experiment_manual thermal training kit_8th jan. 2014_nor

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© Insight Solar. 2013. Ecosense. [email protected], [email protected]

Experiment Manual

Solar Thermal

Training System

Includes 11 experiments with step-by-step guidance



About “Insight Solar” Solar

Thermal Training Kit

“Insight Solar” Solar Thermal

Training Kit is a compact

system in the form of working

laboratory model. It has been

designed indigenously by our

in house team, with guidance

from researchers and industry

experts to help students build

an in-depth understanding of a

Solar Thermal System throughreal-life hands on experience.

This system helps students to

evaluate the performance of

a Solar Thermal System under

different atmospheric conditions

like temperature, pressure, wind,

radiation etc. The experiments

can be performed both in the

stimulated environment and

also in the natural atmospheric

conditions.

Why “Insight Solar”

Solar Thermal Training

Kit

The energy performanceof a solar water heatingsystem is influenced by anumber of factors. Thesemay include resource anddesign elements suchas the amount of solarradiation hitting the solarcollectors, the collectorarea, solar tracking mode(i.e. fixed, one-axis etc),the slope and the azimuth(physical orientation) of thesolar water heater.

‘Insight Solar’ Solar Thermal Training Kit will help thestudents and researchersin developing an in-depthunderstanding of design,installation and operationof Solar water heatingsystem.

Specifications of the

System

• Water heater system

(Collector and hot water

tank)

• Articial Radiation System

and Regulator

• Radiation meter

• External water tanks

• Water pump

• Water ow meter (For force

mode of flow)

2

1

2

1

Flat Plate Collector



1


Solar water heater is one of the simplest

and basic technologies in the solar energy

field. Collector is the heart of any solarwater heating system. It absorbs and

converts the solar energy into heat and

then transfers that heat to a stream of

water. There are different types of solar

energy collector. In our system we have

used a flat plate collector.

IntroductionInsight Solar

Theory

A typical at-plate collector consists of

an absorber plate in an insulated boxtogether with transparent cover sheet(s).

Work and properties of dierent

components of a flat plate collector

y Absorber plate:

It is a flat conducting plate to which

the tubes, fins, or passages are

attached. It may be a continuous

or discrete plate. The plate is usually

coated with a high absorptance andlow emittance layer.

y Cover plate:

One or more sheet of glass or other

radiation-transmitting material forms

the cover plate. The cover plate

serves two purposes, minimization of

convective heat loss and blocking of

IR radiation.

y Heat removal passages: These are tubes, fins, or passages

which conduct or direct the stream

of water from the inlet to the outlet

of the collector.

y Headers or manifolds:

These are the pipes to admit and

discharge water that is meant to be

heated.

JDOs

y Valve positions

are critical, soensure their

posit ion before& after everyexperiment.

y The systemdrains veryhigh current somake sure thatall connectionsare properly

insulated. y Fill cold water

tank through the pipe below thethree way valve.

y Clean theglass before

performing any

experiment.

LDON’Ts

y During draining

from the hot watertank do not openthe exhaust valvein one go.

y Do not touch thehalogen fixture by

your hand

y Do not run the pump in drycondition.

y Do not open the

tap or the threeway valve withouttaking utmostcare.

y Do not touch theback side of thecontrol panel.

y Do not spreadwater over thecontrol unit.

Insight Solar

Introduction



2


y Insulation: Insulations such as Rockwool or Glass

wool are fitted in the back and sides

of the collector to prevent heat loss

from the collector.

Table-A: Overall Specications of the system

Components Specification Remarks

Water heating system

(Collector and watertank)

Collector area: 0.716 m2

Tank capacity: 50 L

Collector: Flat plate collector.

To collect and transfer heat Tank: non pressurized

aluminum tank.

To store water

Halogen system Halogen xture’s area: .0.72 m2

Number of halogen lamp: 21

Power :150 W each

Regulator: 5000 W

Halogen: To supply the

required intensity on the

collector.

Regulator: To adjust the

intensity at the desire level

y Casing: The casing surrounds the

aforementioned components and

protects them from dust, moisture

and any other material.

In the following figure schematic diagram of a typical flat-plate collector is shown with

different parts at their proper locations.

Fig-1: Schematic diagram of a typical flat-plate collector

Insight Solar

Introduction



3



Radiation meter Range: 0 to 1999 W/m2

Power supply: DC

To measure the radiation level

on the collector

External water tanks Capacity: 80 L To supply cold water to the

heating system

Water pump Power supply: AC

Power: 0.12 hp

To lift water upto the desired

level.

