57516 KJ

      In time interval of 12 noon to 1 pm is

      = 4.18(70.2-58.6)

      = 8.424 KJ

      LATENT HEAT ENERGY:

      Q= mcp(T1-T2)+m(^H)+Mpcm cp(Tf-Tw)

      Volume of with PCM =volume of water tank – volume of PCM

      = 200-8.83 = 191.17 litre

      Amount of energy storage /hour

      = 191.17 4.18(68.4 – 59) + (5.2*190) Q = 8100.84 J + 988 J

      Q = 9.088KJ

      In time interval of 11 am to 12 noon is

      = 191.17 4.19 (68.4 -59) + 5.2(190) + 5.2(2.89)(59-68.9)

      = 9.540 KJ

   2. RESULT AND DISCUSSION COMPARE SHE AND LHE

COMPARE THE AMOUNT ENERGY

TEMPERATURE DIFFERENCE

TEMPERATURE

TEMPERATURE

100

80

60

40

20

0

SENSIBLE HEAT

LATERAL HEAT

Fig.5 Comparative Analysis of SHE & LHS

10. REFERENCE

1. Shuhong Li, Yongxin Zhang, Kai Zhang, Xianliang Li, Yang Li, Xiaosong Zhang, Study on performance of storage tanks in solar water heater system in charge and discharge progress, Energy Proc. 48 (2014) 384393.

2. Luisa f.cabeza.( 2015), Advanced in thermal energy storage system, method and application, woodhead publication, pp.185-344

3. A.S. Ramana, R. Venkatesh, V. Antony Aroul Raj, R. Velraj (2014), Experimental investigation of the LHS system and comparison of the stratication performance with the SHS system using CFD simulationhttp://dx.doi.org/10.1016/ j.solener.2014.02.0090038- 092X/2014 Elsevier Ltd.

4. Y.B. Tao, Ya-Ling He (2018) A review of phase change material and performance enhancement method for latent heat storage system, https://doi.org/10.1016/j.rser.2018.05.028 Received 9 December 2016; Received in revised form 17 April 2018; Accepted 13 May 2018 Renewable and Sustainable Energy Reviews 93 (2018) 245259 1364-0321/ © 2018 Elsevier Ltd.

5. G.Murali ,K.Mayilsamy ,B.Mubarak Ali , A Review of Latent Heat Thermal Energy Storage Systems Vol. 787 (2015)

6. Dr. C. Dhandapani Study of Squeeze Casting on Metal Matrix Composite – Al-Sic (P) Substance, International Journal of Information And Computing Science (IJICS), Volume 5, Issue 9, 2018.