Free and Forced Convection Lab Report

ABSTRACTThe objective of this experiment is to find the main contributors to heat transfer in the system. Water is heated and the energy is transferred in two ways throughout the system. The system is run for a period of 30 minutes, in both free and forced convection. The heat produced by the boiler will remain constant throughout the experiment and the actual energy gathered will be a result of the condensed water captured in the three different vessels. The theoretical and experimental data was determined through measurements taken in the experiment by thermocouple, scale and water drainage for the forced and free convection trials. The steam condensed on the outer surface of the inner tube as well as the inner surface of the outer tube. When theoretical values for forced convection were calculated (284KJ) was compared to the 220 KJ for the experimental values, roughly 25% error was experienced.

1

Contents ABSTRACT- ..................................................................................................................................................................... 1 INTRODUCTION- ............................................................................................................................................................ 3 Methodology & Experimental System-.......................................................................................................................... 4 Theory ............................................................................................................................................................................ 5 Results............................................................................................................................................................................ 9 Conculsion- .................................................................................................................................................................. 14 References- .................................................................................................................................................................. 15 APPENDIX- ................................................................................................................................................................... 16 Formulas- ................................................................................................................................................................. 16 Nomenclature-......................................................................................................................................................... 18 Sample Calculations-................................................................................................................................................ 28 Procedure- ............................................................................................................................................................... 33

2

INTRODUCTIONThe experimental system uses a boiler which supplies heat to the water to create steam. Heat is lost in the system and calculations are shown later in the report to analyze this for the two trials in the experiment, forced and free convection. Convection refers to the transfer of thermal energy in the means of diffusion. As a fluid moves around the boundaries of an object, with a given velocity, an amount of heat energy will be transferred. It is used in many processes, such as cooling a circuit board or keeping a room cool during a hot summer. The fluid, which comes in at a certain temperature, will experience the change in temperature. The object is being cooled while the fluid keeps flowing. This process repeats over and over again, keeping the object at a desired temperature. A reservoir in the system was adjusted between forced and free convection levels. This means that the pressure head is being changed. The forced convection setup creates a pressure head capable of moving water through the system with a velocity. The free convection setup does not circulate as much new water into the system. The forced convection setup results in an increase in dissipated heat in the exiting of the fluid into the drainage tank. This results in a larger total heat transfer for the forced convection than the free convection. In the next section of the report the procedure used to complete the actual experiment is shown. After that a general understanding of the equations and methodology used will be explained. Finally, a series of sample calculations are shown that show how achieving the hc = convection heat transfer coefficient was possible and what conclusions can be made through these results.

3

Methodology & Experimental System-

The equipment used for this experiment is basically one piece equipment which includes different components. An electric boiler is the driving force of the experiment. The boiler is set to a constant output (1100 watts) and as a result it heats the water and turns it into steam. This steam is fed into a condensing tower. This tower is comprised of a closed jacket and a central single aluminum tube. Cooling water passes upward though the inside of this condenser tube, causing the steam to condense on the outside surface. Steam also condenses on the inside surface of the jacket as heat escapes out into the room. A boiler supply tank is used to provide and maintain a constant level in the boiler this insures that the mass within the system remains constant during the experiment (glass tube). Cooling water is provided by reservoir that allows the experiment to be performed with either free or forced convection. All the copper-constantan (type T) thermocouples are monitored using a high impedance millivoltmeter. Tube wall and shell wall condensates are collected separately from drain tubes provided, and cooling water flow through the condenser tube is collected in the weigh tank mounted on the scale. When performing the experiment many water levels needed to remain constant in the system. The group members were given different responsibilities such as, maintaining the glass tube water height, maintaining reservoir height (forced/free setting), as well as keeping track of the start and finish water levels. 4

TheoryWhen analyzing convection heat transfer coefficients, three dimension-less values must be acquired. To determine what numerous constants are the initial conditions must be known so tables can be utilized. Nusselt Number:

Prandtl Number:

Grashoff Number: (

)

Reynolds number, for internal flow, is obtained by the following equation:

These equations are crucial to calculate to determine what type of flow exists in the system. In order to use the correct heat transfer equation the type of flow must be known to be laminar or turbulent.

Types of Convection observedForced convection occurs when the fluid flows across the boundary of an object, with the movement caused by external forces. Heat transfer coefficient for the forced convection depends on the relationship between Nusselt number, Prandtl number and the Grashoff number acquired for free convection. The relationship is expressed in the following equation: 5

(

)

Free convection occurs when the fluid is allowed to flow by means of buoyancy forces. This convection method occurs when the temperature differences exist between the two ends of the air. When the end part touching the hot object contacts the object, the fluid becomes warmer and less dense. The air moves up and the colder air moves in to replace the warmer air. The combination of the variables in order to obtain the heat transfer coefficient for the free convection process is: (

)

Heat transfer in condensation, because a phase change is involved, requires complex analysis. Condensation takes place when vapor is cooled down. Once this occurs, heat is transferred in a fundamentally different manner than when heat is added or taken away from a fluid without such phase change. When vapor is condensed, it lets go of considerable amounts of energy. The condensed fluid becomes a barrier, in the form of a liquid film which either completely or partially covers the cooler surface. If the drainage of the fluid is done from vertical or inclined surface, the drainage will be naturally faster than a horizontal surface. The film will be thinner. If the vertical height is great, the accumulation of condensate fluid at the lower portion of the surface will thicken the film and make the lower portion less effective than the upper transmitting heat.

In order to acquire an even more accurate result, the heat transfer that occurs when heat is released during the condensation of the vapor must also be taken into account. This value can be easily calculated by obtaining the latent heat of vaporization value. Nevertheless, as the condensate is cooled below Tsat, the equation must be modified to:

6

h*fg  hfg  0.68Cpl (Tsat  Ts ) Setting up all equations together, the combination of the rate of heat transfer and the heat transfer coefficient formulas, the following equation is obtained. .