To facilitate the forced mode

operation.

Water ow meter

(for forced mode)

Sensor:

Flow range : 0.5 to 25 LPM

Working voltage : 4.5 to 24

VDC

Max. Pressure : 17.5 bar

Working pressure : 0 to 10 bar

Max rated current : 8 mA

Withstand current : 15 mA

Working temp : up to 80°C

Storage temp : 25 to 65°C

Accuracy : 1 % fsd

Supply voltage- 230 V AC.

Mini turbine wheel based

technology.

To measure the water flow

rate during the forced mode

operation.

Stop watch With electronic On-O switch

and a Reset button

To detect the time

during natural flow rate

measurement

Anemometer Air velocity:

Range : 0.4 to 45.0 m/sec

Resolution: 0.1 m/sec

Accuracy: (±2% + 0.1 m/sec)

Air Temperature:

Range: -14 to 60°C

Resolution: 0.1°C

Accuracy: 0.5°C

Power supply:DC 4*1.5 AAA size

The anemometer can

measure the air velocity and

the ambient air temperature.

The air flow sensor is aconventional angled vane

arms with low friction ball

bearing.

The temperature sensor is a

precision thermistor.

Insight Solar

Introduction



4



Pressure Gauges Sensor:

Range: 0 to 6 bar

Accuracy: ±3 kpa

Output: 4 to 20 mA (±3)

Input: 4-20 mA DC

Power: 220 VAC

Semiconductor thin-film

based technology.

Works on the principle of

generation of electrical signal

due to exertion of pressure.

To measure the inlet and

outlet pressure

Thermometers Sensor:

Class A sensor

Range: -200 to 650 °C

Accuracy : ± 0.15 +0.002*(t)

Where t is absolute value of

temperature in °C

Supply Voltage: 230AC

Sensor is RTD based SS probe.

Works on the principle ofvariation of resistance with

temperature.

To measure the inlet,

outlet, plate and tank water

temperature

Fan Range : 0 to 5 m/sec

Power supply: AC with

regulators

To supply the wind at the

desire speed

Insight Solar

Introduction



5


Table-B: Detailed Specication of the Solar water heater system

Overall data

Overall collector dimension mm 915x810x95

Weight of the collector Kg 13

Aperture Area m2 0.63

Glazing

Glazing type and number Type of glass Toughened Glass

Glazing thickness mm 5

Glazing transmission % 85Glazing Emissivity % 88

Absorption plate

Absorber material Copper

Absorber plate thickness mm 0.12

Absorber plate dimension mm 115

Emissivity of surface % 12

Absorption of surface % 96

Risers & headers

Number of risers 6

Riser Length mm 800

Outer diameter of risers mm 12.7

Thickness of risers mm 0.56

Distance between two risers mm 115

Headers dimension mm 882

Header diameter mm 25.4

Header thickness mm 0.71

Test pressure kpa 400

Maximum working pressure kpa 250

Insulation

Insulation material Rockwool

Insulation density g/m3 48

Insulation thickness-base mm 50

Insulation thickness-side mm 25

Conductivity W/mK 0.04

Insight Solar

Introduction



6


Casing

Frame type Aluminum

Frame colour Black

Casing thickness mm 1.4

Insulated tank

Tank type Non-pressurised

Tank materials SS – 304

Tank insulation PUF

Tested pressure kpa 300

Tank size 815 X370

Overall Efficiency

η % (50-70) %

Important parameters of a flat platecollector based solar water heating

system:

The performance of a solar water heating

system depends upon different design

and atmospheric parameters.

The meaning and importance of some

of the most dominating parameters are

described below.

Overall Heat loss coefficient (UL):

All the heat that is generated by the

collector does not resulted into useful

energy. Some of the heat gets losses to

the surroundings. The amount of heat

losses depends upon the convective,

conductive and radiation heat losscoefficients.

Estimation of heat loss coecient of the

flat plate collector is important for its

performance evaluation. A higher value

of heat loss coefficient indicates the lower

heat resistance and hence the lower

efficiency.

Among all heat loss parameters the

top loss contributes the most. The topheat loss coefficient is a function of

various parameters which includes the

temperature of the absorbing plate,

ambient temperature, wind speed,

emissivity of the absorbing and the cover

glass plate, tilt angle etc.

Insight Solar

Introduction



7


Heat Removal Factor (FR):

Heat removal factor represents the ratio

of the actual useful energy gain to the

useful energy gain if the entire collector

were at the fluid inlet temperature. It

depends upon the factors like inlet and

outlet water temperature, the ambient

temperature, area of the collector etc.

