Performance Analysis of Solar Water Heating System using PCM

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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

10

11

12

1

2

3

4

42

49

60

71

75

77

77

41

49

65

69

72

78

80

10

11

12

1

2

3

4

42

49

60

71

75

77

77

41

49

65

69

72

78

80

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.

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