Q conden  hAs (Tsat  Ts )  mh*fg Once every value has been obtained, the heat transfer coefficient for the free and forced convection heat transfer processes can be obtained. The theoretical value for the free convection is expressed as:

 k 3  2 h fg  h  C   Do   T 

.25

The theoretical value for the forced convection is expressed as: .8

k   VDi  Pr .4 hC   Di    In order to determine the heat transferred amount, two equations are needed. The equations will take into account the gains and losses in the system. The first equation needed is the heat transferred from the steam, which is expressed as follows:

QSteam  VSteam h fg  The second equation needed is the heat transfer that occurs in the water. The equation is expressed in the following manner:

QWater  WWater Cp  TWater  7

Therefore, in order to acquire the total amount of heat transferred, the two equations must be combined. The total amount of heat transferred is expressed in the following manner:

QLosses  QSteam  QWater In order to find the heat transfer coefficient, the transfer heat amount must be obtained. Further, the resistance must be taken into account. The resistance value will give us the rate at which the heat is being transferred, which will symbolize the overall heat transfer coefficient. Heat Flow Through a pipe Forced convection

(

) (

)

Natural Convection

(

)(

)

Condensing Steam

8

Free Convenction

T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T0 T11 W4 10-15 min 114.4 87.786 105.25 103.2 99.494 110.51 23.335 92.589 80.441 103.55 26.67285 20.29 25 25 110 135 6.25

Cooling Water Out - kg (W(final)-W(initial))

Boiler Feed Water ( w3 + w4) mL

Tube Wall Condensate Out - mL

10-15 minutes 114.184 46.9844 98.2058 94.901 89.421 110.14 23.01 59.1347 75.0141 92.3296 26.6312 20.812

Outside Wall Condensate Out -mL

Room

Cooling Water Supply Tank

Condenser Steam Inside

Cooling Tube Surface - Lower

Cooling Tube Surface - Upper

Cooling Water Bottom

Boiler Surface - Outside

Condenser Surface - Outside

Tube Wall Condensate Out

Cup Condensate Out

Cooling Water Out

Steam In

Time Intervals Steam In

Cooling Water Out

Cup Condensate Out

Tube Wall Condensate Out

Condenser Surface - Outside

Boiler Surface - Outside

Cooling Water Bottom

Cooling Tube Surface - Upper

Cooling Tube Surface - Lower

Condenser Steam Inside

Cooling Water Supply Tank

Room

Outside Wall Condensate Out -mL

Tube Wall Condensate Out - mL

Boiler Feed Water ( w3 + w4) mL

Cooling Water Out - kg (W(final)-W(initial))

Time Intervals

Results

All calculations are based on data collected from the tenth to fifteenth minutes of the experiment. The data was averaged over the five minute time difference and used to compute empirical and experimental values. The excel copies below show the average temperatures and volume/weight of water/steam-condensate collected.

Forced Convection

T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T0 T11 W4 W3 W1 W2

W3 W1 W2 98 123 2.4375

9

Heat Transfer Coefficient, Forced Convection, Inner

0.8

K   V  Di   Cp    h1 ( Forced )  C     Di     K 

0.4

hi_forced = heat transfer Co efficient of FORCED convection C is a constant = 0.0023 V = mean average velocity of fluid in m/s Do = outer diameter of inner tube =(

( ))

Do = inner diameter of inner tube =( ) g = acceleration due to gravity in m/sec/sec = 9.8 m/s2 k = Thermal Conductivity, in W/m* K Cp= specific heat in kJ/kg k = Thermal Conductivity, in W/m°K µ = Viscosity in kg/m*s ρ= Density of Water in kg/m3

*Properties in red were found in water property tables at atmospheric pressure and Tavg = T2 + T7/2 Tavg = 34.99555769 ⁰C , ρ = 994.0317414 kg/m3, μ = 0.000724071 kg/m*s, Cp= 4.178 kJ/kg k = 0.622917743 W/m*K 10

W2 = 6.25 lbm; mass of water that passed through the inner pipe in a five minute interval ̇ 

Ai 

6.25lbs *0.454kg / lb  0.009449792kg / s ; mass flow rate 5min*60sec/ min  Di2 4



  (0.01905)2 4

 0.000285 m2 ; Cross sectional area of inner tube

̇

(

) *(

)

(

)

+

= 341.08

Heat Transfer Coefficient; Condensing Steam; Outer Surface; Inner Tube

*

+

* Properties used in this calculation were taken at Tfilm = Tsurface + Tsteam EXCEPT hfg taken at Tsteam Tsurface is the average inner pipe outer surface temperature; T8 + T9 Tsteam is the average temperature of condensing steam ; T10

ΔT = Tsteam – Tsurface = 8.521 ⁰C k = 0.677012277

, ρ = 961.4779015

, μ = 0.000290945

, hfg = 2,247,415.8 11

C = 1.666 for vertical pipe with height L= 0.635m

*

+

Heat Transferred; Forced Convection (empirical calculations)  0.02064m    ln 0.01905m  1 1 1 0.01905m   K R        0.09308 W W 0.000285  0.02064m   W  6303.14 W 238 458.06 2    mK m K  m2 K 

(

)

̇ Total heat added to water in a five minute interval; q= ̇

Experimental : Heat Transferred; Losses due to condensing steam on inner Surface of OUTER Tube; Forced Convection (

)

(

)

Experimental: Heat Transferred; Forced Convection ̇

(

) (

)

When all the data was collected the heat transfer coefficient was able to be solved for. Based on our data between the time period of 10 and 15 minutes the heat transferred for the free convection was 186.5 KJ while for forced it was 220 KJ. Through the theory that was previously talked about it would be a logical hypothesis to assume that the forced convection would have a greater heat transferred. This is because a fluid is being forced 12

through having a flow rate that is constantly implementing new cooler fluid to the system. Therefore, the new fluid has a greater difference in temperature and creates a greater heat transfer.

13

ConculsionThe steam condensed on the outer surface of the inner tube as well as the inner surface of the outer tube. This was the primary mode of heat transfer in the experiment. The empirically calculated results varied by roughly 25% when compared to the experimentally calculated results. This can be attributed to the experimental methods. The experiment had its downfalls that could have poorly affected our results and therefore, our calculations. The measurement system of filling up beakers seemed fairly unreliable. Since the trials were 30 minutes long often times the beakers would become full and require emptying, in which water was not being caught and mass was lost. In addition, there was pressure accumulating inside of the cylinder itself that was not accounted for. This pressure was assumed to be atmospheric when in reality it was probably higher.

14

References1. Mills, A.F., Heat Transfer, Prentice-Hall, New Jersey (1999). 2. Bird, R.B., Stewart, W.E., and Lightfoot, E.N., Transport Phenomena, Wiley, New York 2007). 3. Gebhart, B., Jaluria, Y., Mahajan, R.L., and Sammakia, B., Buoyancy-Induced Flows and Transport, Hemisphere, Cambridge (1988).

15

APPENDIXFormulas-

Nusselt Number:

Prandtl Number:

Grashoff Number: (

)

Reynolds number, for internal flow, is obtained by the following equation:

Experimental calculation for heat transfer .

Q conden  hAs (Tsat  Ts )  mh*fg The theoretical value for the free convection is expressed as:

 k 3  2 h fg  h  C   Do   T 

.25

The theoretical value for the forced convection is expressed as: 16

.8

k   VDi  Pr .4 hC   Di    The first equation needed is the heat transferred from the steam

QSteam  VSteam h fg  The second equation needed is the heat transfer that occurs in the water.