The importance of heat removal factors

remains with the efficiency of the system.For a highly ecient system a higher

value of heat removal factor is must.

Eciency (η):

Eciency is the most important factor

for a system. This factor determines the

system’s output. For a at plate collector

based solar water heater system the

efficiency is defined as the ratio of the

useful energy delivered to the energy

incident on the collector aperture .

The value of efficiency is dominated

by parameters like product of glazing’s

transmittance and absorbing plate’s

absorptance, intensity of global radiation

falling on the collector, water inlet

temperature and ambient air temperature.

Collector Time constant:

Collector time constant is required to

evaluate the transient behavior of a

collector. It is define as the time required

rising the outlet temperature by 0.632

of the total temperature increase from

T fo

–T a at time zero to T

fo–T

a at time infinity

i.e. time at which the outlet temperature

attains a stagnant value. It can be

calculated from the curve between R and

time as shown below. The time interval for

which R value is 0.632, is the time constant

of the give collector.

In terms of temperatures R is dene as,

Where,

T fo (t) : Outlet water temperature at anytime t

T fo

(0) : Outlet water temperature at time

zero

T fo

(α) : Outlet water temperature at

infinite time (maximum temperature)

Shape of the graph between R and time is

as shown below.

Insight Solar

Introduction



8


Basic Equations to calculate dierent

parameters:

A. Heat Loss coecient (UL)

UL is the overall heat transfer coefficient

from the absorber plate to the ambient air.

It is a complicated function of the collector

construction and its operating conditions.

In simple term it can be expressed as,

UL= U

t + U

b + U

e

According to Klein (1975), the top loss

coefficient can be calculated by using the

flowing formula.

Where,

The heat loss from the bottom of the

collector is first conducted throughthe insulation and then by a combined

convection and infrared radiation transfer

to the surrounding ambient air. However

the radiation term can be neglected

as the temperature of the bottom part

of the casing is very low. Moreover the

conduction resistance of the insulation

behind the collector plate governs the

heat loss from the collector plate through

the back of the collector casing. The heat

loss from the back of the plate rarely

exceeds 10% of the upward loss. So if we

neglect the convective term there will not

be much effect in the final result. Thus to

calculate the bottom loss coefficients we

can use the following formula

Typical value of the back surface heat losscoecient ranges between 0.3 to 0.6 W/

m2K.

In a similar way, the heat transfer

coefficient for the heat loss from the

collector edges can be obtained by using

the following formula

B. F factors of a at plate collector (F, F’,FR, F”)

1. Fin efficiency (F)

For a straight n with rectangular prole

the fin efficiency is given as

2. Collector efficiency factor (F’)

(4)

(3)

(2)

(1)

Insight Solar

Introduction

(5)



9


Mathematically,

FR= (Actual Useful energy gain)/(useful

energy gain if the entire collector were at

the fluid inlet temperature )

3. Heat Removal Factor (FR)

Mathematically,

(7)

Another formula for FR,

(8)

4. Flow Factor (F”)

It is the ratio of the heat removal factor

(FR) and the collector eciency factor (F’)

Mathematically,

(9)

The parameter is called the collectorcapacitance rate. It is a dimensionless

parameter and the sole parameter upon

which the collector flow factor depends.

C. Collector Plate Temperature (T P)

At any point of time the collector plate

temperature is given as

Where, the useful heat gain Qu is given as

D. Thermal Eciency of the collector

(η)

It is the ratio of the Useful heat gain to the

Total input energy

Mathematically,

E. Thermal Eciency of the collector

when angle of incident is not 90° (ηθ)

The equation number (12) for the thermal

efficiency is applicable for a normal

incident angle situation. In a situation

where angle of incident is not 90° we

will have to add a new parameter in the

equation number (12). The new parameteris known as incident angle modifier

(k θ). The necessity of (k

θ) is arises due to

change in (τα) product.

For a at plate collector (k θ) is given as

For a single glaze collector we can use a

first order equation with, b0=-0.1

Thus for a collector where angle of

incident is not 90°, the eciency can

be calculated by using the following

equation,

(6)

(10)

(11)

(12)

(13)

(14)

Insight Solar

Introduction



10


Experimental set-up: The system has been designed to perform experiments in both Thermosyphonic and

Forced modes of ow.

Schematic diagram of the experimental setup:

Description of dierent components:Radiation meter : To measure the radiation level that is received by the collector a

radiation meter is supplied with the system. It is a sensing based device. It can measure

the radiation level in the range of 0 to 1999 W/m2 .

Thermometer : Four thermometers are connected to the system. The Sensors are

RTD based platinum probe and work on the principle of variation of resistance with

temperature. The probes are class A RTD and can measure the temperature in the range of

-200°C to 650°C.

Insight Solar

Introduction



11


Pressure Gauge : Two pressure gaugesare there in the setup. They work on the

principle of generation of electrical signal

by semiconductor device due to exertion

of pressure. The pressure gauges can

measure the pressure in the range of 101.3

to 650 kpa.

Water flow meter : To measure the

water flow rate a panel mount flow

meter with a mini turbine flow sensor is

connected near the collector inlet. It is aprogrammable meter. It can measure the

ow rate in the range of 0.5 to 25LPM.

The temperature limit of the meter is up

to 80°C.

Pump : We are using an AC pump to ll

up the collector tank as well as to circulate

the water through the collector at some

regulated speed. A continuous regulator is

there to maintain the flow rate.

Anemometer : An anemometer is

supplied with the system. This can be

used to measure the air velocity and the

ambient air temperature.

The air flow sensor is a conventional

angled vane arms with low friction ball

bearing while the temperature sensor is

a precision thermistor. The anemometer

can measure the wind velocity in the

range of 0.4 to 45.0 m/s while the

temperature range is -10 to 60°C

Fan : One AC fan is integrated with the

system to generate the artificial wind

speed. To set the wind speed as per

requirement a regulator is there in the

main control unit.

Valve : Dierent valves are there to direct

the water flow as per requirement.

Assumptions :

To perform different experiments with

this set-up a number of assumptions

need to be made. These assumptions are

not against the basic physical principles

but simplify the problems up to a great

extent.

y The collector is in a steady state

condition.

y The headers cover only a smallarea of the collector and can be

neglected.

y Heaters provide uniform flow to the

riser tubes.

y Flow through the back insulation is

one dimensional.

y Temperature gradients around tubes

are neglected.

y Properties of materials are

independent of temperature.

y No energy is absorbed by the cover.

y Heat flow through the cover is one

dimensional.

y Temperature drop through the cover

is negligible.

y Covers are opaque to infrared

radiation.

y Same ambient temperature exists at

the front and back of the collector.

y Dust eects on the cover are

negligible (if otherwise mention).

y There is no shading of the absorber

plate (if otherwise mention).

Insight Solar

Introduction



12


Objective:

Evaluation of UL, F

R and η in

Thermosyphonic mode of flow with fixed

input parametersMethodology:

1. Keep all valves closed

2. Fill cold water tank number 1

3. Open the valves 1 and 2 and fill coldwater tank 2 by using the pump

4. Once the cold water tank 2 is full,open valve 3 and 4 and allows the

water to flow into the hot water tankand the collector by gravity.

5. Once the hot water tank overows andwater comeback to the cold water tank1 close the valves 1, 2 and 3.

6. Switch ON the wind generating fan

7. Measure the wind speed at dierentlocations of the collector by usingthe Anemometer. Use an average

value for calculation.

8. Similar to the wind speed measure theambient air temperature by using thesame Anemometer at dierent locationsaround the experimental setup. Use anaverage value for calculation.

9. Connect all the meters and note allthe readings

10. Switch ON the Halogen systemand set the regulator for maximumradiation level

11. Measure the radiation level atdifferent locations on the collectorglazing by using the radiation meter. To get the radiation levels at thedesire value apply the regulator. Usean average value for calculation.

12. Note the values shown by differentmeters after every 15 minutes.

13. To know the mass flow rate open thethree ways valve and note the time

required to fill a desire amount of waterin the beaker.

14. Repeat the above step (13) atleast five times during the wholeexperiments. Use an average valuefor calculation.

15. Keep the halogen system ON untilthe outlet water achieved a stabletemperature.

16. Once the experiment is over drainthe hot water to the cold water tank1 by opening valve 5.

For all the calculations refer to Table no. 1

Important:

Before draining the hot water to the coldwater tank 1, make sure that you havefill up the cold water tank 2 for the next

experiment.

Insight Solar

Experiment No. 1

Insight Solar

Experiment No. 1



13


c. Comparison of the experimented

and calculated value of plate

temperature by using equation 10.

Results:

1. Draw the following eciency graph

2. Find the value of optical eciency of

the collector from the graph

3. Find the slop of the curve which

gives the sense of the overall heat

loss coefficient of the collector.

4. Find the gain and loss equalization

point.