QWater  WWater Cp  TWater  The total amount of heat transferred is expressed in the following manner:

QLosses  QSteam  QWater

17

Nomenclature-

hc = convection heat transfer coefficient D = characteristic linear dimension K = thermal conductivity of material Cp = Specific heat Q = heat C = constant (addressed in each individual equation) = viscosity of fluid = density g = acceleration due to gravity U = mean velocity of fluid G = Mass flux = latent heat of vaporization = specific heat of fluid at average temperature = Saturation temperature = surrounding temperature

18

Forced Convection Experimental Observations/Data

Cooling Water Bottom

Cooling Tube Surface - Upper

Cooling Tube Surface - Lower

Condenser Steam Inside

Cooling Water Supply Tank

Room

T5 87.12 88.26 89.03 89.8 89.36 89 88.49 87.79 87.69 88.34 88.67 88.76 88.1 87.11 87.16 87.39 87.97 89.4 89.74 90.03 90.25 90.45 90.98 91.01 90.05 89.12 89.12 88.89 89.01 90.12 90.4 90.86 91.38 90.93 91.48 91.26 89.96 88.62 87.73 87.63 88.3 88.86 89.12 89.14 89.78 90.93 91.23 91.45 90.91 90.94 90.38 88.41 86.41 85.31 89.64

T6 110.67 110.46 110.48 110.34 110.37 110.05 109.83 109.91 109.83 110.11 109.98 109.72 109.87 109.9 110.04 110.2 110.41 110.69 110.35 110.22 110.04 110.53 110.41 110.13 109.95 110.15 110.37 110.19 110.49 110.29 110.2 110.4 110.48 110.41 109.78 109.83 109.7 109.97 110.37 110.06 110.02 110.47 110.29 110.1 110.19 109.89 110.14 110.25 110.25 110.23 109.65 109.15 109.61 109.63 110.07

T7 23.2 22.97 22.79 22.86 22.75 22.84 22.75 22.55 22.47 22.54 22.61 22.65 22.69 22.66 22.59 22.58 22.57 22.54 22.62 22.67 22.72 22.7 23.12 23.08 23.07 22.91 22.88 22.76 22.96 23.05 22.85 22.79 22.79 22.87 23.1 23.11 23.13 23.01 22.96 22.68 22.76 22.78 22.8 23.12 23.15 23.14 23.09 23.07 23.1 23.1 23.09 23.1 23.04 23 22.98

T8 55.21 55.817 57.263 58.174 58.968 56.326 56.474 54.916 54.55 56.357 59.12 59.571 55.261 53.641 55.389 55.765 58.068 58.641 59.531 58.735 60.59 59.017 60.99 61.164 58.496 58.411 57.796 57.564 57.711 59.187 59.779 59.148 58.914 60.605 61.131 61.398 59.073 54.911 55.009 57.008 58.757 59.425 59.242 60.705 60.726 62.13 60.883 60.189 59.994 61.638 59.522 56.64 53.211 52.452 58.823

T9 74.99 75.24 75.26 72.6 74.1 70.05 72.87 74.51 75.1 75.21 71.59 69.37 72.53 73.31 74.37 75.9 75.72 75.54 76.63 75.81 75.34 76.9 77.27 72.48 76.05 77.38 77.78 74.59 78.36 78.2 77.97 77.6 77.41 78.26 77.78 73.23 73.41 76.55 78.2 78.37 78.38 78.08 78.15 78.25 77.82 77.82 77.42 77.75 77.6 73.34 67.94 68.18 72.86 75.94 76.34

T 10 89.96 90.55 91.73 90.54 91.86 90.85 90.19 90.03 90.77 91.51 91.34 90.12 89.58 89.42 90.31 91.25 92.28 93.08 93.8 94.13 94.24 94.66 93.96 92.45 91.74 91.63 92.16 91.63 92.43 92.12 93.36 93.84 93.64 93.71 93.88 92.75 90.93 90.25 90.27 91.05 91.82 92.19 93.41 93.06 92.94 93.19 94.02 93.76 94.09 92.6 90.93 89.18 88.67 87.58 92.14

T0 26.76 26.57 26.51 26.55 26.56 26.57 26.57 26.56 26.55 26.56 26.6 26.57 26.58 26.56 26.57 26.56 26.56 26.57 26.54 26.52 26.54 26.53 26.57 26.58 26.53 26.55 26.54 26.56 26.54 26.59 26.56 26.55 26.59 26.55 26.53 26.61 26.61 26.6 26.55 26.57 26.58 26.58 26.64 26.62 26.6 26.62 26.63 26.58 26.57 26.6 26.61 26.64 26.62 26.56 26.59

T 11 21.13 20.85 20.83 20.84 20.87 20.82 20.83 20.81 20.82 20.85 20.83 20.86 20.82 20.76 20.78 20.82 20.88 20.79 20.84 20.85 20.86 20.84 20.87 20.87 20.83 20.83 20.85 20.84 20.9 20.86 20.88 20.87 20.89 20.85 20.88 20.89 20.87 20.87 20.83 20.85 20.85 20.87 20.9 20.86 20.84 20.85 20.86 20.83 20.82 20.83 20.84 20.86 20.84 20.8 20.86

Cooling Water Out - lbs

Boiler Surface - Outside

T4 94.4 96.06 97.68 96.76 94.93 94.78 92.26 92.63 94.25 96.34 96.45 92.63 90 90.07 92.58 94.82 97.16 98.64 99.16 99.03 98.84 98.61 98.56 95.32 91.77 91.75 92.98 95.13 94.81 96.19 96.98 96.77 97.13 96.85 96.56 94.2 89.95 88.22 89.31 91.56 93.4 94.51 96.12 96.56 96.9 96.58 95.91 95.09 94.71 94.06 89.75 86.58 84.8 85.08 93.41

Boiler Feed Water ( w3 + w4)

Condenser Surface - Outside

T3 97.05 98.31 99.35 99.73 98.66 97.99 96.35 96 96.74 98.07 98.45 97.05 95.33 94.31 95.36 96.59 97.95 99.32 100.2 100.5 100.5 100.8 100.9 99.84 97.89 97.26 97.41 98.07 98.27 99.09 99.46 99.47 100 100 100.2 99.42 97.33 95.43 94.99 96.04 96.92 97.69 98.93 99.52 100.1 99.86 99.6 99.31 99.19 99.09 96.88 94.67 92.34 91.52 97.9

Tube Wall Condensate Out - mL

Tube Wall Condensate Out

T2 44.11 45.1 46.15 46.41 46.38 43.98 44.46 41.04 42.99 45.74 46.87 46.5 41.67 39.82 41.95 43.77 45.61 47.09 47.8 47.93 47.94 48.2 48.17 48.17 45.81 41.71 44.51 45.18 45.78 47.15 47.69 47.68 47.91 47.8 47.84 47.48 45.84 41.11 40.39 43.69 45.92 46.29 47.09 47.89 48.18 47.86 47.96 47.51 46.62 47.31 47.05 41.52 38.27 38.01 45.69