Observations:

Tilt angle of collector (β):__________deg

Wind speed (v):______________ m/sec

Radiation level (I):_____________ W/m2

Calculations:

1. Calculate Ut and hence UL by usingequations 1 through 4

2. Calculate Heat Removal Factor (FR) by

using equation 7

3. Calculate Thermal Eciency (η) of

the collector by using equation 12

4. Evaluate time constant of collector

by drawing the graph between R

and time.

By using the values of different entities

from the Table-1 user can examine some

other characteristic parameters of the

collector. The parameters are,

a. Collector eciency factor (F’) by

using equation 8.

b. Collector Flow Factor (F”) by using

equation 9.

Insight Solar

Experiment No. 1

Table-1: Experimental values of dierent parameters during Thermosyphonic mode offlow with fixed input parameters



14


Objective:

Evaluation of UL, F

R, η in Thermosyphonic

mode of flow at different radiation level

2.1 Highest Radiation Level

User can use all the results from the sub

part of experiment no. 1 provided inlet

water temperature is same.

2.2 Medium Radiation Level

Methodology:

Follow all the steps as in experiment no.1

except setting the halogen regulator at amedium radiation level.

For all the calculations refer to Table no. 2.2

Table-2.2: Experimental values of dierent parameters during Thermosyphonic mode of

ow with Medium Radiation Level

Observations:

y Tilt angle of collector (β)______deg

y Wind speed (v):___________ m/sec

y Radiation level (I):__________ W/m2

2.3 Low Radiation Level

Methodology:

Follow all the steps of experiment 1

except setting the Halogen regulator for a

lower radiation value


Observations:

y Tilt angle of the collector (β)____deg



Insight Solar

Experiment No. 2

Insight Solar

Experiment No. 2



15


Table-2.3: Experimental values of dierent parameters during Thermosyphonic mode ofow with Low Radiation Level

Calculations:

1. Calculate UL, F

R and η for all radiation

levels as in experiment no.1

Results:

Draw the eciency graph for dierent

radiation levels

Notes...................................................................................................................................................................................................

Insight Solar

Experiment No. 2



16


Objective:

Evaluation of UL, F

R, η in Thermosyphonic

mode of flow at different inlet water

temperature.

3.1. Inlet water at the atmospheric

temperature

This part of experiment is exactly same as

the experiment no.1. So for the calculation

user can use all the results from that

experiment.

3.2. Inlet water higher than the

atmospheric water temperature

Methodology:

Same as experiment no. 1 except the inlet

water temperature.


Observations:

y Tilt angle of collector (β)______ deg


y Radiation level (I):__________W/m2

3.3 Inlet water at lower than the

atmospheric temperature

Methodology:

Same as experiment no. 1 except

changing the water temperature by using

the water cooler


Observations:




Calculations:

1. Calculate UL, F

R and η for each of the

each cases as in experiment no.1.

Results:

1. Draw the eciency graph for

different inlet water temperature aswell as for all inlet parameters.

2. Find the value of optical eciency of

the collector from the graph.

3. Find the slope of the curve which

gives the sense of the overall heat

loss coefficient of the collector.

Insight Solar

Experiment No. 3

Insight Solar

Experiment No. 3



17


Table-3.1: Experimental values of different parameters during the Thermosyphonic modeof flow with inlet water temperature higher than the atmospheric water temperature.

Table-3.2 Experimental values of different parameters during the Thermosyphonic mode

of flow with inlet water at lower than the atmospheric water temperature.

Insight Solar

Experiment No. 3



18


Objective:

Evaluation of UL, F

R, and η in

Thermosyphonic mode of flow with

different wind speed

4.1 Low wind speed

Methodology:

Same as the experiment no.1, except the

followings

1. Set the fan regulators for a low wind

speed


Observations:


y Wind speed (v):___________m/sec

y Radiation level (I):_________ W/m2

4.2 Medium wind speed

Methodology:

Follow all the steps as in experiment

no.4.1, except the followings

1. Set the fan regulators for a medium

wind speed.


Observations:


y

Wind speed (v):___________ m/sec


4.3 High wind speed

Methodology:

Follow all the steps as experiment no.1

except setting the fan regulators for a

high wind speed


Observations:




Calculations:

Calculate UL, F

R and η for each case as in

experiment no. 1

Results:


wind speed.

Insight Solar

Experiment No. 4

Insight Solar

Experiment No. 4



19


Table-4.1: Experimental values of different parameters in Thermosyphonic mode of flowwith low wind speed

Table-4.2: Experimental values of different parameters in Thermosyphonic mode of flow

for a medium wind speed


for a high wind speed

Insight Solar

Experiment No. 4



20


Objective:

Evaluation of UL

, FR

, η in forced mode of

flow with fixed input parameters.

Methodology:

1. Fill up the cold water tank 2.

2. Close all valves except valve no. 3

and 4.

3. Once water overflows the hot water

tank close all valves except valve no.6

and 7.

4. Switch ON the pump and set the

regulator at the lowest point.

5. See the ow rate on the ow meter

screen (forced mode).

6. To get the required ow rate rst

open the valve No.8 completely and

then adjust the valve no. 7.

7. Wait for some time to get a stable

flow rate reading.

8. Once ow rate is set note all the

readings.

9. Switch ON the wind generating fan.

10. To know the wind speed and

ambient air temperature follow same

methodology as in experiment No 1.

11. Note all the readings.

12. Switch ON the halogen system and

set the radiation at the desire level.

13. Note all the readings after every 15

minutes.

14. Keep the pump ON throughout the

experiment.

For all the calculations refer to Table no. 5

Observations:

y Tilt angle of collector(β)_______deg



Calculations:

1. Calculate UL, F

R and η for each cases

as in experiment no. 1

Results:

1. Draw the eciency curve

Insight Solar

Experiment No. 5

Insight Solar

Experiment No. 5Experiments related to forced mode of flow



21


Table -5: Experimental values of different parameters in forced mode of flow with fixedinputs

Notes

...................................................................................................................................................................................................

Insight Solar

Experiment No. 5



22


Objective:

Evaluation of UL, F

R, η and drawing of

different curves in forced mode of flow at

different flow rate.

Note: The minimum flow rate that can be

measured by the ow meter is 0.5 LPM. So

user should set the ow rate above 0.5 LPM.

6.1. Flow rate 0.5 LPM

Methodology:

1. Fill the cold water tank 2.

2. Close all valves except valve no. 3 and 4.

3. Once water overflows the hot water tank

close all valves except valve no.6 and 7.


regulator at the middle position.


screen (forced mode).

6. To get the required ow rate rstopen the valve No. 8 completely and

then adjust the valve No. 7.


flow rate reading.


readings.

9. Switch ON the wind generating fan

and set the speed at the desire level.

10. To know the wind speed and

ambient air temperature use samemethodology as in experiment no 1.



12. To know the radiation level use same

methodology as in experiment No 1.


minutes.


experiment.


Observations:




6.2 Flow rate 0.7 LPM

Methodology:

Same as experiment no.6.1 except setting

the pump regulator for a ow rate 0.7 LPM


Insight Solar

Experiment No. 6

Insight Solar

Experiment No. 6



23


Table -6.2 Experimental values of different parameters in forced mode of flow with flow

rate 0.7 LPM

Table -6.1: Experimental values of different parameters in forced mode of flow with flow

rate 0.5 LPM

Observations:



6.3 Flow rate 1 LPM

Methodology:

Same as experiment no. 6.1 except setting

the pump regulator for a ow rate 1 LPM


Observations:




Calculations:

1. Calculate UL, F


as in experiment no. 1.

2. Calculate ow factor (F”) for each

cases.

Insight Solar

Experiment No. 6



24


c. Optimum flow rate

d. Flow factor v/s Collector

capacitance rate

Table -6.3: Experimental values of different parameters in forced mode of flow with flowrate 1 LPM

Results:

Draw the following graphs:

a. Eciency v/s Mass ow rate

b. Outlet temperature v/s Mass

flow rate

Insight Solar

Experiment No. 6



25


f. Heat loss v/s Flow factore. Plate temperature v/s Mass owrate

Notes

...................................................................................................................................................................................................

Insight Solar

Experiment No. 6



26


Objective:

Evaluation of UL, F

R, η in forced mode of

flow at different radiation level

7.1. Maximum Radiation Level

Methodology:

1. Fill up the cold water tank 2 with

water at the desire temperature

2. Close all valves excepts valve No. 3

and 4


tank close all valves except valve

No.6 and 7


regulator


screen (forced mode)

6. To get the required ow rate adjust

the valves no. 7 and 8


flow rate reading


readings


set the Regulator for Radiation at the

desire level


minutes


experiment

12. To know the radiation level, wind

speed and ambient air temperature

use same methodology as in

experiment no.1


Observation:




7.2 Medium Radiation Level

Methodology:

Same as experiment no. 7.1 except

setting the halogen regulator for medium

radiation level


Observation:



Insight Solar

Experiment No. 7

Insight Solar

Experiment No. 7



27


Table -7.1: Experimental values of different parameters in forced mode of flow with

maximum radiation level

Table -7.2: Experimental values of different parameters in forced mode of flow with

medium radiation level

7.3 Low Radiation Level

Methodology:

Same as the experiment no. 7.1 except

setting the halogen regulator for low

radiation level


Observation:




Calculations:

1. Calculate UL, F


as in experiment no.1

Results:


radiation level

Insight Solar

Experiment No. 7



28


Table -7.3: Experimental values of different parameters in forced mode of flow with low

radiation level

Notes

...................................................................................................................................................................................................

Insight Solar

Experiment No. 7



29


Objective:

Evaluation of UL, F


flow at different inlet water temperature

8.1. Inlet water at the atmospheric

temperature

Methodology:

1. Fill up the cold water tank 2

with water at the atmospheric

temperature.


and 4.



and 7.


regulator at the minimum power at

which the pump can work.


screen.


the valve no. 7 and 8.


flow rate reading.


readings.




minutes.


experiment.




experiment no 1.


Observation:




y Water mass ow rate(m) ____ kg/sec

8.2 Inlet water at 5 or 10°C higher

than the atmospheric watertemperature.

Methodology:

Same as the experiment no. 8.1 except the

inlet water temperature


Insight Solar

Experiment No. 8

Insight Solar

Experiment No. 8



30


Observation:



y Water mass ow rate(m)____ kg/sec

8.3 Inlet water temperature lower

than the atmospheric water

temperature.

Methodology:


the inlet water temperature


Table-8.1: Experimental values of different parameters in forced mode of flow with inletwater at atmospheric temperature

Observation:





Calculations:

Calculate UL, F


the experiment no.1

Results:

Draw the eciency graph with dierent

inlet water temperature and all inlet

parameters.

Insight Solar

Experiment No. 8



31


Table-8.2: Experimental values of different parameters in forced mode of flow with inletwater 5 or 10°C higher than the atmospheric water temperature

Table-8.3: Experimental values of different parameters in forced mode of flow with inlet

water at lower than the atmospheric water temperature

Notes

...................................................................................................................................................................................................

Insight Solar

Experiment No. 8



32


Objective:

Evaluation of UL, F


flow at different wind speed

6.1. Low wind speed

Methodology:



temperature.


and 4.

3. Once water overflows the hot water tank

close all valves except valve no.6 and 7.


regulator at the minimum power at

which the pump can work.


screen.


the valve no. 7 and 8.


flow rate reading.

8. Adjust the fan regulator to get the

desire wind speed.

9. Once ow rate and wind speed are

set note all the readings.




minutes.


experiment.




experiment no 1.


Observation:





9.2 Medium wind speed

Methodology:


setting the wind speed for a medium value


Insight Solar

Experiment No. 9

Insight Solar

Experiment No. 9



33


Table -9.1: Experimental values of different parameters in forced mode of flow at low windspeed

Observation:





9.3 High wind speed

Methodology:


inlet water temperature


Observation:





Calculations:

Calculate UL, F


the experiment no.1

Results:

Draw the eciency curve with dierent

wind speed and all inlet parameters

Insight Solar

Experiment No. 9



34


Table-9.3: Experimental values of different parameters in forced mode of flow at high

wind speed

Notes

...................................................................................................................................................................................................

Insight Solar

Experiment No. 9

Table -9.2: Experimental values of different parameters in forced mode of flow at mediumwind speed



35


Objective:

Evaluation of UL, F

R, η in forced mode

of flow at different tilt angle and allother parameter as in 1st forced mode

experiment

10.1. Small Tilt Angle

Methodology:

1. Change the collector tilt by 5° from

its standard position (45°) with the

help of jack. Check the angle by

placing the magnetic-D on the

boundary of the collector



temperature

3. Close all valves excepts valve no. 3

and 4

4. Once water overows the hot water


and 7


regulator


screen


the valve no. 7 and 8


flow rate reading

9. Adjust the fan regulator to get thedesire wind speed

10. Once ow rate and wind speed are

set note all the readings


set the radiation at the desire level


minutes

13. Keep the pump ON throughout theexperiment




experiment no 1.


Observation:





Insight Solar

Experiment No. 10

Insight Solar

Experiment No. 10Experiment related to tilt angle



36


Table -10.1: Experimental values of different parameters in forced mode of flow with a

small tilt angle

10.2 Medium Tilt Angle

Methodology:


the setting the tilt angle for a medium

value. Check the collector angle before

starting the experiment.