Outside Wall Condensate Out -mL

Cup Condensate Out

Time T1 15:16:15 114.4 15:16:26 114.3 15:16:38 114.3 15:16:49 114.3 15:17:01 114.3 15:17:12 114.2 15:17:23 114.3 15:17:35 114.3 15:17:46 114.3 15:17:58 114.3 15:18:09 114.3 15:18:21 114.2 15:18:32 114.3 15:18:44 114.3 15:18:55 114.3 15:19:07 114.3 15:19:18 114.3 15:19:30 114.3 15:19:41 114.3 15:19:53 114.3 15:20:04 114.3 15:20:16 114.2 15:20:27 114.3 15:20:39 114.2 15:20:50 114.2 15:21:02 114.3 15:21:13 114.3 0- 5 Minutes 114.3 15:21:25 114.2 15:21:36 114.2 15:21:48 114.2 15:21:59 114.2 15:22:11 114.3 15:22:22 114.2 15:22:33 114.2 15:22:45 114.2 15:22:56 114.2 15:23:08 114.2 15:23:19 114.2 15:23:31 114.2 15:23:42 114.2 15:23:54 114.2 15:24:05 114.3 15:24:17 114.2 15:24:28 114.2 15:24:40 114.2 15:24:51 114.2 15:25:03 114.2 15:25:14 114.2 15:25:26 114.2 15:25:37 114.2 15:25:49 114.2 15:26:00 114.2 15:26:12 114.2 5-10min 114.2

H20 Quantity Measurements

Cooling Water Out

Steam In

Experimental Data - Forced Convection

T emperatures (Raw Data) - ⁰C

W4 0

W3 0

W1 0

W2 22.563

50

120

170

29.5

75

215

290

36.75

19

Forced Convection Experimental Observations/Data 5-10min 114.2 15:26:23 114.2 15:26:35 114.2 15:26:46 114.2 15:26:58 114.2 15:27:09 114.2 15:27:21 114.2 15:27:32 114.2 15:27:43 114.2 15:27:55 114.2 15:28:06 114.2 15:28:18 114.2 15:28:29 114.2 15:28:41 114.2 15:28:52 114.2 15:29:04 114.2 15:29:15 114.1 15:29:27 114.1 15:29:38 114.1 15:29:50 114.2 15:30:01 114.2 15:30:13 114.2 15:30:24 114.2 15:30:36 114.2 15:30:47 114.2 15:30:59 114.1 15:31:10 114.2 10-15 minutes 114.2 15:31:22 114.2 15:31:33 114.1 15:31:45 114.1 15:31:56 114.1 15:32:08 114.1 15:32:19 114.2 15:32:31 114.1 15:32:42 114.2 15:32:54 114.2 15:33:05 114.1 15:33:16 114.1 15:33:28 114.1 15:33:39 114.2 15:33:51 114.2 15:34:02 114.2 15:34:14 114.2 15:34:25 114.1 15:34:37 114.1 15:34:48 114.1 15:35:00 114.1 15:35:11 114.2 15:35:23 114.1 15:35:34 114.1 15:35:46 114.1 15:35:57 114.1 15:36:09 114.1 15-20 minutes 114.1 15:36:20 114.2 15:36:32 114.1 15:36:43 114.1 15:36:55 114.1 15:37:06 114.1 15:37:18 114.1 15:37:29 114.1 15:37:41 114.1 15:37:52 114.1 15:38:04 114.1 15:38:15 114.1

45.69 40.66 43.53 45.45 46.65 47.59 47.7 44.48 45.2 46.66 47 47.71 47.73 47.85 48.72 49.76 50.29 50.24 45.59 41.35 42.13 47.05 47.71 49.15 49.65 51.02 50.74 46.98 51.41 51.66 51.51 50.78 51.18 50.77 50.27 50.02 50.17 50.05 50.18 47.18 40.61 36.81 36.41 37.42 41.12 42.61 44.44 45.79 46.92 47.05 47.74 47.37 45.72 45.7 46.57 45.52 46.76 47.25 47.61 47.38 47.01 46.57 46.88 46.81 46.69 45.95

97.9 92.54 94.56 96.64 98.03 99.04 98.56 98.04 98.28 98.58 98.99 99.39 99.76 100.2 100.6 100.6 100.5 98.42 95.9 94.5 95.21 96.31 97.37 99.08 100.3 100.9 101.1 98.21 101.5 101.2 101.2 101 100.7 100.4 100 99.95 100.1 99.87 98.71 96.95 94.57 92.09 90.18 90.31 92.26 94.78 97.06 99.18 100.5 101.2 101.6 100.7 100.1 100.1 98.31 100.2 100.5 100.8 101 100.9 100.8 100.4 100.1 99.89 99.78 99.58

93.41 87.52 90.86 93.75 95.65 96.94 94.32 93.78 94.79 96.12 97.15 97.52 97.53 97.72 97.75 97.92 96.94 91.69 88.23 87.97 90.19 92.62 95.1 97.26 98.53 99.72 99.85 94.9 99.85 98.94 98.8 98.27 97.58 97.07 96.27 96.23 96.13 95.68 92.96 88.04 84.25 82.17 81.55 83.1 87.11 91.4 94.61 97.08 98.38 98.97 99.1 96.49 96.03 96.66 93.95 97 97.43 97.85 97.86 97.9 97.17 96.6 95.9 95.68 95.67 95.15

89.64 85.45 86.04 87.21 88.31 89.79 90.39 90.18 89.81 90.31 90.6 90.52 90.52 91.42 91.92 92.08 91.34 90.63 88.91 87.26 86.55 87.4 88.37 88.9 89.73 90.13 91.2 89.42 91.76 91.74 92.1 92.04 92.28 91.69 91.17 90.68 91.28 91.14 91.07 90.09 88 86.33 85.09 84.49 85.1 86.43 87.56 88.94 89.79 89.9 90.47 90.9 90.8 90.57 89.67 90.69 90.63 90.88 91.33 91.45 91.13 90.45 90.2 90.23 90.2 90.07

110.07 109.94 110.04 110.02 110.4 110.5 110.22 110.09 110.23 110.33 109.96 110.16 110.49 110.21 110.49 110.32 110.21 109.5 109.53 110.14 110.12 110.07 110.2 110.2 110.2 110.05 110.04 110.14 110.15 110.38 110.37 110.31 110.08 110.11 110.36 110.26 110.13 110.08 109.12 108.36 108.19 108.83 109.32 109.89 109.83 109.93 110.27 110.43 110.45 110.5 110.57 110.19 110.35 110.5 109.96 110.36 110.11 110.21 110.3 110.3 110.03 110.1 110.29 110.2 110.29 110.19

22.98 23.01 23.05 23.04 23.08 23.13 23.13 23.09 22.84 23.03 23.02 22.96 22.97 22.99 23.05 23.08 23.05 23.15 23.14 23.13 23.2 22.89 22.94 22.87 22.73 22.81 22.81 23.01 22.91 22.79 22.81 22.92 23 23.07 23.12 23.28 23.28 23.33 23.29 23.23 23.16 23.13 23.03 23.12 23.05 23.03 23.09 23.16 23.19 23.23 23.22 23.18 23.21 23.24 23.12 23.16 23.18 23.04 23.16 23.14 23.19 23.15 22.83 22.84 22.8 22.89

58.823 53.636 56.631 58.519 58.479 58.755 59.615 58.848 58.385 58.517 58.814 60.82 60.424 61.271 60.939 60.931 62.346 61.913 57.932 54.901 55.299 57.292 59.611 59.32 60.524 61.684 62.095 59.135 62.586 62.141 63.111 62.448 62.192 62.378 62.449 62.248 61.961 61.386 62.007 59.474 56.404 53.986 51.841 52.951 52.75 55.596 56.54 56.275 58.815 59.365 59.108 59.77 60.486 59.451 59.143 59.437 60.624 59.822 62.182 59.991 59.096 59.232 59.997 59.965 59.63 59.555

76.34 76.25 77.4 77.49 77.07 75.52 75.23 76.14 76.83 77.14 76.6 76.78 76.37 76.58 76.74 77.37 72.36 69.65 72.22 75.34 72.16 72.72 72.57 73.8 73.13 73.09 73.84 75.01 73.82 73.82 73.88 73.57 73.71 73.97 74.38 74.01 73.95 73.16 65.67 63.29 64.99 69.35 72.11 68.85 69.78 69.96 70.27 70.49 70.92 71.96 70.4 71.85 72.21 72.18 71.25 69.94 70.75 71.23 71.48 69.82 70.46 70.7 71.72 71.21 70.66 72.69

92.14 88.61 89.92 91.25 91.61 91.35 91.52 91.5 91.76 93.22 93.53 93.72 93.4 94.04 94 94.44 93.31 92.46 90.42 89.96 90.83 91.32 92.17 93.33 94.15 94.2 94.55 92.33 94.96 94.93 95.67 95.1 94.99 95.26 94.97 94.24 94.16 93.97 92.26 90.45 89.1 87.45 87.39 87.64 89.53 90.85 91.94 91.95 92.61 93.31 93.76 92.61 93.13 92.8 92.5 94.37 93.51 94.11 94.1 94.24 94.28 94.14 93.79 93.35 93.71 93.4

26.59 26.64 26.65 26.62 26.65 26.66 26.62 26.65 26.65 26.66 26.64 26.65 26.65 26.61 26.65 26.63 26.64 26.64 26.6 26.62 26.64 26.61 26.63 26.64 26.6 26.59 26.59 26.63 26.61 26.61 26.62 26.61 26.64 26.64 26.64 26.63 26.63 26.62 26.62 26.65 26.61 26.62 26.63 26.66 26.62 26.58 26.69 26.72 26.72 26.67 26.68 26.69 26.67 26.71 26.65 26.72 26.73 26.72 26.7 26.73 26.69 26.71 26.71 26.69 26.73 26.71

20.86 75 20.86 20.85 20.85 20.81 20.82 20.84 20.8 20.79 20.78 20.74 20.71 20.78 20.8 20.82 20.83 20.82 20.84 20.81 20.79 20.86 20.84 20.83 20.83 20.77 20.8 20.82 20.81 100 20.85 20.79 20.78 20.81 20.83 20.85 20.81 20.82 20.87 20.82 20.83 20.84 20.81 20.81 20.76 20.78 20.7 20.66 20.74 20.72 20.72 20.72 20.73 20.7 20.74 20.72 20.78 125 20.76 20.76 20.75 20.73 20.73 20.75 20.69 20.67 20.69 20.66 20.7

215

290

36.75

325

425

43

425

550

49.25

20

Forced Convection Experimental Observations/Data

15:38:26 114.2 15:38:38 114.2 15:38:49 114.2 15:39:01 114.4 15:39:12 116.1 15:39:24 118.3 15:39:35 120.1 15:39:47 121 15:39:58 122 15:40:10 123.4 15:40:21 125.2 15:40:33 127.6 15:40:44 127.4 15:40:56 125.1 15:41:07 122.8 15:41:19 121 20-25 minutes 117.9 15:41:30 119.9 15:41:42 118.5 15:41:53 114.3 15:42:05 114.1 15:42:16 114.1 15:42:28 114.1 15:42:39 114.1 15:42:51 114.1 15:43:02 114 15:43:14 114 15:43:25 114.1 15:43:36 114.1 15:43:48 114 15:43:59 114.1 15:44:11 114 15:44:22 114.1 15:44:34 114 15:44:45 114.1 15:44:57 114 15:45:08 114 15:45:20 114 15:45:31 114 15:45:43 114 15:45:54 114 15:46:06 114 25-30 minutes 114.5

46.48 45.93 46.43 45.81 45.83 46.4 45.51 45.79 45.45 44.87 44.99 45.09 41.57 38.42 36.75 35.61 45.01 36.37 37.94 40.92 43.17 44.8 46.28 47.09 46.9 46.95 44.1 40.75 41.52 44.73 46.11 47.72 48.08 48.31 48.58 48.54 48.86 47.56 43.27 40.87 43.15 45.61 44.73

99.43 99.02 98.91 98.83 98.55 98.66 98.64 98.74 98.63 98.25 98.01 97.18 95.05 92.67 90.32 88.23 98.26 87.64 90.42 93.43 95.82 97.62 99.54 100.1 100.2 98.77 96.56 95.41 96.14 97.53 99.33 100.1 100.7 100.9 101.4 101.5 101.2 99.63 97.4 96.16 96.88 98.09 97.7

95.05 94.58 94.14 94.29 94.4 94.25 94.04 94.16 94.21 93.74 93.15 89.95 86.5 83.54 81.25 79.91 93.38 80.57 84.12 87.76 91.96 94.94 97.4 97.77 97.35 94.38 90.38 89.56 91.58 94.31 96.79 98.12 99.03 98.92 99.22 99.28 97.75 92.84 89.7 89.69 91.95 94.42 93.59

89.98 89.24 89.36 89 89.31 89.74 89.68 89.56 89.6 90.47 89.94 89.11 88.08 86.24 84.53 83.35 89.42 83.02 83.64 84.12 85.16 86.79 87.98 88.95 89.54 90.17 89.24 88.06 87.14 87.22 88.28 88.2 89.37 90.1 90.93 91.11 90.98 90.78 89.23 88.29 87.95 88.04 88.17

110.18 110.45 110.14 110.18 110.61 110.38 110.35 110.38 110.28 110.3 110.32 109.28 108.2 108.23 108.69 108.77 109.97 109.56 110.06 110.28 110.2 110.45 110.27 110.27 110.14 110.09 109.5 109.8 110.14 110.27 110.16 110.3 110.53 110.45 110.29 110.47 110.34 109.91 109.91 110.24 110.42 110.21 110.17