Observation:





10.3. Large tilt angle

Methodology:


setting the collector for the large tilt angle.

Check the collector angle before starting

the experiment.


Observation:





Calculations:

Calculate UL, F


the experiment no.1 and then calculate ηθ

by using equation 14.

Results:

Draw the eciency graph with dierent

tilt angle

Insight Solar

Experiment No. 10



37


Table -10.2: Experimental values of different parameters in forced mode of flow with amedium tilt angle

Table-10.3 Experimental values of different parameters in forced mode of flow with a large

tilt angle

Notes...................................................................................................................................................................................................

Insight Solar

Experiment No. 10



38


Objective:

Evaluation of UL, F

R, and η in

Thermosyphonic mode of flow at

different tilt angle

11.1. Small tilt angle

Methodology:

Same as the experiment no.1 except

setting the tilt angle at a desire value by

adjusting the jack.


Observations:




11.2 Medium tilt angle

Methodology:

Follow all the steps as in experiment

no.11.1 after changing the tilt by 10 deg

from the standard collector position. Make

the collector angle to be 50 deg. Check

the collector angle before starting the

experiment.


Observations:


y

Wind speed (v):___________ m/sec


11.3 Large tilt angle

Methodology:

Follow all the steps as experiment no.11.1

except Check the collector angle before

starting the experiment.


Observations:




Calculations:

Calculate UL, F


experiment no. 1 and then calculate ηθ by

using equation 14.

Results:

Draw the eciency graph for dierent tilt

angles in thermosyphonic mode

Insight Solar

Experiment No. 11

Insight Solar

Experiment No. 11



39


Table-11.1: Experimental values of different parameters in Thermosyphonic mode of flowwith a small tilt angle


with a medium tilt angle


with a large tilt angle

Insight Solar

Experiment No. 11



40


Ac : Area of the collector (m2)

Ae : Area of the edge (m2)

Cb: Bond conductance

CP : Heat capacity of water (kJ/(kg °C ))

D: Outer diameter of the risers (mm)

hfi : Heat transfer coecient between the

water and the riser wall

It : Radiation falling on the collectors per

unit area (W/m2 )

k b

, k e

: Conductivity of the back and edge

insulation (W/mK)

k : Conductivity of the n (W/mK)

L : Collector’s length (mm)

m : Water mass ow rate (kg/sec)

N: Number of glass cover

T a: Ambient temperature (°C)

T P: Plate temperature (°C)

Ut , U

b , U

e : Top , bottom and edge heat

loss coefficient respectively.

v: Wind velocity (m/sec)

w: Distance between two risers (mm)

xb , x

e :Back and Edge insulation thickness

(mm)

τ0: Transmissivity of the glass cover

α0: Absorptivity of the absorbing plate

εp: Emissivity of the absorbing plate

εg: Emissivity of the glass cover

σ: Stephen Boltzmann constant (W/m2 K 4 )

∂ : Thickness of the n (mm)

θ : angle of incident (Deg)

δ : Absorber plate thickness (mm)

Constant values:

Ac= 0.74115 m2

Ae = 0.32775 m2

k b = 0.04 W/m.k

N = 1

Cp = 4180 J/kg°C

Xb = 0.05 m

Xe = 0.025 m

τ0 = 0.85

α0 = 0.96

ξp = 0.12

ξg = 0.88

σ = 5.67 x 10-8 W/m2 k 4

Cb = 58

Insight Solar

Nomenclatures

Insight Solar

Nomenclatures:

m.



41


Insight Solar

Notes

Notes

...................................................................................................................................................................................................



42


Insight Solar

Notes

Notes

...................................................................................................................................................................................................



43


Notes

...................................................................................................................................................................................................

Insight Solar

Notes



44


Insight Solar

Notes

Notes

...................................................................................................................................................................................................



46

About Ecosense

Ecosense provides world class training solutions in

renewable energy and clean environment. As a group

of engineers, researchers and designers, Ecosense has

developed cutting edge products to create skilled human

resource for renewable energy sector. Founded by group

of IIT graduates, Ecosense is dedicated towards building

mechanisms that will develop highly skilled workforce that

enables the development of clean environment for human

race.

Ecosense Sustainable Solutions Pvt. Ltd.

Correspondence Address:

C-131, Flatted Factory Complex, Okhla Phase-III, New Delhi - 110020

Regd. Address: 124, Himgiri Apartment, Vikaspuri, New Delhi – 110018

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