22.89 22.89 22.9 22.8 23.25 23.18 23.17 23.13 23.1 23.11 23.09 23.08 23.09 23.04 23.06 22.97 23.04 23.02 22.94 22.96 23.1 22.66 22.61 22.56 22.6 22.69 22.74 22.71 22.7 22.67 22.7 22.68 22.57 22.63 22.66 22.7 22.75 22.83 22.74 22.74 22.68 22.63 22.73

58.651 59.048 58.651 58.414 58.245 59.196 58.519 58.795 58.661 59.894 59.362 58.163 54.962 52.69 51.286 50.466 58.316 50.445 50.834 52.677 54.535 55.241 56.877 58.634 58.86 59.382 57.362 55.11 54.058 57.052 57.72 58.319 60.086 58.845 60.026 61.206 61.872 59.503 58.142 56.406 56.546 57.441 57.087

72.29 72.48 72.64 72.13 70.56 71.17 71.38 71.22 70.72 71.42 67.86 67.26 63.62 64.34 63.78 66.88 70.01 71.07 72.54 73.77 74.86 74.6 74.37 74.32 73.03 69.39 70.74 74.16 74.73 74.67 75.08 75.27 74.47 75.3 74.46 75.81 71.51 69.81 72.59 74.73 75.25 75.72 73.69

93.4 93.29 92.94 93.19 93.24 93.22 93.34 93.38 93.16 92.28 91.81 91.39 89.62 88.07 86.46 85.7 92.5 85.59 86.63 88.49 89.9 91.44 91.72 92.88 92.03 91.66 89.74 90.14 90.72 91.07 92.52 93.2 93.65 93.84 93.98 94.6 93.39 91.93 91.23 90.49 90.78 92.74 91.37

26.72 26.71 26.74 26.72 26.74 26.74 26.77 26.79 26.78 26.78 26.75 26.78 26.84 26.75 26.78 26.75 26.74 26.72 26.76 26.79 26.75 26.78 26.77 26.78 26.78 26.76 26.76 26.74 26.78 26.72 26.75 26.79 26.74 26.77 26.82 26.76 26.74 26.75 26.76 26.78 26.8 26.79 26.76

20.69 20.67 20.74 20.73 20.76 20.71 20.72 20.72 20.73 20.7 20.72 20.69 20.75 20.72 20.75 20.69 20.72 150 20.69 20.71 20.67 20.63 20.62 20.67 20.7 20.63 20.67 20.7 20.7 20.71 20.68 20.67 20.69 20.65 20.69 20.72 20.66 20.65 20.62 20.65 20.63 20.65 20.66 20.67 170

550

700

56.25

650

820

63.25

21

Forced Convection Experimental Observations/Data

22

23

Natural Convection Experimental Observations/Data H20 Qua nti ty Mea s urements

Cup Condensate Out

Tube Wall Condensate Out

Condenser Surface - Outside

Boiler Surface - Outside

Cooling Water Bottom

Cooling Tube Surface - Upper

Cooling Tube Surface - Lower

Condenser Steam Inside

Cooling Water Supply Tank

Room

Outside Wall Condensate Out -mL

Tube Wall Condensate Out - mL

Boiler Feed Water ( w3 + w4)

Cooling Water Out - lbs

Time T1 16:47:28 114.39 16:47:40 114.39 16:47:51 114.42 16:48:03 114.42 16:48:14 114.53 16:48:26 114.52 16:48:37 114.5 16:48:49 114.49 16:49:00 114.48 16:49:12 114.49 16:49:23 114.37 16:49:35 114.48 16:49:46 114.45 16:49:58 114.48 16:50:09 114.46 16:50:21 114.45 16:50:32 114.49 16:50:44 114.43 16:50:55 114.47 16:51:07 114.48 16:51:18 114.41 16:51:30 114.46 16:51:41 114.5 16:51:53 114.41 16:52:04 114.49 16:52:16 114.37 16:52:27 114.5 0- 5 Mi nutes 114.46 16:52:39 114.5 16:52:50 114.47 16:53:01 114.5 16:53:13 114.46 16:53:24 114.46 16:53:36 114.45 16:53:47 114.44 16:53:59 114.45 16:54:10 114.43 16:54:22 114.45 16:54:33 114.36 16:54:45 114.41 16:54:56 114.38 16:55:08 114.42 16:55:19 114.44 16:55:31 114.44 16:55:42 114.43 16:55:54 114.45 16:56:05 114.47 16:56:17 114.45 16:56:28 114.36 16:56:40 114.44 16:56:51 114.41

Cooling Water Out

Steam In

Experimental Data - Natural Convection

Tempera tures (Ra w Da ta ) - ⁰C

T2 35.42 38.74 41.19 42.81 43.66 42.95 48.5 62.61 79.2 88.31 88.22 84.46 82.65 81.06 79.99 82.5 84.83 86.24 87.66 86.17 82.97 83.08 85.28 86.4 86.97 87.66 88.47 72.89 89.43 89.92 89.24 89.53 90.81 90.75 90.81 89.22 87.45 87.69 86.31 84.85 85.48 85.47 84.42 84.6 85.55 87.12 87.66 88.86 88.53 89.18 89.2

T3 65.99 69.37 77.65 83.25 91.46 98.32 100.9 103.2 105 105.7 105.3 104 104.1 104.2 104.8 105.2 106.2 104.5 104.2 104.8 104.7 104.3 105 104.7 106.1 106 105 99.4 105.8 105.4 106 106 106.1 105.5 106.2 106.5 105.6 105 105.2 104.2 104.2 104 104.9 105 105.9 105.7 105.9 106.5 105.4 104.8 104.6

T4 56.64 61.54 70.23 76.03 86.22 95.7 98.06 101.6 104.3 105.4 102.8 99.91 102 102.9 104 104.6 105.9 101.9 102.3 103.9 103.4 102.1 103.6 102.9 105.1 104.3 102.3 96.65 104.3 103.9 105.5 105 103.7 103.7 105.2 106.1 102.4 102.5 101.9 100 100.1 100.3 103 103 105 104 104.8 106.1 101.5 101.1 101.8

T5 81.02 80.49 81.26 83.87 85.59 88.05 91.07 93.35 94.46 95.69 97.18 96.43 96.22 96.67 97.42 97.35 97.79 98.2 97.54 97.5 98.57 98.08 97.95 98.23 98.79 99.57 99.83 94.01 99.27 100 99.96 100.2 100.5 99.9 99.57 99.69 100.6 99.7 99.67 99.48 99.22 98.79 98.54 98.29 99.54 99.13 99.21 100.2 100.6 99.62 98.98

T6 109.55 110.11 110.3 110.35 110.32 110.27 110.18 110.28 110.82 110.82 110.12 110.18 110.89 110.89 110.68 110.7 110.48 110.31 110.2 110.44 110.37 110.34 110.68 110.7 110.73 110.41 110.13 110.42 110.29 110.32 110.55 110.53 110.55 110.37 110.94 110.75 110.61 110.83 110.84 110.66 110.72 110.37 110.44 110.89 110.71 110.57 110.52 110.39 110.17 110.44 110.31

T7 24.19 25.17 26.52 27.73 28.36 25.62 24.76 23.89 23.57 23.53 23.53 23.72 23.44 23.55 23.85 23.75 23.58 23.56 23.64 23.76 23.74 23.76 23.74 23.63 23.7 23.75 23.81 24.29 23.76 23.8 23.81 23.9 23.81 23.36 22.95 22.81 22.77 22.92 22.74 23.29 23.43 23.4 23.32 23.46 23.39 23.43 23.47 23.54 23.47 23.53 23.38

T8 44.27 47.75 51.74 54.12 55.06 57.12 63.91 71.26 81.41 86.15 88.58 86.94 85.95 85.08 84.51 86.59 88.44 90.71 91.01 89.5 88.61 89.17 90.71 90.73 90.79 91.91 92.13 78.67 93.03 93.69 93.89 93.23 94.07 93.73 93.5 93.77 93.09 93.56 91.91 91.73 91.88 91.04 90.88 91.34 92.13 92.12 93.39 93.3 93.99 93.09 92.67

T9 78.23 84.16 87.86 90.85 95.22 86.68 82.01 83.03 80.86 83.62 81.98 83.25 84.22 83.84 82.65 83.76 83.4 82.01 83.73 83.63 83.54 84.53 83.31 84.23 84.24 83.12 83.85 84.14 83.51 83.47 81.56 82.87 82.09 81.95 82.17 81.76 81.37 81.53 80.08 81.71 81.15 82.93 78.07 78.91 79.03 78.57 79.08 77.61 78.54 79.04 78.12

T10 83.2 83.72 85.39 87.1 90.26 93.26 95.87 98.6 100 100.2 99.57 99.93 100.7 101 101.4 102.1 102.1 101.3 101.8 102.3 100.9 102.1 102.2 102.9 103.5 102.4 103.5 98.05 103 103.5 104 104.3 104.2 104.2 105.2 105.5 103.9 104.1 103.4 103.1 102.9 102.8 103.4 103.7 103.9 104.5 104.3 104.6 102.3 103 103.7

T0 26.87 26.65 26.62 26.6 26.7 26.7 26.67 26.66 26.66 26.64 26.65 26.69 26.63 26.69 26.64 26.64 26.65 26.62 26.62 26.66 26.62 26.63 26.66 26.58 26.67 26.67 26.62 26.66 26.64 26.64 26.67 26.62 26.64 26.65 26.64 26.65 26.68 26.68 26.61 26.61 26.65 26.65 26.63 26.66 26.62 26.65 26.64 26.66 26.64 26.66 26.63

T11 W4 20.78 0 20.63 20.73 20.77 20.86 21.02 21.1 21.01 20.82 20.7 20.63 20.56 20.52 20.53 20.48 20.48 20.44 20.4 20.42 20.43 20.4 20.37 20.4 20.29 20.39 20.37 20.39 20.59 50 20.39 20.34 20.36 20.31 20.35 20.29 20.21 20.18 20.21 20.19 20.15 20.15 20.19 20.2 20.21 20.18 20.14 20.25 20.21 20.26 20.21 20.26 20.24

W3 0

W1 0

W2 14.875

120

170

16.875

24

Natural Convection Experimental Observations/Data 16:58:34 114.43 16:58:46 114.35 16:58:57 114.43 16:59:09 114.41 16:59:20 114.4 16:59:32 114.41 16:59:43 114.32 16:59:55 114.39 17:00:06 114.38 17:00:18 114.42 17:00:29 114.4 17:00:41 114.42 17:00:52 114.34 17:01:04 114.4 17:01:15 114.38 17:01:27 114.36 17:01:38 114.37 17:01:50 114.41 17:02:01 114.35 17:02:13 114.38 17:02:24 114.38 10-15 mi n 114.39 17:02:36 114.38 17:02:47 114.34 17:02:59 114.36 17:03:10 114.39 17:03:21 114.4 17:03:33 114.34 17:03:44 114.37 17:03:56 114.38 17:04:07 114.37 17:04:19 114.33 17:04:30 114.31 17:04:42 114.35 17:04:53 114.35 17:05:05 114.37 17:05:16 114.37 17:05:28 114.37 17:05:39 114.29 17:05:51 114.37 17:06:02 114.36 17:06:14 114.36 17:06:25 114.34 17:06:37 114.37 17:06:48 114.31 17:07:00 114.34 15-20 mi n 114.35

87.09 86.04 87.56 88.78 87.38 86.2 87.6 88.89 88.99 87.5 85.12 85.86 87.35 88 88.58 88.26 88.26 88.67 88 87.59 88.9 87.79 89.17 86.67 85.91 87.59 88.56 88.17 88.66 89.3 88.18 86.75 88.58 89.95 90.04 88.25 86.54 87.28 87.05 87.62 87.96 87.2 86.79 88.29 89.81 90.6 88.12

105.6 105.3 104.3 105.2 105.8 106.4 104.7 104 104.3 104.5 105.1 105.8 105.5 105.6 106.1 105.5 105.1 106 106.7 105.2 104.9 105.3 105.4 106.2 105.5 106.2 106.6 105.5 104.3 105.1 106.1 106.9 106.5 105.5 105.9 104.9 105.4 106.4 106 105.4 106.3 107.1 107.1 107.4 107.4 105.3 106

105.1 102.6 101.6 104.1 105.8 106.7 101.3 100.2 101.2 102.7 103 105 103.4 103.9 105.4 102.8 102.9 104.7 106.2 101.1 101.8 103.2 104.1 105 103.2 104.9 106.1 103.5 101.6 103.5 105.3 106.7 103.3 101.3 103.6 101 102.9 105.1 102 102.3 104.6 106.5 106.2 106.7 106.3 100.7 104

99.25 99.71 99.35 99.16 99.74 100.2 100 99.23 98.94 98.69 98.87 99.31 99.46 99.65 99.68 99.71 99.45 99.56 99.79 99.69 99.25 99.49 99.16 99.54 99.86 99.54 99.98 100.7 99.73 99.52 99.84 100.2 100.4 99.9 99.48 99.67 99.31 99.12 99.47 99.21 99.13 99.44 100.2 100.2 100.4 100.1 99.76

110.58 110.39 110.61 110.66 110.77 110.68 110.27 110.57 110.56 110.53 110.71 110.99 110.35 110.63 110.59 110.42 110.29 110.63 110.27 110.07 110.29 110.51 110.58 110.52 110.5 110.51 110.81 110.52 110.52 110.74 110.93 111 110.7 110.62 110.84 110.66 110.47 110.7 110.53 110.76 110.81 110.91 110.71 110.85 110.67 110.32 110.67

23.41 23.39 23.41 23.35 23.28 22.9 23.3 23.38 23.31 23.35 23.31 23.36 22.87 23.45 23.3 23.33 23.32 23.38 23.41 23.44 23.45 23.34 23.45 23.46 23.42 23.41 23.36 23.36 23.38 23.34 23.49 23.39 23.48 23.48 23.47 23.52 23.49 23.54 23.57 23.56 23.62 23.57 23.6 23.63 23.65 23.75 23.5

92.19 91.58 91.8 92.26 92.33 92.7 92.18 93.18 93.39 92.08 91.77 91.47 91.52 92.36 93.56 92.75 92.57 92.8 93.36 92.67 93.13 92.59 93.37 92 92.63 93.05 93.63 92.91 93.61 93.3 92.87 93 93.23 94.04 93.63 91.99 92.45 92.53 92.85 92.11 92.79 91.85 91.85 93.28 94.95 94.71 93.03

80.05 79.03 80 79.99 80.89 77.8 76.74 78.12 78.52 78.46 78.69 79.92 80.75 81.36 81.23 81.19 84.97 85.95 83.78 84.21 85.18 80.44 85.78 85.05 86.21 87.05 87.64 85.38 86.48 84.36 83.99 84.18 83.84 85.17 85.18 85.6 86.79 86.37 85.43 86.53 86.5 86.73 86.62 86.82 85.17 85.7 85.77

104.2 102.9 102.9 103.7 104.5 104.7 102.8 103.3 103 102.3 103.5 103.9 104 103.9 104 103.3 103.3 104.3 104.3 102.5 102.8 103.5 103.3 103.5 103.6 104.3 105 104.2 103.7 104.3 104.9 105 103 103.2 103.3 102.6 103.1 103.3 102.3 103.3 103.7 103.9 104.4 105 103.9 103.5 103.8

26.66 26.65 26.68 26.65 26.66 26.67 26.65 26.67 26.66 26.67 26.69 26.7 26.66 26.74 26.67 26.7 26.65 26.69 26.68 26.74 26.71 26.67 26.7 26.72 26.68 26.69 26.75 26.73 26.69 26.73 26.71 26.69 26.75 26.73 26.76 26.73 26.71 26.72 26.73 26.72 26.72 26.73 26.74 26.73 26.75 26.74 26.72

20.27 20.26 20.27 20.23 20.25 20.27 20.22 20.27 20.24 20.28 20.27 20.28 20.31 20.34 20.33 20.35 20.33 20.38 20.42 20.45 20.43 20.29 100 20.42 20.45 20.4 20.45 20.48 20.52 20.45 20.49 20.52 20.48 20.51 20.48 20.54 20.54 20.58 20.59 20.62 20.61 20.58 20.56 20.6 20.63 20.65 20.72 20.54 125

310

410

21.75

425

550

24.25

25

Natural Convection Experimental Observations/Data

26

Natural Convection Experimental Observations/Data

27

Sample CalculationsHeat Transfer Coefficient, Forced Convection, Inner

0.8

K   V  Di   Cp    h1 ( Forced )  C     Di     K 

0.4

hi_forced = heat transfer Co efficient of FORCED convection C is a constant = 0.0023 V = mean average velocity of fluid in m/s Do = outer diameter of inner tube =(

( ))

Do = inner diameter of inner tube =( ) g = acceleration due to gravity in m/sec/sec = 9.8 m/s2 k = Thermal Conductivity, in W/m* K Cp= specific heat in kJ/kg k = Thermal Conductivity, in W/m°K µ = Viscosity in kg/m*s ρ= Density of Water in kg/m3

*Properties in red were found in water property tables at atmospheric pressure and Tavg = T2 + T7/2 Tavg = 34.99555769 ⁰C , ρ = 994.0317414 kg/m3, μ = 0.000724071 kg/m*s, Cp= 4.178 kJ/kg k = 0.622917743 W/m*K 28

W2 = 6.25 lbm; mass of water that passed through the inner pipe in a five minute interval ̇ 

Ai 

6.25lbs *0.454kg / lb  0.009449792kg / s ; mass flow rate 5min*60sec/ min  Di2 4



  (0.01905)2 4

 0.000285 m2 ; Cross sectional area of inner tube

̇

(

) *(

)

(

)

+

= 341.08

Heat Transfer Coefficient, Free Convection, Inner K h1 ( Free)  C L

 L3   2    TWater  g   Cp        2    K  

0.29

K C L

 L3   2    TWater  g      Pr   2    

0.29

*Properties for hi_free were taken at Tavg = T2 + T7/ 2 =55.58782692 ⁰C, ρ = 985.1354918

, μ = 0.000483318

, Cp= 4183.411618

, k = 0.651040899

β = 0.000492467 C-1 ΔTavg = 87.7854615384615 - 23.335 = 64.45057692 ⁰C L = 25 inches

(

; Length of pipe

) *(

)(

)+

29

Heat Transfer Coefficient; Condensing Steam; Outer Surface; Inner Tube

*

+

* Properties used in this calculation were taken at Tfilm = Tsurface + Tsteam EXCEPT hfg taken at Tsteam Tsurface is the average inner pipe outer surface temperature; T8 + T9 Tsteam is the average temperature of condensing steam ; T10

ΔT = Tsteam – Tsurface = 8.521 ⁰C k = 0.677012277

, ρ = 961.4779015

, μ = 0.000290945

, hfg = 2,247,415.8

C = 1.666 for vertical pipe with height L= 0.635m

*

+

Overall Heat Transferred; Free Convection (empirical calculations) ̇ = UAΔT ; rate of heat transfer measured in Watts Where

̇

∑ 30

∑

k = thermal resistance of aluminum

 0.02064m    ln 0.01905m  1 1 1 0.01905m   K R        0.07015 W W 0.000285  0.02064m   W  5433.156 W 238 341.08 2    mK m K  m2 K 

(

)

̇ Total heat added to water in a five minute interval; q= ̇

Heat Transferred; Forced Convection (empirical calculations)  0.02064m   ln   1 1 1 0.01905m   K R    0.01905m     0.09308 W W W 0.000285  0.02064 m W  6303.14  238 458.06 2   mK m K  m2 K  

(

)

̇ Total heat added to water in a five minute interval; q= ̇

31

Experimental : Heat Transferred; Losses due to condensing steam on inner Surface of OUTER Tube; Forced Convection (

)

(

)

Experimental : Heat Transferred; Losses due to condensing steam on inner Surface of OUTER Tube; Free Convection (

)

(

)

Experimental: Heat Transferred; Forced Convection ̇

(

)

(

)

Experimental: Heat Transferred; Free Convection (

)

32

Procedure-

33